miR-494-3p reduces insulin sensitivity in diabetic cardiomyocytes by down-regulation of insulin receptor substrate 1
miR-494-3p reduces insulin sensitivity in diabetic cardiomyocytes by down-regulation of insulin receptor substrate 1
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DOI：
10.13294/j.aps.2018.0095
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发表时间：
2019-04-01
期刊：
影响因子：
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通讯作者：
Gao Feng
中科院分区：
文献类型：
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作者：
Wu Jie;Qin Xing-Hua;Gao Feng
越来越多的证据表明，microRNA广泛参与心血管功能的调节。我们的初步实验表明，糖尿病大鼠心脏中miR-494-3p的表达增加，据报道miR-494-3p与肥胖、运动等代谢有关。因此，本研究旨在探讨miR-494-3p在糖尿病心肌胰岛素敏感性中的作用及相关机制。采用高脂饲料(45kcal%脂肪，12周)联合链脲佐菌素(STZ，30 mg/kg)复制糖尿病大鼠模型，提取心肌组织RNA进行定量聚合酶链式反应。结果表明，糖尿病大鼠心肌miR-494-3p表达水平较正常对照组显著上调(P<；0.05)。随着棕榈酸钠浓度的增加，高糖高脂培养的H9c2细胞miR-494-3p表达水平显著升高(P<；0.01)，而HGHF处理细胞miR-494-3p表达下调导致胰岛素刺激的葡萄糖摄取增加(P<；0.01)，p-Akt/Akt比值增加(P<；0.05)。在H9c2细胞中过表达miR-494-3p显著抑制胰岛素刺激的葡萄糖摄取和Akt的磷酸化(P<；0.01)。生物信息学结合免疫印迹实验证实胰岛素受体底物1(IRS1)是miR-494-3p的靶分子。这些结果表明miR-494-3p通过下调IRS1来降低糖尿病心肌细胞的胰岛素敏感性。
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 slieptozotocin (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.