scholarly journals The Rapid Decrease in Astrocyte-Associated Dystroglycan Expression by Focal Cerebral Ischemia is Protease-Dependent

2007 ◽  
Vol 28 (4) ◽  
pp. 812-823 ◽  
Author(s):  
Richard Milner ◽  
Stephanie Hung ◽  
Xiaoyun Wang ◽  
Maria Spatz ◽  
Gregory J del Zoppo
Keyword(s):  
Cerebral Ischemia ◽  
Basal Lamina ◽  
Focal Cerebral Ischemia ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Receptor Expression ◽  
Cerebral Microvessels ◽  
The Impact

During focal cerebral ischemia, the detachment of astrocytes from the microvascular basal lamina is not completely explained by known integrin receptor expression changes. Here, the impact of experimental ischemia (oxygen—glucose deprivation (OGD)) on dystroglycan expression by murine endothelial cells and astrocytes grown on vascular matrix laminin, perlecan, or collagen and the impact of middle cerebral artery occlusion on αβ-dystroglycan within cerebral microvessels of the nonhuman primate were examined. Dystroglycan was expressed on all cerebral microvessels in cortical gray and white matter, and the striatum. Astrocyte adhesion to basal lamina proteins was managed in part by α-dystroglycan, while ischemia significantly reduced expression of dystroglycan both in vivo and in vitro. Furthermore, dystroglycan and integrin α6β4 expressions on astrocyte end-feet decreased in parallel both in vivo and in vitro. The rapid loss of astrocyte dystroglycan during OGD appears protease-dependent, involving an matrix metalloproteinase-like activity. This may explain the rapid detachment of astrocytes from the microvascular basal lamina during ischemic injury, which could contribute to significant changes in microvascular integrity.

scholarly journals LINGO-1 shRNA protects the brain against ischemia/reperfusion injury by inhibiting the activation of NF-κB and JAK2/STAT3

Human Cell ◽  
2021 ◽  
Author(s):  
Jiaying Zhu ◽  
Zhu Zhu ◽  
Yipin Ren ◽  
Yukang Dong ◽  
Yaqi Li ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Mice Model ◽  
Down Regulation

AbstractLINGO-1 may be involved in the pathogenesis of cerebral ischemia. However, its biological function and underlying molecular mechanism in cerebral ischemia remain to be further defined. In our study, middle cerebral artery occlusion/reperfusion (MACO/R) mice model and HT22 cell oxygen–glucose deprivation/reperfusion (OGD/R) were established to simulate the pathological process of cerebral ischemia in vivo and in vitro and to detect the relevant mechanism. We found that LINGO-1 mRNA and protein were upregulated in mice and cell models. Down-regulation LINGO-1 improved the neurological symptoms and reduced pathological changes and the infarct size of the mice after MACO/R. In addition, LINGO-1 interference alleviated apoptosis and promoted cell proliferation in HT22 of OGD/R. Moreover, down-regulation of LINGO-1 proved to inhibit nuclear translocation of p-NF-κB and reduce the expression level of p-JAK2 and p-STAT3. In conclusion, our data suggest that shLINGO-1 attenuated ischemic injury by negatively regulating NF-KB and JAK2/STAT3 pathways, highlighting a novel therapeutic target for ischemic stroke.

scholarly journals EphrinB2-EphB2 signaling for dendrite protection after neuronal ischemia in vivo and oxygen-glucose deprivation in vitro

2020 ◽  
pp. 0271678X2097311
Author(s):  
Zhanyang Yu ◽  
Wenlu Li ◽  
Jing Lan ◽  
Kazuhide Hayakawa ◽  
Xunming Ji ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Mouse Model ◽  
Therapeutic Potential ◽  
Focal Cerebral Ischemia ◽  
Ischemic Injury ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Neuron Soma

In order to rescue neuronal function, neuroprotection should be required not only for the neuron soma but also the dendrites. Here, we propose the hypothesis that ephrin-B2-EphB2 signaling may be involved in dendritic degeneration after ischemic injury. A mouse model of focal cerebral ischemia with middle cerebral artery occlusion (MCAO) method was used for EphB2 signaling test in vivo. Primary cortical neuron culture and oxygen-glucose deprivation were used to assess EphB2 signaling in vitro. siRNA and soluble ephrin-B2 ectodomain were used to block ephrin-B2-Ephb2 signaling. In the mouse model of focal cerebral ischemia and in neurons subjected to oxygen-glucose deprivation, clustering of ephrin-B2 with its receptor EphB2 was detected. Phosphorylation of EphB2 suggested activation of this signaling pathway. RNA silencing of EphB2 prevented neuronal death and preserved dendritic length. To assess therapeutic potential, we compared the soluble EphB2 ectodomain with the NMDA antagonist MK801 in neurons after oxygen-glucose deprivation. Both agents equally reduced lactate dehydrogenase release as a general marker of neurotoxicity. However, only soluble EphB2 ectodomain protected the dendrites. These findings provide a proof of concept that ephrin-B2-EphB2 signaling may represent a novel therapeutic target to protect both the neuron soma as well as dendrites against ischemic injury.

