Atherosclerosis-Related Circulating MicroRNAs as a Predictor of Stroke Recurrence

Non-coding RNAs in acute ischemic stroke: from brain to periphery

Acute ischemic stroke is a clinical emergency and a condition with high morbidity, mortality, and disability. Accurate predictive, diagnostic, and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain undetermined. With innovations in high-throughput gene sequencing analysis, many aberrantly expressed non-coding RNAs (ncRNAs) in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental models. Differentially expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes, leading to neuroprotection or deterioration, thus ncRNAs can serve as therapeutic targets in acute ischemic stroke. Moreover, distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction, diagnosis, and prognosis. In particular, ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic stroke. In this review, we consolidate the latest progress of research into the roles of ncRNAs (microRNAs, long ncRNAs, and circular RNAs) in the pathological processes of acute ischemic stroke-induced brain damage, as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction, diagnosis, and prognosis. Findings from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.

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.

Expression profile of circulating miRNAs in patients with atrial fibrillation-dominated cardioembolic stroke: A systematic review and bioinformatics analysis

Background

Cardioembolic stroke is a type of ischemic stroke with high disability and mortality, a high recurrence rate and poor prognosis. miRNAs have been explored as potential noninvasive biomarkers in atrial fibrillation and ischemic stroke, but their expression profile in cardioembolic stroke still needs to be explored. This study will explore the differences in miRNA expression between cardioembolic stroke patients and healthy people through meta-analysis and attempt to analyze the target genes by bioinformatics analysis.

Methods

Literature databases and gene expression databases were searched from the inception date to June 2022. The study reported the circulating miRNA expression profiles in cardioembolic stroke patients and healthy controls. miRNAs with significantly differential expression and their target genes were analyzed.

Results

Three articles and one gene expression dataset were included in the analysis. The results showed that miR-21-5p (SMD: 2.16; 95 % CI: 1.57, 2.75; p < 0.001), miR-943, miR-145-3p, and miR-3148 were upregulated in cardioembolic stroke patients compared with controls. The downregulated miRNAs included miR-3136-5p, miR-2277-5p, and miR-2277-3p. The area under the receiver operating characteristic curve of miR-21-5p for cardioembolic stroke was 0.975 (0.933-0.989). For the enrichment results, the target genes of upregulated miRNAs were enriched in the MAPK signaling pathway, Ras signaling pathway, etc. The target genes of downregulated miRNAs were also enriched in the Ras signaling pathway.

Conclusions

This study suggested that circulating miR-21-5p is upregulated in cardioembolic stroke patients compared to healthy controls. The Ras signaling pathway plays an important role in pathogenesis according to enrichment analysis.

miR-328-5p functions as a critical negative regulator in early endothelial inflammation and advanced atherosclerosis

Early proatherogenic inflammation constitutes a significant risk factor for atherogenesis development. Despite this, the precise molecular mechanisms driving this pathological progression largely remain elusive. Our study unveils a pivotal role for the microRNA miR-328-5p in dampening endothelial inflammation by modulating the stability of JUNB (JunB proto-oncogene). Perturbation of miR-328-5p levels results in heightened monocyte adhesion to endothelial cells and enhanced transendothelial migration, while its overexpression mitigates these inflammatory processes. Furthermore, miR-328-5p hinders macrophage polarization toward the pro-inflammatory M1 phenotype, and exerts a negative influence on atherosclerotic plaque formation in vivo. By pinpointing JUNB as a direct miR-328-5p target, our research underscores the potential of miR-328-5p as a therapeutic target for inflammatory atherosclerosis. Reintroduction of JUNB effectively counteracts the anti-atherosclerotic effects of miR-328-5p, highlighting the promise of pharmacological miR-328-5p targeting in managing inflammatory atherosclerosis. [BMB Reports 2024; 57(8): 375-380].

Advances of nanoparticle-mediated diagnostic and theranostic strategies for atherosclerosis

Atherosclerotic plaque remains the primary cause of morbidity and mortality worldwide. Accurate assessment of the degree of atherosclerotic plaque is critical for predicting the risk of atherosclerotic plaque and monitoring the results after intervention. Compared with traditional technology, the imaging technologies of nanoparticles have distinct advantages and great development prospects in the identification and characterization of vulnerable atherosclerotic plaque. Here, we systematically summarize the latest advances of targeted nanoparticle approaches in the diagnosis of atherosclerotic plaque, including multimodal imaging, fluorescence imaging, photoacoustic imaging, exosome diagnosis, and highlighted the theranostic progress as a new therapeutic strategy. Finally, we discuss the major challenges that need to be addressed for future development and clinical transformation.

Functional polymorphism in miR-208 is associated with increased risk for ischemic stroke

BACKGROUND

The miR-208 gene is one of the microRNAs now under active studies, and has been found to play significant roles in an array of cardiovascular diseases. Nevertheless, until now, no studies have examined the relationship between the susceptibility to ischemic stroke (IS) and genetic variations in miR-208. This study explored the association between the miR-208 polymorphisms (rs178642, rs8022522, and rs12894524) and the risk of IS.

METHODS

A total of 205 cases of IS and 211 control subjects were included. The SNPscans genotyping test was employed to determine the genotypes of the three polymorphisms.

RESULTS

Significant correlation was observed between rs8022522 polymorphism and risk of IS on the basis of analyses of genotypes, models and alleles (GA vs. GG: adjusted OR = 2.159, 95% CI: 1.052-4.430, P = 0. 036; AA vs. GG: adjusted OR = 5.154, 95% CI: 1.123-23.660, P = 0.035; dominant model: adjusted OR = 1.746, 95% CI, 1.075-2.838, P = 0.025; G vs. A: adjusted OR = 2.451, 95% CI: 1.374-4.370, P = 0.002).

CONCLUSIONS

The rs8022522 polymorphism of the miR-208 gene is significantly associated with an elevated risk of ischemic stroke in Chinese.

Neuroinflammation-associated miR-106a-5p serves as a biomarker for the diagnosis and prognosis of acute cerebral infarction

BACKGROUND

Acute cerebral infarction (ACI) is a common cerebrovascular disease. Previous studies have shown that some abnormally expressed microRNAs (miRNAs) play important roles in ACI. This study aimed to investigate the role of miR-106a-5p in the diagnosis and prognosis of ACI patients, and analyze the regulatory potential of miR-106a-5p on the inflammation of BV-2 microglial cells.

METHOD

Serum and cerebrospinal fluid (CSF) samples were collected from 98 ACI patients, and the expression of serum miR-106a-5p was analyzed using qRT-PCR. A receiver operating characteristic (ROC) curve analysis was used to evaluate the diagnostic value of miR-106a-5p. The association of miR-106a-5p with ACI prognosis was evaluated using the logistic analysis. In vitro experiments were performed in BV-2 cells by oxygen glucose deprivation (OGD) treatment, and the effects of miR-106a-5p on BV-2 inflammation were assessed using an enzyme linked immunosorbent assay (ELISA).

RESULT

It was observed that miR-106a-5p was significantly upregulated in the serum and CSF of ACI patients (all P < 0.001), and had considerable diagnostic accuracy. The highest serum miR-106a-5p was observed in severe ACI cases, and miR-106a-5p expression was significantly increased in unfavorable prognosis patients. Serum and CSF expression of miR-106a-5p was positively correlated with proinflammatory cytokines in ACI patients, and the inflammation of OGD-induced BV-2 cells was suppressed by miR-106a-5p reduction.

CONCLUSION

MiR-106a-5p is overexpressed in ACI patients and may serve as a diagnostic and prognostic biomarker for ACI. Furthermore, miR-106a-5p may be involved in ACI progression by regulating neuroinflammation.

Relationship Between MicroRNA Signature and Arterial Stiffness in Patients With Ischemic Stroke

BACKGROUND AND PURPOSE

We investigated whether circulating microRNAs (miRNAs) is associated with arterial stiffness in patients with acute ischemic stroke.

