scholarly journals The Role of Alpha-Lipoic Acid in the Pathomechanism of Acute Ischemic Stroke

2018 ◽  
Vol 48 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Qingqing Wang ◽  
Chengmei Lv ◽  
Yongxin Sun ◽  
Xu Han ◽  
Shan Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Lipoic Acid ◽  
Nuclear Translocation ◽  
Infarct Volume ◽  
Neurological Deficits ◽  
Experimental Stroke ◽  
Enzyme Linked Immunosorbent Assay ◽  
M2 Phenotype

Background/Aims: Ischemic stroke results in increased cerebral infarction, neurological deficits and neuroinflammation. The underlying mechanisms involving the anti-inflammatory and neuroprotective properties of α-Lipoic acid (α-LA) remain poorly understood. Herein, we investigated the potential role of α-LA in a middle cerebral artery occlusion (MCAO) rat model and an in vitro lipopolysaccharide (LPS)-induced microglia inflammation model. Methods: In the in vivo study, infarct volume was examined by TTC staining and Garcia score was used to evaluate neurologic recovery. The cytokines were evaluated by enzyme-linked immunosorbent assay, and protein expression of microglia phenotype and NF-κB were measured using western blot. In the in vitro study, the expressions of microglia M1/M2 phenotype were evaluated using qRT-PCR, and immunofluorescence staining was used to assess the nuclear translocation of NF-κB. Results: Both 20 mg/kg and 40 mg/kg of α-LA alleviated infarct size, brain edema, and neurological deficits. Furthermore, α-LA induced the polarization of microglia to the M2 phenotype, modulated the expression of IL-1β, IL-6, TNF-α and IL-10, and attenuated the activation of NF-κB after MCAO. α-LA inhibited the expression of M1 markers, increased activation of the M2 markers, and suppressed the nuclear translocation of NF-κB in LPS-stimulated BV2 microglia. Conclusions: α-LA improved neurological outcome in experimental stroke via modulating microglia M1/M2 polarization. The potential mechanism of α-LA might be mediated by inhibition of NF-κB activation via regulating phosphorylation and nuclear translocation of p65.

scholarly journals RhTrx-1 ameliorates miroglial neuroinflammation after cerebral ischemic stroke

2020 ◽  
Author(s):  
Yang Jiao ◽  
Jianjian Wang ◽  
Huixue Zhang ◽  
Yuze Cao ◽  
Yang Qu ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Inflammatory Response ◽  
Inflammatory Responses ◽  
Inflammatory Factors ◽  
Experimental Stroke ◽  
Inflammasome Activation ◽  
Cerebral Ischemic

Abstract Background Microglia are rapidly activated after ischemic stroke and participate in the occurrence of neuroinflammation, which exacerbates the injury of ischemic stroke. Receptor Interacting Serine Threonine Kinase 1 (RIPK1) is thought to be involved in the development of inflammatory responses, but its role in ischemic microglia remains unclear. Here, we applied recombinant human thioredoxin-1 (rhTrx-1), a potential neuroprotective agent, to explore the role of rhTrx-1 in inhibiting RIPK1-mediated neuroinflammatory responses in microglia. Method Middle cerebral artery occlusion (MCAO) and Oxygen and glucose deprivation (OGD) were conducted for in vivo and in vitro experimental stroke models. The expression of RIPK1 in microglia after ischemia was examined. The inflammatory response of microglia was analyzed after treatment with rhTrx-1 and Necrostatin-1 (Nec-1, inhibitors of RIPK1), and the mechanisms were explored. In addition, the effects of rhTrx-1 on neurobehavioral deficits and cerebral infarct volume were examined. Results RIPK1 expression was detected in microglia after ischemia. Molecular docking results showed that rhTrx-1 could directly bind to RIPK1. In vitro experiments found that rhTrx-1 reduced necroptosis, mitochondrial membrane potential damage, Reactive oxygen species (ROS) accumulation and NLR Family, pyrin domain-containing 3 protein (NLRP3) inflammasome activation by inhibiting RIPK-1 expression, and regulated microglial M1/M2 phenotypic changes, thereby reducing the release of inflammatory factors. Consistently, in vivo experiments found that rhTrx-1 treatment attenuated cerebral ischemic injury by inhibiting the inflammatory response. Conclusion Our study demonstrates the role of RIPK1 in microglia-arranged neuroinflammation after cerebral ischemia. Administration of rhTrx-1 provides neuroprotection in ischemic stroke-induced microglial neuroinflammation by inhibiting RIPK1 expression.

