scholarly journals Sustained blood glutamate scavenging enhances protection in ischemic stroke

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Ahlem Zaghmi ◽  
Antonio Dopico-López ◽  
María Pérez-Mato ◽  
Ramón Iglesias-Rey ◽  
Pablo Hervella ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Infarct Volume ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Treated Group ◽  
The Body ◽  
Glutamate Oxaloacetate Transaminase ◽  
Glutamate Scavenging ◽  
Blood Glutamate Scavenging ◽  
The Brain

AbstractStroke is a major cause of morbidity, mortality, and disability. During ischemic stroke, a marked and prolonged rise of glutamate concentration in the brain causes neuronal cell death. This study explores the protective effect of a bioconjugate form of glutamate oxaloacetate transaminase (hrGOT), which catalyzes the depletion of blood glutamate in the bloodstream for ~6 days following a single administration. When treated with this bioconjugate, a significant reduction of the infarct volume and a better retention of sensorimotor function was observed for ischemic rats compared to those treated with saline. Moreover, the equivalent dose of native hrGOT yielded similar results to the saline treated group for some tests. Targeting the bioconjugate to the blood-brain-barrier did not improve its performance. The data suggest that the bioconjugates draw glutamate out of the brain by displacing homeostasis between the different glutamate pools of the body.

Abstract W P210: Plasma Kallikrein Induces Ischemic Brain Damage Through Cleavage-Dependent Activation of NMDA Receptors

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Gongxiong wu ◽  
Long-Jun Wu ◽  
David E. Clapham ◽  
Edward P. Feener
Keyword(s):  
Cell Culture ◽  
Cell Death ◽  
Ischemic Stroke ◽  
Nmda Receptor ◽  
Brain Damage ◽  
Infarct Volume ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Plasma Kallikrein ◽  
Ischemic Brain

Background and Purpose: Ischemic stroke ultimately leads to brain dysfunction and neurological deficits. However, the mechanisms that contribute to neuronal injury and dysfunction in ischemic stroke are not fully understood. Recent studies have shown that pharmacological inhibition of the serine protease plasma kallikrein (PK) reduced neuron death and neurological impairment in ischemic brain in mice. In this study, we examine the effects of PK on the neuronal cell death and brain damage in mice and investigate the molecular mechanism of PK-induced neuronal cell death in ischemic stroke. Methods: Ischemia was produced in wild-type (WT) and PK knockout mice by permanent middle cerebral artery occlusion (pMCAO). Infarct volume was quantified by TTC staining and brain function was evaluated by neurological scoring. The effect of PK on neuron cell death in cell culture was determined by lactate dehydrogenase (LDH) release. NMDA receptor function was measured by patch clamp and Ca2+ imaging. NR1 cleavage was detected by western blot. The effect of systemic PK inhibition on pMCAO-induced infarct volume was evaluated in mice treated with the PK inhibitor (BPCCB) or vehicle alone delivered using subcutaneously implanted osmotic pumps. Results: We show that PK deficiency in mice decreased MCAO-induced infarct volume by 39.8% (P<0.01) and improved neurological function compared responses in WT mice. Addition of PK to cell culture media enhanced NMDA-induced cell death of cortical neurons. We further show that PK induced cleavage of NR1 and identify the cleavage site in the extracellular N-terminal domain of NR1. The truncated form of NR1 displayed enhanced NMDA-stimulated current and calcium influx. Treatment of mice with a PK inhibitor reduced MCAO-induced brain damage and neuronal injury. Conclusions: PK enhances NMDA receptor-mediated excitotoxicity and ischemic neuronal death. These findings suggest that PK may serve as a potential therapeutic target for treatment of ischemic stroke.

scholarly journals A novel indication of platonin, a therapeutic immunomodulating medicine, on neuroprotection against ischemic stroke in mice

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Joen-Rong Sheu ◽  
Zhih-Cherng Chen ◽  
Thanasekaran Jayakumar ◽  
Duen-Suey Chou ◽  
Ting-Lin Yen ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Ischemic Stroke ◽  
Infarct Volume ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Artery Occlusion ◽  
Neuroprotective Effects ◽  
Occlusion Time ◽  
Oxide Synthase ◽  
Cerebral Artery Occlusion

