APPL1对高糖及炎症因子诱导的胰岛β细胞凋亡和功能损伤的保护作用

The protective effect of APPL1 on high glucose or cytokines-induced pancreatic β-cell apoptosis and dysfunction

目的 明确适配蛋白APPL1在胰岛β细胞中的作用。方法 采用腺病毒转染使INS-1细胞过表达APPL1。Western印迹法检测蛋白表达水平，碘化丙啶/Hoechst染色法检测细胞凋亡，用ELISA检测胰岛素分泌。结果 20 mmol/L葡萄糖或30 U/ml白细胞介素-1β加20 ng/ml TNF-α作用INS-1细胞48 h后，可明显诱导胰岛β细胞凋亡（P〈0.01），并降低2 h葡萄糖刺激的胰岛素分泌水平（P〈0.01）。INS-1细胞过表达APPL1后，与各自的对照病毒组相比，APPL1可使细胞凋亡降低34.16%～42.79%（P〈0.01），并使葡萄糖刺激的胰岛素分泌升高至对照组的1.39～2.20倍（P〈0.05）。结论 APPL1对高糖和炎症因子诱导的胰岛β细胞损伤具有保护作用，可降低β细胞凋亡并改善葡萄糖刺激的胰岛素分泌。

Objective To determine the role of APPL1, an adaptor protein, played in pancreatic β-cell. MethodsAPPL1 was overexpressed in INS-1 cells with adenovirus encoding APPL1. Western blot was conducted to measure protein expression. Propidium iodide/Hoechst staining was used to determine the cell apoptosis. Insulin secretion was measured by ELISA. ResultsExposure of INS-1 cells to 20 mmol/L glucose or 30 U/ml interleukin-1 β plus 20 ng/ml TNF-α 48 h induced β-cell apoptosis （P〈0.01） and impaired 2 h glucose-stimulated insulin secretion （P〈0.01）. Overexpression of APPL1 in INS-1 decreased cell apoptosis by 34.16%-42.79% （P〈0.01） and increased glucose-induced insulin secretion by 1.39-2.20 folds compared with control groups （P〈0.05）. ConclusionAPPL1 decreases β-cell apoptosis and increases glucose-stimulated insulin secretion, and thus protects β-cell against high glucose or cytokines-induced dysfunction.