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Wang Y, Wang X, Chen Y, Du J, Xiao Y, Guo D, Liu S. Adapting to stress: The effects of hibernation and hibernacula temperature on the hepatic transcriptome of Rhinolophus pusillus. FASEB J 2024; 38:e23462. [PMID: 38318662 DOI: 10.1096/fj.202301646r] [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: 08/13/2023] [Revised: 12/11/2023] [Accepted: 01/19/2024] [Indexed: 02/07/2024]
Abstract
Hibernation, a survival strategy in mammals for extreme climates, induces physiological phenomena such as ischemia-reperfusion and metabolic shifts that hold great potential for advancements in modern medicine. Despite this, the molecular mechanisms underpinning hibernation remain largely unclear. This study used RNA-seq and Iso-seq techniques to investigate the changes in liver transcriptome expression of Rhinolophus pusillus during hibernation and active periods, as well as under different microhabitat temperatures. We identified 11 457 differentially expressed genes during hibernation and active periods, of which 395 showed significant differential expression. Genes associated with fatty acid catabolism were significantly upregulated during hibernation, whereas genes related to carbohydrate metabolism and glycogen synthesis were downregulated. Conversely, immune-related genes displayed differential expression patterns: genes tied to innate immunity were significantly upregulated, while those linked to adaptive immunity and inflammatory response were downregulated. The analysis of transcriptomic data obtained from different microhabitat temperatures revealed that R. pusillus exhibited an upregulation of genes associated with lipid metabolism in lower microhabitat temperature. This upregulation facilitated an enhanced utilization rate of triglyceride, ultimately resulting in increased energy provision for the organism. Additionally, R. pusillus upregulated gluconeogenesis-related genes regardless of the microhabitat temperature, demonstrating the importance of maintaining blood glucose levels during hibernation. Our transcriptomic data reveal that these changes in liver gene expression optimize energy allocation during hibernation, suggesting that liver tissue adaptively responds to the inherent stress of its function during hibernation. This study sheds light on the role of differential gene expression in promoting more efficient energy allocation during hibernation. It contributes to our understanding of how liver tissue adapts to the stressors associated with this state.
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Affiliation(s)
- Ying Wang
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Xufan Wang
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Yu Chen
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Jianying Du
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Yanhong Xiao
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Dongge Guo
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Sen Liu
- College of Life Sciences, Henan Normal University, Xinxiang, China
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2
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Schweizer RM, Ivy CM, Natarajan C, Scott GR, Storz JF, Cheviron ZA. Gene regulatory changes underlie developmental plasticity in respiration and aerobic performance in highland deer mice. Mol Ecol 2023; 32:3483-3496. [PMID: 37073620 PMCID: PMC10330314 DOI: 10.1111/mec.16953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 03/27/2023] [Accepted: 04/03/2023] [Indexed: 04/20/2023]
Abstract
Phenotypic plasticity can play an important role in the ability of animals to tolerate environmental stress, but the nature and magnitude of plastic responses are often specific to the developmental timing of exposure. Here, we examine changes in gene expression in the diaphragm of highland deer mice (Peromyscus maniculatus) in response to hypoxia exposure at different stages of development. In highland deer mice, developmental plasticity in diaphragm function may mediate changes in several respiratory traits that influence aerobic metabolism and performance under hypoxia. We generated RNAseq data from diaphragm tissue of adult deer mice exposed to (1) life-long hypoxia (before conception to adulthood), (2) post-natal hypoxia (birth to adulthood), (3) adult hypoxia (6-8 weeks only during adulthood) or (4) normoxia. We found five suites of co-regulated genes that are differentially expressed in response to hypoxia, but the patterns of differential expression depend on the developmental timing of exposure. We also identified four transcriptional modules that are associated with important respiratory traits. Many of the genes in these transcriptional modules bear signatures of altitude-related selection, providing an indirect line of evidence that observed changes in gene expression may be adaptive in hypoxic environments. Our results demonstrate the importance of developmental stage in determining the phenotypic response to environmental stressors.
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Affiliation(s)
- Rena M. Schweizer
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Catherine M. Ivy
- Department of Biology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | | | - Graham R. Scott
- Department of Biology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Jay F. Storz
- School of Biological Sciences, University of Nebraska, Lincoln, NE 68588, USA
| | - Zachary A. Cheviron
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
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3
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Heinis FI, Alvarez S, Andrews MT. Mass spectrometry of the white adipose metabolome in a hibernating mammal reveals seasonal changes in alternate fuels and carnitine derivatives. Front Physiol 2023; 14:1214087. [PMID: 37449012 PMCID: PMC10337995 DOI: 10.3389/fphys.2023.1214087] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 06/15/2023] [Indexed: 07/18/2023] Open
Abstract
Mammalian hibernators undergo substantial changes in metabolic function throughout the seasonal hibernation cycle. We report here the polar metabolomic profile of white adipose tissue isolated from active and hibernating thirteen-lined ground squirrels (Ictidomys tridecemlineatus). Polar compounds in white adipose tissue were extracted from five groups representing different timepoints throughout the seasonal activity-torpor cycle and analyzed using hydrophilic interaction liquid chromatography-mass spectrometry in both the positive and negative ion modes. A total of 224 compounds out of 660 features detected after curation were annotated. Unsupervised clustering using principal component analysis revealed discrete clusters representing the different seasonal timepoints throughout hibernation. One-way analysis of variance and feature intensity heatmaps revealed metabolites that varied in abundance between active and torpid timepoints. Pathway analysis compared against the KEGG database demonstrated enrichment of amino acid metabolism, purine metabolism, glycerophospholipid metabolism, and coenzyme A biosynthetic pathways among our identified compounds. Numerous carnitine derivatives and a ketone that serves as an alternate fuel source, beta-hydroxybutyrate (BHB), were among molecules found to be elevated during torpor. Elevated levels of the BHB-carnitine conjugate during torpor suggests the synthesis of beta-hydroxybutyrate in white adipose mitochondria, which may contribute directly to elevated levels of circulating BHB during hibernation.
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Affiliation(s)
- Frazer I. Heinis
- School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Sophie Alvarez
- Proteomics and Metabolomics Facility, Nebraska Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Matthew T. Andrews
- School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, United States
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4
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Yang Y, Yuan J, Field RL, Ye D, Hu Z, Xu K, Xu L, Gong Y, Yue Y, Kravitz AV, Bruchas MR, Cui J, Brestoff JR, Chen H. Induction of a torpor-like hypothermic and hypometabolic state in rodents by ultrasound. Nat Metab 2023; 5:789-803. [PMID: 37231250 PMCID: PMC10229429 DOI: 10.1038/s42255-023-00804-z,] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 04/11/2023] [Indexed: 08/22/2023]
Abstract
Torpor is an energy-conserving state in which animals dramatically decrease their metabolic rate and body temperature to survive harsh environmental conditions. Here, we report the noninvasive, precise and safe induction of a torpor-like hypothermic and hypometabolic state in rodents by remote transcranial ultrasound stimulation at the hypothalamus preoptic area (POA). We achieve a long-lasting (>24 h) torpor-like state in mice via closed-loop feedback control of ultrasound stimulation with automated detection of body temperature. Ultrasound-induced hypothermia and hypometabolism (UIH) is triggered by activation of POA neurons, involves the dorsomedial hypothalamus as a downstream brain region and subsequent inhibition of thermogenic brown adipose tissue. Single-nucleus RNA-sequencing of POA neurons reveals TRPM2 as an ultrasound-sensitive ion channel, the knockdown of which suppresses UIH. We also demonstrate that UIH is feasible in a non-torpid animal, the rat. Our findings establish UIH as a promising technology for the noninvasive and safe induction of a torpor-like state.
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Affiliation(s)
- Yaoheng Yang
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Jinyun Yuan
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Rachael L Field
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Dezhuang Ye
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Zhongtao Hu
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Kevin Xu
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Lu Xu
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Yan Gong
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Yimei Yue
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Alexxai V Kravitz
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, USA
| | - Michael R Bruchas
- Departments of Anesthesiology and Pain Medicine, Pharmacology, and Bioengineering, Center for Neurobiology of Addiction, Pain, and Emotion, University of Washington, Seattle, WA, USA
| | - Jianmin Cui
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Jonathan R Brestoff
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Hong Chen
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA.
- Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, MO, USA.
- Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO, USA.
- Division of Neurotechnology, Washington University School of Medicine, Saint Louis, MO, USA.
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5
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Yang Y, Yuan J, Field RL, Ye D, Hu Z, Xu K, Xu L, Gong Y, Yue Y, Kravitz AV, Bruchas MR, Cui J, Brestoff JR, Chen H. Induction of a torpor-like hypothermic and hypometabolic state in rodents by ultrasound. Nat Metab 2023; 5:789-803. [PMID: 37231250 PMCID: PMC10229429 DOI: 10.1038/s42255-023-00804-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 04/11/2023] [Indexed: 05/27/2023]
Abstract
Torpor is an energy-conserving state in which animals dramatically decrease their metabolic rate and body temperature to survive harsh environmental conditions. Here, we report the noninvasive, precise and safe induction of a torpor-like hypothermic and hypometabolic state in rodents by remote transcranial ultrasound stimulation at the hypothalamus preoptic area (POA). We achieve a long-lasting (>24 h) torpor-like state in mice via closed-loop feedback control of ultrasound stimulation with automated detection of body temperature. Ultrasound-induced hypothermia and hypometabolism (UIH) is triggered by activation of POA neurons, involves the dorsomedial hypothalamus as a downstream brain region and subsequent inhibition of thermogenic brown adipose tissue. Single-nucleus RNA-sequencing of POA neurons reveals TRPM2 as an ultrasound-sensitive ion channel, the knockdown of which suppresses UIH. We also demonstrate that UIH is feasible in a non-torpid animal, the rat. Our findings establish UIH as a promising technology for the noninvasive and safe induction of a torpor-like state.
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Affiliation(s)
- Yaoheng Yang
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Jinyun Yuan
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Rachael L Field
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Dezhuang Ye
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Zhongtao Hu
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Kevin Xu
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Lu Xu
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Yan Gong
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Yimei Yue
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Alexxai V Kravitz
- Department of Psychiatry, Washington University School of Medicine, Saint Louis, MO, USA
| | - Michael R Bruchas
- Departments of Anesthesiology and Pain Medicine, Pharmacology, and Bioengineering, Center for Neurobiology of Addiction, Pain, and Emotion, University of Washington, Seattle, WA, USA
| | - Jianmin Cui
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA
| | - Jonathan R Brestoff
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Hong Chen
- Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO, USA.
- Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, MO, USA.
- Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO, USA.
- Division of Neurotechnology, Washington University School of Medicine, Saint Louis, MO, USA.
