Detection of platelet microRNA expression in patients with diabetes mellitus with or without ischemic stroke

Platelet-derived microvesicles isolated from type-2 diabetes mellitus patients harbour an altered miRNA signature and drive MDA-MB-231 triple-negative breast cancer cell invasion

The underlying causes of breast cancer are diverse, however, there is a striking association between type 2 diabetes and poor patient outcomes. Platelet activation is a common feature of both type 2 diabetes and breast cancer and has been implicated in tumourigenesis through a multitude of pathways. Here transcriptomic analysis of type 2 diabetes patient-derived platelet microvesicles revealed an altered miRNA signature compared with normoglycaemic control patients. Interestingly, interrogation of these data identifies a shift towards an oncogenic signature in type 2 diabetes-derived platelet microvesicles, with increased levels of miRNAs implicated in breast cancer progression and poor prognosis. Functional studies demonstrate that platelet microvesicles isolated from type 2 diabetes patient blood are internalised by triple-negative breast cancer cells in vitro, and that co-incubation with type 2 diabetes patient-derived platelet microvesicles led to significantly increased expression of epithelial to mesenchymal transition markers and triple-negative breast cancer cell invasion compared with platelet microvesicles from healthy volunteers. Together, these data suggest that circulating PMVs in type 2 diabetes patients may contribute to the progression of triple-negative breast cancer.

Considering Context-Specific microRNAs in Ischemic Stroke with Three "W": Where, When, and What

MicroRNAs are short non-coding RNA molecules that function as critical regulators of various biological processes through negative regulation of gene expression post-transcriptionally. Recent studies have indicated that microRNAs are potential biomarkers for ischemic stroke. In this review, we first illustrate the pathogenesis of ischemic stroke and demonstrate the biogenesis and transportation of microRNAs from cells. We then discuss several promising microRNA biomarkers in ischemic stroke in a context-specific manner from three dimensions: biofluids selection for microRNA extraction (Where), the timing of sample collection after ischemic stroke onset (When), and the clinical application of the differential-expressed microRNAs during stroke pathophysiology (What). We show that microRNAs have the utilities in ischemic stroke diagnosis, risk stratification, subtype classification, prognosis prediction, and treatment response monitoring. However, there are also obstacles in microRNA biomarker research, and this review will discuss the possible ways to improve microRNA biomarkers. Overall, microRNAs have the potential to assist clinical treatment, and developing microRNA panels for clinical application is worthwhile.

Increased intracellular miR-142 in adults with Type 1 diabetes

microRNAs (miRs), including miR-142, modulate gene expression and processes implicated in vascular damage and may serve as therapeutic targets and agents, including in Type 1 diabetes (T1D). The project aimed to assess whether miR-142 levels differ between people with and without T1D, and to analyse miR-142 associations with cardiovascular (CVD) risk factors. Intracellular miRs were isolated from whole blood cell pellets using TRIzol-based methodology. In a cross-sectional study in 102 adults cellular miR-142 levels were significantly higher (on unadjusted and adjusted analyses) in 69 adults with T1D relative to 33 non-diabetic subjects: mean ± SD, 3.53 ± 3.66 vs. 1.25 ± 0.78, p < 0.0002, but were not related to HbA1c levels. Further miR-142 research, including longitudinal and intervention studies and basic science are of interest. miR-142 may be valuable in clinical practice for predicting health and as a treatment target.

PM2.5 induces alterations in gene expression profile of platelet-derived extracellular vesicles and mediates cardiovascular injury in rats

Platelet-derived extracellular vesicles (P-EVs), as the most abundant vesicles in blood, have been proven to play cardinal roles in cardiovascular injury. RNAs (especially miRNAs) carried by P-EVs can be transferred to the receptor, which plays a critical role in regulating vascular endothelial function. PM2.5 is one of the most well-known risk factors that cause cardiovascular disease. Therefore, the objective of the current study was to explore whether exposure to PM2.5 would alter the gene expression profile of P-EVs, and to further elucidate the role of RNAs (especially miRNAs) carried by P-EVs in cardiovascular injury induced by PM2.5 exposure. P-EVs were isolated from the platelet-rich plasma which was exposed and unexposed to PM2.5, and the differentially expressed target genes were evaluated using whole-transcriptome gene sequencing. Rats were treated with P-EVs under different exposure conditions (a protein concentration of 50 µg/mL) and an equal volume of normal saline. The pathological damage of the thoracic aorta and cardiac tissue was evaluated and the coagulation function of the rats was detected. The differentially expressed genes were shown to be mainly concentrated in inflammation, angiogenesis, and apoptosis-related pathways. Moreover, P-EVs extracted from PM2.5-exposed plasma had the potential to trigger an inflammatory response, impair vascular endothelial function, disrupt the normal coagulation process, and promote a prothrombotic state. Our study indicated that PM2.5 induces cardiovascular injury in rats by interfering with the gene expression of P-EVs. It will provide new targets for studying the mechanism involved in PM2.5-induced cardiovascular injury.

Text mining-based identification of promising miRNA biomarkers for diabetes mellitus

Introduction

MicroRNAs (miRNAs) are small, non-coding RNAs that play a critical role in diabetes development. While individual studies investigating the mechanisms of miRNA in diabetes provide valuable insights, their narrow focus limits their ability to provide a comprehensive understanding of miRNAs' role in diabetes pathogenesis and complications.

Methods

To reduce potential bias from individual studies, we employed a text mining-based approach to identify the role of miRNAs in diabetes and their potential as biomarker candidates. Abstracts of publications were tokenized, and biomedical terms were extracted for topic modeling. Four machine learning algorithms, including Naïve Bayes, Decision Tree, Random Forest, and Support Vector Machines (SVM), were employed for diabetes classification. Feature importance was assessed to construct miRNA-diabetes networks.

Results

Our analysis identified 13 distinct topics of miRNA studies in the context of diabetes, and miRNAs exhibited a topic-specific pattern. SVM achieved a promising prediction for diabetes with an accuracy score greater than 60%. Notably, miR-146 emerged as one of the critical biomarkers for diabetes prediction, targeting multiple genes and signal pathways implicated in diabetic inflammation and neuropathy.

Conclusion

This comprehensive approach yields generalizable insights into the network miRNAs-diabetes network and supports miRNAs' potential as a biomarker for diabetes.

Meta-analysis of the characteristic expression of circulating microRNA in type 2 diabetes mellitus with acute ischemic cerebrovascular disease

OBJECTIVE

To comprehensively evaluate the characteristics of the circulating microRNA expression profile in type 2 diabetic patients with acute ischemic cerebrovascular disease by systematic evaluation and meta-analysis.

METHODS

The literatures up to March 2022 related to circulating microRNA and acute ischemic cerebrovascular disease in type 2 diabetes mellitus were searched and screened from multiple databases. The NOS quality assessment scale was used to evaluate methodological quality. Heterogeneity tests and statistical analyses of all data were performed by Stata 16.0. The differences in microRNA levels between groups were illustrated by the standardized mean difference (SMD) and 95% confidence interval (95% CI).