METHODS

We recruited patients with acute ischemic stroke who were admitted to a university hospital stroke center and underwent carotid-femoral pulse wave velocity (cfPWV) measurement using SphygmoCor (AtCor Medical, Sydney, Australia) and brachial-ankle PWV using a volume-plethysmography device (VP-1000, Omron Colin, Komaki, Japan). Circulating miRNAs were measured in venous blood samples stored in EDTA. We selected five miRNAs (miR-17, miR-93, miR-450, miR-629, and let-7i) related to atherosclerosis based on a literature review. Pearson's correlation analysis was applied to the correlations between miRNAs and arterial stiffness parameters. Finally, multivariable linear regression analysis was performed to identify the independent factors for cfPWV.

RESULTS

This study included 70 patients (age=71.1±10.3 years [mean±SD], 29 females). The expression levels of miR-93 (r=-0.27, p=0.049) and let-7i (r=-0.27, p=0.039) were inversely correlated with cfPWV. Multivariable linear regression analysis including age, hypertension, and estimated glomerular filtration rate showed that let-7i was independently related with cfPWV (standardized coefficient=-0.262, p=0.036). Correlation analysis indicated that let-7i was positively associated with visceral muscle Hounsfield units on computed tomography (r=0.264, p=0.043).

CONCLUSIONS

The expression level of let-7i was independently related to arterial stiffness in patients with cerebral infarction, suggesting that it plays a pathophysiological role in atherosclerosis.

The Role of MicroRNA-126 in Atherosclerotic Cardiovascular Diseases

Atherosclerotic cardiovascular diseases remain the leading cause of morbidity and mortality worldwide despite all efforts made towards their management. Other than targeting the traditional risk factors for their development, scientific interest has been shifted towards epigenetic regulation, with microRNAs (miRs) being at the forefront. MiR-126, in particular, has been extensively studied in the context of cardiovascular diseases. Downregulated expression of this miR has been associated with highly prevalent cardiovascular risk factors such as arterial hypertension and diabetes mellitus. At the same time, its diagnostic and prognostic capability concerning coronary artery disease is still under investigation, with up-to-date data pointing towards a dysregulated expression in a stable disease state and acute myocardial infarction. Moreover, a lower expression of miR-126 may indicate a higher disease complexity, as well as an increased risk for future major adverse cardiac and cerebrovascular events. Ultimately, overexpression of miR-126 may emerge as a novel therapeutic target in atherosclerotic cardiovascular diseases due to its potential in promoting therapeutic angiogenesis and anti-inflammatory effects. However, the existing challenges in miR therapeutics need to be resolved before translation to clinical practice.

CircHIPK3 Regulates Vascular Smooth Muscle Cell Calcification Via the miR-106a-5p/MFN2 Axis

Atherosclerosis is the most common arterial disease and is closely related to vascular calcification. CircHIPK3 has been implicated in atherosclerosis development, but the possible downstream regulatory mechanisms remain unclear. The levels of circHIPK3, miR-106a and MFN2 in tissues and blood samples of patients with atherosclerosis were detected by RT-qPCR. The levels of circHIPK3, miR-106a and MFN2 were detected by RT-qPCR and the expression levels of MFN2, osteogenic and cartilage differentiation marker proteins were detected by western blot in vitro. ALP staining, Alizarin Red staining, and calcium content detection evaluated the degree of osteogenic differentiation of cells. Alcian blue staining detected the level of cell cartilage differentiation. Luciferase detected the targeting relationship between circHIPK3 and miR-106a-5p, as well as miR-106a-5p and MFN2. CircHIPK3 and MFN2 were low expressed and miR-106a-5p was highly expressed in tissues and blood samples of patients with atherosclerosis, as well as vascular smooth muscle cell (VSMC) with osteogenic and cartilage differentiation. Overexpression of circHIPK3 reduced the cell mineralization and calcium content. Overexpression of circHIPK3 inhibited osteogenic differentiation by decreasing ALP activity, RUNX2, and OPG expression, and increasing SM22α and SMA level. What's more, overexpression of circHIPK3 decreased the chondrogenic differentiation by inhibiting the protein level of SOX9, aggrecan, and collagen II. CircHIPK3 targeted miR-106a-5p and miR-106a-5p targeted MFN2. MiR-106a-5p overexpression or MFN2 depletion repressed the effect of circHIPK3 overexpression on VSMC calcification. CircHIPK3 regulated osteogenic and cartilage differentiation of VSMC via miR-106a-5p/MFN2 axis, indicating a target for treating vascular calcification.

MicroRNA: An Emerging Predictive, Diagnostic, Prognostic and Therapeutic Strategy in Ischaemic Stroke

Stroke continues to be the third-leading cause of death and disability worldwide. The limited availability of diagnostic tools approved therapeutics and biomarkers that help monitor disease progression or predict future events remain as the major challenges in the field of stroke medicine. Hence, attempts to discover safe and efficacious therapeutics and reliable biomarkers are of paramount importance. MicroRNAs (miRNAs) are a class of non-coding RNAs that play important roles in regulating gene expression. Since miRNAs also play important roles in key mechanisms associated with the pathogenesis of stroke, including energy failure, inflammation and cell death, it is possible that miRNAs may serve as reliable blood-based markers for risk prediction, diagnosis and prognosis of ischaemic stroke. Discovery of better neurological outcome and smaller cerebral infarcts in animal models of ischaemic stroke treated with miRNA agomirs or antagomirs indicate that miRNAs may also play a cerebrovascular protective role after an ischaemic stroke. Nonetheless, further evidences on the optimum time for treatment and route of administration are required before effective translation of these findings into clinical practice. Bearing these in mind, this paper reviews the current literature discussing the involvement of miRNAs in major pathologies associated with ischaemic stroke and evaluates their value as reliable biomarkers and therapeutics for ischaemic stroke.

MicroRNA-134-5p and the Extent of Arterial Occlusive Disease Are Associated with Risk of Future Adverse Cardiac and Cerebral Events in Diabetic Patients Undergoing Carotid Artery Stenting for Symptomatic Carotid Artery Disease

There is little known about the prognostic value of serum microRNAs (miRs) in diabetic patients with symptomatic internal carotid artery disease (ICAS) who underwent stent supported angioplasty (PTA) for ICAS. The present study aimed to investigate expression levels of selected miRs for future major adverse cardiac and cerebral events (MACCE) as a marker in diabetic patients following ICAS-PTA. The expression levels of 11 chosen circulating serum miRs were compared in 37 diabetic patients with symptomatic ICAS and 64 control group patients with symptomatic ICAS, but free of diabetes. The prospective median follow-up of 84 months was performed for cardiovascular outcomes. Diabetic patients, as compared to control subjects, did not differ with respect to age (p = 0.159), distribution of gender (p = 0.375), hypertension (p = 0.872), hyperlipidemia (p = 0.203), smoking (p = 0.115), coronary heart disease (p = 0.182), lower extremities arterial disease (LEAD, p = 0.731), and miRs expressions except from lower miR-16-5p (p < 0.001). During the follow-up period, MACCE occurred in 16 (43.2%) diabetic and 26 (40.6%) non-diabetic patients (p = 0.624). On multivariate Cox analysis, hazard ratio (HR) and 95% Confidence Intervals (95%CI) for diabetic patients associated with MACCE were miR-134-5p (1.12; 1.05−1.21, p < 0.001), miR-499-5p (0.16; 0.02−1.32, p = 0.089), hs-CRP (1.14; 1.02−1.28; p = 0.022), prior myocardial infarction (8.56, 1.91−38.3, p = 0.004), LEAD (11.9; 2.99−47.9, p = 0.005), and RAS (20.2; 2.4−167.5, p = 0.005), while in non-diabetic subjects, only miR-16-5p (1.0006; 1.0001−1.0012, p = 0.016), miR-208b-3p (2.82; 0.91−8.71, p = 0.071), and hypertension (0.27, 0.08−0.95, p = 0.042) were associated with MACCE. Our study demonstrated that different circulating miRs may be prognostic for MACCE in diabetic versus non-diabetic patients with symptomatic ICAS. Higher expression levels of miR-134 were prognostic for MACCE in diabetic patients, while higher expression levels of miR-16 were prognostic in non-diabetic patients.

