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Sone M, Yamaguchi Y. Cold resistance of mammalian hibernators ∼ a matter of ferroptosis? Front Physiol 2024; 15:1377986. [PMID: 38725569 PMCID: PMC11079186 DOI: 10.3389/fphys.2024.1377986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 04/08/2024] [Indexed: 05/12/2024] Open
Abstract
Most mammals adapt thermal physiology around 37°C and large deviations from their range, as observed in severe hypothermia and hyperthermia, resulting in organ dysfunction and individual death. A prominent exception is mammalian hibernation. Mammalian hibernators resist the long-term duration of severe low body temperature that is lethal to non-hibernators, including humans and mice. This cold resistance is supported, at least in part, by intrinsic cellular properties, since primary or immortalized cells from several hibernator species can survive longer than those from non-hibernators when cultured at cold temperatures. Recent studies have suggested that cold-induced cell death fulfills the hallmarks of ferroptosis, a type of necrotic cell death that accompanies extensive lipid peroxidation by iron-ion-mediated reactions. In this review, we summarize the current knowledge of cold resistance of mammalian hibernators at the cellular and molecular levels to organ and systemic levels and discuss key pathways that confer cold resistance in mammals.
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Affiliation(s)
- Masamitsu Sone
- Hibernation Metabolism, Physiology and Development Group, Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan
| | - Yoshifumi Yamaguchi
- Hibernation Metabolism, Physiology and Development Group, Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan
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2
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Haugg E, Borner J, Stalder G, Kübber‐Heiss A, Giroud S, Herwig A. Comparative transcriptomics of the garden dormouse hypothalamus during hibernation. FEBS Open Bio 2024; 14:241-257. [PMID: 37925593 PMCID: PMC10839406 DOI: 10.1002/2211-5463.13731] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 10/25/2023] [Accepted: 11/02/2023] [Indexed: 11/06/2023] Open
Abstract
Torpor or heterothermy is an energy-saving mechanism used by endotherms to overcome harsh environmental conditions. During winter, the garden dormouse (Eliomys quercinus) hibernates with multiday torpor bouts and body temperatures of a few degrees Celsius, interrupted by brief euthermic phases. This study investigates gene expression within the hypothalamus, the key brain area controlling energy balance, adding information on differential gene expression potentially relevant to orchestrate torpor. A de novo assembled transcriptome of the hypothalamus was generated from garden dormice hibernating under constant darkness without food and water at 5 °C. Samples were collected during early torpor, late torpor, and interbout arousal. During early torpor, 765 genes were differentially expressed as compared with interbout arousal. Twenty-seven pathways were over-represented, including pathways related to hemostasis, extracellular matrix organization, and signaling of small molecules. Only 82 genes were found to be differentially expressed between early and late torpor, and no pathways were over-represented. During late torpor, 924 genes were differentially expressed relative to interbout arousal. Despite the high number of differentially expressed genes, only 10 pathways were over-represented. Of these, eight were also observed to be over-represented when comparing early torpor and interbout arousal. Our results are largely consistent with previous findings in other heterotherms. The addition of a transcriptome of a novel species may help to identify species-specific and overarching torpor mechanisms through future species comparisons.
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Affiliation(s)
- Elena Haugg
- Institute of NeurobiologyUlm UniversityGermany
| | - Janus Borner
- Sackler Institute for Comparative GenomicsAmerican Museum of Natural HistoryNew YorkNYUSA
| | - Gabrielle Stalder
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife EcologyUniversity of Veterinary MedicineViennaAustria
| | - Anna Kübber‐Heiss
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife EcologyUniversity of Veterinary MedicineViennaAustria
| | - Sylvain Giroud
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife EcologyUniversity of Veterinary MedicineViennaAustria
- Energetics Lab, Department of BiologyNorthern Michigan UniversityMarquetteMIUSA
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Krishnan JKS, Rice S, Mikes M, Sugiura MH, Drew KL, Barati Z, Oliver SR. Pre-hibernation diet alters skeletal muscle relaxation kinetics, but not force development in torpid arctic ground squirrels. J Comp Physiol B 2024; 194:65-79. [PMID: 38219236 DOI: 10.1007/s00360-023-01527-z] [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: 10/31/2022] [Revised: 11/10/2023] [Accepted: 11/20/2023] [Indexed: 01/16/2024]
Abstract
During the hibernation season, Arctic ground squirrels (AGS) experience extreme temperature fluctuations (body temperature, Tb, as low as - 3 °C), during which they are mostly physically inactive. Once Tb reaches ~ 15 °C during interbout arousals, hibernators recruit skeletal muscle (SkM) for shivering thermogenesis to reach Tb of ~ 35 °C. Polyunsaturated fatty acids (PUFA) in the diet are known to influence SkM function and metabolism. Recent studies in the cardiac muscle of hibernators have revealed that increased levels of ω-6 and the ω-6:ω-3 PUFA ratio correlate with sarco/endoplasmic reticulum calcium ATPase (SERCA) activity and hibernation status. We hypothesized that diet (increased ω-6:ω-3 PUFA ratio) and torpor status are important in the regulation of the SERCA pump and that this may improve SkM performance during hibernation. Ex vivo functional assays were used to characterize performance changes in SkM (diaphragm) from AGS fed the following diets. (1) Standard rodent chow with an ω-6:ω-3 ratio of 5:1, or (2) a balanced diet with an ω-6:ω-3 ratio of 1:1 that roughly mimics wild diet. We collected diaphragms at three different stages of hibernation (early torpor, late torpor, and arousal) and evaluated muscle function under hypothermic temperature stress at 4 °C, 15 °C, 25 °C, and 37 °C to determine functional resilience. Our data show that torpid animals fed standard rodent chow have faster SkM relaxation when compared to the balanced diet animals. Furthermore, we discovered that standard rodent chow AGS during torpor has higher SkM relaxation kinetics, but this effect of torpor is eliminated in balanced diet AGS. Interestingly, neither diet nor torpor influenced the rate of force development (rate of calcium release). This is the first study to show that increasing the dietary ω-6:ω-3 PUFA ratio improves skeletal muscle performance during decreased temperatures in a hibernating animal. This evidence supports the interpretation that diet can change some functional properties of the SkM, presumably through membrane lipid composition, ambient temperature, and torpor interaction, with an impact on SkM performance.
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Affiliation(s)
- Jishnu K S Krishnan
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Sarah Rice
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, USA
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Monica Mikes
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - M Hoshi Sugiura
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Kelly L Drew
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, USA
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Zeinab Barati
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - S Ryan Oliver
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, USA.
- Department of Chemistry, United States Naval Academy, Annapolis, MD, USA.
