Abstract P70: SPAK/OSR1 Signaling as a Novel Target for Post-Stroke Oxidative Stress Brain Injury

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Jun Wang ◽  
Victoria M Fiesler ◽  
Gulnaz Begum ◽  
Mohammad Iqbal H Bhuiyan ◽  
Shuying Dong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ischemic Stroke ◽  
Brain Injury ◽  
Neuronal Damage ◽  
Recombinant Tissue Plasminogen Activator ◽  
Primary Therapy ◽  
Post Stroke ◽  
Stroke Models ◽  
Novel Target

Stroke is the second leading cause of death worldwide, and ischemic stroke accounts for the vast majority of stroke cases. Currently, recombinant tissue plasminogen activator and endovascular thrombectomy are the two primary therapy strategies for acute ischemic stroke patients. Reactive oxygen species (ROS)-mediated oxidative stress can cause brain injury during reperfusion. We have shown that the Ste20/SPS1-related proline-alanine-rich protein kinase/oxidative stress-responsive kinase-1 (SPAK/OSR1) are activated in ischemic stroke brains, resulting in worsened outcomes in murine stroke models. SPAK activation induces the production of pro-inflammatory cytokines. Post-stroke administration of a novel SPAK inhibitor ZT-1a attenuates cerebral edema and protects against brain damage in in vivo model of ischemic stroke. However, whether ROS mediated oxidative stress directly activate SPAK/OSR1 pathway and induces SPAK pro-inflammatory cytokine production in ischemic brains remains unknown. In our extended study, we examined activation of SPAK/OSR1 and its substrate Na-K-Cl cotransporter (NKCC1) in cultured mouse primary neurons in response to hydrogen peroxide (H 2 O 2 )-mediated oxidative stress. We found that exposure of neurons to H 2 O 2 for 24 hrs triggered upregulation of protein expression and phosphorylation activation of SPAK/OSR1 and NKCC1 ( p < 0.05), which are accompanied with an increase in intracellular Na + concentration and neuronal death ( p < 0.01). These changes were blocked by an ROS scavenger ebselen. Interestingly, both novel SPAK inhibitor ZT-1a and NKCC1 inhibitor bumetanide are able to block H 2 O 2 -induced neuronal damage. We are in the process to assess effects of SPAK inhibitor ZT-1a in reducing ROS-mediated inflammation and brain injury in in vivo model of ischemic stroke. Together, our study suggests that ROS can activate SPAK/OSR1 complex during reperfusion injury and the therapeutic potentials of SPAK inhibitor ZT-1a for ischemic stroke.

Abstract TP282: Increased Resiliency of Astrocytic Mitochondria After Focal Ischemic Stroke in Juvenile Mice

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Evelyn K Shih ◽  
Sabrina DaSilva ◽  
Elizabeth Krizman ◽  
Meredith L Lee ◽  
Michael B Robinson
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Viral Vectors ◽  
Fluorescent Protein ◽  
Stroke Onset ◽  
Mitochondrial Morphology ◽  
Post Stroke ◽  
Mca Occlusion ◽  
Age Dependent

Introduction: Astrocytes provide bioenergetic support to neurons, mediate neurovascular coupling, buffer extracellular ions, and limit excitotoxicity. They undergo many rapid changes following ischemic brain injury, which may shape the extent of damage. The role of astrocytic mitochondria in astroglial functioning and response to brain injury remain underexplored. We investigated age dependent changes to astrocytic mitochondria following focal ischemic stroke in vivo using a clot-based mouse model of middle cerebral artery (MCA) occlusion. Methods: Male and female wildtype C57BL/6N neonatal mice underwent retro-orbital injections of AAV2/5 viral vectors containing mitochondrial targeted enhanced green fluorescent protein under the control of the astrocyte-specific glial fibrillary acidic protein promoter. Mice were allowed to age to 21-35 days (juvenile group) or 10-20 weeks (adult group). Proximal right MCA occlusion was provoked via photothrombosis using Rose Bengal dye and a targeted 532 nm laser beam. Control mice underwent sham procedures. Mice were perfused at 1, 3 or 24 hours post-stroke onset. Brains were processed and sectioned for mitochondrial analysis ( n = 3 animals/30 cells per time point per age group). Quantitative analyses were performed using a novel mitochondrial morphology scoring system. Results: Penumbral astrocytic mitochondria are markedly reduced in density, demonstrate decreased network complexity and adopt punctate spherical morphology compared to contralateral non-stroke hemisphere and sham animals. These changes are present within 1 hour of stroke onset. Preliminary data indicate at least 50% change in adult mice. These changes are attenuated in juvenile mice, with increased recovery seen at 24 hours post-stroke ictus. Conclusions: Astrocytic mitochondria within the penumbra undergo rapid loss and morphologic changes suggestive of dysfunction following proximal MCA occlusion. These changes are less severe in young mice indicating age-dependent resiliency of astrocytic mitochondria to ischemic injury. Further investigation into the mechanisms underlying astrocytic mitochondrial resiliency in the developing brain may reveal new strategies to limit stroke injury and improve outcomes.

