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Belov Kirdajova D, Kriska J, Tureckova J, Anderova M. Ischemia-Triggered Glutamate Excitotoxicity From the Perspective of Glial Cells. Front Cell Neurosci 2020; 14:51. [PMID: 32265656 PMCID: PMC7098326 DOI: 10.3389/fncel.2020.00051] [Citation(s) in RCA: 185] [Impact Index Per Article: 46.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/21/2020] [Indexed: 12/21/2022] Open
Abstract
A plethora of neurological disorders shares a final common deadly pathway known as excitotoxicity. Among these disorders, ischemic injury is a prominent cause of death and disability worldwide. Brain ischemia stems from cardiac arrest or stroke, both responsible for insufficient blood supply to the brain parenchyma. Glucose and oxygen deficiency disrupts oxidative phosphorylation, which results in energy depletion and ionic imbalance, followed by cell membrane depolarization, calcium (Ca2+) overload, and extracellular accumulation of excitatory amino acid glutamate. If tight physiological regulation fails to clear the surplus of this neurotransmitter, subsequent prolonged activation of glutamate receptors forms a vicious circle between elevated concentrations of intracellular Ca2+ ions and aberrant glutamate release, aggravating the effect of this ischemic pathway. The activation of downstream Ca2+-dependent enzymes has a catastrophic impact on nervous tissue leading to cell death, accompanied by the formation of free radicals, edema, and inflammation. After decades of “neuron-centric” approaches, recent research has also finally shed some light on the role of glial cells in neurological diseases. It is becoming more and more evident that neurons and glia depend on each other. Neuronal cells, astrocytes, microglia, NG2 glia, and oligodendrocytes all have their roles in what is known as glutamate excitotoxicity. However, who is the main contributor to the ischemic pathway, and who is the unsuspecting victim? In this review article, we summarize the so-far-revealed roles of cells in the central nervous system, with particular attention to glial cells in ischemia-induced glutamate excitotoxicity, its origins, and consequences.
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Affiliation(s)
- Denisa Belov Kirdajova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jan Kriska
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
| | - Jana Tureckova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia
| | - Miroslava Anderova
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic (ASCR), Prague, Czechia.,Second Faculty of Medicine, Charles University, Prague, Czechia
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Song J, Kim YS, Lee DH, Lee SH, Park HJ, Lee D, Kim H. Neuroprotective effects of oleic acid in rodent models of cerebral ischaemia. Sci Rep 2019; 9:10732. [PMID: 31341184 PMCID: PMC6656890 DOI: 10.1038/s41598-019-47057-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 06/06/2019] [Indexed: 01/02/2023] Open
Abstract
Oleic acid (OA) is released from brain phospholipids after cerebral ischaemia; however, its role in ischaemic injury remains unknown. We hypothesised that OA has neuroprotective effects after cerebral ischaemia, which may be exerted through peroxisome proliferator-activated receptor gamma (PPAR-γ) activation, since OA is an endogenous ligand of PPAR-γ. The effects of OA administration were evaluated in rodent models of middle cerebral artery occlusion (MCAO), photothrombosis, and four-vessel occlusion (4-VO). We determined the time window of therapeutic opportunity and examined the ability of the PPAR-γ antagonist GW9662 to reverse OA’s protective effects after MCAO. We found that OA administration decreased the MCAO-induced infarct volume and functional deficits, photothrombosis-induced infarct volume, and 4-VO-induced hippocampal neuronal death. Additionally, OA was highly efficacious when administered up to 3 h after MCAO. Pre-treatment with GW9662 abolished the inhibitory effects of OA on the infarct volume and immunoreactivity of key inflammatory mediators in the ischaemic cortex. Our results indicate that OA has neuroprotective effects against transient and permanent focal cerebral ischaemia, as well as global cerebral ischaemia. It may have therapeutic value for the ischaemic stroke treatment with a clinically feasible therapeutic window. The OA-mediated neuroprotection might be attributable to its anti-inflammatory actions through PPAR-γ activation.
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Affiliation(s)
- Jungbin Song
- Department of Herbal Pharmacology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Young-Sik Kim
- Department of Herbal Pharmacology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Dong Hwan Lee
- Department of Herbal Pharmacology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Sung Hyun Lee
- Korea Institute of Science and Technology for Eastern Medicine (KISTEM) NeuMed Inc., 88 Imun-ro, Dongdaemun-gu, Seoul, 02440, Republic of Korea
| | - Hyo Jin Park
- Korea Institute of Science and Technology for Eastern Medicine (KISTEM) NeuMed Inc., 88 Imun-ro, Dongdaemun-gu, Seoul, 02440, Republic of Korea
| | - Donghun Lee
- Department of Herbal Pharmacology, College of Korean Medicine, Gachon University, 1342 Seongnamdae-ro, Sujeong-gu, Seongnam-si, Gyeonggi-do, 13120, Republic of Korea.
| | - Hocheol Kim
- Department of Herbal Pharmacology, College of Korean Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
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Measuring Respiration in Isolated Murine Brain Mitochondria: Implications for Mechanistic Stroke Studies. Neuromolecular Med 2019; 21:493-504. [PMID: 31172441 DOI: 10.1007/s12017-019-08552-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 05/29/2019] [Indexed: 11/26/2022]
Abstract
Measuring mitochondrial respiration in brain tissue is very critical in understanding the physiology and pathology of the central nervous system. Particularly, measurement of respiration in isolated mitochondria provides the advantage over the whole cells or tissues as the changes in respiratory function are intrinsic to mitochondrial structures rather than the cellular signaling that regulates mitochondria. Moreover, a high-throughput technique for measuring mitochondrial respiration minimizes the experimental time and the sample-to-sample variation. Here, we provide a detailed protocol for measuring respiration in isolated brain non-synaptosomal mitochondria using Agilent Seahorse XFe24 Analyzer. We optimized the protocol for the amount of mitochondria and concentrations of ADP, oligomycin, and trifluoromethoxy carbonylcyanide phenylhydrazone (FCCP) for measuring respiratory parameters for complex I-mediated respiration. In addition, we measured complex II-mediated respiratory parameters. We observed that 10 µg of mitochondrial protein per well, ADP concentrations ranging between 2.5 and 10 mmol/L along with 5 µmol/L of oligomycin, and 5 µmol/L of FCCP are ideal for measuring the complex I-mediated respiration in isolated mouse brain mitochondria. Furthermore, we determined that 2.5 µg of mitochondrial protein per well is ideal for measuring complex II-mediated respiration. Notably, we provide a discussion of logical analysis of data and how the assay could be utilized to design mechanistic studies for experimental stroke. In conclusion, we provide detailed experimental design for measurement of various respiratory parameters in isolated brain mitochondria utilizing a novel high-throughput technique along with interpretation and analysis of data.
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Gorup D, Škokić S, Kriz J, Gajović S. Tlr2 Deficiency is Associated with Enhanced Elements of Neuronal Repair and Caspase 3 Activation Following Brain Ischemia. Sci Rep 2019; 9:2821. [PMID: 30808918 PMCID: PMC6391535 DOI: 10.1038/s41598-019-39541-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/11/2019] [Indexed: 01/08/2023] Open
Abstract
The aim of this study was to apply multimodal in vivo imaging to assess the influence of altered innate immunity on brain repair after ischemic lesion. Tlr2-deficient mice were compared to wild type controls, as they lack Tlr2-mediated pro-inflammatory signaling triggered by postischemic necrosis. The ischemic lesion was induced by transient middle cerebral artery occlusion for 60 min, followed by brain imaging and analysis at four time points until 28 days after ischemia. Multimodal in vivo imaging involved a combination of 3 modalities: (1) magnetic resonance imaging by T2-weighted scans to assess brain lesion size, (2) bioluminescence imaging of Gap43-luc/gfp transgenic mice to visualize the axonal remodeling, and (3) caged-luciferin bioluminescence imaging of DEVD-luciferin allowing for visualization of caspase 3 and 7 activity in Gap43-luc/gfp mice. This enabled innovative correlation of the MRI-determined lesion size to photon fluxes obtained by bioluminescence imaging. Our data revealed that following ischemia, Tlr2-deficient mice had higher Gap43 expression and higher levels of caspases 3 and 7 activity, which was accompanied by enhanced levels of synaptic plasticity markers DLG4 and synaptophysin when compared to wild type controls. Altered inflammation in Tlr2-deficient mice was accompanied by enhanced elements of post-stroke repair, in particular during the chronic phase of recovery, but also with delayed final consolidation of the brain lesion.
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Affiliation(s)
- Dunja Gorup
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, Šalata 12, Zagreb, HR-10000, Croatia
| | - Siniša Škokić
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, Šalata 12, Zagreb, HR-10000, Croatia
| | - Jasna Kriz
- Department of Psychiatry and Neuroscience, Faculty of Medicine Laval University, CERVO Brain Research Center, 2601, de la Canardière, Québec (QC), G1J 2G3, Canada
| | - Srećko Gajović
- Croatian Institute for Brain Research, University of Zagreb School of Medicine, Šalata 12, Zagreb, HR-10000, Croatia.
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Choi JH, Pile-Spellman J. Reperfusion Changes After Stroke and Practical Approaches for Neuroprotection. Neuroimaging Clin N Am 2019; 28:663-682. [PMID: 30322601 DOI: 10.1016/j.nic.2018.06.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Reperfusion is the first line of care in a growing number of eligible acute ischemic stroke patients. Early reperfusion with thrombolytic drugs and endovascular mechanical devices is associated with improved outcome and lower mortality rates compared with natural history. Reperfusion is not without risk, however, and may result in reperfusion injury, which manifests in hemorrhagic transformation, brain edema, infarct progression, and neurologic worsening. In this article, the functional and structural changes and underlying molecular mechanisms of ischemia and reperfusion are reviewed. The pathways that lead to reperfusion injury and novel neuroprotective strategies with endogenous properties are discussed.
