Abstract T P247: Neuronal Sirt1 Activation Negatively Regulates Rho Kinase in Photothrombotic Stroke

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Yong-Joo Ahn ◽  
Maya Hwewon Kim ◽  
Eun-Hye Lee ◽  
Ye-Rim Kwon ◽  
Wenliang Zhong ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Signaling Pathway ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Rho Kinase ◽  
Artery Occlusion ◽  
Over Expression ◽  
Therapeutic Benefits ◽  
Infarction Volume ◽  
Photothrombotic Stroke

Background and Purpose: Sirt1 is a NAD+ dependent deacetylase that is known as one of important regulators for ischemic stroke. Because the role and mechanism of genetic sirt1 over-expression in ischemic brain injury has not yet been studied, we examined that brain-specific sirt1-overexpressing transgenic (BRASTO) mice might have significant beneficial effect in ischemic stroke through regulation of sirt1-Rho kinase (ROCK) signaling pathway. Methods: We induced a middle cerebral artery occlusion model in mice and tested the effect of resveratrol (100 mg/kg, i.p.) in ischemia/reperfusion (2h/22h) injury and tested the role and mechanism with BRASTO mice in photothrombotic stroke. Protein levels in mice brain tissue lysates were determined using western blotting. Results: Sirt1 activation by resveratrol treatment reduced infarction volume and improved neurological deficit score in transient focal cerebral ischemia. BRASTO mice did not show any obvious phenotypic abnormalities and BRASTO mice improved relative cerebral blood flow and reduced infarction volume by 68.4% compare to that of WT in photothrombotic stroke. Sirt1 over-expression in BRASTO mice was significantly increased by 4.2 fold higher than that of WT mice and Rho-kinase activity was significantly decreased by 54.6% in BRASTO mice. Conclusions: These findings indicate that neuronal specific sirt1 activation in BRASTO mice reduced infarction volume in photothrombotic stroke via down-regulation of ROCK signaling pathway. These results suggest that effect of neuronal sirt1 activation may have therapeutic benefits in ischemic stroke via ROCK signaling pathway.

Protective Effect of Capparis spinosa Extract Against Focal Cerebral Ischemia-Reperfusion Injury in Rats

2021 ◽  
Vol 21 ◽  
Author(s):  
Hassan Rakhshandeh ◽  
Samira Asgharzade ◽  
Mohammad Bagher Khorrami ◽  
Fatemeh Forouzanfar
Keyword(s):  
Oxidative Stress ◽  
Ischemic Stroke ◽  
Ischemia Reperfusion Injury ◽  
Focal Cerebral Ischemia ◽  
Infarct Volume ◽  
Ischemia Reperfusion ◽  
Public Health Problem ◽  
Artery Occlusion ◽  
Stroke Group ◽  
Capparis Spinosa

Background: Ischemic stroke is a serious public health problem. Despite extensive research focusing on the area, little is known about novel treatments. Objective: In this study, we aimed to investigate the effects of Capparis spinosa (C. spinosa) extract in the middle cerebral artery occlusion (MCAO) model of ischemic stroke. Methods: Wistar rats underwent 30-min MCAO-induced brain ischemia followed by 24 h of reperfusion. C. spinose was administrated orally once a day for 7 days before the induction of MCAO. The neurologic outcome, infarct volume (TTC staining), histological examination, and markers of oxidative stress, including total thiol content and malondialdehyde (MDA) levels, were measured 24 hr. after the termination of MCAO. Results: Pretreatment with C. spinosa, reduced neurological deficit score, histopathological alterations, and infarct volume in treated groups compared to stroke group. Furthermore, pretreatment with C. spinosa extract significantly reduced the level of MDA with concomitant increases in the levels of thiol in the brain tissues compared with the stroke group. Conclusion: Our study demonstrates that C. spinosa extract effectively protects MCAO injury through attenuation of suppressing oxidative stress.

scholarly journals Targeting Platelet GPVI Plus rt-PA Administration but Not α2β1-Mediated Collagen Binding Protects against Ischemic Brain Damage in Mice

2019 ◽  
Vol 20 (8) ◽  
pp. 2019 ◽  
Author(s):  
Michael K. Schuhmann ◽  
Peter Kraft ◽  
Michael Bieber ◽  
Alexander M. Kollikowski ◽  
Harald Schulze ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Recombinant Tissue Plasminogen Activator ◽  
Artery Occlusion ◽  
Stroke Outcome ◽  
Platelet Surface ◽  
Glycoprotein Vi ◽  
Stroke Study ◽  
Increased Risk

