cGAS-STING signaling regulates control of microglia polarization in cerebral ischemic stroke

2020 ◽  
Author(s):  
Guoliang Jiang ◽  
Xinglong Yang ◽  
Houjun Zhou ◽  
Jiang Long ◽  
Linming Zhang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Inflammatory Response ◽  
Cell Model ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Ht22 Cells ◽  
Bv2 Microglia ◽  
Cerebral Ischemic Stroke ◽  
Sting Pathway ◽  
Cerebral Ischemic

Abstract Background Cerebral ischemic stroke is a highly debilitating disease, in which inflammation is well document to play a pivotal role in its pathophysiology. Microglia are the the major immuncompetent cells of the brain involved in different neuropathologies. Recent discovery of cyclic GMP-AMP synthase(cGAS) activation and its induction of the downstream signaling protein stimulator of interferon genes (STING) is increasingly recognized as a crucial determinant of neuropathophysiology. Although cGAS-STING pathway has been reported to play an important role in inflammatory response in myocardial infarction (MI), its mechanism in inflammatory response in ischemic stroke (IS) has remained to be fully explored.Methods In light of the above, this study sought to explore the roles of cGAS-STING pathway in inflammatory reaction in IS. It is hoped that the results would provide new insights for designing of therapeutic strategies targeting at IS. We used HT22 cells to establish an oxygen-glucose deprivation (OGD) cell model. The supernatant derived from this and which contained OGD-induced DAMPs(OIDs) was used to stimulate the BV2 microglia. Additionally, we used siRNA technology to interfere with cGAS gene expression to observe changes in downstream cytokines. Furthermore, we established middle cerebral artery occlusion (MCAO) mouse model and performed cGAS-siRNA lentivirus infection to further elucidate the mechanism of cGAS-STING pathway in vivo.Results We show here that OIDs strongly activated the cGAS-STING pathway and triggered accumulation of a plethora of proinflammatory factors in activated Microglia. Of note, the cascade reaction was successfully inhibited by cGAS-siRNA. Furthermore, we extended the study of cGAS-STING in a mouse MCAO model, which showed that inhibiting cGAS-STING pathway can effectively diminish MIDs(MCAO-induced DAMPs)-induced neuronal apoptosis and ultimately functional improvement.Conclusion The present results have shown GAS-STING signaling pathway controls the polarity transformation of microglia. The underlying mechanisms of cGAS-STING triggering microglial inflammatory response is now better clarified which made the pathway a potential therapeutic target of IS.

scholarly journals Up-regulation of miR-499a-5p decreases cerebral ischemia/reperfusion injury by targeting PDCD4

2021 ◽  
Author(s):  
Weifeng Shan ◽  
Huifeng Ge ◽  
Bingquan Chen ◽  
Linger Huang ◽  
Shaojun Zhu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Cell Model ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Tunel Staining ◽  
Cerebral Ischemia Reperfusion

Abstract MiR-499a-5p was significantly down-regulated in degenerative tissues and correlated with apoptosis. Nonetheless, the biological function of miR-499a-5p in acute ischemic stroke has been still unclear. In this study, we found the plasma levels of miR-499a-5p were significantly down-regulated in 64 ischemic stroke patients and negatively correlated with the National Institutes of Health Stroke Scale score. Then, we constructed cerebral ischemia/reperfusion (I/R) injury in rats after middle cerebral artery occlusion and subsequent reperfusion and oxygen-glucose deprivation and reoxygenation (OGD/R) treated SH-SY5Y cell model. Transfection with miR-499a-5p mimic was accomplished by intracerebroventricular injection in the in vivo I/R injury model. We further found miR-499a-5p overexpression decreased infarct volumes and cell apoptosis in the in vivo I/R stroke model using TTC and TUNEL staining. PDCD4 was a direct target of miR-499a-5p by luciferase report assay and western blotting. Knockdown of PDCD4 reduced the infarct damage and cortical neuron apoptosis caused by I/R injury. MiR-499a-5p exerted neuroprotective roles mainly through inhibiting PDCD4-mediated apoptosis by CCK-8 assay, LDH release assay and flow cytometry analysis. These findings suggest that miR-499a-5p might represent a novel target that regulates brain injury by inhibiting PDCD4-mediating apoptosis.

