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Erman A, Hawkins LJ, Storey KB. Changes in microRNA expression related to ischemia-reperfusion injury in the kidney of the thirteen-lined ground squirrel during torpor. Biochimie 2024; 225:40-48. [PMID: 38705508 DOI: 10.1016/j.biochi.2024.05.001] [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: 02/11/2024] [Revised: 04/18/2024] [Accepted: 05/02/2024] [Indexed: 05/07/2024]
Abstract
During the hibernation season, the thirteen-lined ground squirrel undergoes cyclical torpor and arousal periods. The decrease and restoration of metabolic rate and oxygen delivery during torpor and arousal, respectively, may cause reperfusion-ischemia injury in the kidneys. In order to maintain the structural integrity of the kidneys necessary for renal function resumption during arousal, the thirteen-lined ground squirrel has developed adaptive methods to prevent and repair kidney injury. In this present study, computational methods were used to clean and analyze sequenced kidney RNA samples. Significantly differentially expressed microRNAs and enriched gene sets were also determined. From the gene set analysis, the results showed an increase in ubiquitin-related processes and p53 signaling pathways which suggested the occurrence of kidney damage during torpor. There was also an observed increase in cell cycle processes and the anchoring junction cellular compartment which may lend to the prevention of kidney injury. From the differentially expressed microRNAs, miR-27a (log2FC = 1.639; p-value = 0.023), miR-129 (log2FC = 2.516; p-value = 0.023), miR-let-7b (log2FC = 2.360; p-value = 0.025), miR-let-7c (log2FC = 2.291; p-value = 0.037) and miR-let-7i (log2FC = 1.564; p-value = 0.039) were found to be significantly upregulated. These biochemical adaptations may allow the thirteen-lined ground squirrel to maintain kidney structure and function during hibernation.
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Affiliation(s)
- Aylin Erman
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada.
| | - Liam J Hawkins
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | - Kenneth B Storey
- Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
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2
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Ishimoto T, Kosumi H, Natsuga K, Yamaguchi Y. Nail growth arrest under low body temperature during hibernation. J Physiol Sci 2024; 74:27. [PMID: 38678189 PMCID: PMC11055321 DOI: 10.1186/s12576-024-00919-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Accepted: 04/06/2024] [Indexed: 04/29/2024]
Abstract
Growth and differentiation are reduced or stopped during hibernation, an energy conserving strategy in harsh seasons by lowered metabolism and body temperature. However, few studies evaluated this in a same individual using a non-invasive method. In this study, we applied a non-invasive tracking method of the nail growth throughout the hibernation period in the same hibernating animals, the Syrian hamster (Mesocricetus auratus). We found that nail growth was markedly suppressed during the hibernation period but rapidly recovered by the exit from the hibernation period. Our data suggest that nail growth was arrested during deep torpor, a hypometabolic and hypothermic state, but recovered during periodic arousal, a euthermic phase. Consistent with this, nail stem cells located in the nail matrix did not exit the cell cycle in the deep torpor. Thus, hibernation stops nail growth in a body temperature-dependent manner.
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Affiliation(s)
- Taiga Ishimoto
- Laboratory of Biochemistry, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
- Department of Neuroscience for Metabolic Control, Graduate School of Medical Science, Kumamoto University, Kumamoto, Japan
| | - Hideyuki Kosumi
- Department of Dermatology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Ken Natsuga
- Department of Dermatology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
| | - Yoshifumi Yamaguchi
- Hibernation Metabolism, Physiology and Development Group, Institute of Low Temperature Science, Hokkaido University, Sapporo, Hokkaido, Japan.
- Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan.
- Inamori Research Institute for Science Fellowship (InaRIS), Kyoto, Japan.
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3
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Havenstein N, Langer F, Weiler U, Stefanski V, Fietz J. Bridging environment, physiology and life history: Stress hormones in a small hibernator. Mol Cell Endocrinol 2021; 533:111315. [PMID: 34052302 DOI: 10.1016/j.mce.2021.111315] [Citation(s) in RCA: 3] [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: 03/31/2021] [Accepted: 05/04/2021] [Indexed: 02/06/2023]
Abstract
Our knowledge of the perception of stress and its implications for animals in the wild is limited, especially in regard to mammals. The aim of this study was therefore to identify sex specific effects of reproductive activity, body mass, food availability and hibernation on stress hormone levels in the edible dormouse (Glis glis), a small mammalian hibernator. Results of our study reveal that reproductive activity and pre-hibernation fattening were associated with high cortisol levels in both sexes. During the mating season, in particular individuals with low body masses had higher stress levels. Elevated levels of cortisol during pre-hibernation fattening were even higher in females that had formerly invested into reproduction compared to non-reproductive females. Previously observed impairments on health parameters and reduced survival rates associated with reproduction emphasize the functional relevance of high stress hormone levels for fitness. Prolonged food limitation, however, did not affect stress levels demonstrating the ability of dormice to predict and cope with food restriction.
