scholarly journals PHLPP1 Gene Deletion Protects the Brain from Ischemic Injury

2012 ◽  
Vol 33 (2) ◽  
pp. 196-204 ◽  
Author(s):  
Bo Chen ◽  
Jessica A Van Winkle ◽  
Patrick D Lyden ◽  
Joan H Brown ◽  
Nicole H Purcell
Keyword(s):  
Protein Phosphatase ◽  
Infarct Volume ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Ph Domain ◽  
Akt Activation ◽  
Cerebral Artery Occlusion ◽  
The Brain ◽  
Leucine Rich Repeat Protein

A recently discovered protein phosphatase PHLPP (PH domain Leucine-rich repeat Protein Phosphatase) has been shown to dephosphorylate Akt on its hydrophobic motif (Ser473) thereby decreasing Akt kinase activity. We generated PHLPP1 knockout (KO) mice and used them to explore the ability of enhanced in vivo Akt signaling to protect the brain against ischemic insult. Brains from KO mice subjected to middle cerebral artery occlusion (MCAO) for 2 hours showed significantly greater increases in Akt activity and less neurovascular damage after reperfusion than wild-type (WT) mice. Remarkably, infarct volume in the PHLPP1 KO was significantly reduced compared with WT (12.7 ± 2.7% versus 22.9 ± 3.1%) and this was prevented by Akt inhibition. Astrocytes from KO mice and neurons in which PHLPP1 was downregulated showed enhanced Akt activation and diminished cell death in response to oxygen-glucose deprivation. Thus, deletion of PHLPP1 can enhance Akt activation in neurons and astrocytes, and can significantly increase cell survival and diminish infarct size after MCAO. Inhibition of PHLPP could be a therapeutic approach to minimize damage after focal ischemia.

scholarly journals Modulator of apoptosis-1 is a potential therapeutic target in acute ischemic injury

2018 ◽  
Vol 39 (12) ◽  
pp. 2406-2418 ◽  
Author(s):  
Su Jing Chan ◽  
Hui Zhao ◽  
Kazuhide Hayakawa ◽  
Chou Chai ◽  
Chong Teik Tan ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Infarct Volume ◽  
Neuronal Loss ◽  
Ischemic Injury ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
In Vivo Models ◽  
The Brain

Modulator of apoptosis 1 (MOAP-1) is a Bax-associating protein highly enriched in the brain. In this study, we examined the role of MOAP-1 in promoting ischemic injuries following a stroke by investigating the consequences of MOAP-1 overexpression or deficiency in in vitro and in vivo models of ischemic stroke. MOAP-1 overexpressing SH-SY5Y cells showed significantly lower cell viability following oxygen and glucose deprivation (OGD) treatment when compared to control cells. Consistently, MOAP-1−/− primary cortical neurons were observed to be more resistant against OGD treatment than the MOAP-1+/+ primary neurons. In the mouse transient middle cerebral artery occlusion (tMCAO) model, ischemia triggered MOAP-1/Bax association, suggested activation of the MOAP-1-dependent apoptotic cascade. MOAP-1−/− mice were found to exhibit reduced neuronal loss and smaller infarct volume 24 h after tMCAO when compared to MOAP-1+/+ mice. Correspondingly, MOAP-1−/− mice also showed better integrity of neurological functions as demonstrated by their performance in the rotarod test. Therefore, both in vitro and in vivo data presented strongly support the conclusion that MOAP-1 is an important apoptotic modulator in ischemic injury. These results may suggest that a reduction of MOAP-1 function in the brain could be a potential therapeutic approach in the treatment of acute stroke.

scholarly journals Image-based stroke rat brain atrophy volume and infarct volume computation

2020 ◽  
Vol 76 (12) ◽  
pp. 10090-10121
Author(s):  
Yung-Kuan Chan ◽  
Chun-Fu Hong ◽  
Meng-Hsiun Tsai ◽  
Ya-Lan Chang ◽  
Ping-Hsuan Sun
Keyword(s):  
Ischemic Stroke ◽  
Rat Brain ◽  
Brain Slice ◽  
Infarct Volume ◽  
Brain Slices ◽  
Artery Occlusion ◽  
Tetrazolium Chloride ◽  
Rat Brain Slice ◽  
Cerebral Artery Occlusion ◽  
The Brain

