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Robichaud K, Duffy B, Staples JF, Craig PM. Mitochondrial microRNA profiles are altered in thirteen-lined ground squirrels ( Ictidomys tridecemlineatus) during hibernation. Physiol Genomics 2024; 56:555-566. [PMID: 38881427 DOI: 10.1152/physiolgenomics.00017.2024] [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: 02/07/2024] [Revised: 05/02/2024] [Accepted: 06/10/2024] [Indexed: 06/18/2024] Open
Abstract
Thirteen-lined ground squirrels (TLGSs) are obligate hibernators that cycle between torpor (low metabolic rate and body temperature) and interbout euthermia (IBE; typical euthermic body temperature and metabolism) from late autumn to spring. Many physiological changes occur throughout hibernation, including a reduction in liver mitochondrial metabolism during torpor, which is reversed during arousal to interbout euthermia. Nuclear-encoded microRNA (miRNA, small posttranscriptional regulator molecules) differ in abundance throughout TLGS hibernation and have been shown to regulate mitochondrial gene expression in mammalian cell culture (where they are referred to as mitomiRs). This study characterized differences in mitomiR profiles from TLGS liver mitochondria isolated during summer, torpor, and IBE, and predicted their mitochondrial targets. Using small RNA sequencing, differentially abundant mitomiRs were identified between hibernation states, and using quantitative PCR analysis, we quantified the expression of predicted mitochondrial mRNA targets. Most differences in mitomiR abundances were seasonal (i.e., between summer and winter) with only one mitomiR differentially abundant between IBE and torpor. Multiple factor analysis (MFA) revealed three clusters divided by hibernation states, where clustering was predominantly driven by mitomiR abundances. Nine of these differentially abundant mitomiRs had predicted mitochondrial RNA targets, including subunits of electron transfer system complexes I and IV, 12S rRNA, and two tRNAs. Overall, mitomiRs were predicted to suppress the expression of their mitochondrial targets and may have some involvement in regulating protein translation in mitochondria. This study found differences in mitomiR abundances between seasons and hibernation states of TLGS and suggests potential mechanisms for regulating the mitochondrial electron transfer system.NEW & NOTEWORTHY During the hibernation season, thirteen-lined ground squirrels periodically increase metabolism remarkably between torpor and interbout euthermia (IBE). This process involves rapid reactivation of mitochondrial respiration. We predicted that mitochondrial microRNA (mitomiRs) might be altered during this response. We found that the abundance of 38 liver mitomiRs differs based on hibernation state (summer, IBE, and torpor). Small RNA sequencing identified mitomiR profiles, including some mitomiRs that are predicted to bind to mitochondrial RNAs.
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Affiliation(s)
- Karyn Robichaud
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
| | - Brynne Duffy
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - James F Staples
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Paul M Craig
- Department of Biology, University of Waterloo, Waterloo, Ontario, Canada
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2
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Sone M, Yamashita J, Shigenobu S, Yamaguchi Y. Slow decrease in temperature produces readthrough transcripts in mammalian hibernation. Biochem Biophys Res Commun 2024; 709:149837. [PMID: 38555839 DOI: 10.1016/j.bbrc.2024.149837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 03/15/2024] [Accepted: 03/26/2024] [Indexed: 04/02/2024]
Abstract
Accumulating evidence suggests that various cellular stresses interfere with the end processing of mRNA synthesis and lead to the production of abnormally long transcripts, known as readthrough transcripts (RTTs), which extend beyond the termination sites. Small mammalian hibernators repeatedly enter a state referred to as deep torpor (DT), where the metabolic rate, respiration rate, and core body temperature become extremely low, which produces various types of cellular stresses and therefore induces RTTs. However, the types of stresses and processes around the DT that cause RTTs are unclear. In the present study, we showed that RTTs are produced from different gene loci in the livers of Syrian hamsters under DT and summer-like conditions. Moreover, in vitro analysis using hamster primary hepatocytes revealed that DT-specific RTTs are induced by a slow decline in temperature, as seen in body temperature in the entrance phase of DT, but not by rapid cold treatment or hypoxia. In addition, it was observed that RTTs were not elongated under a significantly cold temperature (4 °C). These results indicate that DT-specific RTTs are produced during the entrance phase of torpor by a slow decrease in body temperature.
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Affiliation(s)
- Masamitsu Sone
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan; Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan.
| | - Junpei Yamashita
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
| | - Shuji Shigenobu
- National Institute for Basic Biology, National Institutes of Natural Sciences, Okazaki, Japan
| | - Yoshifumi Yamaguchi
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan; Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan; Inamori Research Institute for Science, Kyoto, Japan.
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3
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Hutchinson AJ, Duffy BM, Rego LH, Staples JF. Paper towel shredding as a novel, affordable, noninvasive method for detecting arousals in hibernating rodents. Lab Anim (NY) 2024; 53:117-120. [PMID: 38637688 DOI: 10.1038/s41684-024-01362-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 03/18/2024] [Indexed: 04/20/2024]
Abstract
Many research groups explore the regulation of hibernation or compare the physiology of heterothermic mammals between the torpid and aroused, euthermic states. Current methods for monitoring torpor (for example, infrared cameras, body temperature or heart-rate telemetry, and motion sensing) are costly, require specialized techniques, and can be invasive. Here we present an alternate method for determining torpor-bout duration that is cost-effective, noninvasive and accurate: paper towel shredding. In the winter, euthermic thirteen-lined ground squirrels will shred paper towels placed in the cage, but torpid animals will not. The presence of a shredded paper towel, indicating an arousal from torpor, is easily evaluated during routine daily monitoring. In 12 animals over 52 days, this simple technique detected 59 arousals with 100% accuracy when compared with the body temperature telemetry of the same animals. Moreover, this novel method avoids some of the drawbacks of other cheap monitoring systems such as the sawdust technique.
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Affiliation(s)
- Amalie J Hutchinson
- Department of Biology, The University of Western Ontario, London, Ontario, Canada.
| | - Brynne M Duffy
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
| | - Lauren H Rego
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
| | - James F Staples
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
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4
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Rhodes EM, Yap KN, Mesquita PHC, Parry HA, Kavazis AN, Krause JS, Hill GE, Hood WR. Flexibility underlies differences in mitochondrial respiratory performance between migratory and non-migratory White-crowned Sparrows (Zonotrichia leucophrys). Sci Rep 2024; 14:9456. [PMID: 38658588 PMCID: PMC11043447 DOI: 10.1038/s41598-024-59715-y] [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: 11/08/2023] [Accepted: 04/15/2024] [Indexed: 04/26/2024] Open
Abstract
Migration is one of the most energy-demanding behaviors observed in birds. Mitochondria are the primary source of energy used to support these long-distance movements, yet how mitochondria meet the energetic demands of migration is scarcely studied. We quantified changes in mitochondrial respiratory performance in the White-crowned Sparrow (Zonotrichia leucophrys), which has a migratory and non-migratory subspecies. We hypothesized that the long-distance migratory Gambel's subspecies (Z. l. gambelii) would show higher mitochondrial respiratory performance compared to the non-migratory Nuttall's subspecies (Z. l. nuttalli). We sampled Gambel's individuals during spring pre-migration, active fall migration, and a period with no migration or breeding (winter). We sampled Nuttall's individuals during periods coinciding with fall migration and the winter period of Gambel's annual cycle. Overall, Gambel's individuals had higher citrate synthase, a proxy for mitochondrial volume, than Nuttall's individuals. This was most pronounced prior to and during migration. We found that both OXPHOS capacity (state 3) and basal respiration (state 4) of mitochondria exhibit high seasonal flexibility within Gambel's individuals, with values highest during active migration. These values in Nuttall's individuals were most similar to Gambel's individuals in winter. Our observations indicate that seasonal changes in mitochondrial respiration play a vital role in migration energetics.
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Affiliation(s)
- Emma M Rhodes
- Department of Biological Sciences, Auburn University, Auburn, USA.
| | - Kang Nian Yap
- Department of Biological Sciences, Auburn University, Auburn, USA
- Department of Biology, Norwegian University of Science and Technology, Trondheim, Norway
| | - Paulo H C Mesquita
- School of Kinesiology, Auburn University, Auburn, USA
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Hailey A Parry
- School of Kinesiology, Auburn University, Auburn, USA
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, USA
| | | | | | - Geoffrey E Hill
- Department of Biological Sciences, Auburn University, Auburn, USA
| | - Wendy R Hood
- Department of Biological Sciences, Auburn University, Auburn, USA
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5
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Dang K, Gao Y, Wang H, Yang H, Kong Y, Jiang S, Qian A. Integrated metabolomics and proteomics analysis to understand muscle atrophy resistance in hibernating Spermophilus dauricus. Cryobiology 2024; 114:104838. [PMID: 38097057 DOI: 10.1016/j.cryobiol.2023.104838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 12/04/2023] [Accepted: 12/05/2023] [Indexed: 12/18/2023]
Abstract
Hibernating Spermophilus dauricus experiences minor muscle atrophy, which is an attractive anti-disuse muscle atrophy model. Integrated metabolomics and proteomics analysis was performed on the hibernating S. dauricus during the pre-hibernation (PRE) stage, torpor (TOR) stage, interbout arousal (IBA) stage, and post-hibernation (POST) stage. Time course stage transition-based (TOR vs. PRE, IBA vs. TOR, POST vs. IBA) differential expression analysis was performed based on the R limma package. A total of 14 co-differential metabolites were detected. Among these, l-cystathionine, l-proline, ketoleucine, serine, and 1-Hydroxy-3,6,7-Trimethoxy-2, 8-Diprenylxanthone demonstrated the highest levels in the TOR stage; Beta-Nicotinamide adenine dinucleotide, Dihydrozeatin, Pannaric acid, and Propionylcarnitine demonstrated the highest levels in the IBA stage; Adrenosterone, PS (18:0/14,15-EpETE), S-Carboxymethylcysteine, TxB2, and 3-Phenoxybenzylalcohol demonstrated the highest levels in the POST stage. Kyoto Encyclopedia of Genes and Genomes pathways annotation analysis indicated that biosynthesis of amino acids, ATP-binding cassette transporters, and cysteine and methionine metabolism were co-differential metabolism pathways during the different stages of hibernation. The stage-specific metabolism processes and integrated enzyme-centered metabolism networks in the different stages were also deciphered. Overall, our findings suggest that (1) the periodic change of proline, ketoleucine, and serine contributes to the hindlimb lean tissue preservation; and (2) key metabolites related to the biosynthesis of amino acids, ATP-binding cassette transporters, and cysteine and methionine metabolism may be associated with muscle atrophy resistance. In conclusion, our co-differential metabolites, co-differential metabolism pathways, stage-specific metabolism pathways, and integrated enzyme-centered metabolism networks are informative for biologists to generate hypotheses for functional analyses to perturb disuse-induced muscle atrophy.
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Affiliation(s)
- Kai Dang
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Yuan Gao
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Huiping Wang
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, 710069, China; China Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, Xi'an, 710069, China
| | - Huajian Yang
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, 710069, China; China Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, Xi'an, 710069, China
| | - Yong Kong
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, 710069, China; China Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, Xi'an, 710069, China
| | - Shanfeng Jiang
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Airong Qian
- Lab for Bone Metabolism, Key Lab for Space Biosciences and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China; Research Center for Special Medicine and Health Systems Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China; NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China.
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Jankovic A, Kalezic A, Korac A, Buzadzic B, Storey KB, Korac B. Integrated Redox-Metabolic Orchestration Sustains Life in Hibernating Ground Squirrels. Antioxid Redox Signal 2024; 40:345-368. [PMID: 36802926 DOI: 10.1089/ars.2021.0277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
Significance: The ultimate manifestations of life, birth, survival under various environmental pressures and death are based on bioenergetics. Hibernation is a unique survival strategy for many small mammals that is characterised by severe metabolic depression and transition from euthermia to hypothermia (torpor) at body temperatures close to 0°C. These manifestations of life were made possible by the remarkable "social" behavior of biomolecules during billions of years of evolution: the evolution of life with oxygen. Oxygen was necessary for energy production and the evolutionary explosion of aerobic organisms. Recent Advances: Nevertheless, reactive oxygen species, formed through oxidative metabolism, are dangerous-they can kill a cell and, on the other hand, play a plethora of fundamentally valuable roles. Therefore, the evolution of life depended on energy metabolism and redox-metabolic adaptations. The more extreme the conditions for survival are, the more sophisticated the adaptive responses of organisms become. Hibernation is a beautiful illustration of this principle. Hibernating animals use evolutionarily conserved molecular mechanisms to survive adverse environmental conditions, including reducing body temperature to ambient levels (often to ∼0°C) and severe metabolic depression. This long-built secret of life lies at the intersection of oxygen, metabolism, and bioenergetics, and hibernating organisms have learned to exploit all the underlying capacities of molecular pathways to survive. Critical Issues: Despite such drastic changes in phenotype, tissues and organs of hibernators sustain no metabolic or histological damage during hibernation or upon awakening from hibernation. This was made possible by the fascinating integration of redox-metabolic regulatory networks whose molecular mechanisms remain undisclosed to this day. Future Directions: Discovering these molecular mechanisms is not warranted only to understand hibernation in itself but to help explain complex medical conditions (hypoxia/reoxygenation, organ transplantation, diabetes, and cancer) and to even help overcome limitations associated with space travel. This is a review of integrated redox-metabolic orchestration in hibernation. Antioxid. Redox Signal. 40, 345-368.
