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Ishimoto T, Kosumi H, Natsuga K, Yamaguchi Y. Nail growth arrest under low body temperature during hibernation. J Physiol Sci 2024; 74:27. [PMID: 38678189 PMCID: PMC11055321 DOI: 10.1186/s12576-024-00919-2] [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: 11/25/2023] [Accepted: 04/06/2024] [Indexed: 04/29/2024]
Abstract
Growth and differentiation are reduced or stopped during hibernation, an energy conserving strategy in harsh seasons by lowered metabolism and body temperature. However, few studies evaluated this in a same individual using a non-invasive method. In this study, we applied a non-invasive tracking method of the nail growth throughout the hibernation period in the same hibernating animals, the Syrian hamster (Mesocricetus auratus). We found that nail growth was markedly suppressed during the hibernation period but rapidly recovered by the exit from the hibernation period. Our data suggest that nail growth was arrested during deep torpor, a hypometabolic and hypothermic state, but recovered during periodic arousal, a euthermic phase. Consistent with this, nail stem cells located in the nail matrix did not exit the cell cycle in the deep torpor. Thus, hibernation stops nail growth in a body temperature-dependent manner.
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Affiliation(s)
- Taiga Ishimoto
- Laboratory of Biochemistry, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
- Department of Neuroscience for Metabolic Control, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Hideyuki Kosumi
- Department of Dermatology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Ken Natsuga
- Department of Dermatology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
| | - Yoshifumi Yamaguchi
- Hibernation Metabolism, Physiology and Development Group, Institute of Low Temperature Science, Hokkaido University, Sapporo, Hokkaido, Japan.
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan.
- Inamori Research Institute for Science Fellowship (InaRIS), Kyoto, Japan.
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2
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Power ML, Ransome RD, Riquier S, Romaine L, Jones G, Teeling EC. Hibernation telomere dynamics in a shifting climate: insights from wild greater horseshoe bats. Proc Biol Sci 2023; 290:20231589. [PMID: 37817598 PMCID: PMC10565397 DOI: 10.1098/rspb.2023.1589] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 09/10/2023] [Indexed: 10/12/2023] Open
Abstract
Hibernation is linked with various hypotheses to explain the extended lifespan of hibernating mammals compared with their non-hibernating counterparts. Studies on telomeres, markers of ageing and somatic maintenance, suggest telomere shortening slows during hibernation, and lengthening may reflect self-maintenance with favourable conditions. Bats in temperate zones adjust body temperatures during winter torpor to conserve energy and exploit mild conditions for foraging. Climate change may impact the hibernation cycle of bats, but more research is needed regarding the role of telomeres in understanding their response to a changing climate. Here, relative telomere length (rTL) was measured in the long-lived greater horseshoe bat Rhinolophus ferrumequinum (n = 223 individuals) over three winters, considering climatic conditions. Cross-sectional analyses revealed between-individual variation in rTL with a strong year effect, likely linked to varying weather conditions and foraging success. Additionally, within-individual increases of rTL occurred in 51% of consecutive measurements, with evidence of increasing telomerase expression during hibernation in this species. These findings highlight the beneficial effects of hibernation on telomeres and potential consequences of changing climatic conditions for long-lived temperate bats. Understanding the interplay between hibernation, telomeres, and climate can provide insights into the adaptive capacity and survival of bat populations facing environmental challenges.
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Affiliation(s)
- Megan L Power
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Republic of Ireland
| | - Roger D Ransome
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Sébastien Riquier
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Republic of Ireland
| | - Luke Romaine
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Gareth Jones
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Emma C Teeling
- School of Biology and Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin 4, Republic of Ireland
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3
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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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Giroud S, Ragger MT, Baille A, Hoelzl F, Smith S, Nowack J, Ruf T. Food availability positively affects the survival and somatic maintenance of hibernating garden dormice (Eliomys quercinus). Front Zool 2023; 20:19. [PMID: 37226260 PMCID: PMC10207780 DOI: 10.1186/s12983-023-00498-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/15/2023] [Indexed: 05/26/2023] Open
Abstract
BACKGROUND Torpor is an energy saving strategy achieved by substantial reductions of metabolic rate and body temperature that enables animals to survive periods of low resource availability. During hibernation (multiday torpor), the frequency of periodic rewarming-characterised by high levels of oxidative stress-is associated with shortening of telomeres, a marker of somatic maintenance. OBJECTIVES In this study, we determined the impact of ambient temperature on feeding behaviour and telomere dynamics in hibernating garden dormice (Eliomys quercinus) over winter. This obligate hibernator prepares for hibernation by accumulating fat stores but can also feed during hibernation. METHODOLOGY Food intake, torpor pattern, changes in telomere length, and body mass change were assessed in animals housed at experimentally controlled temperatures of either 14 °C (i.e., a mild winter) or 3 °C (i.e., a cold winter) over 6 months. RESULTS When hibernating at 14 °C, dormice experienced 1.7-fold more frequent and 2.4-fold longer inter-bout euthermia, and spent significantly less time torpid, compared to animals hibernating at 3 °C. Higher food intake enabled individuals to compensate for increased energetic costs when hibernating at milder temperatures (14 °C vs. 3 °C), to buffer body mass loss and thus increase winter survival. Interestingly, we observed a significant increase of telomere length over the entire hibernation period, irrespective of temperature treatment. CONCLUSION We conclude that higher temperatures during winter, if associated with sufficient food availability, can have a positive effect on the individual's energy balance and somatic maintenance. These results suggest that winter food availability might be a crucial determinant for the survival of the garden dormouse in the context of ever-increasing environmental temperatures.
