miR-135a targets IRS2 and regulates insulin signaling and glucose uptake in the diabetic gastrocnemius skeletal muscle
miR-135a targets IRS2 and regulates insulin signaling and glucose uptake in the diabetic gastrocnemius skeletal muscle
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DOI：
10.1016/j.bbadis.2013.03.021
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发表时间：
2013-08-01
影响因子：
6.2
通讯作者：
Datta, Malabika
中科院分区：
文献类型：
--
作者：
Agarwal, Priyanka;Srivastava, Rohit;Datta, Malabika
尽管异常的miRNA特征与糖尿病相关，但是，目前对改变的miRNA在糖尿病骨骼肌中的地位和作用知之甚少。在这里，我们报告了41种miRNAs在糖尿病腓肠肌骨骼肌中发生了改变，其中，被鉴定为肌生成关键调节因子的miR-135 a显著上调。IRS 2被预测为其潜在的推定靶标，并且其水平在糖尿病腓肠肌骨骼肌中下调。在C2 C12细胞中，虽然miR-135 a水平在分化期间降低，但IRS 2水平上调。miR-135 a显著降低IRS 2蛋白水平及其3 'UTR荧光素酶报告基因活性，并且这些被miR-135 a抑制剂和miR-135 a结合位点中的突变钝化。内源性miR-135 a水平的敲低在mRNA和蛋白水平上增加了IRS 2。miR-135 a还减弱胰岛素刺激的PI 3 Kp 85 α和Akt的磷酸化和活化以及葡萄糖摄取。还发现miR-135 a水平在人糖尿病骨骼肌中升高。miR-135 a的体内沉默减轻了高血糖症，改善了葡萄糖耐量，并显著恢复了db/db小鼠腓肠肌骨骼肌中IRS 2和p-Akt的水平，而对其肝脏水平没有任何影响。这些表明miR-135 a通过结合其3 'UTR靶向IRS 2水平，并且这种相互作用调节骨骼肌胰岛素信号传导。(C)2013 Elsevier B. V.保留所有权利。
Although aberrant miRNA signatures are associated with diabetes, yet, the status and role of altered miRNAs in the diabetic skeletal muscle is currently poorly understood. Here, we report that 41 miRNAs are altered in the diabetic gastrocnemius skeletal muscle and of these, miR-135a that is identified as a critical regulator of myogenesis, is significantly up-regulated. IRS2 is predicted as its potential putative target and its levels are down-regulated in the diabetic gastrocnemius skeletal muscle. In C2C12 cells, while miR-135a levels decreased during differentiation, IRS2 levels were up-regulated. miR-135a significantly reduced IRS2 protein levels and its 3'UTR luciferase reporter activity and these were blunted by the miR-135a inhibitor and mutation in the miR-135a binding site. Knock-down of endogenous miR-135a levels increased IRS2 at the mRNA and protein levels. miR-135a also attenuated insulin stimulated phosphorylation and activation of PI3Kp85 alpha and Akt and glucose uptake. miR-135a levels were also found to be elevated in the human diabetic skeletal muscle. In-vivo silencing of miR-135a alleviated hyperglycemia, improved glucose tolerance and significantly restored the levels of IRS2 and p-Akt in the gastrocnemius skeletal muscle of db/db mice without any effect on their hepatic levels. These suggest that miR-135a targets IRS2 levels by binding to its 3'UTR and this interaction regulates skeletal muscle insulin signaling. (C) 2013 Elsevier B.V. All rights reserved.