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Amaro S, Llull L, Renú A, Laredo C, Perez B, Vila E, Torres F, Planas AM, Chamorro Á. Uric acid improves glucose-driven oxidative stress in human ischemic stroke. Ann Neurol 2015; 77:775-83. [PMID: 25627874 DOI: 10.1002/ana.24378] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Revised: 01/24/2015] [Accepted: 01/25/2015] [Indexed: 01/04/2023]
Abstract
OBJECTIVE A study was undertaken to test in a subgroup reanalysis of the URICO-ICTUS trial whether uric acid is superior to placebo in improving the functional outcome in patients with acute stroke and hyperglycemia. METHODS Patients were part of the URICO-ICTUS trial, a double-blind study that compared the administration of uric acid versus placebo in stroke patients treated with alteplase within 4.5 hours of onset. The effect of therapy on the rate of excellent outcome at 90 days (modified Rankin Scale ≤ 2) in each tertile of admission glucose was assessed with multivariate adjusted models in 409 of the 421 randomized patients who had available pretreatment glucose levels. The effect of therapy on infarct growth was assessed in 72 patients who had longitudinal multimodal brain imaging. RESULTS Uric acid was associated with an increased rate of excellent outcome in patients with glucose levels in the upper tertile range (odds ratio [OR] = 2.9, 95% confidence interval [CI] = 1.0-8.3). However, the effect was not apparent for patients in the middle tertile (OR = 1.6, 95% CI = 0.8-3.6) or lower tertile of glucose (OR = 1.1, 95% CI = 0.5-2.6). Uric acid therapy was more effective than placebo in limiting infarct growth in the upper tertile range (Mann-Whitney U test, p = 0.04) but not in the middle tertile (p = 0.95) or lower tertile of glucose (p = 0.30). Uric acid also proved superior to placebo in reducing infarct growth in patients with early recanalization. INTERPRETATION Uric acid therapy was associated with reduced infarct growth and improved outcome in patients with hyperglycemia during acute stroke.
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Affiliation(s)
- Sergio Amaro
- Comprehensive Stroke Center, Department of Neuroscience, Hospital Clinic, University of Barcelona and August Pi i Sunyer Biomedical Research Institute, Barcelona
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Sun L, Wolferts G, Veltkamp R. Oxygen therapy does not increase production and damage induced by reactive oxygen species in focal cerebral ischemia. Neurosci Lett 2014; 577:1-5. [PMID: 24909618 DOI: 10.1016/j.neulet.2014.05.060] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/16/2014] [Accepted: 05/30/2014] [Indexed: 11/26/2022]
Abstract
Oxygen therapy with hyperbaric oxygen (HBO) or normobaric hyperoxia (NBO) improves outcome in experimental cerebral ischemia. However, an increased formation of reactive oxygen species (ROS) may be an undesirable side effect of oxygen therapy. We investigated the effect of both oxygen therapies on ROS production and adverse effects in murine focal ischemia. 25 min after 90 min filament-induced middle cerebral artery occlusion (MCAO), mice breathed either air, 100% O2 (NBO), or 100% O2 at 3 ata (HBO) for 60 min. ROS were depicted on tissue sections after preischemic injection of hydroethidine, a marker of in vivo superoxide production. Moreover, infarct sizes were quantified in experiments using peroxybutinitrite (PBN) in mice treated with HBO. Effects of oxygen therapy were also tested in superoxide 2 knock-out mice. Both NBO and HBO significantly reduced superoxide radicals compared to air. Application of PBN had no additional protective effect when combined with HBO. Infarct volumes did not differ among SOD2 knock-out mice receiving air (34.0 ± 19.6mm(3)), NBO (35.4 ± 14.3mm(3)) or HBO (33.4 ± 12.2mm(3)). In conclusion, brief episodes of oxygen therapy do not appear to promote damage inflicted by ROS in experimental stroke.
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Affiliation(s)
- Li Sun
- Department of Neurology, Ruprecht-Karls-University Heidelberg, Germany.
| | | | - Roland Veltkamp
- Department of Neurology, Ruprecht-Karls-University Heidelberg, Germany.
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Ju C, Hwang S, Cho GS, Kondaji G, Song S, Prather PL, Choi Y, Kim WK. Differential anti-ischemic efficacy and therapeutic time window of trans- and cis-hinokiresinols: stereo-specific antioxidant and anti-inflammatory activities. Neuropharmacology 2013; 67:465-75. [PMID: 23287539 DOI: 10.1016/j.neuropharm.2012.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 12/16/2012] [Accepted: 12/17/2012] [Indexed: 11/30/2022]
Abstract
During cerebral ischemia, neurons are injured by various mechanisms including excitotoxicity, oxidative stress, and inflammatory responses. Thus, pharmacological manipulation of multiple cytotoxic pathways has been pursued for the treatment of ischemic injury. Cis-hinokiresinol, a naturally occurring phenylpropanoid, was previously reported to possess anti-oxidant, anti-inflammatory and estrogen-like activities. In the present study, we investigated anti-ischemic effects of trans- and cis-hinokiresinols using in vitro as well as in vivo experimental models. The ORAC and DPPH assays showed that two isomers had similar free radical scavenging activities. However, only trans-hinokiresinol significantly decreased neuronal injury in cultured cortical neurons exposed to oxygen-glucose deprivation (75 min) followed by re-oxygenation (9 h). The differential neuroprotective effect could be due to the stereo-specific augmentation of Cu/Zn-SOD activity by trans-hinokiresinol, when compared with cis-hinokiresinol. Similarly, in rats subjected to transient middle cerebral artery occlusion (1.5 h) followed by 24-h reperfusion, pre-ischemic treatment with trans-hinokiresinol, but not with cis-isomer, reduced cerebral infarct volume. Interestingly, however, post-ischemic treatment with both hinokiresinols (2 and 7 h after onset of ischemia) significantly reduced cerebral infarct. When administered after onset of ischemia, trans-hinokiresinol, but not its cis-isomer reduced nitrotyrosine immunoreactivity in ischemic regions. In contrast, both hinokiresinols suppressed neutrophil infiltration and IL-1β release to a similar extent. The observed differential anti-oxidant, but comparable anti-inflammatory, activities may explain the stereo-specific anti-ischemic activities and different therapeutic time windows of the hinokiresinols examined. More detailed delineation of the anti-ischemic mechanism(s) of hinokiresinols may provide a better strategy for development of efficacious regimens for cerebral ischemic stroke.
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Affiliation(s)
- Chung Ju
- Department of Neuroscience, College of Medicine, Korea University, Anamdong-5-ga, Seongbuk-gu, Seoul 136-705, Republic of Korea
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Li J, Ma X, Yu W, Lou Z, Mu D, Wang Y, Shen B, Qi S. Reperfusion promotes mitochondrial dysfunction following focal cerebral ischemia in rats. PLoS One 2012; 7:e46498. [PMID: 23029539 PMCID: PMC3460895 DOI: 10.1371/journal.pone.0046498] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Accepted: 08/14/2012] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND AND PURPOSE Mitochondrial dysfunction has been implicated in the cell death observed after cerebral ischemia, and several mechanisms for this dysfunction have been proposed. Reperfusion after transient cerebral ischemia may cause continued and even more severe damage to the brain. Many lines of evidence have shown that mitochondria suffer severe damage in response to ischemic injury. The purpose of this study was to observe the features of mitochondrial dysfunction in isolated mitochondria during the reperfusion period following focal cerebral ischemia. METHODS Male Wistar rats were subjected to focal cerebral ischemia. Mitochondria were isolated using Percoll density gradient centrifugation. The isolated mitochondria were fixed for electron microscopic examination; calcium-induced mitochondrial swelling was quantified using spectrophotometry. Cyclophilin D was detected by Western blotting. Fluorescent probes were used to selectively stain mitochondria to measure their membrane potential and to measure reactive oxidative species production using flow cytometric analysis. RESULTS Signs of damage were observed in the mitochondrial morphology after exposure to reperfusion. The mitochondrial swelling induced by Ca(2+) increased gradually with the increasing calcium concentration, and this tendency was exacerbated as the reperfusion time was extended. Cyclophilin D protein expression peaked after 24 hours of reperfusion. The mitochondrial membrane potential was decreased significantly during the reperfusion period, with the greatest decrease observed after 24 hours of reperfusion. The surge in mitochondrial reactive oxidative species occurred after 2 hours of reperfusion and was maintained at a high level during the reperfusion period. CONCLUSIONS Reperfusion following focal cerebral ischemia induced significant mitochondrial morphological damage and Ca(2+)-induced mitochondrial swelling. The mechanism of this swelling may be mediated by the upregulation of the Cyclophilin D protein, the destruction of the mitochondrial membrane potential and the generation of excessive reactive oxidative species.
