TERT和p-Akt对胰岛β细胞凋亡的影响

Effect of TERT and p-Akt on the apoptosis of islet β cell

目的:通过抑制磷酸化丝/苏氨酸激酶(phosphorylation serine/threonine kinase,p-Akt)的表达,观察并探讨p-Akt和端粒酶逆转录酶(telomerase reverse transcriptase,TERT)对高糖高脂干预的胰岛β细胞凋亡的影响。方法:将NIT-1细胞随机分成对照组(正常培养)、Akt抑制组(正常培养+Akt抑制剂SH5)、高糖高脂干预组(高糖高脂培养)、高糖高脂+Akt抑制组(高糖高脂培养+Akt抑制剂SH5),TUNEL法和流式细胞术检测各组细胞凋亡,Western blot检测各组细胞TERT、Akt和p-Akt蛋白表达水平,ELISA检测各组细胞胰岛素分泌。结果:与正常对照组比较[凋亡率:(2.88±1.25)%;胰岛素分泌:(0.65±0.10);p-Akt:(0.80±0.07);TERT:(1.63±0.12)];高糖高脂干预组胰岛β细胞凋亡率(38.25±8.63)%明显增加,胰岛素分泌(0.40±0.09)下降,p-Akt(0.55±0.05)和TERT(1.03±0.05)表达明显下降,差异均有统计学意义(P<0.05);与高糖高脂干预组[凋亡率:(38.25±8.63)%;胰岛素分泌:(0.40±0.09);p-Akt:(0.55±0.05);TERT:(1.03±0.05)]比较,高糖高脂+Akt抑制组细胞凋亡率(62.00±7.13)%明显增高,胰岛素分泌(0.23±0.10)下降,p-Akt(0.28±0.07)和TERT(0.61±0.07)表达明显下降,差异均有统计学意义(P<0.05)。结论:抑制p-Akt表达可增加高糖高脂诱导的胰岛β细胞凋亡,其机制可能与降低了TERT表达水平有关。

Objective：To ＇observe the inhibition of phosphorylation serine/threonine kinase （p-Akt） on expression of TERT and to explore the effect and mechanism of apoptosis on islet β cells in high glucose and lipid intervention. Methods：Islet β cells were randomly divided into normal control group,Akt inhibit group,glucose and fatty acid intervention group,glucose and fatty acid intervention ＋Akt inhibit group. Cell apoptosis was detected by TUNEL and flow cytometry;the protein expressions of p-Akt and TERT were detected by Western blot;insulin secretion was detected by ELISA. Results：Compared with those of control group（apoptosis rate： （2.88 ± 1.25）%;insulin secretion： （0.65 ± 0.10） ;p-Akt： （0.80 ± 0.07） ;TERT： （1.63 ± 0.12） ,isletβ cell apoptosis rate（38.25 ± 8.63）% was significantly increased and insulin secretion（0.40 ±0.09） was decreased significantly,expression of p-Akt（0.55 ± 0.05） and TERT （1.03 ± 0.05） decreased significantly in glucose and fatty acid intervention group,with statistically significant differences（P〈0.05）. Compared with those of glucose and fatty acid intervention group （apoptosis rate： （38.25 ± 8.63 ）% ;inulin secretion： （0.40 ± 0.09） ; p-Akt： （0.55 ± 0.05）;TERT： （1.03 ± 0.05）, the apoptosis rate（62.00 ± 7.13）% was significantly increased and insulin secretion （0.23 ±0.10） was decreased significantly,expression of p-Akt（0.28 ± 0.07） and TERT（0.61 ± 0.07） was decreased significantly in glucose and fatty acid intervention＋Akt inhibit group,with statistically significant differences （P〈0.05）. Conclusion ：Inhibition of p- Akt expression may increase the apoptosis of islet β cells induced by the glucose and fatty acid intervention, and its mechanism may be reduced expression level of TERT.