microRNAs in Cerebrovascular Disease

The translational potential of miR-26 in atherosclerosis and development of agents for its target genes ACC1/2, COL1A1, CPT1A, FBP1, DGAT2, and SMAD7

Atherosclerosis is one of the leading causes of death worldwide. miR-26 is a potential biomarker of atherosclerosis. Standardized diagnostic tests for miR-26 (MIR26-DX) have been developed, but the fastest progress has been in predicting the efficacy of IFN-α therapy for hepatocellular carcinoma (HCC, phase 3). MiR-26 slows atherosclerosis development by suppressing ACC1/2, ACLY, ACSL3/4, ALDH3A2, ALPL, BMP2, CD36, COL1A1, CPT1A, CTGF, DGAT2, EHHADH, FAS, FBP1, GATA4, GSK3β, G6PC, Gys2, HMGA1, HMGB1, LDLR, LIPC, IL-1β, IL-6, JAG2, KCNJ2, MALT1, β-MHC, NF-κB, PCK1, PLCβ1, PYGL, RUNX2, SCD1, SMAD1/4/5/7, SREBF1, TAB3, TAK1, TCF7L2, and TNF-α expression. Many agents targeting these genes, such as the ACC1/2 inhibitors GS-0976, PF-05221304, and MK-4074; the DGAT2 inhibitors IONIS-DGAT2Rx, PF-06427878, PF-0685571, and PF-07202954; the COL1A1 inhibitor HT-100; the stimulants 68Ga-CBP8 and RCT-01; the CPT1A inhibitors etomoxir, perhexiline, and teglicar; the FBP1 inhibitors CS-917 and MB07803; and the SMAD7 inhibitor mongersen, have been investigated in clinical trials. Interestingly, miR-26 better reduced intima-media thickness (IMT) than PCSK9 or CT-1 knockout. Many PCSK9 inhibitors, including alirocumab, evolocumab, inclisiran, AZD8233, Civi-007, MK-0616, and LIB003, have been investigated in clinical trials. Recombinant CT-1 was also investigated in clinical trials. Therefore, miR-26 is a promising target for agent development. miR-26 promotes foam cell formation by reducing ABCA1 and ARL4C expression. Multiple materials can be used to deliver miR-26, but it is unclear which material is most suitable for mass production and clinical applications. This review focuses on the potential use of miR-26 in treating atherosclerosis to support the development of agents targeting it.

microRNA-223 and microRNA-126 are clinical indicators for predicting the plaque stability in carotid atherosclerosis patients

Studies have demonstrated the essential functions of microRNAs (miRNAs) in cardiovascular disease. Herein, we explored the roles of miR-126 and miR-223 in the prediction of plaque stability in carotid atherosclerosis (CA).Patients with CA (N = 52) and healthy volunteers (N = 25) were recruited as the study subjects and controls. First, a miRNA microarray was performed to analyze the differentially expressed miRNAs in the serum of normal controls and patients with CA. Next, the correlations of miR-223 and miR-126 expression with plaque stability-related factors were analyzed. Then, the predictive efficacy of miR-223 and miR-126 on plaque stability was analyzed by the ROC curve, and the targeting relationships of miR-223 and miR-126 with COX2 were verified. Finally, the relationship between COX2 expression and CA plaque stability was analyzed. miR-223 and miR-126 were decreased in the serum of CA patients and had good diagnostic efficacy for CA. miR-223 and miR-126 in the serum of CA patients with unstable plaques were lower than that in patients with stable plaques. miR-223 and miR-126 were negatively correlated with plaque instability-related indicators, while COX2, a direct target of miR-223 and miR-126, was positively related to plaque instability-related indicators. Lowly expressed miR-223 and miR-126 in the serum of CA patients can be used as indicators for plaque stability.

MiR-146a-5p Contributes to Microglial Polarization Transitions Associated With AGEs

M1/M2 polarization transitions of microglial phenotypes determine the states of neuroinflammation, which is critical in the pathophysiology of diabetic encephalopathy. This study aims to investigate the effects of advanced glycation end products (AGEs) on the microglial polarization state, the role of miR-146a-5p in the regulation of microglial polarization, and the underlying signaling pathways. BV-2 cells were incubated with N-ε-carboxymethyl lysine (CML), one kind of Advanced Glycation End Products (AGEs), to induce polarization. CD11b and iNOS and CD206 and Arg-1 were used to evaluate M1 and M2 microglia, respectively. The mRNA and protein expression levels of miR-146a-5p, transcription factor NF-κB, and inflammasome NLRP3 were measured. High and low expression of miR-146a-5p in the BV-2 cell line was generated by lentivirus transfection technology. RAGE, TLR-4, and NF-κB antagonists were applied to evaluate the underlying signaling pathways. Compared with the control group, CML upregulated the M1 phenotype and downregulated the M2 phenotype. These effects were reversed by overexpression of miR-146a. Furthermore, the expression of inflammasome NLRP3 and NF-κB was upregulated in the CML group and was reduced after miR-146a overexpression. And then overexpression of miR-146a effects was reversed by inhibition miR-146a expression. An NF-κB antagonist (PDTC), a RAGE antagonist (FPS-ZMI), and a TLR-4 antagonist (TLI-095) all reversed the polarization state induced by CML. In summary, CML induced polarization transitions to M1 phenotype and promoted inflammasome NLRP3 expression in BV-2 cells. The RAGE or TLR-4/miR-146a/NLRP3/NF-кB pathway might participate in the regulation of CML-induced BV-2 polarization.

MiR-342-5p protects neurons from cerebral ischemia induced-apoptosis through regulation of Akt/NF-κB pathways by targeting CCAR2

OBJECTIVES

Ischemic stroke causes high morbidity, mortality and health burden in the world. MiR-342-5p was associated with Alzheimer's disease and cardio-protection. Herein, we aimed to reveal effects of miR-342-5p on cerebral ischemia injury as well as novel targets for stroke.

MATERIALS AND METHODS

AgomiR-342-5p was intracerebroventricularly injected into the middle cerebral artery occlusion (MCAO) mouse models to evaluate functions of miR-342-5p on cerebral ischemia. RT-qPCR and western blot assays were used to evaluate genes expression. Oxygen-glucose deprivation (OGD) was used as an in vitro model for ischemia. Viability and apoptosis ratio of neurons was evaluated by CCK-8, LDH release detection, and flow cytometry. The potential targets of miR-342-5p were predicted by Targetscan, and their interaction was confirmed by luciferase assay.

RESULTS

The intervention of miR-342-5p effectively attenuated ischemic injury in MCAO mice. MiR-342-5p overexpression could protect neurons against OGD-induced injury, as revealed by increased cell viability and BCL2 expression, and decreased LDH release, apoptosis ratio, and BAX expression in OGD-induced neurons. Mechanically, miR-342-5p could directly bound with CCAR2 to inhibit its expression. Overexpressing CARR2 aggravated the OGD-induced injury of neurons, which was partly restrained by overexpressing miR-342-5p reversed. Furthermore, miR-342-5p/CARR2 axis regulates Akt/NF-κB signaling pathway in vitro as well as in vivo cerebral ischemia models.

CONCLUSIONS

MiR-342-5p inhibited neuron apoptosis by regulating Akt/NF-kB signaling pathway via CCAR2 suppression. Our findings revealed the neuroprotection of miR-342-5p in cerebral ischemia.

The roles and mechanisms of miR-26 derived from exosomes of adipose-derived stem cells in the formation of carotid atherosclerotic plaque

BACKGROUND

This study explored the serum concentrations of miR-26 in patients with carotid atherosclerosis (CAS) and defined the roles and mechanisms of miR-26 derived from the exosomes of adipose-derived stem cells (ADSC-exos).

METHODS

The carotid artery width was diagnosed by ultrasound examination in patients with different degrees of CAS. The serum levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in patients were detected by biochemistry. The serum levels of miR-26 were determined by quantitative polymerase chain reaction (qPCR). A model of CAS in ApoE-/- mice fed with a rich-fat diet was established to analyze the regulatory effects of serum miR-26 on blood lipids in mice. Adipose mesenchymal stem cell lines transfected with miR-26 were established. The regulatory relationship between the expression levels of inflammatory factors, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β, and the expression levels of miR-26 in the supernatant of each group of cells was determined by qPCR. The ADSC-exos were extracted from ADSCs and injected into model mice through the tail vein. The therapeutic effect of ADSCs expressing miR-26 on model mice was evaluated by detecting the levels of inflammatory factors and blood lipids in the serum of the mice.