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Affiliation(s)
- Jun Li
- Department of Anesthesiology, the Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Xuesong Ma
- Department of Anesthesiology, the Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Wei Yu
- Department of Anesthesiology, the Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Zhangqun Lou
- Department of Anesthesiology, the Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Dunlan Mu
- Department of Anesthesiology, the Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Ying Wang
- Department of Anesthesiology, the Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Baozhong Shen
- Molecular Imaging Key Laboratory of General Universities and Colleges of Heilongjiang Province, Harbin, China
| | - Sihua Qi
- Department of Anesthesiology, the Fourth Affiliated Hospital, Harbin Medical University, Harbin, China
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Im DS, Jeon JW, Lee JS, Won SJ, Cho SI, Lee YB, Gwag BJ. Role of the NMDA receptor and iron on free radical production and brain damage following transient middle cerebral artery occlusion. Brain Res 2012; 1455:114-23. [PMID: 22483792 DOI: 10.1016/j.brainres.2012.03.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Revised: 03/08/2012] [Accepted: 03/09/2012] [Indexed: 11/28/2022]
Abstract
Excess activation of ionotropic glutamate receptors and iron is believed to contribute to free radical production and neuronal death following hypoxic ischemia. We examined the possibility that both NMDA receptor activation and iron overload determine spatial and temporal patterns of free radical production after transient middle cerebral artery occlusion (tMCAO) in male Sprague-Dawley rats. Mitochondrial free radical (MFR) levels were maximally increased in neurons in the core at 1 h and 24 h after tMCAO. Early MFR production was blocked by administration of MK-801, an NMDA receptor antagonist, but not deferoxamine, an iron chelator. Neither MK-801 nor deferoxamine attenuated late MFR production in the core. Increased MFRs were observed in penumbral neurons within 6 h and gradually increased over 24 h after tMCAO. Slowly-evolving MFRs in the core and penumbra were accompanied by iron overload. Deferoxamine blocked iron overload but reduced MFR production only in the penumbra. Combined MK-801/deferoxamine reduced late MFR production in both core and penumbra in an additive manner. Combination therapy significantly ameliorated infarction compared with monotherapy. These findings suggest that the NMDA receptor activation and iron overload mediate late MFR production and infarction after tMCAO.
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Affiliation(s)
- Doo Soon Im
- GNT Pharma Research Institute, Gomae-Dong 381-1, Giheung-Gu, Yongin-Si, 446-901, South Korea
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Leger PL, De Paulis D, Branco S, Bonnin P, Couture-Lepetit E, Baud O, Renolleau S, Ovize M, Gharib A, Charriaut-Marlangue C. Evaluation of cyclosporine A in a stroke model in the immature rat brain. Exp Neurol 2011; 230:58-66. [DOI: 10.1016/j.expneurol.2010.06.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 05/27/2010] [Accepted: 06/08/2010] [Indexed: 11/30/2022]
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Kunimatsu T, Kobayashi K, Yamashita A, Yamamoto T, Lee MCI. Cerebral reactive oxygen species assessed by electron spin resonance spectroscopy in the initial stage of ischemia-reperfusion are not associated with hypothermic neuroprotection. J Clin Neurosci 2011; 18:545-8. [PMID: 21315602 DOI: 10.1016/j.jocn.2010.07.140] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 07/27/2010] [Accepted: 07/27/2010] [Indexed: 11/19/2022]
Abstract
Using an in vivo L-band electron spin resonance (ESR) system, we determined changes in reactive oxygen species (ROS) levels during the early stage (within 60 minutes) of global cerebral ischemia-reperfusion (IR) under normothermic and hypothermic conditions in rats. To confirm the neuroprotective role of hypothermia in this IR model, we immunohistochemically evaluated the levels of active caspase-3 in the hippocampal CA1 sector. ROS levels increased within the first 15 minutes following IR under both normothermic and hypothermic conditions; however, the ROS levels did not differ significantly between normothermic and hypothermic conditions. In the later periods of IR, there were no significant changes in ROS levels for either normothermic or hypothermic conditions relative to the control. As expected, normothermia increased the number of active caspase-3 immunoreactive nuclei in the IR model. However, this induction was prevented by hypothermia. These results suggest that the neuroprotective role of hypothermia does not correlate with the early ROS-induced oxidative stress following IR as measured by ESR.
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Affiliation(s)
- Teruhito Kunimatsu
- Division of Dental Anesthesiology, Department of Dentistry for Special Patients, Kanagawa Dental College, Yokohama Dental and Medical Clinic and Clinical Training Center, Yokohama, Kanagawa 221-0835, Japan.
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Manabe H, Okonkwo DO, Gainer JL, Clarke RH, Lee KS. Protection against focal ischemic injury to the brain by trans-sodium crocetinate. Laboratory investigation. J Neurosurg 2010; 113:802-9. [PMID: 19961314 DOI: 10.3171/2009.10.jns09562] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECT Ischemic injury is a potential complication in a variety of surgical procedures and is a particular impediment to the success of surgeries involving highly vulnerable neural tissue. One approach to limiting this form of injury is to enhance metabolic supply to the affected tissue. Trans-sodium crocetinate (TSC) is a carotenoid compound that has been shown to increase tissue oxygenation by facilitating the diffusivity of small molecules, such as oxygen and glucose. The present study examined the ability of TSC to modify oxygenation in ischemic neural tissue and tested the potential neuroprotective effects of TSC in permanent and temporary models of focal cerebral ischemia. METHODS Adult male rats (330–370 g) were subjected to either permanent or temporary focal ischemia by simultaneous occlusion of both common carotid arteries and the left middle cerebral artery (3-vessel occlusion [3-VO]). Using the permanent ischemia paradigm, TSC was administered intravenously beginning 10 minutes after the onset of ischemia at 1 of 8 dosages, ranging from 0.023 to 4.580 mg/kg. Cerebral infarct volume was measured 24 hours after the onset of ischemia. The effect of TSC on infarct volume was also tested after temporary (2-hour) ischemia using a dosage of 0.092 mg/kg. In other animals undergoing temporary ischemia, tissue oxygenation was monitored in the ischemic penumbra using a Licox probe. RESULTS Administration of TSC reduced infarct volume in a dose-dependent manner in the permanent ischemia model, achieving statistical significance at dosages ranging from 0.046 to 0.229 mg/kg. The most effective dosage of TSC in the permanent ischemia experiment (0.092 mg/kg) was further tested using a temporary (2-hour) ischemia paradigm. Infarct volume was reduced significantly by TSC in this ischemia-reperfusion model as well. Recordings of oxygen levels in the ischemic penumbra of the temporary ischemia model showed that TSC increased tissue oxygenation during vascular occlusion, but reduced the oxygen overshoot (hyperoxygenation) that occurs upon reperfusion. CONCLUSIONS The novel carotenoid compound TSC exerts a neuroprotective influence against permanent and temporary ischemic injury when administered soon after the onset of ischemia. The protective mechanism of TSC remains to be confirmed; however, the permissive effect of TSC on the diffusivity of small molecules is a plausible mechanism based on the observed increase in tissue oxygenation in the ischemic penumbra. This represents a form of protection based on “metabolic reflow” that can occur under conditions of partial vascular perfusion. It is particularly noteworthy that TSC could conceivably limit the progression of a wide variety of cellular injury mechanisms by blunting the ischemic challenge to the brain.
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Affiliation(s)
- Hiroaki Manabe
- Department of Neuroscience, University of Virginia, Charlottesville, Virginia 22908, USA.
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Yamashima T, Oikawa S. The role of lysosomal rupture in neuronal death. Prog Neurobiol 2009; 89:343-58. [PMID: 19772886 DOI: 10.1016/j.pneurobio.2009.09.003] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 09/11/2009] [Accepted: 09/15/2009] [Indexed: 12/19/2022]
Abstract
Apoptosis research in the past two decades has provided an enormous insight into its role in regulating cell death. However, apoptosis is only part of the story, and inhibition of neuronal necrosis may have greater impact than apoptosis, on the treatment of stroke, traumatic brain injury, and neurodegenerative diseases. Since the "calpain-cathepsin hypothesis" was first formulated, the calpain- and cathepsin-mediated regulation of necrotic cascades observed in monkeys, has been demonstrated to be a common neuronal death mechanism occurring from simpler organisms to humans. However, the detailed mechanism inducing lysosomal destabilization still remains poorly understood. Heat-shock protein-70 (Hsp70) is known to stabilize lysosomal membrane and protect cells from oxidative stress and apoptotic stimuli in many cell death pathways. Recent proteomics approach comparing pre- and post-ischemic hippocampal CA1 neurons as well as normal and glaucoma-suffered retina of primates, suggested that the substrate protein upon which activated calpain acts at the lysosomal membrane of neurons might be Hsp70. Understanding the interaction between activated calpains and Hsp70 will help to unravel the mechanism that destabilizes the lysosomal membrane, and will provide new insights into clarifying the whole cascade of neuronal necrosis. Although available evidence is circumferential, it is hypothesized that activated calpain cleaves oxidative stress-induced carbonylated Hsp70.1 (a major human Hsp70) at the lysosomal membrane, which result in lysosomal rupture/permeabilization. This review aims at highlighting the possible mechanism of lysosomal rupture in neuronal death by a modified "calpain-cathepsin hypothesis". As the autophagy-lysosomal degradation pathway is a target of oxidative stress, the implication of autophagy is also discussed.
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Affiliation(s)
- Tetsumori Yamashima
- Department of Restorative Neurosurgery, Kanazawa University Graduate School of Medical Science, Kanazawa 920-8641, Japan.