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Affiliation(s)
- Aleksandra Jankovic
- Department of Physiology, Institute for Biological Research "Sinisa Stankovic," National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Andjelika Kalezic
- Department of Physiology, Institute for Biological Research "Sinisa Stankovic," National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | | | - Biljana Buzadzic
- Department of Physiology, Institute for Biological Research "Sinisa Stankovic," National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | | | - Bato Korac
- Department of Physiology, Institute for Biological Research "Sinisa Stankovic," National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
- Faculty of Biology, University of Belgrade, Belgrade, Serbia
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Hutchinson AJ, Duffy BM, Staples JF. Electron transport system supercomplexes affect reactive-oxygen species production and respiration in both a hibernator (Ictidomys tridecemlineatus) and a nonhibernator (Rattus norvegicus). J Comp Physiol B 2024; 194:81-93. [PMID: 37979043 DOI: 10.1007/s00360-023-01525-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 10/23/2023] [Indexed: 11/19/2023]
Abstract
Across many taxa, the complexes of the electron transport system associate with each other within the inner mitochondrial membrane to form supercomplexes (SCs). These SCs are thought to confer some selective advantage, such as increasing cellular respiratory capacity or decreasing the production of damaging reactive oxygen species (ROS). In this study, we investigate the relationship between supercomplex abundance and performance of liver mitochondria isolated from rats that do not hibernate and hibernating ground squirrels in which metabolism fluctuates substantially. We quantified the abundance of SCs (respirasomes (SCs containing CI, CIII, and CIV) or SCs containing CIII and CIV) and examined the relationship with state 3 (OXPHOS) and state 4 (LEAK) respiration rate, as well as net ROS production. We found that, in rats, state 3 and 4 respiration rate correlated negatively with respirasome abundance, but positively with CIII/CIV SC abundance. Despite the greater range of respiration rates in different hibernation stages, these relationships were similar in ground squirrels. This is, to our knowledge, the first report of differential effects of supercomplex types on mitochondrial respiration and ROS production.
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Affiliation(s)
- Amalie J Hutchinson
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada.
| | - Brynne M Duffy
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - James F Staples
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada
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8
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de Veij Mestdagh CF, Smit AB, Henning RH, van Kesteren RE. Mitochondrial Targeting against Alzheimer's Disease: Lessons from Hibernation. Cells 2023; 13:12. [PMID: 38201215 PMCID: PMC10778235 DOI: 10.3390/cells13010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/14/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia worldwide and yet remains without effective therapy. Amongst the many proposed causes of AD, the mitochondrial cascade hypothesis is gaining attention. Accumulating evidence shows that mitochondrial dysfunction is a driving force behind synaptic dysfunction and cognitive decline in AD patients. However, therapies targeting the mitochondria in AD have proven unsuccessful so far, and out-of-the-box options, such as hibernation-derived mitochondrial mechanisms, may provide valuable new insights. Hibernators uniquely and rapidly alternate between suppression and re-activation of the mitochondria while maintaining a sufficient energy supply and without acquiring ROS damage. Here, we briefly give an overview of mitochondrial dysfunction in AD, how it affects synaptic function, and why mitochondrial targeting in AD has remained unsuccessful so far. We then discuss mitochondria in hibernation and daily torpor in mice, covering current advancements in hibernation-derived mitochondrial targeting strategies. We conclude with new ideas on how hibernation-derived dual mitochondrial targeting of both the ATP and ROS pathways may boost mitochondrial health and induce local synaptic protein translation to increase synaptic function and plasticity. Further exploration of these mechanisms may provide more effective treatment options for AD in the future.
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Affiliation(s)
- Christina F. de Veij Mestdagh
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands; (A.B.S.); (R.E.v.K.)
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands;
- Alzheimer Center Amsterdam, Amsterdam UMC Location VUmc, 1081 HV Amsterdam, The Netherlands
| | - August B. Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands; (A.B.S.); (R.E.v.K.)
| | - Robert H. Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands;
| | - Ronald E. van Kesteren
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands; (A.B.S.); (R.E.v.K.)
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Roberts KT, Szejner-Sigal A, Lehmann P. Seasonal energetics: are insects constrained by energy during dormancy? J Exp Biol 2023; 226:jeb245782. [PMID: 37921417 DOI: 10.1242/jeb.245782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
In seasonal environments, many animals, including insects, enter dormancy, where they are limited to a fixed energy budget. The inability to replenish energetic stores during these periods suggests insects should be constrained by pre-dormancy energy stores. Over the last century, the community of researchers working on survival during dormancy has operated under the strong assumption that energy limitation is a key fitness trait driving the evolution of seasonal strategies. That is, energy use has to be minimized during dormancy because insects otherwise run out of energy and die during dormancy, or are left with too little energy to complete development, reproductive maturation or other costly post-dormancy processes such as dispersal or nest building. But if energy is so strongly constrained during dormancy, how can some insects - even within the same species and population - be dormant in very warm environments or show prolonged dormancy for many successive years? In this Commentary, we discuss major assumptions regarding dormancy energetics and outline cases where insects appear to align with our assumptions and where they do not. We then highlight several research directions that could help link organismal energy use with landscape-level changes. Overall, the optimal energetic strategy during dormancy might not be to simply minimize metabolic rate, but instead to maintain a level that matches the demands of the specific life-history strategy. Given the influence of temperature on energy use rates of insects in winter, understanding dormancy energetic strategies is critical in order to determine the potential impacts of climate change on insects in seasonal environments.
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Affiliation(s)
- Kevin T Roberts
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Andre Szejner-Sigal
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Philipp Lehmann
- Department of Zoology, Stockholm University, SE-106 91 Stockholm, Sweden
- Department of Animal Physiology, Zoological Institute and Museum, University of Greifswald, 17489 Greifswald, Germany
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Wang H, Guo Y, Yan W, Cao L, Bai X, Zhao J, Dang K, Gao Y. Weakened Contractile Performance and Mitochondrial Respiratory Complex Activity in Skeletal Muscle Improve during Interbout Arousal in Hibernating Daurian Ground Squirrel, Spermophilus dauricus. Int J Mol Sci 2023; 24:15785. [PMID: 37958769 PMCID: PMC10650195 DOI: 10.3390/ijms242115785] [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: 09/21/2023] [Revised: 10/28/2023] [Accepted: 10/29/2023] [Indexed: 11/15/2023] Open
Abstract
Mammalian hibernation is composed of multiple episodes of torpor bout, separated by phases of interbout arousal. During torpor, the skeletal muscles of mammals are undoubtedly inactive, but it has been proven to mitigate disuse atrophy. While interbout arousal has been implicated in the prevention of muscle atrophy, the underlying mechanisms sustaining muscle contraction remain to be explored. In the present study, Daurian ground squirrels (Spermophilus dauricus) were divided into four groups: pre-hibernation (PRE), torpor (TOR), interbout arousal (IBA), and post-hibernation (POST). The contractile performance of slow-twitch soleus muscle (SOL) and fast-twitch extensor digitorum longus muscle (EDL) was detected both in situ and in vitro. Concurrently, mitochondrial respiratory chain complex activity in these muscles was quantified. Our findings revealed that in situ contractile properties of both muscles, including force, power output, time duration, and force development/relaxation rates of twitch contraction, and force and power output of tetanic contraction declined in the TOR group compared to the PRE group, but improved in the IBA and POST groups. Fatigue resistance of muscles, determined by the power output of repetitive tetanic contractions in situ, decreased in the TOR group but recovered in the IBA and POST groups. In vitro studies demonstrated that tetanic contraction power output in isolated muscles increased with muscle temperature in both TOR and IBA groups. However, at the same temperature, power output was consistently lower in the TOR group compared to the IBA group. Moreover, the activity of the mitochondrial respiratory chain complex, especially Complexes I and II, decreased in the TOR group but showed recovery in the IBA and POST groups. These findings suggest that both the contractile performance and fatigue resistance of mammalian skeletal muscle are compromised during torpor but can be improved during interbout arousal and post-hibernation. The rebound in body temperature and rise in mitochondrial respiratory chain complex activity in skeletal muscle are involved in enhancing contractile performance and fatigue resistance. This study suggests that interbout arousal functions as a vital temporal interval during which skeletal muscles can transition from the inactivity induced by torpor to a state of restored contractile functionality. Thus, interbout arousal serves as a behavioral safeguard against disuse-induced damage to skeletal muscles during hibernation.
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Affiliation(s)
- Huiping Wang
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi’an 710069, China; (H.W.); (Y.G.); (W.Y.); (L.C.); (X.B.); (J.Z.)
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Xi’an 710069, China
| | - Yuxi Guo
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi’an 710069, China; (H.W.); (Y.G.); (W.Y.); (L.C.); (X.B.); (J.Z.)
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Xi’an 710069, China
| | - Wenjing Yan
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi’an 710069, China; (H.W.); (Y.G.); (W.Y.); (L.C.); (X.B.); (J.Z.)
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Xi’an 710069, China
| | - Liqi Cao
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi’an 710069, China; (H.W.); (Y.G.); (W.Y.); (L.C.); (X.B.); (J.Z.)
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Xi’an 710069, China
| | - Xiaozhuo Bai
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi’an 710069, China; (H.W.); (Y.G.); (W.Y.); (L.C.); (X.B.); (J.Z.)
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Xi’an 710069, China
| | - Jing Zhao
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi’an 710069, China; (H.W.); (Y.G.); (W.Y.); (L.C.); (X.B.); (J.Z.)
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Xi’an 710069, China
| | - Kai Dang
- Lab for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China
| | - Yunfang Gao
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi’an 710069, China; (H.W.); (Y.G.); (W.Y.); (L.C.); (X.B.); (J.Z.)
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Xi’an 710069, China
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11
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Shang Y, Li Z, Cai P, Li W, Xu Y, Zhao Y, Xia S, Shao Q, Wang H. Megamitochondria plasticity: function transition from adaption to disease. Mitochondrion 2023:S1567-7249(23)00053-3. [PMID: 37276954 DOI: 10.1016/j.mito.2023.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/08/2023] [Accepted: 06/02/2023] [Indexed: 06/07/2023]
Abstract
As the cell's energy factory and metabolic hub, mitochondria are critical for ATP synthesis to maintain cellular function. Mitochondria are highly dynamic organelles that continuously undergo fusion and fission to alter their size, shape, and position, with mitochondrial fusion and fission being interdependent to maintain the balance of mitochondrial morphological changes. However, in response to metabolic and functional damage, mitochondria can grow in size, resulting in a form of abnormal mitochondrial morphology known as megamitochondria. Megamitochondria are characterized by their considerably larger size, pale matrix, and marginal cristae structure and have been observed in various human diseases. In energy-intensive cells like hepatocytes or cardiomyocytes, the pathological process can lead to the growth of megamitochondria, which can further cause metabolic disorders, cell damage and aggravates the progression of the disease. Nonetheless, megamitochondria can also form in response to short-term environmental stimulation as a compensatory mechanism to support cell survival. However, extended stimulation can reverse the benefits of megamitochondria leading to adverse effects. In this review, we will focus on the findings of the different roles of megamitochondria, and their link to disease development to identify promising clinical therapeutic targets.
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Affiliation(s)
- Yuxing Shang
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Zhanghui Li
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Peiyang Cai
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Wuhao Li
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Ye Xu
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Yangjing Zhao
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Sheng Xia
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China
| | - Qixiang Shao
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China; Institute of Medical Genetics and Reproductive Immunity, School of Medical Science and Laboratory Medicine, Jiangsu College of Nursing, Huai'an 223002, Jiangsu, PR China.
| | - Hui Wang
- Reproductive Sciences Institute, Jiangsu Key Laboratory of Medical Science and Laboratory Medicine, Department of Immunology, School of Medicine, Jiangsu University, Zhenjiang 212013, Jiangsu, PR China.
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12
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Coussement L, Oosterhof MM, Guryev V, Reitsema VA, Bruintjes JJ, Goris M, Bouma HR, de Meyer T, Rots MG, Henning RH. Liver transcriptomic and methylomic analyses identify transcriptional mitogen-activated protein kinase regulation in facultative hibernation of Syrian hamster. Proc Biol Sci 2023; 290:20230368. [PMID: 37221849 PMCID: PMC10206468 DOI: 10.1098/rspb.2023.0368] [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: 02/14/2023] [Accepted: 05/02/2023] [Indexed: 05/25/2023] Open
Abstract
Hibernation consists of alternating torpor-arousal phases, during which animals cope with repetitive hypothermia and ischaemia-reperfusion. Due to limited transcriptomic and methylomic information for facultative hibernators, we here conducted RNA and whole-genome bisulfide sequencing in liver of hibernating Syrian hamster (Mesocricetus auratus). Gene ontology analysis was performed on 844 differentially expressed genes and confirmed the shift in metabolic fuel utilization, inhibition of RNA transcription and cell cycle regulation as found in seasonal hibernators. Additionally, we showed a so far unreported suppression of mitogen-activated protein kinase (MAPK) and protein phosphatase 1 pathways during torpor. Notably, hibernating hamsters showed upregulation of MAPK inhibitors (dual-specificity phosphatases and sproutys) and reduced levels of MAPK-induced transcription factors (TFs). Promoter methylation was found to modulate the expression of genes targeted by these TFs. In conclusion, we document gene regulation between hibernation phases, which may aid the identification of pathways and targets to prevent organ damage in transplantation or ischaemia-reperfusion.
