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Park TJ, Reznick J. Extreme Physiology Extreme Tolerance to Hypoxia, Hypercapnia, and Pain in the Naked Mole-Rat. J Muscle Res Cell Motil 2023; 44:61-72. [PMID: 35854159 PMCID: PMC10329625 DOI: 10.1007/s10974-022-09623-3] [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: 02/24/2022] [Accepted: 06/04/2022] [Indexed: 10/17/2022]
Abstract
Challenging environmental conditions can drive the evolution of extreme physiological traits. The naked mole-rat has evolved to survive and thrive in a low oxygen, high carbon dioxide environment that would be deadly to humans and most other mammals. The naked mole-rat's lifestyle is unusual in that this species combines subterranean living and living in large, social groups of up to 300 + individuals. Many respiring animals in a closed environment can lead to depletion of oxygen (hypoxia) and accumulation of carbon dioxide (hypercapnia). Naked mole-rats display a variety of physiological traits that negate the adverse effects of living in this atmosphere. For hypoxia tolerance, naked mole-rats have a low resting metabolism, high affinity hemoglobin, intrinsic brain tolerance, the ability to use fructose for anaerobic glycolysis, and the ability to enter a low energy, suspended animation-like state. For hypercapnia tolerance, these animals have a mutation in a voltage gated sodium channel that effectively eliminates neuronal responses to tissue acidosis. In other mammals, acidosis from exposure to high concentrations of carbon dioxide induces pain and pulmonary edema. Understanding these mechanisms of extreme physiology is not only inherently interesting, but it may lead to biomedical breakthroughs in research on heart attacks, strokes, and pain pathologies.
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Affiliation(s)
- Thomas J Park
- Department of Biological Sciences and Laboratory of Integrative Neuroscience, University of Illinois at Chicago, Chicago, IL, United States of America.
| | - Jane Reznick
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), Faculty of Medicine and University Hospital, University of Cologne, Cologne, Germany.
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2
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Gorshkova EA, Gubernatorova EO, Dvorianinova EM, Yurakova TR, Marey MV, Averina OA, Holtze S, Hildebrandt TB, Dmitriev AA, Drutskaya MS, Vyssokikh MY, Nedospasov SA. Macrophages from naked mole-rat possess distinct immunometabolic signatures upon polarization. Front Immunol 2023; 14:1172467. [PMID: 37153552 PMCID: PMC10154529 DOI: 10.3389/fimmu.2023.1172467] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 04/04/2023] [Indexed: 05/09/2023] Open
Abstract
The naked mole-rat (NMR) is a unique long-lived rodent which is highly resistant to age-associated disorders and cancer. The immune system of NMR possesses a distinct cellular composition with the prevalence of myeloid cells. Thus, the detailed phenotypical and functional assessment of NMR myeloid cell compartment may uncover novel mechanisms of immunoregulation and healthy aging. In this study gene expression signatures, reactive nitrogen species and cytokine production, as well as metabolic activity of classically (M1) and alternatively (M2) activated NMR bone marrow-derived macrophages (BMDM) were examined. Polarization of NMR macrophages under pro-inflammatory conditions led to expected M1 phenotype characterized by increased pro-inflammatory gene expression, cytokine production and aerobic glycolysis, but paralleled by reduced production of nitric oxide (NO). Under systemic LPS-induced inflammatory conditions NO production also was not detected in NMR blood monocytes. Altogether, our results indicate that NMR macrophages are capable of transcriptional and metabolic reprogramming under polarizing stimuli, however, NMR M1 possesses species-specific signatures as compared to murine M1, implicating distinct adaptations in NMR immune system.