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Windelborn JA, Lipton P. Lysosomal release of cathepsins causes ischemic damage in the rat hippocampal slice and depends on NMDA-mediated calcium influx, arachidonic acid metabolism, and free radical production. J Neurochem 2008; 106:56-69. [PMID: 18363826 DOI: 10.1111/j.1471-4159.2008.05349.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
NMDA-mediated calcium entry and reactive oxygen species (ROS) production are well-recognized perpetrators of ischemic neuronal damage. The current studies show that these events lead to the release of the protein hydrolase, cathepsin B, from lysosomes 2 h following 5-min oxygen-glucose deprivation in the rat hippocampal slice. This release reflects a lysosomal membrane permeabilization (LMP) and was measured as the appearance of diffuse immunolabeled cathepsin B in the cytosol of CA1 pyramidal neurons. Necrotic neuronal damage begins after the release of cathepsins and is prevented by inhibitors of either cathepsin B or D indicating that the release of cathepsins is an important mediator of severe damage. There was an increase in superoxide levels, measured by dihydroethidium fluorescence, at the same time as LMP and reducing ROS levels with antioxidants, Trolox or N-tert-butyl-alpha-phenyl nitrone, blocked LMP. Both LMP and ROS production were blocked by an NMDA channel blocker (MK-801) and by inhibitors of mitogen-activated protein kinase kinase (U0126), calcium-dependent/independent phospholipases A2 (methyl arachidonyl fluorophosphonate) but not calcium-independent phospholipases A2 (bromoenol lactone) and cyclooxygenase-2 (NS398). A cell-permeant specific inhibitor of calpain (PD150606) prevented LMP, but not ROS production. It is concluded that LMP results in part from calcium-initiated and extracellular signal-regulated kinase-initiated arachidonic acid metabolism, which produces free radicals; it also requires the action of calpain.
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Affiliation(s)
- James A Windelborn
- Neuroscience Training Program, University of Wisconsin, Madison, Wisconsin 53706, USA
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Edaravone neuroprotection effected by suppressing the gene expression of the Fas signal pathway following transient focal ischemia in rats. Neurotox Res 2007; 12:155-62. [DOI: 10.1007/bf03033912] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Uríková A, Babusíková E, Dobrota D, Drgová A, Kaplán P, Tatarková Z, Lehotský J. Impact of Ginkgo Biloba Extract EGb 761 on ischemia/reperfusion - induced oxidative stress products formation in rat forebrain. Cell Mol Neurobiol 2006; 26:1343-53. [PMID: 16614948 DOI: 10.1007/s10571-006-9030-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Accepted: 11/22/2005] [Indexed: 11/25/2022]
Abstract
Dysbalance in reactive oxygen/nitrogen species is involved in the pathogenesis of cerebral ischemia/reperfusion injury (IRI). Ginkgo biloba extract (Egb 761) pre-treatment was used to observe potential antioxidant/neuroprotective effect after global ischemia/reperfusion. Egb 761 significantly decreased the level of lipoperoxidation (LPO) in rat forebrain total membrane fraction (homogenate) induced by in vitro oxidative stress (Fe(2+)+H(2)O(2)). In animals subjected to four-vessel global ischemia for 15 min and 2-24 h reperfusion the EGb pretreatment slightly decreased LPO in forebrain homogenate. However, as detected in EGb treated group, the LPO-induced lysine conjugates are attenuated in comparison to non-treated IRI animals. EGb significantly improved parameters which indicate forebrain protein oxidative damage after IRI. The intensity of tryptophane fluorescence was increased by the 18.2% comparing to non-treated IRI group and bityrosine fluorescence was significantly decreased in ischemic (21%) and 24 h reperfused (15.9%) group in comparison non-treated IRI group. In addition, the level of total free SH- groups in pre-treated animals was significantly higher comparing to non-treated animals. Our results indicate that extract of EGb 761 has potent antioxidant activity and could play a role to attenuate the IRI-induced oxidative protein modification and lipoperoxidation in the neuroprotective process.
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Affiliation(s)
- A Uríková
- Department of Medical Biochemistry, Jessenius Faculty of Medicine, Comenius University, MalaHora 4, SK-03601, Martin, Slovakia
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Schulz R, Heusch G. Angiotensin II type 1 receptors in cerebral ischaemia-reperfusion: initiation of inflammation. J Hypertens 2006; 24:S123-9. [PMID: 16601565 DOI: 10.1097/01.hjh.0000220417.01397.6a] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cerebral ischaemia-reperfusion injury is associated with an inflammatory response, with contributions from leucocytes and microglia. Formation of free radicals and nitric oxide contributes to the development of cerebral infarction and of the neurological deficit that follows transient focal ischaemia. The circulating and cerebral renin-angiotensin systems contribute, via stimulation of the angiotensin II (Ang II) types 1 (AT1) and 2 receptors, to the initiation or progression of inflammatory processes, and blockade of AT1-receptors prevents irreversible tissue injury and improves outcome from stroke in animal experiments. Such cerebral protection can be achieved even when treatment is initiated hours after established reperfusion. Blockade of AT1-receptors also reduces the incidence of stroke and cardiovascular mortality associated with stroke in patients; however, the mechanisms underlying the prevention of stroke by AT1-receptor blockade in patients remain to be elucidated. In this review we summarize the existing experimental and clinical data demonstrating that the renin-angiotensin system contributes to the inflammation and subsequent irreversible injury after cerebral ischaemia-reperfusion. We conclude that AT1-receptor blockade reduces cerebral ischaemia-reperfusion injury in part by attenuating inflammatory processes.
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Affiliation(s)
- Rainer Schulz
- Institute for Pathophysiology, University of Duisburg-Essen, Essen, Germany.
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Van Hemelrijck A, Hachimi-Idrissi S, Sarre S, Ebinger G, Michotte Y. Post-ischaemic mild hypothermia inhibits apoptosis in the penumbral region by reducing neuronal nitric oxide synthase activity and thereby preventing endothelin-1-induced hydroxyl radical formation. Eur J Neurosci 2006; 22:1327-37. [PMID: 16190888 DOI: 10.1111/j.1460-9568.2005.04331.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Previously, we showed that treatment with resuscitative, post-ischaemic mild hypothermia (34 degrees C for 2 h) reduced apoptosis in the penumbra (cortex), but not in the core (striatum) of an endothelin-1 (Et-1)-induced focal cerebral infarct in the anaesthetized rat. Therefore, the purpose of this study was to investigate by which pathways resuscitative mild hypothermia exerts its neuroprotective effect in this model. The amino acids glutamate, serine, glutamine, alanine, taurine, arginine and the NO-related compound citrulline were sampled from the striatum and cortex of the ischaemic hemisphere using in vivo microdialysis. The in vivo salicylate trapping method was applied for monitoring hydroxyl radical formation via 2,3 dihydroxybenzoic acid (2,3 DHBA) detection. Caspase-3, neuronal nitric oxide synthase (nNOS) immunoreactivity and the volume of ischaemic damage were determined 24 h after the insult. In both the striatum and the cortex, Et-1-induced increases in glutamate, taurine and alanine were refractory to mild hypothermia. However, mild hypothermia significantly attenuated the ischaemia-induced 2,3 DHBA levels and the nNOS immunoreactivity in the cortex, but not in the striatum. These observations were associated with a decreased caspase-3 immunoreactivity. These results suggest that mild hypothermia exerts its neuroprotective effect in the penumbra partially by reducing nNOS activity and thereby preventing oxidative stress. Furthermore, we confirm our previous findings that the neuroprotective effect of resuscitative hypothermia is not mediated by changes in ischaemia-induced amino acid release as they could not be associated with the ischaemia-induced damage in the Et-1 rat model.
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Affiliation(s)
- An Van Hemelrijck
- Department of Pharmaceutical Chemistry and Drug Analysis, Research Group Experimental Pharmacology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium
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Cronberg T, Rytter A, Wieloch T. Chelation of intracellular calcium reduces cell death after hyperglycemic in vitro ischemia in murine hippocampal slice cultures. Brain Res 2005; 1049:120-7. [PMID: 15935997 DOI: 10.1016/j.brainres.2005.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Revised: 04/29/2005] [Accepted: 05/03/2005] [Indexed: 11/26/2022]
Abstract
The aggravating effect of high glucose levels during cerebral ischemia has been extensively documented in clinical studies and in vivo models of global and focal ischemia. Detailed mechanistic studies of hyperglycemic ischemia have so far been hampered by the lack of in vitro models since glucose during anoxia in vitro is highly protective. We have previously reported glucose toxicity in murine hippocampal organotypic slice cultures exposed to anoxia in an acidotic medium containing high potassium and low calcium. In the present study, we compared the importance of calcium, nitric oxide and free radicals during in vitro ischemia (IVI) and hyperglycemic (40 mM) IVI. Extracellular calcium was a ubiquitous factor for cell death after IVI, but its removal from the medium had no effect on cell death after hyperglycemic IVI. When intracellular calcium was chelated by the 1,2-Bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis(acetoxymethyl) ester (BAPTA-AM) cell death appeared earlier but was mitigated in hyperglycemic IVI, while it was increased in glucose-free IVI. Addition of the nitric oxide synthase (NOS) inhibitor N(omega)-Nitro-L-arginine methyl ester hydrochloride (L-NAME) or the free radical scavengers N-tert-butyl-alpha-phenylnitrone (PBN), deferoxamine and N-acetyl-L-cysteine (NAC) did not affect cell damage in either paradigm. We conclude that the aggravating effect of hyperglycemia during in vitro ischemia is partially mediated by calcium ions released from intracellular stores.