scholarly journals High-Density Lipoprotein Therapy in Stroke: Evaluation of Endothelial SR-BI-Dependent Neuroprotective Effects

2020 ◽  
Vol 22 (1) ◽  
pp. 106
Author(s):  
Alexy Tran-Dinh ◽  
Angélique Levoye ◽  
David Couret ◽  
Lauriane Galle-Treger ◽  
Martine Moreau ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Acute Ischemic Stroke ◽  
Infarct Volume ◽  
High Density ◽  
High Density Lipoproteins ◽  
Protective Effects ◽  
Neuroprotective Effects

High-density lipoproteins (HDLs) display endothelial protective effects. We tested the role of SR-BI, an HDL receptor expressed by endothelial cells, in the neuroprotective effects of HDLs using an experimental model of acute ischemic stroke. After transient intraluminal middle cerebral artery occlusion (tMCAO), control and endothelial SR-BI deficient mice were intravenously injected by HDLs or saline. Infarct volume and blood-brain barrier (BBB) breakdown were assessed 24 h post tMCAO. The potential of HDLs and the role of SR-BI to maintain the BBB integrity was assessed by using a human cellular model of BBB (hCMEC/D3 cell line) subjected to oxygen-glucose deprivation (OGD). HDL therapy limited the infarct volume and the BBB leakage in control mice relative to saline injection. Interestingly, these neuroprotective effects were thwarted by the deletion of SR-BI in endothelial cells and preserved in mice deficient for SR-BI in myeloid cells. In vitro studies revealed that HDLs can preserve the integrity of the BBB in OGD conditions, and that this effect was reduced by the SR-BI inhibitor, BLT-1. The protection of BBB integrity plays a pivotal role in HDL therapy of acute ischemic stroke. Our results show that this effect is partially mediated by the HDL receptor, SR-BI expressed by endothelial cells.

Abstract WP160: Conivaptan (Combined Vasopressin Receptor Antagonism) Attenuates Cerebral Edema Following Ischemic Stroke in Rodent Model

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Saeed Ansari ◽  
Vishnumurthy Shushrutha Hedna ◽  
Sarah Ganji ◽  
Alireza Sadighi ◽  
Rashi Krishnan ◽  
...  
Keyword(s):  
Cerebral Edema ◽  
Neurological Deficit ◽  
Infarct Volume ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Experimental Stroke ◽  
Vasopressin Receptor ◽  
Receptor Antagonism ◽  
Protein Levels

Objective: To study the potential role of Conivaptan on cerebral edema, infarct volume, neurological deficit and survival. Introduction: Although vasopressin has a significant detrimental role in stroke-related cerebral edema, the effect of mixed vasopressin antagonism in stroke has not been well studied. We studied the effects of conivaptan on the course of cerebral edema, severity of neurological deficit, infarct volume, aquaporin-4 (AQP4) protein levels and survival after experimental stroke. Methods: Animals were randomized to receive either conivaptan or vehicle after reperfusion of experimental middle cerebral artery occlusion. The severity of neurological deficit, edema, and infarct volume assessments were performed by an investigator blinded to group assignment. All assessments were performed at either 12h or 24h and Western blot was subsequently used to investigate AQP4 levels. Results: At 12h, conivaptan-treated mice (n=16) had 6.64±6.50% ipsilateral hemispheric enlargement compared to 16.55±7.05% in control mice (n=16, p=0.0003). Similarly, at 24h, conivaptan-treated mice (n=12) had 6.81±4.63% ipsilateral hemispheric enlargement in comparison to 13.93±5.43% in control mice (n=12, p=0.0023). At 24h, the conivaptan-treated mice had lower neurological deficits in comparison to control (p=0.04). There was no significant effect of conivaptan on infarct size or AQP4 levels in comparison to vehicle, naïve and sham group. Conclusions: The present study highlights the role of mixed vasopressin receptor antagonism in reducing cerebral edema secondary to brain ischemia. This data suggests the possibility of developing vasopressin antagonism as a new adjuvant in treatment of stroke-related brain edema.

