
==== Front
Hum Reprod Update
Hum Reprod Update
humupd
Human Reproduction Update
1355-4786
1460-2369
Oxford University Press

38942605
10.1093/humupd/dmae020
dmae020
Review
AcademicSubjects/MED00460
AcademicSubjects/MED00905
Ovarian microenvironment: challenges and opportunities in protecting against chemotherapy-associated ovarian damage
Guo Yican Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

Xue Liru Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

Tang Weicheng Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

Xiong Jiaqiang Department of Obstetrics and Gynecology, Zhongnan Hospital of Wuhan University, Wuhan, China

Chen Dan Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

Dai Yun Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

Wu Chuqing Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

Wei Simin Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

https://orcid.org/0009-0003-8751-410X
Dai Jun Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

https://orcid.org/0000-0001-8822-4700
Wu Meng Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

https://orcid.org/0000-0002-8610-952X
Wang Shixuan Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
National Clinical Research Center for Obstetrical and Gynecological Diseases, Wuhan, Hubei, China
Key Laboratory of Cancer Invasion and Metastasis, Ministry of Education, Wuhan, Hubei, China

Correspondence address. Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China. E-mail: shixuanwang@tjh.tjmu.edu.cnhttps://orcid.org/0000-0002-8610-952X (S.W.); Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China. E-mail: mengwu@tjh.tjmu.edu.cnhttps://orcid.org/0000-0001-8822-4700 (M.W.); Department of Obstetrics and Gynecology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei, China. E-mail: jundai@tjh.tjmu.edu.cnhttps://orcid.org/0009-0003-8751-410X (J.D.)
Sep-Oct 2024
28 6 2024
28 6 2024
30 5 614647
30 10 2023
27 4 2024
11 6 2024
© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.
2024
https://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

BACKGROUND

Chemotherapy-associated ovarian damage (CAOD) is one of the most feared short- and long-term side effects of anticancer treatment in premenopausal women. Accumulating detailed data show that different chemotherapy regimens can lead to disturbance of ovarian hormone levels, reduced or lost fertility, and an increased risk of early menopause. Previous studies have often focused on the direct effects of chemotherapeutic drugs on ovarian follicles, such as direct DNA damage-mediated apoptotic death and primordial follicle burnout. Emerging evidence has revealed an imbalance in the ovarian microenvironment during chemotherapy. The ovarian microenvironment provides nutritional support and transportation of signals that stimulate the growth and development of follicles, ovulation, and corpus luteum formation. The close interaction between the ovarian microenvironment and follicles can determine ovarian function. Therefore, designing novel and precise strategies to manipulate the ovarian microenvironment may be a new strategy to protect ovarian function during chemotherapy.

OBJECTIVE AND RATIONALE

This review details the changes that occur in the ovarian microenvironment during chemotherapy and emphasizes the importance of developing new therapeutics that protect ovarian function by targeting the ovarian microenvironment during chemotherapy.

SEARCH METHODS

A comprehensive review of the literature was performed by searching PubMed up to April 2024. Search terms included ‘ovarian microenvironment’ (ovarian extracellular matrix, ovarian stromal cells, ovarian interstitial, ovarian blood vessels, ovarian lymphatic vessels, ovarian macrophages, ovarian lymphocytes, ovarian immune cytokines, ovarian oxidative stress, ovarian reactive oxygen species, ovarian senescence cells, ovarian senescence-associated secretory phenotypes, ovarian oogonial stem cells, ovarian stem cells), terms related to ovarian function (reproductive health, fertility, infertility, fecundity, ovarian reserve, ovarian function, menopause, decreased ovarian reserve, premature ovarian insufficiency/failure), and terms related to chemotherapy (cyclophosphamide, lfosfamide, chlormethine, chlorambucil, busulfan, melphalan, procarbazine, cisplatin, doxorubicin, carboplatin, taxane, paclitaxel, docetaxel, 5-fluorouraci, vincristine, methotrexate, dactinomycin, bleomycin, mercaptopurine).

OUTCOMES

The ovarian microenvironment shows great changes during chemotherapy, inducing extracellular matrix deposition and stromal fibrosis, angiogenesis disorders, immune microenvironment disturbance, oxidative stress imbalances, ovarian stem cell exhaustion, and cell senescence, thereby lowering the quantity and quality of ovarian follicles. Several methods targeting the ovarian microenvironment have been adopted to prevent and treat CAOD, such as stem cell therapy and the use of free radical scavengers, senolytherapies, immunomodulators, and proangiogenic factors.

WIDER IMPLICATIONS

Ovarian function is determined by its ‘seeds’ (follicles) and ‘soil’ (ovarian microenvironment). The ovarian microenvironment has been reported to play a vital role in CAOD and targeting the ovarian microenvironment may present potential therapeutic approaches for CAOD. However, the relation between the ovarian microenvironment, its regulatory networks, and CAOD needs to be further studied. A better understanding of these issues could be helpful in explaining the pathogenesis of CAOD and creating innovative strategies for counteracting the effects exerted on ovarian function. Our aim is that this narrative review of CAOD will stimulate more research in this important field.

REGISTRATION NUMBER

Not applicable.

Graphical abstract

Chemotherapy causes an imbalance of the ovarian microenvironment leading to chemotherapy-associated ovarian damage and dysfunction, and further research is needed to explore the possible protective treatments. Created with BioRender.com, with permission.

ovarian microenvironment
chemotherapy
fertility preservation
ovarian reserve
protective therapies
extracellular matrix
vascular system
immune
stem cell
National Key Research and Development Program of China 10.13039/501100012166 2022YFC2704100 National Natural Science Foundation of China 10.13039/501100001809 82001514 22104040
==== Body
pmcIntroduction

In 2024, over 2 million new cancer cases are projected to occur in the USA, and the 5-year relative survival rate for all cancers combined has increased from 49% for diagnoses during the mid-1970s to 69% during 2013–2019 (Siegel et al., 2024). Compared to the general population, women are 38% less likely to become pregnant after a cancer diagnosis and its treatment (Anderson et al., 2018). The ovary is responsible for fertility and for maintaining the woman’s endocrinological balance until menopause. Chemotherapy can lead to ovarian hormone level disturbance, persistent abnormal menses, amenorrhea, infertility, and an increased risk of early menopause (van Dorp et al., 2018). The impacts of oestrogen deficiency, such as menopausal symptoms, osteoporosis, cardiovascular disease, and cognitive decline, are also a critical aspect of the longer-term side of chemotherapy-associated ovarian damage (CAOD) (Lobo, 2017). Therefore, understanding the biological mechanisms of CAOD and developing new ovarian preservation strategies are paramount.

The proposed mechanisms underlying CAOD primarily involve the induction of DNA cross-link formation within oocytes or granulosa cells, triggering apoptosis, or the overactivation and subsequent exhaustion of dormant primordial follicles, ultimately leading to a decreased number of follicles (Soleimani et al., 2011; Kalich-Philosoph et al., 2013; Li et al., 2014; Chang et al., 2015; Luan et al., 2019; Nguyen et al., 2019). Ovarian function is determined by its ‘seeds’ (follicles) and ‘soil’ (ovarian microenvironment). The ovarian microenvironment provides nutritional support and signal transportation for the growth and development of follicles, ovulation, and corpus luteum formation, and the close interaction between follicles and ovarian microenvironment determines the fate of follicles and thus the ovarian lifespan (Ahmed et al., 2020). The ovarian microenvironment comprises: the extracellular matrix (ECM); the ovarian stromal cells and cytokines; the vascular system, which consists of blood vessels and lymphatics; the immune system, including immune cells, chemokines, and inflammatory cytokines; ovarian stem cells; and others, including metabolic products (e.g. amino acid metabolites, glucose metabolites, trance elements), nerves, hormones, etc. Emerging evidence has highlighted the crucial role of the ovarian microenvironment in CAOD. Some studies show that chemotherapy depletes follicles through inducing ovarian stromal fibrosis and destroying ovarian vascular structure and function (Meirow et al., 2007; Oktem and Oktay, 2007; Bar-Joseph et al., 2011; Pascuali et al., 2018). Chemotherapy also leads to an imbalance of immune and oxidative stress in the ovarian microenvironment, further inducing follicle apoptosis and loss (Deng et al., 2021; Dinc et al., 2023). Chemotherapy may induce the apoptosis of ovarian stem cells that might be able to renew oocytes and remodel ovarian function (Jiang et al., 2019; Wu et al., 2019). After chemotherapy, senescent cells accumulate in the ovarian microenvironment and secrete many proteins related to the senescence-associated secretion phenotype (SASP), which contributes to ovarian ageing (Hense et al., 2022). Hence, there is now a pressing need to explore the role of the microenvironment in CAOD and develop methods to improve the balance of the ovarian microenvironment during chemotherapy.

This review introduces the physiological role of the ovarian microenvironment, details its changes during chemotherapy and the mechanisms of damage to ovarian function, and summarizes proposed protective treatments targeting the ovarian microenvironment.

Methods

A comprehension literature review was carried out to identify relevant articles pertaining to changes in the ovarian microenvironment induced by chemotherapy and to new approaches of its protection. All authors contributed to the search and to establish the inclusion and exclusion criteria. As this was an analysis of published data, approval of an ethics committee is not relevant.

The research was performed using PubMed Central as sources, and identified peer-reviewed English publications for human and animal up to April 2024. Searches were performed by adopting the three groups of main terms. The first group included ‘ovarian microenvironment’ (ovarian ECM, ovarian stromal cells, ovarian interstitial, ovarian cytokines, ovarian blood vessels, ovarian lymphatic vessels, ovarian macrophages, ovarian lymphocytes, ovarian immune cytokines, ovarian oxidative stress, ovarian reactive oxygen species (ROS), ovarian senescence cells, ovarian SASPs, ovarian oogonial stem cells, ovarian germline stem cells, ovarian stem cells), the second group included ovarian function-related terms (reproductive health, fertility, infertility, fecundity, ovarian damage, ovarian reserve, ovarian function, decreased ovarian reserve (DOR), premature ovarian failure (POF), premature ovarian insufficiency (POI), menopause), and the third group was chemotherapy-related terms (cyclophosphamide (CTX), lfosfamide, chlormethine, chlorambucil, busulfan (BUL), melphalan, procarbazine, cisplatin (CIS), carboplatin, taxane, paclitaxel, docetaxel, doxorubicin (DOX), 5-fluorouraci, vincristine, methotrexate, dactinomycin, bleomycin, mercaptopurine). In certain areas where human research was limited, data from animal studies were used.

All relevant articles were carefully evaluated. Initially, titles and abstracts were assessed to evaluate the eligibility of the studies. After this selection, the authors proceeded with the complete reading of the papers to identify those relevant for final inclusion. Reference lists of these papers were checked to identify other studies that should be included in this review. Manuscripts were selected concerning changes in the ovarian microenvironment in response to various chemotherapeutic regimens in the context of reproduction, while those concerning chemotherapeutic drugs that only induced changes of the follicle itself were excluded from the review. Manuscripts describing new approaches of CAOD protection, which improved the ovarian microenvironment, were included. To focus the scope of the current review, case reports, duplicate articles, opinion papers, editorials, and congress abstracts were excluded.

Ovarian microenvironment

Historically, research on ovarian function has mainly focused on follicles, revealing that the essence of ovarian dysfunction is a decrease in the number and quality of follicles, but recently the ovarian microenvironment has become an exciting new frontier for research as it seems to hold critical keys to understand the complexity of ovarian function. In this review, we mainly discuss the ECM, ovarian stromal cells and cytokines, the vascular system, immune components, and ovarian stem cells, all of which are essential for follicle development and functional maintenance (Fig. 1).

Figure 1. Schematic of the various contributors to the ovarian microenvironment. ECM, extracellular matrix. Created with BioRender.com, with permission.

Ovarian extracellular matrix

The ovarian ECM provides physical support for follicle development and induces intracellular biochemical signaling pathways to maintain or modify the morphology, differentiation, homeostasis, and mechanical properties of the ovarian tissue (Monslow et al., 2015). Recent proteomic studies have revealed that the ECM of human ovarian cortex comprises 46 core matrisome proteins (collagens, glycoproteins, and proteoglycans) and 39 matrisome-associated proteins (ECM-affiliated proteins, ECM regulators, and secreted factors) known to regulate and remodel the ECM (Ouni et al., 2019). Collagen is the main components of the ovarian ECM and represents 49% of the total matrisome proteins (Ouni et al., 2019). Collagen deposition is mainly observed at the outer edge of human ovary, decreasing towards the inner side (Grosbois et al., 2023). Elastin is primarily found at the cortex-medulla border, particularly near blood vessels, and to a lesser extent within human cortical stroma. Fibronectin and laminin are broadly expressed throughout the human stromal compartment.

Examination of the spatiotemporal evolution of collagen deposition in human ovary under brightfield and polarized light microscopy revealed that collagen level increased with age, while fibrillin-1 and emilin-1 declined (Ouni et al., 2020). Collagen and elastin peak in reproductive-age women compared to prepubertal and menopausal individuals. In another study, micro-scale analysis revealed that ovarian ECM underwent distinct changes across different life stages (Ouni et al., 2021). Prepuberty is marked by thin fibers assembled into thin bundles, while reproductive age sees a densification into thickest bundles. Menopause exhibits a tighter network organization, suggesting age-related ECM changes.

Growing evidence suggests that the ovarian ECM regulates follicle formation, growth, and ovulation. Specifically, the ovarian cortex furnishes a stiff matrix conducive to primate primordial follicle growth and survival (Hornick et al., 2012). Within mouse primordial follicles, oocytes experience compression from surrounding granulosa cells, which secret ECM proteins, resulting in elevated mechanical pressure essential for maintaining follicle dormancy (Nagamatsu et al., 2019). Experimentally, loosening of the ovarian ECM via collagenase treatment induces mouse follicle activation, concurrent with nuclear export of FOXO3 and activation of the phosphoinositide 3-kinase (PI3K)/serine-threonine kinase (AKT) pathway (Nagamatsu et al., 2019). In addition, both the Hippo signaling pathway and the PI3K/AKT signaling pathway are involved in the activation of human and mouse primordial follicles induced by mechanical force on ovarian ECM (Kawamura et al., 2013; Grosbois and Demeestere, 2018; Devos et al., 2020). As human follicles grow, they move to the less dense ovarian medulla because this is most permissive to follicular expansion and maturation (Ouni et al., 2020). Human secondary follicles reorient the majority of collagen fibers to below 50° to induce directional fiber remodeling and folliculogenesis compared to follicles at earlier stages of development (Ouni et al., 2021). As they reach the preovulatory stage, the LH surge stimulates human antral follicles to vigorously remodel the ECM through proteolytic degradation (via matrix metalloproteinases (MMPs)), which degrades the apical follicular connective tissue and facilitates follicular rupture (Fiorentino et al., 2023). The development and luteolysis of the corpus luteum depend upon the precise remodeling of the ECM. When human follicular tissue remodels into the corpus luteum, basement membrane (type IV) collagen is replaced by fibrillar (type I) collagen (Li et al., 2020). Type I collagen (COL1A1 and COL1A2) is more abundant in bovine regressing corpus luteum than in the functional corpus luteum, reinforcing the importance of type I collagen in luteal development (Favero et al., 2019). ECM is also involved in the regulation of oogonial stem cell differentiation and oocyte formation. Specifically, the Arg-Gly-Asp motif-binding integrin subunits on the surface of mouse oogonial stem cells interact with type I and type IV collagen in the ovarian stroma to upregulate the levels of meiosis and oocyte formation (MacDonald et al., 2019). In contrast, human oogonial stem cells are unresponsive to a collagen-based ECM but produce significantly more in vitro-derived oocytes when cultured on laminin (MacDonald et al., 2019). These data indicate that the ovarian ECM acts in a species-specific manner to control oogonial stem cell differentiation in adult mouse and human ovaries.

Mechanical properties of the ovarian ECM play a crucial role in supporting follicle survival and folliculogenesis, and any alterations to its mechanical properties could contribute to ovarian disorders, such as PCOS and POI. Ovaries from patients with PCOS increase collagen deposition, and have a thickened cortex and altered ECM composition that probably creates a biomechanically non-permissive environment for follicle recruitment and growth (Hughesdon, 1982; Takahashi et al., 1994; Papachroni et al., 2010). Wood et al. (2015) used multi-modal magnetic resonance elastography to reveal that patients with a diagnosis of PCOS had stiffer ovaries than those of age-matched controls (Wood et al., 2015). Ovarian laparoscopic drilling, a clinical treatment for PCOS, may destruct the thickened cortical and subcortical stroma, thereby inducing ovulation and promoting follicle growth in patients with PCOS (Seow et al., 2020; Abu Hashim, 2015). Moreover, patients with POI display a highly variable ovarian cortical stiffness and a diminished follicle pool (Li et al., 2010; Mendez et al., 2022). Recent clinical studies have shown that in vitro ovarian fragmentation with AKT stimulators could activate primordial follicles, and patients with POI deliver healthy babies following IVF after auto-transplanted ovarian fragmentation (Kawamura et al., 2013; Suzuki et al., 2015; Zhai et al., 2016). Moreover, utilizing in vitro ovarian cortical fragmentation alone, followed by immediate auto-transplantation, is sufficient to disrupt the Hippo signaling and promote follicle growth in patients with POI and DOR (Lunding et al., 2019; Kawamura et al., 2020; Tanaka et al., 2020; Mendez et al., 2022).

Ovarian stromal cells and cytokines

The majority of the ovarian stroma is composed of a mixed population of incompletely characterized fibroblasts, commonly referred to as stromal cells, which are grouped into four main types, namely, primary stromal cells, secondary stromal cells, follicle theca stromal cells, and portal cells (Reeves, 1971). Recent human single-cell RNA-sequencing studies have confirmed the presence of multiple ovarian stromal cell clusters, but a comprehensive characterization of stromal cell types is lacking (Fan et al., 2019; Wagner et al., 2020; Wu et al., 2024). The distribution and subtypes of ovarian stromal cells may be affected by cyclic structural changes during follicle growth, ovulation, and luteal development. During follicle development, rodent ovarian stromal cells multiply and differentiate into inner theca cells and outer myofibroblast, the former maintaining integrity of the follicle structure while the latter secretes ECM to participate in the formation of follicular capillaries (Cui et al., 2020; Secchi et al., 2021). Ovarian stromal/theca cells provide androgen to support mammalian pre-antral follicular growth and regulate the proliferation and apoptosis of granulosa cells (Young and McNeilly, 2010; Qiu et al., 2014). Additionally, ovarian stromal cell-feeding layers have been demonstrated to have a positive effect on the in vitro survival and/or growth of preantral follicles in both mice and women (Dath et al., 2011; Tingen et al., 2011; Grubliauskaite et al., 2024). Integration of ovarian stromal cells from human fresh medullary tissue into the artificial ovary resulted in higher viability and improved graft vascularization (Soares et al., 2015).

Ovarian stromal cells have the capacity to produce cytokines that actively participate in pivotal ovarian physiological processes (Sirotkin, 2011). Stromal cell-derived factor-1 (SDF-1/CXCL12) and its receptor CXC motif receptor 4 (CXCR4) are expressed in ovarian stroma and follicles (Adamczak et al., 2021). Interactions between SDF-1 and CXCR4 have been suggested to play an essential role in homing primordial germ cells (PGCs) to genital ridges (Doitsidou et al., 2002), with SDF-1 mutant mice displaying delayed migration and decreased numbers of PGCs in the gonads (Ara et al., 2003). A subsequent study suggested the SDF-1/CXCR4 signaling pathway exerted a significant influence on preserving the size and longevity of the mouse primordial follicle pool (Holt et al., 2006). Besides, in human follicular fluid (FF) during IVF, the rates of oocyte recovery increased with higher concentrations of SDF-1 (Nishigaki et al., 2011). A similar result was established in equine, bovine, sheep, and swine (Sayasith and Sirois, 2014; Zhang et al., 2018; Basini et al., 2020). These results suggest that SDF-1 exerts important positive influences on the ovulatory process and follicle development. Additionally, a study involving single-nucleotide polymorphisms (SNPs) conducted on 111 Chinese patients with POF and 183 healthy controls revealed that the polymorphism rs1801157 in CXCL12 exhibited a suggestive association with POF (Wang et al., 2011). SDF-1/CXCR4 signaling has been implicated in the pathogenesis of PCOS by inhibiting ovarian granulosa cell apoptosis in rats (Jin et al., 2021).

Bone morphogenetic protein 4 (BMP-4) and BMP-7, derived from ovarian stromal cells, play essential roles in promoting follicle growth and enhancing follicle survival (Shimizu et al., 2012). These proteins are crucial for the specification, migration, and maintenance of PGCs in mice and humans (Saitou et al., 2002; Abir et al., 2008). In mice with a null mutation for BMP-4 or BMP-7, the number of PGCs was significantly reduced (Lawson et al., 1999; Ross et al., 2007). Additionally, BMP-4 induces the differentiation of mouse ovarian stem cells into oocytes via small mothers against decapentaplegic1 (SMAD1)/SMAD5/SMAD8 signaling (Park et al., 2013). In addition, BMP-4 and BMP-7 have been implicated as regulators of the transition of primordial follicles to primary follicles, and in follicle growth in various species including sheep (Foroughinia et al., 2017), rats (Lee et al., 2001), mice (Tanwar et al., 2008), rabbits (Xie et al., 2014), bovines (da Cunha et al., 2018), and human (Abir et al., 2008). BMP-4 and BMP-7 also act as regulators in cumulus–oocyte complex (COC) expansion and communication between human granulosa cells (Zhang et al., 2016). They also modulate the production of estradiol and progesterone induced by FSH or insulin-like growth factor (IGF) in sheep and mouse granulosa cells (Foroughinia et al., 2017; Liu et al., 2017). In addition, BMP-4 and BMP-7 suppress granulosa cell apoptosis by inhibiting the release of caspase-activated DNase or alleviating endoplasmic reticulum stress in bovine and chicken (Kayamori et al., 2009; Yao et al., 2020).

Ovarian stromal cells are known to express leukemia inhibitory factor (LIF), which plays pivotal roles in growth of the mammal primordial follicle, ovulation, steroidogenesis, and early embryo development (Cadoret et al., 2021; Pena et al., 2023). Studies indicated that LIF concentrations in FF were decreased in patients with PCOS, and that LIF levels could act as a biomarker for predicting outcomes of IVF with embryo transfer (Ledee-Bataille et al., 2001; Li et al., 2018). Furthermore, the frequency of the LIF gene mutation in infertile women is significantly higher compared to fertile controls (Novotny et al., 2009; Vagnini et al., 2019).

The level of monocyte chemotactic protein-1 (MCP-1) in human ovarian stroma increases from the preovulatory to the late ovulatory phase and declines during the postovulatory phase (Dahm-Kahler et al., 2009). High concentrations of MCP-1 in FF from women with tubal factor infertility may indicate chronic inflammatory changes, potentially leading to decreased fertilization rates (Xu et al., 2006). MCP-1 is abnormally elevated in the FF of obese women and is negatively correlated with pregnancy rates in infertile women undergoing IVF (Buyuk et al., 2017).

Sialic acid-binding immunoglobulin superfamily lectins (Siglec-11) expressed by human ovarian stromal fibroblasts interact with its ligands on mast cells, stimulating histamine secretion before ovulation and contributing to the inflammatory reaction during ovulation (Wang et al., 2011). Interestingly, there is a trend of increased Siglec-11 expression in both postmenopausal and PCOS ovaries, which share some features, such as perturbed follicle growth and fertility deficiency, indicating potential roles for Siglec-11 in ovarian physiology (Wang et al., 2011).

Furthermore, ovarian stromal cells are responsible for secreting ECM proteins, as well as MMPs and tissue inhibitors of MMPs (TIMPs), to facilitate maintenance and remodeling of the ovarian ECM (Briley et al., 2016; Kinnear et al., 2020). Mass spectrometry analysis of human FF stromal cells revealed the presence of 97 proteins associated with the stress response, positive regulation of apoptotic cell clearance, and embryo implantation (Skliutė et al., 2023).

Ovarian stromal cells and cytokines are pivotal to ovarian physiology, and their aberrations are linked to IVF failure, POF, and PCOS. Nonetheless, owing to the constraints of present research, a thorough and exhaustive delineation of the contribution of stromal cells to ovarian functionality remains absent.

Ovarian vascular system

The ovarian vasculature mainly consists of blood vessels and lymphatic vessels. The ovarian blood vessel system begins with proliferation and extension of the branches of the primordial gonadal vasculature at ∼11.5 days postcoitus (dpc) in mice (Coveney et al., 2008). In human, the ovarian medulla typically contains larger blood vessels, including spiraling arteries and arterioles. At the cortico-medullary junction, small medullary arteries branch to cortical arterioles. Ovarian blood vessels play essential roles in providing oxygenation, hormone trafficking, nutrients, and facilitating waste removal. Lymphatic vessels develop postnatally, first becoming apparent in the hilus (stalk) of the ovary at postnatal day (P) 8.5 in mice (Brown et al., 2010). These vessels extend from the ovarian medulla into the cortex adjacent to developing follicles and are closely associated with blood vessels (Brown and Russell, 2014). The lymphatic system functions to return extravascular fluid and proteins back to the bloodstream and participates in immune cell trafficking.

Ovarian blood vessels

Blood vessels play critical roles in processes such as tissue oxygenation, metabolism, and immune surveillance as a versatile transport network. Angiogenesis is involved in human folliculogenesis, ovulation, and corpus luteum formation (Devesa and Caicedo, 2019; Tomita, 2021). Resident primordial and early growing follicles do not possess an independent vascular network, therefore mammal ovarian stromal vessels are critical for maintenance of the resting stage of primordial follicles and the growth of primary follicles (Delgado-Rosas et al., 2009; Gao et al., 2013). During follicle maturation, the mouse vascular sheath forms two concentric vascular networks in the theca interna and the theca externa (Park et al., 2022). Maintaining follicular vasculature and ensuring adequate blood supply to follicles are essential for establishing mammalian follicular dominance and the corpus luteum (McFee et al., 2012; Fellus-Alyagor et al., 2021). The moderate permeability observed during angiogenesis of dominance follicles and the corpus luteum may indicate a rapid stabilization of forming vessels, conferring a functional advantage by facilitating efficiency of hormone transmission (Fellus-Alyagor et al., 2021). Additionally, reports on vascular changes in human corpus luteum have shown that angiogenesis is actively occurring during the early luteal phase and is completed by the midluteal phase, and that blood vessels decrease in number during the late luteal phase (Sugino et al., 2005). Human follicle survival relies on ovarian angiogenesis; follicular atresia or death occurs when vascular endothelial cells are damaged or when the capillary network within the sheath layer is inadequately formed (Akiyama et al., 2014).

