Theaflavin Promotes Myogenic Differentiation by Regulating the Cell Cycle and Surface Mechanical Properties of C2C12 Cells

Aging
and muscle diseases often lead to a decline in the differentiation
capacity of myoblasts, which in turn results in the deterioration
of skeletal muscle (SkM) function and impairment of regeneration ability
after injury. Theaflavins, the “gold molecules” found
in black tea, have been reported to possess various biological activities
and have a positive effect on maintaining human health. In this study,
we found that among the four theaflavins (theaflavin (TF1), theaflavin-3-gallate
(TF2A), theaflavin-3′-gallate (TF2B), and theaflavin-3,3′-digallate
(TF3) monomers), TF1 (20 μM) significantly promoted the fusion
index of myoblasts, number of mature myotubes, and degree of myotube
development. By combining transcriptomics, bioinformatics, and molecular
biology experiments, we showed that TF1 may promote myoblast differentiation
by (1) regulating the withdrawal of myoblasts from the cell cycle,
inducing the release of myogenic factors (MyoD, MyoG, and MyHC) and
accelerating myogenic differentiation and (2) regulating the adhesion
force of myoblasts and mechanical properties of mature myotubes and
promoting the migration, fusion, and development of myoblasts. In
conclusion, our study outcomes show that TF1 can promote myoblast
differentiation and regulate myotube mechanical properties. It is
a potential dietary supplement for the elderly. Our findings provide
a new scientific basis for the relationship between tea drinking and
aging.