Circulating microRNAs in cardiovascular diseases: from biomarkers to therapeutic targets.

microRNAs (miRNAs) are a class of conserved, short, non-coding RNAs that have important and potent capacities to regulate gene expression at the posttranscriptional level. In the past several years, the aberrant expressions of miRNAs in the cardiovascular system have been widely reported, and the crucial roles of some special miRNAs in heart development and pathophysiology of various cardiovascular diseases have been gradually recognized. Recently, it was discovered that miRNAs are presented in peripheral circulation abundantly and stably. This has raised the possibility of using circulating miRNAs as biomarkers for diseases. Furthermore, some studies demonstrated that circulating miRNAs may serve as novel extracellular communicators of cell-cell communication. These discoveries not only reveal the functions of circulating miRNAs in cardiovascular system but also inform the development of miRNAs therapeutic strategies. In this review, we discuss the potential roles of circulating miRNAs in a variety of cardiovascular diseases from biomarkers to therapeutic targets to clearly understand the roles of circulating miRNAs in cardiovascular system.