RESULTS

A total of 49 studies on 12 circulating miRNAs were included in this study, including 486 cases of type 2 diabetes complicated with acute ischemic cerebrovascular disease and 855 controls. Compared with the control group (T2DM group), miR-200a, miR-144, and miR-503 were upregulated and positively correlated with acute ischemic cerebrovascular disease in type 2 diabetes mellitus patients. Their comprehensive SMD and 95% CI were 2.71 (1.64~3.77), 5.77 (4.28~7.26) and 0.73 (0.27~1.19), respectively. MiR-126 was downregulated and negatively correlated with acute ischemic cerebrovascular disease in type 2 diabetes mellitus patients, its comprehensive SMD and 95% CI were -3.64 (-5.56~-1.72).

CONCLUSION

In type 2 diabetes mellitus patients with acute ischemic cerebrovascular disease, the expression of serum miR-200a, miR-503, plasma and platelet miR-144 was upregulated and the expression of serum miR-126 was downregulated. It may have diagnostic value in the early identification of type 2 diabetes mellitus with acute ischemic cerebrovascular disease.

Insights Into Platelet-Derived MicroRNAs in Cardiovascular and Oncologic Diseases: Potential Predictor and Therapeutic Target

Non-communicable diseases (NCDs), represented by cardiovascular diseases and cancer, have been the leading cause of death globally. Improvements in mortality from cardiovascular (CV) diseases (decrease of 14%/100,000, United States) or cancers (increase 7.5%/100,000, United States) seem unsatisfactory during the past two decades, and so the search for innovative and accurate biomarkers of early diagnosis and prevention, and novel treatment strategies is a valuable clinical and economic endeavor. Both tumors and cardiovascular system are rich in angiological systems that maintain material exchange, signal transduction and distant regulation. This pattern determines that they are strongly influenced by circulating substances, such as glycolipid metabolism, inflammatory homeostasis and cyclic non-coding RNA and so forth. Platelets, a group of small anucleated cells, inherit many mature proteins, mRNAs, and non-coding RNAs from their parent megakaryocytes during gradual formation and manifest important roles in inflammation, angiogenesis, atherosclerosis, stroke, myocardial infarction, diabetes, cancer, and many other diseases apart from its classical function in hemostasis. MicroRNAs (miRNAs) are a class of non-coding RNAs containing ∼22 nucleotides that participate in many key cellular processes by pairing with mRNAs at partially complementary binding sites for post-transcriptional regulation of gene expression. Platelets contain fully functional miRNA processors in their microvesicles and are able to transport their miRNAs to neighboring cells and regulate their gene expression. Therefore, the importance of platelet-derived miRNAs for the human health is of increasing interest. Here, we will elaborate systematically the roles of platelet-derived miRNAs in cardiovascular disease and cancer in the hope of providing clinicians with new ideas for early diagnosis and therapeutic strategies.

Transient Focal Cerebral Ischemia Leads to miRNA Alterations in Different Brain Regions, Blood Serum, Liver, and Spleen

Ischemic stroke is characterized by an occlusion of a cerebral blood vessel resulting in neuronal cell death due to nutritional and oxygen deficiency. Additionally, post-ischemic cell death is augmented after reperfusion. These events are paralleled by dysregulated miRNA expression profiles in the peri-infarct area. Understanding the underlying molecular mechanism in the peri-infarct region is crucial for developing promising therapeutics. Utilizing a tMCAo (transient Middle Cerebral Artery occlusion) model in rats, we studied the expression levels of the miRNAs (miR) 223-3p, 155-5p, 3473, and 448-5p in the cortex, amygdala, thalamus, and hippocampus of both the ipsi- and contralateral hemispheres. Additionally, the levels in the blood serum, spleen, and liver and the expression of their target genes, namely, Nlrp3, Socs1, Socs3, and Vegfa, were assessed. We observed an increase in all miRNAs on the ipsilateral side of the cerebral cortex in a time-dependent manner and increased miRNAs levels (miR-223-3p, miR-3473, and miR-448-5p) in the contralateral hemisphere after 72 h. Besides the cerebral cortex, the amygdala presented increased expression levels, whereas the thalamus and hippocampus showed no alterations. Different levels of the investigated miRNAs were detected in blood serum, liver, and spleen. The gene targets were altered not only in the peri-infarct area of the cortex but selectively increased in the investigated non-affected brain regions along with the spleen and liver during the reperfusion time up to 72 h. Our results suggest a supra-regional influence of miRNAs following ischemic stroke, which should be studied to further identify whether miRNAs are transported or locally upregulated.

Sex-Specific MicroRNAs in Neurovascular Units in Ischemic Stroke

Accumulating evidence pinpoints sex differences in stroke incidence, etiology and outcome. Therefore, more understanding of the sex-specific mechanisms that lead to ischemic stroke and aggravation of secondary damage after stroke is needed. Our current mechanistic understanding of cerebral ischemia states that endothelial quiescence in neurovascular units (NVUs) is a major physiological parameter affecting the cellular response to neuron, astrocyte and vascular smooth muscle cell (VSMC) injury. Although a hallmark of the response to injury in these cells is transcriptional activation, noncoding RNAs such as microRNAs exhibit cell-type and context dependent regulation of gene expression at the post-transcriptional level. This review assesses whether sex-specific microRNA expression (either derived from X-chromosome loci following incomplete X-chromosome inactivation or regulated by estrogen in their biogenesis) in these cells controls NVU quiescence, and as such, could differentiate stroke pathophysiology in women compared to men. Their adverse expression was found to decrease tight junction affinity in endothelial cells and activate VSMC proliferation, while their regulation of paracrine astrocyte signaling was shown to neutralize sex-specific apoptotic pathways in neurons. As such, these microRNAs have cell type-specific functions in astrocytes and vascular cells which act on one another, thereby affecting the cell viability of neurons. Furthermore, these microRNAs display actual and potential clinical implications as diagnostic and prognostic biomarkers in ischemic stroke and in predicting therapeutic response to antiplatelet therapy. In conclusion, this review improves the current mechanistic understanding of the molecular mechanisms leading to ischemic stroke in women and highlights the clinical promise of sex-specific microRNAs as novel diagnostic biomarkers for (silent) ischemic stroke.

Alternative platelet activation pathways and their role in neurodegenerative diseases

PURPOSE OF THE REVIEW

The study of platelets in the context of neurodegenerative diseases is intensifying, and increasing evidence suggests that platelets may play an important role in the pathogenesis of neurodegenerative disorders. Therefore, we aim to provide a comprehensive overview of the role of platelets and their diverse activation pathways in the development of these diseases.

