Circulating miR-126 and miR-130a levels correlate with lower disease risk, disease severity, and reduced inflammatory cytokine levels in acute ischemic stroke patients

The impact of cytokines in neuroinflammation-mediated stroke

Cerebral stroke is ranked as the third most common contributor to global mortality and disability. The involvement of inflammatory mechanisms, both peripherally and within the CNS, holds significance in the pathophysiological cascades following the initiation of stroke. After the onset of acute stroke, predominantly ischemic, a subsequent phase of neuroinflammation ensues. It is a dual-effect process that not only exacerbates injury, leading to cell death, but paradoxically, it also serves a shielding role in facilitating recovery. Cytokines serve as pivotal mediators within the inflammatory cascade, actively contributing to the progression of ischemic damage. Stroke is followed by increased expression of pro-inflammatory cytokines including TNF-α, IL-1β, IL-6, etc. leading to the recruitment and stimulation of glial cells and peripheral leukocytes at the site of injury, promoting neuroinflammation. Cytokines can directly induce neuronal injury and death through various mechanisms, including excitotoxicity, oxidative stress, HPA-axis activation, secretion of matrix metalloproteinase and apoptosis. They can also amplify the inflammatory response, leading to further neuronal damage. Therapeutic strategies aimed at modulating cytokine release, immune response and cytokine signalling or activity are being explored as potential interventions to mitigate neuroinflammation and its detrimental effects in stroke. In this review, we have given a concise summary of our current knowledge of the function of various cytokines, brain inflammation and various signalling and molecular pathways including JAK/STAT3, TGF-β/Smad, MAPK, HMGB1/TLR and NF-κB modulated cytokines regulation in stroke. Therapeutic agents such as MCC950, genistein, edaravone, minocycline, etc. targeting various cytokines-associated signalling pathways have shown efficacy in preclinical and clinical trials reducing the pathophysiology of the illness were also addressed in this study.

The exo-microRNA (miRNA) signaling pathways in pathogenesis and treatment of stroke diseases: Emphasize on mesenchymal stem cells (MSCs)

A major factor in long-term impairment is stroke. Patients with persistent stroke and severe functional disabilities have few therapy choices. Long noncoding RNAs (lncRNAs) may contribute to the regulation of the pathophysiologic processes of ischemic stroke as shown by altered expression of lncRNAs and microRNA (miRNAs) in blood samples of acute ischemic stroke patients. On the other hand, multipotent mesenchymal stem cells (MSCs) increase neurogenesis, and angiogenesis, dampen neuroinflammation, and boost brain plasticity to improve functional recovery in experimental stroke models. MSCs can be procured from various sources such as the bone marrow, adipose tissue, and peripheral blood. Under the proper circumstances, MSCs can differentiate into a variety of mature cells, including neurons, astrocytes, and oligodendrocytes. Accordingly, the capability of MSCs to exert neuroprotection and also neurogenesis has recently attracted more attention. Nowadays, lncRNAs and miRNAs derived from MSCs have opened new avenues to alleviate stroke symptoms. Accordingly, in this review article, we examined various studies concerning the lncRNAs and miRNAs' role in stroke pathogenesis and delivered an overview of the therapeutic role of MSC-derived miRNAs and lncRNAs in stroke conditions.

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.

Non-coding RNAs and angiogenesis in cardiovascular diseases: a comprehensive review

Non-coding RNAs (ncRNAs) have key roles in the etiology of many illnesses, including heart failure, myocardial infarction, stroke, and in physiological processes like angiogenesis. In transcriptional regulatory circuits that control heart growth, signaling, and stress response, as well as remodeling in cardiac disease, ncRNAs have become important players. Studies on ncRNAs and cardiovascular disease have made great progress recently. Here, we go through the functions of non-coding RNAs (ncRNAs) like circular RNAs (circRNAs), and microRNAs (miRNAs) as well as long non-coding RNAs (lncRNAs) in modulating cardiovascular disorders.

Remote ischemic conditioning alleviates chronic cerebral hypoperfusion-induced cognitive decline and synaptic dysfunction via the miR-218a-5p/SHANK2 pathway

Vascular cognitive impairment (VCI) due to chronic cerebral hypoperfusion (CCH), is the second leading cause of dementia. Although synaptic impairment plays a critical role in VCI, its exact mechanism remains unknown. Our previous research revealed that remote ischemic conditioning (RIC) could alleviate cognitive decline resulting from CCH, however, its effects on synaptic impairment remain unclear. In this study, we confirmed that RIC alleviated both cognitive decline and its associated synaptic dysfunction caused by CCH. RNA sequencing revealed that CCH increased in miR-218a-5p expression, which was decreased by RIC. Elevated miR-218a-5p levels limited the benefits of RIC, however, inhibiting miR-218a-5p in hippocampal CA1 neurons rescued synaptic dysfunction. Additionally, we found that SHANK2 is a downstream target of miR-218a-5p, and inhibiting SHANK2 expression reduced the alleviation caused by hypoxic conditioning in synaptic impairment in vitro. In conclusion, our results suggested that RIC alleviated synaptic impairment via the miR-218a-5p/SHANK2 pathway, which could be a potential biomarker or therapeutic target for cognitive impairment caused by CCH.

Circulating MicroRNAs and Extracellular Vesicle-Derived MicroRNAs as Predictors of Functional Recovery in Ischemic Stroke Patients: A Systematic Review and Meta-Analysis

Stroke accounts for the second leading cause of death and a major cause of disability, with limited therapeutic strategy in both the acute and chronic phases. Blood-based biomarkers are intensively researched and widely recognized as useful tools to predict the prognoses of patients confronted with therapeutically limited diseases. We performed a systematic review of the circulating biomarkers in IS patients with prognostic value, with a focus on microRNAs and exosomes as predictive biomarkers of motor and cognitive recovery. We identified 63 studies, totalizing 72 circulating biomarkers with prognostic value in stroke recovery, as follows: 68 miRNAs and exosomal-miRNAs being identified as predictive for motor recovery after stroke, and seven biomarkers being predictive for cognitive recovery. Twelve meta-analyses were performed using effect sizes (random-effects and fixed-effects model). The most significant correlation findings obtained after pooling were with miR-21, miR-29b, miR-125b-5p, miR-126, and miR-335. We identified several miRNAs that were correlated with clinical outcomes of stroke severity and recovery after ischemic stroke, providing predictive information on motor and cognitive recovery. Based on the current state of research, we identified serum miR-9 and neutrophil miR-29b as the most promising biomarkers for in-depth follow-up studies, followed by serum miR-124 and plasma miR-125b.

