PGC-1β和SREBP-1c在猪脂肪细胞分化过程中的相互作用

为研究过氧化物酶体增殖物激活受体γ辅激活因子1β(PGC-1β)与SREBP-1c在猪前体脂肪细胞分化过程中的表达规律及其相互作用,分析二者功能上的联系，采用Western 印迹及细胞免疫荧光技术检测PGC-1β与SREBP-1c在猪脂肪细胞分化过程中的表达，shRNA干扰和免疫共沉淀技术分别探讨了PGC-1β对SREBP-1c的调节作用及2种蛋白质在体内的结合活性.结果显示,PGC-1β与SREBP-1c 蛋白的表达均随猪脂肪细胞分化逐渐增加，且在分化细胞的核和胞浆中均有分布. 干扰PGC-1β显著下调了SREBP-1c和脂肪细胞分化标记基因C/EBPα的表达(P<0.05)，同时降低了细胞内甘油三酯的积累.免疫共沉淀证明,PGC-1β与SREBP-1c蛋白在猪脂肪细胞分化过程中存在结合作用. 以上结果表明，PGC-1β能够促进猪脂肪细胞分化并对SREBP-1c有调节和结合作用，推测二者的结合可能与其对脂肪细胞的分化调节机制相关，将对PGC-1β调控脂肪细胞分化的功能和机理研究提供新途径.

Interaction of PGC-1β and SREBP-1c during Porcine Adipocyte Differentiation

To study the interaction and function of peroxisome proliferator-activated receptor-γ coactivator-1β (PGC-1β) and sterol regulatory element binding protein 1c (SREBP-1c) during porcine preadipocyte differentiation, the expression of PGC-1β and SREBP-1c were detected by Western blotting and immunofluorescence. The regulation of PGC-1β on the SREBP-1c and the binding activity between the two proteins in vivo were analyzed using shRNA technology and co-immunoprecipitation. The results showed that PGC-1β and SREBP-1c increased gradually during porcine adipocyte differentiation, and the two proteins located both in the nucleus and cytoplasm. PGC-1β interference significantly decreased (P<0.05) the expression of SREBP-1c and C/EBPα, an adipocyte differentiation marker gene, and reduced the accumulation of triglyceride. Further analysis showed that PGC-1β and SREBP-1c could be co-immunoprecipitated. We conclude that PGC-1β interacts with SREBP-1c, and may regulate adipocyte differentiation.