scholarly journals Neuroprotection by Brazilian Green Propolis againstIn vitroandIn vivoIschemic Neuronal Damage

2005 ◽  
Vol 2 (2) ◽  
pp. 201-207 ◽  
Author(s):  
Masamitsu Shimazawa ◽  
Satomi Chikamatsu ◽  
Nobutaka Morimoto ◽  
Satoshi Mishima ◽  
Hiroichi Nagai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cerebral Ischemia ◽  
Neuronal Damage ◽  
Focal Cerebral Ischemia ◽  
Brain Infarction ◽  
Folk Medicine ◽  
Neuroprotective Function ◽  
Brazilian Green Propolis

We examined whether Brazilian green propolis, a widely used folk medicine, has a neuroprotective functionin vitroand/orin vivo.In vitro, propolis significantly inhibited neurotoxicity induced in neuronally differentiated PC12 cell cultures by either 24 h hydrogen peroxide (H2O2) exposure or 48 h serum deprivation. Regarding the possible underlying mechanism, propolis protected against oxidative stress (lipid peroxidation) in mouse forebrain homogenates and scavenged free radicals [induced by diphenyl-p-picrylhydrazyl (DPPH). In micein vivo, propolis [30 or 100 mg/kg; intraperitoneally administered four times (at 2 days, 1 day and 60 min before, and at 4 h after induction of focal cerebral ischemia by permanent middle cerebral artery occlusion)] reduced brain infarction at 24 h after the occlusion. Thus, a propolis-induced inhibition of oxidative stress may be partly responsible for its neuroprotective function againstin vitrocell death andin vivofocal cerebral ischemia.

Neuroprotection via AT2 receptor agonists in ischemic stroke

2018 ◽  
Vol 132 (10) ◽  
pp. 1055-1067 ◽  
Author(s):  
Douglas M. Bennion ◽  
U. Muscha Steckelings ◽  
Colin Sumners
Keyword(s):  
Ischemic Stroke ◽  
Neuronal Damage ◽  
Recombinant Tissue Plasminogen Activator ◽  
Neurological Deficits ◽  
At2 Receptor ◽  
Neuroprotective Effects ◽  
Receptor Agonists ◽  
Stroke Epidemiology ◽  
The Brain

Stroke is a devastating disease that afflicts millions of people each year worldwide. Ischemic stroke, which accounts for ~88% of cases, occurs when blood supply to the brain is decreased, often because of thromboembolism or atherosclerotic occlusion. This deprives the brain of oxygen and nutrients, causing immediate, irreversible necrosis within the core of the ischemic area, but more delayed and potentially reversible neuronal damage in the surrounding brain tissue, the penumbra. The only currently approved therapies for ischemic stroke, the thrombolytic agent recombinant tissue plasminogen activator (rtPA) and the endovascular clot retrieval/destruction processes, are aimed at restoring blood flow to the infarcted area, but are only available for a minority of patients and are not able in most cases to completely restore neurological deficits. Consequently, there remains a need for agents that will protect neurones against death following ischemic stroke. Here, we evaluate angiotensin II (Ang II) type 2 (AT2) receptor agonists as a possible therapeutic target for this disease. We first provide an overview of stroke epidemiology, pathophysiology, and currently approved therapies. We next review the large amount of preclinical evidence, accumulated over the past decade and a half, which indicates that AT2 receptor agonists exert significant neuroprotective effects in various animal models, and discuss the potential mechanisms involved. Finally, after discussing the challenges of delivering blood–brain barrier (BBB) impermeable AT2 receptor agonists to the infarcted areas of the brain, we summarize the evidence for and against the development of these agents as a promising therapeutic strategy for ischemic stroke.

