1
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Synergistic effect of long-term feed deprivation and temperature on the cellular physiology of meagre (Argyrosomus regius). J Therm Biol 2022; 105:103207. [DOI: 10.1016/j.jtherbio.2022.103207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 01/31/2022] [Accepted: 02/05/2022] [Indexed: 11/21/2022]
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2
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Hadj-Moussa H, Hawkins LJ, Storey KB. Role of MicroRNAs in Extreme Animal Survival Strategies. Methods Mol Biol 2022; 2257:311-347. [PMID: 34432286 DOI: 10.1007/978-1-0716-1170-8_16] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The critical role microRNAs play in modulating global functions is emerging, both in the maintenance of homeostatic mechanisms and in the adaptation to diverse environmental stresses. When stressed, cells must divert metabolic requirements toward immediate survival and eventual recovery and the unique features of miRNAs, such as their relatively ATP-inexpensive biogenesis costs, and the quick and reversible nature of their action, renders them excellent "master controllers" for rapid responses. Many animal survival strategies for dealing with extreme environmental pressures involve prolonged retreats into states of suspended animation to extend the time that they can survive on their limited internal fuel reserves until conditions improve. The ability to retreat into such hypometabolic states is only possible by coupling the global suppression of nonessential energy-expensive functions with an activation of prosurvival networks, a process in which miRNAs are now known to play a major role. In this chapter, we discuss the activation, expression, biogenesis, and unique attributes of miRNA regulation required to facilitate profound metabolic rate depression and implement stress-specific metabolic adaptations. We examine the role of miRNA in strategies of biochemical adaptation including mammalian hibernation, freeze tolerance, freeze avoidance, anoxia and hypoxia survival, estivation, and dehydration tolerance. By comparing these seemingly different adaptive programs in traditional and exotic animal models, we highlight both unique and conserved miRNA-meditated mechanisms for survival. Additional topics discussed include transcription factor networks, temperature dependent miRNA-targeting, and novel species-specific and stress-specific miRNAs.
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Affiliation(s)
| | - Liam J Hawkins
- Department of Biology, Carleton University, Ottawa, ON, Canada
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3
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Hernández-Fernández J, Pinzón Velasco AM, López Barrera EA, Rodríguez Becerra MDP, Villanueva-Cañas JL, Alba MM, Mariño Ramírez L. De novo assembly and functional annotation of blood transcriptome of loggerhead turtle, and in silico characterization of peroxiredoxins and thioredoxins. PeerJ 2021; 9:e12395. [PMID: 34820176 PMCID: PMC8606161 DOI: 10.7717/peerj.12395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 10/06/2021] [Indexed: 12/21/2022] Open
Abstract
The aim of this study was to generate and analyze the atlas of the loggerhead turtle blood transcriptome by RNA-seq, as well as identify and characterize thioredoxin (Tnxs) and peroxiredoxin (Prdxs) antioxidant enzymes of the greatest interest in the control of peroxide levels and other biological functions. The transcriptome of loggerhead turtle was sequenced using the Illumina Hiseq 2000 platform and de novo assembly was performed using the Trinity pipeline. The assembly comprised 515,597 contigs with an N50 of 2,631 bp. Contigs were analyzed with CD-Hit obtaining 374,545 unigenes, of which 165,676 had ORFs encoding putative proteins longer than 100 amino acids. A total of 52,147 (31.5%) of these transcripts had significant homology matches in at least one of the five databases used. From the enrichment of GO terms, 180 proteins with antioxidant activity were identified, among these 28 Prdxs and 50 putative Tnxs. The putative proteins of loggerhead turtles encoded by the genes Prdx1, Prdx3, Prdx5, Prdx6, Txn and Txnip were predicted and characterized in silico. When comparing Prdxs and Txns of loggerhead turtle with homologous human proteins, they showed 18 (9%), 52 (18%) 94 (43%), 36 (16%), 35 (33%) and 74 (19%) amino acid mutations respectively. However, they showed high conservation in active sites and structural motifs (98%), with few specific modifications. Of these, Prdx1, Prdx3, Prdx5, Prdx6, Txn and Txnip presented 0, 25, 18, three, six and two deleterious changes. This study provides a high quality blood transcriptome and functional annotation of loggerhead sea turtles.
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Affiliation(s)
- Javier Hernández-Fernández
- Department of Natural and Environmental Sciences, Faculty of Science and Engineering, Genetics, Molecular Biology and Bioinformatic Research Group-GENBIMOL, Universidad Jorge Tadeo Lozano, Bogotá, D.C., Colombia.,Faculty of Sciences, Department of Biology, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia
| | | | - Ellie Anne López Barrera
- Institute of Environmental Studies and Services. IDEASA Research Group-IDEASA, Sergio Arboleda University, Bogotá, D.C., Colombia
| | - María Del Pilar Rodríguez Becerra
- Department of Natural and Environmental Sciences, Faculty of Science and Engineering, Genetics, Molecular Biology and Bioinformatic Research Group-GENBIMOL, Universidad Jorge Tadeo Lozano, Bogotá, D.C., Colombia
| | | | - M Mar Alba
- Evolutionary Genomics Group, Research Program on Biomedical Informatics (GRIB), Hospital del Mar Research Institute (IMIM), Universitat Pompeu Fabra, Barcelona, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
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4
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Xin R, Qu D, Su S, Zhao B, Chen D. Downregulation of miR-23b by transcription factor c-Myc alleviates ischemic brain injury by upregulating Nrf2. Int J Biol Sci 2021; 17:3659-3671. [PMID: 34512173 PMCID: PMC8416714 DOI: 10.7150/ijbs.61399] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 07/24/2021] [Indexed: 12/12/2022] Open
Abstract
Ischemic brain injury (IBI) is a common acute cerebral vessel disease that occurs secondary to blockage in arteries, mainly characterized by insufficient blood supply to the brain. The transcription factor c-Myc in IBI continues to be implicated in numerous studies. This study was conducted with emphasis placed on the underlying mechanism of c-Myc in IBI. Clinical samples were collected from IBI patients. Middle cerebral artery occlusion (MCAO) was induced in mice by inserting a suture from the external carotid artery to the anterior cerebral artery through the internal carotid artery to mechanically block the blood supply at the origin of the middle cerebral artery, and cortical neurons from mice were exposed to oxygen glucose deprivation (OGD) conditions for IBI model in vitro construction. RT-qPCR was performed to determine microRNA-23b (miR-23b) expression. TUNEL staining and Western blot analysis was conducted to detect apoptosis. The regulatory relationship was analyzed by dual-luciferase reporter gene assay. After loss- and gain-of-function assays, triphenyltetrazolium chloride staining was carried out to detect the area of cerebral infarction, after which the spatial memory in mice was evaluated with Morris water maze test. As per our findings, miR-23b was upregulated in the serum of IBI patients and OGD-treated murine primary neurons. Silencing of miR-23b resulted in reduced OGD-induced neuronal apoptosis. miR-23b inversely targeted nuclear factor erythroid 2-related factor 2 (Nrf2) and c-Myc negatively regulated miR-23b expression. Overexpression of c-Myc and inhibition of miR-23b led to reduced neurological scores of infarction area, neuronal apoptosis, shortened platform arrival time and significantly increased the time spent on the platform quadrant and the times of crossing the platform in vivo. Collectively, downregulated miR-23b by c-Myc might alleviate IBI by upregulating Nrf2.
