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Kadamani KL, Logan SM, Pamenter ME. Does hypometabolism constrain innate immune defense? Acta Physiol (Oxf) 2024; 240:e14091. [PMID: 38288574 DOI: 10.1111/apha.14091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 11/30/2023] [Accepted: 01/01/2024] [Indexed: 02/24/2024]
Abstract
Many animals routinely make energetic trade-offs to adjust to environmental demands and these trade-offs often have significant implications for survival. For example, environmental hypoxia is commonly experienced by many organisms and is an energetically challenging condition because reduced oxygen availability constrains aerobic energy production, which can be lethal. Many hypoxia-tolerant species downregulate metabolic demands when oxygen is limited; however, certain physiological functions are obligatory and must be maintained despite the need to conserve energy in hypoxia. Of particular interest is immunity (including both constitutive and induced immune functions) because mounting an immune response is among the most energetically expensive physiological processes but maintaining immune function is critical for survival in most environments. Intriguingly, physiological responses to hypoxia and pathogens share key molecular regulators such as hypoxia-inducible factor-1α, through which hypoxia can directly activate an immune response. This raises an interesting question: do hypoxia-tolerant species mount an immune response during periods of hypoxia-induced hypometabolism? Unfortunately, surprisingly few studies have examined interactions between immunity and hypometabolism in such species. Therefore, in this review, we consider mechanistic interactions between metabolism and immunity, as well as energetic trade-offs between these two systems, in hypoxia-tolerant animals but also in other models of hypometabolism, including neonates and hibernators. Specifically, we explore the hypothesis that such species have blunted immune responses in hypometabolic conditions and/or use alternative immune pathways when in a hypometabolic state. Evidence to date suggests that hypoxia-tolerant animals do maintain immunity in low oxygen conditions, but that the sensitivity of immune responses may be blunted.
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Affiliation(s)
- Karen L Kadamani
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Samantha M Logan
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada
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2
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Hutchinson AJ, Duffy BM, Staples JF. Electron transport system supercomplexes affect reactive-oxygen species production and respiration in both a hibernator (Ictidomys tridecemlineatus) and a nonhibernator (Rattus norvegicus). J Comp Physiol B 2024; 194:81-93. [PMID: 37979043 DOI: 10.1007/s00360-023-01525-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 10/23/2023] [Indexed: 11/19/2023]
Abstract
Across many taxa, the complexes of the electron transport system associate with each other within the inner mitochondrial membrane to form supercomplexes (SCs). These SCs are thought to confer some selective advantage, such as increasing cellular respiratory capacity or decreasing the production of damaging reactive oxygen species (ROS). In this study, we investigate the relationship between supercomplex abundance and performance of liver mitochondria isolated from rats that do not hibernate and hibernating ground squirrels in which metabolism fluctuates substantially. We quantified the abundance of SCs (respirasomes (SCs containing CI, CIII, and CIV) or SCs containing CIII and CIV) and examined the relationship with state 3 (OXPHOS) and state 4 (LEAK) respiration rate, as well as net ROS production. We found that, in rats, state 3 and 4 respiration rate correlated negatively with respirasome abundance, but positively with CIII/CIV SC abundance. Despite the greater range of respiration rates in different hibernation stages, these relationships were similar in ground squirrels. This is, to our knowledge, the first report of differential effects of supercomplex types on mitochondrial respiration and ROS production.
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Affiliation(s)
- Amalie J Hutchinson
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada.
| | - Brynne M Duffy
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - James F Staples
- Department of Biology, University of Western Ontario, London, ON, N6A 5B7, Canada
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3
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Duffy BM, Hayward L, Staples JF. Torpid 13-lined ground squirrel liver mitochondria resist anoxia-reoxygenation despite high levels of protein damage. J Comp Physiol B 2023; 193:715-728. [PMID: 37851102 DOI: 10.1007/s00360-023-01515-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/27/2023] [Accepted: 09/05/2023] [Indexed: 10/19/2023]
Abstract
Hibernation confers resistance to ischemia-reperfusion injury in tissue, but the underlying mechanisms remain unclear. Suppression of mitochondrial respiration during torpor may contribute to this tolerance. To explore this concept, we subjected isolated liver mitochondria from torpid, interbout euthermic (IBE) and summer 13-lined ground squirrels (Ictidomys tridecemlineatus) to 5 min of anoxia, followed by reoxygenation (A/R). We also included rat liver mitochondria as a non-hibernating comparison group. Maximum respiration rates of mitochondria from torpid ground squirrels were not affected by A/R, but in IBE and summer, these rates decreased by 50% following A/R and in rats they decreased by 80%. Comparing net ROS production rates among groups, revealed seasonal differences; mitochondria from IBE and torpor produced 75% less ROS than summer ground squirrels and rats. Measurements of oxidative damage to these mitochondria, both freshly isolated, as well as pre- and post-A/R, demonstrated elevated damage to protein, but not lipids, in all groups. Hibernation likely generates oxidative stress, as freshly isolated mitochondria had greater protein damage in torpor and IBE than in summer and rats. When comparing markers of damage pre- and post-A/R, we found that when RET was active, rat macromolecules were more damaged than when RET is inhibited, but in TLGS markers of damage were similar. This result suggests that suppression of RET during hibernation, both in torpor and IBE, lessens oxidative stress produced during arousal. Taken together our study suggests that ischemia-reperfusion tolerance at the mitochondrial level is associated with metabolically suppressed oxidative phosphorylation during hibernation.
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Affiliation(s)
- Brynne M Duffy
- University of Western Ontario, (Biology), London, ON, Canada.
| | - Leah Hayward
- University of Western Ontario, (Biology), London, ON, Canada
- McMaster University, (Hamilton Health Sciences), Hamilton, ON, Canada
| | - James F Staples
- University of Western Ontario, (Biology), London, ON, Canada
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4
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Ingelson-Filpula WA, Storey KB. Hibernation-Induced microRNA Expression Promotes Signaling Pathways and Cell Cycle Dysregulation in Ictidomys tridecemlineatus Cardiac Tissue. Metabolites 2023; 13:1096. [PMID: 37887421 PMCID: PMC10608741 DOI: 10.3390/metabo13101096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/05/2023] [Accepted: 10/16/2023] [Indexed: 10/28/2023] Open
Abstract
The thirteen-lined ground squirrel Ictidomys tridecemlineatus is a rodent that lives throughout the United States and Canada and uses metabolic rate depression to facilitate circannual hibernation which helps it survive the winter. Metabolic rate depression is the reorganization of cellular physiology and molecular biology to facilitate a global downregulation of nonessential genes and processes, which conserves endogenous fuel resources and prevents the buildup of waste byproducts. Facilitating metabolic rate depression requires a complex interplay of regulatory approaches, including post-transcriptional modes such as microRNA. MicroRNA are short, single-stranded RNA species that bind to mRNA transcripts and target them for degradation or translational suppression. Using next-generation sequencing, we analyzed euthermic vs. hibernating cardiac tissue in I. tridecemlineatus to predict seven miRNAs (let-7e-5p, miR-122-5p, miR-2355-3p, miR-6715b-3p, miR-378i, miR-9851-3p, and miR-454-3p) that may be differentially regulated during hibernation. Gene ontology and KEGG pathway analysis suggested that these miRNAs cause a strong activation of ErbB2 signaling which causes downstream effects, including the activation of MAPK and PI3K/Akt signaling and concurrent decreases in p53 signaling and cell cycle-related processes. Taken together, these results predict critical miRNAs that may change during hibernation in the hearts of I. tridecemlineatus and identify key signaling pathways that warrant further study in this species.
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Affiliation(s)
| | - Kenneth B. Storey
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada;
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5
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Purification and characterization of NADP-isocitrate dehydrogenase from skeletal muscle of Urocitellus richardsonii. Mol Cell Biochem 2023; 478:415-426. [PMID: 35802222 DOI: 10.1007/s11010-022-04516-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 06/24/2022] [Indexed: 02/02/2023]
Abstract
NADP-dependent isocitrate dehydrogenase (NADP-IDH, EC 1.1.1.42) catalyzes the oxidative decarboxylation of isocitrate to α-ketoglutarate with the concomitant production of NADPH. NADPH plays important roles in many biosynthesis pathways, maintenance of proper oxidation-reduction balance, and protection against oxidative damage. This present study investigated the dynamic nature of NADP-IDH during hibernation by purifying it from the skeletal muscle of Richardson's ground squirrel (Urocitellus richardsonii) and analyzing its structural and functional changes in response to hibernation. Kinetic parameters of purified NADP-IDH from euthermic and hibernating ground squirrel skeletal muscle were characterized at 22 °C and 5 °C. Relative to euthermic muscle, -NADP-IDH in hibernating muscle had a higher affinity for its substrate, isocitrate at 22 °C, whereas at 5 °C, there was a significant decrease in isocitrate affinity. Western blot analysis revealed greater serine and threonine phosphorylation in hibernator NADP-IDH as compared to euthermic NADP-IDH. In addition, Bioinformatic analysis predicted the presence of 18 threonine and 21 serine phosphorylation sites on squirrel NADP-IDH. The structural and functional changes in NADP-IDH indicate the ability of the organism to reduce energy consumption during hibernation, while emphasizing increased NADPH production, and thus antioxidant activity, during torpor arousal cycles.