RESULTS

The degree of atherosclerosis (AS) was positively associated with the intima-media thickness (IMT) of the carotid artery. The serum levels of miR-26 in patients were inversely correlated with the levels of blood lipids (TC, TG, and LDL-C), and positively correlated with HDL-C levels. Similarly, in the CAS mouse model, the serum levels of miR-26 were inversely correlated with the levels of blood lipids (TC, TG, and LDL-C), and positively correlated with HDL-C level. In ADSCs transfected with miR-26, the miR-26 expression in the cell supernatant was negatively regulated by the expression of inflammatory factors, TNF-α, IL-6, and IL-1β, in the cell supernatant. ADSC-exos expressing miR-26 has positive effects on correcting blood lipids and inflammatory factors in the mouse model of CAS.

CONCLUSIONS

miR-26 has an active role in CAS and may be a novel target for the treatment of CAS in the future.

MicroRNA and Hemostasis Profile of Carotid Atherosclerosis

Carotid atherosclerosis (CA) is an important risk factor for ischemic stroke. We described the miRNA and hemostasis profile of patients with moderate and advanced stages of carotid atherosclerosis and elucidated potential correlations with hemostatic activation. A prospective case-control study included 61 patients with evidence of carotid atherosclerosis (via ultrasound). The study population was divided into groups depending on the degree of carotid artery stenosis: 60% or more (advanced) and <60% (moderate). All patients underwent the following blood tests: general blood test, hemostatic parameters and microRNA. Extraction of microRNA was performed using Leukocyte RNA Purification Kit (NORGEN Biotec Corp., Thorold, ON, Canada); miRNA quantification was performed via RT-PCR. Statistical analysis was performed in R programming language (v. 4.1.0) using RSudio. MicroRNA expression profile was different depending on CA degree. MiR-33a-5p/3p levels were higher in patients with ≥60% carotid stenosis (42.70 and 42.45 versus 38.50 and 38.50, respectively, p < 0.05). Almost complete separation can be visualized with the levels of miR-126-5p: 9.50 in the moderate CA group versus 5.25 in the advanced CA (p < 0.001). MiR-29-5p was higher in the moderate CA group: 28.60 [25.50;33.05] than in advanced CA group: 25.75 [24.38;29.50] (p = 0.086); miR-29-3p was also higher in the moderate CA group: 10.36 [8.60;14.99] than in advanced CA group: 8.46 [7.47;10.3] (p = 0.001). By-group pairwise correlation analyses revealed at least three clusters with significant positive correlations in the moderate CA group: miR-29-3p with factors V and XII (r = 0.53 and r = 0.37, respectively, p < 0.05); miR-21-5p with ADAMTS13, erythrocyte sedimentation rate and D-dimer (r = 0.42, r = 0.36 and r = 0.44, respectively, p < 0.05); stenosis degree with miR-33a-5p/3p and factor VIII levels (r = 0.43 (both) and r = 0.62, respectively, p < 0.05). Hemostasis parameters did not reveal significant changes in CA patients: the only statistically significant differences concerned factor VIII, plasminogen and (marginally significant) ADAMTS-13 and protein C. Down-regulation of miR-126-5p expression has been identified as a promising biomarker of advanced carotid atherosclerosis with high specificity and sensitivity. Correlation cluster analysis showed potential interplay between miRNAs and hemostatic activation in the setting of carotid atherosclerosis.

Inhibition of miR-423-5p Exerts Neuroprotective Effects in an Experimental Rat Model of Cerebral Ischemia/Reperfusion Injury

MicroRNAs (miRNAs) are widely acknowledged to play a unique role in cerebrovascular disease. This research investigates the function of microRNAs in ischemic stroke via a middle cerebral artery occlusion (MCAO) model. Four differentially expressed microRNAs in rat brains were identified by bioinformatics analysis, and qRT-PCR showed that miR-423-5p exhibited the highest expression in cerebral ischemia/reperfusion injury in rats, with peak levels observed at 24 hours. After microRNA inhibitors and mimics were administrated in the rat model of MCAO, the neurological scores and brain water content were detected, and triphenyltetrazolium chloride (TTC), Hematoxylin and Eosin (H&E), and Nissl staining were conducted to explore the influence of miR-423-5p on ischemic stroke. Subsequently, western blot, ELISA, MPO, TUNEL and commercial assay kits were applied to assess the influence of miR-423-5p on NLRP3 inflammasome, apoptosis, and oxidative stress levels in ischemic penumbra tissue. The results showed that miR-423-5p knockdown could effectively improve neurological indicators, such as cerebral infarct volume, brain water content, neurological scores, and nerve tissue damage, and inhibit the NLRP3 inflammasome, apoptosis, and oxidative stress. In contrast, the miR-423-5p mimic yielded opposite results. In conclusion, inhibition of miR-423-5p expression could effectively attenuate ischemic stroke and might be considered a promising target for stroke.

Serum microRNA miR-491-5p/miR-206 Is Correlated with Poor Outcomes/Spontaneous Hemorrhagic Transformation after Ischemic Stroke: A Case Control Study

Background: It is unclear whether miR-491-5p, miR-206, miR-21-5p or miR-3123 are associated with functional outcomes and hemorrhagic transformation (HT) after acute ischemic stroke (AIS). In this study, we aimed to investigate the correlation between these four microRNAs and functional outcomes, as well as spontaneous HT after AIS; Methods: We included 215 AIS patients and retrospectively assayed for miR-21-5p, miR-206, miR-3123 and miR-491-5p levels in serum. Poor functional outcome was defined as a modified Rankin Scale score ≥ 3. Spontaneous HT referred to hemorrhage detected in follow-up brain imaging but not on admission, without reperfusion therapies. Logistic regression, generalized additive model and 2-piecewise regression model were used to explore the independent, non-linear correlation between miRNA expression levels and outcomes; Results: We included 215 AIS patients. Higher miR-491-5p level independently reduced the risk of poor functional outcomes at 1 year (OR 0.90, 95% CI 0.82–0.98, corrected p value = 0.044). Higher miR-206 level significantly increased the risk of spontaneous HT (OR 1.64, 95% CI 1.17–2.30, corrected p value = 0.016). There was a nonlinear correlation found between miR-491-5p level and 1 year outcome with an inflection point of 2.180, while an approximately linear correlation was observed with an inflection point of 2.037 between miR-206 level and spontaneous HT; Conclusions: Higher serum miR-491-5p level independently reduced risk of 1-year poor functional outcome of AIS patients. Higher serum miR-206 level independently increased the risk of spontaneous HT in AIS patients. These two miRNAs may be as the potential biomarkers for improving prognosis after AIS.

Association of MicroRNAs With Risk of Stroke: A Meta-Analysis

Objectives

Altered expression of microRNAs (miRNAs) may contribute to disease vulnerability. Studies have reported the involvement of miRNA in the pathophysiology of ischemic stroke.

Methods

We performed a meta-analysis of data from 6 studies that used a panel of miRNAs with altered expressions to diagnose ischemic stroke with the Bayesian framework. The I² test and Cochran's Q-statistic were used to assess heterogeneity. Funnel plots were generated and publication bias was assessed using Begg and Egger tests.

Results

On summary receiver operating characteristics (SROC) curve analysis, the pooled sensitivity and specificity of altered miRNA expressions for diagnosis of ischemic stroke was 0.92 (95% confidence interval [CI] 0.80–0.97) and 0.83 (95% CI 0.71–0.90), respectively; the diagnostic odds ratio was 54.35 (95% CI 20.39–144.92), and the area under the SROC curve was 0.93 (95% CI 0.90–0.95).

Conclusions

Our results showed a link between dysregulation of miRNAs and the occurrence of ischemic stroke. Abnormal miRNA expression may be a potential biomarker for ischemic stroke.