Local changes in ovarian blood flow are intricately linked to alterations in the biosynthesis of prostaglandins and steroids and local factors such as IGFs and oxygen tension, which likely modulate ovarian angiogenic processes (Stouffer et al., 2001). Additionally, angiogenic factors, such as members of the vascular endothelial growth factor (VEGF), angiopoietin (ANGPT), fibroblast growth factor 2 (FGF-2), and platelet-derived growth factor (PDGF), have been shown to stimulate endothelial proliferation, migration, and tube formation in the ovary. VEGF promotes an increase in ovarian microvascular permeability, providing nutrients for the development and growth of primary follicles, and facilitating ovulation of dominant follicles. Throughout ovarian follicular development, VEGF isoforms may act in an autocrine manner to stimulate the proliferation and survival of mammalian granulosa cells, or in a paracrine fashion to promote angiogenesis in the theca cells (Rosales-Torres et al., 2010; Zamora-Gutierrez et al., 2019). Conversely, a decrease in the expression of VEGF mRNA in sheep granulosa cells had been reported at the onset of follicular atresia (Rosales-Torres et al., 2010). During cow corpus luteum development, the VEGF system created a proangiogenic milieu, which translates to an antiangiogenic state at the time of luteolysis (Guzman et al., 2015). Treatment with VEGF antagonist or overexpression of VEGF antiangiogenic members has been shown to impair crow and mouse follicle progression, induce follicular atresia, hinder ovulation, and weaken subsequent luteal function (Qiu et al., 2012; Zamora-Gutierrez et al., 2019). Besides, graft incubation with VEGF isoforms had been demonstrated to preserve primary ovarian follicles and enhance angiogenesis in a human xenograft model (Wang et al., 2013).

The density of blood vessels and factors related to angiogenesis are closely associated with ovarian pathological state. Ovaries from women with PCOS showed a 2-fold increase in blood vessel density in the superficial ovarian cortical stroma compared to age-matched controls. Increased vascularization of the superficial cortical stroma in PCOS ovaries can impact the cortical metabolic rate, thereby affecting the survival of primordial follicles and leading to early follicular growth (Delgado-Rosas et al., 2009). Additionally, elevated levels of VEGF in FF had been reported in women with PCOS, suggesting a role for the growth factor in the stromal hypervascularity observed in this syndrome (Artini et al., 2006; Patil et al., 2021). Furthermore, a genome-wide association study identified a significant association between reduced VEGF and increased risk of POI, indicating VEGF may serve as an early biomarker for predicting POI (Wang et al., 2023). VEGF increases vascular permeability and is essential for the process of angiogenesis during embryo implantation in women undergoing IVF treatment (Benkhalifa et al., 2021; Wu et al., 2021), while VEGF polymorphisms may disturb angiogenesis during invasion of the blastocyst, resulting in implantation failure and recurrent implantation failure (Elmi et al., 2023; Mrozikiewicz et al., 2023).

Ovarian lymphatic vessels

Lymphatic vessels regulate interstitial fluid content and transport cells to the immune system. Lymphatic networks have been detected in the ovaries of human, primates, rats, mice, pigs, ewes, and rabbits (Brown and Russell, 2014). Mammalian lymphatic vessels are found within the stromal compartment, in the cortex, and surrounding growing follicles (Svingen et al., 2012; Tomita, 2021). Brown et al. (2010) found an abnormal phenotype of follicular development in a mouse model with lymphatic defects (Brown et al., 2010). They revealed that mouse ovarian lymphatic vessel development lagged behind embryonic gonad vascular development, suggesting that lymphatic function only plays a role in the late stage of follicular maturation. Furthermore, during luteolysis, the bovine ovarian lymphatic system transports luteal cells out and participates in luteal degeneration (Abe et al., 2014).

The VEGFC/VEGF receptor 3 (VEGFR3) signaling pathway is the primary mechanism regulating lymphangiogenesis. VEGFR3 is predominantly expressed on lymphatic endothelial cells, where it is instrumental in orchestrating the formation and morphological evolution of ovarian lymphatic vessels (Brown and Russell, 2014). In a mouse model, VEGFR3 antagonists effectively prevented lymphangiogenesis of mature follicles within ovaries, with fewer secondary follicles, a reduced pregnancy rate, retarded fetal growth, and increased abortion (Rutkowski et al., 2013).

The precise function of the ovarian lymphatic system remains elusive, yet it likely plays a pivotal role in maintaining fluid balance and facilitating hormone transport. Alongside the vascular system, it contributes to the regulation of various disorders linked to ovarian fluid imbalance, such as PCOS, ovarian hyperstimulation syndrome, and massive ovarian oedema. A more comprehensive understanding of the structure and function of lymphatic vessels within human ovaries could shed light on whether lymphatics are further involved in the pathogenesis of ovarian diseases. Thorough investigations into the regulation and function of ovarian lymphatic systems in animal models will offer valuable insights for advancing research into the functional or spatial deficiencies associated with the aforementioned clinical ovarian diseases.

Ovarian immune microenvironment

Approximately 40 years ago, an interaction between the immune system and ovarian function was proposed. The development of the ovary is blocked by removing the thymus, a critical immune organ. Immune cells present in ovaries include three main types: macrophages, T lymphocytes, and B lymphocytes. They are primarily distributed in the immature or static ovarian stroma, particularly in proximity to ovarian blood vessels. These cells, along with inflammatory factors, play pivotal roles in various fertility-related processes within ovaries, ranging from follicle development to ovulation and corpus luteum formation and regression.

Macrophages

The predominant immune cell type in ovaries is the macrophages. Studies conducted in human or animal have revealed a widespread presence throughout various ovarian processes, including follicle development, ovulation, corpus luteum formation and regression, and follicle atresia (Tang et al., 2023). Recently, using high-dimensional single-cell mass cytometry, five macrophage populations have been identified in adult mice ovaries (Jokela et al., 2020). Additionally, single-cell RNA sequencing of human ovaries identified four subtypes of ovarian macrophages, shedding light on their roles in orchestrating diverse immune response within the ovarian microenvironment as individuals age (Zhou et al., 2024). In ovarian research, particular emphasis is placed on investigating the pro-inflammatory M1 type and tissue-remodeling M2 type macrophages.

Ovarian macrophages are involved in the activation and development of follicles. In bovine ovaries, macrophages had been found to regulate the nuclear factor κB (NF-κB) pathway, thereby participating in the process of primordial follicle selection (Liu et al., 2009). Co-culture studies involving newborn mouse ovaries with different macrophage subtypes demonstrated that M1 macrophages activated primordial follicles by upregulating the PI3K/AKT/rapamycin (mTOR) pathway, while M2 macrophages inhibited primordial follicles by downregulating this pathway (Xiao et al., 2022). Additionally, to investigate the role of M1 and M2 macrophages in folliculogenesis, researchers created M1-like CD11c DTR mice (CD11c depletion mice) and M2-like CD206 DTR mice (CD206 depletion mice) (Ono et al., 2018). Compared to wild-type mice, folliculogenesis was impaired in CD11c DTR mice, while it remained normal in CD206 DTR mice, indicating the necessity of M1 populations in folliculogenesis (Ono et al., 2018). Moreover, co-culturing macrophages with primary and early secondary mouse follicles or rat granulosa cells significantly enhanced follicle growth, survival, and granulosa cell proliferation (Tingen et al., 2011). However, aberrant macrophage infiltration in the mouse ovary, induced by endogenous or exogenous factors, increased inflammatory potential, and disrupted folliculogenesis (Thornton et al., 2020; Saccon et al., 2022).

Macrophages also play a role in ovulation and postovulatory repair processes. Mice lacking colony-stimulating factor-1 (CSF-1) experience depleted populations of macrophages in various tissues, leading to prolonged oestrous cycles and reduced ovulation rates in mice (Cohen et al., 2002). Consistent with this, study employing clodronate liposomes to deplete ovarian macrophages showed a significant decrease in ovulation rate of mice or rats (Van der Hoek et al., 2000). Recently, single-cell investigations of the follicular microenvironment surrounding the metaphase II oocyte in human preovulatory follicles have revealed the infiltration of five clusters of macrophages near granulosa cells, highlighting their regulatory role in the subsequent ovulation process (Wu et al., 2022). As ovulation initiates, the increase in LH promotes granulosa cell synthesis of numerous chemoattractants to recruit macrophages, such as MCP-1 (Bersinger et al., 2014), C–C-motif ligand-20 (CCL-20) (Al-Alem et al., 2015), and IL-1 (Dang et al., 2017). Following ovulation, macrophages migrate to the developing corpus luteum, participating in its formation, steroid hormone secretion, and remodeling postdegeneration. Histological studies of human ovaries had shown that corpus luteum macrophages underwent numerical alterations during the menstrual cycle, increasing toward the end of the early luteal phase, remaining relatively stable during the midluteal phase, and decreasing in the late luteal phase (Gaytan et al., 1998). An acute macrophage depletion CD11b-DTR mouse model had revealed the critical role of macrophages in supporting the extensive vascular network necessary for corpus luteum integrity and progesterone (P4) production (Turner et al., 2011; Care et al., 2013). In comparison, mice with transforming growth factor-beta1 (TGF-β1) null mutations, a key factor promoting macrophage alternative activation (M2), produced ∼75% less P4 in early pregnancy (Ingman et al., 2006). In the late luteal phase, macrophages produce tumor necrosis factor-alpha (TNF-α), regulating prostaglandin F2α (PGF2α) synthesis to trigger mouse ovarian luteolysis (Care et al., 2013).

Some pathological conditions of the ovaries can lead to infiltration and functional alterations of macrophages. PCOS is characterized by systematic, chronic, low-grade inflammation, and these patients commonly exhibit an increased number of macrophages in ovarian tissues (Xiong et al., 2011; Rudnicka et al., 2021). In a PCOS rat model induced by prolonged exposure to 5α-dihydrotestosterone, there was an increase in the ratio of M1 macrophages in antral and preovulatory follicles, which was associated with upregulated expression of the pro-inflammatory adipokine chemerin (Lima et al., 2018). When granulosa cells were co-cultured with macrophages or macrophage secretions from PCOS rat ovaries, there was an increase in granulosa cell apoptosis (Figueroa et al., 2015; Lima et al., 2018).

Lymphocytes

Ovarian lymphocytes are classified into B and T lymphocytes, primarily found in ovarian medulla, FF, and corpus luteum (Bukulmez and Arici, 2000). B lymphocytes are exceptionally rare in ovary and are occasionally noted in the luteal tissue. T lymphocytes are generally absent in developing follicles but proliferate significantly after ovulation, primarily participating in ovulation, luteal formation, and luteal degeneration. In buffalo ovarian tissue, T lymphocytes contribute to ovulation by releasing bioactive cytokines (Ramadan et al., 2001). Following follicle rupture, the neovascularization of the developing corpus luteum provides opportunities for direct interaction between luteal cells and resident or migratory immune cells. Specifically, CD8+ T lymphocytes can directly or indirectly communicate with human luteal cells during corpus luteum formation and luteolysis (Walusimbi and Pate, 2013).

In infertile patients with DOR, the FF exhibited an increased number and heightened function of effector CD8+ T lymphocytes compared to infertile patients with normal ovarian reserve (Zhao et al., 2022). These CD8+ T lymphocytes secreted immune cytokine interferon gamma (IFN-γ), inducing granulosa cell apoptosis and exacerbating the progression of DOR. The dysregulation of T lymphocytes is implicated in the pathogenesis of autoimmune ovarian injury, as evidenced by the infiltration of CD3+ T lymphocytes around ovaries follicles in patients with autoimmune oophoritis (Bakalov et al., 2005). CD4+Foxp3+ regulatory T (Treg) cells play a key role in maintaining peripheral immune tolerance and contribute to ovarian immune homeostasis by preventing T helper 1 (TH1)-like inflammation. Jiao et al. (2021) discovered a correlation between the absence of Treg cells and the severity of POI, with Treg cells effectively reversing TH1-mediated ovarian insufficiency in mice (Jiao et al., 2021). Additionally, a recent study has revealed an increased production of TH1 cytokines (IFN-γ, TNF-α, IL-2) in FF lymphocytes of patients with PCOS compared to normal, suggesting the potential involvement of TH1 dominance in ovarian immune pathogenesis in patients with PCOS (Qin et al., 2016). However, another study observed significantly higher levels of IL-13, a TH2 cytokine, and reduced levels of IL-12, a TH1 cytokine, in patients with PCOS than in normally ovulating women (Gallinelli et al., 2003). Moreover, Li et al. (2019) found increased expression of programmed death 1 (PD-1) and decreased expression of IFN-γ in CD4+ T and CD8+ T cells in FF of infertile patients with PCOS (Li et al., 2019). These discrepancies may arise from variations in study populations and analytical methods.

Immune cytokines

Immune cytokines exert diverse roles in follicular development and the maintenance of ovarian function, which is potentially influenced by the type, concentration, and local milieu of cytokines. TNF-α, a proinflammatory cytokine primarily produced by monocytes, is expressed in the ovarian tissues across various species (Faustman and Davis, 2010). TNF-α participates in regulating of gonadotrophin-induced steroid hormone production, granulosa cell proliferation, and differentiation, as well as ovulation and luteal function maintenance (Crespo et al., 2010; Glister et al., 2014; Samir et al., 2017). Some studies have explored the association between FF TNF‐α and IVF outcomes. Elevated levels of TNF‐α in patient FF were associated with poor-quality oocytes, leading to reduced rates of fertilization, embryonic development, and pregnancy outcome (Wyse et al., 2021). Blocking TNF‐α had been shown to improve implantation, clinical pregnancy, and live birth rates in young infertile women (Winger et al., 2009). PCOS shares similar properties with many chronic inflammatory disorders, and elevated TNF-α levels had been observed in patients with PCOS (Artimani et al., 2018). Furthermore, increased FF TNF‐α levels in women with PCOS were significantly and inversely correlated to FF 17β-estradiol (E2) levels (Amato et al., 2003). A study exploring the relation between TNF-α polymorphisms and PCOS susceptibility suggested that TNF-α polymorphisms might influence the risk of developing PCOS in the overall population (Zhang et al., 2020).

IL-1 is synthesized by activated mononuclear macrophages. The two primary prototypic cytokines in this family, IL-1α and IL-1β, are known to trigger the expression of various proinflammatory genes and are implicated in processes such as ovulation, oocyte maturation, and ovarian steroidogenesis (Silva et al., 2020; Wan et al., 2023). However, uncontrolled inflammation has adverse effects on ovarian function. Studies on IL-1α knockout mice revealed a higher pregnancy rate and increased litter size compared to wild-type mice, with these effects appearing from 2.5 months of age and persisting into advanced age (Uri-Belapolsky et al., 2014). Furthermore, polymorphisms in IL-1α and IL-1β gene were found to be more prevalent in the PCOS group, increasing the risk of PCOS (Zhang et al., 2020).

IL-6, predominantly secreted by monocytes/macrophages and granulosa cells under normal ovarian physiological conditions, acts as a powerful autocrine modulator of granulosa cell differentiation, ovarian cumulus cell functionality, COC expansion, and oocyte competence (Liu et al., 2009; Imai et al., 2014). However, IL-6 adversely impacted human and rat ovarian function by inhibiting FSH-stimulated E2 and P4 production in granulosa cells (Tamura et al., 2000; Salmassi et al., 2001). Elevated FF concentrations of IL-6 in patients with PCOS, as compared to non-PCOS women, indicate a significantly enhanced proinflammatory environment in PCOS FF (Kim et al., 2011; Zhang et al., 2017). Additionally, the IL-6-174 G/C polymorphism had been identified as a potential genetic indicator for PCOS susceptibility (Benjamin et al., 2020; Azeez et al., 2022). Notably, a high FF level of IL-6 was associated with improved clinical pregnancy rates and reduced embryo fragmentation during IVF treatments (Yang et al., 2020; Stojanovic Gavrilovic et al., 2022).

IFN-γ belongs to the interferon family that is produced by T lymphocytes, macrophages, and natural killer (NK) cells. IFN-γ regulates ovarian function by influencing granulosa differentiation, follicular atresia, steroid hormone synthesis, and luteal degeneration (Lee et al., 2016; Wei et al., 2022). In infertile patients with DOR, the level of IFN-γ in FF was found to be elevated, indicating a shift in the ovarian immune balance (Zhao et al., 2022). Conversely, infertile patients with PCOS demonstrated significantly decreased expression of IFN-γ in FF compared to women with normal ovulation (Li et al., 2019).

TGF-β1, mainly secreted by macrophages and lymphocytes, stands as a pivotal growth factor orchestrating diverse processes, including follicular development, steroidogenesis, ovulation, oocyte maturation, and luteinization (Cheng et al., 2021; Guo et al., 2022). In TGF-β1 null mutant mice, ovarian function was profoundly compromised with prolonged ovarian cycles, erratic ovulation, and a notable 40% decrease in ovulated oocytes (Ingman et al., 2006). Furthermore, hypomethylation of CpG4 and CpG7 sites in the TGF-β1 gene promoter strongly correlated with the pathogenesis of insulin resistance-associated PCOS by modulating TGF-β1 gene expression (Gao et al., 2024). Notably, individuals with PCOS exhibited an elevated TGF-β1 level, and the TGF-β1/SMAD3 signaling pathway inhibited ovarian follicular development by inducing granulosa cell apoptosis (Shen and Wang, 2019). Moreover, certain SNPs within the TGF-β1 gene, such as rs11466313, rs1800469, rs2317130, and rs4803457, were associated with PCOS susceptibility and phenotypic traits in Korean women (Roh et al., 2017). Among these variants, the rs4803457 polymorphism emerged as a pivotal determinant in the pathogenesis of PCOS among Chinese Han women (Yang et al., 2015).

Ovarian stem cells

For many years, ovarian biology has been based on the doctrine that the oocyte reserve of female mammals is determined by the quantity and quality of the primordial follicle pool that developed during the neonatal period, and that ovarian follicular reserve is generally lost with age, without renewal (Johnson et al., 2004). However, in recent years, proponents of neo-oogenesis have argued for the existence of renewable germ stem cells in mammalian ovaries that are capable of differentiating into oocytes (Gheorghisan-Galateanu et al., 2014).

Johnson et al. (2005) made a groundbreaking discovery, revealing the presence of mitotically active germ cells in mouse ovaries after birth, suggesting a potential origin from bone marrow (Johnson et al., 2005). Subsequently, germline stem cells from mouse ovaries were successfully isolated and cultured (Zou et al., 2009). When transplanted into the ovaries of chemotherapy-induced infertile mice, these germline stem cells differentiated into mature eggs, leading to the birth of offspring. Furthermore, germline stem cells were identified in the ovaries of women of reproductive age (White et al., 2012). Since then, various research groups have reported the presence of germline stem cell populations in the ovaries of numerous mammal species (White et al., 2012; Stimpfel et al., 2013; Woods and Tilly, 2013; Dunlop et al., 2014; Clarkson et al., 2018; Silvestris et al., 2018; Sharma and Bhartiya, 2022). Interestingly, our group recently isolates DEAD-box helicase 4 (DDX4+) germline stem cells from the ovaries of postmenopausal women, demonstrating their capability to enter the meiosis stage and differentiate into oocytes (Wu et al., 2022). Nevertheless, the existence and significance of ovarian germline stem cells remain contentious. Lei and Spradling (2013) failed to detect active germline stem cells in mouse ovaries using a sensitive lineage-labeling system (Lei and Spradling, 2013). Similarly, Wagner et al. (2020) found that the cells captured by DDX4 antibodies in the human ovarian cortex were perivascular cells rather than oogonial stem cells (Wagner et al., 2020). Therefore, much remains to be elucidated regarding the biology of ovarian stem cells and their potential clinical applications.

Changes in the ovarian microenvironment during chemotherapy

In addition to directly inducing follicle apoptosis, chemotherapeutic agents can indirectly affect ovarian function by damaging the ovarian microenvironment. The ovarian microenvironment shows great changes during chemotherapy, inducing ECM deposition and stromal fibrosis, disordered angiogenesis, immune microenvironment disturbance, oxidative stress homeostasis imbalance, ovarian stem cell exhaustion, and cell senescence (Fig. 2; Table 1). The homeostatic imbalance of the microenvironment induced by chemotherapy will lead to ovarian dysfunction and eventually accelerate ovarian ageing.

Figure 2. Changes in the ovarian microenvironment caused by chemotherapy. ROS, reactive oxygen species; SASP, senescence-associated secretion phenotype. Created with BioRender.com, with permission.

Table 1. Damage caused to the ovarian microenvironment by chemotherapy drugs.

Microenvironment damage	Drug	Model	Finding	Reference	
Extracellular matrix deposition and stromal fibrosis	Alkylating agents	Human	Ovarian tissue had been replaced by collagenous connective tissue.	Meirow et al., 2007	
	Alkylating agents and anthracyclines	Human	A higher content of collagen and DNA damage was observed in ovarian stromal.	Pampanini et al., 2019; Shai et al., 2021	
	CTX	Rabbit	Increased collagen fibers.	Abd-Allah et al., 2013	
	CTX	Rat	Hyperplasia was detected in ovarian stromal cells.	Abdel-Raheem et al., 2015	
	CTX	Mouse	The atrophied ovaries were mainly composed of stromal cells.	Liu et al., 2012; Zhu et al., 2015; Huang et al., 2023	
	CTX	Mouse	Increased ovarian fibrotic area.	Chen et al., 2021	
	CTX	Rat	Induced ovarian stromal fibrosis and luteal fibrosis.	Huang et al., 2009; Abdelzaher et al., 2021	
	CTX	Rat	The tensile mechanical properties of the ovarian tissue reduced.	Pan et al., 2017	
	CIS	Rat	Fibrosis was detected in ovarian stroma.	Atli et al., 2017; Chinwe et al., 2018; Said et al., 2019; Ciplak et al., 2023	
	CIS	Rat	Led to excessive synthesis of ovarian ECM.	Cui et al., 2020	
	CIS	Rat	The expression of Col-I, Col-III, fibronectin, CTGF, and α-SMA increased.	Cui et al., 2022	
	DOX	Mouse	Induced an acute insult of ovarian parenchymal fibrosis.	Ben-Aharon et al., 2010	
	DOX	Mouse	The expression of α-SMA, Col-I, TGF-β1, TIMP1, TIMP2, and MMP2 increased.	Gao et al., 2023	
	CTX; PTX; DOX; CIS	Mouse	Ovarian stromal disorder and atrophy.	Zhang et al., 2023	
	CIS; DOX	Human	The growth of ovarian stromal cell was inhibited.	Fabbri et al., 2016; Lopes et al., 2020	
	CIS; DOX	Mouse	The growth inhibition and apoptosis of ovarian stromal cell were induced.	Roti Roti et al., 2012; Yoon et al., 2020	
	CTX/BUL	Mouse	Structural disruption of the ovarian interstitial region.	Buigues et al., 2020	
	CTX/BUL	Mouse	Severe ovarian interstitial fibrosis.	Luo et al., 2017; Yang et al., 2019	
	Docetaxel/CTX	Rat	The expression of TGF-β1, Col-I, and Col-III was increased.	De Moraes et al., 2016	
Vascular structure and angiogenesis disturbance	Alkylating/anthracycline/taxane agents	Human	The narrowing and obliteration of ovarian blood vessels, decreased vessel area, reduced blood flow, and occasional neovascularization.	Nicosia et al., 1985; Marcello et al., 1990; Meirow et al., 2007; Ben-Aharon et al., 2012; Shai et al., 2021; Devos et al., 2023	
	CTX; CIS; PTX	Human	The vascular structure was sparse and the microvascular density decreased.	Bildik et al., 2015	
	CTX	Rabbit	Vascular smooth muscle proliferation and vascular wall thickening.	Abd-Allah et al., 2013	
	CTX	Rat	Thickening of the ovarian tissue vascular wall and hyaluronic degeneration.	Fu et al., 2017	
	CTX	Mouse	
Ovarian microvascularization was impaired.

Reduced the expression of VEGF.	Ezoe et al., 2014; Dynes et al., 2017; Oubina et al., 2021; Huang et al., 2023	
	CTX/BUL	Mouse	
The ovarian vascularization area was decreased.

The expression of vWF, IGF-1, ANGPT, and CD34 decreased.	Herraiz et al., 2018; Yang et al., 2019; Buigues et al., 2020; Huang et al., 2021; Salvatore et al., 2021	
	CIS	Rat	Damaged ovarian vascular structure.	Dayangan Sayan et al., 2018; Said et al., 2019; Ciplak et al., 2023	
	DOX	Mouse	
Disorganized immature ovarian blood vessels with areas of discontinuation in the endothelial layer.

The expression of CD34 and VEGF decreased.	Herrero et al., 2023	
	CTX	Mouse	The mRNA expression of VEGF and IGF-1 decreased.	Eslami et al., 2023	
	CTX	Mouse	Reduced the expression of VEGF, bFGF, PDGFB, and ANG.	Abdelzaher et al., 2021; Zhou et al., 2021	
	CIS	Mouse	The expression of VEGF, IGF-1, FGF, and CD31 was downregulated.	Qu et al., 2022	
Immune microenvironment disorder	CTX	Human; Rhesus; Macaque	The clusters of CD68/CD163+ macrophages, CD4+ lymphocytes, CD3+ T lymphocytes, and MPO-positive neutrophils were increased.	Du et al., 2022	
	CTX	Mouse	Increased infiltration of M0 macrophages, naive B cells, resting NK cells, and reduced infiltration of Treg cells, TH17 cells, NK cells, and M1/M2 macrophages ratio.	He et al., 2023	
	CTX/BUL	Mouse	Macrophages and neutrophils infiltrated in ovary.	Deng et al., 2021	
	CIS	Rat	The infiltration of neutrophils increased.	Dinc et al., 2023	
	CIS	Rat	Led to leukocyte accumulation and elevation of MPO.	Atli et al., 2017; Mentese et al., 2022; Ciplak et al., 2023	
	CTX	Mouse	Decreased the level of IL-2 and TNF-α.	Liu et al., 2019	
	CTX	Mouse	Increased the expression of IL-6, IL-8, and TNF-α, as well as decreased the expression of IL-10 and TSG-6.	Deng et al., 2021; Eslami et al., 2023	
	CTX	Rat	Increased the expression of IL-6, IL-1β, and TNF-α and decreased the expression of IL-10.	Abdel-Raheem et al., 2015; Gabr et al., 2016; Ling et al., 2017; Hassan et al., 2021	
	CTX/BUL	Mouse	Downregulated IL-2 and TNF-α, and upregulated IL-4.	Huang et al., 2021; Li et al., 2023	
	CTX/BUL	Mouse	Increased the expression of TNF-α, IL-8, and IL-6.	Lai et al., 2014	
	CIS	Rat	The levels of TNF-α, IL-1β, NF-kB, and IL-6 were increased.	Said et al., 2019; Ibrahim et al., 2021; Al-Shahat et al., 2022; Mentese et al., 2022; Dinc et al., 2023	
	DOX	Human	The level of TNF-α, COX-2, IL-6, IL-8, MMP2, and MMP9 was increased.	Fabbri et al., 2019	
Oxidation-reduction imbalance	CTX	Mouse	Increased the expression of MDA, LDH and decreased the expression of GPx, CAT, and SOD.	Huang et al., 2019, 2023; Ding et al., 2020; Khanmohammadi et al., 2021; Feng et al., 2022; Zhao et al., 2022	
	CTX	Rat	Increased the expression of MDA and decreased the expression of GSH, GPx, CAT, and SOD.	Abdel-Raheem et al., 2015; Khedr, 2015; Saleh and Mansour, 2016; Yang et al., 2017; Abdelzaher et al., 2021; Hassan et al., 2021; Talebi et al., 2022; Zheng et al., 2022	
	CTX	Mouse	Decreased ATP and mtDNA production and increased mitochondrial membrane potential reduction rate.	Chen et al., 2022	
	CTX	Mouse	The expression of 8-OHdG, NTY, and 4-HNE significantly increased.	Chen et al., 2021	
	CTX	Mouse	Enhanced antioxidant enzymes and decreased ROS and MDA.	Athira et al., 2020	
	CTX/BUL	Mouse	Induced excess ROS.	Chen et al., 2021; Zhang et al., 2021; Peng et al., 2023	
	CTX/BUL	Mouse	Impaired biogenesis of oocyte mitochondria and reduced expression of 8-OHdG, MDA, and PGC1α.	Dai et al., 2022	
	CIS	Rat	Decreased the levels of SOD, GSH, CAT, Cu/Zn-SOD, and increased the levels of oxidized MDA, NOx.	Li et al., 2013; Meng et al., 2015; Chinwe et al., 2018; Soyman et al., 2018; Ibrahim et al., 2021; Al-Shahat et al., 2022; Mentese et al., 2022; Dinc et al., 2023	
	CIS	Mouse	Decreased the levels of CAT and GPx, and increased 4-HNE, NTY, 8-OHdG, and MDA.	Biyik et al., 2021; Wang et al., 2024	
	CIS	Mouse	Increased the production of ROS and decreased the activity of mitochondria.	Chen et al., 2015; Barberino et al., 2017; Lins et al., 2020; Gouveia et al., 2021	
	DOX	Mouse	Decreased the mRNA expression of SOD, GSH and increased the expression of oxidative stress-related genes, such as MDA and NRF2.	Niringiyumukiza et al., 2019; Wang et al., 2020	
	DOX	Mouse	Increased the expression of HO-1 and CAT.	Herrero et al., 2023	
	DOX	Rat	Increased MDA and NO levels, decreased SOD level.	Morsi et al., 2023	
Ovarian stem cell exhaustion	CTX	Mouse	The expression of MVH and OCT4 was reduced.	Jiang et al., 2019	
	CTX	Mouse	Decreased the number of ovarian stem cells and diminished expression of MVH and OCT4.	Jiang et al., 2019	
	CTX/BUL	Mouse	Ovarian stem cell apoptosis and dysfunction.	Lai et al., 2015; Sriraman et al., 2015; Wu et al., 2019.	
	ABVD	Human	Biovular and binucleate follicles were presented in ovaries.	McLaughlin et al., 2017	
Cell senescence	CTX	Mouse	Induced ovarian granulosa cell senescence and stromal cell with higher expression of p53, p66Shc, and p16.	Xiong et al., 2017; Ai et al., 2023; Xu et al., 2023	
	CTX/BUL	Mouse	Senescent ovarian stromal cells increased and the expression of cell p53, p21, and p27 was upregulated.	Dai et al., 2022	
	CIS	Mouse	Increased cell senescence and the expression of SASPs (IL-6, IL-1β).	Marcozzi et al., 2019; Du et al., 2022	
	DOX	Mouse	
The accumulation of senescent cells and the expression of p16 and p21 increased.