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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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Han Y, Miao W, Hao Z, An N, Yang Y, Zhang Z, Chen J, Storey KB, Lefai E, Chang H. The Protective Effects on Ischemia–Reperfusion Injury Mechanisms of the Thoracic Aorta in Daurian Ground Squirrels (Spermophilus dauricus) over the Torpor–Arousal Cycle of Hibernation. Int J Mol Sci 2022; 23:ijms231810248. [PMID: 36142152 PMCID: PMC9499360 DOI: 10.3390/ijms231810248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/28/2022] [Accepted: 09/04/2022] [Indexed: 11/25/2022] Open
Abstract
Hibernators are a natural model of vascular ischemia–reperfusion injury; however, the protective mechanisms involved in dealing with such an injury over the torpor–arousal cycle are unclear. The present study aimed to clarify the changes in the thoracic aorta and serum in summer-active (SA), late-torpor (LT) and interbout-arousal (IBA) Daurian ground squirrels (Spermophilus dauricus). The results show that total antioxidant capacity (TAC) was unchanged, but malondialdehyde (MDA), hydrogen peroxide (H2O2), interleukin-1β (IL-1β) and tumor necrosis factor α (TNFα) were significantly increased for the LT group, whereas the levels of superoxide dismutase (SOD) and interleukin-10 (IL-10) were significantly reduced in the LT group as compared with the SA group. Moreover, the levels of MDA and IL-1β were significantly reduced, whereas SOD and IL-10 were significantly increased in the IBA group as compared with the SA group. In addition, the lumen area of the thoracic aorta and the expression of the smooth muscle cells (SMCs) contractile marker protein 22α (SM22α) were significantly reduced, whereas the protein expression of the synthetic marker proteins osteopontin (OPN), vimentin (VIM) and proliferating cell nuclear antigen (PCNA) were significantly increased in the LT group as compared with the SA group. Furthermore, the smooth muscle layer of the thoracic aorta was significantly thickened, and PCNA protein expression was significantly reduced in the IBA group as compared with the SA group. The contractile marker proteins SM22α and synthetic marker protein VIM underwent significant localization changes in both LT and IBA groups, with localization of the contractile marker protein α-smooth muscle actin (αSMA) changing only in the IBA group as compared with the SA group. In tunica intima, the serum levels of heparin sulfate (HS) and syndecan-1 (Sy-1) in the LT group were significantly reduced, but the serum level of HS in the IBA group increased significantly as compared with the SA group. Protein expression and localization of endothelial nitric oxide synthase (eNOS) was unchanged in the three groups. In summary, the decrease in reactive oxygen species (ROS) and pro-inflammatory factors and increase in SOD and anti-inflammatory factors during the IBA period induced controlled phenotypic switching of thoracic aortic SMCs and restoration of endothelial permeability to resist ischemic and hypoxic injury during torpor of Daurian ground squirrels.
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Affiliation(s)
- Yuting Han
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi’an 710069, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi’an 710069, China
| | - Weilan Miao
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi’an 710069, China
| | - Ziwei Hao
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi’an 710069, China
| | - Ning An
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi’an 710069, China
| | - Yingyu Yang
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi’an 710069, China
| | - Ziwen Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi’an 710069, China
| | - Jiayu Chen
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi’an 710069, China
| | - Kenneth B. Storey
- Department of Biology, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Etienne Lefai
- INRAE, Unité de Nutrition Humaine, Université Clermont Auvergne, UMR 1019, F-63000 Clermont-Ferrand, France
| | - Hui Chang
- Shaanxi Key Laboratory for Animal Conservation, Northwest University, Xi’an 710069, China
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education, 229# North Taibai Road, Xi’an 710069, China
- Correspondence:
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8
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Staples JF, Mathers KE, Duffy BM. Mitochondrial Metabolism in Hibernation: Regulation and Implications. Physiology (Bethesda) 2022; 37:0. [PMID: 35658625 DOI: 10.1152/physiol.00006.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Hibernators rapidly and reversibly suppress mitochondrial respiration and whole animal metabolism. Posttranslational modifications likely regulate these mitochondrial changes, which may help conserve energy in winter. These modifications are affected by reactive oxygen species (ROS), so suppressing mitochondrial ROS production may also be important for hibernators, just as it is important for surviving ischemia-reperfusion injury.
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Affiliation(s)
- James F Staples
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Katherine E Mathers
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Brynne M Duffy
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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9
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Jacobs PJ, Finn KT, van Vuuren AKJ, Suess T, Hart DW, Bennett NC. Defining the link between oxidative stress, behavioural reproductive suppression and heterothermy in the Natal mole-rat (Cryptomys hottentotus natalensis). Comp Biochem Physiol B Biochem Mol Biol 2022; 261:110753. [PMID: 35537667 DOI: 10.1016/j.cbpb.2022.110753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/29/2022] [Accepted: 05/04/2022] [Indexed: 12/31/2022]
Abstract
Sub-lethal effects, such as oxidative stress, can be linked to various breeding and thermophysiological strategies, which themselves can be linked to seasonal variability in abiotic factors. In this study, we investigated the subterranean, social living Natal mole-rat (Cryptomys hottentotus natalensis), which, unlike other social mole-rat species, implements heterothermy seasonally in an attempt to avoid exercise-induced hyperthermia and relies solely on behavioural reproductive suppression to maintain reproductive skew in colonies. Subsequently, we investigated how oxidative stress varied between season, sex and breeding status in Natal mole-rats. Oxidative markers included total oxidant status (TOS measure of total peroxides present), total antioxidant capacity (TAC), OSI (oxidative stress index) and malondialdehyde (MDA) to measure oxidative stress. Breeding and non-breeding mole-rats of both sexes were captured during the summer (wet season) and winter (dry season). Seasonal environmental variables (air temperature, soil temperature and soil moisture) had a significant effect on TOS, OSI and MDA, where season affected each sex differently. Unlike other social mole-rat species that use both physiological and behavioural means of reproductive suppression, no oxidative costs to reproduction were present in the Natal mole-rats. Males had significantly higher MDA than females, which was most apparent in summer (wet season). We conclude that the significant oxidative damage in males is a consequence of exercise-induced oxidative stress, exacerbated by increased burrow humidities and poorer heat dissipation abilities as a function of body mass. This study highlights the importance of both breeding and thermophysiological strategies in affecting oxidative stress.
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Affiliation(s)
- Paul J Jacobs
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria 0002, South Africa.
| | - Kyle T Finn
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria 0002, South Africa
| | - Andries Koch Janse van Vuuren
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria 0002, South Africa
| | - Tobias Suess
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria 0002, South Africa
| | - Daniel William Hart
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria 0002, South Africa
| | - Nigel Charles Bennett
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria 0002, South Africa
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Eaton L, Pamenter ME. What to do with low O 2: Redox adaptations in vertebrates native to hypoxic environments. Comp Biochem Physiol A Mol Integr Physiol 2022; 271:111259. [PMID: 35724954 DOI: 10.1016/j.cbpa.2022.111259] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 06/11/2022] [Accepted: 06/14/2022] [Indexed: 01/05/2023]
Abstract
Reactive oxygen species (ROS) are important cellular signalling molecules but sudden changes in redox balance can be deleterious to cells and lethal to the whole organism. ROS production is inherently linked to environmental oxygen availability and many species live in variable oxygen environments that can range in both severity and duration of hypoxic exposure. Given the importance of redox homeostasis to cell and animal viability, it is not surprising that early studies in species adapted to various hypoxic niches have revealed diverse strategies to limit or mitigate deleterious ROS changes. Although research in this area is in its infancy, patterns are beginning to emerge in the suites of adaptations to different hypoxic environments. This review focuses on redox adaptations (i.e., modifications of ROS production and scavenging, and mitigation of oxidative damage) in hypoxia-tolerant vertebrates across a range of hypoxic environments. In general, evidence suggests that animals adapted to chronic lifelong hypoxia are in homeostasis, and do not encounter major oxidative challenges in their homeostatic environment, whereas animals exposed to seasonal chronic anoxia or hypoxia rapidly downregulate redox balance to match a hypometabolic state and employ robust scavenging pathways during seasonal reoxygenation. Conversely, animals adapted to intermittent hypoxia exposure face the greatest degree of ROS imbalance and likely exhibit enhanced ROS-mitigation strategies. Although some progress has been made, research in this field is patchy and further elucidation of mechanisms that are protective against environmental redox challenges is imperative for a more holistic understanding of how animals survive hypoxic environments.
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Affiliation(s)
- Liam Eaton
- Department of Biology, University of Ottawa, Ottawa, ON, Canada
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON, Canada; University of Ottawa Brain and Mind Research Institute, Ottawa, ON, Canada.
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11
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Telomere dynamics in female Columbian ground squirrels: recovery after emergence and loss after reproduction. Oecologia 2022; 199:301-312. [PMID: 35713713 DOI: 10.1007/s00442-022-05194-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 05/20/2022] [Indexed: 10/18/2022]
Abstract
Telomeres are specialized non-coding DNA sequences located at the end of chromosomes and that protect genetic information. Telomere loss over lifespan is generally viewed as a phenomenon associated with aging in animals. Recently, telomere elongation after hibernation has been described in several mammals. Whether this pattern is an adaptation to repair DNA damage caused during rewarming from torpor or if it coevolved as a mechanism to promote somatic maintenance in preparation for the upcoming reproductive effort remains unclear. In a longitudinal study measuring telomere length using buccal swabs, we tested if telomere elongation was related to reproductive success in wild adult female Columbian ground squirrels (Urocitellus columbianus) that were monitored from emergence from hibernation to the end of the reproductive season. We found three key results. First, female telomere length increased at the start of the breeding season, both in breeding and non-breeding individuals. Second, post-emergence telomere lengthening was unrelated to female future reproductive output. Third, telomere length decreased in breeding females during lactation, but remained stable in non-breeding females over a similar period. Within breeders, telomeres shortened more in females producing larger and heavier litters. We concluded that telomere lengthening after hibernation did not constrain immediate female reproductive capacities. It was more likely to be part of the body recovery process that takes place after hibernation. Telomere erosion that occurs after birth may constitute a physiological cost of female reproduction.
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12
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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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13
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Chazarin B, Benhaim-Delarbre M, Brun C, Anzeraey A, Bertile F, Terrien J. Molecular Liver Fingerprint Reflects the Seasonal Physiology of the Grey Mouse Lemur ( Microcebus murinus) during Winter. Int J Mol Sci 2022; 23:ijms23084254. [PMID: 35457071 PMCID: PMC9028843 DOI: 10.3390/ijms23084254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 12/14/2022] Open
Abstract
Grey mouse lemurs (Microcebus murinus) are primates that respond to environmental energetic constraints through strong physiological seasonality. They notably fatten during early winter (EW), and mobilize their lipid reserves while developing glucose intolerance during late winter (LW), when food availability is low. To decipher how the hepatic mechanisms may support such metabolic flexibility, we analyzed the liver proteome of adult captive male mouse lemurs, whose seasonal regulations are comparable to their wild counterparts. We highlight profound hepatic changes that reflect fat accretion in EW at the whole-body level, without triggering an ectopic storage of fat in the liver, however. Moreover, molecular regulations are consistent with the decrease in liver glucose utilization in LW, and therefore with reduced tolerance to glucose. However, no major regulation was seen in insulin signaling/resistance pathways. Fat mobilization in LW appeared possibly linked to the reactivation of the reproductive system while enhanced liver detoxification may reflect an anticipation to return to summer levels of food intake. Overall, these results show that the physiology of mouse lemurs during winter relies on solid molecular foundations in liver processes to adapt fuel partitioning while opposing the development of a pathological state despite large lipid fluxes.
