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Scott MA, Fagernes CE, Nilsson GE, Stensløkken KO. Maintained mitochondrial integrity without oxygen in the anoxia-tolerant crucian carp. J Exp Biol 2024; 227:jeb247409. [PMID: 38779846 DOI: 10.1242/jeb.247409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 05/20/2024] [Indexed: 05/25/2024]
Abstract
Very few vertebrates survive without oxygen (anoxia) for more than a few minutes. Crucian carp (Carassius carassius) are one example, surviving months of anoxia at low temperatures, and we hypothesised that they maintain mitochondrial membrane potential and function. Isolated crucian carp cardiomyocytes indeed maintained mitochondrial membrane potential after blocking complex IV of the electron transport system with cyanide, while those of anoxia-intolerant trout depolarised. When complexes I-III were inhibited, crucian carp mitochondria depolarised, indicating that these complexes need to function during anoxia. Mitochondrial membrane potential depended on reversal of ATP synthase in chemical anoxia, as blocking with cyanide combined with oligomycin to inhibit ATP synthase led to depolarisation. ATP synthase activity was reduced in the heart after 1 week of anoxia in crucian carp, together with a downregulation of ATP synthase subunit gene expression. However, the morphology of cardiac mitochondria was not affected by 1 week of anoxia, even with a large increase in mitofusin 2 mRNA expression. Cardiac citrate synthase activity was not affected by anoxia, while cytochrome c oxidase activity was increased. We show how mitochondria respond to anoxia. A mechanistic understanding of how mitochondrial function can be maintained in anoxia may provide new perspectives to reduce mitochondrial damage in anoxia-sensitive organisms.
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Affiliation(s)
- Mark A Scott
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, 0361 Oslo, Norway
| | - Cathrine E Fagernes
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, 0361 Oslo, Norway
| | - Göran E Nilsson
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, 0361 Oslo, Norway
| | - Kåre-Olav Stensløkken
- Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, 0372 Oslo, Norway
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Cortes S, Farhat E, Talarico G, Mennigen JA. The dynamic transcriptomic response of the goldfish brain under chronic hypoxia. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2024; 50:101233. [PMID: 38608489 DOI: 10.1016/j.cbd.2024.101233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/26/2024] [Accepted: 04/02/2024] [Indexed: 04/14/2024]
Abstract
Oxygen is essential to fuel aerobic metabolism. Some species evolved mechanisms to tolerate periods of severe hypoxia and even anoxia in their environment. Among them, goldfish (Carassius auratus) are unique, in that they do not enter a comatose state under severely hypoxic conditions. There is thus significant interest in the field of comparative physiology to uncover the mechanistic basis underlying hypoxia tolerance in goldfish, with a particular focus on the brain. Taking advantage of the recently published and annotated goldfish genome, we profile the transcriptomic response of the goldfish brain under normoxic (21 kPa oxygen saturation) and, following gradual reduction, constant hypoxic conditions after 1 and 4 weeks (2.1 kPa oxygen saturation). In addition to analyzing differentially expressed protein-coding genes and enriched pathways, we also profile differentially expressed microRNAs (miRs). Using in silico approaches, we identify possible miR-mRNA relationships. Differentially expressed transcripts compared to normoxia were either common to both timepoints of hypoxia exposure (n = 174 mRNAs; n = 6 miRs), or exclusive to 1-week (n = 441 mRNAs; n = 23 miRs) or 4-week hypoxia exposure (n = 491 mRNAs; n = 34 miRs). Under chronic hypoxia, an increasing number of transcripts, including those of paralogous genes, was downregulated over time, suggesting a decrease in transcription. GO-terms related to the vascular system, oxidative stress, stress signalling, oxidoreductase activity, nucleotide- and intermediary metabolism, and mRNA posttranscriptional regulation were found to be enriched under chronic hypoxia. Known 'hypoxamiRs', such as miR-210-3p/5p, and miRs such as miR-29b-3p likely contribute to posttranscriptional regulation of these pathways under chronic hypoxia in the goldfish brain.
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Affiliation(s)
- S Cortes
- Department of Biology, University of Ottawa, K1N6N5 20 Marie Curie, Ottawa, ON, Canada; Laboratorio de Oncogenómica, Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City 14610, Mexico
| | - E Farhat
- Department of Biology, University of Ottawa, K1N6N5 20 Marie Curie, Ottawa, ON, Canada; Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Ggm Talarico
- Department of Biology, University of Ottawa, K1N6N5 20 Marie Curie, Ottawa, ON, Canada
| | - J A Mennigen
- Department of Biology, University of Ottawa, K1N6N5 20 Marie Curie, Ottawa, ON, Canada.
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3
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Johansen A, Thiede B, Anonsen JH, Nilsson GE. Phosphoproteomic changes in response to anoxia are tissue-specific in the anoxia-tolerant crucian carp ( Carassius carassius). Front Physiol 2024; 15:1407834. [PMID: 38872833 PMCID: PMC11170284 DOI: 10.3389/fphys.2024.1407834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 05/08/2024] [Indexed: 06/15/2024] Open
Abstract
Crucian carp (Carassius carassius), a freshwater fish, can survive chronic anoxia for several months at low temperatures. Consequently, anoxia-related physiological and biochemical adaptations in this species have been studied for more than half a century. Still, despite for the well-known role of protein phosphorylation in regulating cellular processes, no studies have comprehensively characterized the phosphoproteome in crucian carp. In this study, we report the global phosphoproteome in crucian carp brain and liver during anoxia and reoxygenation. By applying a bottom-up proteomic approach on enriched phosphopeptides we found that the brain phosphoproteome shows surprisingly few changes during anoxia-reoxygenation exposure with only 109 out of 4200 phosphopeptides being differentially changed compared to normoxic controls. By contrast, in the liver 395 out of 1287 phosphopeptides changed. Although most changes occurred in the liver phosphoproteome, the pattern of changes indicated metabolic depression and decreased translation in both brain and liver. We also found changes in phosphoproteins involved in apoptotic regulation and reactive oxygen species handling in both tissues. In the brain, some of the most changed phosphopeptides belonged to proteins involved in central nervous system development and neuronal activity at the synaptic cleft. Changed phosphoproteins specific for liver tissue were related to glucose metabolism, such as glycolytic flux and glycogenolysis. In conclusion, protein phosphorylation in response to anoxia and reoxygenation showed both common and tissue-specific changes related to the functional differences between brain and liver.
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Affiliation(s)
| | - Bernd Thiede
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jan Haug Anonsen
- Department of Biosciences, University of Oslo, Oslo, Norway
- Norwegian Research Centre AS, Climate and Environment Department, Stavanger, Norway
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Hasan MM, Sekiya R, Zhang X, Yassouf MY, Li TS. Comparison of hypoxia- and hyperoxia-induced alteration of epigene expression pattern in lungs of Pleurodeles waltl and Mus musculus. PLoS One 2024; 19:e0299661. [PMID: 38416753 PMCID: PMC10901355 DOI: 10.1371/journal.pone.0299661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 02/12/2024] [Indexed: 03/01/2024] Open
Abstract
Epigenetics is an emerging field of research because of its involvement in susceptibility to diseases and aging. Hypoxia and hyperoxia are known to be involved widely in various pathophysiologies. Here, we compared the differential epigene expression pattern between Pleurodeles waltl and Mus musculus (commonly known as Iberian ribbed newt and mouse, respectively) exposed to hypoxia and hyperoxia. Adult healthy newts and mice were exposed to normobaric hypoxia (8% O2) and hyperoxia (80% O2) for 2 hours. We collected the lungs and analyzed the expression of hypoxia-inducible factor 1 alpha (Hif1α) and several key epigenes from DNA methyltransferase (DNMT) family, histone deacetylase (HDAC) family, and methyl-CpG binding domain (MBD) family. The exposure to hypoxia significantly increased the mRNA levels of DNA methyltransferase 3 alpha (Dnmt3α), methyl-CpG binding domain protein 2 (Mbd2), Mbd3, and histone deacetylase 2 (Hdac2) in lungs of newts, but decreased the mRNA levels of DNA methyltransferase 1 (Dnmt1) and Dnmt3α in lungs of mice. The exposure to hyperoxia did not significantly change the expression of any gene in either newts or mice. The differential epigene expression pattern in response to hypoxia between newts and mice may provide novel insights into the prevention and treatment of disorders developed due to hypoxia exposure.
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Affiliation(s)
- Md. Mahmudul Hasan
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Reiko Sekiya
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Xu Zhang
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Mhd Yousuf Yassouf
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
| | - Tao-Sheng Li
- Department of Stem Cell Biology, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan
- Department of Stem Cell Biology, Atomic Bomb Diseases Institute, Nagasaki University, Sakamoto, Nagasaki, Japan
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Gerber L, Resseguier J, Helle-Valle T, Farhat E, Nilsson GE, Lefevre S. Expression of prolyl hydroxylase domains, the upstream regulators of HIF, in the brain of the anoxia-tolerant crucian carp during anoxia-reoxygenation. Am J Physiol Regul Integr Comp Physiol 2024; 326:R184-R195. [PMID: 38145292 DOI: 10.1152/ajpregu.00211.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 11/10/2023] [Accepted: 12/11/2023] [Indexed: 12/26/2023]
Abstract
The hypoxia-inducible factor (HIF) is considered key in the transcriptional response to low oxygen. Yet, the role of HIF in the absence of oxygen (anoxia) and in preparation for reoxygenation remains unclear. Recent studies suggest that mounting a HIF response may be counterproductive for anoxia survival. We here studied one of the champions of anoxia survival, the crucian carp (Carassius carassius), and hypothesized that expression of prolyl hydroxylase domains (PHDs; the upstream regulators of HIF) are upregulated to circumvent an energy-costly activation of HIF in anoxia and to prepare for reoxygenation. We measured whole brain mRNA and protein levels of the three isoforms PHD1, PHD2, and PHD3, coded for by multiple paralogs of the genes egln2, egln1, and egln3, using quantitative PCR and Western blotting in the brain of crucian carps exposed to 5 days normoxia or anoxia, and 5 days anoxia followed by 3 or 24 h of reoxygenation. The mRNA levels of most egln paralogs were increased in anoxia and upon reoxygenation, with egln3 showing the largest increase in mRNA level (up to 17-fold) and highest relative mRNA abundance (up to 75% of expressed egln). The protein level of all PHDs was maintained in anoxia and increased upon reoxygenation. We then explored PHD distribution in different brain regions and found PHD immunoreactivity to be associated with axonal branches and showing region-specific changes during anoxia-reoxygenation. Our results support an overall upregulation of egln under prolonged anoxia and PHDs upon reoxygenation in crucian carp, likely aimed at suppressing HIF responses, although regional differences are apparent in such a complex organ as the brain.NEW & NOTEWORTHY We report a profound upregulation of most egln paralog mRNA levels in anoxia and upon reoxygenation, with egln3ii showing the largest, a 17-fold increase, and highest relative mRNA abundance. The relative abundance of prolyl hydroxylase domain (PHD) proteins was maintained during anoxia and increased at reoxygenation. PHD immunoreactivity was localized to axonal branches with region-specific changes during anoxia-reoxygenation. These dynamic and regional changes in crucian carp, champion of anoxia tolerance, are most likely adaptive and call for further mechanistic studies.
