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Amoroso VG, Zhao A, Vargas I, Park TJ. Naked Mole-Rats Demonstrate Profound Tolerance to Low Oxygen, High Carbon Dioxide, and Chemical Pain. Animals (Basel) 2023; 13:ani13050819. [PMID: 36899677 PMCID: PMC10000161 DOI: 10.3390/ani13050819] [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: 01/17/2023] [Revised: 02/21/2023] [Accepted: 02/21/2023] [Indexed: 03/12/2023] Open
Abstract
Naked mole-rats (Heterocephalus glaber) are very unusual among subterranean mammals in that they live in large colonies and are extremely social, spending large amounts of time gathered together in underground nests more than a meter below the surface. Many respiring individuals resting in deep, poorly ventilated nests deplete the oxygen supply and increase the concentration of carbon dioxide. Consistent with living in that atmosphere, naked mole-rats tolerate levels of low oxygen and high carbon dioxide that are deadly to most surface-dwelling mammals. Naked mole-rats appear to have evolved a number of remarkable adaptations to be able to thrive in this harsh atmosphere. In order to successfully survive low oxygen atmospheres, they conserve energy utilization by reducing the physiological activity of all organs, manifest by reduced heart rate and brain activity. Amazingly, they resort to the anaerobic metabolism of fructose rather than glucose as a fuel to generate energy when challenged by anoxia. Similarly, high carbon dioxide atmospheres normally cause tissue acidosis, while naked mole-rats have a genetic mutation preventing both acid-induced pain and pulmonary edema. Together, these putative adaptations and the tolerances they provide make the naked mole-rat an important model for studying a host of biomedical challenges.
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Affiliation(s)
- Vince G Amoroso
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Aishi Zhao
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Isabel Vargas
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Thomas J Park
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
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Yang W, Wu W, Zhao Y, Li Y, Zhang C, Zhang J, Chen C, Cui S. Caveolin-1 suppresses hippocampal neuron apoptosis via the regulation of HIF1α in hypoxia in naked mole-rats. Cell Biol Int 2022; 46:2060-2074. [PMID: 36054154 PMCID: PMC9826031 DOI: 10.1002/cbin.11890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 07/08/2022] [Accepted: 08/05/2022] [Indexed: 01/11/2023]
Abstract
Naked mole-rats (NMRs) (Heterocephalus glaber) are highly social and subterranean rodents with large communal colonies in burrows containing low oxygen levels. The inhibition of severe hypoxic conditions is of particular interest to this study. To understand the mechanisms that facilitate neuronal preservation during hypoxia, we investigated the proteins regulating hypoxia tolerance in NMR hippocampal neurons. Caveolin-1 (Cav-1), a transmembrane scaffolding protein, confers prosurvival signalling in the central nervous system. The present study aimed to investigate the role of Cav-1 in hypoxia-induced neuronal injury. Western blotting analysis and immunocytochemistry showed that Cav-1 expression was significantly upregulated in NMR hippocampal neurons under 8% O2 conditions for 8 h. Cav-1 alleviates apoptotic neuronal death from hypoxia. Downregulation of Cav-1 by lentiviral vectors suggested damage to NMR hippocampal neurons under hypoxic conditions in vitro and in vivo. Overexpression of Cav-1 by LV-Cav-1 enhanced hypoxic tolerance of NMR hippocampal neurons in vitro and in vivo. Mechanistically, the levels of hypoxia inducible factor-1α (HIF-1α) are also increased under hypoxic conditions. After inhibiting the binding of HIF-1α to hypoxia response elements in the DNA by echinomycin, Cav-1 levels were downregulated significantly. Furthermore, chromatin immunoprecipitation assays showed the direct role of HIF1α in regulating the expression levels of Cav-1 in NMR hippocampal neurons under hypoxic conditions. These findings suggest that Cav-1 plays a critical role in modulating the apoptosis of NMR hippocampal neurons and warrant further studies targeting Cav-1 to treat hypoxia-associated brain diseases.
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Affiliation(s)
- Wenjing Yang
- Department of Laboratory Animal Sciences, School of Basic MedicineNaval Medical UniversityShanghaiChina
| | - Wenqing Wu
- Department of Laboratory Animal CenterAcademy of Military Medical SciencesBeijingChina
| | - Ying Zhao
- Shanghai Laboratory Animal Research CenterShanghaiChina
| | - Yu Li
- Department of Laboratory Animal Sciences, School of Basic MedicineNaval Medical UniversityShanghaiChina
| | - Chengcai Zhang
- Department of Laboratory Animal Sciences, School of Basic MedicineNaval Medical UniversityShanghaiChina
| | - Jingyuan Zhang
- Department of Laboratory Animal Sciences, School of Basic MedicineNaval Medical UniversityShanghaiChina
| | - Chao Chen
- Department of Laboratory Animal Sciences, School of Basic MedicineNaval Medical UniversityShanghaiChina
| | - Shufang Cui
- Department of Laboratory Animal Sciences, School of Basic MedicineNaval Medical UniversityShanghaiChina
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Ekwudo MN, Malek MC, Anderson CE, Yampolsky LY. The interplay between prior selection, mild intermittent exposure, and acute severe exposure in phenotypic and transcriptional response to hypoxia. Ecol Evol 2022; 12:e9319. [PMID: 36248677 PMCID: PMC9548574 DOI: 10.1002/ece3.9319] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/01/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
Hypoxia has profound and diverse effects on aerobic organisms, disrupting oxidative phosphorylation and activating several protective pathways. Predictions have been made that exposure to mild intermittent hypoxia may be protective against more severe exposure and may extend lifespan. Here we report the lifespan effects of chronic, mild, intermittent hypoxia, and short-term survival in acute severe hypoxia in four clones of Daphnia magna originating from either permanent or intermittent habitats. We test the hypothesis that acclimation to chronic mild intermittent hypoxia can extend lifespan through activation of antioxidant and stress-tolerance pathways and increase survival in acute severe hypoxia through activation of oxygen transport and storage proteins and adjustment to carbohydrate metabolism. Unexpectedly, we show that chronic hypoxia extended the lifespan in the two clones originating from intermittent habitats but had the opposite effect in the two clones from permanent habitats, which also showed lower tolerance to acute hypoxia. Exposure to chronic hypoxia did not protect against acute hypoxia; to the contrary, Daphnia from the chronic hypoxia treatment had lower acute hypoxia tolerance than normoxic controls. Few transcripts changed their abundance in response to the chronic hypoxia treatment in any of the clones. After 12 h of acute hypoxia treatment, the transcriptional response was more pronounced, with numerous protein-coding genes with functionality in oxygen transport, mitochondrial and respiratory metabolism, and gluconeogenesis, showing upregulation. While clones from intermittent habitats showed somewhat stronger differential expression in response to acute hypoxia than those from permanent habitats, contrary to predictions, there were no significant hypoxia-by-habitat of origin or chronic-by-acute treatment interactions. GO enrichment analysis revealed a possible hypoxia tolerance role by accelerating the molting cycle and regulating neuron survival through upregulation of cuticular proteins and neurotrophins, respectively.
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Affiliation(s)
- Millicent N. Ekwudo
- Department of Biological SciencesEast Tennessee State UniversityJohnson CityTennesseeUSA
- Ann Romney Center for Neurologic Diseases, Brigham and Women's HospitalHarvard Medical SchoolBostonMassachusettsUSA
| | - Morad C. Malek
- Department of Biological SciencesEast Tennessee State UniversityJohnson CityTennesseeUSA
| | - Cora E. Anderson
- Department of Biological SciencesEast Tennessee State UniversityJohnson CityTennesseeUSA
- Department of Biological SciencesUniversity of Notre DameNotre DameIndianaUSA
| | - Lev Y. Yampolsky
- Department of Biological SciencesEast Tennessee State UniversityJohnson CityTennesseeUSA
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Osuru HP, Lavallee M, Thiele RH. Molecular and Cellular Response of the Myocardium (H9C2 Cells) Towards Hypoxia and HIF-1α Inhibition. Front Cardiovasc Med 2022; 9:711421. [PMID: 35928940 PMCID: PMC9343679 DOI: 10.3389/fcvm.2022.711421] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 06/21/2022] [Indexed: 11/30/2022] Open
Abstract
Introduction Oxidative phosphorylation is an essential feature of Animalian life. Multiple adaptations have developed to protect against hypoxia, including hypoxia-inducible-factors (HIFs). The major role of HIFs may be in protecting against oxidative stress, not the preservation of high-energy phosphates. The precise mechanism(s) of HIF protection is not completely understood. Materials and Methods To better understand the role of hypoxia-inducible-factor-1, we exposed heart/myocardium cells (H9c2) to both normoxia and hypoxia, as well as cobalt chloride (prolyl hydroxylase inhibitor), echniomycin (HIF inhibitor), A2P (anti-oxidant), and small interfering RNA to beclin-1. We measured cell viability, intracellular calcium and adenosine triphosphate, NADP/NADPH ratios, total intracellular reactive oxidative species levels, and markers of oxidative and antioxidant levels measured. Results Hypoxia (1%) leads to increased intracellular Ca2+ levels, and this response was inhibited by A2P and echinomycin (ECM). Exposure of H9c2 cells to hypoxia also led to an increase in both mRNA and protein expression for Cav 1.2 and Cav 1.3. Exposure of H9c2 cells to hypoxia led to a decrease in intracellular ATP levels and a sharp reduction in total ROS, SOD, and CAT levels. The impact of hypoxia on ROS was reversed with HIF-1 inhibition through ECM. Exposure of H9c2 cells to hypoxia led to an increase in Hif1a, VEGF and EPO protein expression, as well as a decrease in mitochondrial DNA. Both A2P and ECM attenuated this response to varying degrees. Conclusion Hypoxia leads to increased intracellular Ca2+, and inhibition of HIF-1 attenuates the increase in intracellular Ca2+ that occurs with hypoxia. HIF-1 expression leads to decreased adenosine triphosphate levels, but the role of HIF-1 on the production of reactive oxidative species remains uncertain. Anti-oxidants decrease HIF-1 expression in the setting of hypoxia and attenuate the increase in Ca2+ that occurs during hypoxia (with no effect during normoxia). Beclin-1 appears to drive autophagy in the setting of hypoxia (through ATG5) but not in normoxia. Additionally, Beclin-1 is a powerful driver of reactive oxidative species production and plays a role in ATP production. HIF-1 inhibition does not affect autophagy in the setting of hypoxia, suggesting that there are other drivers of autophagy that impact beclin-1.