Abstract Stroke is one of the leading causes of death as well as results in a massive economic burden for society. Stroke is a cerebrovascular disease mainly divided into two types: ischemic stroke and hemorrhagic stroke, which, respectively, refer to the partial blockage and bleeding inside brain blood vessels. Both stroke types lead to nutrient and oxygen deprivation in the brain, which ultimately cause brain damage or death. This study focuses on ischemic stroke in rats with middle cerebral artery occlusion (MCAO) as experimental subjects, and the volumes of infarct and atrophy are calculated based on the brain slice images of rat brains stained with 2,3,5-triphenyl tetrazolium chloride. In this study, a stroke rat brain infarct and atrophy volumes computation system (SRBIAVC system) is developed to segment the infarcts and atrophies from the rat brain slice images. Based on the segmentation results, the infarct and atrophy volumes of a rat brain can be computed. In this study, 168 images of brain slices cut from 28 rat brains with MCAO are used as the test samples. The experimental results show that the segmentation results obtained by the SRBIAVC system are close to those obtained by experts.

scholarly journals Blockade of P2X7 Receptors or Pannexin-1 Channels Similarly Attenuates Postischemic Damage

2015 ◽  
Vol 35 (5) ◽  
pp. 843-850 ◽  
Author(s):  
Abraham Cisneros-Mejorado ◽  
Miroslav Gottlieb ◽  
Fabio Cavaliere ◽  
Tim Magnus ◽  
Friederich Koch-Nolte ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Infarct Volume ◽  
Neuroprotective Effect ◽  
Brain Slices ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Organotypic Cultures ◽  
P2x7 Receptors ◽  
Pannexin 1

The role of P2X7 receptors and pannexin-1 channels in ischemic damage remains controversial. Here, we analyzed their contribution to postanoxic depolarization after ischemia in cultured neurons and in brain slices. We observed that pharmacological blockade of P2X7 receptors or pannexin-1 channels delayed the onset of postanoxic currents and reduced their slope, and that simultaneous inhibition did not further enhance the effects of blocking either one. These results were confirmed in acute cortical slices from P2X7 and pannexin-1 knockout mice. Oxygen-glucose deprivation in cortical organotypic cultures caused neuronal death that was reduced with P2X7 and pannexin-1 blockers as well as in organotypic cultures derived from mice lacking P2X7 and pannexin 1. Subsequently, we used transient middle cerebral artery occlusion to monitor the neuroprotective effect of those drugs in vivo. We found that P2X7 and pannexin-1 antagonists, and their ablation in knockout mice, substantially attenuated the motor symptoms and reduced the infarct volume to ~50% of that in vehicle-treated or wild-type animals. These results show that P2X7 receptors and pannexin-1 channels are major mediators of postanoxic depolarization in neurons and of brain damage after ischemia, and that they operate in the same deleterious signaling cascade leading to neuronal and tissue demise.

scholarly journals Protein Phosphatase 1, Protein Phosphatase 2A, and Calcineurin Play a Role in Estrogen-Mediated Neuroprotection

Endocrinology ◽  
2008 ◽  
Vol 149 (10) ◽  
pp. 5235-5243 ◽  
Author(s):  
Kun Don Yi ◽  
James W. Simpkins
Keyword(s):  
Protein Phosphatase ◽  
Protein Phosphatases ◽  
Cellular Function ◽  
Artery Occlusion ◽  
Protective Effects ◽  
The Face ◽  
Phosphatase 2A ◽  
Cerebral Artery Occlusion

It is becoming increasingly clear that protein phosphatases are important modulators of cellular function and that disruption of these proteins are involved in neurodegenerative disease processes. Serine/threonine protein phosphatases (PP) such as protein phosphatase PP1, PP2A, and calcineurin are involved in hyperphosphorylation of τ- as well as β-amyloid-induced cell death. We have previously shown serine/threonine protein phosphatases to be involved in estrogen-mediated neuroprotection. The purpose of this study was to delineate the role of PP1, PP2A, and calcineurin in the mechanism of estrogen mediated neuroprotection against oxidative stress and excitotoxicity. Treatment with protein phosphatases inhibitor II, endothall, or cyclosporin A, which are specific inhibitors of PP1, PP2A, and calcineurin, respectively, did not have an effect on cell viability. However, in combination, these inhibitors adversely affected cell survival, which suggests the importance of serine/threonine protein phosphatases in maintenance of cellular function. Inhibitors of PP1, PP2A, and calcineurin attenuated the protective effects of estrogen against glutamate-induced -neurotoxicity but did not completely abrogate the estrogen-mediated protection. The attenuation of estrogen-induced neuroprotection was achieved through decrease in the activity of theses serine/threonine phosphatases without the concomitant decrease in protein expression. In an animal model, transient middle cerebral artery occlusion caused a 50% decrease in levels of PP1, PP2A, and PP2B ipsilateral to the lesion in a manner that was prevented by estradiol pretreatment. Therefore, we conclude that in the face of cytotoxic challenges in vitro and in vivo, estrogens maintain the function of PP1, PP2A, and calcineurin.