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Gasch K, Hykollari A, Habe M, Haubensak P, Painer-Gigler J, Smith S, Stalder G, Arnold W. Summer fades, deer change: Photoperiodic control of cellular seasonal acclimatization of skeletal muscle. iScience 2024; 27:108619. [PMID: 38155774 PMCID: PMC10753075 DOI: 10.1016/j.isci.2023.108619] [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: 08/11/2023] [Revised: 10/23/2023] [Accepted: 11/30/2023] [Indexed: 12/30/2023] Open
Abstract
We found major seasonal changes of polyunsaturated fatty acids (PUFAs) in muscular phospholipids (PL) in a large non-hibernating mammal, the red deer (Cervus elaphus). Dietary supply of essential linoleic acid (LA) and α-linolenic acid (ALA) had no, or only weak influence, respectively. We further found correlations of PL PUFA concentrations with the activity of key metabolic enzymes, independent of higher winter expression. Activity of the sarcoplasmic reticulum (SR) Ca++-ATPase increased with SR PL concentrations of n-6 PUFA, and of cytochrome c oxidase and citrate synthase, indicators of ATP-production, with concentrations of eicosapentaenoic acid in mitochondrial PL. All detected cyclic molecular changes were controlled by photoperiod and are likely of general relevance for mammals living in seasonal environments, including humans. During winter, these changes at the molecular level presumably compensate for Arrhenius effects in the colder peripheral body parts and thus enable a thrifty life at lower body temperature.
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Affiliation(s)
- Kristina Gasch
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Alba Hykollari
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Manuela Habe
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Patricia Haubensak
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Johanna Painer-Gigler
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Steve Smith
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Gabrielle Stalder
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Walter Arnold
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
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Strandvik B, Qureshi AR, Painer J, Backman-Johansson C, Engvall M, Fröbert O, Kindberg J, Stenvinkel P, Giroud S. Elevated plasma phospholipid n-3 docosapentaenoic acid concentrations during hibernation. PLoS One 2023; 18:e0285782. [PMID: 37294822 PMCID: PMC10256182 DOI: 10.1371/journal.pone.0285782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 04/28/2023] [Indexed: 06/11/2023] Open
Abstract
Factors for initiating hibernation are unknown, but the condition shares some metabolic similarities with consciousness/sleep, which has been associated with n-3 fatty acids in humans. We investigated plasma phospholipid fatty acid profiles during hibernation and summer in free-ranging brown bears (Ursus arctos) and in captive garden dormice (Eliomys quercinus) contrasting in their hibernation patterns. The dormice received three different dietary fatty acid concentrations of linoleic acid (LA) (19%, 36% and 53%), with correspondingly decreased alpha-linolenic acid (ALA) (32%, 17% and 1.4%). Saturated and monounsaturated fatty acids showed small differences between summer and hibernation in both species. The dormice diet influenced n-6 fatty acids and eicosapentaenoic acid (EPA) concentrations in plasma phospholipids. Consistent differences between summer and hibernation in bears and dormice were decreased ALA and EPA and marked increase of n-3 docosapentaenoic acid and a minor increase of docosahexaenoic acid in parallel with several hundred percent increase of the activity index of elongase ELOVL2 transforming C20-22 fatty acids. The highest LA supply was unexpectantly associated with the highest transformation of the n-3 fatty acids. Similar fatty acid patterns in two contrasting hibernating species indicates a link to the hibernation phenotype and requires further studies in relation to consciousness and metabolism.
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Affiliation(s)
- Birgitta Strandvik
- Department of Biosciences and Nutrition, Karolinska Institutet NEO, Stockholm, Sweden
| | | | - Johanna Painer
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | | | - Martin Engvall
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Ole Fröbert
- Department of Cardiology, Faculty of Health, Örebro University, Örebro, Sweden
- Department of Clinical Medicine, Aarhus University Health, Aarhus, Denmark
- Department of Clinical Pharmacology, Aarhus University Hospital, Aarhus, Denmark
- StenoDiabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
| | - Jonas Kindberg
- Department of Wildlife, Fish and Environmental Studies, University of Agricultural Sciences, Umeå, Sweden
- Norwegian Institute for Nature Research, Trondheim, Norway
| | - Peter Stenvinkel
- Division of Renal Medicine, CLINTEC, Karolinska Institutet, Stockholm, Sweden
| | - Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
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Ruf T, Bieber C. Why hibernate? Predator avoidance in the edible dormouse. MAMMAL RES 2022; 68:1-11. [PMID: 36624745 PMCID: PMC9816287 DOI: 10.1007/s13364-022-00652-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 09/29/2022] [Indexed: 01/12/2023]
Abstract
We address the question of ultimate selective advantages of hibernation. Biologists generally seem to accept the notion that multiday torpor is primarily a response to adverse environmental conditions, namely cold climate and low food abundance. We closely examine hibernation, and its summer equivalent estivation, in the edible dormouse, Glis glis. We conclude that in this species, hibernation is not primarily driven by poor conditions. Dormice enter torpor with fat reserves in years that are unfavourable for reproduction but provide ample food supply for animals to sustain themselves and even gain body energy reserves. While staying in hibernacula below ground, hibernators have much higher chances of survival than during the active season. We think that dormice enter prolonged torpor predominantly to avoid predation, mainly nocturnal owls. Because estivation in summer is immediately followed by hibernation, this strategy requires a good body condition in terms of fat reserves. As dormice age, they encounter fewer occasions to reproduce when calorie-rich seeds are available late in the year, and phase advance the hibernation season. By early emergence from hibernation, the best territories can be occupied and the number of mates maximised. However, this advantage comes at the cost of increased predation pressure that is maximal in spring. We argue the predator avoidance is generally one of the primary reasons for hibernation, as increased perceived predation pressure leads to an enhanced torpor use. The edible dormouse may be just an example where this behaviour becomes most obvious, on the population level and across large areas.
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Affiliation(s)
- Thomas Ruf
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Savoyenstrasse 1, 1160 Vienna, Austria
| | - Claudia Bieber
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Savoyenstrasse 1, 1160 Vienna, Austria
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Charlanne LM, Vetter S, Einwaller J, Painer J, Gilbert C, Giroud S. Sticking Together: Energetic Consequences of Huddling Behavior in Hibernating Juvenile Garden Dormice. Physiol Biochem Zool 2022; 95:400-415. [PMID: 35930826 DOI: 10.1086/721184] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
AbstractHibernation, or multiday torpor, allows individuals to save energy via substantial reductions of metabolism and body temperature but is regularly interrupted by euthermic phases called arousals. Social thermoregulation, or "huddling," can act in synergy with torpor in reducing individuals' energy and heat losses. In the wild, the garden dormouse (Eliomys quercinus) combines both strategies, which are crucial for winter survival of juveniles with limited prehibernation body fat reserves. We investigated via thermographic and temperature measurements (i) the energetic impact of huddling during an arousal from deep torpor, (ii) the dynamics of huddling behavior during hibernation, and (iii) its consequences during the entire winter in juvenile garden dormice. Thermographic images revealed a significant effect of huddling on torpor energetics, as it reduced heat exchange and mass loss by two-thirds in huddling versus single individuals during arousal. Our investigation of the dynamics of huddling further revealed a "random-like mechanistic" behavior during winter hibernation, as arousals from torpor were not always initiated by the same individuals. Animals took turns in initiating rewarming within a group, and the individual with highest body temperature during arousal entered into torpor later than the others within the huddle. The animals share both costs and benefits of huddling during arousals, without any energetic benefit of huddling over the entire winter on an individual level. We conclude that the dynamics of social thermoregulation during hibernation seems to counterbalance its benefit of reducing energetic costs associated against the energy-demanding process of rewarming from torpor.