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Affiliation(s)
- Louis Coussement
- Department of Data Analysis and Mathematical Modelling, Faculty of Bioscience Engineering, Ghent University, B-9000 Ghent, Belgium
| | - Marloes M. Oosterhof
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Victor Guryev
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Vera A. Reitsema
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Jojanneke J. Bruintjes
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Maaike Goris
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Hjalmar R. Bouma
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
- Department of Internal Medicine, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Tim de Meyer
- Department of Data Analysis and Mathematical Modelling, Faculty of Bioscience Engineering, Ghent University, B-9000 Ghent, Belgium
| | - Marianne G. Rots
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
| | - Robert H. Henning
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, 9713 GZ Groningen, The Netherlands
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13
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Christmas MJ, Kaplow IM, Genereux DP, Dong MX, Hughes GM, Li X, Sullivan PF, Hindle AG, Andrews G, Armstrong JC, Bianchi M, Breit AM, Diekhans M, Fanter C, Foley NM, Goodman DB, Goodman L, Keough KC, Kirilenko B, Kowalczyk A, Lawless C, Lind AL, Meadows JRS, Moreira LR, Redlich RW, Ryan L, Swofford R, Valenzuela A, Wagner F, Wallerman O, Brown AR, Damas J, Fan K, Gatesy J, Grimshaw J, Johnson J, Kozyrev SV, Lawler AJ, Marinescu VD, Morrill KM, Osmanski A, Paulat NS, Phan BN, Reilly SK, Schäffer DE, Steiner C, Supple MA, Wilder AP, Wirthlin ME, Xue JR, Birren BW, Gazal S, Hubley RM, Koepfli KP, Marques-Bonet T, Meyer WK, Nweeia M, Sabeti PC, Shapiro B, Smit AFA, Springer MS, Teeling EC, Weng Z, Hiller M, Levesque DL, Lewin HA, Murphy WJ, Navarro A, Paten B, Pollard KS, Ray DA, Ruf I, Ryder OA, Pfenning AR, Lindblad-Toh K, Karlsson EK. Evolutionary constraint and innovation across hundreds of placental mammals. Science 2023; 380:eabn3943. [PMID: 37104599 PMCID: PMC10250106 DOI: 10.1126/science.abn3943] [Citation(s) in RCA: 57] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 12/16/2022] [Indexed: 04/29/2023]
Abstract
Zoonomia is the largest comparative genomics resource for mammals produced to date. By aligning genomes for 240 species, we identify bases that, when mutated, are likely to affect fitness and alter disease risk. At least 332 million bases (~10.7%) in the human genome are unusually conserved across species (evolutionarily constrained) relative to neutrally evolving repeats, and 4552 ultraconserved elements are nearly perfectly conserved. Of 101 million significantly constrained single bases, 80% are outside protein-coding exons and half have no functional annotations in the Encyclopedia of DNA Elements (ENCODE) resource. Changes in genes and regulatory elements are associated with exceptional mammalian traits, such as hibernation, that could inform therapeutic development. Earth's vast and imperiled biodiversity offers distinctive power for identifying genetic variants that affect genome function and organismal phenotypes.
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Affiliation(s)
- Matthew J. Christmas
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, 751 32 Uppsala, Sweden
| | - Irene M. Kaplow
- Department of Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | | | - Michael X. Dong
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, 751 32 Uppsala, Sweden
| | - Graham M. Hughes
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Xue Li
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
- Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA 01605, USA
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Patrick F. Sullivan
- Department of Genetics, University of North Carolina Medical School, Chapel Hill, NC 27599, USA
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Allyson G. Hindle
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Gregory Andrews
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Joel C. Armstrong
- Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Matteo Bianchi
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, 751 32 Uppsala, Sweden
| | - Ana M. Breit
- School of Biology and Ecology, University of Maine, Orono, ME 04469, USA
| | - Mark Diekhans
- Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Cornelia Fanter
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - Nicole M. Foley
- Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843, USA
| | - Daniel B. Goodman
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA
| | | | - Kathleen C. Keough
- Fauna Bio, Inc., Emeryville, CA 94608, USA
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA 94158, USA
- Gladstone Institutes, San Francisco, CA 94158, USA
| | - Bogdan Kirilenko
- Faculty of Biosciences, Goethe-University, 60438 Frankfurt, Germany
- LOEWE Centre for Translational Biodiversity Genomics, 60325 Frankfurt, Germany
- Senckenberg Research Institute, 60325 Frankfurt, Germany
| | - Amanda Kowalczyk
- Department of Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Colleen Lawless
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Abigail L. Lind
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA 94158, USA
- Gladstone Institutes, San Francisco, CA 94158, USA
| | - Jennifer R. S. Meadows
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, 751 32 Uppsala, Sweden
| | - Lucas R. Moreira
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Ruby W. Redlich
- Department of Biological Sciences, Mellon College of Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Louise Ryan
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Ross Swofford
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
| | - Alejandro Valenzuela
- Department of Experimental and Health Sciences, Institute of Evolutionary Biology (UPF-CSIC), Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | - Franziska Wagner
- Museum of Zoology, Senckenberg Natural History Collections Dresden, 01109 Dresden, Germany
| | - Ola Wallerman
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, 751 32 Uppsala, Sweden
| | - Ashley R. Brown
- Department of Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Joana Damas
- The Genome Center, University of California Davis, Davis, CA 95616, USA
| | - Kaili Fan
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - John Gatesy
- Division of Vertebrate Zoology, American Museum of Natural History, New York, NY 10024, USA
| | - Jenna Grimshaw
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Jeremy Johnson
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
| | - Sergey V. Kozyrev
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, 751 32 Uppsala, Sweden
| | - Alyssa J. Lawler
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
- Department of Biological Sciences, Mellon College of Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Voichita D. Marinescu
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, 751 32 Uppsala, Sweden
| | - Kathleen M. Morrill
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
- Morningside Graduate School of Biomedical Sciences, UMass Chan Medical School, Worcester, MA 01605, USA
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Austin Osmanski
- Medical Scientist Training Program, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Nicole S. Paulat
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - BaDoi N. Phan
- Department of Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Medical Scientist Training Program, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Steven K. Reilly
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Daniel E. Schäffer
- Department of Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Cynthia Steiner
- Conservation Genetics, San Diego Zoo Wildlife Alliance, Escondido, CA 92027, USA
| | - Megan A. Supple
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Aryn P. Wilder
- Conservation Genetics, San Diego Zoo Wildlife Alliance, Escondido, CA 92027, USA
| | - Morgan E. Wirthlin
- Department of Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - James R. Xue
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | | | - Bruce W. Birren
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
| | - Steven Gazal
- Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | | | - Klaus-Peter Koepfli
- Center for Species Survival, Smithsonian’s National Zoo and Conservation Biology Institute, Washington, DC 20008, USA
- Computer Technologies Laboratory, ITMO University, St. Petersburg 197101, Russia
- Smithsonian-Mason School of Conservation, George Mason University, Front Royal, VA 22630, USA
| | - Tomas Marques-Bonet
- Catalan Institution of Research and Advanced Studies (ICREA), 08010 Barcelona, Spain
- CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), 08036 Barcelona, Spain
- Department of Medicine and Life Sciences, Institute of Evolutionary Biology (UPF-CSIC), Universitat Pompeu Fabra, 08003 Barcelona, Spain
- Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Barcelona, Spain
| | - Wynn K. Meyer
- Department of Biological Sciences, Lehigh University, Bethlehem, PA 18015, USA
| | - Martin Nweeia
- Department of Comprehensive Care, School of Dental Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Vertebrate Zoology, Canadian Museum of Nature, Ottawa, Ontario K2P 2R1, Canada
- Department of Vertebrate Zoology, Smithsonian Institution, Washington, DC 20002, USA
- Narwhal Genome Initiative, Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine, Boston, MA 02115, USA
| | - Pardis C. Sabeti
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA 02138, USA
| | - Beth Shapiro
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
- Howard Hughes Medical Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | | | - Mark S. Springer
- Department of Evolution, Ecology and Organismal Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Emma C. Teeling
- School of Biology and Environmental Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Zhiping Weng
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA
| | - Michael Hiller
- Faculty of Biosciences, Goethe-University, 60438 Frankfurt, Germany
- LOEWE Centre for Translational Biodiversity Genomics, 60325 Frankfurt, Germany
- Senckenberg Research Institute, 60325 Frankfurt, Germany
| | | | - Harris A. Lewin
- The Genome Center, University of California Davis, Davis, CA 95616, USA
- Department of Evolution and Ecology, University of California Davis, Davis, CA 95616, USA
- John Muir Institute for the Environment, University of California Davis, Davis, CA 95616, USA
| | - William J. Murphy
- Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843, USA
| | - Arcadi Navarro
- Catalan Institution of Research and Advanced Studies (ICREA), 08010 Barcelona, Spain
- Department of Medicine and Life Sciences, Institute of Evolutionary Biology (UPF-CSIC), Universitat Pompeu Fabra, 08003 Barcelona, Spain
- BarcelonaBeta Brain Research Center, Pasqual Maragall Foundation, 08005 Barcelona, Spain
- CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), 08003 Barcelona, Spain
| | - Benedict Paten
- Genomics Institute, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Katherine S. Pollard
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA 94158, USA
- Gladstone Institutes, San Francisco, CA 94158, USA
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - David A. Ray
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Irina Ruf
- Division of Messel Research and Mammalogy, Senckenberg Research Institute and Natural History Museum Frankfurt, 60325 Frankfurt am Main, Germany
| | - Oliver A. Ryder
- Conservation Genetics, San Diego Zoo Wildlife Alliance, Escondido, CA 92027, USA
- Department of Evolution, Behavior and Ecology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92039, USA
| | - Andreas R. Pfenning
- Department of Computational Biology, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA 15213, USA
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Kerstin Lindblad-Toh
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratory, Uppsala University, 751 32 Uppsala, Sweden
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
| | - Elinor K. Karlsson
- Broad Institute of MIT and Harvard, Cambridge, MA 02139, USA
- Program in Bioinformatics and Integrative Biology, UMass Chan Medical School, Worcester, MA 01605, USA
- Program in Molecular Medicine, UMass Chan Medical School, Worcester, MA 01605, USA
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14
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Tsiouris JA, Flory M. Downregulation of cyclic adenosine monophosphate levels in leukocytes of hibernating captive black bears is similar to reported cyclic adenosine monophosphate findings in major depressive disorder. Front Psychiatry 2023; 14:1123279. [PMID: 37009099 PMCID: PMC10061222 DOI: 10.3389/fpsyt.2023.1123279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 02/24/2023] [Indexed: 03/18/2023] Open
Abstract
IntroductionCyclic adenosine monophosphate (cAMP) levels in the lymphoblasts and leukocytes of patients with major depressive disorder (MDD) have been reported to be downregulated compared to in controls. cAMP is a derivative of adenosine triphosphate (ATP), and low ATP turnover has been reported in the state of hypometabolism associated with human MDD and with mammalian hibernation due to suppression of mitochondrial metabolism. Similarities have been noted between many state-dependent neurobiological changes associated with MDD in humans and with mammalian hibernation.MethodsTo compare cAMP levels between human MDD and mammalian hibernation and to investigate whether cAMP downregulation is another state-dependent neurobiological finding, we measured cAMP concentrations in lysed leukocytes, plasma, and serum in serial blood specimens from nine female captive black bears (Ursus americanus; CBBs), and cortisol levels in serum from 10 CBBs.ResultsCortisol levels were significantly higher during hibernation in CBBs, confirming previous findings in hibernating black bears and similar to findings in humans with MDD. cAMP levels were significantly lower during hibernation versus active states (pre-hibernation and exit from hibernation) and were similar to the cAMP downregulation reported in MDD patients versus euthymic patients or controls. cAMP level changes during the different states (hibernation, pre-hibernation, active) confirm their state-dependent status.DiscussionThese findings are similar to the neurobiological findings associated with the hypometabolism (metabolic depression) observed during mammalian hibernation and reported during MDD. A sudden increase in cAMP levels was observed before entrance into pre-hibernation and during exit from hibernation. Further investigation is suggested into the possible role of elevated cAMP levels in initiation of the chain reaction of changes in gene expression, proteins, and enzymes leading to the suppression of mitochondrial metabolism and to low ATP turnover. This process leads to hypometabolism, the old adaptive mechanism that is used by organisms for energy preservation and is associated with both mammalian hibernation and human MDD.
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Affiliation(s)
- John A. Tsiouris
- George A. Jervis Clinic, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, United States
- Department of Psychiatry, State University of New York Downstate Medical Center, Brooklyn, NY, United States
- *Correspondence: John A. Tsiouris,
| | - Michael Flory
- Research Design and Analysis Service, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, United States
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15
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Staples JF, Mathers KE, Duffy BM. Mitochondrial Metabolism in Hibernation: Regulation and Implications. Physiology (Bethesda) 2022; 37:0. [PMID: 35658625 DOI: 10.1152/physiol.00006.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Hibernators rapidly and reversibly suppress mitochondrial respiration and whole animal metabolism. Posttranslational modifications likely regulate these mitochondrial changes, which may help conserve energy in winter. These modifications are affected by reactive oxygen species (ROS), so suppressing mitochondrial ROS production may also be important for hibernators, just as it is important for surviving ischemia-reperfusion injury.