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Affiliation(s)
- Jae H Choi
- Center for Unruptured Brain Aneurysms, Neurological Surgery PC, 1991 Marcus Avenue, Suite 108, Lake Success, NY 11042, USA; Department of Neurology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA; Hybernia Medical LLC, 626 RexCorp Plaza, Uniondale, NY 11556, USA.
| | - John Pile-Spellman
- Center for Unruptured Brain Aneurysms, Neurological Surgery PC, 1991 Marcus Avenue, Suite 108, Lake Success, NY 11042, USA; Hybernia Medical LLC, 626 RexCorp Plaza, Uniondale, NY 11556, USA
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Ginsberg MD. Expanding the concept of neuroprotection for acute ischemic stroke: The pivotal roles of reperfusion and the collateral circulation. Prog Neurobiol 2016; 145-146:46-77. [PMID: 27637159 DOI: 10.1016/j.pneurobio.2016.09.002] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/22/2016] [Accepted: 09/10/2016] [Indexed: 12/27/2022]
Abstract
This review surveys the efforts taken to achieve clinically efficacious protection of the ischemic brain and underscores the necessity of expanding our purview to include the essential role of cerebral perfusion and the collateral circulation. We consider the development of quantitative strategies to measure cerebral perfusion at the regional and local levels and the application of these methods to elucidate flow-related thresholds of ischemic viability and to characterize the ischemic penumbra. We stress that the modern concept of neuroprotection must consider perfusion, the necessary substrate upon which ischemic brain survival depends. We survey the major mechanistic approaches to neuroprotection and review clinical neuroprotection trials, focusing on those phase 3 multicenter clinical trials for acute ischemic stroke that have been completed or terminated. We review the evolution of thrombolytic therapies; consider the lessons learned from the initial, negative multicenter trials of endovascular therapy; and emphasize the highly successful positive trials that have finally established a clinical role for endovascular clot removal. As these studies point to the brain's collateral circulation as key to successful reperfusion, we next review the anatomy and pathophysiology of collateral perfusion as it relates to ischemic infarction, as well as the molecular and genetic influences on collateral development. We discuss the current MR and CT-based diagnostic methods for assessing the collateral circulation and the prognostic significance of collaterals in ischemic stroke, and we consider past and possible future therapeutic directions.
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Affiliation(s)
- Myron D Ginsberg
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, United States.
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Zuo X, Hou Q, Jin J, Zhan L, Li X, Sun W, Lin K, Xu E. Inhibition of Cathepsin B Alleviates Secondary Degeneration in Ipsilateral Thalamus After Focal Cerebral Infarction in Adult Rats. J Neuropathol Exp Neurol 2016; 75:816-26. [PMID: 27371711 DOI: 10.1093/jnen/nlw054] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Secondary degeneration in areas beyond ischemic foci can inhibit poststroke recovery. The cysteine protease Cathepsin B (CathB) regulates cell death and intracellular protein catabolism. To investigate the roles of CathB in the development of secondary degeneration in the ventroposterior nucleus (VPN) of the ipsilateral thalamus after focal cerebral infarction, infarct volumes, immunohistochemistry and immunofluorescence, and Western blotting analyses were conducted in a distal middle cerebral artery occlusion (dMCAO) stroke model in adult rats. We observed marked neuron loss and gliosis in the ipsilateral thalamus after dMCAO, and the expression of CathB and cleaved caspase-3 in the VPN was significantly upregulated; glial cells were the major source of CathB. Although it had no effect on infarct volume, delayed intracerebroventricular treatment with the membrane-permeable CathB inhibitor CA-074Me suppressed the expression of CathB and cleaved caspase-3 in ipsilateral VPN and accordingly alleviated the secondary degeneration. These data indicate that CathB mediates a novel mechanism of secondary degeneration in the VPN of the ipsilateral thalamus after focal cortical infarction and suggest that CathB might be a therapeutic target for the prevention of secondary degeneration in patients after stroke.
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Affiliation(s)
- Xialin Zuo
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neurosciences and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China (XZ, QH, JJ, LZ, XL, WS, KL, EX); and Department of Neurology, Provincial People's Hospital, Guangdong No.2, Guangzhou, China (QH)
| | - Qinghua Hou
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neurosciences and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China (XZ, QH, JJ, LZ, XL, WS, KL, EX); and Department of Neurology, Provincial People's Hospital, Guangdong No.2, Guangzhou, China (QH)
| | - Jizi Jin
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neurosciences and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China (XZ, QH, JJ, LZ, XL, WS, KL, EX); and Department of Neurology, Provincial People's Hospital, Guangdong No.2, Guangzhou, China (QH)
| | - Lixuan Zhan
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neurosciences and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China (XZ, QH, JJ, LZ, XL, WS, KL, EX); and Department of Neurology, Provincial People's Hospital, Guangdong No.2, Guangzhou, China (QH)
| | - Xinyu Li
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neurosciences and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China (XZ, QH, JJ, LZ, XL, WS, KL, EX); and Department of Neurology, Provincial People's Hospital, Guangdong No.2, Guangzhou, China (QH)
| | - Weiwen Sun
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neurosciences and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China (XZ, QH, JJ, LZ, XL, WS, KL, EX); and Department of Neurology, Provincial People's Hospital, Guangdong No.2, Guangzhou, China (QH)
| | - Kunqin Lin
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neurosciences and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China (XZ, QH, JJ, LZ, XL, WS, KL, EX); and Department of Neurology, Provincial People's Hospital, Guangdong No.2, Guangzhou, China (QH)
| | - En Xu
- Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Institute of Neurosciences and the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China (XZ, QH, JJ, LZ, XL, WS, KL, EX); and Department of Neurology, Provincial People's Hospital, Guangdong No.2, Guangzhou, China (QH).
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Hu Y, Deng H, Xu S, Zhang J. MicroRNAs Regulate Mitochondrial Function in Cerebral Ischemia-Reperfusion Injury. Int J Mol Sci 2015; 16:24895-917. [PMID: 26492239 PMCID: PMC4632781 DOI: 10.3390/ijms161024895] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Accepted: 10/08/2015] [Indexed: 01/30/2023] Open
Abstract
Cerebral ischemia-reperfusion injury involves multiple independently fatal terminal pathways in the mitochondria. These pathways include the reactive oxygen species (ROS) generation caused by changes in mitochondrial membrane potential and calcium overload, resulting in apoptosis via cytochrome c (Cyt c) release. In addition, numerous microRNAs are associated with the overall process. In this review, we first briefly summarize the mitochondrial changes in cerebral ischemia-reperfusion and then describe the possible molecular mechanism of miRNA-regulated mitochondrial function, which likely includes oxidative stress and energy metabolism, as well as apoptosis. On the basis of the preceding analysis, we conclude that studies of microRNAs that regulate mitochondrial function will expedite the development of treatments for cerebral ischemia-reperfusion injury.
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Affiliation(s)
- Yue Hu
- Graduate School, Tianjin University of Traditional Chinese Medicine, 312 An Shan Xi Road, Nan Kai District, Tianjin 300193, China.
| | - Hao Deng
- Medical Experiment Center, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, 314 An Shan Xi Road, Nan Kai District, Tianjin 300193, China.
| | - Shixin Xu
- Medical Experiment Center, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, 314 An Shan Xi Road, Nan Kai District, Tianjin 300193, China.
| | - Junping Zhang
- Medical Experiment Center, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, 314 An Shan Xi Road, Nan Kai District, Tianjin 300193, China.
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Arnberg F, Grafström J, Lundberg J, Nikkhou-Aski S, Little P, Damberg P, Mitsios N, Mulder J, Lu L, Söderman M, Stone-Elander S, Holmin S. Imaging of a clinically relevant stroke model: glucose hypermetabolism revisited. Stroke 2015; 46:835-42. [PMID: 25657187 DOI: 10.1161/strokeaha.114.008407] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Ischemic stroke has been shown to cause hypermetabolism of glucose in the ischemic penumbra. Experimental and clinical data indicate that infarct-related systemic hyperglycemia is a potential therapeutic target in acute stroke. However, clinical studies aiming for glucose control in acute stroke have neither improved functional outcome nor reduced mortality. Thus, further studies on glucose metabolism in the ischemic brain are warranted. METHODS We used a rat model of stroke that preserves collateral flow. The animals were analyzed by [2-(18)F]-2-fluoro-2-deoxy-d-glucose positron emission tomography or magnetic resonance imaging during 90-minute occlusion of the middle cerebral artery and during 60 minutes after reperfusion. Results were correlated to magnetic resonance imaging of cerebral blood flow, diffusion of water, lactate formation, and histological data on cell death and blood-brain barrier breakdown. RESULTS We detected an increased [2-(18)F]-2-fluoro-2-deoxy-d-glucose uptake within ischemic regions succumbing to infarction and in the peri-infarct region. Magnetic resonance imaging revealed impairment of blood flow to ischemic levels in the infarct and a reduction of cerebral blood flow in the peri-infarct region. Magnetic resonance spectroscopy revealed lactate in the ischemic region and absence of lactate in the peri-infarct region. Immunohistochemical analyses revealed apoptosis and blood-brain barrier breakdown within the infarct. CONCLUSIONS The increased uptake of [2-(18)F]-2-fluoro-2-deoxy-d-glucose in cerebral ischemia most likely reflects hypermetabolism of glucose meeting increased energy needs of ischemic and hypoperfused brain tissue, and it occurs under both anaerobic and aerobic conditions measured by local lactate production. Infarct-related systemic hyperglycemia could serve to facilitate glucose supply to the ischemic brain. Glycemic control by insulin treatment could negatively influence this mechanism.
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Affiliation(s)
- Fabian Arnberg
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Jonas Grafström
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Johan Lundberg
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Sahar Nikkhou-Aski
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Philip Little
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Peter Damberg
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Nicholas Mitsios
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Jan Mulder
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Li Lu
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Michael Söderman
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Sharon Stone-Elander
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden
| | - Staffan Holmin
- From the Department of Clinical Neuroscience (F.A., J.G., J.L., P.L., M.S., S.S.-E., S.H.), Karolinska Experimental Research and Imaging Center (KERIC) (S.N.-A., P.D., L.L.), Science for Life Laboratory, Department of Neuroscience (N.M., J.M.), Karolinska Institutet, Stockholm, Sweden; and Department of Neuroradiology (F.A., J.L., P.L., M.S., S.S.-E., S.H.), Department of Radiology (F.A.), Karolinska University Hospital-Solna, Stockholm, Sweden.