Evaluation of De Ritis (AST/ALT), ALP/ALT, and AST/ALP ratios as prognostic factors in patients with acute ischemic stroke

BACKGROUND

Stroke is one of the leading causes of disability worldwide. Recently, stroke prognosis estimation has received much attention. This study investigates the prognostic role of aspartate transaminase/alanine transaminase (De Ritis, AAR), alkaline phosphatase/alanine transaminase (ALP/ALT), and aspartate transaminase/alkaline phosphatase (AST/ALP) ratios in acute ischemic stroke (AIS).

METHODS

This retrospective cohort study involved patients who experienced their first-ever AIS between September 2019 and June 2021. Clinical and laboratory data were collected within the first 24 hours after admission. Functional and mortality outcomes were evaluated 90 days after hospital discharge in clinical follow-up. Functional outcome was assessed by a modified Rankin Scale (mRS). The correlation between the laboratory data and study outcomes was evaluated using univariate analysis. In addition, regression models were developed to evaluate the predictive role of AST/ALP, ALP/ALT, and AAR ratios on the study outcomes.

RESULTS

Two hundred seventy-seven patients (mean age 69.10 ± 13.55, 53.1% female) were included. According to univariate analysis, there was a weak association between 3-months mRS, and both AST/ALT (r = 0.222, P < 0.001), and AST/ALP (r = 0.164, P = 0.008). Subsequently, higher levels of these ratios and absolute values of AST, ALT, and ALP were reported in deceased patients. Based on regression models adjusted with co-variable (age, gender, underlying disease, and history of smoking) AST/ALT and AST/ALP ratios had a significant independent association with 3-month mRS (CI:1.37-4.52, p = 0.003, and CI: 4.45-11,547.32, p = 0.007, respectively) and mortality (CI: 0.17-1.06, adjusted R² = 0.21, p = 0.007, and CI: 0.10-2.91, p = 0.035, adjusted R² = 0.20, respectively).

CONCLUSIONS

Elevated AST/ALP and AAR ratios at admission were correlated with poorer outcomes at 3 months in patients with first-ever AIS. Prospective studies in larger cohorts are required to confirm our findings and to evaluate further whether the AST/ALP and De Ritis ratios may represent a useful tool for determining the prognosis of AIS patients.

Human platelet lysate-derived extracellular vesicles enhance angiogenesis through miR-126

OBJECTIVES

Extracellular vesicles (EVs) are key biological mediators of several physiological functions within the cell microenvironment. Platelets are the most abundant source of EVs in the blood. Similarly, platelet lysate (PL), the best platelet derivative and angiogenic performer for regenerative purposes, is enriched of EVs, but their role is still too poorly discovered to be suitably exploited. Here, we explored the contribution of the EVs in PL, by investigating the angiogenic features extrapolated from that possessed by PL.

METHODS

We tested angiogenic ability and molecular cargo in 3D bioprinted models and by RNA sequencing analysis of PL-derived EVs.

RESULTS

A subset of small vesicles is highly represented in PL. The EVs do not retain aggregation ability, preserving a low redox state in human umbilical vein endothelial cells (HUVECs) and increasing the angiogenic tubularly-like structures in 3D endothelial bioprinted constructs. EVs resembled the miRNome profile of PL, mainly enriched with small RNAs and a high amount of miR-126, the most abundant angiogenic miRNA in platelets. The transfer of miR-126 by EVs in HUVEC after the in vitro inhibition of the endogenous form, restored angiogenesis, without involving VEGF as a downstream target in this system.

CONCLUSION

PL is a biological source of available EVs with angiogenic effects involving a miRNAs-based cargo. These properties can be exploited for targeted molecular/biological manipulation of PL, by potentially developing a product exclusively manufactured of EVs.

Circulating MicroRNAs as Potential Biomarkers for Ischemic Stroke in Patients with Asymptomatic Intracranial Artery Stenosis

Circulating microRNAs have been shown to be biomarkers of various diseases. We aimed to investigate whether circulating microRNA can serve as a biomarker to predict ischemic stroke risk in asymptomatic intracranial artery stenosis. A total of 716 participants from the Asymptomatic Polyvascular Abnormalities Community study who had asymptomatic intracranial artery stenosis at baseline were enrolled (2010-11). Patients who suffered incident ischemic stroke were classified into the case group, and age- and sex-matched individuals without stroke were used as controls. MicroRNA microarrays were used to distinguish baseline circulating serum microRNA levels between the case and the control groups (GEO accession number GSE201860). The differentially expressed microRNAs were validated by real-time PCR. MicroRNA microarrays were performed in baseline serum samples from12 subjects who developed ischemic stroke and 12 age- and sex-matched subjects without stroke during the 2014-15 follow-up period. Twenty microRNAs were differentially expressed between the two groups (fold change > 1.3 and p < 0.05 for all). Hsa-miR-486-5p, hsa-miR-92a-3p, hsa-miR-6089 from them were selected and validated in the baseline serum samples of ten subjects with incident ischemic stroke and another ten age- and sex-matched subjects without stroke during the 2016-17 follow-up period. Hsa-miR-1225-5p, with a large fold change value and a reported relationship with cardiovascular or cerebrovascular diseases, was also validated. Ultimately, only hsa-miR-6089 was differentially downregulated among patients with intracranial artery stenosis who developed ischemic stroke (p < 0.05). In patients with asymptomatic intracranial artery stenosis, downregulated serum hsa-miR-6089 may be associated with the risk of ischemic stroke.

Effects of Extracorporeal Shockwave Therapy on Functional Recovery and Circulating miR-375 and miR-382-5p after Subacute and Chronic Spinal Cord Contusion Injury in Rats

Extracorporeal shockwave therapy (ESWT) can stimulate processes to promote regeneration, including cell proliferation and modulation of inflammation. Specific miRNA expression panels have been established to define correlations with regulatory targets within these pathways. This study aims to investigate the influence of low-energy ESWT—applied within the subacute and chronic phase of SCI (spinal cord injury) on recovery in a rat spinal cord contusion model. Outcomes were evaluated by gait analysis, µCT and histological analysis of spinal cords. A panel of serum-derived miRNAs after SCI and after ESWT was investigated to identify injury-, regeneration- and treatment-associated expression patterns. Rats receiving ESWT showed significant improvement in motor function in both a subacute and a chronic experimental setting. This effect was not reflected in changes in morphology, µCT-parameters or histological markers after ESWT. Expression analysis of various miRNAs, however, revealed changes after SCI and ESWT, with increased miR-375, indicating a neuroprotective effect, and decreased miR-382-5p potentially improving neuroplasticity via its regulatory involvement with BDNF. We were able to demonstrate a functional improvement of ESWT-treated animals after SCI in a subacute and chronic setting. Furthermore, the identification of miR-375 and miR-382-5p could potentially provide new targets for therapeutic intervention in future studies.