The expression of SASPs (IL-6, MCP-1, TGF-β1) increased.	Gao et al., 2023	
α-SMA, α-smooth muscle actin; ANG/ANGPT, angiopoietin; ABVD, adriamycin, bleomycin, vinblastine and dacarbazine; BUL, busulphan; CTX, cyclophosphamide; CIS, cisplatin; CAT, catalase; CD31, platelet endothelial cell adhesion molecule; CTGF, connective tissue growth factor; Col-I, type I collagen fiber; Col-III, type III collagen fiber; COX-2, cyclooxygenase-2; DOX, doxorubicin; ECM, extracellular matrix; FGF, fibroblast growth factor; GPx, lutathione peroxidase; GSH, glutathione; 8-OHdG, 8-Hydroxy-2′-deoxyguanosine; 4-HNE, 4-hydroxynonenal; HO-1, heme oxygenase-1; IGF-1, insulin-like growth factor-1; LDH, lactate dehydrogenase; MPO, myeloperoxidase positive; MDA, malondialdehyde; MMP2, metalloproteinase 2; MMP9, metalloproteinase 9; MCP-1, monocyte chemoattractant protein-1; MVH, mouse vasa homolog; NRF2, NF-E2-related factor 2; NTY, nitrotyrosine; NF-kB, nuclear factor kappa B; NO, nitric oxide; NOx, total nitric oxide; OCT4, octamer-binding transcription factor 4; PTX, paclitaxel; PDGFB, platelet-derived growth factor B; PGC1α, peroxisome proliferator-activated receptor gamma coactivator 1-alpha; ROS, reactive oxygen species; SOD, superoxide dismutase; SASPs, senescence-associated secretion phenotypes; Cu/Zn-SOD, Cu/Zn superoxide dismutase; TSG-6, TNF-stimulated gene 6; TNF-α, tumor necrosis factor-alpha; TGF-β1, transforming growth factor-beta1; TIMP1, metalloprotease 1; TIMP2, metalloprotease 2; vWF, von Willebrand factor; VEGF, vascular endothelial growth factor.

Extracellular matrix deposition and stromal fibrosis

Under normal physiological conditions, tissues undergo remodeling in response to injury, leading to tissue regeneration without permanent damage. Conversely, fibrosis arises from repeated tissue insult and inflammation. Ovarian fibrosis is characterized by excessive ovarian stromal cell proliferation and ECM deposition and is one of the main causes of ovarian dysfunction (Zhou et al., 2017). Fibrosis will destroy the normal ovarian physiological structure; if not corrected in time, fibrous connective tissue will replace functional tissue, and ovarian function will further decline or even fail, with loss of periodic ovulation and ovarian endocrine function (Briley et al., 2016). Fibrosis in the ovarian stroma tends to increase with advanced reproductive age, although the precise mechanism remains unknown. One reason could be the compromised biomechanical properties of an aged ovary, such as increased synthesis and deposition of collagen, diminished hyaluronan levels, or alteration in posttranslational modifications (Amargant et al., 2020; Babayev et al., 2023; DipaLi et al., 2023). Alternatively, an imbalance of the activities of MMPs and TIMPs disrupts the homeostasis of ECM synthesis and metabolism (Briley et al., 2016). As the ovarian microenvironment or stroma ages, it tends to become fibro-inflammatory, characterized by increased production and release of proinflammatory and pro-fibrotic cytokines and growth factors, as well as a shift in macrophage populations towards multinucleated macrophage giant cells (Machlin et al., 2021; Babayev et al., 2023). Furthermore, one study revealed an accumulation of non-heme iron in the ovarian stroma with reproductive aging, indicating iron accumulation in the aging ovary may contribute to fibrosis (Asano, 2012).

Compared to ovarian fibrosis during natural aging, chemotherapy drugs such as CTX, CIS, and DOX have been implicated in disrupting the balance between the synthesis and degradation of ECM, leading to excessive ECM accumulation and fibrosis (Briley et al., 2016; Zhou et al., 2017). A study conducted on frozen sections of ovarian tissue from cancer survivors undergoing alkylating chemotherapy revealed the replacement of intact ovarian tissue with collagenous connective tissue, with no follicles observed in the fibrotic area (Meirow et al., 2007). This suggests that chemotherapy causes structural damage to the ovary by promoting fibrosis of ovarian cortex, leading to focal loss of primordial follicles. Besides, a significant correlation has been found between the extent of ovarian fibrosis and the cumulative exposure to alkylating agents and anthracyclines in cancer patients (Pampanini et al., 2019; Shai et al., 2021), with fibrosis typically observed 4–6 months after exposure to alkylating agents (Shai et al., 2021).

Animal studies had also shown that low-dose CTX administration for 2 weeks induced a significant increase in collagen fibers, absence of follicles in the fibrotic zone, and ovarian tissue atrophy in rabbits (Abd-Allah et al., 2013). Moreover, hyperplasia was detected in rat ovarian stromal cells, with follicular atresia observed after CTX administration (Abdel-Raheem et al., 2015). In a CTX-induced POF mouse model, atrophied ovaries primarily composed of stromal cells within a fibrous matrix were observed, accompanied by a reduced number of follicles at each stage (Liu et al., 2012; Zhu et al., 2015; Huang et al., 2023). Histological staining of mouse ovaries post-CTX treatment had revealed that fibrotic areas are predominantly located in the interstitium between follicles and near the ovarian cortex (Chen et al., 2021). Similarly, in a rat model, CTX induced ovarian stromal fibrosis, luteal fibrosis, and ovarian vacuolar degeneration (Huang et al., 2009; Abdelzaher et al., 2021). Ovarian fibrosis leads to changes in biomechanical properties, disrupting the normal follicular developmental environment. Parameters such as maximum load, maximum stress, maximum strain, elastic limit strain, elastic limit load, and elastic limit stress in rat ovaries subjected to CTX treatment were found to be lower than those in the normal control group, indicating changes in the tensile mechanical properties of ovarian tissue following the loss of structural integrity and chemotherapy-induced ovarian fibrosis (Pan et al., 2017).

Following CIS therapy, fibrosis has been detected in rat ovarian stroma (Atli et al., 2017; Chinwe et al., 2018; Said et al., 2019; Ciplak et al., 2023). During mammalian follicular development, inner theca cells maintain the integrity of follicular structure, while outer myofibroblasts secrete ECM, including type I collagen fiber (Col-I) and type III collagen fiber (Col-III), facilitating the formation of follicular capillaries (Tingen et al., 2011; Hummitzsch et al., 2019; Kinnear et al., 2020; Isola et al., 2024). In CIS-induced POI rat models, ovarian stromal cells predominantly proliferated and differentiated into outer myofibroblasts, leading to excessive synthesis of ovarian ECM and subsequent ovarian fibrosis (Cui et al., 2020). This process involves activation of the TGF-β1/SMAD3 signal pathway to promote the proliferation of ovarian fibroblasts. Cui et al. (2022) demonstrated that, following CIS treatment, rat ovarian tissue exhibited increased expression of fibrosis-related markers, such as Col-I, Col-III, fibronectin, connective tissue growth factor (CTGF), and alpha-smooth muscle actin (α-SMA) (Cui et al., 2022). In addition, they discovered that CIS promoted the transformation of stromal cells into myofibroblasts by downregulating the expression of orphan nuclear receptor 4A1 (NR4A1) and increasing AMP-activated protein kinase phosphorylation.

DOX chemotherapy has been identified as a potential inducer of ovarian toxicity through promoting ovarian fibrosis. A study of mice subjected to DOX treatment revealed a reduction in ovarian size and weight, which may involve an acute insult of ovarian ischemia and parenchymal fibrosis (Ben-Aharon et al., 2010). The mRNA expression levels of mouse α-SMA, Col-I, TGF-β1, TIMP1, TIMP2, and MMP2, which are involved in tissue remodeling and fibrosis progression, were significantly increased in mouse ovaries of DOX-treatment group (Gao et al., 2023). Interestingly, mice treated with various chemotherapy agents, including CTX, paclitaxel, DOX, and CIS, exhibited ovarian stromal disorder and atrophy alongside significant upregulation of TGF-β. Among these agents, DOX treatment displays the highest toxicity towards ovarian stroma and caused the most pronounced fibrosis (Zhang et al., 2023). Additionally, CIS and DOX could induce growth inhibition and apoptosis in ovarian stromal cells obtained from human and mouse ovarian tissue (Roti Roti et al., 2012; Fabbri et al., 2016; Lopes et al., 2020; Yoon et al., 2020).

Combinations of antitumor agents have long been recognized as a critical approach to treatment. Structural disruption within the ovarian interstitial region had been observed in DOR and POI mouse models induced by combined therapy with CTX and BUL (Buigues et al., 2020). In these models, stromal degeneration was found to be increased by 2.5 times and 3.3 times in the DOR and POI models, respectively. Additionally, other studies had reported that CTX/BUL treatment induced severe ovarian interstitial fibrosis in a mouse model of POF/POI (Luo et al., 2017; Yang et al., 2019). Furthermore, De Moraes et al. (2016) assessed the effects of docetaxel combined with CTX (TC) on ovarian stromal tissue in rats (De Moraes et al., 2016). Their findings revealed increased expression levels of TGF-β1, Col-I, and Col-III in ovarian tissue from the TC group. Moreover, the collagen fiber structure within the ovary was disorganized, suggesting induction of ovarian fibrosis by the TC regimen.

Based on the existing literature, we have summarized the possible mechanisms of ovarian fibrosis associated with chemotherapy. Following chemotherapy treatment, ovarian stromal cells proliferate and differentiate into myofibroblasts, which secrete various fibrosis-related factors (Col-I, Col-III, fibronectin, CTGF, α-SMA, etc) and excessively synthesize ECM, ultimately leading to focal fibrosis of the ovarian cortex. Additionally, ovarian fibrosis leads to a change in the tensile mechanical properties of ovarian tissue, disrupting the normal follicular developmental environment. Furthermore, our results on the changes in ovarian microenvironment during chemotherapy demonstrate that there is decreased vascular density, increased levels of pro-inflammatory cytokines, significant infiltration of immune cells, and excessive production of ROS. Thus, immune cells and pro-inflammatory cytokines may be involved in creating fibrotic regions of ovarian tissue, inducing ovarian stroma degeneration and atrophy. Oxidative stress and the anti-angiogenic effects of chemotherapy result in insufficient stromal nutrient supply and stromal cell damage, ultimately inducing stromal cell apoptosis and stromal degeneration.

Vascular structure and angiogenesis disturbance

As chemotherapy is not selective, it affects both the tumor and the host’s healthy cells. This can lead to chemotherapy-induced vascular toxicity, characterized by direct or acute effects such as endothelial dysfunction, increased vascular muscle tone, and the constriction and distortion of blood vessels (Mizrachi et al., 2021). Likewise, chemotherapy drugs inhibit ovarian angiogenesis and destroy the integrity and function of blood vessels, ultimately resulting in ovarian dysfunction.

Several studies had demonstrated the presence of ovarian vascular alterations in patients exposed to chemotherapy, including narrowing and obliteration of blood vessels, decreased vessel area, reduced blood flow, and occasional neovascularization (Nicosia et al., 1985; Marcello et al., 1990; Meirow et al., 2007; Ben-Aharon et al., 2012; Shai et al., 2021; Devos et al., 2023). Following chemotherapy, the human ovarian cortex exhibited sparse vascular structure, with microvascular density decreased to 18%, 22%, and 56% after treatment with CTX, CIS, and paclitaxel, respectively (Bildik et al., 2015). CTX also induced vascular smooth muscle proliferation and thickening of vascular walls in rabbit ovaries, and resulted in blood vessel narrowing and obliteration (Abd-Allah et al., 2013). Further investigations have linked chemotherapy-induced rabbit ovarian vascular toxicity to abnormal follicle development and ovarian dysfunction (Abd-Allah et al., 2013). In another study, CTX treatment led to thickening of the ovarian tissue vascular wall and hyaluronic degeneration in rats (Fu et al., 2017). Chemotherapy drugs can directly damage ovarian blood vessels, resulting in a decrease in vascular density. The vascularization area of the ovary was significantly decreased in a POF mouse model induced by CTX or CTX/BUL (Herraiz et al., 2018; Buigues et al., 2020; Huang et al., 2021, 2023; Oubina et al., 2021; Salvatore et al., 2021). CIS treatment directly damaged the ovarian vascular structure in rats, leading to vascular congestion and bleeding, which hinders the normal blood supply to the ovary (Dayangan Sayan et al., 2018; Said et al., 2019; Ciplak et al., 2023). DOX treatment also induced disorganized immature ovarian blood vessels with areas of discontinuation in the endothelial layer in mice (Herrero et al., 2023).

Ovarian angiogenesis is a complex process involving various angiogenic factors, such as VEGF, IGF-1, FGF, ANGPT, and platelet-derived growth factor B (PDGFB). Chemotherapy drugs can interfere with the expression of genes related to angiogenesis and damage vascular endothelial cells, leading to ovarian angiogenesis disorders. Studies had shown that chemotherapy, such as CTX, suppressed the mRNA expression level of VEGF and IGF-1 in mouse ovary, resulting in inadequate vascular endothelial cell coverage and poor vascular maturation (Eslami et al., 2023). Additionally, reduced protein expression of VEGF, FGF, PDGFB, and ANGPT was observed in the ovary of CTX-induced POF mouse and rat models (Abdelzaher et al., 2021; Zhou et al., 2021). These findings strongly suggest that CTX downregulates the transcription 3 (STAT3)/hypoxia-inducible factor-1 alpha-/VEGF signaling pathway, thus inhibiting ovarian angiogenesis. Long-term studies had demonstrated a positive correlation between CTX dosage and dysfunctional ovarian angiogenesis in mice, highlighting its lasting effects on VEGF expression (Ezoe et al., 2014; Dynes et al., 2017). Similarly, the expression of VEGF, IGF-1, FGF, and platelet endothelial cell adhesion molecule (CD31) were downregulated in ovary of CIS-treated mice compared with a control group (Qu et al., 2022). Chemotherapy combination therapy with CTX/BUL reduced the expression of VEGF through inhibition of the PI3K/AKT pathway, and suppressed the expression of other angiogenic factors, such as von Willebrand factor (vWF), CD34, IGF-1, and ANGPT, ultimately inhibiting mouse ovarian angiogenesis (Herraiz et al., 2018; Yang et al., 2019; Buigues et al., 2020; Huang et al., 2021; Salvatore et al., 2021). Furthermore, DOX treatment decreased CD34 and VEGF expression in mice, suggesting a decline in endothelial cells number (Herrero et al., 2023). These finding collectively underscore the detrimental effects of chemotherapy on ovarian angiogenesis and highlight the importance of understanding and managing these effects in clinical practice.

Immune microenvironment disorder

Homeostasis of the ovarian immune microenvironment is essential for the proper functioning of various physiological processes in the reproductive system, including follicle development, ovulation, and corpus luteum formation. Chemotherapy drugs have the potential to disrupt the delicate balance by triggering significant infiltration of inflammatory cells and the secretion of immune factors in the ovary, ultimately leading to disruption of the ovarian immune microenvironment.

In a clinical study, clusters of CD68/CD163+ macrophages, CD4+ lymphocytes, CD3+ T lymphocytes, and myeloperoxidase (MPO)-positive neutrophils were significantly increased in the ovarian cortex of cancer patients after chemotherapy (Du et al., 2022). Additionally, macrophage infiltration into ovarian cortex was evident not only in humans and rhesus macaques but also in mouse ovarian cortex after CTX treatment. Prolonged treatment duration of up to 8 weeks resulted in macrophages invading follicles, leading to progressive ovarian tissue damage and follicle loss. This multi-species research indicates that chemotherapy-induced chronic inflammation can cause additional tissue damage to the ovary. In a mouse model receiving CTX treatment, immune cell analysis demonstrated increased infiltration of M0 macrophages, naive B cells, resting NK cells, and T cells in the ovaries, alongside reduced infiltration of Treg cells, TH17 cells, active NK cells, and altered M1/M2 macrophage ratio (He et al., 2023). These results suggest a significant enhancement of inflammatory and immune responses in the ovaries of mice following chemotherapy. Similarly, in mice treated with CTX/BUL, numerous macrophages and neutrophils infiltrated the ovary, with macrophages primarily distributed in the corpus luteum and atretic follicle, while neutrophils were predominantly located around the corpus luteum and within follicles (Deng et al., 2021). In a rat model of ovarian injury induced by CIS, the infiltration of neutrophils in the ovary led to structural disorder and degeneration of the developing follicle, along with local oedema of interstitial tissue and corpus luteum (Dinc et al., 2023). CIS treatment led to leukocyte accumulation and elevated MPO levels, leading to rat ovarian tissue congestion, oedema, and follicular degeneration (Atli et al., 2017; Mentese et al., 2022; Ciplak et al., 2023).

Alongside changes in ovarian immune cell populations, chemotherapy agents disrupt ovarian function by inducing an imbalance of inflammatory factors. In CTX-induced POF mice, ovarian levels of IL-2 and TNF-α decreased, likely attributed to reduced CD4+ T cells (Liu et al., 2019). Additionally, increased expression of proinflammatory factors, IL-6, IL-8, and TNF-α, along with decreased expression of the anti-inflammatory factor IL-10 and TNF-stimulated gene 6 (TSG-6), were found in mouse ovaries after CTX treatment (Deng et al., 2021; Eslami et al., 2023). Similarly, rat ovaries showed increased expression of IL-6, IL-1β, and TNF-α, along with decreased expression of IL-10 after CTX treatment (Abdel-Raheem et al., 2015; Gabr et al., 2016; Ling et al., 2017; Hassan et al., 2021). CTX/BUL treatment decreased expression of IL-2 and TNF-α while increasing expression of IL-4 in mouse ovaries (Huang et al., 2021; Li et al., 2023). The disruption of the TH1/TH2 balance in the ovary by chemotherapy-induced changes in IL-2, TNF-α, and IL-4 suggests potential induction of ovarian dysfunction and immunosuppression. In another study, several proinflammatory cytokines, such as TNF-α, IL-8, and IL-6, were significantly increased in mouse ovaries that received CTX/BUL chemotherapy (Lai et al., 2014). Tissue levels of the proinflammatory cytokines TNF-α, IL-1β, NF-κB, and IL-6 were also elevated in mouse and rat ovaries treated with CIS (Said et al., 2019; Ibrahim et al., 2021; Al-Shahat et al., 2022; Mentese et al., 2022; Dinc et al., 2023). An in vitro study found a significant increase in the expression of pro-inflammatory cytokines (TNF-α, cyclooxygenase-2, IL-6, IL-8, MMP2, and MMP9) in human ovarian tissue exposed to DOX (Fabbri et al., 2019). These findings collectively indicate that inflammation and alterations in immune cell phenotypes occur in the ovary during chemotherapy, contributing to decreased ovarian reserve.

Oxidation–reduction imbalance

Oxidative stress, characterized by an overproduction of ROS and/or a deterioration in antioxidant defenses, directly impacts the intraovarian environment (Zhang et al., 2015). ROS serve as double-edged swords within ovary, functioning as signaling molecules that promote follicle growth, ovulation, and corpus luteum formation when maintained in balance with antioxidants (Timoteo-Ferreira et al., 2021). However, when this balance is disrupted, oxidative stress ensues, leading to follicular atresia and decreased oocyte quantity and quality (Timoteo-Ferreira et al., 2021). Antioxidants present in the ovarian microenvironment, such as glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD), play crucial roles in scavenging ROS to protect ovarian cells from oxidative stress damage.

CTX treatment had been observed to elevate levels of oxidoreductases, specifically malondialdehyde (MDA) and lactate dehydrogenase (LDH), while simultaneously reducing activity of the key antioxidant enzymatic activities of GPx, CAT, and SOD in mouse ovaries, thereby inducing DNA damage and apoptosis of follicles (Huang et al., 2019, 2023; Ding et al., 2020; Khanmohammadi et al., 2021; Feng et al., 2022; Zhao et al., 2022). Similarly, the level of MDA was significantly increased in CTX-treated rat ovaries, while the activities of the antioxidant enzymes SOD, CAT, GPx, and GSH were significantly decreased (Abdel-Raheem et al., 2015; Khedr, 2015; Saleh and Mansour, 2016; Yang et al., 2017; Abdelzaher et al., 2021; Hassan et al., 2021; Talebi et al., 2022; Zheng et al., 2022). Furthermore, CTX-induced accumulation of oxidoreductase compromised the mitochondrial functions within mouse follicles, evident through diminished ATP and mtDNA production, alongside an increase in the rate of mitochondrial membrane potential reduction (Chen et al., 2022). Oxidative stress markers, 8-hydroxy-2′-deoxyguanosine (8-OHdG), nitrotyrosine (NTY), and 4-hydroxynonenal (4-HNE), in mouse ovaries increased significantly after CTX treatment, potentially a result of inhibiting the NF-E2-related factor 2 (NRF2)/heme oxygenase-1 (HO-1) and SOD2 antioxidant pathways (Chen et al., 2021). Intriguingly, administering CTX in multiple smaller doses appeared to enhance antioxidant enzymes activities and lowered ROS and MDA levels in mouse ovaries compared to a single, larger dose (Athira et al., 2020). Likewise, the damage to ovary caused by a single high dose of CTX was more severe than that caused by multiple smaller doses, despite the total amount of CTX administered being greater in the latter case. Concomitantly, the number of healthy follicles of all categories (primordial, primary, preantral, and antral follicles) and proliferating granulosa cells were also higher following multiple smaller doses of CTX treatment. ROS levels increased in mouse ovaries under CTX/BUL chemotherapy, which led to abnormal follicular development and infertility (Chen et al., 2021; Zhang et al., 2021; Peng et al., 2023). Additionally, CTX/BUL treatment hindered mouse oocyte mitochondrial biogenesis and diminished ovarian expression of 8-OHdG, MDA, and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (Dai et al., 2022). Together, these findings underscore the pivotal role of CTX-induced oxidative stress in driving ovarian dysfunction.

The side effects of CIS have also received considerable attention. The side effects of CIS are associated with an excessive production of free radicals and ROS, such as superoxide and H2O2. Following CIS treatment, a decrease in the expression of antioxidants (SOD, GSH, CAT, Cu/Zn-SOD) and an increase in oxidized MDA and total nitric oxide (NOx) levels were observed in rat ovaries, suggesting that CIS induces ovarian toxicity through increased oxidative stress (Li et al., 2013; Meng et al., 2015; Chinwe et al., 2018; Soyman et al., 2018; Ibrahim et al., 2021; Al-Shahat et al., 2022; Mentese et al., 2022; Dinc et al., 2023). Similarly, high 4-HNE, NTY, 8-OHdG, and MDA levels, and low CAT and GPx levels were observed in ovarian tissue of CIS-treated mice (Biyik et al., 2021; Wang et al., 2024). Mitochondria primarily contribute to ROS generation, and excessive oxidative stress can precipitate mitochondrial damage. In mice subjected to CIS treatment, the substantial ROS production within the ovarian microenvironment led to diminished numbers of active mitochondria and triggered follicular apoptosis (Chen et al., 2015; Barberino et al., 2017; Lins et al., 2020; Gouveia et al., 2021). Taken together, these findings underscore the association between CIS-induced ovarian toxicity and the destruction of follicles-mediated oxidative stress.

Some studies have indicated that ovarian toxicity of DOX is associated with ROS accumulation. DOX treatment resulted in a reduction in the mRNA expression of SOD and GSH while increasing the mRNA expression of oxidative stress-related genes, such as MDA and NRF2 in mouse ovaries (Niringiyumukiza et al., 2019; Wang et al., 2020). The stress induced by DOX prompted a protective response within mouse ovary, as shown by the upregulation of mRNA expression of HO-1 and CAT (Herrero et al., 2023). Another study showed that DOX administration led to increased MDA and NOx levels, decreased SOD level, and induced oxidative DNA damage in rat ovaries (Morsi et al., 2023). In conclusion, these studies indicate that DOX-induced ovarian damage is closely linked to disruptions in oxidative stress disturbance within the ovarian microenvironment.

Ovarian stem cell exhaustion

The key significance of ovarian stem cells lies in their ability to sustain neo-oogenesis and replenish the primitive follicle pool within adult ovaries (Bukovsky and Caudle, 2012). The self-renewal and differentiation of stem cells are intricately governed by the homeostasis of their surrounding microenvironment or niche, especially the levels of oxidative stress and inflammation (Gattazzo et al., 2014; Luo et al., 2019). In the face of genotoxic stress induced by chemotherapy, ovarian stem cells are continuously compelled to proliferate and undergo accelerated depletion.