Abstract T MP18: In Vivo Expansion of Regulatory T cells with Interleukin-2/Interleukin-2-antibody Complex Protects against Transient Ischemic Stroke

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Haiyue Zhang ◽  
Peiying Li ◽  
Yanqin Gao ◽  
Jun Chen ◽  
Xiaoming Hu
Keyword(s):  
T Cells ◽  
Ischemic Stroke ◽  
Brain Injury ◽  
Regulatory T Cells ◽  
Interleukin 2 ◽  
Ischemic Brain Injury ◽  
Ischemic Brain ◽  
Treg Population ◽  
Antibody Complex

Background and Purpose: Our previous work documents the transfer of regulatory T cells (Tregs) in rodent models of ischemic stroke protects acute ischemic brain injury by regulating poststroke inflammatory response and thereby ameliorating BBB disruption. However, the low number of Tregs restricts the clinical feasibility of Treg transfer. Recently, in vivo expansion of Tregs with IL-2/IL-2-antibody complex (IL-2/IL-2Ab) was validated protective in autoimmune diseases model,renal ischemia reperfusion model and atherosclerosis. Here we investigate the beneficial effect of IL-2/IL-2Ab on ischemic stroke and decipher the underlying mechanisms. Methods: IL-2/IL-2Ab or isotype IgG was ip injected into C57/BL6 mice for 3 consecutive days. The mice are then subjected to 60-minute middle cerebral artery occlusion (MCAO) or sham operation. Brain infarction, inflammation and neurological performance was assessed up to 7 days after reperfusion. Results: Flow cytometry analysis reveals a marked increase of CD4+CD25+Foxp3+ Tregs in the blood, lymph nodes and spleens collected from IL-2/IL-2Ab-treated mice as compared to those from isotype-treated controls. Such Treg elevation could be observed since 3 days after IL-2/IL-2Ab injection and lasts until 7 days after MCAO. Immunochemistry staining confirms the increased number of Foxp3+ cells in the spleen at 3 days after MCAO in IL-2/IL-2Ab-treated mice. IL-2/IL-2Ab promotes function recovery up to 7 days after stroke, as revealed by significantly improved performance in corner test (n=6-9, ***p<0.001), rotarod test (n=8, **p<0.01), cylinder test (n=8, **p<0.01) and adhesive removal test (n=3, *p<0.05). Quantification of TTC staining and microtubule-associated protein (MAP2) staining shows reductions in brain infarct volume at 3 days (n=5-9,*p<0.05) and 7 days (n=7-9,*p<0.01), respectively, after MCAO. Meanwhile, we observed reduced infiltration of peripheral immune cells (CD3+ T cells, MPO+ neutrophils and F4/80+ macrophages) into the ischemic brain. Conclusions: Our finding suggests that IL-2/IL-2Ab treatment is a novel and clinical feasible immune therapy to expand Treg population in vivo, reduce post-stroke inflammatory responses and protect against ischemic brain injury.

A Review on Preclinical Models of Ischemic Stroke: Insights Into the Pathomechanisms and New Treatment Strategies

2021 ◽  
Vol 19 ◽  
Author(s):  
Aditya A Singh ◽  
Akash Kharwar ◽  
Manoj P. Dandekar
Keyword(s):  
Stem Cell ◽  
Ischemic Stroke ◽  
Cell Therapy ◽  
Stem Cell Therapy ◽  
Neurotrophic Factors ◽  
Treatment Strategies ◽  
Experimental Models ◽  
Cerebral Stroke ◽  
Post Stroke ◽  
Stroke Models