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Affiliation(s)
- Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria.
| | - Marie-Therese Ragger
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria
| | - Amélie Baille
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria
| | - Franz Hoelzl
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Steve Smith
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Julia Nowack
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Thomas Ruf
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Savoyenstraße 1, 1160, Vienna, Austria
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Lin R, Wu J, You Z, Xu D, Li C, Wang W, Qian G. Induction of Hibernation and Changes in Physiological and Metabolic Indices in Pelodiscus sinensis. BIOLOGY 2023; 12:biology12050720. [PMID: 37237532 DOI: 10.3390/biology12050720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 05/02/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023]
Abstract
Pelodiscus sinensis (P. sinensis) is a commonly cultivated turtle species with a habit of hibernation. To study the changes in histone expression and methylation of P. sinensis during hibernation induction, a model was established by artificial induction. Physiological and metabolic indices were measured, and the expression and localization of histone (H1, H2A, H2B, H3, and H4) and methylation-related genes (ASH2L, KMT2A, KMT2E, KDM1A, KDM1B, and KDM5A) were measured by quantitative PCR, immunohistochemistry, and Western blot analysis. The results indicated that the metabolism, antioxidation index, and relative expression of histone methyltransferase were significantly decreased (p < 0.05), whereas the activity and expression of histone demethyltransferase were significantly increased (p < 0.05). Although our results showed significant changes in physiological and gene expression after hibernation induction, we could not confirm that P. sinensis entered deep hibernation. Therefore, for the state after cooling-induced hibernation, cold torpor might be a more accurate description. The results indicate that the P. sinensis can enter cold torpor through artificial induction, and the expression of histones may promote gene transcription. Unlike histones expressed under normal conditions, histone methylation may activate gene transcription during hibernation induction. Western blot analysis revealed that the ASH2L and KDM5A proteins were differentially expressed in the testis at different months (p < 0.05), which may perform a role in regulating gene transcription. The immunohistochemical localization of ASH2L and KDM5A in spermatogonia and spermatozoa suggests that ASH2L and KDM5A may perform a role in mitosis and meiosis. In conclusion, this study is the first to report changes in histone-related genes in reptiles, which provides insight for further studies on the physiological metabolism and histone methylation regulation of P. sinensis during the hibernation induction and hibernation period.
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Affiliation(s)
- Runlan Lin
- College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
- College of Biology and Environment, Zhejiang Wanli University, Ningbo 315100, China
| | - Jiahao Wu
- College of Biology and Environment, Zhejiang Wanli University, Ningbo 315100, China
| | - Ziyi You
- College of Biology and Environment, Zhejiang Wanli University, Ningbo 315100, China
| | - Dongjie Xu
- College of Biology and Environment, Zhejiang Wanli University, Ningbo 315100, China
| | - Caiyan Li
- College of Biology and Environment, Zhejiang Wanli University, Ningbo 315100, China
| | - Wei Wang
- College of Biology and Environment, Zhejiang Wanli University, Ningbo 315100, China
| | - Guoying Qian
- College of Biology and Environment, Zhejiang Wanli University, Ningbo 315100, China
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6
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van Lieshout SHJ, Badás EP, Bright Ross JG, Bretman A, Newman C, Buesching CD, Burke T, Macdonald DW, Dugdale HL. Early-life seasonal, weather and social effects on telomere length in a wild mammal. Mol Ecol 2022; 31:5993-6007. [PMID: 34101279 DOI: 10.1111/mec.16014] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 06/03/2021] [Indexed: 01/31/2023]
Abstract
Early-life environmental conditions can provide a source of individual variation in life-history strategies and senescence patterns. Conditions experienced in early life can be quantified by measuring telomere length, which can act as a biomarker of survival probability in some species. Here, we investigate whether seasonal changes, weather conditions and group size are associated with early-life and/or early-adulthood telomere length in a wild population of European badgers (Meles meles). We found substantial intra-annual changes in telomere length during the first 3 years of life, where within-individual effects showed shorter telomere lengths in the winter following the first spring and a trend for longer telomere lengths in the second spring compared to the first winter. In terms of weather conditions, cubs born in warmer, wetter springs with low rainfall variability had longer early-life (3-12 months old) telomeres. Additionally, cubs born in groups with more cubs had marginally longer early-life telomeres, providing no evidence of resource constraint from cub competition. We also found that the positive association between early-life telomere length and cub survival probability remained when social and weather variables were included. Finally, after sexual maturity, in early adulthood (i.e., 12-36 months) we found no significant association between same-sex adult group size and telomere length (i.e., no effect of intrasexual competition). Overall, we show that controlling for seasonal effects, which are linked to food availability, is important in telomere length analyses, and that variation in telomere length in badgers reflects early-life conditions and also predicts first year cub survival.