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Affiliation(s)
- Tobias Cronberg
- Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, Lund University, BMC A13, S-221 84 Lund, Sweden.
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Perez-Pinzon MA, Dave KR, Raval AP. Role of reactive oxygen species and protein kinase C in ischemic tolerance in the brain. Antioxid Redox Signal 2005; 7:1150-7. [PMID: 16115018 DOI: 10.1089/ars.2005.7.1150] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
It is now understood that the mechanisms leading to neuronal cell death after cerebral ischemia are highly complex. A well established fact in this field is that neurons continue to die over days and months after ischemia, and that reperfusion following cerebral ischemia contributes substantially to ischemic injury. It is now well accepted that central to ischemic/reperfusion-induced injury is what occurs to mitochondria hours to days following the ischemic insult. For many years, it has been established that reactive oxygen species (ROS) and reactive nitrogen species (RNS) promote lipid, protein, and DNA oxidation that affects normal cell physiology and eventually leads to neuronal demise. In addition to oxidation of neuronal molecules by ROS and RNS, a novel pathway for molecular modifications has risen from the concept that ROS can activate specific signal transduction pathways that, depending on the insult degree, can lead to either normal plasticity or pathology. Two examples of these pathways could explain why lethal ischemic insults lead to the translocation of protein kinase Cdelta (deltaPKC), which plays a role in apoptosis after cerebral ischemia, or why sublethal ischemic insults, such as in ischemic preconditioning, lead to the translocation of epsilonPKC, which plays a pivotal role in neuroprotection. A better understanding of the mechanisms by which ROS and/or RNS modulate key protein kinases that are involved in signaling pathways that lead to cell death and survival after cerebral ischemia will help devise novel therapeutic strategies.
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Affiliation(s)
- Miguel A Perez-Pinzon
- Cerebral Vascular Disease Research Center, Department of Neurology and Neuroscience, University of Miami Miller School of Medicine, Miami, FL 33101, USA.
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Amemiya S, Kamiya T, Nito C, Inaba T, Kato K, Ueda M, Shimazaki K, Katayama Y. Anti-apoptotic and neuroprotective effects of edaravone following transient focal ischemia in rats. Eur J Pharmacol 2005; 516:125-30. [PMID: 15921675 DOI: 10.1016/j.ejphar.2005.04.036] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2005] [Revised: 04/18/2005] [Accepted: 04/22/2005] [Indexed: 11/15/2022]
Abstract
To investigate the effect of an antioxidant edaravone on the apoptotic process, we examined Bax and Bcl-2 immunohistochemical expression and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) reactivity. Rat focal ischemia models were prepared by 2 h transient middle cerebral artery occlusion. Edaravone or physiological saline was intravenously administered after reperfusion. After 24 h of reperfusion, infarction volume assessments, Bax and Bcl-2 immunohistochemistry and TUNEL staining were performed as well as neurological evaluation. Cortical cerebral blood flow was not statistically different between the treatment-groups. Edaravone-treated animals showed significantly improved neurological outcome. Total and cortical infarct volumes in the edaravone group significantly decreased. In addition, edaravone-treatment provided a significant reduction in the number of TUNEL-positive apoptotic cells, a decrease in Bax immunoreactivity and an increase in Bcl-2 expression within the peri-infarct area. Edaravone shows an excellent neuroprotective effect against ischemia/reperfusion brain injury through a Bax/Bcl-2 dependent anti-apoptotic mechanism.
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Affiliation(s)
- Shimon Amemiya
- Division of Neurology, Second Department of Internal Medicine, Nippon Medical School, 1-1-5, Sendagi, Bunkyo-ku, Tokyo, 113-8603, Japan.
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18
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Maples KR, Green AR, Floyd RA. Nitrone-related therapeutics: potential of NXY-059 for the treatment of acute ischaemic stroke. CNS Drugs 2005; 18:1071-84. [PMID: 15581379 DOI: 10.2165/00023210-200418150-00003] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
At present, none of the neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease and stroke are treatable with compounds that slow or halt neuronal cell death. However, the prototype nitrone radical trap alpha-phenyl-tert-butylnitrone (PBN) has been shown to be an effective neuroprotective agent in various models of neurodegeneration. Some of these data are briefly reviewed as an introduction to an examination of the effect of the novel nitrone radical trapping agent disodium 2,4-disulfophenyl-N-tert-butylnitrone (NXY-059) in various animal models of stroke. NXY-059 has been shown to be an effective neuroprotective agent in both transient (reperfusion) and permanent focal ischaemia models in rats. In both types of model, NXY-059 has a large window of opportunity, providing effective neuroprotection when given up to 5 hours after the start of the occlusion in transient ischaemia and 4 hours after the start of permanent ischaemia. The compound is also effective in a marmoset permanent ischaemia model when administered up to 4 hours after the start of the occlusion. In this model it has been found to attenuate the problem of spatial neglect and maintain function to the paretic arm. NXY-059 administration also improves motor function in a rat haemorrhagic stroke model and has a neuroprotective effect in a rabbit thromboembolic stroke model. The compound is also well tolerated in stroke patients at plasma levels shown to provide a maximum neuroprotective effect in animal models of stroke.NXY-059, like PBN, is a nitrone with free radical trapping properties and this may be the basis of its neuroprotective action. However, experiments with PBN and NXY-059 suggest the possibility of other mechanisms being involved and these are also reviewed. Further experiments are required to fully elucidate the mechanism of action of these very effective neuroprotective agents.
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Affiliation(s)
- Kirk R Maples
- Anacor Pharmaceuticals Inc., Palo Alto, California, USA
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Nakajima T, Iwabuchi S, Miyazaki H, Okuma Y, Kuwabara M, Nomura Y, Kawahara K. Preconditioning prevents ischemia-induced neuronal death through persistent Akt activation in the penumbra region of the rat brain. J Vet Med Sci 2004; 66:521-7. [PMID: 15187362 DOI: 10.1292/jvms.66.521] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A brief period of ischemia, i.e. preconditioning of the middle cerebral artery territory, induces ischemic tolerance reducing the cerebral infarction volume caused by subsequent lethal ischemia. Nevertheless, little is known about the molecular mechanisms underlying this phenomenon. In the present study, we examined the involvement of the activation of Akt, a serine/threonine kinase, in the cerebral ischemic tolerance. Western blot analysis showed that Akt was activated in both non-preconditioned and preconditioned groups after ischemia for 1 hr, but the activation was long-lasting in the preconditioned rats. Immunohistochemical analysis demonstrated that the preconditioning-induced preventive effect on a rapid decrease in the activation level of Akt was due to the persistent activation of Akt in the penumbra region. In addition, TUNEL staining demonstrated that the preconditioning treatment inhibited the augmentation of neuronal death probably through apoptosis in the penumbra region to prevent the spread of infarction. Since the activation of Akt has been reported to protect cells from stress, the present results suggest that the preconditioning-induced persistent activation of Akt in the penumbra region plays an important role in ischemic tolerance of the brain.
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Affiliation(s)
- Takayuki Nakajima
- Laboratory of Biomedical Control, Research Institute for Electronic Science, Hokkaido University, Sapporo, Japan
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20
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Christensen T, Diemer NH. Reduction of mitochondrial electron transport complex activity is restricted to the ischemic focus after transient focal cerebral ischemia in rats: a histochemical volumetric analysis. Neurochem Res 2004; 28:1805-12. [PMID: 14649721 DOI: 10.1023/a:1026111506307] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Using histochemical methods offering high topographical resolution for evaluation of changes in the ischemic focus and the penumbra, the mitochondrial electron transport chain (ETC) complexes I, II, and IV were examined in rats subjected to 2 h of proximal occlusion of the middle cerebral artery (MCAO) followed by no reperfusion, 1 h reperfusion, 4 h reperfusion, or 4 h reperfusion plus treatment with the free radical scavenger alpha-PBN. Serial brain cryosections were histochemically stained to visualize activity of complexes I, II, and IV, and the volumes of tissue with reduced activity in the ipsilateral cortex and caudate putamen were measured by densitometric image analysis. Reductions in complex I, II, and IV activity were restricted to areas in the ischemic foci in cortex and caudate putamen, which microscopically displayed signs of early morphological damage. In cortex, the tissue volume with reduced activity did not change significantly during reperfusion but progressively increased in the caudate putamen, possibly reflecting a faster maturation of morphological damage in this region. Treatment with alpha-PBN did not affect the observed reductions in activities. We deduce that inhibition of mitochondrial ETC complex activity does not play a critical role for recruitment of the penumbra in the infarction process.
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Affiliation(s)
- Thomas Christensen
- Laboratory of Neuropathology, Institute of Molecular Pathology, University of Copenhagen, Denmark.
