Mechanisms Contributing to Cerebral Infarct Size after Stroke: Gender, Reperfusion, T Lymphocytes, and Nox2-Derived Superoxide

Cerebral infarct volume is typically smaller in premenopausal females than in age-matched males after ischemic stroke, but the underlying mechanisms are poorly understood. In this study we provide evidence in mice that this gender difference only occurs when the ischemic brain is reperfused. The limited tissue salvage achieved by reperfusion in male mice is associated with increased expression of proinflammatory proteins, including cyclooxygenase-2 (Cox-2), Nox2, and vascular cell adhesion molecule-1 (VCAM-1), and infiltration of Nox2-containing T lymphocytes into the infarcted brain, whereas such changes are minimal in female mice after ischemia–reperfusion (I-R). Infarct volume after I-R was no greater at 72 h than at 24 h in either gender. Infarct development was Nox2 dependent in male but not in female mice, and Nox2 within the infarct was predominantly localized in T lymphocytes. Stroke resulted in an ∼15-fold increase in Nox2-dependent superoxide production by circulating, but not spleen-derived, T lymphocytes in male mice, and this was ∼sevenfold greater than in female mice. These circulating immune cells may thus represent a major and previously unrecognized source of superoxide in the acutely ischemic and reperfused brain of males (and potentially in postmenopausal females). Our findings provide novel insights into mechanisms that could be therapeutically targeted in acute ischemic stroke patients who receive thrombolysis therapy to induce cerebral reperfusion.

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Combined Ischemic Preconditioning and Resveratrol Improved Bloodbrain Barrier Breakdown via Hippo/YAP/TAZ Signaling Pathway

CNS & Neurological Disorders - Drug Targets ◽

10.2174/1871527318666191021144126 ◽

2020 ◽

Vol 18 (9) ◽

pp. 713-722 ◽

Cited By ~ 1

Author(s):

Ganji Hong ◽

Ying Yan ◽

Yali Zhong ◽

Jianer Chen ◽

Fei Tong ◽

...

Keyword(s):

Signaling Pathway ◽

Blood Brain Barrier ◽

Ischemic Preconditioning ◽

Infarct Volume ◽

Ischemia Reperfusion ◽

Cerebral Infarct ◽

Brain Barrier ◽

Binding Motif ◽

Blood Brain ◽

Barrier Breakdown

Background: Transient Ischemia/Reperfusion (I/R) is the main reason for brain injury and results in disruption of the Blood-Brain Barrier (BBB). It had been reported that BBB injury is one of the main risk factors for early death in patients with cerebral ischemia. Numerous investigations focus on the study of BBB injury which have been carried out. Objective: The objective of this study was to investigate the treatment function of the activation of the Hippo/Yes-Associated Protein (YAP) signaling pathway by combined Ischemic Preconditioning (IPC) and resveratrol (RES) before brain Ischemia/Reperfusion (BI/R) improves Blood-Brain Barrier (BBB) disruption in rats. Methods: Sprague-Dawley (SD) rats were pretreated with 20 mg/kg RES and IPC and then subjected to 2 h of ischemia and 22 h of reperfusion. The cerebral tissues were collected; the cerebral infarct volume was determined; the Evans Blue (EB) level, the brain Water Content (BWC), and apoptosis were assessed; and the expressions of YAP and TAZ were investigated in cerebral tissues. Results: Both IPC and RES preconditioning reduced the cerebral infarct size, improved BBB permeability, lessened apoptosis, and upregulated expressions of YAP and transcriptional co-activator with PDZ-binding motif (TAZ) compared to the Ischemia/Reperfusion (I/R) group, while combined IPC and RES significantly enhanced this action. Conclusion: combined ischemic preconditioning and resveratrol improved blood-brain barrier breakdown via Hippo/YAP/TAZ signaling pathway.