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Affiliation(s)
- Blandine Chazarin
- Laboratoire de Spectrométrie de Masse Bio-Organique, Institut Pluridisciplinaire Hubert Curien, University of Strasbourg, CNRS, UMR 7178, 25 Rue Becquerel, 67087 Strasbourg, France; (B.C.); (M.B.-D.); (C.B.)
- Infrastructure Nationale de Protéomique ProFI—FR 2048, 25 Rue Becquerel, 67087 Strasbourg, France
| | - Margaux Benhaim-Delarbre
- Laboratoire de Spectrométrie de Masse Bio-Organique, Institut Pluridisciplinaire Hubert Curien, University of Strasbourg, CNRS, UMR 7178, 25 Rue Becquerel, 67087 Strasbourg, France; (B.C.); (M.B.-D.); (C.B.)
- Infrastructure Nationale de Protéomique ProFI—FR 2048, 25 Rue Becquerel, 67087 Strasbourg, France
| | - Charlotte Brun
- Laboratoire de Spectrométrie de Masse Bio-Organique, Institut Pluridisciplinaire Hubert Curien, University of Strasbourg, CNRS, UMR 7178, 25 Rue Becquerel, 67087 Strasbourg, France; (B.C.); (M.B.-D.); (C.B.)
- Infrastructure Nationale de Protéomique ProFI—FR 2048, 25 Rue Becquerel, 67087 Strasbourg, France
| | - Aude Anzeraey
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d’Histoire Naturelle, 1 Avenue du Petit Château, 91800 Brunoy, France;
| | - Fabrice Bertile
- Laboratoire de Spectrométrie de Masse Bio-Organique, Institut Pluridisciplinaire Hubert Curien, University of Strasbourg, CNRS, UMR 7178, 25 Rue Becquerel, 67087 Strasbourg, France; (B.C.); (M.B.-D.); (C.B.)
- Infrastructure Nationale de Protéomique ProFI—FR 2048, 25 Rue Becquerel, 67087 Strasbourg, France
- Correspondence: (F.B.); (J.T.)
| | - Jérémy Terrien
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d’Histoire Naturelle, 1 Avenue du Petit Château, 91800 Brunoy, France;
- Correspondence: (F.B.); (J.T.)
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14
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Duffy BM, Staples JF. Arousal from Torpor Increases Oxidative Damage in the Hibernating Thirteen-Lined Ground Squirrel ( Ictidomys tridecemlineatus). Physiol Biochem Zool 2022; 95:229-238. [DOI: 10.1086/719931] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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15
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Blanco MB, Greene LK, Klopfer PH, Lynch D, Browning J, Ehmke EE, Yoder AD. Body Mass and Tail Girth Predict Hibernation Expression in Captive Dwarf Lemurs. Physiol Biochem Zool 2022; 95:122-129. [PMID: 34986077 DOI: 10.1086/718222] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractHibernation, a metabolic strategy, allows individuals to reduce energetic demands in times of energetic deficits. Hibernation is pervasive in nature, occurring in all major mammalian lineages and geographical regions; however, its expression is variable across species, populations, and individuals, suggesting that trade-offs are at play. Whereas hibernation reduces energy expenditure, energetically expensive arousals may impose physiological burdens. The torpor optimization hypothesis posits that hibernation should be expressed according to energy availability. The greater the energy surplus, the lower the hibernation output. The thrifty female hypothesis, a variation of the torpor optimization hypothesis, states that females should conserve more energy because of their more substantial reproductive costs. Contrarily, if hibernation's benefits offset its costs, hibernation may be maximized rather than optimized (e.g., hibernators with greater fat reserves could afford to hibernate longer). We assessed torpor expression in captive dwarf lemurs, primates that are obligate, seasonal, and tropical hibernators. Across 4.5 mo in winter, we subjected eight individuals at the Duke Lemur Center to conditions conducive to hibernation, recorded estimates of skin temperature hourly (a proxy for torpor), and determined body mass and tail fat reserves bimonthly. Across and between consecutive weigh-ins, heavier dwarf lemurs spent less time in torpor and lost more body mass. At equivalent body mass, females spent more time torpid and better conserved energy than did males. Although preliminary, our results support the torpor optimization and thrifty female hypotheses, suggesting that individuals optimize rather than maximize torpor according to body mass. These patterns are consistent with hibernation phenology in Madagascar, where dwarf lemurs hibernate longer in more seasonal habitats.
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16
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Klichkhanov NK, Nikitina ER, Shihamirova ZM, Astaeva MD, Chalabov SI, Krivchenko AI. Erythrocytes of Little Ground Squirrels Undergo Reversible Oxidative Stress During Arousal From Hibernation. Front Physiol 2021; 12:730657. [PMID: 34690805 PMCID: PMC8529035 DOI: 10.3389/fphys.2021.730657] [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: 06/25/2021] [Accepted: 09/07/2021] [Indexed: 12/30/2022] Open
Abstract
The hibernation of small mammals is characterized by long torpor bouts alternating with short periods of arousal. During arousal, due to a significant increase in oxygen consumption, tissue perfusion, and the launch of thermogenesis in cells, a large amount of reactive oxygen species (ROS) and nitrogen (RNS) can be formed, which can trigger oxidative stress in cells. To estimate this possibility, we studied the intensity of free-radical processes in the red blood cells (RBCs) of little ground squirrels (LGS; Spermophilus pygmaeus) in the dynamics of arousal from hibernation. We found that in the torpid state, the degree of generation of ROS and RNS (8.3%, p>0.09; 20.7%, p<0.001, respectively), the degree of oxidative modification of membrane lipids and RBC proteins is at a low level (47%, p<0.001; 82.7%, p<0.001, respectively) compared to the summer control. At the same time, the activity of superoxide dismutase (SOD) and catalase (CAT) in RBC is significantly reduced (32.8%, p<0.001; 22.2%, p<0.001, respectively), but not the level of glutathione (GSH). In the torpid state, SOD is activated by exogenous GSH in concentration-dependent manner, which indicates reversible enzyme inhibition. During the arousal of ground squirrels, when the body temperature reaches 25°C, RBCs are exposed oxidative stress. This is confirmed by the maximum increase in the level of uric acid (25.4%, p<0.001) in plasma, a marker of oxidative modification of lipids [thiobarbituric acid reactive substances (TBARS); 82%, p < 0.001] and proteins (carbonyl groups; 499%, p < 0.001) in RBC membranes, as well as the decrease in the level of GSH (19.7%, p < 0.001) in erythrocytes relative to the torpid state and activity of SOD and CAT in erythrocytes to values at the Tb 20°C. After full recovery of body temperature, the level of GSH increases, the ratio of SOD/CAT is restored, which significantly reduces the degree of oxidative damage of lipids and proteins of RBC membranes. Thus, the oxidative stress detected at Tb 25°C was transient and physiologically regulated.
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Affiliation(s)
| | - Elena R Nikitina
- Laboratory of Comparative Physiology of Respiration, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | | | - Maria D Astaeva
- Department of Biochemistry, Dagestan State University, Makhachkala, Russia
| | - Shamil I Chalabov
- Department of Biochemistry, Dagestan State University, Makhachkala, Russia.,Laboratory of Comparative Physiology of Respiration, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Aleksandr I Krivchenko
- Laboratory of Comparative Physiology of Respiration, Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
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17
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Abstract
Hibernation is a powerful response of a number of mammalian species to reduce energy during the cold winter season, when food is scarce. Mammalian hibernators survive winter by spending most of the time in a state of torpor, where basal metabolic rate is strongly suppressed and body temperature comes closer to ambient temperature. These torpor bouts are regularly interrupted by short arousals, where metabolic rate and body temperature spontaneously return to normal levels. The mechanisms underlying these changes, and in particular the strong metabolic suppression of torpor, have long remained elusive. As summarized in this Commentary, increasing evidence points to a potential key role for hydrogen sulfide (H2S) in the suppression of mitochondrial respiration during torpor. The idea that H2S could be involved in hibernation originated in some early studies, where exogenous H2S gas was found to induce a torpor-like state in mice, and despite some controversy, the idea persisted. H2S is a widespread signaling molecule capable of inhibiting mitochondrial respiration in vitro and studies found significant in vivo changes in endogenous H2S metabolites associated with hibernation or torpor. Along with increased expression of H2S-synthesizing enzymes during torpor, H2S degradation catalyzed by the mitochondrial sulfide:quinone oxidoreductase (SQR) appears to have a key role in controlling H2S availability for inhibiting respiration. Specifically, in thirteen-lined squirrels, SQR is highly expressed and inhibited in torpor, possibly by acetylation, thereby limiting H2S oxidation and causing inhibition of respiration. H2S may also control other aspects associated with hibernation, such as synthesis of antioxidant enzymes and of SQR itself.
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Affiliation(s)
| | - Angela Fago
- Department of Biology, Aarhus University, Aarhus C 8000, Denmark
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18
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Patnaik P, Sahoo DD. Variations in oxidative stress and antioxidant defense level during different phases of hibernation in common Asian toad, Duttaphrynus melanostictus. Biol Open 2021; 10:bio058567. [PMID: 34350459 PMCID: PMC8353263 DOI: 10.1242/bio.058567] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 06/07/2021] [Indexed: 12/12/2022] Open
Abstract
To assess redox status during hibernation with metabolic depression, oxidative stress parameters and antioxidant defense were assessed during different phases of hibernation including active period, hibernation, arousal, and post-arousal period, in the liver and brain tissues of Duttaphrynus melanostictus. We hypothesized low levels of oxidative stress and antioxidant defense during the hibernation period in comparison to the summer active period, due to hypometabolism and their subsequent increase during the arousal period following an increase in body temperature and metabolism. Contrary to our hypothesis, increased oxidative stress with significantly higher lipid peroxidation, protein carbonylation, oxidized glutathione (GSSG): glutathione (GSH) ratio, and elevated antioxidants defense consisting of higher catalase activity and high ascorbic acid content to control oxidative stress were found during hibernation. However, GSH and uric acid levels were found low with super oxide dismutase (SOD) activities at a steady level during hibernation. Supporting our hypothesis, increased oxidative stress with high lipid peroxidation and GSSG:GSH ratio were found during arousal from hibernation owing to increased oxygen consumption and rewarming. Augmented catalase and SOD activities and nonenzymatic antioxidants (GSH, ascorbic acid, and uric acid) level were found to counteract oxidative stress during arousal periods as it was expected. A steady level of protein carbonylation, indicating no oxidative damage during arousal from hibernation due to elevated antioxidant defense, shows the significance of hibernation to overcome food and water scarcity and cold climatic condition. Decrease in antioxidants levels accompanying coming down of lipid peroxidation, protein carbonylation, and GSSG:GSH ratio to their lower levels during the post-arousal period showing normalcy in redox status as it was during active period indicates controllability of oxidative stress in hibernating toads.