A recent study has discovered that the levels of the germline stem-specific markers mouse vasa homolog (MVH) and octamer-binding transcription factor 4 (OCT4) are significantly reduced in mouse ovaries following CTX treatment, indicating a depletion of ovarian stem cells (Jiang et al., 2019). Subsequent research by the same group reported a near disappearance of ovarian germline stem cells in a CTX-induced POF mouse model, evidenced by diminished expression of MVH and OCT4 (Jiang et al., 2019). Moreover, the activity of Hedgehog (Hh) signaling, which governs ovarian germline stem cell proliferation and stemness, was found to decrease in ovaries postchemotherapy. CTX/BUL chemotherapy induced apoptosis and dysfunction of mouse ovarian stem cells, potentially attributable to excessive oxidative stress in the ovarian microenvironment (Lai et al., 2015; Sriraman et al., 2015; Wu et al., 2019). Interestingly, adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD) treatment did not deplete human ovarian reserve and might even paradoxically increase the population of non-growing follicles. Post-ABVD tissue exhibited the presence of biovular and binucleate follicles, a feature more commonly associated with the prepubertal ovary (McLaughlin et al., 2017). An alternative explanation may be that the ABVD combination, or specific components thereof, may activate germline stem cells to form oocytes or oocyte-like structures.

Despite its potential as a groundbreaking advancement in human reproductive science, the discovery of ovarian stem cells remains contentious. Nevertheless, it opens doors to innovative approaches in addressing ovarian dysfunction induced by chemotherapy. Although this area of research is still nascent, there remains ample opportunity to delve deeper into the biology of ovarian stem cells and explore their potential clinical application in fertility protection.

Cell senescence

Cytotoxic drugs stimulate persistent DNA damage response signaling, which results in irreparable DNA damage and induces cell senescence (Spears et al., 2019). As cells enter a senescent state, they secrete a range of cytokines, growth factors, inflammatory mediators, and proteinases, collectively referred to as the SASP. The abnormal accumulation of senescent cells within a tissue will cause cycle arrest, constrains the regenerative capacity of stem cells, and generates a proinflammatory milieu, ultimately driving senescence and dysfunction in normal cells and adjacent tissues (Calcinotto et al., 2019).

Chemotherapy has been shown to trigger premature cellular senescence, exemplified by various studies. In a POF mouse model, CTX significantly inhibited proliferation and induced senescence in ovarian granulosa cells accompanied by heightened expression of p53, p66Shc, and p16, potentially through the activation of the long non-coding RNA-Meg3-p53-p66Shc pathway (Xiong et al., 2017; Ai et al., 2023; Xu et al., 2023). Treatment with CTX/BUL led to an increase in senescent ovarian stromal cells in mice, concomitant with significant upregulation of cell cycle inhibition-related genes, such as p53, p21, and p27 (Dai et al., 2022). Cell senescence had also been implicated in CIS-induced ovarian damage in mice, resulting in reduced oocyte quality and infertility (Marcozzi et al., 2019; Du et al., 2022). Furthermore, DOX treatment induced the accumulation of senescent cells in mouse ovaries, as evidenced by increased positive staining of β-gal and elevated expression of p16 and p21 in the ovarian stroma microenvironment, potentially contributing to ovarian dysfunction and infertility (Gao et al., 2023).

Senescent cells within ovary have been found to secrete numerous proinflammatory factors, chemokines, and growth factors through autocrine or paracrine pathways (Anerillas et al., 2020; Lopez-Otin et al., 2023). The SASP creates specific microenvironments within mouse ovaries characterized by elevated levels of oxidative stress and inflammation (Hense et al., 2022). Du et al. (2022) identified heightened SASP-related factors, particularly IL-6 and IL-1β, in CIS-treated mouse ovaries (Du et al., 2022). Similarly, another study demonstrated increased expression of several common SASPs, such as IL-6, MCP-1, and TGF-β1, in mouse ovaries following DOX treatment (Gao et al., 2023). Collectively, these findings underscore that senescent cells and SASPs contribute to the establishment of a chronic inflammatory state and ovarian damage during chemotherapy.

Targeting the ovarian microenvironment to protect against chemotherapy-associated ovarian damage

Chemotherapy disrupts the delicate balance of the ovarian microenvironment, leading to poor oocyte developmental competence, follicular atresia, abnormal steroidogenesis, and infertility. Various strategies have been developed in mouse models to mitigate the ovarian damage caused by chemotherapy by targeting the ovarian microenvironment. These include stem cell therapy, free radical scavenging, immunomodulation, senolytherapies, and proangiogenic factors (Fig. 3). However, none of these approaches have been clinically tested for their efficacy in protecting against ovarian damage in humans undergoing chemotherapy.

Figure 3. Potential approaches targeting the ovarian microenvironment to protect against chemotherapy-associated ovarian damage. CAOD, chemotherapy-associated ovarian damage; C1P, ceramide-1-phosphat; G-CSF, granulocyte/colony-stimulating factor; SASP, senescence-associated secretion phenotype. Created with BioRender.com, with permission.

Stem cell therapy

Stem cells possess the remarkable ability to self-renew and differentiate into specific tissues according to their surrounding environment and signals (Na and Kim, 2020). Stem cells and their exosomes have demonstrated promising effects in improving various aspects of the ovarian microenvironment during chemotherapy. These effects include prevention of stromal fibrosis, preservation of blood vessel function, attenuation of inflammatory responses, and inhibition of oxidative stress (Table 2).

Table 2. Stem cell therapy to protect the ovarian microenvironment during chemotherapy.

Ovarian microenvironment	Categories	Drug	Model	Finding	Reference	
Improved ovarian fibrosis	hUMSCs	CTX	Mouse	Decreased ovarian tissue fibrosis.	Zhou et al., 2021	
	hAECs	CTX	Mouse	Inhibited ovarian fibrosis and promoted ECM remodeling.	Huang et al., 2023	
	hUMSCs	CTX/BUL	Rat	Inhibited ovarian collagen deposition.	Chen et al., 2023	
	hUMSCs	CIS	Rat	Downregulated the expression of α-SMA, Collagen I, and III.	Cui et al., 2020	
	MenSCs	CTX	Rat	Reduced ovarian fibrosis by regulating SMAD2/4/6 pathway.	Yamchi et al., 2021	
	MenSCs	CIS	Mouse	Secreted FGF2 to ameliorate ovarian fibrosis.	Wang et al., 2017	
Promoted ovarian angiogenesis	BMSCs	CTX	Rabbit	Secreted VEGF to promote angiogenesis.	Abd-Allah et al., 2013	
	cMSCs	CTX	Mouse	Upregulated VEGF and IGF-1.	Eslami et al., 2023	
	hUMSCs	CTX	Mouse	Promoted ovarian angiogenesis by increasing the expression of VEGF-A.	Zhou et al., 2021	
	hAECs	CTX	Mouse	Promoted the expression of angiopoietin-like factor and CXCL16.	Huang et al., 2023	
	hUMSCs	CIS	Rat	Promoted the expression of VEGF, IGF-1, and FGF.	Qu et al., 2022	
	hUMSCs	CTX/BUL	Mouse	Promoted the expression of angiogenic cytokines VEGF, IGF, and angiogenin through activation of the PI3K/AKT pathway.	Yang et al., 2019	
	hUMSCs	CTX/BUL	Rat	Increased the expression of CD34, VEGF, and HGF to promote ovarian angiogenesis.	Chen et al., 2023	
	hAECs	CTX/BUL	Mouse	Secreted VEGF, TGF-β1, GDF9, and BMP15 to promote ovarian angiogenesis.	Yao et al., 2016; Zhang et al., 2017	
	ES-MSCs	CTX/BUL	Mouse	Increased the secretion of VEGF, IGF-2, and HGF.	Bahrehbar et al., 2020	
Reduced ovarian inflammation	hAMSCs	CTX	Rat	Decreased the expression of IL-1β, IL-6, and TNF-α.	Ling et al., 2017	
	cMSCs	CTX	Mouse	Decreased TNF-α and IL-8 levels.	Eslami et al., 2023	
	hAECs	CTX	Mouse	Secreted 34 immune factors to regulate ovarian immune response.	Zhang et al., 2017	
	hUMSCs	CTX	Mouse	Decreased the expression of IL-6 and IL-1β, increased the expression of IL-10, TSG-6, and VEGF, and reduced the infiltration of neutrophils and macrophages.	Deng et al., 2021	
	SMSCs	CTX	Mouse	Reduced the activity of TNF-α, TGF-β, IL-8, IL-6, IL-1β, and IFN-γ.	Lai et al., 2014	
Restored ovarian oxidative stress balance	fMSCs	CTX	Mouse	Reduced the level of ROS.	Huang et al., 2019	
	hUMSCs	CTX	Mouse	Reduced ROS accumulation.	Ding et al., 2020	
	hAMSCs	CTX	Mouse	Inhibited the level of ROS.	Ding et al., 2020	
	hAECs	CTX	Mouse	Upregulated the level of antioxidant protein thioredoxin1/2, and reduced ROS.	Huang et al., 2023	
AKT, serine-threonine kinase; α-SMA, α-smooth muscle actin; BUL, busulphan; BMSCs, bone marrow mesenchymal stem cells; BMP15, bone morphogenetic protein 15; CTX, cyclophosphamide; CIS, cisplatin; CXCL16, CXC motif chemokine ligand 16; cMSCs, clonal mesenchymal stem cells; ECM, extracellular matrix; ES-MSCs, embryonic stem cell-derived mesenchymal stem cells; fMSCs, liver fetal mesenchymal stem cells; FGF, fibroblast growth factor; GDF9, growth-differentiation factor 9; hUMSCs, human umbilical cord mesenchymal stem cells; hAECs, human amniotic epithelial cells; hAMSCs, human amniotic mesenchymal stem cells; HGF, hepatocyte growth factor; IGF-1, insulin-like growth factor-1; IGF-2, insulin-like growth factor-2; IFN-γ, interferon gamma; MenSCs, menstrual blood-derived mesenchymal stem cells; PI3K, phosphoinositide 3-kinase; ROS, reactive oxygen species; SMAD, small mothers against decapentaplegic; SMSCs, skin-derived mesenchymal stem cells; TNF-α, tumor necrosis factor-alpha; TGF-β1, transforming growth factor-beta1; TSG-6, TNF-stimulated gene 6; VEGF, vascular endothelial growth factor.

Stem cells are capable of tissue regeneration and repair through the secretion of cytokines and extracellular vesicles. They play an important therapeutic role in combating fibrosis in various organs. In mouse models of CTX-induced POF, matrigel scaffolds laden with human umbilical cord mesenchymal stem cells (hUMSCs) effectively decreased the tissue fibrosis ratio by regulating the TGF-β1 pathway (Zhou et al., 2021). Activated human amniotic epithelial cell (hAECs) transplantation produced MMP2 and MMP9 and played important roles in inhibiting fibrosis and promoting ECM remodeling in CTX-induced POI mouse ovaries (Huang et al., 2023). Similarly, in a CTX/BUL-induced rat POF model, hepatocyte growth factor (HGF)-modified hUMSCs with overexpression of HGF exhibited superior inhibition of ovarian collagen deposition compared to hUMSCs-Null, attributable to the antifibrotic effect of HGF (Chen et al., 2023). In a rat model of POI induced by CIS, the expression of the fibrosis markers α-SMA, Col-I, and Col-III was significantly inhibited following hUMSCs transplantation (Cui et al., 2020). hUMSCs are shown to modulate the differentiation of ovarian stromal cells through the TGF-β1/SMAD3 signaling pathway, thus alleviating ovarian fibrosis. Additionally, menstrual blood-derived MSCs (MenSCs) demonstrated efficacy in reducing rat ovarian fibrosis induced by CTX by regulating the SMAD2/SMAD4/SMAD6 pathway (Yamchi et al., 2021). In another study, MenSCs transplantation ameliorated mouse ovarian fibrosis induced by CIS through a paracrine mechanism, mediated by the secretion of FGF-2 (Wang et al., 2017). These findings underscore the therapeutic potential of stem cells in mitigating ovarian fibrosis and preserving ovarian function in CAOD.

Stem cells exhibit remarkable regenerative potential by secreting various biological agents that promote angiogenesis. In a rabbit model of CTX-induced ovarian failure, bone marrow MSCs improved ovarian regeneration by secreting VEGF, thus promoting angiogenesis (Abd-Allah et al., 2013). Similarly, clonal MSCs (cMSCs) and their secreted extracellular vesicles (EV20K and EV110) improved angiogenesis in mouse ovaries during CTX chemotherapy by upregulating VEGF and IGF-1 (Eslami et al., 2023). Furthermore, hUMSCs combined with Matrigel promoted ovarian angiogenesis in a CTX-induced mouse POF model by upregulating VEGF-A (Zhou et al., 2021). Additionally, hAECs, pre-stimulated by TNF-α and IFN-γ, significantly increased the production of proangiogenic factors (ANGPT-like factor and CXC motif chemokine ligand 16 (CXCL16)) in CTX-induced POI mouse ovaries (Huang et al., 2023). In a CIS-induced POF rat model, hUMSC-derived exosomal microRNA (miR)-126-3p enhanced the expression of the angiogenesis-related factors VEGF, IGF-1, and FGF to improve ovarian function (Qu et al., 2022). Similarly, transplantation of hUMSC-derived microvesicle (hUMSC-MV) during CTX/BUL chemotherapy promoted the expression of the angiogenic cytokines VEGF, IGF-1, and ANGPT in mouse ovaries through activation of the PI3K/AKT signaling pathway (Yang et al., 2019). Notably, HGF-modified hUMSCs exhibited superior induction of CD34, VEGF, and HGF expression compared to the hUMSCs-Null group, indicating enhanced promotion of ovarian angiogenesis in CTX/BUL-induced POI rats (Chen et al., 2023). Furthermore, hAECs secreted cytokines, such as VEGF, TGF-β1, growth-differentiation factor 9, and BMP15, to promote mouse ovarian angiogenesis after CTX/BUL-induced injury (Yao et al., 2016; Zhang et al., 2017). Embryonic stem cell-derived MSCs demonstrated restorative effects in CTX/BUL-induced POF mice through increased secretion of VEGF, IGF-2, and HGF from the ovaries (Bahrehbar et al., 2020). These findings underscore the potential of various stem cell therapies to enhance ovarian angiogenesis and mitigate CAOD.

In addition to their progenitor characteristics, stem cells have unique immunomodulatory properties that provide new opportunities for the treatment of CAOD. Human amniotic MSCs (hAMSCs) decreased the expression of proinflammatory cytokines (IL-1β, IL-6, and TNF-α), thereby attenuating CTX-induced rat ovarian inflammation (Ling et al., 2017). cMSCs and their secreted extracellular vesicles (EV20K and EV110) reversed the elevated levels of TNF-α and IL-8 in the ovaries of a CTX-induced mouse POF model (Eslami et al., 2023). Furthermore, hAECs were found to secrete 34 immune factors that regulate the ovarian immune response and follicle development in CTX-induced POF mice (Zhang et al., 2017). In mice treated with CTX, hUMSC transplantation resulted in the downregulation of proinflammatory factors IL-6 and IL-1β, upregulation of anti-inflammatory factors IL-10, TSG-6, and VEGF, and a reduction in the infiltration of neutrophils and macrophages into the ovary (Deng et al., 2021). Furthermore, skin-derived MSC transplantation alleviated the activity of the inflammatory cytokines TNF-α, TGF-β, IL-8, IL-6, IL-1β, and IFN-γ, modulating the mouse ovarian inflammatory response and promoting a higher rate of oogenesis (Lai et al., 2014). These findings underscore the immunomodulatory potential of various stem cell therapies in mitigating chemotherapy-induced ovarian inflammation and preserving ovarian function.

Indeed, stem cell therapy has demonstrated remarkable efficacy in the treatment of CAOD, with oxidative stress mitigation being one of key mechanism underlying their effectiveness. Liver fetal MSCs had been shown to prevent CTX-induced mouse follicle loss and restore sex hormone levels by reducing oxidative damage, enhancing oxidative protection, and restoring ovarian oxidative stress balance (Huang et al., 2019). In a CTX-induced POI mouse model, exosomal miR-17-5P from hUMSCs restored ovarian function, and repressed ROS accumulation by downregulating the expression of Sirtuin 7 (SIRT7) (Ding et al., 2020). Similarly, exosomal miR-320a from hAMSCs inhibited ROS level in CTX-induced POI mouse ovaries (Ding et al., 2020). Additionally, activated hAECs transplantation significantly upregulated the expression of the antioxidant proteins thioredoxin1/2 and downregulated the expression of ROS in CTX-treated mouse ovaries (Huang et al., 2023). These findings underscore the crucial role of stem cells in alleviating oxidative stress and restoring ovarian function in the context of CAOD.

Despite the extensively demonstration of efficacy in rodent models, there is a notable absence of clinical evidence supporting the use of stem cell transplantation as a safe clinical therapeutic option. While there are five registered clinical trials studies (NCT03166189, NCT02043743, NCT03816852, NCT03069209, NCT03877471) listed in the US National Institutes of Health clinical trial database (www.clinicaltrials.gov) investigating the use of stem cells to treat female infertility, all studies are still under investigation and have not progressed to phase III. Besides, the optimization of extraction methods and the administration routes for stem cell remains in the exploratory stage. The maintenance of MSCs for more than five subpassages is exceedingly difficult owing to their heterogeneity and culture inefficiency (Lee et al., 2018). Additionally, safety assessments for stem cell therapy remain a primary concern. Under transplantation, certain stem cells may lose their characteristic features and could potentially undergo risky changes, such as gene mutation and modification, exposing patients to unknown harm (Marks et al., 2017). Moreover, their limited availability, low survival rates of implanted cells, potential autoimmune responses, elusive signaling mechanism, and tumorigenicity associated with stem cell transplantation, as well as ethical obstacles, further complicate the therapeutic landscape. These challenges highlight the need for continued research and rigorous evaluation of stem cell therapy to ensure its safety and efficacy before clinical adoption.

Free radical scavengers

Chemotherapy treatment induces an excessive accumulation of ROS within the ovarian microenvironment, leading to a significant increase in lipid peroxidation, depletion of intraovarian antioxidant, and significant DNA damage to cells (Sohal and Orr, 2012). Antioxidants, including natural antioxidants and synthetic antioxidants, play a crucial role as scavengers of these free radicals, helping to maintain the oxidant/antioxidant balance. Predominantly, natural antioxidants such as polyphenols (phenolic acids, flavonoids, and lignans) and carotenoids are found in a variety of foods and medicinal plants (Xu et al., 2017), such as epigallocatechin gallate, theaflavins, Pleurotus columbines, Lycium barbarum polysaccharide, sesamol, crocin, resveratrol, pyrroloquinoline-quinine, chrysin, rutin, hesperidin, Nigella sativa, silibinin, lycopene, and coenzyme Q10. In addition to these natural substances, a variety of synthetic compounds known for their antioxidant capabilities have been explored for their potential to counteract ROS, such as irbesartan, fenofibrate, mirtazapine, N-acetyl-l-cysteine, erythropoietin, mesna, ebselen, hydrogen-rich saline, melatonin (n-acetyl-5-methoxytryptamine), and several formulations of traditional Chinese medicine (erxian decoction and modified Dihuang decoction).

Natural antioxidants

Natural antioxidants play a pivotal role in safeguarding against ovarian damage during CTX chemotherapy by effectively scavenging excess ROS through various pathways. Epigallocatechin gallate and theaflavins, prominent polyphenols derived from green or black tea, increased the expression of antioxidant enzymes by activating NRF2/HO-1 pathways, and alleviated CTX-induced ovarian oxidative stress and fibrosis in mice (Chen et al., 2021; Barberino et al., 2022). Likewise, Pleurotus columbinus extracts, rich in phenolic and flavonoid compounds, exhibited protective effects against CTX-induced rat ovarian damage by reducing lipid peroxidation levels and enhancing the antioxidant activity (Hassan et al., 2021). Lycium barbarum polysaccharide, a key component extracted from the Lycium barbarum plant, showcases antioxidant properties attributed to its constituents such as carotenoids, flavonoids, ascorbic acid and its derivatives, and polyphenols (Tian et al., 2019). Lycium barbarum polysaccharide reduced oxidative stress, enhanced the activity of antioxidant enzymes, and reduced the level of oxidative products to protect rat ovarian function during CTX chemotherapy (Yang et al., 2017). Similarly, in a rat POF model induced by CTX, the antioxidative enzymatic activity of SOD was increased and the MDA level was decreased after coadministration of sesamol or crocin with CTX (Khanmohammadi et al., 2021; Talebi et al., 2022). In another study, a low concentration of resveratrol or pyrroloquinoline-quinine attenuated the oxidative stress level in CTX/BUL-treated mouse ovaries, fostering a conducive microenvironment for oogonial stem cells (Wu et al., 2019; Dai et al., 2022). Notably, coenzyme Q10 administration during CTX treatment reduced ROS levels in mouse ovaries, correlating with increased oocyte quantity and quality (Delkhosh et al., 2019). Together, these findings suggest that natural antioxidants may be promising drugs for protecting ovarian function, with potential clinical applications during CTX chemotherapy.

Five different natural antioxidants, namely chrysin, rutin, resveratrol, Nigella sativa, and hesperidin, have been tested for their protective effects on the ovaries of mouse and rat treated with CIS (Khedr, 2015; Chinwe et al., 2018; Lins et al., 2020; Ibrahim et al., 2021; Mentese et al., 2022; Cetinkaya et al., 2023). Chrysin pretreatment decreased MDA, total oxidant status (TOS), and oxidative stress index and increased total antioxidant status (TAS) in ovaries during chemotherapy. The antioxidative enzymatic activity (MPO, SOD, and GPx) and GSH were increased after coadministration of flavonoid rutin, hesperidin resveratrol, or Nigella sativa with CIS. These results indicate that the scavenging of ROS in the ovary is important to protect the ovarian reserve during CIS chemotherapy.

Antioxidants also have a protective effect on ovarian damage induced by in other chemotherapy agents. 5-Fluorouracil is an antimetabolite drug and ovarian toxicity is one of the most important side effects. Silibinin, a natural flavonolignan, prevented 5-fluorouracil-induced oxidative damage in rat ovaries by decreasing TOS and increasing TAS (Ayazoglu Demir et al., 2023). Lycopene, a type of carotenoid, increased the expression of GSH and decreased the expression of MDA in methotrexate-treated rat ovaries (Turkler et al., 2020).

Synthetic antioxidants

Four synthetic antioxidants have been tested as ovarian protectants against CTX-induced damage. Irbesartan is a synthetic nonpeptide antagonist of angiotensin II. In addition to its effect of lowering blood pressure, irbesartan acts as a free radical scavenger (Wang et al., 2013). Irbesartan pretreatment significantly prevented CTX-induced rat ovarian dysfunction by reducing oxidative stress (Abdel-Raheem et al., 2015). Fenofibrate, a PPARα agonist, is reported to prevent rat ovarian damage induced by CTX through antioxidant actions (Abdelzaher et al., 2021). Mirtazapine, an antidepressant drug, reversed the ratio of oxidase to antioxidant enzymes in rat ovary and protects fertility against CTX- and CIS-induced toxicity (Altuner et al., 2013; Khedr, 2015). The N-acetyl-l-cysteine is a potent scavenger of free radicals, and it had been suggested to have beneficial effects in inhibiting ROS production and restoring GSH to normal level in human and rat ovaries exposed to chemotherapy, resulting in an improvement of follicle viability and pregnancy rate (Helal, 2016; Li et al., 2019). The traditional Chinese medicine, modified Dihuang decoction, upregulated the levels of SOD and GPx in CTX/BUL-induced DOR mouse ovaries (Zhang et al., 2021).

Synthetic antioxidants can also provide protection against CIS-induced oxidative stress along with underlying disorders in the ovary. In addition to promoting erythropoiesis, erythropoietin has antiapoptotic, antioxidant, anti-inflammatory, and angiogenic effects (Hardee et al., 2006). Erythropoietin improved ovarian function by reducing CIS-induced oxidative stress levels in rat ovaries (Dayangan Sayan et al., 2018). Mesna, a Food and Drug Administration (FDA)-approved antioxidant, prevents the toxic side effects of chemotherapy agents by removing ROS and upregulating antioxidant enzymes (Li et al., 2013; Munoz-Osores et al., 2022). Ebselen could improve CIS-induced rat ovarian damage by increasing SOD and GSH levels and reducing MDA and NOx levels (Soyman et al., 2018). Hydrogen exerts a therapeutic antioxidant effect by selectively alleviating oxidation products and improving the activity of antioxidants (Xie et al., 2010; Qu et al., 2012). Hydrogen-rich saline treatment reversed the effect of CIS on rat ovarian MDA, SOD, and CAT (Meng et al., 2015). Melatonin is mainly secreted by the vertebrate pineal gland and has antioxidation characteristics (Reiter et al., 2013, 2014). The ovarian protective effect of exogenous melatonin in CIS-treated mice could be attributed to its antioxidant activity, manifested as scavenging ROS and stimulating antioxidant activity (Barberino et al., 2017; Huang et al., 2021; Al-Shahat et al., 2022). Erxian decoction of a Chinese herbal formula reduced the amount of MDA and raised the activity of SOD in a CIS-induced rat POF model (Li et al., 2007; Liu et al., 2023). However, the antioxidant mechanisms of traditional Chinese medicines are complex and need further study.

Cancer is also characterized by increased oxidative stress, which can initiate tumor development and contribute to tumor progression by directly oxidizing macromolecules or through oxidative stress-induced aberrant redox signaling (Canli et al., 2017). It is an attractive idea to use antioxidants for cancer treatment and some antioxidants, namely resveratrol and ebselen, have been explored in clinical research (such as breast cancer, neuroendocrine tumor, multiple myeloma, head and neck cancer, and lung cancer) (Luo et al., 2022). However, the major challenge with natural antioxidants is their unstable chemical structure, low oral bioavailability, limited aqueous solubility, low targeted efficacy, and potential hepatotoxicity and nephrotoxicity at high doses; the latter is being targeted for improvement by encapsulating natural antioxidants in nano-sized vehicles for further delivery. Nevertheless, there are still few studies on the safety of natural antioxidant-delivery nanosystems. Alternatively, multiple antioxidants are undergoing pre-clinical study, and high-quality clinical trials of antioxidants in CAOD are lacking. Moreover, safe dosage levels of antioxidants in the human ovary remain undefined. Besides, the molecular mechanism underlying the action of antioxidants against CAOD is not fully elucidated owing to the diverse structures and functionalities of these compounds. Therefore, future research should aim to determine whether antioxidants interfere with the effectiveness of chemotherapy against tumor cell growth. Large-scale, multi-center clinical trials are urgently needed to confirm the safety and antioxidant effect of antioxidants on human ovaries, providing crucial insights for the future perspectives in CAOD management.

Immunomodulators

Immunomodulators are drugs that regulate immune function, primarily by stimulating immune cell activity or modulating the production of inflammatory factors in a nonspecific manner. They have the potential to improve the ovarian environment disrupted by chemotherapy, thus promoting follicular growth and recovery of ovarian function.