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KADAR FIBRIN MONOMER DAN UKURAN INFARK DI STROK ISKEMIK AKUT

INDONESIAN JOURNAL OF CLINICAL PATHOLOGY AND MEDICAL LABORATORY ◽

10.24293/ijcpml.v20i3.470 ◽

2016 ◽

Vol 20 (3) ◽

pp. 171

Author(s):

Ani Kartini ◽

Mansyur Arif ◽

Hardjoeno Hardjoeno

Keyword(s):

Ischemic Stroke ◽

Infarct Size ◽

Acute Ischemic Stroke ◽

Thrombus Formation ◽

Infarct Volume ◽

Cross Sectional Study ◽

Cerebral Infarct ◽

Cross Sectional ◽

Fibrin Monomer ◽

Significant Difference

Coagulation activation and thrombosis frequently exist in ischemic stroke, thrombus formation can be detected early by the presence of fibrin monomer. The purpose of this study was to know the correlation of fibrin monomer level with cerebral infarct size in acute ischemic stroke patients. This was a cross sectional study with a total of 39 samples. The fibrin monomer level was determined by immunoturbidimetry method using STA-Compact and the measurement of the infarct size was done by CT scan of the head using Broderick formula. The results of this study showed that the median level of fibrin monomer in acute ischemic stroke with nonlacunar infarct type and lacunar infarct type were 14.46 μg/mL and 4.29 μg/mL, respectively. Mann-Whitney test showed there was a significant difference of fibrin monomer levels between nonlacunar infarct type and the lacunar type, p=0.000. The cut-off point analysis result of the fibrin monomer level was 5.96 μg/mL with a sensitivity of 88.9% and specificity of 76.4%, respectively. Spearman correlation test showed that fibrin monomer level was positively correlated with cerebral infarct volume in acute ischemic stroke (r=0.56, p=0.000). Based on this study, it can be concluded that fibrin monomer level can be used as a marker to predict the type of cerebral infarct and volume of acute ischemic stroke as well.

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

Stroke ◽

10.1161/str.46.suppl_1.tp229 ◽

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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Abstract 1944: Atorvastatin Reduces Intracerebral Hemorrhage after Experimental Stroke

Circulation ◽

10.1161/circ.116.suppl_16.ii_418-c ◽

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.

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Abstract TP111: Activation of the Brain Renin-Angiotensin System by Translational Approaches Following Stroke Onset Is Neuroprotective in a Rat Model of Ischemic Stroke

Stroke ◽

10.1161/str.44.suppl_1.atp111 ◽

2013 ◽

Vol 44 (suppl_1) ◽

Author(s):

Douglas M Bennion ◽

Lauren Donnangelo ◽

David Pioquinto ◽

Robert Regenhardt ◽

Mohan K Raizada ◽

...

Keyword(s):

Ischemic Stroke ◽

Infarct Volume ◽

Renin Angiotensin System ◽

Cerebral Infarct ◽

Intraventricular Administration ◽

Angiotensin System ◽

Renin Angiotensin ◽

Post Stroke ◽

Neurologic Deficits ◽

The Brain

Background: Toward discovering novel stroke therapies, recent research has shown that activation of the newly-discovered angiotensin converting enzyme 2/angiotensin-(1-7)/mas (ACE2/Ang-(1-7)/Mas) pathway, a counter-regulatory axis of the brain renin-angiotensin system, is neuroprotective in ischemic stroke in rats. Specifically, intraventricular administration of the novel ACE2 activator diminazine aceturate (DIZE) before and during an ischemic stroke decreases cerebral infarct and neurologic deficits. Efficacy must now be demonstrated using minimally-invasive methods if this therapy is to be translated to the care of human patients. In this study, we assessed the hypothesis that systemic administration of DIZE post ischemic stroke would be neuroprotective. Methods: Adult male Sprague-Dawley rats underwent ischemic stroke by endothelin-1 induced middle cerebral artery occlusion and were randomly divided into 2 groups (n=9-10/set): 1) intraperitoneal (IP) administrations of DIZE (7.5 mg/kg) at 4, 24, and 48 h after stroke; 2) IP administrations of 0.9% saline vehicle at the same time points. At 24 and 72 h after stroke, rats underwent blinded neurologic assessments. Immediately following the 72 h tests, animals were sacrificed, cerebral infarct volumes assessed by TTC staining, and IL-1β expression in the stroke region analyzed by rt-PCR. Data are expressed as mean ± SEM with significance inferred at p<0.05. Results: Mean infarct volume was significantly decreased by IP injections of DIZE (9.4% ± 4.35) as compared to control (22.8%±3.6, p=0.039). At 24 h post stroke, neurologic deficits (Garcia Scale) were significantly improved in the DIZE treated group (16.7±0.40) versus the saline group (15.22±0.57, p=0.037). Although DIZE tended to improve neurologic deficits 72 h post stroke, this trend was not significant. Finally, DIZE treatment significantly reduced mRNA expression of IL-1β (0.43 ± 0.14) in the cerebral cortical stroke region as compared to saline treatment (1.47±0.08, p=0.001). Conclusions: Our findings suggest that targeting the ACE2/Ang-(1-7)/Mas axis post stroke can improve function, decrease inflammation, and reduce infarct volume - a significant translational step in brain renin-angiotensin system research.