Synthetic role of miR-200b-3p, ABCD2 score, and carotid ultrasound in the prediction of cerebral infarction in patients with transient ischemic attack

BACKGROUND

Transient ischemic attack (TIA) is a major risk factor for the occurrence of cerebral infarction (CI). This study aimed to evaluate the predictive value of the synthetic role of miR-200b-3p, ABCD2 score, and carotid ultrasound for CI onset in patients with TIA.

METHODS

Expression of miR-200b-3p was detected by reverse transcription quantitative PCR and carotid stenosis degree was evaluated using carotid ultrasound examination. Association of miR-200b-3p with ABCD2 scores and carotid stenosis degree was assessed using t-test and chi-square test. Logistic regression analysis was used to judge the ability of miR-200b-3p, ABCD2 score, and carotid ultrasound to predict the occurrence of CI. Receiver operating characteristic curve was used to analyze the diagnostic value of miR-200b-3p and the accuracy of miR-200b-3p, ABCD2 score, and carotid ultrasound in predicting CI development.

RESULTS

Expression of serum miR-200b-3p was significantly increased in TIA patients compared with healthy controls, and had diagnostic value in TIA patients. Serum miR-200b-3p was significantly associated with dyslipidemia, ABCD2 score, and carotid stenosis degree in TIA patients. ABCD2 score, carotid stenosis degree, and serum miR-200b-3p were independently associated with CI onset, and the synthetic role of these three indicators had the best accuracy in the prediction of CI onset in TIA patients.

CONCLUSION

Serum miR-200b-3p expression was increased in TIA patients with considerable diagnostic value to screen TIA cases from healthy controls. Moreover, we speculated that the combination of miR-200b-3p, ABCD2 score, and carotid stenosis degree by ultrasound may propose as an efficient predictive strategy for the prediction of CI in TIA patients.

Therapeutic Potential of Stem Cell-Derived Extracellular Vesicles on Atherosclerosis-Induced Vascular Dysfunction and Its Key Molecular Players

Atherosclerosis is a progressive, chronic inflammatory disease of the large arteries caused by the constant accumulation of cholesterol, followed by endothelial dysfunction and vascular inflammation. We hypothesized that delivery of extracellular vesicles (EVs), recognized for their potential as therapeutic targets and tools, could restore vascular function in atherosclerosis. We explored by comparison the potential beneficial effects of EVs from subcutaneous adipose tissue stem cells (EVs (ADSCs)) or bone marrow mesenchymal stem cells (EVs (MSCs)) on the consequences of atherogenic diet on vascular health. Also, the influences of siRNA-targeting Smad2/3 (Smad2/3siRNA) on endothelial dysfunction and its key molecular players were analyzed. For this study, an animal model of atherosclerosis (HH) was transplanted with EVs (ADSCs) or EVs (MSCs) transfected or not with Smad2/3siRNA. For controls, healthy or HH animals were used. The results indicated that by comparison with the HH group, the treatment with EVs(ADSCs) or EVs(MSCs) alone or in combination with Smad2/3siRNA of HH animals induced a significant decrease in the main plasma parameters and a noticeable improvement in the structure and function of the thoracic aorta and carotid artery along with a decrease in the selected molecular and cellular targets mediating their changes in atherosclerosis: 1) a decrease in expression of structural and inflammatory markers COL1A1, α-SMA, Cx43, VCAM-1, and MMP-2; 2) a slight infiltration of total/M1 macrophages and T-cells; 3) a reduced level of cytosolic ROS production; 4) a significant diminution in plasma concentrations of TGF-β1 and Ang II proteins; 5) significant structural and functional improvements (thinning of the arterial wall, increase of the inner diameter, enhanced distensibility, diminished VTI and Vel, and augmented contractile and relaxation responses); 6) a reduced protein expression profile of Smad2/3, ATF-2, and NF-kBp50/p65 and a significant decrease in the expression levels of miR-21, miR-29a, miR-192, miR-200b, miR-210, and miR-146a. We can conclude that 1) stem cell-derived EV therapies, especially the EVs (ADSCs) led to regression of structural and functional changes in the vascular wall and of key orchestrator expression in the atherosclerosis-induced endothelial dysfunction; 2) transfection of EVs with Smad2/3siRNA amplified the ability of EVs(ADSCs) or EVs(MSCs) to regress the inflammation-mediated atherosclerotic process.

Recognition of the Possible miRNA-mRNA Controlling Network in Stroke by Bioinformatics Examination

BACKGROUND

Based on the latest research of WHO, it has been revealed that more than 15 million people suffer from stroke every year worldwide. Of these 15 million people, 6 million succumb to death, and 5 million get permanently disabled. This is the prime reason for the substantial economic burden on all parts of the world.

METHODS

These data have been obtained from the GEO database, and the GEO2R tool was used to find out the differentially expressed miRNAs (DEMs) between the stroke and normal patients' blood. FunRich and miRNet were considered to find potential upstream transcription factors and downstream target genes of candidate EMRs. Next, we use GO annotation and KEGG pathway enrichment. Target genes were analyzed with the help of the R software. Then, the STRING database and Cytoscape software were used to conduct PPI and DEM-hub gene networks. Finally, GSE58294 was used to estimate the hub gene expressions.

RESULTS

Six DEMs in total were selected out from GSE95204 and GSE117064 datasets. 663 DEMs' target genes were predicted, and NRF1, EGR1, MYC, YY1, E2F1, SP4, and SP1 were predicted as an upstream transcription factor for DEMs' target genes. Target genes of DEMs were primarily augmented in the PI3K-Akt signaling pathway and p53 signaling pathway. The network construction of DEM hygiene is potentially modulated by hsa-miR-3591-5p, hsa-miR-548as-3p, hsa-miR-206, and hsa-miR-4503 hub genes which were found among the top 10 of the hub genes. Among the top 10 hub genes, justification of CTNNB1, PTEN, ESR1, CCND1, KRAS, AKT1, CCND2, CDKN1B, and MYCN was constant with that in the GSE58294 dataset.

CONCLUSION

In summary, our research first constructs the miRNA-mRNA network in stroke, which probably renders an awakening purview into the pathogenesis and cure of stroke.

Epigenetics Modifications in Large-Artery Atherosclerosis: A Systematic Review

OBJECTIVES

In recent years, the evidence of the relationship between epigenetics and acute ischemic stroke (AIS) were accumulating, however, the epigenetic characteristics that directs specifically towards the aetiology of large-artery atherosclerosis (LAA) remain ambiguous. The aim of this study was to highlight the overall evidence concerning the epigenetic mechanisms associated with the occurrence of LAA.

MATERIALS AND METHODS

Studies that involve investigations related to epigenetic markers (DNA methylation and RNA modifications) and LAA were retrieved from eleven scientific publication databases. The studies were screened through the pre-set inclusion and exclusion criteria prior to the NOS evaluation.

RESULTS

Eligible studies (n=25) were evaluated. Of which, six reported on DNA methylation and 19 studies assessed RNA modifications (16 on miRNAs, two on lncRNAs, and one study on circRNA). Hypomethylation of MTRNR2L8 and ERα promoters; microRNAs (miR-7-2-3p, miR-16, miR-34a-5p, miR-126, miR-143, miR-200b, miR-223, miR-503, miR-1908, miR-146a rs2910164 C/G, miR-149 rs2292832 T/C, miR-200b rs7549819 T/C, miR-34a rs2666433); lncRNA of ZFAS1; and circRNA of hsa_circRNA_102488 were associated with LAA significantly.

