Circulating miRNAs as biomarkers in cardiovascular diseases.

Cardiovascular diseases (CVDs) have shown a high prevalence every year, presenting arterial hypertension as prime factor for their development, also driven by population growth, the aging of population and epidemiologic changes in disease. One of the main challenges in the study of CVD is the identification of reliable biomarkers that can be used in clinical practice and, in this context, microRNAs (miRNAs) have attracted much attention recently. MiRNAs are small non-coding RNAs, identified as post-transcriptional regulators of the expression of several genes both in physiologic and pathologic conditions. They have been studied as possible biomarkers, since they are highly expressed in the vascular system and are crucial modulators for the differentiation, contraction, migration and apoptosis of vascular cells, so modifications in their expression can cause several vascular alterations. Thus, this review aimed to compile the main studies regarding the role of miRNAs in the development of cardiac diseases, their potential applicability in the diagnosis, prognosis and treatment of these disorders. It was possible to verify that alterations in miRNAs expression are present in almost all cardiovascular diseases, such as the development of cardiac hypertrophy, coronary heart disease, heart failure and other conditions. Furthermore, growing evidence indicates that circulating miRNAs may become a potential tool for rapid and easy tests, since they are detected in peripheral blood, also allowing new therapeutic possibilities.

MicroRNA profiling identifies miR-7-5p and miR-26b-5p as differentially expressed in hypertensive patients with left ventricular hypertrophy.

Recent evidence suggests that cell-derived circulating miRNAs may serve as biomarkers of cardiovascular diseases. However, a few studies have investigated the potential of circulating miRNAs as biomarkers for left ventricular hypertrophy (LVH). In this study, we aimed to characterize the miRNA profiles that could distinguish hypertensive patients with LHV, hypertensive patients without LVH and control subjects, and identify potential miRNAs as biomarkers of LVH. LVH was defined by left ventricular mass indexed to body surface area >125 g/m2 in men and >110 g/m2 in women and patients were classified as hypertensive when presenting a systolic blood pressure of 140 mmHg or more, or a diastolic blood pressure of 90 mmHg or more. We employed miRNA PCR array to screen serum miRNAs profiles of patients with LVH, essential hypertension and healthy subjects. We identified 75 differentially expressed miRNAs, including 49 upregulated miRNAs and 26 downregulated miRNAs between LVH and control patients. We chose 2 miRNAs with significant differences for further testing in 59 patients. RT-PCR analysis of serum samples confirmed that miR-7-5p and miR-26b-5p were upregulated in the serum of LVH hypertensive patients compared with healthy subjects. Our findings suggest that these miRNAs may play a role in the pathogenesis of hypertensive LVH and may represent novel biomarkers for this disease.