Prognostic value of neutrophil to lymphocyte ratio in acute ischemic stroke after reperfusion therapy.

The purpose of this study was to investigate whether baseline neutrophil to lymphocyte ratio (NLR) was an independent predictor for early symptomatic intracranial hemorrhage (sICH), poor functional outcome and mortality at 3 months after reperfusion therapy in acute ischemic stroke (AIS) patients. Using PubMed and EMBASE, we searched for literature published before January 19th, 2019. Two reviewers independently confirmed each study's eligibility, assessed risk of bias, and extracted data. One reviewer combined studies using random effects meta-analysis. 9 studies with 3651 patients were pooled in the meta-analysis. Overall, baseline NLR levels were greater in patients with poor outcome. The standardized mean difference (SMD) in the NLR levels between patients with poor functional outcome (mRS > 2) and good functional outcome (mRS ≤ 2) was 0.54 units (95% credible interval [CI] [0.38, 0.70]). Heterogeneity test showed that there were significant differences between individual studies (p = 0.02; I2 = 72.8%). The NLR levels were associated with sICH in four included studies (n = 2003, SMD = 0.78, 95% [CI] [0.18, 1.38], I2 = 73.9%). Higher NLR levels were positively correlated with 3-month mortality (n = 1389, ES = 1.71, 95% CI [1.01,2.42], p < 0.01, I2 = 0%) when data were used as categorical variables. Our meta-analysis suggests that increased NLR levels are positively associated with greater risk of sICH, 3-month poor functional outcome and 3-month mortality in AIS patients undergoing reperfusion treatments. Although there are some deficits in this study, it may be feasible to predict the prognosis of reperfusion therapy in AIS patients with NLR levels.

Synergistic inflammatory signaling by cGAS may be involved in the development of atherosclerosis.

Inappropriate activation or overactivation of cyclic GMP-AMP synthase (cGAS) by double-stranded deoxyribonucleic acid (dsDNA) initiates a regulatory signaling cascade triggering a variety of inflammatory responses, which are a great threat to human health. This study focused on identifying the role of cGAS in atherosclerosis and its potential mechanisms. The relationship between cGAS and atherosclerosis was identified in an ApoE -/- mouse model. Meanwhile, RNA sequencing (RNA-seq) analysis of the underlying mechanisms of atherosclerosis in RAW264.7 macrophages treated with cGAS inhibition was conducted. Results showed that cGAS was positively correlated with atherosclerotic plaque area, and was mainly distributed in macrophages. RNA-seq analysis revealed that inflammatory response, immune response and cytokine-cytokine receptor interaction may play important roles in the development of atherosclerosis. Real-time quantitative polymerase chain reaction (RT-qPCR) results showed that the expression of the pro-inflammatory factors, signal transducer and activator of transcription (Stat), interferon regulatory factor (Irf), toll-like receptors (Tlrs), and type I interferons (Ifns) were synergistically reduced when cGAS was inhibited. Furthermore, cGAS inhibition significantly inhibited RAW264.7 macrophage M1 polarization. These results demonstrate that cGAS may contribute to the development of atherosclerosis through synergistic inflammatory signaling of TLRs, STAT/IRF as well as IFNs, leading to macrophage M1 polarization.

Exosomal CagA derived from Helicobacter pylori-infected gastric epithelial cells induces macrophage foam cell formation and promotes atherosclerosis.

BACKGROUND: Seroepidemiological studies have highlighted a positive relation between CagA-positive Helicobacter pylori (H. pylori), atherosclerosis and related clinic events. However, this link has not been well validated. The present study was designed to explore the role of H. pylori PMSS1 (a CagA-positive strain that can translocate CagA into host cells) and exosomal CagA in the progression of atherosclerosis. METHODS: To evaluate whether H. pylori accelerates or even induces atherosclerosis, H. pylori-infected C57/BL6 mice and ApoE-/- mice were maintained under different dietary conditions. To identify the role of H. pylori-infected gastric epithelial cells-derived exosomes (Hp-GES-EVs) and exosomal CagA in atherosclerosis, ApoE-/- mice were given intravenous or intraperitoneal injections of saline, GES-EVs, Hp-GES-EVs, and recombinant CagA protein (rCagA). FINDINGS: CagA-positive H. pylori PMSS1 infection does not induce but promotes macrophage-derived foam cell formation and augments atherosclerotic plaque growth and instability in two animal models. Meanwhile, circulating Hp-GES-EVs are taken up in aortic plaque, and CagA is secreted in Hp-GES-EVs. Furthermore, the CagA-containing EVs and rCagA exacerbates macrophage-derived foam cell formation and lesion development in vitro and in vivo, recapitulating the pro-atherogenic effects of CagA-positive H. pylori. Mechanistically, CagA suppresses the transcription of cholesterol efflux transporters by downregulating the expression of transcriptional factors PPARγ and LXRα and thus enhances foam cell formation. INTERPRETATION: These results may provide new insights into the role of exosomal CagA in the pathogenesis of CagA-positive H. pylori infection-related atherosclerosis. It is suggested that preventing and eradicating CagA-positive H. pylori infection could reduce the incidence of atherosclerosis and related events.

