Abstract WP321: The Role of Neuronal Sirt1 in Ischemic Stroke: Regulation of the Metabolic Imbalance

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Ge Li ◽  
Xiu-Jun Ren ◽  
Su-In Cho ◽  
Wenliang Zhong ◽  
Yong-Joo Ahn ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Test Strip ◽  
Littermate Control ◽  
Knock Out ◽  
Injury Model ◽  
Infarction Volume ◽  
Metabolic Imbalance

Introduction: Sirt1 is a NAD+ dependent deacetylase that is known as an important metabolic regulator for type 2 diabetes melitus. To determine the role of Sirt1 in ischemic stroke-induced metabolic imbalance, we generated the neuronal specific Sirt1 knock-in (nSirt1 KI) and knock-out (Sirt1 KO) mice and examined its effect and mechanism. Methods: To determine the role of Sirt1 in ischemic stroke-induced impaired metabolic actions including insulin and glucose abnormality, we tested the pharmacological effects of Metformin and Sirtinol as Sirt1 activator and inhibitor. To determine the genetic role of neuronal Sirt1 in the brain, we generated the nSirt1 KI mice and Sirt1 KO. We used the Ischemia/Reperfusion (I/R: 1h middle cerebral artery occlusion (MCAO)/23h reperfusion) injury model to induce the abnormal metabolic changes. Infarction volume was measured by TTC staining and we determined neurological deficit score (NDS) at 23h after 1h MCAO. The level of glucose and insulin were measured by a drop of tail blood using test-strip and ELISA Kit before, during (every 10 minutes interval), and after MCAO. Results: Metformin reduced infarction volume and Sirtinol worsened the infarction volume via Sirt1 signaling pathway. Heterozygous Sirt1 KO (Sirt1 +/-) mice showed decreased relative cerebral blood flow (rCBF) and worsen infarction volume in ischemic areas, whereas nSirt1 KI mice exhibited increased rCBF, improved NDS, regulating abnormal blood glucose and insulin, and reduced infarction volume by 42% compare to that of littermate control in I/R injury model (n=7, p<0.05). Based on western blotting analysis of brain lysates in nSirt1 KI mice, the expression of Sirt1 was significantly increased. Glucose regulation by overexpression of Sirt1 and reduced infarction volume in nSirt1 KI mice were reversed by Sirtinol. Conclusion: These findings indicate that the important neuroprotective effect of neuronal cells is mediated by Sirt1 overexpression and suggest that upregulation of neuronal Sirt1 may be an important therapeutic target for ischemic stroke via regulating metabolic imbalance.

scholarly journals 20-HETE-mediated cytotoxicity and apoptosis in ischemic kidney epithelial cells

2008 ◽  
Vol 294 (3) ◽  
pp. F562-F570 ◽  
Author(s):  
Vani Nilakantan ◽  
Cheryl Maenpaa ◽  
Guangfu Jia ◽  
Richard J. Roman ◽  
Frank Park
Keyword(s):  
Caspase 3 ◽  
Fluorescent Protein ◽  
Ischemia Reperfusion ◽  
Atp Depletion ◽  
Cellular Damage ◽  
Apoptotic Pathway ◽  
Injury Model ◽  
Green Fluorescent

20-HETE, a metabolite of arachidonic acid, has been implicated as a mediator of free radical formation and tissue death following ischemia-reperfusion (IR) injury in the brain and heart. The present study examined the role of this pathway in a simulated IR renal injury model in vitro. Modified self-inactivating lentiviral vectors were generated to stably overexpress murine Cyp4a12 following transduction into LLC-PK1 cells (LLC-Cyp4a12). We compared the survival of control and transduced LLC-PK1 cells following 4 h of ATP depletion and 2 h of recovery in serum-free medium. ATP depletion-recovery of LLC-Cyp4a12 cells resulted in a significantly higher LDH release ( P < 0.05) compared with LLC-enhanced green fluorescent protein (EGFP) cells. Treatment with the SOD mimetic MnTMPyP (100 μM) resulted in decreased cytotoxicity in LLC-Cyp4a12 cells. The selective 20-HETE inhibitor HET-0016 (10 μM) also inhibited cytotoxicity significantly ( P < 0.05) in LLC-Cyp4a12 cells. Dihydroethidium fluorescence showed that superoxide levels were increased to the same degree in LLC-EGFP and LLC-Cyp4a12 cells after ATP depletion-recovery compared with control cells and that this increase was inhibited by MnTMPyP. There was a significant increase ( P < 0.05) of caspase-3 cleavage, an effector protease of the apoptotic pathway, in the LLC-Cyp4a12 vs. LLC-EGFP cells ( P < 0.05). This was abolished in the presence of HET-0016 ( P < 0.05) or MnTMPyP ( P < 0.01). These results demonstrate that 20-HETE overexpression can significantly exacerbate the cellular damage that is associated with renal IR injury and that the programmed cell death is mediated by activation of caspase-3 and is partially dependent on enhanced CYP4A generation of free radicals.