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Siutz C, Nemeth M, Quint R, Wagner KH, Millesi E. PUFA changes in white adipose tissue during hibernation in common hamsters. Physiol Biochem Zool 2022; 95:525-535. [DOI: 10.1086/721444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Ruf T, Giroud S, Geiser F. Hypothesis and Theory: A Two-Process Model of Torpor-Arousal Regulation in Hibernators. Front Physiol 2022; 13:901270. [PMID: 35812322 PMCID: PMC9266152 DOI: 10.3389/fphys.2022.901270] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
Hibernating mammals drastically lower their metabolic rate (MR) and body temperature (Tb) for up to several weeks, but regularly rewarm and stay euthermic for brief periods. It has been hypothesized that the necessity for rewarming is due to the accumulation or depletion of metabolites, or the accrual of cellular damage that can be eliminated only in the euthermic state. Recent evidence for significant inverse relationships between the duration of torpor bouts (TBD) and MR in torpor strongly supports this hypothesis. We developed a new mathematical model that simulates hibernation patterns. The model involves an hourglass process H (Hibernation) representing the depletion/accumulation of a crucial enzyme/metabolite, and a threshold process Hthr. Arousal, modelled as a logistic process, is initiated once the exponentially declining process H reaches Hthr. We show that this model can predict several phenomena observed in hibernating mammals, namely the linear relationship between TMR and TBD, effects of ambient temperature on TBD, the modulation of torpor depth and duration within the hibernation season, (if process Hthr undergoes seasonal changes). The model does not need but allows for circadian cycles in the threshold T, which lead to arousals occurring predominantly at certain circadian phases, another phenomenon that has been observed in certain hibernators. It does not however, require circadian rhythms in Tb or MR during torpor. We argue that a two-process regulation of torpor-arousal cycles has several adaptive advantages, such as an easy adjustment of TBD to environmental conditions as well as to energy reserves and, for species that continue to forage, entrainment to the light-dark cycle.
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Affiliation(s)
- Thomas Ruf
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, Australia
- *Correspondence: Thomas Ruf,
| | - Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Fritz Geiser
- Centre for Behavioural and Physiological Ecology, Zoology, University of New England, Armidale, NSW, Australia
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Rauch H, Pohlin F, Einwaller J, Habe M, Gasch K, Haw A, Arnold W, Stalder G, Painer J. Effect of season and diet on heart rate and blood pressure in female red deer (Cervus elaphus) anaesthetised with medetomidine-tiletamine-zolazepam. PLoS One 2022; 17:e0268811. [PMID: 35671269 PMCID: PMC9173613 DOI: 10.1371/journal.pone.0268811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 05/09/2022] [Indexed: 11/18/2022] Open
Abstract
Temperate zone ungulates like red deer (Cervus elaphus) show pronounced seasonal acclimatisation. Hypometabolism during winter is associated with cardiovascular changes, including a reduction in heart rate (fH) and temporal peripheral vasoconstriction. How anaesthesia with vasoactive substances such as medetomidine affect the seasonally acclimatised cardiovascular system is not yet known. We anaesthetised eleven healthy female red deer with medetomidine (0.1 mg/kg) and tiletamine/zolazepam (3 mg/kg) twice in winter (ad libitum and restricted feed) and in summer (ad libitum and restricted feed), with a two-week washout-period in-between, to test for the effect of season, food availability and supplementation with omega-3 or omega-6 polyunsaturated fatty acid (PUFA) on fH and arterial blood pressure (ABP) during anaesthesia. Six animals received pellets enriched with omega-6 fatty acids (FA), and five animals with omega-3 FA. Anaesthesia significantly decreased fH in summer but not in winter and ABP was lower in winter (p < 0.05). The combination of omega-6 FA enriched pellets and food restriction resulted in a lower fH and higher ABP during anaesthesia with more pronounced changes in winter (p < 0.001). Our results demonstrate that season, food availability and type of PUFA supplementation in red deer affect the cardiovascular system during anaesthesia.
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Affiliation(s)
- Hanna Rauch
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Friederike Pohlin
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Joy Einwaller
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Manuela Habe
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Kristina Gasch
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Anna Haw
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Walter Arnold
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Gabrielle Stalder
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
- * E-mail:
| | - Johanna Painer
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
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Mikes M, Rice SA, Bibus D, Kitaysky A, Drew KL. Translating PUFA omega 6:3 ratios from wild to captive hibernators (Urocitellus parryii) enhances sex-dependent mass-gain without increasing physiological stress indicators. J Comp Physiol B 2022; 192:529-540. [PMID: 35503574 PMCID: PMC9197884 DOI: 10.1007/s00360-022-01437-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 03/20/2022] [Accepted: 03/30/2022] [Indexed: 11/28/2022]
Abstract
Omega 3 polyunsaturated fatty acids (PUFAs) are well-documented for their influence on health and weight loss. Recent studies indicate omega 3 PUFAs may exert a negative impact on cellular stress and physiology in some hibernators. We asked if physiological stress indicators, lipid peroxidation and mass gain in Arctic Ground Squirrels (AGS) were negatively influenced by naturally occurring dietary omega 3 PUFA levels compared to omega 3 PUFA levels found in common laboratory diets. We found plasma fatty acid profiles of free-ranging AGS to be high in omega 3 PUFAs with balanced omega 6:3 ratios, while standard laboratory diets and plasma of captive AGS are high in omega 6 and low in omega 3 PUFAs with higher omega 6:3 ratios. Subsequently, we designed a diet to mimick free-range AGS omega 6:3 ratios in captive AGS. Groups of wild-caught juvenile AGS were either fed: (1) Mazuri Rodent Chow (Standard Rodent chow, 4.95 omega 6:3 ratio), or (2) balanced omega 6:3 chow (Balanced Diet, 1.38 omega 6:3). AGS fed the Balanced Diet had plasma omega 6:3 ratios that mimicked plasma profiles of wild AGS. Balanced Diet increased female body mass before hibernation, but did not influence levels of cortisol in plasma or levels of the lipid peroxidation product 4-HNE in brown adipose tissue. Overall, as the mass gain is critical during pre-hibernation for obligate hibernators, the results show that mimicking a fatty acid profile of wild AGS facilitates sex-dependent mass accumulation without increasing stress indicators.