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Dzhalilova D, Kosyreva A, Vishnyakova P, Zolotova N, Tsvetkov I, Mkhitarov V, Mikhailova L, Kakturskiy L, Makarova O. Age-related differences in hypoxia-associated genes and cytokine profile in male Wistar rats. Heliyon 2021; 7:e08085. [PMID: 34632150 PMCID: PMC8488852 DOI: 10.1016/j.heliyon.2021.e08085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 08/25/2021] [Accepted: 09/26/2021] [Indexed: 11/29/2022] Open
Abstract
Hypoxia tolerance of the organism depends on many factors, including age. High newborn organisms tolerance and high level of oxidative stress throughout aging were demonstrated by many studies. However, there is lack of investigations reflecting the expression of key hypoxia-inducible factor HIF in different age organisms in correlation to levels of pro-inflammatory and anti-inflammatory cytokines. Liver is a sensitive to hypoxia organ, and is an important organ in providing an acute reaction to infections – it synthesizes acute inflammation phase proteins, in particular, C-reactive protein. The aim of study was to determine relationship between age-related tolerance to hypoxia and HIF-1 and PHD2 (prolyl hydroxylase domain protein) expression levels in the liver and the production of cytokines in the spleen in newborn, prepubertal and adult Wistar rats. Newborn rats are characterized by high mRNA Hif-1α expression level in the liver, accompanied by a low content of HIF-1 protein and high level of PHD2. The growth in HIF-1α protein level throughout age is accompanied by the growth of pro-inflammatory cytokines level. Prepubertal animals are the least hypoxia resistant and their HIF-1α mRNA expression level was higher than in adult animals. The PHD2 activity in prepubertal animals was significantly reduced in comparison to newborn rats, and the HIF-1α protein level did not change. Further studies require the identification of additional mechanisms, determining the regulation of the HIF-1α level in prepubertal animals.
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Affiliation(s)
- Dzhuliia Dzhalilova
- Department of Immunomorphology of Inflammation, Federal State Budgetary Institution Research Institute of Human Morphology, 117418, Tsurupa st., 3, Moscow, Russia
| | - Anna Kosyreva
- Department of Immunomorphology of Inflammation, Federal State Budgetary Institution Research Institute of Human Morphology, 117418, Tsurupa st., 3, Moscow, Russia.,Histology Department, Peoples Friendship University of Russia (RUDN University), 117198, Miklukho-Maklaya st. 6, Moscow, Russia
| | - Polina Vishnyakova
- Histology Department, Peoples Friendship University of Russia (RUDN University), 117198, Miklukho-Maklaya st. 6, Moscow, Russia.,National Medical Research Center for Obstetrics, Gynecology and Perinatology Named After Academician V.I. Kulakov of Ministry of Healthcare of Russian Federation, 117997, Oparina st., 4, Moscow, Russia
| | - Natalia Zolotova
- Department of Immunomorphology of Inflammation, Federal State Budgetary Institution Research Institute of Human Morphology, 117418, Tsurupa st., 3, Moscow, Russia
| | - Ivan Tsvetkov
- Department of Immunomorphology of Inflammation, Federal State Budgetary Institution Research Institute of Human Morphology, 117418, Tsurupa st., 3, Moscow, Russia
| | - Vladimir Mkhitarov
- Department of Immunomorphology of Inflammation, Federal State Budgetary Institution Research Institute of Human Morphology, 117418, Tsurupa st., 3, Moscow, Russia
| | - Liliya Mikhailova
- Department of Immunomorphology of Inflammation, Federal State Budgetary Institution Research Institute of Human Morphology, 117418, Tsurupa st., 3, Moscow, Russia
| | - Lev Kakturskiy
- Department of Immunomorphology of Inflammation, Federal State Budgetary Institution Research Institute of Human Morphology, 117418, Tsurupa st., 3, Moscow, Russia
| | - Olga Makarova
- Department of Immunomorphology of Inflammation, Federal State Budgetary Institution Research Institute of Human Morphology, 117418, Tsurupa st., 3, Moscow, Russia
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6
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Glover CN, Goss GG. Hypoxia modifies calcium handling in the Pacific hagfish, Eptatretus stoutii. Comp Biochem Physiol A Mol Integr Physiol 2021; 261:111042. [PMID: 34329740 DOI: 10.1016/j.cbpa.2021.111042] [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: 04/21/2021] [Revised: 07/09/2021] [Accepted: 07/23/2021] [Indexed: 10/20/2022]
Abstract
Hagfishes may encounter low dissolved oxygen in their natural habitats, a consequence of association with hypoxic sediments and their feeding behaviour. In teleost fish, hypoxia exposure decreases ion uptake, speculated to be a mechanism for energy conservation. Although hagfishes osmoconform, they do regulate extracellular fluid concentrations of divalent cations such as calcium. The current study hypothesised that exposure of hagfish to hypoxia (0.4 kPA, 24 h) would reduce calcium uptake (determined via in vitro isolated skin and gut epithelial transport assays) and calcium accumulation (determined by in vivo whole animal exposures, using radiolabelled calcium (45Ca) to assess newly acquired calcium). A decrease in in vitro epidermal uptake was observed at sub-environmental calcium levels (10 μM), but not at environmental calcium levels (10 mM). No changes in gut calcium uptake were determined. Conversely, hypoxia led to a more rapid in vivo accumulation of calcium in tissues (skin, muscle, liver, heart, plasma, brain), mediated mostly by a significant increase in accumulation at the gill. These differences were only apparent after 1-h of exposure to the radiolabel (i.e., the last hour of the 24-h hypoxia exposure) and were not observed after 3 and 24 h periods of radiolabel exposure. This outcome was the opposite of the hypothesised effect. The reasons for a more rapid accumulation of calcium in hypoxic hagfish are unknown but may relate to roles for calcium in enhancing hypoxia tolerance in hagfishes or could be a consequence of changes in ventilatory frequency.
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Affiliation(s)
- Chris N Glover
- Faculty of Science and Technology and Athabasca River Basin Research Institute, Athabasca University, Athabasca, Alberta, Canada; Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada; Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
| | - Greg G Goss
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada; Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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7
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Park TJ, Smith ESJ, Reznick J, Bennett NC, Applegate DT, Larson J, Lewin GR. African Naked Mole-Rats Demonstrate Extreme Tolerance to Hypoxia and Hypercapnia. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1319:255-269. [PMID: 34424519 DOI: 10.1007/978-3-030-65943-1_9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Naked mole-rats are extremely tolerant to low concentrations of oxygen (hypoxia) and high concentrations of carbon dioxide (hypercapnia), which is consistent with the environment that they inhabit. Naked mole-rats combine subterranean living with living in very densely populated colonies where oxygen becomes depleted and carbon dioxide accumulates. In the laboratory, naked mole-rats fully recover from 5 h exposure to 5% O2 and 5 h exposure to 80% CO2, whereas both conditions are rapidly lethal to similarly sized laboratory mice. During anoxia (0% O2) naked mole-rats enter a suspended animation-like state and switch from aerobic metabolism of glucose to anaerobic metabolism of fructose. Additional fascinating characteristics include that naked mole-rats show intrinsic brain tolerance to anoxia; a complete lack of hypoxia-induced and CO2-induced pulmonary edema; and reduced aversion to high concentrations of CO2 and acidic fumes. Here we outline a constellation of physiological and molecular adaptations that correlate with the naked mole-rat's hypoxic/hypercapnic tolerance and which offer potential targets for ameliorating pathological conditions in humans, such as the damage caused during cerebral ischemia.
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Affiliation(s)
- Thomas J Park
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA.
| | - Ewan St J Smith
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Jane Reznick
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - N C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Daniel T Applegate
- Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - John Larson
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, USA
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, Berlin, Germany
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8
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Dzhalilova D, Makarova O. Differences in Tolerance to Hypoxia: Physiological, Biochemical, and Molecular-Biological Characteristics. Biomedicines 2020; 8:E428. [PMID: 33080959 PMCID: PMC7603118 DOI: 10.3390/biomedicines8100428] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 02/07/2023] Open
Abstract
Hypoxia plays an important role in the development of many infectious, inflammatory, and tumor diseases. The predisposition to such disorders is mostly provided by differences in basic tolerance to oxygen deficiency, which we discuss in this review. Except the direct exposure of different-severity hypoxia in decompression chambers or in highland conditions, there are no alternative methods for determining organism tolerance. Due to the variability of the detection methods, differences in many parameters between tolerant and susceptible organisms are still not well-characterized, but some of them can serve as biomarkers of susceptibility to hypoxia. At the moment, several potential biomarkers in conditions after hypoxic exposure have been identified both in experimental animals and humans. The main potential biomarkers are Hypoxia-Inducible Factor (HIF)-1, Heat-Shock Protein 70 (HSP70), and NO. Due to the different mechanisms of various high-altitude diseases, biomarkers may not be highly specific and universal. Therefore, it is extremely important to conduct research on hypoxia susceptibility biomarkers. Moreover, it is important to develop a method for the evaluation of organisms' basic hypoxia tolerance without the necessity of any oxygen deficiency exposure. This can contribute to new personalized medicine approaches' development for diagnostics and the treatment of inflammatory and tumor diseases, taking into account hypoxia tolerance differences.
