Manuscript title Microparticles Containing MiR-625-5p In Coronary Artery Reduce Myocardial Fibrosis After Myocardial Infarction

Purpose: Blood from infarct-related arteries obtained by thrombus aspiration is good material for studying the local microenvironment of blood vessels in myocardial infarction. Here, we aimed to observe the effects of intracoronary microparticles (MPs) on cardiac fibrosis and to find associated microRNAs in MPs.MethodsBlood samples were collected from patients with ST-segment elevation myocardial infarction who underwent emergency percutaneous coronary intervention, and sub-supersonic centrifugation was used to separate the MPs.ResultsWe found that rats treated with intracoronary MPs showed better cardiac function after myocardial infarction compared with rats treated with PBS control or peripheral MPs. RNA microarray analysis indicated that microRNAs, especially miR-625-5p, may play a role in the process. Supplementation with miR-625-5p inhibited proliferation of cardiac fibroblasts and myocardial fibrosis in a mouse myocardial infarction model. ConclusionOur findings indicate that plasma MPs in infarct-related arteries in patients with acute myocardial infarction can inhibit myocardial fibrosis and improve cardiac function, with a process mediated by miR-625-5p and HMGA1 (high mobility group AT-hook 1). The current study may provide a possible reference for thrombus aspiration standard.