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Affiliation(s)
- Lucie Gerber
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Julien Resseguier
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Tellef Helle-Valle
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Elie Farhat
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Göran E Nilsson
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Sjannie Lefevre
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway
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Charpier S. Between life and death: the brain twilight zones. Front Neurosci 2023; 17:1156368. [PMID: 37260843 PMCID: PMC10227869 DOI: 10.3389/fnins.2023.1156368] [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: 02/01/2023] [Accepted: 04/24/2023] [Indexed: 06/02/2023] Open
Abstract
Clinically, and legally, death is considered a well-defined state of the organism characterized, at least, by a complete and irreversible cessation of brain activities and functions. According to this pragmatic approach, the moment of death is implicitly represented by a discrete event from which all cerebral processes abruptly cease. However, a growing body of experimental and clinical evidence has demonstrated that cardiorespiratory failure, the leading cause of death, causes complex time-dependent changes in neuronal activity that can lead to death but also be reversed with successful resuscitation. This review synthesizes our current knowledge of the succeeding alterations in brain activities that accompany the dying and resuscitation processes. The anoxia-dependent brain defects that usher in a process of potential death successively include: (1) a set of changes in electroencephalographic (EEG) and neuronal activities, (2) a cessation of brain spontaneous electrical activity (isoelectric state), (3) a loss of consciousness whose timing in relation to EEG changes remains unclear, (4) an increase in brain resistivity, caused by neuronal swelling, concomitant with the occurrence of an EEG deviation reflecting the neuronal anoxic insult (the so-called "wave of death," or "terminal spreading depolarization"), followed by, (5) a terminal isoelectric brain state leading to death. However, a timely restoration of brain oxygen supply-or cerebral blood flow-can initiate a mirrored sequence of events: a repolarization of neurons followed by a re-emergence of neuronal, synaptic, and EEG activities from the electrocerebral silence. Accordingly, a recent study has revealed a new death-related brain wave: the "wave of resuscitation," which is a marker of the collective recovery of electrical properties of neurons at the beginning of the brain's reoxygenation phase. The slow process of dying still represents a terra incognita, during which neurons and neural networks evolve in uncertain states that remain to be fully understood. As current event-based models of death have become neurophysiologically inadequate, I propose a new mixed (event-process) model of death and resuscitation. It is based on a detailed description of the different phases that succeed each other in a dying brain, which are generally described separately and without mechanistic linkage, in order to integrate them into a continuum of declining brain activity. The model incorporates cerebral twilight zones (with still unknown neuronal and synaptic processes) punctuated by two characteristic cortical waves providing real-time biomarkers of death- and resuscitation.
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Affiliation(s)
- Stéphane Charpier
- Sorbonne Université, Institut du Cerveau – Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié-Salpêtriére, Paris, France
- Sorbonne University, UPMC Université Paris, Paris, France
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7
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Hua Y, Huang W, Wang F, Jing Z, Li J, Wang Q, Zhao Y. Metabolites, gene expression, and gut microbiota profiles suggest the putative mechanisms via which dietary creatine increases the serum taurine and g-ABA contents in Megalobrama amblycephala. FISH PHYSIOLOGY AND BIOCHEMISTRY 2023; 49:253-274. [PMID: 36897433 DOI: 10.1007/s10695-023-01177-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 03/01/2023] [Indexed: 05/04/2023]
Abstract
A 90-day experiment was conducted to explore the effects of creatine on growth performance, liver health status, metabolites, and gut microbiota in Megalobrama amblycephala. There were 6 treatments as follows: control (CD, 29.41% carbohydrates), high carbohydrate (HCD, 38.14% carbohydrates), betaine (BET, 1.2% betaine + 39.76% carbohydrates), creatine 1 (CRE1, 0.5% creatine + 1.2% betaine + 39.29% carbohydrates), creatine 2 (CRE2, 1% creatine + 1.2% betaine + 39.50% carbohydrates), and creatine 3 (CRE3, 2% creatine + 1.2% betaine + 39.44% carbohydrates). The results showed that supplementing creatine and betaine together reduced the feed conversion ratio significantly (P < 0.05, compared to CD and HCD) and improved liver health (compared to HCD). Compared with the BET group, dietary creatine significantly increased the abundances of Firmicutes, Bacteroidota, ZOR0006, and Bacteroides and decreased the abundances of Proteobacteria, Fusobacteriota, Vibrio, Crenobacter, and Shewanella in the CRE1 group. Dietary creatine increased the content of taurine, arginine, ornithine, γ-aminobutyric acid (g-ABA), and creatine (CRE1 vs. BET group) and the expression of creatine kinase (ck), sulfinoalanine decarboxylase (csad), guanidinoacetate N-methyltransferase (gamt), glycine amidinotransferase (gatm), agmatinase (agmat), diamine oxidase1 (aoc1), and glutamate decarboxylase (gad) in the CRE1 group. Overall, these results suggested that dietary supplementation of creatine (0.5-2%) did not affect the growth performance, but it altered the gut microbial composition at the phylum and genus levels, which might be beneficial to the gut health of M. amblycephala; dietary creatine also increased the serum content of taurine by enhancing the expressions of ck and csad and increased the serum content of g-ABA by enhancing the arginine content and the expressions of gatm, agmat, gad, and aoc1.
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Affiliation(s)
- Yizhuo Hua
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
- Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China
- Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Wangwang Huang
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
- Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China
- Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Fan Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
- Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China
- Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Zhao Jing
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
- Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China
- Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Juntao Li
- Institute of Tropical Bioscience and Biotechnology, Haikou, 570102, China
| | - Qingchao Wang
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China
- Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China
- Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Wuhan, 430070, China
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China
| | - Yuhua Zhao
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
- Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, China.
- Key Lab of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, Wuhan, 430070, China.
- Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, China.
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Kolesnikova EE, Golovina IV, Soldatov AA, Gavruseva TV. Synchronized Activity of Oxidoreductases in the Brain and Heart Compartments of the Scorpionfish Scorpaena porcus under Acute Hypoxia. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022060114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Country MW, Jonz MG. Goldfish and crucian carp are natural models of anoxia tolerance in the retina. Comp Biochem Physiol A Mol Integr Physiol 2022; 270:111244. [PMID: 35618216 DOI: 10.1016/j.cbpa.2022.111244] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 10/18/2022]
Abstract
Vertebrates need oxygen to survive. The central nervous system has an especially high energy demand, so brain and retinal neurons quickly die in anoxia. But fish of the genus Carassius are exceptionally anoxia-tolerant: the crucian carp (C. carassius) can survive months without oxygen in ice-covered ponds, and the common goldfish (C. auratus) can withstand hours of anoxia at room temperature. These fish previously offered insights into anoxia tolerance in the brain, heart, and liver. Here, we advance Carassius spp. as models to study anoxia tolerance in the retina. Electroretinogram and evoked potential recordings show that crucian carp reversibly downregulate their visual systems in anoxia, probably to save ATP. Notably, Carassius suppress their visual systems nearly twice as much as anoxia-tolerant turtles, Trachemys and Chrysemys spp., which are often promoted as the champions of anoxia tolerance. We summarize what is known about anoxia tolerance in the goldfish and crucian carp retinas, including cellular pathways which may protect retinal neurons from excitotoxic cell death. We compare the Carassius retina with two relevant models: natural anoxia tolerance in the turtle brain, and ischemic preconditioning in the rat retina. All three models include mitochondria as oxygen sensors: mitochondria depolarize due to mitochondrial ATP-dependent K+ channels, possibly to trigger neuroprotective second messenger cascades. The Carassius retina is an accessible and inexpensive model, with over 70 fruitful years of history in vision research. As a model for anoxia tolerance, it may provide new insights into diseases of the eye (like diabetes, macular degeneration, and eye stroke).
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Affiliation(s)
- Michael W Country
- Department of Biology, University of Ottawa, Canada. https://twitter.com/biologycountry
| | - Michael G Jonz
- Department of Biology, University of Ottawa, Canada; Brain and Mind Research Institute, University of Ottawa, Canada.
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10
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Kolesnikova EE, Soldatov AA, Golovina IV, Sysoeva IV, Sysoev AA. Effect of acute hypoxia on the brain energy metabolism of the scorpionfish Scorpaena porcus Linnaeus, 1758: the pattern of oxidoreductase activity and adenylate system. FISH PHYSIOLOGY AND BIOCHEMISTRY 2022; 48:1105-1115. [PMID: 35851943 DOI: 10.1007/s10695-022-01103-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
The activity of oxidoreductases, malate dehydrogenase and lactate dehydrogenase (MDH, 1.1.1.37; LDH, 1.1.1.27), as well as parameters of adenylate system-[ATP], [ADP], [AMP], total adenylate pool (AP), and adenylate energy charge (AEC) in medulla oblongata (MB) and forebrain, midbrain, and diencephalon (FDMB)-were studied in the scorpionfish under acute hypoxia (0.9-1.2 mg O2·L-1, 90 min). A higher MDH activity level was observed in MB and FDMB, as compared to LDH (p < 0.05). At the same time, MB showed a higher adenylate content and increased AP (p < 0.05). AEC did not exceed ~ 0.7 (vs. the maximum of this index ~ 0.9-1.0) in the brain of the scorpionfish indicating adaptation of the tissue energy status to hypoxia. A rapid decrease in MDH activity (p < 0.05) was observed in MB under acute hypoxia. These changes were accompanied by insignificant LDH activation. A pronounced LDH activation (p < 0.05), a decrease in MDH activity, and the highest AP raise (p < 0.05) were observed in FDMB, suggesting activation of glycolysis and simultaneous decrease in the rate of ATP consumption. MB and FDMB demonstrated the ability to a relative retention of AEC during hypoxia. The unidirectional metabolic adaptation was based on the intensification of glycolysis, a decrease of ATP consumption, and a subsequent increase in adenylate concentration that allowed the scorpionfish brain structures to maintain the energy status under acute hypoxia.
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Affiliation(s)
- Evgenia E Kolesnikova
- Department of Animal Physiology and Biochemistry, A.O. Kovalevsky Institute of Biology of Southern Seas RAS, 38 Leninsky Ave., Moscow, 119991, Russia.
| | - Aleksandr A Soldatov
- Department of Animal Physiology and Biochemistry, A.O. Kovalevsky Institute of Biology of Southern Seas RAS, 38 Leninsky Ave., Moscow, 119991, Russia
| | - Irina V Golovina
- Department of Animal Physiology and Biochemistry, A.O. Kovalevsky Institute of Biology of Southern Seas RAS, 38 Leninsky Ave., Moscow, 119991, Russia
| | - Inna V Sysoeva
- Department of Animal Physiology and Biochemistry, A.O. Kovalevsky Institute of Biology of Southern Seas RAS, 38 Leninsky Ave., Moscow, 119991, Russia
| | - Aleksandr A Sysoev
- Department of Functioning of Marine Ecosystem, A.O. Kovalevsky Institute of Biology of Southern Seas RAS, 38 Leninsky Ave., Moscow, 119991, Russia
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11
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Fago A. New insights into survival strategies to oxygen deprivation in anoxia-tolerant vertebrates. Acta Physiol (Oxf) 2022; 235:e13841. [PMID: 35548887 PMCID: PMC9287066 DOI: 10.1111/apha.13841] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 05/09/2022] [Accepted: 05/09/2022] [Indexed: 11/23/2022]
Abstract
Hypoxic environments pose a severe challenge to vertebrates and even short periods of oxygen deprivation are often lethal as they constrain aerobic ATP production. However, a few ectotherm vertebrates are capable of surviving long‐term hypoxia or even anoxia with little or no damage. Among these, freshwater turtles and crucian carp are the recognized champions of anoxia tolerance, capable of overwintering in complete oxygen deprivation for months at freezing temperatures by entering a stable hypometabolic state. While all steps of the oxygen cascade are adjusted in response to oxygen deprivation, this review draws from knowledge of freshwater turtles and crucian carp to highlight mechanisms regulating two of these steps, namely oxygen transport in the blood and oxygen utilization in mitochondria during three sequential phases: before anoxia, when hypoxia develops, during anoxia, and after anoxia at reoxygenation. In cold hypoxia, reduced red blood cell concentration of ATP plays a crucial role in increasing blood oxygen affinity and/or reducing oxygen unloading to tissues, to adjust aerobic metabolism to decrease ambient oxygen. In anoxia, metabolic rewiring of oxygen utilization keeps largely unaltered NADH/NAD+ ratios and limits ADP degradation and succinate buildup. These critical adjustments make it possible to restart mitochondrial respiration and energy production with little generation of reactive oxygen species at reoxygenation when oxygen is again available. Inhibition of key metabolic enzymes seems to play crucial roles in these responses, in particular mitochondrial complex V, although identifying the nature of such inhibition(s) in vivo remains a challenge for future studies.
