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Heit BS, Chu A, McRay A, Richmond JE, Heckman CJ, Larson J. Interference with glutamate antiporter system x c - enables post-hypoxic long-term potentiation in hippocampus. Exp Physiol 2024. [PMID: 39153228 DOI: 10.1113/ep092045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Accepted: 06/28/2024] [Indexed: 08/19/2024]
Abstract
Our group previously showed that genetic or pharmacological inhibition of the cystine/glutamate antiporter, system xc -, mitigates excitotoxicity after anoxia by increasing latency to anoxic depolarization, thus attenuating the ischaemic core. Hypoxia, however, which prevails in the ischaemic penumbra, is a condition where neurotransmission is altered, but excitotoxicity is not triggered. The present study employed mild hypoxia to further probe ischaemia-induced changes in neuronal responsiveness from wild-type and xCT KO (xCT-/-) mice. Synaptic transmission was monitored in hippocampal slices from both genotypes before, during and after a hypoxic episode. Although wild-type and xCT-/- slices showed equal suppression of synaptic transmission during hypoxia, mutant slices exhibited a persistent potentiation upon re-oxygenation, an effect we termed 'post-hypoxic long-term potentiation (LTP)'. Blocking synaptic suppression during hypoxia by antagonizing adenosine A1 receptors did not preclude post-hypoxic LTP. Further examination of the induction and expression mechanisms of this plasticity revealed that post-hypoxic LTP was driven by NMDA receptor activation, as well as increased calcium influx, with no change in paired-pulse facilitation. Hence, the observed phenomenon engaged similar mechanisms as classical LTP. This was a remarkable finding as theta-burst stimulation-induced LTP was equivalent between genotypes. Importantly, post-hypoxic LTP was generated in wild-type slices pretreated with system xc - inhibitor, S-4-carboxyphenylglycine, thereby confirming the antiporter's role in this phenomenon. Collectively, these data indicate that system xc - interference enables neuroplasticity in response to mild hypoxia, and, together with its regulation of cellular damage in the ischaemic core, suggest a role for the antiporter in post-ischaemic recovery of the penumbra.
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Affiliation(s)
- Bradley S Heit
- Department of Neuroscience and Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, USA
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Alex Chu
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Alyssa McRay
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Janet E Richmond
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Charles J Heckman
- Department of Neuroscience and Department of Biomedical Engineering, Northwestern University, Chicago, Illinois, USA
| | - John Larson
- Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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2
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Escobar I, Xu J, Jackson CW, Stegelmann SD, Fagerli EA, Dave KR, Perez-Pinzon MA. Resveratrol Preconditioning Protects Against Ischemia-Induced Synaptic Dysfunction and Cofilin Hyperactivation in the Mouse Hippocampal Slice. Neurotherapeutics 2023; 20:1177-1197. [PMID: 37208551 PMCID: PMC10457274 DOI: 10.1007/s13311-023-01386-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2023] [Indexed: 05/21/2023] Open
Abstract
Perturbations in synaptic function are major determinants of several neurological diseases and have been associated with cognitive impairments after cerebral ischemia (CI). Although the mechanisms underlying CI-induced synaptic dysfunction have not been well defined, evidence suggests that early hyperactivation of the actin-binding protein, cofilin, plays a role. Given that synaptic impairments manifest shortly after CI, prophylactic strategies may offer a better approach to prevent/mitigate synaptic damage following an ischemic event. Our laboratory has previously demonstrated that resveratrol preconditioning (RPC) promotes cerebral ischemic tolerance, with many groups highlighting beneficial effects of resveratrol treatment on synaptic and cognitive function in other neurological conditions. Herein, we hypothesized that RPC would mitigate hippocampal synaptic dysfunction and pathological cofilin hyperactivation in an ex vivo model of ischemia. Various electrophysiological parameters and synaptic-related protein expression changes were measured under normal and ischemic conditions utilizing acute hippocampal slices derived from adult male mice treated with resveratrol (10 mg/kg) or vehicle 48 h prior. Remarkably, RPC significantly increased the latency to anoxic depolarization, decreased cytosolic calcium accumulation, prevented aberrant increases in synaptic transmission, and rescued deficits in long-term potentiation following ischemia. Additionally, RPC upregulated the expression of the activity-regulated cytoskeleton associated protein, Arc, which was partially required for RPC-mediated attenuation of cofilin hyperactivation. Taken together, these findings support a role for RPC in mitigating CI-induced excitotoxicity, synaptic dysfunction, and pathological over-activation of cofilin. Our study provides further insight into mechanisms underlying RPC-mediated neuroprotection against CI and implicates RPC as a promising strategy to preserve synaptic function after ischemia.
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Affiliation(s)
- Iris Escobar
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Jing Xu
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Charles W Jackson
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Samuel D Stegelmann
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Eric A Fagerli
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Kunjan R Dave
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Miguel A Perez-Pinzon
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA.
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA.
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA.
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3
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Christidis P, Vij A, Petousis S, Ghaemmaghami J, Shah BV, Koutroulis I, Kratimenos P. Neuroprotective effect of Src kinase in hypoxia-ischemia: A systematic review. Front Neurosci 2022; 16:1049655. [PMID: 36507364 PMCID: PMC9730728 DOI: 10.3389/fnins.2022.1049655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/02/2022] [Indexed: 11/25/2022] Open
Abstract
Background Hypoxic-ischemic encephalopathy (HIE) is a major cause of neonatal morbidity and mortality worldwide. While the application of therapeutic hypothermia has improved neurodevelopmental outcomes for some survivors of HIE, this lone treatment option is only available to a subset of affected neonates. Src kinase, an enzyme central to the apoptotic cascade, is a potential pharmacologic target to preserve typical brain development after HIE. Here, we present evidence of the neuroprotective effects of targeting Src kinase in preclinical models of HIE. Methods We performed a comprehensive literature search using the National Library of Medicine's MEDLINE database to compile studies examining the impact of Src kinase regulation on neurodevelopment in animal models. Each eligible study was assessed for bias. Results Twenty studies met the inclusion criteria, and most studies had an intermediate risk for bias. Together, these studies showed that targeting Src kinase resulted in a neuroprotective effect as assessed by neuropathology, enzymatic activity, and neurobehavioral outcomes. Conclusion Src kinase is an effective neuroprotective target in the setting of acute hypoxic injury. Src kinase inhibition triggers multiple signaling pathways of the sub-membranous focal adhesions and the nucleus, resulting in modulation of calcium signaling and prevention of cell death. Despite the significant heterogeneity of the research studies that we examined, the available evidence can serve as proof-of-concept for further studies on this promising therapeutic strategy.
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Affiliation(s)
- Panagiotis Christidis
- Laboratory of Physiology, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Abhya Vij
- Department of Pediatrics, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Stamatios Petousis
- 2nd Department of Obstetrics and Gynecology, “Hippokrateion” General Hospital of Thessaloniki, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Javid Ghaemmaghami
- Center for Neuroscience Research, Children's National Research Institute, Washington, DC, United States
| | - Bhairav V. Shah
- Division of Pediatric Surgery, Department of Pediatrics, School of Medicine, Prisma Health Children's Hospital-Midlands, University of South Carolina, Columbia, SC, United States
| | - Ioannis Koutroulis
- Department of Pediatrics, Division of Emergency Medicine, Children's National Hospital, George Washington University School of Medicine and Health Sciences, Washington, DC, United States
| | - Panagiotis Kratimenos
- Center for Neuroscience Research, Children's National Research Institute, Washington, DC, United States,Division of Neonatology, Department of Pediatrics, Children's National Hospital, George Washington University School of Medicine and Health Sciences, Washington, DC, United States,*Correspondence: Panagiotis Kratimenos
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4
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Dąbrowska-Bouta B, Sulkowski G, Sałek M, Frontczak-Baniewicz M, Strużyńska L. Early and Delayed Impact of Nanosilver on the Glutamatergic NMDA Receptor Complex in Immature Rat Brain. Int J Mol Sci 2021; 22:3067. [PMID: 33802775 PMCID: PMC8002467 DOI: 10.3390/ijms22063067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 01/02/2023] Open
Abstract
Silver nanoparticles (AgNPs) are the one of the most extensively used nanomaterials. The strong antimicrobial properties of AgNPs have led to their use in a wide range of medical and consumer products. Although the neurotoxicity of AgNPs has been confirmed, the molecular mechanisms have not been extensively studied, particularly in immature organisms. Based on information gained from previous in vitro studies, in the present work, we examine whether ionotropic NMDA glutamate receptors contribute to AgNP-induced neurotoxicity in an animal model of exposure. In brains of immature rats subjected to a low dose of AgNPs, we identified ultrastructural and molecular alterations in the postsynaptic region of synapses where NMDA receptors are localized as a multiprotein complex. We revealed decreased expression of several NMDA receptor complex-related proteins, such as GluN1 and GluN2B subunits, scaffolding proteins PSD95 and SynGAP, as well as neuronal nitric oxide synthase (nNOS). Elucidating the changes in NMDA receptor-mediated molecular mechanisms induced by AgNPs, we also identified downregulation of the GluN2B-PSD95-nNOS-cGMP signaling pathway which maintains LTP/LTD processes underlying learning and memory formation during development. This observation is accompanied by decreased density of NMDA receptors, as assessed by a radioligand binding assay. The observed effects are reversible over the post-exposure time. This investigation reveals that NMDA receptors in immature rats are a target of AgNPs, thereby indicating the potential health hazard for children and infants resulting from the extensive use of products containing AgNPs.
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Affiliation(s)
- Beata Dąbrowska-Bouta
- Laboratory of Pathoneurochemistry, Department of Neurochemistr, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland; (B.D.-B.); (G.S.); (M.S.)
| | - Grzegorz Sulkowski
- Laboratory of Pathoneurochemistry, Department of Neurochemistr, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland; (B.D.-B.); (G.S.); (M.S.)
| | - Mikołaj Sałek
- Laboratory of Pathoneurochemistry, Department of Neurochemistr, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland; (B.D.-B.); (G.S.); (M.S.)
| | - Małgorzata Frontczak-Baniewicz
- Electron Microscopy Platform, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland;
| | - Lidia Strużyńska
- Laboratory of Pathoneurochemistry, Department of Neurochemistr, Mossakowski Medical Research Institute, Polish Academy of Sciences, Pawińskiego 5, 02-106 Warsaw, Poland; (B.D.-B.); (G.S.); (M.S.)