Systematic review: Association between circulating microRNA expression & stroke

This systematic review aimed to establish the range and quality of clinical and preclinical evidence supporting the association of individual microRNAs, and the use of microRNA expression in the diagnosis and prognosis of ischaemic or haemorrhagic stroke. Electronic databases were searched from 1993 to October 2021, using key words relevant to concepts of stroke and microRNA. Studies that met specific inclusion and exclusion criteria were selected for data extraction. To minimise erroneous associations, findings were restricted to microRNAs reported to change in more than two independent studies. Of the papers assessed, 155 papers reported a change in microRNA expression observed in more than two independent studies. In ischaemic studies, two microRNAs were consistently differentially expressed in clinical samples (miR-29b & miR-146a) and four were altered in preclinical samples (miR-137, miR-146a, miR-181b & miR-223-3p). Across clinical and preclinical haemorrhagic studies, four microRNAs were downregulated consistently (miR-26a, miR-126, miR-146a & miR-155). Across included studies, miR-126 and miR-146a were the only two microRNAs to be differentially expressed in clinical and preclinical cohorts following ischaemic or haemorrhagic stroke. Further studies, employing larger populations with consistent methodologies, are required to validate the true clinical value of circulating microRNAs as biomarkers of ischaemic and haemorrhagic stroke.

Circulating miRNA-195-5p and -451a in Patients with Acute Hemorrhagic Stroke in Emergency Department

(1) Background: In our previous study, acute ischemic stroke (AIS) patients showed increased levels of circulating miRNAs (-195-5p and -451a) involved in vascular endothelial growth factor A (VEGF-A) regulation. Here, we evaluated, for the first time, both circulating miRNAs in acute intracerebral hemorrhagic (ICH) patients. (2) Methods: Circulating miRNAs and serum VEGF-A were assessed by real-time PCR and ELISA in 20 acute ICH, 21 AIS patients, and 21 controls. These were evaluated at hospital admission (T0) and after 96 h (T96) from admission. (3) Results: At T0, circulating miRNAs were five-times up-regulated in AIS patients, tending to decrease at T96. By contrast, in the acute ICH group, circulating miRNAs were significantly increased at both T0 and T96. Moreover, a significant decrease was observed in serum VEGF-A levels at T0 in AIS patients, tending to increase at T96. Conversely, in acute ICH patients, the levels of VEGF-A were significantly decreased at both T0 and T96. (4) Conclusions: The absence of a reduction in circulating miRNAs (195-5p and -451a), reported in acute ICH subjects after 96 h from hospital admission, together with the absence of increment of serum VEGF-A, may represent useful biomarkers indicating the severe brain damage status that characterizes acute ICH patients.

Mechanism of miR-126 in hypoxia-reoxygenation-induced cardiomyocyte pyroptosis by regulating HMGB1 and NLRP3 inflammasome

OBJECTIVE

Pyroptosis refers to the programmed cell death. This study evaluated the mechanism of miR-126 in hypoxia-reoxygenation (HR)-induced cardiomyocyte pyroptosis.

METHODS

The HR rat cardiomyocyte models were established. The cell viability, cytotoxicity, and levels of miR-126, pro-caspase-1 (p45), activated caspase-1 (p20/p10), caspase-11, gasdermin D (GSDMD), and GSDMD-N were detected. The cells were transfected with miR-126 mimics to verify the effect on rat cardiomyocyte pyroptosis, and added with HMGB1 inhibitor (Glycyrrhizin) or NLRP3 inhibitor (S3680) to explore the regulatory mechanisms on rat cardiomyocyte pyroptosis. The binding relationship of miR-126 and HMGB1 was explored. The regulatory effect of miR-126 and HMGB1 on HR-stimulated cardiomyocytes was verified through co-transfection with miR-126 mimics and pcDNA3.1-HMGB1.

RESULTS

HR treatment inhibited rat cardiomyocyte viability and increased cytotoxicity. After HR treatment, pro-caspase-1 (p45), activated caspase-1 (p20/p10), caspase-11, GSDMD, and GSDMD-N were elevated in rat cardiomyocytes, while miR-126 was evidently downregulated in rat cardiomyocytes. miR-126 overexpression, and inhibition of HMGB1 or NLRP3 partially reversed HR-induced rat cardiomyocyte cytotoxicity and pyroptosis. miR-126 targeted HMGB1 and HMGB1 overexpression partly reversed the inhibition of miR-126 overexpression on HR-induced cardiomyocyte pyroptosis.

CONCLUSION

miR-126 inhibits HMGB1/NLRP3 activity and the caspase-1/11 activation and reduces the GSDMD-N cleaved from GSDMD, ultimately inhibiting HR-induced cardiomyocyte pyroptosis.

Expression and Clinical Value of miR-185 and miR-424 in Patients with Acute Ischemic Stroke

Background

To investigate the expression of serum miR-185 and miR-424 in patients with acute ischemic stroke (AIS) and their predictive value. A total of 142 patients with AIS and 50 healthy controls were enrolled.

Methods

According to the modified Rankin scale (mRS) score, AIS patients were divided into the good prognosis group and the poor prognosis group. Based on the National Institutes of Health Stroke Scale (NIHSS) score, AIS patients were divided into the mild group, the moderate group, and the severe group. RT-qPCR was used to determine the expression. ROC curve and Pearson correlation analysis were adopted to predict poor prognosis and analyze the correlation between the expression and NIHSS, mRS score.

Results

Compared with the control group, the expression of miR-185 and miR-424 in the AIS group was significantly higher (P<0.01). Similarly, significantly higher expressions could be found in the poor prognosis group and the severe group (P<0.01). The ROC curve revealed that the optimal cut-off values were 2.14 and 4.08, respectively. The area under the ROC curve (0.928, 95% CI: 0.870-0.993) was the largest, with sensitivity and specificity of 92.0% and 85.7%. Pearson correlation analysis showed that their expression was positively correlated with NIHSS score and mRS score in AIS patients (r=0.735, 0.802, 0.796, 0.873, P<0.01).

