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MiR-127-3p targeting CISD1 regulates autophagy in hypoxic-ischemic cortex. Cell Death Dis 2021; 12:279. [PMID: 33723216 PMCID: PMC7961148 DOI: 10.1038/s41419-021-03541-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 01/05/2021] [Accepted: 01/19/2021] [Indexed: 02/05/2023]
Abstract
Neonatal hypoxic-ischemic (HI) injury derived from asphyxia during perinatal period, is a serious complication of neonatal asphyxia and the main cause of neonatal acute death and chronic neurological injury. Aberrant autophagy occurs in many nervous system diseases, but its role and underlying mechanism in HI injury is largely unknown. Here, we successfully constructed a newborn rat model of HI brain injury, and the knockout-miR-127-3p (KO-miR-127-3p) rats were structured by using CRISPR/Cas9. Subsequently, the in vitro functional experiments, in vivo zea-longa scores, as well as bioinformatics analyses and biological experiments were applied. The expression of autophagy-related proteins, including ATG12, P62, Beclin-1, LC3II in HI cortex with miR-127-3p knockout was significantly decreased, and autophagic vacuoles were disappeared. Moreover, miR-127-3p has a specific regulatory effect on CISD1 expression, another crucial molecule in autophagy process. Accordingly, the overexpression of CISD1 effectively inhibited the autophagic cell death and physiological dysfunction in the brain of HI injury, whereas si-CISD1 reversed the neuroprotective effects of KO-miR-127-3p. Our findings explained the underlying mechanism for HI injury, and miR-127-3p targeting CISD1 signal could be supposed as a new treatment strategy to prevent and treat HI injury.
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Kreisman NR, Wooliscroft LB, Campbell CF, Dotiwala AK, Cox ML, Denson AC, Betancourt AM, Tomchuck SL. Preconditioning hippocampal slices with hypothermia promotes rapid tolerance to hypoxic depolarization and swelling: Mediation by erythropoietin. Brain Res 2019; 1726:146517. [PMID: 31634451 DOI: 10.1016/j.brainres.2019.146517] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 08/06/2019] [Accepted: 10/17/2019] [Indexed: 12/26/2022]
Abstract
We suggested previously that hippocampal slices were protected from hypoxic depolarization and swelling by preincubating them at room temperature (Kreisman et al., 2000). We postulated that hypothermic preconditioning induced tolerance in our slices, which protected against hypoxic depolarization and swelling. Control hippocampal slices were incubated at 34-35 °C for two hours and the response to 10 min of severe hypoxia was compared to slices which were preconditioned for two hours at room temperature (22-23 °C) prior to warming to 34-35 °C. Recordings of the extracellular DC potential provided an index of tissue depolarization and changes in tissue light transmittance provided an index of swelling. Hypothermic preconditioning significantly reduced hypoxia-induced swelling, particularly in CA3 and the dentate inner blade. Since erythropoietin (EPO) had been shown to mediate hypoxic preconditioning, we tested whether EPO also mediated hypothermic preconditioning in our slices. Recombinant rat EPO (1-10 micromolar) mitigated hypoxia-induced swelling and depolarization in dentate inner blade of unconditioned slices in a dose-dependent manner. We also blocked the protective effects of hypothermic preconditioning on hypoxic depolarization and swelling in the inner blade of the dentate gyrus by administering soluble EPO receptor in the bath and treating slices with wortmannin to block phosphorylation of PI3 kinase, a critical step in the activation of the downstream neuroprotectant, Akt. These results suggest that EPO mediates tolerance to hypoxic depolarization and swelling induced by hypothermic preconditioning. They also emphasize that various preincubation protocols used in experiments with hippocampal slices may differentially affect basal electrophysiological and metabolic properties of those slices.
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Affiliation(s)
- Norman R Kreisman
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112, United States; Tulane Brain Institute, New Orleans, LA 70118, United States.