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5
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Bentea E, Villers A, Moore C, Funk AJ, O’Donovan SM, Verbruggen L, Lara O, Janssen P, De Pauw L, Declerck NB, DePasquale EAK, Churchill MJ, Sato H, Hermans E, Arckens L, Meshul CK, Ris L, McCullumsmith RE, Massie A. Corticostriatal dysfunction and social interaction deficits in mice lacking the cystine/glutamate antiporter. Mol Psychiatry 2021; 26:4754-4769. [PMID: 32366950 PMCID: PMC7609546 DOI: 10.1038/s41380-020-0751-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 04/07/2020] [Accepted: 04/21/2020] [Indexed: 12/11/2022]
Abstract
The astrocytic cystine/glutamate antiporter system xc- represents an important source of extracellular glutamate in the central nervous system, with potential impact on excitatory neurotransmission. Yet, its function and importance in brain physiology remain incompletely understood. Employing slice electrophysiology and mice with a genetic deletion of the specific subunit of system xc-, xCT (xCT-/- mice), we uncovered decreased neurotransmission at corticostriatal synapses. This effect was partly mitigated by replenishing extracellular glutamate levels, indicating a defect linked with decreased extracellular glutamate availability. We observed no changes in the morphology of striatal medium spiny neurons, the density of dendritic spines, or the density or ultrastructure of corticostriatal synapses, indicating that the observed functional defects are not due to morphological or structural abnormalities. By combining electron microscopy with glutamate immunogold labeling, we identified decreased intracellular glutamate density in presynaptic terminals, presynaptic mitochondria, and in dendritic spines of xCT-/- mice. A proteomic and kinomic screen of the striatum of xCT-/- mice revealed decreased expression of presynaptic proteins and abnormal kinase network signaling, that may contribute to the observed changes in postsynaptic responses. Finally, these corticostriatal deregulations resulted in a behavioral phenotype suggestive of autism spectrum disorder in the xCT-/- mice; in tests sensitive to corticostriatal functioning we recorded increased repetitive digging behavior and decreased sociability. To conclude, our findings show that system xc- plays a previously unrecognized role in regulating corticostriatal neurotransmission and influences social preference and repetitive behavior.
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Affiliation(s)
- Eduard Bentea
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Agnès Villers
- grid.8364.90000 0001 2184 581XDepartment of Neurosciences, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Cynthia Moore
- grid.410404.50000 0001 0165 2383Research Services, Neurocytology Laboratory, Veterans Affairs Medical Center, Portland, OR USA
| | - Adam J. Funk
- grid.267337.40000 0001 2184 944XDepartment of Neurosciences, University of Toledo College of Medicine, Toledo, OH USA
| | - Sinead M. O’Donovan
- grid.267337.40000 0001 2184 944XDepartment of Neurosciences, University of Toledo College of Medicine, Toledo, OH USA
| | - Lise Verbruggen
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Olaya Lara
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Pauline Janssen
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Laura De Pauw
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Noemi B. Declerck
- grid.8767.e0000 0001 2290 8069Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Erica A. K. DePasquale
- grid.239573.90000 0000 9025 8099Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH USA ,grid.24827.3b0000 0001 2179 9593Department of Biomedical Informatics, University of Cincinnati, Cincinnati, OH USA
| | - Madeline J. Churchill
- grid.410404.50000 0001 0165 2383Research Services, Neurocytology Laboratory, Veterans Affairs Medical Center, Portland, OR USA
| | - Hideyo Sato
- grid.260975.f0000 0001 0671 5144Department of Medical Technology, Faculty of Medicine, Laboratory of Biochemistry and Molecular Biology, Niigata University, Niigata, Japan
| | - Emmanuel Hermans
- grid.7942.80000 0001 2294 713XInstitute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium
| | - Lutgarde Arckens
- grid.5596.f0000 0001 0668 7884Laboratory of Neuroplasticity and Neuroproteomics, and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven, Belgium
| | - Charles K. Meshul
- grid.410404.50000 0001 0165 2383Research Services, Neurocytology Laboratory, Veterans Affairs Medical Center, Portland, OR USA ,grid.5288.70000 0000 9758 5690Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, OR USA
| | - Laurence Ris
- grid.8364.90000 0001 2184 581XDepartment of Neurosciences, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Robert E. McCullumsmith
- grid.267337.40000 0001 2184 944XDepartment of Neurosciences, University of Toledo College of Medicine, Toledo, OH USA
| | - Ann Massie
- Neuro-Aging & Viro-Immunotherapy, Center for Neurosciences, Vrije Universiteit Brussel (VUB), Brussels, Belgium.
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6
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Escobar I, Xu J, Jackson CW, Perez-Pinzon MA. Altered Neural Networks in the Papez Circuit: Implications for Cognitive Dysfunction after Cerebral Ischemia. J Alzheimers Dis 2020; 67:425-446. [PMID: 30584147 PMCID: PMC6398564 DOI: 10.3233/jad-180875] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cerebral ischemia remains a leading cause of mortality worldwide. Although the incidence of death has decreased over the years, surviving patients may suffer from long-term cognitive impairments and have an increased risk for dementia. Unfortunately, research aimed toward developing therapies that can improve cognitive outcomes following cerebral ischemia has proved difficult given the fact that little is known about the underlying processes involved. Nevertheless, mechanisms that disrupt neural network activity may provide valuable insight, since disturbances in both local and global networks in the brain have been associated with deficits in cognition. In this review, we suggest that abnormal neural dynamics within different brain networks may arise from disruptions in synaptic plasticity processes and circuitry after ischemia. This discussion primarily concerns disruptions in local network activity within the hippocampus and other extra-hippocampal components of the Papez circuit, given their role in memory processing. However, impaired synaptic plasticity processes and disruptions in structural and functional connections within the Papez circuit have important implications for alterations within the global network, as well. Although much work is required to establish this relationship, evidence thus far suggests there is a link. If pursued further, findings may lead toward a better understanding of how deficits in cognition arise, not only in cerebral ischemia, but in other neurological diseases as well.
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Affiliation(s)
- Iris Escobar
- Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, FL, USA.,Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jing Xu
- Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, FL, USA.,Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Charles W Jackson
- Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, FL, USA.,Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Miguel A Perez-Pinzon
- Department of Neurology, Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, FL, USA.,Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL, USA
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7
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Shah FA, Li T, Kury LTA, Zeb A, Khatoon S, Liu G, Yang X, Liu F, Yao H, Khan AU, Koh PO, Jiang Y, Li S. Pathological Comparisons of the Hippocampal Changes in the Transient and Permanent Middle Cerebral Artery Occlusion Rat Models. Front Neurol 2019; 10:1178. [PMID: 31798514 PMCID: PMC6868119 DOI: 10.3389/fneur.2019.01178] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 10/22/2019] [Indexed: 01/04/2023] Open
Abstract
Ischemic strokes are categorized by permanent or transient obstruction of blood flow, which impedes delivery of oxygen and essential nutrients to brain. In the last decade, the therapeutic window for tPA has increased from 3 to 5-6 h, and a new technique, involving the mechanical removal of the clot (endovascular thrombectomy) to allow reperfusion of the injured area, is being used more often. This last therapeutic approach can be done until 24 h after stroke onset. Due to this fact, more acute ischemic stroke patients are now being recanalized, and so tMCAO is probably the "best" model to address these patients that have a potential good outcome in terms of survival and functional recovery. However, permanent occlusion patients are also important, not only to increase survival rate but also to improve functional outcomes, although these are more difficult to achieve. So, both models are important, and which target different stroke patients in the clinical scenario. Hippocampus has a vital role in memory and cognition, is prone to ischemic induced neurodegeneration. This study was designed to delineate the molecular, pathological, and neurological changes in rat models of t-MCAO, permanent MCAO (pMCAO), and pMCAO with diabetic conditions in hippocampal tissue. Our results showed that these three models showed distinct discrepancies at numerous pathological process, including key signaling molecules involved in neuronal apoptosis, glutamate induced excitotoxicity, neuroinflammation, oxidative stress, and neurotrophic changes. Our result suggests that the two commonly used MCAO models exhibited tremendous differences in terms of neuronal cell loss, glutamate excitotoxic related signaling, synaptic transmission markers, neuron inflammatory and oxidative stress molecules. These differences may reflect the variations in different models, which may provide valuable information for mechanistic and therapeutic inconsistences as experienced in both preclinical models and clinical trials.
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Affiliation(s)
- Fawad Ali Shah
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China.,Department of Pharmacology, Riphah Institute of Pharmaceutical Sciences, International University, Islamabad, Pakistan
| | - Tao Li
- Department of Forensic Medicine, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Lina Tariq Al Kury
- College of Natural and Health Sciences, Zayed University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Alam Zeb
- Department of Pharmacology, Riphah Institute of Pharmaceutical Sciences, International University, Islamabad, Pakistan
| | - Shehla Khatoon
- Department of Anatomy, Khyber Medical College, Khyber Medical University, Peshawar, Pakistan
| | - Gongping Liu
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China and Hubei Province for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Xifei Yang
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Fang Liu
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, ON, Canada
| | - Huo Yao
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Arif-Ullah Khan
- Department of Pharmacology, Riphah Institute of Pharmaceutical Sciences, International University, Islamabad, Pakistan
| | - Phil Ok Koh
- Department of Anatomy, College of Veterinary Medicine, Research Institute of Life Science, Gyeongsang National University, Jinju-si, South Korea
| | - Yuhua Jiang
- Cancer Centre, The Second Hospital of Shandong University, Jinan, China
| | - Shupeng Li
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, ON, Canada
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8
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Wilson RS, Rauniyar N, Sakaue F, Lam TT, Williams KR, Nairn AC. Development of Targeted Mass Spectrometry-Based Approaches for Quantitation of Proteins Enriched in the Postsynaptic Density (PSD). Proteomes 2019; 7:12. [PMID: 30986977 PMCID: PMC6630806 DOI: 10.3390/proteomes7020012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 03/27/2019] [Accepted: 03/28/2019] [Indexed: 02/07/2023] Open
Abstract
The postsynaptic density (PSD) is a structural, electron-dense region of excitatory glutamatergic synapses, which is involved in a variety of cellular and signaling processes in neurons. The PSD is comprised of a large network of proteins, many of which have been implicated in a wide variety of neuropsychiatric disorders. Biochemical fractionation combined with mass spectrometry analyses have enabled an in-depth understanding of the protein composition of the PSD. However, the PSD composition may change rapidly in response to stimuli, and robust and reproducible methods to thoroughly quantify changes in protein abundance are warranted. Here, we report on the development of two types of targeted mass spectrometry-based assays for quantitation of PSD-enriched proteins. In total, we quantified 50 PSD proteins in a targeted, parallel reaction monitoring (PRM) assay using heavy-labeled, synthetic internal peptide standards and identified and quantified over 2100 proteins through a pre-determined spectral library using a data-independent acquisition (DIA) approach in PSD fractions isolated from mouse cortical brain tissue.