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Yamato M, Egashira T, Utsumi H. Application of in vivo ESR spectroscopy to measurement of cerebrovascular ROS generation in stroke. Free Radic Biol Med 2003; 35:1619-31. [PMID: 14680685 DOI: 10.1016/j.freeradbiomed.2003.09.013] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
This study used an in vivo ESR spectroscopy/spin probe technique to measure directly the generation of reactive oxygen species (ROS) in the brain after cerebral ischemia-reperfusion. Transient middle cerebral artery occlusion (MCAO) was induced in rats by inserting a nylon thread into the internal carotid artery for 1 h. The in vivo generation of ROS and its location in the brain were analyzed from the enhanced ESR signal decay data of three intra-arterially injected spin probes with different membrane permeabilities. The ESR signal decay of the probe with intermediate permeability was significantly enhanced 30 min after reperfusion following MCAO, whereas no enhancement was observed with the other probes or in the control group. The enhanced in vivo signal decay was significantly suppressed by superoxide dismutase (SOD). Brain damage was barely discernible until 3 h of reperfusion, and was clearly suppressed with the probe of intermediate permeability. The antioxidant MCI-186 completely suppressed the enhanced in vivo signal decay after transient MCAO. These results clearly demonstrate that ROS are generated at the interface of the cerebrovascular cell membrane when reperfusion follows MCAO in rats, and that the ROS generated during the initial stages of transient MCAO cause brain injury.
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Affiliation(s)
- Mayumi Yamato
- Laboratory of Bio-function Sciences, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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22
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Green AR, Ashwood T, Odergren T, Jackson DM. Nitrones as neuroprotective agents in cerebral ischemia, with particular reference to NXY-059. Pharmacol Ther 2003; 100:195-214. [PMID: 14652110 DOI: 10.1016/j.pharmthera.2003.07.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Stroke is a major clinical problem, and acute pharmacological intervention with neuroprotective agents has so far been unsuccessful. Recently, there has been considerable interest in the potential therapeutic benefit of nitrone-derived free radical trapping agents as neuroprotective agents. Nitrone compounds have been shown to be beneficial in animal models of various diseases, and the prototypic compound alpha-phenyl-N-tert-butylnitrone (PBN) has been extensively demonstrated to be neuroprotective in rat models of transient and permanent focal ischemia. The nitrone radical trapping agent disodium 2,4-disulfophenyl-N-tert-butylnitrone (NXY-059) has also been shown to be neuroprotective in these models. Furthermore, it has recently been shown to improve neurological function and reduce infarct volume in a primate model of permanent focal ischemia even when given 4 hr postocclusion. While radical trapping activity is demonstrable with NXY-059 and other nitrone compounds such as PBN, this activity is weak. Arguments for and against ascribing radical trapping as the therapeutic mechanism of action are discussed. This compound is well tolerated in human stroke patients and can be administered to produce plasma concentrations exceeding those effective in animal models; crucially, at the same time, it has also been shown to be effective in animal models. NXY-059 may thus be the first compound to be examined in stroke patients using drug exposure and time to treatment that have been shown to be effective in animal models of stroke.
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Affiliation(s)
- A Richard Green
- AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, Leics LE11 5RH, UK.
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23
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Christensen T, Bruhn T, Diemer NH. The free radical spin-trap α-PBN attenuates periinfarct depolarizations following permanent middle cerebral artery occlusion in rats without reducing infarct volume. Brain Res 2003; 990:66-76. [PMID: 14568331 DOI: 10.1016/s0006-8993(03)03439-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The effect of the free radical spin-trap alpha-phenyl-butyl-tert-nitrone (alpha-PBN) in permanent focal cerebral ischemia in rats was examined in two series of experiments. In the first, rats were subjected to permanent occlusion of the middle cerebral artery (MCAO) and treated 1 h after occlusion with a single dose of alpha-PBN (100 mg/kg) or saline. Body temperature was measured and controlled for the first 24 h to obtain identical temperature curves in the two groups. Cortical infarct volumes were determined on histological sections 7 days later. alpha-PBN did not significantly reduce infarct volume (control: 28.3+/-16.3 mm3 vs. alpha-PBN 23.7+/-7.4 mm3). In the second series of experiments, periinfarct depolarizations (PIDs) were recorded with an extracellular DC electrode at two locations in the ischemic penumbra for the initial 3 h following MCAO. alpha-PBN (100 mg/kg, single dose in conjunction with occlusion) significantly reduced the total number (median value of 3 PIDs in the control groups vs. 1 PID in alpha-PBN groups, p<0.001) and total duration of the PIDs (median value 662 s in the control groups vs. 162 s in the alpha-PBN groups, p<0.006). In spite of this, cortical infarct volumes determined 7 days later in the same rats were not smaller in alpha-PBN-treated rats. The study thus demonstrates that attenuation of PIDs does not always lead to smaller infarcts if permanent arterial occlusion is followed by long survival time and does not support the hypothesis that PIDs per se are critical determinants of infarct size in this situation.
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Affiliation(s)
- Thomas Christensen
- Laboratory of Neuropathology, Institute of Molecular Pathology, University of Copenhagen, Frederik V's vej 11, 6th Floor, DK-2100 Copenhagen, Denmark.
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24
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Blomgren K, Zhu C, Hallin U, Hagberg H. Mitochondria and ischemic reperfusion damage in the adult and in the developing brain. Biochem Biophys Res Commun 2003; 304:551-9. [PMID: 12729590 DOI: 10.1016/s0006-291x(03)00628-4] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The developing and the adult brain respond in similar ways to ischemia, but also display clear differences. For example, the relative contributions of necrosis and apoptosis to neuronal death may be different, such that apoptotic mechanisms would be more prevalent in the developing brain. During normal development, more than half of the neurons in some brain regions are removed through apoptosis, and effectors like caspase-3 are highly upregulated in the immature brain. Mitochondria are pivotal regulators of cell death through their role in energy production and calcium homeostasis, their capacity to release apoptogenic proteins and to produce reactive oxygen species. This review will summarize some of the current studies dealing with mitochondria-related mechanisms of ischemic brain damage, with special reference to developmental aspects.
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Affiliation(s)
- Klas Blomgren
- Department of Physiology, Perinatal Center, Göteborg University, P.O. Box 432, SE 405 30 Göteborg, Sweden.
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25
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Callaway JK, Lawrence AJ, Jarrott B. AM-36, a novel neuroprotective agent, profoundly reduces reactive oxygen species formation and dopamine release in the striatum of conscious rats after endothelin-1-induced middle cerebral artery occlusion. Neuropharmacology 2003; 44:787-800. [PMID: 12681377 DOI: 10.1016/s0028-3908(03)00068-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Elevated generation of reactive oxygen species (ROS) has been demonstrated during ischemia and reperfusion. Dopamine (DA) autooxidation may contribute to increased ROS generation. The novel neuroprotective agent AM-36 has antioxidant and Na(+) channel blocking activity and reduces neuronal damage in both cortex and striatum after middle cerebral artery (MCA) occlusion. Here we sought in vivo evidence of the ability of AM-36 to inhibit intrastriatal ROS generation and DA release after ischemia. Salicylate hydroxylation coupled with in vivo microdialysis in the striatum of conscious Long Evans rats was performed during MCA occlusion by perivascular microinjection of endothelin-1 (ET-1). AM-36 (6 mg/kg) was administered intraperitoneally 30 min after MCA occlusion. Dialysates were analysed using high performance liquid chromatography with electrochemical detection for the salicylate hydroxylation product, 2,3-dihydroxybenzoic acid (2,3 DHBA) and for DA and metabolites. MCA occlusion resulted in a marked increase in 2,3 DHBA and a secondary increase in all analytes, 180-300 min later. Increased DA release coincided with 2,3 DHBA formation. AM-36 significantly reduced ischemia induced increases in 2,3 DHBA and DA, and infarct volume in the striatum. Significant improvements in a battery of behavioural tests was also found in AM-36 treated rats. This study has demonstrated profound inhibition of ROS generation by a novel compound with antioxidant activity, administered post-ischemia in conscious rats.
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Affiliation(s)
- J K Callaway
- Department of Pharmacology, PO Box 13E, Monash University, Clayton, Victoria 3800, Australia.
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26
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Kumar R, Krause GS, Yoshida H, Mori K, DeGracia DJ. Dysfunction of the unfolded protein response during global brain ischemia and reperfusion. J Cereb Blood Flow Metab 2003; 23:462-71. [PMID: 12679723 DOI: 10.1097/01.wcb.0000056064.25434.ca] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A variety of endoplasmic reticulum (ER) stresses trigger the unfolded protein response (UPR), a compensatory response whose most proximal sensors are the ER membrane-bound proteins ATF6, IRE1alpha, and PERK. The authors simultaneously examined the activation of ATF6, IRE1alpha, and PERK, as well as components of downstream UPR pathways, in the rat brain after reperfusion after a 10-minute cardiac arrest. Although ATF6 was not activated, PERK was maximally activated at 10-minute reperfusion, which correlated with maximal eIF2alpha phosphorylation and protein synthesis inhibition. By 4-h reperfusion, there was 80% loss of PERK immunostaining in cortex and 50% loss in brain stem and hippocampus. PERK was degraded in vitro by mu-calpain. Although inactive IRE1alpha was maximally decreased by 90-minute reperfusion, there was no evidence that its substrate xbp-1 messenger RNA had been processed by removal of a 26-nt sequence. Similarly, there was no expression of the UPR effector proteins 55-kd XBP-1, CHOP, or ATF4. These data indicate that there is dysfunction in several key components of the UPR that abrogate the effects of ER stress. In other systems, failure to mount the UPR results in increased cell death. As other studies have shown evidence for ER stress after brain ischemia and reperfusion, the failure of the UPR may play a significant role in reperfusion neuronal death.