CONCLUSION

Current systematic review highlighted hypomethylation of miRNAs and lncRNA might be the potential biomarkers for LAA.

Analysis of microRNA signatures in ischemic stroke thrombus

BACKGROUND

We investigated the microRNA expression pattern from thrombus retrieved by mechanical thrombectomy in acute stroke patients to understand the stroke mechanism.

METHODS

This study included acute ischemic stroke patients who had undergone intra-arterial thrombectomy at Chung-Ang University Hospital in Seoul, Korea between February 2016 and March 2019. The thrombus was retrieved and stored at -70℃ after obtaining informed consent. MicroRNA microarray analysis was performed for the patients with identified stroke mechanisms including (1) large artery atherosclerosis, (2) cardioembolism with atrial fibrillation, and (3) cardioembolism with valvular heart disease. The microRNAs derived from microarray analysis were validated by quantitative real-time polymerase chain reaction (qRT-PCR) from different patient populations. The correlation analysis was performed between microRNA levels and laboratory data to understand the functional relevance of the altered microRNA.

RESULTS

In total, 55 thrombi were obtained from 74 patients, and the microRNAs were analyzed in 45 samples. Microarray analysis of 2578 microRNAs revealed that 50 microRNAs were significantly altered among the three groups. Validation using qRT-PCR showed that miR-378f and miR-450b-5p were significantly elevated among the cardioembolic thrombi; both microRNAs were inversely correlated with the ejection fraction from echocardiography. Thrombi from patients with early neurological deterioration exhibited higher levels of miR-93-5p and lower levels of miR-629-5p than those from neurologically stable patients.

CONCLUSIONS

The microRNA expression pattern can provide information regarding the mechanism of stroke by reflecting the underlying pathological status of the organ from which the thrombus was derived.

MicroRNAs' role in the environment-related non-communicable diseases and link to multidrug resistance, regulation, or alteration

The discovery of microRNAs (miRNAs) 20 years ago has advocated a new era of "small molecular genetics." About 2000 miRNAs are present that regulate one third of the genome. MiRNA dysregulated expression arising as a response to our environment insult or stress or changes may contribute to several diseases, namely non-communicable diseases, including tumor growth. Their presence in body fluids, reflecting level alteration in various cancers, merit circulating miRNAs as the "next-generation biomarkers" for early-stage tumor diagnosis and/or prognosis. Herein, we performed a comprehensive literature search focusing on the origin, biosynthesis, and role of miRNAs and summarized the foremost studies centering on miR value as non-invasive biomarkers in different environment-related non-communicable diseases, including various cancer types. Moreover, during chemotherapy, many miRNAs were linked to multidrug resistance, via modulating numerous, environment triggered or not, biological processes and/or pathways that will be highlighted as well.

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.

Circulating miR-155 and JAK2/STAT3 Axis in Acute Ischemic Stroke Patients and Its Relation to Post-Ischemic Inflammation and Associated Ischemic Stroke Risk Factors

Background

“Micro RNAs and their target genes recently have been identified to play a crucial role in the molecular pathogenesis of post-stroke ischemic cellular injury, which elucidates their new role in ischemic stroke diagnosis and therapy”. Thus, we evaluated the relative serum expression of miR-155, an inflammatory micro RNA, and the mRNAs (JAK2/STAT3) in acute ischemic stroke patients and its associations with the inflammatory cytokine TNF-α and different stroke risk factors.

Subjects and Methods

The relative expression of serum miR-155 and mRNAs (JAK2/STAT3) was assessed using RT-PCR, serum TNF-α was measured using ELIZA in 46 acute ischemic stroke patients and 50 control subjects. Receiver operating characteristic (ROC) curve was constructed to assess the specificity and sensitivity of circulating miR-155, JAK2/STAT3 as biomarkers for acute ischemic stroke.

Results

Circulating miR-155, JAK2/STAT3 were significantly up-regulated among stroke patients (8.5, 2.9, 4.2 fold respectively, P<0.001) with significant increase in TNF-α (263.8 ± 10.7 pg/mL, P <0.001). MiR-155, JAK2/STAT3 were positively correlated with TNF-α. MiR-155, JAK2/STAT3 were significantly increased in stroke patients and associated with risk factors such as hypertension, carotid atherosclerosis, and atrial fibrillation. Our study revealed that miR-155 has diagnostic accuracy for acute ischemic stroke where AUC=0.9, (P<0.001).

Conclusion

The elevated expressions of circulating miR-155, JAK2/STAT3, and TNF-α in acute ischemic stroke patients could trigger post-stroke cellular inflammation. MiR-155 could be used as potential inflammatory biomarker for acute ischemic stroke. However, further clinical studies are still needed to determine the exact role of miRNAs and different signal transduction expressions in the stage of acute ischemic stroke.

MicroRNA-200b-3p promotes endothelial cell apoptosis by targeting HDAC4 in atherosclerosis

Background

Epicardial adipose tissue (EAT) shares the same microcirculation with coronary arteries through coronary arteries branches, and contributes to the development of atherosclerosis. MicroRNAs (miRNAs) are involved in the formation of atherosclerosis. However, the alteration of miRNA profile in EAT during atherosclerosis is still uncovered.

Methods

The miRNA expression profiles of EAT from non-coronary atherosclerosis disease (CON, n = 3) and coronary atherosclerosis disease (CAD, n = 5) patients was performed to detect the differentially expressed miRNA. Then the expression levels of miRNA in other CON (n = 5) and CAD (n = 16) samples were confirmed by realtime-PCR. miR-200b-3p mimic was used to overexpress the miRNA in HUVECs. The apoptosis of HUVECs cells was induced by H₂O₂ and ox-LDL, and detected by Annexin V/PI Staining, Caspase 3/7 activity and the expression of BCL-2 and BAX.

Results

250 miRNAs were differentially expressed in EAT from CAD patients, which were associated with metabolism, extracellular matrix and inflammation process. Among the top 20 up-regulated miRNAs, the expression levels of miR-200 family members (hsa-miR-200b/c-3p, miR-141-3p and miR-429), which were rich in endothelial cells, were increased in EAT from CAD patients significantly. Upregulation of miR-200 family members was dependent on the oxidative stress. The overexpression of miR-200b-3p could promote endothelial cells apoptosis under oxidative stress by targeting HDAC4 inhibition.

Conclusions

Our study suggests that EAT derived miR-200b-3p promoted oxidative stress induced endothelial cells damage by targeting HDAC4, which may provide a new and promising therapeutic target for AS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-01980-0.

Circulating miRNA in atherosclerosis: a clinical biomarker and early diagnostic tool

Atherosclerosis, which is a vascular disease, is characterized by narrowing the arteries and forming plaque inside arteries. There is a record 17.5 million associated deaths recorded annually, representing 31% of global death. It has been noted that there is an association between vascular fibrosis and atherosclerosis. The thickening of the arterial wall and reduction of the lumen diameter may cause unwarranted deposition of extracellular matrix (ECM), and these conditions help in the progression of many clinical diseases and pathological conditions such as atherosclerosis. Here, we reviewed the involvement of various circulating microRNAs (miRNAs) in the very early diagnosis of atherosclerosis. We have also tried to provide an insight into the advantages and validation of circulating miRNAs through different techniques. We have discussed different circulating miRNAs, such as miR-17, miR-17-5p, miR-29b, miR-30, miR-92a, miR-126, miR-143, miR-145, miR-146a, miR-212, miR-218, miR-221, miR-222, miR-361-5p, as a biomarker for clinical diagnosis of atherosclerosis. The insightful demonstration in this review will offer a better opportunity for the researchers and technology developers in understanding the current scenario of circulating miRNA, which could facilitate them in improving the current diagnostic technologies of atherosclerosis in clinics.