RECENT FINDINGS

Platelets participate in synaptic plasticity, learning, memory, and platelets activated by exercise promote neuronal differentiation in several brain regions. Platelets also contribute to the immune response by modulating their surface protein profile and releasing pro- and anti-inflammatory mediators. In Alzheimer's disease, increased levels of platelet amyloid precursor protein raise the production of amyloid-beta peptides promoting platelet activation, triggering at the same time amyloid-beta fibrillation. In Parkinson's disease, increased platelet α-synuclein is associated with elevated ROS production and mitochondrial dysfunction.

SUMMARY

In this review, we revise different platelet activation pathways, those classically involved in hemostasis and wound healing, and alternative activation pathways recently described in the context of neurodegenerative diseases, especially in Alzheimer's disease.

MicroRNAs and nervous system diseases: network insights and computational challenges

The nervous system is one of the most complex biological systems, and nervous system disease (NSD) is a major cause of disability and mortality. Extensive evidence indicates that numerous dysregulated microRNAs (miRNAs) are involved in a broad spectrum of NSDs. A comprehensive review of miRNA-mediated regulatory will facilitate our understanding of miRNA dysregulation mechanisms in NSDs. In this work, we summarized currently available databases on miRNAs and NSDs, star NSD miRNAs, NSD spectrum width, miRNA spectrum width and the distribution of miRNAs in NSD sub-categories by reviewing approximately 1000 studies. In addition, we characterized miRNA-miRNA and NSD-NSD interactions from a network perspective based on miRNA-NSD benchmarking data sets. Furthermore, we summarized the regulatory principles of miRNAs in NSDs, including miRNA synergistic regulation in NSDs, miRNA modules and NSD modules. We also discussed computational challenges for identifying novel miRNAs in NSDs. Elucidating the roles of miRNAs in NSDs from a network perspective would not only improve our understanding of the precise mechanism underlying these complex diseases, but also provide novel insight into the development, diagnosis and treatment of NSDs.

Long-term aerobic exercise training in type two diabetic patients alters the expression of miRNA-223 and its corresponding target, the P2RY12 receptor, attenuating platelet function

BACKGROUND

Type two diabetes mellitus (T2DM) patients are prone to develop atherothrombotic events due to platelet hyper-reactivity stemming from platelet miRNA-223 down-regulation and over-expression of its corresponding target, P2RY12.

OBJECTIVE

The study sought to determine the effects of long-term aerobic training on the expression levels of miRNA-223 and P2RY12 mRNA, and platelet function in T2DM patients.

METHODS

Twenty-four patients with T2DM (age, 60.0±2.8 yrs.) were selected and randomly divided into two groups: aerobic exercise training (AET, n = 12) and control (CON, n = 12). The AET protocol was performed with moderate intensity for 12 weeks, while patients in the CON group followed their usual routine. Weight, body mass index (BMI), peak oxygen consumption (VO2peak), lipid profile, fasting blood glucose (FBG), glycated hemoglobin (HbA1c), insulin resistance index (HOMA-IR), platelet miRNA-223 and P2RY12 expression were measured before and after the period.

RESULTS

There was a significant improvement in body weight, BMI, VO2peak, FBG, HbA1c, and HOMA-IR, after 12 weeks of AET (P <  0.01). Platelet aggregation decreased significantly after 12 weeks in the AET group compared with the CON (P <  0.001) group. Platelets' miRNA-223 and P2RY12 were significantly up- and down-regulated after AET in comparison with the CON group (P <  0.05), respectively. Moreover, the relative expression of miRNA-223 and P2RY12 significantly correlated with FBG changes following the intervention.

CONCLUSIONS

It can be concluded that long-term moderate-intensity aerobic training might be effective for reducing the occurrence of atherothrombotic events leading to premature death in T2DM patients through the modulation of miRNA-223, P2RY12 receptor expression, and platelet function.

Genetics of macrovascular complications in type 2 diabetes

Type 2 diabetes mellitus (T2DM) is a metabolic disorder that currently affects more than 400 million worldwide and is projected to cause 552 million cases by the year 2030. Long-term vascular complications, such as coronary artery disease, myocardial infarction, stroke, are the leading causes of morbidity and mortality among diabetic patients. The recent advances in genome-wide technologies have given a powerful impetus to the study of risk markers for multifactorial diseases. To date, the role of genetic and epigenetic factors in modulating susceptibility to T2DM and its vascular complications is being successfully studied that provides the accumulation of genomic knowledge. In the future, this will provide an opportunity to reveal the pathogenetic pathways in the development of the disease and allow to predict the macrovascular complications in T2DM patients. This review is focused on the evidence of the role of genetic variants and epigenetic changes in the development of macrovascular pathology in diabetic patients.

Aberrant DNA methylation and miRNAs in coronary artery diseases and stroke: a systematic review

Coronary artery disease (CAD) and ischemic stroke are the two most predominant forms of cardiovascular diseases (CVDs) caused by genetic, epigenetic and environmental risk factors. Although studies on the impact of 'epigenetics' in CVDs is not new, its effects are increasingly being realized as a key regulatory determinant that may drive predisposition, pathophysiology and therapeutic outcome. The most widely studied epigenetic risk factors are regulated by DNA methylation and miRNA expression. To keep pace with growing developments and discoveries, a comprehensive review was performed using Pubmed, Science Direct and Scopus databases to highlight the role of DNA methylation and miRNAs in CAD and stroke subjects. Network analysis was performed using ClueGO software and miRTargetLink database. We identified 32 studies of DNA methylation on CAD and stroke, of which, 6 studies showed differences in global DNA methylation, 10 studies reported the genome-wide difference in DNA methylation and 16 studies demonstrated altered DNA methylation at 14 candidate loci. The network analysis showed positive regulation of nitric oxide biosynthetic process, homocysteine metabolic process and negative regulation of lipid storage. About, 155 miRNAs were associated with CAD, stroke and related phenotypes in 83 studies. Interestingly, mir-223 hypomethylation and altered expression were associated with cerebral infarction and stroke. The target prediction for 18 common miRNAs between CAD and stroke showed strong interaction with SP3 and SP1 genes. This systematic review addresses the present knowledge on DNA methylation and miRNAs in CAD and stroke, whose abnormal regulation has been implicated in etiology or progression of the diseases.