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Connolly NMC, Prehn JHM. The metabolic response to excitotoxicity - lessons from single-cell imaging. J Bioenerg Biomembr 2014; 47:75-88. [PMID: 25262286 DOI: 10.1007/s10863-014-9578-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 08/26/2014] [Indexed: 12/26/2022]
Abstract
Excitotoxicity is a pathological process implicated in neuronal death during ischaemia, traumatic brain injuries and neurodegenerative diseases. Excitotoxicity is caused by excess levels of glutamate and over-activation of NMDA or calcium-permeable AMPA receptors on neuronal membranes, leading to ionic influx, energetic stress and potential neuronal death. The metabolic response of neurons to excitotoxicity is complex and plays a key role in the ability of the neuron to adapt and recover from such an insult. Single-cell imaging is a powerful experimental technique that can be used to study the neuronal metabolic response to excitotoxicity in vitro and, increasingly, in vivo. Here, we review some of the knowledge of the neuronal metabolic response to excitotoxicity gained from in vitro single-cell imaging, including calcium and ATP dynamics and their effects on mitochondrial function, along with the contribution of glucose metabolism, oxidative stress and additional neuroprotective signalling mechanisms. Future work will combine knowledge gained from single-cell imaging with data from biochemical and computational techniques to garner holistic information about the metabolic response to excitotoxicity at the whole brain level and transfer this knowledge to a clinical setting.
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Affiliation(s)
- Niamh M C Connolly
- Department of Physiology and Medical Physics, 123 St Stephen's Green, Dublin 2, Ireland
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11
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Kobayashi S, Ishikawa T, Tanabe J, Moroi J, Suzuki A. Quantitative cerebral perfusion assessment using microscope-integrated analysis of intraoperative indocyanine green fluorescence angiography versus positron emission tomography in superficial temporal artery to middle cerebral artery anastomosis. Surg Neurol Int 2014; 5:135. [PMID: 25298917 PMCID: PMC4174671 DOI: 10.4103/2152-7806.140705] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 07/03/2014] [Indexed: 11/12/2022] Open
Abstract
Background: Intraoperative qualitative indocyanine green (ICG) angiography has been used in cerebrovascular surgery. Hyperperfusion may lead to neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. The purpose of this study is to quantitatively evaluate intraoperative cerebral perfusion using microscope-integrated dynamic ICG fluorescence analysis, and to assess whether this value predicts hyperperfusion syndrome (HPS) after STA-MCA anastomosis. Methods: Ten patients undergoing STA-MCA anastomosis due to unilateral major cerebral artery occlusive disease were included. Ten patients with normal cerebral perfusion served as controls. The ICG transit curve from six regions of interest (ROIs) on the cortex, corresponding to ROIs on positron emission tomography (PET) study, was recorded. Maximum intensity (IMAX), cerebral blood flow index (CBFi), rise time (RT), and time to peak (TTP) were evaluated. Results: RT/TTP, but not IMAX or CBFi, could differentiate between control and study subjects. RT/TTP correlated (|r| = 0.534-0.807; P < 0.01) with mean transit time (MTT)/MTT ratio in the ipsilateral to contralateral hemisphere by PET study. Bland–Altman analysis showed a wide limit of agreement between RT and MTT and between TTP and MTT. The ratio of RT before and after bypass procedures was significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.60 ± 0.032 and 0.80 ± 0.056, respectively; P = 0.017). The ratio of TTP was also significantly lower in patients with postoperative HPS than in patients without postoperative HPS (0.64 ± 0.081 and 0.85 ± 0.095, respectively; P = 0.017). Conclusions: Time-dependent intraoperative parameters from the ICG transit curve provide quantitative information regarding cerebral circulation time with quality and utility comparable to information obtained by PET. These parameters may help predict the occurrence of postoperative HPS.
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Affiliation(s)
- Shinya Kobayashi
- Department of Surgical Neurology, Research Institute for Brain and Blood Vessels-AKITA, Akita, Japan
| | - Tatsuya Ishikawa
- Department of Surgical Neurology, Research Institute for Brain and Blood Vessels-AKITA, Akita, Japan
| | - Jun Tanabe
- Department of Surgical Neurology, Research Institute for Brain and Blood Vessels-AKITA, Akita, Japan
| | - Junta Moroi
- Department of Surgical Neurology, Research Institute for Brain and Blood Vessels-AKITA, Akita, Japan
| | - Akifumi Suzuki
- Department of Surgical Neurology, Research Institute for Brain and Blood Vessels-AKITA, Akita, Japan
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12
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Amantea D, Certo M, Russo R, Bagetta G, Corasaniti MT, Tassorelli C. Early reperfusion injury is associated to MMP2 and IL-1β elevation in cortical neurons of rats subjected to middle cerebral artery occlusion. Neuroscience 2014; 277:755-63. [PMID: 25108165 DOI: 10.1016/j.neuroscience.2014.07.064] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/14/2014] [Accepted: 07/29/2014] [Indexed: 12/27/2022]
Abstract
The pathophysiological processes implicated in ischemic brain damage are strongly affected by an inflammatory reaction characterized by activation of immune cells and release of soluble mediators, including cytokines and chemokines. The pro-inflammatory cytokine interleukin (IL)-1β has been implicated in ischemic brain injury, however, to date, the mechanisms involved in the maturation of this cytokine in the ischemic brain have not been completely elucidated. We have previously suggested that matrix metalloproteinases (MMPs) may be implicated in cytokine production under pathological conditions. Here, we demonstrate that significant elevation of IL-1β occurs in the cortex as early as 1h after the beginning of reperfusion in rats subjected to 2-h middle cerebral artery occlusion (MCAo). At this early stage, we observe increased expression of IL-1β in pericallosal astroglial cells and in cortical neurons and this latter signal colocalizes with elevated gelatinolytic activity. By gel zymography, we demonstrate that the increased gelatinolytic signal at 1-h reperfusion is mainly ascribed to MMP2. Thus, MMP2 seems to contribute to early brain elevation of IL-β after transient ischemia and this mechanism may promote damage since pharmacological inhibition of gelatinases by the selective MMP2/MMP9 inhibitor V provides neuroprotection in rats subjected to transient MCAo.
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Affiliation(s)
- D Amantea
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Italy.
| | - M Certo
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Italy
| | - R Russo
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Italy
| | - G Bagetta
- Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Italy
| | - M T Corasaniti
- Department of Health Sciences, University Magna Graecia of Catanzaro, Italy
| | - C Tassorelli
- IRCCS National Neurological Institute C. Mondino Foundation, Pavia, Italy
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13
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Nguyen AQ, Cherry BH, Scott GF, Ryou MG, Mallet RT. Erythropoietin: powerful protection of ischemic and post-ischemic brain. Exp Biol Med (Maywood) 2014; 239:1461-75. [PMID: 24595981 DOI: 10.1177/1535370214523703] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Ischemic brain injury inflicted by stroke and cardiac arrest ranks among the leading causes of death and long-term disability in the United States. The brain consumes large amounts of metabolic substrates and oxygen to sustain its energy requirements. Consequently, the brain is exquisitely sensitive to interruptions in its blood supply, and suffers irreversible damage after 10-15 min of severe ischemia. Effective treatments to protect the brain from stroke and cardiac arrest have proven elusive, due to the complexities of the injury cascades ignited by ischemia and reperfusion. Although recombinant tissue plasminogen activator and therapeutic hypothermia have proven efficacious for stroke and cardiac arrest, respectively, these treatments are constrained by narrow therapeutic windows, potentially detrimental side-effects and the limited availability of hypothermia equipment. Mounting evidence demonstrates the cytokine hormone erythropoietin (EPO) to be a powerful neuroprotective agent and a potential adjuvant to established therapies. Classically, EPO originating primarily in the kidneys promotes erythrocyte production by suppressing apoptosis of proerythroid progenitors in bone marrow. However, the brain is capable of producing EPO, and EPO's membrane receptors and signaling components also are expressed in neurons and astrocytes. EPO activates signaling cascades that increase the brain's resistance to ischemia-reperfusion stress by stabilizing mitochondrial membranes, limiting formation of reactive oxygen and nitrogen intermediates, and suppressing pro-inflammatory cytokine production and neutrophil infiltration. Collectively, these mechanisms preserve functional brain tissue and, thus, improve neurocognitive recovery from brain ischemia. This article reviews the mechanisms mediating EPO-induced brain protection, critiques the clinical utility of exogenous EPO to preserve brain threatened by ischemic stroke and cardiac arrest, and discusses the prospects for induction of EPO production within the brain by the intermediary metabolite, pyruvate.
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Affiliation(s)
- Anh Q Nguyen
- Department of Integrative Physiology and Cardiovascular Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107-2699
| | - Brandon H Cherry
- Department of Integrative Physiology and Cardiovascular Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107-2699
| | - Gary F Scott
- Department of Integrative Physiology and Cardiovascular Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107-2699
| | - Myoung-Gwi Ryou
- Department of Integrative Physiology and Cardiovascular Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107-2699
| | - Robert T Mallet
- Department of Integrative Physiology and Cardiovascular Research Institute, University of North Texas Health Science Center, Fort Worth, TX 76107-2699
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Dhiraj DK, Chrysanthou E, Mallucci GR, Bushell M. miRNAs-19b, -29b-2* and -339-5p show an early and sustained up-regulation in ischemic models of stroke. PLoS One 2013; 8:e83717. [PMID: 24376737 PMCID: PMC3869799 DOI: 10.1371/journal.pone.0083717] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 11/06/2013] [Indexed: 12/18/2022] Open
Abstract
Stroke, the loss of neurons after ischemic insult to the brain, is one of the leading causes of death and disability worldwide. Despite its prevalence and severity, current therapy is extremely limited, highlighting the importance of further understanding the molecular events underlying ischemia-induced neuronal cell death. An ischemic area can be subdivided into two separate pathophysiological regions: the rapidly dying necrotic core, and the potentially salvageable apoptotic penumbra. Understanding molecular events occurring in the apoptotic ischemic penumbra may give greater insight into mechanisms controlling this salvageable tissue. miRNAs are known to have key roles in the regulation of gene expression in numerous pathological conditions, including the modulation of distinct pathways in stroke. However, previous studies have profiled miRNAs in the whole ischemic infarct, and do not differentiate between miRNA regulation in the necrotic core versus the apoptotic penumbra. We asked if there were unique miRNAs that are differentially regulated following ischemic insults in the salvageable apoptotic penumbra. miRNA expression profiles were compared in the whole infarct from in vivo stroke models, using the three vessel occlusion approach, to an in vitro model of the ischemic penumbra, prior to apoptotic induction. Multiple miRNAs were found to be differentially regulated following ischemic insults in each system. However, miR-19b, miR-29b-2* and miR-339-5p were significantly up-regulated in both model systems. Further, we confirmed these results in a neuroblastoma cell line subjected to a penumbra-like ischemic insult that induced the apoptotic cell death pathway. The data show that miR-19b, miR-29b-2* and miR-339-5p are up-regulated following ischemic insults and may be regulating gene expression to control important cellular pathways in the salvageable ischemic penumbra. Further investigation of their role and mRNA target identification may lead to new insights into the molecular mechanisms taking place in the salvageable apoptotic penumbra.