scholarly journals Restoration of Polyamine Metabolic Patterns inIn VivoandIn VitroModel of Ischemic Stroke following Human Mesenchymal Stem Cell Treatment

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Tae Hwan Shin ◽  
Geetika Phukan ◽  
Jeom Soon Shim ◽  
Duc-Toan Nguyen ◽  
Yongman Kim ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cell Model ◽  
Glucose Deprivation ◽  
Human Mesenchymal Stem Cell ◽  
Artery Occlusion ◽  
Control Group ◽  
Stem Cell Treatment ◽  
Cerebral Artery Occlusion

We investigated changes in PA levels by the treatment of human bone-marrow-derived mesenchymal stem cells (hBM-MSCs) in ischemic stroke in rat brain model and in cultured neuronal SH-SY5Y cells exposed to oxygen-glucose deprivation (OGD). In ischemic rat model, transient middle cerebral artery occlusion (MCAo) was performed for 2 h, followed by intravenous transplantation of hBM-MSCs or phosphate-buffered saline (PBS) the day following MCAo. Metabolic profiling analysis of PAs was examined in brains from three groups: control rats, PBS-treated MCAo rats (MCAo), and hBM-MSCs-treated MCAo rats (MCAo + hBM-MSCs). In ischemic cell model, SH-SY5Y cells were exposed to OGD for 24 h, treated with hBM-MSCs (OGD + hBM-MSCs) prior to continued aerobic incubation, and then samples were collected after coculture for 72 h. In thein vivoMCAo ischemic model, levels of some PAs in brain samples of the MCAo and MCAo + hBM-MSCs groups were significantly different from those of the control group. In particular, putrescine, cadaverine, and spermidine in brain tissues of the MCAo + hBM-MSCs group were significantly reduced in comparison to those in the MCAo group. In thein vitroOGD system,N1-acetylspermidine, spermidine,N1-acetylspermine, and spermine in cells of the OGD + hBM-MSCs group were significantly reduced compared to those of OGD group.

scholarly journals The AAA + ATPase Thorase is neuroprotective against ischemic injury

2018 ◽  
Vol 39 (9) ◽  
pp. 1836-1848 ◽  
Author(s):  
Jianmin Zhang ◽  
Jia Yang ◽  
Huaishan Wang ◽  
Omar Sherbini ◽  
Matthew J Keuss ◽  
...  
Keyword(s):  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Glutamate Excitotoxicity ◽  
Experimental Stroke ◽  
Dependent Manner ◽  
Aaa Atpase ◽  
Neurologic Disorders ◽  
Cerebral Artery Occlusion

Neuronal preconditioning in vitro or in vivo with a stressful but non-lethal stimulus leads to new protein expression that mediates a profound neuroprotection against glutamate excitotoxicity and experimental stroke. The proteins that mediate neuroprotection are relatively unknown and under discovery. Here we find that the expression of the AAA + ATPase Thorase is induced by preconditioning stimulation both in vitro and in vivo. Thorase provides neuroprotection in an ATP-dependent manner against oxygen–glucose deprivation (OGD) neurotoxicity or glutamate N-Methyl-D-aspartate (NMDA) receptor-mediated excitotoxicity in vitro. Knock-down of Thorase prevents the establishment of preconditioning induced neuroprotection against OGD or NMDA neurotoxicity. Transgenic overexpression of Thorase provides neuroprotection in vivo against middle cerebral artery occlusion (MCAO)-induced stroke in mice, while genetic deletion of Thorase results in increased injury in vivo following stroke. These results define Thorase as a neuroprotective protein and understanding Thorase signaling could offer a new therapeutic strategy for the treatment of neurologic disorders.

scholarly journals Sphingosine 1-phosphate, a Novel TREM2 Ligand, Promotes Phagocytosis and Reduce Ischemic Injury

