The role of miRNAs in regulation of platelet activity and related diseases - a bioinformatic analysis.

MicroRNAs (miRNAs) are small, non-coding RNAs, able to regulate cellular functions by induction of mRNA degradation and post-transcriptional repression of gene expression. Platelets are the major source of circulating miRNAs, with significant regulatory potential on cardiovascular pathophysiology and other diseases. MiRNAs have been shown to modify the expression of platelet proteins, which influence the platelets reactivity. Circulating miRNAs can be determined from plasma, serum, or whole blood, and they can be used as diagnostic and prognostic biomarkers as well as therapeutic targets including cardiovascular diseases (CVDs). Herein, we present original results from bioinformatic analyses, which identified top 22 platelet-related miRNAs including hsa-miR-320a, hsa-miR-16-5p, hsa-miR-106a-5p, hsa-miR-320b, hsa-miR-15a-5p, hsa-miR-15b-5p, hsa-miR-195-5p, hsa-miR-92a-3p as widely involved in platelet reactivity and associated diseases, including CVDs, Alzheimer's and cerebrovascular diseases, cancer and hypertension. Analysis focused on the identification of the highly regulatory targets shared between those miRNAs identified 43 of them. Best ranked genes associated with overall platelet activity and most susceptible for noncoding regulation were PTEN, PIK3R1, CREB1, APP, and MAPK1. Top targets also strongly associated with CVDs were VEGFA, IGF1, ESR1, BDNF, and PPARG. Top targets associated with other platelet-related diseases including cancer identified in our study were TP53, KRAS, and CCND1. The most affected pathways by top miRNAs and top targets included diseases of signal transduction by Growth Factor Receptors (GDFRs) and second messengers, platelet activation, signaling, and aggregation, signaling by VEGF, MAPK family signaling cascades, and signaling by Interleukins. Terms specific only for platelet-related miRNAs included coronary artery disease, platelet degranulation, and neutrophil degranulation, while for the top platelet-related genes it was Estrogen Signaling Receptor (ESR) mediated signaling, extra-nuclear estrogen signaling, and endometriosis. Our results show the novel features of platelet physiology and may provide a basis for further clinical studies focused on platelet reactivity. They also show in which aspects miRNAs can be promising biomarkers of platelet-related pathological processes.

Antiplatelet drugs and liver fibrosis.

Liver fibrosis results from an imbalance between extracellular matrix formation and degradation. The background of liver fibrosis is chronic inflammation and subsequent microcirculation disturbance including microthrombosis. Platelets actively participate in liver fibrosis not only as a part of the clotting system but also by releasing granules containing important mediators. In fact, platelets may play a dual role in the pathophysiology of liver fibrosis as they are able to stimulate regeneration as well as aggravate the destruction of the liver. Recent studies revealed that antiplatelet therapy correlates with inhibition of liver fibrosis. However, liver impairment is associated with extensive coagulation disorders thus the safety of antiplatelet therapy is an area for detailed exploration. In this review, the role of platelets in liver fibrosis and accompanying hemostatic disorders are discussed. Additionally, results of animal and human studies on antiplatelet drugs in liver disorders and their potential therapeutic utility are presented.

Alterations in Circulating MicroRNAs and the Relation of MicroRNAs to Maximal Oxygen Consumption and Intima-Media Thickness in Ultra-Marathon Runners.

The impact of long-term training on cardiovascular disease (CVD) is not clear. Carotid intima-media thickness (CIMT) test is recommended as a useful measure to diagnose the early stages of atherosclerosis. MicroRNAs (miRNAs) are altered due to endurance exercise and can be promising biomarkers of pathophysiological changes. We aimed to evaluate the association of circulating miRNAs with physical fitness and markers of atherosclerosis in ultra-marathon runners. Ultra-marathon runners had 28-fold upregulation of miR-125a-5p expressions compared to control individuals (p = 0.002), whereas let-7e and miR-126 did not differ statistically between ultra-marathon runners and controls. In the ultra-marathon runners' group, negative correlations were observed between VO2max/kg and relative expression of miR-125a-5p and miR-126 (r = -0.402, p = 0.028; r = -0.438, p = 0.032, respectively). Positive correlations were observed between CIMT and miR-125a-5p and miR-126 (r = 0.388, p = 0.050; r = 0.504, p = 0.023, respectively) in ultra-marathon runners. Individuals with the highest quartile of VO2max/kg had 23-fold lower miR-126 expression in comparison to subgroups with lower VO2max/kg (p = 0.017). Our results may indicate that both miRNAs may serve as a biomarker for early pathological changes leading to atherosclerosis burden in athletes. Furthermore, the association between miRNAs and traditional risk factors for CVD indicate a possible use of these molecules as early biomarkers of future cardiovascular health.