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Affiliation(s)
- Ekaterina A. Gorshkova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Ekaterina O. Gubernatorova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | | | - Taisiya R. Yurakova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Maria V. Marey
- Federal State Budget Institution “National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov”, Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Olga A. Averina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Susanne Holtze
- Department of Reproduction Management, Leibnitz Institute for Wildlife Research, Berlin, Germany
| | - Thomas B. Hildebrandt
- Department of Reproduction Management, Leibnitz Institute for Wildlife Research, Berlin, Germany
| | - Alexey A. Dmitriev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Marina S. Drutskaya
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Mikhail Yu. Vyssokikh
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Federal State Budget Institution “National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov”, Ministry of Healthcare of the Russian Federation, Moscow, Russia
| | - Sergei A. Nedospasov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
- Division of Immunobiology and Biomedicine, Center of Genetics and Life Sciences, Sirius University of Science and Technology, Federal Territory Sirius, Krasnodar Krai, Russia
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3
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Moya EA. Carotid bodies in naked mole rats: Are the sensing mechanisms still there? Acta Physiol (Oxf) 2022; 236:e13880. [PMID: 36031795 DOI: 10.1111/apha.13880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 08/24/2022] [Indexed: 01/29/2023]
Affiliation(s)
- Esteban A Moya
- Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine, University of California San Diego, California, USA
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Peng Y, Nanduri J, Wang N, Khan SA, Pamenter M, Prabhakar NR. Carotid body responses to O 2 and CO 2 in hypoxia-tolerant naked mole rats. Acta Physiol (Oxf) 2022; 236:e13851. [PMID: 35757963 PMCID: PMC9787741 DOI: 10.1111/apha.13851] [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: 03/07/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 02/02/2023]
Abstract
AIM Naked mole rats (NMRs) exhibit blunted hypoxic (HVR) and hypercapnic ventilatory responses (HCVR). The mechanism(s) underlying these responses are largely unknown. We hypothesized that attenuated carotid body (CB) sensitivity to hypoxia and hypercapnia contributes to the near absence of ventilatory responses to hypoxia and CO2 in NMRs. METHODS We measured ex vivo CB sensory nerve activity, phrenic nerve activity (an estimation of ventilation), and blood gases in urethane-anesthetized NMRs and C57BL/6 mice breathing normoxic, hypoxic, or hypercapnic gases. CB morphology, carbon monoxide, and H2 S levels were also determined. RESULTS Relative to mice, NMRs had blunted CB and HVR. Morphologically, NMRs have larger CBs, which contained more glomus cells than in mice. Furthermore, NMR glomus cells form a dispersed pattern compared to a clustered pattern in mice. Hemeoxygenase (HO)-1 mRNA was elevated in NMR CBs, and an HO inhibitor increased CB sensitivity to hypoxia in NMRs. This increase was blocked by an H2 S synthesis inhibitor, suggesting that interrupted gas messenger signaling contributes to the blunted CB responses and HVR in NMRs. Regarding hypercapnia, CB and ventilatory responses to CO2 in NMRs were larger than in mice. Carbonic anhydrase (CA)-2 mRNA is elevated in NMR CBs, and a CA inhibitor blocked the augmented CB response to CO2 in NMRs, indicating CA activity regulates augmented CB response to CO2 . CONCLUSIONS Consistent with our hypothesis, impaired CB responses to hypoxia contribute in part to the blunted HVR in NMRs. Conversely, the HCVR and CB are more sensitive to CO2 in NMRs.
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Affiliation(s)
- Ying‐Jie Peng
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
| | - Jayasri Nanduri
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
| | - Ning Wang
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
| | - Shakil A. Khan
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
| | - Matthew E. Pamenter
- Department of BiologyUniversity of OttawaOttawaOntarioCanada,University of Ottawa Brain and Mind Research InstituteOttawaOntarioCanada
| | - Nanduri R. Prabhakar
- Institute for Integrative Physiology and Center for Systems Biology of O2 SensingUniversity of ChicagoChicagoIllinoisUSA
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Wong HS, Freeman DA, Zhang Y. Not just a cousin of the naked mole-rat: Damaraland mole-rats offer unique insights into biomedicine. Comp Biochem Physiol B Biochem Mol Biol 2022; 262:110772. [PMID: 35710053 PMCID: PMC10155858 DOI: 10.1016/j.cbpb.2022.110772] [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: 03/31/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 11/26/2022]
Abstract
Evolutionary medicine has been a fast-growing field of biological research in the past decade. One of the strengths of evolutionary medicine is to use non-traditional model organisms which often exhibit unusual characteristics shaped by natural selection. Studying these unusual traits could provide valuable insight to understand biomedical questions, since natural selection likely discovers solutions to those complex biological problems. Because of many unusual traits, the naked mole-rat (NMR) has attracted attention from different research areas such as aging, cancer, and hypoxia- and hypercapnia-related disorders. However, such uniqueness of NMR physiology may sometimes make the translational study to human research difficult. Damaraland mole-rat (DMR) shares multiple characteristics in common with NMR, but shows higher degree of similarity with human in some aspects of their physiology. Research on DMR could therefore offer alternative insights and might bridge the gap between experimental findings from NMR to human biomedical research. In this review, we discuss studies of DMR as an extension of the current set of model organisms to help better understand different aspects of human biology and disease. We hope to encourage researchers to consider studying DMR together with NMR. By studying these two similar but evolutionarily distinct species, we can harvest the power of convergent evolution and avoid the potential biased conclusions based on life-history of a single species.
