[Over-expression of FoxO1 inhibits the differentiation of porcine skeletal muscle myoblast].

The Forkhead box O1 (FoxO1) transcription factor governs muscle growth, metabolism and cell differentiation. However, its role in myoblast differentiation is unclear. To study the biological function of FoxO1 during differentiation in porcine primary myoblast, we constructed stably FoxO1 over-expressed porcine myoblast mediated by liposome and adopted morphological observation, quantitative real-time RT-PCR and Western blotting methods to analyze FoxO1 and early and late myogenic regulation factors MyoD and myogenin expression. During differentiation the mRNA level of FoxO1 was significantly increased. However, the total protein did not change but the phosphorylation of FoxO1 was upregulated. Furthermore, overexpression of FoxO1 in porcine myoblast decreased MyoD and myogenin mRNA, whereas MyoD protein changed little and myogenin was significantly suppressed (P < 0.05). These results indicated that FoxO1 delays and negatively regulates the porcine myoblast differentiation. Moreover, FoxO1 may play a critical role in muscle fiber-type specification through the inhibition of myogenic regulation factors.