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Affiliation(s)
- Prabhati Patnaik
- Assistant Scientific Officer, Regional Forensic Science Laboratory, Berhampur, Odisha 760007, India
| | - Deba Das Sahoo
- Post-Graduate Department of Zoology, S.C.S Autonomous College, Puri, Odisha 752001, India
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19
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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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20
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Ensminger DC, Salvador-Pascual A, Arango BG, Allen KN, Vázquez-Medina JP. Fasting ameliorates oxidative stress: A review of physiological strategies across life history events in wild vertebrates. Comp Biochem Physiol A Mol Integr Physiol 2021; 256:110929. [PMID: 33647461 DOI: 10.1016/j.cbpa.2021.110929] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 02/17/2021] [Accepted: 02/21/2021] [Indexed: 02/06/2023]
Abstract
Fasting is a component of many species' life history due to environmental factors or behavioral patterns that limit access to food. Despite metabolic and physiological challenges associated with these life history stages, fasting-adapted wild vertebrates exhibit few if any signs of oxidative stress, suggesting that fasting promotes redox homeostasis. Here we review mammalian, avian, reptilian, amphibian, and piscine examples of animals undergoing fasting during prolonged metabolic suppression (e.g. hibernation and estivation) or energetically demanding processes (e.g. migration and breeding) to better understand the mechanisms underlying fasting tolerance in wild vertebrates. These studies largely show beneficial effects of fasting on redox balance via limited oxidative damage. Though some species exhibit signs of oxidative stress due to energetically or metabolically extreme processes, fasting wild vertebrates largely buffer themselves from the negative consequences of oxidative damage through specific strategies such as elevating antioxidants, selectively maintaining redox balance in critical tissues, or modifying behavioral patterns. We conclude with suggestions for future research to better elucidate the protective effects of fasting on oxidative stress as well as disentangle the impacts from other life history stages. Further research in these areas will facilitate our understanding of the mechanisms wild vertebrates use to mitigate the negative impacts associated with metabolically-extreme life history stages as well as potential translation into therapeutic interventions in non-fasting-adapted species including humans.
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Affiliation(s)
- David C Ensminger
- Department of Integrative Biology, University of California, Berkeley, USA
| | | | - B Gabriela Arango
- Department of Integrative Biology, University of California, Berkeley, USA
| | - Kaitlin N Allen
- Department of Integrative Biology, University of California, Berkeley, USA
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21
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Tian R, Geng Y, Yang Y, Seim I, Yang G. Oxidative stress drives divergent evolution of the glutathione peroxidase (GPX) gene family in mammals. Integr Zool 2021; 16:696-711. [PMID: 33417299 DOI: 10.1111/1749-4877.12521] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The molecular basis for adaptations to extreme environments can now be understood by interrogating the ever-increasing number of sequenced genomes. Mammals such as cetaceans, bats, and highland species can protect themselves from oxidative stress, a disruption in the balance of reactive oxygen species, which results in oxidative injury and cell damage. Here, we consider the evolution of the glutathione peroxidase (GPX) family of antioxidant enzymes by interrogating publicly available genome data from 70 mammalian species from all major clades. We identified 8 GPX subclasses ubiquitous to all mammalian groups. Mammalian GPX gene families resolved into the GPX4/7/8 and GPX1/2/3/5/6 groups and are characterized by several instances of gene duplication and loss, indicating a dynamic process of gene birth and death in mammals. Seven of the eight GPX subfamilies (all but GPX7) were under positive selection, with the residues under selection located at or close to active sites or at the dimer interface. We also reveal evidence of a correlation between ecological niches (e.g. high oxidative stress) and the divergent selection and gene copy number of GPX subclasses. Notably, a convergent expansion of GPX1 was observed in several independent lineages of mammals under oxidative stress and may be important for avoiding oxidative damage. Collectively, this study suggests that the GPX gene family has shaped the adaption of mammals to stressful environments.
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Affiliation(s)
- Ran Tian
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China.,Integrative Biology Laboratory, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Yuepan Geng
- Integrative Biology Laboratory, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Ying Yang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Inge Seim
- Integrative Biology Laboratory, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China.,School of Biology and Environmental Science, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Guang Yang
- Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
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22
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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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23
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Logan SM, Storey KB. Inflammasome signaling could be used to sense and respond to endogenous damage in brown but not white adipose tissue of a hibernating ground squirrel. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 114:103819. [PMID: 32781003 DOI: 10.1016/j.dci.2020.103819] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/30/2020] [Accepted: 07/30/2020] [Indexed: 06/11/2023]
Abstract
Small mammalian hibernators use metabolic suppression to enhance survival during the winter. Torpor is punctuated by periods of euthermia used to clear metabolic by-products and damaged cell components. The current study was performed to determine if the innate immune system, specifically NLRP and AIM2 inflammasome signaling, may detect and respond to cell stress during hibernation. Nlrp3, Casp1, and Il1b genes were significantly upregulated in brown adipose tissue (BAT) during arousal with respect to the euthermic control, suggesting increased NLRP3 inflammasome priming. NLRP3, IL-18, and gasdermin D protein levels increased during torpor, indicating a lag between inflammasome priming and formation. AIM2 and gasdermin D levels increased in BAT during arousal, as did caspase-1 activity. Thus, non-shivering thermogenesis may generate pro-inflammatory triggers of inflammasome signaling. This study is the first to support a role for inflammasome signaling in sensing cellular perturbations at various points of the torpor-arousal cycle, in metabolically-active BAT, but not white adipose tissue (WAT).
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Affiliation(s)
- Samantha M Logan
- Institute of Biochemistry, Departments of Biology and Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
| | - Kenneth B Storey
- Institute of Biochemistry, Departments of Biology and Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
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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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Morrison ML, Iwata A, Wick ML, VandenEkart E, Insko MA, Henning DJ, Frare C, Rice SA, Drew KL, Maier RV, Roth MB. Iodine Redistribution During Trauma, Sepsis, and Hibernation: An Evolutionarily Conserved Response to Severe Stress. Crit Care Explor 2020; 2:e0215. [PMID: 33063025 PMCID: PMC7531756 DOI: 10.1097/cce.0000000000000215] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE We performed these studies to learn how iodine in the form of free iodide behaves during stress. DESIGN Prospective observational trial using samples obtained from human trauma patients and retrospective observational study using remnant samples from human sepsis patients and arctic ground squirrels. Preclinical interventional study using hind-limb ischemia and reperfusion injury in mice. SETTING Level I trauma center emergency room and ICU and animal research laboratories. SUBJECTS Adult human sepsis and trauma patients, wild-caught adult arctic ground squirrels, and sexually mature laboratory mice. INTERVENTIONS Ischemia and reperfusion injury was induced in mice by temporary application of tourniquet to one hind-limb. Iodide was administered IV just prior to reperfusion. MEASUREMENTS AND MAIN RESULTS Free iodide was measured using ion chromatography. Relative to iodide in plasma from normal donors, iodide was increased 17-fold in plasma from trauma patients and 26-fold in plasma from sepsis patients. In arctic ground squirrels, iodide increases over three-fold during hibernation. And during ischemia/reperfusion injury in mice, iodide accumulates in ischemic tissue and reduces both local and systemic tissue damage. CONCLUSIONS Iodide redistributes during stress and improves outcome after injury. Essential functions of iodide may have contributed to its evolutionary selection and be useful as a therapeutic intervention for human patients.
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Affiliation(s)
- Michael L Morrison
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Akiko Iwata
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Merry L Wick
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
| | - Emily VandenEkart
- Laboratory and Clinical Research, Faraday Pharmaceuticals, Seattle, WA
| | - Michael A Insko
- Laboratory and Clinical Research, Faraday Pharmaceuticals, Seattle, WA
| | - Daniel J Henning
- Department of Emergency Medicine, University of Washington, Seattle, WA
| | - Carla Frare
- Department of Chemistry and Biochemistry and Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK
| | - Sarah A Rice
- Department of Chemistry and Biochemistry and Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK
| | - Kelly L Drew
- Department of Chemistry and Biochemistry and Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK
| | - Ronald V Maier
- Department of Surgery, Harborview Medical Center and University of Washington, Seattle, WA
| | - Mark B Roth
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA
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26
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Gagnon MF, Lafleur C, Landry-Cuerrier M, Humphries MM, Kimmins S. Torpor expression is associated with differential spermatogenesis in hibernating eastern chipmunks. Am J Physiol Regul Integr Comp Physiol 2020; 319:R455-R465. [PMID: 32783688 DOI: 10.1152/ajpregu.00328.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hibernators suppress physiological processes when expressing torpor, yet little is known about the effects of torpor on male reproductive physiology. Studies of hibernating mammals suggest that deep torpor negatively impacts spermatogenesis and that transitions between torpor and euthermic arousals increase cellular oxidative stress, with potentially damaging effects on sperm. Here, we hypothesize that variation in torpor expression affects the reproductive readiness of hibernators by impacting their sperm production. To test this, we examined the relationship between torpor expression and spermatogenesis in captive eastern chipmunks (Tamias striatus). We determined torpor depth with temperature data loggers and assessed its relationship with spermatogenesis by examining spermatogenic progression, cell division, sperm counts, sperm maturity, and DNA damage. We show that deep hibernators (high levels of torpor) largely halted spermatogenesis in late hibernation in comparison with shallow hibernators (low levels of torpor), where ongoing spermatogenesis was observed. Despite these differences in spermatogenic state during hibernation, spermatogenic progression, sperm numbers, and maturity did not differ in spring, potentially reflecting similar degrees of reproductive readiness. Interestingly, shallow hibernators exhibited higher rates of DNA damage in spermatogenic cells during hibernation, with this trend reversing in spring. Our results thus indicate that once heterothermy is terminated, deep hibernators resume spermatogenesis but are characterized by higher rates of DNA damage in spermatogenic cells at the seasonal stage when spring mating commences. Therefore, our study confirmed posthibernation recovery of sperm production but also a potential impact of deep torpor expression during winter on DNA damage in spring.