| | | | - Carolyn F Campbell
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112, United States; Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA 70112, United States
| | - Ary K Dotiwala
- Tulane Brain Institute, New Orleans, LA 70118, United States
| | - Michael L Cox
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112, United States
| | - Aaron C Denson
- Department of Physiology, Tulane University School of Medicine, New Orleans, LA 70112, United States
| | - Aline M Betancourt
- Department of Medicine, Tulane University School of Medicine, New Orleans, LA 70112, United States
| | - Suzanne L Tomchuck
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA 70112, United States
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Antonic A, Dottori M, Leung J, Sidon K, Batchelor PE, Wilson W, Macleod MR, Howells DW. Hypothermia protects human neurons. Int J Stroke 2014; 9:544-52. [PMID: 24393199 PMCID: PMC4235397 DOI: 10.1111/ijs.12224] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 10/14/2013] [Indexed: 12/23/2022]
Abstract
BACKGROUND AND AIMS Hypothermia provides neuroprotection after cardiac arrest, hypoxic-ischemic encephalopathy, and in animal models of ischemic stroke. However, as drug development for stroke has been beset by translational failure, we sought additional evidence that hypothermia protects human neurons against ischemic injury. METHODS Human embryonic stem cells were cultured and differentiated to provide a source of neurons expressing β III tubulin, microtubule-associated protein 2, and the Neuronal Nuclei antigen. Oxygen deprivation, oxygen-glucose deprivation, and H2 O2 -induced oxidative stress were used to induce relevant injury. RESULTS Hypothermia to 33°C protected these human neurons against H2 O2 -induced oxidative stress reducing lactate dehydrogenase release and Terminal deoxynucleotidyl transferase dUTP nick end labeling-staining by 53% (P ≤ 0·0001; 95% confidence interval 34·8-71·04) and 42% (P ≤ 0·0001; 95% confidence interval 27·5-56·6), respectively, after 24 h in culture. Hypothermia provided similar protection against oxygen-glucose deprivation (42%, P ≤ 0·001, 95% confidence interval 18·3-71·3 and 26%, P ≤ 0·001; 95% confidence interval 12·4-52·2, respectively) but provided no protection against oxygen deprivation alone. Protection (21%) persisted against H2 O2 -induced oxidative stress even when hypothermia was initiated six-hours after onset of injury (P ≤ 0·05; 95% confidence interval 0·57-43·1). CONCLUSION We conclude that hypothermia protects stem cell-derived human neurons against insults relevant to stroke over a clinically relevant time frame. Protection against H2 O2 -induced injury and combined oxygen and glucose deprivation but not against oxygen deprivation alone suggests an interaction in which protection benefits from reduction in available glucose under some but not all circumstances.
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Affiliation(s)
- Ana Antonic
- Florey Institute of Neuroscience and Mental HealthHeidelberg, Vic, Australia
- Department of Medicine, University of MelbourneHeidelberg, Vic, Australia
| | - Mirella Dottori
- Centre for Neuroscience Research, Department of Anatomy and Neuroscience, University of MelbourneMelbourne, Vic, Australia
| | - Jessie Leung
- Centre for Neuroscience Research, Department of Anatomy and Neuroscience, University of MelbourneMelbourne, Vic, Australia
| | - Kate Sidon
- Florey Institute of Neuroscience and Mental HealthHeidelberg, Vic, Australia
- Department of Medicine, University of MelbourneHeidelberg, Vic, Australia
| | - Peter E Batchelor
- Department of Medicine, University of MelbourneHeidelberg, Vic, Australia
| | - William Wilson
- CSIRO Mathematics, Informatics and Statistics, Riverside Life Sciences PrecinctNorth Ryde, NSW, Australia
| | - Malcolm R Macleod
- Department of Clinical Neurosciences, Western General Hospital, University of EdinburghEdinburgh, UK
| | - David W Howells
- Florey Institute of Neuroscience and Mental HealthHeidelberg, Vic, Australia
- Department of Medicine, University of MelbourneHeidelberg, Vic, Australia
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Stetler RA, Leak RK, Gan Y, Li P, Zhang F, Hu X, Jing Z, Chen J, Zigmond MJ, Gao Y. Preconditioning provides neuroprotection in models of CNS disease: paradigms and clinical significance. Prog Neurobiol 2014; 114:58-83. [PMID: 24389580 PMCID: PMC3937258 DOI: 10.1016/j.pneurobio.2013.11.005] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 11/18/2013] [Accepted: 11/18/2013] [Indexed: 12/14/2022]
Abstract
Preconditioning is a phenomenon in which brief episodes of a sublethal insult induce robust protection against subsequent lethal injuries. Preconditioning has been observed in multiple organisms and can occur in the brain as well as other tissues. Extensive animal studies suggest that the brain can be preconditioned to resist acute injuries, such as ischemic stroke, neonatal hypoxia/ischemia, surgical brain injury, trauma, and agents that are used in models of neurodegenerative diseases, such as Parkinson's disease and Alzheimer's disease. Effective preconditioning stimuli are numerous and diverse, ranging from transient ischemia, hypoxia, hyperbaric oxygen, hypothermia and hyperthermia, to exposure to neurotoxins and pharmacological agents. The phenomenon of "cross-tolerance," in which a sublethal stress protects against a different type of injury, suggests that different preconditioning stimuli may confer protection against a wide range of injuries. Research conducted over the past few decades indicates that brain preconditioning is complex, involving multiple effectors such as metabolic inhibition, activation of extra- and intracellular defense mechanisms, a shift in the neuronal excitatory/inhibitory balance, and reduction in inflammatory sequelae. An improved understanding of brain preconditioning should help us identify innovative therapeutic strategies that prevent or at least reduce neuronal damage in susceptible patients. In this review, we focus on the experimental evidence of preconditioning in the brain and systematically survey the models used to develop paradigms for neuroprotection, and then discuss the clinical potential of brain preconditioning.
