
==== Front
bioRxiv
BIORXIV
bioRxiv
2692-8205
Cold Spring Harbor Laboratory

10.1101/2024.09.11.612543
preprint
1
Article
Tenascin C Deletion Impairs Tendon Healing and Functional Recovery After Rotator Cuff Repair
Tashjian Robert Z.
Zitnay Jared
Kazmers Nikolas H.
Veerabhadraiah Shivakumar R.
Zelada Antonio C.
Honeggar Matthew
Smith Matthew C.
Chalmers Peter N.
Henninger Heath B.
Jurynec Michael J.
15 9 2024
2024.09.11.612543https://creativecommons.org/licenses/by-nc-nd/4.0/ This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which allows reusers to copy and distribute the material in any medium or format in unadapted form only, for noncommercial purposes only, and only so long as attribution is given to the creator.
http://biorxiv.org/lookup/doi/10.1101/2024.09.11.612543
nihpp-2024.09.11.612543.pdf
Abstract

The biological factors that affect healing after rotator cuff repair (RCR) are not well understood. Genetic variants in the extracellular matrix protein Tenascin C ( TNC ) are associated with impaired tendon healing and it is expressed in rotator cuff tendon tissue after injury, suggesting it may have a role in the repair process. The purpose of the current study was to determine the role of TNC on tendon healing after RCR in a murine model. The supraspinatus tendon was transected and repaired on the left shoulder of Wild-Type (WT-RCR), Tenascin C null ( Tnc − - RCR) and Tnc heterozygous ( Tnc +/− -RCR) mice. Controls included the unoperated, contralateral shoulder of WT-RCR, Tnc — RCR, Tnc +/− -RCR mice and unoperated shoulders from age and genotype matched controls. We performed histologic, activity testing, RNA-seq, and biomechanical analyses. At 8-weeks post-RCR, Tnc − and Tnc +/− mice had severe bone and tendon defects following rotator cuff repair. Tnc − -RCR mice had reduced activity after rotator cuff repair including reduced wheel rotations, wheel duration, and wheel episode average velocity compared with WT-RCR. Loss of Tnc following RCR altered gene expression in the shoulder, including upregulation of sex hormone and WNT pathways and a downregulation of inflammation and cell cycle pathways. Tnc − mice had similar biomechanical properties after repair as WT. Further research is required to evaluate tissue specific alterations of Tnc , the interactions of Tnc and sex hormone and inflammation pathways as well as possible adjuvants to improve enthesis healing in the setting of reduced TNC function.
==== Body
pmc