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Affiliation(s)
- Monica Mikes
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA.,Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Sarah A Rice
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, USA. .,Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA.
| | - Doug Bibus
- Lipid Technologies, LLC, Austin, MN, USA
| | - Alexander Kitaysky
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA.,Department of Biology and Wildlife, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Kelly L Drew
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, USA.,Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, USA
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Forcina G, Camacho-Sanchez M, Cornellas A, Leonard JA. Complete mitogenomes reveal limited genetic variability in the garden dormouse Eliomys quercinus of the Iberian Peninsula. ANIMAL BIODIVERSITY AND CONSERVATION 2022. [DOI: 10.32800/abc.2022.45.0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The garden dormouse Eliomys quercinus is a poorly known Western Palearctic species experiencing a global decline. Even though the availability of genetic information is key to assess the driversunderlying demographic changes in wild populations and plan adequate management, data on E. quercinus are still scant. In this study, we reconstructed the complete mitogenomes of four E. quercinus individuals from southern Spain using in–solution enriched libraries, and found evidence of limited genetic variability. We then compared their cytochrome b sequences to those of conspecifics from other countries and supported the divergent but genetically depauperate position of this evolutionarily significant unit (ESU). The information produced will assist future conservation studies on this little–studied rodent.
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Affiliation(s)
- G. Forcina
- Conservation and Evolutionary Genetics Group, Estación Biológica de Doñana, Sevilla, Spain
| | - M. Camacho-Sanchez
- Conservation and Evolutionary Genetics Group, Estación Biológica de Doñana, Sevilla, Spain
| | - A. Cornellas
- Conservation and Evolutionary Genetics Group, Estación Biológica de Doñana, Sevilla, Spain
| | - J. A. Leonard
- Conservation and Evolutionary Genetics Group, Estación Biológica de Doñana, Sevilla, Spain
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13
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Ruf T, Gasch K, Stalder G, Gerritsmann H, Giroud S. An hourglass mechanism controls torpor bout length in hibernating garden dormice. J Exp Biol 2021; 224:jeb243456. [PMID: 34762135 PMCID: PMC8714077 DOI: 10.1242/jeb.243456] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 11/08/2021] [Indexed: 11/20/2022]
Abstract
Hibernating mammals drastically lower their rate of oxygen consumption and body temperature (Tb) for several weeks, but regularly rewarm and stay euthermic for brief periods (<30 h). It has been hypothesized that these periodic arousals are driven by the development of a metabolic imbalance during torpor; that is, the accumulation or the depletion of metabolites or the accrual of cellular damage that can be eliminated only in the euthermic state. We obtained oxygen consumption (as a proxy of metabolic rate) and Tb at 7 min intervals over entire torpor-arousal cycles in the garden dormouse (Eliomys quercinus). Torpor bout duration was highly dependent on mean oxygen consumption during the torpor bout. Oxygen consumption during torpor, in turn, was elevated by Tb, which fluctuated only slightly in dormice kept at ∼3-8°C. This corresponds to a well-known effect of higher Tb on shortening torpor bout lengths in hibernators. Arousal duration was independent from prior torpor length, but arousal mean oxygen consumption increased with prior torpor Tb. These results, particularly the effect of torpor oxygen consumption on torpor bout length, point to an hourglass mechanism of torpor control, i.e. the correction of a metabolic imbalance during arousal. This conclusion is in line with previous comparative studies providing evidence for significant interspecific inverse relationships between the duration of torpor bouts and metabolism in torpor. Thus, a simple hourglass mechanism is sufficient to explain torpor/arousal cycles, without the need to involve non-temperature-compensated circadian rhythms.
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14
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Kulagina TP, Popova SS, Aripovsky AV. Seasonal Changes in the Content of Fatty Acids in the Myocardium and m. longissimus dorsi of the Long-Tailed Ground Squirrel Urocitellus undulatus. Biophysics (Nagoya-shi) 2021. [DOI: 10.1134/s0006350921060087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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15
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Giroud S, Chery I, Arrivé M, Prost M, Zumsteg J, Heintz D, Evans AL, Gauquelin-Koch G, Arnemo JM, Swenson JE, Lefai E, Bertile F, Simon C, Blanc S. Hibernating brown bears are protected against atherogenic dyslipidemia. Sci Rep 2021; 11:18723. [PMID: 34548543 PMCID: PMC8455566 DOI: 10.1038/s41598-021-98085-7] [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: 03/31/2021] [Accepted: 08/23/2021] [Indexed: 11/16/2022] Open
Abstract
To investigate mechanisms by which hibernators avoid atherogenic hyperlipidemia during hibernation, we assessed lipoprotein and cholesterol metabolisms of free-ranging Scandinavian brown bears (Ursus arctos). In winter- and summer-captured bears, we measured lipoprotein sizes and sub-classes, triglyceride-related plasma-enzyme activities, and muscle lipid composition along with plasma-levels of antioxidant capacities and inflammatory markers. Although hibernating bears increased nearly all lipid levels, a 36%-higher cholesteryl-ester transfer-protein activity allowed to stabilize lipid composition of high-density lipoproteins (HDL). Levels of inflammatory metabolites, i.e., 7-ketocholesterol and 11ß-prostaglandin F2α, declined in winter and correlated inversely with cardioprotective HDL2b-proportions and HDL-sizes that increased during hibernation. Lower muscle-cholesterol concentrations and lecithin-cholesterol acyltransferase activity in winter suggest that hibernating bears tightly controlled peripheral-cholesterol synthesis and/or release. Finally, greater plasma-antioxidant capacities prevented excessive lipid-specific oxidative damages in plasma and muscles of hibernating bears. Hence, the brown bear manages large lipid fluxes during hibernation, without developing adverse atherogenic effects that occur in humans and non-hibernators.
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Affiliation(s)
- Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Savoyenstraße 1, 1160, Vienna, Austria.