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Affiliation(s)
- Dzhuliia Dzhalilova
- Department of Immunomorphology of Inflammation, Federal State Budgetary Institution ‘Research Institute of Human Morphology’, Moscow 117418, Russia;
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9
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Kim YS, Won YJ, Lim BG, Min TJ, Kim YH, Lee IO. Neuroprotective effects of magnesium L-threonate in a hypoxic zebrafish model. BMC Neurosci 2020; 21:29. [PMID: 32590943 PMCID: PMC7318545 DOI: 10.1186/s12868-020-00580-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 06/21/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Hypoxia inhibits the uptake of glutamate (a major neurotransmitter in the brain closely related to cognitive function) into brain cells, and the initial response of cells to cortical hypoxia depends on glutamate. Previous studies have suggested that magnesium may have protective effects against hypoxic injuries. In particular, magnesium L-threonate (MgT) may increase magnesium ion concentrations in the brain better than MgSO4 and improve cognitive function. METHODS We evaluated cell viability under hypoxic conditions in the MgT- and MgSO4-treated human SH-SY5Y neurons, in vivo behavior using the T-maze test following hypoxia in MgT-treated zebrafish, activity of brain mitochondrial dehydrogenase by 2,3,5-triphenyltetrazolium chloride (TTC) staining, and protein expression of the excitatory amino acid transporter (EAAT) 4 glutamate transporter by western blotting. RESULTS Among the groups treated with hypoxia, cell viability significantly increased when pre-treated with 1 or 10 mM MgT (p = 0.009 and 0.026, respectively). Despite hypoxic insult, MgT-treated zebrafish showed preferences for the red compartment (p = 0.025 for distance and p = 0.007 for frequency of entries), suggesting memory preservation. TTC staining showed reduced cerebral infarction and preserved absorbance in the MgT-treated zebrafish brain after hypoxia (p = 0.010 compared to the hypoxia group). In addition, western blot showed upregulation of EAAT4 protein in the MgT treated group. CONCLUSIONS Pre-treatment with MgT attenuated cell death and cerebral infarction due to hypoxia and protected cognitive function in zebrafish. In addition, MgT appeared to modulate expression of the glutamate transporter, EAAT4.
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Affiliation(s)
- Young-Sung Kim
- Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Young Ju Won
- Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Byung Gun Lim
- Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Seoul, Korea
| | - Too Jae Min
- Department of Anesthesiology and Pain Medicine, Korea University Ansan Hospital, Ansan, Korea
| | - Yeon-Hwa Kim
- Institute of Medical Science, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea
| | - Il Ok Lee
- Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Seoul, Korea.
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10
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Dynamic regulation of six histone H3 lysine (K) methyltransferases in response to prolonged anoxia exposure in a freshwater turtle. Gene 2018; 649:50-57. [PMID: 29382574 DOI: 10.1016/j.gene.2018.01.086] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 01/03/2018] [Accepted: 01/26/2018] [Indexed: 12/26/2022]
Abstract
The importance of histone lysine methylation is well established in health, disease, early development, aging, and cancer. However, the potential role of histone H3 methylation in regulating gene expression in response to extended periods of oxygen deprivation (anoxia) in a natural, anoxia-tolerant model system is underexplored. Red-eared sliders (Trachemys scripta elegans) can tolerate and survive three months of absolute anoxia and recover without incurring detrimental cellular damage, mainly by reducing the overall metabolic rate by 90% when compared to normoxia. Stringent regulation of gene expression is a vital aspect of metabolic rate depression in red-eared sliders, and as such we examined the anoxia-responsive regulation of histone lysine methylation in the liver during 5 h and 20 h anoxia exposure. Interestingly, this is the first study to illustrate the existence of histone lysine methyltransferases (HKMTs) and corresponding histone H3 lysine methylation levels in the liver of anoxia-tolerant red-eared sliders. In brief, H3K4me1, a histone mark associated with active transcription, and two corresponding histone lysine methyltransferases that modify H3K4me1 site, significantly increased in response to anoxia. On the contrary, H3K27me1, another transcriptionally active histone mark, significantly decreased during 20 h anoxia, and a transcriptionally repressive histone mark, H3K9me3, and the corresponding KMTs, similarly increased during 20 h anoxia. Overall, the results suggest a dynamic regulation of histone H3 lysine methylation in the liver of red-eared sliders that could theoretically aid in the selective upregulation of genes that are necessary for anoxia survival, while globally suppressing others to conserve energy.
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11
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Grant Liska M, Crowley MG, Lippert T, Corey S, Borlongan CV. Delta Opioid Receptor and Peptide: A Dynamic Therapy for Stroke and Other Neurological Disorders. Handb Exp Pharmacol 2017; 247:277-299. [PMID: 28315071 DOI: 10.1007/164_2017_7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Research of the opioid system and its composite receptors and ligands has revealed its promise as a potential therapy for neurodegenerative diseases such as stroke and Parkinson's Disease. In particular, delta opioid receptors (DORs) have been elucidated as a therapeutically distinguished subset of opioid receptors and a compelling target for novel intervention techniques. Research is progressively shedding light on the underlying mechanism of DORs and has revealed two mechanisms of DOR neuroprotection; DORs function to maintain ionic homeostasis and also to trigger endogenous neuroprotective pathways. Delta opioid agonists such as (D-Ala2, D-Leu5) enkephalin (DADLE) have been shown to promote neuronal survival and decrease apoptosis, resulting in a substantial amount of research for its application as a neurological therapeutic. Most notably, DADLE has demonstrated significant potential to reduce cell death following ischemic events. Current research is working to reveal the complex mechanisms of DADLE's neuroprotective properties. Ultimately, our knowledge of the DOR receptors and agonists has made the opioid system a promising target for therapeutic intervention in many neurological disorders.
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Affiliation(s)
- M Grant Liska
- Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, Tampa, FL, 33612, USA
| | - Marci G Crowley
- Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, Tampa, FL, 33612, USA
| | - Trenton Lippert
- Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, Tampa, FL, 33612, USA
| | - Sydney Corey
- Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, Tampa, FL, 33612, USA
| | - Cesar V Borlongan
- Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, Tampa, FL, 33612, USA.
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12
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Olivares-González L, Martínez-Fernández de la Cámara C, Hervás D, Marín MP, Lahoz A, Millán JM, Rodrigo R. cGMP-Phosphodiesterase Inhibition Prevents Hypoxia-Induced Cell Death Activation in Porcine Retinal Explants. PLoS One 2016; 11:e0166717. [PMID: 27861632 PMCID: PMC5115799 DOI: 10.1371/journal.pone.0166717] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/02/2016] [Indexed: 12/11/2022] Open
Abstract
Retinal hypoxia and oxidative stress are involved in several retinal degenerations including diabetic retinopathy, glaucoma, central retinal artery occlusion, or retinopathy of prematurity. The second messenger cyclic guanosine monophosphate (cGMP) has been reported to be protective for neuronal cells under several pathological conditions including ischemia/hypoxia. The purpose of this study was to evaluate whether the accumulation of cGMP through the pharmacological inhibition of phosphodiesterase (PDE) with Zaprinast prevented retinal degeneration induced by mild hypoxia in cultures of porcine retina. Exposure to mild hypoxia (5% O2) for 24h reduced cGMP content and induced retinal degeneration by caspase dependent and independent (PARP activation) mechanisms. Hypoxia also produced a redox imbalance reducing antioxidant response (superoxide dismutase and catalase activities) and increasing superoxide free radical release. Zaprinast reduced mild hypoxia-induced cell death through inhibition of caspase-3 or PARP activation depending on the cell layer. PDE inhibition also ameliorated the effects of mild hypoxia on antioxidant response and the release of superoxide radical in the photoreceptor layer. The use of a PKG inhibitor, KT5823, suggested that cGMP-PKG pathway is involved in cell survival and antioxidant response. The inhibition of PDE, therefore, could be useful for reducing retinal degeneration under hypoxic/ischemic conditions.
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Affiliation(s)
- Lorena Olivares-González
- Grupo de Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | | | - David Hervás
- Unidad de Bioestadística, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | - María Pilar Marín
- Unidad de Microscopía, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | - Agustin Lahoz
- Unidad de Hepatología Experimental, Unidad Analítica, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | - José María Millán
- Grupo de Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Regina Rodrigo
- Grupo de Biomedicina Molecular, Celular y Genómica, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
- CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
- * E-mail:
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13
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Short-Term Differentiation of Glioblastoma Stem Cells Induces Hypoxia Tolerance. Neurochem Res 2016; 41:1545-58. [PMID: 26915110 PMCID: PMC4893075 DOI: 10.1007/s11064-016-1868-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 02/03/2016] [Accepted: 02/08/2016] [Indexed: 01/28/2023]
Abstract
Glioblastoma is the most common and malignant brain cancer. In spite of surgical removal, radiation and chemotherapy, this cancer recurs within short time and median survival after diagnosis is less than a year. Glioblastoma stem cells (GSCs) left in the brain after surgery is thought to explain the inevitable recurrence of the tumor. Although hypoxia is a prime factor contributing to treatment resistance in many cancers, its effect on GSC has been little studied. Especially how differentiation influences the tolerance to acute hypoxia in GSCs is not well explored. We cultured GSCs from three patient biopsies and exposed these and their differentiated (1- and 4-weeks) progeny to acute hypoxia while monitoring intracellular calcium and mitochondrial membrane potential (ΔΨm). Undifferentiated GSCs were not hypoxia tolerant, showing both calcium overload and mitochondrial depolarization. One week differentiated cells were the most tolerant to hypoxia, preserving intracellular calcium stability and ΔΨm during 15 min of acute hypoxia. After 4 weeks of differentiation, mitochondrial mass was significantly reduced. In these cells calcium homeostasis was maintained during hypoxia, although the mitochondria were depolarized, suggesting a reduced mitochondrial dependency. Basal metabolic rate increased by differentiation, however, low oxygen consumption and high ΔΨm in undifferentiated GSCs did not provide hypoxia tolerance. The results suggest that undifferentiated GSCs are oxygen dependent, and that limited differentiation induces relative hypoxia tolerance. Hypoxia tolerance may be a factor involved in high-grade malignancy. This warrants a careful approach to differentiation as a glioblastoma treatment strategy.