14-3-3ζ promotes esophageal squamous cell carcinoma invasion by repressing S1PR2 protein expression through NF-κB signaling.

14-3-3ζ is overexpressed in several cancers, including esophageal squamous cell carcinoma (ESCC), and plays an important role in tumorigenesis. However, the mechanisms underlying its tumorigenesis remain unclear. Here we report that 14-3-3ζ was upregulated in ESCC tumors, compared with adjacent normal tissues; 14-3-3ζ levels were positively correlated with ESCC lymph node metastasis and recurrence. Overexpression of 14-3-3ζ promoted the tumor growth and invasion of ESCC in vitro and in vivo, whereas depletion of 14-3-3ζ suppressed these effects. Moreover, 14-3-3ζ reduces expression of genes mediating S1P/S1PR2 signaling, and this effect is mediated through activation of NF- κ B. Taken together, 14-3-3ζ contributes to ESCC tumorigenesis and progression through repressing S1PR2 signaling and may act as a new therapeutic target for ESCC.

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.

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.

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.

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.

Recombinant human sonic hedgehog protein regulates the expression of ZO-1 and occludin by activating angiopoietin-1 in stroke damage.

This study examines the regulating effect of Sonic Hedgehog (Shh) on the permeability of the blood-brain barrier (BBB) in cerebral ischemia. By employing permanent middle cerebral artery occlusion (pMCAO) model, we find that Shh significantly decreases brain edema and preserves BBB permeability. Moreover, Shh increases zonula occludens-1 (ZO-1), occludin and angiopiotetin-1 (Ang-1) expression in the ischemic penumbra. Blockage of Shh with cyclopamine abolishes the effects of Shh on brain edema, BBB permeability and ZO-1, occludin, Ang-1 expression. Primary brain microvessel endothelial cells (BMECs) and astrocytes were pre-treated with Shh, cyclopamine, Ang-1-neutralizing antibody, and subjected to oxygen-glucose deprivation (OGD). Results show that the Ang-1 protein level in the culture medium of Shh-treated astrocytes is significantly higher. Shh also increased ZO-1, occludin and Ang-1 expression in BMECs, while cyclopamine and Ang-1-neutralizing antibody inhibited the effects of Shh on the ZO-1 and occludin expression, respectively. This study suggests that, under ischemic insults, Shh triggers Ang-1 production predominantly in astrocytes, and the secreted Ang-1 acts on BMECs, thereby upregulating ZO-1 and occludin to repair the tight junction and ameliorate the brain edema and BBB leakage.

Astrocyte-derived sonic hedgehog contributes to angiogenesis in brain microvascular endothelial cells via RhoA/ROCK pathway after oxygen-glucose deprivation.

The human adult brain possesses intriguing plasticity, including neurogenesis and angiogenesis, which may be mediated by the activated sonic hedgehog (Shh). By employing a coculture system, brain microvascular endothelial cells (BMECs) cocultured with astrocytes, which were incubated under oxygen-glucose deprivation (OGD) condition, we tested the hypothesis that Shh secreted by OGD-activated astrocytes promotes cerebral angiogenesis following ischemia. The results of this study demonstrated that Shh was mainly secreted by astrocytes and the secretion was significantly upregulated after OGD. The proliferation, migration, and tube formation of BMECs cocultured with astrocytes after OGD were significantly enhanced, but cyclopamine (a Shh antagonist) or 5E1 (an antibody of Shh) reversed the change. Furthermore, silencing Ras homolog gene family, member A (RhoA) of BMECs by RNAi and blocking Rho-dependent kinase (ROCK) by Y27632, a specific antagonist of ROCK, suppressed the upregulation of proliferation, migration, and tube formation of BMECs after OGD. These findings suggested that Shh derived from activated astrocytes stimulated RhoA/ROCK pathway in BMECs after OGD, which might be involved in angiogenesis in vitro.