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Affiliation(s)
- Marianne F Gagnon
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Québec, Canada
| | - Christine Lafleur
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, Québec, Canada
| | - Manuelle Landry-Cuerrier
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Québec, Canada
| | - Murray M Humphries
- Department of Natural Resource Sciences, McGill University, Sainte-Anne-de-Bellevue, Québec, Canada
| | - Sarah Kimmins
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, Québec, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
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27
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Landes J, Pavard S, Henry PY, Terrien J. Flexibility Is Costly: Hidden Physiological Damage From Seasonal Phenotypic Transitions in Heterothermic Species. Front Physiol 2020; 11:985. [PMID: 32903301 PMCID: PMC7434983 DOI: 10.3389/fphys.2020.00985] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 07/20/2020] [Indexed: 12/20/2022] Open
Abstract
Heterothermy allows organisms to cope with fluctuating environmental conditions. The use of regulated hypometabolism allows seasonal heterothermic species to cope with annual resource shortages and thus to maximize survival during the unfavorable season. This comes with deep physiological remodeling at each seasonal transition to allow the organism to adjust to the changing environment. In the wild, this adaptation is highly beneficial and largely overcomes potential costs. However, researchers recently proposed that it might also generate both ecological and physiological costs for the organism. Here, we propose new perspectives to be considered when analyzing adaptation to seasonality, in particular considering these costs. We propose a list of putative costs, including DNA damage, inflammatory response to fat load, brain and cognitive defects, digestive malfunction and immunodeficiency, that should receive more attention in future research on physiological seasonality. These costs may only be marginal at each transition event but accumulate over time and therefore emerge with age. In this context, studies in captivity, where we have access to aging individuals with limited extrinsic mortality (e.g., predation), could be highly valuable to experimentally assess the costs of physiological flexibility. Finally, we offer new perspectives, which should be included in demographic models, on how the adaptive value of physiological flexibility could be altered in the future in the context of global warming.
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Affiliation(s)
- Julie Landes
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d'Histoire Naturelle, Brunoy, France.,Unité Eco-anthropologie (EA), Muséum National d'Histoire Naturelle, CNRS, Université de Paris, Paris, France
| | - Samuel Pavard
- Unité Eco-anthropologie (EA), Muséum National d'Histoire Naturelle, CNRS, Université de Paris, Paris, France
| | - Pierre-Yves Henry
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Jérémy Terrien
- Unité Mécanismes Adaptatifs et Evolution (MECADEV), UMR 7179, CNRS, Muséum National d'Histoire Naturelle, Brunoy, France
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28
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Jefimow M, Przybylska-Piech AS, Wojciechowski MS. Predictive and reactive changes in antioxidant defence system in a heterothermic rodent. J Comp Physiol B 2020; 190:479-492. [PMID: 32435827 PMCID: PMC7311498 DOI: 10.1007/s00360-020-01280-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 04/03/2020] [Accepted: 04/27/2020] [Indexed: 11/26/2022]
Abstract
Living in a seasonal environment requires periodic changes in animal physiology, morphology and behaviour. Winter phenotype of small mammals living in Temperate and Boreal Zones may differ considerably from summer one in multiple traits that enhance energy conservation or diminish energy loss. However, there is a considerable variation in the development of winter phenotype among individuals in a population and some, representing the non-responding phenotype (non-responders), are insensitive to shortening days and maintain summer phenotype throughout a year. Differences in energy management associated with the development of different winter phenotypes should be accompanied by changes in antioxidant defence capacity, leading to effective protection against oxidative stress resulting from increased heat production in winter. To test it, we analysed correlation of winter phenotypes of Siberian hamsters (Phodopus sungorus) with facultative non-shivering thermogenesis capacity (NST) and oxidative status. We found that in both phenotypes acclimation to winter-like conditions increased NST capacity and improved antioxidant defence resulting in lower oxidative stress (OS) than in summer, and females had always lower OS than males. Although NST capacity did not correlate with the intensity of OS, shortly after NST induction responders had lower OS than non-responders suggesting more effective mechanisms protecting from detrimental effects of reactive oxygen metabolites generated during rewarming from torpor. We suggest that seasonal increase in antioxidant defence is programmed endogenously to predictively prevent oxidative stress in winter. At the same time reactive upregulation of antioxidant defence protects against reactive oxygen species generated during NST itself. It suggests that evolution of winter phenotype with potentially harmful characteristics was counterbalanced by the development of protective mechanisms allowing for the maintenance of phenotypic adjustments to seasonally changing environment.
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Affiliation(s)
- Małgorzata Jefimow
- Department of Animal Physiology and Neurobiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, ul. Lwowska 1, 87-100, Toruń, Poland.
| | - Anna S Przybylska-Piech
- Department of Vertebrate Zoology and Ecology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, ul. Lwowska 1, 87-100, Toruń, Poland
| | - Michał S Wojciechowski
- Department of Vertebrate Zoology and Ecology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, ul. Lwowska 1, 87-100, Toruń, Poland
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29
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Hadj-Moussa H, Wijenayake S, Storey KB. Multi-tissue profile of NFκB pathway regulation during mammalian hibernation. Comp Biochem Physiol B Biochem Mol Biol 2020; 246-247:110460. [PMID: 32445797 DOI: 10.1016/j.cbpb.2020.110460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/12/2020] [Accepted: 05/14/2020] [Indexed: 11/17/2022]
Abstract
Hibernators have evolved effective mechanisms to overcome the challenges of torpor-arousal cycling. This study focuses on the antioxidant and inflammatory defenses under the control of the redox-sensitive and inflammatory-centered NFκB transcription factor in the thirteen-lined ground squirrel (Ictidomys tridecemlineatus), a well-established model of mammalian hibernation. While hibernators significantly depress oxygen consumption and overall metabolic rate during torpor, arousal brings with it a rapid increase in respiration that is associated with an influx of reactive oxygen species. As such, hibernators employ a variety of antioxidant defenses to combat oxidative damage. Herein, we used Luminex multiplex technology to examine the expression of key proteins in the NFκB transcriptional network, including NFκB, super-repressor IκBα, upstream activators TNFR1 and FADD, and downstream target c-Myc. Transcription factor DNA-binding ELISAs were also used to measure the relative degree of NFκB binding to DNA during hibernation. Analyses were performed across eight different tissues, cerebral cortex, brainstem, white and brown adipose tissue, heart, liver, kidney, and spleen, during euthermic control and late torpor to highlight tissue-specific NFκB mediated cytoprotective responses against oxidative stress experienced during torpor-arousal. Our findings demonstrated brain-specific NFκB activation during torpor, with elevated levels of upstream activators, inactive-phosphorylated IκBα, active-phosphorylated NFκB, and enhanced NFκB-DNA binding. Protein levels of downstream protein, c-Myc, also increased in the brain and adipose tissues during late torpor. The results show that NFκB regulation might serve a critical neuroprotective and cytoprotective role in hibernating brains and selective peripheral tissue.
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Affiliation(s)
- Hanane Hadj-Moussa
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, ON, Canada
| | - Sanoji Wijenayake
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, ON, Canada; Department of Biological Sciences and Center for Environmental Epigenetics and Development, University of Toronto, Toronto, ON, Canada
| | - Kenneth B Storey
- Department of Biology and Institute of Biochemistry, Carleton University, Ottawa, ON, Canada.
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30
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Lemieux V, Garant D, Reale D, Bergeron P. Spatio-temporal variation in oxidative status regulation in a small mammal. PeerJ 2019; 7:e7801. [PMID: 31608176 PMCID: PMC6788435 DOI: 10.7717/peerj.7801] [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: 06/06/2019] [Accepted: 08/31/2019] [Indexed: 11/23/2022] Open
Abstract
Life-history allocation trade-offs are dynamic over time and space according to the ecological and demographical context. Fluctuations in food availability can affect physiological trade-offs like oxidative status regulation, reflecting the balance between pro-oxidant production and antioxidant capacity. Monitoring the spatio-temporal stability of oxidative status in natural settings may help understanding its importance in ecological and evolutionary processes. However, few studies have yet conducted such procedures in wild populations. Here, we monitored individual oxidative status in a wild eastern chipmunk (Tamias striatus) population across the 2017 summer active period and over three study sites. Oxidative damage (MDA: Malondialdehyde levels) and non-enzymatic antioxidant levels (FRAP: Ferric reducing antioxidant power and HASC: Hypochlorous acid shock capacity) were quantified across time and space using assays optimized for small blood volumes. Our results showed an increase in oxidative damage mirrored by a decrease in FRAP throughout the season. We also found different antioxidant levels among our three study sites for both markers. Our results also revealed the effects of sex and body mass on oxidative status. Early in the active season, females and individuals with a greater body mass had higher oxidative damage. Males had higher HASC levels than females throughout the summer. This study shows that oxidative status regulation is a dynamic process that requires a detailed spatial and temporal monitoring to yield a complete picture of possible trade-offs between pro-oxidant production and antioxidant capacity.