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Glycogen Fuels Survival During Hyposmotic-Anoxic Stress in Caenorhabditis elegans. Genetics 2015; 201:65-74. [PMID: 26116152 PMCID: PMC4566277 DOI: 10.1534/genetics.115.179416] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 06/18/2015] [Indexed: 11/18/2022] Open
Abstract
Oxygen is an absolute requirement for multicellular life. Animals that are deprived of oxygen for sufficient periods of time eventually become injured and die. This is largely due to the fact that, without oxygen, animals are unable to generate sufficient quantities of energy. In human diseases triggered by oxygen deprivation, such as heart attack and stroke, hyposmotic stress and cell swelling (edema) arise in affected tissues as a direct result of energetic failure. Edema independently enhances tissue injury in these diseases by incompletely understood mechanisms, resulting in poor clinical outcomes. Here, we present investigations into the effects of osmotic stress during complete oxygen deprivation (anoxia) in the genetically tractable nematode Caenorhabditis elegans. Our findings demonstrate that nematode survival of a hyposmotic environment during anoxia (hyposmotic anoxia) depends on the nematode’s ability to engage in glycogen metabolism. We also present results of a genome-wide screen for genes affecting glycogen content and localization in the nematode, showing that nematode survival of hyposmotic anoxia depends on a large number of these genes. Finally, we show that an inability to engage in glycogen synthesis results in suppression of the enhanced survival phenotype observed in daf-2 insulin-like pathway mutants, suggesting that alterations in glycogen metabolism may serve as a basis for these mutants’ resistance to hyposmotic anoxia.
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15
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Turtle anoxia tolerance: Biochemistry and gene regulation. Biochim Biophys Acta Gen Subj 2015; 1850:1188-96. [DOI: 10.1016/j.bbagen.2015.02.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 02/01/2015] [Indexed: 12/16/2022]
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LaMacchia JC, Roth MB. Aquaporins-2 and -4 regulate glycogen metabolism and survival during hyposmotic-anoxic stress in Caenorhabditis elegans. Am J Physiol Cell Physiol 2015; 309:C92-6. [PMID: 26017147 DOI: 10.1152/ajpcell.00131.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 05/20/2015] [Indexed: 12/22/2022]
Abstract
Periods of oxygen deprivation can lead to ion and water imbalances in affected tissues that manifest as swelling (edema). Although oxygen deprivation-induced edema is a major contributor to injury in clinical ischemic diseases such as heart attack and stroke, the pathophysiology of this process is incompletely understood. In the present study we investigate the impact of aquaporin-mediated water transport on survival in a Caenorhabditis elegans model of edema formation during complete oxygen deprivation (anoxia). We find that nematodes lacking aquaporin water channels in tissues that interface with the surrounding environment display decreased edema formation and improved survival rates in anoxia. We also find that these animals have significantly reduced demand for glycogen as an energetic substrate during anoxia. Together, our data suggest that reductions in membrane water permeability may be sufficient to induce a hypometabolic state during oxygen deprivation that reduces injury and extends survival limits.
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Affiliation(s)
- John C LaMacchia
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington; Medical Scientist Training Program, University of Washington, Seattle, Washington; and
| | - Mark B Roth
- Basic Science Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
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17
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Larson J, Drew KL, Folkow LP, Milton SL, Park TJ. No oxygen? No problem! Intrinsic brain tolerance to hypoxia in vertebrates. ACTA ACUST UNITED AC 2014; 217:1024-39. [PMID: 24671961 DOI: 10.1242/jeb.085381] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many vertebrates are challenged by either chronic or acute episodes of low oxygen availability in their natural environments. Brain function is especially vulnerable to the effects of hypoxia and can be irreversibly impaired by even brief periods of low oxygen supply. This review describes recent research on physiological mechanisms that have evolved in certain vertebrate species to cope with brain hypoxia. Four model systems are considered: freshwater turtles that can survive for months trapped in frozen-over lakes, arctic ground squirrels that respire at extremely low rates during winter hibernation, seals and whales that undertake breath-hold dives lasting minutes to hours, and naked mole-rats that live in crowded burrows completely underground for their entire lives. These species exhibit remarkable specializations of brain physiology that adapt them for acute or chronic episodes of hypoxia. These specializations may be reactive in nature, involving modifications to the catastrophic sequelae of oxygen deprivation that occur in non-tolerant species, or preparatory in nature, preventing the activation of those sequelae altogether. Better understanding of the mechanisms used by these hypoxia-tolerant vertebrates will increase appreciation of how nervous systems are adapted for life in specific ecological niches as well as inform advances in therapy for neurological conditions such as stroke and epilepsy.
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Affiliation(s)
- John Larson
- Psychiatric Institute, Department of Psychiatry and Laboratory of Integrative Neuroscience, Department of Biological Sciences, University of Illinois, Chicago, IL 60612, USA
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18
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Zaghloul N, Patel H, Codipilly C, Marambaud P, Dewey S, Frattini S, Huerta PT, Nasim M, Miller EJ, Ahmed M. Overexpression of extracellular superoxide dismutase protects against brain injury induced by chronic hypoxia. PLoS One 2014; 9:e108168. [PMID: 25268361 PMCID: PMC4182464 DOI: 10.1371/journal.pone.0108168] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 08/19/2014] [Indexed: 12/14/2022] Open
Abstract
Extracellular superoxide dismutase (EC-SOD) is an isoform of SOD normally found both intra- and extra-cellularly and accounting for most SOD activity in blood vessels. Here we explored the role of EC-SOD in protecting against brain damage induced by chronic hypoxia. EC-SOD Transgenic mice, were exposed to hypoxia (FiO2.1%) for 10 days (H-KI) and compared to transgenic animals housed in room air (RA-KI), wild type animals exposed to hypoxia (H-WT or wild type mice housed in room air (RA-WT). Overall brain metabolism evaluated by positron emission tomography (PET) showed that H-WT mice had significantly higher uptake of 18FDG in the brain particularly the hippocampus, hypothalamus, and cerebellum. H-KI mice had comparable uptake to the RA-KI and RA-WT groups. To investigate the functional state of the hippocampus, electrophysiological techniques in ex vivo hippocampal slices were performed and showed that H-KI had normal synaptic plasticity, whereas H-WT were severely affected. Markers of oxidative stress, GFAP, IBA1, MIF, and pAMPK showed similar values in the H-KI and RA-WT groups, but were significantly increased in the H-WT group. Caspase-3 assay and histopathological studies showed significant apoptosis/cell damage in the H-WT group, but no significant difference in the H-KI group compared to the RA groups. The data suggest that EC-SOD has potential prophylactic and therapeutic roles in diseases with compromised brain oxygenation.
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Affiliation(s)
- Nahla Zaghloul
- Division of Neonatal-Perinatal Medicine, The Ohio State University and Nationwide Children's Hospital, Columbus, Ohio, United States of America
| | - Hardik Patel
- Division of Neonatal-Perinatal Medicine, Cohen Children's Medical Center of New York and Lilling Family Research laboratory, Feinstein Institute for Medical Research, Manhasset, New York, United States of America
| | - Champa Codipilly
- Division of Neonatal-Perinatal Medicine, Cohen Children's Medical Center of New York and Lilling Family Research laboratory, Feinstein Institute for Medical Research, Manhasset, New York, United States of America
| | - Philippe Marambaud
- Laboratory of Memory Disorders, Feinstein Institute for Medical Research, Manhasset, New York, United States of America
| | - Stephen Dewey
- Neuroimaging Department, Feinstein Institute for Medical Research, Manhasset, New York, United States of America
| | - Stephen Frattini
- Laboratory of Immune & Neural Networks, Feinstein Institute for Medical Research, Manhasset, New York, United States of America
| | - Patricio T. Huerta
- Laboratory of Immune & Neural Networks, Feinstein Institute for Medical Research, Manhasset, New York, United States of America
- Department of Molecular Medicine, Hofstra North Shore LIJ School of Medicine, New York, United States of America
| | - Mansoor Nasim
- Department of Pathology, NSL-IJ, Manhasset, New York, United States of America
| | - Edmund J. Miller
- Department of Molecular Medicine, Hofstra North Shore LIJ School of Medicine, New York, United States of America
- Division of Neonatal-Perinatal Medicine, Cohen Children's Medical Center of New York and Lilling Family Research laboratory, Feinstein Institute for Medical Research, Manhasset, New York, United States of America
| | - Mohamed Ahmed
- Division of Neonatal-Perinatal Medicine, The Ohio State University and Nationwide Children's Hospital, Columbus, Ohio, United States of America
- Division of Neonatal-Perinatal Medicine, Cohen Children's Medical Center of New York and Lilling Family Research laboratory, Feinstein Institute for Medical Research, Manhasset, New York, United States of America
- * E-mail:
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Oxidative stress, hypoxia, and autophagy in the neovascular processes of age-related macular degeneration. BIOMED RESEARCH INTERNATIONAL 2014; 2014:768026. [PMID: 24707498 PMCID: PMC3950832 DOI: 10.1155/2014/768026] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 10/13/2013] [Accepted: 10/13/2013] [Indexed: 11/25/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of severe and irreversible loss of vision in the elderly in developed countries. AMD is a complex chronic neurodegenerative disease associated with many environmental, lifestyle, and genetic factors. Oxidative stress and the production of reactive oxygen species (ROS) seem to play a pivotal role in AMD pathogenesis. It is known that the macula receives the highest blood flow of any tissue in the body when related to size, and anything that can reduce the rich blood supply can cause hypoxia, malfunction, or disease. Oxidative stress can affect both the lipid rich retinal outer segment structure and the light processing in the macula. The response to oxidative stress involves several cellular defense reactions, for example, increases in antioxidant production and proteolysis of damaged proteins. The imbalance between production of damaged cellular components and degradation leads to the accumulation of detrimental products, for example, intracellular lipofuscin and extracellular drusen. Autophagy is a central lysosomal clearance system that may play an important role in AMD development. There are many anatomical changes in retinal pigment epithelium (RPE), Bruch's membrane, and choriocapillaris in response to chronic oxidative stress, hypoxia, and disturbed autophagy and these are estimated to be crucial components in the pathology of neovascular processes in AMD.
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20
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Staples M, Acosta S, Tajiri N, Pabon M, Kaneko Y, Borlongan CV. Delta opioid receptor and its peptide: a receptor-ligand neuroprotection. Int J Mol Sci 2013; 14:17410-9. [PMID: 23979422 PMCID: PMC3794733 DOI: 10.3390/ijms140917410] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 08/15/2013] [Accepted: 08/19/2013] [Indexed: 11/29/2022] Open
Abstract
In pursuit of neurological therapies, the opioid system, specifically delta opioid receptors and delta opioid peptides, demonstrates promising therapeutic potential for stroke, Parkinson’s disease, and other degenerative neurological conditions. Recent studies offer strong evidence in support of the therapeutic use of delta opioid receptors, and provide insights into the underlying mechanisms of action. Delta opioid receptors have been shown to confer protective effects by mediating ionic homeostasis and activating endogenous neuroprotective pathways. Additionally, delta opioid agonists such as (D-Ala 2, D-Leu 5) enkephalin (DADLE) have been shown to decrease apoptosis and promote neuronal survival. In its entirety, the delta opioid system represents a promising target for neural therapies.