Conclusion

There are two factors related to the up-regulated expression of serum miR-185 and miR-424, one is the severity degree of neurological impairment of patients with AIS and the other is their prognosis. These two combined indicators can contribute to predicting the prognosis of AIS patients.

Liraglutide Improves Cognitive and Neuronal Function in 3-NP Rat Model of Huntington's Disease

Huntington’s disease (HD) is an autosomal dominant inherited neurodegenerative disease characterized by progressive motor, psychiatric, and cognitive abnormalities. The antidiabetic drug liraglutide possesses a neuroprotective potential against several neurodegenerative disorders; however, its role in Huntington’s disease (HD) and the possible mechanisms/trajectories remain elusive, which is the aim of this work. Liraglutide (200 μg/kg, s.c) was administered to rats intoxicated with 3-nitropropionic acid (3-NP) for 4 weeks post HD model induction. Liraglutide abated the 3-NP-induced neurobehavioral deficits (open field and elevated plus maze tests) and histopathological changes. Liraglutide downregulated the striatal mRNA expression of HSP 27, PBR, and GFAP, while it upregulated that of DARPP32. On the molecular level, liraglutide enhanced striatal miR-130a gene expression and TrKB protein expression and its ligand BDNF, while it reduced the striatal protein content and mRNA expression of the death receptors sortilin and p75NTR, respectively. It enhanced the neuroprotective molecules cAMP, p-PI3K, p-Akt, and p-CREB, besides modulating the p-GSK-3β/p-β-catenin axis. Liraglutide enhanced the antioxidant transcription factor Nrf2, abrogated TBARS, upregulated both Bcl2 and Bcl-XL, and downregulated Bax along with decreasing caspase-3 activity. Therefore, liraglutide exerts a neurotherapeutic effect on 3-NP-treated rats that is, besides the upturn of behavioral and structural findings, it at least partially, increased miR-130a and modulated PI3K/Akt/CREB/BDNF/TrKB, sortilin, and p75NTR, and Akt/GSK-3β/p-β-catenin trajectories besides its capacity to decrease apoptosis and oxidative stress, as well as its neurotrophic activity.

ceRNA Network and Functional Enrichment Analysis of Preeclampsia by Weighted Gene Coexpression Network Analysis

BACKGROUND

Preeclampsia (PE) is a multisystemic syndrome which has short- and long-term risk to mothers and children and has pluralistic etiology.

OBJECTIVE

This study is aimed at constructing a competitive endogenous RNA (ceRNA) network for pathways most related to PE using a data mining strategy based on weighted gene coexpression network analysis (WGCNA).

METHODS

We focused on pathways involving hypoxia, angiogenesis, and epithelial mesenchymal transition according to the gene set variation analysis (GSVA) scores. The gene sets of these three pathways were enriched by gene set enrichment analysis (GSEA). WGCNA was used to study the underlying molecular mechanisms of the three pathways in the pathogenesis of PE by analyzing the relationship among pathways and genes. The soft threshold power (β) and topological overlap matrix allowed us to obtain 15 modules, among which the red module was chosen for the downstream analysis. We chose 10 hub genes that satisfied ∣log2Fold Change | >2 and had a higher degree of connectivity within the module. These candidate genes were subsequently confirmed to have higher gene significance and module membership in the red module. Coexpression networks were established for the hub genes to unfold the connection between the genes in the red module and PE. Finally, ceRNA networks were constructed to further clarify the underlying molecular mechanism involved in the occurrence of PE. 56 circRNAs, 17 lncRNAs, and 20 miRNAs participated in the regulation of the hub genes. Coagulation factor II thrombin receptor (F2R) and lumican (LUM) were considered the most relevant genes, and ceRNA networks of them were constructed.

CONCLUSION

The microarray data mining process based on bioinformatics methods constructed lncRNA and miRNA networks for ten hub genes that were closely related to PE and focused on ceRNAs of F2R and LUM finally. The results of our study may provide insight into the mechanisms underlying PE occurrence.

Circ_0006768 upregulation attenuates oxygen-glucose deprivation/reoxygenation-induced human brain microvascular endothelial cell injuries by upregulating VEZF1 via miR-222-3p inhibition

Circular RNAs (circRNAs) have been widely implicated in multiple diseases, including ischemic stroke. This study aimed to explore the function and functional mechanism of circ_0006768 in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced brain injury models of ischemic stroke. Human brain microvascular endothelial cells (HBMECs) were induced by OGD/R to mimic ischemic stroke models in vitro. The expression of circ_0006768, microRNA-222-3p (miR-222-3p) and vascular endothelial zinc finger 1 (VEZF1) was detected by quantitative real-time PCR (qPCR). Cell viability, angiogenesis ability and cell migration were assessed by cell counting kit-8 (CCK-8) assay, tube formation assay and wound healing assay, respectively. The releases of pro-inflammatory factors were determined by commercial enzyme-linked immunosorbent assay (ELISA) kits. The protein levels of vascular endothelial growth factor A (VEGFA), N-cadherin and VEZF1 were detected by western blot. The putative relationship between miR-222-3p and circ_0006768 or VEZF1 was validated by dual-luciferase reporter assay, RNA Immunoprecipitation (RIP) assay and pull-down assay. Circ_0006768 was poorly expressed in ischemic stroke plasma and OGD/R-induced HBMECs. OGD/R inhibited cell viability, angiogenesis and cell migration and promoted the releases of pro-inflammatory factors, while circ_0006768 overexpression or miR-222-3p inhibition partially abolished the effects of OGD/R. MiR-222-3p was targeted by circ_0006768, and VEZF1 was a target of miR-222-3p. Circ_0006768 enriched the expression of VEZF1 via mediating miR-222-3p inhibition. Rescue experiments presented that the effects of circ_0006768 overexpression were reversed by miR-222-3p restoration or VEZF1 knockdown. Circ_0006768 overexpression attenuates OGD/R-induced HBMEC injuries by upregulating VEZF1 via miR-222-3p inhibition.

Comparison of different protocols of RNA preparation from circulating blood for RNA sequencing

OBJECTIVE

Circulating miRNAs have been extensively used in studies of neurological diseases. Thus, methods to extract high quantity total RNA for RNA sequencing (RNA-seq) and real-time quantitative polymerase chain reaction (RT-qPCR) are needed. However, the extraction of sufficient high-quality nucleic acids from circulating blood is difficult. Differences in eccentricity, cryopreservation conditions and extraction methods may affect RNA quantity and quality. Here, we systematically compared six blood-RNA extraction protocols (protocols 1, 2, 3, 4, 5, and 6; see the methods section for details).

