Fig. 5: Depletion of CD26⁺ TSPCs leads to poor tendon healing.

a Scheme for establishment of tendon injury model and administration of diphtheria toxin (DTx). b Picrosirius red staining of Achilles tendons from sham, Veh. and DTx group. n = 3 biological replicates. Scale bar: 100 μm. c TEM images of cross section of Achilles tendons from uninjured, Veh. and DTx group. The red asterisk indicates a hole in the matrix. n = 3 biological replicates. Scale bar: Top, 5 μm; Bottom, 500 nm. d Bar graph and dot plot presents the aggregated distribution of collagen fibril diameters using high-magnification TEM images from n  =  3 mice per group. One way ANOVA with Turkey’s test, F = 2128. e Histological analysis of tenogenic genes including Col1a1, Scx, and Fmod in injured tendon treated with diphtheria toxin or vehicle control. n = 6. Scale car: 100 μm. f Quantification of of Col1a1, Scx and Fmod. n = 6 biological replicates. Two-tailed unpaired Student’s t test, Top: t = 4.258, df=10; Middle: t = 7.105, df=10; Buttom: t = 4.946, df=10. g, h Heatmap and quantification of effective modulus of tendons from uninjured, injured with DTx treatment and injured with Veh. treatment. Sixty points were analysed for each tendon (n = 6 per group). One way ANOVA with Turkey’s test, F = 194.4. i–j Quantification of Maxium Force and Stress at failure of tendons from injured with DTx treatment and injured with Veh. treatment. n = 3 biological replicates. Two-tailed unpaired Student’s t test, i: t = 4.653, df=4; j: t = 4.418, df=4. AOD, average of density. Data shown are mean ± SEM. Source data are provided as a Source Data file.