pGhrelin对离体猪脂肪细胞Caspase-3活性及基因表达的影响

研究新近发现的猪Ghrelin (porcine ghrelin，pGhrelin)对猪前体脂肪细胞Caspase-3活性及其基因表达的影响．采用细胞培养技术，以仔猪背部皮下前体脂肪细胞为靶细胞，经0、1、10和100 nmol/L pGhrelin处理细胞48 h后，于倒置生物显微镜下进行脂肪细胞形态学观察．利用MTT法测定pGhrelin对细胞增殖的影响．采用分光光度法检测Caspase-3活性．以实时荧光定量RT-PCR方法测定Caspase-3的基因表达．结果显示，10 nmol/L pGhrelin可以显著降低脂肪细胞Caspase-3的活性与mRNA的表达水平(P < 0.05)，100 nmol/L pGhrelin对猪脂肪前体细胞增殖有极显著促进作用(P < 0.01)．上述结果表明，pGhrelin可以下调Caspase-3的活性与基因表达，促进脂肪细胞增殖，抑制脂肪细胞凋亡，其机制可能与Caspase-3依赖性凋亡调节信号通路有关．

Effects of pGhrelin on caspase-3 activity and gene expression of porcine predipocytes in culture

To investigate the effects of porcine Ghrelin (pGhrelin), a newly discovered peptide on porcine preadipocyte Caspase-3 activity and gene expression, piglet subcutaneous preadipocytes treated with 0, 1, 10 and 100 nmol/L pGhrelin were cultured for 48 h, and preadipocyte morphology was observed under an inverted biological microscope, the effects of preadipocyte prolifaration was mesured by MTT, preadipocyte Caspase-3 activity was detected with spectrophotometric method, Caspase-3 gene expression level was determined using real-time fluorescent quantitative RT-PCR. 10 nmol/L pGhrelin significantly decreased preadipocyte Caspase-3 activity and mRNA expression level (P < 0.05), 100 nmol/L pGhrelin significantly promoted porcine preadipocyte proliferation compared to control group (P < 0.01). pGhrelin downregulated Caspase-3 activity and expression mRNA of porcine preadipocyte, induced preadipocyte proliferation and inhibited apoptosis. Caspase-3 dependent apoptosis regulation signalling was supposed to be involved in the apoptosis mechanism.