RESULTS

Protocol 1 yielded the highest quality and quantity of RNA; protocol 2, protocol 5 and protocol 6 produced RNA of intermediate quality; and protocols 3 and 4 yielded the lowest quality RNA. The RNA integrity number (RIN) for isolated RNA was > 9.0 when protocol 1 or protocol 2 was used, > 8.0 when protocol 5 was used, and > 7.0 when protocol 6 was used; lower values were obtained when protocol 3 or 4 was used. The RNA extracted from circulating blood using protocol 1 was most intact and suitable for RT-qPCR and RNA-seq.

CONCLUSIONS

The quality of RNA extracted from circulating blood is affected by high-speed centrifugation and cryopreservation. Adding an RNA stabilizer during the cryopreservation of circulating blood significantly improved RNA quality and quantity. The quality of extracted RNA from circulating blood is improved when using TRIzol relative to that attained with a commercial kit.

Diagnostic and Prognostic Circulating MicroRNA in Acute Stroke: A Systematic and Bioinformatic Analysis of Current Evidence

BACKGROUND AND PURPOSE

Stroke is the second leading cause of death and disability worldwide and its diagnosis, and assessment of prognosis, remains challenging. There is a need for improved diagnostic and prognostic biomarkers. MicroRNAs (miRNAs) play important roles in the post-transcriptional regulation of gene expression and their secretion and remarkable stability in biofluids highlights their potential as sensitive biomarkers in the diagnosis and prognosis of acute stroke.

METHODS

We carried out a systematic review to assess current evidence supporting the potential of miRNAs to act as unique diagnostic and prognostic biomarkers in blood samples collected from patients suffering acute stroke within 24 hours of symptoms onset.

RESULTS

We identified 22 studies eligible for inclusion with 33 dysregulated miRNAs having diagnostic potential in the acute phase of the disease. We identified miR-16, miR-126, and miR-335 as having the highest sensitivity as diagnostic and prognostic biomarkers in acute ischaemic stroke and present original bioinformatic and pathway enrichment analysis of putative miRNA-target interactions.

CONCLUSIONS

miRNAs represent unique biomarkers which have a promising future in stroke diagnosis and prognosis. However, there is a need for more standardized and consistent methodology for the accurate interpretation and translation of miRNAs as novel specific and sensitive biomarkers into clinical practice.

Circulating miR-21, miR-29a, and miR-126 are associated with premature death risk due to cancer and cardiovascular disease: the JACC Study

Primary prevention of premature death is a public health concern worldwide. Circulating microRNAs (miRNAs) have been described as potential diagnostic biomarkers for diseases as cancer and cardiovascular disease (CVD). This case-cohort study aimed to investigate the potential relationship between circulating miRNAs and the risk of premature death. A total of 39,242 subjects provided baseline serum samples in 1988–1990. Of these, 345 subjects who died of intrinsic disease (< 65 years old) and for which measurable samples were available were included in this study. We randomly selected a sub-cohort of 879 subjects. Circulatring miR-21, miR-29a, and miR-126 were determined using qRT-PCR. Conditional logistic regression models were used to analyse the data with respect to stratified miRNA levels. Multivariable logistic regression revealed that subjects with high circulating miR-21 and miR-29a individual levels had a significantly higher risk of total death, cancer death, and CVD death than those with medium miR-21 and miR-29a individual levels. Conversely, subjects with low circulating miR-126 levels had a significantly higher risk of total death than those with medium levels. This suggests that circulating miRNAs are associated with the risk of premature death from cancer and CVD, identifying them as potential biomarkers for early detection of high-risk individuals.

microRNA-130a-5p suppresses myocardial ischemia reperfusion injury by downregulating the HMGB2/NF-κB axis

BACKGROUND

Myocardial ischemia reperfusion injury (MIRI) is defined as tissue injury in the pathological process of progressive aggravation in ischemic myocardium after the occurrence of acute coronary artery occlusion. Research has documented the involvement of microRNAs (miRs) in MIRI. However, there is obscure information about the role of miR-130a-5p in MIRI. Herein, this study aims to investigate the effect of miR-130a-5p on MIRI.

METHODS

MIRI mouse models were established. Then, the cardiac function and hemodynamics were detected using ultrasonography and multiconductive physiological recorder. Functional assays in miR-130a-5p were adopted to test the degrees of oxidative stress, mitochondrial functions, inflammation and apoptosis. Hematoxylin and eosin (HE) staining was performed to validate the myocardial injury in mice. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was employed to assess the expression patterns of miR-130a-5p, high mobility group box (HMGB)2 and NF-κB. Then, dual-luciferase reporter gene assay was performed to elucidate the targeting relation between miR-130a-5p and HMGB2.

RESULTS

Disrupted structural arrangement in MIRI mouse models was evident from HE staining. RT-qPCR revealed that overexpressed miR-130a-5p alleviated MIRI, MIRI-induced oxidative stress and mitochondrial disorder in the mice. Next, the targeting relation between miR-130a-5p and HMGB2 was ascertained. Overexpressed HMGB2 annulled the protective effects of miR-130a-5p in MIRI mice. Additionally, miR-130a-5p targets HMGB2 to downregulate the nuclear factor kappa-B (NF-κB) axis, mitigating the inflammatory injury induced by MIRI.

CONCLUSION

Our study demonstrated that miR-130a-5p suppresses MIRI by down-regulating the HMGB2/NF-κB axis. This investigation may provide novel insights for development of MIRI treatments.