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Affiliation(s)
- Rui Xin
- Jilin University, Changchun 130000, P. R. China
- Department of Radiology, the Second Hospital of Jilin University, Changchun 130000, P. R. China
| | - Danhua Qu
- Jilin University, Changchun 130000, P. R. China
- Department of Respiratory and Critical Diseases, the Second Hospital of Jilin University, Changchun 130000, P. R. China
| | - Shuang Su
- Sinopec Research Institute of Safety Engineering, Qingdao 266000, P. R. China
| | - Bin Zhao
- Jilin University, Changchun 130000, P. R. China
- Department of Neurosurgery, the Second Hospital of Jilin University, Changchun 130000, P. R. China
| | - Dawei Chen
- Jilin University, Changchun 130000, P. R. China
- Department of Radiation Protection, School of Public Health, Jilin University, Changchun 130000, P. R. China
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5
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Wijenayake S, Storey KB. Oxidative Damage? Not a Problem! The Characterization of Humanin-like Mitochondrial Peptide in Anoxia Tolerant Freshwater Turtles. Protein J 2021; 40:87-107. [PMID: 33387248 DOI: 10.1007/s10930-020-09944-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2020] [Indexed: 11/30/2022]
Abstract
Mitochondria was long thought to be an "end function" organelle that regulated the metabolic flux and apoptosis in the cell. However, with the discovery of the mitochondrial peptide (MDP) humanin (HN/MTRNR2), the cytoprotective and pro-survival applications of MDPs have taken the forefront of therapeutic and diagnostic research. However, the regulation of humanin-like MDPs in natural model systems that can tolerate lethal environmental and cytotoxic insults remains to be investigated. Red-eared sliders are champion anaerobes that can withstand three continuous months of anoxia followed by rapid bouts of oxygen reperfusion without incurring cellular damage. Freshwater turtles employ extensive physiological and biochemical strategies to combat anoxia, with metabolic rate depression and a global enhancement of antioxidant and cytoprotective pathways being the two most important contributors. The main aim of this study was to uncover and characterize the humanin-homologue in freshwater turtles as well as investigate the differential regulation of humanin in response to short and long-term oxygen deprivation. In this study we have used de novo and homology-based protein modelling to elucidate the putative structure of humanin in red-eared sliders as well as an ELISA and western immunoblotting to confirm the protein abundance in the turtle brain and six peripheral tissues during control, 5 h, and 20 h anoxia (n = 4/group). We found that a humanin-homologue (TSE-humanin) is present in red-eared sliders and it may play a cytoprotective role against oxidative damage.
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Affiliation(s)
- Sanoji Wijenayake
- Department of Biology, Institute of Biochemistry, Carleton University, Ottawa, ON, Canada.,Department of Biological Sciences and Center for Environmental Epigenetics and Development, University of Toronto, Toronto, ON, Canada
| | - Kenneth B Storey
- Department of Biology, Institute of Biochemistry, Carleton University, Ottawa, ON, Canada. .,Department of Chemistry, Institute of Biochemistry, 1125 Colonel By Drive, Ottawa, ON, K1S 5B6, Canada.
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6
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Su L, Meng JY, Yang H, Zhang CY. Molecular Characterization and Expression of OfJNK and Ofp38 in Ostrinia furnacalis (Guenée) Under Different Environmental Stressors. Front Physiol 2020; 11:125. [PMID: 32158401 PMCID: PMC7052289 DOI: 10.3389/fphys.2020.00125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 02/04/2020] [Indexed: 01/02/2023] Open
Abstract
Ostrinia furnacalis, an important pest of corn, has substantial detrimental effects on corn production. The mitogen-activated protein kinase (MAPK) signaling pathway plays a pivotal role in an insect’s resistance to environmental stress. The expression levels of JNK and p38 have been well recorded in several insects under different environmental stressors, at different developmental stages, and in various tissue types; however, there is limited information on JNK and p38 in agricultural insects. To clarify the mechanism whereby O. furnacalis responds to environmental stress, we cloned JNK and p38 from O. furnacalis and subsequently named them OfJNK and Ofp38, respectively. Further, we examined the expression levels of OfJNK and Ofp38 under different environmental stressors. In this study, we obtained full-length sequences of OfJNK and Ofp38, and RT-qPCR results showed that these genes were expressed at all developmental stages, in various tissues (head, chest, abdomen, leg, wing, antennae, compound eye, midgut, and ovary) and under different environmental stressors (4°C and ultraviolet A treatment for 0, 30, 60, 90, and 120 min). The expression levels of OfJNK and Ofp38 were relatively higher in eggs and 3-day-old adult females than in other developmental stages. Moreover, the expression level of OfJNK was higher in the wings than in other tissues, whereas that of Ofp38 was significantly higher in the ovaries than in other tissues. OfJNK and Ofp38 showed high expression 90 min after being subjected to treatment at 4°C and ultraviolet A irradiation; the expression of Ofp38 peaked at 30 min, whereas that of OfJNK peaked at 60 min. These results indicate that O. furnacalis differs in terms of its response under different environmental stressors. In summary, our results will provide a foundation for additional research needed to determine the role of the MAPK signaling pathway and the underlying mechanisms by which it shows resistance to environmental stresses in insects.
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Affiliation(s)
- Li Su
- Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions, Institute of Entomology, Guizhou University, Guiyang, China
| | - Jian-Yu Meng
- Guizhou Tobacco Science Research Institute, Guiyang, China
| | - Hong Yang
- Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions, Institute of Entomology, Guizhou University, Guiyang, China
| | - Chang-Yu Zhang
- Provincial Key Laboratory for Agricultural Pest Management of Mountainous Regions, Institute of Entomology, Guizhou University, Guiyang, China
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7
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The expression of genes involved in excitatory and inhibitory neurotransmission in turtle (Trachemys scripta) brain during anoxic submergence at 21 °C and 5 °C reveals the importance of cold as a preparatory cue for anoxia survival. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2019; 30:55-70. [DOI: 10.1016/j.cbd.2018.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Accepted: 12/27/2018] [Indexed: 11/20/2022]
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8
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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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9
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Aguilar OA, Hadj-Moussa H, Storey KB. Freeze-responsive regulation of MEF2 proteins and downstream gene networks in muscles of the wood frog, Rana sylvatica. J Therm Biol 2017; 67:1-8. [DOI: 10.1016/j.jtherbio.2017.04.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 03/24/2017] [Accepted: 04/18/2017] [Indexed: 01/21/2023]
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10
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Arfat Y, Chang H, Gao Y. Stress-responsive microRNAs are involved in re-programming of metabolic functions in hibernators. J Cell Physiol 2017; 233:2695-2704. [PMID: 28574587 DOI: 10.1002/jcp.26034] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/01/2017] [Indexed: 12/21/2022]
Abstract
Mammalian hibernation includes re-programing of metabolic capacities, partially, encouraged by microRNAs (miRNAs). Albeit much is known about the functions of miRNAs, we need learning on low temperature miRNAs target determination. As hibernators can withstand low body temperatures (TB) for a long time without anguish tissue damage, understanding the means and mechanisms that empower them to do as such are of restorative intrigue. Nonetheless, these mechanisms by which miRNAs and the hibernators react to stressful conditions are not much clear. It is evident from recent data that the gene expression and the translation of mRNA to protein are controlled by miRNAs. The miRNAs also influence regulation of major cellular processes. As the significance of miRNAs in stress conditions adaptation are getting clearer, this audit article abridges the key alterations in miRNA expression and the mechanism that facilitates stress survival.
