地塞米松和胰岛素调节猪脂肪细胞SOCS-3、OB、 GLUT4和PPARg 基因的表达

Regulation of SOCS-3, OB, GLUT4 and PPARg Gene Expression by Insulin and Dexamethasone in Porcine Primary Adipocyte

摘要:

猪是研究糖尿病最理想的模型动物, 研究胰岛素和胰岛素抵抗是研究糖尿病的重要环节。为明确SOCS-3在胰岛素抵抗中的作用, 分别用100 nmol/L的胰岛素, 300 nmol/L的地塞米松处理原代培养的猪脂肪细胞诱导胰岛素抵抗; 利用半定量RT-PCR技术分别检测SOCS-3、OB、GLUT4和PPARg 基因表达变化。结果发现, 胰岛素增加了GLUT4、SOCS-3和PPARg 基因的表达, 对OB基因表达变化没有显著性影响; 地塞米松诱导的胰岛素抵抗状态下OB和SOCS-3基因表达水平升高, 而GLUT4和PPARγ基因表达水平显著下调。研究结果表明, GLUT4基因表达量水平的升高可能是由于PPARg的高表达引起, SOCS-3基因的不同表达水平对胰岛素信号的抑制效果不同。地塞米松诱导的胰岛素抵抗不仅表现在对葡萄糖转运的抑制, 也反映在抑制了胰岛素信号; 而SOCS-3基因可能是消除胰岛素抵抗的一个有效靶基因。

Abstract:

Swine is an ideal model for diabetes studies. Insulin and insulin resistance are closely related with diabetes. To investigate the effect of SOCS-3 in insulin resistance, porcine primary adipocyte was treated with insulin (100 nmol/L) and dexamethasone (300 nmol/L) to induce insulin resistance. The simi-quantitative PCR results suggested that insulin increased GLUT4, PPARγ and SOCS-3 gene expression in primary culture porcine adipocytes and no change of OB gene expression. Under insulin resistance conditions, SOCS-3 and OB gene expression were up-regulated, whereas GLUT4 and PPARγ gene expression were down-regulated in primary porcine adipocytes. The overexpression of PPARγ gene resulted in the increase of GLUT4 expression by insulin. Different expression levels of SOCS-3 determined the inhibitory effects of insulin signaling. Induction of insulin resistance by dexamethasone was not only due to inhibition of glucose transportation, but also repression of insulin signaling. SOCS-3 might be a potential gene to block the insulin resistance.