Genetic predisposition and bioinformatics analysis of ATP-sensitive potassium channels polymorphisms with the risks of elevated apolipoprotein B serum levels and its related arteriosclerosis cardiovascular disease

Serum concentration of apolipoprotein B (Apo B) is causally associated with arteriosclerosis cardiovascular disease (ASCVD) risk. Whether ATP-sensitive potassium channels (KATP) variants predict the risk of increased Apo B concentration (≥ 80 mg/dL) and related ASCVD remain less clear. We recruited 522 subjects with elevated Apo B concentration (≥ 80 mg/dL) and 522 counterpart subjects (< 80 mg/dL) from South China to assess the associations of KATP variants (rs11046182, rs78148713, rs145456027 and rs147265929) with the risks of increased Apo B serum concentration (≥ 80 mg/dL), carotid artery stenosis (CAS) ≥ 50% and new-onset ischemic stroke (IS). Our results showed that only KATP SNP rs11046182 (GG genotype) was associated with increased risk of Apo B ≥ 80 mg/dL (adjusted OR=2.17, P<0.001) and CAS ≥ 50% (adjusted OR=2.63, P=0.011). After median 50.6-months follow-up, subjects carrying GG genotype of rs11046182 were associated with higher risk of new-onset IS (adjusted HR=2.24, P=0.024). Further, the exosome-derived microRNAs (exo-miRs) expression profile was identified by next-generation sequencing. 41 exo-miRs were significantly differentially expressed under cross-talk status between high Apo B level (≥ 80 mg/dL) and KATP rs11046182. Our study demonstrated that KATP variant rs11046182 was associated with higher risks of elevated serum Apo B levels and its related ASCVD, and the possible mechanism was related to specific exo-miRs expression profile of KATP rs11046182.

Association of Bone Mineral Density to Cerebral Small Vessel Disease Burden

OBJECTIVE

To test the hypothesis that bone mineral loss is mechanistically related to cerebral small vessel disease (SVD), we investigated the relationship between bone mineral density and the prevalence and intensity of SVD among patients with stroke.

METHODS

We analyzed data of 1,190 consecutive patients with stroke who were >50 years of age and underwent both brain MRI and dual-energy x-ray absorptiometry from the stroke registry of Chung-Ang University Hospital in Seoul, Korea. The patients were categorized into 3 groups according to their bone mineral density (normal, osteopenia, and osteoporosis). White matter hyperintensities, silent lacunes, cerebral microbleeds, and extensive perivascular space were assessed from brain MRI. Multinomial logistic regression model was used to examine the association between osteoporosis and total SVD score. We also recruited 70 patients with stroke to study serum bone turnover markers and microRNAs related to both cerebral atherosclerosis and bone metabolism to understand bone and brain interaction.

RESULTS

Osteoporosis was determined among 284 patients (23.9%), and 450 patients (37.8%) had osteopenia. As bone mineral density decreased, total SVD score and the incidence of every SVD phenotype increased except strictly lobar cerebral microbleeds. Multinomial logistic regression analysis showed that osteoporosis was independently associated with severe SVD burden. The levels of microRNA-378f were significantly increased among the patients with osteoporosis and maximal total SVD score and positively correlated with parathyroid hormone and osteocalcin.

CONCLUSIONS

These findings suggest a pathophysiologic link between bone mineral loss and hypertensive cerebral arteriolar degeneration, possibly mediated by circulating microRNA.

Search for Reliable Circulating Biomarkers to Predict Carotid Plaque Vulnerability

Atherosclerosis is responsible for 20% of ischemic strokes, and the plaques from the internal carotid artery the most frequently involved. Lipoproteins play a key role in carotid atherosclerosis since lipid accumulation contributes to plaque progression and chronic inflammation, both factors leading to plaque vulnerability. Carotid revascularization to prevent future vascular events is reasonable in some patients with high-grade carotid stenosis. However, the degree of stenosis alone is not sufficient to decide upon the best clinical management in some situations. In this context, it is essential to further characterize plaque vulnerability, according to specific characteristics (lipid-rich core, fibrous cap thinning, intraplaque hemorrhage). Although these features can be partly detected by imaging techniques, identifying carotid plaque vulnerability is still challenging. Therefore, the study of circulating biomarkers could provide adjunctive criteria to predict the risk of atherothrombotic stroke. In this regard, several molecules have been found altered, but reliable biomarkers have not been clearly established yet. The current review discusses the concept of vulnerable carotid plaque, and collects existing information about putative circulating biomarkers, being particularly focused on lipid-related and inflammatory molecules.

Expression and short-term prognostic value of miR-126 and miR-182 in patients with acute stroke

Expression and short-term prognostic value of miR-126 and miR-182 in patients with acute stroke were investigated. In total, 153 patients with acute stroke admitted to the Second Affiliated Hospital of Soochow University from February 2016 to February 2018 were enrolled into the observation group as group A [88 patients with acute cerebral infarction (AIS)] or group B [65 patients with cerebral hemorrhage (ICH)]. Furthermore, 69 healthy people receiving physical examinations in the hospital were enrolled into the control group. The relative expression of miR-126 and miR-182 in all subjects were measured and their correlation with the National Institute of Health stroke scale (NIHSS) and activities of daily living (ADL) scores was analyzed. After 3 months of follow-up, the correlation of miR-126 and miR-182 with the Modified Rankin Scale (MRS) score of patients was investigated. The receiver operating characteristic (ROC) curve was employed to explore the value of miR-126 and miR-182, alone or in combination, in predicting the prognosis of acute stroke patients. Subjects in the control group had markedly higher miR-126 expression and lower miR-182 expression than those in group A and group B in the observation group (P<0.05). Pearson's correlation analysis suggested a notable correlation of miR-126 and miR-182 with NIHSS and ADL scores. Patients with a mild condition or good prognosis had higher miR-126 expression and lower miR-182 expression than patients with a severe condition or poor prognosis (P<0.05). Both miR-126 and miR-182 predicted the prognosis of acute stroke, and the combination of miR-126 and miR-182 presented better accuracy. The expression levels of miR-126 and miR-182 are associated with the neurological function, self-care ability, and prognosis in patients with acute stroke is highly valuable for predicting the prognosis of patients.

A functional polymorphism in the promoter of miR-17-92 cluster is associated with decreased risk of ischemic stroke

Background

The microRNA-17-92 (miR-17-92) cluster is one of the most extensively studied miRNA clusters. Abnormal expression of the cluster has been found to play important role in different kinds of human diseases, including ischemic stroke (IS). The aim of our study was to investigate the association between three polymorphisms (rs1491034, rs9301654 and rs982873) in the promoter of the miR-17-92 cluster and risk of IS.

Methods

Three hundred and ninety-eight patients with IS and 397 control subjects were included. The genotypes of the three polymorphisms were determined by Snapshot SNP genotyping assay. Relative expression of the cluster in peripheral blood mononuclear cells (PBMCs) of cases and controls were examined by quantitative real-time PCR.

Results

Significant association between rs9301654 polymorphism and risk of IS were observed basing on genotype, model and allele analyses (GA vs. AA: adjusted OR = 0.63, 95% CI: 0.41~0.97, P = 0.037; GG vs. AA: adjusted OR = 0.23, 95% CI: 0.07~0.78, P = 0.018; GA + GG vs. AA: adjusted OR = 0.57, 95% CI: 0.38~0.87, P = 0.009; GA + AA vs. GG: adjusted OR = 0.27, 95% CI: 0.08~0.89, P = 0.032; G vs. A: adjusted OR = 0.58, 95% CI: 0.40~0.83). Haplotype analysis showed that TGC and TGT haplotypes were associated with decreased risk of IS (OR = 0.59, 95% CI: 0.40~0.87, P = 0.007 for TGC haplotype; OR = 0.21, 95% CI: 0.06~0.75, P = 0.009 for TGT haplotype). Importantly, we found the expression of miR-17-5p was significant higher while miR-19a-3p was significant lower in patient with IS compared with the control group (P < 0.01), and patients with rs9301654GG or GA genotype displayed lower level of miR-19a-3p compared with the AA genotype (P < 0.01).