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Affiliation(s)
- R Anne Stetler
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai Medical College, Shanghai 200032, China; Department of Neurology and Center of Cerebrovascular Disease Research, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA; Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA
| | - Rehana K Leak
- Division of Pharmaceutical Sciences, Mylan School of Pharmacy, Duquesne University, Pittsburgh, PA 15282, USA
| | - Yu Gan
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai Medical College, Shanghai 200032, China; Department of Neurology and Center of Cerebrovascular Disease Research, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA
| | - Peiying Li
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai Medical College, Shanghai 200032, China; Department of Neurology and Center of Cerebrovascular Disease Research, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA
| | - Feng Zhang
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai Medical College, Shanghai 200032, China; Department of Neurology and Center of Cerebrovascular Disease Research, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA; Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA
| | - Xiaoming Hu
- Department of Neurology and Center of Cerebrovascular Disease Research, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA; Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA
| | - Zheng Jing
- Department of Neurology and Center of Cerebrovascular Disease Research, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA; Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA
| | - Jun Chen
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai Medical College, Shanghai 200032, China; Department of Neurology and Center of Cerebrovascular Disease Research, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA; Geriatric Research, Educational and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA 15261, USA
| | - Michael J Zigmond
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai Medical College, Shanghai 200032, China; Department of Neurology and Center of Cerebrovascular Disease Research, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15213, USA
| | - Yanqin Gao
- State Key Laboratory of Medical Neurobiology and Institute of Brain Sciences, Fudan University, Shanghai Medical College, Shanghai 200032, China.
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Brödemann R, Peters B, Höllt V, Becker A. Dynamic aspects of cerebral hypoxic preconditioning measured in an in vitro model. Neurosci Lett 2014; 558:175-9. [PMID: 24240010 DOI: 10.1016/j.neulet.2013.10.069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 10/17/2013] [Accepted: 10/29/2013] [Indexed: 11/25/2022]
Abstract
Preconditioning increases the neurons' resistance to subsequent hypoxia. An in vitro study was conducted to explore kinetic aspects of hypoxic preconditioning. Hippocampal slices were exposed to one single or repeated episodes of oxygen and glucose deprivation (OGD). The interval between OGD episodes varied between 30 min and 180 min. OGD led to a significant reduction in the population spike amplitude. Subsequent episodes of OGD did not result in a further reduction in the population spike amplitude if the interval between the episodes was ca. 60 min, which demonstrated that there were preconditioning effects. In the experiment using an interval of 30 min, population spike amplitude decreased after each OGD episode. The set-up described is useful for detecting damaging effects of OGD as well as preconditioning effects. A time window of ca. 60 min is required to induce protective mechanisms.
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Affiliation(s)
- Rudolf Brödemann
- Otto-von-Guericke University, Faculty of Medicine, Institute of Pharmacology and Toxicology, Leipziger Str. 44, D-39120 Magdeburg, Germany
| | - Brigitte Peters
- Otto-von-Guericke University, Faculty of Medicine, Department of Biometry and Informatics, Leipziger Str. 44, D-39120 Magdeburg, Germany
| | - Volker Höllt
- Otto-von-Guericke University, Faculty of Medicine, Institute of Pharmacology and Toxicology, Leipziger Str. 44, D-39120 Magdeburg, Germany
| | - Axel Becker
- Otto-von-Guericke University, Faculty of Medicine, Institute of Pharmacology and Toxicology, Leipziger Str. 44, D-39120 Magdeburg, Germany.