Chito-oligosaccharide (COS), derived from shrimp and crustacean through deacetylation, acts as a natural immune enhancer (Xia et al., 2019). COS induces cytokine secretion by inducing the accumulation and activation of macrophages and polymorphonuclear cells, thus stimulating the immune system (Mudgal et al., 2019). In a recent study, COS administration reversed the immunosuppression of the mouse ovarian microenvironment caused by CTX/BUL chemotherapy, preventing decreased levels of IL-2 and TNF-α and increased levels of IL-4 (Huang et al., 2021; Li et al., 2023). Furthermore, COS promoted the proliferation of mouse ovarian stem cells by regulating the secretion of the immune factors IL-2 and TNF-α (Huang et al., 2021; Zheng et al., 2023). Squid ink polysaccharide (SIP), a glycosaminoglycan isolated from Sepia esculenta ink, exhibits immunomodulatory properties by enhancing immune function (Zuo et al., 2014). A study conducted in CTX-treated mice proposed that SIP ameliorated ovarian immunosuppression and increased IL-2 and TNF-α expression (Liu et al., 2019).

Immunomodulatory therapeutics, aimed at activating the immune system for tumor suppression and restoring normal immune responses, hold potential for enhancing cancer therapy (Khalil et al., 2016). Several reports have demonstrated that COS induces the death of cancer cells via repressing tumor growth, triggering the apoptosis signaling pathway, and regulating immunity; tumors responding to COS include lung cancer (Ngo et al., 2019), liver cancer (Jing et al., 2019), renal carcinoma (Zhai et al., 2019), colorectal cancer (Han et al., 2016), and osteosarcoma (Pan et al., 2021). Additionally, SIP and its derivative exert their antitumor effects in various cancers, such as liver cancer (Tian et al., 2023), ovarian carcinoma (Zong et al., 2015), and melanoma (Zong et al., 2013), which may be associated with its immunostimulating and proapoptotic activity. However, COS and SIP are relatively recent discoveries and require further investigation in order to elucidate the precise molecular mechanisms involved in their anticancer and ovarian protection effects. Clinical experiments are needed to evaluate the safety and efficacy of these immunomodulators in protecting the human ovary from chemotherapy-induced damage. In addition, comprehensive studies should evaluate whether immunomodulators have an adverse effect on the chemotherapy drug to be used as an adjuvant.

Senolytherapies

Chemotherapy is acknowledged as a common stressor known to induce cellular senescence, with senescent cell-secreted SASPs and exacerbating inflammation in the ovarian microenvironment, potentially driving the progression of CAOD (Gao et al., 2023). Senolytics have emerged as promising agents for selectively targeting senescent cells through the activation of ‘suicide’ genes and the modulation of various cellular pathways (Baker et al., 2011). Recent studies display potential for enhancing female fertility during chemotherapy.

Dasatinib (D) and quercetin (Q), both natural flavonoids and the most typical senolytic agents, bind to B-cell lymphoma-2 (BCL-2) and regulate transcription factors, cyclins, proapoptotic and antiapoptotic proteins, and growth factors (Kirkland and Tchkonia, 2020). In clinical trials, D + Q combination therapy has demonstrated efficacy in reducing senescent cell burden and improving physical performance (Hickson et al., 2019). In CTX-induced POI model mice, the increased expression of the cellular senescence markers p16, p21, p53, and γ-H2AX in granulosa cells was reversed by cotreatment with D + Q (Xu et al., 2023). Similarly, fisetin exhibits senolytic properties and shows promise in mitigating age-related pathology and extending lifespan (Yousefzadeh et al., 2018). Our group demonstrated that short-term intervention with D + Q or fisetin significantly reduced senescent cell accumulation in mouse ovary during DOX treatment, yet failed to reverse DOX-induced follicle loss and ovarian stromal fibrosis caused by DOX (Gao et al., 2023). However, in a separate study, D + Q effectively reversed ovarian fibrosis in CIS-exposed mice by removing senescent cells (Du et al., 2022). The varying degrees of ovarian cell senescence induced by different chemotherapy drugs highlights the complexity of utilizing senolytics for CAOD protection.

Some senotherapeutic drugs, such as quercetin, dasatinib, and fisetin, offer promising anticancer effects with minimal adverse effects and high efficacy (Mamun et al., 2022). Therefore, senotherapeutics not only hold potential for preserving ovarian function but also exert antitumor effects during chemotherapy. However, identifying the mechanistic actions of senotherapeutics, especially in vivo, remains challenging and is influenced by factors such as senescent cell type and drug concentration. Formal assessment of their efficacy and adverse effects in human clinical trials is imperative considering the inherent differences between animal models and humans. Additionally, preserving beneficial senescent cell populations is crucial, as they play vital roles in tissue renewal, wound healing, and cancer prevention. Further research is warranted to explore the impact of senotherapeutics on antitumor activity while safeguarding the ovarian reserve from chemotherapy-induced gonadotoxicity.

Proangiogenic factors

Chemotherapy drugs inhibit ovarian angiogenesis or destroy the structure and function of blood vessels, resulting in ovarian dysfunction. Proangiogenic factors are vital molecules that enhance tissue vascularization within the perivascular and vascular microenvironment (Hamid and Mirshafiey, 2016).

Granulocyte CSF (G-CSF) is a glycoprotein that induces VEGF expression and secretion, promoting angiogenesis through regulating the PI3K/AKT pathway. In CTX/BUL-induced POI mouse ovaries, G-CSF treatment improved follicular development and fertility by promoting ovarian microvessel formation (Skaznik-Wikiel et al., 2013; Buigues et al., 2021). Similarly, treatment with G-CSF increased ovarian neoangiogenesis, leading to a significant increase in follicle number and serum anti-Müllerian hormone level in rats treated with CIS (Akdemir et al., 2014). Besides, G-CSF-mobilized peripheral blood mononuclear cells combined with platelet-rich plasma increased ovarian angiogenesis and the expression of VEGF and CD34 in CTX-induced POI rats (Huang et al., 2019). Ceramide-1-phosphate (C1P), a potent sphingolipid released by damaged tissue cells, modulates vascular development and apoptosis in ovaries affected by chemotherapy (Kim et al., 2013). In a CTX-induced ovarian damage mouse model, C1P restored damaged stromal vascular structures and the continuity of the endothelial layer, thereby promoting ovarian vascular stability (Pascuali et al., 2018). Clinical studies assessing the effects of G-CSF and C1P treatment on CAOD are warranted, alongside investigations to reliably evaluate their ovarian-protective effects and potential side effects.

While proangiogenic factors have a protective role against CAOD, their impacts on tumors need to be considered. Promotion of angiogenesis may inadvertently stimulate tumor growth and metastasis, influencing the efficacy of chemotherapy. Therefore, tumor-bearing models should be utilized to explore the protective effect of proangiogenic factors on CAOD and their effects on tumors. Furthermore, elucidating the precise molecular mechanisms involved in the action of proangiogenic factors through well-designed experiments is crucial for understanding their anticancer and CAOD protective effects.

Conclusion

The risk of CAOD represents a critical concern regarding both short- and long-term adverse effects of anticancer treatments in premenopausal women. According to current guidelines, it is imperative that all premenopausal women undergoing cancer therapy engage in comprehensive oncofertility counseling. This is essential to preserve normal endocrine functionality and to ensure the feasibility of fulfilling their family aspirations. The ovarian microenvironment, serving as the foundational milieu for follicle development, experiences profound alterations in response to chemotherapy. A substantial body of evidence, including clinical studies, human ovarian xenograft research, and mouse model investigations, suggests that certain chemotherapeutic agents may induce changes, such as ECM accumulation and fibrosis, disturbances in ovarian angiogenesis, disruptions in the immune microenvironment, imbalances in oxidative stress homeostasis, ovarian stem cell depletion, and cellular senescence, thereby adversely affecting the quantity and quality of ovarian follicles.

A notable gap in awareness exists regarding the changes to the ovarian microenvironment induced by chemotherapy, including alterations in ovarian lymphatic vessels, nerves, metabolic products, phenotypic and functional shifts in specific stromal cell populations, and their interactions with folliculogenesis, follicle positioning, and hormone synthesis. Advanced techniques, such as single-cell and spatial transcriptomics, could help to elucidate the shifts in cellular composition and the pathways implicated in the impact of chemotherapy. Given the limitations associated with animal models, further research is crucial to delineate the effects of chemotherapeutic agents on the human ovarian microenvironment, particularly to distinguish between the mechanisms involved in the immediate and delayed phases of chemotherapy-induced ovarian imbalance.

While current protective agents primarily focus on averting ovarian follicle loss, it is vital to acknowledge the role of the stromal environment in follicle health, beyond the direct follicular impact. A strategy of targeting the ovarian microenvironment for CAOD treatment is emerging, albeit in its early stages. MSC transplantation, for example, demonstrates promise in mitigating CAOD through enhancements in the ovarian microenvironment, such as reducing fibrosis, fostering angiogenesis, modulating immunity, and alleviating oxidative stress damage, with significant efficacy in animal models yet pending clinical testing/application. Furthermore, the exploration of antioxidants, immunomodulators, senolytics, and proangiogenic factors as novel CAOD protectants necessitates more research to elucidate the exact molecular mechanisms for their combined anticancer and ovarian protective effects. Like stem cell therapies, these approaches currently lack substantial clinical evidence to be considered safe therapeutic options.

Compiling this review has highlighted the challenges, complexities, and uncertainties of transitioning protectants from laboratory settings to clinical application, particularly emphasizing the paramount concern of safety for cancer patients undergoing treatment for malignant conditions. Protectants must not only prevent CAOD but also demonstrate no adverse interference with the efficacy of tumor chemotherapy. Moreover, assessing the clinical efficacy of these protective measures remains challenging, as potential protectants might reduce rather than completely prevent ovarian damage, leaving the impact on future fertility uncertain.

Despite these translational challenges, this review underscores the significance of addressing changes in the ovarian microenvironment during chemotherapy and the development of novel therapeutics targeting this microenvironment to enhance ovarian function. It is our hope that this review will foster professional discourse and inspire future research directions in this field.

Data availability

No new data were generated or analyzed in support of this research.

Authors’ roles

Sh.W., M.W., and J.D. participated in the conception and designing of the review article. Y.G. and M.W. conceived the manuscript, participated in writing, prepared the tables and the figures. Sh.W., M.W., J.D., Y.G., L.X., J.X., Y.D., C.W., W.T., D.C., and Si.W. critically reviewed each version of the manuscript. All the authors confirmed the final version.

Funding

National Key Research and Development Program of China (2022YFC2704100); National Natural Science Foundation of China (82001514, 22104040).