| | - Isabelle Chery
- University of Strasbourg, 4 rue Blaise Pascal, 67081, Strasbourg, France.,CNRS, UMR7178, Institut Pluridisciplinaire Hubert Curien (IPHC), 23 rue du Loess, 67087, Strasbourg, France
| | - Mathilde Arrivé
- University of Strasbourg, 4 rue Blaise Pascal, 67081, Strasbourg, France.,CNRS, UMR7178, Institut Pluridisciplinaire Hubert Curien (IPHC), 23 rue du Loess, 67087, Strasbourg, France
| | | | - Julie Zumsteg
- Plant Imaging & Mass Spectrometry (PIMS), Institute of Plant Molecular Biology, CNRS, University of Strasbourg, 12 rue du Général Zimmer, 67084, Strasbourg, France
| | - Dimitri Heintz
- Plant Imaging & Mass Spectrometry (PIMS), Institute of Plant Molecular Biology, CNRS, University of Strasbourg, 12 rue du Général Zimmer, 67084, Strasbourg, France
| | - Alina L Evans
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, 2480, Koppang, Norway
| | | | - Jon M Arnemo
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, 2480, Koppang, Norway.,Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden
| | - Jon E Swenson
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, PO Box 5003, 1432, Ås, Norway
| | - Etienne Lefai
- University of Auvergne, INRAE, UNH UMR1019, 63122, Saint-Genès Champanelle, France
| | - Fabrice Bertile
- University of Strasbourg, 4 rue Blaise Pascal, 67081, Strasbourg, France.,CNRS, UMR7178, Institut Pluridisciplinaire Hubert Curien (IPHC), 23 rue du Loess, 67087, Strasbourg, France
| | - Chantal Simon
- CARMEN, INSERM U1060/University of Lyon / INRA U1235, Oullins, France
| | - Stéphane Blanc
- University of Strasbourg, 4 rue Blaise Pascal, 67081, Strasbourg, France.,CNRS, UMR7178, Institut Pluridisciplinaire Hubert Curien (IPHC), 23 rue du Loess, 67087, Strasbourg, France
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16
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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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17
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Hepatic resistance to cold ferroptosis in a mammalian hibernator Syrian hamster depends on effective storage of diet-derived α-tocopherol. Commun Biol 2021; 4:796. [PMID: 34172811 PMCID: PMC8233303 DOI: 10.1038/s42003-021-02297-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 06/03/2021] [Indexed: 02/07/2023] Open
Abstract
Mammalian hibernators endure severe and prolonged hypothermia that is lethal to non-hibernators, including humans and mice. The mechanisms responsible for the cold resistance remain poorly understood. Here, we found that hepatocytes from a mammalian hibernator, the Syrian hamster, exhibited remarkable resistance to prolonged cold culture, whereas murine hepatocytes underwent cold-induced cell death that fulfills the hallmarks of ferroptosis such as necrotic morphology, lipid peroxidation and prevention by an iron chelator. Unexpectedly, hepatocytes from Syrian hamsters exerted resistance to cold- and drug-induced ferroptosis in a diet-dependent manner, with the aid of their superior ability to retain dietary α-tocopherol (αT), a vitamin E analog, in the liver and blood compared with those of mice. The liver phospholipid composition is less susceptible to peroxidation in Syrian hamsters than in mice. Altogether, the cold resistance of the hibernator’s liver is established by the ability to utilize αT effectively to prevent lipid peroxidation and ferroptosis. Daisuke Anegawa et al. investigated the mechanisms responsible for cold resistance in the Syrian hamster’s hepatocytes, which exhibited remarkable resistance to prolonged cold culture. Their results suggest that hepatocytes exhibit diet-dependent resistance to cold, which is linked to the retention of α-tocopherol in the liver.
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18
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Cerri M, Hitrec T, Luppi M, Amici R. Be cool to be far: Exploiting hibernation for space exploration. Neurosci Biobehav Rev 2021; 128:218-232. [PMID: 34144115 DOI: 10.1016/j.neubiorev.2021.03.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 01/08/2023]
Abstract
In mammals, torpor/hibernation is a state that is characterized by an active reduction in metabolic rate followed by a progressive decrease in body temperature. Torpor was successfully mimicked in non-hibernators by inhibiting the activity of neurons within the brainstem region of the Raphe Pallidus, or by activating the adenosine A1 receptors in the brain. This state, called synthetic torpor, may be exploited for many medical applications, and for space exploration, providing many benefits for biological adaptation to the space environment, among which an enhanced protection from cosmic rays. As regards the use of synthetic torpor in space, to fully evaluate the degree of physiological advantage provided by this state, it is strongly advisable to move from Earth-based experiments to 'in the field' tests, possibly on board the International Space Station.
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Affiliation(s)
- Matteo Cerri
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| | - Timna Hitrec
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| | - Marco Luppi
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| | - Roberto Amici
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
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19
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Abstract
There are two types of polyunsaturated fatty acids (i.e. fats that contain multiple carbon-carbon double bonds) - omega-6 and omega-3. They are not interconvertible, and they contribute 'double-bonded carbons' to different depths in bilayer membranes, with different effects on membrane processes. This Commentary emphasises the importance of these fats for biological membrane function and examines their evolution and biochemistry. Omega-6 and omega-3 fatty acids are separately essential in the diet of animals, and they pass up the food chain largely from plants, with 'seeds' being a prevalent source of omega-6, and 'leaves' a prevalent source of omega-3. The dietary balance between these fatty acids has a strong influence on membrane composition. Although this aspect of diet has been little investigated outside of the biomedical field, emerging evidence shows it can alter important physiological capacities of animals (e.g. exercise endurance and adiposity), which has implications for activities such as avian migration and hibernation and torpor, as well as significant implications for human health. This Commentary will focus on the separate effects of omega-3 and omega-6 on membrane properties and will emphasise the importance of the balance between these two fatty acids in determining the function of biological membranes; I hope to convince the reader that fats should be considered first and foremost as the basic unit of biological membranes, and secondarily as a means of energy storage.
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Affiliation(s)
- A J Hulbert
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong 2522, Australia
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20
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Huber N, Vetter S, Stalder G, Gerritsmann H, Giroud S. Dynamic Function and Composition Shift in Circulating Innate Immune Cells in Hibernating Garden Dormice. Front Physiol 2021; 12:620614. [PMID: 33746769 PMCID: PMC7970003 DOI: 10.3389/fphys.2021.620614] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 02/09/2021] [Indexed: 11/17/2022] Open
Abstract
Hibernation is characterized by successive torpor bouts during which metabolic rate is down-regulated to 2–4% of euthermic levels along with core body temperatures (Tb) ranging between 0 and 10°C. One characteristic of the torpid state, which is periodically interrupted by a few hours of euthermic phases or arousals during hibernation, resides in an overall impairment of the immune system. The most striking change during torpor is the reduction of circulating white blood cells up to 90%, while their numbers rise to near summer euthermic level upon rewarming. However, potential changes in responsiveness and function of neutrophil granulocytes, accounting for the primary cellular innate immune defense, are unknown. Here we present the first data on shifts in oxidative burst capacity, i.e., the ability to produce reactive oxygen species (ROS), of neutrophils during hibernation. Using a chemiluminescence assay, we measured real-time ROS production in whole blood of hibernating garden dormice (Eliomys quercinus) in early or late torpor, and upon arousals. Accounting for changes in neutrophil numbers along the torpor-arousal cycle, we found significant differences, between torpid and euthermic states, in the neutrophil oxidative burst capacity (NOC), with shallow cell responses during torpor and a highly significant increase by up to 30-fold during arousals. Further, we observed a significant reduction of NOC from aroused animals with euthermic Tb of 36.95 ± 0.37°C, when tested at 6°C, whereas no change occurred in NOC from torpid individuals reaching constant Tb of 4.67 ± 0.42°C, when measured at 35°C. This dynamic indicates that the reduction in NOC during torpor may be temperature-compensated. These results linked to the understanding of immune function during the torpor-arousal cycle might have clinical relevance in the context of therapeutic hypothermia and reperfusion injury.