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Affiliation(s)
- James F Staples
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Katherine E Mathers
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Brynne M Duffy
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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16
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Gerber L, MacSween CE, Staples JF, Gamperl AK. Cold-induced metabolic depression in cunner (Tautogolabrus adspersus): A multifaceted cellular event. PLoS One 2022; 17:e0271086. [PMID: 35917356 PMCID: PMC9345476 DOI: 10.1371/journal.pone.0271086] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/22/2022] [Indexed: 11/19/2022] Open
Abstract
Metabolic depression and dormancy (i.e., stopping/greatly reducing activity and feeding) are strategies used by many animals to survive winter conditions characterized by food shortages and cold temperatures. However, controversy exists on whether the reduced metabolism of some fishes at cold temperatures is due to dormancy alone, or also involves active metabolic depression. Thus, we acclimated winter-dormant cunner [Tautogolabrus adspersus, a north temperate wrasse which in Newfoundland is at the northern limit of its distribution] and winter-active Atlantic salmon (Salmo salar) to winter (0°C; 8h light: 16h dark) and summer (10°C; 16h light: 8 h dark) conditions, and measured the thermal sensitivity of ATP-producing and O2-consuming processes in isolated liver mitochondria and hepatocytes when exposed in vitro to temperatures from 20 to 0°C and 10 to 0°C, respectively. We found that: 1) liver mitochondrial State 3 respiration and hepatocyte O2 consumption in cunner were only ~ one-third and two-thirds of that measured in salmon, respectively, at all measurement temperatures; 2) cunner mitochondria also have proton conductance and leak respiration (State 4) values that are only approximately one-third of those in salmon; 3) the mitochondria of cunner show a dramatic reduction in respiratory control ratio (from ~ 8 to 3), and a much greater drop in State 3 respiration, between 10 and 5°C (Q10 values in 10- and 0°C-acclimated fish of 14.5 and 141.2, respectively), as compared with salmon (3.9 and 9.6, respectively); and 4) lowering temperature from 5 to 0°C resulted in ~ 40 and 30% reductions in hepatocyte O2 consumption due to non-mitochondrial respiration and Na+-K+-ATPase activity, respectively, in cunner, but not in salmon. Collectively, these results highlight the intrinsic capacity for metabolic depression in hepatocytes and mitochondria of cunner, and clearly suggest that several cellular processes play a role in the reduced metabolic rates exhibited by some fishes at cold temperatures.
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Affiliation(s)
- Lucie Gerber
- Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John’s, NL, Canada
| | - Courtney E. MacSween
- Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John’s, NL, Canada
| | - James F. Staples
- Department of Biology, University of Western Ontario, London, ON, Canada
| | - A. Kurt Gamperl
- Department of Ocean Sciences, Memorial University of Newfoundland and Labrador, St. John’s, NL, Canada
- * E-mail:
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Eaton L, Pamenter ME. What to do with low O 2: Redox adaptations in vertebrates native to hypoxic environments. Comp Biochem Physiol A Mol Integr Physiol 2022; 271:111259. [PMID: 35724954 DOI: 10.1016/j.cbpa.2022.111259] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 06/11/2022] [Accepted: 06/14/2022] [Indexed: 01/05/2023]
Abstract
Reactive oxygen species (ROS) are important cellular signalling molecules but sudden changes in redox balance can be deleterious to cells and lethal to the whole organism. ROS production is inherently linked to environmental oxygen availability and many species live in variable oxygen environments that can range in both severity and duration of hypoxic exposure. Given the importance of redox homeostasis to cell and animal viability, it is not surprising that early studies in species adapted to various hypoxic niches have revealed diverse strategies to limit or mitigate deleterious ROS changes. Although research in this area is in its infancy, patterns are beginning to emerge in the suites of adaptations to different hypoxic environments. This review focuses on redox adaptations (i.e., modifications of ROS production and scavenging, and mitigation of oxidative damage) in hypoxia-tolerant vertebrates across a range of hypoxic environments. In general, evidence suggests that animals adapted to chronic lifelong hypoxia are in homeostasis, and do not encounter major oxidative challenges in their homeostatic environment, whereas animals exposed to seasonal chronic anoxia or hypoxia rapidly downregulate redox balance to match a hypometabolic state and employ robust scavenging pathways during seasonal reoxygenation. Conversely, animals adapted to intermittent hypoxia exposure face the greatest degree of ROS imbalance and likely exhibit enhanced ROS-mitigation strategies. Although some progress has been made, research in this field is patchy and further elucidation of mechanisms that are protective against environmental redox challenges is imperative for a more holistic understanding of how animals survive hypoxic environments.
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Affiliation(s)
- Liam Eaton
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - 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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18
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Supplementing cultured human myotubes with hibernating bear serum results in increased protein content by modulating Akt/FOXO3a signaling. PLoS One 2022; 17:e0263085. [PMID: 35077510 PMCID: PMC8789107 DOI: 10.1371/journal.pone.0263085] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 01/11/2022] [Indexed: 12/22/2022] Open
Abstract
Hibernating bears remain in their dens for 5–7 months during winter and survive without eating or drinking while staying inactive. However, they maintain their physical functions with minimal skeletal muscle atrophy and metabolic dysfunction. In bears, resistance to skeletal muscle atrophy during hibernation is likely mediated by seasonally altered systemic factors that are independent of neuromuscular activity. To determine whether there are components in bear serum that regulate protein and energy metabolism, differentiated human skeletal muscle cells were treated with bear serum (5% in DMEM/Ham’s F-12, 24 h) collected during active summer (July) and hibernating winter (February) periods. The serum samples were collected from the same individual bears (Ursus thibetanus japonicus, n = 7 in each season). Total protein content in cultured skeletal muscle cells was significantly increased following a 24 h treatment with hibernating bear serum. Although the protein synthesis rate was not altered, the expression of MuRF1 protein, a muscle-specific E3 ubiquitin ligase was significantly decreased along with a concomitant activation of Akt/FOXO3a signaling. Increased levels of insulin-like growth factor-1 (IGF-1) were also observed in hibernating bear serum. These observations suggest that protein metabolism in cultured human myotubes may be altered when incubated with hibernating bear serum, with a significant increase in serum IGF-1 and diminished MuRF1 expression, a potential target of Akt/FOXO3a signaling. A protein sparing phenotype in cultured muscle cells by treatment with hibernating bear serum holds potential for the development of methods to prevent human muscle atrophy and related disorders.
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19
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Sgarbi G, Hitrec T, Amici R, Baracca A, Di Cristoforo A, Liuzzi F, Luppi M, Solaini G, Squarcio F, Zamboni G, Cerri M. Mitochondrial respiration in rats during hypothermia resulting from central drug administration. J Comp Physiol B 2022; 192:349-360. [PMID: 35001173 DOI: 10.1007/s00360-021-01421-6] [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: 03/16/2021] [Revised: 11/11/2021] [Accepted: 11/22/2021] [Indexed: 11/24/2022]
Abstract
The ability to induce a hypothermia resembling that of natural torpor would be greatly beneficial in medical and non-medical fields. At present, two procedures based on central nervous pharmacological manipulation have been shown to be effective in bringing core body temperature well below 30 °C in the rat, a non-hibernator: the first, based on the inhibition of a key relay in the central thermoregulatory pathway, the other, based on the activation of central adenosine A1 receptors. Although the role of mitochondria in the activation and maintenance of torpor has been extensively studied, no data are available for centrally induced hypothermia in non-hibernators. Thus, in the present work the respiration rate of mitochondria in the liver and in the kidney of rats following the aforementioned hypothermia-inducing treatments was studied. Moreover, to have an internal control, the same parameters were assessed in a well-consolidated model, i.e., mice during fasting-induced torpor. Our results show that state 3 respiration rate, which significantly decreased in the liver of mice, was unchanged in rats. An increase of state 4 respiration rate was observed in both species, although it was not statistically significant in rats under central adenosine stimulation. Also, a significant decrease of the respiratory control ratio was detected in both species. Finally, no effects were detected in kidney mitochondria in both species. Overall, in these hypothermic conditions liver mitochondria of rats remained active and apparently ready to be re-activated to produce energy and warm up the cells. These findings can be interpreted as encouraging in view of the finalization of a translational approach to humans.
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Affiliation(s)
- Gianluca Sgarbi
- Laboratory of Biochemistry and Mitochondrial Pathophysiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Piazza di Porta S. Donato, 2, 40126, Bologna, Italy
| | - Timna Hitrec
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Irnerio, 48, 40126, Bologna, Italy
| | - Roberto Amici
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Irnerio, 48, 40126, Bologna, Italy
| | - Alessandra Baracca
- Laboratory of Biochemistry and Mitochondrial Pathophysiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Piazza di Porta S. Donato, 2, 40126, Bologna, Italy
| | - Alessia Di Cristoforo
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Irnerio, 48, 40126, Bologna, Italy
| | - Francesca Liuzzi
- Laboratory of Biochemistry and Mitochondrial Pathophysiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Piazza di Porta S. Donato, 2, 40126, Bologna, Italy
| | - Marco Luppi
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Irnerio, 48, 40126, Bologna, Italy
| | - Giancarlo Solaini
- Laboratory of Biochemistry and Mitochondrial Pathophysiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Piazza di Porta S. Donato, 2, 40126, Bologna, Italy
| | - Fabio Squarcio
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Irnerio, 48, 40126, Bologna, Italy
| | - Giovanni Zamboni
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Irnerio, 48, 40126, Bologna, Italy
| | - Matteo Cerri
- Laboratory of Autonomic and Behavioral Physiology, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Irnerio, 48, 40126, Bologna, Italy.
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20
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Jobava R, Mao Y, Guan BJ, Hu D, Krokowski D, Chen CW, Shu XE, Chukwurah E, Wu J, Gao Z, Zagore LL, Merrick WC, Trifunovic A, Hsieh AC, Valadkhan S, Zhang Y, Qi X, Jankowsky E, Topisirovic I, Licatalosi DD, Qian SB, Hatzoglou M. Adaptive translational pausing is a hallmark of the cellular response to severe environmental stress. Mol Cell 2021; 81:4191-4208.e8. [PMID: 34686314 PMCID: PMC8559772 DOI: 10.1016/j.molcel.2021.09.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/27/2021] [Accepted: 09/28/2021] [Indexed: 12/12/2022]
Abstract
To survive, mammalian cells must adapt to environmental challenges. While the cellular response to mild stress has been widely studied, how cells respond to severe stress remains unclear. We show here that under severe hyperosmotic stress, cells enter a transient hibernation-like state in anticipation of recovery. We demonstrate this adaptive pausing response (APR) is a coordinated cellular response that limits ATP supply and consumption through mitochondrial fragmentation and widespread pausing of mRNA translation. This pausing is accomplished by ribosome stalling at translation initiation codons, which keeps mRNAs poised to resume translation upon recovery. We further show that recovery from severe stress involves ISR (integrated stress response) signaling that permits cell cycle progression, resumption of growth, and reversal of mitochondria fragmentation. Our findings indicate that cells can respond to severe stress via a hibernation-like mechanism that preserves vital elements of cellular function under harsh environmental conditions.
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Affiliation(s)
- Raul Jobava
- Department of Biochemistry, CWRU, Cleveland, OH 44106, USA; Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Yuanhui Mao
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Bo-Jhih Guan
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Di Hu
- Department of Physiology & Biophysics, CWRU, Cleveland, OH 44106, USA
| | - Dawid Krokowski
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA; Department of Molecular Biology, Faculty of Biology and Biotechnology, Maria Curie-Skłodowska University, Lublin 20-033, Poland
| | - Chien-Wen Chen
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Xin Erica Shu
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Evelyn Chukwurah
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Jing Wu
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Zhaofeng Gao
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA
| | - Leah L Zagore
- Department of Biochemistry, CWRU, Cleveland, OH 44106, USA; Center for RNA Science and Therapeutics, CWRU, Cleveland, OH 44106, USA
| | | | - Aleksandra Trifunovic
- Cologne Excellence Cluster on Cellular Stress Responses in Ageing-Associated Diseases (CECAD), Medical Faculty, University of Cologne, 50931 Cologne, Germany; Institute for Mitochondrial Diseases and Ageing, Medical Faculty and Center for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Andrew C Hsieh
- Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Saba Valadkhan
- Department of Molecular Biology and Microbiology, CWRU, Cleveland, OH 44106, USA
| | - Youwei Zhang
- Department of Pharmacology, CWRU, Cleveland, OH 44106, USA
| | - Xin Qi
- Department of Physiology & Biophysics, CWRU, Cleveland, OH 44106, USA
| | - Eckhard Jankowsky
- Department of Biochemistry, CWRU, Cleveland, OH 44106, USA; Center for RNA Science and Therapeutics, CWRU, Cleveland, OH 44106, USA
| | - Ivan Topisirovic
- Gerald Bronfman Department of Oncology, Departments of Biochemistry and Experimental Medicine and Lady Davis Institute for Medical Research, Jewish General Hospital, McGill University, Montréal, QC H3T 1E2, Canada
| | - Donny D Licatalosi
- Department of Biochemistry, CWRU, Cleveland, OH 44106, USA; Center for RNA Science and Therapeutics, CWRU, Cleveland, OH 44106, USA.
| | - Shu-Bing Qian
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
| | - Maria Hatzoglou
- Department of Genetics and Genome Sciences, CWRU, Cleveland, OH 44106, USA.