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6
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Adipocyte HIF2α functions as a thermostat via PKA Cα regulation in beige adipocytes. Nat Commun 2022; 13:3268. [PMID: 35672324 PMCID: PMC9174489 DOI: 10.1038/s41467-022-30925-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 05/24/2022] [Indexed: 12/14/2022] Open
Abstract
Thermogenic adipocytes generate heat to maintain body temperature against hypothermia in response to cold. Although tight regulation of thermogenesis is required to prevent energy sources depletion, the molecular details that tune thermogenesis are not thoroughly understood. Here, we demonstrate that adipocyte hypoxia-inducible factor α (HIFα) plays a key role in calibrating thermogenic function upon cold and re-warming. In beige adipocytes, HIFα attenuates protein kinase A (PKA) activity, leading to suppression of thermogenic activity. Mechanistically, HIF2α suppresses PKA activity by inducing miR-3085-3p expression to downregulate PKA catalytic subunit α (PKA Cα). Ablation of adipocyte HIF2α stimulates retention of beige adipocytes, accompanied by increased PKA Cα during re-warming after cold stimuli. Moreover, administration of miR-3085-3p promotes beige-to-white transition via downregulation of PKA Cα and mitochondrial abundance in adipocyte HIF2α deficient mice. Collectively, these findings suggest that HIF2α-dependent PKA regulation plays an important role as a thermostat through dynamic remodeling of beige adipocytes. Thermogenic adipocytes maintain body temperature in response to cold, but how this is tuned during cold and re-warming is unclear. Here, the authors show HIF2α inhibits beige adipocyte retention, regulating PKA catalysis to control dynamic adipocyte remodelling.
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7
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Monfort-Ferré D, Caro A, Menacho M, Martí M, Espina B, Boronat-Toscano A, Nuñez-Roa C, Seco J, Bautista M, Espín E, Megía A, Vendrell J, Fernández-Veledo S, Serena C. The Gut Microbiota Metabolite Succinate Promotes Adipose Tissue Browning in Crohn's Disease. J Crohns Colitis 2022; 16:1571-1583. [PMID: 35554517 PMCID: PMC9624294 DOI: 10.1093/ecco-jcc/jjac069] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/17/2022] [Accepted: 05/10/2022] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIMS Crohn's disease [CD] is associated with complex microbe-host interactions, involving changes in microbial communities, and gut barrier defects, leading to the translocation of microorganisms to surrounding adipose tissue [AT]. We evaluated the presence of beige AT depots in CD and questioned whether succinate and/or bacterial translocation promotes white-to-beige transition in adipocytes. METHODS Visceral [VAT] and subcutaneous [SAT] AT biopsies, serum and plasma were obtained from patients with active [n = 21] or inactive [n = 12] CD, and from healthy controls [n = 15]. Adipose-derived stem cells [ASCs] and AT macrophages [ATMs] were isolated from VAT biopsies. RESULTS Plasma succinate levels were significantly higher in patients with active CD than in controls and were intermediate in those with inactive disease. Plasma succinate correlated with the inflammatory marker high-sensitivity C-reactive protein. Expression of the succinate receptor SUCNR1 was higher in VAT, ASCs and ATMs from the active CD group than from the inactive or control groups. Succinate treatment of ASCs elevated the expression of several beige AT markers from controls and from patients with inactive disease, including uncoupling protein-1 [UCP1]. Notably, beige AT markers were prominent in ASCs from patients with active CD. Secretome profiling revealed that ASCs from patients with active disease secrete beige AT-related proteins, and co-culture assays showed that bacteria also trigger the white-to-beige switch of ASCs from patients with CD. Finally, AT depots from patients with CD exhibited a conversion from white to beige AT together with high UCP1 expression, which was corroborated by in situ thermal imaging analysis. CONCLUSIONS Succinate and bacteria trigger white-to-beige AT transition in CD. Understanding the role of beige AT in CD might aid in the development of therapeutic or diagnostic interventions.
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Affiliation(s)
- Diandra Monfort-Ferré
- Hospital Universitari de Tarragona Joan XXIII, Institut d’Investigació Sanitària Pere Virgili, Tarragona, Spain,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Aleidis Caro
- Colorectal Surgery Unit, Hospital Universitari Joan XXIII, Tarragona, Spain
| | | | - Marc Martí
- Colorectal Surgery Unit, General Surgery Service, Hospital Valle de Hebron, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Beatriz Espina
- Colorectal Surgery Unit, Hospital Universitari Joan XXIII, Tarragona, Spain
| | - Albert Boronat-Toscano
- Hospital Universitari de Tarragona Joan XXIII, Institut d’Investigació Sanitària Pere Virgili, Tarragona, Spain,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Cati Nuñez-Roa
- Hospital Universitari de Tarragona Joan XXIII, Institut d’Investigació Sanitària Pere Virgili, Tarragona, Spain,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Jesús Seco
- Hospital Universitari de Tarragona Joan XXIII, Institut d’Investigació Sanitària Pere Virgili, Tarragona, Spain,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Michelle Bautista
- Digestive Unit, Hospital Universitari Joan XXIII, 43007, Tarragona, Spain
| | - Eloy Espín
- Colorectal Surgery Unit, General Surgery Service, Hospital Valle de Hebron, Universitat Autonoma de Barcelona, Barcelona, Spain
| | - Ana Megía
- Hospital Universitari de Tarragona Joan XXIII, Institut d’Investigació Sanitària Pere Virgili, Tarragona, Spain,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain
| | - Joan Vendrell
- Hospital Universitari de Tarragona Joan XXIII, Institut d’Investigació Sanitària Pere Virgili, Tarragona, Spain,CIBER de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Instituto de Salud Carlos III, Madrid, Spain,Universitat Rovira i Virgili, Tarragona, Spain
| | - Sonia Fernández-Veledo
- Corresponding authors: Sonia Fernández-Veledo, PhD, Hospital Universitari de Tarragona Joan XXIII, Institut d’Investigació Sanitària Pere Virgili, Tarragona, Spain. ;
| | - Carolina Serena
- Carolina Serena, PhD, Hospital Universitari de Tarragona Joan XXIII, Institut d’Investigació Sanitària Pere Virgili, Tarragona, Spain. ;
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8
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Hibernation slows epigenetic ageing in yellow-bellied marmots. Nat Ecol Evol 2022; 6:418-426. [PMID: 35256811 PMCID: PMC8986532 DOI: 10.1038/s41559-022-01679-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 01/20/2022] [Indexed: 01/02/2023]
Abstract
Species that hibernate generally live longer than would be expected based solely on their body size. Hibernation is characterized by long periods of metabolic suppression (torpor) interspersed by short periods of increased metabolism (arousal). The torpor–arousal cycles occur multiple times during hibernation, and it has been suggested that processes controlling the transition between torpor and arousal states cause ageing suppression. Metabolic rate is also a known correlate of longevity; we thus proposed the ‘hibernation–ageing hypothesis’ whereby ageing is suspended during hibernation. We tested this hypothesis in a well-studied population of yellow-bellied marmots (Marmota flaviventer), which spend 7–8 months per year hibernating. We used two approaches to estimate epigenetic age: the epigenetic clock and the epigenetic pacemaker. Variation in epigenetic age of 149 samples collected throughout the life of 73 females was modelled using generalized additive mixed models (GAMM), where season (cyclic cubic spline) and chronological age (cubic spline) were fixed effects. As expected, the GAMM using epigenetic ages calculated from the epigenetic pacemaker was better able to detect nonlinear patterns in epigenetic ageing over time. We observed a logarithmic curve of epigenetic age with time, where the epigenetic age increased at a higher rate until females reached sexual maturity (two years old). With respect to circannual patterns, the epigenetic age increased during the active season and essentially stalled during the hibernation period. Taken together, our results are consistent with the hibernation–ageing hypothesis and may explain the enhanced longevity in hibernators. Species that hibernate generally have longer lifespans than expected based on their body size. The authors show epigenetic ageing patterns from a natural population of hibernating yellow-bellied marmots consistent with the hypothesis that ageing is suspended during hibernation.
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9
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Barbosa S, Andrews KR, Goldberg AR, Gour DS, Hohenlohe PA, Conway CJ, Waits LP. The role of neutral and adaptive genomic variation in population diversification and speciation in two ground squirrel species of conservation concern. Mol Ecol 2021; 30:4673-4694. [PMID: 34324748 DOI: 10.1111/mec.16096] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 07/10/2021] [Accepted: 07/19/2021] [Indexed: 11/29/2022]
Abstract
Understanding the neutral (demographic) and adaptive processes leading to the differentiation of species and populations is a critical component of evolutionary and conservation biology. In this context, recently diverged taxa represent a unique opportunity to study the process of genetic differentiation. Northern and southern Idaho ground squirrels (Urocitellus brunneus - NIDGS, and U. endemicus - SIDGS, respectively) are a recently diverged pair of sister species that have undergone dramatic declines in the last 50 years and are currently found in metapopulations across restricted spatial areas with distinct environmental pressures. Here we genotyped single-nucleotide polymorphisms (SNPs) from buccal swabs with restriction site-associated DNA sequencing (RADseq). With these data we evaluated neutral genetic structure at both theinter- and intraspecific level, and identified putatively adaptive SNPs using population structure outlier detection and genotype-environment association (GEA) analyses. At the interspecific level, we detected a clear separation between NIDGS and SIDGS, and evidence for adaptive differentiation putatively linked to torpor patterns. At the intraspecific level, we found evidence of both neutral and adaptive differentiation. For NIDGS, elevation appears to be the main driver of adaptive differentiation, while neutral variation patterns match and expand information on the low connectivity between some populations identified in previous studies using microsatellite markers. For SIDGS, neutral substructure generally reflected natural geographic barriers, while adaptive variation reflected differences in land cover and temperature, as well as elevation. These results clearly highlight the roles of neutral and adaptive processes for understanding the complexity of the processes leading to species and population differentiation, which can have important conservation implications in susceptible and threatened species.
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Affiliation(s)
- Soraia Barbosa
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844-1136, USA
| | - Kimberly R Andrews
- University of Idaho, Institute for Bioinformatics and Evolutionary Studies (IBEST), Moscow, ID, 83844-1136, USA
| | - Amanda R Goldberg
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844-1136, USA
| | - Digpal S Gour
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844-1136, USA
| | - Paul A Hohenlohe
- University of Idaho, Institute for Bioinformatics and Evolutionary Studies (IBEST), Moscow, ID, 83844-1136, USA.,Department of Biological Sciences, College of Science, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844-3051, USA
| | - Courtney J Conway
- U.S. Geological Survey, Idaho Cooperative Fish & Wildlife Research Unit, Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID, 83844-1141, USA
| | - Lisette P Waits
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, 875 Perimeter Drive, Moscow, ID, 83844-1136, USA
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10
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Logan SM, Storey KB. Markers of tissue remodeling and inflammation in the white and brown adipose tissues of a model hibernator. Cell Signal 2021; 82:109975. [PMID: 33711429 DOI: 10.1016/j.cellsig.2021.109975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/04/2021] [Accepted: 03/05/2021] [Indexed: 11/16/2022]
Abstract
The thirteen-lined ground squirrel is a model fat-storing hibernator that nearly doubles its weight in the fall to fuel metabolism with triglycerides throughout the winter months. Hibernator brown and white adipose tissue (BAT, WAT) are important to study in terms of their inflammatory profile and tissue remodeling mechanisms since controlled and natural regulation of these processes could inform new pharmacological interventions that limit oxidative stress and inflammation in the adipose tissues of humans suffering from obesity, promote non-shivering thermogenesis-mediated weight loss, or prevent tissue damage in transplantable organs emerging from cold-storage. Thus, markers of inflammation like cytokines and soluble receptors and tissue remodeling proteins such as matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) were investigated in normothermic, torpid, and arousing ground squirrels. Multiplex protein assays and western blotting revealed fewer changes in WAT compared to BAT. Pro-inflammatory IL-1α levels increased during torpor and soluble epidermal growth factor receptor protein levels increased during arousal in BAT. Given their known roles in other model systems, these proteins could regulate processes like adipogenesis, lipid catabolism, or cell motility. Decreased TIMP2 levels combined with maintained MMP2 or MMP3 protein levels suggested that BAT may avoid tissue remodeling until arousal. No changes in WAT inflammatory cytokines or soluble receptors as well as decreased MMP2 levels during torpor and arousal suggested inflammation and modification to the extracellular matrix is likely suppressed in WAT. This study emphasizes the fat-but-fit nature of the hibernating ground squirrel and the ability of its fat stores to suppress inflammation.