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Affiliation(s)
- Rashaun S Wilson
- Yale/NIDA Neuroproteomics Center, New Haven, CT 06511, USA.
- W.M Keck Biotechnology Resource Laboratory, Yale University School of Medicine, New Haven, CT 06511, USA.
- Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06511, USA.
| | | | - Fumika Sakaue
- Department of Neurology and Neurological Science, Tokyo Medical and Dental University, Tokyo 113-8519, Japan.
- Department of Psychiatry, Yale School of Medicine, Connecticut Mental Health Center, New Haven, CT 06511, USA.
| | - TuKiet T Lam
- Yale/NIDA Neuroproteomics Center, New Haven, CT 06511, USA.
- W.M Keck Biotechnology Resource Laboratory, Yale University School of Medicine, New Haven, CT 06511, USA.
- Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06511, USA.
| | - Kenneth R Williams
- Yale/NIDA Neuroproteomics Center, New Haven, CT 06511, USA.
- Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06511, USA.
| | - Angus C Nairn
- Yale/NIDA Neuroproteomics Center, New Haven, CT 06511, USA.
- Department of Psychiatry, Yale School of Medicine, Connecticut Mental Health Center, New Haven, CT 06511, USA.
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9
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Shah FA, Liu G, Al Kury LT, Zeb A, Abbas M, Li T, Yang X, Liu F, Jiang Y, Li S, Koh PO. Melatonin Protects MCAO-Induced Neuronal Loss via NR2A Mediated Prosurvival Pathways. Front Pharmacol 2019; 10:297. [PMID: 31024297 PMCID: PMC6461025 DOI: 10.3389/fphar.2019.00297] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 03/11/2019] [Indexed: 12/27/2022] Open
Abstract
Stroke is the significant cause of human mortality and sufferings depending upon race and demographic location. Melatonin is a potent antioxidant that exerts protective effects in differential experimental stroke models. Several mechanisms have been previously suggested for the neuroprotective effects of melatonin in ischemic brain injury. The aim of this study is to investigate whether melatonin treatment affects the glutamate N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor signaling in cerebral cortex and striatum 24 h after permanent middle cerebral artery occlusion (MCAO). Melatonin (5 mg/kg) attenuated ischemia-induced down regulation of NMDA receptor 2 (NR2a), postsynaptic density-95 (PSD95) and increases NR2a/PSD95 complex association, which further activates the pro-survival PI3K/Akt/GSK3β pathway with mitigated collapsin response mediator protein 2 (CRMP2) phosphorylation. Furthermore, melatonin increases the expression of γ-enolase, a neurotrophic factor in ischemic cortex and striatum, and preserve the expression of presynaptic (synaptophysin and SNAP25) and postsynaptic (p-GluR1845) protein. Our study demonstrated a novel neuroprotective mechanism for melatonin in ischemic brain injury which could be a promising neuroprotective agent for the treatment of ischemic stroke.
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Affiliation(s)
- Fawad Ali Shah
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China.,Riphah Institute of Pharmaceutical Sciences, Riphah International University Islamabad, Islamabad, Pakistan
| | - Gongping Liu
- Key Laboratory of Ministry of Education of China and Hubei Province for Neurological Disorders, Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Lina T Al Kury
- College of Natural and Health Sciences, Zayed University, Abu Dhabi, United Arab Emirates
| | - Alam Zeb
- Riphah Institute of Pharmaceutical Sciences, Riphah International University Islamabad, Islamabad, Pakistan
| | - Muzaffar Abbas
- Department of Pharmacy, Capital University of Science and Technology, Islamabad, Pakistan
| | - Tao Li
- Department of Forensic Medicine, School of Medicine, Xi'an Jiaotong University, Xi'an, China
| | - Xifei Yang
- Centre for Addiction and Mental Health, Campbell Research Institute, Toronto, ON, Canada
| | - Fang Liu
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Yuhua Jiang
- Cancer Centre, The Second Hospital of Shandong University, Jinan, China
| | - Shupeng Li
- State Key Laboratory of Oncogenomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen, China.,Department of Psychiatry, University of Toronto, Toronto, ON, Canada.,Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Center for Disease Control and Prevention, Shenzhen, China
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10
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Hua S, Wang B, Chen R, Zhang Y, Zhang Y, Li T, Dong L, Fu X. Neuroprotective Effect of Dichloromethane Extraction From Piper nigrum L. and Piper longum L. on Permanent Focal Cerebral Ischemia Injury in Rats. J Stroke Cerebrovasc Dis 2019; 28:751-760. [DOI: 10.1016/j.jstrokecerebrovasdis.2018.11.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 09/29/2018] [Accepted: 11/11/2018] [Indexed: 12/16/2022] Open
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11
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Schaefer ML, Wang M, Perez PJ, Coca Peralta W, Xu J, Johns RA. Nitric Oxide Donor Prevents Neonatal Isoflurane-induced Impairments in Synaptic Plasticity and Memory. Anesthesiology 2019; 130:247-262. [PMID: 30601214 PMCID: PMC6538043 DOI: 10.1097/aln.0000000000002529] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
WHAT WE ALREADY KNOW ABOUT THIS TOPIC Some general anesthetics have been shown to have adverse effects on neuronal development that affect neural function and cognitive behavior.Clinically relevant concentrations of inhalational anesthetics inhibit the postsynaptic density (PSD)-95, discs large homolog, and zona occludens-1 (PDZ) domain-mediated protein-protein interaction between PSD-95 or PSD-93 and N-methyl-D-aspartate receptors or neuronal NO synthase. WHAT THIS ARTICLE TELLS US THAT IS NEW Neonatal PSD-95 PDZ2WT peptide treatment mimics the effects of isoflurane (~1 minimum alveolar concentration) by altering dendritic spine morphology, neural plasticity, and memory without inducing detectable increases in apoptosis or changes in synaptic density.These results indicate that a single dose of isoflurane (~1 minimum alveolar concentration) or PSD-95 PDZ2WT peptide alters dendritic spine architecture and functions important for cognition in the developing brain. This impairment can be prevented by administration of the NO donor molsidomine. BACKGROUND In humans, multiple early exposures to procedures requiring anesthesia constitute a significant risk factor for development of learning disabilities and disorders of attention. In animal studies, newborns exposed to anesthetics develop long-term deficits in cognition. Previously, our laboratory showed that postsynaptic density (PSD)-95, discs large homolog, and zona occludens-1 (PDZ) domains may serve as a molecular target for inhaled anesthetics. This study investigated a role for PDZ interactions in spine development, plasticity, and memory as a potential mechanism for early anesthetic exposure-produced cognitive impairment. METHODS Postnatal day 7 mice were exposed to 1.5% isoflurane for 4 h or injected with 8 mg/kg active PSD-95 PDZ2WT peptide. Apoptosis, hippocampal dendritic spine changes, synapse density, long-term potentiation, and cognition functions were evaluated (n = 4 to 18). RESULTS Exposure of postnatal day 7 mice to isoflurane or PSD-95 PDZ2WT peptide causes a reduction in long thin spines (median, interquartile range [IQR]: wild type control [0.54, 0.52 to 0.86] vs. wild type isoflurane [0.31, 0.16 to 0.38], P = 0.034 and PDZ2MUT [0.86, 0.67 to 1.0] vs. PDZ2WT [0.55, 0.53 to 0.59], P = 0.028), impairment in long-term potentiation (median, IQR: wild type control [123, 119 to 147] and wild type isoflurane [101, 96 to 118], P = 0.049 and PDZ2MUT [125, 119 to 131] and PDZ2WT [104, 97 to 107], P = 0.029), and deficits in acute object recognition (median, IQR: wild type control [79, 72 to 88] vs. wild type isoflurane [63, 55 to 72], P = 0.044 and PDZ2MUT [81, 69 to 84] vs. PDZ2WT [67, 57 to 77], P = 0.039) at postnatal day 21 without inducing detectable differences in apoptosis or changes in synaptic density. Impairments in recognition memory and long-term potentiation were preventable by introduction of a NO donor. CONCLUSIONS Early disruption of PDZ domain-mediated protein-protein interactions alters spine morphology, synaptic function, and memory. These results support a role for PDZ interactions in early anesthetic exposure-produced cognitive impairment. Prevention of recognition memory and long-term potentiation deficits with a NO donor supports a role for the N-methyl-D-aspartate receptor/PSD-95/neuronal NO synthase pathway in mediating these aspects of isoflurane-induced cognitive impairment.
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Affiliation(s)
- Michele L Schaefer
- From the Department Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
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12
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Jeanneret V, Ospina JP, Diaz A, Manrique LG, Merino P, Gutierrez L, Torre E, Wu F, Cheng L, Yepes M. Tissue-type plasminogen activator protects the postsynaptic density in the ischemic brain. J Cereb Blood Flow Metab 2018; 38:1896-1910. [PMID: 29547062 PMCID: PMC6259311 DOI: 10.1177/0271678x18764495] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Cerebral ischemia causes the presynaptic release of tissue-type plasminogen activator (tPA). The postsynaptic density (PSD) is a postsynaptic structure that provides a matrix where signaling transduction of excitatory synapses takes place. The postsynaptic density protein-95 (PSD-95) is the most abundant scaffolding protein in the postsynaptic density (PSD), where it modulates the postsynaptic response to the presynaptic release of glutamate by regulating the anchoring of glutamate receptors to the PSD. We found that tPA induces the local translation of PSD-95 mRNA and the subsequent recruitment of PSD-95 protein to the PSD, via plasminogen-independent activation of TrkB receptors. Our data show that PSD-95 is removed from the PSD during the early stages of cerebral ischemia, and that this effect is abrogated by either the release of neuronal tPA, or intravenous administration of recombinant tPA (rtPA). We report that the effect of tPA on PSD-95 is associated with inhibition of the phosphorylation and recruitment of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors to the PSD, known to amplify the effect of the excitotoxic injury, and that this is followed by TrkB-mediated protection of dendritic spines from the harmful effects of the hypoxic insult. These data reveal that tPA is a synaptic protector in the ischemic brain.
