Comparative Single-Cell Analysis Reveals Tendon Progenitor Dysfunction by Age-Associated Oxidative Stress and Its Restoration by Antioxidant Treatments.

Impaired healing of adult tendons with fibrosis remains clinical challenges while neonatal tendons have full functional restoration. However, age-associated cellular and molecular changes in tendon cells and tendon stem/progenitor cells (TSPCs) remain unknown. Here, comparative single cell transcriptomics of early postnatal (2 weeks old) and adult (20 weeks old) mouse tendons revealed that adult tendons have reduced number of TSPCs, decreased gene expression in tendon and cartilage development, and a greater population of fibro-tenogenic cells.