Knockdown of circular RNA tousled-like kinase 1 relieves ischemic stroke in middle cerebral artery occlusion mice and oxygen-glucose deprivation and reoxygenation-induced N2a cell damage

Ischemic stroke (IS) is an essential contributor to the neurological morbidity and mortality throughout the world. The significance of circular RNA tousled-like kinase 1 (circTLK1) in IS has been documented. This study set out to explore the mechanism of circTLK1 in IS. Middle cerebral artery occlusion (MCAO) mouse models in vivo and oxygen-glucose deprivation and reoxygenation (OGD/R) cell models in vitro were first established, followed by evaluation of infarct volume and neurological impairment, and cell viability and apoptosis. The expression patterns of circTLK1, miR-26a-5p, phosphatase and tensin homolog (PTEN), insulin-like growth factor type 1 receptor (IGF-1 R), and glucose transporter type 1 (GLUT1) were detected by RT-qPCR and Western blotting. Co-localization of circTLK1 and miR-26a-5p in N2a cells was tested by fluorescence in situ hybridization assay. The binding relationships among circTLK1, PTEN, and miR-26a-5p were verified by dual-luciferase assay and RNA pull-down. circTLK1 and PTEN were highly expressed while miR-26a-5p was under-expressed in IS models. circTLK1 knockdown decreased infarct volume and neurological impairment in MCAO mouse models and relieved OGD/R-induced neuronal injury in vitro. circTLK1 and miR-26a-5p were co-located in the N2a cell cytoplasm. circTLK1 regulated PTEN as a sponge of miR-26a-5p. PTEN positively regulated IGF-1 R and GLUT1 expressions. miR-26a-5p inhibitor annulled the repressive effects of circTLK1 silencing on OGD/R-induced neuronal injury. sh-PTEN partially annulled the effects of the miR-26a-5p inhibitor on OGD/R-induced neuronal injury. In conclusion, circTLK1 knockdown relieved IS via the miR-26a-5p/PTEN/IGF-1 R/GLUT1 axis. These results may provide a new direction to IS potential therapeutic targets.

Curcumin improves atherosclerosis by inhibiting the epigenetic repression of lncRNA MIAT to miR-124

Objectives: Atherosclerosis is a dominant cardiovascular disease. Curcumin has protective effect on atherosclerosis. However, the mechanisms remain to be explored. Methods: Atherosclerosis was induced by feeding mice with high-fat diet (HFD) and ox-low-density lipoprotein (LDL)-induced human umbilical vein endothelial cells (HUVECs) were structured. Oil Red O staining was used to evaluate the plaques in the artery. Quantitative real-time PCR (qRT-PCR) was conducted to detect the level of myocardial infarction associated transcript (MIAT), miR-124, and enhancer of zeste homolog 2 (EZH2). We performed western blotting and enzyme linked immunosorbent assay to examine the expression of EZH2 and cytokines including IL-1β, TNFα, IL-6, and IL-8, respectively. RNA immunoprecipitation and chromatin immunoprecipitation (ChIP) were used to validate the interaction between myocardial infarction associated transcript and EZH2. Flow cytometry and CCK-8 assay were used to examine cell apoptosis and proliferation, respectively. Results: Curcumin suppressed inflammation in atherosclerosis mouse model and ox-LDL-induced cell model. MIAT overexpression and miR-124 inhibition relieved the anti-inflammation effect of curcumin in ox-LDL-induced cell. MIAT regulated miR-124 by interacting with EZH2. Curcumin relieved ox-LDL-induced cell inflammation via regulating MIAT/miR-124 pathway. Conclusion: MIAT/miR-124 axis mediated the effect of curcumin on atherosclerosis and altered cell apoptosis and proliferation, both in vivo and in vitro. These data further support the application of curcumin in control of atherosclerosis advancement.

Neuroinflammation in Cerebral Ischemia and Ischemia/Reperfusion Injuries: From Pathophysiology to Therapeutic Strategies

Its increasing incidence has led stroke to be the second leading cause of death worldwide. Despite significant advances in recanalization strategies, patients are still at risk for ischemia/reperfusion injuries in this pathophysiology, in which neuroinflammation is significantly involved. Research has shown that in the acute phase, neuroinflammatory cascades lead to apoptosis, disruption of the blood-brain barrier, cerebral edema, and hemorrhagic transformation, while in later stages, these pathways support tissue repair and functional recovery. The present review discusses the various cell types and the mechanisms through which neuroinflammation contributes to parenchymal injury and tissue repair, as well as therapeutic attempts made in vitro, in animal experiments, and in clinical trials which target neuroinflammation, highlighting future therapeutic perspectives.

MicroRNA-21-5p Reduces Hypoxia/Reoxygenation-Induced Neuronal Cell Damage through Negative Regulation of CPEB3

Objectives

To explore the role of microRNA-21-5p (miR-21-5p) in hypoxia/reoxygenation- (H/R-) induced HT22 cell damage.

Methods

The hypoxia/reoxygenation (H/R) model was established in mouse neuronal cells HT22. Cell Counting Kit-8 (CCK-8) and qRT-PCR were used to determine the effects of H/R treatment on cell viability and miR-21-5p expression. HT22 cells were transfected with miR-21-5p mimic or negative control (NC) followed by the induction of H/R; cell viability, apoptosis, and SOD, MDA, and LDH activities were detected. Besides, the apoptosis-related proteins including BAX, BCL2, cleaved caspase-3, and caspase-3 as well as proteins of EGFR/PI3K/AKT signaling pathways were measured by Western blot. To verify the target relation between cytoplasmic polyadenylation element binding protein 3 (CPEB3) and miR-21-5p, luciferase reporter gene experiment was performed. After cotransfection with miR-21-5p mimic and CPEB3 plasmids, the reversal effects of CPEB3 on miR-21-5p in H/R damage were studied.

Results

H/R treatment could significantly reduce the cell viability (P < 0.05) and miR-21-5p levels (P < 0.05) in HT22 cells. After overexpressing miR-21-5p, cell viability was increased (P < 0.05) under H/R treatment, and the apoptosis rate and the levels of apoptosis-related proteins were suppressed (all P < 0.05). Furthermore, SOD activity was increased (P < 0.05), while MDA and LDH activity was decreased (both P < 0.05). Besides, miR-21-5p could restore the activation of the EGFR/PI3K/AKT signaling pathway inhibited by H/R treatment (all P < 0.05). The luciferase reporter gene experiment verified that CPEB3 is the target of miR-21-5p (P < 0.05). When coexpressing miR-21-5p mimic and CPEB3 in the cells, the protective effects of miR-21-5p under H/R were reversed (all P < 0.05), and the activation of the EGFR/PI3K/AKT pathway was also inhibited (all P < 0.05).

Conclusion

This study showed that miR-21-5p may regulate the EGFR/PI3K/AKT signaling pathway by targeting CPEB3 to reduce H/R-induced cell damage and apoptosis.

MicroRNA-124: A Key Player in Microglia-Mediated Inflammation in Neurological Diseases

Neurological disorders are mainly characterized by progressive neuron loss and neurological deterioration, which cause human disability and death. However, many types of neurological disorders have similar pathological mechanisms, including the neuroinflammatory response. Various microRNAs (miRs), such as miR-21, miR-124, miR-146a, and miR-132 were recently shown to affect a broad spectrum of biological functions in the central nervous system (CNS). Microglia are innate immune cells with important roles in the physiological and pathological activities of the CNS. Recently, abnormal expression of miR-124 was shown to be associated with the occurrence and development of various diseases in CNS via regulating microglia function. In addition, miR-124 is a promising biomarker and therapeutic target. Studies on the role of miR-124 in regulating microglia function involved in pathogenesis of neurological disorders at different stages will provide new ideas for the use of miR-124 as a therapeutic target for different CNS diseases.

Long non-coding RNA MEG3 regulates autophagy after cerebral ischemia/reperfusion injury

Severe cerebral ischemia/reperfusion injury has been shown to induce high-level autophagy and neuronal death. Therefore, it is extremely important to search for a target that inhibits autophagy activation. Long non-coding RNA MEG3 participates in autophagy. However, it remains unclear whether it can be targeted to regulate cerebral ischemia/reperfusion injury. Our results revealed that in oxygen and glucose deprivation/reoxygenation-treated HT22 cells, MEG3 expression was obviously upregulated, and autophagy was increased, while knockdown of MEG3 expression greatly reduced autophagy. Furthermore, MEG3 bound miR-181c-5p and inhibited its expression, while miR-181c-5p bound to autophagy-related gene ATG7 and inhibited its expression. Further experiments revealed that mir-181c-5p overexpression reversed the effect of MEG3 on autophagy and ATG7 expression in HT22 cells subjected to oxygen and glucose deprivation/reoxygenation. In vivo experiments revealed that MEG3 knockdown suppressed autophagy, infarct volume and behavioral deficits in cerebral ischemia/reperfusion mice. These findings suggest that MEG3 knockdown inhibited autophagy and alleviated cerebral ischemia/reperfusion injury through the miR-181c-5p/ATG7 signaling pathway. Therefore, MEG3 can be considered as an intervention target for the treatment of cerebral ischemia/reperfusion injury. This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Zhengzhou University, China (approval No. XF20190538) on January 4, 2019.