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Affiliation(s)
- Angela Fago
- Department of Biology Aarhus University Aarhus Denmark
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12
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Perret-Thiry C, Raulic J, Vergneau-Grosset C. Evaluation of prolonged immersion in tricaine methanesulfonate for juvenile goldfish (Carassius auratus) euthanasia. J Am Vet Med Assoc 2022; 260:911-915. [PMID: 35143411 DOI: 10.2460/javma.21.09.0416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Doses of buffered tricaine methanesulfonate (MS-222) up to 1000 mg/L for 15 minutes are reported inefficient to produce euthanasia in goldfish. The goal of this study was to determine if goldfish can be euthanized by more prolonged immersion in MS-222. ANIMALS 24 healthy goldfish (weight range: 1 to 10 g) were randomly assigned to 4 groups of 6 fish. PROCEDURES The first group (G1) was exposed to 500 mg/L buffered MS-222 for 15 minutes then placed in freshwater for 3 hours. The second (G2) and third groups (G3) were exposed to 1000 mg/L of buffered MS-222 for 15 minutes then placed in freshwater for 3 hours and 18 hours respectively. The fourth group (G4) was exposed to 1000 mg/L of buffered MS-222 for 60 minutes then placed in freshwater for 3 hours. Time to cessation and return of operculation were recorded. If the goldfish did not resume operculation, heart rate was evaluated by Doppler ultrasonic flow detector. RESULTS Median times to apnea were 35 seconds at 1000 mg/L and 65 seconds at 500 mg/L. Re-operculation occurred only in G1 in 5 out of 6 individuals. All fish from G1, 3 fish from G2, 0 fish from G3, 1 fish from G4 had remaining heartbeats at the end of the observation period. CLINICAL RELEVANCE Overall, a dose of 1000 mg/L of buffered MS-222 for 15 minutes was efficient to euthanize juvenile goldfish at 20 °C. Different fish body mass and water quality parameters might explain different results compared to previous studies.
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Affiliation(s)
- Clément Perret-Thiry
- Centre Hospitalier Universitaire Vétérinaire, Faculté de médecine vétérinaire, Université de Montréal, St-Hyacinthe, Québec, Canada.,VetAgro Sup, Marcy l'Étoile, France
| | - Juliette Raulic
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, St-Hyacinthe, Québec, Canada
| | - Claire Vergneau-Grosset
- Department of Clinical Sciences, Faculté de médecine vétérinaire, Université de Montréal, St-Hyacinthe, Québec, Canada
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13
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Intracellular Signaling. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00006-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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14
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Role of Na +/K +-ATPase in ischemic stroke: in-depth perspectives from physiology to pharmacology. J Mol Med (Berl) 2021; 100:395-410. [PMID: 34839371 DOI: 10.1007/s00109-021-02143-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 08/27/2021] [Accepted: 09/20/2021] [Indexed: 12/26/2022]
Abstract
Na+/K+-ATPase (NKA) is a large transmembrane protein expressed in all cells. It is well studied for its ion exchanging function, which is indispensable for the maintenance of electrochemical gradients across the plasma membrane and herein neuronal excitability. The widely recognized pump function of NKA closely depends on its unique structure features and conformational changes upon binding of specific ions. Various Na+-dependent secondary transport systems are rigorously controlled by the ionic gradients generated by NKA and are essential for multiple physiological processes. In addition, roles of NKA as a signal transducer have also been unveiled nowadays. Plethora of signaling cascades are defined including Src-Ras-MAPK signaling, IP3R-mediated calcium oscillation, inflammation, and autophagy though most underlying mechanisms remain elusive. Ischemic stroke occurs when the blood flow carrying nutrients and oxygen into the brain is disrupted by blood clots, which is manifested by excitotoxicity, oxidative stress, inflammation, etc. The protective effect of NKA against ischemic stress is emerging gradually with the application of specific NKA inhibitor. However, NKA-related research is limited due to the opposite effects caused by NKA inhibitor at lower doses. The present review focuses on the recent progression involving different aspects about NKA in cellular homeostasis to present an in-depth understanding of this unique protein. Moreover, essential roles of NKA in ischemic pathology are discussed to provide a platform and bright future for the improvement in clinical research on ischemic stroke.
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15
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Hypoxia Tolerant Species: The Wisdom of Nature Translated into Targets for Stroke Therapy. Int J Mol Sci 2021; 22:ijms222011131. [PMID: 34681788 PMCID: PMC8537001 DOI: 10.3390/ijms222011131] [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: 09/15/2021] [Revised: 10/05/2021] [Accepted: 10/12/2021] [Indexed: 12/13/2022] Open
Abstract
Human neurons rapidly die after ischemia and current therapies for stroke management are limited to restoration of blood flow to prevent further brain damage. Thrombolytics and mechanical thrombectomy are the available reperfusion treatments, but most of the patients remain untreated. Neuroprotective therapies focused on treating the pathogenic cascade of the disease have widely failed. However, many animal species demonstrate that neurons can survive the lack of oxygen for extended periods of time. Here, we reviewed the physiological and molecular pathways inherent to tolerant species that have been described to contribute to hypoxia tolerance. Among them, Foxo3 and Eif5A were reported to mediate anoxic survival in Drosophila and Caenorhabditis elegans, respectively, and those results were confirmed in experimental models of stroke. In humans however, the multiple mechanisms involved in brain cell death after a stroke causes translation difficulties to arise making necessary a timely and coordinated control of the pathological changes. We propose here that, if we were able to plagiarize such natural hypoxia tolerance through drugs combined in a pharmacological cocktail it would open new therapeutic opportunities for stroke and likely, for other hypoxic conditions.
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16
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Country MW, Jonz MG. Mitochondrial KATP channels stabilize intracellular Ca2+ during hypoxia in retinal horizontal cells of goldfish (Carassius auratus). J Exp Biol 2021; 224:271844. [PMID: 34402511 DOI: 10.1242/jeb.242634] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 08/11/2021] [Indexed: 01/20/2023]
Abstract
Neurons of the retina require oxygen to survive. In hypoxia, neuronal ATP production is impaired, ATP-dependent ion pumping is reduced, transmembrane ion gradients are dysregulated, and intracellular Ca2+ concentration ([Ca2+]i) increases enough to trigger excitotoxic cell death. Central neurons of the common goldfish (Carassius auratus) are hypoxia tolerant, but little is known about how goldfish retinas withstand hypoxia. To study the cellular mechanisms of hypoxia tolerance, we isolated retinal interneurons (horizontal cells; HCs), and measured [Ca2+]i with Fura-2. Goldfish HCs maintained [Ca2+]i throughout 1 h of hypoxia, whereas [Ca2+]i increased irreversibly in HCs of the hypoxia-sensitive rainbow trout (Oncorhynchus mykiss) with just 20 min of hypoxia. Our results suggest mitochondrial ATP-dependent K+ channels (mKATP) are necessary to stabilize [Ca2+]i throughout hypoxia. In goldfish HCs, [Ca2+]i increased when mKATP channels were blocked with glibenclamide or 5-hydroxydecanoic acid, whereas the mKATP channel agonist diazoxide prevented [Ca2+]i from increasing in hypoxia in trout HCs. We found that hypoxia protects against increases in [Ca2+]i in goldfish HCs via mKATP channels. Glycolytic inhibition with 2-deoxyglucose increased [Ca2+]i, which was rescued by hypoxia in a mKATP channel-dependent manner. We found no evidence of plasmalemmal KATP channels in patch-clamp experiments. Instead, we confirmed the involvement of KATP in mitochondria with TMRE imaging, as hypoxia rapidly (<5 min) depolarized mitochondria in a mKATP channel-sensitive manner. We conclude that mKATP channels initiate a neuroprotective pathway in goldfish HCs to maintain [Ca2+]i and avoid excitotoxicity in hypoxia. This model provides novel insight into the cellular mechanisms of hypoxia tolerance in the retina.
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Affiliation(s)
- Michael W Country
- Department of Biology, University of Ottawa, Ottawa, ON, CanadaK1N 6N5
| | - Michael G Jonz
- Department of Biology, University of Ottawa, Ottawa, ON, CanadaK1N 6N5.,Brain and Mind Research Institute, University of Ottawa, Ottawa, ON, CanadaK1H 8M5
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17
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Stacey BS, Campbell Z, Bailey DM. Elevated cerebral perfusion and preserved cognition in elite Brazilian Jiu-Jitsu athletes: Evidence for neuroprotection. Scand J Med Sci Sports 2021; 31:2115-2122. [PMID: 34343371 DOI: 10.1111/sms.14031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 07/23/2021] [Accepted: 07/30/2021] [Indexed: 12/01/2022]
Abstract
Brazilian Jiu-Jitsu (BJJ) is a popular martial art that exposes participants to recurrent intermittent asphyxiation due to controlled application of neck chokes. To what extent the sport impacts the regulation of cerebral blood flow (CBF) and cognition has not been examined. This study compared eleven elite Brazilian Jiu-Jitsu athletes (aged 30 ± 8 y) who trained 12 ± 6 hours/week for 8 ± 4 years against eleven cardiorespiratory fitness (CRF)- and age-matched controls. Internal carotid (ICA) and vertebral artery (VA) blood flow were measured via duplex ultrasound to determine global cerebral blood flow (gCBF). Mild cognitive impairment and sub-domains of memory, attention/concentration/visual motor coordination, and executive function were determined by psychometric testing. There was no evidence of mild cognitive impairment in the athletes, and cognitive function was comparable between groups (all p > 0.05). In contrast, resting gCBF was selectively elevated in the athletes (741 ± 186 mL∙min-1 vs. 573 ± 166 mL∙min-1 , p = 0.037) due to combined differences in ICA (+65 mL∙min-1 , p = 0.079) and VA (+19 mL∙min-1 , p = 0.277) flow. In conclusion, the sustained elevation in resting cerebral perfusion provides preliminary evidence for adaptive neuroprotection that is independent of CRF and likely mediated by choke-induced cerebral preconditioning and/or lifelong exposure to BJJ-specific high-intensity interval training.
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Affiliation(s)
- Benjamin S Stacey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
| | - Zac Campbell
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, UK
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18
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Hypoxia Tolerance Declines with Age in the Absence of Methionine Sulfoxide Reductase (MSR) in Drosophila melanogaster. Antioxidants (Basel) 2021; 10:antiox10071135. [PMID: 34356368 PMCID: PMC8301005 DOI: 10.3390/antiox10071135] [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: 05/30/2021] [Revised: 07/07/2021] [Accepted: 07/13/2021] [Indexed: 11/17/2022] Open
Abstract
Unlike the mammalian brain, Drosophila melanogaster can tolerate several hours of hypoxia without any tissue injury by entering a protective coma known as spreading depression. However, when oxygen is reintroduced, there is an increased production of reactive oxygen species (ROS) that causes oxidative damage. Methionine sulfoxide reductase (MSR) acts to restore functionality to oxidized methionine residues. In the present study, we have characterized in vivo effects of MSR deficiency on hypoxia tolerance throughout the lifespan of Drosophila. Flies subjected to sudden hypoxia that lacked MSR activity exhibited a longer recovery time and a reduced ability to survive hypoxic/re-oxygenation stress as they approached senescence. However, when hypoxia was induced slowly, MSR deficient flies recovered significantly quicker throughout their entire adult lifespan. In addition, the wildtype and MSR deficient flies had nearly 100% survival rates throughout their lifespan. Neuroprotective signaling mediated by decreased apoptotic pathway activation, as well as gene reprogramming and metabolic downregulation are possible reasons for why MSR deficient flies have faster recovery time and a higher survival rate upon slow induction of spreading depression. Our data are the first to suggest important roles of MSR and longevity pathways in hypoxia tolerance exhibited by Drosophila.
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19
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Dahl HA, Johansen A, Nilsson GE, Lefevre S. The Metabolomic Response of Crucian Carp ( Carassius carassius) to Anoxia and Reoxygenation Differs between Tissues and Hints at Uncharacterized Survival Strategies. Metabolites 2021; 11:435. [PMID: 34357329 PMCID: PMC8304758 DOI: 10.3390/metabo11070435] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/16/2021] [Accepted: 06/25/2021] [Indexed: 01/15/2023] Open
Abstract
The anoxia-tolerant crucian carp (Carassius carassius) has been studied in detail for numerous years, with particular focus on unravelling the underlying physiological mechanisms of anoxia tolerance. However, relatively little work has been focused on what occurs beyond anoxia, and often the focus is a single organ or tissue type. In this study, we quantified more than 100 metabolites by capillary electrophoresis-mass spectrometry (CE-MS) in brain, heart, liver, and blood plasma from four experimental groups, being normoxic (control) fish, anoxia-exposed fish, and two groups that had been exposed to anoxia followed by reoxygenation for either 3 h or 24 h. The heart, which maintains cardiac output during anoxia, unexpectedly, was slower to recover compared to the brain and liver, mainly due to a slower return to control concentrations of the energy-carrying compounds ATP, GTP, and phosphocreatine. Crucian carp accumulated amino acids in most tissues, and also surprisingly high levels of succinate in all tissues investigated during anoxia. Purine catabolism was enhanced, leading to accumulation of uric acid during anoxia and increasing urea formation that continued into 24 h of reoxygenation. These tissue-specific differences in accumulation and distribution of the metabolites may indicate an intricate system of transport between tissues, opening for new avenues of investigation of possible mechanisms aimed at reducing the generation of reactive oxygen species (ROS) and resultant tissue damage during reoxygenation.
