Downregulation of miR-200c protects cardiomyocytes from hypoxia-induced apoptosis by targeting GATA-4

Int J Mol Med. 2017 Jun;39(6):1589-1596. doi: 10.3892/ijmm.2017.2959. Epub 2017 Apr 20.

Abstract

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.

MeSH terms

  • Animals
  • Apoptosis*
  • Cell Hypoxia
  • Cell Line
  • Down-Regulation*
  • GATA4 Transcription Factor / genetics*
  • MicroRNAs / genetics*
  • Myocytes, Cardiac / cytology*
  • Myocytes, Cardiac / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / genetics
  • Rats
  • Up-Regulation

Substances

  • GATA4 Transcription Factor
  • MIRN200 microRNA, rat
  • MicroRNAs
  • Proto-Oncogene Proteins c-bcl-2