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Affiliation(s)
- Meaghan Staples
- Department of Neurosurgery and Brain Repair, University of South Florida College of Medicine, Tampa, FL 33612, USA.
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21
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Nathaniel TI, Otukonyong EE, Okon M, Chaves J, Cochran T, Nathaniel AI. Metabolic regulatory clues from the naked mole rat: toward brain regulatory functions during stroke. Brain Res Bull 2013; 98:44-52. [PMID: 23886571 DOI: 10.1016/j.brainresbull.2013.07.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 07/03/2013] [Accepted: 07/15/2013] [Indexed: 12/30/2022]
Abstract
Resistance to tissue hypoxia is a robust fundamental adaptation to low oxygen supply, and represents a novel neuroscience problem with significance to mammalian physiology as well as human health. With the underlying mechanisms strongly conserved in evolution, the ability to resist tissue hypoxia in natural systems has recently emerged as an interesting model in mammalian physiology research to understand mechanisms that can be manipulated for the clinical management of stroke. The extraordinary ability to resist tissue hypoxia by the naked mole rat (NMR) indicates the presence of a unique mechanism that underlies the remarkable healthy life span and exceptional hypoxia resistance. This opens an interesting line of research into understanding the mechanisms employed by the naked mole rat (Heterocephalus glaber) to protect the brain during hypoxia. In a series of studies, we first examined the presence of neuroprotection in the brain cells of naked mole rats (NMRs) subjected to hypoxic insults, and then characterized the expression of such neuroprotection in a wide range of time intervals. We used oxygen nutrient deprivation (OND), an in vitro model of resistance to tissue hypoxia to determine whether there is evidence of neuronal survival in the hippocampal (CA1) slices of NMRs that are subjected to chronic hypoxia. Hippocampus neurons of NMRs that were kept in hypoxic condition consistently tolerated OND right from the onset time of 5h. This tolerance was maintained for 24h. This finding indicates that there is evidence of resistance to tissue hypoxia by CA1 neurons of NMRs. We further examined the effect of hypoxia on metabolic rate in the NMR. Repeated measurement of metabolic rates during exposure of naked mole rats to hypoxia over a constant ambient temperature indicates that hypoxia significantly decreased metabolic rates in the NMR, suggesting that the observed decline in metabolic rate during hypoxia may contribute to the adaptive mechanism used by the NMR to resist tissue hypoxia. This work is aimed to contribute to the understanding of mechanisms of resistance to tissue hypoxia in the NMR as an important life-sustaining process, which can be translated into therapeutic interventions during stroke.
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Affiliation(s)
- Thomas I Nathaniel
- University of South Carolina School of Medicine, HSEB, 607 Grove Road, Greenville, SC 29605, United States.
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22
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Braga MM, Rico EP, Córdova SD, Pinto CB, Blaser RE, Dias RD, Rosemberg DB, Oliveira DL, Souza DO. Evaluation of spontaneous recovery of behavioral and brain injury profiles in zebrafish after hypoxia. Behav Brain Res 2013; 253:145-51. [PMID: 23867150 DOI: 10.1016/j.bbr.2013.07.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2013] [Revised: 07/03/2013] [Accepted: 07/09/2013] [Indexed: 02/07/2023]
Abstract
Cerebral hypoxia-ischemia can lead to motor and sensory impairments which can be dependent on the extent of infarcted regions. Since a better understanding of the neurochemical mechanisms involved in this injury is needed, the use of zebrafish as a cerebral hypoxia model has become quite promising because it could improve the knowledge about hypoxia-ischemia. In the current study, we aimed to investigate the spontaneous recovery of brain and behavioral impairments induced by hypoxia in adult zebrafish. Brain injury levels were analyzed by spectrophotometric measurement of mitochondrial dehydrogenase activity by staining with 2,3,5-triphenyltetrazolium chloride, and behavioral profiles were assessed by the open tank test. The induction of hypoxia substantially decreased mitochondrial activity in the brain and impaired behavior. The spontaneous recovery of fish subjected to hypoxia was assessed after 1, 3, 6, 24, and 48h under normoxia. The quantification of brain injury levels showed a significant increase until 24h after hypoxia, but after 48h this effect was completely reversed. Regarding behavioral parameters, we verified that locomotor activity and vertical exploration were impaired by hypoxia and these effects were reversed after 3h under normoxia. Taken together, these results show that zebrafish exhibited transient cerebral and behavioral impairments when submitted to hypoxia, and 1h under normoxic conditions was insufficient to reverse both effects. Therefore, our data help to elucidate the time window of spontaneous recovery in zebrafish after hypoxia and also the behavioral phenotypes involved in this phenomenon.
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Affiliation(s)
- Marcos M Braga
- Programa de Pós-graduação em Bioquímica, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600-Anexo, 90035-003 Porto Alegre, RS, Brazil.
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23
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He X, Sandhu HK, Yang Y, Hua F, Belser N, Kim DH, Xia Y. Neuroprotection against hypoxia/ischemia: δ-opioid receptor-mediated cellular/molecular events. Cell Mol Life Sci 2013; 70:2291-303. [PMID: 23014992 PMCID: PMC11113157 DOI: 10.1007/s00018-012-1167-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Revised: 09/08/2012] [Accepted: 09/10/2012] [Indexed: 12/24/2022]
Abstract
Hypoxic/ischemic injury remains the most dreaded cause of neurological disability and mortality. Despite the humbling experiences due to lack of promising therapy, our understanding of the complex cascades underlying the neuronal insult has led to advances in basic science research. One of the most noteworthy has been the effect of opioid receptors, especially the delta-opioid receptor (DOR), on hypoxic/ischemic neurons. Our recent studies, and those of others worldwide, present strong evidence that sheds light on DOR-mediated neuroprotection in the brain, especially in the cortex. The mechanisms of DOR neuroprotection are broadly categorized as: (1) stabilization of the ionic homeostasis, (2) inhibition of excitatory transmitter release, (3) attenuation of disrupted neuronal transmission, (4) increase in antioxidant capacity, (5) regulation of intracellular pathways-inhibition of apoptotic signals and activation of pro-survival signaling, (6) regulation of specific gene and protein expression, and (7) up-regulation of endogenous opioid release and/or DOR expression. Depending upon the severity and duration of hypoxic/ischemic insult, the release of endogenous opioids and DOR expression are regulated in response to the stress, and DOR signaling acts at multiple levels to confer neuronal tolerance to harmful insult. The phenomenon of DOR neuroprotection offers a potential clue for a promising target that may have significant clinical implications in our quest for neurotherapeutics.
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Affiliation(s)
- Xiaozhou He
- The Third Clinical College of Suzhou University, Changzhou, Jiangsu China
| | - Harleen K. Sandhu
- The Vivian L Smith Department of Neurosurgery, The University of Texas Medical School at Houston, Houston, 77030 TX USA
| | - Yilin Yang
- The Third Clinical College of Suzhou University, Changzhou, Jiangsu China
| | - Fei Hua
- The Third Clinical College of Suzhou University, Changzhou, Jiangsu China
| | - Nathalee Belser
- The Vivian L Smith Department of Neurosurgery, The University of Texas Medical School at Houston, Houston, 77030 TX USA
| | - Dong H. Kim
- The Vivian L Smith Department of Neurosurgery, The University of Texas Medical School at Houston, Houston, 77030 TX USA
| | - Ying Xia
- The Vivian L Smith Department of Neurosurgery, The University of Texas Medical School at Houston, Houston, 77030 TX USA
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CHARACTERIZING CALCIUM INFLUX VIA VOLTAGE- AND LIGAND-GATED CALCIUM CHANNELS IN EMBRYONIC ALLIGATOR NEURONS IN CULTURE. Transl Neurosci 2013; 4. [PMID: 24260711 DOI: 10.2478/s13380-013-0132-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vertebrate brains share many features in common. Early in development, both the hindbrain and diencephalon are built similarly. Only later in time do differences in morphology occur. Factors that could potentially influence such changes include certain physiological properties of neurons. As an initial step to investigate this problem, embryonic Alligator brain neurons were cultured and calcium responses were characterized. The present report is the first to document culture of Alligator brain neurons in artificial cerebrospinal fluid (ACSF) as well as in standard mammalian tissue culture medium supplemented with growth factors. Alligator brain neuron cultures were viable for at least 1 week with unipolar neurites emerging by 24 hours. Employing Fura-2 AM, robust depolarization-induced calcium influx, was observed in these neurons. Using selective blockers of the voltage-gated calcium channels, the contributions of N-, P/Q-, R-, T-, and L-type channels in these neurons were assessed and their presence documented. Lastly, Alligator brain neurons were challenged with an excitotoxic stimulus (glutamate + glycine) where delayed calcium deregulation could be prevented by a classical NMDA receptor antagonist.
