scholarly journals Involvement of the Microglial Aryl Hydrocarbon Receptor in Neuroinflammation and Vasogenic Edema after Ischemic Stroke

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 718
Author(s):  
Miki Tanaka ◽  
Masaho Fujikawa ◽  
Ami Oguro ◽  
Kouichi Itoh ◽  
Christoph F. A. Vogel ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ischemic Stroke ◽  
Aryl Hydrocarbon Receptor ◽  
Vasogenic Edema ◽  
Artery Occlusion ◽  
Aryl Hydrocarbon ◽  
Inflammatory Conditions ◽  
Severity Scores ◽  
Factor Α ◽  
Cerebral Artery Occlusion

Microglia are activated after ischemic stroke and induce neuroinflammation. The expression of the aryl hydrocarbon receptor (AhR) has recently been reported to elicit cytokine expression. We previously reported that microglial activation mediates ischemic edema progression. Thus, the purpose of this study was to examine the role of AhR in inflammation and edema after ischemia using a mouse middle cerebral artery occlusion (MCAO) model. MCAO upregulated AhR expression in microglia during ischemia. MCAO increased the expression of tumor necrosis factor α (TNFα) and then induced edema progression, and worsened the modified neurological severity scores, with these being suppressed by administration of an AhR antagonist, CH223191. In THP-1 macrophages, the NADPH oxidase (NOX) subunit p47phox was significantly increased by AhR ligands, especially under inflammatory conditions. Suppression of NOX activity by apocynin or elimination of superoxide by superoxide dismutase decreased TNFα expression, which was induced by the AhR ligand. AhR ligands also elicited p47phox expression in mouse primary microglia. Thus, p47phox may be important in oxidative stress and subsequent inflammation. In MCAO model mice, P47phox expression was upregulated in microglia by ischemia. Lipid peroxidation induced by MCAO was suppressed by CH223191. Taken together, these findings suggest that AhR in the microglia is involved in neuroinflammation and subsequent edema, after MCAO via p47phox expression upregulation and oxidative stress.

Cerebrolysin and Aquaporin 4 Inhibition Improve Pathological and Motor Recovery after Ischemic Stroke

2018 ◽  
Vol 17 (4) ◽  
pp. 299-308 ◽  
Author(s):  
Bogdan Catalin ◽  
Otilia-Constantina Rogoveanu ◽  
Ionica Pirici ◽  
Tudor Adrian Balseanu ◽  
Adina Stan ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Vasogenic Edema ◽  
Artery Occlusion ◽  
Aquaporin 4 ◽  
Hypertonic Solution ◽  
Water Metabolism ◽  
Scar Region ◽  
Function Preservation ◽  
Neurotropic Factor ◽  
Cerebral Artery Occlusion

Background: Edema represents one of the earliest negative markers of survival and consecutive neurological deficit following stroke. The mixture of cellular and vasogenic edema makes treating this condition complicated, and to date, there is no pathogenically oriented drug treatment for edema, which leaves parenteral administration of a hypertonic solution as the only non-surgical alternative. Objective: New insights into water metabolism in the brain have opened the way for molecular targeted treatment, with aquaporin 4 channels (AQP4) taking center stage. We aimed here to assess the effect of inhibiting AQP4 together with the administration of a neurotropic factor (Cerebrolysin) in ischemic stroke. Methods: Using a permanent medial cerebral artery occlusion rat model, we administrated a single dose of the AQP4 inhibitor TGN-020 (100 mg/kg) at 15 minutes after ischemia followed by daily Cerebrolysin dosing (5ml/kg) for seven days. Rotarod motor testing and neuropathology examinations were next performed. Results: We showed first that the combination treatment animals have a better motor function preservation at seven days after permanent ischemia. We have also identified distinct cellular contributions that represent the bases of behavior testing, such as less astrocyte scarring and a larger neuronalsurvival phenotype rate in animals treated with both compounds than in animals treated with Cerebrolysin alone or untreated animals. Conclusion: Our data show that water diffusion inhibition and Cerebrolysin administration after focal ischemic stroke reduces infarct size, leading to a higher neuronal survival in the peri-core glial scar region.