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Affiliation(s)
- Nikolaus Huber
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Vienna, Austria.,Unit of Veterinary Public Health and Epidemiology, Institute of Food Safety, Food Technology and Veterinary Public Health Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Sebastian Vetter
- Institute of Animal Welfare Science, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Gabrielle Stalder
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Hanno Gerritsmann
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine Vienna, Vienna, Austria
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21
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Giroud S, Habold C, Nespolo RF, Mejías C, Terrien J, Logan SM, Henning RH, Storey KB. The Torpid State: Recent Advances in Metabolic Adaptations and Protective Mechanisms †. Front Physiol 2021; 11:623665. [PMID: 33551846 PMCID: PMC7854925 DOI: 10.3389/fphys.2020.623665] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/21/2020] [Indexed: 12/18/2022] Open
Abstract
Torpor and hibernation are powerful strategies enabling animals to survive periods of low resource availability. The state of torpor results from an active and drastic reduction of an individual's metabolic rate (MR) associated with a relatively pronounced decrease in body temperature. To date, several forms of torpor have been described in all three mammalian subclasses, i.e., monotremes, marsupials, and placentals, as well as in a few avian orders. This review highlights some of the characteristics, from the whole organism down to cellular and molecular aspects, associated with the torpor phenotype. The first part of this review focuses on the specific metabolic adaptations of torpor, as it is used by many species from temperate zones. This notably includes the endocrine changes involved in fat- and food-storing hibernating species, explaining biomedical implications of MR depression. We further compare adaptive mechanisms occurring in opportunistic vs. seasonal heterotherms, such as tropical and sub-tropical species. Such comparisons bring new insights into the metabolic origins of hibernation among tropical species, including resistance mechanisms to oxidative stress. The second section of this review emphasizes the mechanisms enabling heterotherms to protect their key organs against potential threats, such as reactive oxygen species, associated with the torpid state. We notably address the mechanisms of cellular rehabilitation and protection during torpor and hibernation, with an emphasis on the brain, a central organ requiring protection during torpor and recovery. Also, a special focus is given to the role of an ubiquitous and readily-diffusing molecule, hydrogen sulfide (H2S), in protecting against ischemia-reperfusion damage in various organs over the torpor-arousal cycle and during the torpid state. We conclude that (i) the flexibility of torpor use as an adaptive strategy enables different heterothermic species to substantially suppress their energy needs during periods of severely reduced food availability, (ii) the torpor phenotype implies marked metabolic adaptations from the whole organism down to cellular and molecular levels, and (iii) the torpid state is associated with highly efficient rehabilitation and protective mechanisms ensuring the continuity of proper bodily functions. Comparison of mechanisms in monotremes and marsupials is warranted for understanding the origin and evolution of mammalian torpor.
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Affiliation(s)
- Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine, Vienna, Austria
| | - Caroline Habold
- University of Strasbourg, CNRS, IPHC, UMR 7178, Strasbourg, France
| | - Roberto F. Nespolo
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, ANID – Millennium Science Initiative Program-iBio, Valdivia, Chile
- Center of Applied Ecology and Sustainability, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Carlos Mejías
- Instituto de Ciencias Ambientales y Evolutivas, Universidad Austral de Chile, ANID – Millennium Science Initiative Program-iBio, Valdivia, Chile
- Center of Applied Ecology and Sustainability, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jérémy Terrien
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d’Histoire Naturelle, Brunoy, France
| | | | - Robert H. Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, Groningen, Netherlands
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22
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Omega 3 fatty acids stimulate thermogenesis during torpor in the Arctic Ground Squirrel. Sci Rep 2021; 11:1340. [PMID: 33446684 PMCID: PMC7809411 DOI: 10.1038/s41598-020-78763-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Accepted: 10/20/2020] [Indexed: 11/29/2022] Open
Abstract
Omega 3 polyunsaturated fatty acids (PUFAs) influence metabolism and thermogenesis in non-hibernators. How omega 3 PUFAs influence Arctic Ground Squirrels (AGS) during hibernation is unknown. Prior to hibernation we fed AGS chow composed of an omega 6:3 ratio approximately 1:1 (high in omega 3 PUFA, termed Balanced Diet), or an omega 6:3 ratio of 5:1 (Standard Rodent Chow), and measured the influence of diet on core body temperature (Tb), brown adipose tissue (BAT) mass, fatty acid profiles of BAT, white adipose tissue (WAT) and plasma as well as hypothalamic endocannabinoid and endocannabinoid-like bioactive fatty acid amides during hibernation. Results show feeding a diet high in omega 3 PUFAs, with a more balanced omega 6:3 ratio, increases AGS Tb in torpor. We found the diet-induced increase in Tb during torpor is most easily explained by an increase in the mass of BAT deposits of Balanced Diet AGS. The increase in BAT mass is associated with elevated levels of metabolites DHA and EPA in tissue and plasma suggesting that these omega 3 PUFAs may play a role in thermogenesis during torpor. While we did not observe diet-induced change in endocannabinoids, we do report altered hypothalamic levels of some endocannabinoids, and endocannabinoid-like compounds, during hibernation.
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23
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Watts AJ, Logan SM, Kübber-Heiss A, Posautz A, Stalder G, Painer J, Gasch K, Giroud S, Storey KB. Regulation of Peroxisome Proliferator-Activated Receptor Pathway During Torpor in the Garden Dormouse, Eliomys quercinus. Front Physiol 2020; 11:615025. [PMID: 33408645 PMCID: PMC7779809 DOI: 10.3389/fphys.2020.615025] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/03/2020] [Indexed: 11/16/2022] Open
Abstract
Differential levels of n-6 and n-3 essential polyunsaturated fatty acids (PUFAs) are incorporated into the hibernator’s diet in the fall season preceding prolonged, multi-days bouts of torpor, known as hibernation. Peroxisome proliferator-activated receptor (PPAR) transcriptional activators bind lipids and regulate genes involved in fatty acid transport, beta-oxidation, ketogenesis, and insulin sensitivity; essential processes for survival during torpor. Thus, the DNA-binding activity of PPARα, PPARδ, PPARγ, as well as the levels of PPARγ coactivator 1α (PGC-1α) and L-fatty acid binding protein (L-FABP) were investigated in the hibernating garden dormouse (Eliomys quercinus). We found that dormice were hibernating in a similar way regardless of the n-6/n-3 PUFA diets fed to the animals during the fattening phase prior to hibernation. Further, metabolic rates and body mass loss during hibernation did not differ between dietary groups, despite marked differences in fatty acid profiles observed in white adipose tissue prior and at mid-hibernation. Overall, maintenance of PPAR DNA-binding activity was observed during torpor, and across three n-6/n-3 ratios, suggesting alternate mechanisms for the prioritization of lipid catabolism during torpor. Additionally, while no change was seen in L-FABP, significantly altered levels of PGC-1α were observed within the white adipose tissue and likely contributes to enhanced lipid metabolism when the diet favors n-6 PUFAs, i.e., high n-6/n-3 ratio, in both the torpid and euthermic state. Altogether, the maintenance of lipid metabolism during torpor makes it likely that consistent activity or levels of the investigated proteins are in aid of this metabolic profile.