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Affiliation(s)
- Valerie Jeanneret
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA
| | - Juan P Ospina
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA
| | - Ariel Diaz
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Luis G Manrique
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Paola Merino
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Laura Gutierrez
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA
| | - Enrique Torre
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Fang Wu
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Lihong Cheng
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA
| | - Manuel Yepes
- 1 Department of Neurology & Center for Neurodegenerative Disease, School of Medicine, Emory University, Atlanta, GA, USA.,2 Division of Neuropharmacology and Neurologic Diseases, Yerkes National Primate Research Center, Atlanta, GA, USA.,3 Department of Neurology, Veterans Affairs Medical Center, Atlanta, GA, USA
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13
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Molecular Communication of a Dying Neuron in Stroke. Int J Mol Sci 2018; 19:ijms19092834. [PMID: 30235837 PMCID: PMC6164443 DOI: 10.3390/ijms19092834] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 09/14/2018] [Accepted: 09/15/2018] [Indexed: 02/06/2023] Open
Abstract
When a main artery of the brain occludes, a cellular response involving multiple cell types follows. Cells directly affected by the lack of glucose and oxygen in the neuronal core die by necrosis. In the periphery surrounding the ischemic core (the so-called penumbra) neurons, astrocytes, microglia, oligodendrocytes, pericytes, and endothelial cells react to detrimental factors such as excitotoxicity, oxidative stress, and inflammation in different ways. The fate of the neurons in this area is multifactorial, and communication between all the players is important for survival. This review focuses on the latest research relating to synaptic loss and the release of apoptotic bodies and other extracellular vesicles for cellular communication in stroke. We also point out possible treatment options related to increasing neuronal survival and regeneration in the penumbra.
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14
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Long-term treadmill exercise improves memory impairment through restoration of decreased synaptic adhesion molecule 1/2/3 induced by transient cerebral ischemia in the aged gerbil hippocampus. Exp Gerontol 2018; 103:124-131. [DOI: 10.1016/j.exger.2018.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 01/05/2018] [Accepted: 01/12/2018] [Indexed: 01/13/2023]
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15
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Bentea E, Moore C, Deneyer L, Verbruggen L, Churchill MJ, Hood RL, Meshul CK, Massie A. Plastic changes at corticostriatal synapses predict improved motor function in a partial lesion model of Parkinson’s disease. Brain Res Bull 2017; 130:257-267. [DOI: 10.1016/j.brainresbull.2017.02.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 02/16/2017] [Indexed: 12/15/2022]
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16
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Jeanneret V, Wu F, Merino P, Torre E, Diaz A, Cheng L, Yepes M. Tissue-type Plasminogen Activator (tPA) Modulates the Postsynaptic Response of Cerebral Cortical Neurons to the Presynaptic Release of Glutamate. Front Mol Neurosci 2016; 9:121. [PMID: 27881952 PMCID: PMC5101231 DOI: 10.3389/fnmol.2016.00121] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/31/2016] [Indexed: 01/31/2023] Open
Abstract
Tissue-type plasminogen activator (tPA) is a serine proteinase released by the presynaptic terminal of cerebral cortical neurons following membrane depolarization (Echeverry et al., 2010). Recent studies indicate that the release of tPA triggers the synaptic vesicle cycle and promotes the exocytosis (Wu et al., 2015) and endocytic retrieval (Yepes et al., 2016) of glutamate-containing synaptic vesicles. Here we used electron microscopy, proteomics, quantitative phosphoproteomics, biochemical analyses with extracts of the postsynaptic density (PSD), and an animal model of cerebral ischemia with mice overexpressing neuronal tPA to study whether the presynaptic release of tPA also has an effect on the postsynaptic terminal. We found that tPA has a bidirectional effect on the composition of the PSD of cerebral cortical neurons that is independent of the generation of plasmin and the presynaptic release of glutamate, but depends on the baseline level of neuronal activity and the extracellular concentrations of calcium (Ca2+). Accordingly, in neurons that are either inactive or incubated with low Ca2+ concentrations tPA induces phosphorylation and accumulation in the PSD of the Ca2+/calmodulin-dependent protein kinase IIα (pCaMKIIα), followed by pCaMKIIα-mediated phosphorylation and synaptic recruitment of GluR1-containing α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors. In contrast, in neurons with previously increased baseline levels of pCaMKIIα in the PSD due to neuronal depolarization in vivo or incubation with high concentrations of either Ca2+ or glutamate in vitro, tPA induces pCaMKIIα and pGluR1 dephosphorylation and their subsequent removal from the PSD. We found that these effects of tPA are mediated by synaptic N-methyl-D-aspartate (NMDA) receptors and cyclin-dependent kinase 5 (Cdk5)-induced phosphorylation of the protein phosphatase 1 (PP1) at T320. Our data indicate that by regulating the pCaMKIIα/PP1 balance in the PSD tPA acts as a homeostatic regulator of the postsynaptic response of cerebral cortical neurons to the presynaptic release of glutamate.
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Affiliation(s)
- Valerie Jeanneret
- Department of Neurology and Center for Neurodegenerative Disease, Emory University School of Medicine Atlanta, GA, USA
| | - Fang Wu
- Department of Neurology and Center for Neurodegenerative Disease, Emory University School of Medicine Atlanta, GA, USA
| | - Paola Merino
- Department of Neurology and Center for Neurodegenerative Disease, Emory University School of Medicine Atlanta, GA, USA
| | - Enrique Torre
- Department of Neurology and Center for Neurodegenerative Disease, Emory University School of Medicine Atlanta, GA, USA
| | - Ariel Diaz
- Department of Neurology and Center for Neurodegenerative Disease, Emory University School of Medicine Atlanta, GA, USA
| | - Lihong Cheng
- Department of Neurology and Center for Neurodegenerative Disease, Emory University School of Medicine Atlanta, GA, USA
| | - Manuel Yepes
- Department of Neurology and Center for Neurodegenerative Disease, Emory University School of MedicineAtlanta, GA, USA; Department of Neurology, Veterans Affairs Medical CenterAtlanta, GA, USA
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17
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Perez EJ, Cepero ML, Perez SU, Coyle JT, Sick TJ, Liebl DJ. EphB3 signaling propagates synaptic dysfunction in the traumatic injured brain. Neurobiol Dis 2016; 94:73-84. [PMID: 27317833 PMCID: PMC5662938 DOI: 10.1016/j.nbd.2016.06.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 05/25/2016] [Accepted: 06/14/2016] [Indexed: 12/25/2022] Open
Abstract
Traumatic brain injury (TBI), ranging from mild concussion to severe penetrating wounds, can involve brain regions that contain damaged or lost synapses in the absence of neuronal death. These affected regions significantly contribute to sensory, motor and/or cognitive deficits. Thus, studying the mechanisms responsible for synaptic instability and dysfunction is important for protecting the nervous system from the consequences of progressive TBI. Our controlled cortical impact (CCI) injury produces ~20% loss of synapses and mild changes in synaptic protein levels in the CA3-CA1 hippocampus without neuronal losses. These synaptic changes are associated with functional deficits, indicated by >50% loss in synaptic plasticity and impaired learning behavior. We show that the receptor tyrosine kinase EphB3 participates in CCI injury-induced synaptic damage, where EphB3(-/-) mice show preserved long-term potentiation and hippocampal-dependent learning behavior as compared with wild type (WT) injured mice. Improved synaptic function in the absence of EphB3 results from attenuation in CCI injury-induced synaptic losses and reduced d-serine levels compared with WT injured mice. Together, these findings suggest that EphB3 signaling plays a deleterious role in synaptic stability and plasticity after TBI.
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Affiliation(s)
- Enmanuel J Perez
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Maria L Cepero
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Sebastian U Perez
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Joseph T Coyle
- Harvard Medical School, Department of Psychiatry, McLean Hospital, Boston, MA 02115, USA
| | - Thomas J Sick
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Daniel J Liebl
- The Miami Project to Cure Paralysis, Department of Neurosurgery, University of Miami Miller School of Medicine, Miami, FL, USA.
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18
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Dosemeci A, Weinberg RJ, Reese TS, Tao-Cheng JH. The Postsynaptic Density: There Is More than Meets the Eye. Front Synaptic Neurosci 2016; 8:23. [PMID: 27594834 PMCID: PMC4990544 DOI: 10.3389/fnsyn.2016.00023] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 07/25/2016] [Indexed: 11/28/2022] Open
Abstract
The postsynaptic density (PSD), apparent in electron micrographs as a dense lamina just beneath the postsynaptic membrane, includes a deeper layer, the “pallium”, containing a scaffold of Shank and Homer proteins. Though poorly defined in traditionally prepared thin-section electron micrographs, the pallium becomes denser and more conspicuous during intense synaptic activity, due to the reversible addition of CaMKII and other proteins. In this Perspective article, we review the significance of CaMKII-mediated recruitment of proteins to the pallium with respect to both the trafficking of receptors and the remodeling of spine shape that follow synaptic stimulation. We suggest that the level and duration of CaMKII translocation and activation in the pallium will shape activity-induced changes in the spine.
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Affiliation(s)
- Ayse Dosemeci
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH) Bethesda, MD, USA
| | - Richard J Weinberg
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill Chapel Hill, NC, USA
| | - Thomas S Reese
- Laboratory of Neurobiology, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH) Bethesda, MD, USA
| | - Jung-Hwa Tao-Cheng
- Electron Microscopy Facility, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH) Bethesda, MD, USA
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19
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Hasbani MJ, Underhill SM, De Erausquin G, Goldberg MP. Synapse Loss and Regeneration: A Mechanism for Functional Decline and Recovery after Cerebral Ischemia? Neuroscientist 2016. [DOI: 10.1177/107385840000600208] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Little is known of the mechanisms governing functional recovery after ischemic brain injury, and there is no clinical therapy established to restore neurologic function after ischemic injury is complete. Even so, pronounced spontaneous recovery of function is often observed in a subset of patients. Resolution of neurological deficits after ischemia must occur through replacement of lost tissue via production of new neurons, or through changes in the structure, function, or connectivity of surviving neurons. This review focuses on the neuronal synapse as a potential locus for functional recovery. Selective disruption of synaptic elements is a characteristic feature of hypoxic-ischemic brain injury, such as that seen in ischemic stroke or cardiac arrest. Ischemic damage to synapses occurs even in the absence of neuronal loss, and therefore might underlie the clinical disability observed in patients following mild or transient ischemia. We review evidence that recovery of lost synapses occurs after ischemic injury and that this recovery may be a necessary step for restoration of neurological function. The process of synapse loss and recovery can be examined in neuronal cultures and experimental stroke models. Such studies may help to gain a better understanding of the extracellular factors and intracellular cascades that facilitate recovery of synapses, and may result in therapeutic approaches to improve function after cerebral ischemia.
