Exosomes of bone-marrow stromal cells inhibit cardiomyocyte apoptosis under ischemic and hypoxic conditions via miR-486-5p targeting the PTEN/PI3K/AKT signaling pathway

Thromb Res. 2019 May:177:23-32. doi: 10.1016/j.thromres.2019.02.002. Epub 2019 Feb 2.

Authors

Xiang-Hua Sun¹, Xu Wang², You Zhang³, Jie Hui⁴

Affiliations

¹ Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou 215006, PR China; Department of Cardiology, Shaoyang Central Hospital, Shaoyang 422000, PR China.
² Department of Cardiovascular Surgery, The First Affiliated Hospital of Soochow University, Suzhou 215006, PR China.
³ Department of Cardiology, The Second Affiliated Hospital of Soochow University, Suzhou 215004, PR China.
⁴ Department of Cardiology, The First Affiliated Hospital of Soochow University, Suzhou 215006, PR China. Electronic address: huijie92@163.com.

PMID: 30844685
DOI: 10.1016/j.thromres.2019.02.002

Abstract

Background: Myocardial ischemia-reperfusion injury (MIRI) is a major obstacle in the treatment of ischemic heart disease. Recent studies have shown that exosomes-small membrane vesicles secreted by most cell types-could have a protective effect on the ischemic myocardium. In this study we explored the effect of exosomes derived from bone-marrow stromal cells (BMSC-exo) on cardiomyocyte apoptosis and MIRI.

Methods: Exosomes were purified from culture media using the ExoQuick kit and observed using transmission electron microscopy. Cell viability was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell apoptosis was analyzed by flow cytometry using the Annexin-V/PI stain. The expression levels of microRNA (miRNA), messenger RNA (mRNA) and PTEN/PI3K/AKT-pathway-related proteins were detected by qRT-PCR and western blot, respectively. Myocardial ischemia was simulated by incubating H9C2 cells in a hypoxia/reoxygenation (H/R) conditioned rat MIRI model.

Results: BMSC-exo induced the proliferation of H9C2 cells and rescued H9C2 cells from apoptosis in the H/R model, indicating that BMSC-exo has a protective effect on cardiomyocyte injury caused by H/R. Using transgenic H9C2 cells, we found that miR-486-5p in BMSC-exo suppressed the H/R-triggered apoptosis of H9C2 cells. In addition, BMSC-exo repressed the expression of PTEN in H9C2 cells via miR-486-5p, and subsequently activated the PI3K/AKT pathway in vitro. Moreover, the myocardial injury caused by ischemia/reperfusion was repaired by BMSC-exo which activates the PI3K/AKT pathway via miR-486-5p in vivo.

Conclusion: Our results suggested that exosomes from BMSCs have a protective effect on myocardium ischemic injury. MiR-486-5p carried by BMSC-exo plays a pivotal role in the regulatory process by suppressing PTEN expression, activating the PI3K/AKT signaling pathway, and subsequently inhibiting the apoptosis of injured cardiomyocytes.

Keywords: Apoptosis; BMSC; Exosome; MiR-486-5p; Myocardial ischemia-reperfusion injury; PTEN/PI3K/AKT.

MeSH terms

Animals
Apoptosis
Cells, Cultured
Exosomes / genetics
Exosomes / metabolism
Exosomes / transplantation*
Gene Expression Regulation
Male
Mesenchymal Stem Cells / metabolism
MicroRNAs / genetics*
Myocardial Reperfusion Injury / genetics
Myocardial Reperfusion Injury / metabolism
Myocardial Reperfusion Injury / therapy*
Myocytes, Cardiac / cytology*
Myocytes, Cardiac / metabolism
PTEN Phosphohydrolase / genetics
PTEN Phosphohydrolase / metabolism
Phosphatidylinositol 3-Kinases / metabolism
Proto-Oncogene Proteins c-akt / metabolism
Rats, Sprague-Dawley
Signal Transduction*

Substances

MIRN486 microRNA, rat
MicroRNAs
Proto-Oncogene Proteins c-akt
PTEN Phosphohydrolase