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Affiliation(s)
- Sil H J van Lieshout
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.,NERC Environmental Omics Visitor Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Elisa P Badás
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Julius G Bright Ross
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Abingdon, UK
| | - Amanda Bretman
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Chris Newman
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Abingdon, UK
| | - Christina D Buesching
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Abingdon, UK.,Department of Biology, The University of British Columbia, Okanagan, Kelowna, British Columbia, Canada
| | - Terry Burke
- NERC Environmental Omics Visitor Facility, Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - David W Macdonald
- Wildlife Conservation Research Unit, Department of Zoology, The Recanati-Kaplan Centre, University of Oxford, Abingdon, UK
| | - Hannah L Dugdale
- School of Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
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Clonidine for sedation in infants during therapeutic hypothermia with neonatal encephalopathy: pilot study. J Perinatol 2022; 42:319-327. [PMID: 34531532 PMCID: PMC8917970 DOI: 10.1038/s41372-021-01151-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 01/25/2021] [Accepted: 02/04/2021] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To determine a safe dose of clonidine (CLON) to be used in infants with hypoxic ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH). STUDY DESIGN A pilot prospective study was performed to determine the effect of CLON on autonomic parameters, the pharmacokinetics (PK) of CLON, and the amount of morphine (MOR) given "as needed" for shivering and agitation in a cohort of infants (n = 12) with HIE undergoing TH compared to a historical control group (n = 28). RESULTS The CLON group received less "as needed" MOR than the MOR-only group for agitation/shivering (p < 0.001), and the CLON vs. MOR-only group spent 92% vs. 79% of cooling time at the target core body temperature (CBT; p = 0.03, CLON vs. MOR). CONCLUSIONS Intravenous CLON (1 mcg/kg Q8h) is well tolerated in infants treated with TH for HIE. CLON stabilizes CBT in the ideal range during cooling, which may be optimal for neuroprotection.
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Golpich M, Amini E, Kefayat A, Fesharaki M, Moshtaghian J. In vitro and in vivo anti-cancer effects of hibernating common carp (Cyprinus carpio) plasma on metastatic triple-negative breast cancer. Sci Rep 2022; 12:2855. [PMID: 35190572 PMCID: PMC8861139 DOI: 10.1038/s41598-022-06368-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 01/28/2022] [Indexed: 11/28/2022] Open
Abstract
Uncontrollable proliferation is a hallmark of cancer cells. Cell proliferation and migration are significantly depressed during hibernation state. Many studies believe some factors in the plasma of hibernating animals cause these effects. This study aimed to assess the anti-cancer effects of hibernating common carp (Cyprinus carpio) plasma on 4T1 cancer cells in vitro and in vivo. The effect of hibernating plasma on cell viability, morphology, migration, apoptosis rate, and cell cycle distribution of 4T1 cells was investigated in vitro and in vivo. Hibernating plasma at a concentration of 16 mg/ml significantly reduced the viability of 4T1 cancer cells, without any toxicity on L929 normal fibroblast cells. It could change the morphology of cancer cells, induced apoptosis and cell cycle arrest at the G2/M phase, and inhibited migration. Furthermore, intratumoral injection of hibernating plasma (200 µl, 16 mg/ml) in the tumor-bearing mice caused a significant inhibition of 4T1 breast tumors volume (46.9%) and weight (58.8%) compared with controls. A significant decrease in the number of metastatic colonies at the lungs (80%) and liver (52.8%) of hibernating plasma-treated animals was detected which increased the survival time (21.9%) compared to the control groups. Immunohistochemical analysis revealed a considerable reduction in the Ki-67-positive cells in the tumor section of the hibernating plasma-treated animals compared with controls. Taken together, the SDS-PAGE and mass spectrometry analysis indicated the alpha-2-macroglobulin level in the hibernating fish plasma was significantly increased. It could exert an anti-cancer effect on breast cancer cells and suggested as a novel cancer treatment strategy.
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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: 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: 11/01/2020] [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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10
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Nowack J, Tarmann I, Hoelzl F, Smith S, Giroud S, Ruf T. Always a price to pay: hibernation at low temperatures comes with a trade-off between energy savings and telomere damage. Biol Lett 2019; 15:20190466. [PMID: 31573426 PMCID: PMC6832184 DOI: 10.1098/rsbl.2019.0466] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/10/2019] [Indexed: 12/16/2022] Open
Abstract
We experimentally tested the costs of deep torpor at low temperatures by comparing telomere dynamics in two species of rodents hibernating at either 3 or 14°C. Our data show that hibernators kept at the warmer temperature had higher arousal frequencies, but maintained longer telomeres than individuals hibernating at the colder temperature. We suggest that the high-energy demand of frequent arousals is counteracted by a lower temperature differential between torpid and euthermic body temperature and that telomere length is restored during arousals when the body temperature is returned to normothermic values. Taken together, our study shows that hibernation at low body temperatures comes with costs on a cellular level and that hibernators need to actively counterbalance the shortening of telomeres.
