Manifestations and Outcomes of Intracerebral Hemorrhage During the COVID-19 Pandemic in China: Multicenter, Longitudinal Cohort Study.

BACKGROUND: The COVID-19 pandemic has inevitably affected the distribution of medical resources, and epidemic lockdowns have had a significant impact on the nursing and treatment of patients with other acute diseases, including intracerebral hemorrhage (ICH). OBJECTIVE: This study aimed to investigate how the COVID-19 pandemic affected the manifestations and outcomes of patients with ICH. METHODS: Patients with acute ICH before (December 1, 2018-November 30, 2019) and during (December 1, 2019-November 30, 2020) the COVID-19 pandemic at 31 centers in China from the Chinese Cerebral Hemorrhage: Mechanism and Intervention (CHEERY) study were entered into the analysis. Demographic information and clinical manifestations and outcomes were collected and compared between the 2 groups. RESULTS: From December 1, 2018, to November 30, 2020, a total of 3460 patients with ICH from the CHEERY study were enrolled and eventually analyzed. The results showed that during the COVID-19 pandemic, patients with ICH were more likely to be older (P<.001) with a history of ischemic stroke (P=.04), shorter time from onset to admission (P<.001), higher blood pressure (P<.001), higher fasting blood glucose (P=.003), larger hematoma volume (P<.001), and more common deep ICH (P=.01) and intraventricular hemorrhage (P=.02). These patients required more intensive care unit treatment (P<.001) and preferred to go to the hospital directly rather than call an ambulance (P<.001). In addition, the COVID-19 pandemic was associated with an increased risk of pulmonary infection during hospitalization (adjusted risk ratio [RRadjusted] 1.267, 95% CI 1.065-1.509), lower probability of a 3-month good outcome (RRadjusted 0.975, 95% CI 0.956-0.995), and a higher probability of in-hospital (RRadjusted 3.103, 95% CI 2.156-4.465), 1-month (RRadjusted 1.064, 95% CI 1.042-1.087), and 3-month (RRadjusted 1.069, 95% CI 1.045-1.093) mortality. CONCLUSIONS: Our study indicated that the cloud of COVID-19 has adversely impacted the presentation and outcomes of ICH. Medical workers may pay more attention to patients with ICH, while the public should pay more attention to hypertension control and ICH prevention. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900020872; https://www.chictr.org.cn/showprojEN.html?proj=33817.

Cell Heterogeneity Uncovered by Single-Cell RNA Sequencing Offers Potential Therapeutic Targets for Ischemic Stroke.

Ischemic stroke is a detrimental neurological disease characterized by an irreversible infarct core surrounded by an ischemic penumbra, a salvageable region of brain tissue. Unique roles of distinct brain cell subpopulations within the neurovascular unit and peripheral immune cells during ischemic stroke remain elusive due to the heterogeneity of cells in the brain. Single-cell RNA sequencing (scRNA-seq) allows for an unbiased determination of cellular heterogeneity at high-resolution and identification of cell markers, thereby unveiling the principal brain clusters within the cell-type-specific gene expression patterns as well as cell-specific subclusters and their functions in different pathways underlying ischemic stroke. In this review, we have summarized the changes in differentiation trajectories of distinct cell types and highlighted the specific pathways and genes in brain cells that are impacted by stroke. This review is expected to inspire new research and provide directions for investigating the potential pathological mechanisms and novel treatment strategies for ischemic stroke at the level of a single cell.

Inhibition of Sema4D/PlexinB1 signaling alleviates vascular dysfunction in diabetic retinopathy.