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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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Jiao D, Ji K, Liu H, Wang W, Wu X, Zhou J, Zhang Y, Zhou H, Hickford JGH, Degen AA, Yang G. Transcriptome Analysis Reveals Genes Involved in Thermogenesis in Two Cold-Exposed Sheep Breeds. Genes (Basel) 2021; 12:genes12030375. [PMID: 33800742 PMCID: PMC7999592 DOI: 10.3390/genes12030375] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/26/2021] [Accepted: 03/04/2021] [Indexed: 01/07/2023] Open
Abstract
Thermogenesis plays an important role in the survival of sheep exposed to low temperatures; however, little is known about the genetic mechanisms underlying cold adaptation in sheep. We examined 6 Altay (A) and 6 Hu (H) six-month-old ewe lambs. Altay sheep are raised in northern China and are adapted to dry, cold climates, while Hu sheep are raised in southern China and are adapted to warm, humid climates. Each breed was divided into two groups: chronic cold sheep, exposed to -5 °C for 25 days (3 Ac; 3 Hc), and thermo-neutral sheep, maintained at 20 °C (3 Aw; 3 Hw). The transcriptome profiles of hypothalamus, tail-fat and perirenal fat tissues from these four groups were determined using paired-end sequencing for RNA expression analysis. There are differences in cold tolerance between Hu and Altay sheep. Under cold exposure of the lambs: (1) UCP1-dependent thermogenesis and calcium- and cAMP-signaling pathways were activated; and (2) different fat tissues were activated in Hu and Altay lambs. Several candidate genes involved in thermogenesis including UCP1, ADRB3, ADORA2A, ATP2A1, RYR1 and IP6K1 were identified. Molecular mechanisms of thermogenesis in the sheep are discussed and new avenues for research are suggested.
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Affiliation(s)
- Dan Jiao
- Northwest Institute of Ecological Environment and Resources, Chinese Academy of Sciences, Lanzhou 730070, China; (D.J.); (K.J.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kaixi Ji
- Northwest Institute of Ecological Environment and Resources, Chinese Academy of Sciences, Lanzhou 730070, China; (D.J.); (K.J.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hu Liu
- School of Life Sciences, Lanzhou University, Lanzhou 730070, China; (H.L.); (W.W.); (J.Z.)
| | - Wenqiang Wang
- School of Life Sciences, Lanzhou University, Lanzhou 730070, China; (H.L.); (W.W.); (J.Z.)
| | - Xiukun Wu
- Key Laboratory of Desert and Desertification, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China;
- Key Laboratory of Extreme Environmental Microbial Resources and Engineering, Lanzhou 730000, China
| | - Jianwei Zhou
- School of Life Sciences, Lanzhou University, Lanzhou 730070, China; (H.L.); (W.W.); (J.Z.)
| | - Yunsheng Zhang
- Institute of Animal Husbandry, Xinjiang Academy of Animal Science, Xinjiang 830000, China;
| | - Huitong Zhou
- Gene-Marker Laboratory, Department of Agricultural Sciences, Lincoln University, Lincoln 7647, New Zealand; (H.Z.); (J.G.H.H.)
| | - Jon G. H. Hickford
- Gene-Marker Laboratory, Department of Agricultural Sciences, Lincoln University, Lincoln 7647, New Zealand; (H.Z.); (J.G.H.H.)
| | - Allan A. Degen
- Desert Animal Adaptations and Husbandry, Wyler Department of Dryland Agriculture, Blaustein Institutes for Desert Research, Ben-Gurion University of Negev, Beer Sheva l8410500, Israel;
| | - Guo Yang
- Northwest Institute of Ecological Environment and Resources, Chinese Academy of Sciences, Lanzhou 730070, China; (D.J.); (K.J.)
- Correspondence: ; Tel.: +86-(0931)-4967298
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12
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MicroRNA expression patterns in the brown fat of hibernating 13-lined ground squirrels. Genomics 2021; 113:769-781. [PMID: 33529780 DOI: 10.1016/j.ygeno.2021.01.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 01/05/2021] [Accepted: 01/24/2021] [Indexed: 11/24/2022]
Abstract
The sequence diversity of microRNAs (miRNAs) allows these potent regulators of mRNA fate to bind multiple transcripts, giving them the power to inhibit diverse cellular processes. Therefore, miRNAs may regulate metabolic rate suppression (also termed torpor), an adaptation used by capable species to reduce energy expenditure, minimize tissue damage, and prolong life. Small RNA-sequencing of brown fat from control (37 °C) and torpid (5-8 °C) ground squirrels revealed a central role for miRNAs in torpor. Unsupervised clustering analysis of all 319 conserved miRNAs showed separation of control and torpor samples, which was supported by PCA analysis. Of the 76 miRNAs that were differentially expressed, 45 were upregulated during torpor. KEGG and GO analyses suggested these miRNAs inhibit genes within the ribosome, oxidative phosphorylation, and glycolysis/gluconeogenesis pathways. Some of the most downregulated miRNAs (miR-1-3p, miR-206 and miR-133a/b) had significant Pearson correlation coefficients, suggesting these myomiRs may be co-expressed in control animals. Only 3 of the 16 enriched KEGG pathways were less targeted by miRNAs during torpor, including cytokine-cytokine receptor interactions and the coagulation and complement cascades, suggesting epigenetic or post-translation modifications may inhibit these potentially damaging processes. Alternatively, their activation could promote damage sensing, wound repair, and improve tissue homeostasis. Overall, miRNA-seq analysis of brown fat revealed a strong role for miRNAs in the downregulation of central metabolic processes necessary for MRS, and highlighted miRNAs that could be inhibited by antagomiRs to promote brown fat activity in potential obesity treatments, or that could be used to replicate torpor in non-hibernating mammals.
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13
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Gignoux-Wolfsohn SA, Pinsky ML, Kerwin K, Herzog C, Hall M, Bennett AB, Fefferman NH, Maslo B. Genomic signatures of selection in bats surviving white-nose syndrome. Mol Ecol 2021; 30:5643-5657. [PMID: 33476441 DOI: 10.1111/mec.15813] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 01/13/2021] [Accepted: 01/14/2021] [Indexed: 02/06/2023]
Abstract
Rapid evolution of advantageous traits following abrupt environmental change can help populations recover from demographic decline. However, for many introduced diseases affecting longer-lived, slower reproducing hosts, mortality is likely to outpace the acquisition of adaptive de novo mutations. Adaptive alleles must therefore be selected from standing genetic variation, a process that leaves few detectable genomic signatures. Here, we present whole genome evidence for selection in bat populations that are recovering from white-nose syndrome (WNS). We collected samples both during and after a WNS-induced mass mortality event in two little brown bat populations that are beginning to show signs of recovery and found signatures of soft sweeps from standing genetic variation at multiple loci throughout the genome. We identified one locus putatively under selection in a gene associated with the immune system. Multiple loci putatively under selection were located within genes previously linked to host response to WNS as well as to changes in metabolism during hibernation. Results from two additional populations suggested that loci under selection may differ somewhat among populations. Through these findings, we suggest that WNS-induced selection may contribute to genetic resistance in this slowly reproducing species threatened with extinction.
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Affiliation(s)
- Sarah A Gignoux-Wolfsohn
- Department of Ecology, Evolution, and Natural Resources, Rutgers The State University of New Jersey, New Brunswick, NJ, USA
| | - Malin L Pinsky
- Department of Ecology, Evolution, and Natural Resources, Rutgers The State University of New Jersey, New Brunswick, NJ, USA
| | - Kathleen Kerwin
- Department of Ecology, Evolution, and Natural Resources, Rutgers The State University of New Jersey, New Brunswick, NJ, USA
| | - Carl Herzog
- New York State Department of Environmental Conservation, Albany, NY, USA
| | - MacKenzie Hall
- Endangered and Nongame Species Program, New Jersey Department of Environmental Protection, Trenton, NJ, USA
| | | | - Nina H Fefferman
- Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, USA.,National Institute for Mathematical and Biological Synthesis, University of Tennessee, Tennessee, TN, USA
| | - Brooke Maslo
- Department of Ecology, Evolution, and Natural Resources, Rutgers The State University of New Jersey, New Brunswick, NJ, USA
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14
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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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15
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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: 4] [Impact Index Per Article: 1.3] [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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16
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Lin JQ, Yu J, Jiang H, Zhang Y, Wan QH, Fang SG. Multi-omics analysis reveals that natural hibernation is crucial for oocyte maturation in the female Chinese alligator. BMC Genomics 2020; 21:774. [PMID: 33167853 PMCID: PMC7653761 DOI: 10.1186/s12864-020-07187-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Accepted: 10/26/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Hibernation in an appropriate environment not only is important for the survival of hibernators in winter, but also is crucial for breeding in the following season for many hibernating species. However, the genetic and epigenetic mechanism underlying this process remain unclear. In the current study, we performed an integrative multi-omics analysis of gonads collected from Chinese alligators that overwintered in wild cave and artificial warmroom to explore transcriptomic and epigenomic alternations in these organs. RESULTS The data revealed that in the breeding season, female alligators were more strongly affected in terms of gene expression than males by non-hibernation because of overwintering in a warm room, especially for genes related to oocyte maturation, and this effect commenced in winter with the downregulation of STAR, which is the rate limiting factor of steroid biosynthesis. Further, miRNAs were found to play essential roles in this negative effect of overwintering in the warm room on hibernation. The upregulated miRNAs likely were responsible for the suppression of oocyte maturation in the breeding season. Finally, DNA methylome changes, especially hypomethylation, were found to play an important role in the alterations in ovarian function-related gene expression induced by non-hibernation. CONCLUSIONS Our study revealed the crucial role of hibernation quality for oocyte maturation in the Chinese alligator and the underlying genetic and epigenetic mechanisms, and highlights the importance of habitat, and especially, the overwintering site, in the conservation of not only the Chinese alligator, but also other endangered hibernators.
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Affiliation(s)
- Jian-Qing Lin
- MOE Key Laboratory of Biosystems Homeostasis & Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Jun Yu
- MOE Key Laboratory of Biosystems Homeostasis & Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Hua Jiang
- MOE Key Laboratory of Biosystems Homeostasis & Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Yi Zhang
- MOE Key Laboratory of Biosystems Homeostasis & Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Qiu-Hong Wan
- MOE Key Laboratory of Biosystems Homeostasis & Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China
| | - Sheng-Guo Fang
- MOE Key Laboratory of Biosystems Homeostasis & Protection, State Conservation Centre for Gene Resources of Endangered Wildlife, College of Life Sciences, Zhejiang University, Hangzhou, 310058, People's Republic of China.