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25
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Giusi G, Zizza M, Facciolo RM, Chew SF, Ip YK, Canonaco M. Aestivation and hypoxia-related events share common silent neuron trafficking processes. BMC Neurosci 2012; 13:39. [PMID: 22520032 PMCID: PMC3407487 DOI: 10.1186/1471-2202-13-39] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 04/20/2012] [Indexed: 11/10/2022] Open
Abstract
Background The availability of oxygen is a limiting factor for neuronal survival since low levels account not only for the impairment of physiological activities such as sleep-wake cycle, but above all for ischemic-like neurodegenerative disorders. In an attempt to improve our knowledge concerning the type of molecular mechanisms operating during stressful states like those of hypoxic conditions, attention was focused on eventual transcriptional alterations of some key AMPAergic silent neuronal receptor subtypes (GluR1 and GluR2) along with HSPs and HIF-1α during either a normoxic or a hypoxic aestivation of a typical aquatic aestivator, i.e. the lungfish (Protopterus annectens). Results The identification of partial nucleotide fragments codifying for both AMPA receptor subtypes in Protopterus annectens displayed a putative high degree of similarity to that of not only fish but also to those of amphibians, birds and mammals. qPCR and in situ hybridization supplied a very high (p < 0.001) reduction of GluR1 mRNA expression in diencephalic areas after 6 months of aerial normoxic aestivation (6mAE). Concomitantly, high (p < 0.01) levels of HSP70 mRNAs in hypothalamic, mesencephalic and cerebellar areas of both 6mAE and after 6 months of mud hypoxic aestivation (6mMUD) were detected together with evident apoptotic signals. Surprisingly, very high levels of GluR2 mRNAs were instead detected in thalamic along with mesencephalic areas after 6 days of normoxic (6dAE) and hypoxic (6dMUD) aestivation. Moreover, even short- and long-term hypoxic states featured high levels of HIF-1α and HSP27 transcripts in the different brain regions of the lungfish. Conclusions The distinct transcriptional variations of silent neurons expressing GluR1/2 and HSPs tend to corroborate these factors as determining elements for the physiological success of normoxic and hypoxic aestivation. A distinct switching among these AMPA receptor subtypes during aestivation highlights new potential adaptive strategies operating in key brain regions of the lungfish in relation to oxygen availability. This functional relationship might have therapeutic bearings for hypoxia-related dysfunctions, above all in view of recently identified silent neuron-dependent motor activity ameliorations in mammals.
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Affiliation(s)
- Giuseppina Giusi
- Comparative Neuroanatomy Laboratory, University of Calabria, 87030 Arcavacata di Rende-CS, Italy.
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Peterson BL, Larson J, Buffenstein R, Park TJ, Fall CP. Blunted neuronal calcium response to hypoxia in naked mole-rat hippocampus. PLoS One 2012; 7:e31568. [PMID: 22363676 PMCID: PMC3283646 DOI: 10.1371/journal.pone.0031568] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 01/13/2012] [Indexed: 01/09/2023] Open
Abstract
Naked mole-rats are highly social and strictly subterranean rodents that live in large communal colonies in sealed and chronically oxygen-depleted burrows. Brain slices from naked mole-rats show extreme tolerance to hypoxia compared to slices from other mammals, as indicated by maintenance of synaptic transmission under more hypoxic conditions and three fold longer latency to anoxic depolarization. A key factor in determining whether or not the cellular response to hypoxia is reversible or leads to cell death may be the elevation of intracellular calcium concentration. In the present study, we used fluorescent imaging techniques to measure relative intracellular calcium changes in CA1 pyramidal cells of hippocampal slices during hypoxia. We found that calcium accumulation during hypoxia was significantly and substantially attenuated in slices from naked mole-rats compared to slices from laboratory mice. This was the case for both neonatal (postnatal day 6) and older (postnatal day 20) age groups. Furthermore, while both species demonstrated more calcium accumulation at older ages, the older naked mole-rats showed a smaller calcium accumulation response than even the younger mice. A blunted intracellular calcium response to hypoxia may contribute to the extreme hypoxia tolerance of naked mole-rat neurons. The results are discussed in terms of a general hypothesis that a very prolonged or arrested developmental process may allow adult naked mole-rat brain to retain the hypoxia tolerance normally only seen in neonatal mammals.
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Affiliation(s)
- Bethany L. Peterson
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - John Larson
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Laboratory of Integrative Neuroscience, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Psychiatric Institute, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Rochelle Buffenstein
- Barshop Institute and Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, United States of America
| | - Thomas J. Park
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Laboratory of Integrative Neuroscience, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Christopher P. Fall
- Department of BioEngineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Computer Science, Georgetown University, Washington, D. C., United States of America
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Adult naked mole-rat brain retains the NMDA receptor subunit GluN2D associated with hypoxia tolerance in neonatal mammals. Neurosci Lett 2011; 506:342-5. [PMID: 22155615 DOI: 10.1016/j.neulet.2011.11.042] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 11/03/2011] [Accepted: 11/23/2011] [Indexed: 11/20/2022]
Abstract
Adult naked mole-rats show a number of systemic adaptations to a crowded underground habitat that is low in oxygen and high in carbon dioxide. Remarkably, brain slice tissue from adult naked mole-rats also is extremely tolerant to oxygen deprivation as indicated by maintenance of synaptic transmission under hypoxic conditions as well as by a delayed neuronal depolarization during anoxia. These characteristics resemble hypoxia tolerance in brain slices from neonates in a variety of mammal species. An important component of neonatal tolerance to hypoxia involves the subunit composition of NMDA receptors. Neonates have a high proportion of NMDA receptors with GluN2D subunits which are protective because they retard calcium entry into neurons during hypoxic episodes. Therefore, we hypothesized that adult naked mole-rats retain a protective, neonatal-like, NMDA receptor subunit profile. We used immunoblotting to assess age-related changes in NMDA receptor subunits in naked mole-rats and mice. The results show that adult naked mole-rat brain retains a much greater proportion of the hypoxia-protective GluN2D subunit compared to adult mice. However, age-related changes in other subunits (GluN2A and GluN2B) from the neonatal period to adulthood were comparable in mice and naked mole-rats. Hence, adult naked mole-rat brain only retains the neonatal NMDA receptor subunit that is associated with hypoxia tolerance.
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Ward DS, Karan SB, Pandit JJ. Hypoxia: developments in basic science, physiology and clinical studies. Anaesthesia 2011; 66 Suppl 2:19-26. [DOI: 10.1111/j.1365-2044.2011.06930.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Reversible metabolic depression in lamprey hepatocytes during prespawning migration: dynamics of mitochondrial membrane potential. Comp Biochem Physiol B Biochem Mol Biol 2011; 160:194-200. [PMID: 21893210 DOI: 10.1016/j.cbpb.2011.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Revised: 08/22/2011] [Accepted: 08/23/2011] [Indexed: 11/22/2022]
Abstract
The lamprey (Lampetra fluviatilis L.) is an extant representative of the ancient vertebrate group of Agnathans. During the prespawning migration (the river period of life from autumn until spring) lamprey hepatocytes exhibit widely different energy states: a high-energy state in autumn and spring, corresponding to a normal physiological standard, and a low-energy state in winter, which is provoked by prolonged starvation and profound metabolic arrest. In spring the restoration of energy status (return to an active state) is associated with hormonally induced lipolysis of the lipid droplets stored in the cells. Lamprey hepatocytes demonstrate an aerobic metabolism based on oxidation of free fatty acids. The dynamics of mitochondrial membrane potential (MMP) were measured throughout the prespawning migration. Pharmacological inhibition of the electron transport chain decreased the MMP and caused extensive depletion of cellular ATP without loss of cell viability. The potential molecular mechanisms responsible for winter metabolic depression in lamprey hepatocytes are discussed.
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Turner SMF, Johnson SM. Delta-opioid receptor activation prolongs respiratory motor output during oxygen-glucose deprivation in neonatal rat spinal cord in vitro. Neuroscience 2011; 187:70-83. [PMID: 21571044 DOI: 10.1016/j.neuroscience.2011.04.059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 03/31/2011] [Accepted: 04/29/2011] [Indexed: 10/18/2022]
Abstract
Delta opioid receptor (DOR) activation protects the adult mammalian brain during oxygen-glucose deprivation (OGD), but it is not known whether neonatal spinal motor circuits are also protected. Also, it is unclear whether the timing of spinal DOR activation relative to spinal OGD is important for neuroprotection. Thus, a split-bath in vitro neonatal rat brainstem/spinal cord preparation was used to record spontaneous respiratory motor output from cervical (C4-C5) and thoracic (T5-T6) ventral spinal roots while exposing only the spinal cord to OGD solution (0 mM glucose, bubbled with 95% N(2)/5% CO(2)) or DOR agonist drugs (DADLE, DPDPE). Spinal OGD solution application caused respiratory motor output frequency and amplitude to decrease until all activity was abolished (i.e. end-point times) after 25.9±1.4 min (cervical) and 25.2±1.4 min (thoracic). Spinal DOR activation via DPDPE (1.0 μM) prior-to and during spinal OGD increased cervical and thoracic end-point times to 35-48 min. Spinal DADLE or DPDPE (1.0 μM) application 15 min following spinal OGD onset increased cervical and thoracic end-point times to 36-45 min. Brief spinal DPDPE (1.0 μM) application for 10 min at 25 min before spinal OGD onset increased cervical and thoracic end-point times to 41-46 min. Overall, the selective DOR agonist, DPDPE, was more effective at increasing end-point times than DADLE. Naltrindole (DOR antagonist; 10 μM) pretreatment blocked DPDPE-dependent increase in end-point times, suggesting that DOR activation was required. Spinal naloxone (1.0 μM) application before and during spinal OGD also increased end-point times to 31-33 min, but end-point times were not altered by Mu opioid receptor (MOR) activation or DOR activation/MOR blockade, indicating that there are complex interactions between OGD and opioid signaling pathways. These data suggest DOR activation before, during, and after spinal OGD protects central motor networks and may provide neuroprotection during unpredictable perinatal ischemic events.
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Affiliation(s)
- S M F Turner
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706, USA
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de Fraga LS, da Silva RSM, Zancan DM. Control of carbohydrate metabolism in an anoxia-tolerant nervous system. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL GENETICS AND PHYSIOLOGY 2010; 313:539-547. [PMID: 20960558 DOI: 10.1002/jez.624] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Anoxia-tolerant animal models are crucial to understand protective mechanisms during low oxygen excursions. As glycogen is the main fermentable fuel supporting energy production during oxygen tension reduction, understanding glycogen metabolism can provide important insights about processes involved in anoxia survival. In this report we studied carbohydrate metabolism regulation in the central nervous system (CNS) of an anoxia-tolerant land snail during experimental anoxia exposure and subsequent reoxygenation. Glucose uptake, glycogen synthesis from glucose, and the key enzymes of glycogen metabolism, glycogen synthase (GS) and glycogen phosphorylase (GP), were analyzed. When exposed to anoxia, the nervous ganglia of the snail achieved a sustained glucose uptake and glycogen synthesis levels, which seems important to maintain neural homeostasis. However, the activities of GS and GP were reduced, indicating a possible metabolic depression in the CNS. During the aerobic recovery period, the enzyme activities returned to basal values. The possible strategies used by Megalobulimus abbreviatus CNS to survive anoxia are discussed.