Background: Stroke is a serious neurovascular problem and the leading cause of disability and death worldwide. The disrupted demand to supply ratio of blood and glucose during cerebral ischemia develops hypoxic shock, and subsequently necrotic neuronal death in the affected regions. Multiple causal factors like age, sex, race, genetics, diet, and lifestyle play an important role in the occurrence as well as progression of post-stroke deleterious events. These biological and environmental factors may be contributed to vasculature variable architecture and abnormal neuronal activity. Since recombinant tissue plasminogen activator is the only clinically effective clot bursting drug, there is a huge unmet medical need for newer therapies for the treatment of stroke. Innumerous therapeutic interventions have shown promise in the experimental models of stroke but failed to translate it into clinical counterparts. Methods: Original publications regarding pathophysiology, preclinical experimental models, new targets and therapies targeting ischemic stroke have been reviewed since the 1970s. Results: We highlighted the critical underlying pathophysiological mechanisms of cerebral stroke and preclinical stroke models. We discuss the strengths and caveats of widely used ischemic stroke models, and commented on the potential translational problems. We also describe the new emerging treatment strategies, including stem cell therapy, neurotrophic factors and gut microbiome-based therapy for the management of post-stroke consequences. Results : We highlighted the critical underlying pathophysiological mechanisms of cerebral stroke and preclinical stroke models. We discuss the strengths and caveats of widely used ischemic stroke models, and commented on the potential translational problems. We also describe the new emerging treatment strategies, including stem cell therapy, neurotrophic factors and gut microbiome-based therapy for the management of post-stroke consequences. Conclusion: There are still many inter-linked pathophysiological alterations with regards to stroke, animal models need not necessarily mimic the same conditions of stroke pathology and newer targets and therapies are the need of the hour in stroke research.

scholarly journals AP-1 (Activated Protein-1) Transcription Factor JunD Regulates Ischemia/Reperfusion Brain Damage via IL-1β (Interleukin-1β)

Stroke ◽  
2019 ◽  
Vol 50 (2) ◽  
pp. 469-477 ◽  
Author(s):  
Candela Diaz-Cañestro ◽  
Martin F. Reiner ◽  
Nicole R. Bonetti ◽  
Luca Liberale ◽  
Mario Merlini ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Acute Ischemic Stroke ◽  
Peripheral Blood ◽  
Ischemia Reperfusion ◽  
Interleukin 1Β ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes

Background and Purpose— Inflammation is a major pathogenic component of ischemia/reperfusion brain injury, and as such, interventions aimed at inhibiting inflammatory mediators promise to be effective strategies in stroke therapy. JunD—a member of the AP-1 (activated protein-1) family of transcription factors—was recently shown to regulate inflammation by targeting IL (interleukin)-1β synthesis and macrophage activation. The purpose of the present study was to assess the role of JunD in ischemia/reperfusion-induced brain injury. Methods— WT (wild type) mice randomly treated with either JunD or scramble (control) siRNA were subjected to 45 minutes of transient middle cerebral artery occlusion followed by 24 hours of reperfusion. Stroke size, neurological deficit, plasma/brain cytokines, and oxidative stress determined by 4-hydroxynonenal immunofluorescence staining were evaluated 24 hours after reperfusion. Additionally, the role of IL-1β was investigated by treating JunD siRNA mice with an anti–IL-1β monoclonal antibody on reperfusion. Finally, JunD expression was assessed in peripheral blood monocytes isolated from patients with acute ischemic stroke. Results— In vivo JunD knockdown resulted in increased stroke size, reduced neurological function, and increased systemic inflammation, as confirmed by higher neutrophil count and lymphopenia. Brain tissue IL-1β levels were augmented in JunD siRNA mice as compared with scramble siRNA, whereas no difference was detected in IL-6, TNF-α (tumor necrosis factor-α), and 4-hydroxynonenal levels. The deleterious effects of silencing of JunD were rescued by treating mice with an anti–IL-1β antibody. In addition, JunD expression was decreased in peripheral blood monocytes of patients with acute ischemic stroke at 6 and 24 hours after onset of stroke symptoms compared with sex- and age-matched healthy controls. Conclusions— JunD blunts ischemia/reperfusion-induced brain injury via suppression of IL-1β.

scholarly journals Inhibition of Oxidative Neurotoxicity and Scopolamine-Induced Memory Impairment by γ-Mangostin: In Vitro and In Vivo Evidence

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Youngmun Lee ◽  
Sunyoung Kim ◽  
Yeonsoo Oh ◽  
Young-Mi Kim ◽  
Young-Won Chin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Memory Impairment ◽  
Neuronal Damage ◽  
Biological Activities ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Ros Generation ◽  
Garcinia Mangostana

