小窝蛋白-1在猪前体脂肪细胞分化中的作用及其机理

以体外培养1日龄猪皮下前体脂肪细胞为研究对象,通过脂质体LipofectamineTM2000介导小窝蛋白-1（Caveolin-1,CAV1）过表达载体pEGFP-N1-CAV1及CAV1的干扰片段siRNA-CAV1分别转染猪皮下前体脂肪细胞,采用RT-PCR定量分析转染后24、48、72、96h的CAV1mRNA表达量以及转染后72h脂肪细胞分化相关基因的mRNA表达量;其后又进行了CAV1过表达或干扰且诱导分化后甘油三脂含量以及脂肪细胞分化相关基因的mRNA表达量测定。结果显示,过表达CAV1基因上调前体脂肪细胞分化相关基因PPARγ、C/EBPβ、AP2、GPDH的表达量,干扰CAV1基因下调C/EBPβ、PPARγ、AP2、LPL、VLDLR的表达量;诱导分化后干扰组C/EBPβ、LPL、VLDLR的表达量仍显著降低,而甘油三脂含量检测结果说明过表达CAV1基因能促进脂肪细胞分化,提示CAV1可能通过C/EBPβ、LPL、VLDLR等基因影响猪前体脂肪细胞分化。

Effects of caveolin-1 on the porcine preadipocyte differentiation and the underlying regulatory mechanism

To investigate the effects of caveolin-1 （CAV1） on the differentiation of porcine preadipocytes into adipo- cytes,subcutaneous preadipocytes were isolated from 1 day-old piglet and transfected with CAV1 over-expression vector （pEGFP-N1-CAV1） or anti-CAV1 small interfering RNA （siRNA-CAV1） by LipofectamineTM 2000. The mRNA level of CAV1 at 24,48,72 and 96 h post-transfection and the mRNA levels of adipigenesis-related gene at 72 h post-transfection were measured by Real-time PCR. The triglyceride content and the mRNA level of genes involved in adipogenesis were detected after induction of adipogenic differentiation of preadipocytes. The results showed that over-expression of CAV1 in preadipocytes can significantly increase the expression of PPART, C/EBPB, AP2 and GPDH,knockdown of CAV1 by RNA interference can significantly decrease the expression level of C/EBPB, PPART,AP2,LPL and VLDLR. After preadipocytes were induced to differentiate towards adipocytes, the mRNA level of C/EBPB, LPL and VLDLR were still significantly reduced in cells transfected with siRNA-CAV1. The meas- urement result of triglyceride amount indicates that CAM1 can promote the differentiation of preadipocytes into adi-pocyptes probably by regulating the expression of genes such as C/EBPB,LPL and VLDLR.