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Affiliation(s)
- Rita Kumar
- Department of Emergency Medicine, Wayne State University, Detroit, Michigan, U.S.A
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27
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Liu S, Liu M, Peterson S, Miyake M, Vallyathan V, Liu KJ. Hydroxyl radical formation is greater in striatal core than in penumbra in a rat model of ischemic stroke. J Neurosci Res 2003; 71:882-8. [PMID: 12605415 DOI: 10.1002/jnr.10534] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Although hydroxyl radical ((*)OH) formation has been implicated in the pathophysiological changes of ischemic stroke, (*)OH production in the core and penumbra regions is not clear. It is extremely important to distinguish penumbra from ischemic core in focal cerebral ischemia studies, because the penumbra contains viable tissue, which can be salvaged by appropriate treatment. This study evaluated (*)OH production in both core and penumbra regions of ischemic striatum during ischemia and reperfusion. Microdialysis probes were placed in striatal tissue of rats subjected to the middle cerebral artery occlusion model of ischemic stroke. The (*)OH-trapping agent 4-hydroxybenzoic acid (4-HBA) was administered by both i.v. and probe infusion. Dialysate levels of the 4-HBA oxidation products, 3,4-dihydroxybenzoic acid (3,4-DHBA), were determined by HPLC-ECD. After microdialysis probe delivery of 4-HBA, (*)OH production was significantly increased in the striatal core during both ischemia and reperfusion. Penumbra (*)OH production increased only during reperfusion. Alterations of 3,4-DHBA concentration in dialysate following i.v. 4-HBA administration were likely related to alterations in tissue blood flow. The findings were confirmed by a greater oxidation of dihydroethidium in the ischemic core than in the penumbra as determined by fluorescent microscopy. The findings of (*)OH production in ischemic striatum are the opposite of those reported for ischemic cortex and suggest critical regional variations in (*)OH production that may have significant clinical implications in the treatment of ischemic stroke.
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Affiliation(s)
- Shimin Liu
- College of Pharmacy, University of New Mexico Health Science Center, Albuquerque, New Mexico
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28
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Avshalumov MV, Rice ME. NMDA receptor activation mediates hydrogen peroxide-induced pathophysiology in rat hippocampal slices. J Neurophysiol 2002; 87:2896-903. [PMID: 12037193 DOI: 10.1152/jn.2002.87.6.2896] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Endogenous reactive oxygen species (ROS) can act as modulators of neuronal activity, including synaptic transmission. Inherent in this process, however, is the potential for oxidative damage if the balance between ROS production and regulation becomes disrupted. Here we report that inhibition of synaptic transmission in rat hippocampal slices by H2O2 can be followed by electrical hyperexcitability when transmission returns during H2O2 washout. As in previous studies, H2O2 exposure (15 min) reversibly depressed the extracellular population spike (PS) evoked by Schaffer collateral stimulation. Recovery of PS amplitude, however, was typically accompanied by mild epileptiform activity. Inclusion of ascorbate (400 microM) during H2O2 washout prevented this pathophysiology. No protection was seen with isoascorbate, which is a poor substrate for the stereoselective ascorbate transporter and thus remains primarily extracellular. Epileptiform activity was also prevented by the N-methyl-D-aspartate (NMDA) receptor antagonist, DL-2-amino-5-phosphonopentanoic acid (AP5) during H2O2 washout. Once hyperexcitability was induced, however, AP5 did not reverse it. When present during H2O2 exposure, AP5 did not alter PS depression by H2O2 but did inhibit the recovery of PS amplitude seen during pulse-train stimulation (10 Hz, 5 s) in H2O2. Inhibition of glutamate uptake by l-trans-2,4-pyrrolidine dicarboxylate (PDC; 50 microM) during H2O2 washout markedly enhanced epileptiform activity; coapplication of ascorbate with PDC prevented this. These data indicate that H2O2 exposure can cause activation of normally silent NMDA receptors, possibly via inhibition of redox-sensitive glutamate uptake. When synaptic transmission returns during H2O2 washout, enhanced NMDA receptor activity leads to ROS generation and consequent oxidative damage. These data reveal a pathological cycle that could contribute to progressive degeneration in neurological disorders that involve oxidative stress, including cerebral ischemia.
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Affiliation(s)
- Marat V Avshalumov
- Departments of Physiology and Neuroscience, New York University School of Medicine, New York, New York 10016, USA
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29
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Ste-Marie L, Hazell AS, Bémeur C, Butterworth R, Montgomery J. Immunohistochemical detection of inducible nitric oxide synthase, nitrotyrosine and manganese superoxide dismutase following hyperglycemic focal cerebral ischemia. Brain Res 2001; 918:10-9. [PMID: 11684037 DOI: 10.1016/s0006-8993(01)02903-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have characterized the temporal changes in iNOS, MnSOD and nitrotyrosine immune reactivity in a rat model of permanent middle cerebral artery occlusion under acute hyperglycemic or normoglycemic conditions followed by either 3- or 24-h recovery. We found that the macroscopic labeling pattern for all three antibodies colocalized with the ischemic core and penumbra which was determined by cresyl violet histological evaluation in adjacent sections. Hyperglycemia induced prior to ischemia resulted in earlier infarction which correlated with increased immunoreactivity for iNOS, MnSOD and nitrotyrosine. In the penumbral region of the frontal cortex, labeling of specific cell structures was largely limited to cortical neurons near the corpus callosum and was apparent earlier in the hyperglycemic rats. Increased polymorphonuclear leukocyte adhesion in blood vessels was observed at 24 h in the hyperglycemic group. At both of the recovery times studied, we observed only minor vascular staining for nitrotyrosine and none for iNOS. Our results are consistent with hyperglycemia resulting in an early and concomitant increase in both superoxide and nitric oxide production which can lead to peroxynitrite formation that then nitrates tyrosine residues. It would appear that hyperglycemic ischemia contributes to the early induction of key enzymes involved in nitric oxide bioavailability.
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Affiliation(s)
- L Ste-Marie
- Laboratoire de Neurobiologie, Centre de Recherche du CHUM, Hôpital Notre-Dame, 1560 Sherbrooke St. E., Montréal, Québec, Canada H2L 4M1
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30
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Abstract
The brain has the highest metabolic rate of all organs and depends predominantly on oxidative metabolism as a source of energy. Oxidative metabolism generates reactive oxygen species, which can damage all cellular components, including protein, lipids and nucleic acids. The processes of DNA repair normally remove spontaneous gene damage with few errors. However, cerebral ischemia followed by reperfusion leads to elevated oxidative stress and damage to genes in brain tissue despite a functional mechanism of DNA repair. These critical events occur at the same time as the expression of immediate early genes, the products of which trans-activate late effector genes that are important for sustaining neuronal viability. These findings open the possibility of applying genetic tools to identify molecular mechanisms of gene repair and to derive new therapies for stroke and brain injury.
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Affiliation(s)
- P K Liu
- Department of Neurosurgery, Baylor College of Medicine, Houston, TX 77030, USA.
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31
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CUI JIANKUN, HOLMES ERICH, GREENE THOMASG, LIU PHILIPK. Oxidative DNA damage precedes DNA fragmentation after experimental stroke in rat brain. FASEB J 2000; 14:955-67. [PMID: 10783150 PMCID: PMC2709847 DOI: 10.1096/fasebj.14.7.955] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Experimental stroke using a focal cerebral ischemia and reperfusion (FCIR) model was induced in male Long-Evans rats by a bilateral occlusion of both common carotid arteries and the right middle cerebral artery for 30-90 min, followed by various periods of reperfusion. Oxidative DNA lesions in the ipsilateral cortex were demonstrated using Escherichia coli formamidopyrimidine DNA N-glycosylase (Fpg protein)-sensitive sites (FPGSS), as labeled in situ using digoxigenin-dUTP and detected using antibodies against digoxigenin. Because Fpg protein removes 8-hydroxy-2'-deoxyguanine (oh8dG) and other lesions in DNA, FPGSS measure oxidative DNA damage. The number of FPGSS-positive cells in the cortex from the sham-operated control group was 3 +/- 3 (mean +/- SD per mm(2)). In animals that received 90 min occlusion and 15 min of reperfusion (FCIR 90/15), FPGSS-positive cells were significantly increased by 200-fold. Oxidative DNA damage was confirmed by using monoclonal antibodies against 8-hydroxy-guanosine (oh8G) and oh8dG. A pretreatment of RNase A (100 microg/ml) to the tissue reduced, but did not abolish, the oh8dG signal. The number of animals with positive FPGSS or oh8dG was significantly (P<0.01) higher in the FCIR group than in the sham-operated control group. We detected few FPGSS of oh8dG-positive cells in the animals treated with FCIR of 90/60. No terminal UTP nicked-end labeling (TUNEL)-positive cells, as a detection of cell death, were detected at this early reperfusion time. Our data suggest that early oxidative DNA lesions elicited by experimental stroke could be repaired. Therefore, the oxidative DNA lesions observed in the nuclear and mitochondrial DNA of the brain are different from the DNA fragmentation detected using TUNEL.
