MicroRNA expression signature and the role of MicroRNA-21 in the early phase of acute myocardial infarction

Shimin Dong, Yunhui Cheng, Jian Yang, Jingyuan Li, Xiaojun Liu, Xiaobin Wang, Dong Wang, Thomas J. Krall, Ellise S. Delphin, Chunxiang Zhang

Research output: Contribution to journalArticlepeer-review

407 Scopus citations


Several recent reports have suggested that microRNAs (miRNAs) might play critical roles in acute myocardial infarction (AMI). However, the miRNA expression signature in the early phase of AMI has not been identified. In this study, the miRNA expression signature was investigated in rat hearts 6 h after AMI. Compared with the expression signature in the non-infarcted areas, 38 miRNAs were differentially expressed in infarcted areas and 33 miRNAs were aberrantly expressed in the border areas. Remarkably, miR-21 expression was significantly down-regulated in infarcted areas, but was up-regulated in border areas. The down-regulation of miR-21 in the infarcted areas was inhibited by ischemic preconditioning, a known cardiac protective method. Overexpression of miR-21 via adenovirus expressing miR-21 (Ad-miR-21) decreased myocardial infarct size by 29% at 24 h and decreased the dimension of left ventricles at 2 weeks after AMI. Using both gain-of-function and loss-of-function approaches in cultured cardiac myocytes, we identified that miR-21 had a protective effect on ischemia-induced cell apoptosis that was associated with its target gene programmed cell death 4 and activator protein 1 pathway. The protective effect of miR-21 against ischemia-induced cardiac myocyte damage was further confirmed in vivo by decreased cell apoptosis in the border and infarcted areas of the infarcted rat hearts after treatment with Ad-miR-21. The results suggest that miRNAs such as miR-21 may play critical roles in the early phase of AMI.

Original languageEnglish (US)
Pages (from-to)29514-29525
Number of pages12
JournalJournal of Biological Chemistry
Issue number43
StatePublished - Oct 23 2009
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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