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Affiliation(s)
- Hoi-Shan Wong
- Nine Square Therapeutics, South San Francisco, CA 94080, United States of America.
| | - David A Freeman
- Department of Biological Sciences, The University of Memphis, Memphis, TN 38152, United States of America
| | - Yufeng Zhang
- College of Health Sciences, The University of Memphis, Memphis, TN 38152, United States of America.
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6
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Pamenter ME, Cheng H. Supermole-rat to the rescue: Does the naked mole-rat offer a panacea for all that ails us? Comp Biochem Physiol A Mol Integr Physiol 2022; 266:111139. [PMID: 34990825 DOI: 10.1016/j.cbpa.2021.111139] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/21/2021] [Accepted: 12/28/2021] [Indexed: 11/16/2022]
Abstract
Over the previous several decades, many non-traditional research models have offered new avenues of exploration for biomedical research. The promise of these animals is primarily derived from adaptations to unique or challenging environments that share key factors with a disease or pathology of interest (e.g., hypoxemia or hypercarbia are clinically relevant and are also in vivo consequences of environmental hypoxia and hypercapnia, respectively). Animals adapted to such environments allow us to ask the question: how has nature solved a particular problem and what can we learn to inform novel translational research into the treatment of related diseases and pathologies? One of the most promising mammalian models that have garnered increasing attention from researchers and the public are naked mole-rats (NMRs). The NMR is a small and eusocial subterranean rodent species that live in a putatively hypoxic and hypercapnic burrow environment. Intriguingly, whereas most non-traditional biomedical models offer insight into one or only a few diseases related to a common physiological stress, NMRs in contrast have proven to be resistant to a very wide range of ailments, including aging, cancer, and hypoxia- and hypercapnia-related disorders, among many others. In the present commentary, we discuss progress made in understanding how NMRs overcome these challenges and speculate on the origins of their remarkable abilities.
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Affiliation(s)
- Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
| | - Hang Cheng
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
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Braude S, Holtze S, Begall S, Brenmoehl J, Burda H, Dammann P, Marmol D, Gorshkova E, Henning Y, Hoeflich A, Höhn A, Jung T, Hamo D, Sahm A, Shebzukhov Y, Šumbera R, Miwa S, Vyssokikh MY, Zglinicki T, Averina O, Hildebrandt TB. Surprisingly long survival of premature conclusions about naked mole‐rat biology. Biol Rev Camb Philos Soc 2020; 96:376-393. [DOI: 10.1111/brv.12660] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/06/2020] [Accepted: 10/13/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Stan Braude
- Biology Department Washington University, One Brookings Drive St. Louis MO 63130 U.S.A
| | - Susanne Holtze
- Department of Reproduction Management Leibniz‐Institute for Zoo and Wildlife Research Berlin 10315 Germany
| | - Sabine Begall
- Department of General Zoology, Faculty of Biology University of Duisburg‐Essen, Universitätsstr Essen 45147 Germany
| | - Julia Brenmoehl
- Institute for Genome Biology Leibniz‐Institute for Farm Animal Biology Dummerstorf 18196 Germany
| | - Hynek Burda
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences Czech University of Life Sciences Praha 16500 Czech Republic
| | - Philip Dammann
- Department of General Zoology, Faculty of Biology University of Duisburg‐Essen, Universitätsstr Essen 45147 Germany
- University Hospital Essen Hufelandstr Essen 45141 Germany
| | - Delphine Marmol