scholarly journals A novel therapeutic approach using peripheral blood mononuclear cells preconditioned by oxygen-glucose deprivation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Masahiro Hatakeyama ◽  
Masato Kanazawa ◽  
Itaru Ninomiya ◽  
Kaoru Omae ◽  
Yasuko Kimura ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Therapeutic Strategy ◽  
Mononuclear Cells ◽  
Focal Cerebral Ischemia ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Peripheral Blood Mononuclear ◽  
Novel Therapeutic

AbstractCell therapies that invoke pleiotropic mechanisms may facilitate functional recovery in patients with stroke. Based on previous experiments using microglia preconditioned by oxygen-glucose deprivation, we hypothesized that the administration of peripheral blood mononuclear cells (PBMCs) preconditioned by oxygen-glucose deprivation (OGD-PBMCs) to be a therapeutic strategy for ischemic stroke. Here, OGD-PBMCs were identified to secrete remodelling factors, including the vascular endothelial growth factor and transforming growth factor-β in vitro, while intra-arterial administration of OGD-PBMCs at 7 days after focal cerebral ischemia prompted expression of such factors in the brain parenchyma at 28 days following focal cerebral ischemia in vivo. Furthermore, administration of OGD-PBMCs induced an increasing number of stage-specific embryonic antigen-3-positive cells both in vitro and in vivo. Finally, it was found to prompt angiogenesis and axonal outgrowth, and functional recovery after cerebral ischemia. In conclusion, the administration of OGD-PBMCs might be a novel therapeutic strategy against ischemic stroke.

scholarly journals A Probable Dual Mode of Action for Both L- and D-Lactate Neuroprotection in Cerebral Ischemia

2015 ◽  
Vol 35 (10) ◽  
pp. 1561-1569 ◽  
Author(s):  
Ximena Castillo ◽  
Katia Rosafio ◽  
Matthias T Wyss ◽  
Konstantin Drandarov ◽  
Alfred Buck ◽  
...  
Keyword(s):  
Alternative Energy ◽  
Receptor Agonist ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Receptor Expression ◽  
Neuroprotective Effects ◽  
Energy Substrate ◽  
Deprivation Model

Lactate has been shown to offer neuroprotection in several pathologic conditions. This beneficial effect has been attributed to its use as an alternative energy substrate. However, recent description of the expression of the HCA1 receptor for lactate in the central nervous system calls for reassessment of the mechanism by which lactate exerts its neuroprotective effects. Here, we show that HCA1 receptor expression is enhanced 24 hours after reperfusion in an middle cerebral artery occlusion stroke model, in the ischemic cortex. Interestingly, intravenous injection of L-lactate at reperfusion led to further enhancement of HCA1 receptor expression in the cortex and striatum. Using an in vitro oxygen-glucose deprivation model, we show that the HCA1 receptor agonist 3,5-dihydroxybenzoic acid reduces cell death. We also observed that D-lactate, a reputedly non-metabolizable substrate but partial HCA1 receptor agonist, also provided neuroprotection in both in vitro and in vivo ischemia models. Quite unexpectedly, we show D-lactate to be partly extracted and oxidized by the rodent brain. Finally, pyruvate offered neuroprotection in vitro whereas acetate was ineffective. Our data suggest that L- and D-lactate offer neuroprotection in ischemia most likely by acting as both an HCA1 receptor agonist for non-astrocytic (most likely neuronal) cells as well as an energy substrate.

scholarly journals Altered Biosynthesis of Neuropeptide Processing Enzyme Carboxypeptidase E after Brain Ischemia: Molecular Mechanism and Implication

2004 ◽  
Vol 24 (6) ◽  
pp. 612-622 ◽  
Author(s):  
An Zhou ◽  
Manabu Minami ◽  
Xiaoman Zhu ◽  
Sylvia Bae ◽  
John Minthorne ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Brain Ischemia ◽  
Cortical Neurons ◽  
Focal Cerebral Ischemia ◽  
Proteolytic Processing ◽  
Carboxypeptidase E ◽  
Processing Enzyme ◽  
The Impact

In this study, using both in vivo and in vitro ischemia models, the authors investigated the impact of brain ischemia on the biosynthesis of a key neuropeptide-processing enzyme, carboxypeptidase E (CPE). The response to brain ischemia of animals that lacked an active CPE was also examined. Combined in situ hybridization and immunocytochemical analyses for CPE showed reciprocal changes of CPE mRNA and protein, respectively, in the same cortical cells in rat brains after focal cerebral ischemia. Western blot analysis revealed an accumulation of the precursor protein of CPE in the ischemic cortex in vivo and in ischemic cortical neurons in vitro. Detailed metabolic labeling experiments on ischemic cortical neurons showed that ischemic stress caused a blockade in the proteolytic processing of CPE. When mice lacking an active CPE protease were subjected to a sublethal episode of focal cerebral ischemia, abundant TUNEL-positive cells were seen in the ischemic cortex whereas only a few were seen in the cortex of wild-type animals. These findings suggest that ischemia has an adverse impact on the neuropeptide-processing system in the brain and that the lack of an active neuropeptide-processing enzyme exacerbates ischemic brain injury.