Conclusions

Our findings indicated that rs9301654 polymorphism in the promoter of miR-17-92 cluster may be associated with susceptibility of IS in the Chinese population. However, we found that rs9301654 polymorphism and its respective gene expression did not demonstrate consistent association with IS in the Chinese population. Further studies such as gene-gene interaction are warranted to reveal the role of miR-19a and its regulatory genes in the etiology of IS.

Altered Extracellular Vesicle MicroRNA Expression in Ischemic Stroke and Small Vessel Disease

Active transport of microRNAs (miRNA) in extracellular vesicles (EV) occurs in disease. Circulating EV-packaged miRNAs in the serum of stroke patients were compared to stroke mimics with matched cardio- and cerebrovascular risk factors, with corroboration of results in a pre-clinical model. An unbiased miRNA microarray was performed in stroke vs. stroke mimic patients (n = 39). Results were validated (n = 173 patients) by real-time quantitative polymerase chain reaction. miRNA expression was quantified in total serum/EV (n = 5-7) of naïve adult spontaneously hypertensive stroke-prone rats (SHRSP), their normotensive reference strain (Wistar Kyoto, WKY) and in circulating EV (n = 3), peri-infarct brain (n = 6), or EV derived from this region (n = 3) in SHRSP following transient middle cerebral artery occlusion (tMCAO). Circulating EV concentration did not differ between stroke and stroke mimic patients. The microarray identified many altered EV-packaged miRNAs: levels of miRNA-17-5p, -20b-5p and -93-5p (miRNA-17 family members) and miRNA-27b-3p were significantly (p ≤ 0.05) increased in stroke vs. stroke mimic patients. Patients with small vessel disease (SVD) consistently had the highest miRNA levels. Circulating EV concentration was unaltered between naïve SHRSP and WKY but levels of miRNA-17-5p and -93-5p were significantly increased in SHRSP. tMCAO in SHRSP did not further alter circulating EV miRNA-17 family member expression and nor did it change total miRNA-17 family levels in peri-infarct brain tissue or in EV isolated from this region at 24 h post-tMCAO. Changes in EV packaged miRNA expression was validated in patients with stroke, particularly those with SVD and corroborated pre-clinically. Together, altered circulating EV levels of miRNA-17 family members may reflect the chronic sequelae underlying cerebrovascular SVD rather than the acute ischemic stroke itself.

MicroRNA-323 suppresses nerve cell toxicity in cerebral infarction via the transforming growth factor-β1/SMAD3 signaling pathway

In the present study, the aim was to investigate the function of microRNA‑323 (miR‑323) in cerebral infarction and its underlying mechanism. A rat model of cerebral infarction was established and hippocampal tissues were analyzed. In addition, to further understand the role of miR‑323, PC12 cells were transfected with miR‑323 mimics or inhibitors and subjected to hypoxia to model cerebral infarction. Reverse transcription‑quantitative polymerase chain reaction was used to measure the expression of miR‑323. A luciferase reporter assay was conducted to analyze miR‑323 target sites the partial sequence of the 3'‑untranslated region of SMAD3 mRNA in vitro. Western blot analysis was also used to analyze transforming growth factor‑β1 (TGF‑β1) and SMAD3 protein expression levels. It was observed that miR‑323 expression was significantly upregulated in rats with cerebral infarction compared with rats in the sham‑control group. In addition, overexpression of miR‑323 induced nerve cell toxicity and reduced nerve cell growth in an in vitro model of cerebral infarction, whereas downregulation of miR‑323 caused the opposite effects on nerve cell toxicity and growth in this model. In addition, overexpression of miR‑323 directly targeted and suppressed SMAD3 expression in the in vitro model of cerebral infarction, while inhibition of miR‑323 induced SMAD3 expression. The use of a SMAD3 inhibitor suppressed the effect of anti‑miR‑323 on nerve cell toxicity in the in vitro model of cerebral infarction. Collectively, these findings suggested that miR‑323 suppresses nerve cell apoptosis in cerebral infarction via the TGF‑β1/SMAD3 signaling pathway.

Sex differences in miRNA as therapies for ischemic stroke

MicroRNAs, a subset of non-coding RNAs, are present in virtually all tissues including body fluids and are global regulators of the transcriptome. In view of the expanding number of microRNAs and the large number of gene targets that each microRNA can potentially regulate, they have been compared to hormones in the scope of their effects. MicroRNA have been implicated as biomarkers for several diseases including stroke, as well as chronic conditions that are associated with stroke. Recent research has focused on manipulating miRNA to improve stroke outcomes. Although several miRNAs have been shown to have neuroprotective properties, the overwhelming majority of these studies have employed only male animals. This review will focus on two miRNAs, Let7f and mir363-3p, whose effectiveness as a stroke neuroprotectant is sex-specific.

MicroRNA-146a and microRNA-155 as novel crevicular fluid biomarkers for periodontitis in non-diabetic and type 2 diabetic patients

AIM

Recent studies point at the crucial role of epigenetic mechanisms in the development of multifactorial diseases such as periodontitis and diabetes mellitus (DM) type 2. In addition, circulatory microRNAs (miRs) have emerged as novel biomarkers for various diseases. Aim of this study was to investigate the levels of miR-146a and miR-155 and superoxide dismutase (SOD) activity in gingival crevicular fluid (GCF) of periodontitis patients with (CPDM) and without (CP) DM type 2 as well as in periodontally healthy, control groups (PHDM and PH, respectively).

MATERIAL AND METHODS

miR modulation was analysed using quantitative real-time PCR while SOD activity was measured spectrophotometrically.

RESULTS

The upregulation of miR-146a and miR-155 was observed in CP and CPDM patients' baseline, while the levels decreased after 6 weeks of the non-surgical therapy to the levels comparable to PH and PHDM, respectively. Expression levels of miRs positively correlated with SOD activity. Levels of miR-146a were higher in PHDM compared to PH patients. Multivariate analysis revealed that levels of miR-146a and miR-155 were significantly associated with periodontitis when adjusting for age and gender.

CONCLUSIONS

miR-146a and miR-155 may be considered as possible novel biomarkers for periodontitis in non-diabetic and type 2 diabetic patients.

Circulating miRNA levels differ with respect to carotid plaque characteristics and symptom occurrence in patients with carotid artery stenosis and provide information on future cardiovascular events

Introduction

Circulating microRNAs (miRNAs) levels are potentially important biomarkers and therapeutic targets of cerebral ischemic event (CIE) in patients with internal carotid artery stenosis (ICAS).

Aim

This prospective study investigated associations between circulating miRNAs and symptomatic and asymptomatic ICAS, carotid plaque morphology and future cardiovascular events.

Material and methods

Circulating miRNAs (miR-1-3p, miR-16-5p, miR-34a-5p, miR-124-3p, miR-133a-3p, miR-133b, miR-134-5p, miR-208b-3p, miR-375 and miR-499-5p) were analyzed in 92 consecutive patients with significant ICAS referred for revascularization. Group I comprised 65 subjects (41 males, age 69.3 ±9.7 years) with a recent CIE. Group II comprised 27 patients (15 males, age 68.2 ±8.4 years) with asymptomatic ICAS. The ICAS degree and plaque morphology was assessed by ultrasonography. The incidences of cardiovascular death (CVD), myocardial infarction (MI) and recurrent CIE (CVD/MI/CIE) were recorded prospectively (mean: 38.7 ±3.8 months).