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Affiliation(s)
| | | | | | - Sjannie Lefevre
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, 0371 Oslo, Norway; (H.-A.D.); (A.J.); (G.E.N.)
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20
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Increased polyamine levels and maintenance of γ-aminobutyric acid (Gaba) homeostasis in the gills is indicative of osmotic plasticity in killifish. Comp Biochem Physiol A Mol Integr Physiol 2021; 257:110969. [PMID: 33915271 DOI: 10.1016/j.cbpa.2021.110969] [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: 02/03/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 11/23/2022]
Abstract
The Fundulus genus of killifish includes species that inhabit marshes along the U.S. Atlantic coast and the Gulf of Mexico, but differ in their ability to adjust rapidly to fluctuations in salinity. Previous work suggests that euryhaline killifish stimulate polyamine biosynthesis and accumulate putrescine in the gills during acute hypoosmotic challenge. Despite evidence that polyamines have an osmoregulatory role in euryhaline killifish species, their function in marine species is unknown. Furthermore, the consequences of hypoosmotic-induced changes in polyamine synthesis on downstream pathways, such as ƴ-aminobutyric acid (Gaba) production, have yet to be explored. Here, we examined the effects of acute hypoosmotic exposure on polyamine, glutamate, and Gaba levels in the gills of a marine (F. majalis) and two euryhaline killifish species (F. heteroclitus and F. grandis). Fish acclimated to 32 ppt or 12 ppt water were transferred to fresh water, and concentrations of glutamate (Glu), Gaba, and the polyamines putrescine (Put), spermidine (Spd), and spermine (Spm) were measured in the gills using high-performance liquid chromatography. F. heteroclitus and F. grandis exhibited an increase in gill Put concentration, but showed no change in Glu or Gaba levels following freshwater transfer. F. heteroclitus also accumulated Spd in the gills, whereas F. grandis showed transient increases in Spd and Spm levels. In contrast, gill Put, Spm, Glu, and Gaba levels decreased in F. majalis following freshwater transfer. Together, these findings suggest that increasing polyamine levels and maintaining Glu and Gaba levels in the gills may enable euryhaline teleosts to acclimate to shifts in environmental salinity.
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21
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EVALUATION OF POTASSIUM CHLORIDE ADMINISTERED VIA THREE ROUTES FOR EUTHANASIA OF ANESTHETIZED KOI ( CYPRINUS CARPIO ). J Zoo Wildl Med 2021; 51:485-489. [PMID: 33480523 DOI: 10.1638/2019-0207] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2020] [Indexed: 11/21/2022] Open
Abstract
Immersion in tricaine methanesulfonate (MS-222) is insufficient for euthanasia in at least one species of fish. The current study investigated the effectiveness of potassium chloride (KCl) to euthanize anesthetized koi (Cyprinus carpio). Twenty-eight healthy koi were anesthetized via immersion in 500 mg/L of buffered MS-222 for 10-12 min, manually removed to room air, and randomly administered 10 mEq/kg KCl (333 mg/ml) via one of three routes-intracardiac injection (IC) (n = 7), intracoelomic injection (ICe) (n = 7), or topical instillment over the gill filaments bilaterally (T) (n = 7)-or received no treatment (control, C) (n = 7). A Doppler ultrasonic flow detector was placed over the heart, and sounds were assessed continuously from immediately prior to treatment until 5 min posttreatment and every 5 min thereafter until Doppler sound cessation, resumption of operculation, or 30 min. Time to Doppler sound cessation or resumption of operculation was recorded. Doppler sound cessation occurred in 7/7 fish in IC (median 0.08, range 0-2.75 min) and 1/7 fish in T (10 min). In T, ICe, and C, 6/7, 7/7, and 7/7 fish, respectively, maintained Doppler sounds to 30 min. All fish in ICe (7/7) and C (7/7) resumed operculation with median (range) times of 22 (7-30) min and 16 (9-29) min from treatment, respectively. Intracardiac KCl at 10 mEq/kg rapidly ceases Doppler sounds and is a successful technique for euthanasia of anesthetized koi. Intracoelomic and topical KCl at 10 mEq/kg were not effective for euthanasia of koi.
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22
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Kim YS, van der Ster BJP, Brassard P, Secher NH, van Lieshout JJ. Cerebral vs. Cardiovascular Responses to Exercise in Type 2 Diabetic Patients. Front Physiol 2021; 11:583155. [PMID: 33519500 PMCID: PMC7844205 DOI: 10.3389/fphys.2020.583155] [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: 07/14/2020] [Accepted: 12/23/2020] [Indexed: 12/17/2022] Open
Abstract
The human brain is constantly active and even small limitations to cerebral blood flow (CBF) may be critical for preserving oxygen and substrate supply, e.g., during exercise and hypoxia. Exhaustive exercise evokes a competition for the supply of oxygenated blood between the brain and the working muscles, and inability to increase cardiac output sufficiently during exercise may jeopardize cerebral perfusion of relevance for diabetic patients. The challenge in diabetes care is to optimize metabolic control to slow progression of vascular disease, but likely because of a limited ability to increase cardiac output, these patients perceive aerobic exercise to be more strenuous than healthy subjects and that limits the possibility to apply physical activity as a preventive lifestyle intervention. In this review, we consider the effects of functional activation by exercise on the brain and how it contributes to understanding the control of CBF with the limited exercise tolerance experienced by type 2 diabetic patients. Whether a decline in cerebral oxygenation and thereby reduced neural drive to working muscles plays a role for "central" fatigue during exhaustive exercise is addressed in relation to brain's attenuated vascular response to exercise in type 2 diabetic subjects.
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Affiliation(s)
- Yu-Sok Kim
- Laboratory for Clinical Cardiovascular Physiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Department of Internal Medicine, Medisch Centrum Leeuwarden, Leeuwarden, Netherlands
| | - Björn J. P. van der Ster
- Laboratory for Clinical Cardiovascular Physiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Department of Anesthesiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Research Center of the Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada
| | - Niels H. Secher
- Department of Anesthesia, The Copenhagen Muscle Research Center, University of Copenhagen, Copenhagen, Denmark
| | - Johannes J. van Lieshout
- Laboratory for Clinical Cardiovascular Physiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- MRC/Arthritis Research UK Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham Medical School, Queen’s Medical Centre, Nottingham, United Kingdom
- Department of Internal Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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23
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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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24
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Zajic DE, Podrabsky JE. GABA metabolism is crucial for long-term survival of anoxia in annual killifish embryos. J Exp Biol 2020; 223:jeb229716. [PMID: 32859669 DOI: 10.1242/jeb.229716] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 08/24/2020] [Indexed: 08/25/2023]
Abstract
In most vertebrates, a lack of oxygen quickly leads to irreparable damages to vital organs, such as the brain and heart. However, there are some vertebrates that have evolved mechanisms to survive periods of no oxygen (anoxia). The annual killifish (Austrofundulus limnaeus) survives in ephemeral ponds in the coastal deserts of Venezuela and their embryos have the remarkable ability to tolerate anoxia for months. When exposed to anoxia, embryos of A. limnaeus respond by producing significant amounts of γ-aminobutyric acid (GABA). This study aims to understand the role of GABA in supporting the metabolic response to anoxia. To explore this, we investigated four developmentally distinct stages of A. limnaeus embryos that vary in their anoxia tolerance. We measured GABA and lactate concentrations across development in response to anoxia and aerobic recovery. We then inhibited enzymes responsible for the production and degradation of GABA and observed GABA and lactate concentrations, as well as embryo mortality. Here, we show for the first time that GABA metabolism affects anoxia tolerance in A. limnaeus embryos. Inhibition of enzymes responsible for GABA production (glutamate decarboxylase) and degradation (GABA-transaminase and succinic acid semialdehyde dehydrogenase) led to increased mortality, supporting a role for GABA as an intermediate product and not a metabolic end-product. We propose multiple roles for GABA during anoxia and aerobic recovery in A. limnaeus embryos, serving as a neurotransmitter, an energy source, and an anti-oxidant.
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Affiliation(s)
- Daniel E Zajic
- Department of Biology, Portland State University, PO Box 751, Portland, OR 97207, USA
- Health, Human Performance, and Athletics Department, Linfield University, 900 SE Baker, McMinnville, OR 97128, USA
| | - Jason E Podrabsky
- Department of Biology, Portland State University, PO Box 751, Portland, OR 97207, USA
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25
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Bailey DM. Oxygen and brain death; back from the brink. Exp Physiol 2020; 104:1769-1779. [PMID: 31605408 DOI: 10.1113/ep088005] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/09/2019] [Indexed: 12/25/2022]
Abstract
NEW FINDINGS • What is the topic of this review? To explore the unique evolutionary origins of the human brain and critically appraise its energy budget, including limits of oxygen and glucose deprivation during anoxia and ischaemia. • What advances does it highlight? The brain appears to be more resilient to substrate depletion than traditionally thought, highlighting greater resilience and an underappreciated capacity for functional recovery. ABSTRACT The human brain has evolved into an unusually large, complex and metabolically expensive organ that relies entirely on a continuous supply of O2 and glucose. It has traditionally been assumed that its exorbitant energy budget, combined with little to no energy reserves, renders it especially vulnerable to anoxia and ischaemia, with substrate depletion and progression towards cell death largely irreversible and rapid. However, new and exciting evidence suggests that neurons can survive for longer than previously thought, highlighting an unexpected resilience and underappreciated capacity for functional recovery that has changed the way we think about brain cell death. Nature has the potential to unlock some of the mysteries underlying ischaemic survival, with select vertebrates having solved the problem of anoxia-hypoxia tolerance over millions of years of evolution. Better understanding of their survival strategies, including remarkable adaptations in brain physiology and redox homeostasis, might help to identify new therapeutic targets for human diseases characterized by O2 deprivation, ischaemia-reperfusion injury and ageing.
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Affiliation(s)
- Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, Glamorgan, UK
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26
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Cox GK, Gillis TE. Surviving anoxia: the maintenance of energy production and tissue integrity during anoxia and reoxygenation. J Exp Biol 2020; 223:223/13/jeb207613. [DOI: 10.1242/jeb.207613] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
ABSTRACT
The development of anoxia within tissues represents a significant challenge to most animals because of the decreased capacity for aerobic ATP production, the associated loss of essential cellular functions and the potential for detrimental tissue oxidation upon reoxygenation. Despite these challenges, there are many animals from multiple phyla that routinely experience anoxia and can fully recover. In this Review, we integrate knowledge gained from studies of anoxia-tolerant species across many animal taxa. We primarily focus on strategies used to reduce energy requirements, minimize the consequences of anaerobic ATP production and reduce the adverse effects of reactive oxygen species, which are responsible for tissue damage with reoxygenation. We aim to identify common strategies, as well as novel solutions, to the challenges of anoxia exposure. This Review chronologically examines the challenges faced by animals as they enter anoxia, as they attempt to maintain physiological function during prolonged anoxic exposure and, finally, as they emerge from anoxia. The capacity of animals to survive anoxia is also considered in relation to the increasing prevalence of anoxic zones within marine and freshwater environments, and the need to understand what limits survival.
