Recent research reveals the crucial role microRNAs (miRNAs) in the pathogenesis and progression of many pathological conditions, including cardiovascular diseases. It is widely documented that miRNAs represent critical regulators of cardiovascular function and participate in almost all aspects of cardiovascular biology. In particular, they are involved in several pathophysiological pathways of various manifestations of cardiovascular disease, such as coronary artery disease, heart failure, stroke, diabetes mellitus, arterial hypertension and cardiac arrhythmias. In the present article we review the available literature regarding to the role of miRNAs in certain cardiovascular conditions. Moreover, we discuss the therapeutic potential of miRNAs for treating cardiovascular diseases and we attempt to highlight future directions.

During the last decade, a growing body of evidence has shown an interplay of genetics and inflammation which leads to a greater understanding of the complex pathophysiology of atherosclerotic vascular disease. Of great interest are non-coding RNAs, called microRNAs due to their importance for many aspects of homeostasis and disease. According significant data they have been implicated in the regulation of several human physiological processes, while they seem to participate in cardiovascular disease pathogenesis including atherosclerosis and acute coronary syndromes. Accordingly, other biomarkers beyond troponins such as microRNAs could be proved very useful in the aim of enhancing diagnostic or therapeutic effectiveness. Notably, there is evidence that patients with unstable angina pectoris could be discriminated from stable patients, given higher expression levels of several microRNAs, suggesting that they could be used to identify patients at risk for acute coronary syndromes. Also, they may have a substantial therapeutic impact in the management of athero-thrombotic vascular disorders, even though there are still obstacles in their use for that purposes, such as the delivery of the drug to target cells. Thus, it will be necessary to further explore their complications, before their use as therapeutic option.

Peripheral arterial disease (PAD) is due to diffuse atherosclerosis. The pathological process is characterized mainly by the aberrant proliferation of vascular smooth muscle cells and the formation of neointimal lesions. MicroRNAs (miRNAs) are highly conserved non-coding small RNA molecules that regulate a large fraction of the genome by binding to complementary mRNA sequences, resulting in post-transcriptional gene silencing. Recent evidence has demonstrated that specific miRNAs are involved in the pathological development of PAD. In this review, the roles of specific miRNAs in PAD are summarized.

MicroRNAs (miRNAs) are small non-coding RNAs approximately 22 nucleotides in length that play a pivotal role in post-transcriptional gene regulation by binding to complementary sites in the 3'-untranslated region of messenger RNAs. In the past decade, their role in several human diseases, from cancer to cardiovascular disease, has been established by a wealth of evidence. Stroke is responsible for 10% of deaths worldwide and is one of the leading causes of disability. MiRNAs are involved in stroke risk factors including hypertension, atherosclerosis, atrial fibrillation, diabetes and dyslipidemia. The role of miRNAs in the pathophysiology of stroke has been the subject of more recent investigations. Animal studies, which dominate the field, have demonstrated the differential expression of miRNAs in brain and blood following ischemic or hemorrhagic insult and the potential use of miRNA antagonists to reduce focal cerebral damage. In particular, antagomirs to miR-145, -497, -181a, -1 and let-7f have been found to be neuroprotective in vivo. The discovery of circulating miRNAs in peripheral blood, which are unexpectedly stable, has allowed the recent completion of several studies in human stroke patients that have confirmed the differential expression of specific miRNAs following stroke and have addressed their potential use as diagnostic and prognostic markers. With miRNA research in stroke still in its infancy, it is anticipated that in the next few years significant discoveries that may have important therapeutic implications will emerge.

MicroRNAs (miRNAs) are non-coding RNAs of ~22 nucleotides which act as down regulators of gene expression in the post-transcription level and/or in the translation level. Several studies have shown that the process of their maturation is rather crucial for the development of cardiovascular system thus their regulation (up-,down-) is implicated with many cardiac pathologies. This is evaluated through their circulating levels which are reliable, stable and the changes in their serum profiles are representative of tissue alterations serum levels. Furthermore, they have been shown to participate in cardiovascular disease pathogenesis including atherosclerosis, coronary artery disease, myocardial infarction, heart failure cardiac arrhythmias and aortic stenosis. In the present review, we will first describe i) the process of miRNAs' maturation ii) their role in the cardiovascular development, iii) their role as biomarkers of cardiac diseases, iv) the cardiac myo-miR families and the v) their role in cardiac remodeling and the development of cardiac diseases. Second we will review the miRNA families that participate in aortic stenosis separated according to its main pathways (imflammation, fibrosis, calcification). Finally, we will describe the miRNAs that participate in the development of aortic aneurysm and aortic dissection according to their serum levels.