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Affiliation(s)
- Dalbir K. Dhiraj
- MRC Toxicology Unit, Medical Research Council, Leicester, England, United Kingdom
| | - Elvina Chrysanthou
- MRC Toxicology Unit, Medical Research Council, Leicester, England, United Kingdom
| | - Giovanna R. Mallucci
- MRC Toxicology Unit, Medical Research Council, Leicester, England, United Kingdom
| | - Martin Bushell
- MRC Toxicology Unit, Medical Research Council, Leicester, England, United Kingdom
- * E-mail:
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15
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Yuan H, Frank JE, Hong Y, An H, Eldeniz C, Nie J, Bunevicius A, Shen D, Lin W. Spatiotemporal uptake characteristics of [18]F-2-fluoro-2-deoxy-D-glucose in a rat middle cerebral artery occlusion model. Stroke 2013; 44:2292-9. [PMID: 23743978 DOI: 10.1161/strokeaha.113.000903] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Alterations of cerebral glucose metabolism are well anticipated during cerebral ischemia. However, detailed spatiotemporal characteristics of disturbed cerebral glucose metabolism during acute ischemia remain largely elusive. This study aims to delineate spatiotemporal distributions of [18]F-2-fluoro-2-deoxy-D-glucose (FDG) uptake using positron emission tomography imaging, particularly at the peri-ischemic zone, and its correlation with tissue outcome. METHODS The intraluminal suture middle cerebral artery occlusion model was used to induce focal cerebral ischemia in rats (n=48). All animals underwent sequential MRI and FDG positron emission tomography imaging at different times (30-150 minutes) after middle cerebral artery occlusion. MR and positron emission tomography images were coregistered. FDG uptake in the peri-ischemic zone was assessed in relation to middle cerebral artery occlusion duration, cerebral blood flow, apparent diffusion coefficient, and 24-hour T2 lesions. RESULTS Elevated FDG uptake was consistently observed at the peri-ischemic zone surrounding the presumed ischemic core with low FDG uptake. Both the spatial volume and the uptake level of the hyper-uptake region were inversely correlated with the duration of middle cerebral artery occlusion. The hyper-uptake regions exhibited a mild reduction of cerebral blood flow (28.2±3.2%) and apparent diffusion coefficient (9.1±1.4%) when compared with that in the contralateral hemisphere. Colocalization analysis revealed that, with reperfusion, an average of 12.1±1.7% of the hyper-uptake volume was recruited into final infarction. CONCLUSIONS Elevated FDG uptake at the peri-ischemic zone is consistently observed during acute cerebral ischemia. The region with elevated FDG uptake likely reflects viable tissues that can be salvaged with reperfusion. Therefore, acute FDG positron emission tomography imaging might hold promise in the management of patients with acute stroke.
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Affiliation(s)
- Hong Yuan
- Department of Radiology, University of North Carolina at Chapel Hill, NC, USA
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16
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Li WA, Moore-Langston S, Chakraborty T, Rafols JA, Conti AC, Ding Y. Hyperglycemia in stroke and possible treatments. Neurol Res 2013; 35:479-91. [PMID: 23622737 DOI: 10.1179/1743132813y.0000000209] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hyperglycemia affects approximately one-third of acute ischemic stroke patients and is associated with poor clinical outcomes. In experimental and clinical stroke studies, hyperglycemia has been shown to be detrimental to the penumbral tissue for several reasons. First, hyperglycemia exacerbates both calcium imbalance and the accumulation of reactive oxygen species (ROS) in neurons, leading to increased apoptosis. Second, hyperglycemia fuels anaerobic energy production, causing lactic acidosis, which further stresses neurons in the penumbral regions. Third, hyperglycemia decreases blood perfusion after ischemic stroke by lowering the availability of nitric oxide (NO), which is a crucial mediator of vasodilation. Lastly, hyperglycemia intensifies the inflammatory response after stroke, causing edema, and hemorrhage through disruption of the blood brain barrier and degradation of white matter, which leads to a worsening of functional outcomes. Many neuroprotective treatments addressing hyperglycemia in stroke have been implemented in the past decade. Early clinical use of insulin provided mixed results due to insufficiently controlled glucose levels and heterogeneity of patient population. Recently, however, the latest Stroke Hyperglycemia Insulin Network Effort trial has addressed the shortcomings of insulin therapy. While glucagon-like protein-1 administration, hyperbaric oxygen preconditioning, and ethanol therapy appear promising, these treatments remain in their infancy and more research is needed to better understand the mechanisms underlying hyperglycemia-induced injuries. Elucidation of these mechanistic pathways could lead to the development of rational treatments that reduce hyperglycemia-associated injuries and improve functional outcomes for ischemic stroke patients.
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Affiliation(s)
- William A Li
- Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, MI, USA
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17
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Ishii T, Fukuta T, Agato Y, Oyama D, Yasuda N, Shimizu K, Kawaguchi AT, Asai T, Oku N. Nanoparticles accumulate in ischemic core and penumbra region even when cerebral perfusion is reduced. Biochem Biophys Res Commun 2013; 430:1201-5. [DOI: 10.1016/j.bbrc.2012.12.080] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 12/14/2012] [Indexed: 01/12/2023]
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18
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Dalkara T, Arsava EM. Can restoring incomplete microcirculatory reperfusion improve stroke outcome after thrombolysis? J Cereb Blood Flow Metab 2012; 32:2091-9. [PMID: 23047270 PMCID: PMC3519416 DOI: 10.1038/jcbfm.2012.139] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 08/31/2012] [Accepted: 09/03/2012] [Indexed: 12/27/2022]
Abstract
Substantial experimental data and recent clinical evidence suggesting that tissue reperfusion is a better predictor of outcome after thrombolysis than recanalization necessitate that patency of microcirculation after recanalization should be reevaluated. If indeed microcirculatory blood flow cannot be sufficiently reinstituted despite complete recanalization as commonly observed in coronary circulation, it may be one of the factors contributing to low efficacy of thrombolysis in stroke. Although microvascular no-reflow is considered an irreversible process that prevents tissue recovery from injury, emerging evidence suggests that it might be reversed with pharmacological agents administered early during recanalization. Therefore, therapeutic approaches aiming at reducing microvascular obstructions may improve success rate of recanalization therapies. Importantly, promoting oxygen delivery to the tissue, where entrapped erythrocytes cannot circulate in capillaries, with ongoing serum flow may improve survival of the underreperfused tissue. Altogether, these developments bring about the exciting possibility that benefit of reperfusion therapies can be further improved by restoring microcirculatory function because survival in the penumbra critically depends on adequate blood supply. Here, we review the available evidence suggesting presence of an 'incomplete microcirculatory reperfusion' (IMR) after focal cerebral ischemia and discuss potential means that may help investigate IMR in stroke patients after recanalization therapies despite technical limitations.
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Affiliation(s)
- Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey.
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19
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Kamp MA, Slotty P, Turowski B, Etminan N, Steiger HJ, Hänggi D, Stummer W. Microscope-integrated quantitative analysis of intraoperative indocyanine green fluorescence angiography for blood flow assessment: first experience in 30 patients. Neurosurgery 2012; 70:65-73; discussion 73-4. [PMID: 21811190 DOI: 10.1227/neu.0b013e31822f7d7c] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Intraoperative measurements of cerebral blood flow are of interest during vascular neurosurgery. Near-infrared indocyanine green (ICG) fluorescence angiography was introduced for visualizing vessel patency intraoperatively. However, quantitative information has not been available. OBJECTIVE To report our experience with a microscope with an integrated dynamic ICG fluorescence analysis system supplying semiquantitative information on blood flow. METHODS We recorded ICG fluorescence curves of cortex and cerebral vessels using software integrated into the surgical microscope (Flow 800 software; Zeiss Pentero) in 30 patients undergoing surgery for different pathologies. The following hemodynamic parameters were assessed: maximum intensity, rise time, time to peak, time to half-maximal fluorescence, cerebral blood flow index, and transit times from arteries to cortex. RESULTS For patients without obvious perfusion deficit, maximum fluorescence intensity was 177.7 arbitrary intensity units (AIs; 5-mg ICG bolus), mean rise time was 5.2 seconds (range, 2.9-8.2 seconds; SD, 1.3 seconds), mean time to peak was 9.4 seconds (range, 4.9-15.2 seconds; SD, 2.5 seconds), mean cerebral blood flow index was 38.6 AI/s (range, 13.5-180.6 AI/s; SD, 36.9 seconds), and mean transit time was 1.5 seconds (range, 360 milliseconds-3 seconds; SD, 0.73 seconds). For 3 patients with impaired cerebral perfusion, time to peak, rise time, and transit time between arteries and cortex were markedly prolonged (>20, >9 , and >5 seconds). In single patients, the degree of perfusion impairment could be quantified by the cerebral blood flow index ratios between normal and ischemic tissue. Transit times also reflected blood flow perturbations in arteriovenous fistulas. CONCLUSION Quantification of ICG-based fluorescence angiography appears to be useful for intraoperative monitoring of arterial patency and regional cerebral blood flow.
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Affiliation(s)
- Marcel A Kamp
- Klinik für Neurochirurgie, Heinrich-Heine-Universität, Düsseldorf, Germany.