Results

Groups II and I differed significantly in levels of miR-124-3p (p = 0.036), miR-133a-3p (p = 0.043) and miR-134-5p (p = 0.02). Hypoechogenic, as compared to echogenic, plaques differed in levels of miR-124-3p (p = 0.038), miR-34a-5p (p = 0.006), miR-133b (p = 0.048), miR-134-5p (p = 0.045), and miR-375 (p = 0.016), while calcified plaques differed in miR-16-5p (p = 0.023). Ulcerated plaques showed higher levels of miR-1-3p (p = 0.04) and miR-16-5p (p = 0.003), while thrombotic plaques showed lower levels of miR-1-3p (p = 0.032). CVD/MI/CIE occurred in 14 (15.5%) out of 90 follow-up patients. Multivariate Cox and ROC analysis showed associations between miR-1-3p and CVD (AUC = 0.634; HR = 4.84; 95% CI: 1.62–14.5; p = 0.005), MI (AUC = 0.743; HR = 7.8; 95% CI: 2.01–30.0; p = 0.003), and CVD/MI/CIE (AUC = 0.560; HR = 4.6; 95% CI: 1.61–13.1; p = 0.004), while miR-133b was associated with recurrent CIE (AUC = 0.581; HR = 2.25; 95% CI: 1.01–5.02; p = 0.047).

Conclusions

A significant difference in levels of selected miRNAs is observed in symptomatic vs. asymptomatic ICAS. Plaque morphology and structure is associated with change of miRNA levels. The expression of miR-1-3p may be a potential prognostic factor for future cardiovascular events.

Sex differences in the brain: Implications for behavioral and biomedical research

Biological differences between males and females are found at multiple levels. However, females have too often been under-represented in behavioral neuroscience research, which has stymied the study of potential sex differences in neurobiology and behavior. This review focuses on the study of sex differences in the neurobiology of social behavior, memory, emotions, and recovery from brain injury, with particular emphasis on the role of estrogens in regulating forebrain function. This work, presented by the authors at the 2016 meeting of the International Behavioral Neuroscience Society, emphasizes varying approaches from several mammalian species in which sex differences have not only been documented, but also become the focus of efforts to understand the mechanistic basis underlying them. This information may provide readers with useful experimental tools to successfully address recently introduced regulations by granting agencies that either require (e.g. the National Institutes of Health in the United States and the Canadian Institutes of Health Research in Canada) or recommend (e.g. Horizon 2020 in Europe) the inclusion of both sexes in biomedical research.

Lipoprotein (a) as a Predictor of Early Stroke Recurrence in Acute Ischemic Stroke

Inflammation plays a crucial role in the pathogenesis of stroke. This study aims to determine lipoprotein (a) [Lp(a)] levels in serum and to investigate their associations with stroke recurrence events in a 3-month follow-up study in patients with acute ischemic stroke (AIS). Serum Lp(a) levels were determined in 203 ischemic stroke patients and 120 normal controls at admission. The severity and clinical outcome of ischemic stroke patients were evaluated by the National Institutes of Health Stroke Scale (NIHSS). We followed the participants for a median of 3 months using a standard questionnaire to determine the stroke recurrence events. The correlation analysis and multiple linear regression analysis were performed. Compared with controls, serum Lp(a) levels were significantly increased in ischemic stroke patients than in controls. NIHSS scores and infarct volume were positively correlated with Lp(a) (P < 0.001). Finally, 34 patients (16.7%; 95% CI, 11.6-21.9%) had a stroke recurrence. Serum Lp(a) levels in patients with recurrent stroke were significantly higher as compared with those in patients without recurrent stroke (P < 0.001). In multivariate analysis, there was an increased risk of stroke recurrence associated with Lp(a) levels ≥300 mg/l (OR, 2.87; 95% CI, 1.98-4.32; P = 0.009) after adjusting for possible confounders. With an AUC of 0.872 (95% CI, 0.816-0.927), Lp(a) showed a significantly greater discriminatory ability to predict stroke recurrence as compared with NIHSS score (AUC, 0.782; 95% CI, 0.704-0.859; P < 0.01). Our findings suggest that elevated serum Lp(a) levels can predict the risk of early stroke recurrence in patients with first-ever ischemic stroke. Further research is needed to replicate these findings.

Association of miR-21, miR-126 and miR-605 gene polymorphisms with ischemic stroke risk

We investigated whether three common microRNA polymorphisms (miR-21T>C [rs1292037], miR-126G>A [rs4636297] and miR-605T>C [rs2043556]) were associated with ischemic stroke (IS) risk in a Chinese population. The study population comprised 592 ischemic stroke patients and 456 normal controls. The polymorphisms were measured using Snapshot SNP genotyping assays and confirmed by sequencing. Relative expressions of miR-21, miR-126 and miR-605 were measured by quantitative real-time PCR. We found that miR-126 gene rs4636297 polymorphism was associated with decreased ischemic stroke risk (GA vs. GG: AOR=0.64, adjust P=0.025; AA vs. GG: AOR=0.32, adjust P=0.007; dominant model: AOR=0.58, adjust P=0.004). MiR-21 gene rs1292037 and miR-605 gene rs2043556 polymorphisms were not associated with ischemic stroke risk. In addition, compared with normal controls, serum miR-126 level was significantly decreased in ischemic stroke patients, while the miR-21 level was significantly increased. Importantly, patients carrying rs4636297 GA/AA genotypes had higher serum miR-126 level (P<0.05). MiR-126 gene rs4636297 polymorphism and serum miR-126/-21 levels are associated with ischemic stroke risk. Our data indicates that miR-126 and miR-21 play roles in the development of ischemic stroke.

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.

Serum cystatin C is associated with large cerebral artery stenosis in acute ischemic stroke

Large cerebral artery stenosis is a major cause of acute ischemic stroke (AIS); however, the correlation between serum cystatin C (CysC) and the stenosis of large cerebral arteries in patients with AIS has not been established. We performed a retrospective review of acute ischemic stroke patients, who were examined by cerebral digital subtraction angiography(DSA). Participants (252 cases) included 131 patients without stenosis and 121 patients with large cerebral artery stenosis. Serum CysC levels in patients with large cerebral artery stenosis were much higher than that of control subjects (p<0.001). However, serum CysC levels were not related to the location of stenosis. Further, logistic regression analyses showed that increased serum CysC was an independent risk factor of large cerebral artery stenosis in patients with acute ischemic stroke. Total participants were subdivided into quintiles based on serum CysC levels. Compared with the first quintile, the odds ratios of risk for large cerebral artery stenosis in the fourth and the fifth quintile were 1.26 (p<0.05) and 4.71(p<0.05) respectively, after the adjustment for age, sex, and smoking, hypertension, type 2 diabetes mellitus(DM), dyslipidemia, creatinine(Cr), urea, uric acid, and C reactive protein(CRP). Therefore, a significant positive correlation was observed between elevated serum CysC levels and large cerebral artery stenosis in patients with acute ischemic stroke. In summary, our findings provide new insights into the correlation between increased serum CysC and large cerebral artery stenosis in patients with acute ischemic stroke.

MicroRNA-99a-5p in circulating immune cells as a potential biomarker for the early diagnosis of ischemic stroke

OBJECTIVES:

We have previously shown the neuroprotective function of microRNA-99a-5p in experimental stroke. Here, we explore its diagnostic potential for acute stroke patients.

MATERIALS AND METHODS:

MiR-99a-5p levels in circulating from acute stroke patients and control were measured by real-time polymerase chain reaction. Pearson's correlation and receiver operator characteristic (ROC) curves were used to analyze clinical significance of miR-99a-5p and its sensitivity and specificity for stroke diagnosis.

RESULTS:

We demonstrated that miR-99a-5p expression was upregulated in neutrophils of both ischemic stroke and hemorrhage patients, while was only increased in the lymphocytes of hemorrhage patients. ROC analysis revealed that the miR-99a-5p level in neutrophils and lymphocytes had a moderate diagnostic value for stroke. Moreover, a positive correlation existed between plasma miR-99a-5p levels and neutrophil numbers or neutrophil/lymphocyte ratio. Meanwhile, miR-99a-5p levels in neutrophils were negatively correlated with thrombin time, while positively correlated with D-dimer and urea levels. Lymphocytic miR-99a-5p levels were positively correlated with platelet mean volume and distribution width.

