Uncoupling Protein 3 Promotes the Myogenic Differentiation of Type IIb Myotubes in C2C12 Cells

Uncoupling protein 3 (Ucp3) is an important transporter within mitochondria and is mainly expressed in skeletal muscle, brown adipose tissue and the myocardium. However, the effects of Ucp3 on myogenic differentiation are still unclear. This study evaluated the effects of Ucp3 on myogenic differentiation, myofiber type and energy metabolism in C2C12 cells. Gain- and loss-of-function studies revealed that Ucp3 could increase the number of myotubes and promote the myogenic differentiation of C2C12 cells. Furthermore, Ucp3 promoted the expression of the type IIb myofiber marker gene myosin heavy chain 4 (Myh4) and decreased the expression of the type I myofiber marker gene myosin heavy chain 7 (Myh7). In addition, energy metabolism related to the expression of PPARG coactivator 1 alpha (Pgc1-α), ATP synthase, H⁺ transportation, mitochondrial F1 complex, alpha subunit 1 (Atp5a1), lactate dehydrogenase A (Ldha) and lactate dehydrogenase B (Ldhb) increased with Ucp3 overexpression. Ucp3 could promote the myogenic differentiation of type IIb myotubes and accelerate energy metabolism in C2C12 cells. This study can provide the theoretical basis for understanding the role of Ucp3 in energy metabolism.