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20
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Albumin therapy enhances collateral perfusion after laser-induced middle cerebral artery branch occlusion: a laser speckle contrast flow study. J Cereb Blood Flow Metab 2012; 32:2012-22. [PMID: 22781334 PMCID: PMC3493990 DOI: 10.1038/jcbfm.2012.102] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Laser speckle contrast (LSC) was used to compare the extent of cortical ischemia in two inbred mouse strains that differed in their degree of collateral circulation, after laser occlusion of the distal middle cerebral artery, and after treatment with 25% albumin (ALB) or saline (control). Sequential LSC images acquired over ∼90 minutes were coaligned, converted to relative flow, and normalized to baseline. After 3-day survival, infarction was quantified by triphenyl tetrazolium chloride or magnetic resonance imaging. In the sparsely collateralized BALB/c strain, mean flow fell to 13% to 14% and 33% to 34% of baseline in central (core) and peripheral (penumbral) regions of interest, and ALB treatment at 30 minutes enhanced perfusion in both regions by ∼2-fold relative to saline, restoring flow to the benign-oligemic range centrally, and to the hyperemic range peripherally. The ALB-induced increment in parenchymal perfusion was disproportionate to the subtle flow increase in the occluded artery itself, suggesting that ALB improved collateral circulation. Cortical infarction in BALB/c mice was reduced 45% by ALB treatment. In contrast to BALB/c mice, the better-collateralized CD-1 strain developed milder ischemia, had smaller infarcts, and showed no differential benefit of ALB. We conclude that where native collateralization is insufficient (BALB/c strain), ALB treatment exerts a significant therapeutic effect after ischemia by augmenting collateral perfusion.
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21
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Dickman CA. Thoracoscopic correction and placement of anterior instrumentation for scoliotic deformity. Case report. Neurosurg Focus 2012; 7:e2. [PMID: 16918210 DOI: 10.3171/foc.1999.7.5.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Correction of rigid scoliotic deformities involving the thoracic spine has required that a thoracotomy be performed to obtain anterior release to mobilize the deformity, as well as placement of corrective spinal instrumentation either via a separate posterior or anterior thoracic approach. To the best of the author's knowledge, this is the first published report of a case in which anterior correction of a deformity was achieved endoscopically. A 27-year-old man presented with a rigid 85 degrees thoracic kyphoscoliotic deformity that had developed over several years. He had previously undergone a C7-T12 laminectomy to decompress the spinal cord from a lipoma. Using thoracoscopic techniques, the author performed an anterior release and interbody fusion. Endoscopically, an anterior screw/rod system applied from T-5 to T-9 corrected the deformity to 55 degrees . There were no surgery-related complications. At follow-up examiniation 1.5 years after surgery, the patient had developed a solid fusion and the correction was maintained at an angle of 58 degrees . It is feasible to use thoracoscopic techniques to perform an anterior release and to apply anterior corrective spinal instrumentation to treat thoracic scoliotic deformities, thereby avoiding the need for an open posterior approach in which instrumentation is placed.
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Affiliation(s)
- C A Dickman
- Division of Neurological Surgery, Barrow Neurological Institute, Phoenix, Arizona
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22
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Eady TN, Khoutorova L, Atkins KD, Bazan NG, Belayev L. Docosahexaenoic acid complexed to human albumin in experimental stroke: neuroprotective efficacy with a wide therapeutic window. EXPERIMENTAL & TRANSLATIONAL STROKE MEDICINE 2012; 4:19. [PMID: 22980673 PMCID: PMC3540001 DOI: 10.1186/2040-7378-4-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 09/06/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Docosahexaenoic acid (DHA) complexed to human serum albumin (Alb) is neuroprotective after experimental stroke. Here we tested using lower concentrations of albumin as part of the complex to achieve neuroprotection. We found that lower Alb concentrations extend the therapeutic window of protection beyond 5 h after stroke onset. METHODS Sprague-Dawley rats were received 2 h middle cerebral artery occlusion (MCAo). The behavior was evaluated on day 1, 2, 3 and 7 after MCAo. In the dose-response study, animals were given either DHA (5mg/kg), Alb (0.63g/kg), DHA-Alb (5mg/kg + 0.32, 0.63 or 1.25 g/kg) or saline, i.v. 3 h after onset of stroke (n=6-8 per group). In the therapeutic window study, DHA-Alb (5mg/kg + 1.25g/kg) was administered i.v. at either 3, 4, 5, 6 or 7 h after onset of stroke (n=7-9 per group). Alb (1.25g/kg) was given at 3 h or 5 h and saline at 3h after onset of reperfusion. Seven days after MCAo, infarct volumes and number of GFAP, ED-1, NeuN, SMI-71 positive cells and vessels were counted. RESULTS Moderate DHA-Alb doses (0.63 and 1.25 g/kg) improved neurological scores compared to albumin-treated rats on days 1, 2, 3 and 7. All DHA-Alb doses (0.32, 0.63 and 1.25 g/kg) markedly reduced cortical (by 65-70%), striatal (by 52-63%) and total infarct volumes (by 60-64%) compared to native Alb group. In the therapeutic window study DHA-Alb led to improved neurological score and significant reductions of infarct volumes (especially in the cortical or penumbral region), even when treatment was initiated as late as 7 hours after onset of MCAo. CONCLUSIONS The DHA-Alb complex affords high-grade neurobehavioral neuroprotection in focal cerebral ischemia, equaling or exceeding that afforded by native Alb or DHA, at considerably moderate doses. It has a broad therapeutic window extending to 7 h after stroke onset. Taken together, these finding support the potential clinical feasibility of administering DHA-Alb therapy to patients with acute ischemic stroke.
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Affiliation(s)
- Tiffany N Eady
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Larissa Khoutorova
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Kristal D Atkins
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Nicolas G Bazan
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
| | - Ludmila Belayev
- Neuroscience Center of Excellence, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
- Department of Neurosurgery, School of Medicine, Louisiana State University Health New Orleans, New Orleans, LA, 70112, USA
- Neuroscience Center of Excellence, Louisiana State University Health Sciences Center, New 2020 Gravier Street, Suite D, Orleans, LA, 70112, USA
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High-Dose Albumin for Neuroprotection in Acute Ischemic Stroke: From Basic Investigations to Multicenter Clinical Trial. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_34] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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25
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Robertson CA, McCabe C, Gallagher L, Lopez-Gonzalez MDR, Holmes WM, Condon B, Muir KW, Santosh C, Macrae IM. Stroke penumbra defined by an MRI-based oxygen challenge technique: 1. Validation using [14C]2-deoxyglucose autoradiography. J Cereb Blood Flow Metab 2011; 31:1778-87. [PMID: 21559032 PMCID: PMC3154682 DOI: 10.1038/jcbfm.2011.66] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Accurate identification of ischemic penumbra will improve stroke patient selection for reperfusion therapies and clinical trials. Current magnetic resonance imaging (MRI) techniques have limitations and lack validation. Oxygen challenge T(2)(*) MRI (T(2)(*) OC) uses oxygen as a biotracer to detect tissue metabolism, with penumbra displaying the greatest T(2)(*) signal change during OC. [(14)C]2-deoxyglucose (2-DG) autoradiography was combined with T(2)(*) OC to determine metabolic status of T(2)(*)-defined penumbra. Permanent middle cerebral artery occlusion was induced in anesthetized male Sprague-Dawley rats (n=6). Ischemic injury and perfusion deficit were determined by diffusion- and perfusion-weighted imaging, respectively. At 147 ± 32 minutes after stroke, T(2)(*) signal change was measured during a 5-minute 100% OC, immediately followed by 125 μCi/kg 2-DG, intravenously. Magnetic resonance images were coregistered with the corresponding autoradiograms. Regions of interest were located within ischemic core, T(2)(*)-defined penumbra, equivalent contralateral structures, and a region of hyperglycolysis. A T(2)(*) signal increase of 9.22% ± 3.9% (mean ± s.d.) was recorded in presumed penumbra, which displayed local cerebral glucose utilization values equivalent to contralateral cortex. T(2)(*) signal change was negligible in ischemic core, 3.2% ± 0.78% in contralateral regions, and 1.41% ± 0.62% in hyperglycolytic tissue, located outside OC-defined penumbra and within the diffusion abnormality. The results support the utility of OC-MRI to detect viable penumbral tissue following stroke.
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Affiliation(s)
- Craig A Robertson
- Glasgow Experimental MRI Centre, Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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Hennings LJ, Flores R, Roberson PK, Brown A, Lowery J, Borrelli M, Culp WC. Persistent penumbra in a rabbit stroke model: incidence and histologic characteristics. Stroke Res Treat 2011; 2011:764830. [PMID: 21776366 PMCID: PMC3138104 DOI: 10.4061/2011/764830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Revised: 04/04/2011] [Accepted: 04/20/2011] [Indexed: 11/20/2022] Open
Abstract
Duration and extent of penumbra determine the window and brain volume in which interventions may save injured tissue after stroke. Understanding the penumbra in animals is necessary in order to design models that translate to effective clinical therapies. New Zealand white rabbits were embolized with aged autologous clot (n = 23) or insoluble microspheres (n = 21). To examine effects of treatment on penumbra, sphere-stroked animals were treated with 3 μm microbubbles plus ultrasound (n = 19). Rabbits were euthanized at 4 or 24 hr. Infarct volume was measured following triphenyltetrazolium chloride (TTC) staining of brain sections. Penumbra was visualized using immunostaining of pimonidazole injected fifteen minutes prior to euthanasia. Potentially reversible penumbra was present in 14.3% stroked rabbits at 4 hours and 15.7% at 24 hours after embolic stroke and represented up to 35% of total lost tissue. Intervention at up to 24 hours may benefit a significant patient population.