Abstract Thrombosis and stroke are major causes of disability and death worldwide. However, the regular antithrombotic drugs may have unsatisfactory results and side effects. Platonin, a cyanine photosensitizing dye, has been used to treat trauma, ulcers and some acute inflammation. Here, we explored the neuroprotective effects of platonin against middle cerebral artery occlusion (MCAO)-induced ischemic stroke in mice. Platonin(200 μg/kg) substantially reduced cerebral infarct volume, brain edema, neuronal cell death and neurological deficit scores, and improved the MCAO-reduced locomotor activity and rotarod performance. Platonin(5–10 μM) potently inhibited platelet aggregation and c-Jun NH2-terminal kinase (JNK) phosphorylation in collagen-activated platelets. The antiaggregation effect did not affect bleeding time but increased occlusion time in platonin(100 and 200 μg/kg)-treated mice. Platonin(2–10 μM) was potent in diminishing collagen- and Fenton reaction-induced ∙OH formation. Platonin(5–10 μM) also suppressed the expression of nitric oxide, inducible nitric oxide synthase, cyclooxygenase-2, interleukin-1β, and JNK phosphorylation in lipopolysaccharide-stimulated macrophages. MCAO-induced expression of 3-nitrotyrosine and Iba1 was apparently attenuated in platonin(200 μg/kg)-treated mice. In conclusion, platonin exhibited remarkable neuroprotective properties against MCAO-induced ischemia in a mouse model through its antiaggregation, antiinflammatory and antiradical properties. The observed therapeutic efficacy of platonin may consider being a novel medcine against ischemic stroke.

scholarly journals Calcium/Calmodulin–Dependent Protein Kinase II in Cerebrovascular Diseases

2021 ◽  
Author(s):  
Xuejing Zhang ◽  
Jaclyn Connelly ◽  
Edwin S. Levitan ◽  
Dandan Sun ◽  
Jane Q. Wang
Keyword(s):  
Cell Death ◽  
Ischemic Stroke ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Cerebrovascular Diseases ◽  
Biological Processes ◽  
Dependent Protein Kinase ◽  
Calcium Calmodulin Dependent ◽  
Dependent Protein ◽  
The Brain

AbstractCerebrovascular disease is the most common life-threatening and debilitating condition that often leads to stroke. The multifunctional calcium/calmodulin-dependent protein kinase II (CaMKII) is a key Ca2+ sensor and an important signaling protein in a variety of biological systems within the brain, heart, and vasculature. In the brain, past stroke-related studies have been mainly focused on the role of CaMKII in ischemic stroke in neurons and established CaMKII as a major mediator of neuronal cell death induced by glutamate excitotoxicity and oxidative stress following ischemic stroke. However, with growing understanding of the importance of neurovascular interactions in cerebrovascular diseases, there are clearly gaps in our understanding of how CaMKII functions in the complex neurovascular biological processes and its contributions to cerebrovascular diseases. Additionally, emerging evidence demonstrates novel regulatory mechanisms of CaMKII and potential roles of the less-studied CaMKII isoforms in the ischemic brain, which has sparked renewed interests in this dynamic kinase family. This review discusses past findings and emerging evidence on CaMKII in several major cerebrovascular dysfunctions including ischemic stroke, hemorrhagic stroke, and vascular dementia, focusing on the unique roles played by CaMKII in the underlying biological processes of neuronal cell death, neuroinflammation, and endothelial barrier dysfunction triggered by stroke. We also highlight exciting new findings, promising therapeutic agents, and future perspectives for CaMKII in cerebrovascular systems.

Abstract 114: Neuroprotective Role of Brain Pericytes through PDGFRβ-Akt Signaling in Ischemic Stroke

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Koichi Arimura ◽  
Tetsuro Ago ◽  
Masahiro Kamouchi ◽  
Hiroshi Sugimori ◽  
Junya Kuroda ◽  
...  
Keyword(s):  
Cell Death ◽  
Ischemic Stroke ◽  
Infarct Volume ◽  
Neurovascular Unit ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
Akt Signaling ◽  
Artery Occlusion ◽  
Brain Functions ◽  
Brain Pericytes

Brain pericytes are a constituent of the neurovascular unit and play various important roles in brain functions, such as regulation of capillary blood flow, maintenance of blood-brain barrier and angiogenesis. Previous reports have elucidated that PDGF-B prevents neuronal cell death during ischemic insults in adult rodent models; however, the detailed mechanisms by which PDGF-B signaling protects neurons from ischemic damage are not fully understood. In the present study, we investigated whether brain pericytes play neuroprotective roles in brain ischemia, using a permanent middle cerebral artery occlusion stroke model (MCAO) and cultured human brain pericytes. Immunohistochemistry revealed that the expression of PDGF receptorβ(PDGFRβ) was induced predominantly in pericytes in peri-infarct areas. PDGF-B induced marked phosphorylation of Akt in cultured pericytes. Consistently, Akt was markedly phosphorylated in the PDGFRβ-expressing pericytes in peri-infarct areas. PDGF-B upregulated the expression of neurotrophins, such as neuronal growth factor (NGF) and neurotrophin-3 (NT-3), through Akt activation in the cultured pericytes. We subjected PDGFRβheterozygous knockout (PDGFRβ+/-) mice to MCAO. Infarct volume, as assessed by MAP2 immunostaining, was significantly greater in PDGFRβ+/- than wild-type mice ( 48% increase at day 7, p < 0.01 , n=5). The number of TUNEL positive apoptotic cells was significantly greater in PDGFRβ+/- mice (54 % increase at day 4, p < 0.001 , n=6). Production of NGF and NT-3 at mRNA and protein levels in infarct areas was significantly decreased in PDGFRβ+/- mice (NGF: 28% decrease, p<0.05, NT-3: 22% decrease, p<0.05). Since it has been established that neurotrophin receptors are induced in peri-infarct areas, the decreases in neurotrophin production may increase apoptotic neuronal cell death in the PDGFRβ+/- mice. In conclusion, brain pericytes may have a direct neuroprotective role through secreting neurotrophins via PDGFRβ-Akt signaling, thereby decreasing infarct volume in ischemic stroke.

