Insulin ameliorates miR-1-induced injury in H9c2 cells under oxidative stress via Akt activation
Insulin ameliorates miR-1-induced injury in H9c2 cells under oxidative stress via Akt activation
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DOI：
10.1007/s11010-012-1379-7
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发表时间：
2012-10-01
影响因子：
4.3
通讯作者：
Yuan, Zuyi
中科院分区：
文献类型：
--
作者：
Chen, Tao;Ding, Guoliang;Yuan, Zuyi
越来越多的证据表明，缺血心肌中存在microRNA-1（miR-1）的异常上调。此外，胰岛素还具有非代谢依赖性的心脏保护作用。本研究的目的是确定胰岛素是否改善miR-1诱导的H9 c2细胞在氧化应激下的损伤，并探讨其潜在机制。通过实时定量RT-PCR（qRT-PCR），我们发现，miR-1在H9 c2细胞用过氧化氢（H2 O2）处理后上调，这种效果是剂量和时间依赖性的。此外，胰岛素治疗后miR-1的表达显著降低（4.5 +/- A 0.1对3.0 +/- A 0.2，p < 0.05）。为了确定miR-1在细胞损伤和基因调控中的潜在作用，使用腺病毒介导的miR-1过表达。miR-1的过表达使细胞活力降低28 +/-A2%（n = 6，p < 0.05），并且在有或没有H2 O2处理的情况下损害Akt活化。为了进一步研究磷脂酰肌醇3-激酶（PI 3 K）/Akt途径在miR-1诱导的损伤中的作用，用LY 294002（10 μ M LY，PI 3 K的特异性抑制剂）与或不与胰岛素（100 nM）预处理H9 c2细胞，并进行H2 O2处理。LY预处理抑制Akt活化，导致活性氧（ROS）增加，并进一步降低氧化应激下miR-1诱导的细胞活力（n = 6，p < 0.05，n = 9-10个细胞/组，p < 0.05和n = 6，p < 0.05）。这种作用被胰岛素消除。综上所述，我们的研究结果表明miR-1的表达对H2 O2刺激敏感。此外，胰岛素降低miR-1表达，并诱导对miR-1诱导的氧化应激损伤的显著保护作用，这可能是由Akt介导的途径介导的。这些结果为胰岛素的心血管作用机制提供了一条重要的新线索。
Growing evidence indicates that aberrant upregulation of microRNA-1 (miR-1) occurs in ischemic myocardium. In addition, insulin elicits metabolism-independent cardioprotection against cardiovascular diseases. The aim of this study is to determine whether insulin ameliorates miR-1-induced injury in H9c2 cells under oxidative stress and to investigate the underlying mechanisms. By quantitative real-time RT-PCR (qRT-PCR), we show that miR-1 is upregulated in H9c2 cells after treatment with hydrogen peroxide (H2O2), and this effect is both dose- and time dependent. Furthermore, expression of miR-1 decreased significantly after insulin treatment (4.5 +/- A 0.1 vs. 3.0 +/- A 0.2, p < 0.05). To determine the potential role of miR-1 in cellular injury and gene regulation, adenovirus-mediated overexpression of miR-1 was used. Overexpression of miR-1 decreased cell viability by 28 +/- A 2 % (n = 6, p < 0.05) and damaged Akt activation with or without H2O2 treatment. To further investigate the effect of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway in miR-1-induced injury, H9c2 cells were pretreated with LY294002 (10 mu M LY, a specific inhibitor of PI3K) with or without insulin (100 nM) and subjected to H2O2 treatment. LY pretreatment-inhibited Akt activation, lead to increased reactive oxygen species (ROS), and further decreased cell viability induced by miR-1 (n = 6, p < 0.05, n = 9-10 cells/group, p < 0.05 and n = 6, p < 0.05) under oxidative stress. This effect was abolished by insulin. In summary, our findings suggest that miR-1expression is sensitive to H2O2 stimulation. In addition, insulin decreases miR-1 expression and induces a marked protective effect on miR-1-induced injury under oxidative stress, which may be mediated by the Akt-mediated pathway. These results provide an important, novel clue as to the mechanism of the cardiovascular action of insulin.