Abstract：
The growth and development of bovine skeletal muscle and beef yield is closely intertwined. Our previous research found that forkhead box O1 (FOXO1) plays an important role in the regulation of beef muscle formation, but its specific mechanism is still unknown. In this study, we aimed to clarify the regulatory mechanism of FOXO1 in proliferation and differentiation of bovine skeletal muscle cells (BSMCs). The results showed that interfering with FOXO1 can promote proliferation and the cell G1/S phase of BSMCs by up-regulating the expression of PCNA, CDK1, CDK2, CCNA2, CCNB1, CCND1 and CCNE2. Besides, interfering with FOXO1 inhibited the apoptosis of BSMCs by up-regulating the expression of anti-apoptosis gene BCL2, while simultaneously down-regulating the expression of the pro-apoptosis genes BAD and BAX. Inversely, interfering with FOXO1 can promote the differentiation of BSMCs by up-regulating the expression of myogenic differentiation marker genes MYOD, MYOG, MYF5, MYF6 and MYHC. Furthermore, RNA-seq combined with western bolt, immunofluorescence and chromatin immunoprecipitation analysis showed that FOXO1 could regulate BSMCs differentiation process by influencing PI3K-Akt, Relaxin and TGF-beta signaling pathways, and target MYH3 for transcriptional inhibition. In conclusion, this study provides a basis for studying the role and molecular mechanism of FOXO1 in BSMCs.
摘要：
牛骨骼肌的生长发育与牛肉产量密切相关。我们之前的研究发现叉头盒O1(FOXO1)在牛肉肌肉形成的调控中起着重要作用,但其具体机制尚不清楚。在这项研究中,本研究旨在阐明FOXO1对牛骨骼肌细胞增殖和分化的调控机制。结果表明,干扰FOXO1可通过上调PCNA的表达,促进BSMCs的增殖和细胞G1/S期,CDK1、CDK2、CCNA2、CCNB1、CCND1和CCNE2。此外,干扰FOXO1通过上调抗凋亡基因BCL2的表达抑制BSMCs的凋亡，同时下调促凋亡基因BAD和BAX的表达。相反，干扰FOXO1可通过上调成肌分化标记基因MYOD的表达促进BSMCs的分化,MYOG,MYF5、MYF6和MYHC。此外，RNA-seq结合西方的螺栓，免疫荧光和染色质免疫沉淀分析表明,FOXO1可以通过影响PI3K-Akt,松弛素和TGF-β信号通路,和靶向MYH3用于转录抑制。总之,本研究为研究FOXO1在BSMCs中的作用及分子机制提供了基础。