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Glutathione Suppresses Cerebral Infarct Volume and Cell Death after Ischemic Injury: Involvement of FOXO3 Inactivation and Bcl2 Expression

Oxidative Medicine and Cellular Longevity ◽

10.1155/2015/426069 ◽

2015 ◽

Vol 2015 ◽

pp. 1-11 ◽

Cited By ~ 17

Author(s):

Juhyun Song ◽

Joohyun Park ◽

Yumi Oh ◽

Jong Eun Lee

Keyword(s):

Cell Death ◽

Ischemic Stroke ◽

Cerebral Infarction ◽

Infarct Size ◽

Cell Survival ◽

Ischemia Reperfusion ◽

Ischemic Injury ◽

Cerebral Infarct ◽

Ros Scavenging ◽

The Brain

Ischemic stroke interrupts the flow of blood to the brain and subsequently results in cerebral infarction and neuronal cell death, leading to severe pathophysiology. Glutathione (GSH) is an antioxidant with cellular protective functions, including reactive oxygen species (ROS) scavenging in the brain. In addition, GSH is involved in various cellular survival pathways in response to oxidative stress. In the present study, we examined whether GSH reduces cerebral infarct size after middle cerebral artery occlusionin vivoand the signaling mechanisms involved in the promotion of cell survival after GSH treatment under ischemia/reperfusion conditionsin vitro. To determine whether GSH reduces the extent of cerebral infarction, cell death after ischemia, and reperfusion injury, we measured infarct size in ischemic brain tissue and the expression of claudin-5 associated with brain infarct formation. We also examined activation of the PI3K/Akt pathway, inactivation of FOXO3, and expression of Bcl2 to assess the role of GSH in promoting cell survival in response to ischemic injury. Based on our results, we suggest that GSH might improve the pathogenesis of ischemic stroke by attenuating cerebral infarction and cell death.

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Microthrombi Correlates With Infarction and Delayed Neurological Deficits After Subarachnoid Hemorrhage in Mice

Stroke ◽

10.1161/strokeaha.120.029753 ◽

2020 ◽

Vol 51 (7) ◽

pp. 2249-2254 ◽

Cited By ~ 1

Author(s):

Ari Dienel ◽

Remya Ammassam Veettil ◽

Sung-Ha Hong ◽

Kanako Matsumura ◽

Peeyush Kumar T. ◽

...

Keyword(s):