scholarly journals Overexpression of MicroRNA-145 Ameliorates Astrocyte Injury by Targeting Aquaporin 4 in Cerebral Ischemic Stroke

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Lifang Zheng ◽  
Wei Cheng ◽  
Xijia Wang ◽  
Zhigang Yang ◽  
Xiangling Zhou ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Ischemic Injury ◽  
Glucose Deprivation ◽  
Expression Levels ◽  
Cultured Astrocytes ◽  
Cerebral Ischemic Stroke ◽  
Cerebral Ischemic ◽  
Induced Apoptosis ◽  
Global Population

Cerebral ischemic stroke, which affects the global population, is a major disease with high incidence, mortality, and disability. Accumulating evidence has indicated that abnormal microRNA (miRNA) expression plays essential roles in the pathologies of ischemic stroke. Yet, the underlying regulatory mechanism of miRNAs in cerebral ischemic stroke remains unclear. We investigated the role of miR-145 in cerebral ischemic stroke and its potential mechanism in a model using primary cultured astrocytes. We detected the expression levels of miR-145 and its target gene AQP4 and assessed the role of miR-145 in cell death and apoptosis caused by oxygen-glucose deprivation (OGD). Bioinformatics analysis was used to explore the targets of miR-145. miR-145 expression levels were significantly decreased in primary astrocytes subjected to OGD. miR-145 overexpression promoted astrocyte health and inhibited OGD-induced apoptosis. AQP4 was a direct target of miR-145, and miR-145 suppressed AQP4 expression. Moreover, AQP4 enhanced astrocyte injury in ischemic stroke, and AQP4 knockdown diminished the miR-145-mediated protective effect on ischemic injury. Taken together, our results show that miR-145 plays an important role in protecting astrocytes from ischemic injury by downregulating AQP4 expression. These findings may highlight a novel therapeutic target in cerebral ischemic stroke.

scholarly journals Restoration of Polyamine Metabolic Patterns inIn VivoandIn VitroModel of Ischemic Stroke following Human Mesenchymal Stem Cell Treatment

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Tae Hwan Shin ◽  
Geetika Phukan ◽  
Jeom Soon Shim ◽  
Duc-Toan Nguyen ◽  
Yongman Kim ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cell Model ◽  
Glucose Deprivation ◽  
Human Mesenchymal Stem Cell ◽  
Artery Occlusion ◽  
Control Group ◽  
Stem Cell Treatment ◽  
Cerebral Artery Occlusion

We investigated changes in PA levels by the treatment of human bone-marrow-derived mesenchymal stem cells (hBM-MSCs) in ischemic stroke in rat brain model and in cultured neuronal SH-SY5Y cells exposed to oxygen-glucose deprivation (OGD). In ischemic rat model, transient middle cerebral artery occlusion (MCAo) was performed for 2 h, followed by intravenous transplantation of hBM-MSCs or phosphate-buffered saline (PBS) the day following MCAo. Metabolic profiling analysis of PAs was examined in brains from three groups: control rats, PBS-treated MCAo rats (MCAo), and hBM-MSCs-treated MCAo rats (MCAo + hBM-MSCs). In ischemic cell model, SH-SY5Y cells were exposed to OGD for 24 h, treated with hBM-MSCs (OGD + hBM-MSCs) prior to continued aerobic incubation, and then samples were collected after coculture for 72 h. In thein vivoMCAo ischemic model, levels of some PAs in brain samples of the MCAo and MCAo + hBM-MSCs groups were significantly different from those of the control group. In particular, putrescine, cadaverine, and spermidine in brain tissues of the MCAo + hBM-MSCs group were significantly reduced in comparison to those in the MCAo group. In thein vitroOGD system,N1-acetylspermidine, spermidine,N1-acetylspermine, and spermine in cells of the OGD + hBM-MSCs group were significantly reduced compared to those of OGD group.

