New Fundamentals Of MicrorRNAs In Regulation Of Atrial Fibrillation

Atrial fibrillation (AF) is one of the most common clinical arrhythmias. Epidemiological assessment shows that the prevalence rate in general population is1%, and7.1%in those>85years. The main harm of AF is that it can cause ischemic stroke due to thromboembolism, and can lead to exacerbation of heart failure and ventricular fibrillation. At present, the drug of AF is not ideal, thus in-depth insight into the mechanism of AF has profound guiding significance in the future treatment strategies.Presently, the known mechanisms of AF include structural remodeling (such as changes in cardiocytes and myocardial interstitium), electrical remodeling (such as changes in calcium channel, potassium channel and autorhythmic activity), ionic remodeling (the calcium ionic remodeling), inflammation, and oxidative stress. MicroRNAs (miRNAs) are single-stranded endogenous non-coding small RNAs with the length of21-23nucleotides, regulating the gene expression at the post-transcriptional level, and playing a significant regulatory role in the development of AF.Currently, studies on AF-related miRNAs are in the beginning stage, and most of the studies are limited to animal samples, especially myocardial samples. Studies have shown that various miRNAs including miR-1, miR-133, miR-26, miR-328, miR-590play a role in structural remodeling, electrical remodeling and ionic remodeling of AF, and the same miRNA may be involve in different remodeling process. MiRNA in peripheral blood can resist the degradation of RNAase through multiple approaches, thus keeping their stability.Only a few studies have analyzed the regulatory changes of several miRNAs, including miR-208a/b, miR-499, miR-1, miR-133and miR-423, in peripheral blood after cardiomyocyte damage in coronary heart disease, acute myocardial infarction, acute heart failure and viral myocarditis, but no studies are performed to investigate the change of miRNA in peripheral blood in AF patients. Advanced knowledge in the role of miRNA in the regulation of AF contributes to the further understanding of the development of AF, and has an important significance in the discovery of new therapeutic targets.