Abstract TP268: Induction Profile of Mesencephalic Astrocyte-derived Neurotrophic Factor by Cerebral Ischemia and its Implication for Neuroprotection

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Ludmila Belayev ◽  
Sung-Ha Hong ◽  
Pranab K Mukherjee ◽  
Hemant Menghani ◽  
Larissa Khoutorova ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Dentate Gyrus ◽  
Mrna Expression ◽  
Neurotrophic Factor ◽  
Focal Cerebral Ischemia ◽  
Artery Occlusion ◽  
Ischemic Penumbra ◽  
Protein Levels

Introduction: Mesencephalic astrocyte-derived neurotrophic factor (MANF) has been identified as a secretion protein, which biases immune cells toward an anti-inflammatory phenotype, thereby promoting tissue repair after various injuries to neurons in vivo or in vitro. However, the function of MANF during and after brain ischemia is still not known. The purpose of our study was to examine the characteristics and implication of MANF expression induced by focal cerebral ischemia. In addition we investigated if docosahexaenoic acid (DHA) potentiates MANF mRNA expression and provides additional neuroprotection. Methods: Male SD (280-320) rats were anesthetized with isoflurane and subjected to 2 h of middle cerebral artery occlusion (MCAo) by intraluminal suture. DHA (5 mg/kg; n=13) or vehicle (saline; n=8) was administered IV at 3 h after the onset of MCAo. Neurological function was evaluated during occlusion (60 min) and on days 1, 3 and 7 after MCAo. MANF mRNA expression, protein levels, and apoptosis were measured by immunohistochemistry and Western blotting. Results: Behavioral deficit was significantly improved by treatment with DHA compared to vehicle on days 1, 3 and 7. MANF was found to be extremely upregulated in the ischemic penumbra. The expression of MANF was neuronal in the cortex and dentate gyrus. DHA administration significantly increased the number of MANF + /NeuN + cells in the cortex (by 76.6 %) and dentate gyrus (by 20.5 %) compared to saline-treated animals. The number of MANF/NeuN-positive cells was not different in the subcortex, CA1 and CA3 regions between DHA- and saline-treated groups. Treatment with DHA increased MANF + /GFAP + cells in the subcortex (by 27.7 %) and dentate gyrus (by 38.0 %) compared to the vehicle-treated brains. Total and cortical infarct volumes were attenuated by DHA treatment by 48 % and by 73 % compared to vehicle treatment at 24 h after MCAo. Conclusion: MANF mRNA expression and protein levels are increased after focal cerebral ischemia. It was found to be extremely upregulated in the ischemic penumbra and dentate gyrus. The expression of MANF was mostly neuronal and astrocytic. DHA potentiates MANF expression and provides additional neuroprotection.

scholarly journals Effects of Cerebral Ischemia on Neuronal Hemoglobin

2008 ◽  
Vol 29 (3) ◽  
pp. 596-605 ◽  
Author(s):  
Yangdong He ◽  
Ya Hua ◽  
Wenquan Liu ◽  
Haitao Hu ◽  
Richard F Keep ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Middle Cerebral Artery ◽  
Cerebral Artery ◽  
Ischemic Preconditioning ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Sprague Dawley ◽  
Cerebral Neurons

This study examined whether neuronal hemoglobin (Hb) is present in rats. It then examined whether cerebral ischemia or ischemic preconditioning (IPC) affects neuronal Hb levels in vivo and in vitro. In vivo, male Sprague-Dawley rats were subjected to either 15 mins of transient middle cerebral artery occlusion (MCAO) with 24 h of reperfusion, an IPC stimulus, or 24 h of permanent MCAO (pMCAO), or IPC followed 3 days later by 24 h of pMCAO. In vitro, primary cultured neurons were exposed to 2 h of oxygen—glucose deprivation (OGD) with 22 h of reoxygenation. Results showed that Hb is widely expressed in rat cerebral neurons but not astrocytes. Hemoglobin expression was significantly upregulated in the ipsilateral caudate and the cortical core of the middle cerebral artery territory after IPC. Hemoglobin levels also increased more in the penumbral cortex and the contralateral hemisphere 24 h after pMCAO, but expressions in the ipsilateral caudate and the cortical core area were decreased. Ischemic preconditioning modified pMCAO-induced brain Hb changes. Neuronal Hb levels in vitro were increased by 2 h of OGD and 22 h of reoxygenation. These results indicate that Hb is synthesized in neurons and can be upregulated by ischemia.