Adhesion of monocytes and endothelial cells isolated from the human aorta suppresses by miRNA-PEI particles

Background

Knowledge of stenosis in coronary arteries requires an understanding of the cellular and molecular processes that occur throughout the leukocyte rolling process. In this study, the roles of miR-125a-5p and miR-495-3p were investigated on the adhesion of endothelial cells (ECs) isolated from the human aorta.

Methods

Human primary endothelial cells were obtained from the aorta of people who had died of brain death. Whole blood was used to isolate the monocytes. The miR-125 and miR-495 were predicted and transfected into ECs using Poly Ethylene Imine (PEI). The expression levels of adhesion molecules and monocyte recruitment were identified by the RT-qPCR technique and Leukocyte-Endothelial Adhesion Assay kit, respectively.

Results

The ICAM-1, ICAM-2 and VCAM-1 expression levels decreased significantly in the miR-495/PEI-transfected ECs (P < 0.05) while in the miR-125/PEI-transfected ECs only the ICAM-2 and ITGB-2 expression levels decreased significantly (P < 0.05) as compared to the miR-synthetic/PEI-transfected ECs. Furthermore, the monocyte adhesion was decreased in the miR-125 and miR-mix/PEI-transfected ECs as compared to the miR-synthetic/PEI-transfected ECs (P = 0.01 and P = 0.04, respectively).

Conclusion

According to the findings, the efficient relations between miR-125 and adhesion molecules may be responsible for the inhibition of monocyte rolling.

Study on potential differentially expressed genes in stroke by bioinformatics analysis

Stroke is a sudden cerebrovascular circulatory disorder with high morbidity, disability, mortality, and recurrence rate, but its pathogenesis and key genes are still unclear. In this study, bioinformatics was used to deeply analyze the pathogenesis of stroke and related key genes, so as to study the potential pathogenesis of stroke and provide guidance for clinical treatment. Gene Expression profiles of GSE58294 and GSE16561 were obtained from Gene Expression Omnibus (GEO), the differentially expressed genes (DEGs) were identified between IS and normal control group. The different expression genes (DEGs) between IS and normal control group were screened with the GEO2R online tool. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the DEGs were performed. Using the Database for Annotation, Visualization and Integrated Discovery (DAVID) and gene set enrichment analysis (GSEA), the function and pathway enrichment analysis of DEGS were performed. Then, a protein–protein interaction (PPI) network was constructed via the Search Tool for the Retrieval of Interacting Genes (STRING) database. Cytoscape with CytoHubba were used to identify the hub genes. Finally, NetworkAnalyst was used to construct the targeted microRNAs (miRNAs) of the hub genes. A total of 85 DEGs were screened out in this study, including 65 upward genes and 20 downward genes. In addition, 3 KEGG pathways, cytokine − cytokine receptor interaction, hematopoietic cell lineage, B cell receptor signaling pathway, were significantly enriched using a database for labeling, visualization, and synthetic discovery. In combination with the results of the PPI network and CytoHubba, 10 hub genes including CEACAM8, CD19, MMP9, ARG1, CKAP4, CCR7, MGAM, CD79A, CD79B, and CLEC4D were selected. Combined with DEG-miRNAs visualization, 5 miRNAs, including hsa-mir-146a-5p, hsa-mir-7-5p, hsa-mir-335-5p, and hsa-mir-27a- 3p, were predicted as possibly the key miRNAs. Our findings will contribute to identification of potential biomarkers and novel strategies for the treatment of ischemic stroke, and provide a new strategy for clinical therapy.

All-Trans Retinoic Acid Enhances Chemosensitivity to 5-FU by Targeting miR-378c/E2F7 Axis in Colorectal Cancer

Colorectal carcinoma (CRC), a life-threatening malignancy, has been found to present resistance to 5-fluorouracil (5-FU) and cause a poor prognosis for patients. Previous studies have proved that all-trans retinoic acid (ATRA) could inhibit the development of CRC cells. In addition, miR-378c was discovered to exert a vital role in various cancers. In this study, we utilized MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), transwell assay, and flow cytometry to confirm that ATRA was able to enhance the inhibitory effects of 5-FU on HCT116 cells effectively by promoting cell apoptosis. Then, ENCORI database (http://starbase.sysu.edu.cn/) was employed to predict that miR-378c was downregulated dramatically in CRC and E2F7 was the direct target of miR-378c. QRT-PCR (quantitative real-time polymerase chain reaction) was conducted to verify that the expression level of miR-378c was decreased while E2F7 expression was upregulated in CRC tissues compared with para-carcinoma tissues. Additionally, treatment of 5-FU combined with ATRA could increase miR-378c expression, whereas it decreased the expression of E2F7. Dual-Luciferase Reporter assay results revealed that miR-378c could regulate the load of E2F7 by binding to its 3′UTR directly. Furthermore, miR-378c inhibitor or vector with E2F7 partially counteracted the effects of 5-FU combined with ATRA on viability, migration, invasion, and apoptosis of HCT116 cells. In conclusion, our study aims to confirm that ATRA enhances chemosensitivity to 5-FU of patients with CRC and expound the potential molecular mechanisms.

Relationship between miR-378c and YY1 expression in patients with gastric cancer and the clinicopathological features

Background

The purpose of this study was to explore the clinical value of miR-378c and its target gene YY1 in gastric cancer.

Methods

The TCGA database was employed to analyse miR-378c expression in gastric cancer. qRT-PCR was applied to identify miR-378c and YY1 in tissues and serum of patients suffering from gastric cancer. The association of miR-378c with the clinical data of patients with gastric cancer was analysed. Receiver operating characteristics (ROC) curve analysis was used to determine the diagnostic value of miR-378c and YY1 in gastric cancer, and analyse the relationship between miR-378c and YY1 and patients’ survival. Pearson’s test was applied to determine the association between miR-378c and YY1 in tissue and serum of patients. Dual-Luciferase Reporter assay was employed to examine the targeting association between miR-378c and YY1. Finally, independent prognostic factors was determined in patients with gastric cancer using Cox regression analysis.

Results

In the TCGA database, miR-378c was weakly expressed in gastric cancer. Overall, patients with low expression had a lower survival rate. The expression of miR-378c decreased and the expression of YY1 increased in cancer tissues and serum of tumour patients. In patients with low expression of miR-378c the tumour size was ≥ 5 cm. Low differentiation, high TNM staging and lymph node invasion rate increased significantly, but the 5-year survival rate decreased in the patients. miR-378c and YY1 had better diagnostic value in gastric cancer. TargetScan, miRDB, starBase and miRTarBase predicted that YY1 was a potential gene of miR-378c, and the Dual-Luciferase Reporter assay revealed that there was a targeting relationship between the two, which was proved by correlation analysis. Multivariate Cox analysis revealed that differentiation, TNM staging and miR-378c were independent prognostic factors for patients.

Conclusions

MiR-378c is weakly expressed in gastric cancer patients and may be considered as a promising diagnostic and prognostic indicator for gastric cancer.

miR-29 family: A potential therapeutic target for cardiovascular disease

Cardiovascular disease (CVD), including heart failure, myocardial fibrosis and myocardial infarction, etc, remains one of the leading causes of mortality worldwide. Evidence shows that miRNA plays an important role in the pathogenesis of CVD. miR-29 family is one of miRNA, and over the past decades, many studies have demonstrated that miR-29 is involved in maintaining the integrity of arteries and in the regulation of atherosclerosis, especially in the process of myocardial fibrosis. Besides, heart failure, myocardial fibrosis and myocardial infarction are inseparable from the regulatory role of miR-29. Here, we comprehensively review recent studies regarding miR-29 and CVD, illustrate the possibility of miR-29 as a potential marker for prevention, treatment and prognostic observation.

MiRNA Polymorphisms and Hepatocellular Carcinoma Susceptibility: A Systematic Review and Network Meta-Analysis

Background

Hepatocellular carcinoma (HCC) is an intractable public health threat worldwide, representing the second leading cause of cancer-related mortality, with limited early detection and therapeutic options. Recent findings have revealed that the susceptibility of HCC is closely related to microRNA (miRNA). We performed this systematic review with a network meta-analysis to investigated four single nucleotide polymorphisms (SNPs) that most regularly reported in miRNAs, exploring their involvement in HCC susceptibility and interaction with hepatitis B virus (HBV).