Platelet collagen interactions at sites of vascular injuries predominantly involve glycoprotein VI (GPVI) and the integrin α2β1. Both proteins are primarily expressed on platelets and megakaryocytes whereas GPVI expression is also shown on endothelial and integrin α2β1 expression on epithelial cells. We recently showed that depletion of GPVI improves stroke outcome without increasing the risk of cerebral hemorrhage. Genetic variants associated with higher platelet surface integrin α2 (ITGA2) receptor levels have frequently been found to correlate with an increased risk of ischemic stroke in patients. However until now, no preclinical stroke study has addressed whether platelet integrin α2β1 contributes to the pathophysiology of ischemia/reperfusion (I/R) injury. Focal cerebral ischemia was induced in C57BL/6 and Itga2−/− mice by a 60 min transient middle cerebral artery occlusion (tMCAO). Additionally, wild-type animals were pretreated with anti-GPVI antibody (JAQ1) or Fab fragments of a function blocking antibody against integrin α2β1 (LEN/B). In anti-GPVI treated animals, intravenous (IV) recombinant tissue plasminogen activator (rt-PA) treatment was applied immediately prior to reperfusion. Stroke outcome, including infarct size and neurological scoring was determined on day 1 after tMCAO. We demonstrate that targeting the integrin α2β1 (pharmacologic; genetic) did neither reduce stroke size nor improve functional outcome on day 1 after tMCAO. In contrast, depletion of platelet GPVI prior to stroke was safe and effective, even when combined with rt-PA treatment. Our results underscore that GPVI, but not ITGA2, is a promising and safe target in the setting of ischemic stroke.

scholarly journals Effect of Tetramethylpyrazine on Neuroplasticity after Transient Focal Cerebral Ischemia Reperfusion in Rats

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Junbin Lin ◽  
Chizi Hao ◽  
Yu Gong ◽  
Ying Zhang ◽  
Ying Li ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Synaptic Cleft ◽  
Artery Occlusion ◽  
Neurological Function ◽  
Group Model ◽  
Model Group ◽  
Transient Focal Cerebral Ischemia ◽  
Transmission Electron

Tetramethylpyrazine (TMP) has been widely used in ischemic stroke in China. The regulation of neuroplasticity may underlie the recovery of some neurological functions in ischemic stroke. Middle cerebral artery occlusion (MCAO) model was established in this study. Rats were divided into three groups: sham group, model group, and TMP group. The neurological function was evaluated using modified neurological severity score (mNSS). Following the neurological function test, expression of synaptophysin (SYP) and growth-associated protein 43 (GAP-43) were analyzed through immunohistochemistry at 3 d, 7 d, 14 d, and 28 d after MCAO. Finally, the synaptic structural plasticity was investigated using transmission electron microscopy (TEM). The TMP group showed better neurological function comparing to the model group. SYP levels increased gradually in ischemic penumbra (IP) in the model group and could be enhanced by TMP treatment at 7 d, 14 d, and 28 d, whereas GAP-43 levels increased from 3 d to 7 d and thereafter decreased gradually from 14 d to 28 d in the model group, which showed no significant improvement in the TMP group. The results of TEM showed a flatter synaptic interface, a thinner postsynaptic density (PSD), and a wider synaptic cleft in the model group, and the first two alterations could be ameliorated by TMP. Then, a Pearson’s correlation test revealed mNSS markedly correlated with SYP and synaptic ultrastructures. Taken together, TMP is capable of promoting functional outcome after ischemic stroke, and the mechanisms may be partially associated with regulation of neuroplasticity.

scholarly journals Sirt1 Mediates Improvement in Cognitive Defects Induced by Focal Cerebral Ischemia Following Hyperbaric Oxygen Preconditioning in Rats

2017 ◽  
pp. 1029-1039 ◽  
Author(s):  
P. DING ◽  
D. REN ◽  
S. HE ◽  
M. HE ◽  
G. ZHANG ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Hyperbaric Oxygen ◽  
Cognitive Deficits ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Artery Occlusion ◽  
Beneficial Effects ◽  
Mechanistic Basis ◽  
Hyperbaric Oxygen Preconditioning