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Affiliation(s)
- JIANKUN CUI
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas 77030, USA
| | - ERIC H. HOLMES
- Northwest Hospital, Pacific Northwest Cancer Foundation, Seattle, Washington 98125, USA
| | - THOMAS G. GREENE
- Northwest Hospital, Pacific Northwest Cancer Foundation, Seattle, Washington 98125, USA
| | - PHILIP K. LIU
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas 77030, USA
- Department of Medicine Cardiovascular Program, and Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
- Correspondence: Department of Neurosurgery, Baylor College of Medicine, Suite 944, 6560 Fannin, Houston, TX 77030, USA. E-mail:
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Feng Y, LeBlanc MH, LeBlanc EB, Parker CC, Fratkin JD, Qian XB, Patel DM, Huang M, Smith EE, Vig PJ. Desmethyl tirilazad improves neurologic function after hypoxic ischemic brain injury in piglets. Crit Care Med 2000; 28:1431-8. [PMID: 10834691 DOI: 10.1097/00003246-200005000-00029] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Desmethyl tirilazad is a lipid-soluble free radical quencher. Deferoxamine reduces free radicals by chelating iron and reducing hydroxyl formation. Free radical inhibitors have shown promise in several hypoxic ischemic brain injury models, and we wished to see if this work could be extended to our newborn piglet model. DESIGN Randomized controlled trial. SUBJECTS Piglets (0 to 3 days old). INTERVENTION Carotid snares and arterial and venous catheters were placed under 1.5% isoflurane anesthesia. In Experiment 1, piglets were randomly assigned to receive either 3 mg/kg desmethyl tirilazad or vehicle at -15 and 90 mins. In Experiment 2, piglets were randomly assigned to receive either 20 mg/kg desmethyl tirilazad at -15 mins followed by 8 mg/kg/hr for 90 mins or 100 mg/kg deferoxamine at -15 mins or vehicle. At time 0, both carotid arteries were clamped and blood was withdrawn to reduce the blood pressure to two-thirds normal. At 15 mins, inspired oxygen was reduced to 6%. At 30 mins, the carotid snares were released, the withdrawn blood was reinfused, and the oxygen was switched to 100%. On the third day after the hypoxic ischemic injury, the animals were killed by perfusing their brains with 10% formalin. We tested the timing of lipid peroxidation and inhibition of lipid peroxidation by these agents by freezing the brains of a subset of pigs in liquid nitrogen. MEASUREMENTS Neurologic examination and brain pathology were scored by blinded observers. Thiobarbituric acid-reactive substance and oxidized and reduced glutathione were measured on frozen brains. MAIN RESULTS Desmethyl tirilazad (20 mg/kg) and 100 mg/kg deferoxamine inhibit lipid peroxidation. Desmethyl tirilazad (20 mg/kg) improves neurologic exam, but 3 mg/kg Desmethyl tirilazad or 100 mg/kg deferoxamine does not. Neither desmethyl tirilazad nor deferoxamine improves pathologic results. CONCLUSIONS High-dose desmethyl tirilazad improves neurologic function after hypoxic ischemic brain injury in the newborn piglet.
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Affiliation(s)
- Y Feng
- Department of Pediatrics, University of Mississippi Medical Center, Jackson 39216-4505, USA
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Solenski NJ, Kwan A. Attenuation of free radical generation during reversible focal cerebral ischemia with the nitric oxide inhibitor, L-NAME (L-N(G)-nitro-L-arginine methyl ester). Brain Res 2000; 862:262-5. [PMID: 10799696 DOI: 10.1016/s0006-8993(00)02088-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The role of oxygen free radical generation during reversible focal cerebral ischemia and its relationship to nitric oxide mediated mechanisms were examined. In this study, a left frontal cortex microdialysis probe was placed into the previously defined ischemic penumbra region and perfused with a salicylate/CSF solution in the presence or absence of the nitric oxide synthase (NOS) inhibitor L-NAME. Rats were then subjected to transient left hemisphere focal cerebral ischemia. Dialysate was collected at baseline and during the ischemic/reperfusion phase, and the hydroxylation products of salicylate were measured by HPLC with electrochemical detection. A significant elevation of free radical adduct formation was observed in the penumbra region during ischemia/reperfusion. This elevation was significantly attenuated by L-NAME during the reperfusion phase. Elevation of free radical adduct formation within the penumbra region during cerebral ischemia/reperfusion may be mediated in part by NOS-dependent mechanisms.
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Affiliation(s)
- N J Solenski
- Department of Neurology, University of Virginia, Charlottesville, VA, USA.
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Toyoda T, Kassell NF, Lee KS. Induction of tolerance against ischemia/reperfusion injury in the rat brain by preconditioning with the endotoxin analog diphosphoryl lipid A. J Neurosurg 2000; 92:435-41. [PMID: 10701530 DOI: 10.3171/jns.2000.92.3.0435] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Inflammatory responses and oxygen free radicals have increasingly been implicated in the development of ischemic brain injury. In some cases, an attenuation of inflammation or free-radical injury can provide tissue protection. Diphosphoryl lipid A (DPL) is a detoxified derivative of a lipopolysaccharide (endotoxin) of Salmonella minnesota strain R595, which is capable of stimulating the immune system without eliciting direct toxic effects. In this study the authors examined the influence of preconditioning with DPL on ischemia/reperfusion injury in rats. METHODS Sprague-Dawley rats were injected intravenously with either DPL or vehicle. Twenty-four hours later, some animals were tested for superoxide dismutase (SOD) activity. Others were subjected to a 3-hour period of focal cerebral ischemia and, after a reperfusion period of 24 hours, were killed. Infarction volume, SOD activity, and myeloperoxidase (MPO) activity were assayed in the postischemic animals. Pretreatment with DPL produced significant reductions in cerebral infarction and MPO activity in the ischemic penumbra. A significant enhancement of basal SOD activity was observed 24 hours after DPL treatment (that is, before ischemia), and a further enhancement of SOD activity was seen in the ischemic penumbra 24 hours after reperfusion. CONCLUSIONS These data provide the first evidence of a neuroprotective effect of preconditioning with DPL in an in vivo model of cerebral ischemia. Although the precise mechanisms through which DPL exerts its neuroprotective influence remain to be established, an inhibition of the complex inflammatory response to ischemia and an enhancement of endogenous antioxidant activity are leading candidates.
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Affiliation(s)
- T Toyoda
- Department of Neuroscience, University of Virginia Health Sciences Center, Charlottesville 22908, USA
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Solenski NJ, diPierro CG, Kassell NF, Helm GA. Cerebral ischemia-reperfusion injury: a novel therapeutic approach with TAK-218. Clin Neuropharmacol 2000; 23:69-74. [PMID: 10803795 DOI: 10.1097/00002826-200003000-00002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The goal of the present study was to evaluate the potential neuroprotective effect of TAK-218 in an in vivo rat focal cerebral ischemia/reperfusion model. TAK-218 is a novel compound with multiple antiischemic properties, including suppression of aberrant dopamine release, modulation of sodium channels, and inhibition of lipid peroxidation. The study was a blinded, randomized, placebo-controlled study of TAK-218 in a three-vessel focal ischemic rat model. A total of 22 rats were randomly assigned to the treatment or placebo group. Animals were injected intrapertoneally with either a 2 mg/kg dose of drug or saline at 2 hours after reperfusion. Infarction volume was measured with use of 2,3,5-triphenyltetrazolium chloride. Total adjusted infarction volume in treated animals decreased by 10%. With use of a statistical analysis requiring 80% power with a 20% reduction desired effect, there was no statistically significant difference in the end-point of infarction volume between drug and placebo treatment groups. In light of the proven efficacy of thrombolytic therapy for acute stroke, it is now desirable to test neuroprotective agents during the 3-hour therapeutic window after ischemia. Further research is necessary to discern if a therapeutic agent with multiple antiischemic properties may provide a more robust neuroprotective effect than an agent with a single neuroprotective action.