scholarly journals P2Y6 receptor inhibition aggravates ischemic brain injury by reducing microglial phagocytosis

2019 ◽  
Author(s):  
Ruoxue Wen ◽  
Hui Shen ◽  
Shuxian Huang ◽  
Liping Wang ◽  
Zongwei Li ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Myosin Light Chain ◽  
Artery Occlusion ◽  
Walking Test ◽  
Microglial Phagocytosis ◽  
Tnf Α ◽  
Severity Scores ◽  
P2y6 Receptor ◽  
Cerebral Artery Occlusion ◽  
The Brain

Abstract Background Clearance of damaged cells is beneficial for the functional recovery after brain injury. Phagocytosis of tissue and cell debris is an important function of microglia during the development and pathological diseases. However, which specific phagocytic receptor mediates microglial phagocytosis after ischemic stroke is obscure. Methods ICR mice (n=59) underwent 90 minutes transient middle cerebral artery occlusion. P2Y6R, Iba1, GFAP and Tuj-1 double immunostainings were performed to determine P2Y6 receptor location. MRS2578 was injected into mice to inhibit P2Y6 receptor activity. Iba1 and TUNEL staining were performed to examine microglia phagocytosis. Modified neurological severity scores and Grid walking test were used to evaluate the neurological function after ischemic stoke. The expression of IL-1 α, IL-1 β, IL-6, IL-10, TNF-α, TGF-β and MPO was used to examine the inflammation response in the brain. Results The expression of P2Y6 receptor in microglia increased within three days after transient middle cerebral artery occlusion. Inhibition of microglial phagocytosis by the selective inhibitor MRS2578 enlarged the brain atrophy and edema volume after ischemic stroke, subsequently aggravated neurological function using modified neurological severity scores and Grid walking test. MRS2578 treatment had no effect on the expression of IL-1α, IL-1β, IL-6, IL-10, TNF-α, TGF-β and MPO after ischemic stroke, which suggested that it had no effect on the inflammation in the brain. Finally, we found that the expression of myosin light chain kinase decreased after microglial phagocytosis inhibition in ischemic mice, which suggested that myosin light chain kinase was involved in P2Y6 receptor mediated phagocytosis. Conclusion Our results indicated that the P2Y6 receptor mediated microglial phagocytosis played an important role during the acute stage of ischemic stroke, which was a potential target for ischemic stroke treatment.

scholarly journals Depleting SOX2 improves ischemic stroke via lncRNA PVT1/microRNA-24-3p/STAT3 axis

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Zhongjun Chen ◽  
Tieping Fan ◽  
Xusheng Zhao ◽  
Zhichen Zhang
Keyword(s):  
Oxidative Stress ◽  
Ischemic Stroke ◽  
Brain Injury ◽  
Water Content ◽  
Artery Occlusion ◽  
Neurological Deficits ◽  
Neuron Survival ◽  
Non Coding Rna ◽  
Cerebral Artery Occlusion ◽  
And Oxidative Stress

Abstract Objectives Studies have widely explored in the filed of ischemic stroke (IS) with their focus on transcription factors. However, few studies have pivoted on sex determining region Y-box 2 (SOX2) in IS. Thus, this study is launched to figure out the mechanisms of SOX2 in IS. Methods Rat middle cerebral artery occlusion (MCAO) was established as a stroke model. MCAO rats were injected with depleted SOX2 or long non-coding RNA plasmacytoma variant translocation 1 (PVT1) to explore their roles in neurological deficits, cerebral water content, neuron survival, apoptosis and oxidative stress. The relationship among SOX2, PVT1, microRNA (miR)-24-3p and signal transducer and activator of transcription 3 (STAT3) was verified by a series of experiments. Results SOX2, PVT1 and STAT3 were highly expressed while miR-24-3p was poorly expressed in cerebral cortex tissues of MCAO rats. Depleted SOX2 or PVT1 alleviated brain injury in MCAO rats as reflected by neuronal apoptosis and oxidative stress restriction, brain water content reduction, and neurological deficit and neuron survival improvements. Overexpression of PVT1 functioned oppositely. Restored miR-24-3p abolished PVT1 overexpression-induced brain injury in MCAO rats. SOX2 directly promoted PVT1 expression and further increased STAT3 by sponging miR-24-3p. Conclusion This study presents that depleting SOX2 improves IS via PVT1/miR-24-3p/STAT3 axis which may broaden our knowledge about the mechanisms of SOX2/PVT1/miR-24-3p/STAT3 axis and provide a reference of therapy for IS.