CONCLUSION:

This study demonstrated that miR-99a-5p levels in circulating immune cells might facilitate the diagnosis of ischemic stroke.

Associations of microRNA single nucleotide polymorphisms and disease risk and pathophysiology

Single nucleotide polymorphisms (SNPs) are genetic variations that contribute to human phenotypes associated with various diseases. SNPs are involved in the regulation of a broad range of physiological and pathological processes, such as cellular senescence, apoptosis, inflammation, and immune response, by upregulating the expression of classical inflammation markers. Recent studies have suggested that SNPs located in gene-encoding microRNAs (miRNAs) affect various aspects of diseases by regulating the expression or activity of miRNAs. In the last few years, miRNA polymorphisms that increase and/or reduce the risk of developing many diseases, such as cancers, autoimmune diseases, and cardiovascular diseases, have attracted increasing attention not only because of their involvement in the pathophysiology of diseases but also because they can be used as prognostic biomarkers for a variety of diseases. In this review, we summarize the relationships between miRNA SNPs and the pathophysiology and risk of diseases.

Molecular Links and Biomarkers of Stroke, Vascular Dementia, and Alzheimer's Disease

Stroke is a very common neurological disease, and it occurs when the blood supply to part of the brain is interrupted and the subsequent shortage of oxygen and nutrients causes damage to the brain tissue. Stroke is the second leading cause of death and the third leading cause of disability-adjusted life years. The occurrence of stroke increases with age, but anyone at any age can suffer a stroke. Stroke can be broadly classified in two major clinical types: ischemic stroke (IS) and hemorrhagic stroke. Research also revealed that stroke, vascular dementia (VaD), and Alzheimer's disease (AD) increase with a number of modifiable factors, and most strokes can be prevented and/or controlled through pharmacological or surgical interventions and lifestyle changes. The pathophysiology of stroke, VaD, and AD is complex, and recent molecular and postmortem brain studies have revealed that multiple cellular changes have been implicated, including inflammatory responses, microRNA alterations, and marked changes in brain proteins. These molecular and cellular changes provide new information for developing therapeutic strategies for stroke and related vascular disorders treatment. IS is the major risk factor for VaD and AD. This chapter summarizes the (1) links among stroke-VaD-AD; (2) updates the latest developments of research in identifying protein biomarkers in peripheral and central nervous system tissues; and (3) critically evaluates miRNA profile and function in human blood samples, animal, and postmortem brains.

MiR-126 Affects Brain-Heart Interaction after Cerebral Ischemic Stroke

Cardiovascular diseases are approximately three times higher in patients with neurological deficits than in patients without neurological deficits. MicroRNA-126 (MiR-126) facilitates vascular remodeling and decreases fibrosis and is emerging as an important factor in the pathogenesis of cardiovascular diseases and cerebral stroke. In this study, we tested the hypothesis that decreased miR-126 after ischemic stroke may play an important role in regulating cardiac function. Wild-type (WT), specific conditional-knockout endothelial cell miR-126 (miR-126^EC-/-), and miR-126 knockout control (miR-126^fl/fl) mice were subjected to distal middle cerebral artery occlusion (dMCAo) (n = 10/group). Cardiac hemodynamics and function were measured using transthoracic Doppler echocardiography. Mice were sacrificed at 28 days after dMCAo. WT mice subjected to stroke exhibited significantly decreased cardiac ejection fraction and increased myocyte hypertrophy, fibrosis as well as increased heart inflammation, infiltrating macrophages, and oxidative stress compared to non-stroke animals. Stroke significantly decreased serum and heart miR-126 expression and increased miR-126 target genes, vascular cell adhesion protein-1, and monocyte chemotactic protein-1 gene, and protein expression in the heart compared to non-stroke mice. MiR-126^EC-/- mice exhibited significantly decreased cardiac function and increased cardiomyocyte hypertrophy, fibrosis, and inflammatory factor expression after stroke compared to miR-126^fl/fl stroke mice. Exosomes derived from endothelial cells of miR-126^EC-/- (miR-126^EC-/-EC-Exo) mice exhibited significantly decreased miR-126 expression than exosomes derived from miR-126^fl/fl (miR-126^fl/fl-EC-Exo) mice. Treatment of cardiomyocytes subjected to oxygen glucose deprivation with miR-126^fl/fl-EC-Exo exhibited significantly decreased hypertrophy than with miR-126^EC-/-EC-Exo treatment. Ischemic stroke directly induces cardiac dysfunction. Decreasing miR-126 expression may contribute to cardiac dysfunction after stroke in mice.

HDL and microRNA therapeutics in cardiovascular disease

microRNAs (miRNA) are small non-coding RNAs (sRNA) that post-transcriptionally regulate gene (mRNA) expression and are implicated in many biological processes and diseases. Many miRNAs have been reported to be altered in cardiovascular disease (CVD); both cellular and extracellular miRNA levels are affected by hypercholesterolemia and atherosclerosis. We and other groups have reported that lipoproteins transport miRNAs in circulation and these lipoprotein signatures are significantly altered in hypercholesterolemia and coronary artery disease (CAD). Extracellular miRNAs are a new class of potential biomarkers for CVD; however, they may also be new drug targets as high-density lipoproteins (HDL) transfer functional miRNAs to recipient cells in an endocrine-like form of intercellular communication that likely suppresses vascular inflammation. Recently, RNA-based drugs have emerged as the next frontier in drug therapy, and there are many miRNA inhibitors and mimics in clinical development. Here, we discuss specific miRNA drug targets and how their manipulation may impact CVD. We also address the potential for manipulating HDL-miRNA levels to treat CVD and the use of HDL as a delivery vehicle for RNA and chemical drugs. Finally, we outline the current and future challenges for HDL and miRNA-based therapeutics for the prevention and treatment of CVD.

IGF-1 deficiency in a critical period early in life influences the vascular aging phenotype in mice by altering miRNA-mediated post-transcriptional gene regulation: implications for the developmental origins of health and disease hypothesis

Epidemiological findings support the concept of Developmental Origins of Health and Disease, suggesting that early-life hormonal influences during a sensitive period of development have a fundamental impact on vascular health later in life. The endocrine changes that occur during development are highly conserved across mammalian species and include dramatic increases in circulating IGF-1 levels during adolescence. The present study was designed to characterize the effect of developmental IGF-1 deficiency on the vascular aging phenotype. To achieve that goal, early-onset endocrine IGF-1 deficiency was induced in mice by knockdown of IGF-1 in the liver using Cre-lox technology (Igf1 ^f/f mice crossed with mice expressing albumin-driven Cre recombinase). This model exhibits low-circulating IGF-1 levels during the peripubertal phase of development, which is critical for the biology of aging. Due to the emergence of miRNAs as important regulators of the vascular aging phenotype, the effect of early-life IGF-1 deficiency on miRNA expression profile in the aorta was examined in animals at 27 months of age. We found that developmental IGF-1 deficiency elicits persisting late-life changes in miRNA expression in the vasculature, which significantly differed from those in mice with adult-onset IGF-1 deficiency (TBG-Cre-AAV8-mediated knockdown of IGF-1 at 5 month of age in Igf1 ^f/f mice). Using a novel computational approach, we identified miRNA target genes that are co-expressed with IGF-1 and associate with aging and vascular pathophysiology. We found that among the predicted targets, the expression of multiple extracellular matrix-related genes, including collagen-encoding genes, were downregulated in mice with developmental IGF-1 deficiency. Collectively, IGF-1 deficiency during a critical period during early in life results in persistent changes in post-transcriptional miRNA-mediated control of genes critical targets for vascular health, which likely contribute to the deleterious late-life cardiovascular effects known to occur with developmental IGF-1 deficiency.