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Affiliation(s)
- Yasir Arfat
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, China
| | - Hui Chang
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, China
| | - Yunfang Gao
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China (College of Life Sciences, Northwest University), Ministry of Education, Xi'an, China
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11
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Wang H, Li C, Wang Z, Shao Y, Lv Z, Zhang W. p44/42MAPK and p90RSK modulate thermal stressed physiology response in Apostichopus japonicus. Comp Biochem Physiol B Biochem Mol Biol 2016; 196-197:57-66. [DOI: 10.1016/j.cbpb.2016.02.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/26/2016] [Accepted: 02/26/2016] [Indexed: 01/31/2023]
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12
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Keenan SW, Hill CA, Kandoth C, Buck LT, Warren DE. Transcriptomic Responses of the Heart and Brain to Anoxia in the Western Painted Turtle. PLoS One 2015; 10:e0131669. [PMID: 26147940 PMCID: PMC4493013 DOI: 10.1371/journal.pone.0131669] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 06/05/2015] [Indexed: 12/23/2022] Open
Abstract
Painted turtles are the most anoxia-tolerant tetrapods known, capable of surviving without oxygen for more than four months at 3°C and 30 hours at 20°C. To investigate the transcriptomic basis of this ability, we used RNA-seq to quantify mRNA expression in the painted turtle ventricle and telencephalon after 24 hours of anoxia at 19°C. Reads were obtained from 22,174 different genes, 13,236 of which were compared statistically between treatments for each tissue. Total tissue RNA contents decreased by 16% in telencephalon and 53% in ventricle. The telencephalon and ventricle showed ≥ 2x expression (increased expression) in 19 and 23 genes, respectively, while only four genes in ventricle showed ≤ 0.5x changes (decreased expression). When treatment effects were compared between anoxic and normoxic conditions in the two tissue types, 31 genes were increased (≥ 2x change) and 2 were decreased (≤ 0.5x change). Most of the effected genes were immediate early genes and transcription factors that regulate cellular growth and development; changes that would seem to promote transcriptional, translational, and metabolic arrest. No genes related to ion channels, synaptic transmission, cardiac contractility or excitation-contraction coupling changed. The generalized expression pattern in telencephalon and across tissues, but not in ventricle, correlated with the predicted metabolic cost of transcription, with the shortest genes and those with the fewest exons showing the largest increases in expression.
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Affiliation(s)
- Sarah W. Keenan
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Craig A. Hill
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
| | - Cyriac Kandoth
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Leslie T. Buck
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Daniel E. Warren
- Department of Biology, Saint Louis University, St. Louis, Missouri, United States of America
- * E-mail:
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13
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The transcription factor c-Myc suppresses MiR-23b and MiR-27b transcription during fetal distress and increases the sensitivity of neurons to hypoxia-induced apoptosis. PLoS One 2015; 10:e0120217. [PMID: 25781629 PMCID: PMC4363589 DOI: 10.1371/journal.pone.0120217] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/20/2015] [Indexed: 11/26/2022] Open
Abstract
Previous studies reported that the expression of miR-23b-27b cluster was downregulated in embryonic brain cortices during hypoxia-induced neuronal apoptosis. However, the mechanism underlying this downregulation is not completely understood. Here, we report that the transcription factor c-Myc plays an important role in regulating the expression of miR-23b-27b cluster during hypoxia. First, the c-Myc protein level was significantly elevated in embryonic brain cortices in a mouse model of fetal distress. Second, forced overexpression or knockdown of c-Myc could suppress or increase the expression of miR-23b-27b cluster polynucleotides. Third, we identified 2 conserved c-Myc binding sites (E-boxes) in the enhancer and promoter regions of miR-23b-27b cluster in the mouse genome. Finally, we showed that elevated c-Myc expression led to an increase in the Apaf-1 level by suppressing miR-23b-27b cluster expression and that this enhanced neuronal sensitivity to apoptosis. In summary, our study demonstrates that c-Myc may suppress the expression of the miR-23b-27b cluster, resulting in additional neuronal apoptosis during hypoxia.
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14
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Nilsson GE, Vaage J, Stensløkken KO. Oxygen- and temperature-dependent expression of survival protein kinases in crucian carp (Carassius carassius) heart and brain. Am J Physiol Regul Integr Comp Physiol 2015; 308:R50-61. [PMID: 25377478 DOI: 10.1152/ajpregu.00094.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Living without oxygen is limited to very few vertebrates, one species being the fresh water fish crucian carp (Carassius carassius), which can survive months of anoxia at low temperatures. Mammalian heart and brain are particularly intolerant to oxygen deprivation, yet these organs can be conditioned to display increased resistance, possibly due to activation of several protein kinases. We hypothesized increased phosphorylation status of these kinases in hypoxic and anoxic crucian carp heart and brain. Moreover, we wanted to investigate whether the kinases showing the strongest phosphorylation during hypoxia/anoxia, ERK 1/2, p38-MAPK, JNK, PKCε, and PKCδ, also had increased expression and phosphorylation at cold temperatures, to better cope with the anoxic periods during winter. We found small differences in the phosphorylation status of ERK 1/2, p38-MAPK, JNK, PKCε, and PKCδ during 10 days of severe hypoxia in both heart and brain (0.3 mg O₂/l) and varying responses to reoxygenation. In contrast, 7 days of anoxia (<0.01 mg O₂/l) markedly increased phosphorylation of ERK 1/2, p38-MAPK, JNK in the heart, and p38-MAPK and PKCε in the brain. Similarly, varying acclimation temperature between 4, 10 and 20°C induced large changes in phosphorylation status. Total protein expression in heart and brain neither changed during different oxygen regimes nor with different acclimation temperatures, except for ERK 1/2, which slightly decreased in the heart at 4°C compared with 20°C. A phylogenetic analysis confirmed that these protein kinases are evolutionarily conserved across a wide range of vertebrate species. Our findings indicate important roles of several protein kinases during oxygen deprivation.