scholarly journals A New NF-κB Inhibitor, MEDS-23, Reduces the Severity of Adverse Post-Ischemic Stroke Outcomes in Rats

2021 ◽  
Vol 12 (1) ◽  
pp. 35
Author(s):  
Elina Rubin ◽  
Agnese C. Pippione ◽  
Matthew Boyko ◽  
Giacomo Einaudi ◽  
Stefano Sainas ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Artery Occlusion ◽  
Brain Inflammation ◽  
Neurological Deficits ◽  
Stroke Outcomes ◽  
Post Stroke ◽  
Factor Α ◽  
Cerebral Artery Occlusion ◽  
First Time

Aim: Nuclear factor kappa B (NF-κB) is known to play an important role in the inflammatory process which takes place after ischemic stroke. The major objective of the present study was to examine the effects of MEDS-23, a potent inhibitor of NF-κB, on clinical outcomes and brain inflammatory markers in post-ischemic stroke rats. Main methods: Initially, a Toxicity Experiment was performed to determine the appropriate dose of MEDS-23 for use in animals, as MEDS-23 was analyzed in vivo for the first time. We used the middle cerebral artery occlusion (MCAO) model for inducing ischemic stroke in rats. The effects of MEDS-23 (at 10 mg/kg, ip) on post-stroke outcomes (brain inflammation, fever, neurological deficits, mortality, and depression- and anxiety-like behaviours) was tested in several efficacy experiments. Key findings: MEDS-23 was found to be safe and significantly reduced the severity of some adverse post-stroke outcomes such as fever and neurological deficits. Moreover, MEDS-23 significantly decreased prostaglandin E2 levels in the hypothalamus and hippocampus of post-stroke rats, but did not prominently alter the levels of interleukin-6 and tumor necrosis factor-α. Significance: These results suggest that NF-κB inhibition is a potential therapeutic strategy for the treatment of ischemic stroke.

scholarly journals Intraarterial administration of norcantharidin attenuates ischemic stroke damage in rodents when given at the time of reperfusion: novel uses of endovascular capabilities

2016 ◽  
Vol 125 (1) ◽  
pp. 152-159 ◽  
Author(s):  
Imad S. Khan ◽  
Mitchell Odom ◽  
Moneeb Ehtesham ◽  
Daniel Colvin ◽  
C. Chad Quarles ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Spontaneously Hypertensive Rat ◽  
Infarct Volume ◽  
Vasogenic Edema ◽  
Critical Role ◽  
Immunohistochemical Analysis ◽  
Artery Occlusion ◽  
Spontaneously Hypertensive ◽  
Ischemic Region ◽  
Cerebral Artery Occlusion

OBJECT Matrix metalloprotease-9 (MMP-9) plays a critical role in infarct progression, blood-brain barrier (BBB) disruption, and vasogenic edema. While systemic administration of MMP-9 inhibitors has shown neuroprotective promise in ischemic stroke, there has been little effort to incorporate these drugs into endovascular modalities. By modifying the rodent middle cerebral artery occlusion (MCAO) model to allow local intraarterial delivery of drugs, one has the ability to mimic endovascular delivery of therapeutics. Using this model, the authors sought to maximize the protective potential of MMP-9 inhibition by intraarterial administration of an MMP-9 inhibitor, norcantharidin (NCTD). METHODS Spontaneously hypertensive rats were subjected to 90-minute MCAO followed immediately by local intraarterial administration of NCTD. The rats’ neurobehavioral performances were scored according to the ladder rung walking test results and the Garcia neurological test for as long as 7 days after stroke. MRI was also conducted 24 hours after the stroke to assess infarct volume and BBB disruption. At the end of the experimental protocol, rat brains were used for active MMP-9 immunohistochemical analysis to assess the degree of MMP-9 inhibition. RESULTS NCTD-treated rats showed significantly better neurobehavioral scores for all days tested. MR images also depicted significantly decreased infarct volumes and BBB disruption 24 hours after stroke. Inhibition of MMP-9 expression in the ischemic region was depicted on immunohistochemical analysis, wherein treated rats showed decreased active MMP-9 staining compared with controls. CONCLUSIONS Intraarterial NCTD significantly improved outcome when administered at the time of reperfusion in a spontaneously hypertensive rat stroke model. This study suggests that supplementing endovascular revascularization with local neuroprotective drug therapy may be a viable therapeutic strategy.

