固醇调节元件结合蛋白基因的过表达对促进牛胎儿成纤维细胞脂肪形成的影响

为了研究固醇调节元件结合蛋白(sterol regulatory element binding factor 1,SREBP1)基因的表达与细胞脂肪形成的关系,本研究构建了pEGFP-C1-SREBP1重组质粒,利用脂质体介导法将重组质粒pEGFP-C1-SREBP1及pEGFP-C1空质粒转染至牛胎儿骨骼肌成纤维细胞培养48 h,实时荧光定量PCR和Western blotting分析目标基因表达水平的变化,并采用油红O染色检测细胞内脂滴。结果发现,pEGFP-C1-SREBP1重组质粒转染细胞内SREBP1 mRNA的表达水平显著高于空白对照组和阴性对照组(P<0.05);SREBP1蛋白也出现明显上调;空白对照组和pEGFP-C1阴性对照组细胞内均未见有红染细胞,而pEGFP-C1-SREBP1重组质粒转染组中出现了清晰的红染细胞。说明SREBP1的表达可促进牛胎儿骨骼肌成纤维细胞脂肪合成,证实牛胎儿成纤维细胞中SREBP1表达和脂滴形成之间存在直接关系。

Effect of the Overexpression on Sterol Regulatory Element Binding Factor 1 Gene Increases Lipid Droplet Formation in Bovine Fetal Fibroblasts

The objective of this study was to investigate the relationship between sterol regulatory element binding factor 1 (SREBP1) gene expression and cell fat formation, recombinant plasmid pEGFP-C1-SREBP1 was constructed and transferred into bovine fetal fibroblasts with Lipofectamine 2000, and then the cells were cultured for 48 h. Furthermore, the expressions of SREBP1 mRNA and protein were detected by Real-time PCR and Western blotting. Oil red O staining was used to explore cellular lipid droplet formation. The results showed that an up-regulation of SREBP1 mRNA in recombinant plasmid transfection group compared with normal control group and pEGFP-C1 transfected group, SREBP1 protein also appeared obvious rise. Oil red O found no lipid droplet in normal control group and pEGFP-C1 transfected group, but marked lipid droplets were detected in pEGFP-C1-SREBP1 transfected group. In conclusion, the up-regulation of SREBP1 directly resulteds in cellular lipid droplet formation in bovine fetal fibroblasts.