沙奎那韦致大鼠INS-1细胞胰岛素抵抗

Saquinavir induces insulin resistance in rat INS-1 cells

目的探讨HIV-1蛋白酶抑制剂沙奎那韦对大鼠INS-1细胞内胰岛素信号转导通路及β细胞功能的影响。方法INS-1细胞经10μmol／L沙奎那韦处理48h后，台盼蓝染色计数细胞，MTT试验评估沙奎那韦对细胞活力的影响，Western印迹法测定100nmol／L胰岛素刺激的细胞裂解产物中的胰岛素信号转导蛋白的含量及其磷酸化，免疫酶标法测定20mmol／L葡萄糖刺激的胰岛素释放量，并用细胞内DNA含量标准化。结果沙奎那韦处理后，INS-1细胞内胰岛素刺激的胰岛素受体底物1（IRS-1）及IRS-2酪氨酸磷酸化和Akt—Thr^308磷酸化分别降低了60％、66％和55％，基础胰岛素分泌速率和葡萄糖刺激的胰岛素释放速率分别下降了39％和49％。结论沙奎那韦可损害胰岛β细胞内胰岛素信号的转导，导致β细胞自身胰岛素抵抗，这一作用可能影响胰岛β细胞功能。

Objective To investigate the effect of HIV-1 protease inhibitor saquinavir on insulin signaling and β-cell function in rat INS-1 cells. Methods INS-1 cells were preincubated with 0 or 10μmol/L saquinavir for 48 h, stimulated with 100 nmol/L insulin for 2 min or 20 mmol/L glucose for 30 min. Insulin signaling parameters were analyzed by immunoprecipitation and Western blot on cell lysates. Insulin concentrations in the supernatant were measured by ELISA, and standardized by cellular DNA contents. Cell count with trypan blue stain and MTT test were determined to evaluate the effect of saquinavir on cell viability. Results Treatment with saquinavir for 48 h significantly decreased insulin- stimulated phosphorylation of IRS-1, IRS-2 and Thr^308-phosphorylation of Akt in INS-1 cells by 60%, 66% and 55%, decreased the rate of basal insulin secretion and glucose-stimulated insulin release by 39% and 49% compared with control cells, respectively. Conclusions Treatment with saquinavir impairs insulin signal transmission in pancreatic β ceils and results in insulin resistance in β cells, This effect might influence the function of β cells.