Biomarkers for Antiplatelet Therapies in Acute Ischemic Stroke: A Clinical Review

Stroke is one of the world's leading causes of disability and death. Antiplatelet agents are administered to acute ischemic stroke patients as secondary prevention. Clopidogrel involves biotransformation by cytochrome P450 (CYP) enzymes into an active metabolite, and single nucleotide polymorphisms (SNPs) can influence the efficacy of this biotransformation. Despite the therapeutic advantages of aspirin, there is significant inter-individual heterogeneity in response to this antiplatelet drug. In this clinical review, the recent advances in the biomarkers of antiplatelet agents in acute ischemic stroke are discussed. The studies reviewed herein highlight the clinical relevance of antiplatelet resistance, pharmacotherapy of antiplatelet agents predicting drug response, strategies for identifying aspirin resistance, pharmacogenetic variants of antiplatelet agents, miRNAs, and extracellular vesicles (EVs) as biomarkers toward the personalized approach in the management of acute ischemic stroke. The precise pathways contributing to antiplatelet resistance are not very well known but are presumably multi-factorial. It is essential to understand the clinical relevance of clopidogrel and aspirin-related single nucleotide polymorphism (SNPs) as potential predictive and prognostic biomarkers. Prasugrel is a next-generation antiplatelet agent that prevents ADP-platelet activation by binding irreversibly to P2Y12 receptor. There are sporadic reports of prasugrel resistance and polymorphisms in the Platelet endothelial aggregation receptor-1 (PEAR1) that may contribute to a change in the pharmacodynamics response. Ticagrelor, a direct-acting P2Y12-receptor antagonist, is easily absorbed and partly metabolized to major AR-C124910XX metabolite (ARC). Ticagrelor's primary active metabolite, ARC124910XX (ARC), is formed via the most abundant hepatic cytochrome P450 (CYP) enzyme, CYP3A4, and CYP3A5. The integration of specific biomarkers, genotype as well as phenotype-related data in antiplatelet therapy stratification in patients with acute ischemic stroke will be of great clinical significance and could be used as a guiding tool for more effective, personalized therapy.

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.

Whole Blood miR-210, miR-122, miR-223 Expression Levels and Their Relationship With Iron Status Parameters and Hypercoagulability Indices in Children With Iron Deficiency Anemia

MicroRNAs have the potential to regulate systemic and cellular iron homeostasis at multiple points. In iron deficiency anemia (IDA), hypoxia, platelet reactivity, and potentially microRNAs play a role in the development of hypercoagulability. A total of 57 children diagnosed with IDA between October 2016 and October 2017 and 48 healthy children were included in this cross-sectional study. Blood count parameters, serum iron, transferrin saturation, ferritin level, maximum clot firmness (MCF), and clot formation time index, which are indicators of hypercoagulability in rotational thromboelastometry test, of the IDA and control groups obtained in our previous study were recorded. miR-210, miR-122, and miR-223 levels were analyzed. There was no difference in the miR-210, miR-122, and miR-223 levels between the IDA and control groups. Patients with hemoglobin (Hb) <8 g/dL had higher miR-210 levels than patients with Hb>8 g/dL (P<0.05). There was a negative correlation between miR-210 and Hb and ferritin levels, a positive correlation between miR-122 and ferritin levels, and a negative correlation between miR-223 and MCF index. In IDA, there is a close relationship between the severity of anemia and miR-210, and miR-210 expression is slightly increased in those with severe anemia. miR-210 and miR-122 collectively play a role in maintaining the iron balance. The correlation between miR-223, a platelet function regulator, and the MCF index, suggested that miR-223 has a role in the development of hypercoagulability in IDA.

Recent Highlights of Research on miRNAs as Early Potential Biomarkers for Cardiovascular Complications of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) and its complications pose a serious threat to the life and health of patients around the world. The most dangerous complications of this disease are vascular complications. Microvascular complications of T2DM include retinopathy, nephropathy, and neuropathy. In turn, macrovascular complications include coronary artery disease, peripheral artery disease, and cerebrovascular disease. The currently used diagnostic methods do not ensure detection of the disease at an early stage, and they also do not predict the risk of developing specific complications. MicroRNAs (miRNAs) are small, endogenous, noncoding molecules that are involved in key processes, such as cell proliferation, differentiation, and apoptosis. Recent research has assigned them an important role as potential biomarkers for detecting complications related to diabetes. We suggest that utilizing miRNAs can be a routine approach for early diagnosis and prognosis of diseases and may enable the development of better therapeutic approaches. In this paper, we conduct a review of the latest reports demonstrating the usefulness of miRNAs as biomarkers in the vascular complications of T2DM.

Association of AMPK Pathway-Related Gene Polymorphisms with Symptomatic Intracranial Atherosclerotic Stenosis in a Chinese Han Population

Background and Objective: Recently, AMP-activated protein kinase (AMPK) signaling was confirmed to be intimately associated with atherosclerosis. Evidence indicates that genetic susceptibility plays an important role in the etiology of symptomatic intracranial atherosclerotic stenosis (sICAS), however few genes have been pinpointed being etiologically associated. This study investigated possible links between single nucleotide polymorphisms (SNPs) of AMPK-related genes and sICAS in Han Chinese subjects. Methods: Target gene sequencing was carried out in 400 sICAS Han Chinese patients and 1007 healthy controls for 11 AMPK pathway-related genes. Chi-squared testing and multiple logistic regression in dominant, recessive, and additive models were used to evaluate the association between SNPs and risk of sICAS. Bonferroni corrections were performed with a p < (0.05/44 = 0.0011) as statistically significant. Further subgroup data analyses was conducted using chi-squared or t-tests. Results: There were 44 common variants of 11 candidate genes distributed differently between sICAS patients and healthy controls, among which the INSR rs78312382 SNP remained significant even after a Bonferroni correction. Logistic regression analysis showed that rs78312382 was significantly associated with the risk of sICAS in both dominant and additive models (p_Bonferroni = 7.874e^-5 and 0.000506, respectively), with the A allele being much more prevalent in the sICAS group (p = 0.000404). Conclusions: Variants of the INSR rs7831282 locus may play an important role in the development of sICAS among the Han Chinese with the A allele being a risk factor and a potential biomarker for this illness.

miRNA dysregulation in ischaemic stroke: Focus on diagnosis, prognosis, therapeutic and protective biomarkers

Stroke is one of the leading causes of death and disability in both developing and developed countries. Biomarkers for stroke and its outcome can greatly facilitate early detection and management of the disease. miRNAs have been explored for their potential as biomarkers for diagnosis, prognosis and brain injury in ischaemic stroke. A substantial body of evidence suggests that miRNAs play key roles in numerous cellular changes following ischaemic stroke including mitochondrial dysfunction, energy failure, cytokine-mediated cytotoxicity, oxidative stress, activation of glial cells, increased intracellular calcium levels inflammatory responses and disruption of the blood-brain barrier (BBB). In addition, targeting specific miRNAs, therapeutic modulation of brain injury and apoptosis can also be achieved. Therefore, the current review has been compiled within an aim to give an overview of the developments exploiting miRNAs at different stages of stroke as prognostic, diagnostic, protective and therapeutic biomarkers.

Antioxidant, anti-inflammatory and hypoglycemic effects of Fagonia olivieri DC on STZ-nicotinamide induced diabetic rats - In vivo and in vitro study

ETHNOPHARMACOLOGICAL RELEVANCE

Fagonia olivieri (Zygophyllaceae) is used in Pakistan for management of diabetes and for treatment of stress related disorders of liver and kidneys. The objective of present study was to evaluate antidiabetic activity of F. olivieri using streptozotocin-nicotinamide induced diabetic rat model.