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Affiliation(s)
| | | | - Anna Kübber-Heiss
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Annika Posautz
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Gabrielle Stalder
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Johanna Painer
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Kristina Gasch
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Sylvain Giroud
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine Vienna, Vienna, Austria
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24
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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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25
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Ebert T, Painer J, Bergman P, Qureshi AR, Giroud S, Stalder G, Kublickiene K, Göritz F, Vetter S, Bieber C, Fröbert O, Arnemo JM, Zedrosser A, Redtenbacher I, Shiels PG, Johnson RJ, Stenvinkel P. Insights in the regulation of trimetylamine N-oxide production using a comparative biomimetic approach suggest a metabolic switch in hibernating bears. Sci Rep 2020; 10:20323. [PMID: 33230252 PMCID: PMC7684304 DOI: 10.1038/s41598-020-76346-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 10/27/2020] [Indexed: 12/17/2022] Open
Abstract
Experimental studies suggest involvement of trimethylamine N-oxide (TMAO) in the aetiology of cardiometabolic diseases and chronic kidney disease (CKD), in part via metabolism of ingested food. Using a comparative biomimetic approach, we have investigated circulating levels of the gut metabolites betaine, choline, and TMAO in human CKD, across animal species as well as during hibernation in two animal species. Betaine, choline, and TMAO levels were associated with renal function in humans and differed significantly across animal species. Free-ranging brown bears showed a distinct regulation pattern with an increase in betaine (422%) and choline (18%) levels during hibernation, but exhibited undetectable levels of TMAO. Free-ranging brown bears had higher betaine, lower choline, and undetectable TMAO levels compared to captive brown bears. Endogenously produced betaine may protect bears and garden dormice during the vulnerable hibernating period. Carnivorous eating habits are linked to TMAO levels in the animal kingdom. Captivity may alter the microbiota and cause a subsequent increase of TMAO production. Since free-ranging bears seems to turn on a metabolic switch that shunts choline to generate betaine instead of TMAO, characterisation and understanding of such an adaptive switch could hold clues for novel treatment options in burden of lifestyle diseases, such as CKD.
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Affiliation(s)
- Thomas Ebert
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Johanna Painer
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, Veterinary University Vienna, Savoyenstreet 1, 1160, Vienna, Austria
| | - Peter Bergman
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Abdul Rashid Qureshi
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Sylvain Giroud
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, Veterinary University Vienna, Savoyenstreet 1, 1160, Vienna, Austria
| | - Gabrielle Stalder
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, Veterinary University Vienna, Savoyenstreet 1, 1160, Vienna, Austria
| | - Karolina Kublickiene
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Frank Göritz
- Leibniz Institute for Zoo and Wildlife Ecology, Berlin, Germany
| | - Sebastian Vetter
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, Veterinary University Vienna, Savoyenstreet 1, 1160, Vienna, Austria
| | - Claudia Bieber
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, Veterinary University Vienna, Savoyenstreet 1, 1160, Vienna, Austria
| | - Ole Fröbert
- Department of Cardiology, Faculty of Health, Örebro University, Örebro, Sweden
| | - Jon M Arnemo
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, Koppang, Norway.,Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Andreas Zedrosser
- Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Bø i Telemark, Norway.,Institute for Wildlife Biology and Game Management, University for Natural Resources and Life Sciences, Vienna, Austria
| | | | - Paul G Shiels
- Wolfson Wohl Cancer Research Centre, Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Richard J Johnson
- Division of Renal Diseases, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Peter Stenvinkel
- Division of Renal Medicine, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden. .,Department of Renal Medicine M99, Karolinska University Hospital, 141 86, Stockholm, Sweden.
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26
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Wang Z, Zhang J, Ma XF, Chang H, Peng X, Xu SH, Wang HP, Gao YF. A Temporal Examination of Cytoplasmic Ca 2 + Levels, Sarcoplasmic Reticulum Ca 2 + Levels, and Ca 2 + -Handling-Related Proteins in Different Skeletal Muscles of Hibernating Daurian Ground Squirrels. Front Physiol 2020; 11:562080. [PMID: 33192559 PMCID: PMC7609816 DOI: 10.3389/fphys.2020.562080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 09/30/2020] [Indexed: 12/13/2022] Open
Abstract
To explore the possible mechanism of the sarcoplasmic reticulum (SR) in the maintenance of cytoplasmic calcium (Ca2+) homeostasis, we studied changes in cytoplasmic Ca2+, SR Ca2+, and Ca2+-handling proteins of slow-twitch muscle (soleus, SOL), fast-twitch muscle (extensor digitorum longus, EDL), and mixed muscle (gastrocnemius, GAS) in different stages in hibernating Daurian ground squirrels (Spermophilus dauricus). Results showed that the level of cytoplasmic Ca2+ increased and SR Ca2+ decreased in skeletal muscle fiber during late torpor (LT) and inter-bout arousal (IBA), but both returned to summer active levels when the animals aroused from and re-entered into torpor (early torpor, ET), suggesting that intracellular Ca2+ is dynamic during hibernation. The protein expression of ryanodine receptor1 (RyR1) increased in the LT, IBA, and ET groups, whereas the co-localization of calsequestrin1 (CSQ1) and RyR1 in GAS muscle decreased in the LT and ET groups, which may increase the possibility of RyR1 channel-mediated Ca2+ release. Furthermore, calcium pump (SR Ca2+-ATPase 1, SERCA1) protein expression increased in the LT, IBA, and ET groups, and the signaling pathway-related factors of SERCA activity [i.e., β-adrenergic receptor2 protein expression (in GAS), phosphorylation levels of phospholamban (in GAS), and calmodulin kinase2 (in SOL)] all increased, suggesting that these factors may be involved in the up-regulation of SERCA1 activity in different groups. The increased protein expression of Ca2+-binding proteins CSQ1 and calmodulin (CaM) indicated that intracellular free Ca2+-binding ability also increased in the LT, IBA, ET, and POST groups. In brief, changes in cytoplasmic and SR Ca2+ concentrations, SR RyR1 and SERCA1 protein expression levels, and major RyR1 and SERCA1 signaling pathway-related factors were unexpectedly active in the torpor stage when metabolic functions were highly inhibited.
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Affiliation(s)
- Zhe Wang
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Ministry of Education, Xi'an, China.,College of Life Sciences, Qufu Normal University, Qufu, China
| | - Jie Zhang
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Ministry of Education, Xi'an, China
| | - Xiu-Feng Ma
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Ministry of Education, Xi'an, China
| | - Hui Chang
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Ministry of Education, Xi'an, China
| | - Xin Peng
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Ministry of Education, Xi'an, China
| | - Shen-Hui Xu
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Ministry of Education, Xi'an, China
| | - Hui-Ping Wang
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Ministry of Education, Xi'an, China
| | - Yun-Fang Gao
- Shaanxi Key Laboratory for Animal Conservation, College of Life Sciences, Northwest University, Xi'an, China.,Key Laboratory of Resource Biology and Biotechnology in Western China, Northwest University, Ministry of Education, Xi'an, China
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27
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Logan SM, Watts AJ, Posautz A, Kübber-Heiss A, Painer J, Stalder G, Giroud S, Storey KB. The Ratio of Linoleic and Linolenic Acid in the Pre-hibernation Diet Influences NFκB Signaling in Garden Dormice During Torpor. Front Mol Biosci 2020; 7:97. [PMID: 32528974 PMCID: PMC7253707 DOI: 10.3389/fmolb.2020.00097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 04/27/2020] [Indexed: 11/13/2022] Open
Abstract
The fatty acid composition of a pre-hibernation diet can influence the depth and duration of metabolic suppression achieved by hibernators. More specifically, a diet high in n-6 polyunsaturated fatty acids (PUFAs) relative to n-3 PUFAs is essential to maximize torpor expression. However, few studies have investigated how diets with different n-6/n-3 PUFA ratios change stress-inducible cell signaling. Garden dormice (Eliomys quercinus) were fed one of three diets designed with different ratios of n-6 PUFA linoleic acid (LA) and n-3 PUFA linolenic acid (ALA). Then, NFκB signaling was assessed in the white adipose, brown adipose, and liver tissues of euthermic and hibernating dormice via multiplex and RT-qPCR analyses of relative protein and transcript levels, respectively. Dormice fed a high LA diet regulated NFκB signaling in a protective manner in all tissues. NFκB signaling was generally decreased in the high LA group, with significant decreases in the protein levels of NFκB mediators IKKα/β, IκBα, and downstream pro-apoptotic protein FADD. Liver and white adipose from torpid dormice fed a high LA diet increased sod2 expression relative to the other diets or relative to euthermic controls, indicating protection against ROS generated from potentially increased β-oxidation of n-6 PUFAs. The low LA diet increased biomarkers for apoptosis relative to other diets and relative to euthermia, suggesting low LA diets may be detrimental to hibernator health. Overall, this study suggests that changes in the ratio of n-6/ n-3 PUFAs in the diet influences apoptotic and antioxidant responses in white adipose, brown adipose, and liver of hibernating garden dormice.