Diabetic retinopathy (DR) is a common complication of diabetes and leads to blindness. Anti-VEGF is a primary treatment for DR. Its therapeutic effect is limited in non- or poor responders despite frequent injections. By performing a comprehensive analysis of the semaphorins family, we identified the increased expression of Sema4D during oxygen-induced retinopathy (OIR) and streptozotocin (STZ)-induced retinopathy. The levels of soluble Sema4D (sSema4D) were significantly increased in the aqueous fluid of DR patients and correlated negatively with the success of anti-VEGF therapy during clinical follow-up. We found that Sema4D/PlexinB1 induced endothelial cell dysfunction via mDIA1, which was mediated through Src-dependent VE-cadherin dysfunction. Furthermore, genetic disruption of Sema4D/PlexinB1 or intravitreal injection of anti-Sema4D antibody reduced pericyte loss and vascular leakage in STZ model as well as alleviated neovascularization in OIR model. Moreover, anti-Sema4D had a therapeutic advantage over anti-VEGF on pericyte dysfunction. Anti-Sema4D and anti-VEGF also conferred a synergistic therapeutic effect in two DR models. Thus, this study indicates an alternative therapeutic strategy with anti-Sema4D to complement or improve the current treatment of DR.

Microglia-derived TNF-α mediates endothelial necroptosis aggravating blood brain-barrier disruption after ischemic stroke.

Endothelium (EC) is a key component of blood-brain barrier (BBB), and has an important position in the neurovascular unit. Its dysfunction and death after cerebral ischemic/reperfusion (I/R) injury not only promote evolution of neuroinflammation and brain edema, but also increase the risk of intracerebral hemorrhage of thrombolytic therapies. However, the mechanism and specific interventions of EC death after I/R injury are poorly understood. Here we showed that necroptosis was a mechanism underlying EC death, which promoted BBB breakdown after I/R injury. Treatment of rats with receptor interacting protein kinase 1 (RIPK1)-inhibitor, necrostatin-1 reduced endothelial necroptosis and BBB leakage. We furthermore showed that perivascular M1-like microglia-induced endothelial necroptosis leading to BBB disruption requires tumor necrosis factor-α (TNF-α) secreted by M1 type microglia and its receptor, TNF receptor 1 (TNFR1), on endothelium as the primary mediators of these effects. More importantly, anti-TNFα (infliximab, a potent clinically used drug) treatment significantly ameliorate endothelial necroptosis, BBB destruction and improve stroke outcomes. Our data identify a previously unexplored role for endothelial necroptosis in BBB disruption and suggest infliximab might serve as a potential drug for stroke therapy.

Sema3E/PlexinD1 signaling inhibits postischemic angiogenesis by regulating endothelial DLL4 and filopodia formation in a rat model of ischemic stroke.

Angiogenesis is a crucial defense response to hypoxia that regulates the process of raising the promise of long-term neurologic recovery during the management of stroke. A high expression of antiangiogenic factors leads to the loss of neovascularization capacity in pathologic conditions. We have previously documented an impairment of the cerebral vessel perfusion and neovascularization in the cortex neighboring the stroke-induced lesion, which was accompanied by an activation of semaphorin 3E (Sema3E)/PlexinD1 after ischemic stroke. In this study, we employed micro-optical sectioning tomography to fully investigate the details of the vascular pattern, including the capillaries. We found that after transient middle cerebral artery occlusion, inhibiting PlexinD1 signaling led to an organized recovery of the vascular network in the ischemic area. We then further explored the possible mechanisms. In vivo, Sema3E substantially decreased dynamic delta-like 4 (DLL4) expression. In cultured brain microvascular endothelial cells, Sema3E down-regulated DLL4 expression via inhibiting Ras-related C3 botulinum toxin substrate 1-induced JNK phosphorylation. At the microcosmic level, Sema3E/PlexinD1 signaling promoted F-actin disassembly and focal adhesion reduction by activating the small guanosine triphosphatase Ras homolog family member J by releasing RhoGEF Tuba from direct binding to PlexinD1, thus mediating endothelial cell motility and filopodia retraction. Our study reveals that Sema3E/PlexinD1 signaling, which suppressed endothelial DLL4 expression, cell motility, and filopodia formation, is expected to be a novel druggable target for angiogenesis during poststroke progression.-Zhou, Y.-F., Chen, A.-Q., Wu, J.-H., Mao, L., Xia, Y.-P., Jin, H.-J., He, Q.-W., Miao, Q. R., Yue, Z.-Y., Liu, X.-L., Huang, M., Li, Y.-N., Hu, B. Sema3E/PlexinD1 signaling inhibits postischemic angiogenesis by regulating endothelial DLL4 and filopodia formation in a rat model of ischemic stroke.