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17
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Singhal NS, Bai M, Lee EM, Luo S, Cook KR, Ma DK. Cytoprotection by a naturally occurring variant of ATP5G1 in Arctic ground squirrel neural progenitor cells. eLife 2020; 9:55578. [PMID: 33050999 PMCID: PMC7671683 DOI: 10.7554/elife.55578] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 10/08/2020] [Indexed: 02/06/2023] Open
Abstract
Many organisms in nature have evolved mechanisms to tolerate severe hypoxia or ischemia, including the hibernation-capable Arctic ground squirrel (AGS). Although hypoxic or ischemia tolerance in AGS involves physiological adaptations, little is known about the critical cellular mechanisms underlying intrinsic AGS cell resilience to metabolic stress. Through cell survival-based cDNA expression screens in neural progenitor cells, we identify a genetic variant of AGS Atp5g1 that confers cell resilience to metabolic stress. Atp5g1 encodes a subunit of the mitochondrial ATP synthase. Ectopic expression in mouse cells and CRISPR/Cas9 base editing of endogenous AGS loci revealed causal roles of one AGS-specific amino acid substitution in mediating cytoprotection by AGS ATP5G1. AGS ATP5G1 promotes metabolic stress resilience by modulating mitochondrial morphological change and metabolic functions. Our results identify a naturally occurring variant of ATP5G1 from a mammalian hibernator that critically contributes to intrinsic cytoprotection against metabolic stress. When animals hibernate, they lower their body temperature and metabolism to conserve the energy they need to withstand cold harsh winters. One such animal is the Arctic ground squirrel, an extreme hibernator that can drop its body temperatures to below 0°C. This hibernation ability means the cells of Arctic ground squirrels can survive severe shortages of blood and oxygen. But, it is unclear how their cells are able to endure this metabolic stress. To answer this question, Singhal, Bai et al. studied the cells of Arctic ground squirrels for unique features that might make them more durable to stress. Examining the genetic code of these resilient cells revealed that Arctic ground squirrels may have a variant form of a protein called ATP5G1. This protein is found in a cellular compartment called the mitochondria, which is responsible for supplying energy to the rest of the cell and therefore plays an important role in metabolic processes. Singhal, Bai et al. found that when this variant form of ATP5G1 was introduced into the cells of mice, their mitochondria was better at coping with stress conditions, such as low oxygen, low temperature and poisoning. Using a gene editing tool to selectively substitute some of the building blocks, also known as amino acids, that make up the ATP5G1 protein revealed that improvements to the mitochondria were caused by switching specific amino acids. However, swapping these amino acids, which presumably affects the role of ATP5G1, did not completely remove the cells’ resilience to stress. This suggests that variants of other genes and proteins may also be involved in providing protection. These findings provide the first evidence of a protein variant that is responsible for protecting cells during the metabolic stress conditions caused by hibernation. The approach taken by Singhal, Bai et al. could be used to identify and study other proteins that increase resilience to metabolic stress. These findings could help develop new treatments for diseases caused by a limited blood supply to human organs, such as a stroke or heart attack.
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Affiliation(s)
- Neel S Singhal
- Department of Neurology, University of California-San Francisco, San Francisco, United States
| | - Meirong Bai
- Cardiovascular Research Institute, University of California-San Francisco, San Francisco, United States.,Department of Physiology, University of California-San Francisco, San Francisco, United States
| | - Evan M Lee
- Cardiovascular Research Institute, University of California-San Francisco, San Francisco, United States.,Department of Physiology, University of California-San Francisco, San Francisco, United States
| | - Shuo Luo
- Cardiovascular Research Institute, University of California-San Francisco, San Francisco, United States.,Department of Physiology, University of California-San Francisco, San Francisco, United States
| | - Kayleigh R Cook
- Cardiovascular Research Institute, University of California-San Francisco, San Francisco, United States.,Department of Physiology, University of California-San Francisco, San Francisco, United States
| | - Dengke K Ma
- Cardiovascular Research Institute, University of California-San Francisco, San Francisco, United States.,Department of Physiology, University of California-San Francisco, San Francisco, United States.,Innovative Genomics Institute, Berkeley, United States
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18
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Li Y, Schwalie PC, Bast-Habersbrunner A, Mocek S, Russeil J, Fromme T, Deplancke B, Klingenspor M. Systems-Genetics-Based Inference of a Core Regulatory Network Underlying White Fat Browning. Cell Rep 2020; 29:4099-4113.e5. [PMID: 31851936 DOI: 10.1016/j.celrep.2019.11.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/02/2019] [Accepted: 11/13/2019] [Indexed: 02/06/2023] Open
Abstract
Recruitment of brite/beige cells, known as browning of white adipose tissue (WAT), is an efficient way to turn an energy-storing organ into an energy-dissipating one and may therefore be of therapeutic value in combating obesity. However, a comprehensive understanding of the regulatory mechanisms mediating WAT browning is still lacking. Here, we exploit the large natural variation in WAT browning propensity between inbred mouse strains to gain an inclusive view of the core regulatory network coordinating this cellular process. Combining comparative transcriptomics, perturbation-based validations, and gene network analyses, we present a comprehensive gene regulatory network of inguinal WAT browning, revealing up to four distinct regulatory modules with key roles for uncovered transcriptional factors, while also providing deep insights into the genetic architecture of brite adipogenesis. The presented findings therefore greatly increase our understanding of the molecular drivers mediating the intriguing cellular heterogeneity and plasticity of adipose tissue.
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Affiliation(s)
- Yongguo Li
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany; EKFZ-Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany
| | - Petra C Schwalie
- Institute of Bio-engineering, School of Life Sciences, EPFL and Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Andrea Bast-Habersbrunner
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany; EKFZ-Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany
| | - Sabine Mocek
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany; EKFZ-Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany
| | - Julie Russeil
- Institute of Bio-engineering, School of Life Sciences, EPFL and Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Tobias Fromme
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany; EKFZ-Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany
| | - Bart Deplancke
- Institute of Bio-engineering, School of Life Sciences, EPFL and Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland.
| | - Martin Klingenspor
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany; EKFZ-Else Kröner-Fresenius Center for Nutritional Medicine, Technical University of Munich, Gregor-Mendel-Str. 2, 85354 Freising, Germany.
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19
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A Unique Energy-Saving Strategy during Hibernation Revealed by Multi-Omics Analysis in the Chinese Alligator. iScience 2020; 23:101202. [PMID: 32534442 PMCID: PMC7298530 DOI: 10.1016/j.isci.2020.101202] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/16/2020] [Accepted: 05/22/2020] [Indexed: 12/11/2022] Open
Abstract
Many ectotherms hibernate in face of the harsh winter conditions to improve their survival rate. However, the molecular mechanism underlying this process remains unclear. Here, we explored the hibernation mechanism of Chinese alligator using integrative multi-omics analysis. We revealed that (1) the thyroid hormone biosynthesis, nutrition absorption and metabolism, muscle contraction, urinary excretion and immunity function pathways are overall downregulated during hibernation; (2) the fat catabolism is completely suppressed, contrasting with the upregulation of hepatic fatty-acid-transporter CPT1A, suggesting a unique energy-saving strategy that differs from that in hibernating mammals; (3) the hibernation-related genes are not only directly regulated by DNA methylation but also controlled by methylation-dependent transcription networks. In addition, we identified and compared tissue-specific, species-specific, and conserved season-biased miRNAs, demonstrating complex post-transcriptional regulation during hibernation. Our study revealed the genetic and epigenetic mechanisms underlying hibernation in the Chinese alligator and provided molecular insights into the evolution of hibernation regulation.
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20
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Hu CK, Wang W, Brind'Amour J, Singh PP, Reeves GA, Lorincz MC, Alvarado AS, Brunet A. Vertebrate diapause preserves organisms long term through Polycomb complex members. Science 2020; 367:870-874. [PMID: 32079766 DOI: 10.1126/science.aaw2601] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 11/26/2019] [Accepted: 12/23/2019] [Indexed: 12/27/2022]
Abstract
Diapause is a state of suspended development that helps organisms survive extreme environments. How diapause protects living organisms is largely unknown. Using the African turquoise killifish (Nothobranchius furzeri), we show that diapause preserves complex organisms for extremely long periods of time without trade-offs for subsequent adult growth, fertility, and life span. Transcriptome analyses indicate that diapause is an active state, with dynamic regulation of metabolism and organ development genes. The most up-regulated genes in diapause include Polycomb complex members. The chromatin mark regulated by Polycomb, H3K27me3, is maintained at key developmental genes in diapause, and the Polycomb member CBX7 mediates repression of metabolism and muscle genes in diapause. CBX7 is functionally required for muscle preservation and diapause maintenance. Thus, vertebrate diapause is a state of suspended life that is actively maintained by specific chromatin regulators, and this has implications for long-term organism preservation.
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Affiliation(s)
- Chi-Kuo Hu
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Wei Wang
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA.,Howard Hughes Medical Institute, Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Julie Brind'Amour
- Department of Medical Genetics, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Param Priya Singh
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - G Adam Reeves
- Department of Genetics, Stanford University, Stanford, CA 94305, USA.,Graduate Program of Genetics, Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Matthew C Lorincz
- Department of Medical Genetics, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Alejandro Sánchez Alvarado
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA.,Howard Hughes Medical Institute, Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Anne Brunet
- Department of Genetics, Stanford University, Stanford, CA 94305, USA. .,Glenn Laboratories for the Biology of Aging, Stanford University, Stanford, CA 94305, USA
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21
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Green CL, Mitchell SE, Derous D, Wang Y, Chen L, Han JDJ, Promislow DEL, Lusseau D, Douglas A, Speakman JR. The Effects of Graded Levels of Calorie Restriction: XIV. Global Metabolomics Screen Reveals Brown Adipose Tissue Changes in Amino Acids, Catecholamines, and Antioxidants After Short-Term Restriction in C57BL/6 Mice. J Gerontol A Biol Sci Med Sci 2020; 75:218-229. [PMID: 31220223 PMCID: PMC7530471 DOI: 10.1093/gerona/glz023] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Indexed: 12/15/2022] Open
Abstract
Animals undergoing calorie restriction (CR) often lower their body temperature to conserve energy. Brown adipose tissue (BAT) is stimulated through norepinephrine when rapid heat production is needed, as it is highly metabolically active due to the uncoupling of the electron transport chain from ATP synthesis. To better understand how BAT metabolism changes with CR, we used metabolomics to identify 883 metabolites that were significantly differentially expressed in the BAT of C57BL/6 mice, fed graded CR (10%, 20%, 30%, and 40% CR relative to their individual baseline intake), compared with mice fed ad libitum (AL) for 12 hours a day. Pathway analysis revealed that graded CR had an impact on the TCA cycle and fatty acid degradation. In addition, an increase in nucleic acids and catecholamine pathways was seen with graded CR in the BAT metabolome. We saw increases in antioxidants with CR, suggesting a beneficial effect of mitochondrial uncoupling. Importantly, the instigator of BAT activation, norepinephrine, was increased with CR, whereas its precursors l-tyrosine and dopamine were decreased, indicating a shift of metabolites through the activation pathway. Several of these key changes were correlated with food anticipatory activity and body temperature, indicating BAT activation may be driven by responses to hunger.
