Human epicardial adipose tissue-secreted miR-92a-3p regulates myocardial redox state via paracrine signalling: implications for cardiovascular clinical outcomes
European Heart Journal(2023)
摘要
Abstract Background Visceral obesity is directly linked to increased cardiovascular risk, including heart failure. Purpose We explored the ability of human epicardial adipose tissue (EAT)-derived microRNAs (miRNAs) to regulate the myocardial redox state and clinical outcomes. Methods The 5 study arms included 466 patients undergoing cardiac surgery to perform: 1) the discovery phase in which we screened for 351 miRNAs expressed and released from human EAT; 2) correlation analyses between EAT microRNAs and myocardial expression of their targets or myocardial superoxide production in paired EAT/atrial biopsies; 3) genome-wide association screening for miR-92a-3p expression in EAT to test causality/directionality; 4) ex vivo experiments to investigate the underlying mechanisms that were also studied in vitro and in vivo; 5) an 8-year follow-up study to test the prognostic value of the discovered miRNA. Superoxide (O2.-) generation was measured by lucigenin chemiluminescence with NADPH 100μM stimulation as indicator of NADPH-oxidases activity. Vas2870 400 μM (a specific pan-NADPH oxidase inhibitor) was used to obtain the Vas2870-inhibitable O2.- signal which constitutes a more specific index of NADPH oxidase activity. Activation of Rac1, a key NADPH-oxidases subunit, was evaluated by a commercially available kit. Differentiated H9c2 cells were used as an in vitro model of cardiomyocytes. Doxycycline-inducible Wnt5a-overexpressing mice were used for in vivo experiments. Results The EAT secretome profiling on study 1 patients led us to identify 3 microRNAs both expressed and released by EAT whose levels in EAT correlated with oxidative stress in human myocardium. Among these miRNAs only miR-92a-3p reduced NADPH-oxidase-derived superoxide (O2.-) in cardiomyocytes (A). A genetic screening identified 7 SNPs that were associated with high miR-92a-3p levels in EAT (EAT-miR-92a-3p SNPs) and were related to lower myocardial superoxide production (B). miR-92a-3p decreased both activation of Rac1 (not shown) and Wnt5a protein levels in vitro (C). Patients with high EAT miR-92a-3p levels had lower WNT5A levels in the myocardium (not shown). Ex vivo, in vivo and in vitro experiments showed opposite effects of Wnt5a on Rac1-mediated NADPH-oxidases activity (D and not shown). Finally, we found an association of miR-92a-3p levels in EAT with lower relative risk of adverse cardiovascular events (E). Conclusions EAT-derived miRNAs exert paracrine effects on the human heart. Indeed miR-92a-3p suppresses the Wnt5a/Rac1/NADPH oxidase axis and improves myocardial redox state. EAT-derived miR-92a-3p is related with improved clinical outcomes and is a rational therapeutic target for the prevention and treatment of obesity-related heart disease.
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关键词
myocardial redox state,cardiovascular,paracrine signalling,tissue-secreted
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