肾素-血管紧张素系统对胰岛β细胞功能的影响及AT1R在其中的作用机制  

Effect of RAS on islets β-cell function and the role and the mechanism in which AT1R involves

作　　者：田景琰[1] 李风英[1] 王晓[1] 刘赟[1] 龙红梅[1] 张宏利[1] 李文毅[1] 李果[1] 罗敏[1] 

机构地区：[1]上海交通大学医学院附属瑞金医院内分泌代谢科,上海市内分泌代谢病研究所,上海市内分泌代谢病临床医学中心,200025

出　　处：《中华内分泌代谢杂志》2010年第8期686-689,共4页Chinese Journal of Endocrinology and Metabolism

基　　金：国家自然科学基金（30570879）、上海市教委创新课题（09YZ105）

摘　　要：目的研究血管紧张素Ⅱ对胰岛β细胞的分泌、增殖、凋亡、氧化应激和纤维化的作用。方法应用βTC3细胞株、Western印迹检测、实时定量PCR检测、共聚焦显微镜监测Furo3标记的细胞内游离钙离子荧光强度的变化和流式细胞仪检测细胞凋亡及活性氧簇（ROS）产生等方法，研究血管紧张素Ⅱ对β细胞功能的影响，并进一步通过RNA干扰技术减少β细胞中AT1R的表达，研究AT1R在其中的作用机制。结果βTC3细胞在高浓度葡萄糖刺激下胰岛素分泌增加4倍。高糖作用可引起细胞内Ca^2＋荧光强度急剧增加。血管紧张素Ⅱ急性刺激并不直接引起胰岛素分泌的改变，其对β细胞促分泌作用可能与其促增殖功能相关。血管紧张素Ⅱ部分是通过AT1R和蛋白激酶C介导的NAD（P）H途径在β细胞中引起氧化应激。RNAi减少AT1R的表达可以改善血管紧张素Ⅱ引起的细胞凋亡和纤维化。结论血管紧张素Ⅱ通过其1型受体在β细胞的激素分泌、增殖、氧化应激、凋亡和纤维化等过程中发挥着重要作用。Objective To study the role of pancreatic renin-angiotensin system （RAS） on insulin secretion, proliferation, apoptosis, oxidative stress, and fibrosis of β-cells. Methods The effect of angiotensin Ⅱ on βTC3 cells was studied and the role and mechanism of AT1 R were analyzed with RNAi technology. The expression of ATIR was measured by Western Blotting. The change of intracellular calcium was detected by microfluorimetry with Furo3-1oaded cells. Peroxide-sensitive fluorescent probe DCFH-DA was used to analyze intracellular ROS by flow cytometry. Real-time PCR was performed to evaluate mRNA levels related to proliferation and fibrosis in βTC3 ceils. Apoptosis was detected by flow cytometry and Tunel method. Results Insulin secretion was significantly increased up to four fold and the level of intracellular calcium was sharply increased in response to high glucose in βTC3 cells, Angiotensin Ⅱ has no direct effect on insulin secretion in βTC3 cells and its role in secretion was associated with the role in proliferation. Oxidative stress in βTC3 cells caused by angiotensin Ⅱ may be partially mediated through AT1R, protein kinase C and NAD（P） H. With the decrease of AT1R expression by RNAi technology, apoptosis, and fibrosis of βTC3 cells induced by angiotensin Ⅱ might be ameliorated. Conclusions By means of ATIR, angiotensin Ⅱ plays an important role in insulin secretion, proliferation, apoptosis, oxidative stress and fibrosis in β-cells.

关 键 词：血管紧张素Ⅱ βTC3细胞株 血管紧张素受体 NAD(P)H RNA干扰 

分 类 号：R587.1[医药卫生—内分泌]