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 Emerging Role of Ferroptosis in the Pathogenesis of Ischemic Stroke: A New Therapeutic Target?

ASN NEURO ◽  
2021 ◽  
Vol 13 ◽  
pp. 175909142110375
Author(s):  
Zhong-Qi Bu ◽  
Hai-Yang Yu ◽  
Jue Wang ◽  
Xin He ◽  
Yue-Ran Cui ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
High Morbidity ◽  
Treatment And Prevention ◽  
Regulated Cell Death ◽  
Programmed Death ◽  
Research Findings

Ischemic stroke is one of the main causes of high morbidity, mortality, and disability worldwide; however, the treatment methods are limited and do not always achieve satisfactory results. The pathogenesis of ischemic stroke is complex, defined by multiple mechanisms; among them, programmed death of neuronal cells plays a significant role. Ferroptosis is a novel type of regulated cell death characterized by iron redistribution or accumulation and increased lipid peroxidation in the membrane. Ferroptosis is implicated in many pathological conditions, such as cancer, neurodegenerative diseases, and ischemia-reperfusion injury. In this review, we summarize current research findings on ferroptosis, including possible molecular mechanisms and therapeutic applications of ferroptosis regulators, with a focus on the involvement of ferroptosis in the pathogenesis and treatment of ischemic stroke. Understanding the role of ferroptosis in ischemic stroke will throw some light on the development of methods for diagnosis, treatment, and prevention of this devastating disease.

scholarly journals Butylphthalide Inhibits TLR4/NF-κB Pathway by Upregulation of miR-21 to Have the Neuroprotective Effect

2022 ◽  
Vol 2022 ◽  
pp. 1-10
Author(s):  
Lan Zhan ◽  
Yu Pang ◽  
Hao Jiang ◽  
Shicun Zhang ◽  
Hongwei Jin ◽  
...  
Keyword(s):  
Sham Group ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Treated Group ◽  
Neurologic Impairment ◽  
Injury Model ◽  
Group A ◽  
Neuro2a Cells ◽  
And Control

Stroke is a disease with the highest incidence rate and the highest mortality rate in the world. The study aims to verify the neuroprotective effect of Butylphthalide. The mice were divided into sham group, MCAO group, and MCAO + Butylphthalide-treated group. The mice in MCAO + Butylphthalide-treated group were administered with 70 mg/kg Butylphthalide injection intraperitoneally after cerebral ischemia-reperfusion. The normal saline with the same volume was administered intraperitoneally for the mice in the MCAO group and sham group. The levels of miR-21 in brain tissue and cells were detected by qPCR. The OGD/R injury model of Neuro2A cells was used to simulate the hypoxic-ischemic environment of neurons in vitro. The proliferation rate of Neuro2A cells was detected with CCK-8. The production of ROS was detected with DCFH-DA. Compared with the mice in MCAO group, a decrease ( P < 0.01 ) was observed in the functional neurologic impairment scoring, cerebral infarction volume, and brain loss volume in the mice treated with MCAO + Butylphthalide, but an increase ( P < 0.01 ) was observed in the level of miR-21, which was positively correlated with functional neurologic impairment scoring (r = −0.8933, P < 0.001 ). MTT assay showed that the cell viability of OGD/R + Butylphthalide group was significantly higher than that of other groups ( P < 0.001 ), and the activity of ROS was significantly decreased ( P < 0.001 ). The WB results showed that, compared with OGD/R + miR-NC and control groups, the ratio of Bcl-2/Bax in OGD/R + Butylphthalide group and OGD/R + miR-21 mimics group was significantly higher ( P < 0.05 ), while the ratio of caspase-3/GAPDH was significantly lower ( P < 0.05 ). In conclusion, Butylphthalide has neuroprotective effect on the mouse model of MCAO. It may upregulate the level of miR-21 to inhibit neuronal apoptosis and ROS production and improve the proliferation activity. The specific mechanism may lie in inhibiting TLR4/NF-κB pathway.