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Affiliation(s)
- Luciano Stürmer de Fraga
- Departamento de Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Ellefsen S, Stensløkken KO. Gene-family profiling: a normalization-free real-time RT-PCR approach with increased physiological resolution. Physiol Genomics 2010; 42:1-4. [PMID: 20215416 DOI: 10.1152/physiolgenomics.00196.2009] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Here we present gene-family profiling, an approach for improved real-time RT-PCR analyses. It is based on recently published data, and we argue that it bring solutions to two major problems. First, it is normalization-free and therefore unbiased by variation in normalization agents such as reference gene expression. This strengthens data validity and also increases data resolution, reducing coefficients of variation by approximately 48% in our data sets. Second, it includes all members of a particular gene family, treating individual genes as constituting fractions of collective gene-family expression rather than as unrelated entities. Because different family members typically fulfill similar, but complementary roles, this increases the physiological relevance. Gene-family profiling is particularly useful for evaluation of cellular adaptations to physiological challenges and for comparison of properties between different experimental systems such as species, tissues or tissue regions. In addition, it seems suitable for analyses of inherent patterns of gene expression in singular biological samples. In our opinion, the approach is valuable for both research and diagnostic purposes, and should be readily applicable for many studies of gene expression. Its value is likely to increase as science continues to unravel gene function.
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The Involvement of Calcium Transport Systems of the Plasma Membrane in Calcium Exchange in Neurons of the Carassius gibelio Cerebellum. NEUROPHYSIOLOGY+ 2010. [DOI: 10.1007/s11062-010-9105-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Ludvigsen S, Folkow LP. Differences in in vitro cerebellar neuronal responses to hypoxia in eider ducks, chicken and rats. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2009; 195:1021-30. [DOI: 10.1007/s00359-009-0476-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Revised: 07/19/2009] [Accepted: 08/31/2009] [Indexed: 12/11/2022]
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Molecular cloning, characterization and expression of two tryptophan hydroxylase (TPH-1 and TPH-2) genes in the hypothalamus of Atlantic croaker: down-regulation after chronic exposure to hypoxia. Neuroscience 2008; 158:751-65. [PMID: 19015006 DOI: 10.1016/j.neuroscience.2008.10.029] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Revised: 09/02/2008] [Accepted: 10/10/2008] [Indexed: 11/20/2022]
Abstract
Recently we discovered that hypoxia causes marked impairment of reproductive neuroendocrine function in Atlantic croaker, a marine teleost, which is due to a decline in hypothalamic serotonergic activity. As a first step in understanding the molecular responses of the hypothalamic serotonergic system to hypoxia, we cloned and characterized the genes for the enzymes regulating the rate-limiting step in serotonin biosynthesis, tryptophan hydroxylase (TPH-1 and TPH-2) in the croaker brain. The full-length croaker TPH-1 and TPH-2 cDNAs contain open reading frames encoding proteins with 479 and 487 amino acids, respectively, which are highly homologous to the TPH-1 (76-93%) and TPH-2 (64-92%) proteins of other vertebrates. Croaker TPH-1 and TPH-2 mRNA expression was detected throughout the brain but was greatest in the hypothalamic region. Both Northern blot analysis and real-time PCR showed that TPH-1 (transcript size approximately 2.1 kb) and TPH-2 ( approximately 1.9 kb) mRNA levels were significantly decreased in the hypothalami of croaker exposed for 2 weeks to hypoxic conditions compared with those in fish exposed to normoxic conditions. Immunohistochemistry of hypothalamic neurons with TPH antibodies showed reduced expression of TPHs in hypoxia-exposed fish compared with normoxic fish. Western blot analysis confirmed that hypoxia caused a marked decline in hypothalamic TPH protein levels, which was associated with decreases in hypothalamic TPH enzyme activity and 5-hydroxytryptophan levels. These results suggest that TPH is a major site of hypoxia-induced down-regulation of serotonergic function in croaker brains. Moreover, they provide the first evidence that hypoxia decreases the expression of TPH transcripts in vertebrate brains.
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Wang H, Xue Z, Wang Q, Feng X, Shen Z. Propofol Protects Hepatic L02 Cells from Hydrogen Peroxide-Induced Apoptosis via Activation of Extracellular Signal-Regulated Kinases Pathway. Anesth Analg 2008; 107:534-40. [DOI: 10.1213/ane.0b013e3181770be9] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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37
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Ellefsen S, Sandvik GK, Larsen HK, Stensløkken KO, Hov DAS, Kristensen TA, Nilsson GE. Expression of genes involved in excitatory neurotransmission in anoxic crucian carp (Carassius carassius) brain. Physiol Genomics 2008; 35:5-17. [PMID: 18593861 DOI: 10.1152/physiolgenomics.90221.2008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The crucian carp, Carassius carassius, survives months without oxygen. During anoxia it needs to keep energy expenditure low, particularly in the brain, with its high rate of ATP use related to neuronal activity. This could be accomplished by reducing neuronal excitability through altered expression of genes involved in excitatory neurotransmission. Through cloning and the use of a recently developed real-time RT-PCR approach, with an external RNA control for normalization, we investigated the effect of 1 and 7 days of anoxia (12 degrees C) on the expression of 29 genes, including 8 3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptor subunits, 6 N-methyl-d-aspartate (NMDA) receptor subunits, 7 voltage-gated sodium and calcium channels, 4 glutamate transporters, and 4 genes involved in NMDA receptor-mediated neuroplasticity. The subunits of the majority of the gene families had expression profiles similar to those observed in the mammalian brain and showed remarkably stable expression during anoxia. This suggests that the genes may have similar functions in crucian carp and mammals, and that the excitatory abilities of the crucian carp brain are retained during anoxia. Although the data generally argue against profound neural depression ("channel arrest"), NMDA receptor subunit (NR) expression showed features that could mediate reduced neural excitability. Primarily, the NR2 subunit expression, which was dominated by NR2B and NR2D, resembled that seen in hypoxia-tolerant neonatal rats, and decreased anoxic expression of NR1, NR2C, and NR3A indicated reduced numbers of functional NMDA receptors. We also report the full-length sequence of crucian carp NR1 mRNA and a novel NR1 splice cassette introducing an N-glycosylation site into the extracellular S1S2 domain.
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Affiliation(s)
- Stian Ellefsen
- Physiology Programme, Department of Molecular Biosciences, University of Oslo, Oslo.
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38
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Roesner A, Mitz SA, Hankeln T, Burmester T. Globins and hypoxia adaptation in the goldfish, Carassius auratus. FEBS J 2008; 275:3633-43. [DOI: 10.1111/j.1742-4658.2008.06508.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Storey KB. Anoxia tolerance in turtles: Metabolic regulation and gene expression. Comp Biochem Physiol A Mol Integr Physiol 2007; 147:263-76. [PMID: 17035057 DOI: 10.1016/j.cbpa.2006.03.019] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2005] [Revised: 03/14/2006] [Accepted: 03/24/2006] [Indexed: 01/08/2023]
Abstract
Freshwater turtles of the Trachemys and Chrysemys genera are champion facultative anaerobes able to survive for several months without oxygen during winter hibernation in cold water. They have been widely used as models to identify and understand the molecular mechanisms of natural anoxia tolerance and the molecular basis of the hypoxic/ischemic injuries that occur in oxygen-sensitive systems and underlie medical problems such as heart attack and stroke. Peter L. Lutz spent much of his career investigating turtle anaerobiosis with a particular focus on the mechanisms of brain ion homeostasis and neurotransmitter responses to anoxia exposure and the mechanisms that suppress brain ion channel function and neuronal excitability during anaerobiosis. Our interests intersected over the mechanisms of metabolic rate depression which is key to long term anoxia survival. Studies in my lab have shown that a key mechanism of metabolic arrest is reversible protein phosphorylation which provides coordinated suppression of the rates of multiple ATP-producing, ATP-utilizing and related cellular processes to allow organisms to enter a stable hypometabolic state. Anoxia tolerance is also supported by selective gene expression as revealed by recent studies using cDNA library and DNA array screening. New studies with both adult T. scripta elegans and hatchling C. picta marginata have identified prominent groups of genes that are up-regulated under anoxia in turtle organs, in several cases suggesting aspects of cell function and metabolic regulation that have not previously been associated with anaerobiosis. These groups of anoxia-responsive genes include mitochondrially-encoded subunits of electron transport chain proteins, iron storage proteins, antioxidant enzymes, serine protease inhibitors, transmembrane solute carriers, neurotransmitter receptors and transporters, and shock proteins.
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Affiliation(s)
- Kenneth B Storey
- Institute of Biochemistry, College of Natural Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6.
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Abstract
All mammals and birds must develop effective strategies to cope with reduced oxygen availability. These animals achieve tolerance to acute and chronic hypoxia by (a) reductions in metabolism, (b) the prevention of cellular injury, and (c) the maintenance of functional integrity. Failure to meet any one of these tasks is detrimental. Birds and mammals accomplish this triple task through a highly coordinated, systems-level reconfiguration involving the partial shutdown of some but not all organs. This reconfiguration is achieved through a similarly complex reconfiguration at the cellular and molecular levels. Reconfiguration at these various levels depends on numerous factors that include the environment, the degree of hypoxic stress, and developmental, behavioral, and ecological conditions. Although common molecular strategies exist, the cellular and molecular changes in any given cell are very diverse. Some cells remain metabolically active, whereas others shut down or rely on anaerobic metabolism. This cellular shutdown is temporarily regulated, and during hypoxic exposure, active cellular networks must continue to control vital functions. The challenge for future research is to explore the cellular mechanisms and conditions that transform an organ or a cellular network into a hypometabolic state, without loss of functional integrity. Much can be learned in this respect from nature: Diving, burrowing, and hibernating animals living in diverse environments are masters of adaptation and can teach us how to deal with hypoxia, an issue of great clinical significance.
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Affiliation(s)
- Jan-Marino Ramirez
- Department of Organismal Biology & Anatomy, University of Chicago, Chicago, Illinois 60637, USA.