Conflict of interest

The authors declare that they have no competing interests.
==== Refs
References

Abd-Allah SH , ShalabySM, PashaHF, El-ShalAS, RaafatN, ShabrawySM, AwadHA, AmerMG, GharibMA, El GendyEA  et al  Mechanistic action of mesenchymal stem cell injection in the treatment of chemically induced ovarian failure in rabbits. Cytotherapy  2013;15 :64–75.23260087
Abdel-Raheem IT , OmranGA, KataryMA.  Irbesartan, an angiotensin II receptor antagonist, with selective PPAR-gamma-modulating activity improves function and structure of chemotherapy-damaged ovaries in rats. Fundam Clin Pharmacol  2015;29 :286–298.25824615
Abdelzaher WY , Abdel-HafezSMN, RofaeilRR, AliA, HegazyA, BahaaHA.  The protective effect of fenofibrate, triptorelin, and their combination against premature ovarian failure in rats. Naunyn Schmiedebergs Arch Pharmacol  2021;394 :137–149.32924068
Abe H , Al-Zi’abiMO, SekizawaF, AcostaTJ, SkarzynskiDJ, OkudaK.  Lymphatic involvement in the disappearance of steroidogenic cells from the corpus luteum during luteolysis. PLoS One  2014;9 :e88953.24586455
Abir R , Ben-HaroushA, MelamedN, FelzC, KrissiH, FischB.  Expression of bone morphogenetic proteins 4 and 7 and their receptors IA, IB, and II in human ovaries from fetuses and adults. Fertil Steril  2008;89 :1430–1440.17624341
Abu Hashim H.  Predictors of success of laparoscopic ovarian drilling in women with polycystic ovary syndrome: an evidence-based approach. Arch Gynecol Obstet  2015;291 :11–18.25186279
Adamczak R , Ukleja-SokołowskaN, LisK, DubielM.  Function of follicular cytokines: roles played during maturation, development and implantation of embryo. Medicina (Kaunas)  2021;57 :1251.34833469
Ahmed TA , AhmedSM, El-GammalZ, ShoumanS, AhmedA, MansourR, El-BadriN.  Oocyte aging: the role of cellular and environmental factors and impact on female fertility. Adv Exp Med Biol  2020;1247 :109–123.31802446
Ai G , MengM, GuoJ, LiC, ZhuJ, LiuL, LiuB, YangW, ShaoX, ChengZ  et al  Adipose-derived stem cells promote the repair of chemotherapy-induced premature ovarian failure by inhibiting granulosa cells apoptosis and senescence. Stem Cell Res Ther  2023;14 :75.37038203
Akdemir A , ZeybekB, AkmanL, ErgenogluAM, YenielAO, ErbasO, YavasogluA, TerekMC, TaskiranD.  Granulocyte-colony stimulating factor decreases the extent of ovarian damage caused by cisplatin in an experimental rat model. J Gynecol Oncol  2014;25 :328–333.25142624
Akiyama I , YoshinoO, OsugaY, ShiJ, HaradaM, KogaK, HirotaY, HirataT, FujiiT, SaitoS  et al  Bone morphogenetic protein 7 increased vascular endothelial growth factor (VEGF)-a expression in human granulosa cells and VEGF receptor expression in endothelial cells. Reprod Sci  2014;21 :477–482.24023033
Al-Alem L , PuttabyatappaM, RosewellK, BrannstromM, AkinJ, BoldtJ, MuseK, CurryTEJr. Chemokine ligand 20: a signal for leukocyte recruitment during human ovulation?  Endocrinology  2015;156 :3358–3369.26125463
Al-Shahat A , HulailMAE, SolimanNMM, KhamisT, FericeanLM, ArishaAH, MoawadRS.  Melatonin mitigates cisplatin-induced ovarian dysfunction via altering steroidogenesis, inflammation, apoptosis, oxidative stress, and PTEN/PI3K/Akt/mTOR/AMPK signaling pathway in female rats. Pharmaceutics  2022;14 :2769.36559263
Altuner D , GulabogluM, YapcaOE, CetinN.  The effect of mirtazapine on cisplatin-induced oxidative damage and infertility in rat ovaries. ScientificWorldJournal  2013;2013 :327240.23737712
Amargant F , ManuelSL, TuQ, ParkesWS, RivasF, ZhouLT, RowleyJE, VillanuevaCE, HornickJE, ShekhawatGS  et al  Ovarian stiffness increases with age in the mammalian ovary and depends on collagen and hyaluronan matrices. Aging Cell  2020;19 :e13259.33079460
Amato G , ConteM, MazziottiG, LalliE, VitoloG, TuckerAT, BellastellaA, CarellaC, IzzoA.  Serum and follicular fluid cytokines in polycystic ovary syndrome during stimulated cycles. Obstet Gynecol  2003;101 :1177–1182.12798522
Anderson RA , BrewsterDH, WoodR, NowellS, FischbacherC, KelseyTW, WallaceWHB.  The impact of cancer on subsequent chance of pregnancy: a population-based analysis. Hum Reprod  2018;33 :1281–1290.29912328
Anerillas C , AbdelmohsenK, GorospeM.  Regulation of senescence traits by MAPKs. Geroscience  2020;42 :397–408.32300964
Ara T , NakamuraY, EgawaT, SugiyamaT, AbeK, KishimotoT, MatsuiY, NagasawaT.  Impaired colonization of the gonads by primordial germ cells in mice lacking a chemokine, stromal cell-derived factor-1 (SDF-1). Proc Natl Acad Sci USA  2003;100 :5319–5323.12684531
Artimani T , KarimiJ, MehdizadehM, YavangiM, KhanlarzadehE, GhorbaniM, AsadiS, KheiripourN.  Evaluation of pro-oxidant-antioxidant balance (PAB) and its association with inflammatory cytokines in polycystic ovary syndrome (PCOS). Gynecol Endocrinol  2018;34 :148–152.28868943
Artini PG , MontiM, MatteucciC, ValentinoV, CristelloF, GenazzaniAR.  Vascular endothelial growth factor and basic fibroblast growth factor in polycystic ovary syndrome during controlled ovarian hyperstimulation. Gynecol Endocrinol  2006;22 :465–470.17012110
Asano Y.  Age-related accumulation of non-heme ferric and ferrous iron in mouse ovarian stroma visualized by sensitive non-heme iron histochemistry. J Histochem Cytochem  2012;60 :229–242.22108647
Athira VR , SaranyaMK, ShivanandappaT, YajurvediHN.  Multiple dose treatment reduces cyclophosphamide-induced ovarian follicular loss in mice. Birth Defects Res  2020;112 :71–80.31643145
Atli M , Engin-UstunY, TokmakA, CaydereM, HucumenogluS, TopcuogluC.  Dose dependent effect of resveratrol in preventing cisplatin-induced ovarian damage in rats: an experimental study. Reprod Biol  2017;17 :274–280.28716446
Ayazoglu Demir E , MenteseA, KucukH, Turkmen AlemdarN, DemirS.  The therapeutic effect of silibinin against 5-fluorouracil-induced ovarian toxicity in rats. J Biochem Mol Toxicol  2023;37 :e23408.37335224
Azeez SH , IsmailIB, DaroghaSN.  The effect of interleukin-6 and tumor necrosis factor-alpha gene polymorphism and hormone replacement therapy on polycystic ovary syndrome. Cell Mol Biol (Noisy-le-Grand)  2022;67 :278–285.35818242
Babayev E , SuebthawinkulC, GokyerD, ParkesWS, RivasF, PavoneME, HallAR, PritchardMT, DuncanFE.  Cumulus expansion is impaired with advanced reproductive age due to loss of matrix integrity and reduced hyaluronan. Aging Cell  2023;22 :e14004.37850336
Bahrehbar K , Rezazadeh ValojerdiM, EsfandiariF, FathiR, HassaniSN, BaharvandH.  Human embryonic stem cell-derived mesenchymal stem cells improved premature ovarian failure. World J Stem Cells  2020;12 :857–878.32952863
Bakalov VK , AnastiJN, CalisKA, VanderhoofVH, PremkumarA, ChenS, FurmaniakJ, SmithBR, MerinoMJ, NelsonLM.  Autoimmune oophoritis as a mechanism of follicular dysfunction in women with 46,XX spontaneous premature ovarian failure. Fertil Steril  2005;84 :958–965.16213850
Baker DJ , WijshakeT, TchkoniaT, LeBrasseurNK, ChildsBG, van de SluisB, KirklandJL, van DeursenJM.  Clearance of p16Ink4a-positive senescent cells delays ageing-associated disorders. Nature  2011;479 :232–236.22048312
Barberino RS , LinsT, MonteAPO, SilvaRLS, AndradeKO, CampinhoDSP, Palheta JuniorRC, SmitzJEJ, MatosMHT.  Epigallocatechin-3-gallate attenuates cyclophosphamide-induced damage in mouse ovarian tissue via suppressing inflammation, apoptosis, and expression of phosphorylated Akt, FOXO3a and rpS6. Reprod Toxicol  2022;113 :42–51.35981663
Barberino RS , MenezesVG, RibeiroA, PalhetaRCJr, JiangX, SmitzJEJ, MatosMHT.  Melatonin protects against cisplatin-induced ovarian damage in mice via the MT1 receptor and antioxidant activity. Biol Reprod  2017;96 :1244–1255.28595266
Bar-Joseph H , Ben-AharonI, TzabariM, TsarfatyG, StemmerSM, ShalgiR.  In vivo bioimaging as a novel strategy to detect doxorubicin-induced damage to gonadal blood vessels. PLoS One  2011;6 :e23492.21931602
Basini G , RagionieriL, BussolatiS, Di LecceR, CacchioliA, DettinM, CantoniAM, GrolliS, La BellaO, ZamunerA  et al  Expression and function of the stromal cell-derived factor-1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) in the swine ovarian follicle. Domest Anim Endocrinol  2020;71 :106404.31955063
Ben-Aharon I , Bar-JosephH, TzarfatyG, KuchinskyL, RizelS, StemmerSM, ShalgiR.  Doxorubicin-induced ovarian toxicity. Reprod Biol Endocrinol  2010;8 :20.20202194
Ben-Aharon I , MeiznerI, GranotT, UriS, HaskyN, RizelS, YerushalmiR, SulkesA, StemmerSM.  Chemotherapy-induced ovarian failure as a prototype for acute vascular toxicity. Oncologist  2012;17 :1386–1393.22956534
Benjamin JJ , KoshyT, KumarKM, MaruthyKN, PadmavathiR.  Meta-analysis of association between il-6-174 g/c polymorphism and female infertility related disorders. J Reprod Immunol  2020;140 :103134.32402924
Benkhalifa M , ZidiW, BahriH, MahjoubS, BoudhraaK, SanhajiH, Khorsi-CauetH, FekiM, BenkhalifaM, Allal-ElasmiM.  Circulating MMP-7 and VEGF as potential predictive biomarkers for recurrent implantation failures. Zygote  2021;29 :365–371.33736747
Bersinger NA , KollmannZ, Von WolffM.  Serum but not follicular fluid cytokine levels are increased in stimulated versus natural cycle IVF: a multiplexed assay study. J Reprod Immunol  2014;106 :27–33.25103590
Bildik G , AkinN, SenbabaogluF, SahinGN, KarahuseyinogluS, InceU, TaskiranC, SelekU, YakinK, GuzelY  et al  GnRH agonist leuprolide acetate does not confer any protection against ovarian damage induced by chemotherapy and radiation in vitro. Hum Reprod  2015;30 :2912–2925.26466909
Biyik I , OzatikFY, AlbayrakM, OzatikO, TeksenY, AriNS, SoysalC.  The effects of recombinant klotho in cisplatin-induced ovarian failure in mice. J Obstet Gynaecol Res  2021;47 :1817–1824.33611838
Briley SM , JastiS, McCrackenJM, HornickJE, FegleyB, PritchardMT, DuncanFE.  Reproductive age-associated fibrosis in the stroma of the mammalian ovary. Reproduction  2016;152 :245–260.27491879
Brown HM , RobkerRL, RussellDL.  Development and hormonal regulation of the ovarian lymphatic vasculature. Endocrinology  2010;151 :5446–5455.20843998
Brown HM , RussellDL.  Blood and lymphatic vasculature in the ovary: development, function and disease. Hum Reprod Update  2014;20 :29–39.24097804
Buigues A , MarchanteM, de Miguel-GomezL, MartinezJ, CervelloI, PellicerA, HerraizS.  Stem cell-secreted factor therapy regenerates the ovarian niche and rescues follicles. Am J Obstet Gynecol  2021;225 :65.e1–14.
Buigues A , MarchanteM, HerraizS, PellicerA.  Diminished ovarian reserve chemotherapy-induced mouse model: a tool for the preclinical assessment of new therapies for ovarian damage. Reprod Sci  2020;27 :1609–1619.32430713
Bukovsky A , CaudleMR.  Immunoregulation of follicular renewal, selection, POF, and menopause in vivo, vs. neo-oogenesis in vitro, POF and ovarian infertility treatment, and a clinical trial. Reprod Biol Endocrinol  2012;10 :97.23176151
Bukulmez O , AriciA.  Leukocytes in ovarian function. Hum Reprod Update  2000;6 :1–15.10711825
Buyuk E , AsemotaOA, MerhiZ, CharronMJ, BergerDS, ZapantisA, JindalSK.  Serum and follicular fluid monocyte chemotactic protein-1 levels are elevated in obese women and are associated with poorer clinical pregnancy rate after in vitro fertilization: a pilot study. Fertil Steril  2017;107 :632–640.e3.28104240
Cadoret V , Jarrier-GaillardP, PapillierP, MonniauxD, GuerifF, Dalbies-TranR.  Leukaemia inhibitory factor modulates the differentiation of granulosa cells during sheep in vitro preantral to antral follicle development and improves oocyte meiotic competence. Mol Hum Reprod  2021;27 :gaab051.34411256
Calcinotto A , KohliJ, ZagatoE, PellegriniL, DemariaM, AlimontiA.  Cellular senescence: aging, cancer, and injury. Physiol Rev  2019;99 :1047–1078.30648461
Canli O , NicolasAM, GuptaJ, FinkelmeierF, GoncharovaO, PesicM, NeumannT, HorstD, LowerM, SahinU  et al  Myeloid cell-derived reactive oxygen species induce epithelial mutagenesis. Cancer Cell  2017;32 :869–883.e5.29232557
Care AS , DienerKR, JasperMJ, BrownHM, IngmanWV, RobertsonSA.  Macrophages regulate corpus luteum development during embryo implantation in mice. J Clin Invest  2013;123 :3472–3487.23867505
Cetinkaya K , AtaseverM, ErisginZ, SonmezC, OzerC, CoskunB, AlisikM.  The role of oxidative stress in chemotherapy-induced gonadotoxicity in a rat model, and the protective effects of Nigella Sativa oil on oxidative stress, the anti-Mullerian hormone level, and apoptosis. Eur Rev Med Pharmacol Sci  2023;27 :6343–6350.37458651
Chang EM , LimE, YoonS, JeongK, BaeS, LeeDR, YoonTK, ChoiY, LeeWS.  Cisplatin induces overactivation of the dormant primordial follicle through PTEN/AKT/FOXO3a pathway which leads to loss of ovarian reserve in mice. PLoS One  2015;10 :e0144245.26656301
Chen J , JiaZ, ZhangF, HanC, ZhaoL, JiaY, CuiM.  HGF-modified human umbilical cord mesenchymal stem cells rescue impaired ovarian reserve function in chemotherapy-induced POI rats by improving angiogenesis while decreasing apoptosis and fibrosis in the ovary. Tissue Cell  2023;82 :102121.37285749
Chen Q , XuZ, LiX, DuD, WuT, ZhouS, YanW, WuM, JinY, ZhangJ  et al  Epigallocatechin gallate and theaflavins independently alleviate cyclophosphamide-induced ovarian damage by inhibiting the overactivation of primordial follicles and follicular atresia. Phytomedicine  2021;92 :153752.34601223
Chen W , XuX, WangL, BaiG, XiangW.  Low expression of Mfn2 is associated with mitochondrial damage and apoptosis of ovarian tissues in the premature ovarian failure model. PLoS One  2015;10 :e0136421.26327438
Chen Y , McAndrewsKM, KalluriR.  Clinical and therapeutic relevance of cancer-associated fibroblasts. Nat Rev Clin Oncol  2021;18 :792–804.34489603
Chen Y , ZhaoY, MiaoC, YangL, WangR, ChenB, ZhangQ.  Quercetin alleviates cyclophosphamide-induced premature ovarian insufficiency in mice by reducing mitochondrial oxidative stress and pyroptosis in granulosa cells. J Ovarian Res  2022;15 :138.36572950
Cheng JC , FangL, YanY, HeJ, GuoY, JiaQ, GaoY, HanX, SunYP.  TGF-beta1 stimulates aromatase expression and estradiol production through SMAD2 and ERK1/2 signaling pathways in human granulosa-lutein cells. J Cell Physiol  2021;236 :6619–6629.33512728
Chinwe GS , AzukaOI, AdaezeNC.  Resveratrol supplementation rescues pool of growing follicles and ovarian stroma from cisplatin-induced toxicity on the ovary in Sprague-Dawley rats: an experimental study. Int J Reprod Biomed  2018;16 :19–30.29675484
Ciplak B , TurmusEG, KaraO, DagliogluG, AltindagMM, SimsekY, DagliogluYK, KaraM.  Does resveratrol reduce cisplatin-induced ovarian damage?  Rev Assoc Med Bras (1992)  2023;69 :e20230314.37585992
Clarkson YL , McLaughlinM, WaterfallM, DunlopCE, SkehelPA, AndersonRA, TelferEE.  Initial characterisation of adult human ovarian cell populations isolated by DDX4 expression and aldehyde dehydrogenase activity. Sci Rep  2018;8 :6953.29725036
Cohen PE , ZhuL, NishimuraK, PollardJW.  Colony-stimulating factor 1 regulation of neuroendocrine pathways that control gonadal function in mice. Endocrinology  2002;143 :1413–1422.11897698
Coveney D , CoolJ, OliverT, CapelB.  Four-dimensional analysis of vascularization during primary development of an organ, the gonad. Proc Natl Acad Sci USA  2008;105 :7212–7217.18480267
Crespo D , BonnetE, RoherN, MacKenzieSA, KrasnovA, GoetzFW, BobeJ, PlanasJV.  Cellular and molecular evidence for a role of tumor necrosis factor alpha in the ovulatory mechanism of trout. Reprod Biol Endocrinol  2010;8 :34.20385004
Cui L , BaoH, LiuZ, ManX, LiuH, HouY, LuoQ, WangS, FuQ, ZhangH.  hUMSCs regulate the differentiation of ovarian stromal cells via TGF-beta(1)/Smad3 signaling pathway to inhibit ovarian fibrosis to repair ovarian function in POI rats. Stem Cell Res Ther  2020;11 :386.32894203
Cui L , BaoH, ZhuW, TangY, LuoQ, SiY, FuQ, JiangZ.  hUMSCs transplantation regulates AMPK/NR4A1 signaling axis to inhibit ovarian fibrosis in POI rats. Stem Cell Rev Rep  2022;19 :1449–1465.36307672
da Cunha EV , MeloLRF, SousaGB, AraujoVR, VasconcelosGL, SilvaAWB, SilvaJRV.  Effect of bone morphogenetic proteins 2 and 4 on survival and development of bovine secondary follicles cultured in vitro. Theriogenology  2018;110 :44–51.29331831
Dahm-Kahler P , GhahremaniM, LindAK, SundfeldtK, BrannstromM.  Monocyte chemotactic protein-1 (MCP-1), its receptor, and macrophages in the perifollicular stroma during the human ovulatory process. Fertil Steril  2009;91 :231–239.18829011
Dai X , YiX, WangY, XiaW, TaoJ, WuJ, MiaoD, ChenL.  PQQ dietary supplementation prevents alkylating agent-induced ovarian dysfunction in mice. Front Endocrinol (Lausanne)  2022;13 :781404.35340329
Dang X , ZhuQ, HeY, WangY, LuY, LiX, QiJ, WuH, SunY.  IL-1beta upregulates StAR and progesterone production through the ERK1/2- and p38-mediated CREB signaling pathways in human granulosa-lutein cells. Endocrinology  2017;158 :3281–3291.28651331
Dath C , DethyA, Van LangendoncktA, Van EyckAS, AmorimCA, LuyckxV, DonnezJ, DolmansMM.  Endothelial cells are essential for ovarian stromal tissue restructuring after xenotransplantation of isolated ovarian stromal cells. Hum Reprod  2011;26 :1431–1439.21421662
Dayangan Sayan C , TulmacOB, KaracaG, OzkanZS, YalcinS, DevrimT, Dindar BademN.  Could erythropoietin reduce the ovarian damage of cisplatin in female rats?  Gynecol Endocrinol  2018;34 :309–313.29084473
De Moraes AC , AndradeCB, SalataC, NascimentoAL, RamosIP, GoldenbergRC, CarvalhoJJ, MachadoAC.  A combination of stereological methods, biochemistry and electron microscopy for the investigation of drug treatment effects in experimental animals. J Microsc  2016;261 :267–276.26484626
Delgado-Rosas F , GaytanM, MoralesC, GomezR, GaytanF.  Superficial ovarian cortex vascularization is inversely related to the follicle reserve in normal cycling ovaries and is increased in polycystic ovary syndrome. Hum Reprod  2009;24 :1142–1151.19189992
Delkhosh A , DelashoubM, TehraniAA, BahramiAM, NiaziV, ShooreiH, BanimohammadM, KalarestaghiH, ShokoohiM, AgabalazadehA  et al  Upregulation of FSHR and PCNA by administration of coenzyme Q10 on cyclophosphamide-induced premature ovarian failure in a mouse model. J Biochem Mol Toxicol  2019;33 :e22398.31557371
Deng T , HeJ, YaoQ, WuL, XueL, WuM, WuD, LiC, LiY.  Human umbilical cord mesenchymal stem cells improve ovarian function in chemotherapy-induced premature ovarian failure mice through inhibiting apoptosis and inflammation via a paracrine mechanism. Reprod Sci  2021;28 :1718–1732.33751459
Devesa J , CaicedoD.  The role of growth hormone on ovarian functioning and ovarian angiogenesis. Front Endocrinol (Lausanne)  2019;10 :450.31379735
Devos M , Diaz VidalP, BouziotisJ, AnckaertE, DolmansMM, DemeestereI.  Impact of first chemotherapy exposure on follicle activation and survival in human cryopreserved ovarian tissue. Hum Reprod  2023;38 :408–420.36723906
Devos M , GrosboisJ, DemeestereI.  Interaction between PI3K/AKT and Hippo pathways during in vitro follicular activation and response to fragmentation and chemotherapy exposure using a mouse immature ovary model. Biol Reprod  2020;102 :717–729.31786608
Dinc K , OzyurtR, CobanTA, YaziciGN, SuleymanZ, YavuzerB, SuleymanH.  The effect of carvacrol on the proinflammatory cytokines, histology, and fertility outcome of cisplatin-related ovarian change in a rat model. Taiwan J Obstet Gynecol  2023;62 :256–263.36965892
Ding C , QianC, HouS, LuJ, ZouQ, LiH, HuangB.  Exosomal miRNA-320a is released from hAMSCs and regulates SIRT4 to prevent reactive oxygen species generation in POI. Mol Ther Nucleic Acids  2020;21 :37–50.32506013
Ding C , ZhuL, ShenH, LuJ, ZouQ, HuangC, LiH, HuangB.  Exosomal miRNA-17-5p derived from human umbilical cord mesenchymal stem cells improves ovarian function in premature ovarian insufficiency by regulating SIRT7. Stem Cells  2020;38 :1137–1148.32442343
Dipali SS , KingCD, RoseJP, BurdetteJE, CampisiJ, SchillingB, DuncanFE.  Proteomic quantification of native and ECM-enriched mouse ovaries reveals an age-dependent fibro-inflammatory signature. Aging (Albany NY)  2023;15 :10821–10855.37899138
Doitsidou M , Reichman-FriedM, SteblerJ, KoprunnerM, DorriesJ, MeyerD, EsguerraCV, LeungT, RazE.  Guidance of primordial germ cell migration by the chemokine SDF-1. Cell  2002;111 :647–659.12464177
Du D , TangX, LiY, GaoY, ChenR, ChenQ, WenJ, WuT, ZhangY, LuH  et al  Senotherapy protects against cisplatin-induced ovarian injury by removing senescent cells and alleviating DNA damage. Oxid Med Cell Longev  2022;2022 :9144644.35693700
Du Y , CarranzaZ, LuanY, Busman-SahayK, WolfS, CampbellSP, KimSY, PejovicT, EstesJD, ZelinskiM  et al  Evidence of cancer therapy-induced chronic inflammation in the ovary across multiple species: a potential cause of persistent tissue damage and follicle depletion. J Reprod Immunol  2022;150 :103491.35176661
Dunlop CE , BayneRA, McLaughlinM, TelferEE, AndersonRA.  Isolation, purification, and culture of oogonial stem cells from adult human and bovine ovarian cortex. Lancet  2014;383 :S45.
Dynes J , OszK, HooperA, PetrikJ.  Low-dose metronomic delivery of cyclophosphamide is less detrimental to granulosa cell viability, ovarian function, and fertility than maximum tolerated dose delivery in the mouse. Biol Reprod  2017;97 :449–465.29024988
Elmi M , GhandilP, HemadiM, BirganiMT, SaberiA.  Association of rs1570360 and rs2010963 in VEGF and rs2279744 in the MDM2 gene with recurrent implantation failure in Iranian women. JBRA Assist Reprod  2023;27 :342–347.37257061
Eslami N , BahrehbarK, EsfandiariF, ShekariF, HassaniSN, NazariA, PakzadM, BaharvandH.  Regenerative potential of different extracellular vesicle subpopulations derived from clonal mesenchymal stem cells in a mouse model of chemotherapy-induced premature ovarian failure. Life Sci  2023;321 :121536.36868400
Ezoe K , MurataN, YabuuchiA, OkunoT, KobayashiT, KatoO, KatoK.  Long-term adverse effects of cyclophosphamide on follicular growth and angiogenesis in mouse ovaries. Reprod Biol  2014;14 :238–242.25152523
Fabbri R , MaccioccaM, VicentiR, CapraraG, PiccinniMP, ParadisiR, TerzanoP, PapiA, SeracchioliR.  Epigallocatechin-3-gallate inhibits doxorubicin-induced inflammation on human ovarian tissue. Biosci Rep  2019;39 :BSR20181424.30996116
Fabbri R , MaccioccaM, VicentiR, ParadisiR, KlingerFG, PasquinelliG, SpisniE, SeracchioliR, PapiA.  Doxorubicin and cisplatin induce apoptosis in ovarian stromal cells obtained from cryopreserved human ovarian tissue. Future Oncol  2016;12 :1699–1711.27173589
Fan X , BialeckaM, MoustakasI, LamE, Torrens-JuanedaV, BorggrevenNV, TrouwL, LouweLA, PilgramGSK, MeiH  et al  Single-cell reconstruction of follicular remodeling in the human adult ovary. Nat Commun  2019;10 :3164.31320652
Faustman D , DavisM.  TNF receptor 2 pathway: drug target for autoimmune diseases. Nat Rev Drug Discov  2010;9 :482–493.20489699
Favero PF , Vieira de LimaVA, Helena Dos SantosP, Marques AndradeAP, MendesLO, PacagnelliFL, Cesar de Souza CastilhoA.  Differential fractal dimension is associated with extracellular matrix remodeling in developing bovine corpus luteum. Biochem Biophys Res Commun  2019;516 :888–893.31270026
Fellus-Alyagor L , BitonIE, DafniH, BochnerF, RotkopfR, DekelN, NeemanM.  Prediction of ovarian follicular dominance by MRI phenotyping of hormonally induced vascular remodeling. Front Med (Lausanne)  2021;8 :711810.34490300
Feng J , MaWW, LiHX, PeiXY, DengSL, JiaH, MaWZ.  Melatonin prevents cyclophosphamide-induced primordial follicle loss by inhibiting ovarian granulosa cell apoptosis and maintaining AMH expression. Front Endocrinol (Lausanne)  2022;13 :895095.35992124
Figueroa F , MottaA, AcostaM, MohamedF, OliverosL, FornerisM.  Role of macrophage secretions on rat polycystic ovary: its effect on apoptosis. Reproduction  2015;150 :437–448.26264225
Fiorentino G , CimadomoD, InnocentiF, SosciaD, VaiarelliA, UbaldiFM, GennarelliG, GaragnaS, RienziL, ZuccottiM.  Biomechanical forces and signals operating in the ovary during folliculogenesis and their dysregulation: implications for fertility. Hum Reprod Update  2023;29 :1–23.35856663
Foroughinia G , FazilehA, EghbalsaiedS.  Expression of genes involved in BMP and estrogen signaling and AMPK production can be important factors affecting total number of antral follicles in ewes. Theriogenology  2017;91 :36–43.28215684
Fu X , HeY, WangX, PengD, ChenX, LiX, WangQ.  Overexpression of miR-21 in stem cells improves ovarian structure and function in rats with chemotherapy-induced ovarian damage by targeting PDCD4 and PTEN to inhibit granulosa cell apoptosis. Stem Cell Res Ther  2017;8 :187.28807003
Gabr H , RatebMA, El SissyMH, Ahmed SeddiekH, Ali Abdelhameed GoudaS.  The effect of bone marrow-derived mesenchymal stem cells on chemotherapy induced ovarian failure in albino rats. Microsc Res Tech  2016;79 :938–947.27453009
Gallinelli A , CiaccioI, GiannellaL, SalvatoriM, MarsellaT, VolpeA.  Correlations between concentrations of interleukin-12 and interleukin-13 and lymphocyte subsets in the follicular fluid of women with and without polycystic ovary syndrome. Fertil Steril  2003;79 :1365–1372.12798884
Gao JM , YanJ, LiR, LiM, YanLY, WangTR, ZhaoHC, ZhaoY, YuY, QiaoJ.  Improvement in the quality of heterotopic allotransplanted mouse ovarian tissues with basic fibroblast growth factor and fibrin hydrogel. Hum Reprod  2013;28 :2784–2793.23892320
Gao M , LiuX, GuH, XuH, ZhongW, WeiX, ZhongX.  Association between single nucleotide polymorphisms, TGF-beta1 promoter methylation, and polycystic ovary syndrome. BMC Pregnancy Childbirth  2024;24 :5.38166771
Gao Y , WuT, TangX, WenJ, ZhangY, ZhangJ, WangS.  Increased cellular senescence in doxorubicin-induced murine ovarian injury: effect of senolytics. Geroscience  2023;45 :1775–1790.36648735
Gattazzo F , UrciuoloA, BonaldoP.  Extracellular matrix: a dynamic microenvironment for stem cell niche. Biochim Biophys Acta  2014;1840 :2506–2519.24418517
Gaytan F , MoralesC, Garcia-PardoL, ReymundoC, BellidoC, Sanchez-CriadoJE.  Macrophages, cell proliferation, and cell death in the human menstrual corpus luteum. Biol Reprod  1998;59 :417–425.9687316
Gheorghisan-Galateanu AA , HinescuME, EnciuAM.  Ovarian adult stem cells: hope or pitfall?  J Ovarian Res  2014;7 :71.25018783
Glister C , HatzirodosN, HummitzschK, KnightPG, RodgersRJ.  The global effect of follicle-stimulating hormone and tumour necrosis factor alpha on gene expression in cultured bovine ovarian granulosa cells. BMC Genomics  2014;15 :72.24467805
Gouveia BB , BarberinoRS, Dos Santos SilvaRL, LinsT, da Silva GuimaraesV, do MonteAPO, PalhetaRCJr, de MatosMHT.  Involvement of PTEN and FOXO3a proteins in the protective activity of protocatechuic acid against cisplatin-induced ovarian toxicity in mice. Reprod Sci  2021;28 :865–876.33174187
Grosbois J , BailieEC, KelseyTW, AndersonRA, TelferEE.  Spatio-temporal remodelling of the composition and architecture of the human ovarian cortical extracellular matrix during in vitro culture. Hum Reprod  2023;38 :444–458.36721914
Grosbois J , DemeestereI.  Dynamics of PI3K and Hippo signaling pathways during in vitro human follicle activation. Hum Reprod  2018;33 :1705–1714.30032281
Grubliauskaite M , VliegheH, MoghassemiS, DadashzadehA, CamboniA, GudlevicieneZ, AmorimCA.  Influence of ovarian stromal cells on human ovarian follicle growth in a 3D environment. Hum Reprod Open  2024;2024 :hoad052.38204939
