Serum Extracellular Vesicles Attenuate Cardiomyocyte Injury Induced by Hypoxic/Reoxygenation by Regulating miR-1229-5p

Serum Extracellular Vesicles Attenuate Cardiomyocyte Injury Induced by Hypoxic/Reoxygenation by Regulating miR-1229-5p

Yinhao Jin,¹ Guiqing Liu,¹ Qianqian Yu,¹ Shumin Ma¹ and Ming Chang¹

¹Department of Cardiology, The First Affiliated Hospital of Qiqihar Medical College, Qiqihar, Heilongjiang, China

Ischemic heart disease and the resulting heart failure remain the leading causes of death and disability worldwide. This study aimed to investigate the role of miR-1229-5p in serum extracellular vesicles (EVs) mediated myocardial protection by constructing a hypoxia/reoxygenation model (HR) in H9c2 cells. Cardiomyocytes were cultured and divided into different treatment groups: control group, HR group, serum-EVs group, and serum-EVs + miR-1229-5p inhibitor group. The expression levels of miR-1229-5p were detected using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The changes in cell proliferation and apoptosis were detected by MTT assay and flow cytometry. The myocardial injury-related indicators, cardiac troponin I (cTnI), creatinine kinase MB (CK-MB), and lactate dehydrogenase (LDH), were measured by enzyme-linked immunosorbent assay (ELISA). Finally, the luciferase reporter assay was used to verify the miR-1229-5p target. The proliferation of myocardial cells in the HR group was reduced, the number of apoptotic cells was increased, and myocardial injury indicators concentration was decreased. Transfection of miR-1229-5p inhibitor under serum-EVs treatment reduced the protective effect of serum-EVs on myocardial cell injury, decreased cell proliferation, increased the number of apoptotic cells, and increased myocardial injury indicator concentration. Additionally, FOXO4 may be the target of miR-1229-5p. Our data suggest that serum-EVs alleviate HR-induced cardiomyocyte injury by regulating miR-1229-5p/FOXO4.

Keywords —— hypoxia/reoxygenation; miR-129-5p; myocardial injury; serum extracellular vesicles

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Tohoku J. Exp. Med 2022, 258, 35-41.

Correspondence: Ming Chang, Department of Cardiology, The First Affiliated Hospital of Qiqihar Medical College, No.26 Xiangyang Street, Fulaerji District, Qiqihar, Heilongjiang 161041, China.

e-mail: changmingqqhe@163.com