Semaphorin-3A protects against neointimal hyperplasia after vascular injury.

BACKGROUND: Neointimal hyperplasia is a prominent pathological event during in-stent restenosis. Phenotype switching of vascular smooth muscle cells (VSMCs) from a differentiated/contractile to a dedifferentiated/synthetic phenotype, accompanied by migration and proliferation of VSMCs play an important role in neointimal hyperplasia. However, the molecular mechanisms underlying phenotype switching of VSMCs have yet to be fully understood. METHODS: The mouse carotid artery ligation model was established to evaluate Sema3A expression and its role during neointimal hyperplasia in vivo. Bioinformatics analysis, chromatin immunoprecipitation (ChIP) assays and promoter-luciferase reporter assays were used to examine regulatory mechanism of Sema3A expression. SiRNA transfection and lentivirus infection were performed to regulate Sema3A expression. EdU assays, Wound-healing scratch experiments and Transwell migration assays were used to assess VSMC proliferation and migration. FINDINGS: In this study, we found that semaphorin-3A (Sema3A) was significantly downregulated in VSMCs during neointimal hyperplasia after vascular injury in mice and in human atherosclerotic plaques. Meanwhile, Sema3A was transcriptionally downregulated by PDGF-BB via p53 in VSMCs. Furthermore, we found that overexpression of Sema3A inhibited VSMC proliferation and migration, as well as increasing differentiated gene expression. Mechanistically, Sema3A increased the NRP1-plexin-A1 complex and decreased the NRP1-PDGFRß complex, thus inhibiting phosphorylation of PDGFRß. Moreover, we found that overexpression of Sema3A suppressed neointimal hyperplasia after vascular injury in vivo. INTERPRETATION: These results suggest that local delivery of Sema3A may act as a novel therapeutic option to prevent in-stent restenosis.

Acute stroke patients' knowledge of stroke at discharge in China: a cross-sectional study.

OBJECTIVES: A good mastery of stroke-related knowledge can be of great benefit in developing healthy behaviours. This study surveyed the knowledge about stroke and influencing factors among patients with acute ischaemic stroke (AIS) at discharge in a Chinese province. METHODS: A cross-section study was conducted from November 1, 2014 to January 31, 2015. A total of 1531 AIS patients in Hubei Province completed a questionnaire at discharge. Multivariate linear regression was used to identify the influencing factors of their knowledge of stroke. RESULTS: About 31.2% of the respondents did not know that stroke is caused by blockage or rupture of cerebral blood vessels and 20.3% did not realise they need immediate medical attention after onset. Approximately 50% did not know that sudden blurred vision, dizziness, headache and unconsciousness are the warning signs of stroke. Over 40% were not aware of the risk factors of the condition, such as hypertension, hyperlipidaemia, diabetes mellitus, smoking and obesity. Over 20% had no idea that they need long-term medication and strict control of blood pressure, blood lipids and blood sugar. Their knowledge levels were correlated with regions of residence (P < 0.0001), socioeconomic status (P < 0.05), physical condition (P < 0.01), previous stroke (P < 0.0001) and family members and friends having had a stroke (P < 0.01). CONCLUSIONS: Most AIS patients in Hubei Province, China, had little knowledge of stroke at discharge. Further efforts should be devoted to strengthening the in-hospital education of stroke patients, especially those with a low income and those from rural areas.

Sema3E/PlexinD1 inhibition is a therapeutic strategy for improving cerebral perfusion and restoring functional loss after stroke in aged rats.

