Fig 2: Asymmetry of fiber type and Tent5a expression in AIS paravertebral muscles. (A) The differential expression of Tent5a was verified with qPCR in 10 pairs of paravertebral muscles from AIS patients. Paired sample t-test. *p < 0.05. (B–E) Representative Western blots showing asymmetric expression of Tent5a and MHC I in paravertebral muscles. Each bar represents mean ± SD. Paired sample t-test. *p < 0.05. (F and G) Representative immunofluorescence showing a significantly lower proportion of type I muscle fibers on the concave side. Paired sample t-test. ***p < 0.001. (H and I) Representative immunofluorescence showing a significantly higher proportion of type IIa muscle fibers on the concave side. Paired sample t-test. **p < 0.01. The scale bar represents 50 µm. (J) The relative mRNA expression of myofiber-related genes among the convex side, concave side, and control muscles. One-way ANOVA test. *p < 0.05

Fig 3: Schematic drawing of Tent5a modulates muscle fiber formation in adolescent idiopathic scoliosis. The poly(A) polymerase Tent5a promotes myogenic differentiation by maintaining the mRNA stability of myogenin, and it is involved in the pathogenesis of AIS by modulating muscle fiber formation

Fig 4: Tent5a knockdown inhibited the proliferation and migration of C2C12 cells. (A and B) qPCR and Western blots were conducted to verify Tent5a knockdown in C2C12 cells. Each bar represents mean ± SD. One-way ANOVA with multiple comparison test. ***p < 0.001. (C and D) Cell counting and Cell Counting Kit-8 assay showing lower proliferation viability in the Tent5a knockdown group. Each bar represents mean ± SD. One-way ANOVA with multiple comparison test. *p < 0.05, **p < 0.01. (E and F) Representative wound-healing assay showing lower migration viability in the Tent5a knockdown group. Each bar represents mean ± SD. One-way ANOVA with multiple comparison test. **p < 0.01. (G and H) Representative TUNEL assay showing a comparable percentage of apoptosis among groups. Each bar represents mean ± SD. One-way ANOVA with multiple comparison test. The scale bar represents 200 µm

Fig 5: Tent5a knockdown inhibited the maturation of type I muscle fibers in vivo. (A) Paradigm showing the operation process in vivo. (B and C) Representative immunofluorescence showing a lower percentage of MHC I/EGFP muscle fibers in the Tent5a knockdown group. Each bar represents mean ± SD. Paired t-test. *p < 0.05. (D) qPCR showing decreased mRNA expression of Myh7 and Tnnc1 in the Tent5a knockdown group. Each bar represents mean ± SD. Paired t-test. *p < 0.05. The scale bar represents 100 µm