胰岛素样生长因子-1对小鼠胰岛细胞凋亡的保护作用

Protective effect of insulin-like growth factor-1 on apoptosis in murine pancreatic β-cells

目的:探讨胰岛素样生长因子-1(IGF-1)对第三丁基过氧化氢(tBHP)诱导小鼠胰岛β细胞株MIN6凋亡的保护作用。方法:体外培养小鼠胰岛β细胞株MIN6,分为:对照组、tBHP(25μmol/L)组、IGF-1(100ng/mL)组和IGF-1+tBHP组。丫啶橙-溴化乙锭(AO-EB)荧光染色法及原位末端标记法(TUNEL)镜下观测各实验组细胞凋亡情况,Griess法检测各实验组细胞内NO水平。结果:25μmol/LtB-HP作用1h可诱导MIN6细胞凋亡,并使细胞内NO含量明显增加。预先经过100ng/mLIGF-1作用24h后,tBHP诱导的MIN6细胞凋亡明显减少,同时细胞内NO含量亦显著降低。结论:IGF-1对tBHP诱导凋亡的小鼠胰岛β细胞株MIN6有一定的保护作用,其机制可能与IGF-1减少tBHP诱导的NO合成有关。

To investigate the protective effect of insulin-like growth factor-1 （IGF-1） on apoptosis in murine pancreatic β-cells MIN6 induced by tert-butyl hydroperoxide（tBHP）. METHODS： MIN6 cells were cul- tured and divided into four groups： control group, tBHP （25 μmol/L） group, IGF-1（100 ng/mL） group and IGF-1 ＋ tBHP group. Cell damage was detected by AO-EB staining and TUNEL assay. The levels of nitric oxide were measured by Griess assay. RESULTS： Induced cell ap- optosis and increased NO production were observed when MIN6 cells treated with 25 μmol/L of tBHP for 1 h,When the cells were pretreated with 100 ng/mL IGF-1 for 24 h before tBI-IP exposured, cell apoptosis induced by tBHP was significantly inhibited and NO production was also decreased. CONCLUSION： The present study suggests that IGF-1 has protective effect on apoptosis in mufine pancreatic β-cells MIN6 induced by tBHP. The mechanism of this effect is possibly attributed to IGF-1 reduces NO production which induced by tBHP.