Brain tissue survival and functional recovery after ischemic stroke greatly depend on cerebral vessel perfusion and functional collateral circulation in the ischemic area. Semaphorin 3E (Sema3E), one of the class 3 secreted semaphorins, has been demonstrated to be a critical regulator in embryonic and postnatal vascular formation via binding to its receptor PlexinD1. However, whether Sema3E/PlexinD1 signaling is involved in poststroke neovascularization remains unknown. To determine the contribution of Sema3E/PlexinD1 signaling to poststroke recovery, aged rats (18 months) were subjected to a transient middle cerebral artery occlusion. We found that depletion of Sema3E/PlexinD1 signaling with lentivirus-mediated PlexinD1-specific-shRNA improves tissue survival and functional outcome. Sema3E/PlexinD1 inhibition not only increases cortical perfusion but also ameliorates blood-brain barrier damage, as determined by positron emission tomography and magnetic resonance imaging. Mechanistically, we demonstrated that Sema3E suppresses endothelial cell proliferation and angiogenic capacity. More importantly, Sema3E/PlexinD1 signaling inhibits recruitment of pericytes by decreasing production of platelet derived growth factor-BB in endothelial cells. Overall, our study revealed that inhibition of Sema3E/PlexinD1 signaling in the ischemic penumbra, which increases both endothelial angiogenic capacity and recruitment of pericytes, contributed to functional neovascularization and blood-brain barrier integrity in the aged rats. Our findings imply that Sema3E/PlexinD1 signaling is a novel therapeutic target for improving brain tissue survival and functional recovery after ischemic stroke.

Sema4D/PlexinB1 inhibition ameliorates blood-brain barrier damage and improves outcome after stroke in rats.

The inflammatory process in stroke is the major contributor to blood-brain barrier (BBB) breakdown. Previous studies indicated that semaphorin 4D (Sema4D), an axon guidance molecule, initiated inflammatory microglial activation and disrupted endothelial function in the CNS. However, whether Sema4D disrupts BBB integrity after stroke remains unclear. To study the effect of Sema4D on BBB disruption in stroke, rats were subjected to transient middle cerebral artery occlusion and targeted injection of lentivirus-mediated clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene disruption of PlexinB1. We found that Sema4D synchronously increased with BBB permeability and accumulated in the perivascular area after stroke. Suppressing Sema4D/PlexinB1 signaling in the periinfarct cortex significantly decreased BBB permeability as detected by MRI and fibrin deposition, and thereby improved stroke outcome. In vitro, we confirmed that Sema4D disrupted BBB integrity and endothelial tight junctions. Moreover, we found that Sema4D induced pericytes to acquire a CD11b-positive phenotype and express proinflammatory cytokines. In addition, Sema4D inhibited AUF1-induced proinflammatory mRNA decay effect. Taken together, our data provides evidence that Sema4D disrupts BBB integrity and promotes an inflammatory response by binding to PlexinB1 in pericytes after transient middle cerebral artery occlusion. Our study indicates that Sema4D may be a novel therapeutic target for treatment in the acute phase of stroke.-Zhou, Y.-F., Li, Y.-N., Jin, H.-J., Wu, J.-H., He, Q.-W., Wang, X.-X., Lei, H., Hu, B. Sema4D/PlexinB1 inhibition ameliorates blood-brain barrier damage and improves outcome after stroke in rats.

MicroRNA-130a regulates cerebral ischemia-induced blood-brain barrier permeability by targeting Homeobox A5.

Blood-brain barrier (BBB) disruption plays a critical role in brain injury induced by cerebral ischemia, and preserving BBB integrity during ischemia could alleviate cerebral injury. We examined the role of miR-130a in ischemic BBB disruption by using models of rat middle cerebral artery occlusion and cell oxygen-glucose deprivation. We found that ischemia significantly increased microRNA-130a (miR-130a) level and that miR-130a was predominantly from brain microvascular endothelial cells. Antagomir-130a, an antagonist of miR-130a, could attenuate brain edema, lower BBB permeability, reduce infarct volume, and improve neurologic function. MiR-130a overexpression induced by miR-130a mimic increased monolayer permeability, and intercellular inhibition of miR-130a by a miR-130a inhibitor suppressed oxygen-glucose deprivation-induced increase in monolayer permeability. Moreover, dual luciferase reporter system showed that Homeobox A5 was the direct target of miR-130a. MiR-130a, by inhibiting Homeobox A5 expression, could down-regulate occludin, thereby increasing BBB permeability. Our results suggested that miR-130a might be implicated in ischemia-induced BBB dysfunction and serve as a target for the treatment of ischemic stroke.-Wang, Y., Wang, M.-D., Xia, Y.-P., Gao, Y., Zhu, Y.-Y., Chen, S.-C., Mao, L., He, Q.-W., Yue, Z.-Y., Hu, B. MicroRNA-130a regulates cerebral ischemia-induced blood-brain barrier permeability by targeting Homeobox A5.

