Extracellular circulating microRNAs (miRNAs) are currently a focus of interest as non-invasive biomarkers of cardiovascular pathologies, including coronary artery disease (CAD) and acute coronary syndromes (ACS): myocardial infarction with and without ST-segment elevation (STEMI and NSTEMI) and unstable angina (UA). However, the current data for some miRNAs are controversial and inconsistent, probably due to pre-analytical and methodological variances in different studies. In this work, we fulfilled the basic pre-analytical requirements provided for circulating miRNA studies for application to stable CAD and ACS research. We used quantitative PCR to determine the relative plasma levels of eight circulating miRNAs that are potentially associated with atherosclerosis. In a cohort of 136 adult clinic CAD patients and outpatient controls, we found that the plasma levels of miR-21-5p and miR-146a-5p were significantly elevated in ACS patients, and the level of miR-17-5p was decreased in ACS and stable CAD patients compared to both healthy controls and hypertensive patients without CAD. Within the ACS patient group, no differences were found in the plasma levels of these miRNAs between patients with positive and negative troponin, nor were any differences found between STEMI and NSTEMI. Our results indicate that increased plasma levels of miR-146a-5p and miR-21-5p can be considered general ACS circulating biomarkers and that lowered miR-17-5p can be considered a general biomarker of CAD.

The potential of extracellular circulating microRNAs (miRNAs) as non-invasive biomarkers of atrial fibrillation (AF) has been confirmed by a number of recent studies. However, the current data for some miRNAs are controversial and inconsistent, probably due to pre-analytical and methodological differences. In this work, we attempted to fulfill the basic pre-analytical requirements provided for circulating miRNA studies for application to paroxysmal atrial fibrillation (PAF) research. We used quantitative PCR (qPCR) to determine the relative plasma levels of circulating miRNAs expressed in the heart or associated with atrial remodeling or fibrillation with reported altered plasma/serum levels in AF: miR-146a-5p, miR-150-5p, miR-19a-3p, miR-21-5p, miR-29b-3p, miR-320a-3p, miR-328-3p, miR-375-3p, and miR-409-3p. First, in a cohort of 90 adult outpatient clinic patients, we found that the plasma level of miR-320a-3p was elevated in PAF patients compared to healthy controls and hypertensive patients without AF. We further analyzed the impact of medication therapies on miRNA relative levels and found elevated miR-320a-3p levels in patients receiving angiotensin-converting-enzyme inhibitors (ACEI) therapy. Additionally, we found that miR-320a-3p, miR-21-5p, and miR-146a-5p plasma levels positively correlated with the CHA₂DS₂-Vasc score and were elevated in subjects with CHA₂DS₂-Vasc ≥ 2. Our results indicate that, amongst the analyzed miRNAs, miR-320a-3p may be considered as a potential PAF circulating plasma biomarker, leading to speculation as to whether this miRNA is a marker of platelet state change due to ACEI therapy.

Aim. To study the plasma profiles of circulating extracellular microribonucleic acids (miRNAs), potentially including in pathogenesis of cardiovascular diseases, in patients with atrial fibrillation (AF) in combination with hypertension (HTN) or coronary artery disease (CAD).Material and methods. The study included patients with AF in combi nation with HTN (n=21) or CAD (n=10), as well as following control groups: patients with uncomplicated HTN without AF (n=28), patients with stable CAD without AF (n=10) and healthy individuals (n=30). MiRNA samples were isolated from blood plasma of the study participants. MiRNAs were detected by TaqMan quantitative polymerase chain reaction assay. The relative plasma levels of five candidate miRNAs were estimated relative to the reference miR-16-5p.Results. Among the analyzed circulating plasma miRNAs, a higher level of miR-320a-3p was associated with AF, while increased levels of miR 146a-5p and miR-21-5p are potentially associated with presence of both AF and CAD.Conclusion. Differences were found in the plasma miRNA profiles (miR-21-5p, miR-320a-3p, miR-146a-5p) between patients with AF, regardless of concomitant disease (CAD or HTN), and healthy individuals in the control group.