Downregulation of miR-126-3p expression contributes to increased inflammatory response in placental trophoblasts in preeclampsia

MiR-126-3p is a prototype of an endothelial miRNA and has protective effects on endothelial cells. However, little is known about the effects of miR-126-3p on placental trophoblasts. In the present study, we tested the hypothesis that aberrant miR-126-3p expression is present in preeclamptic placenta which contributes to increased inflammatory response in trophoblasts. Placentas were obtained immediately after delivery from normotensive and preeclamptic pregnancies. Villous tissue was either fixed with formalin or used for trophoblast isolation. Trophoblast miR-126-3p expression was assessed by in situ hybridization of formalin-fixed tissue sections and by RT-PCR in cultured syncytiotrophoblasts. Culture medium was collected for measurement of IL-6, TNFα, and 8-Isoprostane production by ELISA and total cellular protein was collected for evaluation of HIF1α expression by Western blot. Effects of overexpression of miR-126-3p in trophoblasts on cytokine production were tested by transfection of pre-mir-126, a precursor of miR-126, into primary isolated trophoblasts. We found that downregulation of miR-126-3p expression was associated with increased IL-6 and TNFα production in trophoblasts from preeclamptic placentas vs. normal placentas. Moreover, transient overexpression of miR-126-3p significantly reduced IL-6 and TNFα production in trophoblasts from both normal and preeclamptic placentas. We further found that increase in miR-126-3p expression not only suppressed hypoxia-induced increases in IL-6 and TNFα production, but also attenuated hypoxia-induced increases in HIF1α expression and 8-Isoprostane production in trophoblasts cultured under hypoxic condition. These results provide plausible evidence that downregulation of miR-126-3p expression reduces anti-inflammatory and anti-oxidative stress activities in placental trophoblasts in preeclampsia.

miR-16-5p, miR-103-3p, and miR-27b-3p as Early Peripheral Biomarkers of Fetal Growth Restriction

Current tests available to diagnose fetal hypoxia in-utero lack sensitivity thus failing to identify many fetuses at risk. Emerging evidence suggests that microRNAs derived from the placenta circulate in the maternal blood during pregnancy and may be used as non-invasive biomarkers for pregnancy complications. With the intent to identify putative markers of fetal growth restriction (FGR) and new therapeutic druggable targets, we examined, in maternal blood samples, the expression of a group of microRNAs, known to be regulated by hypoxia. The expression of microRNAs was evaluated in maternal plasma samples collected from (1) women carrying a preterm FGR fetus (FGR group) or (2) women with an appropriately grown fetus matched at the same gestational age (Control group). To discriminate between early- and late-onset FGR, the study population was divided into two subgroups according to the gestational age at delivery. Four microRNAs were identified as possible candidates for the diagnosis of FGR: miR-16-5p, miR-103-3p, miR-107-3p, and miR-27b-3p. All four selected miRNAs, measured by RT-PCR, resulted upregulated in FGR blood samples before the 32nd week of gestation. By contrast, miRNA103-3p and miRNA107-3p, analyzed between the 32nd and 37th week of gestation, showed lower expression in the FGR group compared to aged matched controls. Our results showed that measurement of miRNAs in maternal blood may form the basis for a future diagnostic test to determine the degree of fetal hypoxia in FGR, thus allowing the start of appropriate therapeutic interventions to alleviate the burden of this disease.

MiR-130a in the adipogenesis of human SGBS preadipocytes and its susceptibility to androgen regulation

Objectives: Adipogenesis is the differentiation process generating mature adipocytes from undifferentiated mesenchymal stem cells. The differentiation can be inhibited by androgens, although knowledge about intracellular effectors of this inhibition is scarce. Recently, androgen-regulated microRNAs were detected as interesting candidates in this context. In this study, we analyse the role of miR-130a and miR-301 in the adipogenesis of human SGBS preadipocytes and whether they are prone to androgen regulation. Materials and Methods: microRNA expression during adipogenic differentiation with or without androgen stimulation was measured by qPCR. Putative target genes of miR-130a and miR-301 were identified by target database search and validated in luciferase reporter assays. Results: miR-130a and miR-301 are both significantly downregulated on day 3 and day 5 of adipogenic differentiation in comparison to day 0. Under androgen stimulation, a significant upregulation of miR-130a was detected after 7 days of adipogenesis lasting to day 14, while miR-301 did not change significantly until day 14. Luciferase reporter assays revealed the androgen receptor (AR), adiponectin (ADIPOQ) and tumour necrosis factor alpha (TNFα) as miR-130a target genes. Conclusions: miR-130a is an androgen-regulated microRNA that is downregulated during the early phase of adipogenesis and exerts its functions by regulating AR and ADIPOQ translation. These data may help to identify new signalling pathways associated with the androgen-mediated inhibition of adipogenesis.

miR-135b levels in the peripheral blood serve as a marker associated with acute ischemic stroke

The protective role of microRNA (miR)-135b in cerebral neurons has been previously identified. However, to the best of our knowledge, the involvement of miR-135b in acute ischemic stroke has yet to be elucidated. The present study aimed to investigate the expression profile of miR-135b in peripheral blood obtained from patients with acute ischemic stroke. A total of 76 patients with acute ischemic stroke were selected as the case group, which included 33 cases of aorta atheromatous plague, 19 cases of cardioembolism, 16 cases of small arterial occlusion and 8 cases with unknown causes. In addition, 60 healthy subjects were selected as the control group. Reverse transcription-quantitative PCR was used to measure the expression of miR-135b in the peripheral blood of the patients. The National Institutes of Health Stroke Scale (NIHSS) score was used to evaluate the severity of acute ischemic stroke. The relationship between miR-135b levels and acute stroke was subsequently analyzed. The expression of miR-135b in the peripheral blood of the case group was found to be significantly higher compared with that in the control group. By contrast, the expression levels of miR-135b in the case group did not differ significantly between the different etiology types of acute ischemic stroke. In addition, a significant positive correlation was observed between levels of miR-135b expression and NIHSS scores. Further analysis demonstrated that hypertension, hyperglycemia, platelet count, international normalized ratio and miR-135b were risk factors for acute ischemic stroke. Based on bioinformatics analysis, a conserved binding site for miR-135b was identified in the 3'-untranslated region of the transient receptor potential cation channel subfamily C member 6 (TRPC6). Dual luciferase reporter and western blot analysis showed that TRPC6 was a target gene of miR-135b. In conclusion, data from the present study suggest that elevated expression of miR-135b in the peripheral blood of patients with acute ischemic stroke is closely associated with disease severity.