Alleviative effects of fluoxetine on depressive-like behaviors by epigenetic regulation of BDNF gene transcription in mouse model of post-stroke depression.

Fluoxetine, one of the selective serotonin reuptake inhibitor (SSRI) antidepressants, has been thought to be effective for treating post-stroke depression (PSD). Recent work has shown that fluoxetine may exert an antidepressive effect through increasing the level of brain-derived neurotrophic factor (BDNF), but the underlying mechanism still remains unclear. In the present study, we successfully established the PSD model using male C57BL/6 J mice by photothrombosis of the left anterior cortex combined with isolatied-housing conditions. In the process, we confirmed that fluoxetine could improve the depression-like behaviors of PSD mice and upregulate the expression of BDNF in the hippocampus. However, depletion of BDNF by transfecting lentivirus-derived shBDNF in hippocampus suppressed the effect of fluoxetine. Furthermore, we demonstrated the epigenetic mechanisms involved in regulation of BDNF expression induced by fluoxetine. We found a statistically significant increase in DNA methylation at specific CpG sites (loci 2) of Bdnf promoter IV in the hippocampus of PSD mice. We also found that fluoxetine treatment could disassociate the MeCP2-CREB-Bdnf promoter IV complex via phosphorylation of MeCP2 at Ser421 by Protein Kinase A (PKA). Our research highlighted the importance of fluoxetine in regulating BDNF expression which could represent a potential strategy for preventing PSD.

Administration of sonic hedgehog protein induces angiogenesis and has therapeutic effects after stroke in rats.

The Sonic hedgehog (Shh) signaling pathway is recapitulated in response to ischemic injury. Here, we investigated the clinical implications of Shh protein in the ischemic stroke and explored the underlying mechanism. Intracerebroventricular injection of Shh, Cyclopamine, or anti-vascular endothelial growth factor (VEGF) was performed immediately after permanent middle cerebral artery occlusion (pMCAO) surgery and lasted for 7days (d). Phosphate-buffered saline (PBS) was used as control. Neurological deficits and infarct volume were examined 7d after pMCAO. Microvascular density with fluorescein-iso-thiocyanate (FITC) assay and double staining with CD31 and Ki-67 was measured at 7d. To observe in vitro angiogenesis, rat brain microvascular endothelial cells (RBMECs) were incubated under oxygen glucose deprivation (OGD) for 6h (h) and treated with Shh/anti-VEGF. We found that (1) Shh improved neurological scores and reduced infarct volume, which was blocked by Cyclopamine, (2) Shh improved the microvascular density and promoted angiogenesis and neuron survival in the ischemic boundary zone, (3) Shh enhanced VEGF expression and VEGF antibody could reverse angiogenic and protective effect of Shh in vivo and in vitro. These data demonstrate that the administration of Shh protein could protect brain from ischemic injury, in part by promoting angiogenic repair.

P2Y12 Promotes Migration of Vascular Smooth Muscle Cells Through Cofilin Dephosphorylation During Atherogenesis.

OBJECTIVE: P2Y12 is a well-recognized receptor expressed on platelets and the target of thienopyridine-type antiplatelet drugs. However, recent evidence suggests that P2Y12 expressed in vessel wall plays a role in atherogenesis, but the mechanisms remain elusive. In this study, we examined the molecular mechanisms of how vessel wall P2Y12 mediates vascular smooth muscle cells (VSMCs) migration and promotes the progression of atherosclerosis. APPROACH AND RESULTS: Using a high-fat diet-fed apolipoprotein E-deficient mice model, we found that the expression of P2Y12 in VSMCs increased in a time-dependent manner and had a linear relationship with the plaque area. Moreover, administration of P2Y12 receptor antagonist for 12 weeks caused significant reduction in atheroma and decreased the abundance of VSMCs in plaque. In cultured VSMCs, we found that activation of P2Y12 receptor inhibited cAMP/protein kinase A signaling pathway, which induced cofilin dephosphorylation and filamentous actin disassembly, thereby enhancing VSMCs motility and migration. In addition, the number of P2Y12-positive VSMCs was decreased in the carotid artery plaque from patients receiving clopidogrel. CONCLUSIONS: Vessel wall P2Y12 receptor, which promotes VSMCs migration through cofilin dephosphorylation, plays a critical role in the development of atherosclerotic lesion and may be used as a therapeutic target for atherosclerosis.