Sex Differences ◽

Subarachnoid Hemorrhage ◽

Infarct Volume ◽

Neurological Deficits ◽

Behavioral Performance ◽

Large Artery ◽

Male Mice ◽

Functional Deficits ◽

Female Mice ◽

Correlation Analyses

Background and Purpose: Delayed neurological deficits are a devastating consequence of subarachnoid hemorrhage (SAH), which affects about 30% of surviving patients. Although a very serious concern, delayed deficits are understudied in experimental SAH models; it is not known whether rodents recapitulate the delayed clinical decline seen in SAH patients. We hypothesized that mice with SAH develop delayed functional deficits and that microthrombi and infarction correlate with delayed decline. Methods: Adult C57BL/6J mice of both sexes were subjected to endovascular perforation to induce SAH. Mice were allowed to survive for up to 1 week post-ictus and behavioral performance was assessed daily. Postmortem microthrombi, large artery diameters (to assess vasospasm), and infarct volume were measured. These measures were analyzed for differences between SAH mice that developed delayed deficits and SAH mice that did not get delayed deficits. Correlation analyses were performed to identify which measures correlated with delayed neurological deficits, sex, and infarction. Results: Twenty-three percent of males and 47% of females developed delayed deficits 3 to 6 days post-SAH. Female mice subjected to SAH had a significantly higher incidence of delayed deficits than male mice with SAH. Mice that developed delayed deficits had significantly more microthrombi and larger infarct volumes than SAH mice that did not get delayed deficits. Microthrombi positively correlated with infarct volume, and both microthrombi and infarction correlated with delayed functional deficits. Vasospasm did not correlate with either infarction delayed functional deficits. Conclusions: We discovered that delayed functional deficits occur in mice following SAH. Sex differences were seen in the prevalence of delayed deficits. The mechanism by which microthrombi cause delayed deficits may be via formation of infarcts.

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Abstract 113: Regulatory T Cells Contribute to Sexual Dimorphic Outcomes After Acute Ischemic Brain Injury

Stroke ◽

10.1161/str.51.suppl_1.113 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Zeyu Sun ◽

Wei Su ◽

Ligen Shi ◽

Jie Chen ◽

Xiaoming Hu

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Immune Cell ◽

Infarct Volume ◽

Young Male ◽

Young Female ◽

Male Mice ◽

Stroke Outcomes ◽

Female Mice ◽

Ifn Γ

Introduction: The contribution of CD4 + Foxp3 + regulatory T cells (Treg) to acute stroke outcomes has been controversially reported in young male murine models of stroke, their effects in female stroke mice, however, are not characterized. This study explored the sexual dimorphisms in Treg and its contribution to acute stroke outcomes. Methods: Cerebral ischemia was induced by 60 min tMCAO in male or female (Young: 10-week, aged: 15-month) wild type (WT) mice and DTR mice expressing the diphtheria toxin (DT) receptor under the control of Foxp3 promoter. Tregs depletion was achieved by DT injection in DTR mice for 3 days prior to tMCAO. Infarct volume, sensorimotor functions and peripheral immune cell populations were assessed up to 5d after stroke. For RNA sequencing analysis, Tregs were sorted from blood of male or female DTR mice at 5d after sham or tMCAO surgery. Results: Young Treg competent (WT mice or DTR mice without DT) female mice exhibited significantly reduced infarct volume, as assessed by MRI T2 scanning and MAP2 staining, and greatly improved sensorimotor functions (rotarod test and adhesive removal test) compared to age- and genotype-matched male mice (n=8/group) 5d after tMCAO. Treg depletion deprived the neuroprotection in young female, while showed no significant effect on young male or aged female mice (n=8/group). RNA-seq analysis showed that IFN-γ signaling was downregulated in female Treg while upregulated in male Treg, suggesting a sexual difference in Treg-mediated immune response after stroke. Flow cytometry revealed ameliorated immune cell activation in blood and brain in female vs male mice 5d after stroke. Furthermore, Treg were isolated from young female, young male, aged female or female mice subjected to ovariectomy, and adoptively transferred (1 million cell/animal, iv) to young male mice 1 hour after tMCAO. Only young female Treg significantly reduced the infarct volume and improved sensorimotor functions compared to other treatment groups (n=7-8/group). Conclusion: Treg contribute to the neuroprotection in young female vs male in an age- and hormone-dependent manner. Transcriptomic analysis uncovered sexual differences in an IFN-γ centered regulatory pathways in Tregs, which keep post-stroke immune responses in check.

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Hypothermia Protects Against Ischemic Stroke Through Peroxisome-proliferator-activated-receptor Gamma

10.21203/rs.3.rs-754337/v1 ◽

2021 ◽

Author(s):

Feng Jia ◽

Shuai Shao ◽

Yanlin Chen ◽

Jiansong Zhang ◽

Dilimulati Dilirebati ◽

...