Guo Y , LiuM, MfoundouJDL, WangX.  Expression and distribution patterns of VEGF, TGF-beta(1) and HIF-1alpha in the ovarian follicles of Tibetan sheep. Vet Med Sci  2022;8 :2223–2229.36044612
Guzman A , Macias-ValenciaR, Fierro-FierroF, GutierrezCG, Rosales-TorresAM.  The corpora lutea proangiogenic state of VEGF system components is turned to antiangiogenic at the later phase of the oestrous cycle in cows. Animal  2015;9 :301–307.25229247
Hamid KM , MirshafieyA.  Role of proangiogenic factors in immunopathogenesis of multiple sclerosis. Iran J Allergy Asthma Immunol  2016;15 :1–12.26996106
Han FS , YangSJ, LinMB, ChenYQ, YangP, XuJM.  Chitooligosaccharides promote radiosensitivity in colon cancer line SW480. World J Gastroenterol  2016;22 :5193–5200.27298562
Hardee ME , ArcasoyMO, BlackwellKL, KirkpatrickJP, DewhirstMW.  Erythropoietin biology in cancer. Clin Cancer Res  2006;12 :332–339.16428469
Hassan AI , GhoneimMAM, MahmoudMG, AskerMS.  Assessment role of total phenols and flavonoids extracted from Pleurotus columbinus mushroom on the premature ovarian failure induced by chemotherapy in rats. J Genet Eng Biotechnol  2021;19 :182.34889997
He R , FanQ, LiY, ZhuQ, HuD, DuJ, XingY, LiH, LiangX, YangY.  Identification of common and specific genes involved in mouse models of age-related and cyclophosphamide-induced diminished ovarian reserve. Reprod Sci  2023;30 :1965–1978.36587055
Helal MA.  The effects of N-acetyl-L-cysteine on the female reproductive performance and nephrotoxicity in rats. Ren Fail  2016;38 :311–320.26837610
Hense JD , GarciaDN, IsolaJV, Alvarado-RinconJA, ZaniniBM, ProsczekJB, StoutMB, MasonJB, WalshPT, Brieno-EnriquezMA  et al  Senolytic treatment reverses obesity-mediated senescent cell accumulation in the ovary. Geroscience  2022;44 :1747–1759.35460445
Herraiz S , BuiguesA, Diaz-GarciaC, RomeuM, MartinezS, Gomez-SeguiI, SimonC, HsuehAJ, PellicerA.  Fertility rescue and ovarian follicle growth promotion by bone marrow stem cell infusion. Fertil Steril  2018;109 :908–918.e2.29576341
Herrero Y , VelazquezC, PascualiN, MayM, AbramovichD, ScottiL, ParborellF.  Resveratrol alleviates doxorubicin-induced damage in mice ovary. Chem Biol Interact  2023;376 :110431.36925030
Hickson LJ , Langhi PrataLGP, BobartSA, EvansTK, GiorgadzeN, HashmiSK, HerrmannSM, JensenMD, JiaQ, JordanKL  et al  Senolytics decrease senescent cells in humans: preliminary report from a clinical trial of dasatinib plus quercetin in individuals with diabetic kidney disease. EBioMedicine  2019;47 :446–456.31542391
Holt JE , JacksonA, RomanSD, AitkenRJ, KoopmanP, McLaughlinEA.  CXCR4/SDF1 interaction inhibits the primordial to primary follicle transition in the neonatal mouse ovary. Dev Biol  2006;293 :449–460.16545793
Hornick JE , DuncanFE, SheaLD, WoodruffTK.  Isolated primate primordial follicles require a rigid physical environment to survive and grow in vitro. Hum Reprod  2012;27 :1801–1810.22456922
Huang B , QianC, DingC, MengQ, ZouQ, LiH.  Fetal liver mesenchymal stem cells restore ovarian function in premature ovarian insufficiency by targeting MT1. Stem Cell Res Ther  2019;10 :362.31783916
Huang J , ShanW, LiN, ZhouB, GuoE, XiaM, LuH, WuY, ChenJ, WangB  et al  Melatonin provides protection against cisplatin-induced ovarian damage and loss of fertility in mice. Reprod Biomed Online  2021;42 :505–519.33388265
Huang Q , LiuB, JiangR, LiaoS, WeiZ, BiY, LiuX, DengR, JinY, TanY  et al  G-CSF-mobilized peripheral blood mononuclear cells combined with platelet-rich plasma accelerate restoration of ovarian function in cyclophosphamide-induced POI ratsdagger. Biol Reprod  2019;101 :91–101.31034039
Huang Y , MaZ, KuangX, ZhangQ, LiH, LaiD.  Sodium alginate-bioglass-encapsulated hAECs restore ovarian function in premature ovarian failure by stimulating angiogenic factor secretion. Stem Cell Res Ther  2021;12 :223.33794993
Huang Y , YeH, ZhuF, HuC, ZhengY.  The role of chito-oligosaccharide in regulating ovarian germ stem cells function and restoring ovarian function in chemotherapy mice. Reprod Biol Endocrinol  2021;19 :14.33494759
Huang Y , ZhangQ, CaoW, ZhangQ, WangL, LaiD.  TNF-alpha and IFN-gamma prestimulation enhances the therapeutic efficacy of human amniotic epithelial stem cells in chemotherapy-induced ovarian dysfunction. Inflamm Regen  2023;43 :57.37993924
Huang YH , ZhaoXJ, ZhangQH, XinXY.  The GnRH antagonist reduces chemotherapy-induced ovarian damage in rats by suppressing the apoptosis. Gynecol Oncol  2009;112 :409–414.19038435
Hughesdon PE.  Morphology and morphogenesis of the Stein-Leventhal ovary and of so-called “hyperthecosis”. Obstet Gynecol Surv  1982;37 :59–77.7033852
Hummitzsch K , HatzirodosN, MacphersonAM, SchwartzJ, RodgersRJ, Irving-RodgersHF.  Transcriptome analyses of ovarian stroma: tunica albuginea, interstitium and theca interna. Reproduction  2019;157 :545–565.30925461
Ibrahim MA , AlbahlolIA, WaniFA, Abd-Eltawab TammamA, KelleniMT, SayeedMU, Abd El-FadealNM, MohamedAA.  Resveratrol protects against cisplatin-induced ovarian and uterine toxicity in female rats by attenuating oxidative stress, inflammation and apoptosis. Chem Biol Interact  2021;338 :109402.33587916
Imai F , KishiH, NakaoK, NishimuraT, MinegishiT.  IL-6 up-regulates the expression of rat LH receptors during granulosa cell differentiation. Endocrinology  2014;155 :1436–1444.24467743
Ingman WV , RobkerRL, WoittiezK, RobertsonSA.  Null mutation in transforming growth factor beta1 disrupts ovarian function and causes oocyte incompetence and early embryo arrest. Endocrinology  2006;147 :835–845.16269452
Isola JVV , OcanasSR, HubbartCR, KoS, MondalSA, HenseJD, CarterHNC, SchneiderA, KovatsS, Alberola-IlaJ  et al  A single-cell atlas of the aging murine ovary. Nat Aging  2024;4 :145–162.38200272
Jiang Y , ZhangZ, ChaL, LiL, ZhuD, FangZ, HeZ, HuangJ, PanZ.  Resveratrol plays a protective role against premature ovarian failure and prompts female germline stem cell survival. Int J Mol Sci  2019;20 :3605.31340581
Jiang Y , ZhuD, LiuW, QinQ, FangZ, PanZ.  Hedgehog pathway inhibition causes primary follicle atresia and decreases female germline stem cell proliferation capacity or stemness. Stem Cell Res Ther  2019;10 :198.31277696
Jiao X , ZhangX, LiN, ZhangD, ZhaoS, DangY, ZanvitP, JinW, ChenZJ, ChenW  et al  T(reg) deficiency-mediated T(H) 1 response causes human premature ovarian insufficiency through apoptosis and steroidogenesis dysfunction of granulosa cells. Clin Transl Med  2021;11 :e448.34185428
Jin L , RenL, LuJ, WenX, ZhuangS, GengT, ZhangY.  CXCL12 and its receptors regulate granulosa cell apoptosis in PCOS rats and human KGN tumor cells. Reproduction  2021;161 :145–157.33258800
Jing B , ChengG, LiJ, WangZA, DuY.  Inhibition of liver tumor cell metastasis by partially acetylated chitosan oligosaccharide on a tumor-vessel microsystem. Mar Drugs  2019;17 :415.31337016
Johnson J , BagleyJ, Skaznik-WikielM, LeeHJ, AdamsGB, NiikuraY, TschudyKS, TillyJC, CortesML, ForkertR  et al  Oocyte generation in adult mammalian ovaries by putative germ cells in bone marrow and peripheral blood. Cell  2005;122 :303–315.16051153
Johnson J , CanningJ, KanekoT, PruJK, TillyJL.  Germline stem cells and follicular renewal in the postnatal mammalian ovary. Nature  2004;428 :145–150.15014492
Jokela H , LokkaE, KivirantaM, TyystjarviS, GerkeH, ElimaK, SalmiM, RantakariP.  Fetal-derived macrophages persist and sequentially maturate in ovaries after birth in mice. Eur J Immunol  2020;50 :1500–1514.32459864
Kalich-Philosoph L , RonessH, CarmelyA, Fishel-BartalM, LigumskyH, PaglinS, WolfI, KanetyH, SredniB, MeirowD.  Cyclophosphamide triggers follicle activation and “burnout”; AS101 prevents follicle loss and preserves fertility. Sci Transl Med  2013;5 :185ra62.
Kawamura K , ChengY, SuzukiN, DeguchiM, SatoY, TakaeS, HoCH, KawamuraN, TamuraM, HashimotoS  et al  Hippo signaling disruption and Akt stimulation of ovarian follicles for infertility treatment. Proc Natl Acad Sci USA  2013;110 :17474–17479.24082083
Kawamura K , IshizukaB, HsuehAJW.  Drug-free in-vitro activation of follicles for infertility treatment in poor ovarian response patients with decreased ovarian reserve. Reprod Biomed Online  2020;40 :245–253.31753712
Kayamori T , KosakaN, MiyamotoA, ShimizuT.  The differential pathways of bone morphogenetic protein (BMP)-4 and -7 in the suppression of the bovine granulosa cell apoptosis. Mol Cell Biochem  2009;323 :161–168.19083154
Khalil DN , SmithEL, BrentjensRJ, WolchokJD.  The future of cancer treatment: immunomodulation, CARs and combination immunotherapy. Nat Rev Clin Oncol  2016;13 :273–290.26977780
Khanmohammadi F , ShahroozR, AhmadiA, RaziM.  Possible protective effects of crocin on destructive side effects of cyclo-phosphamide in mice ovarian tissue: evaluation of histomorphometrical and biochemical changes. Vet Res Forum  2021;12 :217–222.34345389
Khedr NF.  Protective effect of mirtazapine and hesperidin on cyclophosphamide-induced oxidative damage and infertility in rat ovaries. Exp Biol Med (Maywood)  2015;240 :1682–1689.25787947
Kim C , SchneiderG, Abdel-LatifA, MierzejewskaK, SunkaraM, BorkowskaS, RatajczakJ, MorrisAJ, KuciaM, RatajczakMZ.  Ceramide-1-phosphate regulates migration of multipotent stromal cells and endothelial progenitor cells—implications for tissue regeneration. Stem Cells  2013;31 :500–510.23193025
Kim CH , AhnJW, YouRM, KimSH, ChaeHD, KangBM.  Pioglitazone treatment decreases follicular fluid levels of tumor necrosis factor-alpha and interleukin-6 in patients with polycystic ovary syndrome. Clin Exp Reprod Med  2011;38 :98–102.22384426
Kinnear HM , TomaszewskiCE, ChangFL, MoravekMB, XuM, PadmanabhanV, ShikanovA.  The ovarian stroma as a new frontier. Reproduction  2020;160 :R25–R39.32716007
Kirkland JL , TchkoniaT.  Senolytic drugs: from discovery to translation. J Intern Med  2020;288 :518–536.32686219
Lai D , WangF, DongZ, ZhangQ.  Skin-derived mesenchymal stem cells help restore function to ovaries in a premature ovarian failure mouse model. PLoS One  2014;9 :e98749.24879098
Lai D , WangF, YaoX, ZhangQ, WuX, XiangC.  Human endometrial mesenchymal stem cells restore ovarian function through improving the renewal of germline stem cells in a mouse model of premature ovarian failure. J Transl Med  2015;13 :155.25964118
Lawson KA , DunnNR, RoelenBA, ZeinstraLM, DavisAM, WrightCV, KorvingJP, HoganBL.  Bmp4 is required for the generation of primordial germ cells in the mouse embryo. Genes Dev  1999;13 :424–436.10049358
Ledee-Bataille N , Lapree-DelageG, TaupinJL, DubanchetS, TaiebJ, MoreauJF, ChaouatG.  Follicular fluid concentration of leukaemia inhibitory factor is decreased among women with polycystic ovarian syndrome during assisted reproduction cycles. Hum Reprod  2001;16 :2073–2078.11574494
Lee BY , LiQ, SongWJ, ChaeHK, KweonK, AhnJO, YounHY.  Altered properties of feline adipose-derived mesenchymal stem cells during continuous in vitro cultivation. J Vet Med Sci  2018;80 :930–938.29669964
Lee HJ , KimJY, ParkJE, YoonYD, TsangBK, KimJM.  Induction of Fas-mediated apoptosis by interferon-gamma is dependent on granulosa cell differentiation and follicular maturation in the rat ovary. Dev Reprod  2016;20 :315–329.28144637
Lee WS , OtsukaF, MooreRK, ShimasakiS.  Effect of bone morphogenetic protein-7 on folliculogenesis and ovulation in the rat. Biol Reprod  2001;65 :994–999.11566718
Lei L , SpradlingAC.  Female mice lack adult germ-line stem cells but sustain oogenesis using stable primordial follicles. Proc Natl Acad Sci USA  2013;110 :8585–8590.23630252
Li F , TuranV, LiermanS, CuvelierC, De SutterP, OktayK.  Sphingosine-1-phosphate prevents chemotherapy-induced human primordial follicle death. Hum Reprod  2014;29 :107–113.24221908
Li H , ChangHM, ShiZ, LeungPCK.  The p38 signaling pathway mediates the TGF-beta1-induced increase in type I collagen deposition in human granulosa cells. FASEB J  2020;34 :15591–15604.32996643
Li J , KawamuraK, ChengY, LiuS, KleinC, LiuS, DuanEK, HsuehAJ.  Activation of dormant ovarian follicles to generate mature eggs. Proc Natl Acad Sci USA  2010;107 :10280–10284.20479243
Li JJ , LiJT, FuJP.  Erxian tang—introduction of a Chinese herbal formula, clinical practice, and experimental studies. Chin J Integr Med  2007;13 :67–73.17578324
Li X , YangS, LvX, SunH, WengJ, LiangY, ZhouD.  The mechanism of mesna in protection from cisplatin-induced ovarian damage in female rats. J Gynecol Oncol  2013;24 :177–185.23653836
Li X , YeH, SuT, HuC, HuangY, FuX, ZhongZ, DuX, ZhengY.  Immunity and reproduction protective effects of chitosan oligosaccharides in cyclophosphamide/busulfan-induced premature ovarian failure model mice. Front Immunol  2023;14 :1185921.37228612
Li Y , RuanX, LiebenthronJ, MontagM, ZhouQ, KongW, DuJ, JinF, LiS, ChengJ  et al  Ovarian tissue cryopreservation for patients with premature ovary insufficiency caused by cancer treatment: optimal protocol. Climacteric  2019;22 :383–389.30676094
Li Z , PengA, FengY, ZhangX, LiuF, ChenC, YeX, QuJ, JinC, WangM  et al  Detection of T lymphocyte subsets and related functional molecules in follicular fluid of patients with polycystic ovary syndrome. Sci Rep  2019;9 :6040.30988342
Li Z , ZhuY, LiH, JiangW, LiuH, YanJ, ChenZJ, LiW.  Leukaemia inhibitory factor in serum and follicular fluid of women with polycystic ovary syndrome and its correlation with IVF outcome. Reprod Biomed Online  2018;36 :483–489.29397316
Lima PDA , NivetAL, WangQ, ChenYA, LeaderA, CheungA, TzengCR, TsangBK.  Polycystic ovary syndrome: possible involvement of androgen-induced, chemerin-mediated ovarian recruitment of monocytes/macrophages. Biol Reprod  2018;99 :838–852.29688269
Ling L , FengX, WeiT, WangY, WangY, ZhangW, HeL, WangZ, ZengQ, XiongZ.  Effects of low-intensity pulsed ultrasound (LIPUS)-pretreated human amnion-derived mesenchymal stem cell (hAD-MSC) transplantation on primary ovarian insufficiency in rats. Stem Cell Res Ther  2017;8 :283.29258619
Lins T , GouveiaBB, BarberinoRS, SilvaRLS, MonteAPO, PintoJGC, CampinhoDSP, PalhetaRC, MatosMHT.  Rutin prevents cisplatin-induced ovarian damage via antioxidant activity and regulation of PTEN and FOXO3a phosphorylation in mouse model. Reprod Toxicol  2020;98 :209–217.33031932
Liu H , ZhangY, LiM, LuoP.  Beneficial effect of Sepia esculenta ink polysaccharide on cyclophosphamide-induced immunosuppression and ovarian failure in mice. Int J Biol Macromol  2019;140 :1098–1105.31449864
Liu J , YangY, HeY, FengC, OuH, YangJ, ChenY, YouF, ShaoB, BaoJ  et al  Erxian decoction alleviates cisplatin-induced premature ovarian failure in rats by reducing oxidation levels in ovarian granulosa cells. J Ethnopharmacol  2023;304 :116046.36567042
Liu T , HuangY, GuoL, ChengW, ZouG.  CD44+/CD105+ human amniotic fluid mesenchymal stem cells survive and proliferate in the ovary long-term in a mouse model of chemotherapy-induced premature ovarian failure. Int J Med Sci  2012;9 :592–602.23028242
Liu Y , DuSY, DingM, DouX, ZhangFF, WuZY, QianSW, ZhangW, TangQQ, XuCJ.  The BMP4-Smad signaling pathway regulates hyperandrogenism development in a female mouse model. J Biol Chem  2017;292 :11740–11750.28572510
Liu Z , de MatosDG, FanHY, ShimadaM, PalmerS, RichardsJS.  Interleukin-6: an autocrine regulator of the mouse cumulus cell-oocyte complex expansion process. Endocrinology  2009;150 :3360–3368.19299453
Liu Z , YoungquistRS, GarverickHA, AntoniouE.  Molecular mechanisms regulating bovine ovarian follicular selection. Mol Reprod Dev  2009;76 :351–366.18932212
Lobo RA.  Hormone-replacement therapy: current thinking. Nat Rev Endocrinol  2017;13 :220–231.27716751
Lopes F , LiuJ, MorganS, MatthewsR, NevinL, AndersonRA, SpearsN.  Single and combined effects of cisplatin and doxorubicin on the human and mouse ovary in vitro. Reproduction  2020;159 :193–204.31821159
Lopez-Otin C , BlascoMA, PartridgeL, SerranoM, KroemerG.  Hallmarks of aging: an expanding universe. Cell  2023;186 :243–278.36599349
Luan Y , EdmondsME, WoodruffTK, KimSY.  Inhibitors of apoptosis protect the ovarian reserve from cyclophosphamide. J Endocrinol  2019;240 :243–256.30530902
Lunding SA , PorsSE, KristensenSG, LandersoeSK, JeppesenJV, FlachsEM, PinborgA, MacklonKT, PedersenAT, AndersenCY  et al  Biopsying, fragmentation and autotransplantation of fresh ovarian cortical tissue in infertile women with diminished ovarian reserve. Hum Reprod  2019;34 :1924–1936.31593582
Luo M , ZhouL, HuangZ, LiB, NiceEC, XuJ, HuangC.  Antioxidant therapy in cancer: rationale and progress. Antioxidants (Basel)  2022;11 :1128.35740025
Luo Q , YinN, ZhangL, YuanW, ZhaoW, LuanX, ZhangH.  Role of SDF-1/CXCR4 and cytokines in the development of ovary injury in chemotherapy drug induced premature ovarian failure mice. Life Sci  2017;179 :103–109.28478265
Luo Z , WuF, XueE, HuangL, YanP, PanX, ZhouY.  Hypoxia preconditioning promotes bone marrow mesenchymal stem cells survival by inducing HIF-1alpha in injured neuronal cells derived exosomes culture system. Cell Death Dis  2019;10 :134.30755595
MacDonald JA , TakaiY, IshiharaO, SekiH, WoodsDC, TillyJL.  Extracellular matrix signaling activates differentiation of adult ovary-derived oogonial stem cells in a species-specific manner. Fertil Steril  2019;111 :794–805.30871765
Machlin JH , BarishanskySJ, KelshJ, LarmoreMJ, JohnsonBW, PritchardMT, PavoneME, DuncanFE.  Fibroinflammatory signatures increase with age in the human ovary and follicular fluid. Int J Mol Sci  2021;22 :4902.34063149
Mamun AA , SufianMA, UddinMS, SumsuzzmanDM, JeandetP, IslamMS, ZhangHJ, KongAN, SarwarMS.  Exploring the role of senescence inducers and senotherapeutics as targets for anticancer natural products. Eur J Pharmacol  2022;928 :174991.35513016
Marcello MF , NuciforoG, RomeoR, Di DinoG, RussoI, RussoA, PalumboG, SchiliroG.  Structural and ultrastructural study of the ovary in childhood leukemia after successful treatment. Cancer  1990;66 :2099–2104.2224764
Marcozzi S , RossiV, SalvatoreG, Di RellaF, De FeliciM, KlingerFG.  Distinct effects of epirubicin, cisplatin and cyclophosphamide on ovarian somatic cells of prepuberal ovaries. Aging (Albany NY)  2019;11 :10532–10556.31711044
Marks PW , WittenCM, CaliffRM.  Clarifying stem-cell therapy’s benefits and risks. N Engl J Med  2017;376 :1007–1009.27959704
McFee RM , RozellTG, CuppAS.  The balance of proangiogenic and antiangiogenic VEGFA isoforms regulate follicle development. Cell Tissue Res  2012;349 :635–647.22322423
McLaughlin M , KelseyTW, WallaceWH, AndersonRA, TelferEE.  Non-growing follicle density is increased following adriamycin, bleomycin, vinblastine and dacarbazine (ABVD) chemotherapy in the adult human ovary. Hum Reprod  2017;32 :165–174.27923859
Meirow D , DorJ, KaufmanB, ShrimA, RabinoviciJ, SchiffE, RaananiH, LevronJ, FridmanE.  Cortical fibrosis and blood-vessels damage in human ovaries exposed to chemotherapy. Potential mechanisms of ovarian injury. Hum Reprod  2007;22 :1626–1633.17324957
Mendez M , FabreguesF, FerreriJ, CalafellJM, VillarinoA, OteroJ, FarreR, CarmonaF.  Biomechanical characteristics of the ovarian cortex in POI patients and functional outcomes after drug-free IVA. J Assist Reprod Genet  2022;39 :1759–1767.35904669
Meng X , ChenH, WangG, YuY, XieK.  Hydrogen-rich saline attenuates chemotherapy-induced ovarian injury via regulation of oxidative stress. Exp Ther Med  2015;10 :2277–2282.26668628
Mentese A , AlemdarNT, LivaogluA, Ayazoglu DemirE, AliyaziciogluY, DemirS.  Suppression of cisplatin-induced ovarian injury in rats by chrysin: an experimental study. J Obstet Gynaecol  2022;42 :3584–3590.36193760
Mizrachi A , Ben-AharonI, LiH, Bar-JosephH, BoddenC, HikriE, PopovtzerA, ShalgiR, Haimovitz-FriedmanA.  Chemotherapy-induced acute vascular injury involves intracellular generation of ROS via activation of the acid sphingomyelinase pathway. Cell Signal  2021;82 :109969.33647448
Monslow J , GovindarajuP, PureE.  Hyaluronan—a functional and structural sweet spot in the tissue microenvironment. Front Immunol  2015;6 :231.26029216
Morsi AA , FarukEM, MedhatE, TahaNM, EbrahimUFA.  Modulatory effects of concomitant quercetin/sitagliptin administration on the ovarian histological and biochemical alterations provoked by doxorubicin in a streptozotocin-induced diabetic rat model. J Histotechnol  2023;46 :65–79.35912926
Mrozikiewicz AE , KurzawińskaG, OżarowskiM, WalczakM, OżegowskaK, JędrzejczakP.  Polymorphic variants of genes encoding angiogenesis-related factors in infertile women with recurrent implantation failure. Int J Mol Sci  2023;24 :4267.36901702
Mudgal J , MudgalPP, KinraM, RavalR.  Immunomodulatory role of chitosan-based nanoparticles and oligosaccharides in cyclophosphamide-treated mice. Scand J Immunol  2019;89 :e12749.30664262
Munoz-Osores E , WietstruckA, Hoyos-BachilogluR.  Mesna, an unusual agent causing hypersensitivity reactions during chemotherapy. Ann Allergy Asthma Immunol  2022;129 :119–120.35476968
Na J , KimGJ.  Recent trends in stem cell therapy for premature ovarian insufficiency and its therapeutic potential: a review. J Ovarian Res  2020;13 :74.32576209
Nagamatsu G , ShimamotoS, HamazakiN, NishimuraY, HayashiK.  Mechanical stress accompanied with nuclear rotation is involved in the dormant state of mouse oocytes. Sci Adv  2019;5 :eaav9960.31249869
Ngo DH , NgoDN, KimSK, VoTS.  Antiproliferative effect of aminoethyl-chitooligosaccharide on human lung A549 cancer cells. Biomolecules  2019;9 :195.31109093
Nguyen QN , ZerafaN, LiewSH, FindlayJK, HickeyM, HuttKJ.  Cisplatin- and cyclophosphamide-induced primordial follicle depletion is caused by direct damage to oocytes. Mol Hum Reprod  2019;25 :433–444.30953068
Nicosia SV , Matus-RidleyM, MeadowsAT.  Gonadal effects of cancer therapy in girls. Cancer  1985;55 :2364–2372.3986739
Niringiyumukiza JD , CaiH, ChenL, LiY, WangL, ZhangM, XuX, XiangW.  Protective properties of glycogen synthase kinase-3 inhibition against doxorubicin-induced oxidative damage to mouse ovarian reserve. Biomed Pharmacother  2019;116 :108963.31125824
Nishigaki A , OkadaH, OkamotoR, SugiyamaS, MiyazakiK, YasudaK, KanzakiH.  Concentrations of stromal cell-derived factor-1 and vascular endothelial growth factor in relation to the diameter of human follicles. Fertil Steril  2011;95 :742–746.21071025
Novotny Z , KrizanJ, SimaR, SimaP, UherP, ZechN, HutelovaR, BaborovaP, Ulcova-GallovaZ, SubrtI  et al  Leukaemia inhibitory factor (LIF) gene mutations in women diagnosed with unexplained infertility and endometriosis have a negative impact on the IVF outcome. A pilot study. Folia Biol (Praha)  2009;55 :92–97.19545488
Oktem O , OktayK.  Quantitative assessment of the impact of chemotherapy on ovarian follicle reserve and stromal function. Cancer  2007;110 :2222–2229.17932880
Ono Y , NagaiM, YoshinoO, KogaK, NawazA, HattaH, NishizonoH, IzumiG, NakashimaA, ImuraJ  et al  CD11c+ M1-like macrophages (MPhis) but not CD206+ M2-like MPhi are involved in folliculogenesis in mice ovary. Sci Rep  2018;8 :8171.29802255
Oubina G , PascualiN, ScottiL, BianchiS, MayM, MartinezJE, Marchese RagonaC, HigueraJ, AbramovichD, ParborellF.  Local application of low level laser therapy in mice ameliorates ovarian damage induced by cyclophosphamide. Mol Cell Endocrinol  2021;531 :111318.33989716
Ouni E , BouzinC, DolmansMM, MarbaixE, Pyr Dit RuysS, VertommenD, AmorimCA.  Spatiotemporal changes in mechanical matrisome components of the human ovary from prepuberty to menopause. Hum Reprod  2020;35 :1391–1410.32539154
Ouni E , PeaucelleA, HaasKT, Van KerkO, DolmansMM, TuuriT, OtalaM, AmorimCA.  A blueprint of the topology and mechanics of the human ovary for next-generation bioengineering and diagnosis. Nat Commun  2021;12 :5603.34556652
Ouni E , VertommenD, ChitiMC, DolmansMM, AmorimCA.  A draft map of the human ovarian proteome for tissue engineering and clinical applications. Mol Cell Proteomics  2019;18 :S159–S173.29475978
Pampanini V , WagnerM, Asadi-AzarbaijaniB, OskamIC, SheikhiM, SjodinMOD, LindbergJ, HovattaO, SahlinL, BjorvangRD  et al  Impact of first-line cancer treatment on the follicle quality in cryopreserved ovarian samples from girls and young women. Hum Reprod  2019;34 :1674–1685.31411325
Pan Y , ZhangL, ZhangX, HuC, LiuR.  Biological and biomechanical analysis of two types of mesenchymal stem cells for intervention in chemotherapy-induced ovarian dysfunction. Arch Gynecol Obstet  2017;295 :247–252.27928675
Pan Z , ChengDD, WeiXJ, LiSJ, GuoH, YangQC.  Chitooligosaccharides inhibit tumor progression and induce autophagy through the activation of the p53/mTOR pathway in osteosarcoma. Carbohydr Polym  2021;258 :117596.33593530
Papachroni KK , PiperiC, LevidouG, KorkolopoulouP, PawelczykL, Diamanti-KandarakisE, PapavassiliouAG.  Lysyl oxidase interacts with AGE signalling to modulate collagen synthesis in polycystic ovarian tissue. J Cell Mol Med  2010;14 :2460–2469.19583806
Park ES , WoodsDC, TillyJL.  Bone morphogenetic protein 4 promotes mammalian oogonial stem cell differentiation via Smad1/5/8 signaling. Fertil Steril  2013;100 :1468–1475.23993924
Park H , SeokJ, YouJH, KimJY, LimJY, KimGJ.  Increased phosphatase regenerating liver-1 trigger vascular remodeling in injured ovary via platelet-derived growth factor signaling pathway. Stem Cell Res Ther  2022;13 :95.35255961
Pascuali N , ScottiL, Di PietroM, OubinaG, BasD, MayM, Gomez MunozA, CuasnicuPS, CohenDJ, TesoneM  et al  Ceramide-1-phosphate has protective properties against cyclophosphamide-induced ovarian damage in a mice model of premature ovarian failure. Hum Reprod  2018;33 :844–859.29534229
Patil K , HindujaI, MukherjeeS.  Alteration in angiogenic potential of granulosa-lutein cells and follicular fluid contributes to luteal defects in polycystic ovary syndrome. Hum Reprod  2021;36 :1052–1064.33377483
Pena S , RubioM, VargasC, AlanisC, ParedesAH.  Participation of leukaemia inhibitory factor in follicular development and steroidogenesis in rat ovaries. J Endocrinol  2023;258 :e220255.37078922
Peng Y , SunL, GuoW, LiuZ, WangT, ZouT, ZhouJ, YangX, FanX.  Berberine protects cyclophosphamide and busulfan-induced premature ovarian insufficiency in mouse model. J Pharmacol Sci  2023;153 :46–54.37524454
Qin L , XuW, LiX, MengW, HuL, LuoZ, WangY, LuoS, LiS.  Differential expression profile of immunological cytokines in local ovary in patients with polycystic ovarian syndrome: analysis by flow cytometry. Eur J Obstet Gynecol Reprod Biol  2016;197 :136–141.26751822
Qiu M , LiuJ, HanC, WuB, YangZ, SuF, QuanF, ZhangY.  The influence of ovarian stromal/theca cells during in vitro culture on steroidogenesis, proliferation and apoptosis of granulosa cells derived from the goat ovary. Reprod Domest Anim  2014;49 :170–176.24256504
Qiu Y , SeagerM, OsmanA, Castle-MillerJ, BevanH, TortoneseDJ, MurphyD, HarperSJ, FraserHM, DonaldsonLF  et al  Ovarian VEGF(165)b expression regulates follicular development, corpus luteum function and fertility. Reproduction  2012;143 :501–511.22232745
Qu J , LiX, WangJ, MiW, XieK, QiuJ.  Inhalation of hydrogen gas attenuates cisplatin-induced ototoxicity via reducing oxidative stress. Int J Pediatr Otorhinolaryngol  2012;76 :111–115.22055279
Qu Q , LiuL, CuiY, LiuH, YiJ, BingW, LiuC, JiangD, BiY.  miR-126-3p containing exosomes derived from human umbilical cord mesenchymal stem cells promote angiogenesis and attenuate ovarian granulosa cell apoptosis in a preclinical rat model of premature ovarian failure. Stem Cell Res Ther  2022;13 :352.35883161