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Affiliation(s)
- Julia Nowack
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
- School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, UK
| | - Iris Tarmann
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Franz Hoelzl
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Steve Smith
- Department of Interdisciplinary Life Sciences, Konrad Lorenz Institute of Ethology, University of Veterinary Medicine, Vienna, Austria
| | - Sylvain Giroud
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Thomas Ruf
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
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11
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Wilbur SM, Barnes BM, Kitaysky AS, Williams CT. Tissue-specific telomere dynamics in hibernating arctic ground squirrels ( Urocitellus parryii). ACTA ACUST UNITED AC 2019; 222:jeb.204925. [PMID: 31515236 DOI: 10.1242/jeb.204925] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 09/03/2019] [Indexed: 01/25/2023]
Abstract
Hibernation is used by a variety of mammals to survive seasonal periods of resource scarcity. Reactive oxygen species (ROS) released during periodic rewarming throughout hibernation, however, may induce oxidative damage in some tissues. Telomeres, which are the terminal sequences of linear chromosomes, may shorten in the presence of ROS, and thus the telomere length of an individual reflects the degree of accrued oxidative damage. This study quantified telomere length dynamics throughout hibernation in arctic ground squirrels (Urocitellus parryii). We hypothesized that telomere dynamics are tissue specific and predicted that telomere shortening would be most pronounced in brown adipose tissue (BAT), the organ that directly supports non-shivering thermogenesis during arousals. We used qPCR to determine relative telomere length (RTL) in DNA extracted from liver, heart, skeletal muscle (SM) and BAT of 45 juvenile and adult animals sampled either at mid- or late hibernation. Age did not have a significant effect on RTL in any tissue. At mid-hibernation, RTL of juvenile females was longer in BAT and SM than in liver and heart. In juvenile females, RTL in BAT and SM, but not in liver and heart, was shorter at late hibernation than at mid-hibernation. At late hibernation, juvenile males had longer RTL in BAT than did juvenile females, perhaps due to the naturally shorter hibernation duration of male arctic ground squirrels. Finally, BAT RTL at late hibernation negatively correlated with arousal frequency. Overall, our results suggest that, in a hibernating mammal, telomere shortening is tissue specific and that metabolically active tissues might incur higher levels of molecular damage.
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Affiliation(s)
- Sara M Wilbur
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Brian M Barnes
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Alexander S Kitaysky
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Cory T Williams
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
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Ashraf MA, Rahman A. Cold stress response in Arabidopsis thaliana is mediated by GNOM ARF-GEF. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 97:500-516. [PMID: 30362633 DOI: 10.1111/tpj.14137] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 10/14/2018] [Accepted: 10/16/2018] [Indexed: 05/29/2023]
Abstract
Endosomal trafficking plays an important role in regulating plant growth and development both at optimal and stressed conditions. Cold stress response in Arabidopsis root is directly linked to inhibition of the endosomal trafficking of auxin efflux carriers. However, the cellular components that link cold stress and the endosomal trafficking remain elusive. By screening available endosomal trafficking mutants against root growth recovery response under cold stress, we identified GNOM, a SEC7 containing ARF-GEF, as a major modulator of cold response. Contrasting response of partial loss of function mutant gnomB4049/emb30-1 and the engineered Brefeldin A (BFA)-resistant GNOM line, both of which contain mutations within SEC7 domain, to cold stress at the whole-plant level highlights the importance of this domain in modulating the cold response pathway of plants. Cold stress selectively and transiently inhibits GNOM expression. The engineered point mutation at 696 amino acid position (Methionine to Leucine) that makes GNOM resistant to BFA in fact results in overexpression of GNOM both at transcriptional and translational levels, and also alters its subcellular localization. Overexpression and altered cellular localization of GNOM were found to be directly linked to conferring striking cold-resistant phenotype in Arabidopsis. Collectively, these results provide a mechanistic link between GNOM, BFA-sensitive GNOM-regulated trafficking and cold stress.
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Affiliation(s)
- Mohammad A Ashraf
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, 020-8550, Japan
| | - Abidur Rahman
- United Graduate School of Agricultural Sciences, Iwate University, Morioka, 020-8550, Japan
- Department of Plant Bio Sciences, Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan
- Agro-Innovation Center, Iwate University, Morioka, Japan
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Andrews MT. Molecular interactions underpinning the phenotype of hibernation in mammals. J Exp Biol 2019; 222:222/2/jeb160606. [DOI: 10.1242/jeb.160606] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
ABSTRACT
Mammals maintain a constant warm body temperature, facilitating a wide variety of metabolic reactions. Mammals that hibernate have the ability to slow their metabolism, which in turn reduces their body temperature and leads to a state of hypothermic torpor. For this metabolic rate reduction to occur on a whole-body scale, molecular interactions that change the physiology of cells, tissues and organs are required, resulting in a major departure from normal mammalian homeostasis. The aim of this Review is to cover recent advances in the molecular biology of mammalian hibernation, including the role of small molecules, seasonal changes in gene expression, cold-inducible RNA-binding proteins, the somatosensory system and emerging information on hibernating primates. To underscore the importance of differential gene expression across the hibernation cycle, mRNA levels for 14,261 ground squirrel genes during periods of activity and torpor are made available for several tissues via an interactive transcriptome browser. This Review also addresses recent findings on molecular interactions responsible for multi-day survival of near-freezing body temperatures, single-digit heart rates and a slowed metabolism that greatly reduces oxygen consumption. A better understanding of how natural hibernators survive these physiological extremes is beginning to lead to innovations in human medicine.