Hyperbaric oxygen preconditioning (HBO-PC) has been proposed as a safe and practical approach for neuroprotection in ischemic stroke. However, it is not known whether HPO-PC can improve cognitive deficits induced by cerebral ischemia, and the mechanistic basis for any beneficial effects remains unclear. We addressed this in the present study using rats subjected to middle cerebral artery occlusion (MCAO) as an ischemic stroke model following HBO-PC. Cognitive function and expression of phosphorylated neurofilament heavy polypeptide (pNF-H) and doublecortin (DCX) in the hippocampus were evaluated 14 days after reperfusion and after short interfering RNA-mediated knockdown of sirtuin1 (Sirt1). HBO-PC increased pNF-H and DCX expression and mitigated cognitive deficits in MCAO rats. However, these effects were abolished by Sirt1 knockdown. Our results suggest that HBO-PC can protect the brain from injury caused by ischemia-reperfusion and that Sirt1 is a potential molecular target for therapeutic approaches designed to minimize cognitive deficits caused by cerebral ischemia.

scholarly journals Electroacupuncture Could Regulate the NF-κB Signaling Pathway to Ameliorate the Inflammatory Injury in Focal Cerebral Ischemia/Reperfusion Model Rats

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Wen-yi Qin ◽  
Yong Luo ◽  
Ling Chen ◽  
Tao Tao ◽  
Yang Li ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Signaling Pathway ◽  
Nuclear Translocation ◽  
Focal Cerebral Ischemia ◽  
Ischemia Reperfusion ◽  
Critical Role ◽  
Artery Occlusion ◽  
Sprague Dawley ◽  
Inflammatory Injury ◽  
Cerebral Ischemia Reperfusion

The activated nuclear factor-KappaB signaling pathway plays a critical role in inducing inflammatory injury. It has been reported that electroacupuncture could be an effective anti-inflammatory treatment. We aimed to explore the complex mechanism by which EA inhibits the activation of the NF-κB signal pathway and ameliorate inflammatory injury in the short term; the effects of NEMO Binding Domain peptide for this purpose were compared. Focal cerebral I/R was induced by middle cerebral artery occlusion for 2 hrs. Total 380 male Sprague-Dawley rats are in the study. The neurobehavioral scores, infarction volumes, and the levels of IL-1βand IL-13 were detected. NF-κB p65, IκBα, IKKα, and IKKβwere analyzed and the ability of NF-κB binding DNA was investigated. The EA treatment and the NBD peptide treatment both reduced infarct size, improved neurological scores, and regulated the levels of IL-1βand IL-13. The treatment reduced the expression of IKKαand IKKβand altered the expression of NF-κB p65 and IκBαin the cytoplasm and nucleus; the activity of NF-κB was effectively reduced. We conclude that EA treatment might interfere with the process of NF-κB nuclear translocation. And it also could suppress the activity of NF-κB signaling pathway to ameliorate the inflammatory injury after focal cerebral ischemia/reperfusion.

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.

Abstract T P229: Deletion of Voltage Gated Proton Channel in Microglial Cells is Neurovascular Protective After Ischemic Brain Injury

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Weiguo Li ◽  
Becca Ward ◽  
Mohammed Abdelsaid ◽  
Tianzheng Yu ◽  
Yisang Yoon ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Ischemia Reperfusion ◽  
Hemorrhagic Transformation ◽  
Artery Occlusion ◽  
Proton Channel ◽  
Ros Generation ◽  
Vascular Integrity ◽  
Voltage Gated ◽  
Underlying Mechanisms ◽  
Cerebral Artery Occlusion

Despite the failure of antioxidant treatments in clinical trials, the undoubted role of reactive oxygen species (ROS) in neurovascular damage after ischemic stroke calls for a more targeted approach. ROS production by microglia, the primary resident immune cells in the brain, is a key event of this process in ischemic stroke. Voltage gated proton channel, Hv1, is localized primarily to microglia and sustains NADPH oxidase activity. Deletion of Hv1 is neuroprotective after permanent middle cerebral artery occlusion (MCAO). We hypothesized that Hv1-mediated microglial ROS generation is also critical for vascular integrity and contributes to reperfusion injury after transient ischemic stroke. The wildtype (WT) and Hv1 knockout (KO) rats (n=4) were subjected to permanent or 3/24 h transient MCAO. The neurological deficiency, infarct, hemorrhagic transformation, and edema ratio were assessed. We found that in both permanent and transient MCAO model, KO rats develop smaller infarct, less vascular injury, edema, and hemorrhagic transformation, resulting in better short-term functional outcome. These results suggest that deletion of microglial Hv1 channel is vasculoprotective after ischemia/reperfusion and the underlying mechanisms need to be further studied.

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