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Affiliation(s)
- Nadine Havenstein
- Institute of Biology, Dep. Zoology, University of Hohenheim, Stuttgart, Germany; Institute of Behavioral Physiology of Livestock, University of Hohenheim, Stuttgart, Germany
| | - Franz Langer
- Institute of Biology, Dep. Zoology, University of Hohenheim, Stuttgart, Germany; Institute of Behavioral Physiology of Livestock, University of Hohenheim, Stuttgart, Germany
| | - Ulrike Weiler
- Institute of Behavioral Physiology of Livestock, University of Hohenheim, Stuttgart, Germany
| | - Volker Stefanski
- Institute of Behavioral Physiology of Livestock, University of Hohenheim, Stuttgart, Germany
| | - Joanna Fietz
- Institute of Biology, Dep. Zoology, University of Hohenheim, Stuttgart, Germany; Institute of Behavioral Physiology of Livestock, University of Hohenheim, Stuttgart, Germany.
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Dias IB, Bouma HR, Henning RH. Unraveling the Big Sleep: Molecular Aspects of Stem Cell Dormancy and Hibernation. Front Physiol 2021; 12:624950. [PMID: 33867999 PMCID: PMC8047423 DOI: 10.3389/fphys.2021.624950] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 03/11/2021] [Indexed: 12/14/2022] Open
Abstract
Tissue-resident stem cells may enter a dormant state, also known as quiescence, which allows them to withstand metabolic stress and unfavorable conditions. Similarly, hibernating mammals can also enter a state of dormancy used to evade hostile circumstances, such as food shortage and low ambient temperatures. In hibernation, the dormant state of the individual and its cells is commonly known as torpor, and is characterized by metabolic suppression in individual cells. Given that both conditions represent cell survival strategies, we here compare the molecular aspects of cellular quiescence, particularly of well-studied hematopoietic stem cells, and torpor at the cellular level. Critical processes of dormancy are reviewed, including the suppression of the cell cycle, changes in metabolic characteristics, and cellular mechanisms of dealing with damage. Key factors shared by hematopoietic stem cell quiescence and torpor include a reversible activation of factors inhibiting the cell cycle, a shift in metabolism from glucose to fatty acid oxidation, downregulation of mitochondrial activity, key changes in hypoxia-inducible factor one alpha (HIF-1α), mTOR, reversible protein phosphorylation and autophagy, and increased radiation resistance. This similarity is remarkable in view of the difference in cell populations, as stem cell quiescence regards proliferating cells, while torpor mainly involves terminally differentiated cells. A future perspective is provided how to advance our understanding of the crucial pathways that allow stem cells and hibernating animals to engage in their 'great slumbers.'
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Affiliation(s)
- Itamar B. Dias
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Hjalmar R. Bouma
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Robert H. Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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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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6
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Life history written in blood: erythrocyte parameters in a small hibernator, the edible dormouse. J Comp Physiol B 2017; 188:359-371. [DOI: 10.1007/s00360-017-1111-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 05/13/2017] [Accepted: 05/17/2017] [Indexed: 02/02/2023]
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7
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It takes two to tango: Phagocyte and lymphocyte numbers in a small mammalian hibernator. Brain Behav Immun 2016; 52:71-80. [PMID: 26431693 DOI: 10.1016/j.bbi.2015.09.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/21/2015] [Accepted: 09/29/2015] [Indexed: 12/25/2022] Open
Abstract
Immunity is energetically costly and competes for resources with other physiological body functions, which may result in trade-offs that impair fitness during demanding situations. Endocrine mediators, particularly stress hormones, play a central role in these relationships and directly impact leukocyte differentials. To determine the effects of external stressors, energetic restraints and competing physiological functions on immune parameters and their relevance for fitness, we investigated leukocyte profiles during the active season of a small obligate hibernator, the edible dormouse (Glis glis), in five different study sites in south-western Germany. The highly synchronized yearly cycle of this species and the close adaptation of its life history to the irregular abundance of food resources provide a natural experiment to elucidate mechanisms underlying variations in fitness parameters. In contrast to previous studies on hibernators, that showed an immediate recovery of all leukocyte subtypes upon emergence, our study revealed that hibernation results in depleted phagocyte (neutrophils and monocytes) stores that recovered only slowly. As the phenomenon of low phagocyte counts was even more pronounced at the beginning of a low food year and primarily immature neutrophils were present in the blood upon emergence, preparatory mechanisms seem to determine the regeneration of phagocytes before hibernation is terminated. Surprisingly, the recovery of phagocytes thereafter took several weeks, presumably due to energetic restrictions. This impaired first line of defense coincides with lowest survival probabilities during the annual cycle of our study species. Reduced survival could furthermore be linked to drastic increases in the P/L ratio (phagocytes/lymphocytes), an indicator of physiological stress, during reproduction. On the other hand, moderate augmentations in the P/L ratio occurred during periods of low food availability and were associated with increased survival, but reproductive failure. In this case, the stress response probably represents an adaptive reaction that contributes to survival by activating energy resources. In contrast to our expectation, we could not detect an amplification of stress through high population densities. Summarized, results of our study clearly reveal that the leukocyte picture of active edible dormice responds sensitively to physiological conditions associated with hibernation, reproductive activity and food availability and can be linked to fitness parameters such as survival. Thus edible dormice represent an excellent model organism to investigate regulatory mechanisms of the immune system under natural conditions.