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21
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Huang YG, Flaherty SJ, Pothecary CA, Foster RG, Peirson SN, Vyazovskiy VV. The relationship between fasting-induced torpor, sleep, and wakefulness in laboratory mice. Sleep 2021; 44:zsab093. [PMID: 33838033 PMCID: PMC8436144 DOI: 10.1093/sleep/zsab093] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 04/03/2021] [Indexed: 11/30/2022] Open
Abstract
STUDY OBJECTIVES Torpor is a regulated and reversible state of metabolic suppression used by many mammalian species to conserve energy. Whereas the relationship between torpor and sleep has been well-studied in seasonal hibernators, less is known about the effects of fasting-induced torpor on states of vigilance and brain activity in laboratory mice. METHODS Continuous monitoring of electroencephalogram (EEG), electromyogram (EMG), and surface body temperature was undertaken in adult, male C57BL/6 mice over consecutive days of scheduled restricted feeding. RESULTS All animals showed bouts of hypothermia that became progressively deeper and longer as fasting progressed. EEG and EMG were markedly affected by hypothermia, although the typical electrophysiological signatures of non-rapid eye movement (NREM) sleep, rapid eye movement (REM) sleep, and wakefulness enabled us to perform vigilance-state classification in all cases. Consistent with previous studies, hypothermic bouts were initiated from a state indistinguishable from NREM sleep, with EEG power decreasing gradually in parallel with decreasing surface body temperature. During deep hypothermia, REM sleep was largely abolished, and we observed shivering-associated intense bursts of muscle activity. CONCLUSIONS Our study highlights important similarities between EEG signatures of fasting-induced torpor in mice, daily torpor in Djungarian hamsters and hibernation in seasonally hibernating species. Future studies are necessary to clarify the effects on fasting-induced torpor on subsequent sleep.
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Affiliation(s)
- Yi-Ge Huang
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT,UK
| | - Sarah J Flaherty
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT,UK
| | - Carina A Pothecary
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE,UK
| | - Russell G Foster
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE,UK
| | - Stuart N Peirson
- Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, Oxford Molecular Pathology Institute, Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE,UK
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford, OX1 3PT,UK
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22
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Abstract
Hibernation is a powerful response of a number of mammalian species to reduce energy during the cold winter season, when food is scarce. Mammalian hibernators survive winter by spending most of the time in a state of torpor, where basal metabolic rate is strongly suppressed and body temperature comes closer to ambient temperature. These torpor bouts are regularly interrupted by short arousals, where metabolic rate and body temperature spontaneously return to normal levels. The mechanisms underlying these changes, and in particular the strong metabolic suppression of torpor, have long remained elusive. As summarized in this Commentary, increasing evidence points to a potential key role for hydrogen sulfide (H2S) in the suppression of mitochondrial respiration during torpor. The idea that H2S could be involved in hibernation originated in some early studies, where exogenous H2S gas was found to induce a torpor-like state in mice, and despite some controversy, the idea persisted. H2S is a widespread signaling molecule capable of inhibiting mitochondrial respiration in vitro and studies found significant in vivo changes in endogenous H2S metabolites associated with hibernation or torpor. Along with increased expression of H2S-synthesizing enzymes during torpor, H2S degradation catalyzed by the mitochondrial sulfide:quinone oxidoreductase (SQR) appears to have a key role in controlling H2S availability for inhibiting respiration. Specifically, in thirteen-lined squirrels, SQR is highly expressed and inhibited in torpor, possibly by acetylation, thereby limiting H2S oxidation and causing inhibition of respiration. H2S may also control other aspects associated with hibernation, such as synthesis of antioxidant enzymes and of SQR itself.
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Affiliation(s)
| | - Angela Fago
- Department of Biology, Aarhus University, Aarhus C 8000, Denmark
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23
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Farhat E, Weber JM. Hypometabolic Responses to Chronic Hypoxia: A Potential Role for Membrane Lipids. Metabolites 2021; 11:503. [PMID: 34436444 PMCID: PMC8399526 DOI: 10.3390/metabo11080503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 07/26/2021] [Accepted: 07/29/2021] [Indexed: 02/06/2023] Open
Abstract
Metabolic suppression is an essential strategy to cope with chronic hypoxia. This review examines the physiological processes used to survive in low oxygen environments. It proposes a novel mechanism-the remodeling of membrane lipids-to suppress ATP use and production. Temperature (homeoviscous adaptation), diet (natural doping in migrant birds) and body mass (membrane pacemaker of metabolism) have an impact on the lipid composition of membranes, which, in turn, modulates metabolic capacity. Vertebrate champions of hypoxia tolerance show extensive changes in membrane lipids upon in vivo exposure to low oxygen. These changes and those observed in hibernating mammals can promote the downregulation of ion pumps (major ATP consumers), ion channels, mitochondrial respiration capacity (state 3, proton leak, cytochrome c oxidase), and energy metabolism (β-oxidation and glycolysis). A common membrane signal regulating the joint inhibition of ion pumps and channels could be an exquisite way to preserve the balance between ATP supply and demand in hypometabolic states. Membrane remodeling together with more traditional mechanisms could work in concert to cause metabolic suppression.
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Affiliation(s)
| | - Jean-Michel Weber
- Biology Department, University of Ottawa, Ottawa, ON K1N 6N5, Canada;
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24
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Skeletal muscle of torpid Richardson's ground squirrels (Urocitellus richardsonii) exhibits a less active form of citrate synthase associated with lowered lysine succinylation. Cryobiology 2021; 101:28-37. [PMID: 34186087 DOI: 10.1016/j.cryobiol.2021.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 11/21/2022]
Abstract
Hibernation is a metabolic/physiological strategy employed by many mammals to cope with periods when energy usage is greater than its input. Animals undergoing hibernation need to greatly reduce their metabolic rate and reshape their catabolic processes to survive on stored triglycerides. Citrate synthase (CS) is one of only two irreversible steps in the citric acid cycle (CAC) and forms an important regulatory checkpoint that gates the entry of acetyl-CoA formed in glycolysis or fatty acid catabolism into this critical central metabolic hub. This study investigated the regulation of citrate synthase in the muscle tissue of a small mammalian hibernator through comparison of functional and structural properties. The results demonstrated a significant decrease in the Vmax of purified torpid CS compared to the control euthermic enzyme (1.2-1.7 fold greater in the control) that was evident over a wide range of temperatures (8, 22 and 37 °C) that are encountered by the enzyme in hibernation. This was also reflected in the specific activity of the enzyme in crude muscle protein extracts. Analyzing the purified CS through immunoblotting demonstrated that the enzyme contained noticeably less lysine succinylation in the torpid state (about 50% of euthermic levels) and this was correlated with an increase in total levels of SIRT5, the enzyme responsible for mediating desuccinylation in the mitochondria (2.2 fold increase). Taken together, the results of this study support the idea that CS is inhibited during hibernation in the ground squirrel skeletal muscle and that this alteration could be mediated by decreases in succinylation.
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25
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Jensen BS, Pardue S, Duffy B, Kevil CG, Staples JF, Fago A. Suppression of mitochondrial respiration by hydrogen sulfide in hibernating 13-lined ground squirrels. Free Radic Biol Med 2021; 169:181-186. [PMID: 33887435 PMCID: PMC8809085 DOI: 10.1016/j.freeradbiomed.2021.04.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/18/2021] [Accepted: 04/08/2021] [Indexed: 12/30/2022]
Abstract
Hibernating mammals may suppress their basal metabolic rate during torpor by up to 95% to reduce energy expenditure during winter, but the underlying mechanisms remain poorly understood. Here we show that hydrogen sulfide (H2S), a ubiquitous signaling molecule, is a powerful inhibitor of respiration of liver mitochondria isolated from torpid 13-lined ground squirrels, but has a weak effect on mitochondria isolated during summer and hibernation arousals, where metabolic rate is normal. Consistent with these in vitro effects, we find strong seasonal variations of in vivo levels of H2S in plasma and increases of H2S levels in the liver of squirrels during torpor compared to levels during arousal and summer. The in vivo changes of liver H2S levels correspond with low activity of the mitochondrial H2S oxidizing enzyme sulfide:quinone oxidoreductase (SQR) during torpor. Taken together, these results suggest that during torpor, H2S accumulates in the liver due to a low SQR activity and contributes to inhibition of mitochondrial respiration, while during arousals and summer these effects are reversed, H2S is degraded by active SQR and mitochondrial respiration rates increase. This study provides novel insights into mechanisms underlying mammalian hibernation, pointing to SQR as a key enzyme involved in the control of mitochondrial function.
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Affiliation(s)
- Birgitte S Jensen
- Department of Biology, Aarhus University, Aarhus C, 8000, Denmark; Department of Biology, University of Western Ontario, London, ON N6A 5B8, Canada
| | - Sibile Pardue
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - Brynne Duffy
- Department of Biology, University of Western Ontario, London, ON N6A 5B8, Canada
| | - Christopher G Kevil
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA, 71130, USA
| | - James F Staples
- Department of Biology, University of Western Ontario, London, ON N6A 5B8, Canada
| | - Angela Fago
- Department of Biology, Aarhus University, Aarhus C, 8000, Denmark.
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26
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Dias IB, Bouma HR, Henning RH. Unraveling the Big Sleep: Molecular Aspects of Stem Cell Dormancy and Hibernation. Front Physiol 2021; 12:624950. [PMID: 33867999 PMCID: PMC8047423 DOI: 10.3389/fphys.2021.624950] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 03/11/2021] [Indexed: 12/14/2022] Open
Abstract
Tissue-resident stem cells may enter a dormant state, also known as quiescence, which allows them to withstand metabolic stress and unfavorable conditions. Similarly, hibernating mammals can also enter a state of dormancy used to evade hostile circumstances, such as food shortage and low ambient temperatures. In hibernation, the dormant state of the individual and its cells is commonly known as torpor, and is characterized by metabolic suppression in individual cells. Given that both conditions represent cell survival strategies, we here compare the molecular aspects of cellular quiescence, particularly of well-studied hematopoietic stem cells, and torpor at the cellular level. Critical processes of dormancy are reviewed, including the suppression of the cell cycle, changes in metabolic characteristics, and cellular mechanisms of dealing with damage. Key factors shared by hematopoietic stem cell quiescence and torpor include a reversible activation of factors inhibiting the cell cycle, a shift in metabolism from glucose to fatty acid oxidation, downregulation of mitochondrial activity, key changes in hypoxia-inducible factor one alpha (HIF-1α), mTOR, reversible protein phosphorylation and autophagy, and increased radiation resistance. This similarity is remarkable in view of the difference in cell populations, as stem cell quiescence regards proliferating cells, while torpor mainly involves terminally differentiated cells. A future perspective is provided how to advance our understanding of the crucial pathways that allow stem cells and hibernating animals to engage in their 'great slumbers.'
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Affiliation(s)
- Itamar B. Dias
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Hjalmar R. Bouma
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Robert H. Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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27
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Cheng H, Munro D, Huynh K, Pamenter ME. Naked mole-rat skeletal muscle mitochondria exhibit minimal functional plasticity in acute or chronic hypoxia. Comp Biochem Physiol B Biochem Mol Biol 2021; 255:110596. [PMID: 33757832 DOI: 10.1016/j.cbpb.2021.110596] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 01/10/2023]
Abstract
Oxidative phosphorylation is compromised in hypoxia, but many organisms live and exercise in low oxygen environments. Hypoxia-driven adaptations at the mitochondrial level are common and may enhance energetic efficiency or minimize deleterious reactive oxygen species (ROS) generation. Mitochondria from various hypoxia-tolerant animals exhibit robust functional changes following in vivo hypoxia and we hypothesized that similar plasticity would occur in naked mole-rat skeletal muscle. To test this, we exposed adult subordinate naked mole-rats to normoxia (21% O2) or acute (4 h, 7% O2) or chronic hypoxia (4-6 weeks, 11% O2) and then isolated skeletal muscle mitochondria. Using high-resolution respirometry and a fluorescent indicator of ROS production, we then probed for changes in: i) lipid- (palmitoylcarnitine-malate), ii) carbohydrate- (pyruvate-malate), and iii) succinate-fueled metabolism, and also iv) complex IV electron transfer capacity, and v) H2O2 production. Compared to normoxic values, a) lipid-fueled uncoupled respiration was reduced ~15% during acute and chronic hypoxia, b) complex I-II capacity and the rate of ROS efflux were both unaffected, and c) complex II and IV uncoupled respiration were supressed ~16% following acute hypoxia. Notably, complex II-linked H2O2 efflux was 33% lower after acute hypoxia, which may reduce deleterious ROS bursts during reoxygenation. These mild changes in lipid- and carbohydrate-fueled respiratory capacity may reflect the need for this animal to exercise regularly in highly variable and intermittently hypoxic environments in which more robust plasticity may be energetically expensive.
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Affiliation(s)
- Hang Cheng
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Daniel Munro
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Kenny Huynh
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - 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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28
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Bertile F, Habold C, Le Maho Y, Giroud S. Body Protein Sparing in Hibernators: A Source for Biomedical Innovation. Front Physiol 2021; 12:634953. [PMID: 33679446 PMCID: PMC7930392 DOI: 10.3389/fphys.2021.634953] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/12/2021] [Indexed: 12/11/2022] Open
Abstract
Proteins are not only the major structural components of living cells but also ensure essential physiological functions within the organism. Any change in protein abundance and/or structure is at risk for the proper body functioning and/or survival of organisms. Death following starvation is attributed to a loss of about half of total body proteins, and body protein loss induced by muscle disuse is responsible for major metabolic disorders in immobilized patients, and sedentary or elderly people. Basic knowledge of the molecular and cellular mechanisms that control proteostasis is continuously growing. Yet, finding and developing efficient treatments to limit body/muscle protein loss in humans remain a medical challenge, physical exercise and nutritional programs managing to only partially compensate for it. This is notably a major challenge for the treatment of obesity, where therapies should promote fat loss while preserving body proteins. In this context, hibernating species preserve their lean body mass, including muscles, despite total physical inactivity and low energy consumption during torpor, a state of drastic reduction in metabolic rate associated with a more or less pronounced hypothermia. The present review introduces metabolic, physiological, and behavioral adaptations, e.g., energetics, body temperature, and nutrition, of the torpor or hibernation phenotype from small to large mammals. Hibernating strategies could be linked to allometry aspects, the need for periodic rewarming from torpor, and/or the ability of animals to fast for more or less time, thus determining the capacity of individuals to save proteins. Both fat- and food-storing hibernators rely mostly on their body fat reserves during the torpid state, while minimizing body protein utilization. A number of them may also replenish lost proteins during arousals by consuming food. The review takes stock of the physiological, molecular, and cellular mechanisms that promote body protein and muscle sparing during the inactive state of hibernation. Finally, the review outlines how the detailed understanding of these mechanisms at play in various hibernators is expected to provide innovative solutions to fight human muscle atrophy, to better help the management of obese patients, or to improve the ex vivo preservation of organs.