scholarly journals Thiamet G mediates neuroprotection in experimental stroke by modulating microglia/macrophage polarization and inhibiting NF-κB p65 signaling

2016 ◽  
Vol 37 (8) ◽  
pp. 2938-2951 ◽  
Author(s):  
Yating He ◽  
Xiaofeng Ma ◽  
Daojing Li ◽  
Junwei Hao
Keyword(s):  
Ischemic Stroke ◽  
Inflammatory Responses ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Macrophage Polarization ◽  
Neurological Deficits ◽  
Experimental Stroke ◽  
Bv2 Cells ◽  
Anti Inflammatory

Inflammatory responses are accountable for secondary injury induced by acute ischemic stroke (AIS). Previous studies indicated that O-GlcNAc modification (O-GlcNAcylation) is involved in the pathology of AIS, and increase of O-GlcNAcylation by glucosamine attenuated the brain damage after ischemia/reperfusion. Inhibition of β-N-acetylglucosaminidase (OGA) with thiamet G (TMG) is an alternative option for accumulating O-GlcNAcylated proteins. In this study, we investigate the neuroprotective effect of TMG in a mouse model of experimental stroke. Our results indicate that TMG administration either before or after middle cerebral artery occlusion (MCAO) surgery dramatically reduced infarct volume compared with that in untreated controls. TMG treatment ameliorated the neurological deficits and improved clinical outcomes in neurobehavioral tests by modulating the expression of pro-inflammatory and anti-inflammatory cytokines. Additionally, TMG administration reduced the number of Iba1+ cells in MCAO mice, decreased expression of the M1 markers, and increased expression of the M2 markers in vivo. In vitro, M1 polarization of BV2 cells was inhibited by TMG treatment. Moreover, TMG decreased the expression of iNOS and COX2 mainly by suppressing NF-κB p65 signaling. These results suggest that TMG exerts a neuroprotective effect and could be useful as an anti-inflammatory agent for ischemic stroke therapy.

scholarly journals MiR-298 Exacerbates Ischemia/Reperfusion Injury Following Ischemic Stroke by Targeting Act1

2018 ◽  
Vol 48 (2) ◽  
pp. 528-539 ◽  
Author(s):  
Hongxue Sun ◽  
Di Zhong ◽  
Cheng Wang ◽  
Yilei Sun ◽  
Jiaying Zhao ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Luciferase Assay ◽  
Regulatory Relationship

Background/Aims: This study investigated the role of the microRNA miR-298 and its target Act1 in ischemic stroke. Methods: Cell viability was assessed with the 3-(4,5-dimethythiazol-2- yl)-2,5-diphenyl tetrazolium bromide assay. Apoptotic cells were detected by flow cytometry, and mRNA and protein expression were assessed by quantitative real-time PCR and western blotting, respectively. The regulatory relationship between miR-298 and Act1 was evaluated with the luciferase assay. To clarify the role of Act1 following ischemic stroke, the transcript was knocked down by short interfering RNA. The in vitro findings were validated in a mouse model of middle cerebral artery occlusion by administration of miR-298 mimic. Results: Act1 was upregulated whereas miR-298 was downregulated in ischemic stroke. miR-298 overexpression by transfection of a mimic suppressed Act1 protein levels in vitro and in vivo, and the luciferase assay showed that miR-298 directly binds to the 3’ untranslated region of the Act1 transcript. miR-298 overexpression enhanced cell apoptosis and autophagy and exacerbated ischemic infarction and neurological deficits, effects that were exerted via negative regulation of Act1/c-Jun N-terminal kinase (JNK)/nuclear factor (NF)-κB signaling and downstream autophagy pathways. Conclusions: Upregulation of miR-298 following ischemic stroke promotes brain injury in vitro and vivo by inhibiting the Act1/JNK/NF-κB signaling cascade and the downstream autophagy pathway. Therapeutic strategies that target miR-298 could be beneficial for the treatment of ischemic stroke.