Energy-Sensing Pathways in Ischemia: The Counterbalance Between AMPK and mTORC

2020 ◽  
Vol 25 (45) ◽  
pp. 4763-4770
Author(s):  
Angel Cespedes ◽  
Mario Villa ◽  
Irene Benito-Cuesta ◽  
Maria J. Perez-Alvarez ◽  
Lara Ordoñez ◽  
...  
Keyword(s):  
Blood Flow ◽  
Ischemic Stroke ◽  
Middle Cerebral Artery ◽  
Cause Of Death ◽  
Artery Occlusion ◽  
Brain Pathology ◽  
Common Cause ◽  
Specific Analysis ◽  
Energy Sensing ◽  
Cerebral Artery Occlusion

: Stroke is an important cause of death and disability, and it is the second leading cause of death worldwide. In humans, middle cerebral artery occlusion (MCAO) is the most common cause of ischemic stroke. The damage occurs due to the lack of nutrients and oxygen contributed by the blood flow. : The present review aims to analyze to what extent the lack of each of the elements of the system leads to damage and which mechanisms are unaffected by this deficiency. We believe that the specific analysis of the effect of lack of each component could lead to the emergence of new therapeutic targets for this important brain pathology.

scholarly journals The Key Regulator of Necroptosis, RIP1 Kinase, Contributes to the Formation of Astrogliosis and Glial Scar in Ischemic Stroke

2021 ◽  
Author(s):  
Yong-Ming Zhu ◽  
Liang Lin ◽  
Chao Wei ◽  
Yi Guo ◽  
Yuan Qin ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Glial Scar ◽  
Scar Formation ◽  
Reactive Astrocytes ◽  
Interacting Protein ◽  
Protein Levels ◽  
Endothelial Growth Factor ◽  
Cerebral Artery Occlusion

AbstractNecroptosis initiation relies on the receptor-interacting protein 1 kinase (RIP1K). We recently reported that genetic and pharmacological inhibition of RIP1K produces protection against ischemic stroke-induced astrocytic injury. However, the role of RIP1K in ischemic stroke-induced formation of astrogliosis and glial scar remains unknown. Here, in a transient middle cerebral artery occlusion (tMCAO) rat model and an oxygen and glucose deprivation and reoxygenation (OGD/Re)-induced astrocytic injury model, we show that RIP1K was significantly elevated in the reactive astrocytes. Knockdown of RIP1K or delayed administration of RIP1K inhibitor Nec-1 down-regulated the glial scar markers, improved ischemic stroke-induced necrotic morphology and neurologic deficits, and reduced the volume of brain atrophy. Moreover, knockdown of RIP1K attenuated astrocytic cell death and proliferation and promoted neuronal axonal generation in a neuron and astrocyte co-culture system. Both vascular endothelial growth factor D (VEGF-D) and its receptor VEGFR-3 were elevated in the reactive astrocytes; simultaneously, VEGF-D was increased in the medium of astrocytes exposed to OGD/Re. Knockdown of RIP1K down-regulated VEGF-D gene and protein levels in the reactive astrocytes. Treatment with 400 ng/ml recombinant VEGF-D induced the formation of glial scar; conversely, the inhibitor of VEGFR-3 suppressed OGD/Re-induced glial scar formation. RIP3K and MLKL may be involved in glial scar formation. Taken together, these results suggest that RIP1K participates in the formation of astrogliosis and glial scar via impairment of normal astrocyte responses and enhancing the astrocytic VEGF-D/VEGFR-3 signaling pathways. Inhibition of RIP1K promotes the brain functional recovery partially via suppressing the formation of astrogliosis and glial scar. Graphical Abstract

scholarly journals Uric acid promotes oxidative stress and enhances vascular endothelial cell apoptosis in rats with middle cerebral artery occlusion