- Molecular Physiology Research Unit (URPhyM), NARILIS University of Namur Namur 5000 Belgium
| | - Ekaterina Gorshkova
- Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Vavilova str. 32 Moscow 119991 Russia
- Faculty of Biology Lomonosov Moscow State University Moscow 119991 Russia
| | - Yoshiyuki Henning
- University Hospital Essen Hufelandstr Essen 45141 Germany
- Institute of Physiology Department of General Zoology University of Duisburg Essen Germany
| | - Andreas Hoeflich
- Division Signal Transduction Institute for Genome Biology, Leibniz‐Institute for Farm Animal Biology, FBN Dummerstorf, Wilhelm‐Stahl‐Allee 2 Dummerstorf 18196 Germany
| | - Annika Höhn
- Department of Molecular Toxicology German Institute of Human Nutrition (DIfE) Potsdam‐Rehbrücke Nuthetal 14558 Germany
- German Center for Diabetes Research (DZD) München‐Neuherberg 85764 Germany
| | - Tobias Jung
- Department of Molecular Toxicology German Institute of Human Nutrition (DIfE) Potsdam‐Rehbrücke Nuthetal 14558 Germany
| | - Dania Hamo
- Charité ‐ Universitätsmedizin Berlin Berlin Institute of Health Center for Regenerative Therapies (BCRT) Berlin 13353 Germany
- German Rheumatism Research Centre Berlin (DRFZ) Berlin 10117 Germany
| | - Arne Sahm
- Computational Biology Group Leibniz Institute on Aging – Fritz Lipmann Institute Jena 07745 Germany
| | - Yury Shebzukhov
- Engelhardt Institute of Molecular Biology Russian Academy of Sciences, Vavilova str. 32 Moscow 119991 Russia
- Charité ‐ Universitätsmedizin Berlin Berlin Institute of Health Center for Regenerative Therapies (BCRT) Berlin 13353 Germany
| | - Radim Šumbera
- Faculty of Science University of South Bohemia České Budějovice 37005 Czech Republic
| | - Satomi Miwa
- Biosciences Institute, Edwardson building, Campus for Ageing and Vitality Newcastle University Newcastle upon Tyne NE4 5PL U.K
| | - Mikhail Y. Vyssokikh
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow 119991 Russia
| | - Thomas Zglinicki
- Biosciences Institute, Edwardson building, Campus for Ageing and Vitality Newcastle University Newcastle upon Tyne NE4 5PL U.K
| | - Olga Averina
- Belozersky Institute of Physico‐Chemical Biology Lomonosov Moscow State University Moscow 119991 Russia
| | - Thomas B. Hildebrandt
- Department of Reproduction Management Leibniz‐Institute for Zoo and Wildlife Research Berlin 10315 Germany
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8
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Effects of state anxiety on gait: a 7.5% carbon dioxide challenge study. PSYCHOLOGICAL RESEARCH 2020; 85:2444-2452. [PMID: 32737585 PMCID: PMC8357656 DOI: 10.1007/s00426-020-01393-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 07/14/2020] [Indexed: 11/20/2022]
Abstract
We used the 7.5% carbon dioxide (CO2) model of anxiety induction to investigate the effects of state anxiety on normal gait and gait when navigating an obstacle. Healthy volunteers (n = 22) completed a walking task during inhalations of 7.5% CO2 and medical air (placebo) in a within-subjects design. The order of inhalation was counterbalanced across participants and the gas was administered double-blind. Over a series of trials, participants walked the length of the laboratory, with each trial requiring participants to navigate through an aperture (width adjusted to participant size), with gait parameters measured via a motion capture system. The main findings were that walking speed was slower, but the adjustment in body orientation was greater, during 7.5% CO2 inhalation compared to air. These findings indicate changes in locomotor behaviour during heightened state anxiety that may reflect greater caution when moving in an agitated state. Advances in sensing technology offer the opportunity to monitor locomotor behaviour, and these findings suggest that in doing so, we may be able to infer emotional states from movement in naturalistic settings.