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Affiliation(s)
- Vincent Lemieux
- Départment de biologie, Université de Sherbrooke, Sherbrooke, Canada
- Biological Sciences, Bishop’s University, Sherbrooke, Canada
| | - Dany Garant
- Départment de biologie, Université de Sherbrooke, Sherbrooke, Canada
| | - Denis Reale
- Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, Canada
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31
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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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32
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Chazarin B, Ziemianin A, Evans AL, Meugnier E, Loizon E, Chery I, Arnemo JM, Swenson JE, Gauquelin-Koch G, Simon C, Blanc S, Lefai E, Bertile F. Limited Oxidative Stress Favors Resistance to Skeletal Muscle Atrophy in Hibernating Brown Bears ( Ursus Arctos). Antioxidants (Basel) 2019; 8:antiox8090334. [PMID: 31443506 PMCID: PMC6770786 DOI: 10.3390/antiox8090334] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 08/18/2019] [Accepted: 08/21/2019] [Indexed: 12/14/2022] Open
Abstract
Oxidative stress, which is believed to promote muscle atrophy, has been reported to occur in a few hibernators. However, hibernating bears exhibit efficient energy savings and muscle protein sparing, despite long-term physical inactivity and fasting. We hypothesized that the regulation of the oxidant/antioxidant balance and oxidative stress could favor skeletal muscle maintenance in hibernating brown bears. We showed that increased expressions of cold-inducible proteins CIRBP and RBM3 could favor muscle mass maintenance and alleviate oxidative stress during hibernation. Downregulation of the subunits of the mitochondrial electron transfer chain complexes I, II, and III, and antioxidant enzymes, possibly due to the reduced mitochondrial content, indicated a possible reduction of the production of reactive oxygen species in the hibernating muscle. Concomitantly, the upregulation of cytosolic antioxidant systems, under the control of the transcription factor NRF2, and the maintenance of the GSH/GSSG ratio suggested that bear skeletal muscle is not under a significant oxidative insult during hibernation. Accordingly, lower levels of oxidative damage were recorded in hibernating bear skeletal muscles. These results identify mechanisms by which limited oxidative stress may underlie the resistance to skeletal muscle atrophy in hibernating brown bears. They may constitute therapeutic targets for the treatment of human muscle atrophy.
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Affiliation(s)
- Blandine Chazarin
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France
- Centre National d'Etudes Spatiales, CNES, F-75001 Paris, France
| | - Anna Ziemianin
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France
- Centre National d'Etudes Spatiales, CNES, F-75001 Paris, France
| | - Alina L Evans
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, NO-2480 Koppang, Norway
| | - Emmanuelle Meugnier
- CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Emmanuelle Loizon
- CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Isabelle Chery
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France
| | - Jon M Arnemo
- Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, NO-2480 Koppang, Norway
- Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
| | - Jon E Swenson
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway
- Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway
| | | | - Chantal Simon
- CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Stéphane Blanc
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France
| | - Etienne Lefai
- CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
- Université d'Auvergne, INRA, UNH UMR1019, F-63122 Saint-Genès Champanelle, France
| | - Fabrice Bertile
- Université de Strasbourg, CNRS, IPHC UMR 7178, F-670000 Strasbourg, France.
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33
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Bi K, Linderoth T, Singhal S, Vanderpool D, Patton JL, Nielsen R, Moritz C, Good JM. Temporal genomic contrasts reveal rapid evolutionary responses in an alpine mammal during recent climate change. PLoS Genet 2019; 15:e1008119. [PMID: 31050681 PMCID: PMC6519841 DOI: 10.1371/journal.pgen.1008119] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 05/15/2019] [Accepted: 04/01/2019] [Indexed: 12/12/2022] Open
Abstract
Many species have experienced dramatic changes in their abundance and distribution during recent climate change, but it is often unclear whether such ecological responses are accompanied by evolutionary change. We used targeted exon sequencing of 294 museum specimens (160 historic, 134 modern) to generate independent temporal genomic contrasts spanning a century of climate change (1911-2012) for two co-distributed chipmunk species: an endemic alpine specialist (Tamias alpinus) undergoing severe range contraction and a stable mid-elevation species (T. speciosus). Using a novel analytical approach, we reconstructed the demographic histories of these populations and tested for evidence of recent positive directional selection. Only the retracting species showed substantial population genetic fragmentation through time and this was coupled with positive selection and substantial shifts in allele frequencies at a gene, Alox15, involved in regulation of inflammation and response to hypoxia. However, these rapid population and gene-level responses were not detected in an analogous temporal contrast from another area where T. alpinus has also undergone severe range contraction. Collectively, these results highlight that evolutionary responses may be variable and context dependent across populations, even when they show seemingly synchronous ecological shifts. Our results demonstrate that temporal genomic contrasts can be used to detect very recent evolutionary responses within and among contemporary populations, even in the face of complex demographic changes. Given the wealth of specimens archived in natural history museums, comparative analyses of temporal population genomic data have the potential to improve our understanding of recent and ongoing evolutionary responses to rapidly changing environments.
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Affiliation(s)
- Ke Bi
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Computational Genomics Resource Laboratory (CGRL), California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California, United States of America
| | - Tyler Linderoth
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Department of Integrative Biology, University of California, Berkeley, California, United States of America
| | - Sonal Singhal
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Department of Integrative Biology, University of California, Berkeley, California, United States of America
| | - Dan Vanderpool
- Division of Biological Sciences, University of Montana, Missoula, Montana, United States of America
| | - James L. Patton
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Department of Integrative Biology, University of California, Berkeley, California, United States of America
| | - Rasmus Nielsen
- Department of Integrative Biology, University of California, Berkeley, California, United States of America
| | - Craig Moritz
- Museum of Vertebrate Zoology, University of California, Berkeley, California, United States of America
- Department of Integrative Biology, University of California, Berkeley, California, United States of America
- Research School of Biology and Centre for Biodiversity Analysis, Australian National University, Canberra, ACT, Australia
| | - Jeffrey M. Good
- Division of Biological Sciences, University of Montana, Missoula, Montana, United States of America
- Wildlife Biology Program, University of Montana, Missoula, MT, United States of America
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34
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Caneo M, Julian V, Byrne AB, Alkema MJ, Calixto A. Diapause induces functional axonal regeneration after necrotic insult in C. elegans. PLoS Genet 2019; 15:e1007863. [PMID: 30640919 PMCID: PMC6347329 DOI: 10.1371/journal.pgen.1007863] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 01/25/2019] [Accepted: 11/29/2018] [Indexed: 02/07/2023] Open
Abstract
Many neurons are unable to regenerate after damage. The ability to regenerate after an insult depends on life stage, neuronal subtype, intrinsic and extrinsic factors. C. elegans is a powerful model to test the genetic and environmental factors that affect axonal regeneration after damage, since its axons can regenerate after neuronal insult. Here we demonstrate that diapause promotes the complete morphological regeneration of truncated touch receptor neuron (TRN) axons expressing a neurotoxic MEC-4(d) DEG/ENaC channel. Truncated axons of different lengths were repaired during diapause and we observed potent axonal regrowth from somas alone. Complete morphological regeneration depends on DLK-1 but neuronal sprouting and outgrowth is DLK-1 independent. We show that TRN regeneration is fully functional since animals regain their ability to respond to mechanical stimulation. Thus, diapause induced regeneration provides a simple model of complete axonal regeneration which will greatly facilitate the study of environmental and genetic factors affecting the rate at which neurons die.
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Affiliation(s)
- Mauricio Caneo
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
- Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso, Chile
| | - Victoria Julian
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Alexandra B. Byrne
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Mark J. Alkema
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Andrea Calixto
- Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago de Chile, Chile
- Centro Interdisciplinario de Neurociencias de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaiso, Chile
- * E-mail: ,
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35
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Gerow CM, Rapin N, Voordouw MJ, Elliot M, Misra V, Subudhi S. Arousal from hibernation and reactivation of Eptesicus fuscus gammaherpesvirus (EfHV) in big brown bats. Transbound Emerg Dis 2018; 66:1054-1062. [PMID: 30554475 DOI: 10.1111/tbed.13102] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 12/05/2018] [Accepted: 12/10/2018] [Indexed: 01/03/2023]
Abstract
Many viruses that cause serious and often fatal disease in humans have spilled over from bats. Recent evidence suggests that stress may enhance virus shedding by bats increasing the possibility of transmission to other species. To understand the reasons for spillover is therefore important to determine the molecular pathways that link stress to virus reactivation and shedding in bats. We recently isolated and characterized a gammaherpesvirus (Eptesicus fuscus herpesvirus, EfHV) autochthonous to North American big brown bats. Since herpesviruses are known to reactivate from latent infections in response to a wide variety of stressors, EfHV presents us with an opportunity to study how physiological, behavioural or environmental changes may influence the big brown bats' relationship with EfHV. To understand the biology of the virus and how the extended periods of torpor experienced by these bats during hibernation along with the stress of arousal might influence the virus-host relationship, we attempted to detect the virus in the blood of wild-caught non-hibernating bats as well as captive bats arising from hibernation. We compared the prevalence of EfHV in the blood (using PCR) and EfHV-specific antibodies (using ELISA) between captive hibernating bats and wild-caught non-hibernating bats. We detected EfHV only in the blood of captive hibernating bats (27.8% = 10/36) and not in wild-caught non-hibernating bats (0.0% = 0/43). In contrast, the EfHV-specific antibody titres were higher in the non-hibernating bats compared to the hibernating bats. Our study suggests that: (a) viral DNA in blood indicates reactivation from latency, (b) long periods of hibernation lead to suppression of immunity, (c) stress of arousal from hibernation reactivates the virus in bats with lower levels of anti-viral immunity (indicated by humoral immune response), and (d) levels of anti-viral immunity increase in non-hibernating bats following reactivation.
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Affiliation(s)
- Caleigh M Gerow
- Department of Microbiology, Western College of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Noreen Rapin
- Department of Microbiology, Western College of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Maarten J Voordouw
- Department of Microbiology, Western College of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Melanie Elliot
- Wildlife Rehab Society of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Vikram Misra
- Department of Microbiology, Western College of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Sonu Subudhi
- Department of Microbiology, Western College of Veterinary Microbiology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Subtropical hibernation in juvenile tegu lizards (Salvator merianae): insights from intestine redox dynamics. Sci Rep 2018; 8:9368. [PMID: 29921981 PMCID: PMC6008456 DOI: 10.1038/s41598-018-27263-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/21/2018] [Indexed: 12/11/2022] Open
Abstract
Juvenile tegu lizards (Salvator merianae) experience gradual and mild temperature changes from autumn to winter in their habitat. This tropical/subtropical reptile enter a state of dormancy, with an 80% reduction in metabolic rate, that remains almost constant during winter. The redox metabolism in non-mammalian vertebrates that hibernate under such distinguished conditions is poorly understood. We analyzed the redox metabolism in the intestine of juvenile tegus during different stages of their first annual cycle. The effect of food deprivation (in spring) was also studied to compare with fasting during hibernation. Both winter dormancy and food deprivation caused decreases in reduced glutathione levels and glutathione transferase activity. While glutathione peroxidase and glutathione transferase activities decreased during winter dormancy, as well as glutathione (GSH) levels, other antioxidant enzymes (catalase, superoxide dismutase and glutathione reductase) remained unchanged. Notably, levels of disulfide glutathione (GSSG) were 2.1-fold higher in late autumn, when animals were in the process of depressing metabolism towards hibernation. This increased “oxidative tonus” could be due to a disruption in NADPH-dependent antioxidant systems. In dormancy, GSSG and lipid hydroperoxides were diminished by 60–70%. The results suggest that the entrance into hibernation is the main challenge for the redox homeostasis in the intestine of juvenile tegus.