2018 ◽  
Vol 38 (3) ◽  
Author(s):  
Chengfu Song ◽  
Xiangdong Zhao
Keyword(s):  
Oxidative Stress ◽  
Uric Acid ◽  
Endothelial Cell ◽  
Cell Apoptosis ◽  
Vascular Endothelial Cell ◽  
Artery Occlusion ◽  
Vascular Endothelial ◽  
Endothelial Cell Apoptosis ◽  
Related Factors ◽  
Cerebral Artery Occlusion

In patients with cerebral infarction (CI), elevated serum uric acid (UA) level may exacerbate the occurrence and development of carotid atherosclerosis (AS). Our study intended to explore the underlying mechanism. We enrolled 86 patients with CI, and divided them into four groups: Non-AS, AS-mild, AS-moderate, and AS-severe groups; the levels of UA and oxidative stress-related factors in serum were detected. The middle cerebral artery occlusion (MCAO) model was used to stimulate CI in rats, and different doses of UA were administrated. The levels of oxidative stress-related factors in serum were detected. Hematoxylin & eosin (H&E) staining was used to observe the morphological alterations, and the apoptotic cell death detection kit was used to detect apoptotic cells. Increased UA concentration and enhanced oxidative stress were found in AS patients. H&E staining results showed that UA treatment exacerbated morphological damage in rats with MCAO, promoted oxidative stress, and enhanced vascular endothelial cell apoptosis in rats with MCAO.

Abstract 3773: The Impact Of Reperfusion On Vasogenic Edema Following Middle Cerebral Artery Occlusion In Experimental Ischemia

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Gregory Christoforidis ◽  
Cameron Rink ◽  
Nitn Garg ◽  
Shahid Khan ◽  
Chandan Sen
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Infarct Volume ◽  
Vasogenic Edema ◽  
Canine Model ◽  
Artery Occlusion ◽  
Permanent Occlusion ◽  
Linear Fit ◽  
Cerebral Artery Occlusion ◽  
The Impact

Objective: In order to assess the impact of reperfusion on the degree of subsequent cerebral edema following cerebral ischemia, this work sought to compare 24 hour infarct volume progression between permanent and transient middle cerebral artery occlusion (MCAO) in a canine model. Methods: Using a previously published endovascular transient MCAO method, 5 mongrel canines underwent 1-hour transient MCAO and 5 underwent permanent MCAO. Model parameters were altered to result in varying infarct volumes. Magnetic resonanace imaging (MRI) (3T Achieva, Philips) was performed one hour and 24 hours following reperfusion as well as 60 minutes following permanent occlusion. Infarct volumes were calculated using a previously published threshold technique by two observers using 1 hour mean diffusivity (MD) maps and 24hour FLAIR MRI. Reproducibility was assessed using Bland-Altman statistic. Average infarct volumes between the observers were calculated. Bivariate linear fit analysis were used to assess the correlation between immediate and 24 hours infarct volume determinations. Results: R square (r2) for linear fit was 0.964 (p=0.0005) for permanent occlusion and 0.971 (p= 0.0022) for transient occlusion ( figure 1 ). The infarct volumes measured at 1 hour increased by a factor of 1.42 relative to 24 hour infarct volumes for permanent occlusion and 2.05 for transient occlusion. Bland-Altman statistic indicates that reproducibility using the MD maps (15.9%) and FLAIR images (13.3%) is not substantially different. None of the animals demonstrated hemorrhagic conversion by 24 hours. Conclusion: MD maps generated one hour post reperfusion following transient and permanent MCAO in a canine model can serve as a reliable assessment for infarct volume determination. Increase in infarct volume at 24 hours, presumably due to vasogenic edema, was greater in reperfused infarctions than with permanent occlusion. Figure 1: Bivariate linear fit analysis comparing immediate and 24-hour infarct volume calculations for permanent and transient occlusions.

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