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Affiliation(s)
| | | | - Annika Posautz
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Anna Kübber-Heiss
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Johanna Painer
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Gabrielle Stalder
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
| | - Sylvain Giroud
- Department of Interdisciplinary Life Sciences, Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Austria
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28
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Nowack J, Levesque DL, Reher S, Dausmann KH. Variable Climates Lead to Varying Phenotypes: “Weird” Mammalian Torpor and Lessons From Non-Holarctic Species. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.00060] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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29
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Giroud S, Chery I, Bertile F, Bertrand-Michel J, Tascher G, Gauquelin-Koch G, Arnemo JM, Swenson JE, Singh NJ, Lefai E, Evans AL, Simon C, Blanc S. Lipidomics Reveals Seasonal Shifts in a Large-Bodied Hibernator, the Brown Bear. Front Physiol 2019; 10:389. [PMID: 31031634 PMCID: PMC6474398 DOI: 10.3389/fphys.2019.00389] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/21/2019] [Indexed: 01/10/2023] Open
Abstract
Prior to winter, heterotherms retain polyunsaturated fatty acids (“PUFA”), resulting in enhanced energy savings during hibernation, through deeper and longer torpor bouts. Hibernating bears exhibit a less dramatic reduction (2–5°C) in body temperature, but lower their metabolism to a degree close to that of small hibernators. We determined the lipid composition, via lipidomics, in skeletal muscle and white adipose tissues (“WAT”), to assess lipid retention, and in blood plasma, to reflect lipid trafficking, of winter hibernating and summer active wild Scandinavian brown bears (Ursus arctos). We found that the proportion of monounsaturated fatty acids in muscle of bears was significantly higher during winter. During hibernation, omega-3 PUFAs were retained in WAT and short-length fatty acids were released into the plasma. The analysis of individual lipid moieties indicated significant changes of specific fatty acids, which are in line with the observed seasonal shift in the major lipid categories and can be involved in specific regulations of metabolisms. These results strongly suggest that the shift in lipid composition is well conserved among hibernators, independent of body mass and of the animals’ body temperature.
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Affiliation(s)
- Sylvain Giroud
- Research Institute of Wildlife Ecology, Department of Integrative Biology and Evolution, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Isabelle Chery
- IPHC, University of Strasbourg, Strasbourg, France.,UMR7178, CNRS, Strasbourg, France
| | - Fabrice Bertile
- IPHC, University of Strasbourg, Strasbourg, France.,UMR7178, CNRS, Strasbourg, France
| | | | - Georg Tascher
- IPHC, University of Strasbourg, Strasbourg, France.,UMR7178, CNRS, Strasbourg, France
| | | | - Jon M Arnemo
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Koppang, Norway.,Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Jon E Swenson
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway.,Norwegian Institute for Nature Research, Trondheim, Norway
| | - Navinder J Singh
- Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå, Sweden
| | - Etienne Lefai
- CARMEN, INSERM U1060, University of Lyon, INRA U1235, Oullins, France
| | - Alina L Evans
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Koppang, Norway
| | - Chantal Simon
- CARMEN, INSERM U1060, University of Lyon, INRA U1235, Oullins, France
| | - Stéphane Blanc
- IPHC, University of Strasbourg, Strasbourg, France.,UMR7178, CNRS, Strasbourg, France
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30
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Chayama Y, Ando L, Sato Y, Shigenobu S, Anegawa D, Fujimoto T, Taii H, Tamura Y, Miura M, Yamaguchi Y. Molecular Basis of White Adipose Tissue Remodeling That Precedes and Coincides With Hibernation in the Syrian Hamster, a Food-Storing Hibernator. Front Physiol 2019; 9:1973. [PMID: 30745884 PMCID: PMC6360343 DOI: 10.3389/fphys.2018.01973] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Accepted: 12/31/2018] [Indexed: 12/31/2022] Open
Abstract
Mammalian hibernators store fat extensively in white adipose tissues (WATs) during pre-hibernation period (Pre-HIB) to prepare for hibernation. However, the molecular mechanisms underlying the pre-hibernation remodeling of WAT have not been fully elucidated. Syrian hamsters, a food-storing hibernator, can hibernate when exposed to a winter-like short day photoperiod and cold ambient temperature (SD-Cold). Animals subjected to prolonged SD-Cold had smaller white adipocytes and beige-like cells within subcutaneous inguinal WAT (iWAT). Time-course analysis of gene expression with RNA-sequencing and quantitative PCR demonstrated that the mRNA expression of not only genes involved in lipid catabolism (lipolysis and beta-oxidation) but also lipid anabolism (lipogenesis and lipid desaturation) was simultaneously up-regulated prior to hibernation onset in the animals. The enhanced capacity of both lipid catabolism and lipid anabolism during hibernation period (HIB) is striking contrast to previous observations in fat-storing hibernators that only enhance catabolism during HIB. The mRNA expression of mTORC1 and PPAR signaling molecules increased, and pharmacological activation of PPARs indeed up-regulated lipid metabolism genes in iWAT explants from Syrian hamsters. These results suggest that the Syrian hamster rewires lipid metabolisms while preparing for hibernation to effectively utilize body fat and synthesize it from food intake during HIB.
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Affiliation(s)
- Yuichi Chayama
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Lisa Ando
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yuya Sato
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Shuji Shigenobu
- Functional Genomics Facility, National Institute for Basic Biology, Okazaki, Japan
| | - Daisuke Anegawa
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Takayuki Fujimoto
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Hiroki Taii
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yutaka Tamura
- Department of Pharmacology, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, Fukuyama, Japan
| | - Masayuki Miura
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Yoshifumi Yamaguchi
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.,Hibernation Metabolism, Physiology and Development Group, Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
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