Ramadan AA , SelimSA, HassanHM, WahbaMA.  Immune regulation of ovarian function in buffaloes (Bubalus bubalus). Theriogenology  2001;55 :661–669.11233791
Reeves G.  Specific stroma in the cortex and medulla of the ovary. Cell types and vascular supply in relation to follicular apparatus and ovulation. Obstet Gynecol  1971;37 :832–844.4143757
Reiter RJ , Rosales-CorralSA, ManchesterLC, TanDX.  Peripheral reproductive organ health and melatonin: ready for prime time. Int J Mol Sci  2013;14 :7231–7272.23549263
Reiter RJ , TanDX, TamuraH, CruzMH, Fuentes-BrotoL.  Clinical relevance of melatonin in ovarian and placental physiology: a review. Gynecol Endocrinol  2014;30 :83–89.24319996
Roh EY , YoonJH, SongEY, KimJJ, HwangKR, SeoSH, ShinS.  Single nucleotide polymorphisms in the TGF-beta1 gene are associated with polycystic ovary syndrome susceptibility and characteristics: a study in Korean women. J Assist Reprod Genet  2017;34 :139–147.27796807
Rosales-Torres AM , AlonsoI, VergaraM, RomanoMC, Castillo-JuarezH, AvalosA, RosadoA, GutierrezCG.  Vascular endothelial growth factor isoforms 120, 164 and 205 are reduced with atresia in ovarian follicles of sheep. Anim Reprod Sci  2010;122 :111–117.20800394
Ross A , MungerS, CapelB.  Bmp7 regulates germ cell proliferation in mouse fetal gonads. Sex Dev  2007;1 :127–137.18391523
Roti Roti EC , LeismanSK, AbbottDH, SalihSM.  Acute doxorubicin insult in the mouse ovary is cell- and follicle-type dependent. PLoS One  2012;7 :e42293.22876313
Rudnicka E , SuchtaK, GrymowiczM, Calik-KsepkaA, SmolarczykK, DuszewskaAM, SmolarczykR, MeczekalskiB.  Chronic low grade inflammation in pathogenesis of PCOS. Int J Mol Sci  2021;22 :3789.33917519
Rutkowski JM , IhmJE, LeeST, KilarskiWW, GreenwoodVI, PasquierMC, QuazzolaA, TronoD, HubbellJA, SwartzMA.  VEGFR-3 neutralization inhibits ovarian lymphangiogenesis, follicle maturation, and murine pregnancy. Am J Pathol  2013;183 :1596–1607.24036251
Saccon TD , RovaniMT, GarciaDN, PradieeJ, MondadoriRG, CruzLAX, BarrosCC, FangY, McFaddenS, MasonJB  et al  Growth hormone increases DNA damage in ovarian follicles and macrophage infiltration in the ovaries. Geroscience  2022;44 :1071–1081.33954912
Said RS , MantawyEM, El-DemerdashE.  Mechanistic perspective of protective effects of resveratrol against cisplatin-induced ovarian injury in rats: emphasis on anti-inflammatory and anti-apoptotic effects. Naunyn Schmiedebergs Arch Pharmacol  2019;392 :1225–1238.31129703
Saitou M , BartonSC, SuraniMA.  A molecular programme for the specification of germ cell fate in mice. Nature  2002;418 :293–300.12124616
Saleh DO , MansourDF.  Ovario-protective effects of genistein against cyclophosphamide toxicity in rats: role of anti-mullerian hormone and oestradiol. Eur J Pharmacol  2016;789 :163–171.27448503
Salmassi A , LuS, HedderichJ, OettinghausC, JonatW, MettlerL.  Interaction of interleukin-6 on human granulosa cell steroid secretion. J Endocrinol  2001;170 :471–478.11479143
Salvatore G , De FeliciM, DolciS, TudiscoC, CicconiR, CampagnoloL, CamaioniA, KlingerFG.  Human adipose-derived stromal cells transplantation prolongs reproductive lifespan on mouse models of mild and severe premature ovarian insufficiency. Stem Cell Res Ther  2021;12 :537.34629095
Samir M , GlisterC, MattarD, LairdM, KnightPG.  Follicular expression of pro-inflammatory cytokines tumour necrosis factor-alpha (TNFalpha), interleukin 6 (IL6) and their receptors in cattle: TNFalpha, IL6 and macrophages suppress thecal androgen production in vitro. Reproduction  2017;154 :35–49.28432091
Sayasith K , SiroisJ.  Expression and regulation of stromal cell-derived factor-1 (SDF1) and chemokine CXC motif receptor 4 (CXCR4) in equine and bovine preovulatory follicles. Mol Cell Endocrinol  2014;391 :10–21.24784705
Secchi C , BelliM, HarrisonTNH, SwiftJ, KoC, DulebaAJ, StupackD, ChangRJ, ShimasakiS.  Effect of the spatial-temporal specific theca cell Cyp17 overexpression on the reproductive phenotype of the novel TC17 mouse. J Transl Med  2021;19 :428.34654452
Seow K-M, , ChangY-W, , ChenK-H, , JuanC-C, , HuangC-Y, , LinL-T, , TsuiK-H, , ChenY-J, , LeeW-L, , WangP-H.  Molecular Mechanisms of Laparoscopic Ovarian Drilling and Its Therapeutic Effects in Polycystic Ovary Syndrome. Int J Mol Sci  2020;21 :8147. Doi: 10.3390/ijms2121814733142702.33142702
Shai D , Aviel-RonenS, SpectorI, RaananiH, ShapiraM, GatI, RonessH, MeirowD.  Ovaries of patients recently treated with alkylating agent chemotherapy indicate the presence of acute follicle activation, elucidating its role among other proposed mechanisms of follicle loss. Fertil Steril  2021;115 :1239–1249.33485607
Sharma D , BhartiyaD.  Aged mice ovaries harbor stem cells and germ cell nests but fail to form follicles. J Ovarian Res  2022;15 :37.35321734
Shen H , WangY.  Activation of TGF-beta1/Smad3 signaling pathway inhibits the development of ovarian follicle in polycystic ovary syndrome by promoting apoptosis of granulosa cells. J Cell Physiol  2019;234 :11976–11985.30536903
Shimizu T , KayamoriT, MurayamaC, MiyamotoA.  Bone morphogenetic protein (BMP)-4 and BMP-7 suppress granulosa cell apoptosis via different pathways: BMP-4 via PI3K/PDK-1/Akt and BMP-7 via PI3K/PDK-1/PKC. Biochem Biophys Res Commun  2012;417 :869–873.22209843
Siegel RL , GiaquintoAN, JemalA.  Cancer statistics, 2024. CA Cancer J Clin  2024;74 :12–49.38230766
Silva JRV , LimaFEO, SouzaALP, SilvaAWB.  Interleukin-1beta and TNF-alpha systems in ovarian follicles and their roles during follicular development, oocyte maturation and ovulation. Zygote  2020;28 :270–277.32383419
Silvestris E , CafforioP, D’OronzoS, FeliciC, SilvestrisF, LoverroG.  In vitro differentiation of human oocyte-like cells from oogonial stem cells: single-cell isolation and molecular characterization. Hum Reprod  2018;33 :464–473.29304224
Sirotkin AV.  Cytokines: signalling molecules controlling ovarian functions. Int J Biochem Cell Biol  2011;43 :857–861.21382504
Skaznik-Wikiel ME , McGuireMM, SukhwaniM, DonohueJ, ChuT, KrivakTC, RajkovicA, OrwigKE.  Granulocyte colony-stimulating factor with or without stem cell factor extends time to premature ovarian insufficiency in female mice treated with alkylating chemotherapy. Fertil Steril  2013;99 :2045–2054.e3.23453120
Skliutė G , Vaigauskaitė-MažeikienėB, KaupinisA, ValiusM, KazėnaitėE, NavakauskienėR.  The effects of the follicle-stimulating hormone on human follicular fluid-derived stromal cells. Int J Mol Sci  2023;24 :2450.36768772
Soares M , SahrariK, ChitiMC, AmorimCA, AmbroiseJ, DonnezJ, DolmansMM.  The best source of isolated stromal cells for the artificial ovary: medulla or cortex, cryopreserved or fresh?  Hum Reprod  2015;30 :1589–1598.25994668
Sohal RS , OrrWC.  The redox stress hypothesis of aging. Free Radic Biol Med  2012;52 :539–555.22080087
Soleimani R , HeytensE, DarzynkiewiczZ, OktayK.  Mechanisms of chemotherapy-induced human ovarian aging: double strand DNA breaks and microvascular compromise. Aging (Albany NY)  2011;3 :782–793.21869459
Soyman Z , UzunH, BayindirN, EsrefogluM, BoranB.  Can ebselen prevent cisplatin-induced ovarian damage?  Arch Gynecol Obstet  2018;297 :1549–1555.29600321
Spears N , LopesF, StefansdottirA, RossiV, De FeliciM, AndersonRA, KlingerFG.  Ovarian damage from chemotherapy and current approaches to its protection. Hum Reprod Update  2019;25 :673–693.31600388
Sriraman K , BhartiyaD, AnandS, BhutdaS.  Mouse ovarian very small embryonic-like stem cells resist chemotherapy and retain ability to initiate oocyte-specific differentiation. Reprod Sci  2015;22 :884–903.25779995
Stimpfel M , SkutellaT, CvjeticaninB, MeznaricM, DovcP, NovakovicS, CerkovnikP, Vrtacnik-BokalE, Virant-KlunI.  Isolation, characterization and differentiation of cells expressing pluripotent/multipotent markers from adult human ovaries. Cell Tissue Res  2013;354 :593–607.23820736
Stojanovic Gavrilovic AZ , CekovicJM, ParandilovicAZ, NikolovAB, SazdanovicPS, VelickovicAM, AndjelkovicMV, SorakMP.  IL-6 of follicular fluid and outcome of in vitro fertilization. Medicine (Baltimore)  2022;101 :e29624.35866786
Stouffer RL , Martinez-ChequerJC, MolsknessTA, XuF, HazzardTM.  Regulation and action of angiogenic factors in the primate ovary. Arch Med Res  2001;32 :567–575.11750732
Sugino N , SuzukiT, SakataA, MiwaI, AsadaH, TaketaniT, YamagataY, TamuraH.  Angiogenesis in the human corpus luteum: changes in expression of angiopoietins in the corpus luteum throughout the menstrual cycle and in early pregnancy. J Clin Endocrinol Metab  2005;90 :6141–6148.16118339
Suzuki N , YoshiokaN, TakaeS, SugishitaY, TamuraM, HashimotoS, MorimotoY, KawamuraK.  Successful fertility preservation following ovarian tissue vitrification in patients with primary ovarian insufficiency. Hum Reprod  2015;30 :608–615.25567618
Svingen T , FrancoisM, WilhelmD, KoopmanP.  Three-dimensional imaging of Prox1-EGFP transgenic mouse gonads reveals divergent modes of lymphangiogenesis in the testis and ovary. PLoS One  2012;7 :e52620.23285114
Takahashi K , OzakiT, OkadaM, UchidaA, KitaoM.  Relationship between ultrasonography and histopathological changes in polycystic ovarian syndrome. Hum Reprod  1994;9 :2255–2258.7714140
Talebi A , HayatP, GhanbariA, ArdekanianM, ZarbakhshS.  Sesamol protects the function and structure of rat ovaries against side effects of cyclophosphamide by decreasing oxidative stress and apoptosis. J Obstet Gynaecol Res  2022;48 :1786–1794.35613704
Tamura K , KawaguchiT, HaraT, TakatoshiS, ToheiA, MiyajimaA, SeishiT, KogoH.  Interleukin-6 decreases estrogen production and messenger ribonucleic acid expression encoding aromatase during in vitro cytodifferentiation of rat granulosa cell. Mol Cell Endocrinol  2000;170 :103–111.11162894
Tanaka Y , HsuehAJ, KawamuraK.  Surgical approaches of drug-free in vitro activation and laparoscopic ovarian incision to treat patients with ovarian infertility. Fertil Steril  2020;114 :1355–1357.32907748
Tang M , ZhaoM, ShiY.  New insight into the role of macrophages in ovarian function and ovarian aging. Front Endocrinol (Lausanne)  2023;14 :1282658.38027176
Tanwar PS , O’SheaT, McFarlaneJR.  In vivo evidence of role of bone morphogenetic protein-4 in the mouse ovary. Anim Reprod Sci  2008;106 :232–240.17644284
Thornton K , MerhiZ, JindalS, GoldsammlerM, CharronMJ, BuyukE.  Dietary advanced glycation end products (AGEs) could alter ovarian function in mice. Mol Cell Endocrinol  2020;510 :110826.32339649
Tian W , SongX, WangF, JiangW.  Study on the preparation and biological activities of low molecular weight squid ink polysaccharide from Sepiella maindroni. Int J Biol Macromol  2023;237 :124040.36933594
Tian X , LiangT, LiuY, DingG, ZhangF, MaZ.  Extraction, structural characterization, and biological functions of Lycium barbarum polysaccharides: a review. Biomolecules  2019;9 :389.31438522
Timoteo-Ferreira F , AbreuD, MendesS, MatosL, RodriguesAR, AlmeidaH, SilvaE.  Redox imbalance in age-related ovarian dysfunction and perspectives for its prevention. Ageing Res Rev  2021;68 :101345.33894395
Tingen CM , KiesewetterSE, JozefikJ, ThomasC, TaglerD, SheaL, WoodruffTK.  A macrophage and theca cell-enriched stromal cell population influences growth and survival of immature murine follicles in vitro. Reproduction  2011;141 :809–820.21389078
Tomita T.  Immunohistochemical staining for lymphatic and blood vessels in normal tissues: comparison between routinely paraffin-embedded tissues and frozen sections. Acta Med Acad  2021;50 :13–28.34075761
Turkler C , OnatT, YildirimE, KaplanS, YaziciGN, MammadovR, SunarM.  An experimental study on the use of lycopene to prevent infertility due to acute oxidative ovarian damage caused by a single high dose of methotrexate. Adv Clin Exp Med  2020;29 :5–11.31965764
Turner EC , HughesJ, WilsonH, ClayM, MylonasKJ, KipariT, DuncanWC, FraserHM.  Conditional ablation of macrophages disrupts ovarian vasculature. Reproduction  2011;141 :821–831.21393340
Uri-Belapolsky S , ShaishA, EliyahuE, GrossmanH, LeviM, ChuderlandD, Ninio-ManyL, HaskyN, ShasharD, AlmogT  et al  Interleukin-1 deficiency prolongs ovarian lifespan in mice. Proc Natl Acad Sci USA  2014;111 :12492–12497.25114230
Vagnini LD , RenziA, PetersenB, CanasM, PetersenCG, MauriAL, MattilaMC, RicciJ, DieamantF, OliveiraJBA  et al  Association between estrogen receptor 1 (ESR1) and leukemia inhibitory factor (LIF) polymorphisms can help in the prediction of recurrent implantation failure. Fertil Steril  2019;111 :527–534.30611552
Van der Hoek KH , MaddocksS, WoodhouseCM, van RooijenN, RobertsonSA, NormanRJ.  Intrabursal injection of clodronate liposomes causes macrophage depletion and inhibits ovulation in the mouse ovary. Biol Reprod  2000;62 :1059–1066.10727278
van Dorp W , HauptR, AndersonRA, MulderRL, van den Heuvel-EibrinkMM, van Dulmen-den BroederE, SuHI, WintherJF, HudsonMM, LevineJM  et al  Reproductive function and outcomes in female survivors of childhood, adolescent, and young adult cancer: a review. J Clin Oncol  2018;36 :2169–2180.29874135
Wagner M , YoshiharaM, DouagiI, DamdimopoulosA, PanulaS, PetropoulosS, LuH, PetterssonK, PalmK, KatayamaS  et al  Single-cell analysis of human ovarian cortex identifies distinct cell populations but no oogonial stem cells. Nat Commun  2020;11 :1147.32123174
Walusimbi SS , PateJL.  Physiology and Endocrinology Symposium: role of immune cells in the corpus luteum. J Anim Sci  2013;91 :1650–1659.23422006
Wan S , ChenQ, XiangY, SangY, TangM, SongY, FengG, YeB, BaiL, ZhuY.  Interleukin-1 increases cyclooxygenase-2 expression and prostaglandin E2 production in human granulosa-lutein cell via nuclear factor kappa B/P65 and extracellular signal-regulated kinase 1/2 signaling pathways. Mol Cell Endocrinol  2023;566-567 :111891.36801432
Wang B , SuoP, ChenB, WeiZ, YangL, ZhouS, WangJ, CaoY, MaX.  Haplotype analysis of chemokine CXCL12 polymorphisms and susceptibility to premature ovarian failure in Chinese women. Hum Reprod  2011;26 :950–954.21296802
Wang CY , LiuQ, HuangQX, LiuJT, HeYH, LuJJ, BaiXY.  Activation of PPARgamma is required for hydroxysafflor yellow A of Carthamus tinctorius to attenuate hepatic fibrosis induced by oxidative stress. Phytomedicine  2013;20 :592–599.23523101
Wang J , ZhaoX, LuoR, XiaD, LiuY, ShenT, LiangY.  The causal association between systemic inflammatory regulators and primary ovarian insufficiency: a bidirectional mendelian randomization study. J Ovarian Res  2023;16 :191.37710281
Wang L , YingYF, OuyangYL, WangJF, XuJ.  VEGF and bFGF increase survival of xenografted human ovarian tissue in an experimental rabbit model. J Assist Reprod Genet  2013;30 :1301–1311.24062194
Wang N , LiH, ZhuY, LiN, ChenZJ, ZhangC.  Melatonin protects against epirubicin-induced ovarian damage. J Reprod Dev  2020;66 :19–27.31735743
Wang S , LiX, LiJ, WangA, LiF, HuH, LongT, PeiX, LiH, ZhongF  et al  Inhibition of cisplatin-induced Acsl4-mediated ferroptosis alleviated ovarian injury. Chem Biol Interact  2024;387 :110825.38056807
Wang X , ChowR, DengL, AndersonD, WeidnerN, GodwinAK, BewtraC, ZlotnikA, BuiJ, VarkiA  et al  Expression of Siglec-11 by human and chimpanzee ovarian stromal cells, with uniquely human ligands: implications for human ovarian physiology and pathology. Glycobiology  2011;21 :1038–1048.21467073
Wang Z , WangY, YangT, LiJ, YangX.  Study of the reparative effects of menstrual-derived stem cells on premature ovarian failure in mice. Stem Cell Res Ther  2017;8 :11.28114977
Wei J , LiangY, JiangN, HuG.  IFN-gamma differential expression in the hypothalamus-pituitary-ovary axis of thyroidectomized rats. BMC Endocr Disord  2022;22 :317.36514041
White YA , WoodsDC, TakaiY, IshiharaO, SekiH, TillyJL.  Oocyte formation by mitotically active germ cells purified from ovaries of reproductive-age women. Nat Med  2012;18 :413–421.22366948
Winger EE , ReedJL, AshoushS, AhujaS, El-ToukhyT, TaranissiM.  Treatment with adalimumab (Humira) and intravenous immunoglobulin improves pregnancy rates in women undergoing IVF. Am J Reprod Immunol  2009;61 :113–120.19055656
Wood CD , VijayvergiaM, MillerFH, CarrollT, FasanatiC, SheaLD, BrinsonLC, WoodruffTK.  Multi-modal magnetic resonance elastography for noninvasive assessment of ovarian tissue rigidity in vivo. Acta Biomater  2015;13 :295–300.25463483
Woods DC , TillyJL.  Isolation, characterization and propagation of mitotically active germ cells from adult mouse and human ovaries. Nat Protoc  2013;8 :966–988.23598447
Wu H , ZhuR, ZhengB, LiaoG, WangF, DingJ, LiH, LiM.  Single-cell sequencing reveals an intrinsic heterogeneity of the preovulatory follicular microenvironment. Biomolecules  2022;12 :231.35204732
Wu M , LuZ, ZhuQ, MaL, XueL, LiY, ZhouS, YanW, YeW, ZhangJ  et al  DDX04+ stem cells in the ovaries of postmenopausal women: existence and differentiation potential. Stem Cells  2022;40 :88–101.35511860
Wu M , MaL, XueL, YeW, LuZ, LiX, JinY, QinX, ChenD, TangW  et al  Resveratrol alleviates chemotherapy-induced oogonial stem cell apoptosis and ovarian aging in mice. Aging (Albany NY)  2019;11 :1030–1044.30779707
Wu M , TangW, ChenY, XueL, DaiJ, LiY, ZhuX, WuC, XiongJ, ZhangJ  et al  Spatiotemporal transcriptomic changes of human ovarian aging and the regulatory role of FOXP1. Nat Aging  2024;4 :527–545.38594460
Wu WB , ChenHT, LinJJ, LaiTH.  VEGF concentration in a preovulatory leading follicle relates to ovarian reserve and oocyte maturation during ovarian stimulation with GnRH antagonist protocol in in vitro fertilization cycle. J Clin Med  2021;10 :5032.34768551
Wyse BA , Fuchs WeizmanN, DeferM, MontbriandJ, SzarazP, LibrachC.  The follicular fluid adipocytokine milieu could serve as a prediction tool for fertility treatment outcomes. Reprod Biomed Online  2021;43 :738–746.34474976
Xia IF , CheungJS, WuM, WongKS, KongHK, ZhengXT, WongKH, KwokKW.  Dietary chitosan-selenium nanoparticle (CTS-SeNP) enhance immunity and disease resistance in zebrafish. Fish Shellfish Immunol  2019;87 :449–459.30703551
Xiao Y , PengX, PengY, ZhangC, LiuW, YangW, DouX, JiangY, WangY, YangS  et al  Macrophage-derived extracellular vesicles regulate follicular activation and improve ovarian function in old mice by modulating local environment. Clin Transl Med  2022;12 :e1071.36229897
Xie K , YuY, PeiY, HouL, ChenS, XiongL, WangG.  Protective effects of hydrogen gas on murine polymicrobial sepsis via reducing oxidative stress and HMGB1 release. Shock  2010;34 :90–97.19997046
Xie SY , WangD, ZhuH, ZhangW, GengNQ, FengX, SunCX, LiM.  Cloning and spatio-temporal expression of bone morphogenetic proteins-2,-4 gene during ovarian development in New Zealand white rabbit. Reprod Domest Anim  2014;49 :1000–1003.25256420
Xiong Y , LiuT, WangS, ChiH, ChenC, ZhengJ.  Cyclophosphamide promotes the proliferation inhibition of mouse ovarian granulosa cells and premature ovarian failure by activating the lncRNA-Meg3-p53-p66Shc pathway. Gene  2017;596 :1–8.27729272
Xiong YL , LiangXY, YangX, LiY, WeiLN.  Low-grade chronic inflammation in the peripheral blood and ovaries of women with polycystic ovarian syndrome. Eur J Obstet Gynecol Reprod Biol  2011;159 :148–150.21908093
Xu DP , LiY, MengX, ZhouT, ZhouY, ZhengJ, ZhangJJ, LiHB.  Natural antioxidants in foods and medicinal plants: extraction, assessment and resources. Int J Mol Sci  2017;18 :96.28067795
Xu H , Schultze-MosgauA, AgicA, DiedrichK, TaylorRN, HornungD.  Regulated upon activation, normal T cell expressed and secreted (RANTES) and monocyte chemotactic protein 1 in follicular fluid accumulate differentially in patients with and without endometriosis undergoing in vitro fertilization. Fertil Steril  2006;86 :1616–1620.16997300
Xu Z , TakahashiN, HaradaM, KunitomiC, KusamotoA, KoikeH, TanakaT, SakaguchiN, UrataY, Wada-HiraikeO  et al  The role of cellular senescence in cyclophosphamide-induced primary ovarian insufficiency. Int J Mol Sci  2023;24 :17193.38139022
Yamchi NN , RahbarghaziR, BedateAM, MahdipourM, NouriM, KhanbabaeeR.  Menstrual blood CD146(+) mesenchymal stem cells reduced fibrosis rate in the rat model of premature ovarian failure. Cell Biochem Funct  2021;39 :998–1008.34477225
Yang DM , ZhangJQ, FeiYF.  Lycium barbarum polysaccharide attenuates chemotherapy-induced ovarian injury by reducing oxidative stress. J Obstet Gynaecol Res  2017;43 :1621–1628.28817219
Yang J , YangX, YangH, BaiY, ZhaH, JiangF, MengY.  Interleukin 6 in follicular fluid reduces embryo fragmentation and improves the clinical pregnancy rate. J Assist Reprod Genet  2020;37 :1171–1176.32189182
Yang J , ZhongT, XiaoG, ChenY, LiuJ, XiaC, DuH, KangX, LinY, GuanR  et al  Polymorphisms and haplotypes of the TGF-beta1 gene are associated with risk of polycystic ovary syndrome in Chinese Han women. Eur J Obstet Gynecol Reprod Biol  2015;186 :1–7.25594618
Yang Z , DuX, WangC, ZhangJ, LiuC, LiY, JiangH.  Therapeutic effects of human umbilical cord mesenchymal stem cell-derived microvesicles on premature ovarian insufficiency in mice. Stem Cell Res Ther  2019;10 :250.31412919
Yao J , MaY, LinX, ZhouS, MiY, ZhangC.  The attenuating effect of the intraovarian bone morphogenetic protein 4 on age-related endoplasmic reticulum stress in chicken follicular cells. Oxid Med Cell Longev  2020;2020 :4175613.32587659
Yao X , GuoY, WangQ, XuM, ZhangQ, LiT, LaiD.  The paracrine effect of transplanted human amniotic epithelial cells on ovarian function improvement in a mouse model of chemotherapy-induced primary ovarian insufficiency. Stem Cells Int  2016;2016 :4148923.26664408
Yoon SY , YoonJA, ParkM, ShinEY, JungS, LeeJE, EumJH, SongH, LeeDR, LeeWS  et al  Recovery of ovarian function by human embryonic stem cell-derived mesenchymal stem cells in cisplatin-induced premature ovarian failure in mice. Stem Cell Res Ther  2020;11 :255.32586410
Young JM , McNeillyAS.  Theca: the forgotten cell of the ovarian follicle. Reproduction  2010;140 :489–504.20628033
Yousefzadeh MJ , ZhuY, McGowanSJ, AngeliniL, Fuhrmann-StroissniggH, XuM, LingYY, MelosKI, PirtskhalavaT, InmanCL  et al  Fisetin is a senotherapeutic that extends health and lifespan. EBioMedicine  2018;36 :18–28.30279143
Zamora-Gutierrez D , GuzmanA, Hernandez-CoronadoCG, Castillo-JuarezH, FierroF, GutierrezCG, BojalilR, Rosales-TorresAM.  Co-ordinated expression of the VEGF system components in granulosa cells to develop a proangiogenic autocrine milieu during ovarian follicle development. Mol Reprod Dev  2019;86 :156–165.30431677
Zhai J , YaoG, DongF, BuZ, ChengY, SatoY, HuL, ZhangY, WangJ, DaiS  et al  In vitro activation of follicles and fresh tissue auto-transplantation in primary ovarian insufficiency patients. J Clin Endocrinol Metab  2016;101 :4405–4412.27571179
Zhai X , YuanS, YangX, ZouP, LiL, LiG, ShaoY, Abd El-AtyAM, HacımüftüoğluA, WangJ.  Chitosan oligosaccharides induce apoptosis in human renal carcinoma via reactive-oxygen-species-dependent endoplasmic reticulum stress. J Agric Food Chem  2019;67 :1691–1701.30658530
Zhang H , DaviesKJA, FormanHJ.  Oxidative stress response and Nrf2 signaling in aging. Free Radic Biol Med  2015;88 :314–336.26066302
Zhang H , TianS, KlausenC, ZhuH, LiuR, LeungPC.  Differential activation of noncanonical SMAD2/SMAD3 signaling by bone morphogenetic proteins causes disproportionate induction of hyaluronan production in immortalized human granulosa cells. Mol Cell Endocrinol  2016;428 :17–27.26992562
Zhang Q , BuS, SunJ, XuM, YaoX, HeK, LaiD.  Paracrine effects of human amniotic epithelial cells protect against chemotherapy-induced ovarian damage. Stem Cell Res Ther  2017;8 :270.29179771
Zhang RN , PangB, XuSR, WanPC, GuoSC, JiHZ, JiaGX, HuLY, ZhaoXQ, YangQE.  The CXCL12-CXCR4 signaling promotes oocyte maturation by regulating cumulus expansion in sheep. Theriogenology  2018;107 :85–94.29132039
Zhang S , LiuQ, ChangM, PanY, YahayaBH, LiuY, LinJ.  Chemotherapy impairs ovarian function through excessive ROS-induced ferroptosis. Cell Death Dis  2023;14 :340.37225709
Zhang S , ZhouHF, LiuYN, LiuB, YuanYZ, ShanJJ, JiJJ.  Modified Dihuang decoction improves ovarian reserve in mice by regulating Bcl-2-related mitochondrial apoptosis pathway. Zhongguo Zhong Yao Za Zhi  2021;46 :6493–6501.34994142
Zhang T , TianF, HuoR, TangA, ZengY, DuanYG.  Detection of dendritic cells and related cytokines in follicular fluid of patients with polycystic ovary syndrome. Am J Reprod Immunol  2017;78 :e12717.
Zhang Y , CheL, ZhangM, HeJ.  Common cytokine polymorphisms and predisposition to polycystic ovary syndrome: a meta-analysis. Endocr J  2020;67 :561–567.32295989
Zhao N , ZhangC, DingJ, WuH, ChengW, LiM, ZhuR, LiH.  Altered T lymphocyte subtypes and cytokine profiles in follicular fluid associated with diminished ovary reserve. Am J Reprod Immunol  2022;87 :e13522.35006631
Zhao YT , YinH, HuC, ZengJ, ShiX, ChenS, ZhangK, ZhengW, WuW, LiuS.  Tilapia skin peptides restore cyclophosphamide-induced premature ovarian failure via inhibiting oxidative stress and apoptosis in mice. Food Funct  2022;13 :1668–1679.35083997
Zheng K , HongW, YeH, ZhouZ, LingS, LiY, DaiY, ZhongZ, YangZ, ZhengY.  Chito-oligosaccharides and macrophages have synergistic effects on improving ovarian stem cells function by regulating inflammatory factors. J Ovarian Res  2023;16 :76.37060101
Zheng S , MaM, ChenY, LiM.  Effects of quercetin on ovarian function and regulation of the ovarian PI3K/Akt/FoxO3a signalling pathway and oxidative stress in a rat model of cyclophosphamide-induced premature ovarian failure. Basic Clin Pharmacol Toxicol  2022;130 :240–253.34841658
Zhou C , GuoQ, LinJ, WangM, ZengZ, LiY, LiX, XiangY, LiangQ, LiuJ  et al  Single-cell atlas of human ovaries reveals the role of the pyroptotic macrophage in ovarian aging. Adv Sci (Weinh)  2024;11 :e2305175.38036420
Zhou F , ShiLB, ZhangSY.  Ovarian fibrosis: a phenomenon of concern. Chin Med J (Engl)  2017;130 :365–371.28139522
Zhou F , SongY, LiuX, ZhangC, LiF, HuR, HuangY, MaW, SongK, ZhangM.  Si-Wu-Tang facilitates ovarian function through improving ovarian microenvironment and angiogenesis in a mouse model of premature ovarian failure. J Ethnopharmacol  2021;280 :114431.34293457
Zhou Y , ZhouJ, XuX, DuF, NieM, HuL, MaY, LiuM, YuS, ZhangJ  et al  Matrigel/umbilical cord-derived mesenchymal stem cells promote granulosa cell proliferation and ovarian vascularization in a mouse model of premature ovarian failure. Stem Cells Dev  2021;30 :782–796.34030464
Zhu SF , HuHB, XuHY, FuXF, PengDX, SuWY, HeYL.  Human umbilical cord mesenchymal stem cell transplantation restores damaged ovaries. J Cell Mol Med  2015;19 :2108–2117.25922900
Zong A , LiuY, ZhangY, SongX, ShiY, CaoH, LiuC, ChengY, JiangW, DuF  et al  Anti-tumor activity and the mechanism of SIP-S: a sulfated polysaccharide with anti-metastatic effect. Carbohydr Polym  2015;129 :50–54.26050887
Zong A , ZhaoT, ZhangY, SongX, ShiY, CaoH, LiuC, ChengY, QuX, CaoJ  et al  Anti-metastatic and anti-angiogenic activities of sulfated polysaccharide of Sepiella maindroni ink. Carbohydr Polym  2013;91 :403–409.23044150
Zou K , YuanZ, YangZ, LuoH, SunK, ZhouL, XiangJ, ShiL, YuQ, ZhangY  et al  Production of offspring from a germline stem cell line derived from neonatal ovaries. Nat Cell Biol  2009;11 :631–636.19363485
Zuo T , CaoL, SunX, LiX, WuJ, LuS, XueC, TangQ.  Dietary squid ink polysaccharide could enhance SIgA secretion in chemotherapeutic mice. Food Funct  2014;5 :3189–3196.25308407