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Affiliation(s)
- Georgina K. Cox
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Todd E. Gillis
- Department of Integrative Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
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Reyes RV, Herrera EA, Ebensperger G, Sanhueza EM, Giussani DA, Llanos AJ. Perinatal cardiopulmonary adaptation to the thin air of the Alto Andino by a native Altiplano dweller, the llama. J Appl Physiol (1985) 2020; 129:152-161. [PMID: 32584666 DOI: 10.1152/japplphysiol.00800.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Most mammals have a poor tolerance to hypoxia, and prolonged O2 restriction can lead to organ injury, particularly during fetal and early postnatal life. Nevertheless, the llama (Lama Glama) has evolved efficient mechanisms to adapt to acute and chronic perinatal hypoxia. One striking adaptation is the marked peripheral vasoconstriction measured in the llama fetus in response to acute hypoxia, which allows efficient redistribution of cardiac output toward the fetal heart and adrenal glands. This strong peripheral vasoconstrictor tone is triggered by a carotid body reflex and critically depends on α-adrenergic signaling. A second adaptation is the ability of the llama fetus to protect its brain against hypoxic damage. During hypoxia, in the llama fetus there is no significant increase in brain blood flow. Instead, there is a fall in brain O2 consumption and temperature, together with a decrease of Na+-K+-ATPase activity and Na+ channels expression, protecting against seizures and neuronal death. Finally, the newborn llama does not develop pulmonary hypertension in response to chronic hypoxia. In addition to maintaining basal pulmonary arterial pressure at normal levels the pulmonary arterial pressor response to acute hypoxia is lower in highland than in lowland llamas. The protection against hypoxic pulmonary arterial hypertension and pulmonary contractile hyperreactivity is partly due to increased hemoxygenase-carbon monoxide signaling and decreased Ca2+ sensitization in the newborn llama pulmonary vasculature. These three striking physiological adaptations of the llama allow this species to live and thrive under the chronic influence of the hypobaric hypoxia of life at high altitude.
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Affiliation(s)
- R V Reyes
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - E A Herrera
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - G Ebensperger
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
| | - E M Sanhueza
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - D A Giussani
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - A J Llanos
- Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,International Center for Andean Studies (INCAS), Universidad de Chile, Santiago, Chile
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Melleby AO, Sandvik GK, Couturier CS, Nilsson GE, Stecyk JAW. H 2S-producing enzymes in anoxia-tolerant vertebrates: Effects of cold acclimation, anoxia exposure and reoxygenation on gene and protein expression. Comp Biochem Physiol B Biochem Mol Biol 2020; 243-244:110430. [PMID: 32105700 DOI: 10.1016/j.cbpb.2020.110430] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 02/16/2020] [Accepted: 02/20/2020] [Indexed: 12/22/2022]
Abstract
To lend insight into the potential role of the gasotransmitter hydrogen sulfide (H2S) in facilitating anoxia survival of anoxia-tolerant vertebrates, we quantified the gene expression of the primary H2S-synthesizing enzymes, 3-mercaptopyruvate sulfurtransferase (3MST), cystathionine γ-lyase (CSE) and cystathionine β-synthase (CBS), in ventricle and brain of normoxic, anoxic and reoxygenated 21 °C- and 5 °C-acclimated freshwater turtles (Trachemys scripta) and 10 °C-acclimated crucian carp (Carassius carassius). Semi-quantitative Western blotting analysis was also conducted to assess 3MST and CBS protein abundance in ventricle and brain of 5 °C turtles and 10 °C crucian carp subjected to normoxia, anoxia and reoxygenation. We hypothesized that if H2S was advantageous for anoxia survival, expression levels would remain unchanged or be upregulated with anoxia and/or reoxygenation. Indeed, for both species, gene and protein expression were largely maintained with anoxia exposure (24 h, 21 °C; 5 d, 10 °C; 14 d, 5 °C). With reoxygenation, 3MST expression was increased in turtle and crucian carp brain at the protein and gene level, respectively. Additionally, the effect of cold acclimation on gene expression was assessed in several tissues of the turtle. Expression levels were maintained in most tissues, but decreased in others. The maintenance of gene and protein expression of the H2S-producing enzymes with anoxia exposure and the up-regulation of 3MST with reoxygenation suggests that H2S may facilitate anoxic survival of the two champions of vertebrate anoxia survival. The differential effects of cold acclimation on H2S enzyme expression may influence blood flow to different tissues during winter anoxia.
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Affiliation(s)
- Arne O Melleby
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway; Institute for Experimental Medical Research, University of Oslo, Oslo, Norway
| | - Guro K Sandvik
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway; Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
| | - Christine S Couturier
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway; Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, United States
| | - Göran E Nilsson
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Jonathan A W Stecyk
- Section for Physiology and Cell Biology, Department of Biosciences, University of Oslo, Oslo, Norway; Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, United States.
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Walsh CJ, Cocilova C, Restivo J, Flewelling L, Milton S. Immune function in Trachemys scripta following exposure to a predominant brevetoxin congener, PbTx-3, as a model for potential health impacts for sea turtles naturally exposed to brevetoxins. ECOTOXICOLOGY (LONDON, ENGLAND) 2019; 28:1085-1104. [PMID: 31559558 DOI: 10.1007/s10646-019-02110-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/09/2019] [Indexed: 06/10/2023]
Abstract
Many species of marine life in southwestern Florida, including sea turtles, are impacted by blooms of the toxic dinoflagellate, Karenia brevis. Sublethal exposure to toxins produced by K. brevis has been shown to impact sea turtle health. Since all sea turtles in the Gulf of Mexico have protected status, a freshwater turtle, Trachemys scripta, was used as a model for immune system effects following experimental exposure to a predominant brevetoxin congener in K. brevis blooms, PbTx-3. Exposure to PbTx-3 was oral or intratracheal and health effects were assessed using a suite of immune function parameters: innate immune function (phagocytosis, plasma lysozyme activity), adaptive immune function (lymphocyte proliferation), and measures of oxidative stress (superoxide dismutase (SOD) and glutathione-S-transferase (GST) activity in plasma). Inflammation was also measured using plasma protein electrophoresis. In addition, differential expression of genes in peripheral blood leukocytes was determined using suppression subtractive hybridization followed by real-time PCR of specific genes. The primary immune effects of sublethal brevetoxin exposure in T. scripta following PbTx-3 administration, appear to be an increase in oxidative stress, a decrease in lysozyme activity, and modulation of immune function through lymphocyte proliferation responses. Plasma protein electrophoresis showed a decreased A:G ratio which may indicate potential inflammation. Genes coding for oxidative stress, such as thioredoxin and GST, were upregulated in exposed animals. That sublethal brevetoxin exposures impact immune function components suggests potential health implications for sea turtles naturally exposed to toxins. Knowledge of physiological stressors induced by brevetoxins may contribute to the ultimate goal of developing directed treatment strategies in exposed animals for reduced mortality resulting from red tide toxin exposure in sea turtles.
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Affiliation(s)
- Catherine J Walsh
- Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL, 34236, USA.
| | - Courtney Cocilova
- Florida Atlantic University, 777 Glades Road, Boca Raton, FL, 33431, USA
| | - Jessica Restivo
- Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL, 34236, USA
| | - Leanne Flewelling
- Florida Fish and Wildlife Conservation Commission, 100 8th Ave SE, St. Petersburg, FL, 33701, USA
| | - Sarah Milton
- Florida Atlantic University, 777 Glades Road, Boca Raton, FL, 33431, USA
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The potential of drug repurposing combined with reperfusion therapy in cerebral ischemic stroke: A supplementary strategy to endovascular thrombectomy. Life Sci 2019; 236:116889. [PMID: 31610199 DOI: 10.1016/j.lfs.2019.116889] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/09/2019] [Accepted: 09/18/2019] [Indexed: 11/21/2022]
Abstract
Stroke is the major cause of adult disability and the second or third leading cause of death in developed countries. The treatment options for stroke (thrombolysis or thrombectomy) are restricted to a small subset of patients with acute ischemic stroke because of the limited time for an efficacious response and the strict criteria applied to minimize the risk of cerebral hemorrhage. Attempts to develop new treatments, such as neuroprotectants, for acute ischemic stroke have been costly and time-consuming and to date have yielded disappointing results. The repurposing approved drugs known to be relatively safe, such as statins and minocycline, may provide a less costly and more rapid alternative to new drug discovery in this clinical condition. Because adequate perfusion is thought to be vital for a neuroprotectant to be effective, endovascular thrombectomy (EVT) with advanced imaging modalities offers the possibility of documenting reperfusion in occluded large cerebral vessels. An examination of established medications that possess neuroprotective characters using in a large-vessel occlusive disorder with EVT may speed the identification of new and more broadly efficacious medications for the treatment of ischemic stroke. These approaches are highlighted in this review along with a critical assessment of drug repurposing combined with reperfusion therapy as a supplementary means for halting or mitigating stroke-induced brain damage.
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31
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Key J, Kohli A, Bárcena C, López-Otín C, Heidler J, Wittig I, Auburger G. Global Proteome of LonP1+/- Mouse Embryonal Fibroblasts Reveals Impact on Respiratory Chain, but No Interdependence between Eral1 and Mitoribosomes. Int J Mol Sci 2019; 20:E4523. [PMID: 31547314 PMCID: PMC6770551 DOI: 10.3390/ijms20184523] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/02/2019] [Accepted: 09/09/2019] [Indexed: 12/11/2022] Open
Abstract
Research on healthy aging shows that lifespan reductions are often caused by mitochondrial dysfunction. Thus, it is very interesting that the deletion of mitochondrial matrix peptidase LonP1 was observed to abolish embryogenesis, while deletion of the mitochondrial matrix peptidase Caseinolytic Mitochondrial Matrix Peptidase Proteolytic Subunit (ClpP) prolonged survival. To unveil the targets of each enzyme, we documented the global proteome of LonP1+/- mouse embryonal fibroblasts (MEF), for comparison with ClpP-/- depletion. Proteomic profiles of LonP1+/- MEF generated by label-free mass spectrometry were further processed with the STRING (Search tool for the retrieval of interacting genes) webserver Heidelberg for protein interactions. ClpP was previously reported to degrade Eral1 as a chaperone involved in mitoribosome assembly, so ClpP deficiency triggers the accumulation of mitoribosomal subunits and inefficient translation. LonP1+/- MEF also showed Eral1 accumulation, but no systematic effect on mitoribosomal subunits. In contrast to ClpP-/- profiles, several components of the respiratory complex-I membrane arm, of the glutathione pathway and of lysosomes were accumulated, whereas the upregulation of numerous innate immune defense components was similar. Overall, LonP1, as opposed to ClpP, appears to have no effect on translational machinery, instead it shows enhanced respiratory dysfunction; this agrees with reports on the human CODAS syndrome (syndrome with cerebral, ocular, dental, auricular, and skeletal anomalies) caused by LonP1 mutations.
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Affiliation(s)
- Jana Key
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany.
| | - Aneesha Kohli
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany.
| | - Clea Bárcena
- Departamento de Bioquimica y Biologia Molecular, Facultad de Medicina, Instituto Universitario de Oncologia (IUOPA), Universidad de Oviedo, 33006 Oviedo, Spain.
| | - Carlos López-Otín
- Departamento de Bioquimica y Biologia Molecular, Facultad de Medicina, Instituto Universitario de Oncologia (IUOPA), Universidad de Oviedo, 33006 Oviedo, Spain.
| | - Juliana Heidler
- Functional Proteomics Group, Goethe-University Hospital, 60590 Frankfurt am Main, Germany.
| | - Ilka Wittig
- Functional Proteomics Group, Goethe-University Hospital, 60590 Frankfurt am Main, Germany.
| | - Georg Auburger
- Experimental Neurology, Goethe University Medical School, 60590 Frankfurt am Main, Germany.