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Affiliation(s)
- Göran E Nilsson
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jarle Vaage
- Department of Emergency Medicine and Intensive Care, Oslo University Hospital and Institute of Clinical Medicine, University of Oslo Hospital, Oslo, Norway; and
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15
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Quinones QJ, Ma Q, Zhang Z, Barnes BM, Podgoreanu MV. Organ protective mechanisms common to extremes of physiology: a window through hibernation biology. Integr Comp Biol 2014; 54:497-515. [PMID: 24848803 DOI: 10.1093/icb/icu047] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Supply and demand relationships govern survival of animals in the wild and are also key determinants of clinical outcomes in critically ill patients. Most animals' survival strategies focus on the supply side of the equation by pursuing territory and resources, but hibernators are able to anticipate declining availability of nutrients by reducing their energetic needs through the seasonal use of torpor, a reversible state of suppressed metabolic demand and decreased body temperature. Similarly, in clinical medicine the majority of therapeutic interventions to care for critically ill or trauma patients remain focused on elevating physiologic supply above critical thresholds by increasing the main determinants of delivery of oxygen to the tissues (cardiac output, perfusion pressure, hemoglobin concentrations, and oxygen saturation), as well as increasing nutritional support, maintaining euthermia, and other general supportive measures. Techniques, such as induced hypothermia and preconditioning, aimed at diminishing a patient's physiologic requirements as a short-term strategy to match reduced supply and to stabilize their condition, are few and underutilized in clinical settings. Consequently, comparative approaches to understand the mechanistic adaptations that suppress metabolic demand and alter metabolic use of fuel as well as the application of concepts gleaned from studies of hibernation, to the care of critically ill and injured patients could create novel opportunities to improve outcomes in intensive care and perioperative medicine.
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Affiliation(s)
- Quintin J Quinones
- *Department of Anesthesiology, Systems Modeling of Perioperative Organ Injury Laboratory, Duke University, Box 3094, Durham, NC 27710, USA; Institute for Arctic Biology, University of Alaska, Fairbanks, AK, USA
| | - Qing Ma
- *Department of Anesthesiology, Systems Modeling of Perioperative Organ Injury Laboratory, Duke University, Box 3094, Durham, NC 27710, USA; Institute for Arctic Biology, University of Alaska, Fairbanks, AK, USA
| | - Zhiquan Zhang
- *Department of Anesthesiology, Systems Modeling of Perioperative Organ Injury Laboratory, Duke University, Box 3094, Durham, NC 27710, USA; Institute for Arctic Biology, University of Alaska, Fairbanks, AK, USA
| | - Brian M Barnes
- *Department of Anesthesiology, Systems Modeling of Perioperative Organ Injury Laboratory, Duke University, Box 3094, Durham, NC 27710, USA; Institute for Arctic Biology, University of Alaska, Fairbanks, AK, USA
| | - Mihai V Podgoreanu
- *Department of Anesthesiology, Systems Modeling of Perioperative Organ Injury Laboratory, Duke University, Box 3094, Durham, NC 27710, USA; Institute for Arctic Biology, University of Alaska, Fairbanks, AK, USA*Department of Anesthesiology, Systems Modeling of Perioperative Organ Injury Laboratory, Duke University, Box 3094, Durham, NC 27710, USA; Institute for Arctic Biology, University of Alaska, Fairbanks, AK, USA
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16
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Krivoruchko A, Storey KB. Anoxia-responsive regulation of the FoxO transcription factors in freshwater turtles, Trachemys scripta elegans. Biochim Biophys Acta Gen Subj 2013; 1830:4990-8. [PMID: 23850471 DOI: 10.1016/j.bbagen.2013.06.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 06/10/2013] [Accepted: 06/29/2013] [Indexed: 11/25/2022]
Abstract
BACKGROUND The forkhead class O (FoxO) transcription factors are important regulators of multiple aspects of cellular metabolism. We hypothesized that activation of these transcription factors could play crucial roles in low oxygen survival in the anoxia-tolerant turtle, Trachemys scripta elegans. METHODS Two FoxOs, FoxO1 and FoxO3, were examined in turtle tissues in response to 5 and 20h of anoxic submergence using techniques of RT-PCR, western immunoblotting and DNA-binding assays to assess activation. Transcript levels of FoxO-responsive genes were also quantified using RT-PCR. RESULTS FoxO1 was anoxia-responsive in the liver, with increases in transcript levels, protein levels, nuclear levels and DNA-binding of 1.7-4.8fold in response to anoxia. Levels of phosphorylated FoxO1 also decreased to 57% of control values in response to 5h of anoxia, indicating activation. FoxO3 was activated in the heart, kidney and liver in response to anoxia, with nuclear levels increasing by 1.5-3.7fold and DNA-binding activity increasing by 1.3-2.9fold. Transcript levels of two FoxO-target genes, p27kip1 and catalase, also rose by 2.4-2.5fold in the turtle liver under anoxia. CONCLUSIONS The results suggest that the FoxO transcription factors are activated in response to anoxia in T. scripta elegans, potentially contributing to the regulation of stress resistance and metabolic depression. GENERAL SIGNIFICANCE This study provides the first demonstration of activation of FoxOs in a natural model for vertebrate anoxia tolerance, further improving understanding of how tissues can survive without oxygen.
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Affiliation(s)
- Anastasia Krivoruchko
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada.
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Zhang J, Biggar KK, Storey KB. Regulation of p53 by reversible post-transcriptional and post-translational mechanisms in liver and skeletal muscle of an anoxia tolerant turtle, Trachemys scripta elegans. Gene 2013; 513:147-55. [PMID: 23124036 DOI: 10.1016/j.gene.2012.10.049] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 06/25/2012] [Accepted: 10/10/2012] [Indexed: 01/07/2023]
Abstract
The red-eared slider turtle (Trachemys scripta elegans) exhibits well-developed natural anoxia tolerance that depends on multiple biochemical adaptations, including anoxia-induced hypometabolism. We hypothesized that signaling by the p53 protein could aid in establishing the hypometabolic state by arresting the cell cycle, protecting against DNA damage as well as altering pathways of energy metabolism. Immunoblotting was used to evaluate the regulation and post-transcriptional modifications of p53 in liver and skeletal muscle of red-eared slider turtles subjected to 5h or 20h of anoxic submergence. Tissue specific regulation of p53 was observed with the liver showing a more rapid activation of p53 in response to anoxia as well as differential expression of seven serine phosphorylation and two lysine acetylation sites when compared with skeletal muscle. Protein expression of MDM2, a major p53 inhibitor, was also examined but did not change during anoxia. Reverse-transcriptase PCR was used to assess transcript levels of selected p53 target genes (14-3-3σ, Gadd45α and Pgm) and one microRNA (miR-34a); results showed down-regulation of Pgm and up-regulation of the other three. These findings show an activation of p53 in response to anoxia exposure and suggest an important role for the p53 stress response pathway in regulating natural anoxia tolerance and hypometabolism in a vertebrate facultative anaerobe.