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Affiliation(s)
- Cara L Green
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - Sharon E Mitchell
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - Davina Derous
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - Yingchun Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, China
| | - Luonan Chen
- Key Laboratory of Systems Biology, Innovation Center for Cell Signaling Network, Institute of Biochemistry and Cell Biology, China
| | - Jing-Dong J Han
- Chinese Academy of Sciences Key Laboratory of Computational Biology, Chinese Academy of Sciences-Max Planck Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, China
| | - Daniel E L Promislow
- Department of Pathology and Department of Biology, University of Washington at Seattle
| | - David Lusseau
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - Alex Douglas
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
| | - John R Speakman
- School of Biological Sciences, Institute of Biological and Environmental Sciences, University of Aberdeen, Scotland, UK
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, China
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22
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Abstract
Adaptive thermogenesis is a catabolic process that consumes energy-storing molecules and expends that energy as heat in response to environmental changes. This process occurs primarily in brown and beige adipose tissue. Thermogenesis is regulated by many factors, including lipid derived paracrine and endocrine hormones called lipokines. Recently, technologic advances for identifying new lipid biomarkers of thermogenic activity have shed light on a diverse set of lipokines that act through different pathways to regulate energy expenditure. In this review, we highlight a few examples of lipokines that regulate thermogenesis. The biosynthesis, regulation, and effects of the thermogenic lipokines in several families are reviewed, including oloeylethanolamine, endocannabinoids, prostaglandin E2, and 12,13-diHOME. These thermogenic lipokines present potential therapeutic targets to combat states of excess energy storage, such as obesity and related metabolic disorders.
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Affiliation(s)
- Matthew D Lynes
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
| | - Sean D Kodani
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
| | - Yu-Hua Tseng
- Section on Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts
- Harvard Stem Cell Institute, Harvard University, Cambridge, Massachusetts
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23
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Jansen HT, Trojahn S, Saxton MW, Quackenbush CR, Evans Hutzenbiler BD, Nelson OL, Cornejo OE, Robbins CT, Kelley JL. Hibernation induces widespread transcriptional remodeling in metabolic tissues of the grizzly bear. Commun Biol 2019; 2:336. [PMID: 31531397 PMCID: PMC6744400 DOI: 10.1038/s42003-019-0574-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 08/12/2019] [Indexed: 12/20/2022] Open
Abstract
Revealing the mechanisms underlying the reversible physiology of hibernation could have applications to both human and animal health as hibernation is often associated with disease-like states. The present study uses RNA-sequencing to reveal the tissue and seasonal transcriptional changes occurring in grizzly bears (Ursus arctos horribilis). Comparing hibernation to other seasons, bear adipose has a greater number of differentially expressed genes than liver and skeletal muscle. During hyperphagia, adipose has more than 900 differentially expressed genes compared to active season. Hibernation is characterized by reduced expression of genes associated with insulin signaling, muscle protein degradation, and urea production, and increased expression within muscle protein anabolic pathways. Across all three tissues we find a subset of shared differentially expressed genes, some of which are uncharacterized, that together may reflect a common regulatory mechanism. The identified gene families could be useful for developing novel therapeutics to treat human and animal diseases.
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Affiliation(s)
- Heiko T. Jansen
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164 USA
| | - Shawn Trojahn
- School of Biological Sciences, Washington State University, Pullman, WA 99164 USA
| | - Michael W. Saxton
- School of Biological Sciences, Washington State University, Pullman, WA 99164 USA
| | - Corey R. Quackenbush
- School of Biological Sciences, Washington State University, Pullman, WA 99164 USA
| | - Brandon D. Evans Hutzenbiler
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164 USA
- School of the Environment, Washington State University, Pullman, WA 99164 USA
| | - O. Lynne Nelson
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA 99164 USA
| | - Omar E. Cornejo
- School of Biological Sciences, Washington State University, Pullman, WA 99164 USA
| | - Charles T. Robbins
- School of Biological Sciences, Washington State University, Pullman, WA 99164 USA
- School of the Environment, Washington State University, Pullman, WA 99164 USA
| | - Joanna L. Kelley
- School of Biological Sciences, Washington State University, Pullman, WA 99164 USA
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24
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Hadj-Moussa H, Watts AJ, Storey KB. Genes of the undead: hibernation and death display different gene profiles. FEBS Lett 2019; 593:527-532. [PMID: 30767213 DOI: 10.1002/1873-3468.13338] [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: 01/16/2019] [Revised: 02/08/2019] [Accepted: 02/12/2019] [Indexed: 02/01/2023]
Abstract
A degree of regulation continues into death according to post-mortem transcriptome studies, which have identified 'zombie genes' that come alive hours and days after organismal death. We hypothesized that hibernation, representing the closest natural mammalian phenomenon to death, would display similar gene expression profiles. Exploring zombie genes using qPCR and available transcriptomic resources from multiple torpid tissues in 13-lined ground squirrels showed little in common with gene profiles observed following death. Hibernators repress transcription, surviving only on the transcripts required during profound slowdowns of metabolic rate and of most physiological functions, therefore not requiring zombie gene expression that could be the cell's last resort during stress. This is the first study to explore zombie gene responses to a near-death situation in a living system.
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25
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Andrews MT. Molecular interactions underpinning the phenotype of hibernation in mammals. J Exp Biol 2019; 222:222/2/jeb160606. [DOI: 10.1242/jeb.160606] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
ABSTRACT
Mammals maintain a constant warm body temperature, facilitating a wide variety of metabolic reactions. Mammals that hibernate have the ability to slow their metabolism, which in turn reduces their body temperature and leads to a state of hypothermic torpor. For this metabolic rate reduction to occur on a whole-body scale, molecular interactions that change the physiology of cells, tissues and organs are required, resulting in a major departure from normal mammalian homeostasis. The aim of this Review is to cover recent advances in the molecular biology of mammalian hibernation, including the role of small molecules, seasonal changes in gene expression, cold-inducible RNA-binding proteins, the somatosensory system and emerging information on hibernating primates. To underscore the importance of differential gene expression across the hibernation cycle, mRNA levels for 14,261 ground squirrel genes during periods of activity and torpor are made available for several tissues via an interactive transcriptome browser. This Review also addresses recent findings on molecular interactions responsible for multi-day survival of near-freezing body temperatures, single-digit heart rates and a slowed metabolism that greatly reduces oxygen consumption. A better understanding of how natural hibernators survive these physiological extremes is beginning to lead to innovations in human medicine.
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Affiliation(s)
- Matthew T. Andrews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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26
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Oliver SR, Anderson KJ, Hunstiger MM, Andrews MT. Turning down the heat: Down-regulation of sarcolipin in a hibernating mammal. Neurosci Lett 2018; 696:13-19. [PMID: 30528880 DOI: 10.1016/j.neulet.2018.11.059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/30/2018] [Accepted: 11/30/2018] [Indexed: 02/01/2023]
Abstract
Hibernation in mammals is a whole-body phenotype that involves profound reductions in oxygen consumption, metabolic reactions, core body temperature, neural activity and heart rate. An important aspect of mammalian hibernation is the ability to reverse this state of hypothermic torpor by rewarming and subsequent arousal. Brown adipose tissue (BAT) and skeletal muscle shivering have been characterized as the predominant driving forces for thermogenesis during arousal. Conversely, the thermogenic contribution of these organs needs to be minimized as hibernating mammals enter torpor. Because skeletal muscle accounts for approximately 40% of the dry mass of the typical mammalian body, we aim to broaden the spotlight to include the importance of down-regulating skeletal muscle non-shivering thermogenesis during hibernation to allow for whole-body cooling and long-term maintenance of a depressed core body temperature when the animal is in torpor. This minireview will briefly describe the current understanding of thermoregulation in hibernating mammals and present new preliminary data on the importance of skeletal muscle and the micro-peptide sarcolipin as a major thermogenic target.
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Affiliation(s)
- S Ryan Oliver
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
| | - Kyle J Anderson
- Department of Biomedical Sciences, University of Minnesota Medical School Duluth, Duluth, MN 55812, USA.
| | - Moriah M Hunstiger
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
| | - Matthew T Andrews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA.
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27
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Pahlavani M, Wijayatunga NN, Kalupahana NS, Ramalingam L, Gunaratne PH, Coarfa C, Rajapakshe K, Kottapalli P, Moustaid-Moussa N. Transcriptomic and microRNA analyses of gene networks regulated by eicosapentaenoic acid in brown adipose tissue of diet-induced obese mice. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:1523-1531. [PMID: 30261280 PMCID: PMC6298436 DOI: 10.1016/j.bbalip.2018.09.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 09/01/2018] [Accepted: 09/17/2018] [Indexed: 12/11/2022]
Abstract
Brown adipose tissue (BAT) dissipates chemical energy as heat via thermogenesis and protects against obesity by increasing energy expenditure. However, regulation of BAT by dietary factors remains largely unexplored at the mechanistic level. We investigated the effect of eicosapentaenoic acid (EPA) on BAT metabolism. Male C57BL/6J (B6) mice were fed either a high-fat diet (HF, 45% kcal fat) or HF diet supplemented with EPA (HF-EPA, 6.75% kcal EPA) for 11 weeks. RNA sequencing (RNA-Seq) and microRNA (miRNA) profiling were performed on RNA from BAT using Illumina HiSeq and Illumina Genome Analyzer NextSeq, respectively. We conducted pathway analyses using ingenuity pathway analysis software (IPA®) and validated some genes and miRNAs using qPCR. We identified 479 genes that were differentially expressed (2-fold change, n = 3, P ≤ 0.05) in BAT from HF compared to HF-EPA. Genes negatively correlated with thermogenesis such as hypoxia inducible factor 1 alpha subunit inhibitor (Hif1an), were downregulated by EPA. Pathways related to thermogenesis such as peroxisome proliferator-activated receptor (PPAR) were upregulated by EPA while pathways associated with obesity and inflammation such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) were downregulated by EPA. MiRNA profiling identified nine and six miRNAs that were upregulated and downregulated by EPA, respectively (log2 fold change > 1.25, n = 3, P ≤ 0.05). Key regulatory miRNAs which were involved in thermogenesis, such as miR-455-3p and miR-129-5p were validated using qPCR. In conclusion, the depth of transcriptomic and miRNA profiling revealed novel mRNA-miRNA interaction networks in BAT which are involved in thermogenesis, and regulated by EPA.
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Affiliation(s)
- Mandana Pahlavani
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, United States; Obesity Research Cluster, Texas Tech University, Lubbock, TX, United States
| | - Nadeeja N Wijayatunga
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, United States
| | - Nishan S Kalupahana
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, United States; Obesity Research Cluster, Texas Tech University, Lubbock, TX, United States; Department of Physiology, University of Peradeniya, Sri Lanka
| | - Latha Ramalingam
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, United States; Obesity Research Cluster, Texas Tech University, Lubbock, TX, United States
| | - Preethi H Gunaratne
- Department of Biology and Biochemistry, University of Houston, United States
| | - Cristian Coarfa
- Department of Molecular and Cell Biology, Houston, TX, United States
| | - Kimal Rajapakshe
- Department of Molecular and Cell Biology, Houston, TX, United States
| | - Pratibha Kottapalli
- Center for Biotechnology and Genomics, Texas Tech University, Lubbock, TX, United States
| | - Naima Moustaid-Moussa
- Department of Nutritional Sciences, Texas Tech University, Lubbock, TX, United States; Obesity Research Cluster, Texas Tech University, Lubbock, TX, United States.