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Affiliation(s)
- Fabrice Bertile
- University of Strasbourg, CNRS, IPHC UMR 7178, Laboratoire de Spectrométrie de Masse Bio-Organique, Strasbourg, France
| | - Caroline Habold
- University of Strasbourg, CNRS, IPHC UMR 7178, Ecology, Physiology & Ethology Department, Strasbourg, France
| | - Yvon Le Maho
- University of Strasbourg, CNRS, IPHC UMR 7178, Ecology, Physiology & Ethology Department, Strasbourg, France.,Centre Scientifique de Monaco, Monaco, Monaco
| | - Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
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Markussen FAF, Melum VJ, Bothorel B, Hazlerigg DG, Simonneaux V, Wood SH. A refined method to monitor arousal from hibernation in the European hamster. BMC Vet Res 2021; 17:14. [PMID: 33413328 PMCID: PMC7791859 DOI: 10.1186/s12917-020-02723-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 12/10/2020] [Indexed: 11/16/2022] Open
Abstract
Background Hibernation is a physiological and behavioural adaptation that permits survival during periods of reduced food availability and extreme environmental temperatures. This is achieved through cycles of metabolic depression and reduced body temperature (torpor) and rewarming (arousal). Rewarming from torpor is achieved through the activation of brown adipose tissue (BAT) associated with a rapid increase in ventilation frequency. Here, we studied the rate of rewarming in the European hamster (Cricetus cricetus) by measuring both BAT temperature, core body temperature and ventilation frequency. Results Temperature was monitored in parallel in the BAT (IPTT tags) and peritoneal cavity (iButtons) during hibernation torpor-arousal cycling. We found that increases in brown fat temperature preceded core body temperature rises by approximately 48 min, with a maximum re-warming rate of 20.9℃*h-1. Re-warming was accompanied by a significant increase in ventilation frequency. The rate of rewarming was slowed by the presence of a spontaneous thoracic mass in one of our animals. Core body temperature re-warming was reduced by 6.2℃*h-1 and BAT rewarming by 12℃*h-1. Ventilation frequency was increased by 77% during re-warming in the affected animal compared to a healthy animal. Inspection of the position and size of the mass indicated it was obstructing the lungs and heart. Conclusions We have used a minimally invasive method to monitor BAT temperature during arousal from hibernation illustrating BAT re-warming significantly precedes core body temperature re-warming, informing future study design on arousal from hibernation. We also showed compromised re-warming from hibernation in an animal with a mass obstructing the lungs and heart, likely leading to inefficient ventilation and circulation.
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Affiliation(s)
- Fredrik A F Markussen
- Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, NO-9037, Tromsø, Norway
| | - Vebjørn J Melum
- Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, NO-9037, Tromsø, Norway
| | - Béatrice Bothorel
- Institute of Cellular and Integrative Neurosciences, CNRS UPR 3212, University of Strasbourg, Strasbourg, France
| | - David G Hazlerigg
- Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, NO-9037, Tromsø, Norway
| | - Valérie Simonneaux
- Institute of Cellular and Integrative Neurosciences, CNRS UPR 3212, University of Strasbourg, Strasbourg, France
| | - Shona H Wood
- Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, NO-9037, Tromsø, Norway.
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Logan SM, Storey KB. Inflammasome signaling could be used to sense and respond to endogenous damage in brown but not white adipose tissue of a hibernating ground squirrel. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 114:103819. [PMID: 32781003 DOI: 10.1016/j.dci.2020.103819] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/30/2020] [Accepted: 07/30/2020] [Indexed: 06/11/2023]
Abstract
Small mammalian hibernators use metabolic suppression to enhance survival during the winter. Torpor is punctuated by periods of euthermia used to clear metabolic by-products and damaged cell components. The current study was performed to determine if the innate immune system, specifically NLRP and AIM2 inflammasome signaling, may detect and respond to cell stress during hibernation. Nlrp3, Casp1, and Il1b genes were significantly upregulated in brown adipose tissue (BAT) during arousal with respect to the euthermic control, suggesting increased NLRP3 inflammasome priming. NLRP3, IL-18, and gasdermin D protein levels increased during torpor, indicating a lag between inflammasome priming and formation. AIM2 and gasdermin D levels increased in BAT during arousal, as did caspase-1 activity. Thus, non-shivering thermogenesis may generate pro-inflammatory triggers of inflammasome signaling. This study is the first to support a role for inflammasome signaling in sensing cellular perturbations at various points of the torpor-arousal cycle, in metabolically-active BAT, but not white adipose tissue (WAT).
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Affiliation(s)
- Samantha M Logan
- Institute of Biochemistry, Departments of Biology and Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
| | - Kenneth B Storey
- Institute of Biochemistry, Departments of Biology and Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
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Anderson G, Maes M. Mitochondria and immunity in chronic fatigue syndrome. Prog Neuropsychopharmacol Biol Psychiatry 2020; 103:109976. [PMID: 32470498 DOI: 10.1016/j.pnpbp.2020.109976] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 05/19/2020] [Indexed: 02/07/2023]
Abstract
It is widely accepted that the pathophysiology and treatment of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) could be considerably improved. The heterogeneity of ME/CFS and the confusion over its classification have undoubtedly contributed to this, although this would seem a consequence of the complexity of the array of ME/CFS presentations and high levels of diverse comorbidities. This article reviews the biological underpinnings of ME/CFS presentations, including the interacting roles of the gut microbiome/permeability, endogenous opioidergic system, immune cell mitochondria, autonomic nervous system, microRNA-155, viral infection/re-awakening and leptin as well as melatonin and the circadian rhythm. This details not only relevant pathophysiological processes and treatment options, but also highlights future research directions. Due to the complexity of interacting systems in ME/CFS pathophysiology, clarification as to its biological underpinnings is likely to considerably contribute to the understanding and treatment of other complex and poorly managed conditions, including fibromyalgia, depression, migraine, and dementia. The gut and immune cell mitochondria are proposed to be two important hubs that interact with the circadian rhythm in driving ME/CFS pathophysiology.
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Affiliation(s)
- G Anderson
- CRC Scotland & London, Eccleston Square, London, UK.
| | - M Maes
- Dept Psychiatry, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand; Dept Psychiatry, Medical University Plovdiv, Plovdiv, Bulgaria.; IMPACT Research Center, Deakin University, Geelong, Australia
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Shi Z, Qin M, Huang L, Xu T, Chen Y, Hu Q, Peng S, Peng Z, Qu LN, Chen SG, Tuo QH, Liao DF, Wang XP, Wu RR, Yuan TF, Li YH, Liu XM. Human torpor: translating insights from nature into manned deep space expedition. Biol Rev Camb Philos Soc 2020; 96:642-672. [PMID: 33314677 DOI: 10.1111/brv.12671] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/09/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
During a long-duration manned spaceflight mission, such as flying to Mars and beyond, all crew members will spend a long period in an independent spacecraft with closed-loop bioregenerative life-support systems. Saving resources and reducing medical risks, particularly in mental heath, are key technology gaps hampering human expedition into deep space. In the 1960s, several scientists proposed that an induced state of suppressed metabolism in humans, which mimics 'hibernation', could be an ideal solution to cope with many issues during spaceflight. In recent years, with the introduction of specific methods, it is becoming more feasible to induce an artificial hibernation-like state (synthetic torpor) in non-hibernating species. Natural torpor is a fascinating, yet enigmatic, physiological process in which metabolic rate (MR), body core temperature (Tb ) and behavioural activity are reduced to save energy during harsh seasonal conditions. It employs a complex central neural network to orchestrate a homeostatic state of hypometabolism, hypothermia and hypoactivity in response to environmental challenges. The anatomical and functional connections within the central nervous system (CNS) lie at the heart of controlling synthetic torpor. Although progress has been made, the precise mechanisms underlying the active regulation of the torpor-arousal transition, and their profound influence on neural function and behaviour, which are critical concerns for safe and reversible human torpor, remain poorly understood. In this review, we place particular emphasis on elaborating the central nervous mechanism orchestrating the torpor-arousal transition in both non-flying hibernating mammals and non-hibernating species, and aim to provide translational insights into long-duration manned spaceflight. In addition, identifying difficulties and challenges ahead will underscore important concerns in engineering synthetic torpor in humans. We believe that synthetic torpor may not be the only option for manned long-duration spaceflight, but it is the most achievable solution in the foreseeable future. Translating the available knowledge from natural torpor research will not only benefit manned spaceflight, but also many clinical settings attempting to manipulate energy metabolism and neurobehavioural functions.
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Affiliation(s)
- Zhe Shi
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China.,Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China.,State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, 200030, China
| | - Meng Qin
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Lu Huang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, China
| | - Tao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Ying Chen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qin Hu
- College of Life Sciences and Bio-Engineering, Beijing University of Technology, Beijing, 100024, China
| | - Sha Peng
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Zhuang Peng
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Li-Na Qu
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Shan-Guang Chen
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Qin-Hui Tuo
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Duan-Fang Liao
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Xiao-Ping Wang
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China
| | - Ren-Rong Wu
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China
| | - Ti-Fei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, 200030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226000, China
| | - Ying-Hui Li
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Xin-Min Liu
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China.,State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China.,Research Center for Pharmacology and Toxicology, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
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Hypothermic oxygenated perfusion protects from mitochondrial injury before liver transplantation. EBioMedicine 2020; 60:103014. [PMID: 32979838 PMCID: PMC7519249 DOI: 10.1016/j.ebiom.2020.103014] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Revised: 09/06/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Mitochondrial succinate accumulation has been suggested as key event for ischemia reperfusion injury in mice. No specific data are however available on behavior of liver mitochondria during ex situ machine perfusion in clinical transplant models. METHODS We investigated mitochondrial metabolism of isolated perfused rat livers before transplantation. Livers were exposed to warm and cold ischemia to simulate donation after circulatory death (DCD) and organ transport. Subsequently, livers were perfused with oxygenated Belzer-MPS for 1h, at hypothermic or normothermic conditions. Various experiments were performed with supplemented succinate and/or mitochondrial inhibitors. The perfusate, liver tissues, and isolated mitochondria were analyzed by mass-spectroscopy and fluorimetry. Additionally, rat DCD livers were transplanted after 1h hypothermic or normothermic oxygenated perfusion. In parallel, perfusate samples were analysed during HOPE-treatment of human DCD livers before transplantation. FINDINGS Succinate exposure during rat liver perfusion triggered a dose-dependent release of mitochondrial Flavin-Mononucleotide (FMN) and NADH in perfusates under normothermic conditions. In contrast, perfusate FMN was 3-8 fold lower under hypothermic conditions, suggesting less mitochondrial injury during cold re-oxygenation compared to normothermic conditions. HOPE-treatment induced a mitochondrial reprogramming with uploading of the nucleotide pool and effective succinate metabolism. This resulted in a clear superiority after liver transplantation compared to normothermic perfusion. Finally, the degree of mitochondrial injury during HOPE of human DCD livers, quantified by perfusate FMN and NADH, was predictive for liver function. INTERPRETATION Mitochondrial injury determines outcome of transplanted rodent and human livers. Hypothermic oxygenated perfusion improves mitochondrial function, and allows viability assessment of liver grafts before implantation. FUNDING detailed information can be found in Acknowledgments.
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Mohr SM, Bagriantsev SN, Gracheva EO. Cellular, Molecular, and Physiological Adaptations of Hibernation: The Solution to Environmental Challenges. Annu Rev Cell Dev Biol 2020; 36:315-338. [PMID: 32897760 DOI: 10.1146/annurev-cellbio-012820-095945] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Thriving in times of resource scarcity requires an incredible flexibility of behavioral, physiological, cellular, and molecular functions that must change within a relatively short time. Hibernation is a collection of physiological strategies that allows animals to inhabit inhospitable environments, where they experience extreme thermal challenges and scarcity of food and water. Many different kinds of animals employ hibernation, and there is a spectrum of hibernation phenotypes. Here, we focus on obligatory mammalian hibernators to identify the unique challenges they face and the adaptations that allow hibernators to overcome them. This includes the cellular and molecular strategies used to combat low environmental and body temperatures and lack of food and water. We discuss metabolic, neuronal, and hormonal cues that regulate hibernation and how they are thought to be coordinated by internal clocks. Last, we touch on questions that are left to be addressed in the field of hibernation research. Studies from the last century and more recent work reveal that hibernation is not simply a passive reduction in body temperature and vital parameters but rather an active process seasonally regulated at the molecular, cellular, and organismal levels.