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32
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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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33
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Hoiland RL, Howe CA, Carter HH, Tremblay JC, Willie CK, Donnelly J, MacLeod DB, Gasho C, Stembridge M, Boulet LM, Niroula S, Ainslie PN. UBC‐Nepal expedition: phenotypical evidence for evolutionary adaptation in the control of cerebral blood flow and oxygen delivery at high altitude. J Physiol 2019; 597:2993-3008. [DOI: 10.1113/jp277596] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 04/09/2019] [Indexed: 01/26/2023] Open
Affiliation(s)
- Ryan L. Hoiland
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia–Okanagan Campus, School of Health and Exercise Sciences 3333 University Way Kelowna British Columbia Canada V1V 1V7
| | - Connor A. Howe
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia–Okanagan Campus, School of Health and Exercise Sciences 3333 University Way Kelowna British Columbia Canada V1V 1V7
| | - Howard H. Carter
- Department of Nutrition, Exercise and SportsUniversity of Copenhagen Nørre Allé 51 DK‐2200 Copenhagen Denmark
| | - Joshua C. Tremblay
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health StudiesQueen's University 28 Division Street Kingston Ontario Canada K7L 3N6
| | - Chris K. Willie
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia–Okanagan Campus, School of Health and Exercise Sciences 3333 University Way Kelowna British Columbia Canada V1V 1V7
| | - Joseph Donnelly
- Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical NeurosciencesCambridge Biomedical Campus, University of Cambridge Cambridge CB2 0QQ UK
| | - David B. MacLeod
- Human Pharmacology and Physiology Lab, Department of AnesthesiologyDuke University Medical Center Durham NC 27708 USA
| | - Chris Gasho
- VA Loma Linda Healthcare System and Loma Linda University School of Medicine Loma Linda CA USA
| | - Mike Stembridge
- Cardiff Centre for Exercise and HealthCardiff Metropolitan University Cyncoed Road Cardiff CF23 6XD UK
| | - Lindsey M. Boulet
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia–Okanagan Campus, School of Health and Exercise Sciences 3333 University Way Kelowna British Columbia Canada V1V 1V7
| | | | - Philip N. Ainslie
- Centre for Heart, Lung and Vascular HealthUniversity of British Columbia–Okanagan Campus, School of Health and Exercise Sciences 3333 University Way Kelowna British Columbia Canada V1V 1V7
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34
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Bundgaard A, James AM, Gruszczyk AV, Martin J, Murphy MP, Fago A. Metabolic adaptations during extreme anoxia in the turtle heart and their implications for ischemia-reperfusion injury. Sci Rep 2019; 9:2850. [PMID: 30808950 PMCID: PMC6391391 DOI: 10.1038/s41598-019-39836-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 01/30/2019] [Indexed: 02/01/2023] Open
Abstract
ATP depletion and succinate accumulation during ischemia lead to oxidative damage to mammalian organs upon reperfusion. In contrast, freshwater turtles survive weeks of anoxia at low temperatures without suffering from oxidative damage upon reoxygenation, but the mechanisms are unclear. To determine how turtles survive prolonged anoxia, we measured ~80 metabolites in hearts from cold-acclimated (5 °C) turtles exposed to 9 days anoxia and compared the results with those for normoxic turtles (25 °C) and mouse hearts exposed to 30 min of ischemia. In turtles, ATP and ADP decreased to new steady-state levels during fasting and cold-acclimation and further with anoxia, but disappeared within 30 min of ischemia in mouse hearts. High NADH/NAD+ ratios were associated with succinate accumulation in both anoxic turtles and ischemic mouse hearts. However, succinate concentrations and succinate/fumarate ratios were lower in turtle than in mouse heart, limiting the driving force for production of reactive oxygen species (ROS) upon reoxygenation in turtles. Furthermore, we show production of ROS from succinate is prevented by re-synthesis of ATP from ADP. Thus, maintenance of an ATP/ADP pool and low succinate accumulation likely protects turtle hearts from anoxia/reoxygenation injury and suggests metabolic interventions as a therapeutic approach to limit ischemia/reperfusion injury in mammals.
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Affiliation(s)
- Amanda Bundgaard
- Department of Bioscience, Aarhus University, Aarhus, Denmark
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Andrew M James
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Anja V Gruszczyk
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Jack Martin
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge, UK.
| | - Angela Fago
- Department of Bioscience, Aarhus University, Aarhus, Denmark.
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35
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Bailey DM. Oxygen, evolution and redox signalling in the human brain; quantum in the quotidian. J Physiol 2018; 597:15-28. [PMID: 30315729 DOI: 10.1113/jp276814] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 09/27/2018] [Indexed: 12/20/2022] Open
Abstract
Rising atmospheric oxygen (O2 ) levels provided a selective pressure for the evolution of O2 -dependent micro-organisms that began with the autotrophic eukaryotes. Since these primordial times, the respiring mammalian cell has become entirely dependent on the constancy of electron flow, with molecular O2 serving as the terminal electron acceptor in mitochondrial oxidative phosphorylation. Indeed, the ability to 'sense' O2 and maintain homeostasis is considered one of the most important roles of the central nervous system (CNS) and probably represented a major driving force in the evolution of the human brain. Today, modern humans have evolved with an oversized brain committed to a continually active state and, as a consequence, paradoxically vulnerable to failure if the O2 supply is interrupted. However, our pre-occupation with O2 , the elixir of life, obscures the fact that it is a gas with a Janus face, capable of sustaining life in physiologically controlled amounts yet paradoxically deadly to the CNS when in excess. A closer look at its quantum structure reveals precisely why; the triplet ground state diatomic O2 molecule is paramagnetic and exists in air as a free radical, constrained from reacting aggressively with the brain's organic molecules due to its 'spin restriction', a thermodynamic quirk of evolutionary fate. By further exploring O2 's free radical 'quantum quirkiness', including emergent (quantum) physiological phenomena, our understanding of precisely how the human brain senses O2 deprivation (hypoxia) and the elaborate redox-signalling defence mechanisms that defend O2 homeostasis has the potential to offer unique insights into the pathophysiology and treatment of human brain disease.
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Affiliation(s)
- Damian Miles Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, UK
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36
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Bailey DM. RETRACTED ARTICLE: The quantum physiology of oxygen; from electrons to the evolution of redox signaling in the human brain. Bioelectron Med 2018; 4:13. [PMID: 32232089 PMCID: PMC7098224 DOI: 10.1186/s42234-018-0014-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 09/19/2018] [Indexed: 12/11/2022] Open
Abstract
Rising atmospheric oxygen (O2) levels provided a selective pressure for the evolution of O2-dependent micro-organisms that began with the autotrophic eukaryotes. Since these primordial times, the respiring mammalian cell has become entirely dependent on the constancy of electron flow with molecular O2 serving as the terminal electron acceptor in mitochondrial oxidative phosphorylation. Indeed, the ability to “sense” O2 and maintain homeostasis is considered one of the most important roles of the central nervous system (CNS) and likely represented a major driving force in the evolution of the human brain. Today, modern humans have evolved with an oversized brain committed to a continually active state and as a consequence, paradoxically vulnerable to failure if the O2 supply is interrupted. However, our pre-occupation with O2, the elixir of life, obscures the fact that it is a gas with a Janus Face, capable of sustaining life in physiologically controlled amounts yet paradoxically deadly to the CNS when in excess. A closer look at its quantum structure reveals precisely why; the triplet ground state diatomic O2 molecule is paramagnetic and exists in air as a free radical, constrained from reacting aggressively with the brain’s organic molecules due to its “spin restriction”, a thermodynamic quirk of evolutionary fate. By further exploring O2’s free radical “quantum quirkiness” including emergent quantum physiological phenomena, our understanding of precisely how the human brain senses O2 deprivation (hypoxia) and the elaborate redox-signaling defense mechanisms that defend O2 homeostasis has the potential to offer unique insights into the pathophysiology and treatment of human brain disease.
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Affiliation(s)
- Damian Miles Bailey
- Neurovascular Research Laboratory, Alfred Russel Wallace Building, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, CF37 4AT UK
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37
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Impact of diet-induced obesity on the mouse brain phosphoproteome. J Nutr Biochem 2018; 58:102-109. [DOI: 10.1016/j.jnutbio.2018.04.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 04/16/2018] [Accepted: 04/26/2018] [Indexed: 12/27/2022]
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38
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Balko JA, Oda A, Posner LP. Use of tricaine methanesulfonate or propofol for immersion euthanasia of goldfish (Carassius auratus). J Am Vet Med Assoc 2018; 252:1555-1561. [DOI: 10.2460/javma.252.12.1555] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Campbell JB, Andersen MK, Overgaard J, Harrison JF. Paralytic hypo-energetic state facilitates anoxia tolerance despite ionic imbalance in adult Drosophila melanogaster. ACTA ACUST UNITED AC 2018; 221:jeb.177147. [PMID: 29615525 DOI: 10.1242/jeb.177147] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 03/28/2018] [Indexed: 12/24/2022]
Abstract
Oxygen limitation plays a key role in many pathologies; yet, we still lack a fundamental understanding of the mechanisms responsible for variation in anoxia tolerance. Most vertebrate studies suggest that anoxia tolerance involves the ability to maintain cellular ATP despite the loss of aerobic metabolism. However, insects such as adult Drosophila melanogaster are able to survive long periods of anoxia (LT50: ∼8 h) in a hypo-energetic state characterized by low [ATP]. In this study, we tested for possible mechanisms that allow D. melanogaster adults to survive long periods of anoxia. Adults are paralyzed within 30 s, and after 2 h of anoxia, ATP was 3% of normal, extracellular potassium concentration ([K+]o) increased threefold, pH dropped 1 unit, yet survival was 100%. With 0.5-6 h of anoxia, adults maintained low but constant ATP levels while [K+]o and pHo continued to change. When returned to normoxia, adults restored [K+]o and activity. With longer durations of anoxia, ATP levels decreased and [K+]o rose further, and both correlated tightly with decreased survival. This response contrasts with the anoxia-sensitive larval stage (LT50: ∼1 h). During anoxia, larvae attempted escape for up to 30 min and after 2 h of anoxia, ATP was <1% of resting, [K+]o increased by 50%, hemolymph pH fell by 1 unit, and survival was zero. The superior anoxia tolerance of adult D. melanogaster appears to be due to the capacity to maintain a paralytic hypometabolic state with low but non-zero ATP levels, and to be able to tolerate extreme extracellular ionic variability.
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Affiliation(s)
- Jacob B Campbell
- School of Life Sciences, Arizona State University, Tempe, AZ, USA 85287
| | | | - Johannes Overgaard
- Zoophysiology, Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark
| | - Jon F Harrison
- School of Life Sciences, Arizona State University, Tempe, AZ, USA 85287
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40
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Potential role for microRNA in regulating hypoxia-induced metabolic suppression in jumbo squids. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:586-593. [DOI: 10.1016/j.bbagrm.2018.04.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/30/2018] [Accepted: 04/30/2018] [Indexed: 12/19/2022]
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41
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Lefevre S, Stecyk JAW, Torp MK, Løvold LY, Sørensen C, Johansen IB, Stensløkken KO, Couturier CS, Sloman KA, Nilsson GE. Re-oxygenation after anoxia induces brain cell death and memory loss in the anoxia-tolerant crucian carp. ACTA ACUST UNITED AC 2018; 220:3883-3895. [PMID: 29093186 DOI: 10.1242/jeb.165118] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 09/01/2017] [Indexed: 01/15/2023]
Abstract
Crucian carp (Carassius carassius) survive without oxygen for several months, but it is unknown whether they are able to protect themselves from cell death normally caused by the absence, and particularly return, of oxygen. Here, we quantified cell death in brain tissue from crucian carp exposed to anoxia and re-oxygenation using the terminal deoxy-nucleotidyl transferase dUTP nick-end labelling (TUNEL) assay, and cell proliferation by immunohistochemical staining for proliferating cell nuclear antigen (PCNA) as well as PCNA mRNA expression. We also measured mRNA and protein expression of the apoptosis executer protease caspase 3, in laboratory fish exposed to anoxia and re-oxygenation and fish exposed to seasonal anoxia and re-oxygenation in their natural habitat over the year. Finally, a behavioural experiment was used to assess the ability to learn and remember how to navigate in a maze to find food, before and after exposure to anoxia and re-oxygenation. The number of TUNEL-positive cells in the telencephalon increased after 1 day of re-oxygenation following 7 days of anoxia, indicating increased cell death. However, there were no consistent changes in whole-brain expression of caspase 3 in either laboratory-exposed or naturally exposed fish, indicating that cell death might occur via caspase-independent pathways or necrosis. Re-oxygenated crucian carp appeared to have lost the memory of how to navigate in a maze (learnt prior to anoxia exposure), while the ability to learn remained intact. PCNA mRNA was elevated after re-oxygenation, indicating increased neurogenesis. We conclude that anoxia tolerance involves not only protection from damage but also repair after re-oxygenation.