Xuesaitong May Protect Against Ischemic Stroke by Modulating Microglial Phenotypes and Inhibiting Neuronal Cell Apoptosis via the STAT3 Signaling Pathway

2019 ◽  
Vol 18 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Fangfang Li ◽  
Haiping Zhao ◽  
Ziping Han ◽  
Rongliang Wang ◽  
Zhen Tao ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cell Apoptosis ◽  
Infarct Volume ◽  
Neuronal Cell ◽  
Treated Group ◽  
Stat3 Signaling ◽  
Stat3 Signaling Pathway ◽  
Vehicle Treatment ◽  
Vehicle Treated Group

Background: Xuesaitong mainly comprises Panax notoginseng saponins and has shown a promising feature in an acute ischemic stroke model; however, its effect on long-term recovery following stroke, and the related mechanisms, are unknown. Methods: The objective of this study was to investigate the long-term protective effects of xuesaitong against ischemic stroke and its effect on microglial polarization. Experimental cerebral ischemia was induced by middle cerebral artery occlusion (MCAO) for 45 min, and C57BL/6 mice were immediately injected with xuesaitong or vehicle through the caudal vein at the onset of cerebral reperfusion consecutively for 14 days. The animals were randomly divided into three groups: a sham-operated group, vehicle-treated group and xuesaitong-treated group at a dose of 15μg/g. Subsequently, 2,3,5-triphenyltetrazolium chloride staining was used to assess infarct volume, and adhesive removal tests and balance beam tests were used to evaluate neurological deficits at days 1, 3, 7 and 14 following ischemia. Reverse-transcriptase polymerase chain reaction and immunofluorescence staining for M1 markers (CD16, iNOS) and M2 markers (CD206, arginase-1) were performed to characterize phenotypic changes in microglia. Elisa was used to determine the release of pro-inflammatory and anti-inflammatory cytokines. TUNEL staining was conducted to detect neuronal cell apoptosis, and western blots were used to determine the activation of signal transducer and activator of transcription 3 (STAT3). Results: Our results revealed that xuesaitong treatment, compared with vehicle treatment, significantly reduced cerebral infarct volume 1 and 3 days after MCAO and resulted in significant improvements in long-term neurological outcomes. Furthermore, xuesaitong treatment, compared with vehicle treatment, significantly reduced M1 markers and elevated M2 markers 7 and 14 days after MCAO at both the mRNA and protein level in ipsilateral brain tissue. This finding was also accompanied by a reduction in neuronal cell apoptosis and p-STAT3 transcription factor levels in the xuesaitong-treated group compared with the vehicle-treated group. Conclusion: We demonstrated that xuesaitong has long-term neuroprotective effects against ischemic stroke, possibly by promoting the polarization of microglia to an M2 phenotype and by inhibiting neuronal cell death via down-regulation of the STAT3 signaling pathway, providing new evidence that xuesaitong might be a promising therapeutic strategy for ischemic stroke.

scholarly journals High blood glutamate oxaloacetate transaminase levels are associated with good functional outcome in acute ischemic stroke

2011 ◽  
Vol 31 (6) ◽  
pp. 1387-1393 ◽  
Author(s):  
Francisco Campos ◽  
Tomás Sobrino ◽  
Pedro Ramos-Cabrer ◽  
Mar Castellanos ◽  
Miguel Blanco ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Clinical Outcome ◽  
Acute Ischemic Stroke ◽  
Functional Outcome ◽  
Infarct Volume ◽  
Experimental Models ◽  
Glutamate Oxaloacetate Transaminase ◽  
Beneficial Effects ◽  
Time Of Admission ◽  
The Brain