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Xiao Y, Wu Y, Sun K, Wang H, Jiang T, Lin A, Huang X, Yue X, Shi L, Feng J. Gene expression and adaptive evolution of ZBED1 in the hibernating greater horseshoe bat (Rhinolophus ferrumequinum). ACTA ACUST UNITED AC 2016; 219:834-43. [PMID: 26787476 DOI: 10.1242/jeb.133272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/08/2016] [Indexed: 01/11/2023]
Abstract
Mammalian hibernators experience physiological extremes, e.g. ischemia, muscle disuse and hypothermia, which are lethal to non-hibernators, implying the existence of underlying mechanisms that allow hibernators to withstand these physiological extremes. Increased cell proliferation is suggested to be such a strategy, but its molecular basis remains unknown. In this study, we characterized the expression pattern of ZBED1 (zinc finger, BED-type containing 1), a transcription factor that plays a crucial role in regulating cell proliferation, in five tissues of the greater horseshoe bat (Rhinolophus ferrumequinum) during pre-hibernation, deep hibernation and post-hibernation. Moreover, we investigated the ZBED1 genetic divergence from individuals with variable hibernation phenotypes that cover all three known mtDNA lineages of the species. Expression analyses showed that ZBED1 is overexpressed only in brain and skeletal muscle, not in the other three tissues, suggesting an increased cell proliferation in these two tissues during deep hibernation. Evolutionary analyses showed that ZBED1 sequences were clustered into two well-supported clades with each one dominated by hibernating and non-hibernating individuals, respectively. Positive selection analyses further showed some positively selected sites and a divergent selection pressure among hibernating and non-hibernating groups of R. ferrumequinum. Our results suggest that ZBED1 as a potential candidate gene that regulates cell proliferation for hibernators to face physiological extremes during hibernation.
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Affiliation(s)
- Yanhong Xiao
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Yonghua Wu
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China School of Life Sciences, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China
| | - Keping Sun
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Hui Wang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Tinglei Jiang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Aiqing Lin
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Xiaobin Huang
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Xinke Yue
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
| | - Limin Shi
- School of Life Science, Yunnan Normal University, Chenggong District, Kunming 650500, China
| | - Jiang Feng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, 2555 Jingyue Street, Changchun 130117, China
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9
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In Vivo Evaluation of Wound Bed Reaction and Graft Performance After Cold Skin Graft Storage. J Burn Care Res 2014; 35:e187-96. [DOI: 10.1097/bcr.0b013e3182a226df] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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10
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Origgi FC, Sattler U, Pilo P, Waldvogel AS. Fatal combined infection with canine distemper virus and orthopoxvirus in a group of Asian marmots (Marmota caudata). Vet Pathol 2013; 50:914-20. [PMID: 23381928 DOI: 10.1177/0300985813476060] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A fatal combined infection with canine distemper virus (CDV) and orthopoxvirus (OPXV) in Asian marmots (Marmota caudata) is reported in this article. A total of 7 Asian marmots from a small zoological garden in Switzerland were found dead in hibernation during a routine check in the winter of 2011. The marmots died in February 2011. No clinical signs of disease were observed at any time. The viruses were detected in all individuals for which the tissues were available (n = 3). Detection of the viruses was performed by reverse transcription polymerase chain reaction. The most consistent gross lesion was a neck and thorax edema. A necrotizing pharyngitis and a multifocal necrotizing pneumonia were observed histologically. Numerous large intracytoplasmic eosinophilic inclusions were seen in the epithelial cells of the pharynx, of the airways, and in the skin keratinocytes. Brain lesions were limited to mild multifocal gliosis. Phylogenetic analysis revealed that the marmot CDV strain was closely related to the clusters of CDVs detected in Switzerland in wild carnivores during a local outbreak in 2002 and the 2009-2010 nationwide epidemic, suggesting a spillover of this virus from wildlife. The OPXV was most closely related to a strain of cowpoxvirus, a poxvirus species considered endemic in Europe. This is the first reported instance of CDV infection in a rodent species and of a combined CDV and OPXV infection.