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Affiliation(s)
- M. Josh Hasbani
- Department of Neurology and Neuroscience Program, Washington University School of Medicine, St. Louis, Missouri
| | - Suzanne M. Underhill
- Department of Neurology and Neuroscience Program, Washington University School of Medicine, St. Louis, Missouri
| | - Gabriel De Erausquin
- Department of Neurology and Neuroscience Program, Washington University School of Medicine, St. Louis, Missouri
| | - Mark P. Goldberg
- Department of Neurology and Neuroscience Program, Washington University School of Medicine, St. Louis, Missouri
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20
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Changes in synaptic plasticity and expression of glutamate receptor subunits in the CA1 and CA3 areas of the hippocampus after transient global ischemia. Neuroscience 2016; 327:64-78. [PMID: 27090818 DOI: 10.1016/j.neuroscience.2016.04.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 12/26/2022]
Abstract
Excess glutamate release from the presynaptic membrane has been thought to be the major cause of ischemic neuronal death. Although both CA1 and CA3 pyramidal neurons receive presynaptic glutamate input, transient cerebral ischemia induces CA1 neurons to die while CA3 neurons remain relatively intact. This suggests that changes in the properties of pyramidal cells may be the main cause related to ischemic neuronal death. Our previous studies have shown that the densities of dendritic spines and asymmetric synapses in the CA1 area are increased at 12h and 24h after ischemia. In the present study, we investigated changes in synaptic structures in the CA3 area and compared the expression of glutamate receptors in the CA1 and CA3 hippocampal regions of rats after ischemia. Our results demonstrated that the NR2B/NR2A ratio became larger after ischemia although the expression of both the NR2B subunit (activation of apoptotic pathway) and NR2A subunit (activation of survival pathway) decreased in the CA1 area from 6h to 48h after reperfusion. Furthermore, expression of the GluR2 subunit (calcium impermeable) of the AMPA receptor class significantly decreased while the GluR1 subunit (calcium permeable) remained unchanged at the same examined reperfusion times, which subsequently caused an increase in the GluR1/GluR2 ratio. Despite these notable differences in subunit expression, there were no obvious changes in the density of synapses or expression of NMDAR and AMPAR subunits in the CA3 area after ischemia. These results suggest that delayed CA1 neuronal death may be related to the dramatic fluctuation in the synaptic structure and relative upregulation of NR2B and GluR1 subunits induced by transient global ischemia.
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21
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Schmidt-Kastner R. Genomic approach to selective vulnerability of the hippocampus in brain ischemia–hypoxia. Neuroscience 2015; 309:259-79. [DOI: 10.1016/j.neuroscience.2015.08.034] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Revised: 08/12/2015] [Accepted: 08/17/2015] [Indexed: 01/06/2023]
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22
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Korogod N, Petersen CCH, Knott GW. Ultrastructural analysis of adult mouse neocortex comparing aldehyde perfusion with cryo fixation. eLife 2015; 4. [PMID: 26259873 PMCID: PMC4530226 DOI: 10.7554/elife.05793] [Citation(s) in RCA: 242] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 07/03/2015] [Indexed: 12/18/2022] Open
Abstract
Analysis of brain ultrastructure using electron microscopy typically relies on chemical fixation. However, this is known to cause significant tissue distortion including a reduction in the extracellular space. Cryo fixation is thought to give a truer representation of biological structures, and here we use rapid, high-pressure freezing on adult mouse neocortex to quantify the extent to which these two fixation methods differ in terms of their preservation of the different cellular compartments, and the arrangement of membranes at the synapse and around blood vessels. As well as preserving a physiological extracellular space, cryo fixation reveals larger numbers of docked synaptic vesicles, a smaller glial volume, and a less intimate glial coverage of synapses and blood vessels compared to chemical fixation. The ultrastructure of mouse neocortex therefore differs significantly comparing cryo and chemical fixation conditions.
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Affiliation(s)
- Natalya Korogod
- BioEM Facility, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Carl C H Petersen
- Laboratory of Sensory Processing, Brain Mind Institute, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Graham W Knott
- BioEM Facility, Faculty of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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23
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Activation of NMDA receptors thickens the postsynaptic density via proteolysis. Neurosci Res 2015; 101:6-14. [PMID: 26188126 DOI: 10.1016/j.neures.2015.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Revised: 06/22/2015] [Accepted: 07/06/2015] [Indexed: 01/25/2023]
Abstract
The postsynaptic density (PSD) is a protein complex that is critical for synaptic transmission. Ultrastructural changes in the PSD are therefore likely to modify synaptic functions. In this study, we investigated the ultrastructural changes in the PSD in the hippocampal CA1 stratum radiatum following neuronal excitation. Oxygen-glucose deprivation-induced PSD thickening in hippocampal slice cultures was blocked by the N-methyl-d-aspartate (NMDA) receptor antagonist MK801. To gain more insight into the mechanisms underlying NMDA receptor-mediated PSD thickening, we assessed the area, length, and thickness of the PSD after NMDA treatment. The PSDs thickened with just 2 min of NMDA receptor stimulation, and this treatment was considered sublethal. When N-acetyl-leucyl-leucyl-norleucinal, an inhibitor of calpain, cathepsins, and the proteasome, was applied, NMDA-induced PSD thickening was abolished. Furthermore, the calcium-induced calcium release inhibitor, ryanodine, reduced NMDA receptor-mediated PSD thickening. These results suggest that NMDA receptor activation induces PSD thickening by proteolysis through intracellular calcium increase, including that induced by calcium.
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Park Y, Liu C, Luo T, Dietrich WD, Bramlett H, Hu B. Chaperone-Mediated Autophagy after Traumatic Brain Injury. J Neurotrauma 2015; 32:1449-57. [PMID: 25891649 DOI: 10.1089/neu.2014.3694] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Chaperone-mediated autophagy (CMA) and the ubiquitin-proteasomal system (UPS) are two major protein degradation systems responsible for maintaining cellular homeostasis, but how these two systems are regulated after traumatic brain injury (TBI) remains unknown. TBI produces primary mechanical damage that must be repaired to maintain neuronal homeostasis. The level of lysosomal-associated membrane protein type 2A (LAMP2A) is the hallmark of CMA activity. The level of polyubiquitinated proteins (ubi-proteins) reflects UPS activity. This study utilized a moderate fluid percussion injury model in rats to investigate the changes in CMA and the UPS after TBI. Induction of CMA was manifested by significant upregulation of LAMP2A and secondary lysosomes during the periods of 1-15 days of recovery after TBI. In comparison, the levels of ubi-proteins were increased only moderately after TBI. The increases in the levels of LAMP2A and 70 kDa heat-shock protein for CMA after TBI were seen mainly in the secondary lysosome-containing fractions. Confocal and electron microscopy further showed that increased LAMP2A or lysosomes were found mainly in neurons and proliferated microglia. Because CMA and the UPS are two major routes for elimination of different types of cellular aberrant proteins, the consecutive activation of these two pathways may serve as a protective mechanism for maintaining cellular homeostasis after TBI.
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Affiliation(s)
- Yujung Park
- 1 Neurochemistry Laboratory of Brain Injury, Shock Trauma and Anesthesiology Research Center; University of Maryland School of Medicine , Baltimore, Maryland
| | - Chunli Liu
- 1 Neurochemistry Laboratory of Brain Injury, Shock Trauma and Anesthesiology Research Center; University of Maryland School of Medicine , Baltimore, Maryland
| | - Tianfei Luo
- 1 Neurochemistry Laboratory of Brain Injury, Shock Trauma and Anesthesiology Research Center; University of Maryland School of Medicine , Baltimore, Maryland
| | - W Dalton Dietrich
- 2 Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami School of Medicine , Miami, Florida
| | - Helen Bramlett
- 2 Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami School of Medicine , Miami, Florida
| | - Bingren Hu
- 1 Neurochemistry Laboratory of Brain Injury, Shock Trauma and Anesthesiology Research Center; University of Maryland School of Medicine , Baltimore, Maryland
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Luo T, Roman P, Liu C, Sun X, Park Y, Hu B. Upregulation of the GEF-H1 pathway after transient cerebral ischemia. Exp Neurol 2014; 263:306-13. [PMID: 25447939 DOI: 10.1016/j.expneurol.2014.10.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/10/2014] [Accepted: 10/22/2014] [Indexed: 01/10/2023]
Abstract
The microtubule-dependent GEF-H1 pathway controls synaptic re-networking and overall gene expression via regulating cytoskeleton dynamics. Understanding this pathway after ischemia is essential to developing new therapies for neuronal function recovery. However, how the GEF-H1 pathway is regulated following transient cerebral ischemia remains unknown. This study employed a rat model of transient forebrain ischemia to investigate alterations of the GEF-H1 pathway using Western blotting, confocal and electron microscopy, dephosphorylation analysis, and pull-down assay. The GEF-H1 activity was significantly upregulated by: (i) dephosphorylation and (ii) translocation to synaptic membrane and nuclear structures during the early phase of reperfusion. GEF-H1 protein was then downregulated in the brain regions where neurons were destined to undergo delayed neuronal death, but markedly upregulated in neurons that were resistant to the same episode of cerebral ischemia. Consistently, GTP-RhoA, a GEF-H1 substrate, was significantly upregulated after brain ischemia. Electron microscopy further showed that neuronal microtubules were persistently depolymerized in the brain region where GEF-H1 protein was downregulated after brain ischemia. The results demonstrate that the GEF-H1 activity is significantly upregulated in both vulnerable and resistant brain regions in the early phase of reperfusion. However, GEF-H1 protein is downregulated in the vulnerable neurons but upregulated in the ischemic resistant neurons during the recovery phase after ischemia. The initial upregulation of GEF-H1 activity may contribute to excitotoxicity, whereas the late upregulation of GEF-H1 protein may promote neuroplasticity after brain ischemia.
