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2型糖尿病是一种具有明显遗传倾向的复杂的多基因疾病。CDC2L2是中国北方汉族人2型糖尿病的一个易感基因。目前,该基因与2型糖尿病发生发展的关系尚不清楚。本文针对CDC2L2编码的蛋白p58与胰岛β细胞凋亡的关系及其作用的分子机制进行了研究。INS-1(大鼠胰岛β细胞瘤细胞株)高糖浓度(20mmol/L)下培养,分为三个组:空白对照组、空载体对照组(转染载体pcDNA3.0)和实验组(转染质粒pcDNA3.0-HA-p58),Annexin V-FITC/PI双染法检测胰岛β细胞的凋亡状况。结果显示,在高糖培养条件下,p58高表达组INS-1细胞的凋亡率显著高于空白对照组和空载体对照组(P<0.01,P<0.05)。Western blot检测显示,与两对照组相比,p58高表达组的INS-1细胞中Caspase-3和Bax的表达水平明显上升(P<0.05,P<0.01),胞浆内CytoC的含量显著升高(P<0.01),Bcl-2的表达水平显著下降(P<0.05)。以上结果提示,p58在高糖条件下可能通过上调Bax和下调Bcl-2的表达,使线粒体外膜的通透性增加,从而引起CytoC由线粒体向胞浆的释放,最终活化Caspase-3,引起INS-1细胞凋亡。本实验为进一步研究CDC2L2与胰岛β细胞凋亡的关系及其分子作用机制奠定了重要的实验基础。
Type 2 diabetes is a complex polygenic disease with a clear genetic predisposition. CDC2L2 is a susceptible gene to type 2 diabetes in Han Chinese in northern China. At present, the relationship between the gene and type 2 diabetes is still unclear. In this paper, CDC2L2-encoded protein p58 and pancreatic islet β-cell apoptosis and the molecular mechanism of its role were studied. INS-1 cells were cultured in high glucose (20mmol / L) and divided into three groups: blank control group, empty vector control group (transfected with pcDNA3.0) and experimental group ( Transfection of plasmid pcDNA3.0-HA-p58), Annexin V-FITC / PI double staining was used to detect the apoptosis of islet β cells. The results showed that under high glucose conditions, the apoptosis rate of INS-1 cells in p58 overexpression group was significantly higher than that in blank control group and empty vector control group (P <0.01, P <0.05). Western blot showed that the expression of Caspase-3 and Bax in INS-1 cells was significantly increased (P <0.05, P <0.01), and the content of CytoC in cytoplasm significantly increased compared with the two control groups (P <0.01), the expression of Bcl-2 was significantly decreased (P <0.05). The above results suggest that p58 may increase the permeability of mitochondrial outer membrane by up-regulating Bax and down-regulating the expression of Bcl-2 under high glucose conditions, causing the release of CytoC from the mitochondria to the cytoplasm, eventually activating Caspase-3 INS-1 cell apoptosis. This experiment lays an important experimental foundation for the further study of the relationship between CDC2L2 and pancreatic β-cell apoptosis and its molecular mechanism.