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Ariyaratnam P, Loubani M, Cale ARJ, Chaudhry M, Cowen ME, Jarvis MA, Griffin S, Morice AH. The effect of deep hypothermia on the human pulmonary circulation. J Therm Biol 2014; 40:20-4. [PMID: 24556256 DOI: 10.1016/j.jtherbio.2014.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 01/02/2014] [Accepted: 01/06/2014] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Acute rises in pulmonary artery pressures following complex cardiac surgery are associated with high morbidity and mortality. We hypothesised that periods of deep hypothermia predispose to elevated pulmonary pressures upon rewarming. We investigated the effect of this hypothermic preconditioning on isolated human pulmonary arteries and isolated perfused lungs. METHODS Isometric tension was measured in human pulmonary artery rings (n=24). We assessed the constriction and dilation of these arteries at 37 °C and 17 °C. Isolated perfused human lung models consisted of lobes ventilated via a bronchial cannula and perfused with Krebs via a pulmonary artery cannula. Bronchial and pulmonary artery pressures were recorded. We investigated the effect of temperature using a heat exchanger. RESULTS Rewarming from 17 °C to 37 °C caused a 1.3 fold increase in resting tension (p<0.05). Arteries constricted 8.6 times greater to 30 nM KCl, constricted 17 times greater to 1 nM Endothelin-1 and dilated 30.3 times greater to 100 μM SNP at 37 °C than at 17 °C (p<0.005). No difference was observed in the responses of arteries originally maintained at 37 °C compared to those arteries maintained at 17 °C and rewarmed to 37 °C. Hypothermia blunted the increase in pulmonary artery pressures to stimulants such as potassium chloride as well as to H-R but did not precondition arteries to higher pulmonary artery pressures upon re-warming. CONCLUSIONS Deep hypothermia reduces the responsiveness of human pulmonary arteries but does not, however, precondition an exaggerated response to vasoactive agents upon re-warming.
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Affiliation(s)
| | - Mahmoud Loubani
- Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham HU16 5JQ, UK
| | - Alexander R J Cale
- Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham HU16 5JQ, UK
| | - Mubarak Chaudhry
- Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham HU16 5JQ, UK
| | - Michael E Cowen
- Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham HU16 5JQ, UK
| | - Martin A Jarvis
- Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham HU16 5JQ, UK
| | - Steven Griffin
- Department of Cardiothoracic Surgery, Castle Hill Hospital, Cottingham HU16 5JQ, UK
| | - Alyn H Morice
- Department of Academic Medicine, Castle Hill Hospital, Cottingham HU16 5JQ, UK
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Abstract
Excitatory amino-acid transporters (EAATs) transport glutamate into cells under physiologic conditions. Excitatory amino-acid transporter type 3 (EAAT3) is the major neuronal EAAT and also uptakes cysteine, the rate-limiting substrate for synthesis of glutathione. Thus, we hypothesize that EAAT3 contributes to providing brain ischemic tolerance. Male 8-week-old EAAT3 knockout mice on CD-1 mouse gene background and wild-type CD-1 mice were subjected to right middle cerebral artery occlusion for 90 minutes. Their brain infarct volumes, neurologic functions, and brain levels of glutathione, nitrotyrosine, and 4-hydroxy-2-nonenal (HNE) were evaluated. The EAAT3 knockout mice had bigger brain infarct volumes and worse neurologic deficit scores and motor coordination functions than did wild-type mice, no matter whether these neurologic outcome parameters were evaluated at 24 hours or at 4 weeks after brain ischemia. The EAAT3 knockout mice contained higher levels of HNE in the ischemic penumbral cortex and in the nonischemic cerebral cortex than did wild-type mice. Glutathione levels in the ischemic and nonischemic cortices of EAAT3 knockout mice tended to be lower than those of wild-type mice. Our results suggest that EAAT3 is important in limiting ischemic brain injury after focal brain ischemia. This effect may involve attenuating brain oxidative stress.
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8
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Hypothermic protection in an acute hypoxia model in rats: Acid-base and oxidant/antioxidant profiles. Resuscitation 2010; 81:609-16. [PMID: 20207468 DOI: 10.1016/j.resuscitation.2010.01.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 12/22/2009] [Accepted: 01/20/2010] [Indexed: 11/22/2022]
Abstract
AIM OF THE STUDY Recent works demonstrate the benefits of hypothermia when used to preserve brain, cardiac, hepatic, and intestinal function against hypoxic-ischemic injury. However, it is also known that hypothermia affects systemic parameters and also induces the generation of reactive oxygen species in cells and tissues. Here we studied the acid-base related parameters and the antioxidant-oxidant effects of deep hypothermia induction before an acute hypoxic insult in rats. METHODS Acid-base indicators and parameters related to oxidative stress were analyzed in hypothermic rats (21-22 degrees C) breathing room air during 2h (control hypothermia), and hypothermic animals switched to hypoxic air (10% O(2)) during the second hour (hypothermia hypoxia group), and they were compared with corresponding normothermia groups maintained at 37 degrees C (control normothermia and normothermia hypoxia groups). RESULTS Mild metabolic acidosis appeared early in arterial blood during hypothermia. After exposure to hypoxia, evidence of tissue injury (plasma transaminases and blood lactate) and oxidative stress (increase in lipid peroxidation, decrease in glutathione levels and in the glutathione reduction potential in liver) was found. In contrast, in the hypothermia hypoxia group, plasmatic parameters remained as the control values, and the hepatic glutathione reduction potential were significantly more negative when compared with the normothermia hypoxia group. CONCLUSIONS We propose that acidosis induced by hypothermia contributes to the maintenance of intracellular reduction potential in liver, regarding the GSSG/2GSH couple and may help to increase plasmatic antioxidant pool. Our findings provide new insights into the protective effects of hypothermia in vivo.