Methods

Databases were reviewed for related studies published up to May 2019 to identify all studies that compared genotypes of miR-146a rs2910164, miR-149 rs2292832, miR-196a2 rs11614913, and miR-499 rs3746444 with no language and date restrictions. A pairwise meta-analysis was performed to estimate pooled odds ratios and 95% confidence intervals incorporating heterogeneity to assess the relationship between four miRNA polymorphisms and HCC. To further clarify the effect of polymorphisms on HCC, a Bayesian network meta-analysis was conducted to combine the effective sizes of direct and indirect comparisons. Calculations were performed by R version 3.6.1 and STATA 14.0. All steps were performed according to PRISMA guidelines.

Results

A total of 20 studies were enrolled in this network meta-analysis, providing 5,337 hepatocellular carcinoma cases and 6,585 controls. All included studies had an acceptable quality. Pairwise meta-analysis demonstrated that miR-196a2 rs11614913 was significantly associated with the susceptibility of HCC, while the other three SNPs were not found to have a significant association. In the analysis of HCC patients under different HBV infection status, only miR-196a2 revealed correlation of threefold risk. The network results showed no significant difference in the distribution of genotype frequencies except for miR-196a2, which appeared to have the highest superiority index when comparing and ranking four SNPs.

Conclusion

MiR-196a2 rs11614913 was significantly associated with the susceptibility of HCC, especially for HBV- related HCC, and that individuals with TC/CC were more susceptible. No significant association was found in the other three miRNA genes. MiR-196a2 could serve as the best predictor of susceptibility in HCC.

miR-22 protect PC12 from ischemia/reperfusion-induced injury by targeting p53 upregulated modulator of apoptosis (PUMA)

MicroRNAs have been implicated as critical regulatory molecules in many cerebrovascular diseases. Recent studies demonstrated miR-22 might provide a potential neuroprotective effect. However, the neuroprotective effect of miR-22 in ischemia/reperfusion (I/R) injury has not been thoroughly elucidated. In this study, the PC12 cells were subjected to 4 h oxygen and glucose deprivation (I) and 24 h reoxygenation (R). The PC12 cells were pre-transfected with miR-22 or anti-miR-22 or siRNA-mediated downregulation of p53-upregulated-modulator-of-apoptosis (PUMA)(PUMA siRNA) or their controls at 24 h prior to exposure to I/R. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot were employed to analyze mRNA and protein expression. PI and Annexin V assays and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assay were used to quantify the rate of apoptosis. We found that miR-22 expression was significantly downregulated in the PC12 cells subjected to I/R. Loss of function of miR-22 increased PC12 apoptosis after I/R, and overexpression of miR-22 decreases PC12 apoptosis after I/R. PUMA protein was upregulated in the I/R group as compared with the sham group. The increased PUMA protein expression and apoptosis induced by I/R was reversed by transfection with PUMA siRNA. We concluded that I/R enhanced apoptosis and PUMA expression in PC12 cells via downregulation of miR-22. Enhanced miR-22 expression reversed both PUMA expression and apoptosis induced by I/R in PC12 cells. miR-22/PUMA axis has important implications for their clinical applications.

Novel Ultrafast Spiral Head MR Angiography Compared to Standard MR and CT Angiography

BACKGROUND AND PURPOSE

Intracranial vessel imaging by time-of-flight MR angiography (TOF-MRA) is one of the most frequently performed investigations in clinical neuroradiology. Particularly in the acute setting, fast imaging is needed for diagnostics, with a sequence ideally depicting even small vessels. The purpose of this study was to compare image and diagnostic quality of a novel ultrashort TOF-MRA sequence accelerated by spiral imaging (TOF-Spiral-short) to a standard TOF-MRA sequence accelerated by compressed sensing (TOF-CS) and to CT angiography (CTA).

METHODS

Forty-one patients (36.6% showing vessel pathologies) who had undergone TOF-CS (acquisition duration: 4 minutes 8 seconds), TOF-Spiral-short (acquisition duration: 51 seconds; spiral imaging [accelerating factor 1.3], decreased field of view [accelerating factor 1.2], and increased voxel size [accelerating factor 3.3]), and CTA were retrospectively evaluated. Assessment of image quality, diagnostic confidence, and quantification of stenosis or aneurysm diameter were performed by two readers.

RESULTS

Image quality at the skull base was slightly reduced with TOF-Spiral-short compared to CTA and TOF-CS (P < .05). Delineation of small intracranial vessels was improved by TOF-Spiral-short compared to CTA (P < .0001). In TOF-Spiral-short, diagnostic confidence was not reduced compared to TOF-CS in patients with vessel pathologies. We observed no significant difference in quantitative pathology assessment between TOF-Spiral-short and the other two modalities. TOF-Spiral-short enabled the correct identification of all vessel pathologies.

CONCLUSIONS

Accelerating TOF-MRA of brain-feeding arteries by a novel ultrashort spiral imaging sequence shows adequate image quality and sufficient diagnostic performance. Thus, TOF-Spiral-short holds potential for fast and reliable diagnostics of vessel pathologies, particularly in the acute setting.

Electro-Acupuncture Promotes the Differentiation of Endogenous Neural Stem Cells via Exosomal microRNA 146b After Ischemic Stroke

Background: Evidences indicate that exosomes-mediated delivery of microRNAs (miRNAs or miRs) is involved in the neurogenesis of stroke. This study was to investigate the role of exosomal miRNAs in non-drug therapy of electro-acupuncture (EA) regulating endogenous neural stem cells for stroke recovery.

Methods: The model of focal cerebral ischemia and reperfusion in rats were established by middle cerebral artery occlusion (MCAO) and treated by EA. The exosomes were extracted from peri-ischemic striatum and identified by exosomal biomarkers, and detected differentially expressed miRNAs with microarray chip. Primary stem cells were cultured, and oxygen–glucose deprivation and reperfusion (OGD/R) was used to mimic vitro ischemic injury.

Results: The levels of exosomal biomarkers TSG101 and CD81 were increased in peri-ischemic striatum after EA treatment, and we revealed 25 differentially expressed miRNAs in isolated exosomes, of which miR-146b was selected for further analysis, and demonstrated that EA increased miR-146b expression and its inhibitors could block the effects. Subsequently, we confirmed that EA upregulated miR-146b expression to promote neural stem cells differentiation into neurons in peri-ischemic striatum. In vitro, it was verified that OGD/R hindered neural stem cells differentiation, and miR-146b inhibitors furtherly suppressed its differentiation, simultaneously NeuroD1 was involved in neural stem cells differentiation into neurons. Moreover, in vivo we found EA promoted NeuroD1-mediated neural stem cells differentiation via miR-146b. In addition, EA also could improve neurological deficits through miR-146b after ischemic stroke.

Conclusion: EA promotes the differentiation of endogenous neural stem cells via exosomal miR-146b to improve neurological injury after ischemic stroke.

Diagnostic value of miR-92a in asymptomatic carotid artery stenosis patients and its ability to predict cerebrovascular events

Background

Early diagnosis of asymptomatic carotid artery stenosis (ACAS) is important to prevent the incidence of cerebrovascular events. This study aimed to investigate the circulating expression of microRNA-92a (miR-92a) in ACAS patients and evaluate its diagnostic value for ACAS and predictive value for cerebrovascular events.

Methods

Circulating expression of miR-92a was measured using quantitative real-time PCR. Chi-square test was used to analyze the association of miR-92a with ACAS patients’ clinical characteristics. A receiver operating characteristic (ROC) was used to evaluate the diagnostic value of miR-92a, and the Kaplan-Meier method and Cox regression analysis were used to assess the predictive value of miR-92a for cerebrovascular events.

Results

Serum expression of miR-92a was higher in ACAS patients than that in the healthy controls (P <  0.001), and associated with patients’ degree of carotid stenosis (P = 0.013). The elevated miR-92a expression could distinguish ACAS patients from healthy individual, and was an independent predictive factor for the occurrence of cerebrovascular events (P = 0.015).

Conclusion

The data from this study indicated that circulating increased miR-92a may serve as a noninvasive diagnostic biomarker for ACAS and a potential risk factor for the future onset of cerebrovascular events.