Objective. To analyze serum circulating microRNAs (c-microRNAs) in patients with various forms of coronary artery disease (CAD) considering basic pre-analytical requirements necessary for analysis of c-microRNAs. Material and methods. Quantitative PCR was used to analyze serum c-microRNA (miR-21-5p, miR-155-5p, miR-17-5p, miR-92a-3p, miR-126-3p, miR-145-5p, miR-146a -5p and miR-375-3p) potentially associated with atherosclerosis. Results. We assessed 136 men and women and found that serum miR-146a-5p and miR-21-5p were significantly higher in patients with acute coronary syndrome (ACS). Serum miR-17-5p was lower in patients with ACS and stable CAD compared to healthy individuals and patients with arterial hypertension without CAD. In patients with ACS, there were no differences in serum microRNAs among patients with myocardial infarction and unstable angina. In addition, serum microRNAs in patients with myocardial infarction with and without ST segment elevation did not show significant differences. Conclusion. Elevated serum miR-21-5p and miR-146a-5p can be considered as a significant biomarker of ACS, while serum miR-17-5p should be regarded as a general biomarker of CAD.

Aim. To compare the relative expression levels of circulating microRNAs associated with cardiovascular diseases, selected according to the literature review, in the blood plasma samples of patients with two variants of chronic vascular wall injury: coronary artery atherosclerosis (CAA) and thoracic aortic aneurysm (TAA).Material and methods. Patients admitted to the Clinical Center of the I. M. Sechenov First Moscow State Medical University (University Clinical Hospital No. 1) with CAA (n=45), TAA (n=38), as well as a control group (n=17) were included. Standard clinical and demographic, laboratory and instrumental data were collected in accordance with Russian clinical guidelines, and additional sampling and preparation of blood plasma of patients was carried out with further quantitative determination of the circulating microRNAs level via real-time polymerase chain reaction with reverse transcription. A comprehensive comparative analysis of the profiles of circulating microRNAs in the blood plasma of patients with two different variants of arterial pathology: atherosclerosis and aneurysmal changes, as well as with the control group was carried out. The levels of 12 circulating microRNAs were studied: miR-21-5p, -23a-3p, -29b-3p, -92a-3p, -126-5p, -143-3p, -145-5p, -146a-5p, -150-5p, -181b-5p, 2-23-3p and -451a.Results. The strongest difference with the control group in patients with CAA and TAA was observed for miR-21-5p, -29b-3p and -126-3p. Most of the circulating microRNAs studied were higher in the TAA group compared with CAA and controls these include miR-21-5p, -23a-3p, -29b-3p, -92a-3p, -126-3p, -126-5p, -146a-5p, -150-5p, -181b-5p. Significant differences between the pathology groups were noted for miR-126-3p and miR-205-5p. Some microRNAs (­miR-143-3p, -92 a3, -195-5 p) can be used to diagnose coronary artery atherosclerosis, other microRNAs (miR-21-5p, -23a-3p, -126-3p, -126-5p, -451a) are TAA-specific.Conclusion. The present study showed significant differences in the circulating microRNAs in patients with atherosclerotic and aneurysmal lesions of the arteries in comparison with the control group. The most significant difference between norm and pathology was found for miR-21-5p, -29b-5p and -126-3p. The levels of miR-126-3p and -205-5p can be used to differentiate CAA and TAA.

OBJECTIVE To analyze expression of microRNAs miRNAlet7a, miRNA21, miRNA92 and miRNA221 in reversible atherosclerotic plaques. MATERIAL AND METHODS The main group included patients with coronary endarterectomy during coronary artery bypass grafting (n=6) and patients after carotid endarterectomy (n=5). The control group included specimens of coronary arteries in 6 patients with atherosclerosis who died from non-cardiac causes. Molecular genetic analysis of microRNA was carried out using in situ hybridization with LNA probes. We analyzed expression of short microRNAs in carotid and coronary plaques, as well as relationship between microRNA and stability/instability of atherosclerotic plaques. The Mann-Whitney U test was used to compare microRNA expression in coronary and carotid arteries. RESULTS According to the Mann-Whitney test for expression of microRNA 221 in smooth muscle cells, the apparent value was greater than critical value at initialization level of <0.05. This demonstrates a significant relationship between microRNA 221 expression in smooth muscle cells and plaque localization in coronary arteries. There was significantly more active microRNA 221 staining in smooth muscle cells of coronary artery plaques compared to carotid arteries (p<0.05). CONCLUSION Increased expression of some microRNAs was revealed in unstable atherosclerotic plaques in coronary and carotid atherosclerosis. However, expression of microRNA 221 is characteristic exclusively for coronary lesions.