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9
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Cell death and proliferation in acute slices and organotypic cultures of mammalian CNS. Prog Neurobiol 2009; 88:221-45. [DOI: 10.1016/j.pneurobio.2009.01.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Revised: 12/09/2008] [Accepted: 01/07/2009] [Indexed: 11/24/2022]
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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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Katz LM, Frank JE, Dvorak A, Finch A, Szymanowski A, Gordon CJ. Independence of brain and trunk temperature during hypothermic preconditioning in rats. J Neurosci Methods 2009; 179:179-83. [PMID: 19428525 DOI: 10.1016/j.jneumeth.2009.01.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 01/24/2009] [Accepted: 01/26/2009] [Indexed: 12/01/2022]
Abstract
UNLABELLED Hypothermic preconditioning is rapid cooling and warming to induce tolerance to ischemia. The purpose of the study was to examine differences in brain and trunk temperature during hypothermic preconditioning. METHODS Rats (n=18) were implanted with telemetric probes for simultaneous measure of brain and trunk temperature. Hypothermic preconditioning was produced by exposing rats to cool and warm environments that produced rapid cooling to 30 degrees C and warming to 35 degrees C. RESULTS Brain temperature was warmer (37.56+/-0.45 degrees C) than trunk (37.17+/-0.29 degrees C) temperature in unanesthetized, free roaming rats at room temperature (t-test p=0.04). The brain cooled (0.59+/-0.1 degrees C/min) quicker than the trunk (0.44+/-0.19 degrees C/min) during cooling cycles of hypothermic preconditioning and the brain (0.28+/-0.04 degrees C/min) warmed quicker than the trunk (0.18+/-0.07 degrees C/min) during the warming cycle of hypothermic preconditioning (t-test p<0.0001). When the trunk temperature probe was designated to reach the target temperature of 35 degrees C during warming, the brain temperature (38.1+/-0.44 degrees C) was warmer than trunk temperature (34.95+/-0.16 degrees C) during the peak of warming (t-test p<0.0001). CONCLUSION The brain cools and warms quicker than the trunk during hypothermic preconditioning. Failure to anticipate these differences could lead to unrecognized brain hyperthermia during warming. Appreciation of differences in rates of change between brain and trunk temperature may be important when designing hypothermic preconditioning experiments.
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Affiliation(s)
- Laurence M Katz
- University of North Carolina School of Medicine, Department of Emergency Medicine, CB 7594, Neurosciences Hospital Ground Floor, 101 Manning Drive, Chapel Hill, NC 27599, USA.
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Wang ZF, Tang XC. Huperzine A protects C6 rat glioma cells against oxygen-glucose deprivation-induced injury. FEBS Lett 2007; 581:596-602. [PMID: 17257593 DOI: 10.1016/j.febslet.2007.01.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 12/28/2006] [Accepted: 01/10/2007] [Indexed: 10/23/2022]
Abstract
The protective effects of huperzine A against oxygen-glucose deprivation (OGD)-induced injury in C6 cells were investigated. OGD for 6h and reoxygenation for 6h enhanced phosphorylation and degradation of IkappaBalpha and nuclear translocation of nuclear factor-kappa B (NF-kappaB), triggered overexpression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and nitric oxide (NO) in C6 cells. Along with inhibiting acetylcholinesterase activity, treatment with 1 microM huperzine A inhibited activation of NF-kappaB, attenuated iNOS, COX-2 and NO overexpression, and promoted survival in C6 cells subjected to OGD insult. The protective effects of huperzine A were partly mediated by "cholinergic anti-inflammatory pathway" through alpha7 nicotinic acetylcholine receptor.
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Affiliation(s)
- Zhi Fei Wang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, People's Republic of China
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