过表达山羊ATF3抑制肌内前体脂肪细胞分化

Overexpression of ATF3 inhibits the differentiation of goat intramuscular preadipocytes

摘要:

本研究旨在探究山羊转录激活因子3(activating transcription factor 3,ATF3)对肌内前体脂肪细胞分化的影响，并从分子水平阐明其可能作用途径。利用基因重组方法构建pEGFP-N1-ATF3过表达重组质粒，脂质体转染肌内前体脂肪细胞，通过油红O脂肪染色法从细胞形态学水平确定对分化的影响，利用实时荧光定量PCR (qRT-PCR)技术检测脂肪细胞分化标记基因相对表达水平，从分子水平确定对分化的影响。最终成功构建pEGFP-N1-ATF3过表达载体，转染山羊肌内前体脂肪细胞后发现脂滴积聚被抑制，qRT-PCR检测到脂肪细胞分化标志基因PPARγ、C/EBPα、SREBP1极显著下调(P<0.01)，C/EBPβ、AP2显著下调(P<0.05)，通过ALGGEN PROMO程序预测PPARγ、C/EBPα和AP2的启动子区域存在ATF3结合位点。研究表明，过表达山羊ATF3抑制肌内前体脂肪细胞脂滴积聚，这种作用通过下调PPARγ、C/EBPα和AP2来实现，研究结果为阐明山羊ATF3调控肌内前体脂肪细胞分化机制提供重要的基础数据。

Abstract:

The aim of this study was to investigate the effect of activating transcription factor 3 (ATF3) on the differentiation of intramuscular preadipocytes in goat, and to elucidate its possible action pathway at the molecular level. In this study, the recombinant plasmid of goat pEGFP-N1-ATF3 was constructed, and the intramuscular preadipocytes were transfected with liposomes. The relative expression levels of adipocyte differentiation marker genes were detected by quantitative real-time PCR (qRT-PCR). After transfection of goat intramuscular preadipocytes with the goat pEGFP-N1-ATF3 overexpression vector, it was found that the accumulation of lipid droplets was inhibited, and the adipocyte differentiation markers PPARγ, C/EBPα and SREBP1 were extremely significantly down-regulated (P<0.01), while C/EBPβ and AP2 were significantly down-regulated (P<0.05). The ATF3 binding sites were predicted to exist in the promoter regions of PPARγ, C/EBPα and AP2 by the ALGGEN PROMO program. The overexpression of goat ATF3 inhibits the accumulation of lipid droplets in intramuscular preadipocytes, and this effect may be achieved by down-regulating PPARγ, C/EBPα and AP2. These results may facilitate elucidation of the regulatory mechanism of ATF3 in regulating the differentiation of goat intramuscular preadipocytes.