Protective Effects of MicroRNA-200b-3p Encapsulated by Mesenchymal Stem Cells–Secreted Extracellular Vesicles in Myocardial Infarction Via Regulating BCL2L11

Abstract

BACKGROUND: Extracellular vesicles (EVs) are a popular treatment candidate for myocardial injury. This work investigated the effects of mesenchymal stem cells (MSCs)–secreted EVs–derived miR-200b-3p on cardiomyocyte apoptosis and inflammatory response after myocardial infarction (MI) through targeting BCL2L11 (Bcl-2–like protein 11). METHODS AND RESULTS: EVs from MSCs were isolated and identified. EVs from MSCs with transfection of miR-200b-3p for overexpression were injected into MI mice. The effect of miR-200b-3p on cardiac function, infarction area, myocardial fibrosis, cardiomyocyte apoptosis, and inflammatory response was determined in MI mice. The targeting relationship between miR200b-3p and BCL2L11 was verified, and the interaction between BCL2L11 and NLR family pyrin domain containing 1 (NLRP1) was also verified. MI mice were injected with an overexpressing BCL2L11 lentiviral vector to clarify whether BCL2L11 can regulate the effect of miR-200b-3p on MI mice. EVs from MSCs were successfully extracted. MSCs-EVs improved cardiac function and reduced infarction area, apoptosis of cardiomyocytes, myocardial fibrosis, and inflammation in MI mice. Upregulation of miR-200b-3p further enhanced the effects of MSCs-EVs on the myocardial injury of MI mice. BCL2L11 was targeted by miR200b-3p and bound to NLRP1. Upregulation of BCL2L11 negated the role of miR-200b-3p–modified MSCs-EVs in MI mice. CONCLUSIONS: A summary was obtained that miR-200b-3p–encapsulated MSCs-EVs protect against MI-induced apoptosis of cardiomyocytes and inflammation via suppressing BCL2L11.