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Affiliation(s)
- Sjannie Lefevre
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Jonathan A W Stecyk
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - May-Kristin Torp
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Lisa Y Løvold
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Christina Sørensen
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Ida B Johansen
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Kåre-Olav Stensløkken
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Christine S Couturier
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
| | - Katherine A Sloman
- Institute of Biomedical and Environmental Health Research, School of Science and Sport, University of the West of Scotland, PA1 2BE, UK
| | - Göran E Nilsson
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0371 Oslo, Norway
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42
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Wagner JT, Singh PP, Romney AL, Riggs CL, Minx P, Woll SC, Roush J, Warren WC, Brunet A, Podrabsky JE. The genome of Austrofundulus limnaeus offers insights into extreme vertebrate stress tolerance and embryonic development. BMC Genomics 2018; 19:155. [PMID: 29463212 PMCID: PMC5819677 DOI: 10.1186/s12864-018-4539-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 02/12/2018] [Indexed: 11/21/2022] Open
Abstract
Background The annual killifish Austrofundulus limnaeus inhabits ephemeral ponds in northern Venezuela, South America, and is an emerging extremophile model for vertebrate diapause, stress tolerance, and evolution. Embryos of A. limnaeus regularly experience extended periods of desiccation and anoxia as a part of their natural history and have unique metabolic and developmental adaptations. Currently, there are limited genomic resources available for gene expression and evolutionary studies that can take advantage of A. limnaeus as a unique model system. Results We describe the first draft genome sequence of A. limnaeus. The genome was assembled de novo using a merged assembly strategy and was annotated using the NCBI Eukaryotic Annotation Pipeline. We show that the assembled genome has a high degree of completeness in genic regions that is on par with several other teleost genomes. Using RNA-seq and phylogenetic-based approaches, we identify several candidate genes that may be important for embryonic stress tolerance and post-diapause development in A. limnaeus. Several of these genes include heat shock proteins that have unique expression patterns in A. limnaeus embryos and at least one of these may be under positive selection. Conclusion The A. limnaeus genome is the first South American annual killifish genome made publicly available. This genome will be a valuable resource for comparative genomics to determine the genetic and evolutionary mechanisms that support the unique biology of annual killifishes. In a broader context, this genome will be a valuable tool for exploring genome-environment interactions and their impacts on vertebrate physiology and evolution. Electronic supplementary material The online version of this article (10.1186/s12864-018-4539-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Josiah T Wagner
- Department of Biology, Center for Life in Extreme Environments, Portland State University, Portland, Oregon, USA. .,Knight Cancer Early Detection Advanced Research Center, Oregon Health and Science University, Portland, Oregon, USA.
| | - Param Priya Singh
- Department of Genetics, Stanford University, Stanford, California, USA
| | - Amie L Romney
- Department of Biology, Center for Life in Extreme Environments, Portland State University, Portland, Oregon, USA
| | - Claire L Riggs
- Department of Biology, Center for Life in Extreme Environments, Portland State University, Portland, Oregon, USA
| | - Patrick Minx
- McDonnell Genome Institute at Washington University, St Louis, Missouri, USA
| | - Steven C Woll
- Department of Biology, Center for Life in Extreme Environments, Portland State University, Portland, Oregon, USA
| | - Jake Roush
- Department of Biology, Center for Life in Extreme Environments, Portland State University, Portland, Oregon, USA
| | - Wesley C Warren
- McDonnell Genome Institute at Washington University, St Louis, Missouri, USA
| | - Anne Brunet
- Department of Genetics, Stanford University, Stanford, California, USA.,Glenn Center for the Biology of Aging, Stanford, California, USA
| | - Jason E Podrabsky
- Department of Biology, Center for Life in Extreme Environments, Portland State University, Portland, Oregon, USA
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43
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Dhillon RS, Mandic M, Yao L, Cao ZD, Fu SJ, Brauner CJ, Wang YS, Richards JG. Ethanol metabolism varies with hypoxia tolerance in ten cyprinid species. J Comp Physiol B 2017; 188:283-293. [PMID: 29032388 DOI: 10.1007/s00360-017-1131-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 09/22/2017] [Accepted: 10/07/2017] [Indexed: 11/25/2022]
Abstract
During periods of severe hypoxia or anoxia, Carassius spp. are known for their ability to produce ethanol as their anaerobic end product, which diffuses into the environment thereby reducing the osmotic and acidotic load associated with "anaerobic" glycolysis. However, the relationship between alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities, key ethanol metabolizing enzymes, and hypoxia tolerance among Carassius spp. and their closely related non-ethanol-producing cyprinids remains unclear. To address this, we quantified the activity levels of key anaerobic enzymes in liver and muscle in species of cyprinids over 48 h of severe hypoxia exposure (0.7 kPa). As predicted, muscle ADH activity was highest in the two most hypoxia-tolerant species (Carassius spp.), with very low levels present in the other species examined. However, liver ADH activities showed an inverse relationship with hypoxia tolerance, with the most hypoxia-tolerant fish having the lowest ADH activity. There was no correlation between hypoxia tolerance and ALDH and LDH activities in muscle or liver. All species produced lactate, reaching their highest levels after 8 h, but returning to near-baseline levels by 48 h of sustained exposure to hypoxia, suggesting lactate oxidation or depressed ATP demand. Liver glycogen content was not affected by 48 h hypoxia exposure in the most hypoxia-tolerant species, whereas the least tolerant species consumed the majority of the liver glycogen stores, which is probably due to the greater relative hypoxia exposure experienced by these species. Our findings that liver ADH activities were inversely related to hypoxia tolerance suggests that in all but Carassius spp., the ethanol metabolizing pathways in cyprinids is largely similar to that observed in other vertebrates and plays a role in the detoxification of ethanol. Furthermore, conservation of glycogen stores may be the result of metabolic-depressing pathways in the more tolerant species, regardless of the ability to produce ethanol, or adaptations that improve oxygen uptake to reduce metabolic demands due to hypoxia.
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Affiliation(s)
- Rashpal S Dhillon
- Department of Biomolecular Chemistry, University of Wisconsin, 330 North Orchard Street, Madison, WI, 53715, USA.
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada.
| | - Milica Mandic
- Department of Biology, University of Ottawa, 30 Marie Curie Private, Ottawa, ON, K1N 6N5, Canada
| | - Lili Yao
- Department of Biomolecular Chemistry, University of Wisconsin, 330 North Orchard Street, Madison, WI, 53715, USA
| | - Zhen-Dong Cao
- Laboratory of Evolutionary Physiology and Behaviour, Chongqing Key Laboratory of Animal Biology, Chongqing Normal University, Chongqing, China
| | - Shi-Jian Fu
- Laboratory of Evolutionary Physiology and Behaviour, Chongqing Key Laboratory of Animal Biology, Chongqing Normal University, Chongqing, China
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
| | - Yuxiang S Wang
- Department of Biology, Queen's University, 116 Barrie Street, Kingston, ON, K7L 3N6, Canada
| | - Jeffrey G Richards
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
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44
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Petrushanko IY, Mitkevich VA, Lakunina VA, Anashkina AA, Spirin PV, Rubtsov PM, Prassolov VS, Bogdanov NB, Hänggi P, Fuller W, Makarov AA, Bogdanova A. Cysteine residues 244 and 458-459 within the catalytic subunit of Na,K-ATPase control the enzyme's hydrolytic and signaling function under hypoxic conditions. Redox Biol 2017; 13:310-319. [PMID: 28601781 PMCID: PMC5470536 DOI: 10.1016/j.redox.2017.05.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 03/16/2017] [Accepted: 05/26/2017] [Indexed: 12/21/2022] Open
Abstract
Our previous findings suggested that reversible thiol modifications of cysteine residues within the actuator (AD) and nucleotide binding domain (NBD) of the Na,K-ATPase may represent a powerful regulatory mechanism conveying redox- and oxygen-sensitivity of this multifunctional enzyme. S-glutathionylation of Cys244 in the AD and Cys 454-458-459 in the NBD inhibited the enzyme and protected cysteines' thiol groups from irreversible oxidation under hypoxic conditions. In this study mutagenesis approach was used to assess the role these cysteines play in regulation of the Na,K-ATPase hydrolytic and signaling functions. Several constructs of mouse α1 subunit of the Na,K-ATPase were produced in which Cys244, Cys 454-458-459 or Cys 244-454-458-459 were replaced by alanine. These constructs were expressed in human HEK293 cells. Non-transfected cells and those expressing murine α1 subunit were exposed to hypoxia or treated with oxidized glutathione (GSSG). Both conditions induced inhibition of the wild type Na,K-ATPase. Enzymes containing mutated mouse α1 lacking Cys244 or all four cysteines (Cys 244-454-458-459) were insensitive to hypoxia. Inhibitory effect of GSSG was observed for wild type murine Na,K-ATPase, but was less pronounced in Cys454-458-459Ala mutant and completely absent in the Cys244Ala and Cys 244-454-458-459Ala mutants. In cells, expressing wild type enzyme, ouabain induced activation of Src and Erk kinases under normoxic conditions, whereas under hypoxic conditions this effect was inversed. Cys454-458-459Ala substitution abolished Src kinase activation in response to ouabain treatment, uncoupled Src from Erk signaling, and interfered with O2-sensitivity of Na,K-ATPase signaling function. Moreover, modeling predicted that S-glutathionylation of Cys 458 and 459 should prevent inhibitory binding of Src to NBD. Our data indicate for the first time that cysteine residues within the AD and NBD influence hydrolytic as well as receptor function of the Na,K-ATPase and alter responses of the enzyme to hypoxia or upon treatment with cardiotonic steroids.
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Affiliation(s)
- Irina Yu Petrushanko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Vladimir A Mitkevich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Valentina A Lakunina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anastasia A Anashkina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Pavel V Spirin
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Peter M Rubtsov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Vladimir S Prassolov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Nikolay B Bogdanov
- Institute of Veterinary Physiology, Vetsuisse Faculty and the Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Pascal Hänggi
- Institute of Veterinary Physiology, Vetsuisse Faculty and the Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - William Fuller
- Cardiovascular and Diabetes Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Alexander A Makarov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Anna Bogdanova
- Institute of Veterinary Physiology, Vetsuisse Faculty and the Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland.
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45
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Riggs CL, Podrabsky JE. Small noncoding RNA expression during extreme anoxia tolerance of annual killifish (Austrofundulus limnaeus) embryos. Physiol Genomics 2017; 49:505-518. [DOI: 10.1152/physiolgenomics.00016.2017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 07/10/2017] [Accepted: 08/09/2017] [Indexed: 12/11/2022] Open
Abstract
Small noncoding RNAs (sncRNA) have recently emerged as specific and rapid regulators of gene expression, involved in a myriad of cellular and organismal processes. MicroRNAs, a class of sncRNAs, are differentially expressed in diverse taxa in response to environmental stress, including anoxia. In most vertebrates, a brief period of oxygen deprivation results in severe tissue damage or death. Studies on sncRNA and anoxia have focused on these anoxia-sensitive species. Studying sncRNAs in anoxia-tolerant organisms may provide insight into adaptive mechanisms supporting anoxia tolerance. Embryos of the annual killifish Austrofundulus limnaeus are the most anoxia-tolerant vertebrates known, surviving over 100 days at their peak tolerance at 25°C. Their anoxia tolerance and physiology vary over development, such that both anoxia-tolerant and anoxia-sensitive phenotypes comprise the species. This allows for a robust comparison to identify sncRNAs essential to anoxia-tolerance. For this study, RNA sequencing was used to identify and quantify expression of sncRNAs in four embryonic stages of A. limnaeus in response to an exposure to anoxia and subsequent aerobic recovery. Unique stage-specific patterns of expression were identified that correlate with anoxia tolerance. In addition, embryos of A. limnaeus appear to constitutively express stress-responsive miRNAs. Most differentially expressed sncRNAs were expressed at higher levels during recovery. Many novel groups of sncRNAs with expression profiles suggesting a key role in anoxia tolerance were identified, including sncRNAs derived from mitochondrial tRNAs. This global analysis has revealed groups of candidate sncRNAs that we hypothesize support anoxia tolerance.