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Affiliation(s)
- Matthew T. Andrews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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Aksyonova GE, Logvinovich OS, Ignat’ev DA, Kolomiytseva IK. The Dynamics of Adaptive Changes in the Spleen of the Hibernating Ground Squirrel Spermophilus undulatus. Biophysics (Nagoya-shi) 2018. [DOI: 10.1134/s0006350918020033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Dugbartey GJ, Hardenberg MC, Kok WF, Boerema AS, Carey HV, Staples JF, Henning RH, Bouma HR. Renal Mitochondrial Response to Low Temperature in Non-Hibernating and Hibernating Species. Antioxid Redox Signal 2017; 27:599-617. [PMID: 28322600 DOI: 10.1089/ars.2016.6705] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
SIGNIFICANCE Therapeutic hypothermia is commonly applied to limit ischemic injury in organ transplantation, during cardiac and brain surgery and after cardiopulmonary resuscitation. In these procedures, the kidneys are particularly at risk for ischemia/reperfusion injury (IRI), likely due to their high rate of metabolism. Although hypothermia mitigates ischemic kidney injury, it is not a panacea. Residual mitochondrial failure is believed to be a key event triggering loss of cellular homeostasis, and potentially cell death. Subsequent rewarming generates large amounts of reactive oxygen species that aggravate organ injury. Recent Advances: Hibernators are able to withstand periods of profoundly reduced metabolism and body temperature ("torpor"), interspersed by brief periods of rewarming ("arousal") without signs of organ injury. Specific adaptations allow maintenance of mitochondrial homeostasis, limit oxidative stress, and protect against cell death. These adaptations consist of active suppression of mitochondrial function and upregulation of anti-oxidant enzymes and anti-apoptotic pathways. CRITICAL ISSUES Unraveling the precise molecular mechanisms that allow hibernators to cycle through torpor and arousal without precipitating organ injury may translate into novel pharmacological approaches to limit IRI in patients. FUTURE DIRECTIONS Although the precise signaling routes involved in natural hibernation are not yet fully understood, torpor-like hypothermic states with increased resistance to ischemia/reperfusion can be induced pharmacologically by 5'-adenosine monophosphate (5'-AMP), adenosine, and hydrogen sulfide (H2S) in non-hibernators. In this review, we compare the molecular effects of hypothermia in non-hibernators with natural and pharmacologically induced torpor, to delineate how safe and reversible metabolic suppression may provide resistance to renal IRI. Antioxid. Redox Signal. 27, 599-617.
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Affiliation(s)
- George J Dugbartey
- 1 Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen , Groningen, the Netherlands .,2 Division of Cardiology, Cincinnati Children's Hospital Medical Center , Cincinnati, Ohio
| | - Maarten C Hardenberg
- 1 Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen , Groningen, the Netherlands
| | - Wendelinde F Kok
- 1 Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen , Groningen, the Netherlands
| | - Ate S Boerema
- 3 Groningen Institute for Evolutionary Life Sciences, University of Groningen , Groningen, the Netherlands .,4 Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen , Groningen, the Netherlands
| | - Hannah V Carey
- 5 Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin , Madison, Wisconsin
| | - James F Staples
- 6 Department of Biology, University of Western Ontario , London, Canada
| | - Robert H Henning
- 1 Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen , Groningen, the Netherlands
| | - Hjalmar R Bouma
- 1 Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen , Groningen, the Netherlands .,7 Department of Internal Medicine, University Medical Center Groningen, University of Groningen , Groningen, the Netherlands
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Hoelzl F, Cornils JS, Smith S, Moodley Y, Ruf T. Telomere dynamics in free-living edible dormice (Glis glis): the impact of hibernation and food supply. ACTA ACUST UNITED AC 2017; 219:2469-74. [PMID: 27535986 PMCID: PMC5004978 DOI: 10.1242/jeb.140871] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/02/2016] [Indexed: 01/01/2023]
Abstract
We studied the impact of hibernation and food supply on relative telomere length (RTL), an indicator for aging and somatic maintenance, in free-living edible dormice. Small hibernators such as dormice have ∼50% higher maximum longevity than non-hibernators. Increased longevity could theoretically be due to prolonged torpor directly slowing cellular damage and RTL shortening. However, although mitosis is arrested in mammals at low body temperatures, recent evidence points to accelerated RTL shortening during periodic re-warming (arousal) from torpor. Therefore, we hypothesized that these arousals during hibernation should have a negative effect on RTL. Here, we show that RTL was shortened in all animals over the course of ∼1 year, during which dormice hibernated for 7.5–11.4 months. The rate of periodic arousals, rather than the time spent euthermic during the hibernation season, was the best predictor of RTL shortening. This finding points to negative effects on RTL of the transition from low torpor to high euthermic body temperature and metabolic rate during arousals, possibly because of increased oxidative stress. The animals were, however, able to elongate their telomeres during the active season, when food availability was increased by supplemental feeding in a year of low natural food abundance. We conclude that in addition to their energetic costs, periodic arousals also lead to accelerated cellular damage in terms of RTL shortening. Although dormice are able to counteract and even over-compensate for the negative effects of hibernation, restoration of RTL appears to be energetically costly. Highlighted Article: Telomeres in edible dormice shorten over the hibernation season, but these long-lived rodents are able to fully restore telomeres during summer if food supply is sufficient.
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Affiliation(s)
- Franz Hoelzl
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
| | - Jessica S Cornils
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
| | - Steve Smith
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
| | - Yoshan Moodley
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, University of Veterinary Medicine, Vienna, Savoyenstraße 1, Vienna 1160, Austria
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More functions of torpor and their roles in a changing world. J Comp Physiol B 2017; 187:889-897. [PMID: 28432393 PMCID: PMC5486538 DOI: 10.1007/s00360-017-1100-y] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/26/2016] [Accepted: 02/26/2017] [Indexed: 02/06/2023]
Abstract
Increased winter survival by reducing energy expenditure in adult animals is often viewed as the primary function of torpor. However, torpor has many other functions that ultimately increase the survival of heterothermic mammals and birds. In this review, we summarize new findings revealing that animals use torpor to cope with the conditions during and after natural disasters, including fires, storms, and heat waves. Furthermore, we suggest that torpor, which also prolongs longevity and was likely crucial for survival of mammals during the time of the dinosaur extinctions, will be advantageous in a changing world. Climate change is assumed to lead to an increase in the occurrence and intensity of climatic disasters, such as those listed above and also abnormal floods, droughts, and extreme temperatures. The opportunistic use of torpor, found in many heterothermic species, will likely enhance survival of these challenges, because these species can reduce energy and foraging requirements. However, many strictly seasonal hibernators will likely face the negative consequences of the predicted increase in temperature, such as range contraction. Overall, available data suggest that opportunistic heterotherms with their flexible energy requirements have an adaptive advantage over homeotherms in response to unpredictable conditions.