METHODS

Powder of the whole plant of F. olivieri was extracted with methanol (FOME) and the residue was fractionated with n-hexane (FOHE), chloroform (FOCE), ethyl acetate (FOCE), n-butanol (FOBE) and the remaining soluble aqueous fraction (FOAE). The extract/fractions were evaluated for in vitro inhibition of α-amylase and α-glucosidase and for the antidiabetic studies in Sprague-Dawley rats. FOAE was evaluated in 21 day chronic multiple dose study. Glibenclamide (10 mg/kg) and FOAE were used at a concentration of 200 mg/kg (164.8 μg of catechin) and 400 mg/kg (329.6 μg of catechin) in streptozotocin (STZ)-induced diabetic rats. Various serum parameters, blood cell parameters and oxidative stress induced parameters of the liver and kidneys were investigated.

RESULTS

Results showed that aqueous fraction of F. olivieri (FOAE) potentially inhibited activity of pancreatic α-amylase, intestinal maltase and sucrase. Administration of FOAE (200 mg/kg; 400 mg/kg) to diabetic rats for 21 days increased body weight, hemoglobin and its indices, RBCs, platelets, lymphocytes and neutrophils against diabetic group. In serum level of glucose, transaminases, ALP, LDH, total bilirubin, creatinine and lipids decreased while insulin, total protein and albumin increased in contrast to diabetic group. Further, level of cytokines; TGF-β1, TNF-α and IL-6 in serum and altered level of antioxidant enzymes, glutathione and lipid peroxides of liver and kidney tissues restored towards control animals.

CONCLUSION

This study demonstrated that FOAE inhibited activity of digestive enzymes and exhibited antioxidant, anti-inflammatory and antihyperglycemic activity in STZ-nicotinamide prompted diabetic rats and suggested that FOAE might be used as a therapeutic agent for the management of type-2 diabetes.

Can MiR-503 be used as a marker in diabetic patients with ischemic stroke?

BACKGROUND

Some microRNAs are involved in diabetes pathology and some are known to have role in stroke. MiR-503 causes endothelial dysfunction in diabetic patients, predisposing to ischemia. There has been no study evaluating Mir-503 level in diabetic patients with or without ischemic stroke.

METHODS

We designed a cross-sectional study to assess and compare serum level of MiR-503 in 4 groups of diabetic patients with ischemic stroke (I), non-diabetic patients with stroke (II), diabetic patients (III), and healthy controls (IV) in acute phase and 3 months later.

RESULTS

Our data analysis showed that mean relative expression of MiR-503 in group (I) was significantly higher than 3 other groups (p < 0.05). The level of miR-503 was related to the patients' fasting blood glucose, Cholesterol level, NIHSS score and acute-phase modified Rankin Scale (mRS) (r = 0.49, p = 0.001, r = 0.5, p = 0.009, r = 0.45, p = 0.009, r = 0.48, p = 0.003, CI = 95%). Relative expression of miR in patients with mRS ≤ 2 (good outcome) was lower than in patients with mRS > 2 (poor outcome) (p = 0.008). After 3 months, level of miR decreased significantly only in group (I) (p = 0.002). Mean relative expression of miR-503 in chronic phase was not significantly different among groups (p-value> 0.05). There was no relation between miRNA level and mRS in chronic phase.

CONCLUSION

Hyperglycemia and ischemia together raise the level of MiR-503 acutely but it does not remain at high level after 3 months. Although higher miR was related to more disability in acute phase, it does not affect long-term outcome in ischemic patients. As MiR-503 is stable enough in blood it can be used as a potential diagnostic marker of an ischemic stroke in diabetic patient. Its level also is an indicator of stroke severity and patients' short-term outcome. It is recommended to study whether antagomiR-503 is a new therapeutic agent reducing the severity of and disability due to stroke.

Molecular Mechanisms Underpinning Microparticle-Mediated Cellular Injury in Cardiovascular Complications Associated with Diabetes

Microparticles (MPs) are small vesicles shed from the cytoplasmic membrane of healthy, activated, or apoptotic cells. MPs are very heterogeneous in size (100–1,000 nm), and they harbor proteins and surface antigens specific to cells they originate from. Virtually, all cells can shed MPs, and therefore, they can be found in all body fluids, but also entrapped in tissues. Of interest and because of their easy detection using a variety of techniques, circulating MPs were recognized as biomarkers for cell activation. MPs were also found to mediate critical actions in intercellular communication and transmitting biological messages by acting as paracrine vehicles. High plasma numbers of MPs were reported in many cardiovascular and metabolic disturbances that are closely associated with insulin resistance and low-grade inflammation and have been linked to adverse actions on cardiovascular function. This review highlights the involvement of MPs in cardiovascular complications associated with diabetes and discusses the molecular mechanisms that underpin the pathophysiological role of MPs in the onset and progression of cellular injury in diabetes.

Platelet microRNAs and vascular injury

Vascular smooth muscle cell (VSMC) phenotype switching from a contractile state to a synthetic phenotype has been implicated in intimal remodeling during vascular injury. While multiple studies have focused on dedifferentiation of VSMCs, prevention of VSMC-mediated excessive repair remains poorly understood. In this issue of the JCI, Zeng et al. identified a mechanism by which platelet-derived microRNA-223 (miRNA-223) reverses VSMC dedifferentiation. The authors show that suppression of proliferation occurs after platelet internalization by VSMCs. Moreover, they demonstrate that miRNA-223 inhibits dedifferentiation and intimal hyperplasia in diabetic mice by decreasing PDGFRβ expression in VSMCs. Together, these results identify platelet-derived miRNA-223 as a potential therapeutic target in vascular injury.

Identification of microRNAs and messenger RNAs involved in human umbilical cord mesenchymal stem cell treatment of ischemic cerebral infarction using integrated bioinformatics analysis

In recent years, a large number of differentially expressed genes have been identified in human umbilical cord mesenchymal stem cell (hUMSC) transplants for the treatment of ischemic cerebral infarction. These genes are involved in various biochemical processes, but the role of microRNAs (miRNAs) in this process is still unclear. From the Gene Expression Omnibus (GEO) database, we downloaded two microarray datasets for GSE78731 (messenger RNA (mRNA) profile) and GSE97532 (miRNA profile). The differentially expressed genes screened were compared between the hUMSC group and the middle cerebral artery occlusion group. Gene ontology enrichment and pathway enrichment analyses were subsequently conducted using the online Database for Annotation, Visualization, and Integrated Discovery. Identified genes were applied to perform weighted gene co-suppression analyses, to establish a weighted co-expression network model. Furthermore, the protein-protein interaction network for differentially expressed genes from turquoise modules was built using Cytoscape (version 3.40) and the most highly correlated subnetwork was extracted from the protein-protein interaction network using the MCODE plugin. The predicted target genes for differentially expressed miRNAs were also identified using the online database starBase v3.0. A total of 3698 differentially expressed genes were identified. Gene ontology analysis demonstrated that differentially expressed genes that are related to hUMSC treatment of ischemic cerebral infarction are involved in endocytosis and inflammatory responses. We identified 12 differentially expressed miRNAs in middle cerebral artery occlusion rats after hUMSC treatment, and these differentially expressed miRNAs were mainly involved in signaling in inflammatory pathways, such as in the regulation of neutrophil migration. In conclusion, we have identified a number of differentially expressed genes and differentially expressed mRNAs, miRNA-mRNAs, and signaling pathways involved in the hUMSC treatment of ischemic cerebral infarction. Bioinformatics and interaction analyses can provide novel clues for further research into hUMSC treatment of ischemic cerebral infarction.

