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高糖条件下p58 促胰岛β 细胞凋亡的机制

张洁, 刘洋, 杨红旺, 许海燕, 孟雁

中国医学科学院基础医学研究所 生理学系； 生物医学工程系，北京 100005中国医学科学院基础医学研究所 生理学系；生物医学工程系，北京

摘要

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(20 mmol/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。

关键词： 2 型糖尿病; CDC2L2; β 细胞; 凋亡

分类号：R587.102

[Molecular mechanism of β cell apoptosis induced by p58 in high glucose medium.] [Ariticle in Chinese]

Zhang Jie, LIU Yang, YANG Hong-Wang, XU Hai-Yan, MENG Yan

100005Departments of Physiology and Biomedical Engineering, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100005, China

Abstract

Type 2 diabetes is a complex disorder with a strong genetic background. CDC2L2 is one of the susceptibility genes of type 2 diabetes in Chinese Han population in northern area. The relationship between CDC2L2 and type 2 diabetes remains unknown. In this paper, the function and its molecular pathway of p58, a protein coded by CDC2L2, in β cell apoptosis were investigated. INS-1 cells cultured in high glucose (20 mmol/L) medium were divided into control, vector control (transfected with pcDNA3.0) and experimental (transfected with pcDNA3.0-HA-p58) groups. Beta cell apoptosis level was detected by Annexin V-FITC/PI double staining assay. The flow cytometry results showed that in high glucose medium (20 mmol/L), high expression of p58 increased β cell apoptosis significantly compared with that in blank and vector controls (P<0.01, P<0.05). Western blot revealed that the expressions of Caspase-3, Bax and cytochrome C in cytoplasm increased significantly (P<0.05, P<0.01, P<0.01), whereas the expression of Bcl-2 decreased significantly (P< 0.05) in the INS-1 cells with high expression of p58, compared with those in both control groups. However, the Bad and Bik expression levels of INS-1 cells did not show obviously changes compared with those in both controls. The above results suggest that in high glucose condition, p58 may induce INS-1 cell apoptosis through up-regulating the expression of Bax and down-regulating the expression of Bcl-2, since both of them could promote the release of cytochrome C into cytoplasm, and finally activate Caspase-3. These results provide an important basis for the further exploration of the molecular mechanism of β cell apoptosis induced by CDC2L2.

Key words: type 2 diabetes mellitus; CDC2L2; beta cell; apoptosis

收稿日期：2009-03-27　　录用日期：2009-05-22

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引用本文：

张洁, 刘洋, 杨红旺, 许海燕, 孟雁 . 高糖条件下p58 促胰岛β 细胞凋亡的机制[J]. 生理学报 2009; 61 (4): 379-385.

Zhang Jie, LIU Yang, YANG Hong-Wang, XU Hai-Yan, MENG Yan . [Molecular mechanism of β cell apoptosis induced by p58 in high glucose medium.] [Ariticle in Chinese] . Acta Physiol Sin 2009; 61 (4): 379-385 (in Chinese with English abstract).