MiR-370 accelerated cerebral ischemia reperfusion injury via targeting SIRT6 and regulating Nrf2/ARE signal pathway

Cerebral ischemia reperfusion (CIR) is one of the highly lethal diseases in the world. MicroRNA-370 (miR-370) exerts multiple functions in different diseases. However, further research is needed to investigate the potential role of miR-370 in CIR injury. The in vivo middle cerebral artery occlusion (MCAO) rat model and in vitro oxygen-glucose deprivation/reoxygenation (OGD/R) SH-SY5Y cell model were successfully established to mimic CIR injury. The infarct sizes of brain tissues from rats were evaluated. The relationship between miR-370 and silencing information regulatory protein 6 (SIRT6) was confirmed by luciferase activity assay. The cell viability and apoptosis were determined by CCK-8 assay and terminal-deoxynucleoitidyl transferase mediated nick end labeling staining. In this study, miR-370 was upregulated in brain tissues of MCAO rats and knockdown of miR-370 decreased cerebral infarction volume of MCAO rats and it alleviated CIR injury in vivo. The in vitro experiments indicated that knockdown of miR-370 promoted cell viability and alleviated OGD/R-induced SH-SY5Y cell apoptosis. Additionally, the TargetScan predicted that SIRT6 was a target of miR-370 and confirmed by luciferase activity assay. Moreover, miR-370 inhibited SIRT6 expression and regulated Nrf2/ARE signal pathway, whereas overexpression of SIRT6 partly reversed the effect of miR-370 on OGD/R-induced SH-SY5Y cell injury. Thus, we could conclude that miR-370 accelerated CIR injury via targeting SIRT6 and regulating Nrf2/ARE signal pathway, which might provide novel therapeutic targets for CIR injury treatment.

miR‑210 enhances mesenchymal stem cell‑modulated neural precursor cell migration

The migration of endogenous neural stem cells and neural precursor cells (NPCs) to sites of injury is essential for neuroregeneration following hypoxic‑ischemic events. Bone marrow‑derived mesenchymal stem cells (BMSCs) are a potential therapeutic source of cells following central nervous system damage; however, few studies have investigated the effects of BMSCs on cell migration. Thus, in the present study, the effects of BMSCs on NPC migration were investigated. In the present study, BMSCs and NPCs were isolated and cultured from mice. The effects of BMSCs on the migration of NPCs were analyzed using a Transwell cell migration assay. BMSCs were transfected with microRNA‑210 (miR‑210) mimics and inhibitors to examine the effects of the respective upregulation and downregulation of miR‑210 in BMSCs on the migration of NPCs. Then, miR‑210 expression in BMSCs were quantified and the expression levels of vascular endothelial growth factor‑C (VEGF‑C), brain derived neurotrophic factor (BDNF) and chemokine C‑C motif ligand 3 (CCL3) in the supernatant under hypoxic conditions were investigated via reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and ELISA. Subsequently, the expression of VEGF‑C, BDNF and CCL3 in BMSCs overexpressing miR‑210 or BMSCs suppressing miR‑210 was examined by RT‑qPCR and western blot analyses. BMSCs promoted the migration of NPC, particularly when pre‑cultured with BMSCs for 24 h and co‑cultured with NPCs for 24 h; the miR‑210 expression levels increased under hypoxic conditions. Additionally, the migration of NPCs was also increased when the BMSCs overexpressed miR‑210 compared with the BMSCs transfected with a negative control miR and BMSCs with downregulated miR‑210 levels. The expression levels of VEGF‑C increased in the BMSCs that overexpressed miR‑210 and were decreased in BMSCs transfected with a miR‑210 inhibitor. The results of the present study indicated that BMSCs promote the migration of NPCs. Overexpression of miR‑210 in BMSCs enhanced NPC migration and may be associated with increases in VEGF‑C expression levels.

Circulating and tissue microRNAs as a potential diagnostic biomarker in patients with thrombotic events

Venous and arterial thrombosis are conditions that have a considerable burden if left untreated. The hypoxia-induced by the occluded vessel can disrupt the circulation of any organ, the cornerstone of treating thrombosis is rapid diagnosis and appropriate treatment. Diagnosis of thrombosis may be made by using laboratory tests or imaging techniques in individuals who have clinical manifestations of a thrombotic event. The use of serum micro ribonucleic acids (RNAs) has recently been applied to the diagnosis of thrombosis. These small RNA molecules are emerging as new diagnostic markers but have had very limited applications in vascular disease. Most of the articles provided various microRNAs with different levels of accuracy. However, there remains a lack of an appropriate panel of the most specific microRNA in the literature. The purpose of the present review was to summarize the existing data on the use of microRNAs as a diagnostic biomarker for venous thrombosis.

MiRNA Expression is Associated with Clinical Variables Related to Vascular Remodeling in the Kidney and the Brain in Type 2 Diabetes Mellitus Patients

Background: The association of vascular remodeling in the kidney and the brain with a particular microRNAs (miRNA) profile is not well studied.Methods: Seventy-six patients with Type 2 diabetes and 11 healthy subjects were assessed concerning urine albumin: creatinine ratio (UACR), biomarkers of podocyte injury and of proximal tubule (PT) dysfunction. MiRNA were quantified in blood and urine by a real-time PCR System. Cerebrovascular ultrasound measurements were performed in the carotid and middle cerebral arteries.Results: MiRNA21 and miRNA124 correlated positively with nephrin, podocalyxin, synaptopodin, urinary N-acetyl-D-glucosaminidase (NAG), urinary kidney-injury molecule-1 (KIM-1), UACR, and negatively with eGFR; miRNA125a, 126, 146a, 192 correlated negatively with nephrin, podocalyxin, synaptopodin, urinary NAG, urinary KIM-1, UACR, and directly with eGFR. Plasma miRNA-21 and miRNA192 correlated directly with cerebral hemodynamics parameters of atherosclerosis and arteriosclerosis. MiRNA-124, 125a, 126, 146a showed negative correlations with the same parameters.Conclusions: In Type 2 diabetes patients there is an association of vascular remodeling in the brain and the kidney with a specific miRNAs pattern. Cerebrovascular changes occur even in normoalbuminuric patients, with 'high-to-normal' levels of podocyte injury and PT dysfunction biomarkers. These phenomena may be explained by the variability of miRNA expression within the two organs in early DKD.

Integrated analysis of the proteome and transcriptome in a MCAO mouse model revealed the molecular landscape during stroke progression

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DIA proteomics was applied to MCAO mice detection for the first time.

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Proteomics and bioinformatics revealed relationship between stroke process and immunity, especially inflammation.

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C3, Apoa4 and S100a9 were highlighted as a marker or drug targets for stroke.

Strokes usually results in long-term disability and death, and they occur worldwide. Recently, increased research on both on the physiopathological mechanisms and the transcriptome during stroke progression, have highlighted the relationship between stroke progression and immunity, with a special focus on inflammation. Here, we applied proteome analysis to a middle carotid artery occlusion (MCAO) mouse model at 0 h, 6 h, 12 h and 24 h, in which proteome profiling was performed with 23 samples, and 41 differentially expressed proteins (DEPs) were identified. Bioinformatics studies on our data revealed the importance of the immune response and particularly identified the inflammatory response, cytokine- cytokine receptor interactions, the innate immune response and reactive oxygen species (ROS) during stroke progression. In addition, we compared our data with multiple gene expression omnibus (GEO) datasets with and without a time series, in which similar pathways were identified, and three proteins, C3, Apoa4 and S100a9, were highlighted as markers or drug targets for stroke; these three proteins were significantly upregulated in the MCAO model, both in our proteomic data and in the GEO database.

The Potential Role of MicroRNA-124 in Cerebral Ischemia Injury

Cerebral ischemia injury, the leading cause of morbidity and mortality worldwide, initiates sequential molecular and cellular pathologies that underlie ischemic encephalopathy (IE), such as ischemic stroke, Alzheimer disease (AD), Parkinson's disease (PD), epilepsy, etc. Targeted therapeutic treatments are urgently needed to tackle the pathological processes implicated in these neurological diseases. Recently, accumulating studies demonstrate that microRNA-124 (miR-124), the most abundant miRNA in brain tissue, is aberrant in peripheral blood and brain vascular endothelial cells following cerebral ischemia. Importantly, miR-124 regulates a variety of pathophysiological processes that are involved in the pathogenesis of age-related IE. However, the role of miR-124 has not been systematically illustrated. Paradoxically, miR-124 exerts beneficial effects in the age-related IE via regulating autophagy, neuroinflammation, oxidative stress, neuronal excitability, neurodifferentiation, Aβ deposition, and hyperphosphorylation of tau protein, while it may play a dual role via regulating apoptosis and exerts detrimental effects on synaptic plasticity and axonal growth. In the present review, we thus focus on the paradoxical roles of miR-124 in age-related IE, as well as the underlying mechanisms. A great understanding of the effects of miR-124 on the hypoxic-ischemic brain will open new avenues for therapeutic approaches to protect against cerebral ischemia injury.