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Devereaux MEM, Pamenter ME. Fossorial giant Zambian mole-rats have blunted ventilatory responses to environmental hypoxia and hypercapnia. Comp Biochem Physiol A Mol Integr Physiol 2020; 243:110672. [PMID: 32032753 DOI: 10.1016/j.cbpa.2020.110672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/28/2020] [Accepted: 02/02/2020] [Indexed: 10/25/2022]
Abstract
Fossorial giant Zambian mole-rats are believed to live in a hypoxic and hypercapnic subterranean environment but their physiological responses to these challenges are entirely unknown. To investigate this, we exposed awake and freely-behaving animals to i) 6 h of normoxia, ii) acute graded normocapnic hypoxia (21, 18, 15, 12, 8, and 5% O2, 0% CO2, balance N2; 1 h each), or iii) acute graded normoxic hypercapnia (0, 2, 5, 7, 9, and 10% CO2, 21% O2, balance N2; 1 h each), followed by a 1 h normoxic normocapnic recovery period, while non-invasively measuring ventilation, metabolic rate, and body temperature (Tb). We found that these mole-rats had a blunted hypoxic ventilatory response that manifested at 12% inhaled O2, a robust hypoxic metabolic response (up to a 68% decrease, starting at 15% O2), and decreased Tb (at or below 8% O2). Upon reoxygenation, metabolic rate increased 52% above normoxic levels, suggesting the paying off of an O2 debt. Ventilation was less sensitive to environmental hypercapnia than to environmental hypoxia and animals also exhibited a blunted hypercapnic ventilatory response that did not manifest below 9% inhaled CO2. Conversely, metabolism and Tb were not affected by hypercapnia. Taken together, these results indicate that, like most other fossorial rodents, giant Zambian mole-rats have blunted hypoxic and hypercapnic ventilatory responses and employ metabolic suppression to tolerate acute hypoxia. Blunted physiological responses to hypoxia and hypercapnia likely reflect the subterranean lifestyle of this mammal, wherein intermittent but severe hypoxia and/or hypercapnia may be common challenges.
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Affiliation(s)
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
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10
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Zions M, Meehan EF, Kress ME, Thevalingam D, Jenkins EC, Kaila K, Puskarjov M, McCloskey DP. Nest Carbon Dioxide Masks GABA-Dependent Seizure Susceptibility in the Naked Mole-Rat. Curr Biol 2020; 30:2068-2077.e4. [PMID: 32359429 DOI: 10.1016/j.cub.2020.03.071] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 11/27/2019] [Accepted: 03/30/2020] [Indexed: 01/29/2023]
Abstract
African naked mole-rats were likely the first mammals to evolve eusociality, and thus required adaptations to conserve energy and tolerate the low oxygen (O2) and high carbon dioxide (CO2) of a densely populated fossorial nest. As hypercapnia is known to suppress neuronal activity, we studied whether naked mole-rats might demonstrate energy savings in GABAergic inhibition. Using whole-colony behavioral monitoring of captive naked mole-rats, we found a durable nest, characterized by high CO2 levels, where all colony members spent the majority of their time. Analysis of the naked mole-rat genome revealed, uniquely among mammals, a histidine point variation in the neuronal potassium-chloride cotransporter 2 (KCC2). A histidine missense substitution mutation at this locus in the human ortholog of KCC2, found previously in patients with febrile seizures and epilepsy, has been demonstrated to diminish neuronal Cl- extrusion capacity, and thus impairs GABAergic inhibition. Seizures were observed, without pharmacological intervention, in adult naked mole-rats exposed to a simulated hyperthermic surface environment, causing systemic hypocapnic alkalosis. Consistent with the diminished function of KCC2, adult naked mole-rats demonstrate a reduced efficacy of inhibition that manifests as triggering of seizures at room temperature by the GABAA receptor (GABAAR) positive allosteric modulator diazepam. These seizures are blocked in the presence of nest-like levels of CO2 and likely to be mediated through GABAAR activity, based on in vitro recordings. Thus, altered GABAergic inhibition adds to a growing list of adaptations in the naked mole-rat and provides a plausible proximate mechanism for nesting behavior, where a return to the colony nest restores GABA-mediated inhibition.