Inhibiting the Migration of M1 Microglia at Hyperacute Period Could Improve Outcome of tMCAO Rats.

AIM: To study whether inhibiting microglia migration to the ischemic boundary zone (IBZ) at the early phase could improve neurological outcomes after stroke. METHODS: The transient middle cerebral artery occlusion (tMCAO) was induced in adult male Sprague-Dawley rats. AMD3100, a highly selective CXC-chemokine receptor 4 (CXCR4) antagonist, was used to inhibit microglia migration. Microglia was evaluated by immunofluorescence in vivo, and their migration was tested by transwell assay in vitro. Expressions of cytokines were detected by real-time PCR. Infarct volume was determined by triphenyltetrazolium chloride (TTC) staining. Functional recovery of tMCAO rats was evaluated by behavior tests. RESULTS: M1 microglia in the IBZ was rapidly increased within 3 days after tMCAO, accompanied with enhanced expression of CXCR4. Chemokine CXC motif chemokine ligand 12 (CXCL12) was also increased in the IBZ. And AMD3100 could obviously decline M1 microglia migration induced by CXCL12 and secretion of related inflammatory cytokines in the IBZ after stroke. This was accompanied by significant attenuated infarct volume and improved neurological outcomes. CONCLUSION: This study confirms the protective efficacy of inhibiting microglia migration at the hyperacute phase as a therapeutic strategy for ischemic stroke in tMCAO model of rats, and its therapeutic time window could last for 24 h after cerebral ischemia reperfusion.

MiR-181b Antagonizes Atherosclerotic Plaque Vulnerability Through Modulating Macrophage Polarization by Directly Targeting Notch1.

Atherosclerotic plaque vulnerability is the major cause for acute stroke and could be regulated by macrophage polarization. MicroRNA-181b (miR-181b) was involved in macrophage differential. Here, we explore whether miR-181b could regulate atherosclerotic plaque vulnerability by modulating macrophage polarization and the underline mechanisms. In acute stroke patients with atherosclerotic plaque, we found that the serum level of miR-181b was decreased. Eight-week apolipoprotein E knockout (ApoE-/-) mice were randomly divided into three groups (N = 10): mice fed with normal saline (Ctrl), mice fed with high-fat diet, and tail vein injection with miRNA agomir negative control (AG-NC)/miR-181b agomir (181b-AG, a synthetic miR-181b agonist). We found that the serum level of miR-181b in AG-NC group was lower than that in Ctrl group. Moreover, 181b-AG could upregulate miR-181b expression, reduce artery burden and attenuate atherosclerotic plaque vulnerability by modulating macrophage polarization. In RAW264.7 cells treated with oxidized low-density lipoprotein (ox-LDL), we found miR-181b could reverse the function of ox-LDL on M1/M2 markers at both mRNA and protein levels. Furthermore, by employing luciferase reporter assay, we found that Notch1 was a direct target of miR-181b and could be regulated by miR-181b in vivo and in vitro. Finally, inhibition of Notch1 could abolish the function of downregulating miR-181b on increasing M2 phenotype macrophages. Our study demonstrates that administration of miR-181b could reduce atherosclerotic plaque vulnerability partially through modulating macrophage phenotype by directly targeting Notch1.

MiR-150 Regulates Poststroke Cerebral Angiogenesis via Vascular Endothelial Growth Factor in Rats.