2020 ◽  
Author(s):  
Xiu-Lan Sun ◽  
Teng-Fei Xue ◽  
Juan Ji ◽  
Ruo-Bing Guo ◽  
Yu-Qin Sun ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Infarct Volume ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Endogenous Ligand ◽  
Microglial Phagocytosis ◽  
Neurological Score ◽  
Cellular Debris ◽  
Sphingosine 1 Phosphate ◽  
Cerebral Artery Occlusion

Abstract Background: Activation of TREM2 protects against brain injury in ischemic stroke via immunoregulation. However, the endogenous ligand of TREM2 remains unknown. Here, we tested the hypothesis that S1P, an immunoregulator, functions as TREM2 ligand to promote microglial phagocytosis.Methods: SD rats, C57BL/6J mice and TREM2-/- mice were subjected to transient middle cerebral artery occlusion, and primary microglia were subjected to oxygen-glucose deprivation. Phagocytosis was investigated via immunofluorescence and two-photon microscope. LC-MS/MS, microscale thermophoresis and surface plasmon resonance were used to confirm the TREM2-S1P interaction.Results: FTY720, an analog of S1P, promoted microglial phagocytosis in ischemic stroke independent of S1PRs expressed on microglia. S1P was confirmed to be a novel endogenous ligand for TREM2 and promote cellular debris clearance. The enhanced cellular debris clearance ameliorated neurological score and infarct volume, relying on TREM2. Moreover, FTY720 was demonstrated to promote hemoglobin clearance in intracerebral hemorrhage and ameliorate hemorrhagic injury.Conlusions: The present work reveals for the first time that S1P acts as a novel endogenous ligand of TREM2 to effectively promote microglial phagocytosis, and provides a new lead compound for developing TREM2 modulator.

GATA3 (GATA-Binding Protein 3)/KMT2A (Lysine-Methyltransferase-2A) Complex by Increasing H3K4-3me (Trimethylated Lysine-4 of Histone-3) Upregulates NCX3 (Na + -Ca 2+ Exchanger 3) Transcription and Contributes to Ischemic Preconditioning Neuroprotection

Stroke ◽  
2021 ◽  
Vol 52 (11) ◽  
pp. 3680-3691
Author(s):  
Natascia Guida ◽  
Luigi Mascolo ◽  
Angelo Serani ◽  
Ornella Cuomo ◽  
Serenella Anzilotti ◽  
...  
Keyword(s):  
Ischemic Preconditioning ◽  
Cortical Neurons ◽  
Promoter Region ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Histone 3 ◽  
Lysine Methyltransferase ◽  
Cerebral Artery Occlusion

Background and Purpose: NCX3 (Na + -Ca 2+ exchanger 3) plays a relevant role in stroke; indeed its pharmacological blockade or its genetic ablation exacerbates brain ischemic damage, whereas its upregulation takes part in the neuroprotection elicited by ischemic preconditioning. To identify an effective strategy to induce an overexpression of NCX3, we examined transcription factors and epigenetic mechanisms potentially involved in NCX3 gene regulation. Methods: Brain ischemia and ischemic preconditioning were induced in vitro by exposure of cortical neurons to oxygen and glucose deprivation plus reoxygenation (OGD/Reoxy) and in vivo by transient middle cerebral artery occlusion. Western blot and quantitative real-time polymerase chain reaction were used to evaluate transcripts and proteins of GATA3 (GATA-binding protein 3), KMT2A (lysine-methyltransferase-2A), and NCX3. GATA3 and KMT2A binding on NCX3 gene was evaluated by chromatin immunoprecipitation and Rechromatin immunoprecipitation experiments. Results: Among the putative transcription factors sharing a consensus sequence on the ncx3 brain promoter region, GATA3 was the only able to up-regulate ncx3. Interestingly, GATA3 physically interacted with KMT2A, and their overexpression or knocking-down increased or downregulated NCX3 mRNA and protein, respectively. Notably, site-direct mutagenesis of GATA site on ncx3 brain promoter region counteracted GATA3 and KMT2A binding on NCX3 gene. More importantly, we found that in the perischemic cortical regions of preconditioned rats GATA3 recruited KMT2A and the complex H3K4-3me (trimethylated lysine-4 of histone-3) on ncx3 brain promoter region, thus reducing transient middle cerebral artery occlusion–induced damage. Consistently, in vivo silencing of either GATA3 or KMT2A prevented NCX3 upregulation and consequently the neuroprotective effect of preconditioning stimulus. The involvement of GATA3/KMT2A complex in neuroprotection elicited by ischemic preconditioning was further confirmed by in vitro experiments in which the knocking-down of GATA3 and KMT2A reverted the neuroprotection induced by NCX3 overexpression in cortical neurons exposed to anoxic preconditioning followed by oxygen and glucose deprivation plus reoxygenation. Conclusions: Collectively, our results revealed that GATA3/KMT2A complex epigenetically activates NCX3 gene transcription during ischemic preconditioning.

