Upregulated microRNA-381-5p strengthens the effect of dexmedetomidine preconditioning to protect against myocardial ischemia-reperfusion injury in mouse models by inhibiting CHI3L1

objective: Over the years, roles of microRNAs (miRNAs) in development of human diseases has been broadly investigated, while the role of dexmedetomidine (DEX) regulating miR-381-5p in myocardial ischemia-reperfusion injury (MIRI) remains largely unknown. Thus, we aimed to identify the effect of DEX on MIRI via mediating miR-381-5p. methods: The MIRI mice models were established by the ligation of the left anterior descending (LAD) artery and treated with miR-381-5p agomir, silenced chitinase-3-like 1 protein (CHI3L1) and DEX. The cardiac function, serum inflammatory factors, pathological changes and cardiomyocyte apoptosis of the mice' myocardial tissues were measured. The targeting relationship between miR-381-5p and CHI3L1 was predicted. results: MiR-381-5p expression was decreased while CHI3L1 expression was increased in myocardial tissues of MIRI mice. DEX preconditioning could improve cardiac function and attenuate the pathological changes, cardiomyocyte apoptosis in myocardial tissues and inflammatory response in serum of MIRI mice. MiR-381-5p agomir improved the protective impact of DEX on myocardial injury in MIRI mice. Moreover, there existed a target relation between miR-381-5p and CHI3L1. conclusions: Our study demonstrated that upregulated miR-381-5p strengthens the effect of DEX preconditioning to protect against MIRI in mouse models by inhibiting CHI3L1.