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28
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Bonis A, Anderson L, Talhouarne G, Schueller E, Unke J, Krus C, Stokka J, Koepke A, Lehrer B, Schuh A, Andersen JJ, Cooper S. Cardiovascular resistance to thrombosis in 13-lined ground squirrels. J Comp Physiol B 2018; 189:167-177. [PMID: 30317383 DOI: 10.1007/s00360-018-1186-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 08/08/2018] [Accepted: 10/06/2018] [Indexed: 12/24/2022]
Abstract
13-lined ground squirrels (Ictidomys tridecemlineatus) enter hibernation as a survival strategy during extreme environmental conditions. Typical ground squirrel hibernation is characterized by prolonged periods of torpor with significantly reduced heart rate, blood pressure, and blood flow, interrupted every few weeks by brief interbout arousals (IBA) during which blood flow fluctuates dramatically. These physiological conditions should increase the risk of stasis-induced blood clots and myocardial ischemia. However, ground squirrels have adapted to survive repeated bouts of torpor and IBA without forming lethal blood clots or sustaining lethal ischemic myocardial damage. The purpose of this study was to determine if ground squirrels are resistant to thrombosis and myocardial ischemia during hibernation. Blood markers of coagulation, fibrinolysis, thrombosis, and ischemia, as well as histological markers of myocardial ischemia were measured throughout the annual hibernation cycle. Hibernating ground squirrels were also treated with isoprenaline to induce myocardial ischemia. Thrombin-antithrombin complex levels were significantly reduced (p < 0.05) during hibernation, while D-dimer level remained unchanged throughout the annual cycle, both consistent with an antithrombotic state. During torpor, the ground squirrels were in a hyperfibrinolytic state with an elevated ratio of tissue plasminogen activator complexed with plasminogen activator inhibitor to total plasminogen activator inhibitor (p < 0.05). Histological markers of myocardial ischemia were reversibly elevated during hibernation with no increase in markers of myocardial cell death in the blood. These data suggest that ground squirrels do not form major blood clots during hibernation through suppression of coagulation and a hyperfibrinolytic state. These animals also demonstrate myocardial resistance to ischemia.
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Affiliation(s)
- Alison Bonis
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | - Leah Anderson
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | - Gaëlle Talhouarne
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | - Emily Schueller
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | - Jenna Unke
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | - Catherine Krus
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | - Jordan Stokka
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | - Anna Koepke
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | - Brittany Lehrer
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | - Anthony Schuh
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA
| | | | - Scott Cooper
- Biology Department, University of Wisconsin-La Crosse, 1725 State St. La Crosse, La Crosse, WI, 54601, USA.
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29
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Gene expression profiling during hibernation in the European hamster. Sci Rep 2018; 8:13167. [PMID: 30177816 PMCID: PMC6120936 DOI: 10.1038/s41598-018-31506-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 08/21/2018] [Indexed: 12/14/2022] Open
Abstract
Hibernation is an exceptional physiological response to a hostile environment, characterized by a seasonal period of torpor cycles involving dramatic reductions of body temperature and metabolism, and arousal back to normothermia. As the mechanisms regulating hibernation are still poorly understood, here we analysed the expression of genes involved in energy homeostasis, torpor regulation, and daily or seasonal timing using digital droplet PCR in various central and peripheral tissues sampled at different stages of torpor/arousal cycles in the European hamster. During torpor, the hypothalamus exhibited strongly down-regulated gene expression, suggesting that hypothalamic functions were reduced during this period of low metabolic activity. During both torpor and arousal, many structures (notably the brown adipose tissue) exhibited altered expression of deiodinases, potentially leading to reduced tissular triiodothyronine availability. During the arousal phase, all analysed tissues showed increased expression of the core clock genes Per1 and Per2. Overall, our data indicated that the hypothalamus and brown adipose tissue were the tissues most affected during the torpor/arousal cycle, and that clock genes may play critical roles in resetting the body’s clocks at the beginning of the active period.
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30
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Field KA, Sewall BJ, Prokkola JM, Turner GG, Gagnon MF, Lilley TM, Paul White J, Johnson JS, Hauer CL, Reeder DM. Effect of torpor on host transcriptomic responses to a fungal pathogen in hibernating bats. Mol Ecol 2018; 27:3727-3743. [PMID: 30080945 DOI: 10.1111/mec.14827] [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: 11/14/2017] [Revised: 07/25/2018] [Accepted: 07/28/2018] [Indexed: 01/07/2023]
Abstract
Hibernation, the use of prolonged torpor to depress metabolism, is employed by mammals to conserve resources during extended periods of extreme temperatures and/or resource limitation. Mammalian hibernators arouse to euthermy periodically during torpor for reasons that are not well understood, and these arousals may facilitate immune processes. To determine whether arousals enable host responses to pathogens, we used dual RNA-Seq and a paired sampling approach to examine gene expression in a hibernating bat, the little brown myotis (Myotis lucifugus). During torpor, transcript levels differed in only a few genes between uninfected wing tissue and adjacent tissue infected with Pseudogymnoascus destructans, the fungal pathogen that causes white-nose syndrome. Within 70-80 min after emergence from torpor, large changes in gene expression were observed due to local infection, particularly in genes involved in pro-inflammatory host responses to fungal pathogens, but also in many genes involved in immune responses and metabolism. These results support the hypothesis that torpor is a period of relative immune dormancy and arousals allow for local immune responses in infected tissues during hibernation. Host-pathogen interactions were also found to regulate gene expression in the pathogen differently depending on the torpor state of the host. Hibernating species must balance the benefits of energy and water conservation achieved during torpor with the costs of decreased immune competence. Interbout arousals allow hibernators to optimize these, and other, trade-offs during prolonged hibernation by enabling host responses to pathogens within brief, periodic episodes of euthermy.
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Affiliation(s)
- Kenneth A Field
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
| | - Brent J Sewall
- Department of Biology, Temple University, Philadelphia, Pennsylvania
| | - Jenni M Prokkola
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
| | - Gregory G Turner
- Wildlife Diversity Division, Pennsylvania Game Commission, Harrisburg, Pennsylvania
| | - Marianne F Gagnon
- Department of Biology, Temple University, Philadelphia, Pennsylvania
| | - Thomas M Lilley
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
| | - J Paul White
- Wisconsin Department of Natural Resources, Madison, Wisconsin
| | - Joseph S Johnson
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
| | | | - DeeAnn M Reeder
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania
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31
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Blanco MB, Dausmann KH, Faherty SL, Yoder AD. Tropical heterothermy is “cool”: The expression of daily torpor and hibernation in primates. Evol Anthropol 2018; 27:147-161. [DOI: 10.1002/evan.21588] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 03/15/2018] [Indexed: 12/19/2022]
Affiliation(s)
| | | | | | - Anne D. Yoder
- Duke Lemur Center; Durham North Carolina
- Department of Biology; Duke University; Durham North Carolina
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32
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Martinez B, Khudyakov J, Rutherford K, Crocker DE, Gemmell N, Ortiz RM. Adipose transcriptome analysis provides novel insights into molecular regulation of prolonged fasting in northern elephant seal pups. Physiol Genomics 2018; 50:495-503. [PMID: 29625017 DOI: 10.1152/physiolgenomics.00002.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The physiological and cellular adaptations to extreme fasting in northern elephant seals ( Mirounga angustirostris, NES) are remarkable and may help to elucidate endocrine mechanisms that regulate lipid metabolism and energy homeostasis in mammals. Recent studies have highlighted the importance of thyroid hormones in the maintenance of a lipid-based metabolism during prolonged fasting in weaned NES pups. To identify additional molecular regulators of fasting, we used a transcriptomics approach to examine changes in global gene expression profiles before and after 6-8 wk of fasting in weaned NES pups. We produced a de novo assembly and identified 98 unique protein-coding genes that were differentially expressed between early and late fasting. Most of the downregulated genes were associated with lipid, carbohydrate, and protein metabolism. A number of downregulated genes were also associated with maintenance of the extracellular matrix, consistent with tissue remodeling during weight loss and the multifunctional nature of blubber tissue, which plays both metabolic and structural roles in marine mammals. Using this data set, we predict potential mechanisms by which NES pups sustain metabolism and regulate adipose stores throughout the fast, and provide a valuable resource for additional studies of extreme metabolic adaptations in mammals.
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Affiliation(s)
- Bridget Martinez
- Department of Molecular & Cellular Biology, University of California, Merced, California.,Department of Medicine, St. George's University School of Medicine, St. George, Grenada.,Department of Anatomy, University of Otago , Dunedin , New Zealand.,Department of Physics and Engineering, Los Alamos National Laboratory , Los Alamos, New Mexico
| | - Jane Khudyakov
- Department of Biological Sciences, University of the Pacific , Stockton, California
| | - Kim Rutherford
- Department of Anatomy, University of Otago , Dunedin , New Zealand
| | - Daniel E Crocker
- Department of Biology, Sonoma State University , Rohnert Park, California
| | - Neil Gemmell
- Department of Anatomy, University of Otago , Dunedin , New Zealand
| | - Rudy M Ortiz
- Department of Molecular & Cellular Biology, University of California, Merced, California
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33
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Ou J, Ball JM, Luan Y, Zhao T, Miyagishima KJ, Xu Y, Zhou H, Chen J, Merriman DK, Xie Z, Mallon BS, Li W. iPSCs from a Hibernator Provide a Platform for Studying Cold Adaptation and Its Potential Medical Applications. Cell 2018; 173:851-863.e16. [PMID: 29576452 DOI: 10.1016/j.cell.2018.03.010] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 12/12/2017] [Accepted: 03/02/2018] [Indexed: 12/22/2022]
Abstract
Hibernating mammals survive hypothermia (<10°C) without injury, a remarkable feat of cellular preservation that bears significance for potential medical applications. However, mechanisms imparting cold resistance, such as cytoskeleton stability, remain elusive. Using the first iPSC line from a hibernating mammal (13-lined ground squirrel), we uncovered cellular pathways critical for cold tolerance. Comparison between human and ground squirrel iPSC-derived neurons revealed differential mitochondrial and protein quality control responses to cold. In human iPSC-neurons, cold triggered mitochondrial stress, resulting in reactive oxygen species overproduction and lysosomal membrane permeabilization, contributing to microtubule destruction. Manipulations of these pathways endowed microtubule cold stability upon human iPSC-neurons and rat (a non-hibernator) retina, preserving its light responsiveness after prolonged cold exposure. Furthermore, these treatments significantly improved microtubule integrity in cold-stored kidneys, demonstrating the potential for prolonging shelf-life of organ transplants. Thus, ground squirrel iPSCs offer a unique platform for bringing cold-adaptive strategies from hibernators to humans in clinical applications. VIDEO ABSTRACT.