scholarly journals MLIF Modulates Microglia Polarization in Ischemic Stroke by Targeting eEF1A1

2021 ◽  
Vol 12 ◽  
Author(s):  
Yulan Liu ◽  
Shanshan Deng ◽  
Zhibing Song ◽  
Qian Zhang ◽  
Yuchen Guo ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Macrophage Polarization ◽  
Elongation Factor ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Human Neuroblastoma ◽  
Associated Proteins ◽  
Bv2 Microglia

Monocyte locomotion inhibitory factor (MLIF) is a heat-stable pentapeptide from Entamoeba histolytica. Our previous study found that MLIF protects against ischemic stroke in rats and mice and exerts a neuroprotection effect in human neuroblastoma SH-SY5Y cells. Microglia/macrophage polarization has been proven to be vital in the pathology of ischemic stroke. Nevertheless, whether MLIF is able to modulate microglia/macrophage polarization remains unclear. We performed middle cerebral artery occlusion (MCAO) on C57BL/6J male mice and induced cultured BV2 microglia by oxygen-glucose deprivation (OGD), respectively. Immunfluorescence was utilized to detect the M1/2 markers, such as CD206 and CD16/32. qPCR and ELISA were used to detect the signature gene change of M1/2. The MAPK and NF-κB pathway associated proteins were measured by Western blot. To identify the protein target of MLIF, a pull-down assay was performed. We found that MLIF promoted microglia transferring from a “sick” M1 phenotype to a “healthy” M2 phenotype in vivo or in vitro. Furthermore, we proved that eukaryotic elongation factor 1A1 (eEF1A1) was involved in the modulation of microglia/macrophage polarization. Knocking down eEF1A1 by siRNA exhibited the M1 promotion effect and M2 inhibition effect. Taken together, our results demonstrated MLIF modulated microglia/macrophage polarization by targeting eEF1A1 in ischemic stroke.

scholarly journals The Neuroprotective Effect of l-Borneolum on Cerebral Ischemic Stroke by Regulating Dll4/Notch1 Pathway

2021 ◽  
Author(s):  
Taiwei Dong ◽  
Nian Chen ◽  
Rong Ma ◽  
Qian Xie ◽  
Xiaoqing Guo ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Caspase 3 ◽  
Neuroprotective Effect ◽  
Artery Occlusion ◽  
Neurological Function ◽  
Immunohistochemical Method ◽  
Triphenyltetrazolium Chloride ◽  
Severity Scores ◽  
Cerebral Ischemic Stroke ◽  
Cerebral Ischemic

Abstract Aiml-Borneolum is a monoterpene compound witch deserved from Blumea balsamifera (L.) DC, this study aimed to investigate the potential mechanism of l-borneolum on cerebral ischemic stroke (CIS) rats and provide evidence for the development of l-borneolum in CIS.MethodsPermanent middle cerebral artery occlusion (pMCAO) model rats were applied to this study. Neurological function was assessed by modified neurological severity scores (mNSS) and Longa neurological function scoring methods. The pathological changes of cerebral tissue were evaluated by 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin-eosin (HE) staining. Ultrastructure of blood brain barrier (BBB) was observed by transmission electron microscopy. Additionally, the expression of Notch1, Dll4, Hey1, Hes1, Hes5, VEGFA and p65 in the cortex were determined by Western blotting (WB) while expression of caspase 3 were determined by immunohistochemical method (IHC). Resultsl-Borneolum improved neurological function in a dose-dependently. l-Borneolum significantly alleviated brainstem edema and inflammation, as well as improved the ultrastructure of capillary and BBB in cortex. Moreover, 0.2 g/kg l-borneolum substantially decreased the protein expressions of Dll4, Notch1, Hes1, Hes5, and VEGFA in the cortex while decreased the level of Caspase-3 in the cortex of rats. Conclusionsl-Borneolum could repair neurological function by regulating Dll4/Notch1 signaling pathway.