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Affiliation(s)
- Michael Zions
- PhD Program in Neuroscience, Graduate Center of The City University of New York, New York, NY 10016, USA; Center for Developmental Neuroscience, College of Staten Island in the City University of New York, Staten Island, NY 10314, USA
| | - Edward F Meehan
- Department of Psychology, College of Staten Island in the City University of New York, Staten Island, NY 10314, USA; Department of Computer Science, College of Staten Island in the City University of New York, Staten Island, NY 10314, USA
| | - Michael E Kress
- Department of Computer Science, College of Staten Island in the City University of New York, Staten Island, NY 10314, USA; PhD Program in Computer Science, Graduate Center of the City University of New York, New York, NY 10016, USA
| | - Donald Thevalingam
- PhD Program in Neuroscience, Graduate Center of The City University of New York, New York, NY 10016, USA; Center for Developmental Neuroscience, College of Staten Island in the City University of New York, Staten Island, NY 10314, USA
| | - Edmund C Jenkins
- Center for Developmental Neuroscience, College of Staten Island in the City University of New York, Staten Island, NY 10314, USA
| | - Kai Kaila
- Neuroscience Center (HiLIFE), University of Helsinki, Helsinki, Finland; Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Martin Puskarjov
- Center for Developmental Neuroscience, College of Staten Island in the City University of New York, Staten Island, NY 10314, USA; Molecular and Integrative Biosciences, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
| | - Dan P McCloskey
- PhD Program in Neuroscience, Graduate Center of The City University of New York, New York, NY 10016, USA; Center for Developmental Neuroscience, College of Staten Island in the City University of New York, Staten Island, NY 10314, USA; Department of Psychology, College of Staten Island in the City University of New York, Staten Island, NY 10314, USA.
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11
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Clayson MS, Devereaux MEM, Pamenter ME. Neurokinin-1 receptor activation is sufficient to restore the hypercapnic ventilatory response in the Substance P-deficient naked mole-rat. Am J Physiol Regul Integr Comp Physiol 2020; 318:R712-R721. [PMID: 31967860 DOI: 10.1152/ajpregu.00251.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Naked mole-rats (NMRs) live in large colonies within densely populated underground burrows. Their collective respiration generates significant metabolic carbon dioxide (CO2) that diffuses slowly out of the burrow network, creating a hypercapnic environment. Currently, the physiological mechanisms that underlie the ability of NMRs to tolerate environmental hypercapnia are largely unknown. To address this, we used whole-body plethysmography and respirometry to elucidate the hypercapnic ventilatory and metabolic responses of awake, freely behaving NMRs to 0%-10% CO2. We found that NMRs have a blunted hypercapnic ventilatory response (HCVR): ventilation increased only in 10% CO2. Conversely, metabolism was unaffected by hypercapnia. NMRs are insensitive to cutaneous acid-based pain caused by modified substance P (SP)-mediated peripheral neurotransmission, and SP is also an important neuromodulator of ventilation. Therefore, we re-evaluated physiological responses to hypercapnia in NMRs after an intraperitoneal injection of exogenous substance P (2 mg/kg) or a long-lived isoform of substance P {[pGlu5-MePhe8-MeGly9]SP(5-11), DiMe-C7; 40-400 μg/kg}. We found that both drugs restored hypercapnia sensitivity and unmasked an HCVR in animals breathing 2%-10% CO2. Taken together, our findings indicate that NMRs are remarkably tolerant of hypercapnic environments and have a blunted HCVR; however, the signaling network architecture required for a "normal" HCVR is retained but endogenously inactive. This muting of chemosensitivity likely suits the ecophysiology of this species, which presumably experiences hypercapnia regularly in their underground niche.
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Affiliation(s)
- Maxwell S Clayson
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada.,University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada
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12
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Zhang SY, Pamenter ME. Fossorial Damaraland mole rats do not exhibit a blunted hypercapnic ventilatory response. Biol Lett 2019; 15:20190006. [PMID: 30862308 DOI: 10.1098/rsbl.2019.0006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Damaraland mole rats (DMRs, Fukomys damarensis) are a eusocial fossorial species that spend the majority of their life in densely populated underground burrows, in which they likely experience intermittent periods of elevated CO2 (i.e. hypercapnia). The primary physiological response to hypercapnia in most mammals is to increase depth and rate of breathing (i.e. hyperpnoea), but this response is often blunted in species that inhabit hypercapnic environments. In their natural habitat, DMRs putatively experience a gaseous environment ranging from normocapnic (0.1% CO2) to hypercapnic (6.0% CO2) conditions (Roper et al. 2001 J. Zool. 254, 101-107). As such, we hypothesized that DMRs would exhibit blunted hypercapnic ventilatory and metabolic responses, relative to those of non-fossorial rodent species. To test this hypothesis, we exposed awake, freely behaving DMRs to normoxic normocapnia (21% O2, 0% CO2, balance N2) or graded normoxic hypercapnia (21% O2, 0, 2, 5, 7 and 10% CO2, balance N2), and measured ventilation and metabolism using whole-body plethysmography and indirect calorimetry, respectively. We found that ventilation and metabolism were unchanged during prolonged normocapnia, whereas during graded hypercapnia, ventilation was elevated at 2% CO2 and above. As a result, O2 extraction efficiency at the lungs decreased with increasing hyperpnoea. Conversely, metabolic rate did not increase until 10% CO2, presumably due to the metabolic cost of hyperpnoea. Taken together, our results suggest that despite their fossorial lifestyle, DMRs do not exhibit adaptations in their ventilatory or metabolic responses to environmental hypercapnia.