scholarly journals Inhibition of histone deacetylase 3 by MiR-494 alleviates neuronal loss and improves neurological recovery in experimental stroke

2019 ◽  
Vol 39 (12) ◽  
pp. 2392-2405 ◽  
Author(s):  
Haiping Zhao ◽  
Guangwen Li ◽  
Sijia Zhang ◽  
Fangfang Li ◽  
Rongliang Wang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Infarct Volume ◽  
Neuronal Loss ◽  
Predictive Biomarker ◽  
Acute Stage ◽  
Negative Regulator ◽  
Experimental Stroke ◽  
Cerebral Ischemic

HDAC3 is an essential negative regulator of neuronal plasticity and memory formation. Although a chemical inhibitor has been invented, little is known about its endogenous modulators. We explored whether miR-494 affects HDAC3-mediated neuronal injury following acute ischemic stroke. A substantial increase in plasma miR-494 was detected in AIS patients and was positively associated with the mRS at one year after symptom onset. The miR-494 levels were transiently increased in the infarcted brain tissue of mice. In contrast, miR-494 levels were reduced in neurons but increased in the medium after OGD. Intracerebroventricular injection of miR-494 agomir reduced neuronal apoptosis and infarct volume at the acute stage of MCAO, promoted axonal plasticity and long-term outcomes at the recovery stage, suppressed neuronal ataxin-3 and HDAC3 expression and increased acetyl-H3K9 levels in the ipsilateral hemisphere. In vitro studies confirmed that miR-494 posttranslationally inhibited HDAC3 in neurons and prevented OGD-induced neuronal axonal injury. The HDAC3 inhibitor increased acetyl-H3K9 levels and reversed miR-494 antagomir-aggravated acute cerebral ischemic injury, as well as brain atrophy and long-term functional recovery. These results suggest that miR-494 may serve as a predictive biomarker of functional outcomes in AIS patients and a potential therapeutic target for the treatment of ischemic stroke.

scholarly journals Phaseolin Attenuates Lipopolysaccharide-Induced Inflammation in RAW 264.7 Cells and Zebrafish

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 420
Author(s):  
Su-Jung Hwang ◽  
Ye-Seul Song ◽  
Hyo-Jong Lee
Keyword(s):  
Nitric Oxide ◽  
Nuclear Translocation ◽  
Raw 264.7 Cells ◽  
Network Pharmacology ◽  
Raw 264.7 ◽  
Dependent Manner ◽  
Bioactive Constituents

Kushen (Radix Sophorae flavescentis) is used to treat ulcerative colitis, tumors, and pruritus. Recently, phaseolin, formononetin, matrine, luteolin, and quercetin, through a network pharmacology approach, were tentatively identified as five bioactive constituents responsible for the anti-inflammatory effects of S. flavescentis. However, the role of phaseolin (one of the primary components of S. flavescentis) in the direct regulation of inflammation and inflammatory processes is not well known. In this study, the beneficial role of phaseolin against inflammation was explored in lipopolysaccharide (LPS)-induced inflammation models of RAW 264.7 macrophages and zebrafish larvae. Phaseolin inhibited LPS-mediated production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS), without affecting cell viability. In addition, phaseolin suppressed pro-inflammatory mediators such as cyclooxygenase 2 (COX-2), interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), and interleukin-6 (IL-6) in a dose-dependent manner. Furthermore, phaseolin reduced matrix metalloproteinase (MMP) activity as well as macrophage adhesion in vitro and the recruitment of leukocytes in vivo by downregulating Ninjurin 1 (Ninj1), an adhesion molecule. Finally, phaseolin inhibited the nuclear translocation of nuclear factor-kappa B (NF-κB). In view of the above, our results suggest that phaseolin could be a potential therapeutic candidate for the management of inflammation.