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Affiliation(s)
- Leah J Hennings
- Department of Pathology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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27
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Prajapati KD, Sharma SS, Roy N. Current perspectives on potential role of albumin in neuroprotection. Rev Neurosci 2011; 22:355-63. [PMID: 21591907 DOI: 10.1515/rns.2011.028] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Albumin is the most abundant plasma protein synthesised mainly in the liver. It is also a major component of extracellular fluids including cerebrospinal fluid, interstitial fluid and lymph. Albumin has several biochemical properties including regulation of colloid osmotic pressure of plasma, transportation of hormones, fatty acids, drugs and metabolites across plasma, regulation of microvascular permeability, antioxidant activity, anti-thrombotic activity and anti-inflammatory activity. This multifunctional protein has been implicated in many neurological diseases owing to its ability to regulate hemodynamic properties of the brain circulation as well as the direct neuroprotective actions on neuronal and glial cells. In this review, we summarise various neuroprotective actions of the albumin in the brain. In experimental ischemic stroke, exogenous human serum albumin administration has been found to be neuroprotective via reducing brain swelling, prevention of post-ischemic thrombosis, anti-oxidant activity, hemodilution and increasing the perfusion to the ischemic tissue. Also, human serum albumin administration is currently under clinical trials for treatment of cerebral ischemia. In the experimental models of Alzheimer's disease, albumin has been implicated in neuroprotection by inhibiting polymerisation and enhancing the clearance of amyloid β. The direct neuroprotective actions on neuronal and glial cells are mediated via endogenously produced albumin or cellular uptake of blood derived albumin. These neuroprotective effects of albumin are partly attributed to anti-oxidant property and modulation of intracellular signalling of neuronal or glial cells. The recent finding of de novo synthesis of albumin in microglial cells directs us to explore newer roles of this endogenously produced multifunctional protein in normal as well as pathological conditions of the brain.
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Affiliation(s)
- Kanaiyalal D Prajapati
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Sector-67, S.A.S. Nagar, Punjab 160 062, India
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Hattori K, Kajimura M, Hishiki T, Nakanishi T, Kubo A, Nagahata Y, Ohmura M, Yachie-Kinoshita A, Matsuura T, Morikawa T, Nakamura T, Setou M, Suematsu M. Paradoxical ATP elevation in ischemic penumbra revealed by quantitative imaging mass spectrometry. Antioxid Redox Signal 2010; 13:1157-67. [PMID: 20486758 PMCID: PMC2956403 DOI: 10.1089/ars.2010.3290] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Local responses of energy metabolism during brain ischemia are too heterogeneous to decipher redox distribution between anoxic core and adjacent salvageable regions such as penumbra. Imaging mass spectrometry combined by capillary electrophoresis/mass spectrometry providing quantitative metabolomics revealed spatio-temporal changes in adenylates and NADH in a mouse middle-cerebral artery occlusion model. Unlike the core where ATP decreased, the penumbra displayed paradoxical elevation of ATP despite the constrained blood supply. It is noteworthy that the NADH elevation in the ischemic region is clearly demarcated by the ATP-depleting core. Results suggest that metabolism in ischemic penumbra does not respond passively to compromised circulation, but actively compensates energy charges.
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Affiliation(s)
- Katsuji Hattori
- Department of Biochemistry, School of Medicine, Keio University, Shinjuku-ku, Tokyo, Japan
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29
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Hoffman GM, Ghanayem NS. Perioperative neuromonitoring in pediatric cardiac surgery: Techniques and targets. PROGRESS IN PEDIATRIC CARDIOLOGY 2010. [DOI: 10.1016/j.ppedcard.2010.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Modulation of the blood–brain barrier permeability by plasma glycoprotein orosomucoid. Microvasc Res 2010; 80:148-57. [DOI: 10.1016/j.mvr.2010.03.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 03/07/2010] [Accepted: 03/19/2010] [Indexed: 12/11/2022]
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31
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Planas AM. Noninvasive Brain Imaging in Small Animal Stroke Models: MRI and PET. NEUROMETHODS 2010. [DOI: 10.1007/978-1-60761-750-1_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Anderson J, Sandhir R, Hamilton ES, Berman NEJ. Impaired expression of neuroprotective molecules in the HIF-1alpha pathway following traumatic brain injury in aged mice. J Neurotrauma 2009; 26:1557-66. [PMID: 19203226 DOI: 10.1089/neu.2008.0765] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Elderly traumatic brain injury (TBI) patients have higher rates of mortality and worse functional outcome than non-elderly TBI patients. The mechanisms involved in poor outcomes in the elderly are not well understood. Hypoxia-inducible factor-1 alpha (HIF-1alpha) is a basic helix-loop-helix transcription factor that modulates expression of key genes involved in neuroprotection. In this study, we studied the expression of HIF-1alpha and its target survival genes, heme oxygenase-1 (HO-1), vascular endothelial growth factor (VEGF), and erythropoietin (EPO) in the brains of adult versus aged mice following controlled cortical impact (CCI) injury. Adult (5-6 months) and aged (23-24 months) C57Bl/6 mice were injured using a CCI device. At 72 h post-injury, mice were sacrificed and the injured cortex was used for mRNA and protein analysis using real-time reverse transcription--polymerase chain reaction (RT-PCR) and Western blotting protocols. Following injury, HIF-1alpha, HO-1, and VEGF showed upregulation in both the young and aged mice, but in the aged animals the increase in HIF-1alpha and VEGF in response to injury was much lower than in the adult injured animals. EPO was upregulated in the adult injured brain, but not in the aged injured brain. These results support the hypothesis that reduced expression of genes in the HIF-1alpha neuroprotective pathway in aging may contribute to poor prognosis in the elderly following TBI.
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Affiliation(s)
- Joshua Anderson
- Steve Palermo Nerve Regeneration Laboratory, University of Kansas Medical Center, Kansas City, Kansas, USA
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Mitochondria, oxidative metabolism and cell death in stroke. Biochim Biophys Acta Mol Basis Dis 2009; 1802:80-91. [PMID: 19751827 DOI: 10.1016/j.bbadis.2009.09.003] [Citation(s) in RCA: 460] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2009] [Revised: 08/28/2009] [Accepted: 09/08/2009] [Indexed: 11/21/2022]
Abstract
Stroke most commonly results from occlusion of a major artery in the brain and typically leads to the death of all cells within the affected tissue. Mitochondria are centrally involved in the development of this tissue injury due to modifications of their major role in supplying ATP and to changes in their properties that can contribute to the development of apoptotic and necrotic cell death. In animal models of stroke, the limited availability of glucose and oxygen directly impairs oxidative metabolism in severely ischemic regions of the affected tissue and leads to rapid changes in ATP and other energy-related metabolites. In the less-severely ischemic "penumbral" tissue, more moderate alterations develop in these metabolites, associated with near normal glucose use but impaired oxidative metabolism. This tissue remains potentially salvageable for at least the first few hours following stroke onset. Early restoration of blood flow can result in substantial recovery of energy-related metabolites throughout the affected tissue. However, glucose oxidation is markedly decreased due both to lower energy requirements in the post-ischemic tissue and limitations on the mitochondrial oxidation of pyruvate. A secondary deterioration of mitochondrial function subsequently develops that may contribute to progression to cell loss. Mitochondrial release of multiple apoptogenic proteins has been identified in ischemic and post-ischemic brain, mostly in neurons. Pharmacological interventions and genetic modifications in rodent models strongly implicate caspase-dependent and caspase-independent apoptosis and the mitochondrial permeability transition as important contributors to tissue damage, particularly when induced by short periods of temporary focal ischemia.
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Alterations in Membrane Potential in Mitochondria Isolated from Brain Subregions During Focal Cerebral Ischemia and Early Reperfusion: Evaluation Using Flow Cytometry. Neurochem Res 2009; 34:1857-66. [DOI: 10.1007/s11064-009-0001-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Accepted: 05/14/2009] [Indexed: 10/20/2022]
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35
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Diversity of neurodegenerative processes in the model of brain cortex tissue ischemia. Neurochem Int 2009; 54:322-9. [DOI: 10.1016/j.neuint.2008.12.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 12/09/2008] [Accepted: 12/15/2008] [Indexed: 11/21/2022]
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36
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Ischemia independent lesion evolution during focal stroke in rats. Exp Neurol 2009; 218:41-6. [PMID: 19348795 DOI: 10.1016/j.expneurol.2009.03.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2008] [Revised: 02/25/2009] [Accepted: 03/26/2009] [Indexed: 11/20/2022]
Abstract
Lesion evolution during focal cerebral ischemia may depend on flow restrictions or on accumulation of toxic mediators within the infarct and expansion of these factors to the periinfarct region. So far, the precise contribution of flow dependent versus spreading-mediated impairment of viable periinfarct tissue has not been determined. Therefore, we measured lesion expansion, flow restrictions and glutamate distribution on serial brain sections at different time points after experimental focal ischemia. Permanent focal ischemia was induced by occlusion of the right middle cerebral artery in male rats and the flow reduction was subsequently measured at 1, 12 and 24 h using iodo[14C]antipyrine autoradiography. Additionally, the necrotic volume was determined on serial brain sections and the glutamate content was measured in tissue samples from adjacent microdissections. Twelve hours after focal ischemia no noteworthy viable areas with blood flow restrictions of 20-40 ml 100 g(-1) min(-1) existed but at 24 h the necrotic tissue exceeded the hemodynamically compromised region by 40 +/- 21 mm3 (24%). Furthermore, at 12 and 24 h the glutamate content was elevated in areas surrounding the infarct. Relevant flow restrictions are detectable only during early stages of infarct maturation, whereas the propagation of secondary factors may be the predominant mechanism for delayed infarct evolution.
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37
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Anderson J, Sandhir R, Hamilton ES, Berman NE. Impaired Expression of Neuroprotective Molecules in the HIF-1-α Pathway following Traumatic Brain Injury in Aged Mice. J Neurotrauma 2009. [DOI: 10.1089/neu.2008-0765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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38
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Potential use of oxygen as a metabolic biosensor in combination with T2*-weighted MRI to define the ischemic penumbra. J Cereb Blood Flow Metab 2008; 28:1742-53. [PMID: 18545262 PMCID: PMC3119432 DOI: 10.1038/jcbfm.2008.56] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We describe a novel magnetic resonance imaging technique for detecting metabolism indirectly through changes in oxyhemoglobin:deoxyhemoglobin ratios and T2(*) signal change during 'oxygen challenge' (OC, 5 mins 100% O(2)). During OC, T2(*) increase reflects O(2) binding to deoxyhemoglobin, which is formed when metabolizing tissues take up oxygen. Here OC has been applied to identify tissue metabolism within the ischemic brain. Permanent middle cerebral artery occlusion was induced in rats. In series 1 scanning (n=5), diffusion-weighted imaging (DWI) was performed, followed by echo-planar T2(*) acquired during OC and perfusion-weighted imaging (PWI, arterial spin labeling). Oxygen challenge induced a T2(*) signal increase of 1.8%, 3.7%, and 0.24% in the contralateral cortex, ipsilateral cortex within the PWI/DWI mismatch zone, and ischemic core, respectively. T2(*) and apparent diffusion coefficient (ADC) map coregistration revealed that the T2(*) signal increase extended into the ADC lesion (3.4%). In series 2 (n=5), FLASH T2(*) and ADC maps coregistered with histology revealed a T2(*) signal increase of 4.9% in the histologically defined border zone (55% normal neuronal morphology, located within the ADC lesion boundary) compared with a 0.7% increase in the cortical ischemic core (92% neuronal ischemic cell change, core ADC lesion). Oxygen challenge has potential clinical utility and, by distinguishing metabolically active and inactive tissues within hypoperfused regions, could provide a more precise assessment of penumbra.