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Affiliation(s)
- F C Origgi
- DVM, PhD, DACVM, DACVP, Centre for Fish and Wildlife Health (FIWI), Institute of Animal Pathology, College of Veterinary Medicine, Vetsuisse Faculty, University of Bern; Laenggassstrasse 122, 3012 Bern, Switzerland.
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11
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Zimmerman LM, Paitz RT, Vogel LA, Bowden RM. Variation in the seasonal patterns of innate and adaptive immunity in the red-eared slider (Trachemys scripta). ACTA ACUST UNITED AC 2010; 213:1477-83. [PMID: 20400632 DOI: 10.1242/jeb.037770] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The primary function of the immune system is to protect the organism from invading pathogens. In vertebrates, this has resulted in a multifaceted system comprised of both innate and adaptive components. The immune system of all jawed vertebrates is complex, but unlike the endothermic vertebrates, relatively little is known about the functioning of the ectothermic vertebrate immune system, especially the reptilian system. Because turtles are long-lived ectotherms, factors such as temperature and age may affect their immune response, but comprehensive studies are lacking. We investigated variation in immune responses of adult male and female red-eared sliders (Trachemys scripta) across the entire active season. We characterized seasonal variation in innate, cell-mediated and humoral components via bactericidal capacity of plasma, delayed-type hypersensitivity and total immunoglobulin levels, respectively. Results indicate that all immune measures varied significantly across the active season, but each measure had a different pattern of variation. Interestingly, temperature alone does not explain the observed seasonal variation. Immune measures did not vary between males and females, but immunoglobulin levels did vary with age. This study demonstrates the highly dynamic nature of the reptilian immune system, and provides information on how biotic and abiotic factors influence the immune system of a long-lived ectotherm.
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Affiliation(s)
- Laura M Zimmerman
- School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA.
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12
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Zimmerman LM, Vogel LA, Bowden RM. Understanding the vertebrate immune system: insights from the reptilian perspective. J Exp Biol 2010; 213:661-71. [DOI: 10.1242/jeb.038315] [Citation(s) in RCA: 285] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Summary
Reptiles are ectothermic amniotes, providing the key link between ectothermic anamniotic fishes and amphibians, and endothermic amniotic birds and mammals. A greater understanding of reptilian immunity will provide important insights into the evolutionary history of vertebrate immunity as well as the growing field of eco-immunology. Like mammals, reptile immunity is complex and involves innate, cell-mediated and humoral compartments but, overall, there is considerably less known about immune function in reptiles. We review the current literature on each branch of the reptilian immune system, placing this information in context to other vertebrates. Further, we identify key areas that are prime for research as well as areas that are lagging because of lack of reagents in non-model systems.
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Affiliation(s)
- L. M. Zimmerman
- School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - L. A. Vogel
- School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
| | - R. M. Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61790-4120, USA
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13
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Ross AP, Drew KL. Potential for discovery of neuroprotective factors in serum and tissue from hibernating species. Mini Rev Med Chem 2006; 6:875-84. [PMID: 16918494 PMCID: PMC4454377 DOI: 10.2174/138955706777934964] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hibernation is a unique phenotype displayed by a phylogenetically diverse group of organisms including several species of mammals and one species of primate. Here we review evidence for blood and tissue borne signaling molecules in hibernating animals, achievements in isolating and characterizing these molecules, and potential medicinal applications.