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Affiliation(s)
- Jing Zhang
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6
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Nayak GH, Prentice HM, Milton SL. Neuroprotective signaling pathways are modulated by adenosine in the anoxia tolerant turtle. J Cereb Blood Flow Metab 2011; 31:467-75. [PMID: 20648037 PMCID: PMC3049502 DOI: 10.1038/jcbfm.2010.109] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Cumulative evidence shows a protective role for adenosine A1 receptors (A1R) in hypoxia/ischemia; A1R stimulation reduces neuronal damage, whereas blockade exacerbates damage. The signal transduction pathways may involve the mitogen-activated protein kinase (MAPK) pathways and serine/threonine kinase (AKT), with cell survival depending on the timing and degree of upregulation of these cascades as well as the balance between pro-survival and pro-death pathways. Here, we show in vitro that extracellular signal-regulated kinase (ERK1/2) and phosphatidylinositol 3-kinase (PI3-K/AKT) activation is dependent on A1R stimulation, with further downstream effects that promote neuronal survival. Phosphorylated ERK1/2 (p-ERK) and AKT (p-AKT) as well as Bcl-2 are upregulated in anoxic neuronally enriched primary cultures from turtle brain. This native upregulation is further increased by the selective A1R agonist 2-chloro-N-cyclopentyladenosine (CCPA), whereas the selective antagonist 8-cyclopentyl-1,3-dihydropylxanthine (DPCPX) decreases p-ERK and p-AKT expression. Conversely, A1R antagonism resulted in increases in phosphorylated JNK (p-JNK), p38 (p-p38), and Bax. As pathological and adaptive changes occur simultaneously during anoxia/ischemia in mammalian neurons, the turtle provides an alternative model to analyze protective mechanisms in the absence of evident pathologies.
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Affiliation(s)
- Gauri H Nayak
- Department of Biology, Boston University, Boston, Massachusetts 02215, USA.
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19
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Dowd WW, Renshaw GMC, Cech JJ, Kültz D. Compensatory proteome adjustments imply tissue-specific structural and metabolic reorganization following episodic hypoxia or anoxia in the epaulette shark (Hemiscyllium ocellatum). Physiol Genomics 2010; 42:93-114. [PMID: 20371547 PMCID: PMC2888556 DOI: 10.1152/physiolgenomics.00176.2009] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2009] [Accepted: 04/05/2010] [Indexed: 12/31/2022] Open
Abstract
The epaulette shark (Hemiscyllium ocellatum) represents an ancestral vertebrate model of episodic hypoxia and anoxia tolerance at tropical temperatures. We used two-dimensional gel electrophoresis and mass spectrometry-based proteomics approaches, combined with a suite of physiological measures, to characterize this species' responses to 1) one episode of anoxia plus normoxic recovery, 2) one episode of severe hypoxia plus recovery, or 3) two episodes of severe hypoxia plus recovery. We examined these responses in the cerebellum and rectal gland, two tissues with high ATP requirements. Sharks maintained plasma ionic homeostasis following all treatments, and activities of Na(+)/K(+)-ATPase and caspase 3/7 in both tissues were unchanged. Oxygen lack and reoxygenation elicited subtle adjustments in the proteome. Hypoxia led to more extensive proteome responses than anoxia in both tissues. The cerebellum and rectal gland exhibited treatment-specific responses to oxygen limitation consistent with one or more of several strategies: 1) neurotransmitter and receptor downregulation in cerebellum to prevent excitotoxicity, 2) cytoskeletal/membrane reorganization, 3) metabolic reorganization and more efficient intracellular energy shuttling that are more consistent with sustained ATP turnover than with long-term metabolic depression, 4) detoxification of metabolic byproducts and oxidative stress in light of continued metabolic activity, particularly following hypoxia in rectal gland, and 5) activation of prosurvival signaling. We hypothesize that neuronal morphological changes facilitate prolonged protection from excitotoxicity via dendritic spine remodeling in cerebellum (i.e., synaptic structural plasticity). These results recapitulate several highly conserved themes in the anoxia and hypoxia tolerance, preconditioning, and oxidative stress literature in a single system. In addition, several of the identified pathways and proteins suggest potentially novel mechanisms for enhancing anoxia or hypoxia tolerance in vertebrates. Overall, our data show that episodic hypoxic or anoxic exposure and recovery in the epaulette shark amplifies a constitutive suite of compensatory mechanisms that further prepares them for subsequent insults.
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Affiliation(s)
- W Wesley Dowd
- Department of Animal Science, University of California, Davis, California, USA
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20
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Ramnanan CJ, McMullen DC, Bielecki A, Storey KB. Regulation of sarcoendoplasmic reticulum Ca2+-ATPase (SERCA) in turtle muscle and liver during acute exposure to anoxia. J Exp Biol 2010; 213:17-25. [DOI: 10.1242/jeb.036087] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
SUMMARY
The freshwater turtle Trachemys scripta elegans naturally tolerates extended periods of anoxia during winter hibernation at the bottom of ice-locked ponds. Survival in this anoxic state is facilitated by a profound depression of metabolic rate. As calcium levels are known to be elevated in anoxic turtles, and ion pumping is an ATP-expensive process, we proposed that activity of the sarcoendoplasmic reticulum Ca2+-ATPase (SERCA) would be reduced in muscle and liver of T. s. elegans during acute (up to 20 h) exposure to anoxia. SERCA activity decreased ∼30% in liver and ∼40% in muscle after 1 h anoxia exposure and was ∼50% lower after 20 h of anoxia exposure in both tissues, even though SERCA protein levels did not change. SERCA kinetic parameters (increased substrate Km values, increased Arrhenius activation energy) were indicative of a less active enzyme form under anoxic conditions. Interestingly, the less active SERCA in anoxic turtles featured greater stability than the enzyme from normoxic animals as determined by both kinetic analysis (effect of low pH and low temperatures on Km MgATP) and conformational resistance to urea denaturation. The quick time course of deactivation and the stable changes in kinetic parameters that resulted suggested that SERCA was regulated by a post-translational mechanism. In vitro experiments indicated that SERCA activity could be blunted by protein phosphorylation and enhanced by dephosphorylation in a tissue-specific manner.
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Affiliation(s)
- C. J. Ramnanan
- Vanderbilt University School of Medicine, Department of Molecular Physiology, 710 Robinson Research Building, 2200 Pierce Avenue, Nashville, TN 37232, USA
| | - D. C. McMullen
- Stroke Branch, National Institute of Neurological Disorder and Stroke, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - A. Bielecki
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada, K1S 5B6
| | - K. B. Storey
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada, K1S 5B6
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Malik AI, Storey KB. Activation of extracellular signal-regulated kinases during dehydration in the African clawed frog, Xenopus laevis. J Exp Biol 2009; 212:2595-603. [DOI: 10.1242/jeb.030627] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
In its native environment the African clawed frog, Xenopus laevis,can experience seasonally arid conditions that impose dehydration stress. Activation of intracellular signal transduction cascades can mediate and coordinate biochemical responses to ameliorate dehydration stress. This study examines the extracellular signal-regulated kinase (ERK) signaling cascade,analyzing responses of both upstream and downstream components in six tissues of X. laevis experiencing medium and high levels of dehydration,16.6±1.59 and 28.0±1.6% of total body water lost, respectively. Immunoblotting was used to assess the three tiers in this mitogen-activated protein kinase (MAPK) cascade: the initiating MAPK kinase kinases (c-Raf,MEKK), the MAPK kinase (MEK1/2), and finally the MAPK (ERK1/2). The amount of active phosphorylated c-RafSer338 rose by 2- to 2.5-fold under high dehydration in muscle, lung and skin whereas MEKK protein levels rose in these organs and also increased 4-fold in liver. As a result, phosphorylated active MEK1/2Ser217/221 increased significantly by 2- to 6-fold during dehydration which, in turn, led to 2- to 6-fold increases in phospho-ERKThr202/Tyr204 content in all tissues except skin. Given this clear demonstration of ERK cascade activation, two downstream targets of ERK2 were then evaluated. The amount of phosphorylated active transcription factor, STAT3Ser727 and p90 ribosomal S6 kinase(RSKSer380) increased particularly in muscle, lung and kidney. Furthermore, RSK activation was correlated with a 5- to 8-fold increase in phosphorylation of its target, S6 ribosomal protein. Overall, the results show a strong conserved activation of the ERK cascade in X. laevis tissues in response to dehydration.