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Hertz L. Bioenergetics of cerebral ischemia: a cellular perspective. Neuropharmacology 2008; 55:289-309. [PMID: 18639906 DOI: 10.1016/j.neuropharm.2008.05.023] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Revised: 05/14/2008] [Accepted: 05/14/2008] [Indexed: 12/27/2022]
Abstract
In cerebral ischemia survival of neurons, astrocytes, oligodendrocytes and endothelial cells is threatened during energy deprivation and/or following re-supply of oxygen and glucose. After a brief summary of characteristics of different cells types, emphasizing the dependence of all on oxidative metabolism, the bioenergetics of focal and global ischemia is discussed, distinguishing between events during energy deprivation and subsequent recovery attempt after re-circulation. Gray and white matter ischemia are described separately, and distinctions are made between mature and immature brains. Next comes a description of bioenergetics in individual cell types in culture during oxygen/glucose deprivation or exposure to metabolic inhibitors and following re-establishment of normal aerated conditions. Due to their expression of NMDA and non-NMDA receptors neurons and oligodendrocytes are exquisitely sensitive to excitotoxicity by glutamate, which reaches high extracellular concentrations in ischemic brain for several reasons, including failing astrocytic uptake. Excitotoxicity kills brain cells by energetic exhaustion (due to Na(+) extrusion after channel-mediated entry) combined with mitochondrial Ca(2+)-mediated injury and formation of reactive oxygen species. Many (but not all) astrocytes survive energy deprivation for extended periods, but after return to aerated conditions they are vulnerable to mitochondrial damage by cytoplasmic/mitochondrial Ca(2+) overload and to NAD(+) deficiency. Ca(2+) overload is established by reversal of Na(+)/Ca(2+) exchangers following Na(+) accumulation during Na(+)-K(+)-Cl(-) cotransporter stimulation or pH regulation, compensating for excessive acid production. NAD(+) deficiency inhibits glycolysis and eventually oxidative metabolism, secondary to poly(ADP-ribose)polymerase (PARP) activity following DNA damage. Hyperglycemia can be beneficial for neurons but increases astrocytic death due to enhanced acidosis.
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Affiliation(s)
- Leif Hertz
- College of Basic Medical Sciences, China Medical University, Shenyang, PR China.
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40
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Ginsberg MD. Neuroprotection for ischemic stroke: past, present and future. Neuropharmacology 2008; 55:363-89. [PMID: 18308347 DOI: 10.1016/j.neuropharm.2007.12.007] [Citation(s) in RCA: 535] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 12/03/2007] [Accepted: 12/06/2007] [Indexed: 12/30/2022]
Abstract
Neuroprotection for ischemic stroke refers to strategies, applied singly or in combination, that antagonize the injurious biochemical and molecular events that eventuate in irreversible ischemic injury. There has been a recent explosion of interest in this field, with over 1000 experimental papers and over 400 clinical articles appearing within the past 6 years. These studies, in turn, are the outgrowth of three decades of investigative work to define the multiple mechanisms and mediators of ischemic brain injury, which constitute potential targets of neuroprotection. Rigorously conducted experimental studies in animal models of brain ischemia provide incontrovertible proof-of-principle that high-grade protection of the ischemic brain is an achievable goal. Nonetheless, many agents have been brought to clinical trial without a sufficiently compelling evidence-based pre-clinical foundation. At this writing, around 160 clinical trials of neuroprotection for ischemic stroke have been initiated. Of the approximately 120 completed trials, two-thirds were smaller early-phase safety-feasibility studies. The remaining one-third were typically larger (>200 subjects) phase II or III trials, but, disappointingly, only fewer than one-half of these administered neuroprotective therapy within the 4-6h therapeutic window within which efficacious neuroprotection is considered to be achievable. This fact alone helps to account for the abundance of "failed" trials. This review presents a close survey of the most extensively evaluated neuroprotective agents and classes and considers both the strengths and weakness of the pre-clinical evidence as well as the results and shortcomings of the clinical trials themselves. Among the agent-classes considered are calcium channel blockers; glutamate antagonists; GABA agonists; antioxidants/radical scavengers; phospholipid precursor; nitric oxide signal-transduction down-regulator; leukocyte inhibitors; hemodilution; and a miscellany of other agents. Among promising ongoing efforts, therapeutic hypothermia, high-dose human albumin therapy, and hyperacute magnesium therapy are considered in detail. The potential of combination therapies is highlighted. Issues of clinical-trial funding, the need for improved translational strategies and clinical-trial design, and "thinking outside the box" are emphasized.
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Affiliation(s)
- Myron D Ginsberg
- Department of Neurology (D4-5), University of Miami Miller School of Medicine, Miami, FL 33101, USA.
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41
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Amantea D, Corasaniti M, Mercuri N, Bernardi G, Bagetta G. Brain regional and cellular localization of gelatinase activity in rat that have undergone transient middle cerebral artery occlusion. Neuroscience 2008; 152:8-17. [DOI: 10.1016/j.neuroscience.2007.12.030] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 12/13/2007] [Accepted: 12/14/2007] [Indexed: 12/25/2022]
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Guo S, Bragina O, Xu Y, Cao Z, Chen H, Zhou B, Morgan M, Lin Y, Jiang BH, Liu KJ, Shi H. Glucose up-regulates HIF-1 alpha expression in primary cortical neurons in response to hypoxia through maintaining cellular redox status. J Neurochem 2008; 105:1849-60. [PMID: 18266932 DOI: 10.1111/j.1471-4159.2008.05287.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
It has been suggested that hypoxia-inducible factor 1 (HIF-1), a key regulator in cell's adaptation to hypoxia, plays an important role in the fate of neurons during ischemia. However, the mechanism of HIF-1 regulation is still not fully understood in neurons subjected to ischemia. In this study, we demonstrated that glucose up-regulated the expression of HIF-1alpha, the oxygen-dependent subunit of HIF-1, in rat primary cortical neurons exposed to hypoxia. To understand the mechanism of glucose-regulated HIF-1alpha expression, we investigated the relationships between HIF-1alpha expression, reactive oxygen species (ROS), and redox status. Low levels of HIF-1alpha protein expression were observed in the neurons exposed to in vitro ischemic conditions that had high levels of ROS (oxidizing environments), and vice versa. The glutathione (GSH) precursor, N-acetyl cysteine, induced HIF-1alpha protein expression in hypoxic neurons while the GSH synthesis inhibitor, l-buthionine sulfoximine, inhibited the expression. Moreover, (-)-epicatechin gallate, a ROS scavenger, elevated HIF-1alpha expression in the neurons subjected to in vitro ischemia. Furthermore, results from a systemic hypoxia model showed that a reducing environment increased HIF-1alpha expression in rat brains. Taken together, these data presented the first evidence that glucose promoted HIF-1alpha stabilization through regulating redox status in primary neurons exposed to hypoxia. The results imply that hypoxia only may not be sufficient to stabilize HIF-1alpha and that a reducing environment is required to stabilize HIF-1alpha in neurons exposed to hypoxia.
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Affiliation(s)
- Shuhong Guo
- College of Pharmacy, University of New Mexico, Albuquerque, New Mexico 87131, USA
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43
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Parry-Jones AR, Liimatainen T, Kauppinen RA, Gröhn OH, Rothwell NJ. Interleukin-1 exacerbates focal cerebral ischemia and reduces ischemic brain temperature in the rat. Magn Reson Med 2008; 59:1239-49. [DOI: 10.1002/mrm.21531] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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44
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Ennis SR, Keep RF. Effect of sustained-mild and transient-severe hyperglycemia on ischemia-induced blood-brain barrier opening. J Cereb Blood Flow Metab 2007; 27:1573-82. [PMID: 17293843 DOI: 10.1038/sj.jcbfm.9600454] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of this study was to examine what levels of hyperglycemia cause blood-brain barrier (BBB) disruption during permanent and transient middle cerebral artery occlusion in the rat and when the adverse effects of hyperglycemia occur. Cerebrovascular function was assessed by measuring the influx rate constant (K(i)) for (3)H-inulin and by measuring cerebral plasma ((14)C-inulin) and (51)Cr-labeled red blood cell (RBC) volume. Different glucose protocols were used to produce mild sustained hyperglycemia (blood glucose approximately 150 mg/dL) or transient-severe hyperglycemia (with a spike in blood glucose of approximately 400 mg/dL). As expected, transient-severe hyperglycemia at the time of occlusion induced marked BBB disruption in animals undergoing 2 h of ischemia with 2 h of reperfusion (25-fold increase in permeability compared with the contralateral core). However, the mild hyperglycemia model induced similar disruption. Similarly, after permanent occlusion, both hyperglycemia models enhanced disruption and they both produced marked ( approximately 50%) reductions in cerebral plasma volume. Apparent cerebral RBC volume also decreased when measured during the final 5 mins of 2 h of ischemia with transient-severe hyperglycemia. However, there was no decrease if the (51)Cr-labeled RBCs were circulated for the whole 2 h, indicating RBC trapping. The spike in blood glucose in the severe hyperglycemia model was used to examine when hyperglycemia induced BBB disruption. Hyperglycemia shortly after occlusion caused severe disruption. In contrast, hyperglycemia after 90 mins of occlusion caused little disruption. These results suggest that mild hyperglycemia has a profound effect on BBB function and that very early correction of hyperglycemia is necessary to prevent adverse effects.
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Affiliation(s)
- Steven R Ennis
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, Michigan 48109-2200, USA.