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Affiliation(s)
- Tianfei Luo
- Neurochemistry Laboratory of Brain Injury, Shock Trauma & Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD 21201, United States; Department of Neurology, The First Teaching Hospital, Jilin University, Changchun, China
| | - Philip Roman
- Neurochemistry Laboratory of Brain Injury, Shock Trauma & Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Chunli Liu
- Neurochemistry Laboratory of Brain Injury, Shock Trauma & Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Xin Sun
- Neurochemistry Laboratory of Brain Injury, Shock Trauma & Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD 21201, United States; Department of Neurology, The First Teaching Hospital, Jilin University, Changchun, China
| | - Yujung Park
- Neurochemistry Laboratory of Brain Injury, Shock Trauma & Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD 21201, United States
| | - Bingren Hu
- Neurochemistry Laboratory of Brain Injury, Shock Trauma & Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD 21201, United States.
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Liu Y, Sun Z, Sun S, Duan Y, Shi J, Qi Z, Meng R, Sun Y, Zeng X, Chui D, Ji X. Effects of hypoxic preconditioning on synaptic ultrastructure in mice. Synapse 2014; 69:7-14. [PMID: 25155519 DOI: 10.1002/syn.21777] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/21/2014] [Accepted: 08/08/2014] [Indexed: 11/06/2022]
Abstract
Hypoxic preconditioning (HPC) elicits resistance to more drastic subsequent insults, which potentially provide neuroprotective therapeutic strategy, but the underlying mechanisms remain to be fully elucidated. Here, we examined the effects of HPC on synaptic ultrastructure in olfactory bulb of mice. Mice underwent up to five cycles of repeated HPC treatments, and hypoxic tolerance was assessed with a standard gasp reflex assay. As expected, HPC induced an increase in tolerance time. To assess synaptic responses, Western blots were used to quantify protein levels of representative markers for glia, neuron, and synapse, and transmission electron microscopy was used to examine synaptic ultrastructure and mitochondrial density. HPC did not significantly alter the protein levels of astroglial marker (GFAP), neuron-specific markers (GAP43, Tuj-1, and OMP), synaptic number markers (synaptophysin and SNAP25) or the percentage of excitatory synapses versus inhibitory synapses. However, HPC significantly affected synaptic curvature and the percentage of synapses with presynaptic mitochondria, which showed concomitant change pattern. These findings demonstrate that HPC is associated with changes in synaptic ultrastructure.
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Affiliation(s)
- Yi Liu
- China-America Joint Institute of Neuroscience, CAJIN, Xuanwu Hospital, Capital Medical University, Beijing, China; Neuroprotection Research Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Neuroprotection Research Laboratory, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Kim JW, Ha GY, Jung YW. Chronic renal failure induces cell death in rat hippocampal CA1 via upregulation of αCaMKII/NR2A synaptic complex and phosphorylated GluR1-containing AMPA receptor cascades. Kidney Res Clin Pract 2014; 33:132-8. [PMID: 26877964 PMCID: PMC4714159 DOI: 10.1016/j.krcp.2014.07.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/04/2014] [Accepted: 07/20/2014] [Indexed: 12/03/2022] Open
Abstract
Background N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propinoic acid (AMPA) receptors bound to postsynaptic density-95 (PSD-95) and α isoform of calcium/calmodulin-dependent protein kinase II (αCaMKII) is fundamentally involved in the regulation of working memory. The aim of present study was to investigate the alterations of NMDA and AMPA receptors responsible for hippocampal synaptic dysfunction and selective neuronal cell death after chronic renal failure (CRF) which may be associated with impairment of working memory. Methods Altered interactions between NMDA and AMPA receptors and PSD-95 and αCaMKII were analyzed in the cornu ammonis (CA) 1 and CA3/dentate gyrus (DG) subfields of the uremic rat hippocampi using the immunoblotting and immunoprecipitation methods. Results Uremia induced by CRF produced necrotic cell death and decreased neuronal nucleoli protein levels in the hippocampal CA1 subfield, but not in the CA3/DG subfields. The CA1 subfields of CRF rats exhibited significant decreases and increases, respectively, in the expressions of PSD-95/NR2B and αCaMKII/NR2A synaptic complex. Moreover, increased phosphorylation of glutamate receptor type 1 (GluR1) AMPA receptor at ser831 was observed in the CA1 subfield after CRF. Conclusion These hippocampal CA1 neuronal vulnerability may be responsible for memory dysfunction after CRF as mediated by an increase in NR2A-containing NMDA receptors bound to αCaMKII and subsequent activation of GluR1-containing AMPA receptors caused by the phosphorylation of GluR1 at ser831.
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Affiliation(s)
- Jong Wan Kim
- Section of Neuroscience Research, Medical Institute of Dongguk University, Gyeongju, Korea; Department of Anatomy, College of Medicine, Dongguk University, Gyeongju, Korea
| | - Gyoung Yim Ha
- Department of Laboratory Medicine, College of Medicine, Dongguk University, Gyeongju, Korea
| | - Yong Wook Jung
- Section of Neuroscience Research, Medical Institute of Dongguk University, Gyeongju, Korea; Department of Anatomy, College of Medicine, Dongguk University, Gyeongju, Korea
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Muñiz J, Romero J, Holubiec M, Barreto G, González J, Saint-Martin M, Blanco E, Carlos Cavicchia J, Castilla R, Capani F. Neuroprotective effects of hypothermia on synaptic actin cytoskeletal changes induced by perinatal asphyxia. Brain Res 2014; 1563:81-90. [DOI: 10.1016/j.brainres.2014.03.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 01/28/2014] [Accepted: 03/17/2014] [Indexed: 10/25/2022]
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Luo T, Park Y, Sun X, Liu C, Hu B. Protein misfolding, aggregation, and autophagy after brain ischemia. Transl Stroke Res 2013; 4:581-8. [PMID: 24323413 DOI: 10.1007/s12975-013-0299-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/17/2013] [Accepted: 10/20/2013] [Indexed: 01/02/2023]
Abstract
Ischemic brain injury is a common disorder linked to a variety of diseases. Significant progress has been made in our understanding of the underlying mechanisms. Previous studies show that protein misfolding, aggregation, and multiple organelle damage are major pathological events in postischemic neurons. The autophagy pathway is the chief route for bulk degradation of protein aggregates and damaged organelles. The latest studies suggest that impairment of autophagy contributes to abnormal protein aggregation and organelle damages after brain ischemia. This article reviews recent studies of protein misfolding, aggregation, and impairment of autophagy after brain ischemia.
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Affiliation(s)
- Tianfei Luo
- Shock, Trauma and Anesthesiology Research Center, Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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Zhang T, Yan W, Li Q, Fu J, Liu K, Jia W, Sun X, Liu X. 3-n-butylphthalide (NBP) attenuated neuronal autophagy and amyloid-beta expression in diabetic mice subjected to brain ischemia. Neurol Res 2013; 33:396-404. [DOI: 10.1179/1743132810y.0000000006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Jung YJ, Suh EC, Lee KE. Oxygen/Glucose Deprivation and Reperfusion Cause Modifications of Postsynaptic Morphology and Activity in the CA3 Area of Organotypic Hippocampal Slice Cultures. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2012; 16:423-9. [PMID: 23269905 PMCID: PMC3526747 DOI: 10.4196/kjpp.2012.16.6.423] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 10/08/2012] [Accepted: 10/20/2012] [Indexed: 12/25/2022]
Abstract
Brain ischemia leads to overstimulation of N-methyl-D-aspartate (NMDA) receptors, referred as excitotoxicity, which mediates neuronal cell death. However, less attention has been paid to changes in synaptic activity and morphology that could have an important impact on cell function and survival following ischemic insult. In this study, we investigated the effects of reperfusion after oxygen/glucose deprivation (OGD) not only upon neuronal cell death, but also on ultrastructural and biochemical characteristics of postsynaptic density (PSD) protein, in the stratum lucidum of the CA3 area in organotypic hippocampal slice cultures. After OGD/reperfusion, neurons were found to be damaged; the organelles such as mitochondria, endoplasmic reticulum, dendrites, and synaptic terminals were swollen; and the PSD became thicker and irregular. Ethanolic phosphotungstic acid staining showed that the density of PSD was significantly decreased, and the thickness and length of the PSD were significantly increased in the OGD/reperfusion group compared to the control. The levels of PSD proteins, including PSD-95, NMDA receptor 1, NMDA receptor 2B, and calcium/calmodulin-dependent protein kinase II, were significantly decreased following OGD/reperfusion. These results suggest that OGD/reperfusion induces significant modifications to PSDs in the CA3 area of organotypic hippocampal slice cultures, both morphologically and biochemically, and this may contribute to neuronal cell death and synaptic dysfunction after OGD/reperfusion.
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Affiliation(s)
- Yeon Joo Jung
- Department of Pharmacology and Ewha Medical Research Institute, Ewha Womans University School of Medicine, Seoul 158-710, Korea
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32
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Zhang F, Guo A, Liu C, Comb M, Hu B. Phosphorylation and assembly of glutamate receptors after brain ischemia. Stroke 2012; 44:170-6. [PMID: 23212166 DOI: 10.1161/strokeaha.112.667253] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND PURPOSE Overassembly of synaptic glutamate receptors leads to excitotoxicity. The goal of this study is to investigate phosphorylation and assembly of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid and N-methyl-D-aspartate receptors after brain ischemia with reperfusion (I/R). METHODS Rats were subjected to 15 minutes of global ischemia followed by 0.5, 4, and 24 hours of reperfusion. Phosphotyrosine peptides of glutamate receptors in synaptosomal fraction after I/R were identified and quantified by state-of-the-art immuno-affinity purification of phosphotyrosine peptides followed by liquid chromatography/mass spectrometry/mass spectrometry analysis (immunoaffinity purification-coupled liquid chromatography/mass spectrometry/mass spectrometry). Glutamate receptor phosphorylation and synaptic assembly after I/R were studied by biochemical methods. RESULTS Numerous phosphotyrosine-sites of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid and N-methyl-D-aspartate were upregulated by approximately 2- to 37-fold after I/R. A core glutamate receptor kinase, Src kinase, was significantly activated. GluR2/3 and NR2A/B were rapidly clustered from extrasynaptic to synaptic membrane fractions after I/R. GluR2/3 was then translocated into the intracellular pool, whereas NR2A/B remained in the synaptic fraction for as long as 24 hours. Consistently, trafficking-related phosphorylation of GluR2/3-S880 was significantly but transiently upregulated, whereas NR2A/B-Y1246 and NR2A/B-Y1472 were significantly and persistently upregulated after I/R. CONCLUSIONS Phosphorylation of glutamate receptors at synapses may lead to overassembly of glutamate receptors, probably via activation of Src family kinases, after I/R. This study provides global proteomic information about glutamate receptor tyrosine phosphorylation after brain ischemia.