Abstract 1944: Atorvastatin Reduces Intracerebral Hemorrhage after Experimental Stroke

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Hazem F Elewa ◽  
Anna Kozak ◽  
David Rychly ◽  
Adviye Ergul ◽  
Reginald Frye ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Intracerebral Hemorrhage ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Methyl Cellulose ◽  
The United States ◽  
Experimental Stroke ◽  
High Risk Population ◽  
Protective Agent ◽  
Oral Gavage

Ischemic stroke is a leading cause of death and disability in the United States and diabetes mellitus is the fastest growing risk factor for stroke. In addition, hyperglycemia, which is usually associated with diabetes, tends to worsen ischemia/reperfusion injury and to induce more oxidative stress damage. Preliminary data from our laboratory showed that diabetic animals (Goto-Kakizaki rats (GKs) are more susceptible to vascular damage leading to intracerebral hemorrhage. Many studies have indicated that statins possess neuroprotective properties even when administered after the onset of ischemia. However, the acute vascular effects of statins after ischemic stroke have not been studied to date. Objective: to evaluate the efficacy and magnitude of vascular protection of acute statin therapy in both GKs and their normoglycemic controls after experimental ischemic stroke. Methods: Male Wistar (W) and GK rats (270–305 g) underwent 3 hours of middle cerebral artery occlusion (MCAO) followed by reperfusion for 21 hours. Animals were randomized to receive either atorvastatin (15mg/Kg) or methyl cellulose (0.5%), administered by oral gavage, the first dose 5 minutes after reperfusion and the second dose after 12 hours. Brain tissue was analyzed for infarct volume and hemoglobin content. In another set of Wistar rats (n=3), atorvastatin (15mg/Kg) was administered by oral gavage to compare its pharmacokinetic profile with that of humans Results: Atorvastatin-treated groups had significantly lower hemoglobin (p=0.0156) and infarct volume (p=0.0132) compared to their controls. Atorvastatin peak concentration (27–77 ng/ml) in rats’ plasma was found to be similar to that seen after 80mg/day of atorvastatin in humans. Conclusion: Atorvastatin can be a novel vascular protective agent after acute ischemic stroke especially in a high risk population like diabetics. The mechanisms through which these effects are mediated are currently being investigated.

Abstract TP269: Lncrna-u90926 Aggravates Ischemic Brain Injury via Promoting Neutrophils Infiltration After Experimental Stroke

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Jian Chen ◽  
Yun Xu
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Expression Level ◽  
Neurological Deficits ◽  
Neurological Injury ◽  
Experimental Stroke ◽  
Ischemic Brain Injury ◽  
Triphenyltetrazolium Chloride ◽  
Ischemic Brain ◽  
Severity Scores