MicroRNAs are a class of evolutionarily small non-coding RNAs of 19 to 25 nucleotides in length, that represent one of the most exciting areas of current medical science as they can regulate a complex regulatory network of gene expression and physiologic processes including differentiation, proliferation and apoptosis in a highly context dependent fashion. Recently, their role in cardiovascular disease and in the regulation of cardiomyocyte size and function, in the action potential, in angiogenesis and in mitochondrial function was recognized. Importantly, they have been evaluated for their prognostic and diagnostic role in heart failure and modification of specific microRNAs levels has been tested as a therapeutic option in experimental heart failure models. In this review article we refer the most emerging evidence, concerning the role of microRNAs in myocardial development in heart failure pathophysiology and prognosis, and their therapeutic implications.

The increasing prevalence of coronary artery disease (CAD) as well as its' monitoring remain the crucial problems and fields of long debate. Thus, several circulating biomarkers have been found during the last decade and examined in terms of their potential to assist in the prognosis of CAD. Of great interest, are small non-coding RNAs (microRNAs or miRNAS or miRs), due to their association with many aspects of CAD. microRNAs circulate in the bloodstream, while they exist in tissues and affect plaque initiation and progression. In addition, they have been found to contribute to the pathophysiology of CAD and to the CAD-related manifestations such as myocardial infarction, heart failure and cardiac arrhythmias. Therefore, evaluating the role of these molecules may be of great importance in the understanding of atherogenesis providing new evidence for diagnosis and prognosis of CAD.

Diabetes mellitus (DM) is a complex metabolic disorder characterized by low insulin production/secretion by pancreatic beta cells and/or low responsiveness by insulin target tissues MicroRNAs have been associated with DM, but it is not clear whether this is a cause or an effect of metabolic abnormalities related to DM. In the hyperglycemic environment miRNAs are in involved in multiple stages of cardiovascular disease development and progression. In diabetic patients with cardiovascular disease miRNAs could potentially serve as early biomarkers for diagnosis and as therapeutic agents. The current review focuses on the involvement of miRNAs in molecular mechanisms underlying the pathogenesis of DM and its cardiovascular complications.

Arterial hypertension is an epidemic currently affecting almost a billion people worldwide. The consequences from high blood pressure vary, from peripheral arterial disease and chronic kidney failure to acute myocardial infarction and stroke. MicroRNAs (miRNAs) are small non-coding RNA molecules comprised of 22-26 nucleotides and provide post-transcriptional protein expression regulation. The many biological processes in which they are implicated, such as cell proliferation, apoptosis, metabolism, cell differentiation and morphogenesis confirms the functional significance of miRNAs. It has been found that miRNAs are expressed in cardiovascular disorders and seem to be important players in the pathogenesis of arterial hypertension. The elucidation of which miRNAs are key players and at what level is of high value since it is necessary in order to better understand the mechanisms underlying hypertension, thus leading to better diagnostic modalities and therapeutic regimes.

Endothelial dysfunction reflected by reduced nitric oxide availability is nowadays considered as a causative factor of atherosclerosis. A variety of biomarkers has been used as indicators of endothelial dysfunction in cardiovascular disease. Discovered just over a decade ago, microRNAs have evoked a great deal of interest, due to their importance for many aspects of homeostasis and disease. miRNAs comprise a novel class of endogenous, single-stranded, short RNA sequences able to regulate gene expression by binding to complementary sequences on mRNAs According to a growing body of evidence, they have been implicated in the regulation of several human physiological processes. They have been shown to participate in cardiovascular disease pathogenesis including atherosclerosis and endothelial dysfunction and this may have important clinical implications.