MicroRNA-532 protects the heart in acute myocardial infarction, and represses prss23, a positive regulator of endothelial-to-mesenchymal transition.
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ABSTRACT: Aims:Acute myocardial infarction (MI) leads to cardiac remodelling and development of heart failure. Insufficient myocardial capillary density after MI is considered a critical determinant of this process. MicroRNAs (miRs), negative regulators of gene expression, have emerged as important players in MI. We previously showed that miR-532-5p (miR-532) is up-regulated by the ?-arrestin-biased ?-adrenergic receptor antagonist (?-blocker) carvedilol, which activates protective pathways in the heart independent of G protein-mediated second messenger signalling. Here, we hypothesize that ?2-adrenergic receptor/?-arrestin-responsive miR-532 confers cardioprotection against MI. Methods and results:Using cultured cardiac endothelial cell (CEC) and in vivo approaches, we show that CECs lacking miR-532 exhibit increased transition to a fibroblast-like phenotype via endothelial-to-mesenchymal transition (EndMT), while CECs over-expressing miR-532 display decreased EndMT. We also demonstrate that knockdown of miR-532 in mice causes abnormalities in cardiac structure and function as well as reduces CEC proliferation and cardiac vascularization after MI. Mechanistically, cardioprotection elicited by miR-532 is in part attributed to direct repression of a positive regulator of maladaptive EndMT, prss23 (a protease serine 23) in CECs. Conclusions:In conclusion, these findings reveal a pivotal role for miR-532-prss23 axis in regulating CEC function after MI, and this novel axis could be suitable for therapeutic intervention in ischemic heart disease.
SUBMITTER: Bayoumi AS
PROVIDER: S-EPMC5852516 | biostudies-literature | 2017 Nov
REPOSITORIES: biostudies-literature
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