scholarly journals BK Channel-Mediated Microglial Phagocytosis Alleviates Neurological Deficit After Ischemic Stroke

2021 ◽  
Vol 15 ◽  
Author(s):  
Shuxian Huang ◽  
Tingting Chen ◽  
Qian Suo ◽  
Rubing Shi ◽  
Haroon Khan ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Neurological Deficit ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Bk Channels ◽  
Acute Stage ◽  
Bk Channel ◽  
Microglial Phagocytosis ◽  
Cerebral Ischemic ◽  
Channel Activator

Microglial phagocytosis benefits neurological recovery after stroke. Large-conductance Ca2+-activated K+ currents are expressed in activated microglia, and BK channel knockout aggravates cerebral ischemic injury. However, the effect of BK channels on microglial phagocytosis after ischemic stroke remains unknown. Here, we explored whether BK channel activation is beneficial for neurological outcomes through microglial phagocytosis after ischemic stroke. ICR mice after transient middle cerebral artery occlusion (tMCAO) were treated with dimethyl sulfoxide (DMSO), BK channel activator NS19504, and inhibitor Paxilline. The results showed a decrease in BK channel expression after tMCAO. BK channel activator NS19504 alleviates neurological deficit after experimental modeling of tMCAO in mice compared to the control. Furthermore, we treated primary microglia with DMSO, NS19504, and Paxilline after oxygen glucose deprivation (OGD). NS19504 promoted primary microglial phagocytosing fluorescent beads and neuronal debris, which reduced neuronal apoptosis after stroke. These effects could be reversed by BK channel inhibitor Paxilline. Finally, NS19504 increased relative phosphorylated extracellular signal-regulated kinase 1/2 expression compared to the Paxilline group at the third day after stroke. Our findings indicate that microglial BK channels are a potential target for acute stage of ischemic stroke therapy.

scholarly journals Mesenchymal stem cell-derived exosome miR-542-3p suppresses inflammation and prevents cerebral infarction

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guofeng Cai ◽  
Guoliang Cai ◽  
Haichun Zhou ◽  
Zhe Zhuang ◽  
Kai Liu ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Cerebral Infarction ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Cerebral Injury ◽  
Inflammatory Factors ◽  
Toll Like Receptor 4 ◽  
Cerebral Disease ◽  
Cerebral Ischemic ◽  
Cerebral Artery Occlusion

Abstract Background Cerebral infarction ranks as the second leading cause of disability and death globally, and inflammatory response of glial cells is the main cause of brain damage during cerebral infarction. Methods Studies have shown that mesenchymal stem cells (MSCs) can secrete exosomes and contribute to cerebral disease. Here, we would explore the function of MSC-derived exosome in cerebral infarction. Results Microarray indicated a decrease of miR-542-3p and an increase of Toll-Like Receptor 4 (TLR4) in middle cerebral artery occlusion (MCAO) mice comparing with sham mice. And luciferase and RIP analysis indicated a binding of miR-542-3p and TLR4. Then, we injected AAV9-miR-542-3p into paracele of sham or MCAO mice. Functional analysis showed that AAV9-miR-542-3p inhibited infarction area and the number of degenerating neurons and suppressed inflammatory factors’ expression and inflammatory cell infiltration. As well, transfection of miR-542-3p mimics into HA1800 cells underwent oxygen and glucose deprivation (OGD). Similarly, overexpression of miR-542-3p alleviated OGD induced cell apoptosis, ROS, and activation of inflammation response. Moreover, miR-542-3p could be packaged into MSCs and secreted into HA1800 cells. The extractive exosome-miR-21-3p treatment relieved MCAO- or OGD-induced cerebral injury and inflammation through targeting TLR4. Conclusion These results confirmed that MSC-derived exosome miR-542-3p prevented ischemia-induced glial cell inflammatory response via inhibiting TLR4. These results suggest possible therapeutic strategies for using exosome delivery of miR-542-3p to cure cerebral ischemic injury.

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