AIMS: Angiogenesis is a harmonized target for poststroke recovery. Therefore, exploring the mechanisms involved in angiogenesis after stroke is vitally significant. In this study, we are reporting a miR-150-based mechanism underlying cerebral poststroke angiogenesis. METHODS: Rat models of middle cerebral artery occlusion (MCAO) and cell models of oxygen-glucose deprivation were conducted. Capillary density, tube formation, cell proliferation, and cell migration were measured by FITC-dextran assay, matrigel assay, Ki-67 staining, and wound healing assay, respectively. The expression of miR-150 and vascular endothelial growth factor (VEGF) was, respectively, measured by RT-PCR and Western blotting. Dual-luciferase assay was conducted to confirm the binding sites between miR-150 and VEGF. RESULTS: We found that miR-150 expression in the brain and serum of rats subjected to cerebral ischemia, and in oxygen-glucose-deprived brain microvascular endothelial cells (BMVECs) and astrocytes. Upregulation of miR-150 expression could decrease vascular density of infarct border zone in rat after MCAO and decrease tube formation, proliferation, and migration of BMVECs. We also found that miR-150 could negatively regulate the expression of VEGF, and VEGF was confirmed to be a direct target of miR-150. Moreover, VEGF mediated the function of miR-150 on tube formation, proliferation, and migration of BMVECs. CONCLUSIONS: Our data suggested that miR-150 could regulate cerebral poststroke angiogenesis in rats through VEGF.

MicroRNA-150 regulates blood-brain barrier permeability via Tie-2 after permanent middle cerebral artery occlusion in rats.

The mechanism of blood-brain barrier (BBB) disruption, involved in poststroke edema and hemorrhagic transformation, is important but elusive. We investigated microRNA-150 (miR-150)-mediated mechanism in the disruption of BBB after stroke in rats. We found that up-regulation of miR-150 increased permeability of BBB as detected by MRI after permanent middle cerebral artery occlusion in vivo as well as increased permeability of brain microvascular endothelial cells after oxygen-glucose deprivation in vitro. The expression of claudin-5, a key tight junction protein, was decreased in the ischemic boundary zone after up-regulation of miR-150. We found in brain microvascular endothelial cells that overexpression of miR-150 decreased not only cell survival rate but also the expression levels of claudin-5 after oxygen-glucose deprivation. With dual-luciferase assay, we confirmed that miR-150 could directly regulate the angiopoietin receptor Tie-2. Moreover, silencing Tie-2 with lentivirus-delivered small interfering RNA reversed the effect of miR-150 on endothelial permeability, cell survival, and claudin-5 expression. Furthermore, poststroke treatment with antagomir-150, a specific miR-150 antagonist, contributed to BBB protection, infarct volume reduction, and amelioration of neurologic deficits. Collectively, our findings suggested that miR-150 could regulate claudin-5 expression and endothelial cell survival by targeting Tie-2, thus affecting the permeability of BBB after permanent middle cerebral artery occlusion in rats, and that miR-150 might be a potential alternative target for the treatment of stroke.-Fang, Z., He, Q.-W., Li, Q., Chen, X.-L., Baral, S., Jin, H.-J., Zhu, Y.-Y., Li, M., Xia, Y.-P., Mao, L., Hu, B. MicroRNA-150 regulates blood-brain barrier permeability via Tie-2 after permanent middle cerebral artery occlusion in rats.

High Serum MiR-130a Levels Are Associated with Severe Perihematomal Edema and Predict Adverse Outcome in Acute ICH.