MMP-9-Related microRNAs as Prognostic Markers for Hemorrhagic Transformation in Cardioembolic Stroke Patients

Studies suggest that microRNAs that regulate expression of matrix metalloproteinase (MMP)-9 may be involved in hemorrhagic transformation (HT) after cardioembolic stroke, so we examined whether such microRNAs could predict HT in acute cardioembolic stroke patients. Blood samples were prospectively collected from patients who later experienced HT (n = 29) or did not (n = 29), and the samples were assayed for eight microRNAs identified as related to MMP-9 based on three microRNA databases. Expression levels of these microRNAs were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) in 28 of the 58 patients, 14 of whom suffered HT and 14 of whom did not. Four differentially expressed miRNAs were identified: hsa-miR-21-5p, hsa-miR-206, hsa-miR-491-5p, and hsa-miR-3123. Subsequent qRT-PCR analysis of these four miRNAs across all 58 patients showed that levels of miR-21-5p, miR-206, and miR-3123 were significantly higher in patients with HT than in those without HT, while expression of miR-491-5p was similar between the two groups. The area under the receiver operating characteristic curve for predicting HT was 0.677 (95% CI 0.535–0.818) for miR-21-5p, 0.687 (95% CI 0.543–0.830) for miR-206, and 0.661 (95% CI 0.512–0.810) for miR-3123. Our results suggest that these three microRNAs may be prognostic markers for HT after cardioembolic stroke, which should be verified by future studies with large samples.

MiR-145 protected the cell viability of human cerebral cortical neurons after oxygen-glucose deprivation by downregulating EPHA4

Our previous study indicated that microRNA 145 (miR-145) and its predicated target, erythropoietin-producing hepatoma (EPH) receptor A4 (EPHA4), was closely associated with ischemic stroke. In this study, we aimed to further explore their function in a model of oxygen-glucose deprivation (OGD). The expression of miR-145 in the blood of 44 patients with ischemic stroke and 37 normal controls was detected by qRT-PCR. After transfection with either the wild- or mutant-type pGL3-promoter EPHA4 3'UTR into the miR-145 mimic and miR-145 inhibitor, a dual-luciferase reporter assay was performed to explore the interaction between miR-145 and EPHA4. qRT-PCR and Western blot were performed to further explore the effects of miR-145 on EPHA4 expression after an miR-145 mimic, an miR-145 inhibitor or LV-sh-EPHA4 was transfected into cerebral cortical neurons. The expression of miR-145 was significantly upregulated in the blood of patients with ischemic stroke compared to that of normal controls. Dual-luciferase reporter assay, qRT-PCR and Western blot results indicated that miR-145 indeed targets EPHA4 through its 3'-UTR and regulates the expression level of EPHA4 at both the mRNA and protein levels. Moreover, the OGD model was successfully constructed, and miR-145 exerted a protective effects in cell viability in the OGD model by downregulating EPHA4. The expression of LOC105376244 could be regulated by the miR-145-EPHA4 interaction. MiR-145 exerted a protective effects in cell viability in the OGD model by downregulating EPHA4, which suggested their potential roles in ischemic stroke and requires further research.

Whole blood microRNA expression associated with stroke: Results from the Framingham Heart Study

Emerging evidence suggests microRNAs (miRNAs) may play an important role in explaining variation in stroke risk and recovery in humans, yet there are still few longitudinal studies examining the association between whole blood miRNAs and stroke. Accounting for multiple testing and adjusting for potentially confounding technical and clinical variables, here we show that whole blood miR-574-3p expression was significantly lower in participants with chronic stroke compared to non-cases. To explore the functional relevance of our findings, we analyzed miRNA-mRNA whole blood co-expression, pathway enrichment, and brain tissue gene expression. Results suggest miR-574-3p is involved in neurometabolic and chronic neuronal injury response pathways, including brain gene expression of DBNDD2 and ELOVL1. These results suggest miR-574-3p plays a role in regulating chronic brain and systemic cellular response to stroke and thus may implicate miR-574-3p as a partial mediator of long-term stroke outcomes.

Identification of key genes and upstream regulators in ischemic stroke

INTRODUCTION

Ischemic stroke (IS) causes severe neurological impairments and physical disabilities and has a high economic burden. Our study aims to identify the key genes and upstream regulators in IS by integrated microarray analysis.

METHODS

An integrated analysis of microarray studies of IS was performed to identify the differentially expressed genes (DEGs) in IS compared to normal control. Based on these DEGs, we performed the functional annotation and transcriptional regulatory network constructions. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to verify the expression of DEGs.

RESULTS

From two Gene Expression Omnibus datasets obtained, we obtained 1526 DEGs (534 up-regulated and 992 down-regulated genes) between IS and normal control. The results of functional annotation showed that Oxidative phosphorylation and Alzheimer's disease were significantly enriched pathways in IS. Top four transcription factors (TFs) with the most downstream genes including PAX4, POU2F1, ELK1, and NKX2-5. The expression of six genes (ID3, ICAM2, DCTPP1, ANTXR2, DUSP1, and RGS2) was detected by qRT-PCR. Except for DUSP1 and RGS2, the other four genes in qRT-PCR played the same pattern with that in our integrated analysis.

CONCLUSIONS

The dysregulation of these six genes may involve with the process of ischemic stroke (IS). Four TFs (PAX4, POU2F1, ELK1 and NKX2-5) were concluded to play a role in IS. Our finding provided clues for exploring mechanism and developing novel diagnostic and therapeutic strategies for IS.

MicroRNAs in brain development and cerebrovascular pathophysiology

MicroRNAs (miRNAs) are a class of highly conserved non-coding RNAs with 21-25 nucleotides in length and play an important role in regulating gene expression at the posttranscriptional level via base-paring with complementary sequences of the 3'-untranslated region of the target gene mRNA, leading to either transcript degradation or translation inhibition. Brain-enriched miRNAs act as versatile regulators of brain development and function, including neural lineage and subtype determination, neurogenesis, synapse formation and plasticity, neural stem cell proliferation and differentiation, and responses to insults. Herein, we summarize the current knowledge regarding the role of miRNAs in brain development and cerebrovascular pathophysiology. We review recent progress of the miRNA-based mechanisms in neuronal and cerebrovascular development as well as their role in hypoxic-ischemic brain injury. These findings hold great promise, not just for deeper understanding of basic brain biology but also for building new therapeutic strategies for prevention and treatment of pathologies such as cerebral ischemia.

Role of rno-miR-124-3p in regulating MCT1 expression in rat brain after permanent focal cerebral ischemia

This study aimed to assess the role of microRNAs (miRNAs) in regulating monocarboxylate transporter-1 (MCT1) expression in rat brain after permanent focal cerebral ischemia to identify a new target for early treatment of cerebral ischemia. Focal cerebral ischemia was induced by permanent middle cerebral artery occlusion (pMCAO) in rats. Morphology and protein expression levels of MCT1 were assessed by immunofluorescence and Western blotting. Using bioinformatics and double luciferase reporter assays, rno-miR-124-3p was selected as a direct target for rat MCT1. Expression of rno-miR-124-3p after pMCAO was detected. Then, rats were treated with rno-miR-124-3p agomir via lateral ventricle injection, and after 6 h or 24 h ischemia, rno-miR-124-3p expression and gene and protein expression of MCT-1 were detected by qRT-PCR and Western blotting. Brain infarction was identified by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. Results showed that pMCAO induced brain infarction and increased the expression of MCT1. The levels of rno-miR-124-3p after pMCAO were in contrast to those of MCT1 protein in ischemic region, while declined after 3, 6 and 12 h of pMCAO in ischemic penumbra. After administration of rno-miR-124-3p agomir, MCT1 mRNA and protein levels were increased after 6 h of pMCAO, while decreased after 24 h of pMCAO. Meanwhile, rno-miR-124-3p levels increased after both times. TTC staining showed treatment with rno-miR-124-3p agomir reduced brain infarction. The role of rno-miR-124-3p in regulating MCT1 was as a positive regulator after 6 h of pMCAO, while a negative regulator after 24 h of pMCAO, however, both activities had protective effects against cerebral ischemia.