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Affiliation(s)
- Claire L. Riggs
- Department of Biology, Portland State University, Portland, Oregon
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46
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Carpenè E, Andreani G, Isani G. Trace elements in unconventional animals: A 40-year experience. J Trace Elem Med Biol 2017; 43:169-179. [PMID: 28215718 DOI: 10.1016/j.jtemb.2017.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 12/22/2016] [Accepted: 02/04/2017] [Indexed: 12/13/2022]
Abstract
The role of trace elements in animal health has attracted increasing interest in recent years. The essentiality and toxicity of these elements have been extensively investigated in humans, laboratory animal models and partially in domestic animals, whereas little is known about trace element metabolism in most living organisms. Forty years ago our research started on Cd metabolism in molluscs, thereafter expanding to Zn, Cu, and Fe metabolism in many unconventional animal species of veterinary interest. This review summarizes the main results obtained over this long period of time: some of the findings are original and have not been published to date. They are discussed in more detail and compared with data obtained in conventional animals, including man.
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Affiliation(s)
- Emilio Carpenè
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia, Bologna, Italy
| | - Giulia Andreani
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia, Bologna, Italy
| | - Gloria Isani
- Department of Veterinary Medical Sciences, Alma Mater Studiorum-University of Bologna, Via Tolara di Sopra 50, 40064 Ozzano Emilia, Bologna, Italy.
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47
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Fagernes CE, Stensløkken KO, Røhr ÅK, Berenbrink M, Ellefsen S, Nilsson GE. Extreme anoxia tolerance in crucian carp and goldfish through neofunctionalization of duplicated genes creating a new ethanol-producing pyruvate decarboxylase pathway. Sci Rep 2017; 7:7884. [PMID: 28801642 PMCID: PMC5554223 DOI: 10.1038/s41598-017-07385-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 06/23/2017] [Indexed: 11/09/2022] Open
Abstract
Without oxygen, most vertebrates die within minutes as they cannot meet cellular energy demands with anaerobic metabolism. However, fish of the genus Carassius (crucian carp and goldfish) have evolved a specialized metabolic system that allows them to survive prolonged periods without oxygen by producing ethanol as their metabolic end-product. Here we show that this has been made possible by the evolution of a pyruvate decarboxylase, analogous to that in brewer's yeast and the first described in vertebrates, in addition to a specialized alcohol dehydrogenase. Whole-genome duplication events have provided additional gene copies of the pyruvate dehydrogenase multienzyme complex that have evolved into a pyruvate decarboxylase, while other copies retained the essential function of the parent enzymes. We reveal the key molecular substitution in duplicated pyruvate dehydrogenase genes that underpins one of the most extreme hypoxic survival strategies among vertebrates and that is highly deleterious in humans.
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Affiliation(s)
| | - Kåre-Olav Stensløkken
- Institute of Basic Medical Sciences, University of Oslo, N-0372, Oslo, Norway.,Center for Heart Failure Research, University of Oslo, N-0317, Oslo, Norway
| | - Åsmund K Røhr
- Department of Biosciences, University of Oslo, N-0316, Oslo, Norway
| | - Michael Berenbrink
- Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, United Kingdom
| | - Stian Ellefsen
- The Lillehammer Research Center for Medicine and Exercise Physiology, Inland Norway University of Applied Sciences, N-2604, Lillehammer, Norway
| | - Göran E Nilsson
- Department of Biosciences, University of Oslo, N-0316, Oslo, Norway.
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48
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Fago A. Functional roles of globin proteins in hypoxia-tolerant ectothermic vertebrates. J Appl Physiol (1985) 2017; 123:926-934. [PMID: 28428250 DOI: 10.1152/japplphysiol.00104.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 03/28/2017] [Accepted: 04/16/2017] [Indexed: 11/22/2022] Open
Abstract
Globins are heme-containing proteins ubiquitously expressed in vertebrates, where they serve a broad range of biological functions, directly or indirectly related to the tight control of oxygen levels and its toxic products in vivo. Perhaps the most investigated of all proteins, hemoglobin and myoglobin are primarily involved in oxygen transport and storage, but also in facilitating arterial vasodilation, suppressing mitochondrial respiration, and preventing tissue oxidative damage via accessory redox enzymatic activities during hypoxia. By contrast, the more recently discovered neuroglobin and cytoglobin do not seem to function as reversible oxygen carriers and are instead involved in redox activities, although their exact biological roles remain to be clarified. In this context, hypoxia-tolerant ectotherms, such as freshwater turtles and members of the carp family that survive winter in extreme hypoxia, have proven as excellent models to appreciate the diversity of biological functions of globin proteins. Unraveling physiological roles of globin proteins in these extreme animals will clarify an important part of the adaptive mechanisms for surviving extreme fluctuations of oxygen availability that are prohibitive to mammals.
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Affiliation(s)
- Angela Fago
- Department of Bioscience, Aarhus University, Aarhus, Denmark
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49
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Tekko T, Lakspere T, Allikalt A, End J, Kõlvart KR, Jagomäe T, Terasmaa A, Philips MA, Visnapuu T, Väärtnõu F, Gilbert SF, Rinken A, Vasar E, Lilleväli K. Wfs1 is expressed in dopaminoceptive regions of the amniote brain and modulates levels of D1-like receptors. PLoS One 2017; 12:e0172825. [PMID: 28267787 PMCID: PMC5436468 DOI: 10.1371/journal.pone.0172825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 02/10/2017] [Indexed: 11/27/2022] Open
Abstract
During amniote evolution, the construction of the forebrain has diverged across
different lineages, and accompanying the structural changes, functional
diversification of the homologous brain regions has occurred. This can be
assessed by studying the expression patterns of marker genes that are relevant
in particular functional circuits. In all vertebrates, the dopaminergic system
is responsible for the behavioral responses to environmental stimuli. Here we
show that the brain regions that receive dopaminergic input through dopamine
receptor D1 are relatively conserved, but with some important
variations between three evolutionarily distant vertebrate lines–house mouse
(Mus musculus), domestic chick (Gallus gallus
domesticus) / common quail (Coturnix coturnix) and
red-eared slider turtle (Trachemys scripta). Moreover, we find
that in almost all instances, those brain regions expressing D1-like dopamine
receptor genes also express Wfs1. Wfs1 has been studied
primarily in the pancreas, where it regulates the endoplasmic reticulum (ER)
stress response, cellular Ca2+ homeostasis, and insulin production
and secretion. Using radioligand binding assays in wild type and
Wfs1-/- mouse brains, we show that the number of
binding sites of D1-like dopamine receptors is increased in the hippocampus of
the mutant mice. We propose that the functional link between Wfs1 and D1-like
dopamine receptors is evolutionarily conserved and plays an important role in
adjusting behavioral reactions to environmental stimuli.
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Affiliation(s)
- Triin Tekko
- Department of Physiology, Institute of Biomedicine and Translational
Medicine, University of Tartu, Tartu, Estonia
- Centre of Excellence in Genomics and Translational Medicine, University
of Tartu, Tartu, Estonia
| | - Triin Lakspere
- Department of Developmental Biology, Institute of Molecular and Cell
Biology, University of Tartu, Tartu, Estonia
| | - Anni Allikalt
- Institute of Chemistry, University of Tartu, Tartu,
Estonia
| | - Jaanus End
- Department of Developmental Biology, Institute of Molecular and Cell
Biology, University of Tartu, Tartu, Estonia
| | | | - Toomas Jagomäe
- Department of Physiology, Institute of Biomedicine and Translational
Medicine, University of Tartu, Tartu, Estonia
- Centre of Excellence in Genomics and Translational Medicine, University
of Tartu, Tartu, Estonia
| | - Anton Terasmaa
- Department of Physiology, Institute of Biomedicine and Translational
Medicine, University of Tartu, Tartu, Estonia
- Centre of Excellence in Genomics and Translational Medicine, University
of Tartu, Tartu, Estonia
| | - Mari-Anne Philips
- Department of Physiology, Institute of Biomedicine and Translational
Medicine, University of Tartu, Tartu, Estonia
- Centre of Excellence in Genomics and Translational Medicine, University
of Tartu, Tartu, Estonia
| | - Tanel Visnapuu
- Department of Physiology, Institute of Biomedicine and Translational
Medicine, University of Tartu, Tartu, Estonia
- Centre of Excellence in Genomics and Translational Medicine, University
of Tartu, Tartu, Estonia
| | - Fred Väärtnõu
- Department of Developmental Biology, Institute of Molecular and Cell
Biology, University of Tartu, Tartu, Estonia
| | - Scott F. Gilbert
- Department of Biology, Swarthmore College, Swarthmore, PA, United States
of America
| | - Ago Rinken
- Institute of Chemistry, University of Tartu, Tartu,
Estonia
| | - Eero Vasar
- Department of Physiology, Institute of Biomedicine and Translational
Medicine, University of Tartu, Tartu, Estonia
- Centre of Excellence in Genomics and Translational Medicine, University
of Tartu, Tartu, Estonia
| | - Kersti Lilleväli
- Department of Physiology, Institute of Biomedicine and Translational
Medicine, University of Tartu, Tartu, Estonia
- Centre of Excellence in Genomics and Translational Medicine, University
of Tartu, Tartu, Estonia
- * E-mail:
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50
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Valentin-Kahan A, García-Tejedor GB, Robello C, Trujillo-Cenóz O, Russo RE, Alvarez-Valin F. Gene Expression Profiling in the Injured Spinal Cord of Trachemys scripta elegans: An Amniote with Self-Repair Capabilities. Front Mol Neurosci 2017; 10:17. [PMID: 28223917 PMCID: PMC5293771 DOI: 10.3389/fnmol.2017.00017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/12/2017] [Indexed: 12/19/2022] Open
Abstract
Slider turtles are the only known amniotes with self-repair mechanisms of the spinal cord that lead to substantial functional recovery. Their strategic phylogenetic position makes them a relevant model to investigate the peculiar genetic programs that allow anatomical reconnection in some vertebrate groups but are absent in others. Here, we analyze the gene expression profile of the response to spinal cord injury (SCI) in the turtle Trachemys scripta elegans. We found that this response comprises more than 1000 genes affecting diverse functions: reaction to ischemic insult, extracellular matrix re-organization, cell proliferation and death, immune response, and inflammation. Genes related to synapses and cholesterol biosynthesis are down-regulated. The analysis of the evolutionary distribution of these genes shows that almost all are present in most vertebrates. Additionally, we failed to find genes that were exclusive of regenerating taxa. The comparison of expression patterns among species shows that the response to SCI in the turtle is more similar to that of mice and non-regenerative Xenopus than to Xenopus during its regenerative stage. This observation, along with the lack of conserved “regeneration genes” and the current accepted phylogenetic placement of turtles (sister group of crocodilians and birds), indicates that the ability of spinal cord self-repair of turtles does not represent the retention of an ancestral vertebrate character. Instead, our results suggest that turtles developed this capability from a non-regenerative ancestor (i.e., a lineage specific innovation) that was achieved by re-organizing gene expression patterns on an essentially non-regenerative genetic background. Among the genes activated by SCI exclusively in turtles, those related to anoxia tolerance, extracellular matrix remodeling, and axonal regrowth are good candidates to underlie functional recovery.
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Affiliation(s)
- Adrián Valentin-Kahan
- Department of Cellular and Molecular Neurophysiology, Instituto de Investigaciones Biológicas Clemente Estable Montevideo, Uruguay
| | - Gabriela B García-Tejedor
- Department of Cellular and Molecular Neurophysiology, Instituto de Investigaciones Biológicas Clemente Estable Montevideo, Uruguay
| | - Carlos Robello
- Molecular Biology Unit, Institut Pasteur de MontevideoMontevideo, Uruguay; Departamento de Bioquímica, Facultad de Medicina, Universidad de la RepublicaMontevideo, Uruguay
| | - Omar Trujillo-Cenóz
- Department of Cellular and Molecular Neurophysiology, Instituto de Investigaciones Biológicas Clemente Estable Montevideo, Uruguay
| | - Raúl E Russo
- Department of Cellular and Molecular Neurophysiology, Instituto de Investigaciones Biológicas Clemente Estable Montevideo, Uruguay
| | - Fernando Alvarez-Valin
- Sección Biomatemática, Unidad de Genómica Evolutiva, Facultad de Ciencias, Universidad de la República Montevideo, Uruguay
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