MiR-126 Is an Independent Predictor of Long-Term All-Cause Mortality in Patients with Type 2 Diabetes Mellitus.

MicroRNAs are endogenous non-coding RNAs that are involved in numerous biological processes through regulation of gene expression. The aim of our study was to determine the ability of several miRNAs to predict mortality and response to antiplatelet treatment among T2DM patients. Two hundred fifty-two patients with diabetes were enrolled in the study. Among the patients included, 26 (10.3%) patients died within a median observation time of 5.9 years. The patients were receiving either acetylsalicylic acid (ASA) 75 mg (65%), ASA 150 mg (15%) or clopidogrel (19%). Plasma miR-126, miR-223, miR-125a-3p and Let-7e expressions were assessed by quantitative real time PCR and compared between the patients who survived and those who died. Adjusted Cox-regression analysis was used for prediction of mortality. Differential miRNA expression due to different antiplatelet treatment was analyzed. After including all miRNAs into one multivariate Cox regression model, only miR-126 was predictive of future occurrence of long-term all-cause death (HR = 5.82, 95% CI: 1.3-24.9; p = 0.024). Furthermore, miR-126, Let-7e and miR-223 expressions in the clopidogrel group were significantly higher than in the ASA group (p = 0.014; p = 0.013; p = 0.028, respectively). To conclude, miR-126 expression is a strong and independent predictor of long-term all-cause mortality among patients with T2DM. Moreover, miR-223, miR-126 and Let-7e present significant interactions with antiplatelet treatment regimens and clinical outcomes.

MicroRNA as Potential Biomarkers of Platelet Function on Antiplatelet Therapy: A Review.

MicroRNAs (miRNAs) are small, non-coding RNAs, able to regulate cellular functions by specific gene modifications. Platelets are the major source for circulating miRNAs, with significant regulatory potential on cardiovascular pathophysiology. MiRNAs have been shown to modify the expression of platelet proteins influencing platelet reactivity. Circulating miRNAs can be determined from plasma, serum, or whole blood, and they can be used as diagnostic and prognostic biomarkers of platelet reactivity during antiplatelet therapy as well as novel therapeutic targets in cardiovascular diseases (CVDs). Herein, we review diagnostic and prognostic value of miRNAs levels related to platelet reactivity based on human studies, presenting its interindividual variability as well as the substantial role of genetics. Furthermore, we discuss antiplatelet treatment in the context of miRNAs alterations related to pathways associated with drug response.

MicroRNAs and long non-coding RNAs in the pathophysiological processes of diabetic cardiomyopathy: emerging biomarkers and potential therapeutics.

The epidemic of diabetes mellitus (DM) necessitates the development of novel therapeutic and preventative strategies to attenuate complications of this debilitating disease. Diabetic cardiomyopathy (DCM) is a frequent disorder affecting individuals diagnosed with DM characterized by left ventricular hypertrophy, diastolic and systolic dysfunction and myocardial fibrosis in the absence of other heart diseases. Progression of DCM is associated with impaired cardiac insulin metabolic signaling, increased oxidative stress, impaired mitochondrial and cardiomyocyte calcium metabolism, and inflammation. Various non-coding RNAs, such as microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), as well as their target genes are implicated in the complex pathophysiology of DCM. It has been demonstrated that miRNAs and lncRNAs play an important role in maintaining homeostasis through regulation of multiple genes, thus they attract substantial scientific interest as biomarkers for diagnosis, prognosis and as a potential therapeutic strategy in DM complications. This article will review the different miRNAs and lncRNA studied in the context of DM, including type 1 and type 2 diabetes and the contribution of pathophysiological mechanisms including inflammatory response, oxidative stress, apoptosis, hypertrophy and fibrosis to the development of DCM .