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Affiliation(s)
- Sarah M Mohr
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA; .,Department of Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut 06510, USA;
| | - Sviatoslav N Bagriantsev
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA;
| | - Elena O Gracheva
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA; .,Department of Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut 06510, USA;
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Over-Winter Survival and Nest Site Selection of the West-European Hedgehog ( Erinaceus europaeus) in Arable Dominated Landscapes. Animals (Basel) 2020; 10:ani10091449. [PMID: 32825054 PMCID: PMC7552789 DOI: 10.3390/ani10091449] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/12/2020] [Accepted: 08/13/2020] [Indexed: 12/16/2022] Open
Abstract
The West-European hedgehog (Erinaceus europaeus) has declined markedly in the UK. The winter hibernation period may make hedgehogs vulnerable to anthropogenic habitat and climate changes. Therefore, we studied two contrasting populations in England to examine patterns of winter nest use, body mass changes and survival during hibernation. No between-site differences were evident in body mass prior to hibernation nor the number of winter nests used, but significant differences in overwinter mass change and survival were observed. Mass change did not, however, affect survival rates; all deaths occurred prior to or after the hibernation period, mainly from predation or vehicle collisions. Hedgehogs consistently nested in proximity to hedgerows, roads and woodlands, but avoided pasture fields; differences between sites were evident for the selection for or avoidance of arable fields, amenity grassland and buildings. Collectively, these data indicate that hibernation was not a period of significant mortality for individuals that had attained sufficient weight (>600 g) pre-hibernation. Conversely, habitat composition did significantly affect the positioning of winter nests, such that different land management practices (historic and current) might potentially influence hibernation success. The limitations of this study and suggestions for future research are discussed.
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Hadj-Moussa H, Zhang J, Pifferi F, Perret M, Storey KB. Profiling torpor-responsive microRNAs in muscles of the hibernating primate Microcebus murinus. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1863:194473. [DOI: 10.1016/j.bbagrm.2019.194473] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/09/2019] [Accepted: 12/09/2019] [Indexed: 12/25/2022]
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Expression patterns of natriuretic peptides in pre-hibernating and hibernating Anatolian ground squirrel (Spermophilus xanthoprymnus) kidney. Vet Res Commun 2019; 43:249-259. [PMID: 31754910 DOI: 10.1007/s11259-019-09767-7] [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: 06/27/2019] [Accepted: 10/02/2019] [Indexed: 10/25/2022]
Abstract
Hibernation is characterized by marked suppression of renal function. Natriuretic peptides (NPs) are involved in the regulation of renal function. However, the role of NPs in the renal function during hibernation remains unclear. We aimed to investigate the distribution patterns of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) in Anatolian ground squirrel (Spermophilus xanthoprymnus) kidneys during pre-hibernation and hibernation periods. Cortical proximal tubules showed weak ANP immunoreactivity, with moderate staining on the brush border during the pre-hibernation period. In the hibernation period, moderate ANP immunoreactivity was seen in cortical proximal tubules, with very weak reaction in hibernating cortical distal tubules, medullary proximal and collecting tubules. Cortical proximal and distal tubules of both periods had strong and weak BNP immunoreactivity, respectively. Medullary proximal, distal and Henle's loop segments showed very weak BNP immunoreactivity during pre-hibernation. Medullary distal, proximal and collecting tubules and Henle's loop segments had moderate staining during hibernation. In both periods, cortical proximal tubules displayed strong immunoreactivity to CNP. Distal tubules had moderate CNP staining during pre-hibernation, albeit weak staining during hibernation. Medullary proximal tubules exhibited moderate to strong immunoreactivity during pre-hibernation. Medullary distal and proximal tubules had weak and moderate CNP staining, respectively, during pre-hibernation. In both periods, Henle's loop segments displayed moderate CNP immunoreactivity. Glomeruli had similar weak ANP, BNP and CNP staining in both periods. These results suggest that heterothermic conditions differently affected the expression of NPs in the squirrel kidney. This different expression of NPs may contribute to the renal adaptation during hibernation.
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Do critical care patients hibernate? Theoretical support for less is more. Intensive Care Med 2019; 46:495-497. [PMID: 31705167 DOI: 10.1007/s00134-019-05813-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 09/27/2019] [Indexed: 10/25/2022]
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Kim AB, Milsom WK. pH regulation in hibernation: Implications for ventilatory and metabolic control. Comp Biochem Physiol A Mol Integr Physiol 2019; 237:110536. [DOI: 10.1016/j.cbpa.2019.110536] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 08/01/2019] [Accepted: 08/02/2019] [Indexed: 10/26/2022]
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Ou J, Rosa S, Berchowitz LE, Li W. Induced pluripotent stem cells as a tool for comparative physiology: lessons from the thirteen-lined ground squirrel. J Exp Biol 2019; 222:jeb196493. [PMID: 31585999 PMCID: PMC6806009 DOI: 10.1242/jeb.196493] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Comparative physiologists are often interested in adaptive physiological phenomena found in unconventional model organisms; however, research on these species is frequently constrained by the limited availability of investigative tools. Here, we propose that induced pluripotent stem cells (iPSCs) from unconventional model organisms may retain certain species-specific features that can consequently be investigated in depth in vitro; we use hibernating mammals as an example. Many species (including ground squirrels, bats and bears) can enter a prolonged state of physiological dormancy known as hibernation to survive unfavorable seasonal conditions. Our understanding of the mechanisms underpinning the rapid transition and adaptation to a hypothermic, metabolically suppressed winter torpor state remains limited partially because of the lack of an easily accessible model. To address the fascinating unanswered questions underlying hibernation biology, we have developed a powerful model system: iPSCs from a hibernating species, the thirteen-lined ground squirrel (Ictidomys tridecemlineatus). These stem cells can potentially be differentiated into any cell type, and can be used for the analysis of cell-autonomous mechanisms that facilitate adaptation to hibernation and for comparisons with non-hibernators. Furthermore, we can manipulate candidate molecular and cellular pathways underlying relevant physiological phenomena by pharmacological or RNAi-based methods, and CRISPR/Cas9 gene editing. Moreover, iPSC strategies can be applied to other species (e.g. seals, naked mole rats, humming birds) for in vitro studies on adaptation to extreme physiological conditions. In this Commentary, we discuss factors to consider when attempting to generate iPSCs from unconventional model organisms, based on our experience with the thirteen-lined ground squirrel.
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Affiliation(s)
- Jingxing Ou
- Retinal Neurophysiology Section, National Eye Institute, US National Institutes of Health, Bethesda, MD 20892, USA
| | - Sarah Rosa
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
- Taub Institute for Research on Alzheimer's and the Aging Brain, New York, NY 10032, USA
| | - Luke E Berchowitz
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
- Taub Institute for Research on Alzheimer's and the Aging Brain, New York, NY 10032, USA
| | - Wei Li
- Retinal Neurophysiology Section, National Eye Institute, US National Institutes of Health, Bethesda, MD 20892, USA
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Wang X, Watt CF, Sinclair KJ, McKenzie CA, Staples JF, MacCannell ADV. Thermoneutral temperature reduces liver volume but increases fat content in a mammalian hibernator. J Therm Biol 2019; 83:172-177. [PMID: 31331516 DOI: 10.1016/j.jtherbio.2019.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 05/04/2019] [Accepted: 05/19/2019] [Indexed: 11/25/2022]
Abstract
Hibernators survive challenging winters by entering torpor, which lowers body temperature (Tb) to ∼5 °C for 12-14 days, followed by spontaneous arousals where Tb increases to ∼37 °C for 10-12 h before entering another torpor bout. This Tb cycle is accompanied by significant fluctuations in metabolic rate. Little is known about the role of the liver in lipid metabolism during hibernation. In this study we measured the effect of ambient temperature on liver volume and lipid content in 13-lined ground squirrels (Ictidomys tridecemlineatus). We housed animals at thermoneutral (25 °C) or cold (5 °C) ambient temperatures, with the same photoperiod (12 h light:12 h dark) for an entire year. We determined volume and water-fat ratio of the liver using magnetic resonance imaging (MRI). Ambient temperature significantly affected both liver volume and fat content. From October to August squirrels housed at 25 °C had 25% smaller livers compared to the squirrels housed at 5 °C, but their average lipid content (13.3%) was 37% higher. Because the squirrels housed at 25 °C appeared to continue feeding throughout the winter but did not enter extended torpor, more carbohydrates may have been diverted to lipid stores. By contrast, animals housed at 5 °C did not appear to feed, and carbohydrates would likely be preferentially stored in the liver as glycogen to supply glucose for brain metabolism. These results suggest that the fat burden caused by hibernators preparing for winter can lead to symptoms of metabolic syndrome, but that these symptoms are reversible in the spring.
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Affiliation(s)
- Xingyi Wang
- Dept. of Biology, University of Western Ontario, London ON, N6A5B8, Canada; Dept. of Medical Biophysics, University of Western Ontario, London ON, N6A5B7, Canada
| | - Christine F Watt
- Dept. of Biology, University of Western Ontario, London ON, N6A5B8, Canada
| | - Kevin J Sinclair
- Dept. of Medical Biophysics, University of Western Ontario, London ON, N6A5B7, Canada
| | - Charles A McKenzie
- Dept. of Medical Biophysics, University of Western Ontario, London ON, N6A5B7, Canada
| | - James F Staples
- Dept. of Biology, University of Western Ontario, London ON, N6A5B8, Canada
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42
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Mathers KE, Staples JF. Differential posttranslational modification of mitochondrial enzymes corresponds with metabolic suppression during hibernation. Am J Physiol Regul Integr Comp Physiol 2019; 317:R262-R269. [PMID: 31067076 DOI: 10.1152/ajpregu.00052.2019] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During hibernation, small mammals, including the 13-lined ground squirrel (Ictidomys tridecemlineatus), cycle between two distinct metabolic states: torpor, where metabolic rate is suppressed by >95% and body temperature falls to ~5°C, and interbout euthermia (IBE), where both metabolic rate and body temperature rapidly increase to euthermic levels. Suppression of whole animal metabolism during torpor is paralleled by rapid, reversible suppression of mitochondrial respiration. We hypothesized that these changes in mitochondrial metabolism are regulated by posttranslational modifications to mitochondrial proteins. Differential two-dimensional gel electrophoresis and two-dimensional blue-native PAGE revealed differences in the isoelectric point of several liver mitochondrial proteins between torpor and IBE. Quadrupole time-of-flight LC/MS and matrix-assisted laser desorption/ionization MS identified these as proteins involved in β-oxidation, the tricarboxylic acid cycle, reactive oxygen species detoxification, and the electron transport system (ETS). Immunoblots revealed that subunit 1 of ETS complex IV was acetylated during torpor but not IBE. Phosphoprotein staining revealed significantly greater phosphorylation of succinyl-CoA ligase and the flavoprotein subunit of ETS complex II in IBE than torpor. In addition, the 75-kDa subunit of ETS complex I was 1.5-fold more phosphorylated in torpor. In vitro treatment with alkaline phosphatase increased the maximal activity of complex I from liver mitochondria isolated from torpid, but not IBE, animals. By contrast, phosphatase treatment decreased complex II activity in IBE but not torpor. These findings suggest that the rapid changes in mitochondrial metabolism in hibernators are mediated by posttranslational modifications of key metabolic enzymes, perhaps by intramitochondrial kinases and deacetylases.
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Affiliation(s)
- Katherine E Mathers
- Department of Biology, University of Western Ontario , London, Ontario , Canada.,Department of Physiology and Pharmacology, University of Western Ontario , London, Ontario , Canada
| | - James F Staples
- Department of Biology, University of Western Ontario , London, Ontario , Canada
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43
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Sajdak BS, Salmon AE, Litts KM, Wells C, Allen KP, Dubra A, Merriman DK, Carroll J. Evaluating seasonal changes of cone photoreceptor structure in the 13-lined ground squirrel. Vision Res 2019; 158:90-99. [PMID: 30826354 PMCID: PMC6538439 DOI: 10.1016/j.visres.2019.02.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/21/2019] [Accepted: 02/24/2019] [Indexed: 12/15/2022]
Abstract
Cone photoreceptors of the 13-lined ground squirrel (13-LGS) undergo reversible structural changes during hibernation, including cone outer segment disc degeneration and inner segment mitochondria depletion. Here, we evaluated cone structure with adaptive optics scanning light ophthalmoscopy (AOSLO) before, during, and after hibernation. Also, intra-animal comparisons of cone structure were made at distinct physiological states (pre-hibernation, torpor, interbout euthermia, and post-hibernation) with AOSLO and transmission electron microscopy. Our results indicate that the 13-LGS cone mosaic is only transiently affected by structural remodeling during hibernation. Outer segment remodeling starts during torpid states during a period of fall transition in room temperature, with more severe structural changes during bouts of torpor in cold temperature. Cones return to euthermic-like structure during brief periods of interbout euthermia and recover normal waveguiding properties as soon as 24 h post-hibernation. Cone structure is visible with split-detector AOSLO throughout hibernation, providing evidence that intact outer segments are not necessary to visualize cones with this technique. Despite the changes to cone structure during hibernation, cone density and packing remained unchanged throughout the seasonal cycle. Pairing non-invasive imaging with ultrastructural assessment may provide insight to the biological origins of cone photoreceptor signals observed with AOSLO.
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Affiliation(s)
- Benjamin S Sajdak
- Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Alexander E Salmon
- Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Katie M Litts
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Clive Wells
- Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Kenneth P Allen
- Biomedical Resource Center, Medical College of Wisconsin, Milwaukee, WI, USA; Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Alfredo Dubra
- Ophthalmology, Stanford University, Stanford, CA, USA
| | | | - Joseph Carroll
- Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA; Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA; Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA.