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Affiliation(s)
- Fan Zhang
- University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Grimaldi M, Romer I, de Apodaca MTG, Iturbe L, Catania ID, González J, Kolliker-Fres R, Barreto G, Capani F. Early changes in the synapses of the neostriatum induced by perinatal asphyxia. Nutr Neurosci 2012; 15:103-10. [PMID: 22732353 DOI: 10.1179/1476830511y.0000000026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Perinatal asphyxia (PA) is a medical condition associated with a high short-term morbimortality and different long-term neurological diseases. In previous work we have observed at 6 months post-synaptic densities (PSDs) alterations compatible with neurodegeneration highly correlated with the increment in the ubiquitination. Although alterations in the synaptic organization and function have been related with neuronal death after hypoxia, little is known about the synaptic changes in young animals exposed to PA. The main aim of this work is to study the PSDs changes in striatum of 30-day-old rats subjected to PA. Using two-dimensional electron microscopic analyses of synapses staining with ethanolic phosphotungstic acid we observed an increment of PSD thickness in severe hypoxic rats. These data are consistent with the western blot analysis that showed an increment in ubiquitination levels in the synapses of severe hypoxic rat. We did observe any alterations neither in synaptic structure nor in ubiquitinization in mild asphyctic rats. These data suggest that hypoxia might cause early misfolding and aggregation of synaptic proteins in severe anoxic animas that could induce long-term neurodegeneration.
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Affiliation(s)
- M Grimaldi
- Universidad Argentina John F Kennedy, Buenos Aires, Argentina
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Ruan YW, Han XJ, Shi ZS, Lei ZG, Xu ZC. Remodeling of synapses in the CA1 area of the hippocampus after transient global ischemia. Neuroscience 2012; 218:268-77. [PMID: 22634576 DOI: 10.1016/j.neuroscience.2012.05.035] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 04/30/2012] [Accepted: 05/14/2012] [Indexed: 10/28/2022]
Abstract
Synapses are essential to neuronal functions. Synaptic changes occur under physiological and pathological conditions. Here we report the remodeling of synapses in the CA1 area of the hippocampus after transient global ischemia using electron microscopy. Much electron-dense material appeared in the cytoplasm of dendrites at 24h after ischemia. Many dark axons or terminals were found in the CA1 neuropil; some of which were phagocytized by dendrites. Interestingly autophagosomes appeared in many axons or dendrites at 48 h after ischemia. In addition, postsynaptic density (PSD) - like structures or synaptic - like structures were found inside spines and dendrites. Statistical analysis demonstrated that the thickness of PSDs in the CA1 neuropil increased from 12 to 48 h after ischemia. The frequency of autophagosomes appeared to escalate from 12 to 48 h after ischemia. The frequency of asymmetric synapses was significantly increased at 12h and 24h after ischemia in stratum oriens, proximal and distal stratum radiatum. Among asymmetric synapses, the number of perforated synapses consistently increased and reached a peak (approximately 10-fold increase) at 48 h after ischemia. On the other hand, the number of multiple synaptic boutons decreased after ischemia reaching a two to fourfold decrease at 48 h after ischemia. These results have shown that ischemia induces an increase of asymmetric synapses as well as synaptic autophagy, which may contribute to the neuronal death in the CA1 area after transient global ischemia.
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Affiliation(s)
- Y-W Ruan
- Joint Laboratory for Brain Health and Function of Jinan University, The University of Hong Kong, Jinan University School of Medicine, Guangzhou 510632, China.
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Hippocampal dendritic spines modifications induced by perinatal asphyxia. Neural Plast 2012; 2012:873532. [PMID: 22645692 PMCID: PMC3356716 DOI: 10.1155/2012/873532] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 11/17/2011] [Accepted: 11/20/2011] [Indexed: 01/16/2023] Open
Abstract
Perinatal asphyxia (PA) affects the synaptic function and morphological organization. In previous works, we have shown neuronal and synaptic changes in rat neostriatum subjected to hypoxia leading to long-term ubi-protein accumulation. Since F-actin is highly concentrated in dendritic spines, modifications in its organization could be related with alterations induced by hypoxia in the central nervous system (CNS). In the present study, we investigate the effects of PA on the actin cytoskeleton of hippocampal postsynaptic densities (PSD) in 4-month-old rats. PSD showed an increment in their thickness and in the level of ubiquitination. Correlative fluorescence-electron microscopy photooxidation showed a decrease in the number of F-actin-stained spines in hippocampal excitatory synapses subjected to PA. Although Western Blot analysis also showed a slight decrease in β-actin in PSD in PA animals, the difference was not significant. Taken together, this data suggests that long-term actin cytoskeleton might have role in PSD alterations which would be a spread phenomenon induced by PA.
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The changes of signal transduction pathways in hippocampal regions and postsynaptic densities after chronic cerebral hypoperfusion in rats. Brain Res 2012; 1429:9-17. [DOI: 10.1016/j.brainres.2011.10.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Revised: 10/11/2011] [Accepted: 10/12/2011] [Indexed: 11/15/2022]
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Liu CH, Zhang F, Krisrian T, Polster B, Fiskum GM, Hu B. Protein Aggregation and Multiple Organelle Damage After Brain Ischemia. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Zhang Y, Zhang FG, Meng C, Tian SY, Wang YX, Zhao W, Chen J, Zhang XS, Liang Y, Zhang SD, Xing YJ. Inhibition of sevoflurane postconditioning against cerebral ischemia reperfusion-induced oxidative injury in rats. Molecules 2011; 17:341-54. [PMID: 22210172 PMCID: PMC6268413 DOI: 10.3390/molecules17010341] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 12/23/2011] [Accepted: 12/23/2011] [Indexed: 11/16/2022] Open
Abstract
The volatile anesthetic sevoflurane is capable of inducing preconditioning and postconditioning effects in the brain. In this study, we investigated the effects of sevoflurane postconditioning on antioxidant and immunity indexes in cerebral ischemia reperfusion (CIR) rats. Rats were randomly assigned to five separate experimental groups I–V. In the sham group (I), rats were subjected to the same surgery procedures except for occlusion of the middle cerebral artery and exposed to 1.0 MAC sevoflurane 90 min after surgery for 30 min. IR control rats (group II) were subjected to middle cerebral artery occlusion (MCAO) for 90 min and exposed to O2 for 30 min at the beginning of reperfusion. Sevoflurane 0.5, 1.0 and 1.5 groups (III, IV, V) were all subjected to MCAO for 90 min, but at the beginning of reperfusion exposed to 0.5 MAC, 1.0 MAC or 1.5 MAC sevoflurane for 30 min, respectively. Results showed that sevoflurane postconditioning can decrease serum tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), nitric oxide (NO), nitric oxide synthase (NOS) and increase serum interleukin-10 (IL-10) levels in cerebral ischemia reperfusion rats. In addition, sevoflurane postconditioning can still decrease blood lipid, malondialdehyde (MDA) levels, infarct volume and increase antioxidant enzymes activities, normal pyramidal neurons density in cerebral ischemia reperfusion rats. It can be concluded that sevoflurane postconditioning may decrease blood and brain oxidative injury and enhance immunity indexes in cerebral ischemia reperfusion rats.
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Affiliation(s)
- Yan Zhang
- Department of Anesthesiology, Tianjin Huanhu Hospital, Tianjin 300060, China; (Y.Z.); (Y.-X.W.); (J.C.); (X.-S.Z.); (Y.L.)
| | - Fu-Geng Zhang
- Department of Pharmacy, Tianjin Huanhu Hospital, Tianjin 300060, China;
| | - Chun Meng
- Department of Anesthesiology, Tianjin Huanhu Hospital, Tianjin 300060, China; (Y.Z.); (Y.-X.W.); (J.C.); (X.-S.Z.); (Y.L.)
- Author to whom correspondence should be addressed; ; Tel.: +86-022-6036-7500; Fax: +86-022-6036-7500
| | - Shou-Yuan Tian
- Department of Anesthesiology, The First Hospital Affiliated Shanxi Medical University, Taiyuan, Shanxi 030001, China;
| | - Ya-Xin Wang
- Department of Anesthesiology, Tianjin Huanhu Hospital, Tianjin 300060, China; (Y.Z.); (Y.-X.W.); (J.C.); (X.-S.Z.); (Y.L.)
| | - Wei Zhao
- Metabolic Disease Hospital, Tianjin Medical University, Tianjin 300070, China
- Key Lab of Hormones and Development, Ministry of Health and Tianjin, Tianjin 300070, China;
| | - Jun Chen
- Department of Anesthesiology, Tianjin Huanhu Hospital, Tianjin 300060, China; (Y.Z.); (Y.-X.W.); (J.C.); (X.-S.Z.); (Y.L.)
| | - Xiu-Shan Zhang
- Department of Anesthesiology, Tianjin Huanhu Hospital, Tianjin 300060, China; (Y.Z.); (Y.-X.W.); (J.C.); (X.-S.Z.); (Y.L.)
| | - Yu Liang
- Department of Anesthesiology, Tianjin Huanhu Hospital, Tianjin 300060, China; (Y.Z.); (Y.-X.W.); (J.C.); (X.-S.Z.); (Y.L.)
| | - Shi-Dong Zhang
- Department of Anesthesiology, Jinghai Hospital, Tianjin 300060, China;
| | - Yan-Jie Xing
- Department of Anesthesiology, Tangshan City Worker Hospital, Tianjin 300060, China;
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Abstract
In the human brain, ≈30% of the energy is spent on synaptic transmission. Disappearance of synaptic activity is the earliest consequence of cerebral ischemia. The changes of synaptic function are generally assumed to be reversible and persistent damage is associated with membrane failure and neuronal death. However, there is overwhelming experimental evidence of isolated, but persistent, synaptic failure resulting from mild or moderate cerebral ischemia. Early failure results from presynaptic damage with impaired transmitter release. Proposed mechanisms include dysfunction of adenosine triphosphate-dependent calcium channels and a disturbed docking of glutamate-containing vesicles resulting from impaired phosphorylation. We review energy distribution among neuronal functions, focusing on energy usage of synaptic transmission. We summarize the effect of ischemia on neurotransmission and the evidence of long-lasting synaptic failure as a cause of persistent symptoms in patients with cerebral ischemia. Finally, we discuss the implications of synaptic failure in the diagnosis of cerebral ischemia, including the limited sensitivity of diffusion-weighted MRI in those cases in which damage is presumably limited to the synapses.