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Affiliation(s)
- Jingxing Ou
- Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - John M Ball
- Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yizhao Luan
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Lab of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China; School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Tantai Zhao
- Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; Department of Ophthalmology, The Second Xiang-Ya Hospital, Central South University, Changsha 410011, China
| | - Kiyoharu J Miyagishima
- Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yufeng Xu
- Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University, College of Medicine, Hangzhou 310009, China
| | - Huizhi Zhou
- Trans-NIH Center for Human Immunology, Autoimmunity, and Inflammation, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jinguo Chen
- Trans-NIH Center for Human Immunology, Autoimmunity, and Inflammation, National Institutes of Health, Bethesda, MD 20892, USA
| | - Dana K Merriman
- Department of Biology, University of Wisconsin, Oshkosh, WI 54901, USA
| | - Zhi Xie
- State Key Laboratory of Ophthalmology, Guangdong Provincial Key Lab of Ophthalmology and Visual Science, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Barbara S Mallon
- NIH Stem Cell Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wei Li
- Retinal Neurophysiology Section, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Ballinger MA, Andrews MT. Nature's fat-burning machine: brown adipose tissue in a hibernating mammal. ACTA ACUST UNITED AC 2018. [PMID: 29514878 DOI: 10.1242/jeb.162586] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Brown adipose tissue (BAT) is a unique thermogenic tissue in mammals that rapidly produces heat via nonshivering thermogenesis. Small mammalian hibernators have evolved the greatest capacity for BAT because they use it to rewarm from hypothermic torpor numerous times throughout the hibernation season. Although hibernator BAT physiology has been investigated for decades, recent efforts have been directed toward understanding the molecular underpinnings of BAT regulation and function using a variety of methods, from mitochondrial functional assays to 'omics' approaches. As a result, the inner-workings of hibernator BAT are now being illuminated. In this Review, we discuss recent research progress that has identified players and pathways involved in brown adipocyte differentiation and maturation, as well as those involved in metabolic regulation. The unique phenotype of hibernation, and its reliance on BAT to generate heat to arouse mammals from torpor, has uncovered new molecular mechanisms and potential strategies for biomedical applications.
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Affiliation(s)
- Mallory A Ballinger
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
| | - Matthew T Andrews
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
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35
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Jastroch M, Oelkrug R, Keipert S. Insights into brown adipose tissue evolution and function from non-model organisms. ACTA ACUST UNITED AC 2018. [PMID: 29514888 DOI: 10.1242/jeb.169425] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Brown adipose tissue (BAT) enables adaptive thermoregulation through heat production that is catalyzed by mitochondrial uncoupling protein 1 (UCP1). BAT is frequently studied in rodent model organisms, and recently in adult humans to treat metabolic diseases. However, complementary studies of many non-model species, which have diversified to many more ecological niches, may significantly broaden our understanding of BAT regulation and its physiological roles. This Review highlights the research on non-model organisms, which was instrumental to the discovery of BAT function, and the unique evolutionary history of BAT/UCP1 in mammalian thermogenesis. The comparative biology of BAT provides a powerful integrative approach that could identify conserved and specialized functional changes in BAT and UCP1 by considering species diversity, ecology and evolution, and by fusing multiple scientific disciplines such as physiology and biochemistry. Thus, resolving the complete picture of BAT biology may fail if comparative studies of non-model organisms are neglected.
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Affiliation(s)
- Martin Jastroch
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, D-85764 Neuherberg, Germany .,German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany.,Department of Animal Physiology, Faculty of Biology, Philipps University of Marburg, D-35032 Marburg, Germany
| | - Rebecca Oelkrug
- Department of Molecular Endocrinology, Center of Brain, Behavior and Metabolism (CBBM), University of Lübeck, D-23562 Lübeck, Germany
| | - Susanne Keipert
- Institute for Diabetes and Obesity, Helmholtz Diabetes Center at Helmholtz Zentrum München, D-85764 Neuherberg, Germany.,German Center for Diabetes Research (DZD), D-85764 Neuherberg, Germany
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36
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Abstract
Mice subjected to cold or caloric deprivation can reduce body temperature and metabolic rate and enter a state of torpor. Here we show that administration of pyruvate, an energy-rich metabolic intermediate, can induce torpor in mice with diet-induced or genetic obesity. This is associated with marked hypothermia, decreased activity, and decreased metabolic rate. The drop in body temperature correlates with the degree of obesity and is blunted by housing mice at thermoneutrality. Induction of torpor by pyruvate in obese mice relies on adenosine signaling and is accompanied by changes in brain levels of hexose bisphosphate and GABA as detected by mass spectroscopy-based imaging. Pyruvate does not induce torpor in lean mice but results in the activation of brown adipose tissue (BAT) with an increase in the level of uncoupling protein-1 (UCP1). Denervation of BAT in lean mice blocks this increase in UCP1 and allows the pyruvate-induced torpor phenotype. Thus, pyruvate administration induces torpor in obese mice by pathways involving adenosine and GABA signaling and a failure of normal activation of BAT.
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37
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Optical visualisation of thermogenesis in stimulated single-cell brown adipocytes. Sci Rep 2017; 7:1383. [PMID: 28469146 PMCID: PMC5431191 DOI: 10.1038/s41598-017-00291-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 02/20/2017] [Indexed: 01/07/2023] Open
Abstract
The identification of brown adipose deposits in adults has led to significant interest in targeting this metabolically active tissue for treatment of obesity and diabetes. Improved methods for the direct measurement of heat production as the signature function of brown adipocytes (BAs), particularly at the single cell level, would be of substantial benefit to these ongoing efforts. Here, we report the first application of a small molecule-type thermosensitive fluorescent dye, ERthermAC, to monitor thermogenesis in BAs derived from murine brown fat precursors and in human brown fat cells differentiated from human neck brown preadipocytes. ERthermAC accumulated in the endoplasmic reticulum of BAs and displayed a marked change in fluorescence intensity in response to adrenergic stimulation of cells, which corresponded to temperature change. ERthermAC fluorescence intensity profiles were congruent with mitochondrial depolarisation events visualised by the JC-1 probe. Moreover, the averaged fluorescence intensity changes across a population of cells correlated well with dynamic changes such as thermal power, oxygen consumption, and extracellular acidification rates. These findings suggest ERthermAC as a promising new tool for studying thermogenic function in brown adipocytes of both murine and human origins.
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38
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Bogren LK, Grabek KR, Barsh GS, Martin SL. Comparative tissue transcriptomics highlights dynamic differences among tissues but conserved metabolic transcript prioritization in preparation for arousal from torpor. J Comp Physiol B 2017; 187:735-748. [PMID: 28332019 DOI: 10.1007/s00360-017-1073-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/02/2016] [Accepted: 02/26/2017] [Indexed: 12/01/2022]
Abstract
During the hibernation season, 13-lined ground squirrels spend days to weeks in torpor with body temperatures near freezing then spontaneously rewarm. The molecular drivers of the drastic physiological changes that orchestrate and permit torpor are not well understood. Although transcription effectively ceases at the low body temperatures of torpor, previous work has demonstrated that some transcripts are protected from bulk degradation in brown adipose tissue (BAT), consistent with the importance of their protein products for metabolic heat generation during arousal from torpor. We examined the transcriptome of skeletal muscle, heart, and liver to determine the patterns of differentially expressed genes in these tissues, and whether, like BAT, a subset of these were relatively increased during torpor. EDGE-tags were quantified from five distinct physiological states representing the seasonal and torpor-arousal cycles of 13-lined ground squirrels. Supervised clustering on relative transcript abundances with Random Forest separated the two states bracketing prolonged torpor, entrance into and aroused from torpor, in all three tissues. Independent analyses identified 3347, 6784, and 2433 differentially expressed transcripts among all sampling points in heart, skeletal muscle, and liver, respectively. There were few differentially expressed genes in common across all three tissues; these were enriched in mitochondrial and apoptotic pathway components. Divisive clustering of these data revealed unique cohorts of transcripts that increased across the torpor bout in each tissue with patterns reflecting various combinations of cycling within and between seasons as well as between torpor and arousal. Transcripts that increased across the torpor bout were likewise tissue specific. These data shed new light on the biochemical pathways that alter in concert with hibernation phenotype and provide a rich resource for further hypothesis-based studies.
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Affiliation(s)
- Lori K Bogren
- Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, USA.
| | | | | | - Sandra L Martin
- Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, USA
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MacCannell A, Sinclair K, Friesen-Waldner L, McKenzie CA, Staples JF. Water-fat MRI in a hibernator reveals seasonal growth of white and brown adipose tissue without cold exposure. J Comp Physiol B 2017; 187:759-767. [PMID: 28324157 DOI: 10.1007/s00360-017-1075-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/13/2016] [Accepted: 02/26/2017] [Indexed: 11/24/2022]
Abstract
Obligate hibernators, such as ground squirrels, display circannual patterns which persist even under constant laboratory conditions, suggesting that they are regulated by endogenous rhythms. Brown adipose tissue (BAT) is important for thermogenesis during periodic arousals from hibernation when core body temperature rises spontaneously from 5 to 37 °C. In most small eutherians BAT growth requires several weeks of cold exposure. We hypothesized that in the thirteen-lined ground squirrel (Ictidomys tridecemlineatus), a hibernator, BAT growth is regulated, in part, by an endogenous rhythm and we predicted that this growth would precede the hibernation season without cold exposure. We tested this prediction using repeated water-fat magnetic resonance imaging over a year, including the hibernation season. Thoracic BAT depots increased in volume from spring through autumn even though animals were housed at ~22 °C. Subsequent cold exposure (5 °C) enlarged the thoracic BAT further. The fat fraction of this tissue fell significantly during the period of peak growth, indicating relative increases in non-triglyceride components, perhaps mitochondria or vasculature. We also found that the proportion of the body consisting of white adipose tissue (WAT) increased steadily from spring through autumn, and fell throughout hibernation, mirroring changes in body mass. Unlike BAT, WAT fat fractions remained constant (near 90%) throughout the year. Future studies will evaluate the significance of photoperiod and cold exposure on the growth of these tissues. We also found tissue with a fat fraction characteristic of BAT in the head near the eyes, a potentially novel discovery that requires further confirmation.
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Affiliation(s)
- Amanda MacCannell
- Department of Biology, University of Western Ontario, London, ON, N6A 5B8, Canada
| | - Kevin Sinclair
- Medical Biophysics, University of Western Ontario, London, ON, N6A 5B8, Canada
| | | | - Charles A McKenzie
- Medical Biophysics, University of Western Ontario, London, ON, N6A 5B8, Canada
| | - James F Staples
- Department of Biology, University of Western Ontario, London, ON, N6A 5B8, Canada.
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40
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Cubuk C, Kemmling J, Fabrizius A, Herwig A. Transcriptome Analysis of Hypothalamic Gene Expression during Daily Torpor in Djungarian Hamsters ( Phodopus sungorus). Front Neurosci 2017; 11:122. [PMID: 28348515 PMCID: PMC5346580 DOI: 10.3389/fnins.2017.00122] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 02/27/2017] [Indexed: 01/03/2023] Open
Abstract
Animals living at high or temperate latitudes are challenged by extensive changes in environmental conditions over seasons. Djungarian hamsters (Phodopus sungorus) are able to cope with extremely cold ambient temperatures and food scarcity in winter by expressing spontaneous daily torpor. Daily torpor is a circadian controlled voluntary reduction of metabolism that can reduce energy expenditure by up to 65% when used frequently. In the past decades it has become more and more apparent, that the hypothalamus is likely to play a key role in regulating induction and maintenance of daily torpor, but the molecular signals, which lead to the initiation of daily torpor, are still unknown. Here we present the first transcriptomic study of hypothalamic gene expression patterns in Djungarian hamsters during torpor entrance. Based on Illumina sequencing we were able to identify a total number of 284 differentially expressed genes, whereby 181 genes were up- and 103 genes down regulated during torpor entrance. The 20 most up regulated group contained eight genes coding for structure proteins, including five collagen genes, dnha2 and myo15a, as well as the procoagulation factor vwf. In a proximate approach we investigated these genes by quantitative real-time PCR (qPCR) analysis over the circadian cycle in torpid and normothermic animals at times of torpor entrance, mid torpor, arousal and post-torpor. These qPCR data confirmed up regulation of dnah2, myo15a, and vwf during torpor entrance, but a decreased mRNA level for all other investigated time points. This suggests that gene expression of structure genes as well as the procoagulation factor are specifically initiated during the early state of torpor and provides evidence for protective molecular adaptions in the hypothalamus of Djungarian hamsters including changes in structure, transport of biomolecules and coagulation.