Remote ischemic conditioning for acute moderate ischemic stroke (RICAMIS): Rationale and design

2019 ◽  
Vol 15 (4) ◽  
pp. 454-460
Author(s):  
Xiao-Qiu Li ◽  
Lin Tao ◽  
Zhong-He Zhou ◽  
Yu Cui ◽  
Hui-Sheng Chen ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Clinical Studies ◽  
Ischemia Reperfusion Injury ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Control Group ◽  
Open Label ◽  
Remote Ischemic Conditioning ◽  
Ischemic Conditioning ◽  
Experimental Group

Rationale A large number of basic and clinical studies have proved that remote ischemic conditioning has neuroprotective effect. For example, remote ischemic conditioning showed a neuroprotective role in cerebral ischemia-reperfusion injury model. Recent clinical studies suggested that remote ischemic conditioning may improve neurological function and reduce the risk of recurrence in ischemic stroke patients. However, there is a lack of convincing evidence for the neuroprotective effect of remote ischemic conditioning on ischemic stroke, which deserves further study. Aim To explore the efficacy and safety of remote ischemic conditioning for acute moderate ischemic stroke. Sample size estimates A maximum of 1800 subjects are required to test the superiority hypothesis with 80% power according to a one-sided 0.025 level of significance, stratified by gender, age, time from onset to treatment, National Institutes of Health Stroke Scale (6–10 vs. 11–16), degree of responsible vessel stenosis, location of stenosis, and stroke etiology. Methods and design Remote Ischemic Conditioning for Acute Moderate Ischemic Stroke is a prospective, random, open label, blinded endpoint and multi-center study. The subjects are divided into experimental group and control group randomly. The experimental group was treated with remote ischemic conditioning twice daily with 200 mmHg pressure for 10–14 days besides guideline-based therapy. The control group was treated according to the guidelines. Study outcome The primary efficacy endpoint is favorable functional outcome, defined as modified Rankin Scale 0–1 at 90 days post-randomization.

scholarly journals Neuroprotective Effect of Phosphocreatine on Focal Cerebral Ischemia-Reperfusion Injury

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Tiegang Li ◽  
Nana Wang ◽  
Min Zhao
Keyword(s):  
Ischemia Reperfusion Injury ◽  
Focal Cerebral Ischemia ◽  
Protective Efficacy ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Creatine Phosphate ◽  
High Energy ◽  
Aquaporin 4 ◽  
Neurological Score ◽  
Infarction Volume

Phosphocreatine (PCr) is a natural compound, which can donate high-energy phosphate group to ADP to synthesize ATP, even in the absence of oxygen and glucose. At present, it is widely used in cardiac and renal ischemia-reperfusion (IR) disease. In this study, to examine the protective efficacy of PCr against cerebral IR, disodium creatine phosphate was injected intravenously into rats before focal cerebral IR. Intracranial pressure (ICP), neurological score, cerebral infarction volume, and apoptotic neurons were observed. Expression of caspase-3 and aquaporin-4 (AQP4) was analyzed. Compared with IR group, rats pretreated with PCr had better neurologic score, less infarction volume, fewer ultrastructural histopathologic changes, reduced apoptosis, and lower aquaporin-4 level. In conclusion, PCr is neuroprotective after transient focal cerebral IR injury. Such a protection might be associated with apoptosis regulating proteins.

scholarly journals Melatonin and Ischemic Stroke: Mechanistic Roles and Action

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Syed Suhail Andrabi ◽  
Suhel Parvez ◽  
Heena Tabassum
Keyword(s):  
Ischemic Stroke ◽  
Brain Injury ◽  
Neurological Diseases ◽  
Neuroprotective Effect ◽  
Economic Loss ◽  
Protective Role ◽  
Physiological Processes ◽  
Cord Injury ◽  
The Brain

Stroke is one of the most devastating neurological disabilities and brain’s vulnerability towards it proves to be fatal and socio-economic loss of millions of people worldwide. Ischemic stroke remains at the center stage of it, because of its prevalence amongst the several other types attacking the brain. The various cascades of events that have been associated with stroke involve oxidative stress, excitotoxicity, mitochondrial dysfunction, upregulation of Ca2+level, and so forth. Melatonin is a neurohormone secreted by pineal and extra pineal tissues responsible for various physiological processes like sleep and mood behaviour. Melatonin has been implicated in various neurological diseases because of its antioxidative, antiapoptotic, and anti-inflammatory properties. We have previously reviewed the neuroprotective effect of melatonin in various models of brain injury like traumatic brain injury and spinal cord injury. In this review, we have put together the various causes and consequence of stroke and protective role of melatonin in ischemic stroke.

scholarly journals The role of arachidonic acid in a rat renal ischemia-reperfusion injury model

2008 ◽  
Author(s):  
Masahide Matsuyama ◽  
Rikio Yoshimura ◽  
Kiyoaki Funao ◽  
Yutaka Kawahito ◽  
Hajime Sano ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Ischemia ◽  
Injury Model ◽  
Renal Ischemia Reperfusion Injury

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.

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