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miR-494-3p通过下调胰岛素受体底物-1促糖尿病大鼠心肌细胞胰岛素抵抗

吴洁, 秦兴华, 侯作旭, 付子豪, 李国华, 杨红燕, 张星^*, 高峰

中国人民解放军空军军医大学航空航天医学系，西安 710032

摘要

越来越多的证据表明microRNA广泛参与调控心血管功能。我们预实验结果显示糖尿病大鼠心肌miR-494-3p增加，且有研究表明miR-494-3p与肥胖等代谢异常有关。因此，本研究旨在探讨miR-494-3p在糖尿病心肌胰岛素敏感性改变中的作用及其机制。利用高脂饲料联合链脲佐菌素诱导糖尿病大鼠模型，提取心肌组织RNA进行qPCR检测，结果显示糖尿病大鼠的心肌miR-494-3p表达水平与正常大鼠相比明显上调(P < 0.05)。体外高糖高脂诱导H9c2细胞胰岛素抵抗模型，qPCR结果显示细胞中miR-494-3p水平明显升高(P < 0.01)，并随高脂程度加重而增加；抑制miR-494-3p表达可以增加胰岛素刺激下细胞对葡萄糖的摄取(P < 0.01)，并提高胰岛素刺激后Akt磷酸化水平(P < 0.05)；单纯过表达H9c2细胞中的miR-494-3p可以抑制胰岛素刺激的葡萄糖摄取，并降低Akt磷酸化水平(P < 0.01)。生物信息学联合蛋白免疫印迹实验证实胰岛素受体底物-1 (insulin receptor substrate 1, IRS1)是miR-494-3p负性调节胰岛素信号转导的靶分子之一。上述结果提示，miR-494-3p通过下调IRS1促进糖尿病大鼠心肌细胞胰岛素抵抗的形成。

关键词： miR-494-3p; 2型糖尿病; 心肌细胞; 胰岛素受体底物-1; 胰岛素抵抗

分类号：R332;R363.2;R329.2

miR-494-3p reduces insulin sensitivity in diabetic cardiomyocytes by down-regulation of insulin receptor substrate 1

WU Jie, QIN Xing-Hua, HOU Zuo-Xu, FU Zi-Hao, LI Guo-Hua, YANG Hong-Yan, ZHANG Xing^*, GAO Feng

School of Aerospace Medicine, the Fourth Military Medical University, Xi’an 710032, China

Abstract

More and more evidence suggests that microRNA is widely involved in the regulation of cardiovascular function. Our preliminary experiment showed that miR-494-3p was increased in heart of diabetic rats, and miR-494-3p was reported to be related to metabolism such as obesity and exercise. Therefore, this study was aimed to explore the role of miR-494-3p in diabetic myocardial insulin sensitivity and the related mechanism. The diabetic rat model was induced by high fat diet (45 kcal% fat, 12 weeks) combined with streptozotocin (STZ, 30 mg/kg), and cardiac tissue RNA was extracted for qPCR. The results showed that the level of miR-494-3p was significantly up-regulated in the myocardium of diabetic rats compared with the control (P < 0.05). The level of miR-494-3p in H9c2 cells cultured in high glucose and high fat medium (HGHF) was significantly increased (P < 0.01) with the increase of sodium palmitate concentration, whereas down-regulation of miR-494-3p in HGHF treated cells led to an increase in insulin-stimulated glucose uptake (P < 0.01) and the ratio of p-Akt/Akt (P < 0.05). Over-expression of miR-494-3p in H9c2 cell line significantly inhibited insulin-stimulated glucose uptake and phosphorylation of Akt (P < 0.01). Bioinformatics combined with Western blotting experiments confirmed insulin receptor substrate 1 (IRS1) as a target molecule of miR-494-3p. These results suggest that miR-494-3p reduces insulin sensitivity in diabetic cardiomyocytes by down-regulating IRS1.

Key words: miR-494-3p; type 2 diabetes; cardiomyocyte; insulin receptor substrate 1; insulin resistance

收稿日期：2018-07-21　　录用日期：2018-10-30

通讯作者：张星　　E-mail: zhangxing@fmmu.edu.cn

DOI: 10.13294/j.aps.2018.0095

引用本文：

吴洁, 秦兴华, 侯作旭, 付子豪, 李国华, 杨红燕, 张星, 高峰. miR-494-3p通过下调胰岛素受体底物-1促糖尿病大鼠心肌细胞胰岛素抵抗[J]. 生理学报 2019; 71 (2): 271-278.

WU Jie, QIN Xing-Hua, HOU Zuo-Xu, FU Zi-Hao, LI Guo-Hua, YANG Hong-Yan, ZHANG Xing, GAO Feng. miR-494-3p reduces insulin sensitivity in diabetic cardiomyocytes by down-regulation of insulin receptor substrate 1. Acta Physiol Sin 2019; 71 (2): 271-278 (in Chinese with English abstract).