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Affiliation(s)
- N J Solenski
- Department of Neurology, Health Sciences Center, University of Virginia, Charlottesville 22908, USA
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Gidö G, Cronberg T, Wieloch T. The effect of alpha-phenyl-tert-butyl nitrone (PBN) on free radical formation in transient focal ischaemia measured by microdialysis and 3,4-dihydroxybenzoate formation. ACTA PHYSIOLOGICA SCANDINAVICA 2000; 168:277-85. [PMID: 10712565 DOI: 10.1046/j.1365-201x.2000.00657.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
alpha-phenyl-tert-butyl nitrone (PBN) reduces infarct size, improves recovery of brain energy metabolism and delays the secondary increase in extracellular potassium after focal ischaemia, presumably by trapping OH radicals. We investigated the effect of PBN on the formation of 3,4-dihydroxybenzoic acid (3,4-DHBA) as a measure of OH radical formation, during and following middle cerebral artery occlusion (MCAO). Rats, subjected to 2 h of ischaemia followed by 3 h of recirculation, were injected with either vehicle or PBN (100 mg kg-1 i.p.) prior to MCAO or immediately after recirculation, respectively. The in vivo microdialysis technique was used to collect samples for analysis of 3,4-DHBA by HPLC. The basal levels of 3,4-DHBA were 56-77 nmol L-1 in the four groups. During ischaemia, the formation of 3,4-DHBA decreased by about 50% in all groups. Upon recirculation, a 3-fold rise in 3,4-DHBA formation was seen. At 2 h of recirculation the mean value of 3,4-DHBA in the pretreated, vehicle-injected animals was 125 +/- 18 nmol L-1 and in the PBN-injected 145 +/- 48 nmol L-1, respectively. When the animals were treated after MCAO either with vehicle or PBN the values at 2 h recirculation were 155 +/- 148 and 189 +/- 145 nmol L-1, respectively. No statistically significant difference between vehicle- and PBN-injected groups was seen. We conclude that during reperfusion following MCAO, hydroxyl radical formation increases. The increase is not ameliorated by PBN which suggests that PBN does not protect the brain by a general scavenging of OH radicals, although tissue specific actions cannot be excluded.
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Affiliation(s)
- G Gidö
- Laboratory for Experimental Brain Research, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
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Yamaguchi A, Hori O, Stern DM, Hartmann E, Ogawa S, Tohyama M. Stress-associated endoplasmic reticulum protein 1 (SERP1)/Ribosome-associated membrane protein 4 (RAMP4) stabilizes membrane proteins during stress and facilitates subsequent glycosylation. J Cell Biol 1999; 147:1195-204. [PMID: 10601334 PMCID: PMC2168098 DOI: 10.1083/jcb.147.6.1195] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Application of differential display to cultured rat astrocytes subjected to hypoxia allowed cloning of a novel cDNA, termed stress-associated endoplasmic reticulum protein 1 (SERP1). Expression of SERP1 was enhanced in vitro by hypoxia and/or reoxygenation or other forms of stress, causing accumulation of unfolded proteins in endoplasmic reticulum (ER) stress, and in vivo by middle cerebral artery occlusion in rats. The SERP1 cDNA encodes a 66-amino acid polypeptide which was found to be identical to ribosome-associated membrane protein 4 (RAMP4) and bearing 29% identity to yeast suppressor of SecY 6 protein (YSY6p), suggesting participation in pathways controlling membrane protein biogenesis at ER. In cultured 293 cells subjected to ER stress, overexpression of SERP1/RAMP4 suppressed aggregation and/or degradation of newly synthesized integral membrane proteins, and subsequently, facilitated their glycosylation when the stress was removed. SERP1/RAMP4 interacted with Sec61alpha and Sec61beta, which are subunits of translocon, and a molecular chaperon calnexin. Furthermore, Sec61alpha and Sec61beta, but not SERP1/RAMP4, were found to associate with newly synthesized integral membrane proteins under stress. These results suggest that stabilization of membrane proteins in response to stress involves the concerted action of a rescue unit in the ER membrane comprised of SERP1/RAMP4, other components of translocon, and molecular chaperons in ER.
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Affiliation(s)
- Atsushi Yamaguchi
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita City, Osaka 565-0871, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology, Tokyo 105, Japan
| | - Osamu Hori
- Department of Anatomy III, Kanazawa University, School of Medicine, Kanazawa City, Ishikawa 290-8640, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology, Tokyo 105, Japan
| | - David M. Stern
- Department of Surgery, Department of Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, New York, New York 10032
| | - Enno Hartmann
- Abteilung Biochemie II, Zentrum Biochemie und Moleculare Zellbiologie, Georg-August-Universität, 37073 Göttingen, Germany
| | - Satoshi Ogawa
- Department of Anatomy III, Kanazawa University, School of Medicine, Kanazawa City, Ishikawa 290-8640, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology, Tokyo 105, Japan
| | - Masaya Tohyama
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita City, Osaka 565-0871, Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology, Tokyo 105, Japan
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Abstract
This review is directed at understanding how neuronal death occurs in two distinct insults, global ischemia and focal ischemia. These are the two principal rodent models for human disease. Cell death occurs by a necrotic pathway characterized by either ischemic/homogenizing cell change or edematous cell change. Death also occurs via an apoptotic-like pathway that is characterized, minimally, by DNA laddering and a dependence on caspase activity and, optimally, by those properties, additional characteristic protein and phospholipid changes, and morphological attributes of apoptosis. Death may also occur by autophagocytosis. The cell death process has four major stages. The first, the induction stage, includes several changes initiated by ischemia and reperfusion that are very likely to play major roles in cell death. These include inhibition (and subsequent reactivation) of electron transport, decreased ATP, decreased pH, increased cell Ca(2+), release of glutamate, increased arachidonic acid, and also gene activation leading to cytokine synthesis, synthesis of enzymes involved in free radical production, and accumulation of leukocytes. These changes lead to the activation of five damaging events, termed perpetrators. These are the damaging actions of free radicals and their product peroxynitrite, the actions of the Ca(2+)-dependent protease calpain, the activity of phospholipases, the activity of poly-ADPribose polymerase (PARP), and the activation of the apoptotic pathway. The second stage of cell death involves the long-term changes in macromolecules or key metabolites that are caused by the perpetrators. The third stage of cell death involves long-term damaging effects of these macromolecular and metabolite changes, and of some of the induction processes, on critical cell functions and structures that lead to the defined end stages of cell damage. These targeted functions and structures include the plasmalemma, the mitochondria, the cytoskeleton, protein synthesis, and kinase activities. The fourth stage is the progression to the morphological and biochemical end stages of cell death. Of these four stages, the last two are the least well understood. Quite little is known of how the perpetrators affect the structures and functions and whether and how each of these changes contribute to cell death. According to this description, the key step in ischemic cell death is adequate activation of the perpetrators, and thus a major unifying thread of the review is a consideration of how the changes occurring during and after ischemia, including gene activation and synthesis of new proteins, conspire to produce damaging levels of free radicals and peroxynitrite, to activate calpain and other Ca(2+)-driven processes that are damaging, and to initiate the apoptotic process. Although it is not fully established for all cases, the major driving force for the necrotic cell death process, and very possibly the other processes, appears to be the generation of free radicals and peroxynitrite. Effects of a large number of damaging changes can be explained on the basis of their ability to generate free radicals in early or late stages of damage. Several important issues are defined for future study. These include determining the triggers for apoptosis and autophagocytosis and establishing greater confidence in most of the cellular changes that are hypothesized to be involved in cell death. A very important outstanding issue is identifying the critical functional and structural changes caused by the perpetrators of cell death. These changes are responsible for cell death, and their identity and mechanisms of action are almost completely unknown.
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Affiliation(s)
- P Lipton
- Department of Physiology, University of Wisconsin School of Medicine, Madison, Wisconsin, USA
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Schmid-Elsaesser R, Hungerhuber E, Zausinger S, Baethmann A, Reulen HJ. Neuroprotective efficacy of combination therapy with two different antioxidants in rats subjected to transient focal ischemia. Brain Res 1999; 816:471-9. [PMID: 9878871 DOI: 10.1016/s0006-8993(98)01197-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The vascular endothelium and parenchyma of the brain have both potential pathways to generate free radicals under pathological conditions. We evaluated the neuroprotective efficacy of two different antioxidants, a microvascularly acting 21-aminosteroid (U-74389G) and a brain-penetrating pyrrolopyrimidine (U-101033E) alone and in combination. Forty Sprague-Dawley rats were randomly assigned to one of four treatment groups: (1) vehicle-treated controls, (2) U-74389G, (3) U-101033E, (4) U-74389G+U-101033E. Drugs were administered in a dosage of 3x3 mg/kg i.v. before, during, and after ischemia. All animals were subjected to 90 min of middle cerebral artery occlusion. Local cortical blood flow (LCBF) was continuously recorded by bilateral laser Doppler flowmetry. Functional deficits were quantified by daily neurological examinations. Infarct volume was assessed after 7 days. There were no significant differences in LCBF among groups. U-101033E improved neurological function from postoperative day 4 to 7, while U-74389G did not improve neurological recovery. Animals treated with both drugs showed significantly less deficits from postoperative day 1 to 7. U-101033E and combination therapy reduced total infarct volume by 53% and 54% (P<0.05). U-74389G non-significantly reduced total infarct volume by 25%. Cortical infarct volume was significantly reduced in all treatment groups but only U-101033E and combination therapy protected the basal ganglia from infarction. In conclusion, brain-penetrating antioxidants have superior neuroprotective properties compared to microvascularly acting agents. Combination therapy, affording antioxidation plus radical scavenging in blood vessels and brain parenchyma, might yield the highest degree of neuronal protection from peroxidative damage. The neuroprotective efficacy seems to be independent of CBF.
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Affiliation(s)
- R Schmid-Elsaesser
- Department of Neurosurgery, Ludwig-Maximilians-Universität, Klinikum Grosshadern, Marchioninistr. 15, 81377, Munich, Germany.
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