Effects of ambient ozone exposure on circulating extracellular vehicle microRNA levels in coronary artery disease patients

Exposure to ambient air pollutants such as ozone (O₃) and particulate matter (PM) is associated with increased cardiovascular morbidity and rate of mortality, but the underlying biological mechanisms have yet to be described. Emerging evidence shows that extracellular vehicle (EV) microRNAs (miRNAs) may facilitate cell-to-cell and organ-to-organ communications and play a role in the air pollution-induced cardiovascular effects. This study aims to explore the association between air pollutant exposure and miRNA changes related to cardiovascular diseases. Using a panel study design, 14 participants with coronary artery diseases were enrolled in this study. Each participant had up to 10 clinical visits and their plasma samples were collected and measured for expression of miRNA-21 (miR-21), miR-126, miR-146, miR-150, and miR-155. Mixed effects models adjusted for temperature, humidity, and season were used to examine the association between miRNA levels and exposure to 8-hr O₃ or 24-hr PM_2.5 up to 4 days prior. Results demonstrated that miR-150 expression was positively associated with O₃ exposure at 1-4 days lag and 5day moving average while miR-155 expression tracked with O₃ exposure at lag 0. No significant association was found between miRNA expression and ambient PM_2.5 at any time point. β-blocker and diabetic medication usage significantly modified the correlation between O₃ exposure and miR-150 expression where the link was more prominent among non-users. In conclusion, evidence indicated an association between exposure to ambient O₃ and circulating levels of EV miR-150 and miR-155 was observed. These findings pointed to a future research direction involving miRNA-mediated mechanisms of O₃-induced cardiovascular effects.

From animal models to patients: the role of placental microRNAs, miR-210, miR-126, and miR-148a/152 in preeclampsia

Placental microRNAs (miRNAs) regulate the placental transcriptome and play a pathological role in preeclampsia (PE), a hypertensive disorder of pregnancy. Three PE rodent model studies explored the role of placental miRNAs, miR-210, miR-126, and miR-148/152 respectively, by examining expression of the miRNAs, their inducers, and potential gene targets. This review evaluates the role of miR-210, miR-126, and miR-148/152 in PE by comparing findings from the three rodent model studies with in vitro studies, other animal models, and preeclamptic patients to provide comprehensive insight into genetic components and pathological processes in the placenta contributing to PE. The majority of studies demonstrate miR-210 is upregulated in PE in part driven by HIF-1α and NF-κBp50, stimulated by hypoxia and/or immune-mediated processes. Elevated miR-210 may contribute to PE via inhibiting anti-inflammatory Th2-cytokines. Studies report an up- and downregulation of miR-126, arguably reflecting differences in expression between cell types and its multifunctional capacity. MiR-126 may play a pro-angiogenic role by mediating the PI3K-Akt pathway. Most studies report miR-148/152 family members are upregulated in PE. Evidence suggests they may inhibit DNA methylation of genes involved in metabolic and inflammatory pathways. Given the genetic heterogeneity of PE, it is unlikely that a single placental miRNA is a suitable therapeutic target for all patients. Investigating miRNAs in PE subtypes in patients and animal models may represent a more appropriate approach going forward. Developing methods for targeting placental miRNAs and specific placental cell types remains crucial for research seeking to target placental miRNAs as a novel treatment for PE.

Implication of MicroRNA503 in Brain Endothelial Cell Function and Ischemic Stroke

The role of miR-503 in brain endothelium and ischemic stroke (IS) remains unclear. We aimed to study the relationship between plasma miR-503 and the onset time, severity, subtypes, and von Willebrand Factor (vWF) level in IS patients and to investigate the roles and underlying mechanisms of miR-503 in middle cerebral artery occlusion (MCAO) mice and cultured cerebral vascular endothelial cells (ECs). In MCAO mice, the effects of plasma from acute severe IS patients (ASS) with or without miR-503 antagomir on brain and ECs damage were determined. In cultured human ECs, the effects of miR-503 overexpression or knockdown on the monolayer permeability, apoptosis, ROS, and NO generation were investigated. For mechanism study, the PI3K/Akt/eNOS pathway, cleaved caspase-3, and bcl-2 were analyzed. Results showed that plasma miR-503 was significantly increased in IS patients, especially in acute period and severe cases and subtypes of LAA and TACI, and was positively correlated with vWF. Logistic analysis indicated that miR-503 was an independent risk factor for IS, with the area under curve of 0.796 in ROC analysis. In MCAO mice, ASS pretreatment aggravated neurological injury, BBB damage, brain edema, CBF reduction, and decreased NO production while increased apoptosis and ROS generation in brain ECs, which were partly abolished by miR-503 antagomir. In cultured ECs, miR-503 overexpression and knockdown confirmed its effects on regulating monolayer permeability, cell apoptosis, NO, and ROS generation via PI3K/Akt/eNOS pathway or bcl-2 and cleaved caspase-3 proteins. These together indicate that miR-503 is a promising biomarker and novel therapeutic target for IS.

Downregulation of MiR-218-5p Protects Against Oxygen-Glucose Deprivation/Reperfusion-Induced Injuries of PC12 Cells via Upregulating N-myc Downstream Regulated Gene 4 (NDRG4)

Background

Cerebral ischemia is a major player of acute ischemic stroke (AIS) and mainly caused by blood vessels obstruction-induced reduced blood flow. Furthermore, miR-218-5p level was elevated in patients with AIS compared with controls. The present study investigated the biochemical mechanisms underlying the role of miR-218-5p in AIS in vitro.

Material/Methods

PC12 cells were chosen to establish oxidative-glucose deprivation/re-oxygenation (OGD/R) injury model. The interaction between miR-218-5p and N-myc downstream regulated gene 4 (NDRG4) was evaluated by Luciferase reporter assay. The levels of NDRG4, endothelial nitric oxide synthase (eNOS) and protein related to cell apoptosis were quantitatively analyzed with real-time quantitative polymerase chain reaction (RT-qPCR) or western blotting. Inflammatory cytokines, myeloperoxidase (MPO) and oxidative stress status were measured using specific commercial assay kits. Further, the cells apoptosis was analyzed with flow cytometry assay.

Results

MiR-218-5p level was notably increased in OGD/R injured PC12 cells and directly targeted NDRG4. MiR-218-5p inhibitor significantly inhibited inflammatory cytokines release, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and monocyte chemotactic protein 1 (MCP-1). In addition, miR-218-5p downregulation ameliorated nitric oxide (NO) and eNOS levels and suppressed the inducible nitric oxide synthase (iNOS) expression and cell apoptosis. However, NDRG4 silencing abolished all corrective effects of miR-218-5p inhibitor in OGD/R injured PC12 cells.

Conclusions

Downregulation of miR-218-5p protect against OGDR-induced injuries of PC12 cells through reducing inflammatory cytokines secretion, oxidative stress status, apoptosis rate and maintenance of endovascular homeostasis via upregulating NDRG4. MiR-218-5p may serve as a novel effective biomarker to monitor AIS progression.

Prediction of miRNA interaction with mRNA of stroke candidate genes

BACKGROUND

The role of miRNA in tissue affected by stroke is actively studied, but it remains unclear which miRNAs and target genes are involved in the development of stroke.