Background: Long non-coding RNAs (LncRNAs) are expressed at high levels in the brain in a variety of neuropathologic conditions, including stroke. However, the potential role of LncRNAs in ischemic stroke-associated microglial biological function and neurological injury remains largely unknown. Methods: Oxygen-glucose deprivation and transient middle cerebral artery occlusion (MCAO) in C57BL/6 mice were used as in vitro and in vivo ischemic stroke models. Microarray analysis was performed to explore the overall expression level changes of LncRNAs. Real-time polymerase chain reaction (RT-qPCR) was used to detect expression level of LncU90926 in brain, plasma and microglia. ShRNA-LncU90926 in lentivirus and microglia specific Adeno-associated virus (AAV) were used to knockdown LncU90926 in vitro and in vivo separately. Infarct volumes and neurological impairments were assessed by 2,3,5-triphenyltetrazolium chloride (TTC) staining, Neurological Severity Scores (NSS), rotarod test and grip strength respectively. Immunofluorescence staining and flow cytometry were performed to detect the number of neutrophils recruited to brain. RT-qPCR was used to detect the level of chemokines (CXCL, CCL2) and inflammatory mediators associated with neutrophils (MPO, MMP3 and TIMP1). Results: (1). LncU90926 was markedly up-regulated in the infarcted brain and plasma after MCAO. Both MCAO and OGD treatment induced remarkable up-regulation of LncU90926 in microglia. (2). LncU90926 knockdown definitely attenuated brain infarct size and neurological deficits after ischemic stroke. (3). LncU90926 knockdown in microglia reduced the number of neutrophils recruited to brain, and CXCL1 and CCL2 were down-regulated in both MCAO and OGD models. LncU90926 knockdown also induced reduction of MPO, MMP3 and TIMP1 in the infarcted brain. Conclusions: LncU90926 was up-regulated in microglia after experimental stroke, and aggravates ischemic brain injury through facilitating neutrophils infiltration via up-regulating microglial chemokine.

Abstract WMP76: Interleukin-33 Protects Against Transient Ischemic Stroke by Enhancing Regulatory T-Cell Expansion and Accumulation

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Xinjing Liu ◽  
Ruiyao Hu ◽  
Lulu Pei ◽  
Yuming Xu ◽  
Bo Song
Keyword(s):  
Cell Death ◽  
Ischemic Stroke ◽  
T Cell ◽  
Regulatory T Cell ◽  
Cell Expansion ◽  
Neuronal Apoptosis ◽  
Infarct Volume ◽  
Intraperitoneal Administration

Background: The interleukin (IL)-33 could promote proliferation of regulatory T lymphocytes (Tregs) which are negatively related with brain damage after ischemic stroke. How IL-33 works on Tregs after stroke is unclear. The purpose of this study was to investigate the role of IL-33 for Tregs-mediated neuroprotection and further expounded the mechanisms of protection in mice. Methods: In vitro study, primary mice neuronal cells were subjected to 3h oxygen-glucose deprivation (OGD). The vehicle or drug conditioned Tregs were applied to neurons at the time of induction of hypoxia respectively. Neuronal apoptosis, Tregs related cytokines were measured by MTT assay, Western blotting and enzyme-linked immune-sorbent assay (ELISA). In vivo study, Tregs were depleted by intraperitoneal administration of anti-CD25Ab. Intraperitoneal injection of IL-33 immediately post 60 min transient middle cerebral artery occlusion (tMCAO) modeling. The neurological function test at days 1, 3, 5, 7 and 14 after tMCAO. Infarct volume, Brain edema, cell death, percentage of Tregs and related cytokines were respectively measured by 2,3,5-triphenyltetrazolium chloride or MAP2 staining, dry-wet method, TUNEL staining, flow cytometry and immunofluorescence, Western blotting and ELISA. Results: The supernatant of IL-33-treated Tregs reduced neuronal apoptosis in the OGD model meanwhile elevated the production of Tregs related cytokines IL-10, IL-35 and TGF- β in vitro. Intraperitoneal administration of IL-33 significantly reduced infarct volume and stroke-induced cell death and improved sensorimotor functions. Notably, the protective effect of IL-33 was abolished in mice depleted of Tregs. IL-33 increased CD4+CD25+Foxp3+ Tregs in spleens, blood, and brain in vivo. Yet, ST2 blocking muted these IL-33 activities. Mechanistically, the protection of IL-33 was associated with reduced apoptosis protein and production of Tregs related cytokine. Conclusions: This study elucidated that IL-33 afforded neuroprotection against ischemic brain injury by enhancing ST2-dependent regulatory T-cell expansion and activation, which suggested a promising immune modulatory target for the treatment of stroke.

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