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Affiliation(s)
- Amal Idris Malik
- Institute of Biochemistry and Department of Biology, Carleton University,1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
| | - Kenneth B. Storey
- Institute of Biochemistry and Department of Biology, Carleton University,1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6
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Matching cellular metabolic supply and demand in energy-stressed animals. Comp Biochem Physiol A Mol Integr Physiol 2009; 153:95-105. [PMID: 19535026 DOI: 10.1016/j.cbpa.2009.02.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2008] [Revised: 01/30/2009] [Accepted: 02/02/2009] [Indexed: 12/31/2022]
Abstract
Certain environmental stressors can impair cellular ATP production to the point of harming or even killing an animal. Some exceptional animals employ strategies that maintain the balance between ATP production and consumption, allowing them to tolerate prolonged exposure to stressors such as hypoxia and anoxia. Anoxia- and hypoxia-tolerant animals reduce ATP consumption by ion-motive ATPases while concomitant reductions in passive ion flux reduce the demand for ion pumping and maintain transmembrane ion gradients. Reductions in gene transcription and protein turnover decrease ATP demand in hibernating and hypoxia-tolerant animals. Proton leak uncouples mitochondrial substrate oxidation from ATP synthesis and accounts for a considerable proportion of cellular energy demand, but there is little evidence that the proton permeability of inner mitochondrial membranes decreases in animals that tolerate energy stress. Indeed in some cases proton leak increases, possibly reducing reactive oxygen species production. Because substrate oxidation is important to the control of cellular metabolism, the downregulation of ATP supply pathways contributes significantly to metabolic suppression under energy stress. Mechanisms that coordinate the downregulation of both ATP supply and demand pathways include AMP kinase and ATP-sensitive ion channels. Strategies employed by animals tolerant to one energy stress often convey "cross-tolerance" to completely different stresses.
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Adenosine modulates ERK1/2, PI3K/Akt, and p38MAPK activation in the brain of the anoxia-tolerant turtle Trachemys scripta. J Cereb Blood Flow Metab 2008; 28:1469-77. [PMID: 18506199 DOI: 10.1038/jcbfm.2008.45] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The fate of cells under anoxic or ischemic stress is determined by intracellular signaling pathways including the mitogen-activated protein kinases (MAPKs) and phosphatidylinositol 3-kinase (PI3K/Akt), which affect downstream members of the apoptotic cascade. The freshwater turtle Trachemys scripta is extremely tolerant of anoxia, surviving up to 48 h at room temperature and for weeks at 3 degrees C in the complete absence of oxygen. We investigated the relationship between the neuroprotective purine adenosine, which increases greatly in the anoxic turtle brain, and MAPK and Akt activation during both short (1 h) and long-term (4 h) anoxia. ERK1/2 and Akt were significantly upregulated during the first hour of transition to full anoxia, but returned to baseline by 4 h anoxia. Conversely, p38MAPK levels were suppressed by a mean 71% at 1 h anoxia but also returned to baseline by 4 h anoxia. Systemic administration of the general adenosine receptor antagonist aminophylline abrogated the increases in both phosphorylated ERK1/2 and Akt, as well as the initial suppression of p38MAPK. The differential modulation of the MAPK/Akt pathways may be critical for neuronal protection during the initial transition to the hypometabolic state during anoxia, when physiologic stress is likely to be greatest.
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Marques IJ, Leito JTD, Spaink HP, Testerink J, Jaspers RT, Witte F, van den Berg S, Bagowski CP. Transcriptome analysis of the response to chronic constant hypoxia in zebrafish hearts. J Comp Physiol B 2007; 178:77-92. [PMID: 17828398 PMCID: PMC2200676 DOI: 10.1007/s00360-007-0201-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Revised: 07/26/2007] [Accepted: 08/01/2007] [Indexed: 12/17/2022]
Abstract
Insufficient blood supply during acute infarction and chronic ischemia leads to tissue hypoxia which can significantly alter gene expression patterns in the heart. In contrast to most mammals, some teleost fishes are able to adapt to extremely low oxygen levels. We describe here that chronic constant hypoxia (CCH) leads to a smaller ventricular outflow tract, reduced lacunae within the central ventricular cavity and around the trabeculae and an increase in the number of cardiac myocyte nuclei per area in the hearts of two teleost species, zebrafish (Danio rerio) and cichlids (Haplochromis piceatus). In order to identify the molecular basis for the adaptations to CCH, we profiled the gene expression changes in the hearts of adult zebrafish. We have analyzed over 15,000 different transcripts and found 376 differentially regulated genes, of which 260 genes showed increased and 116 genes decreased expression levels. Two notch receptors (notch-2 and notch-3) as well as regulatory genes linked to cell proliferation were transcriptionally upregulated in hypoxic hearts. We observed a simultaneous increase in expression of IGF-2 and IGFbp1 and upregulation of several genes important for the protection against reactive oxygen species (ROS). We have identified here many novel genes involved in the response to CCH in the heart, which may have potential clinical implications in the future.
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Affiliation(s)
- Ines J. Marques
- Department of Integrative Zoology, Institute of Biology, University of Leiden, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands
| | - Jelani T. D. Leito
- Department of Dental Basic Sciences, Section of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit, Amsterdam, The Netherlands
| | - Herman P. Spaink
- Department of Molecular Cellular Biology, Institute of Biology, University of Leiden, 2333 AL Leiden, The Netherlands
| | - Janwillem Testerink
- Department of Molecular Cellular Biology, Institute of Biology, University of Leiden, 2333 AL Leiden, The Netherlands
- Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands
| | - Richard T. Jaspers
- Research Institute MOVE, Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, The Netherlands
| | - Frans Witte
- Department of Integrative Zoology, Institute of Biology, University of Leiden, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands
| | - Sjoerd van den Berg
- Department of Integrative Zoology, Institute of Biology, University of Leiden, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands
| | - Christoph P. Bagowski
- Department of Integrative Zoology, Institute of Biology, University of Leiden, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands
- Department of Molecular Cellular Biology, Institute of Biology, University of Leiden, 2333 AL Leiden, The Netherlands
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25
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Zambotti-Villela L, Marinho CE, Alponti RF, Silveira PF. Hypothalamic activity during altered salt and water balance in the snake Bothrops jararaca. J Comp Physiol B 2007; 178:57-66. [PMID: 17703311 DOI: 10.1007/s00360-007-0199-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Revised: 07/20/2007] [Accepted: 07/28/2007] [Indexed: 11/29/2022]
Abstract
The effects of water and salt overload on the activities of the supraoptic and paraventricular nuclei and the adjacent periventricular zone of the hypothalamus of the snake Bothrops jararaca were investigated by measurements of Fos-like immunoreactivity (Fos-ir). Both water and salt overload resulted in changes in body mass, plasma osmolality, and plasma concentrations of sodium, potassium, and chloride. Hyper-osmolality increased Fos immunoreactivity in the rostral supraoptic nucleus (SON), the paraventricular nucleus (PVN), and adjacent periventricular areas. Both hyper- and hypo-osmolality increased Fos immunoreactivity in the intermediate SON, but not in other areas of the hypothalamus. Immunostaining was abundant in cerebrospinal fluid (CSF)-contacting tanycyte-like cells in the ependymal layer of the third ventricle. These data highlight some features of regional distribution of Fos immunoreactivity that are consistent with vasotocin functioning as a hormone, and support the role of hypothalamic structures in the response to disruption of salt and water balance in this snake.