METHODS

The MirTarget program defines the following features of a miRNA binding to a mRNA: the binding start site, the location of the binding site in mRNA, the free energy of a miRNA binding with a mRNA, and the interaction schemes of miRNA and mRNA.

RESULTS

The interaction of 6565 miRNAs with mRNAs of stroke candidate genes was determined. The association of the mRNAs of stroke candidate genes with miRNAs depends on the level of gene expression. Some highly expressed candidate genes are targets of miR-619-5p and miR-5095, which have binding sites located on overlapping mRNA nucleotide sequences (clusters). miR-619-5p and miR-5095 bind to mRNA of 15 genes. Clusters for the binding of miR-1273f,d,e are in mRNAs of highly expressed genes. The start sites of miR-1273d and miR-1273e binding in all clusters are in sequences with one and ten nucleotides, respectively. The clusters of multiple miR-574-5p and ID00470.5p-miR binding sites and the clusters of the miR-466, ID01030.3p-miR, and ID00436.3p-miR binding sites are in mRNAs of some genes expressed at low levels.

CONCLUSION

The organization of miRNA binding sites into clusters reduces the length of mRNA and creates competition between miRNAs for binding to mRNA of a target gene. The characteristics of miRNA associations with target genes can be used to recommend markers for a diagnosis of stroke.

miR‑126a‑5p‑Dbp and miR‑31a‑Crot/Mrpl4 interaction pairs crucial for the development of hypertension and stroke

The present study aimed to integrate the mRNA and microRNA (miRNA) expression profiles of spontaneously hypertensive rats (SHR rats) and stroke-prone spontaneously hypertensive rats (SHRSP rats) to screen for potential therapeutic targets for hypertension and stroke. The datasets GSE41452, GSE31457, GSE41453 and GSE53363 were collected from the Gene Expression Omnibus (GEO) database to screen differentially expressed genes (DEGs). The GSE53361 dataset was obtained to analyze differentially expressed miRNAs (DEMs). The DEGs and DEMs were identified between SHR (or SHRSP) rats and normotensive Wistar-Kyoto (WKY) rats using the Linear Models for Microarray (limma) data method. Venn diagrams were used to show the SHR-specific, SHRSP-specific and SHR-SHRSP shared DEGs and DEMs, and these were utilized to construct the protein-protein interaction (PPI) and miRNA-mRNA regulatory networks. The Database for Annotation, Visualization and Integrated Discovery (DAVID) was used to explore the function of the genes. Subsequently, the connectivity Map (CMAP) database was searched to identify small-molecule drugs. Comparisons between the GSE41452-GSE31457-GSE41453 merged and GSE53363 datasets identified 2 SHR-specific, 8 SHRSP-specific and 15 SHR-SHRSP shared DEGs. Function enrichment analysis showed that SHRSP-specific D-box binding PAR bZIP transcription factor (Dbp) was associated with circadian rhythm, and SHR-SHRSP shared carnitine O-octanoyltransferase (Crot) was involved in fatty acid metabolic processes or the inflammatory response via interacting with epoxide hydrolase 2 (EPHX2). SHR-SHRSP shared mitochondrial ribosomal protein L4 (Mrpl4) may exert roles by interacting with the threonine-tRNA ligase, TARS2. The miRNA regulatory network predicted that upregulated Dbp could be regulated by rno-miR-126a-5p, whereas downregulated Crot and Mrpl4 could be modulated by rno-miR-31a. The CMAP database predicted that small-molecule drugs, including botulin, Gly-His-Lys, and podophyllotoxin, may possess therapeutic potential. In conclusion, the present study has identified Dbp, Crot and Mrpl4 as potential targets for the treatment of hypertension and stroke. Furthermore, the expression of these genes may be reversed by the above miRNAs or drugs.

Knockdown of LncRNA H19 Relieves LPS-Induced Damage by Modulating miR-130a in Osteoarthritis

PURPOSE

Osteoarthritis (OA) is a commonly occurring illness without a definitive cure, at present. Long non-coding RNAs (lncRNAs) have been widely confirmed to be involved in the modulation of OA progression. This study aimed to investigate the role and mechanism of lncRNA H19 in OA.

MATERIALS AND METHODS

Abundances of H19 and microRNA-130a (miR-130a) in lipopolysaccharide (LPS)-treated C28/I2 cells were measured by reverse-transcription quantitative PCR (RT-qPCR). CCK-8 and flow cytometry analyses were carried out to assess cell viability and apoptosis. Starbase online software was used to predict the putative binding sites between H19 and miR-130a. Luciferase reporter, RNA pull down, and RT-qPCR were performed to analyze the true interaction between H19 and miR-130a.

RESULTS

A notably dose-dependent elevation of H19 levels was observed in LPS-treated C28/I2 cells. Knockdown of H19 ameliorated the injury of LPS-induced C28/I2 cells, reflected by induced viability, decreased apoptosis, and reduced inflammatory factor secretions. Moreover, H19 negatively regulated the expression of miR-130a via acting as a molecular sponge for miR-130a. The stimulatory effects of H19 on cell damage were abolished following the restoration of miR-130a.

CONCLUSION

LncRNA H19 aggravated the injury of LPS-induced C28/I2 cells by sponging miR-130a, hinting a novel regulatory mechanism and a potential therapeutic target for OA.

MiRNA-27b Regulates Angiogenesis by Targeting AMPK in Mouse Ischemic Stroke Model

Stroke is a leading cause of mortality and serious disability worldwide with limited treatment options. Angiogenesis has been reported to be involved in post-stroke recovery. Although the molecular mechanisms that regulate angiogenesis remain ambiguous, microRNAs have emerged as effective regulators of angiogenesis, involved in neurological function outcome. The present study aims to investigate the regulatory effects of miRNA-27b on post-stroke angiogenesis. In primary cultured brain microvascular endothelial cells (BMECs), the inhibition of miRNA-27b induced the activation of adenosine monophosphate-activated protein kinase (AMPK), which increased tube formation and migration. This action was attenuated when AMPKα2 was knocked down. Mice were subjected to middle cerebral artery occlusion (MCAo) surgery and administrated with Lentivirus miR-27b inhibitor. Enhanced angiogenesis in ischemic boundary zone (IBZ) was observed, and the neurological outcome during the entire study period was improved. The number of phosphate-AMPKα2⁺ cells that co-expressed endothelial cell marker CD31 was significantly increased. Taken together, the present study demonstrated that downregulated miRNA-27b promoted recovery after ischemic stroke via AMPK stimulus.