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18
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Regulation of blood oxygen transport in hibernating mammals. J Comp Physiol B 2017; 187:847-856. [DOI: 10.1007/s00360-017-1085-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 12/19/2016] [Accepted: 03/07/2017] [Indexed: 12/23/2022]
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19
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It takes two to tango: Phagocyte and lymphocyte numbers in a small mammalian hibernator. Brain Behav Immun 2016; 52:71-80. [PMID: 26431693 DOI: 10.1016/j.bbi.2015.09.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/21/2015] [Accepted: 09/29/2015] [Indexed: 12/25/2022] Open
Abstract
Immunity is energetically costly and competes for resources with other physiological body functions, which may result in trade-offs that impair fitness during demanding situations. Endocrine mediators, particularly stress hormones, play a central role in these relationships and directly impact leukocyte differentials. To determine the effects of external stressors, energetic restraints and competing physiological functions on immune parameters and their relevance for fitness, we investigated leukocyte profiles during the active season of a small obligate hibernator, the edible dormouse (Glis glis), in five different study sites in south-western Germany. The highly synchronized yearly cycle of this species and the close adaptation of its life history to the irregular abundance of food resources provide a natural experiment to elucidate mechanisms underlying variations in fitness parameters. In contrast to previous studies on hibernators, that showed an immediate recovery of all leukocyte subtypes upon emergence, our study revealed that hibernation results in depleted phagocyte (neutrophils and monocytes) stores that recovered only slowly. As the phenomenon of low phagocyte counts was even more pronounced at the beginning of a low food year and primarily immature neutrophils were present in the blood upon emergence, preparatory mechanisms seem to determine the regeneration of phagocytes before hibernation is terminated. Surprisingly, the recovery of phagocytes thereafter took several weeks, presumably due to energetic restrictions. This impaired first line of defense coincides with lowest survival probabilities during the annual cycle of our study species. Reduced survival could furthermore be linked to drastic increases in the P/L ratio (phagocytes/lymphocytes), an indicator of physiological stress, during reproduction. On the other hand, moderate augmentations in the P/L ratio occurred during periods of low food availability and were associated with increased survival, but reproductive failure. In this case, the stress response probably represents an adaptive reaction that contributes to survival by activating energy resources. In contrast to our expectation, we could not detect an amplification of stress through high population densities. Summarized, results of our study clearly reveal that the leukocyte picture of active edible dormice responds sensitively to physiological conditions associated with hibernation, reproductive activity and food availability and can be linked to fitness parameters such as survival. Thus edible dormice represent an excellent model organism to investigate regulatory mechanisms of the immune system under natural conditions.
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20
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Seidel HS, Kimble J. Cell-cycle quiescence maintains Caenorhabditis elegans germline stem cells independent of GLP-1/Notch. eLife 2015; 4. [PMID: 26551561 PMCID: PMC4718729 DOI: 10.7554/elife.10832] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/07/2015] [Indexed: 12/13/2022] Open
Abstract
Many types of adult stem cells exist in a state of cell-cycle quiescence, yet it has remained unclear whether quiescence plays a role in maintaining the stem cell fate. Here we establish the adult germline of Caenorhabditis elegans as a model for facultative stem cell quiescence. We find that mitotically dividing germ cells--including germline stem cells--become quiescent in the absence of food. This quiescence is characterized by a slowing of S phase, a block to M-phase entry, and the ability to re-enter M phase rapidly in response to re-feeding. Further, we demonstrate that cell-cycle quiescence alters the genetic requirements for stem cell maintenance: The signaling pathway required for stem cell maintenance under fed conditions--GLP-1/Notch signaling--becomes dispensable under conditions of quiescence. Thus, cell-cycle quiescence can itself maintain stem cells, independent of the signaling pathway otherwise essential for such maintenance.
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Affiliation(s)
- Hannah S Seidel
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.,The Ellison Medical Foundation Fellow of the Life Sciences Research Foundation, The Lawrence Ellison Foundation, Mount Airy, United States
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, United States.,Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, United States
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Giroud S, Zahn S, Criscuolo F, Chery I, Blanc S, Turbill C, Ruf T. Late-born intermittently fasted juvenile garden dormice use torpor to grow and fatten prior to hibernation: consequences for ageing processes. Proc Biol Sci 2015; 281:rspb.2014.1131. [PMID: 25377448 DOI: 10.1098/rspb.2014.1131] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Torpor is thought to slow age-related processes and to sustain growth and fattening of young individuals. Energy allocation into these processes represents a challenge for juveniles, especially for those born late in the season. We tested the hypothesis that late-born juvenile garden dormice (Eliomys quercinus) fed ad libitum ('AL', n = 9) or intermittently fasted ('IF', n = 9) use short torpor bouts to enhance growth and fat accumulation to survive winter. IF juveniles displayed more frequent and longer torpor bouts, compared with AL individuals before hibernation. Torpor frequency correlated negatively with energy expenditure and water turnover. Hence, IF juveniles gained mass at the same rate, reached similar pre-hibernation fattening and displayed identical hibernating patterns and mass losses as AL animals. We found no group differences in relative telomere length (RTL), an indicator of ageing, during the period of highest summer mass gain, despite greater torpor use by IF juveniles. Percentage change in RTL was negatively associated with mean and total euthermic durations among all individuals during hibernation. We conclude that torpor use promotes fattening in late-born juvenile dormice prior to hibernation. Furthermore, we provided the first evidence for a functional link between time spent in euthermy and ageing processes over winter.