The development and/or progression of perihematomal edema (PHE) in patients with acute spontaneous intracerebral hemorrhage (ICH) vary substantially with different individuals. Although hematoma volume is a useful indicator for predicting PHE, its predictive power was not good at the early stage of ICH. Better predictors are urgently needed. In this study, we found that miR-130a was elevated in the serum of ICH patients and was an independent indicator positively associated with PHE volume within the first 3 days after onset. The R (2) was further evaluated when it is used in combination with hematoma mass. Serum miR-130a levels were associated with clinical outcome (National Institute of Health Stroke Scale (NIHSS) scores at day 14 and modified Rankin Scale (mRS) scores at day 90) only in patients with deep hematoma. Moreover, miR-130a was significantly increased in rat serum and perihematomal tissues and was in line with the change in brain edema. MiR-130a inhibitors reduced brain edema, blood-brain barrier (BBB) permeability, and increased neurological deficit scores, and miR-130a mimics increased monolayer permeability. Thrombin-stimulated brain microvascular endothelial cells (BMECs) were a main source of miR-130a under ICH. In the experimental model, the elevated miR-130a level was accompanied by the decreased caveolin-1 and increased matrix metalloproleinase (MMP)-2/9. Meanwhile, caveolin-1 (cav-1) was reduced by miR-130a mimics, accompanied by an increase in MMP-2/9 expression. The upregulated MMP-2/9 was then downregulated by cavtratin, a cav-1 scaffolding domain peptide. This regulation mechanism was authenticated in a thrombin-induced cellular ICH model. Our results suggest that serum miR-130a may serve as a useful early biomarker for monitoring post-ICH PHE and predicting prognosis and may be helpful in the decision-making of individualized therapy.

CYP2C19 polymorphism and clinical outcomes among patients of different races treated with clopidogrel: A systematic review and meta-analysis.

Several studies have investigated the association between CYP2C19 polymorphism and clinical outcomes of patients treated with clopidogrel, but few have noticed the difference in association between Westerners and Asians. We searched MEDLINE, EMBASE and Cochrane Library database and conducted a systematic review and meta-analysis. Thirty-six studies involving 44 655 patients with coronary artery disease (CAD) treated with clopidogrel were included, of which more than 68% had undergone percutaneous coronary intervention (PCI). The primary outcome of our interest was the recurrence of major adverse cardiovascular events (MACE) in those CAD patients. Firstly, we found that the distribution of reduced-function CYP2C19 allele varied between Westerners and Asians. Among Asians, 1 and 2 reduced-function CYP2C19 mutant allele carriers accounted for 42.5% and 10%, respectively. While among Westerners, 1 and 2 reduced-function CYP2C19 mutant allele carriers accounted for 25.5% and 2.4%, respectively. Secondly, the impact of CYP2C19 polymorphism on clinical outcomes of patients treated with clopidogrel varied with races. Among Asians, only 2 reduced-function CYP2C19 mutant allele carriers had the reduced effect of clopidogrel. And the reduced effect was significant only after the 30th day of treatment. While among Westerners, both 1 and 2 reduced-function CYP2C19 allele carriers had the reduced effect, and it mainly occurred within the first 30 days. Thirdly, the safety of clopidogrel was almost the same among races. Reduced-function allele non-carriers had higher risk for total bleeding but did not have higher risk for major bleeding. It is suggested that CYP2C19 polymorphism affects the efficacy of clopidogrel differently among Westerners and Asians.

Endogenous endothelial progenitor cells participate in neovascularization via CXCR4/SDF-1 axis and improve outcome after stroke.

AIM: To study whether endogenous endothelial progenitor cells (EPCs) are involved in neovascularization after stroke. MATERIALS AND METHODS: Animal stroke models were established by subjecting male SD rats to permanent middle cerebral artery occlusion (pMCAO). Vessels in ischemic boundary zone (IBZ) were stained with antibody against laminin at 1 to 21 days after pMCAO. EPCs and newly formed vessels were identified by staining with special markers. After inhibiting recruitment of EPCs with AMD3100, a CXCR4 antagonist, endogenous EPCs, capillary density, cerebral blood flow (CBF) in IBZ, and neurobehavioral functions were assessed by staining, FITC-dextran, laser-Doppler perfusion monitor, and neurologic severity score. RESULTS: After pMCAO, vessels were found in IBZ at day 3, reaching a peak at day 14. The change in number of laminin-positive cells showed a similar pattern with that of vessels. Apart from few endothelial cells, most of laminin-positive cells were endogenous EPCs. After treatment with AMD3100, the number of endogenous EPCs, capillary density, and CBF in IBZ were significantly reduced, and neurobehavioral functions were worse as compared with the normal saline group. CONCLUSIONS: Our findings suggested that endogenous EPCs participated in the neovascularization via CXCR4/SDF-1 axis after pMCAO and mobilizing endogenous EPCs could be a treatment alternative for stroke.