外源性胰岛素通过P糖蛋白调节INS-1 832/13细胞胰岛素分泌的研究

Exogenous insulin regulating insulin secretion may be associated with P-glycoprotein in INS-1 832/13 cells

目的观察外源性胰岛素对胰岛β细胞(INS-1 832/13)P糖蛋白(P-gp)表达及胰岛素分泌功能的影响。方法 0.5μmol/L外源性胰岛素孵育832/13细胞30d,MTT检测细胞活性,定量RTPCR、Western blot分别检测细胞P-gp mRNA和蛋白的表达水平,RIA测定高糖刺激下胰岛素分泌(GSIS)的变化。结果与对照组比较,0.5μmol/L的胰岛素可以增加INS-1 832/13细胞活性[(102.00±12.99)vs(356.00±35.51),P<0.05],并能增加P-gp转录水平[(107.50±17.08)vs(307.50±44.25)]及蛋白水平[(105.00±12.91)vs(192.50±35.94)]的表达(P<0.05),GSIS与P-gp表达水平呈正相关,但对基础胰岛素分泌没有影响。结论外源性胰岛素可以促进INS-1 832/13细胞分泌,机制可能与P-gp表达相关。

Objective To observe the effect of exogenous insulin on the expression of P-glycoprotein （P-gp）and the secretion of insulin in pancreatic beta cells （INS-1 832/13）. Methods Insulinoma cells （INS-1 832/13） were cultured with 0.5 /μmol/L exogenous insulin for 30 days. MTT assay was used to measure cell viability. Quantitative RT-PCR and western blot were used to detect the expression of P-gp mRNA and protein respectively, and glucose stimulated insulin secretion （GSIS） were measured by radioimmunoassay. Results Compared with control group, 0.5 μmol/L exogenous insulin promoted the viability of INS-1 832/13 cells [（102.00±12.99） vs （356.00±35.51）,P〈0.05] and accelerated P-gp expression [-（107. 50±17.08） vs （307.50±44.25）] both at mRNA and protein levels [（105.00±12.91） vs （192.50±35.94）,P〈0. 05]. Glucose stimulated insulin secretion was positively correlated with P-gp expression level, but had no significant effect on basal insulin secretion. Conclusion Exogenous insulin can promote the secretion function of INS-1 832/13 cells, and the mechanism may be related to the expression of P-gp.