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Logan SM, Storey KB. Pro-inflammatory AGE-RAGE signaling is activated during arousal from hibernation in ground squirrel adipose. PeerJ 2018; 6:e4911. [PMID: 29888131 PMCID: PMC5991297 DOI: 10.7717/peerj.4911] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 05/15/2018] [Indexed: 12/26/2022] Open
Abstract
Background Inflammation is generally suppressed during hibernation, but select tissues (e.g. lung) have been shown to activate both antioxidant and pro-inflammatory pathways, particularly during arousal from torpor when breathing rates increase and oxidative metabolism fueling the rewarming process produces more reactive oxygen species. Brown and white adipose tissues are now understood to be major hubs for the regulation of immune and inflammatory responses, yet how these potentially damaging processes are regulated by fat tissues during hibernation has hardly been studied. The advanced glycation end-product receptor (RAGE) can induce pro-inflammatory responses when bound by AGEs (which are glycated and oxidized proteins, lipids, or nucleic acids) or damage associated molecular pattern molecules (DAMPs, which are released from dying cells). Methods Since gene expression and protein synthesis are largely suppressed during torpor, increases in AGE-RAGE pathway proteins relative to a euthermic control could suggest some role for these pro-inflammatory mediators during hibernation. This study determined how the pro-inflammatory AGE-RAGE signaling pathway is regulated at six major time points of the torpor-arousal cycle in brown and white adipose from a model hibernator, Ictidomys tridecemlineatus. Immunoblotting, RT-qPCR, and a competitive ELISA were used to assess the relative gene expression and protein levels of key regulators of the AGE-RAGE pathway during a hibernation bout. Results The results of this study revealed that RAGE is upregulated as animals arouse from torpor in both types of fat, but AGE and DAMP levels either remain unchanged or decrease. Downstream of the AGE-RAGE cascade, nfat5 was more highly expressed during arousal in brown adipose. Discussion An increase in RAGE protein levels and elevated mRNA levels of the downstream transcription factor nfat5 during arousal suggest the pro-inflammatory response is upregulated in adipose tissue of the hibernating ground squirrel. It is unlikely that this cascade is activated by AGEs or DAMPs. This research sheds light on how a fat-but-fit organism with highly regulated metabolism may control the pro-inflammatory AGE-RAGE pathway, a signaling cascade that is often dysregulated in other obese organisms.
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Affiliation(s)
- Samantha M Logan
- Institute of Biochemistry, Departments of Biology and Chemistry, Carleton University, Ottawa, Ontario, Canada
| | - Kenneth B Storey
- Institute of Biochemistry, Departments of Biology and Chemistry, Carleton University, Ottawa, Ontario, Canada
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Niu Y, Cao W, Zhao Y, Zhai H, Zhao Y, Tang X, Chen Q. The levels of oxidative stress and antioxidant capacity in hibernating Nanorana parkeri. Comp Biochem Physiol A Mol Integr Physiol 2018; 219-220:19-27. [PMID: 29454142 DOI: 10.1016/j.cbpa.2018.02.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 02/06/2018] [Accepted: 02/07/2018] [Indexed: 01/18/2023]
Abstract
The effect of hibernation on oxidative stress and antioxidant defense was assessed in the frog Nanorana parkeri which inhabits the southern Tibetan Plateau. We compared the indices of oxidative stress (GSSG/GSH), the degree of oxidative damage (content of carbonyl proteins and lipid peroxide products) and the activities of antioxidant enzymes (SOD, CAT, GPx, GST and GR) in liver, brain, heart and muscle of N. parkeri sampled during summer and winter. Obtained results showed that hibernation induced a significant decrease in the level of GSH in heart, liver, and muscle, while the ratio of GSSG/GSH markedly increased in all tissues except for muscle. Regarding oxidative damage, significant increases in TBARS were observed in all tissues of N. parkeri in the midst of hibernation, and the lipid peroxides level also clearly elevated in these tissues except the liver. In liver and brain, the level of carbonyl proteins was significantly higher in winter relative to summer. Additionally, the activity of antioxidant enzymes obviously reduced in the liver of hibernating N. parkeri. The total antioxidant capacity was also significantly lower in all tissues during winter than summer. In conclusion, hibernation in N. parkeri induced oxidative stress which was supported by oxidative damage to lipids and proteins with suppression of antioxidant defense.
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Affiliation(s)
- Yonggang Niu
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Wangjie Cao
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yaofeng Zhao
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Haotian Zhai
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yao Zhao
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xiaolong Tang
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Qiang Chen
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
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Viblanc VA, Schull Q, Roth JD, Rabdeau J, Saraux C, Uhlrich P, Criscuolo F, Dobson FS. Maternal oxidative stress and reproduction: Testing the constraint, cost and shielding hypotheses in a wild mammal. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
| | - Quentin Schull
- Université de Strasbourg CNRS IPHC UMR 7178 Strasbourg France
| | - Jeffrey D. Roth
- Department of Biological Sciences Auburn University Auburn AL USA
| | | | - Claire Saraux
- UMR MARBEC IFREMER (Institut Français de Recherche pour l'Exploitation de la Mer) Sète France
| | - Pierre Uhlrich
- Université de Strasbourg CNRS IPHC UMR 7178 Strasbourg France
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Giraud-Billoud M, Castro-Vazquez A, Campoy-Diaz AD, Giuffrida PM, Vega IA. Tolerance to hypometabolism and arousal induced by hibernation in the apple snail Pomacea canaliculata (Caenogastropoda, Ampullariidae). Comp Biochem Physiol B Biochem Mol Biol 2017; 224:129-137. [PMID: 29277604 DOI: 10.1016/j.cbpb.2017.12.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 12/06/2017] [Accepted: 12/15/2017] [Indexed: 12/30/2022]
Abstract
Pomacea canaliculata may serve as a model organism for comparative studies of oxidative damage and antioxidant defenses in active, hibernating and arousing snails. Oxidative damage (as TBARS), free radical scavenging capacity (as ABTS+ oxidation), uric acid (UA) and glutathione (GSH) concentrations, activities of superoxide dismutase (SOD) and catalase (CAT), and the protein expression levels of heat shock proteins (Hsp70, Hsc70, Hsp90) were studied in digestive gland, kidney and foot. Tissue TBARS of hibernating snails (45days) was higher than active snails. Hibernation produced an increase of ABTS+ in digestive gland, probably because of the sustained antioxidant defenses (UA and/or GSH and SOD levels). Kidney protection during the activity-hibernation cycle seemed provided by increased UA concentrations. TBARS in the foot remained high 30min after arousal with no changes in ABTS+, but this tissue increased ABTS+ oxidation at 24h to expenses increased UA and decreased GSH levels, and with no changes in SOD and CAT activities. The level of Hsp70 in kidney showed no changes throughout the activity-hibernation cycle but it increased in the foot after hibernation. The tissue levels of Hsp90 in snails hibernating were higher than active snails and returned to baseline 24h after arousal. Results showed that chronic cooling produces a significant oxidative damage in three studied tissues and that these tissue damages are overcome quickly (between 30min to 24h) with fluctuations in different antioxidant defenses (UA, GSH, CAT) and heat shock proteins (Hsp70 and Hsp90).
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Affiliation(s)
- Maximiliano Giraud-Billoud
- IHEM, Universidad Nacional de Cuyo, CONICET, Casilla de Correo 33, 5500 Mendoza, Argentina; Universidad Nacional de Cuyo, Facultad de Ciencias Médicas, Instituto de Fisiología, Casilla de Correo 33, 5500 Mendoza, Argentina.
| | - Alfredo Castro-Vazquez
- IHEM, Universidad Nacional de Cuyo, CONICET, Casilla de Correo 33, 5500 Mendoza, Argentina; Universidad Nacional de Cuyo, Facultad de Ciencias Médicas, Instituto de Fisiología, Casilla de Correo 33, 5500 Mendoza, Argentina; Universidad Nacional de Cuyo, Facultad de Ciencias Exactas y Naturales, Departamento de Biología, Casilla de Correo 33, 5500 Mendoza, Argentina
| | - Alejandra D Campoy-Diaz
- IHEM, Universidad Nacional de Cuyo, CONICET, Casilla de Correo 33, 5500 Mendoza, Argentina; Universidad Nacional de Cuyo, Facultad de Ciencias Médicas, Instituto de Fisiología, Casilla de Correo 33, 5500 Mendoza, Argentina
| | - Pablo M Giuffrida
- Universidad Nacional de Cuyo, Facultad de Ciencias Médicas, Instituto de Fisiología, Casilla de Correo 33, 5500 Mendoza, Argentina
| | - Israel A Vega
- IHEM, Universidad Nacional de Cuyo, CONICET, Casilla de Correo 33, 5500 Mendoza, Argentina; Universidad Nacional de Cuyo, Facultad de Ciencias Médicas, Instituto de Fisiología, Casilla de Correo 33, 5500 Mendoza, Argentina; Universidad Nacional de Cuyo, Facultad de Ciencias Exactas y Naturales, Departamento de Biología, Casilla de Correo 33, 5500 Mendoza, Argentina
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Prokić MD, Borković-Mitić SS, Krizmanić II, Mutić JJ, Gavrić JP, Despotović SG, Gavrilović BR, Radovanović TB, Pavlović SZ, Saičić ZS. Oxidative stress parameters in two Pelophylax esculentus complex frogs during pre- and post-hibernation: Arousal vs heavy metals. Comp Biochem Physiol C Toxicol Pharmacol 2017; 202:19-25. [PMID: 28757213 DOI: 10.1016/j.cbpc.2017.07.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/21/2017] [Accepted: 07/25/2017] [Indexed: 11/29/2022]
Abstract
In spring, frogs from temperate regions are faced with arousal-induced oxidative stress and exposure to various xenobiotics from the environment. The question is whether pollutants can significantly modify the antioxidative defense system (AOS) response of hibernators during recovery from hibernation. If this assumption is true, we would then expect different patterns of seasonal variations in the AOS between individuals exposed to different levels of pollution. To examine this assumption, we determined the relationship between seasonal variations of accumulated metals and AOS parameters in the skin and muscle of two frog species from the Pelophylax esculentus complex (P. ridibundus and P. esculentus) inhabiting two localities (the Danube-Tisza-Danube canal and the Ponjavica River) with different levels of pollution during pre- and post-hibernation periods, respectively autumn and spring. Our results showed that even though there were differences in the concentrations of accumulated metals and AOS parameters between localities and species, the frogs displayed almost the same patterns of AOS variations during seasons, with a higher AOS response observed in spring. The parameters SH groups, GSH, GR and SOD had been contributed most rather than others. Our findings indicate that oxidative stress during the post-hibernation period was mainly caused by the organisms' recovery from hibernation, as the result of natural selection acting on the AOS, and that the accumulated metals did not significantly modify the AOS response. The present study provides new insight into the biological and physiological cellular responses of frogs to arousal stress.