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Haase CG, Fuller NW, Hranac CR, Hayman DTS, Olson SH, Plowright RK, McGuire LP. Bats are not squirrels: Revisiting the cost of cooling in hibernating mammals. J Therm Biol 2019; 81:185-193. [PMID: 30975417 DOI: 10.1016/j.jtherbio.2019.01.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 12/18/2018] [Accepted: 01/21/2019] [Indexed: 01/23/2023]
Abstract
Many species use stored energy to hibernate through periods of resource limitation. Hibernation, a physiological state characterized by depressed metabolism and body temperature, is critical to winter survival and reproduction, and therefore has been extensively quantified and modeled. Hibernation consists of alternating phases of extended periods of torpor (low body temperature, low metabolic rate), and energetically costly periodic arousals to normal body temperature. Arousals consist of multiple phases: warming, euthermia, and cooling. Warming and euthermic costs are regularly included in energetic models, but although cooling to torpid body temperature is an important phase of the torpor-arousal cycle, it is often overlooked in energetic models. When included, cooling cost is assumed to be 67% of warming cost, an assumption originally derived from a single study that measured cooling cost in ground squirrels. Since this study, the same proportional value has been assumed across a variety of hibernating species. However, no additional values have been derived. We derived a model of cooling cost from first principles and validated the model with empirical energetic measurements. We compared the assumed 67% proportional cooling cost with our model-predicted cooling cost for 53 hibernating mammals. Our results indicate that using 67% of warming cost only adequately represents cooling cost in ground squirrel-sized mammals. In smaller species, this value overestimates cooling cost and in larger species, the value underestimates cooling cost. Our model allows for the generalization of energetic costs for multiple species using species-specific physiological and morphometric parameters, and for predictions over variable environmental conditions.
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Affiliation(s)
- Catherine G Haase
- Department of Microbiology and Immunology, Montana State University, 109 Lewis Hall, PO Box 173520, Bozeman, MT 59717, USA.
| | - Nathan W Fuller
- Department of Biological Sciences, Texas Tech University, 2901 Main St., Lubbock, TX 79409, USA
| | - C Reed Hranac
- Molecular Epidemiology and Public Health Laboratory, Hopkirk Research Institute, Massey University, Private Bag, 11 222, Palmerston North 4442, New Zealand
| | - David T S Hayman
- Molecular Epidemiology and Public Health Laboratory, Hopkirk Research Institute, Massey University, Private Bag, 11 222, Palmerston North 4442, New Zealand
| | - Sarah H Olson
- Wildlife Conservation Society, 2300 Southern Boulevard, Bronx, NY 10460, USA
| | - Raina K Plowright
- Department of Microbiology and Immunology, Montana State University, 109 Lewis Hall, PO Box 173520, Bozeman, MT 59717, USA
| | - Liam P McGuire
- Department of Biological Sciences, Texas Tech University, 2901 Main St., Lubbock, TX 79409, USA
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Oliver SR, Anderson KJ, Hunstiger MM, Andrews MT. Turning down the heat: Down-regulation of sarcolipin in a hibernating mammal. Neurosci Lett 2018; 696:13-19. [PMID: 30528880 DOI: 10.1016/j.neulet.2018.11.059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/30/2018] [Accepted: 11/30/2018] [Indexed: 02/01/2023]
Abstract
Hibernation in mammals is a whole-body phenotype that involves profound reductions in oxygen consumption, metabolic reactions, core body temperature, neural activity and heart rate. An important aspect of mammalian hibernation is the ability to reverse this state of hypothermic torpor by rewarming and subsequent arousal. Brown adipose tissue (BAT) and skeletal muscle shivering have been characterized as the predominant driving forces for thermogenesis during arousal. Conversely, the thermogenic contribution of these organs needs to be minimized as hibernating mammals enter torpor. Because skeletal muscle accounts for approximately 40% of the dry mass of the typical mammalian body, we aim to broaden the spotlight to include the importance of down-regulating skeletal muscle non-shivering thermogenesis during hibernation to allow for whole-body cooling and long-term maintenance of a depressed core body temperature when the animal is in torpor. This minireview will briefly describe the current understanding of thermoregulation in hibernating mammals and present new preliminary data on the importance of skeletal muscle and the micro-peptide sarcolipin as a major thermogenic target.
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Affiliation(s)
- S Ryan Oliver
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
| | - Kyle J Anderson
- Department of Biomedical Sciences, University of Minnesota Medical School Duluth, Duluth, MN 55812, USA.
| | - Moriah M Hunstiger
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
| | - Matthew T Andrews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA.
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Cortes PA, Bozinovic F, Blier PU. Mitochondrial phenotype during torpor: Modulation of mitochondrial electron transport system in the Chilean mouse-opossum Thylamys elegans. Comp Biochem Physiol A Mol Integr Physiol 2018; 221:7-14. [PMID: 29551753 DOI: 10.1016/j.cbpa.2017.12.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 11/30/2017] [Accepted: 12/08/2017] [Indexed: 12/20/2022]
Abstract
Mammalian torpor is a phenotype characterized by a controlled decline of metabolic rate, generally followed by a reduction in body temperature. During arousal from torpor, both metabolic rate and body temperature rapidly returns to resting levels. Metabolic rate reduction experienced by torpid animals is triggered by active suppression of mitochondrial respiration, which is rapidly reversed during rewarming process. In this study, we analyzed the changes in the maximal activity of key enzymes related to electron transport system (complexes I, III and IV) in six tissues of torpid, arousing and euthermic Chilean mouse-opossums (Thylamys elegans). We observed higher maximal activities of complexes I and IV during torpor in brain, heart and liver, the most metabolically active organs in mammals. On the contrary, higher enzymatic activities of complexes III were observed during torpor in kidneys and lungs. Moreover, skeletal muscle was the only tissue without significant differences among stages in all complexes evaluated, suggesting no modulation of oxidative capacities of electron transport system components in this thermogenic tissue. In overall, our data suggest that complexes I and IV activity plays a major role in initiation and maintenance of metabolic suppression during torpor in Chilean mouse-opossum, whereas improvement of oxidative capacities in complex III might be critical to sustain metabolic machinery in organs that remains metabolically active during torpor.
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Affiliation(s)
- Pablo A Cortes
- Escuela de Agronomía, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide, 5750, Huechuraba, Chile; Departamento de Ecología, Center of Applied Ecology and Sustainability, Facultad de Ciencias Biológicas, Universidad Católica de Chile, Santiago 6513677, Chile.
| | - Francisco Bozinovic
- Departamento de Ecología, Center of Applied Ecology and Sustainability, Facultad de Ciencias Biológicas, Universidad Católica de Chile, Santiago 6513677, Chile
| | - Pierre U Blier
- Département de Biologie, Laboratoire de Physiologie Animale Intégrative, Université du Québec, Rimouski G5L 3A1, QC, Canada
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Ballinger MA, Andrews MT. Nature's fat-burning machine: brown adipose tissue in a hibernating mammal. ACTA ACUST UNITED AC 2018. [PMID: 29514878 DOI: 10.1242/jeb.162586] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Brown adipose tissue (BAT) is a unique thermogenic tissue in mammals that rapidly produces heat via nonshivering thermogenesis. Small mammalian hibernators have evolved the greatest capacity for BAT because they use it to rewarm from hypothermic torpor numerous times throughout the hibernation season. Although hibernator BAT physiology has been investigated for decades, recent efforts have been directed toward understanding the molecular underpinnings of BAT regulation and function using a variety of methods, from mitochondrial functional assays to 'omics' approaches. As a result, the inner-workings of hibernator BAT are now being illuminated. In this Review, we discuss recent research progress that has identified players and pathways involved in brown adipocyte differentiation and maturation, as well as those involved in metabolic regulation. The unique phenotype of hibernation, and its reliance on BAT to generate heat to arouse mammals from torpor, has uncovered new molecular mechanisms and potential strategies for biomedical applications.
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Affiliation(s)
- Mallory A Ballinger
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Matthew T Andrews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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Roussel D, Boël M, Romestaing C. Fasting enhances mitochondrial efficiency in duckling skeletal muscle by acting on the substrate oxidation system. ACTA ACUST UNITED AC 2018; 221:jeb.172213. [PMID: 29361595 DOI: 10.1242/jeb.172213] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 12/14/2017] [Indexed: 01/15/2023]
Abstract
During food deprivation, animals must develop physiological responses to maximize energy conservation and survival. At the subcellular level, energy conservation is mainly achieved by a reduction in mitochondrial activity and an upregulation of oxidative phosphorylation efficiency. The aim of this study was to decipher mechanisms underlying the increased mitochondrial coupling efficiency reported in fasted birds. Mitochondrial oxidative phosphorylation activity, efficiency and membrane potential were measured in mitochondria isolated from the gastrocnemius muscle of ducklings. The content and activities of respiratory chain complexes were also determined. Results from ducklings fasted for 6 days were compared with ducklings fed ad libitum Here, we report that 6 days of fasting improved coupling efficiency in muscle mitochondria of ducklings by depressing proton-motive force through the downregulation of substrate oxidation reactions. Fasting did not change the basal proton conductance of mitochondria but largely decreased the oxidative phosphorylation activity, which was associated with decreased activities of succinate-cytochrome c reductase (complexes II-III) and citrate synthase, and altered contents in cytochromes b and c+c1 In contrast, fasting did not change cytochrome aa3 content or the activity of complexes I, II and IV. Altogether, these data show that the lower capacity of the respiratory machinery to pump protons in ducklings fasted for 6 days generates a lower membrane potential, which triggers a decreased proton leak activity and thus a higher coupling efficiency. We propose that the main site of action would be located at the level of co-enzyme Q pool/complex III of the electron transport chain.
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Affiliation(s)
- Damien Roussel
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, UMR 5023, CNRS, Université Claude Bernard Lyon 1, ENTPE, F-69622, Villeurbanne, France
| | - Mélanie Boël
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, UMR 5023, CNRS, Université Claude Bernard Lyon 1, ENTPE, F-69622, Villeurbanne, France
| | - Caroline Romestaing
- Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés, UMR 5023, CNRS, Université Claude Bernard Lyon 1, ENTPE, F-69622, Villeurbanne, France
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Singer M. Critical illness and flat batteries. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2017; 21:309. [PMID: 29297363 PMCID: PMC5751585 DOI: 10.1186/s13054-017-1913-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
An exaggerated, dysregulated host response to insults such as infection (i.e. sepsis), trauma and ischaemia-reperfusion injury can result in multiple organ dysfunction and death. While the focus of research in this area has largely centred on inflammation and immunity, a crucial missing link is the precise identification of mechanisms at the organ level that cause this physiological-biochemical failure. Any hypothesis must reconcile this functional organ failure with minimal signs of cell death, availability of oxygen, and (often) minimal early local inflammatory cell infiltrate. These failed organs also retain the capacity to usually recover, even those that are poorly regenerative. A metabolic-bioenergetic shutdown, akin to hibernation or aestivation, is the most plausible explanation currently advanced. This shutdown appears driven by a perfect storm of compromised mitochondrial oxidative phosphorylation related to inhibition by excessive inflammatory mediators, direct oxidant stress, a tissue oxygen deficit in the unresuscitated phase, altered hormonal drive, and downregulation of genes encoding mitochondrial proteins. In addition, the efficiency of oxidative phosphorylation may be affected by a substrate shift towards fat metabolism and increased uncoupling. A lack of sufficient ATP provision to fuel normal metabolic processes will drive downregulation of metabolism, and thus cellular functionality. In turn, a decrease in metabolism will provide negative feedback to the mitochondrion, inducing a bioenergetic shutdown. Arguably, these processes may offer protection against a prolonged inflammatory hit by sparing the cell from initiation of death pathways, thereby explaining the lack of significant morphological change. A narrow line may exist between adaptation and maladaptation. This places a considerable challenge on any therapeutic modulation to provide benefit rather than harm.
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Affiliation(s)
- Mervyn Singer
- Bloomsbury Institute of Intensive Care Medicine, Cruciform Building, University College London, London, WC1E 6BT, UK.
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50
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Differences in mitochondrial function and morphology during cooling and rewarming between hibernator and non-hibernator derived kidney epithelial cells. Sci Rep 2017; 7:15482. [PMID: 29138454 PMCID: PMC5686174 DOI: 10.1038/s41598-017-15606-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 10/30/2017] [Indexed: 01/06/2023] Open
Abstract
Hibernators show superior resistance to ischemia and hypothermia, also outside the hibernation season. Therefore, hibernation is a promising strategy to decrease cellular damage in a variety of fields, such as organ transplantation. Here, we explored the role of mitochondria herein, by comparing epithelial cell lines from a hibernator (hamster kidney cells, HaK) and a non-hibernator (human embryonic kidney cells, HEK293) during cold preservation at 4 °C and rewarming. Cell survival (Neutral Red), ATP and MDA levels, mitochondrial membrane potential (MMP), mitochondrial morphology (using fluorescent probes) and metabolism (seahorse XF) were assessed. Hypothermia induced dispersion of the tubular mitochondrial network, a loss of MMP, increased oxygen radical (MDA) and decreased ATP production in HEK293. In contrast, HaK maintained MMP and ATP production without an increase in oxygen radicals during cooling and rewarming, resulting in superior cell survival compared to HEK293. Further, normothermic HaK showed a dispersed mitochondrial network and higher respiratory and glycolysis capacity compared to HEK293. Disclosing the mechanisms that hibernators use to counteract cell death in hypothermic and ischemic circumstances may help to eventually improve organ preservation in a variety of fields, including organ transplantation.
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