胰高血糖素样多肽1拮抗游离脂肪酸诱导的胰岛β细胞胰腺衍生因子表达与机制

目的 观察游离脂肪酸(FFA)对胰岛β-TC3细胞胰腺衍生因子(PANDER)表达的影响,并探讨胰高血糖素样多肽1(GLP-1)对其的拮抗作用及与蛋白激酶B(Akt)信号通路的关系.方法 培养β-TC3细胞,以不同浓度棕榈酸(PA)处理12 h,0.5 mmol/L的PA处理不同时间后实时荧光定量PCR法检测PANDER mRNA表达;Western印迹检测对照组、PA组、PA+GLP-1组、GLP-1组处理12 h后PANDER、P-Akt及半胱氨酸天冬氨酸蛋白酶-3酶原蛋白表达;在上述各组加入Akt特异阻断剂(Akti-1/2)后,再检测PANDER蛋白表达,并以Hoechst33258核染色法检测细胞凋亡情况.结果 (1)PA浓度依赖性及时间依赖性增加PANDER mRNA表达(P<0.05);(2)与对照组(100%)比较,PA组诱导PANDER蛋白表达高(148±18)%,P<0.05),PA+GLP-1组PA诱导PANDER表达为(70±17)%,P<0.01];(3)Akti-1/2减弱GLP-1抑制PA诱导的PANDER表达及细胞凋亡的效应:PA+GLP-1+Akti-1/2组较PA+GLP-1组PANDER蛋白显著高(249+49)%比(110±54)%,P<0.01],细胞凋亡率显著高(37.8±-1.5)%比(20.1±3.5)%,P<0.01].结论 PA可诱导PANDER的表达及胰岛B细胞凋亡,GLP-1通过激活Akt通路拮抗PA诱导的PANDER表达及胰岛B细胞凋亡.

Abstract：

Objective To investigate the effects of free fatty acid(FFA)on the expression of pancreatic derived factor(PANDER)in β-cells and to explore the possible relationship between PANDER and Akt signaling pathway at the anti-apoptotic effects of glucagon-like peptide-l(GLP-1).Methods β-TC3 cells were cultured in vitro witH palmitic acid(PA)of different concentrations and different time courses.The expression of PANDER mRNA was analyzed by realtime quantitative PCR β-TC3 cells were cultured with vehicle.0.5 mmol/L PA.0.5 mmol/L PA+10 nmol/L GLP-1 and 10nmol/L GLP-1respectively with or without Akti-1/2, a selective inhibitor of Akt, for 12 hours.The protein levels of PANDER, P-Akt and pro-caspase3 were detected by Western blot And cell apoptosis was analyzed by Hoechst33258 staining.Results (1)PA could dose and time dependently increased the expression of PANDER mRNA in β cells(vs control, P<0.05);(2)PA increased the PANDER protein expression (148±18)%vs control 100%.P<0.05].However,these effects were attenuated by GLP-1 (70±17)%vs PA group,P<0.01];(3)Akt inhibitor-1/2 alleviated the effects of GLP-1 on PA inducing the expression of PANDER.The expression of PANDER increased significantly in PA+GLP-1+Akti-1/2 group (249±49)%vs PA+GLP-1 group(110±54)%,P<0.01],and cell apoptosis increased significantly as well(37.8±1.5)%vs PA+GLP-1 group(20.1±3.5)%,P<0.01].Conclusion PA induces the expression of PANDER and the apoptosis of β cell while GLP-1 counteracts the above effects through an activation of Akt signaling pathway.