scholarly journals Prunus cerasoides Extract and Its Component Compounds Upregulate Neuronal Neuroglobin Levels, Mediate Antioxidant Effects, and Ameliorate Functional Losses in the Mouse Model of Cerebral Ischemia

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 99
Author(s):  
So-Dam Kim ◽  
Minha Kim ◽  
Hong-Hua Wu ◽  
Byung Kwan Jin ◽  
Myung-Shin Jeon ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Mouse Model ◽  
Infarct Volume ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Novel Approach ◽  
Vehicle Treatment ◽  
Prunus Cerasoides

Prunus cerasoides (PC) has been reported to have antimicrobial and anti-inflammatory properties, but its potential as a neuroprotective agent in a mouse model of cerebral ischemia has not been explored. Considering neuroglobin (Ngb), an endogenous neuroprotective factor, as a novel approach to neuroprotection, in this study, Ngb promoter activity, Ngb expression changes, and antioxidant protection by PC extract (PCE) and PC component compounds (PCCs) were analyzed in oxygen–glucose deprivation (OGD)-treated neurons. In vivo analysis involved transient middle cerebral artery occlusion (tMCAO) in mice with pre- and post-treatment exposure to PCE. Following ischemic stroke induction, neurological behavior scores were obtained, and cellular function-related signals were evaluated in the ischemic infarct areas. In addition to PCE, certain component compounds from PCE also significantly increased Ngb levels and attenuated the intracellular ROS production and cytotoxicity seen with OGD in primary neurons. Administration of PCE reduced the infarct volume and improved neurological deficit scores in ischemic stroke mice compared with the vehicle treatment. Increased Ngb levels in infarct penumbra with PCE treatment were also accompanied by decreased markers of apoptosis (activated p38 and cleaved caspase-3). Our findings point to the benefits of Ngb-mediated neuroprotection via PCE and its antioxidant activity in an ischemic stroke model.

scholarly journals Improved reperfusion following alternative surgical approach for experimental stroke in mice

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 188
Author(s):  
Melissa Trotman-Lucas ◽  
Raymond Wong ◽  
Stuart M. Allan ◽  
Claire L. Gibson
Keyword(s):  
Ischemic Stroke ◽  
Surgical Approach ◽  
Artery Occlusion ◽  
Laser Speckle ◽  
Experimental Stroke ◽  
Contrast Imaging ◽  
Ipsilateral Hemisphere ◽  
Cerebral Artery Occlusion ◽  
The Brain

Background: Following ischemic stroke, recanalisation and restoration of blood flow to the affected area of the brain is critical and directly correlates with patient recovery.  In vivo models of ischemic stroke show high variability in outcomes, which may be due to variability in reperfusion.  We previously reported that a surgical refinement in the middle cerebral artery occlusion (MCAO) model of stroke, via repair of the common carotid artery (CCA), removes the reliance on the Circle of Willis for reperfusion and reduced infarct variability.  Here we further assess this refined surgical approach on reperfusion characteristics following transient MCAO in mice. Methods: Mice underwent 60 min of MCAO, followed by either CCA repair or ligation at reperfusion.  All mice underwent laser speckle contrast imaging at baseline, 24 h and 48 h post-MCAO. Results: CCA ligation reduced cerebral perfusion in the ipsilateral hemisphere compared to baseline (102.3 ± 4.57%) at 24 h (85.13 ± 16.09%; P < 0.01) and 48 h (75.04 ± 12.954%; P < 0.001) post-MCAO. Repair of the CCA returned perfusion to baseline (94.152 ± 2.44%) levels and perfusion was significantly improved compared to CCA ligation at both 24 h (102.83 ± 8.41%; P < 0.05) and 48 h (102.13 ± 9.34%; P < 0.001) post-MCAO. Conclusions: Our findings show CCA repair, an alternative surgical approach for MCAO, results in improved ischemic hemisphere perfusion during the acute phase.

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