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Affiliation(s)
- Sarah Y Zhang
- 1 Department of Biology, University of Ottawa , Ottawa, Ontario K1N 6N5 , Canada
| | - Matthew E Pamenter
- 1 Department of Biology, University of Ottawa , Ottawa, Ontario K1N 6N5 , Canada.,2 University of Ottawa Brain and Mind Research Institute , Ottawa, Ontario , Canada
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Tolstun DA, Knyazer A, Tushynska TV, Dubiley TA, Bezrukov VV, Fraifeld VE, Muradian KK. Metabolic remodelling of mice by hypoxic-hypercapnic environment: imitating the naked mole-rat. Biogerontology 2019; 21:143-153. [DOI: 10.1007/s10522-019-09848-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 10/22/2019] [Indexed: 01/09/2023]
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Pamenter ME, Uysal-Onganer P, Huynh KW, Kraev I, Lange S. Post-Translational Deimination of Immunological and Metabolic Protein Markers in Plasma and Extracellular Vesicles of Naked Mole-Rat ( Heterocephalus glaber). Int J Mol Sci 2019; 20:E5378. [PMID: 31671738 PMCID: PMC6862702 DOI: 10.3390/ijms20215378] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/17/2019] [Accepted: 10/28/2019] [Indexed: 12/16/2022] Open
Abstract
Naked mole-rats are long-lived animals that show unusual resistance to hypoxia, cancer and ageing. Protein deimination is an irreversible post-translational modification caused by the peptidylarginine deiminase (PAD) family of enzymes, which convert arginine into citrulline in target proteins. Protein deimination can cause structural and functional protein changes, facilitating protein moonlighting, but also leading to neo-epitope generation and effects on gene regulation. Furthermore, PADs have been found to regulate cellular release of extracellular vesicles (EVs), which are lipid-vesicles released from cells as part of cellular communication. EVs carry protein and genetic cargo and are indicative biomarkers that can be isolated from most body fluids. This study was aimed at profiling deiminated proteins in plasma and EVs of naked mole-rat. Key immune and metabolic proteins were identified to be post-translationally deiminated, with 65 proteins specific for plasma, while 42 proteins were identified to be deiminated in EVs only. Using protein-protein interaction network analysis, deiminated plasma proteins were found to belong to KEEG (Kyoto Encyclopedia of Genes and Genomes) pathways of immunity, infection, cholesterol and drug metabolism, while deiminated proteins in EVs were also linked to KEEG pathways of HIF-1 signalling and glycolysis. The mole-rat EV profiles showed a poly-dispersed population of 50-300 nm, similar to observations of human plasma. Furthermore, the EVs were assessed for three key microRNAs involved in cancer, inflammation and hypoxia. The identification of post-translational deimination of critical immunological and metabolic markers contributes to the current understanding of protein moonlighting functions, via post-translational changes, in the longevity and cancer resistance of naked mole-rats.
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Affiliation(s)
- Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
- Brain and Mind Research Institute, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | - Pinar Uysal-Onganer
- Cancer Research Group, School of Life Sciences, College of Liberal Arts and Sciences, University of Westminster, London W1W 6 UW, UK.
| | - Kenny W Huynh
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
- Brain and Mind Research Institute, University of Ottawa, Ottawa, ON K1H 8M5, Canada.
| | - Igor Kraev
- Electron Microscopy Suite, Faculty of Science, Technology, Engineering and Mathematics, Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
| | - Sigrun Lange
- Tissue Architecture and Regeneration Research Group, School of Life Sciences, College of Liberal Arts and Sciences, University of Westminster, London W1W 6 UW, UK.
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