Keyword(s):

Ischemic Stroke ◽

Infarct Size ◽

Cell Viability ◽

Brain Edema ◽

Infarct Volume ◽

Ischemia Reperfusion ◽

Neuronal Cells ◽

Microglial Cells ◽

Peroxisome Proliferator ◽

Peroxisome Proliferator Activated Receptor

Abstract Background: IS (ischemic stroke) remains to be a global public health burden and urgently demands novel strategies. Hypothermia plays a beneficial role in central nervous system diseases. However, the function of hypothermia in IS has not been elucidated. Here we demonstrated the role of hypothermia in IS and explore the mechanism.Methods: IS phenotype was detected by infarct size and infarct volume as well as brain edema in mice. The neuroinflammation was evaluated by activation of microglial cells and expression of inflammatory genes after ischemia/reperfusion (I/R) and oxygen-glucose deprivation/reperfusion (OGD/R). The apoptosis of neuronal cells was assessed by Tunnel staining, expression of Cleaved Caspase-3 and Bax/Bcl-2, cell viability, and LDH release after I/R and OGD/R. Blood-brain-barrier (BBB) permeability was calculated by Evans blue extravasation, the expression of tight junction proteins and MMP-9, cell viability, and LDH release after I/R and OGD/R. The expression of peroxisome-proliferator-activated-receptor gamma (PPARγ) was detected by western blotting after I/R and OGD/R.Results：Hypothermia significantly reduced the infarct size and infarct volume as well as brain edema after ischemia/reperfusion. Consistency, hypothermia induced attenuated neuroinflammation, apoptosis of neuronal cells, and BBB disruption after I/R and OGD/R. Mechanistic studies revealed that hypothermia protected against IS by upregulating the expression of PPARγ in microglial cells, the effect of hypothermia was reversed by GW9662, a PPARγ inhibitor. Conclusions：Our data showed that hypothermia inhibited the activation of microglial cells and microglial cell-mediated neuroinflammation by upregulating the expression of PPARγ in microglial cells. Targeting hypothermia may be a feasible approach for IS treatment.

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Female and male mice have differential longterm cardiorenal outcomes following a matched degree of ischemia–reperfusion acute kidney injury

Scientific Reports ◽

10.1038/s41598-021-04701-x ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Danielle E. Soranno ◽

Peter Baker ◽

Lara Kirkbride-Romeo ◽

Sara A. Wennersten ◽

Kathy Ding ◽

...

Keyword(s):

Blood Pressure ◽

Acute Kidney Injury ◽

Mitochondrial Function ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Cardiovascular Outcomes ◽

Male Mice ◽

Male And Female ◽

Female Mice

AbstractAcute kidney injury (AKI) is common in patients, causes systemic sequelae, and predisposes patients to long-term cardiovascular disease. To date, studies of the effects of AKI on cardiovascular outcomes have only been performed in male mice. We recently demonstrated that male mice developed diastolic dysfunction, hypertension and reduced cardiac ATP levels versus sham 1 year after AKI. The effects of female sex on long-term cardiac outcomes after AKI are unknown. Therefore, we examined the 1-year cardiorenal outcomes following a single episode of bilateral renal ischemia–reperfusion injury in female C57BL/6 mice using a model with similar severity of AKI and performed concomitantly to recently published male cohorts. To match the severity of AKI between male and female mice, females received 34 min of ischemia time compared to 25 min in males. Serial renal function, echocardiograms and blood pressure assessments were performed throughout the 1-year study. Renal histology, and cardiac and plasma metabolomics and mitochondrial function in the heart and kidney were evaluated at 1 year. Measured glomerular filtration rates (GFR) were similar between male and female mice throughout the 1-year study period. One year after AKI, female mice had preserved diastolic function, normal blood pressure, and preserved levels of cardiac ATP. Compared to males, females demonstrated pathway enrichment in arginine metabolism and amino acid related energy production in both the heart and plasma, and glutathione in the plasma. Cardiac mitochondrial respiration in Complex I of the electron transport chain demonstrated improved mitochondrial function in females compared to males, regardless of AKI or sham. This is the first study to examine the long-term cardiac effects of AKI on female mice and indicate that there are important sex-related cardiorenal differences. The role of female sex in cardiovascular outcomes after AKI merits further investigation.

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