Effects of taurine on skeletal muscle in senescence-accelerated mice and C2C12 myoblasts and myotubes

Taurine is a semi-essential amino acid with diverse cytoprotective effects and is associated with anti-aging. This study explores the role and molecular mechanism of taurine in muscle aging. Senescence(definition)-accelerated mouse prone 8 (SAMP8) and its resistant (senescence-accelerated mouse resistant 1, SAMR1) mice were given 1% taurine water from 5 to 10 months of age, while control mice were given distilled water (DW). At 10 months of age, a rotarod test was performed to assess muscle endurance. SAMP8 mice had a shorter running time on the rotarod test than SAMR1 mice. Taurine significantly extended running time compared with that of DW-drinking group in SAMP8 mice, a similar trend was observed in SAMR1 mice. The gastrocnemius muscle was used for the RNA-sequencing analysis. Among differentially expressed genes between taurine and DW, Tbx5 and Alb showed some significant differences between the treatment by RT-qPCR. Myoblast C2C12 cells underwent cellular senescence induction with D-galactose (D-gal), which was detected by SA-β-gal staining. Taurine reduced SA-β-gal-positive area induced by D-gal, suggesting its protective effect against cellular senescence. Myotube induction was inhibited by D-gal treatment and restored by taurine, as detected by immunocytochemistry of myosin heavy chain (MHC) and Western blot of myogenin. D-gal-induced decrease trend in protein level of TBX5 was significantly increased in C2C12 myotubes treated with taurine. Taurine may have a protective effect on muscle senescence and myotube regeneration.