Update on pathological platelet activation in coronary thrombosis

Although coronary thrombosis (CT) is integral to cardiovascular outcomes, the underlying pathophysiological mechanisms remain unclear. CT may occur in case of atherosclerotic plaque erosion/rupture, or even after stenting implantation. Platelets (PLT) activation is the keystone of atherothrombosis and depends on many dysregulated elements, including endothelial dysfunction, oxidized lipoproteins, and immune response. Besides the classical view of PLT as an effector of hemostatic response, a new repertoire of PLT activities is emerging. PLT lipidome oxidation is a self-maintaining process which promotes PLT reactivity, coagulation cascade, and inflammatory cell activation. PLT-innate immune cell interaction is also sustained by neutrophil extracellular traps and NLRP3 inflammasome pathways. Other noteworthy emerging mechanisms are implicated in the crosstalk between PLT and surrounding cells. Especially, microvesicles (MVs) released from PLT may extend their signaling network far beyond the classical cell-cell interactions. Moreover, the recognition of noncoding RNA in PLT MVs introduce another layer of complexity in terms of intercellular signaling by a direct regulation of messenger RNA profile and gene expression in the recipient cells. The aim of this narrative review is to update the recent advance in CT and intracoronary stent thrombosis, including causal factors and potential translation of experimental evidence into the clinical setting.

MicroRNA and Diabetic Complications: A Clinical Perspective

SIGNIFICANCE

The rising global prevalence of diabetes and its debilitating complications give rise to significant disability and premature mortality. Due to the silent nature of diabetes and its vascular complications, and limitations in current methods for detection, there is a need for novel biomarkers for early detection and prognosis. Recent Advances: Metabolic memory and epigenetic factors are important in the pathogenesis of diabetic complications and interact with genetic variants, metabolic factors, and clinical risk factors. Micro(mi)RNAs interact with epigenetic mechanisms and pleiotropically mediate the effects of hyperglycemia on the vasculature. Utilizing mature profiling techniques and platforms, an increasing number of miRNA signatures and interaction networks have been identified for diabetes and its related cardiorenal complications. As a result, these short, single-stranded molecules are emerging as potential diagnostic and predictive tools in human studies, and may function as disease biomarkers, as well as treatment targets.

CRITICAL ISSUES

However, there is complex interaction between the genome and epigenome. The regulation of miRNAs may differ across species and tissues. Most profiling studies to date lack validation, often requiring large, well-characterized cohorts and reliable normalization strategies. Furthermore, the incremental benefits of miRNAs as biomarkers, beyond prediction provided by traditional risk factors, are critical issues to consider, yet often neglected in published studies.

FUTURE DIRECTIONS

All in all, the future for miRNA-based diagnostics and therapeutics for diabetic complications appears promising. Improved understanding of the complex mechanisms underlying miRNA dysregulation, and more well-designed studies utilizing prospective samples would facilitate the translation to clinical use.

Platelet-Enriched MicroRNAs and Cardiovascular Homeostasis

SIGNIFICANCE

Platelets are anucleate blood cells that are involved in hemostasis and thrombosis. Although no longer able to generate ribonucleic acid (RNA) de novo, platelets contain messenger RNA (mRNA), YRNA fragments, and premature microRNAs (miRNAs) that they inherit from megakaryocytes. Recent Advances: Novel sequencing techniques have helped identify the unexpectedly large number of RNA species present in platelets. Throughout their life time, platelets can process the pre-existing pool of premature miRNA to give the fully functional miRNA that can regulate platelet protein expression and function.

CRITICAL ISSUES

Platelets make a major contribution to the circulating miRNA pool but platelet activation can have major consequences on Dicer levels and thus miRNA maturation, which has implications for studies that are focused on screening-stored platelets.

FUTURE DIRECTIONS

It will be important to determine the importance of platelets as donors for miRNA-containing microvesicles that can be taken up and processed by other (particularly vascular) cells, thus contributing to homeostasis as well as disease progression. Antioxid. Redox Signal. 29, 902-921.

Aerobic training improves platelet function in type 2 diabetic patients: role of microRNA-130a and GPIIb

AIMS

MicroRNAs (miRs) that are mediators of gene expression have been implicated in type 2 diabetes mellitus (T2DM). Platelet hyper-reactivity is one of the most important disorders in T2DM patients. In this study, we explored the effects of aerobic training (AT) on platelet aggregation and Glycoprotein IIb (GPIIb) receptor and miR-130a expression.

METHODS

In a quasi-experimental controlled trial, 24 sedentary, eligible female participants with T2DM were selected (age 61.92 ± 3.63) and divided into AT and control (CON) groups based on their peak oxygen consumption (VO_2peak). AT protocol was performed three times per week in non-consecutive days on a treadmill with mean intensity (60-75% VO_2peak) for 8 weeks, while the control group refrained from any type of exercise training. Two blood samples were taken before and after this period. Real-time PCR was used to determine the expression of platelet GPIIb and miR-130a. Moreover, platelet indices (PLT, MPV, PDW, and PCT), collagen-induced platelet aggregation and glycemic variables were measured.

RESULTS

Analyses of data showed that anthropometric variables, VO_2peak and glycemic control improved significantly (P < 0.01) after AT. Furthermore, MPV, PDW (P < 0.01), and platelet aggregation (P < 0.001) decreased significantly following AT compared with control group. Platelet GPIIb expression down-regulated significantly (P < 0.05) in AT group but up-regulation of miR-130a expression was not significant between two groups (P > 0.05).

CONCLUSIONS

Platelet hyper-reactivity in T2DM females might be decreased not only by glycemic control and amelioration of anthropometric and platelet indices, but also the down-regulation of GPIIb following AT. However, more research is needed to determine the effects of exercise training on platelet miR-130a.

Aspirin Resistance and Stroke

Stroke is a leading cause of death and disability worldwide. Aspirin is the most commonly used antiplatelet drug in both primary and secondary prevention of cerebrovascular and cardiovascular diseases. A proportion of patients may have stroke recurrence while they are on treatment with aspirin, giving rise to term aspirin resistance or aspirin failure. Studies have suggested that such recurrence could partly be attributed to biochemical aspirin resistance, with an estimated prevalence ranging between 5% and 65% among patients with ischemic stroke in the published studies. Common methods to evaluate laboratory aspirin resistance include light transmission aggregometry, PFA-100, VerifyNow-Aspirin assay, serum thromboxane B2, and urinary 11-dehydrothromboxane B2. Aspirin resistance is multifactorial in origin and involves diverse environmental and genetic factors, including single-nucleotide polymorphisms, miRNAs, drug interactions, and co-morbid risk factors. The current review overviews the concept of aspirin resistance, its evaluation and relationship with stroke recurrence, its outcome, and its implications on stroke management in the future.