Altered Long Non-Coding RNA Transcriptomic Profiles in Ischemic Stroke

A previous study described the important regulatory roles of microRNAs (miRNAs) in ischemic stroke. However, the functional significance of long non-coding RNA (lncRNAs) in ischemic stroke was largely unknown. This study aimed to identify lncRNA profiling and elucidate the regulatory mechanisms in the pathophysiology of stroke. RNA sequencing was performed on the blood of three ischemic stroke patients and three normal controls. Differential expression analysis was used to identify differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs). After further correlation and co-expression analysis, the corresponding co-expression networks and miRN-lncRNA-mRNA interaction network were then constructed. The expression of DElncRNAs and DEmRNAs was verified in Gene Expression Omnibus. RNA sequencing and subsequent bioinformatics analysis produced a total of 61 DElncRNAs (14 upregulated and 47 downregulated) and 673 DEmRNAs (432 upregulated and 241 downregulated). LOC105372881 and LOC101929707 were the most highly increased and decreased lncRNAs in ischemic stroke. LncRNA-mRNA co-expression networks were constructed according to 3,008 positively co-expressed and 607 negatively co-expressed lncRNA-mRNA pairs. The DElncRNAs may play roles in the pathways of glycolysis/gluconeogenesis, arrhythmogenic right ventricular cardiomyopathy, adherens junction, lysosome, and hematopoietic cell lineage by regulating their co-expressed mRNAs. Combined with previous data, a miRNA-lncRNA-mRNA interaction network for ischemic stroke was constructed. Based on GSE22255, the expression of six DElncRNAs (CEBPA-AS1, LINC00884, HCG27, MATN1-AS1, HCG26, and LINC01184) and 11 DEmRNAs (TREML4, AHSP, PI3, TESC, ANXA3, OAS1, OAS2, IFI6, ISG15, IFI44L, and LY6E) was similar to the current sequencing data. This study is the first to identify blood lncRNAs in human ischemic stroke using RNA sequencing. The findings may be the foundation for understanding the potential role of lncRNAs in ischemic stroke.

Diagnosis of Hyperacute and Acute Ischaemic Stroke: The Potential Utility of Exosomal MicroRNA-21-5p and MicroRNA-30a-5p

BACKGROUND

Early and accurate diagnosis of ischaemic stroke (IS) requires the use of an optimized biomarker. Exosomal microRNAs have the potential to serve as biomarkers owing to their stability and specificity. We investigated the expression levels of plasma-derived exosomal microRNA-21-5p and microRNA-30a-5p in the different phases of IS.

METHODS

One hundred forty-three patients with IS and 24 non-stroke controls were enrolled. The patients were divided into the following 5 groups: 1 group for the hyperacute phase IS (HIS, within 6 h); two for the acute phase IS (AIS, including days 1-3 and days 4-7); one for the subacute phase IS (SIS, days 8-14); and one for the recovery phase IS (RIS, days >14). Plasma exosomes were isolated using a QIAGEN exoRNeasy kit and examined by transmission electron -microscopy, nanoparticle tracking, and flow cytometry. The expression levels of miRNA-21-5p and miRNA-30a-5p were detected by quantitative real-time polymerase chain reaction.

RESULTS

The plasma exosomal miR-21-5p levels in SIS and RIS were significantly higher than that in controls (p < 0.05 and p < 0.01 respectively). The levels of miR-30a-5p in HIS were significantly higher (p < 0.05) and in AIS (days 1-3) were lower than that in controls (p < 0.05). In AIS (days 1-3), both miRNAs were decreased compared with the HIS group (p = 0.053 and 0.001, respectively). The area under the curve (AUC) of the miR-21-5p was 0.714 for SIS (95% CI 0.570-0.859, p = 0.007), 0.734 for RIS (95% CI 0.596-0.871, p = 0.003); the AUC of the miR-30a-5p was 0.826 for HIS (95% CI 0.665-0.988, p = 0.001), 0.438 for AIS (days 1-3; 95% CI 0.240-0.635, p = 0.516).

CONCLUSIONS

The plasma-derived exosomal miR-21-5p and miRNA-30a-5p in combination are promising biomarkers for diagnosing IS and distinguishing among HIS, SIS, and RIS, especially miRNA-30a-5p for the diagnosis of the HIS phase. Our results provide a new reference for clinicians to apply in early-stage diagnosis and identifies the possible value of biomarkers for IS thrombolysis therapy.

MiR-181b regulates autophagy in a model of Parkinson's disease by targeting the PTEN/Akt/mTOR signaling pathway

OBJECTIVE

Parkinson's disease (PD) is the second most common neurodegenerative disease. Recent studies have shown that dysregulation of microRNA plays an important role in PD, and defects in autophagy are also critically associated with mechanisms underlying PD. We aim to investigate the effect of miR-181b on autophagy, particularly the involvement of miR-181b in the regulation of the phosphatase and tensin homolog (PTEN)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway and neuronal autophagy in a 1-methyl-4- phenylpyridinium iodide(MPP⁺)-induced cellular model of Parkinson's disease.

MATERIALS AND METHODS

We used MPP⁺ as a tool to construct the PD cell model, using miR-181b mimics or inhibitors to regulate the expression of miR-181b. PC12 cell viability was detected by MTT. The expression of miR-181b was determined by quantitative real-time PCR analysis. The expression of autophagy protein markers (LC3II) and PTEN/Akt/mTOR signaling proteins (PTEN, p-AKT,p-mTOR and p-p70S6K) were determined by Western blotting analysis.

RESULTS

The expression of miR-181b and autophagy-related proteins was gradually decreased with increasing MPP⁺ content. Overexpression of miR-181b significantly decreased the LC3II/GAPDH ratio and increased cell viability compared to the MPP⁺ treated group, whereas inhibition of miR-181b attenuated these effects. In addition, we observed that PTEN expression was reduced by miR-181b mimics and induced by its inhibitors in MPP⁺-treated PC12 cells. Additionally, the indicators of AKT/mTOR signaling, phosphorylated (active) AKT, mTOR and p70S6K were both increased by miR-181b mimics and decreased by its inhibitors.

CONCLUSIONS

Our results suggest that miR-181b regulates autophagy by targeting the PTEN/Akt/mTOR signaling pathway, thereby affecting cell viability in PD.

Inhibition of miR-29b suppresses MAPK signaling pathway through targeting SPRY1 in atherosclerosis

The treatment of atherosclerosis (AS), a severe condition associated with the pathogenesis of cardiovascular diseases (CVDs), is still not satisfactory worldwide. In this study, we aim to investigate whether protein sprout homologue 1 (SPRY1), a upstream mediator of MAPK signal pathway, is the target of miR-29b in vascular endothelium during the development of AS. ApoE^-/- mice model was established, and an inverse correlation was noticed between level of miR-29b and SPRY1 expression in the aortic tissues. Meanwhile, the tumor necrosis factor-α (TNF-α), reactive oxygen species (ROS) expression and NADPH oxidase activity were up-regulated in atherosclerotic tissues. In vitro experiments were carried out to investigate the roles of miR-29b in regulating the expression of SPRY1 in cultured human umbilical vein endothelial cells (HUVECs). We found that miR-29b mimic and antagomir could modulate the expression of SPRY1 protein in cultured HUVECs. However, the expression of SPRY1 mRNA showed no statistical difference when treating with miR-29b mimic or antagomir. These indicated that the modulation of SPRY1 induced by miR-29b was at the posttranslational level. Dural luciferase reporter assay was conducted to detect the potential interaction between miR-29b and the 3'UTR of SPRY1, which indicated that SPRY1 was a target of miR-29b. Besides, miR-29b antagomir induced decrease of TNF-α, ROS production and NADPH oxidase activity and down-regulated the expression of p-ERK and p-p38 in the presence of oxLDL. In conclusion, inhibition of miR-29b could attenuate AS by inhibiting the SPRY1/MAPK signaling pathway and inflammation in aorta. In future, treatment options based on miR-29b may be applicable for the treatment of AS.