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Affiliation(s)
- Austin P. Ross
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Kelly L. Drew
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
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14
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Vidal Pizarro I, Swain GP, Selzer ME. Cell proliferation in the lamprey central nervous system. J Comp Neurol 2004; 469:298-310. [PMID: 14694540 DOI: 10.1002/cne.11013] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
After spinal cord transection, axons regenerate both in larval and adult lampreys. It is not known to what degree cells proliferate, even in the uninjured animal. Therefore, we have determined the prevalence of mitosis in the lamprey central nervous system (CNS). Bromodeoxyuridine (BrdU) was injected and incorporated for 4 hours into 2- to 5-year-old larvae, animals undergoing metamorphosis, and young adults. Labeled cells were counted in the rhombencephalon (where most supraspinal projecting neurons are located) and spinal cord. A mitotic index (MI) was calculated as the percentage of nuclei that were labeled. There was a seasonal variation in mitotic activity, with higher MIs occurring in summer. Within the summer, there was an additional transient spike in mitosis, especially in the rhombencephalon. There was no correlation between age and MI within the range of developmental stages examined. Baseline MIs in the rhombencephalon and spinal cord were approximately 0.15% and 0.20%, respectively. In most animals, the highest mitotic rates in both the rhombencephalon and spinal cord were seen in the ependyma, but many labeled cells were found in nonependymal regions as well. During the summer spike, almost all of the additional mitosis in the rhombencephalon was in the ependyma, but this finding was not true in the spinal cord. Many BrdU-labeled cells in the spinal cord and rhombencephalon were also stained by monoclonal antibodies specific for lamprey glial keratin but were never labeled by anti-neurofilament antibodies. These results suggest that (1) neurogenesis is uncommon in the lamprey CNS; (2) during most of the year, baseline gliogenesis occurs mainly in the ependyma with substantial contribution by nonependymal areas. During the summer, a spike of mitotic activity occurs in the ependyma of the rhombencephalon and throughout the spinal cord.
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Affiliation(s)
- Ivonne Vidal Pizarro
- University of Pennsylvania, Institute of Neurological Sciences, Philadelphia, Pennsylvania 19104, USA
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15
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Carey HV, Andrews MT, Martin SL. Mammalian hibernation: cellular and molecular responses to depressed metabolism and low temperature. Physiol Rev 2003; 83:1153-81. [PMID: 14506303 DOI: 10.1152/physrev.00008.2003] [Citation(s) in RCA: 792] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Mammalian hibernators undergo a remarkable phenotypic switch that involves profound changes in physiology, morphology, and behavior in response to periods of unfavorable environmental conditions. The ability to hibernate is found throughout the class Mammalia and appears to involve differential expression of genes common to all mammals, rather than the induction of novel gene products unique to the hibernating state. The hibernation season is characterized by extended bouts of torpor, during which minimal body temperature (Tb) can fall as low as -2.9 degrees C and metabolism can be reduced to 1% of euthermic rates. Many global biochemical and physiological processes exploit low temperatures to lower reaction rates but retain the ability to resume full activity upon rewarming. Other critical functions must continue at physiologically relevant levels during torpor and be precisely regulated even at Tb values near 0 degrees C. Research using new tools of molecular and cellular biology is beginning to reveal how hibernators survive repeated cycles of torpor and arousal during the hibernation season. Comprehensive approaches that exploit advances in genomic and proteomic technologies are needed to further define the differentially expressed genes that distinguish the summer euthermic from winter hibernating states. Detailed understanding of hibernation from the molecular to organismal levels should enable the translation of this information to the development of a variety of hypothermic and hypometabolic strategies to improve outcomes for human and animal health.
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Affiliation(s)
- Hannah V Carey
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706, USA.
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Van Breukelen F, Martin SL. Invited review: molecular adaptations in mammalian hibernators: unique adaptations or generalized responses? J Appl Physiol (1985) 2002; 92:2640-7. [PMID: 12015384 DOI: 10.1152/japplphysiol.01007.2001] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hibernators are unique among mammals in their ability to attain, withstand, and reverse low body temperatures. Hibernators repeatedly cycle between body temperatures near zero during torpor and 37 degrees C during euthermy. How do these mammals maintain cardiac function, cell integrity, blood fluidity, and energetic balance during their prolonged periods at low body temperature and avoid damage when they rewarm? Hibernation is often considered an example of a unique adaptation for low-temperature function in mammals. Although such adaptation is apparent at the level of whole animal physiology, it is surprisingly difficult to demonstrate clear examples of adaptations at the cellular and biochemical levels that improve function in the cold and are unique to hibernators. Instead of adaptation for improved function in the cold, the key molecular adaptations of hibernation may be to exploit the cold to depress most aspects of biochemical function and then rewarm without damage to restore optimal function of all systems. These capabilities are likely due to novel regulation of biochemical pathways shared by all mammals, including humans.
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Affiliation(s)
- Frank Van Breukelen
- Department of Cellular and Structural Biology, University of Colorado School of Medicine, Denver, Colorado 80262, USA
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