The role of KATP channels in cerebral ischemic stroke and diabetes

ATP-sensitive potassium (KATP) channels are ubiquitously expressed on the plasma membrane of cells in multiple organs, including the heart, pancreas and brain. KATP channels play important roles in controlling and regulating cellular functions in response to metabolic state, which are inhibited by ATP and activated by Mg-ADP, allowing the cell to couple cellular metabolic state (ATP/ADP ratio) to electrical activity of the cell membrane. KATP channels mediate insulin secretion in pancreatic islet beta cells, and controlling vascular tone. Under pathophysiological conditions, KATP channels play cytoprotective role in cardiac myocytes and neurons during ischemia and/or hypoxia. KATP channel is a hetero-octameric complex, consisting of four pore-forming Kir6.x and four regulatory sulfonylurea receptor SURx subunits. These subunits are differentially expressed in various cell types, thus determining the sensitivity of the cells to specific channel modifiers. Sulfonylurea class of antidiabetic drugs blocks KATP channels, which are neuroprotective in stroke, can be one of the high stoke risk factors for diabetic patients. In this review, we discussed the potential effects of KATP channel blockers when used under pathological conditions related to diabetics and cerebral ischemic stroke.

Regulation of Hypertension for Secondary Prevention of Stroke: The Possible 'Bridging Function' of Acupuncture

Worldwide, stroke is the leading cause of mortality and disability, with hypertension being an independent risk factor for a secondary stroke. Acupuncture for the treatment of hypertension gains more attention in alternative and complementary medicine, but the results are inconsistent. Few studies regarding the secondary prevention of stroke by managing hypertension with acupuncture have been carried out as there are some problems regarding the antihypertensive drug status in the secondary prevention of stroke. Still, the potential of acupuncture in regulating the blood pressure for secondary stroke prevention deserves our focus. This review is based on papers recorded in the PubMed, Embase, and Web of Science databases, from their inception until March 28, 2017, and retrieved with the following search terms: hypertension and acupuncture, limited in spontaneously hypertensive rats (SHRs), stress-induced (or cold-induced) hypertensive or pre-hypertensive models. We find that, in these hypertensive animals, acupuncture could mainly influence factors related to the nervous system, oxidative stress, the endocrine system, cardiovascular function, and hemorheology, which are closely associated with the stroke outcome. This trend may give us a hint that acupuncture might well participate in the secondary prevention of stroke through these pathways when used in the management of hypertension.

Type 2 Diabetes Mellitus and Cardiovascular Disease: Genetic and Epigenetic Links

Type 2 diabetes mellitus (DM) is a common metabolic disorder predisposing to diabetic cardiomyopathy and atherosclerotic cardiovascular disease (CVD), which could lead to heart failure through a variety of mechanisms, including myocardial infarction and chronic pressure overload. Pathogenetic mechanisms, mainly linked to hyperglycemia and chronic sustained hyperinsulinemia, include changes in metabolic profiles, intracellular signaling pathways, energy production, redox status, increased susceptibility to ischemia, and extracellular matrix remodeling. The close relationship between type 2 DM and CVD has led to the common soil hypothesis, postulating that both conditions share common genetic and environmental factors influencing this association. However, although the common risk factors of both CVD and type 2 DM, such as obesity, insulin resistance, dyslipidemia, inflammation, and thrombophilia, can be identified in the majority of affected patients, less is known about how these factors influence both conditions, so that efforts are still needed for a more comprehensive understanding of this relationship. The genetic, epigenetic, and environmental backgrounds of both type 2 DM and CVD have been more recently studied and updated. However, the underlying pathogenetic mechanisms have seldom been investigated within the broader shared background, but rather studied in the specific context of type 2 DM or CVD, separately. As the precise pathophysiological links between type 2 DM and CVD are not entirely understood and many aspects still require elucidation, an integrated description of the genetic, epigenetic, and environmental influences involved in the concomitant development of both diseases is of paramount importance to shed new light on the interlinks between type 2 DM and CVD. This review addresses the current knowledge of overlapping genetic and epigenetic aspects in type 2 DM and CVD, including microRNAs and long non-coding RNAs, whose abnormal regulation has been implicated in both disease conditions, either etiologically or as cause for their progression. Understanding the links between these disorders may help to drive future research toward an integrated pathophysiological approach and to provide future directions in the field.

The Potential Role of Platelet-Related microRNAs in the Development of Cardiovascular Events in High-Risk Populations, Including Diabetic Patients: A Review

Platelet activation plays a pivotal role in the development and progression of atherosclerosis, which often leads to potentially fatal ischemic events at later stages of the disease. Platelets and platelet microvesicles (PMVs) contain large amounts of microRNA (miRNA), which contributes largely to the pool of circulating miRNAs. Hence, they represent a promising option for the development of innovative diagnostic biomarkers, that can be specific for the underlying etiology. Circulating miRNAs can be responsible for intracellular communication and may have a biological effect on target cells. As miRNAs associated to both cardiovascular diseases (CVD) and diabetes mellitus can be measured by means of a wide array of techniques, they can be exploited as an innovative class of smart disease biomarkers. In this manuscript, we provide an outline of miRNAs associated with platelet function and reactivity (miR-223, miR-126, miR-197, miR-191, miR-21, miR-150, miR-155, miR-140, miR-96, miR-98) that should be evaluated as novel biomarkers to improve diagnostics and treatment of CVD.

The Expression of microRNA-223 and FAM5C in Cerebral Infarction Patients with Diabetes Mellitus

The aim of the study was to investigate the expression of miR-223 and FAM5C in the peripheral blood mononuclear cells (PBMCs) of cerebral infarction patients with or without diabetes. Sixteen cases with diabetes mellitus (DM), 14 cases with cerebral infarction (CI), 12 cases with cerebral infarction and diabetes mellitus (CIDM), and 18 healthy subjects were included in this study. Real-time PCR was used to quantify mRNA expression. Western blot was used to detect FAM5C protein level. Recombinant plasmids expressing miR-223-3p and 3' UTR of FAM5C were constructed. Dual-luciferase reporter system was used to analyze the binding of miR-223-3p to FAM5C 3' UTR. FAM5C mRNA and protein level were significantly higher in the PBMCs of CIDM patients compared with healthy controls (P < 0.05). miR-223-3p expression in PBMCs was significantly lower in DM patients than in healthy controls (P < 0.05). The expression of miR-223-3p was negatively correlated with FAM5C mRNA in all patients and healthy controls. Co-transfection of miR-223-3p plasmid with FAM5C 3'UTR dual-luciferase plasmid significantly inhibited the luciferase activity (P < 0.01). FAM5C, but not miR-223, is a risk factor for CI in type 2 DM patients.