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26
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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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Zhou D, Xue J, Chen J, Morcillo P, Lambert JD, White KP, Haddad GG. Experimental selection for Drosophila survival in extremely low O(2) environment. PLoS One 2007; 2:e490. [PMID: 17534440 PMCID: PMC1871610 DOI: 10.1371/journal.pone.0000490] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 05/11/2007] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Cellular hypoxia, if severe enough, results usually in injury or cell death. Our research in this area has focused on the molecular mechanisms underlying hypoxic tissue injury to explore strategies to prevent injury or enhance tolerance. The current experiments were designed to determine the genetic basis for adaptation to long term low O(2) environments. METHODOLOGY/PRINCIPAL FINDINGS With long term experimental selection over many generations, we obtained a Drosophila melanogaster strain that can live perpetually in extremely low, normally lethal, O(2) condition (as low as 4% O(2)). This strain shows a dramatic phenotypic divergence from controls, including a decreased recovery time from anoxic stupor, a higher rate of O(2 )consumption in hypoxic conditions, and a decreased body size and mass due to decreased cell number and size. Expression arrays showed that about 4% of the Drosophila genome altered in expression and about half of the alteration was down-regulation. The contribution of some altered transcripts to hypoxia tolerance was examined by testing the survival of available corresponding P-element insertions (and their excisions) under extremely low O(2) conditions. We found that down-regulation of several candidate genes including Best1, broad, CG7102, dunce, lin19-like and sec6 conferred severe hypoxia tolerance in Drosophila. CONCLUSIONS/SIGNIFICANCE We have identified a number of genes that play an important role in the survival of a selected Drosophila strain in extremely low O(2) conditions, selected by decreasing O(2) availability over many generations. Because of conservation of pathways, we believe that such genes are critical in hypoxia adaptation in physiological or pathological conditions not only in Drosophila but also in mammals.
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Affiliation(s)
- Dan Zhou
- Departments of Pediatrics, Section of Respiratory Medicine, and Neuroscience, University of California San Diego, La Jolla, California, United States of America
- The Rady Children's Hospital - San Diego, San Diego, California, United States of America
| | - Jin Xue
- Departments of Pediatrics, Section of Respiratory Medicine, and Neuroscience, University of California San Diego, La Jolla, California, United States of America
- The Rady Children's Hospital - San Diego, San Diego, California, United States of America
| | - Jianming Chen
- Department of Immunology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Patrick Morcillo
- Department of Cell Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York, United States of America
| | - J. David Lambert
- Department of Biology, University of Rochester, Rochester, New York, United States of America
| | - Kevin P. White
- Institute for Genomics & Systems Biology and Departments of Human Genetics and Ecology and Evolution, The University of Chicago, Chicago, Illinois, United States of America
- * To whom correspondence should be addressed. E-mail: (GH), (KP)
| | - Gabriel G. Haddad
- Departments of Pediatrics, Section of Respiratory Medicine, and Neuroscience, University of California San Diego, La Jolla, California, United States of America
- The Rady Children's Hospital - San Diego, San Diego, California, United States of America
- * To whom correspondence should be addressed. E-mail: (GH), (KP)
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Milton SL, Prentice HM. Beyond anoxia: the physiology of metabolic downregulation and recovery in the anoxia-tolerant turtle. Comp Biochem Physiol A Mol Integr Physiol 2006; 147:277-90. [PMID: 17049896 PMCID: PMC1975785 DOI: 10.1016/j.cbpa.2006.08.041] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Revised: 08/17/2006] [Accepted: 08/21/2006] [Indexed: 01/05/2023]
Abstract
The freshwater turtle Trachemys scripta is among the most anoxia-tolerant of vertebrates, a true facultative anaerobe able to survive without oxygen for days at room temperature to weeks or months during winter hibernation. Our good friend and colleague Peter Lutz devoted nearly 25 years to the study of the physiology of anoxia tolerance in these and other model organisms, promoting not just the basic science but also the idea that understanding the physiology and molecular mechanisms behind anoxia tolerance provides insights into critical survival pathways that may be applicable to the hypoxic/ischemic mammalian brain. Work by Peter and his colleagues focused on the factors which enable the turtle to enter a deep hypometabolic state, including decreases in ion flux ("channel arrest"), increases in inhibitory neuromodulators like adenosine and GABA, and the maintenance of low extracellular levels of excitatory compounds such as dopamine and glutamate. Our attention has recently turned to molecular mechanisms of anoxia tolerance, including the upregulation of such protective factors as heat shock proteins (Hsp72, Hsc73), the reversible downregulation of voltage gated potassium channels, and the modulation of MAP kinase pathways. In this review we discuss three phases of anoxia tolerance, including the initial metabolic downregulation over the first several hours, the long-term maintenance of neuronal function over days to weeks of anoxia, and finally recovery upon reoxygenation, with necessary defenses against reactive oxygen stress.
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Affiliation(s)
- Sarah L Milton
- Department of Biological Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA.
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Milton SL, Nayak G, Lutz PL, Prentice HM. Gene transcription of neuroglobin is upregulated by hypoxia and anoxia in the brain of the anoxia-tolerant turtle Trachemys scripta. J Biomed Sci 2006; 13:509-14. [PMID: 16636779 DOI: 10.1007/s11373-006-9084-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Accepted: 03/21/2006] [Indexed: 11/29/2022] Open
Abstract
Neuroglobin is a heme protein expressed in the vertebrate brain in mammals, fishes, and birds. The physiological role of neuroglobin is not completely understood but possibilities include serving as an intracellular oxygen-carrier or oxygen-sensor, as a terminal oxidase to regenerate NAD(+) under anaerobic conditions, or involvement in NO or ROS metabolism. As the vertebrate nervous system is particularly sensitive to hypoxia, an intracellular protein that helps sustain cellular respiration would aid hypoxic survival. However, the regulation of Neuroglobin (Ngb) under conditions of varying oxygen is controversial. This study examines the regulation of Ngb in an anoxia-tolerant vertebrate under conditions of hypoxia and anoxia. The freshwater turtle Trachemys scripta can withstand complete anoxia for days, and adaptations that permit neuronal survival have been extensively examined. Turtle neuroglobin specific primers were employed in RT-PCR for determining the regulation of neuroglobin mRNA expression in turtles placed in normoxia, hypoxia (4 h), anoxia (1 and 4 h), and anoxia-reoxygenation. Whole brain expression of neuroglobin is strongly upregulated by hypoxia and post-anoxic-reoxygenation in T. scripta, with a lesser degree of upregulation at 1 and 4 h anoxia. Our data implicate neuroglobin in mediating brain anoxic survival.
