Yuan Yuan, Shi Xin'e, Liu Yueguang, Yang Gongshe
Laboratory of Animal Fat Deposition and Muscle Development, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China.
Sheng Wu Gong Cheng Xue Bao. 2010 Dec;26(12):1668-73.
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.
叉头框O1（FoxO1）转录因子调控肌肉生长、代谢及细胞分化。然而，其在成肌细胞分化中的作用尚不清楚。为研究FoxO1在猪原代成肌细胞分化过程中的生物学功能，我们构建了由脂质体介导的FoxO1稳定过表达猪成肌细胞，并采用形态学观察、定量实时RT-PCR及蛋白质免疫印迹法分析FoxO1及早期和晚期成肌调节因子MyoD和肌细胞生成素的表达。在分化过程中，FoxO1的mRNA水平显著升高。然而，总蛋白水平未发生变化，但FoxO1的磷酸化水平上调。此外，FoxO1在猪成肌细胞中的过表达降低了MyoD和肌细胞生成素的mRNA水平，而MyoD蛋白变化不大，肌细胞生成素则受到显著抑制（P < 0.05）。这些结果表明，FoxO1延迟并负向调控猪成肌细胞的分化。此外，FoxO1可能通过抑制成肌调节因子在肌纤维类型特化中发挥关键作用。