The capacity of the blood enzyme glutamate oxaloacetate transaminase (GOT) to remove glutamate from the brain by means of blood glutamate degradation has been shown in experimental models to be an efficient and novel neuroprotective tool against ischemic stroke; however, the beneficial effects of this enzyme should be tested in patients with stroke to validate these results. This study aims to investigate the association of GOT levels in blood with clinical outcome in patients with acute ischemic stroke. In two clinical independent studies, we found that patients with poor outcome show higher glutamate and lower GOT levels in blood at the time of admission. Lower GOT levels and higher glutamate levels were independently associated with poorer functional outcome at 3 months and higher infarct volume. These findings show a clear association between high blood glutamate levels and worse outcome and vice versa for GOT, presumably explained by the capacity of this enzyme to metabolize blood glutamate.

scholarly journals Three-dimensional cultured mesenchymal stem cells enhance repair of ischemic stroke through inhibition of microglia

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuejiao Li ◽  
Yankai Dong ◽  
Ye Ran ◽  
Yanan Zhang ◽  
Boyao Wu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Ischemic Stroke ◽  
Proinflammatory Cytokines ◽  
Infarct Volume ◽  
Brain Lesion ◽  
Three Dimensional ◽  
Artery Occlusion ◽  
Rna Seq ◽  
The Brain

Abstract Background We show previously that three-dimensional (3D) spheroid cultured mesenchymal stem cells (MSCs) exhibit reduced cell size thus devoid of lung entrapment following intravenous (IV) infusion. In this study, we determined the therapeutic effect of 3D-cultured MSCs on ischemic stroke and investigated the mechanisms involved. Methods Rats underwent middle cerebral artery occlusion (MCAO) and reperfusion. 1 × 106 of 3D- or 2D-cultured MSCs, which were pre-labeled with GFP, were injected through the tail vain three and seven days after MCAO. Two days after infusion, MSC engraftment into the ischemic brain tissues was assessed by histological analysis for GFP-expressing cells, and infarct volume was determined by MRI. Microglia in the lesion were sorted and subjected to gene expressional analysis by RNA-seq. Results We found that infusion of 3D-cultured MSCs significantly reduced the infarct volume of the brain with increased engraftment of the cells into the ischemic tissue, compared to 2D-cultured MSCs. Accordingly, in the brain lesion of 3D MSC-treated animals, there were significantly reduced numbers of amoeboid microglia and decreased levels of proinflammatory cytokines, indicating attenuated activation of the microglia. RNA-seq of microglia derived from the lesions suggested that 3D-cultured MSCs decreased the response of microglia to the ischemic insult. Interestingly, we observed a decreased expression of mincle, a damage-associated molecular patterns (DAMPs) receptor, which induces the production of proinflammatory cytokines, suggestive of a potential mechanism in 3D MSC-mediated enhanced repair to ischemic stroke. Conclusions Our data indicate that 3D-cultured MSCs exhibit enhanced repair to ischemic stroke, probably through a suppression to ischemia-induced microglial activation.

scholarly journals Induction of the Nrf2 Pathway by Sulforaphane Is Neuroprotective in a Rat Temporal Lobe Epilepsy Model

Antioxidants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1702
Author(s):  
Sereen Sandouka ◽  
Tawfeeq Shekh-Ahmad
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Status Epilepticus ◽  
Temporal Lobe Epilepsy ◽  
Antioxidant Capacity ◽  
Temporal Lobe ◽  
Epileptiform Activity ◽  
Neuronal Cell Death ◽  
Neuronal Cell ◽  
The Brain

Epilepsy is a chronic disease of the brain that affects over 65 million people worldwide. Acquired epilepsy is initiated by neurological insults, such as status epilepticus, which can result in the generation of ROS and induction of oxidative stress. Suppressing oxidative stress by upregulation of the transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2) has been shown to be an effective strategy to increase endogenous antioxidant defences, including in brain diseases, and can ameliorate neuronal damage and seizure occurrence in epilepsy. Here, we aim to test the neuroprotective potential of a naturally occurring Nrf2 activator sulforaphane, in in vitro epileptiform activity model and a temporal lobe epilepsy rat model. Sulforaphane significantly decreased ROS generation during epileptiform activity, restored glutathione levels, and prevented seizure-like activity-induced neuronal cell death. When given to rats after 2 h of kainic acid-induced status epilepticus, sulforaphane significantly increased the expression of Nrf2 and related antioxidant genes, improved oxidative stress markers, and increased the total antioxidant capacity in both the plasma and hippocampus. In addition, sulforaphane significantly decreased status epilepticus-induced neuronal cell death. Our results demonstrate that Nrf2 activation following an insult to the brain exerts a neuroprotective effect by reducing neuronal death, increasing the antioxidant capacity, and thus may also modify epilepsy development.

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 ◽  
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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