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Lou M, Zhang H, Wang J, Wen SQ, Tang ZQ, Chen YZ, Yan WQ, Ding MP. Hyperbaric oxygen treatment attenuated the decrease in regional glucose metabolism of rats subjected to focal cerebral ischemia: A high resolution positron emission tomography study. Neuroscience 2007; 146:555-61. [PMID: 17367940 DOI: 10.1016/j.neuroscience.2007.01.046] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2006] [Revised: 01/19/2007] [Accepted: 01/22/2007] [Indexed: 11/19/2022]
Abstract
Cerebral hypoxia may be the main component of cell damage caused by ischemia. Previous studies demonstrated a neuroprotective effect of early hyperbaric oxygen (HBO) treatment in various animal models of focal cerebral ischemia. Neuropathologic study showed that exposure of HBO may prevent cell death in ischemic cortex. In the present study, we aimed to assess cellular function of ischemic rat brain after HBO treatment by means of a high-resolution positron emission tomography scanner (microPET) used specifically for small animal imaging. The male Sprague-Dawley rats were subjected to permanent middle cerebral artery occlusion (MCAO), with the regional cerebral blood flow monitored in vivo by laser Doppler flowmetry. One hour after ischemia, HBO therapy (3 atm absolute, 1 h) was initiated. Local cerebral glucose utilization in the ischemic area was measured before, 1 h and 3 h after ischemia, with 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG) as a tracer. Neurological deficits and infarct volumes were assessed at 24 h after ischemia. Our study showed that early HBO therapy significantly reduced infarct volume of brain 24 h after ischemia. Moreover, glucose utilization in the ischemic area underwent a severe decrease during 1-3 h after MCAO, while the early HBO treatment significantly attenuated the decrease in cerebral metabolic rate of glucose in the ischemic core of the cortex compared with controls. We report for the first time the application of microPET to quantify the rates of glucose metabolism in the ischemic core of rats exposed to HBO. Our results suggest that the early exposure of HBO can partially reverse the downward trend for glucose utilization in the ischemic core, which might contribute to the reported beneficial effects of early HBO therapy on permanent cerebral ischemia.
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Affiliation(s)
- M Lou
- Department of Neurology, The Second Affiliated Hospital, Zhejiang University, School of Medicine, Hangzhou, 310009, People's Republic of China.
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Temma T, Magata Y, Kuge Y, Shimonaka S, Sano K, Katada Y, Kawashima H, Mukai T, Watabe H, Iida H, Saji H. Estimation of oxygen metabolism in a rat model of permanent ischemia using positron emission tomography with injectable15O-O2. J Cereb Blood Flow Metab 2006; 26:1577-83. [PMID: 16552423 DOI: 10.1038/sj.jcbfm.9600302] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The threshold of cerebral blood flow (CBF) into infarction in rats has been indicated to be similar to that in patients. However, CBF does not reflect metabolic function, and so estimations of oxygen metabolism have been required. Here, we estimated changes in oxygen metabolism after occluding the right middle cerebral artery (MCA) in rats using an injectable (15)O-O(2) we developed. A decrease in CBF (left: 0.67+/-0.22 mL/min/g, right: 0.44+/-0.17 mL/min/g, P<0.05) and compensatory increase in the oxygen extraction fraction (OEF) (left: 0.42+/-0.13, right: 0.50+/-0.19, P<0.05) were observed at 1-h after occlusion. In contrast, a marked decrease in CBF and the cerebral metabolic rate for oxygen and a collapse of the compensatory OEF mechanism were found at 24 h after occlusion. Injectable (15)O-O(2) could be used to reliably estimate oxygen metabolism in an infarction rat model with positron emission tomography.
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Affiliation(s)
- Takashi Temma
- Department of Patho-Functional Bioanalysis, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
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Helps SC, Sims NR. Inhibition of nitric oxide synthase with 7-nitroindazole does not modify early metabolic recovery following focal cerebral ischemia in rats. Neurochem Res 2006; 32:663-70. [PMID: 17024570 DOI: 10.1007/s11064-006-9160-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Accepted: 08/31/2006] [Indexed: 01/15/2023]
Abstract
Nitric oxide has been strongly implicated in the development of tissue infarction in response to focal cerebral ischemia. Nitric oxide and its derivatives can inhibit components of the electron transport chain, providing a likely target for these substances in ischemic and post-ischemic brain. Lactate content is increased during post-ischemic reperfusion in tissue destined to become infarcted, consistent with impairment of mitochondrial respiration. To investigate the possible involvement of nitric oxide in generating these changes, we have tested the effect of 7-nitroindazole, a nitric oxide synthase (NOS) inhibitor, on the content of lactate and other metabolites during early reperfusion following temporary focal ischemia. This treatment inhibited total NOS by approximately 50%. However, the treatment did not significantly affect the marked increases in lactate in post-ischemic brain nor did it alter the recovery of other energy-related metabolites. These findings indicate that inhibition of oxidative metabolism is probably not the primary site of the deleterious effects of nitric oxide and derivatives during early post-ischemic reperfusion.
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Affiliation(s)
- Stephen C Helps
- Department of Medical Biochemistry, Centre for Neuroscience, School of Medicine, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
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Thoren AE, Helps SC, Nilsson M, Sims NR. The metabolism of C-glucose by neurons and astrocytes in brain subregions following focal cerebral ischemia in rats. J Neurochem 2006; 97:968-78. [PMID: 16606370 DOI: 10.1111/j.1471-4159.2006.03778.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To provide insights into the effects of temporary focal ischemia on the function of neurons and astrocytes in vivo, we measured the incorporation of radiolabel from [U-14C]glucose into both glutamate and glutamine in brain subregions at 1 h of reperfusion following occlusion of the middle cerebral artery for 2 or 3 h. Under the experimental conditions used, 14C-glutamate is mainly produced in neurons whereas 14C-glutamine is generated in astrocytes from 14C-glutamate of both neuronal and astrocytic origin. Radiolabel incorporation into both amino acids was greatly decreased. The change in 14C-glutamate accumulation provides strong evidence for substantial reductions in neuronal glucose metabolism. The resulting decrease in delivery of 14C-glutamate from the neurons to astrocytes was probably also the major contributor to the change in 14C-glutamine content. These alterations probably result in part from a marked depression of glycolytic activity in the neurons, as suggested by previous studies assessing deoxyglucose utilization. Alterations in 14C-glucose metabolism were not restricted to tissue that would subsequently become infarcted. Thus, these changes did not inevitably lead to death of the affected cells. The ATP : ADP ratio and phosphocreatine content were essentially preserved during recirculation following 2 h of ischemia and showed at most only moderate losses in some subregions following 3 h of ischemia. This retention of energy reserves despite the decreases in 14C-glucose metabolism in neurons suggests that energy needs were substantially reduced in the post-ischemic brain. Marked increases in tissue lactate accumulation during recirculation, particularly following 3 h of ischemia, provided evidence that impaired pyruvate oxidation probably also contributed to the altered 14C-glucose metabolism. These findings indicate the presence of complex changes in energy metabolism that are likely to greatly influence the responses of neurons and astrocytes to temporary focal ischemia.
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Affiliation(s)
- Anna E Thoren
- Centre for Neuroscience and Department of Medical Biochemistry, School of Medicine, Flinders University, Adelaide, Australia
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Abstract
The extent to which a substance in the circulation gains access to the CNS needs to be determined for potential neuropharmaceuticals as well as for drug candidates with primary targets in the periphery. Characteristics of the in vivo methods, ranging from classical pharmacokinetic techniques (intravenous administration and tissue sampling) over brain perfusions to microdialysis and imaging techniques, are highlighted. In vivo measurements remain unmatched with respect to sensitivity and for the characterization of carrier-mediated uptake, receptor-mediated transport, and active efflux. Isolated microvessels are valuable tools for molecular characterization of transporters. Endothelial cell culture models of the blood-brain barrier (BBB) are pursued as in vitro systems suitable for screening procedures. Recent applications of conditionally immortalized cell lines indicate that a particular weakness of culture models because of downregulation of BBB-specific transporter systems can be overcome. In silico approaches are being developed with the goal of predicting brain uptake from molecular structure at early stages of drug development. Currently, the predictive capability is limited to passive, diffusional uptake and predominantly relies on few molecular descriptors related to lipophilicity, hydrogen bonding capacity, charge, and molecular weight. A caveat with most present strategies is their reliance on surrogates of BBB transport, like CNS activity/inactivity or brain-to-blood partitioning rather than actual BBB permeability data.
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Affiliation(s)
- Ulrich Bickel
- Department of Pharmaceutical Sciences, Texas Tech University Health Sciences Center, Amarillo, Texas 79106, USA.
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Bardutzky J, Meng X, Bouley J, Duong TQ, Ratan R, Fisher M. Effects of intravenous dimethyl sulfoxide on ischemia evolution in a rat permanent occlusion model. J Cereb Blood Flow Metab 2005; 25:968-77. [PMID: 15744247 PMCID: PMC2949963 DOI: 10.1038/sj.jcbfm.9600095] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Dimethyl sulfoxide (DMSO) has a variety of biological actions that suggest efficacy as a neuroprotectant. We (1) tested the neuroprotective potential of DMSO at different time windows on infarct size using 2,3,5-triphenyltetrazolium staining and (2) investigated the effects of DMSO on ischemia evolution using quantitative diffusion and perfusion imaging in a permanent middle cerebral artery occlusion (MCAO) model in rats. In experiment 1, DMSO treatment (1.5 g/kg intravenously over 3 h) reduced infarct volume 24 h after MCAO by 65% (P<0.00001) when initiated 20 h before MCAO, by 44% (P=0.0006) when initiated 1 h after MCAO, and by 17% (P=0.11) when started 2 h after MCAO. Significant infarct reduction was also observed after a 3-day survival in animals treated 1 h after MCAO (P=0.005). In experiment 2, treatment was initiated 1 h after MCAO and maps for cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) were acquired before treatment and then every 30 mins up to 4 h. Cerebral blood flow characteristics and CBF-derived lesion volumes did not differ between treated and untreated animals, whereas the ADC-derived lesion volume essentially stopped progressing during DMSO treatment, resulting in a persistent diffusion/perfusion mismatch. This effect was mainly observed in the cortex. Our data suggest that DMSO represents an interesting candidate for acute stroke treatment.
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Affiliation(s)
- Juergen Bardutzky
- Department of Neurology, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
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