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Affiliation(s)
- Sarah L Milton
- Department of Biological Sciences SC 281, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431, USA.
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Chown SL, Storey KB. Linking Molecular Physiology to Ecological Realities. Physiol Biochem Zool 2006; 79:314-23. [PMID: 16555190 DOI: 10.1086/499989] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2004] [Indexed: 11/03/2022]
Abstract
Although molecular physiology and ecology have drifted apart as a consequence of early separation in the questions posed and techniques used, there is a resurgence of interest in forging links between them. Here we explore the reasons for this renewed interest and provide four examples of how this is happening. Specifically, we examine links between molecular physiology and ecological realities in insect responses to thermal stress, vertebrate responses to anoxia, metabolic fuel use and torpor in mammals, and the recently developed "metabolic theory of ecology." Several novel insights are emerging from integrated approaches to these problems that might not have come forward from any single perspective on them. Nonetheless, prospects for linking molecular physiology and ecological realities are likely to remain poor if greater focus is not given to developing these links. Mostly, this is a consequence of the differing approaches and "languages" adopted by these fields. We discuss approaches by which the prospects for synthetic work might be improved.
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Affiliation(s)
- Steven L Chown
- Centre for Invasion Biology, Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa.
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31
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Storey KB. Reptile freeze tolerance: Metabolism and gene expression. Cryobiology 2006; 52:1-16. [PMID: 16321368 DOI: 10.1016/j.cryobiol.2005.09.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 09/21/2005] [Accepted: 09/21/2005] [Indexed: 01/08/2023]
Abstract
Terrestrially hibernating reptiles that live in seasonally cold climates need effective strategies of cold hardiness to survive the winter. Use of thermally buffered hibernacula is very important but when exposure to temperatures below 0 degrees C cannot be avoided, either freeze avoidance (supercooling) or freeze tolerance strategies can be employed, sometimes by the same species depending on environmental conditions. Several reptile species display ecologically relevant freeze tolerance, surviving for extended times with 50% or more of their total body water frozen. The use of colligative cryoprotectants by reptiles is poorly developed but metabolic and enzymatic adaptations providing anoxia tolerance and antioxidant defense are important aids to freezing survival. New studies using DNA array screening are examining the role of freeze-responsive gene expression. Three categories of freeze responsive genes have been identified from recent screenings of liver and heart from freeze-exposed (5h post-nucleation at -2.5 degrees C) hatchling painted turtles, Chrysemys picta marginata. These genes encode (a) proteins involved in iron binding, (b) enzymes of antioxidant defense, and (c) serine protease inhibitors. The same genes were up-regulated by anoxia exposure (4 h of N2 gas exposure at 5 degrees C) of the hatchlings which suggests that these defenses for freeze tolerance are aimed at counteracting the injurious effects of the ischemia imposed by plasma freezing.
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Affiliation(s)
- Kenneth B Storey
- Institute of Biochemistry, College of Natural Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, Ont., Canada K1S 5B6.
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Haddad JJ. Hypoxia and the regulation of mitogen-activated protein kinases: gene transcription and the assessment of potential pharmacologic therapeutic interventions. Int Immunopharmacol 2005; 4:1249-85. [PMID: 15313426 DOI: 10.1016/j.intimp.2004.06.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2004] [Revised: 06/09/2004] [Accepted: 06/15/2004] [Indexed: 12/20/2022]
Abstract
Oxygen is an environmental/developmental signal that regulates cellular energetics, growth, and differentiation processes. Despite its central role in nearly all higher life processes, the molecular mechanisms for sensing oxygen levels and the pathways involved in transducing this information are still being elucidated. Altering gene expression is the most fundamental and effective way for a cell to respond to extracellular signals and/or changes in its microenvironment. During development, the expression of specific sets of genes is regulated spatially (by position/morphogenetic gradients) and temporally, presumably via the sensing of molecular oxygen available within the microenvironment. Regulation of signaling responses is governed by transcription factors that bind to control regions (consensus sequences) of target genes and alter their expression in response to specific signals. Complex signal transduction during hypoxia (deficiency of oxygen in inspired gases or in arterial blood and/or in tissues) involves the coupling of ligand-receptor interactions to many intracellular events. These events basically include phosphorylations by tyrosine kinases and/or serine/threonine kinases, such as those of mitogen-activated protein kinases (MAPKs), a superfamily of kinases responsive to stress nonhomeostatic conditions. Protein phosphorylations imposed during hypoxia change enzyme activities and protein conformations, and the eventual outcome is rather complex, comprising of an alteration in cellular activity and changes in the programming of genes expressed within the responding cells. These molecular changes serve as signals that are crucial for cell survival under contingent conditions imposed during hypoxia. This review correlates current concepts of hypoxic sensing pathways with hypoxia-related phosphorylation mechanisms mediated by MAPKs via the genetic and pharmacologic regulation/manipulation of specific transcription factors and related cofactors.
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Affiliation(s)
- John J Haddad
- Severinghaus-Radiometer Research Laboratories, University of California, San Francisco, CA, USA.
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Cowan KJ, Storey KB. Mitogen-activated protein kinases: new signaling pathways functioning in cellular responses to environmental stress. J Exp Biol 2003; 206:1107-15. [PMID: 12604570 DOI: 10.1242/jeb.00220] [Citation(s) in RCA: 432] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The mitogen-activated protein kinase (MAPK) superfamily consists of three main protein kinase families: the extracellular signal-regulated protein kinases (ERKs), the c-Jun N-terminal kinases (JNKs) and the p38 family of kinases. Each is proving to have major roles in the regulation of intracellular metabolism and gene expression and integral actions in many areas including growth and development, disease, apoptosis and cellular responses to external stresses. To date, this cellular signal transduction network has received relatively little attention from comparative biochemists, despite the high probability that MAPKs have critical roles in the adaptive responses to thermal, osmotic and oxygen stresses. The present article reviews the current understanding of the roles and regulation of ERKs, JNKs and p38, summarizes what is known to date about MAPK roles in animal models of anoxia tolerance, freeze tolerance and osmoregulation, and highlights the potential that studies of MAPK pathways have for advancing our understanding of the mechanisms of biochemical adaptation.
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Affiliation(s)
- Kyra J Cowan
- Department of Surgery, Surgical Research Laboratory, San Francisco General Hospital and University of California, San Francisco, San Francisco, California 94110, USA
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