Long Non-coding RNAs as Promising Therapeutic Approach in Ischemic Stroke: a Comprehensive Review.

In recent years, ischemic stroke (IS) has been one of the major causes of disability and mortality worldwide. The general mechanism of IS is based on reduced blood supply to neuronal tissue, resulting in neuronal cell damage by various pathological reactions. One of the main techniques for acute IS treatment entails advanced surgical approaches for restoration of cerebral blood supply but this is often associated with secondary brain injury, also known as ischemic reperfusion injury (I/R injury). Many researches have come to emphasize the significant role of long non-coding RNAs (lncRNAs) in IS, especially in I/R injury and their potential as therapeutic approaches. LncRNAs are non-protein transcripts that are able to regulate cellular processes and gene expression. Further, lncRNAs have been shown to be involved in neuronal signaling pathways. Several lncRNAs are recognized as key factors in the physiological and pathological processes of IS. In this review, we discuss the role of lncRNAs in neuronal injury mechanisms and their association with brain neuroprotection. Moreover, we identify the lncRNAs that show the greatest potential as novel therapeutic approaches in IS, which therefore merit further investigation in preclinical research. Graphical Abstract.

The Importance of Non-Coding RNAs in Neurodegenerative Processes of Diabetes-Related Molecular Pathways.

Diabetes mellitus (DM) is a complex condition and serious health problem, with growing occurrence of DM-associated complications occurring globally. Persistent hyperglycemia is confirmed as promoting neurovascular dysfunction leading to irreversible endothelial cell dysfunction, increased neuronal cell apoptosis, oxidative stress and inflammation. These collaboratively and individually result in micro- and macroangiopathy as well as neuropathy demonstrated by progressive neuronal loss. Recently, major efforts have been pursued to select not only useful diagnostic and prognostic biomarkers, but also novel therapeutic approaches. Both microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) belong to a class of non-coding RNAs identified in most of the body fluids i.e., peripheral blood, cerebrospinal fluid, brain tissue and neurons. Numerous miRNAs, lncRNAs and their target genes are able to modulate signaling pathways known to play a role in the pathophysiology of progressive neuronal dysfunction. Therefore, they pose as promising biomarkers and treatment for the vast majority of neurodegenerative disorders. This review provides an overall assessment of both miRNAs' and lncRNAs' utility in decelerating progressive nervous system impairment, including neurodegeneration in diabetic pathways.

Significance of circulating microRNAs in diabetes mellitus type 2 and platelet reactivity: bioinformatic analysis and review.

In the light of growing global epidemic of type 2 diabetes mellitus (T2DM), significant efforts are made to discover next-generation biomarkers for early detection of the disease. Multiple mechanisms including inflammatory response, abnormal insulin secretion and glucose metabolism contribute to the development of T2DM. Platelet activation, on the other hand, is known to be one of the underlying mechanisms of atherosclerosis, which is a common T2DM complication that frequently results in ischemic events at later stages of the disease. Available data suggest that platelets contain large amounts of microRNAs (miRNAs) that are found in circulating body fluids, including the blood. Since miRNAs have been illustrated to play an important role in metabolic homeostasis through regulation of multiple genes, they attracted substantial scientific interest as diagnostic and prognostic biomarkers in T2DM. Various miRNAs, as well as their target genes are implicated in the complex pathophysiology of T2DM. This article will first review the different miRNAs studied in the context of T2DM and platelet reactivity, and subsequently present original results from bioinformatic analyses of published reports, identifying a common gene (PRKAR1A) linked to glucose metabolism, blood coagulation and insulin signalling and targeted by miRNAs in T2DM. Moreover, miRNA-target gene interaction networks built upon Gene Ontology information from electronic databases were developed. According to our results, miR-30a-5p, miR-30d-5p and miR-30c-5p are the most widely regulated miRNAs across all specified ontologies, hence they are the most promising biomarkers of T2DM to be investigated in future clinical studies.