scholarly journals Sphk1-induced Autophagy in Microglia Promotes Neuronal Injury Following Cerebral Ischemia-Reperfusion

2020 ◽  
Author(s):  
Manhua Lv ◽  
Yongjia Jiang ◽  
Dayong Zhang ◽  
Dan Yao ◽  
Yuefeng Cheng ◽  
...  
Keyword(s):  
Cerebral Ischemia ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Neuronal Injury ◽  
Glucose Deprivation ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cerebral Ischemia Reperfusion ◽  
The Impact

Abstract Background: Microglial hyperactivation driven by SphK1/S1P signaling and consequent inflammatory mediator production is a key driver of cerebral ischemia-reperfusion injury (CIRI). While SphK1 reportedly controls autophagy and microglial activation, it remains uncertain as to whether it is similarly able to regulate damage mediated by CIRI-activated microglia. Methods: In the present study, we utilized both an in vitro oxygen-glucose deprivation reperfusion (OGDR) model and an in vivo rat model of focal CIRI to test whether Sphk1 and autophagy is expressed in microglia. Western blot analysis was used to estimate the autophagy protein level (LC3 and SQSTM ) at different time points after OGDR. To detect cytokine secretion in microglial supernatants in response to OGDR, we measured the concentration of IL-1β, IL-6 and TNF-α in the culture supernatants using an enzyme-linked immunosorbent assay (ELISA). To evaluate whether microglia subjected to OGDR exhibited neuronal injury, we used a commercially available terminal transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) kit and flow cytometry to detect apoptotic neurons.Results: We determined that in the context of CIRI, microglia upregulated SphK1 and induced autophagy, while inhibiting these changes by lentivirus targeting SphK1 significantly decreased expression of autophagy . Moreover, we determined that autophagic body formation was enhanced in cerebral tissues following I/R. We also explored the impact of SphK1-induced autophagy on microglial inflammatory cytokine production and associated neuronal apoptosis using an in vitro OGDR model system. At a mechanistic level, we found that SphK1 promotes autophagy via the tumor necrosis factor receptor-associated factor 2 (TRAF2) pathway. Conclusion: These results reveal a novel mechanism whereby SphK1-induced autophagy in microglia can contribute to the pathogenesis of CIRI, potentially highlighting novel avenues for future therapeutic intervention in IS patients.

scholarly journals Role of CX3CR1 (Fractalkine Receptor) in Brain Damage and Inflammation Induced by Focal Cerebral Ischemia in Mouse

2008 ◽  
Vol 28 (10) ◽  
pp. 1707-1721 ◽  
Author(s):  
Ádám Dénes ◽  
Szilamér Ferenczi ◽  
József Halász ◽  
Zsuzsanna Környei ◽  
Krisztina J Kovács
Keyword(s):  
Cerebral Ischemia ◽  
Focal Cerebral Ischemia ◽  
Glucose Deprivation ◽  
Ischemic Damage ◽  
Fractalkine Receptor ◽  
Microglial Phenotype ◽  
Tnf Α

CX3CR1 (fractalkine receptor) is important for sustaining normal microglial activity in the brain. Lack of CX3CR1 reportedly results in neurotoxic microglial phenotype in disease models. The objective of this study was to test the hypothesis that the absence of CX3CR1 worsens the outcome in cerebral ischemia. We observed significantly smaller (56%) infarcts and blood—brain barrier damage in CX3CR1-deficient (CX3CR1−/−) animals compared with CX3CR1 +/− and wild-type mice after transient occlusion of the middle cerebral artery (MCAo). Functional recovery of CX3CR1−/−animals was enhanced, while less number of apoptotic cells and infiltrating leukocytes were found in the ipsilateral hemisphere. Expression of IL-1β mRNA, protein, and interleukin (IL)-1Ra and tumor necrosis factor (TNF)-α mRNAs was lower in CX3CR1−/− mice, whereas no difference was observed in the number of IL-1β-expressing microglia or plasma IL-1β concentration. We observed early IL-1β expression in astrocytes in vivo after MCAo and after oxygen—glucose deprivation in vitro, which might contribute to the ischemic damage. Our findings indicate that lack of CX3CR1 does not result in microglial neurotoxicity after MCAo, but rather significantly reduces ischemic damage and inflammation. Reduced IL-1β and TNFα expression as well as decreased leukocyte infiltration might be involved in the development of smaller infarcts in CX3CR1−/− animals.

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