Association of MiR-146a Expression and Type 2 Diabetes Mellitus: A Meta-Analysis

Although deregulation of miR-146a has been reported in type 2 diabetes repeatedly, the direction of deregulation events (up or down) remained to be inconsistent in literatures. Therefore, in this study we performed a meta-analysis on the possible association between miR-146a expression levels and type 2 diabetes. A systematic literature searching of PubMed, ISI Web of Science and Google Scholar was performed up to the end of September 2016. Finally, a total of 12 studies including 344 diabetic patients and 316 controls were selected for meta-analysis. All statistical analysis was performed using the metafor package with R software. Moreover, publication bias was assessed by Egger’s and sensitivity analysis was applied on the meta-analysis. The results are presented as log10 odds ratios (logORs), 95% confidence intervals (CI) with relevant P values. The results revealed that miR-146a was downregulated in type 2 diabetes cases compared with normal subjects (P=0.01, logOR:-4.76, 95% CI:-8.41, -1.11). Furthermore, sub-group analysis showed that the association between miR-146a expression levels and type 2 diabetes in whole blood (P<0.001) and PBMCs (P<0.001) samples were significant. However, this association was not significant in the serum (P=0.67) and plasma (P=0.90) samples. Our finding suggests that miR-146a downregulation could be associated with type 2 diabetes susceptibility. Further investigations with larger sample size are required to evaluate this association in the type 2 diabetes pathogenesis.

The Involvement of miRNA in Carotid-Related Stroke

Cardiovascular disease is the leading cause of morbidity and mortality in developed countries. Stroke is associated with a marked disability burden and has a major economic impact; this is especially true for carotid artery stroke. Major advances in primary and secondary prevention during the last few decades have helped to tackle this public health problem. However, better knowledge of the physiopathology of stroke and its underlying genetic mechanisms is needed to improve diagnosis and therapy. miRNAs are an important, recently identified class of post-transcriptional regulators of gene expression and are known to be involved in cerebrovascular disease. These endogenous, small, noncoding RNAs may have applications as noninvasive biomarkers and therapeutic tools in practice. Here, we review the involvement of several miRNAs in cell-based and whole-animal models of stroke, with a focus on human miRNA profiling studies of carotid artery stroke. Lastly, we describe the miRNAs' potential role as a biomarker of stroke.

Comparison of the release of microRNAs and extracellular vesicles from platelets in response to different agonists

On activation platelets release microRNAs and extracellular vesicles (EV) into circulation. The release of EV from platelets has been shown to be dependent on the agonist; in this study, we investigated whether the microRNA profile or EV released from platelets was also agonist specific. Washed platelets from healthy subjects were maximally stimulated with agonists specific for the receptors for collagen (Glycoprotein VI (GPVI)), thrombin (PAR1/PAR4), or ADP (P2Y1/P2Y12) with/without inhibiting secondary mediators, using aspirin to block cyclooxygenase-1 and apyrase to remove ADP. The released microRNAs were profiled using TaqMan microRNA microarray cards. Platelet-derived EV (pdEV) were characterized by size (Nanoparticle Tracking Analysis, NTA), for procoagulant activity (Annexin-V binding and support of thrombin generation), and for the EV markers CD63 and HSP70. Platelet activation triggered the release of 57-79 different microRNAs, dependent upon agonist, with a core of 46 microRNAs observed with all agonists. There was a high level of correlation between agonists (r² > 0.98; p < 0.0001 for all), and with the microRNA content of the parent platelets (r² > 0.98; p < 0.0001). The 46 microRNAs seen in all samples are predicted to have significant effects on the translation of proteins involved in endocytosis, cell cycle control, and differentiation. MiR-223-3p was the most abundant in all samples and has previously been implicated in myeloid lineage development and demonstrated to have anti-inflammatory effects. Stimulation through GPVI produced a pdEV population with significantly more procoagulant activity than the other agonists. Apyrase significantly reduced microRNA and pdEV release, while aspirin had little effect. These data suggest that all tested agonists trigger the release of a similar microRNA profile while the procoagulant activity of the pdEV was agonist dependent. ADP was shown to play an important role in the release of both microRNAs and pdEV.

MicroRNA Biomarkers and Platelet Reactivity: The Clot Thickens

Over the last few years, several groups have evaluated the potential of microRNAs (miRNAs) as biomarkers for cardiometabolic disease. In this review, we discuss the emerging literature on the role of miRNAs and other small noncoding RNAs in platelets and in the circulation, and the potential use of miRNAs as biomarkers for platelet activation. Platelets are a major source of miRNAs, YRNAs, and circular RNAs. By harnessing multiomics approaches, we may gain valuable insights into their potential function. Because not all miRNAs are detectable in the circulation, we also created a gene ontology annotation for circulating miRNAs using the gene ontology term extracellular space as part of blood plasma. Finally, we share key insights for measuring circulating miRNAs. We propose ways to standardize miRNA measurements, in particular by using platelet-poor plasma to avoid confounding caused by residual platelets in plasma or by adding RNase inhibitors to serum to reduce degradation. This should enhance comparability of miRNA measurements across different cohorts. We provide recommendations for future miRNA biomarker studies, emphasizing the need for accurate interpretation within a biological and methodological context.

Increased Circulating Exosomal miRNA-223 Is Associated with Acute Ischemic Stroke

Recent studies have demonstrated that exosomal microRNAs (miRNAs) are novel biomarkers and therapeutic targets for various diseases including vascular disease. However, specific exosomal miRNAs expression in stroke patients has not been reported yet. Here, we explored whether circulating exosomal miRNAs can serve as potential biomarkers for the diagnosis of acute ischemic stroke and discussed the potential for clinical application. Blood samples were collected from acute ischemic stroke patients within the first 72 h (n = 50). Circulating exosomes were exacted by Exoquick exosome isolation kit and characterized by transmission electron microscopy. Western blot was performed to assess the expression of exosomal protein makers. Exosomal miRNA-223 (miR-223) was detected by RT-PCR assay. The relationship between the expression levels of miR-223 and National Institutes of Health Stroke Scale (NIHSS) scores, brain infarct volume, and neurological outcomes were analyzed. Circulating exosomes were isolated and the size of vesicles ranged between 30 and 100 nm. The identification of exosomes was further confirmed by the detection of specific exosomal protein markers CD9, CD63, and Tsg101. Exosomal miR-223 in acute ischemic stroke patients was significantly upregulated compared to control group (p < 0.001). Exosomal miR-223 level was positively correlated with NIHSS scores (r = 0.31, p = 0.03). Exosomal miR-223 expression in stroke patients with poor outcomes was higher than those with good outcomes (p < 0.05). Increased exosomal miR-223 was associated with acute ischemic stroke occurrence, stroke severity, and short-term outcomes. Future studies with large sample are needed to assess the clinical application of exosomal miR-223 as a novel biomarker for ischemic stroke diagnosis.