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Affiliation(s)
- Sylvain Giroud
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstraße 1, 1160 Vienna, Austria
| | - Sandrine Zahn
- Université de Strasbourg, IPHC, 23 rue Becquerel 67087 Strasbourg, France CNRS, UMR7178, 67087 Strasbourg, France
| | - François Criscuolo
- Université de Strasbourg, IPHC, 23 rue Becquerel 67087 Strasbourg, France CNRS, UMR7178, 67087 Strasbourg, France
| | - Isabelle Chery
- Université de Strasbourg, IPHC, 23 rue Becquerel 67087 Strasbourg, France CNRS, UMR7178, 67087 Strasbourg, France
| | - Stéphane Blanc
- Université de Strasbourg, IPHC, 23 rue Becquerel 67087 Strasbourg, France CNRS, UMR7178, 67087 Strasbourg, France
| | - Christopher Turbill
- Hawkesbury Institute for the Environment, Hawkesbury Campus, University of Western Sydney, Bourke Street, Richmond, 2753 NSW, Australia
| | - Thomas Ruf
- Department of Integrative Biology and Evolution, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Savoyenstraße 1, 1160 Vienna, Austria
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Mitosis in vertebrates: the G2/M and M/A transitions and their associated checkpoints. Chromosome Res 2011; 19:291-306. [PMID: 21194009 DOI: 10.1007/s10577-010-9178-z] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
In this review, I stress the importance of direct data and accurate terminology when formulating and communicating conclusions on how the G2/M and metaphase/anaphase transitions are regulated. I argue that entry into mitosis (i.e., the G2/M transition) is guarded by several checkpoint control pathways that lose their ability to delay or stop further cell cycle progression once the cell becomes committed to divide, which in vertebrates occurs in the late stages of chromosome condensation. After this commitment, progress through mitosis is then mediated by a single Mad/Bub-based checkpoint that delays chromatid separation, and exit from mitosis (i.e., completion of the cell cycle) in the presence of unattached kinetochores. When cells cannot satisfy the mitotic checkpoint, e.g., when in concentrations of spindle poisons that prohibit the stable attachment of all kinetochores, they are delayed in mitosis for many hours. In normal cells, the duration of this delay depends on the organism and ranges from ∼4 h in rodents to ∼22 h in humans. Recent live cell studies reveal that under this condition, many cancer cells (including HeLa and U2OS) die in mitosis by apoptosis within ∼24 h, which implies that biochemical studies on cancer cell populations harvested in mitosis after a prolonged mitotic arrest are contaminated with dead or dying cells.
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23
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Logvinovich OS, Aksyonova GE, Fialkovskaya LA, Afanasyev VN, Ignat'ev DA, Kolomiytseva IK, Fesenko EE. Ornithine decarboxylase in the liver, spleen, and bone marrow of ground squirrels Spermophilus undulatus. DOKL BIOCHEM BIOPHYS 2010; 433:216-8. [PMID: 20714860 DOI: 10.1134/s1607672910040186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Indexed: 11/23/2022]
Affiliation(s)
- O S Logvinovich
- Institute of Cell Biophysics, Russian Academy of Sciences, Moscow oblast, Russia
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24
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Yan J, Barnes BM, Kohl F, Marr TG. Modulation of gene expression in hibernating arctic ground squirrels. Physiol Genomics 2008; 32:170-81. [DOI: 10.1152/physiolgenomics.00075.2007] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We performed a broadscale screening of differential gene expression using both high-throughput bead-array technology and real-time PCR assay in brown adipose tissue, liver, heart, hypothalamus, and skeletal muscle in hibernating arctic ground squirrels, comparing animals sampled after two durations of steady-state torpor, during two stages of spontaneous arousal episodes, and in animals after they ended hibernation. Significant seasonal and torpor-arousal cycle differences of gene expression were detected in genes involved in glycolysis, fatty acid metabolism, gluconeogenesis, amino acid metabolism, molecular transport, detoxification, cardiac contractility, circadian rhythm, cell growth and apoptosis, muscle dystrophy, and RNA and protein protection. We observed, for the first time, complex modulation of gene expression during multiple stages of torpor-arousal cycles. The mRNA levels of certain metabolic genes drop significantly during the transition from late torpor to early arousal, perhaps due to the rapid turnover of mRNA transcripts resulting from the translational demands during thermogenesis in early arousal, whereas the mRNA levels of genes related to circadian rhythm, cell growth, and apoptosis rise significantly in the early or late arousal phases during torpor-arousal cycle, suggesting the resumption of circadian rhythm and cell cycle during arousal.
