Circulatory miRNAs in essential hypertension

MicroRNAs (miRNAs) are short non-coding RNAs, that regulate gene-expression at post-transcriptional level. Unlike other RNA species, blood miRNAs circulate in a highly stable form, either within extracellular vesicles or bound to proteins. In recent years, circulatory miRNA profiles have been proposed as potential biomarkers for multitude of pathologies, including essential hypertension. However, the evidence of miRNA biomarker potential is limited, mainly due to the scarcity of profiling studies associating miRNA levels with hypertension. Furthermore, most of these studies have been performed with preselected miRNA pool, limiting their discovery potential. Here, we summarize the results of the unbiased profiling studies and additionally discuss findings from targeted miRNA analysis. Only miR-30e has been found to be associated with hypertension in more than one unbiased study. The targeted analyses highlight the association of miR-1, -21, −34a, −92a, −122, −126, −143, −145, −605, −623, −1299, as well as let-7 and miR-30 families with hypertension. Current literature indicates that some of these miRNAs are involved in hypertension-associated vascular dysfunction and the development of atherosclerosis, suggesting a novel mechanism for cardiovascular disease risk posed by hypertension. All in all, studies associating hypertension with circulatory miRNA profiles are scarce, with several limitations affecting the comparability of the studies. This review discusses the functions and potential mechanisms linking the identified miRNAs to hypertension and underscores the need for further research.