Downregulation of miR-200c protects cardiomyocytes from hypoxia-induced apoptosis by targeting GATA-4
Downregulation of miR-200c protects cardiomyocytes from hypoxia-induced apoptosis by targeting GATA-4
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DOI：
10.3892/ijmm.2017.2959
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发表时间：
2017-06-01
影响因子：
5.4
通讯作者：
Sang, Wenfeng
中科院分区：
文献类型：
--
作者：
Chen, Zhigang;Zhang, Shaoli;Sang, Wenfeng
缺氧诱导心肌细胞凋亡在缺血性心脏病的发生发展中起重要作用。MicroRNAs （miRNAs或miRs）正在成为缺氧诱导的心肌细胞凋亡的关键调节因子。miR-200c是一种被报道在多种病理过程中与细胞凋亡相关的miRNA；然而，其在缺氧诱导的心肌细胞凋亡中的作用尚不清楚。在本研究中，我们旨在探讨miR-200c在调节缺氧诱导的心肌细胞凋亡中的潜在作用和潜在机制。我们发现，通过逆转录-定量聚合酶链反应（RT-qPCR）检测，miR-200c在心肌细胞缺氧时显著上调。乳酸脱氢酶、MTT、膜联蛋白V/碘化丙啶凋亡和caspase-3活性检测显示，miR-200c下调可显著提高细胞存活率，抑制心肌细胞对缺氧的凋亡反应。生物信息学分析和双荧光素酶报告基因实验表明，miR-200c直接靶向GATA-4的3'-非翻译区，GATA-4是心肌细胞存活的重要转录因子。RT-qPCR和western blot分析显示，抑制miR-200c可显著提高GATA-4的表达。此外，miR-200c的下调上调了抗凋亡基因Bcl-2的表达。然而，miR-200c下调诱导的缺氧保护作用被GATA-4敲低明显取消。综上所述，我们的研究结果表明，miR-200c的下调通过靶向GATA-4来保护心肌细胞免受缺氧诱导的凋亡，为缺血性心脏病的治疗提供了一个潜在的治疗分子靶点。
Hypoxia-induced cardiomyocyte apoptosis plays an important role in the development of ischemic heart disease. MicroRNAs (miRNAs or miRs) are emerging as critical regulators of hypoxia-induced cardiomyocyte apoptosis. miR-200c is an miRNA that has been reported to be related to apoptosis in various pathological processes; however, its role in hypoxia-induced cardiomyocyte apoptosis remains unclear. In the present study, we aimed to investigate the potential role and underlying mechanism of miR-200c in regulating hypoxia-induced cardiomyocyte apoptosis. We found that miR-200c was significantly upregulated by hypoxia in cardiomyocytes, as detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The lactate dehydrogenase, MTT, Annexin V/propidium iodide apoptosis and caspase-3 activity assays showed that downregulation of miR-200c markedly improved cell survival and suppressed the apoptosis of cardiomyocytes in response to hypoxia. Bioinformatics analysis and the dual-luciferase reporter assay demonstrated that miR-200c directly targeted the 3'-untranslated region of GATA-4, an important transcription factor for cardiomyocyte survival. RT-qPCR and western blot analysis showed that suppression of miR-200c significantly increased GATA-4 expression. Furthermore, downregulation of miR-200c upregulated the expression of the anti-apoptotic gene Bcl-2. However, the protective effects against hypoxia induced by the downregulation of miR-200c were significantly abolished by GATA-4 knockdown. Taken together, our results suggest that downregulation of miR-200c protects cardiomyocytes from hypoxia-induced apoptosis by targeting GATA-4, providing a potential therapeutic molecular target for the treatment of ischemic heart disease.