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Affiliation(s)
- Marko D Prokić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
| | - Slavica S Borković-Mitić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Imre I Krizmanić
- Faculty of Biology, Institute of Zoology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia
| | - Jelena J Mutić
- Faculty of Chemistry, University of Belgrade, Studentski trg 12-16, 11158 Belgrade, Serbia
| | - Jelena P Gavrić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Svetlana G Despotović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Branka R Gavrilović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Tijana B Radovanović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Slađan Z Pavlović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Zorica S Saičić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
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Munro D, Treberg JR. A radical shift in perspective: mitochondria as regulators of reactive oxygen species. ACTA ACUST UNITED AC 2017; 220:1170-1180. [PMID: 28356365 DOI: 10.1242/jeb.132142] [Citation(s) in RCA: 158] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mitochondria are widely recognized as a source of reactive oxygen species (ROS) in animal cells, where it is assumed that over-production of ROS leads to an overwhelmed antioxidant system and oxidative stress. In this Commentary, we describe a more nuanced model of mitochondrial ROS metabolism, where integration of ROS production with consumption by the mitochondrial antioxidant pathways may lead to the regulation of ROS levels. Superoxide and hydrogen peroxide (H2O2) are the main ROS formed by mitochondria. However, superoxide, a free radical, is converted to the non-radical, membrane-permeant H2O2; consequently, ROS may readily cross cellular compartments. By combining measurements of production and consumption of H2O2, it can be shown that isolated mitochondria can intrinsically approach a steady-state concentration of H2O2 in the medium. The central hypothesis here is that mitochondria regulate the concentration of H2O2 to a value set by the balance between production and consumption. In this context, the consumers of ROS are not simply a passive safeguard against oxidative stress; instead, they control the established steady-state concentration of H2O2 By considering the response of rat skeletal muscle mitochondria to high levels of ADP, we demonstrate that H2O2 production by mitochondria is far more sensitive to changes in mitochondrial energetics than is H2O2 consumption; this concept is further extended to evaluate how the muscle mitochondrial H2O2 balance should respond to changes in aerobic work load. We conclude by considering how differences in the ROS consumption pathways may lead to important distinctions amongst tissues, along with briefly examining implications for differing levels of activity, temperature change and metabolic depression.
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Affiliation(s)
- Daniel Munro
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.,Centre on Aging, University of Manitoba, Winnipeg, MB, Canada R3T 2N2
| | - Jason R Treberg
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada R3T 2N2 .,Centre on Aging, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.,Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, Canada R3T 2N2
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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: 65] [Impact Index Per Article: 9.3] [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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Zhang W, Niu C, Liu Y, Chen B. Glutathione redox balance in hibernating Chinese soft-shelled turtle Pelodiscus sinensis hatchlings. Comp Biochem Physiol B Biochem Mol Biol 2017; 207:9-14. [DOI: 10.1016/j.cbpb.2017.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 02/03/2017] [Accepted: 02/09/2017] [Indexed: 02/07/2023]
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Gavrić J, Anđelković M, Tomović L, Prokić M, Despotović S, Gavrilović B, Radovanović T, Borković-Mitić S, Pavlović S, Saičić Z. Oxidative stress biomarkers, cholinesterase activity and biotransformation enzymes in the liver of dice snake (Natrix tessellata Laurenti) during pre-hibernation and post-hibernation: A possible correlation with heavy metals in the environment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 138:154-162. [PMID: 28043034 DOI: 10.1016/j.ecoenv.2016.12.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/15/2016] [Accepted: 12/27/2016] [Indexed: 06/06/2023]
Abstract
We investigated in the liver of dice snakes during pre- and post-hibernation changes in the following antioxidant parameters: total, manganese and copper zinc containing superoxide dismutases (Tot SOD, MnSOD, CuZn SOD, respectively), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR) and the concentrations of total glutathione (GSH) and sulfhydryl groups (-SH). In addition, we examined the expression of phase I biotransformation enzyme cytochrome P4501A (CYP1A) and the activity of phase II biotransformation enzyme glutathioneS-transferase (GST), the level of lipid peroxidation (by measuring the thiobarbituric acid-reactive substances (TBARS)), cholinesterase activity (ChE) and metallothionein expression (MT). We also measured the concentrations of heavy metals, including Al, Cd, As, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb and Zn in the water and snake liver during both periods. During the post-hibernation period, the activities of Tot SOD, CuZn SOD and GST and the concentration of GSH were significantly decreased, while GSH-Px and GR activities, the concentrations of -SH groups and TBARS were significantly increased. The activities of Mn SOD, CAT and ChE, and the relative amounts of CYP1A and MT did not significantly change during the investigated periods. The observed differences in the examined parameters probably represent adaptive physiological responses to sudden changes in tissue oxygenation during arousal from hibernation. Our findings also indicate that the accumulated metals modulated the responses of the examined parameters during the investigated periods.
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Affiliation(s)
- Jelena Gavrić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia.
| | - Marko Anđelković
- Department of Evolutionary Biology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Ljiljana Tomović
- Institute of Zoology, Faculty of Biology, University of Belgrade, Studentski trg 16, 11000 Belgrade, Serbia
| | - Marko Prokić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Svetlana Despotović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Branka Gavrilović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Tijana Radovanović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Slavica Borković-Mitić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Slađan Pavlović
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
| | - Zorica Saičić
- Department of Physiology, Institute for Biological Research "Siniša Stanković", University of Belgrade, Bulevar despota Stefana 142, 11060 Belgrade, Serbia
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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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Telomeres are elongated in older individuals in a hibernating rodent, the edible dormouse (Glis glis). Sci Rep 2016; 6:36856. [PMID: 27883035 PMCID: PMC5121655 DOI: 10.1038/srep36856] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 10/14/2016] [Indexed: 12/11/2022] Open
Abstract
Telomere shortening is thought to be an important biomarker for life history traits such as lifespan and aging, and can be indicative of genome integrity, survival probability and the risk of cancer development. In humans and other animals, telomeres almost always shorten with age, with more rapid telomere attrition in short-lived species. Here, we show that in the edible dormouse (Glis glis) telomere length significantly increases from an age of 6 to an age of 9 years. While this finding could be due to higher survival of individuals with longer telomeres, we also found, using longitudinal measurements, a positive effect of age on the rate of telomere elongation within older individuals. To our knowledge, no previous study has reported such an effect of age on telomere lengthening. We attribute this exceptional pattern to the peculiar life-history of this species, which skips reproduction in years with low food availability. Further, we show that this “sit tight” strategy in the timing of reproduction is associated with an increasing likelihood for an individual to reproduce as it ages. As reproduction could facilitate telomere attrition, this life-history strategy may have led to the evolution of increased somatic maintenance and telomere elongation with increasing age.
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Levesque DL, Nowack J, Stawski C. Modelling mammalian energetics: the heterothermy problem. ACTA ACUST UNITED AC 2016. [DOI: 10.1186/s40665-016-0022-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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49
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Domankevich V, Opatowsky Y, Malik A, Korol AB, Frenkel Z, Manov I, Avivi A, Shams I. Adaptive patterns in the p53 protein sequence of the hypoxia- and cancer-tolerant blind mole rat Spalax. BMC Evol Biol 2016; 16:177. [PMID: 27590526 PMCID: PMC5010716 DOI: 10.1186/s12862-016-0743-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 08/17/2016] [Indexed: 12/19/2022] Open
Abstract
Background The subterranean blind mole rat, Spalax (genus Nannospalax) endures extreme hypoxic conditions and fluctuations in oxygen levels that threaten DNA integrity. Nevertheless, Spalax is long-lived, does not develop spontaneous cancer, and exhibits an outstanding resistance to carcinogenesis in vivo, as well as anti-cancer capabilities in vitro. We hypothesized that adaptations to similar extreme environmental conditions involve common mechanisms for overcoming stress-induced DNA damage. Therefore, we aimed to identify shared features among species that are adapted to hypoxic stress in the sequence of the tumor-suppressor protein p53, a master regulator of the DNA-damage response (DDR). Results We found that the sequences of p53 transactivation subdomain 2 (TAD2) and tetramerization and regulatory domains (TD and RD) are more similar among hypoxia-tolerant species than expected from phylogeny. Specific positions in these domains composed patterns that are more frequent in hypoxia-tolerant species and have proven to be good predictors of species’ classification into stress-related categories. Some of these positions, which are known to be involved in the interactions between p53 and critical DDR proteins, were identified as positively selected. By 3D modeling of p53 interactions with the coactivator p300 and the DNA repair protein RPA70, we demonstrated that, compared to humans, these substitutions potentially reduce the binding of these proteins to Spalax p53. Conclusions We conclude that extreme hypoxic conditions may have led to convergent evolutionary adaptations of the DDR via TAD2 and TD/RD domains of p53. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0743-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vered Domankevich
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Yarden Opatowsky
- Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar-Ilan University, Ramat-Gan, Israel
| | - Assaf Malik
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Abraham B Korol
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Zeev Frenkel
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Irena Manov
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Aaron Avivi
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel
| | - Imad Shams
- Institute of Evolution & Department of Evolutionary and Environmental Biology, University of Haifa, Haifa, Israel.
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50
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Beneficial effects of group size on oxidative balance in a wild cooperative breeder. Behav Ecol 2016. [DOI: 10.1093/beheco/arw114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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