Among a series of xanthones identified from mangosteen, the fruit of Garcinia mangostana L. (Guttifereae), α- and γ-mangostins are known to be major constituents exhibiting diverse biological activities. However, the effects of γ-mangostin on oxidative neurotoxicity and impaired memory are yet to be elucidated. In the present study, the protective effect of γ-mangostin on oxidative stress-induced neuronal cell death and its underlying action mechanism(s) were investigated and compared to that of α-mangostin using primary cultured rat cortical cells. In addition, the effect of orally administered γ-mangostin on scopolamine-induced memory impairment was evaluated in mice. We found that γ-mangostin exhibited prominent protection against H2O2- or xanthine/xanthine oxidase-induced oxidative neuronal death and inhibited reactive oxygen species (ROS) generation triggered by these oxidative insults. In contrast, α-mangostin had no effects on the oxidative neuronal damage or associated ROS production. We also found that γ-mangostin, not α-mangostin, significantly inhibited H2O2-induced DNA fragmentation and activation of caspases 3 and 9, demonstrating its antiapoptotic action. In addition, only γ-mangostin was found to effectively inhibit lipid peroxidation and DPPH radical formation, while both mangostins inhibited β-secretase activity. Furthermore, we observed that the oral administration of γ-mangostin at dosages of 10 and 30 mg/kg markedly improved scopolamine-induced memory impairment in mice. Collectively, these results provide both in vitro and in vivo evidences for the neuroprotective and memory enhancing effects of γ-mangostin. Multiple mechanisms underlying this neuroprotective action were suggested in this study. Based on our findings, γ-mangostin could serve as a potentially preferable candidate over α-mangostin in combatting oxidative stress-associated neurodegenerative diseases including Alzheimer’s disease.

scholarly journals Indomethacin Ameliorates Trimethyltin-Induced Neuronal Damage in Vivo by Attenuating Oxidative Stress in the Dentate Gyrus of Mice

2011 ◽  
Vol 34 (12) ◽  
pp. 1856-1863 ◽  
Author(s):  
Nguyen Quynh Huong ◽  
Yukary Nakamura ◽  
Nobuyuki Kuramoto ◽  
Masanori Yoneyama ◽  
Reiko Nagashima ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Dentate Gyrus ◽  
Neuronal Damage

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 Isoquercetin Improves Inflammatory Response in Rats Following Ischemic Stroke

2021 ◽  
Vol 15 ◽  
Author(s):  
Yunwei Shi ◽  
Xinyi Chen ◽  
Jiaxing Liu ◽  
Xingjuan Fan ◽  
Ying Jin ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Inflammatory Response ◽  
Signaling Pathway ◽  
Neurological Deficits ◽  
Cell Recovery ◽  
C5a Receptor ◽  
Neuroprotective Agent

Inflammatory response contributes to brain injury after ischemia and reperfusion (I/R). Our previous literature has shown isoquercetin plays an important role in protecting against cerebral I/R injury. The present study was conducted to further investigate the effect of isoquercetin on inflammation-induced neuronal injury in I/R rats with the involvement of cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) and inhibitor of NF-κB (I-κB)/nuclear factor-kappa B (NF-κB) signaling pathway mediated by Toll-like receptor 4 (TLR4) and C5a receptor 1 (C5aR1). In vivo middle cerebral artery occlusion and reperfusion (MCAO/R) rat model and in vitro oxygen-glucose deprivation and reperfusion (OGD/R) neuron model were used. MCAO/R induced neurological deficits, cell apoptosis, and release of cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in ischemic brain in rats. Simultaneously, the expression of TLR4 and C5aR1 was significantly up-regulated in both MCAO/R rats and OGD/R neurons, accompanied with the inhibition of cAMP/PKA signaling and activation of I-κB/NF-κB signaling in the cortex of MCAO/R rats. Over-expression of C5aR1 in neurons induced decrease of cell viability, exerting similar effects with OGD/R injury. Isoquercetin acted as a neuroprotective agent against I/R brain injury to suppress inflammatory response and improve cell recovery by inhibiting TLR4 and C5aR1 expression, promoting cAMP/PKA activation, and inhibiting I-κB/NF-κB activation and Caspase 3 expression. TLR4 and C5aR1 contributed to inflammation and apoptosis via activating cAMP/PKA/I-κB/NF-κB signaling during cerebral I/R, suggesting that this signaling pathway may be a potent therapeutic target in ischemic stroke. Isoquercetin was identified as a neuroprotective agent, which maybe a promising therapeutic agent used for the treatment of ischemic stroke and related diseases.

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