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Affiliation(s)
- Jeannette Hofmeijer
- Department of Neurology, Rijnstate Hospital, Wagnerlaan 55, 6815 AD Arnhem, The Netherlands.
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Saraceno G, Ayala M, Badorrey M, Holubiec M, Romero J, Galeano P, Barreto G, Giraldez-Alvárez L, Kölliker-fres R, Coirini H, Capani F. Effects of perinatal asphyxia on rat striatal cytoskeleton. Synapse 2011; 66:9-19. [DOI: 10.1002/syn.20978] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2011] [Accepted: 08/17/2011] [Indexed: 11/11/2022]
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Costain WJ, Haqqani AS, Rasquinha I, Giguere MS, Slinn J, Zurakowski B, Stanimirovic DB. Proteomic analysis of synaptosomal protein expression reveals that cerebral ischemia alters lysosomal Psap processing. Proteomics 2011; 10:3272-91. [PMID: 20718007 DOI: 10.1002/pmic.200900447] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cerebral ischemia (CI) induces dramatic changes in synaptic structure and function that precedes delayed post-ischemic neuronal death. Here, a proteomic analysis was used to identify the effects of focal CI on synaptosomal protein levels. Contralateral and ipsilateral synaptosomes, prepared from adult mice subjected to 60 min middle cerebral artery occlusion, were isolated following 3, 6 and 20 h of reperfusion. Synaptosomal protein samples (n=3) were labeled using the cleavable ICAT system prior to analysis with nanoLC-MS/MS. Each sample was analyzed by LC-MS to identify differential expressions using InDEPT software and differentially expressed peptides were identified by targeted LC-MS/MS. A total of 62 differentially expressed proteins were identified and Gene Ontology classification (cellular component) indicated that the majority of the proteins were located in the mitochondria and other components consistent with synaptic localization. The observed alterations in synaptic protein levels poorly correlated with gene expression, indicating the involvement of post-transcriptional regulatory mechanisms in determining post-ischemic synaptic protein content. Additionally, immunohistochemistry analysis of prosaposin (Psap) and saposin C (SapC) indicates that CI disrupts Psap processing and glycosphingolipid metabolism. These results demonstrate that the synapse is adversely affected by CI and may play a role in mediating post-ischemic neuronal viability.
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Affiliation(s)
- Willard J Costain
- Glycosyltransferases and Neuroglycomics, Institute for Biological Sciences, National Research Council, Ottawa, ON, Canada.
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Changes in neostriatal and hippocampal synaptic densities in perinatal asphyctic male and female young rats: Role of hypothermia. Brain Res Bull 2011; 84:31-8. [DOI: 10.1016/j.brainresbull.2010.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 09/21/2010] [Accepted: 10/12/2010] [Indexed: 11/20/2022]
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Abstract
Autophagy is the main degradation pathway responsible for eliminating abnormal protein aggregates and damaged organelles prevalent in neurons after transient cerebral ischemia. This study investigated whether accumulation of protein aggregate-associated organelles in post-ischemic neurons is a consequence of changes in autophagy. Electron microscopic analysis indicated that both autophagosomes and autolysosomes are significantly up-regulated in hippocampal CA1 and DG neurons after ischemia. The microtubule-associated protein light chain 3 (LC3)-II conjugate, a marker for autophagosomes assessed by western blotting, was up-regulated in post-ischemic brain tissues. Confocal microscopy showed that LC3 isoforms were located in living post-ischemic neurons. Treatment with chloriquine resulted in accumulation of LC3-II in sham-operated rats, but did not further change the LC3-II levels in post-ischemic brain tissues. The results indicate that at least part of the accumulation of protein aggregate-associated organelles seen following ischemia is likely to be because of failure of the autophagy pathway. The resulting protein aggregation on subcellular organelle membranes could lead to multiple organelle damage and to delayed neuronal death after transient cerebral ischemia.
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Affiliation(s)
- Chunli Liu
- Department of Neurology, University of Miami School of Medicine, Miami, Florida 33136, USA
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Exacerbation of ischemia-induced amyloid-beta generation by diabetes is associated with autophagy activation in mice brain. Neurosci Lett 2010; 479:215-20. [PMID: 20553803 DOI: 10.1016/j.neulet.2010.05.064] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2010] [Revised: 05/19/2010] [Accepted: 05/21/2010] [Indexed: 11/22/2022]
Abstract
To evaluate effect of diabetes on transient ischemia-induced brain damage and autophagy activity, streptozotocin (STZ)-induced diabetic mellitus (DM) mice were subjected to transient common carotid artery occlusion (CCAO) operation. After the operation, immunohistochemistry and transmission electron microscopy (EM) were performed to investigate the astrocytes activation, amyloid-beta protein (Abeta) expression and accumulation of autophagy-like vacuoles containing electron-dense material (avd); and hallmarks of autophagy, the microtubule-associated protein light chain 3 (LC3)-II, was detected by western blot analysis. The results showed that DM amplified stroke-induced astrocytes activation and Abeta generation. Western blot analysis showed that LC3-II conjugate was drastically up-regulated at early stages post ischemia and it last for at least 72h in DM mice brain. DM mice demonstrated increased baseline level of LC3-II as comparing to normal mice; DM also amplified stroke-induced LC3-II level. Under EM, avd was most markedly accumulated in neurons of DM mice brain after ischemia. Immunofluorescence double-staining showed that most Abeta and autophagosomes co-localized. Therefore, our results suggested that exacerbation of ischemia-induced Abeta generation by diabetes might be associated with autophagy activation in mice brain, and modulating neuronal autophagy might be a new therapeutic strategy to depress the risk of development of dementia in diabetic patients with stroke.
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Abstract
Brain plasticity describes the potential of the organ for adaptive changes involved in various phenomena in health and disease. A substantial amount of experimental evidence, received in animal and cell models, shows that a cascade of plastic changes at the molecular, cellular, and tissue levels, is initiated in different regions of the postischemic brain. Underlying mechanisms include neurochemical alterations, functional changes in excitatory and inhibitory synapses, axonal and dendritic sprouting, and reorganization of sensory and motor central maps. Multiple lines of evidence indicate numerous points in which the process of postischemic recovery may be influenced with the aim to restore the full capacity of the brain tissue injured by an ischemic episode.
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Affiliation(s)
- Galyna G Skibo
- Department of Cytology, Bogomoletz Institute of Physiology, Kiev, Ukraine
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Nikonenko AG, Radenovic L, Andjus PR, Skibo GG. Structural Features of Ischemic Damage in the Hippocampus. Anat Rec (Hoboken) 2009; 292:1914-21. [DOI: 10.1002/ar.20969] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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47
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Protein ubiquitination in postsynaptic densities after hypoxia in rat neostriatum is blocked by hypothermia. Exp Neurol 2009; 219:404-13. [PMID: 19555686 DOI: 10.1016/j.expneurol.2009.06.007] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 05/24/2009] [Accepted: 06/14/2009] [Indexed: 11/23/2022]
Abstract
Synaptic dysfunction has been associated with neuronal cell death following hypoxia. The lack of knowledge on the mechanisms underlying this dysfunction prompted us to investigate the morphological changes in the postsynaptic densities (PSDs) induced by hypoxia. The results presented here demonstrate that PSDs of the rat neostriatum are highly modified and ubiquitinated 6 months after induction of hypoxia in a model of perinatal asphyxia. Using both two dimensional (2D) and three dimensional (3D) electron microscopic analyses of synapses stained with ethanolic phosphotungstic acid (E-PTA), we observed an increment of PSD thickness dependent on the duration and severity of the hypoxic insult. The PSDs showed clear signs of damage and intense staining for ubiquitin. These morphological and molecular changes were effectively blocked by hypothermia treatment, one of the most effective strategies for hypoxia-induced brain injury available today. Our data suggest that synaptic dysfunction following hypoxia may be caused by long-term misfolding and aggregation of proteins in the PSD.
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Lin C, Tao P, Jong Y, Chen W, Yang C, Huang L, Chao C, Yang S. Prenatal morphine alters the synaptic complex of postsynaptic density 95 with N-methyl-d-aspartate receptor subunit in hippocampal CA1 subregion of rat offspring leading to long-term cognitive deficits. Neuroscience 2009; 158:1326-37. [DOI: 10.1016/j.neuroscience.2008.11.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2008] [Revised: 11/02/2008] [Accepted: 11/04/2008] [Indexed: 11/28/2022]
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Jiang X, Mu D, Biran V, Faustino J, Chang S, Rincón CM, Sheldon RA, Ferriero DM. Activated Src kinases interact with theN-methyl-D-aspartate receptor after neonatal brain ischemia. Ann Neurol 2008; 63:632-41. [DOI: 10.1002/ana.21365] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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50
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Abstract
Autophagy is the chief machinery for bulk degradation of superfluous or aberrant cytoplasmic components. This study used the rat moderate fluid percussion injury model to investigate whether the autophagy pathway plays a key role after traumatic brain injury (TBI). Induction of autophagy is manifested by accumulation of autophagosomes (APs), observable under transmission electron microscopy (EM). Two hallmarks of autophagy, i.e., the microtubule-associated protein light chain 3 (LC3)-II and the autophagy-related gene (ATG)12-ATG5 conjugates, were explored by biochemical and confocal microscopic analyses of brain tissues. Under EM, both APs and autolysosomes were markedly accumulated in neurons from 4 h onward after TBI. Western blot analysis showed that ATG12-ATG5 conjugate was markedly redistributed during 5 to 15 days in brain tissues after TBI. LC3-II conjugate was initially unchanged but was drastically upregulated from 24 h onward in the pre-AP-containing fraction after TBI. LC-3 immunostaining was mainly located in living neurons under confocal microscopy. These results clearly show that the autophagy pathway is persistently activated after TBI. Because the autophagy pathway is the chief machinery for bulk elimination of aberrant cell components, we propose that activation of this pathway serves as a protective mechanism for maintaining cellular homeostasis after TBI.
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