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Affiliation(s)
- Jun Yan
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
- CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes of Biological Sciences, Shanghai, China
| | - Brian M. Barnes
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
| | - Franziska Kohl
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
| | - Thomas G. Marr
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska
- Hiberna Corporation, Boulder, Colorado
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25
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Fleck CC, Carey HV. Modulation of apoptotic pathways in intestinal mucosa during hibernation. Am J Physiol Regul Integr Comp Physiol 2005; 289:R586-R595. [PMID: 15831769 DOI: 10.1152/ajpregu.00100.2005] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mammalian hibernation is associated with several events that can affect programmed cell death (apoptosis) in nonhibernators, including marked changes in blood flow, extended fasting, and oxidative stress. However, the effect of hibernation on apoptosis is poorly understood. Here, we investigated apoptosis and expression of proteins involved in apoptotic pathways in intestinal mucosa of summer and hibernating ground squirrels. We used terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) to identify possible apoptotic enterocytes in small intestine of summer squirrels and hibernating squirrels throughout the winter. Nuclear TUNEL staining increased as hibernation progressed, but the staining pattern was diffuse and not accompanied by chromatin condensation or apoptotic bodies. Electrophoresis of mucosal DNA revealed no ladders typical of apoptosis. Nuclear levels of proapoptotic p53 protein were fourfold less in hibernators compared with summer squirrels. A 12-fold increase in anti-apoptotic Bcl-x(L) compared with a 2-fold increase in proapoptotic Bax suggested a balance in favor of antiapoptotic signaling in hibernators. There was no change in Bcl-2 protein expression but phospho-Bcl-2 increased in mucosa of hibernators. Hibernation had minimal effects on expression of active caspase-8 or -9, whereas caspase-3-specific activity was lower in hibernators during an interbout arousal compared with summer squirrels. Expression of the prosurvival protein Akt increased 20-fold during hibernation, but phospho-Akt was not altered. These data provide evidence for enhanced expression of antiapoptotic proteins during hibernation that may promote enterocyte survival in a pro-oxidative, proapoptotic environment.
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Affiliation(s)
- Courtney C Fleck
- Dept. of Comparative Biosciences, University of Wisconsin, 2015 Linden Drive, Madison, WI 53706, USA
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26
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Carey HV, Andrews MT, Martin SL. Mammalian hibernation: cellular and molecular responses to depressed metabolism and low temperature. Physiol Rev 2003; 83:1153-81. [PMID: 14506303 DOI: 10.1152/physrev.00008.2003] [Citation(s) in RCA: 792] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Mammalian hibernators undergo a remarkable phenotypic switch that involves profound changes in physiology, morphology, and behavior in response to periods of unfavorable environmental conditions. The ability to hibernate is found throughout the class Mammalia and appears to involve differential expression of genes common to all mammals, rather than the induction of novel gene products unique to the hibernating state. The hibernation season is characterized by extended bouts of torpor, during which minimal body temperature (Tb) can fall as low as -2.9 degrees C and metabolism can be reduced to 1% of euthermic rates. Many global biochemical and physiological processes exploit low temperatures to lower reaction rates but retain the ability to resume full activity upon rewarming. Other critical functions must continue at physiologically relevant levels during torpor and be precisely regulated even at Tb values near 0 degrees C. Research using new tools of molecular and cellular biology is beginning to reveal how hibernators survive repeated cycles of torpor and arousal during the hibernation season. Comprehensive approaches that exploit advances in genomic and proteomic technologies are needed to further define the differentially expressed genes that distinguish the summer euthermic from winter hibernating states. Detailed understanding of hibernation from the molecular to organismal levels should enable the translation of this information to the development of a variety of hypothermic and hypometabolic strategies to improve outcomes for human and animal health.
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Affiliation(s)
- Hannah V Carey
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706, USA.
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27
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Van Breukelen F, Martin SL. Invited review: molecular adaptations in mammalian hibernators: unique adaptations or generalized responses? J Appl Physiol (1985) 2002; 92:2640-7. [PMID: 12015384 DOI: 10.1152/japplphysiol.01007.2001] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hibernators are unique among mammals in their ability to attain, withstand, and reverse low body temperatures. Hibernators repeatedly cycle between body temperatures near zero during torpor and 37 degrees C during euthermy. How do these mammals maintain cardiac function, cell integrity, blood fluidity, and energetic balance during their prolonged periods at low body temperature and avoid damage when they rewarm? Hibernation is often considered an example of a unique adaptation for low-temperature function in mammals. Although such adaptation is apparent at the level of whole animal physiology, it is surprisingly difficult to demonstrate clear examples of adaptations at the cellular and biochemical levels that improve function in the cold and are unique to hibernators. Instead of adaptation for improved function in the cold, the key molecular adaptations of hibernation may be to exploit the cold to depress most aspects of biochemical function and then rewarm without damage to restore optimal function of all systems. These capabilities are likely due to novel regulation of biochemical pathways shared by all mammals, including humans.
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Affiliation(s)
- Frank Van Breukelen
- Department of Cellular and Structural Biology, University of Colorado School of Medicine, Denver, Colorado 80262, USA
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28
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Affiliation(s)
- R. S. BURTON
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - O. J. REICHMAN
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
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Seasonal patterns of epithelium mitotic activity in the duodenum of two representatives of the sciuridae with different ecological specialization. Bull Exp Biol Med 1995. [DOI: 10.1007/bf02443706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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