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Fordel E, Thijs L, Martinet W, Schrijvers D, Moens L, Dewilde S. Anoxia or oxygen and glucose deprivation in SH-SY5Y cells: a step closer to the unraveling of neuroglobin and cytoglobin functions. Gene 2007; 398:114-22. [PMID: 17532579 DOI: 10.1016/j.gene.2007.03.022] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2006] [Revised: 03/05/2007] [Accepted: 03/10/2007] [Indexed: 11/20/2022]
Abstract
Several studies support the hypothesis that neuroglobin and cytoglobin play a protective role against cell death when cellular oxygen supply is critical. Although the underlying molecular mechanisms are unknown, previous reports suggest that this protection can be realised by the fact that they act as ROS scavengers. In this study, expression of neuroglobin and cytoglobin was evaluated in a human neuroblastoma cell line (SH-SY5Y) under conditions of anoxia or oxygen and glucose deprivation (OGD). The cells could survive prolonged anoxia without significant loss of viability. They became anoxia sensitive when deprived of glucose. OGD induced significant cell death after 16 h resulting in 54% dead cells after 32 h. Necrosis was the main process involved in OGD-induced cell death. After reoxygenation, apoptotic neurons became more abundant. Real-time quantitative PCR and Western blotting revealed that neuroglobin and cytoglobin were upregulated, the former under OGD and the latter under anoxic conditions. Under OGD, cell survival was significantly reduced after inhibiting cytoglobin expression by transfection with antisense ODN. Moreover, cell survival was significantly enhanced by neuroglobin or cytoglobin overexpression. When neuroglobin or cytoglobin protein expression increased or decreased, the H(2)O(2) level was found to be lower or higher, respectively. We conclude that neuroglobin or cytoglobin act as ROS scavengers under ischemic conditions.
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Affiliation(s)
- Elke Fordel
- Department of Biomedical Sciences, University of Antwerp, Universiteitsplein 1, T.1, 2610 Wilrijk, Belgium
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Abstract
Adaptation is one of physiology's fundamental tenets, operating not only at the level of species, as Darwin proposed, but also at the level of tissues, cells, molecules and, perhaps, genes. During recent years, stroke neurobiologists have advanced a considerable body of evidence supporting the hypothesis that, with experimental coaxing, the mammalian brain can adapt to injurious insults such as cerebral ischaemia to promote cell survival in the face of subsequent injury. Establishing this protective phenotype in response to stress depends on a coordinated response at the genomic, molecular, cellular and tissue levels. Here, I summarize our current understanding of how 'preconditioning' stimuli trigger a cerebroprotective state known as cerebral 'ischaemic tolerance'.
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Affiliation(s)
- Jeffrey M Gidday
- Department of Neurosurgery, Washington University School of Medicine, St Louis, Missouri 63110, USA.
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Wölfer J, Bantel C, Köhling R, Speckmann EJ, Wassmann H, Greiner C. Electrophysiology in ischemic neocortical brain slices: species differences vs. influences of anaesthesia and preparation. Eur J Neurosci 2006; 23:1795-800. [PMID: 16623836 DOI: 10.1111/j.1460-9568.2006.04696.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ischemia models are indispensable for the evaluation of measures to be clinically applied to brain trauma or stroke patients. Slice models provide good control over experimental parameters and allow for comparative examinations of human and animal brain tissue. Experimental tissue, however, may be altered by anaesthesia, preparatory technique, and, in the case of human tissue, by underlying diseases. These influences on tissue behaviour under ischemia were examined electrophysiologically. Native rat tissue slices were prepared either immediately after decapitation (n = 13), during short ether/barbiturate narcosis (n = 18), or after two hours of inhalation anaesthesia (n = 12) imitating clinical narcosis. Tissue from rats in which generalized amygdala-kindled seizures had been triggered by electric stimulation (n = 10) was prepared according to the decapitation protocol, while human tissue (n = 10) was obtained during epilepsy or tumour surgery. Electrophysiological data (latency and amplitude of anoxic depolarization, recovery of evoked potentials) were recorded during ischemia simulation. Neither details of preparation or anaesthesia nor a history of epileptic fits were associated with significant changes of electrophysiological reactions under ischemia. Human tissue showed a significantly higher ability to uphold transmembrane ion gradients under ischemia. The ability of brain tissue to withstand ischemia is obviously species dependent. For the transfer of experimental results into clinical use it is important that interspecies differences alone can bring about a significant change of tissue behaviour.
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Affiliation(s)
- Johannes Wölfer
- Klinik und Poliklinik für Neurochirurgie am Universitätsklinikum Münster, Albert-Schweitzer-Strasse 33, D-48149 Münster, Germany.
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Long C, Gao Y, Gao G, Han S, Zu P, Fang L, Li J. Decreased phosphorylation and protein expression of ERK1/2 in the brain of hypoxic preconditioned mice. Neurosci Lett 2006; 397:307-12. [PMID: 16406314 DOI: 10.1016/j.neulet.2005.12.045] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Revised: 12/03/2005] [Accepted: 12/14/2005] [Indexed: 11/29/2022]
Abstract
Accumulated reports have suggested that activation of protein kinase C (PKC) isoforms may involve the activation of extracellular signal-regulated kinases 1/2 (ERK1/2) in the neuronal response to hypoxic stimuli. We have previously demonstrated that the membrane translocation or activation of conventional PKC (cPKC) betaII, gamma and novel PKC (nPKC) epsilon are increased in the early phase of cerebral hypoxic preconditioning in mice. However, the role of ERK1/2 in the development of cerebral hypoxic preconditioning is unclear. In the current study, we used Western blot analysis to investigate the effects of repetitive hypoxic exposure (H0-H6, n=6 for each group) on the levels of phosphorylation and protein expression of ERK1/2 in the frontal cortex and the whole hippocampus of mice. We found that the levels of phosphorylated ERK1/2, not protein expression of ERK1/2, decreased significantly in both cortex and hippocampus of the early hypoxic preconditioned mice (H1-H4), when compared to that of the normoxic group (p<0.05). In addition, a significant decrease (p<0.05) in the ERK1/2 protein expression, not the phosphorylated form of ERK1/2, was found both in the frontal cortex and hippocampus of mice followed hypoxia with previous hypoxia (H5 and H6). These results suggest that the decreased phosphorylation and downregulation of protein expression of ERK1/2 might be involved in the development of hypoxic preconditioning.
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Affiliation(s)
- Caixia Long
- Institute for Biomedical Science of Pain, Beijing Key Laboratory for Neural Regeneration and Repairing, Department of Neurobiology, Capital University of Medical Sciences, #10 You An Men Wai Xi Tou Tiao, Beijing 100054, China
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McAneney J, Gheshmy A, Uthayalingam S, Reid SG. Chronic hypoxia modulates NMDA-mediated regulation of the hypoxic ventilatory response in an amphibian, Bufo marinus. Respir Physiol Neurobiol 2005; 153:23-38. [PMID: 16344006 DOI: 10.1016/j.resp.2005.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2005] [Revised: 08/31/2005] [Accepted: 09/01/2005] [Indexed: 10/25/2022]
Abstract
This study examined whether a hypoxia-tolerant amphibian, the Cane toad, undergoes mammalian-like ventilatory acclimatisation to hypoxia (VAH) and whether chronic hypoxia (CH) alters NMDA-mediated regulation of the acute hypoxic ventilatory response (HVR). Toads were exposed to 10 days of CH (10% O2) followed by acute hypoxic breathing trials or an intra-arterial injection of NaCN. Trials were conducted before and after i.p. treatment with an NMDA-receptor channel blocker (MK801). CH blunted the acute HVR but did not alter resting breathing. MK801 did not alter resting ventilation. In control animals, MK801 augmented breathing frequency (fR) during acute hypoxia by increasing the number of breaths per episode. This effect was attenuated following CH although MK801 did enhance the number of episodes per minute during acute hypoxia. MK801 enhanced the fR response to NaCN in both groups. The results indicate that CH did not produce mammalian-like VAH (i.e. increased resting ventilation and an augmented acute HVR) but did alter MK801-sensitive regulation of breathing pattern and the acute HVR.
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Affiliation(s)
- Jessica McAneney
- Centre for the Neurobiology of Stress, Department of Life Sciences, University of Toronto at Scarborough, 1265 Military Trail, Toronto, Ont., Canada M1C 1A4
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Hedrick MS, Fahlman CS, Bickler PE. Intracellular calcium and survival of tadpole forebrain cells in anoxia. J Exp Biol 2005; 208:681-6. [PMID: 15695760 DOI: 10.1242/jeb.01436] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYThe frog brain survives hypoxia with a slow loss of energy charge and ion homeostasis. Because hypoxic death in most neurons is associated with increases in intracellular calcium ([Ca2+]i), we examined the relationship between [Ca2+]i and survival of a mixed population of isolated cells from the forebrain of North American bullfrog Rana catesbeiana tadpoles. Forebrain cells from stage V-XV tadpoles were isolated by enzymatic digestion and loaded with one of three different calcium indicators (Fura-2, Fura 2-FF and BTC) to provide estimates of [Ca2+]i accurate at low and high[Ca2+]i. Propidium iodide (PI) fluorescence was used as an indicator of cell viability. Cells were exposed to anoxia (100%N2) and measurements of [Ca2+]i and cell survival made from 1 h to 18 h. Intracellular [Ca2+] increased significantly after 3-6 h anoxia (P<0.05), regardless of the type of Ca2+ indicator used; however, there were substantial differences in the measurements of [Ca2+]i with the different indicators, reflecting their varying affinities for Ca2+. Resting[Ca2+]i was approximately 50 nmol l-1 and increased to about 9-30 μmol l-1 after 4-6 h anoxia. The significant increase in [Ca2+]i during anoxia was not associated with significant increases in cell death, with 85-95% survival over this time period. Cells exposed to anoxia for 18 h, or those made anoxic for 4-6 and reoxygenated for 12 h to 16 h, had survival rates greater than 70%,but survival was significantly less than normoxic controls. These results indicate that large increases in [Ca2+]i are not necessarily associated with hypoxic cell death in vertebrate brain cells.
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Affiliation(s)
- Michael S Hedrick
- Department of Anesthesia, University of California, San Francisco, CA 94143-0542, USA.
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