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Affiliation(s)
- Ceyda Cubuk
- Zoologisches Institut, Universität Hamburg Hamburg, Germany
| | - Julia Kemmling
- Zoologisches Institut, Universität Hamburg Hamburg, Germany
| | | | - Annika Herwig
- Zoologisches Institut, Universität Hamburg Hamburg, Germany
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41
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McFarlane SV, Mathers KE, Staples JF. Reversible temperature-dependent differences in brown adipose tissue respiration during torpor in a mammalian hibernator. Am J Physiol Regul Integr Comp Physiol 2017; 312:R434-R442. [PMID: 28077390 DOI: 10.1152/ajpregu.00316.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 12/06/2016] [Accepted: 01/06/2017] [Indexed: 01/23/2023]
Abstract
Although seasonal modifications of brown adipose tissue (BAT) in hibernators are well documented, we know little about functional regulation of BAT in different phases of hibernation. In the 13-lined ground squirrel, liver mitochondrial respiration is suppressed by up to 70% during torpor. This suppression is reversed during arousal and interbout euthermia (IBE), and corresponds with patterns of maximal activities of electron transport system (ETS) enzymes. Uncoupling of BAT mitochondria is controlled by free fatty acid release stimulated by sympathetic activation of adipocytes, so we hypothesized that further regulation at the level of the ETS would be of little advantage. As predicted, maximal ETS enzyme activities of isolated BAT mitochondria did not differ between torpor and IBE. In contrast to this pattern, respiration rates of mitochondria isolated from torpid individuals were suppressed by ~60% compared with rates from IBE individuals when measured at 37°C. At 10°C, however, mitochondrial respiration rates tended to be greater in torpor than IBE. As a result, the temperature sensitivity (Q10) of mitochondrial respiration was significantly lower in torpor (~1.4) than IBE (~2.4), perhaps facilitating energy savings during entrance into torpor and thermogenesis at low body temperatures. Despite the observed differences in isolated mitochondria, norepinephrine-stimulated respiration rates of isolated BAT adipocytes did not differ between torpor and IBE, perhaps because the adipocyte isolation requires lengthy incubation at 37°C, potentially reversing any changes that occur in torpor. Such changes may include remodeling of BAT mitochondrial membrane phospholipids, which could change in situ enzyme activities and temperature sensitivities.
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Affiliation(s)
- Sarah V McFarlane
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Katherine E Mathers
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - James F Staples
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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42
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Frigault JJ, Morin MD, Morin PJ. Differential expression and emerging functions of non-coding RNAs in cold adaptation. J Comp Physiol B 2016; 187:19-28. [PMID: 27866230 DOI: 10.1007/s00360-016-1049-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 10/07/2016] [Accepted: 10/26/2016] [Indexed: 01/16/2023]
Abstract
Several species undergo substantial physiological and biochemical changes to confront the harsh conditions associated with winter. Small mammalian hibernators and cold-hardy insects are examples of natural models of cold adaptation that have been amply explored. While the molecular picture associated with cold adaptation has started to become clearer in recent years, notably through the use of high-throughput experimental approaches, the underlying cold-associated functions attributed to several non-coding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), remain to be better characterized. Nevertheless, key pioneering work has provided clues on the likely relevance of these molecules in cold adaptation. With an emphasis on mammalian hibernation and insect cold hardiness, this work first reviews various molecular changes documented so far in these processes. The cascades leading to miRNA and lncRNA production as well as the mechanisms of action of these non-coding RNAs are subsequently described. Finally, we present examples of differentially expressed non-coding RNAs in models of cold adaptation and elaborate on the potential significance of this modulation with respect to low-temperature adaptation.
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Affiliation(s)
- Jacques J Frigault
- Department of Chemistry and Biochemistry, Université de Moncton, 18 Antonine-Maillet Avenue, Moncton, NB, E1A 3E9, Canada
| | - Mathieu D Morin
- Department of Chemistry and Biochemistry, Université de Moncton, 18 Antonine-Maillet Avenue, Moncton, NB, E1A 3E9, Canada
| | - Pier Jr Morin
- Department of Chemistry and Biochemistry, Université de Moncton, 18 Antonine-Maillet Avenue, Moncton, NB, E1A 3E9, Canada.
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43
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Faherty SL, Villanueva-Cañas JL, Klopfer PH, Albà MM, Yoder AD. Gene Expression Profiling in the Hibernating Primate, Cheirogaleus Medius. Genome Biol Evol 2016; 8:2413-26. [PMID: 27412611 PMCID: PMC5010898 DOI: 10.1093/gbe/evw163] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2016] [Indexed: 12/24/2022] Open
Abstract
Hibernation is a complex physiological response that some mammalian species employ to evade energetic demands. Previous work in mammalian hibernators suggests that hibernation is activated not by a set of genes unique to hibernators, but by differential expression of genes that are present in all mammals. This question of universal genetic mechanisms requires further investigation and can only be tested through additional investigations of phylogenetically dispersed species. To explore this question, we use RNA-Seq to investigate gene expression dynamics as they relate to the varying physiological states experienced throughout the year in a group of primate hibernators-Madagascar's dwarf lemurs (genus Cheirogaleus). In a novel experimental approach, we use longitudinal sampling of biological tissues as a method for capturing gene expression profiles from the same individuals throughout their annual hibernation cycle. We identify 90 candidate genes that have variable expression patterns when comparing two active states (Active 1 and Active 2) with a torpor state. These include genes that are involved in metabolic pathways, feeding behavior, and circadian rhythms, as might be expected to correlate with seasonal physiological state changes. The identified genes appear to be critical for maintaining the health of an animal that undergoes prolonged periods of metabolic depression concurrent with the hibernation phenotype. By focusing on these differentially expressed genes in dwarf lemurs, we compare gene expression patterns in previously studied mammalian hibernators. Additionally, by employing evolutionary rate analysis, we find that hibernation-related genes do not evolve under positive selection in hibernating species relative to nonhibernators.
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Affiliation(s)
| | - José Luis Villanueva-Cañas
- Evolutionary Genomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute (IMIM), Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | | | - M Mar Albà
- Evolutionary Genomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Research Institute (IMIM), Universitat Pompeu Fabra (UPF), Barcelona, Spain Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain
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44
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Ballinger MA, Hess C, Napolitano MW, Bjork JA, Andrews MT. Seasonal changes in brown adipose tissue mitochondria in a mammalian hibernator: from gene expression to function. Am J Physiol Regul Integr Comp Physiol 2016; 311:R325-36. [PMID: 27225952 DOI: 10.1152/ajpregu.00463.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 05/24/2016] [Indexed: 12/25/2022]
Abstract
Brown adipose tissue (BAT) is a thermogenic organ that is vital for hibernation in mammals. Throughout the hibernation season, BAT mitochondrial uncoupling protein 1 (UCP1) enables rapid rewarming from hypothermic torpor to periodic interbout arousals (IBAs), as energy is dissipated as heat. However, BAT's unique ability to rewarm the body via nonshivering thermogenesis is not necessary outside the hibernation season, suggesting a potential seasonal change in the regulation of BAT function. Here, we examined the BAT mitochondrial proteome and mitochondrial bioenergetics in the thirteen-lined ground squirrel (Ictidomys tridecemlineatus) across four time points: spring, fall, torpor, and IBA. Relative mitochondrial content of BAT was estimated by measuring BAT pad mass, UCP1 protein content, and mitochondrial DNA (mtDNA) copy number. BAT mtDNA content was significantly lower in spring compared with torpor and IBA (P < 0.05). UCP1 mRNA and protein levels were highest during torpor and IBA. Respiration rates of isolated BAT mitochondria were interrogated at each complex of the electron transport chain. Respiration at complex II was significantly higher in torpor and IBA compared with spring (P < 0.05), suggesting an enhancement in mitochondrial respiratory capacity during hibernation. Additionally, proteomic iTRAQ labeling identified 778 BAT mitochondrial proteins. Proteins required for mitochondrial lipid translocation and β-oxidation were upregulated during torpor and IBA and downregulated in spring. These data imply that BAT bioenergetics and mitochondrial content are not static across the year, despite the year-round presence of UCP1.
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Affiliation(s)
| | - Clair Hess
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota
| | - Max W Napolitano
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota
| | - James A Bjork
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota
| | - Matthew T Andrews
- Department of Biology, University of Minnesota Duluth, Duluth, Minnesota
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45
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Cooper ST, Sell SS, Fahrenkrog M, Wilkinson K, Howard DR, Bergen H, Cruz E, Cash SE, Andrews MT, Hampton M. Effects of hibernation on bone marrow transcriptome in thirteen-lined ground squirrels. Physiol Genomics 2016; 48:513-25. [PMID: 27207617 DOI: 10.1152/physiolgenomics.00120.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 05/17/2016] [Indexed: 12/17/2022] Open
Abstract
Mammalian hibernators adapt to prolonged periods of immobility, hypometabolism, hypothermia, and oxidative stress, each capable of reducing bone marrow activity. In this study bone marrow transcriptomes were compared among thirteen-lined ground squirrels collected in July, winter torpor, and winter interbout arousal (IBA). The results were consistent with a suppression of acquired immune responses, and a shift to innate immune responses during hibernation through higher complement expression. Consistent with the increase in adipocytes found in bone marrow of hibernators, expression of genes associated with white adipose tissue are higher during hibernation. Genes that should strengthen the bone by increasing extracellular matrix were higher during hibernation, especially the collagen genes. Finally, expression of heat shock proteins were lower, and cold-response genes were higher, during hibernation. No differential expression of hematopoietic genes involved in erythrocyte or megakaryocyte production was observed. This global view of the changes in the bone marrow transcriptome over both short term (torpor vs. IBA) and long term (torpor vs. July) hypothermia can explain several observations made about circulating blood cells and the structure and strength of the bone during hibernation.
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Affiliation(s)
- Scott T Cooper
- Biology Department, University of Wisconsin-La Crosse, La Crosse, Wisconsin;
| | - Shawn S Sell
- Biology Department, University of Wisconsin-La Crosse, La Crosse, Wisconsin
| | - Molly Fahrenkrog
- Biology Department, University of Wisconsin-La Crosse, La Crosse, Wisconsin
| | - Kory Wilkinson
- Biology Department, University of Wisconsin-La Crosse, La Crosse, Wisconsin
| | - David R Howard
- Biology Department, University of Wisconsin-La Crosse, La Crosse, Wisconsin
| | - Hannah Bergen
- Biology Department, University of Wisconsin-La Crosse, La Crosse, Wisconsin
| | - Estefania Cruz
- Biology Department, University of Wisconsin-La Crosse, La Crosse, Wisconsin
| | - Steve E Cash
- Hematology/Oncology, Gundersen Lutheran Medical Foundation, La Crosse, Wisconsin
| | - Matthew T Andrews
- Department of Biology, University of Minnesota-Duluth, Duluth, Minnesota; and
| | - Marshall Hampton
- Department of Mathematics and Statistics, University of Minnesota-Duluth, Duluth, Minnesota
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46
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Abstract
Extended bouts of fasting are ingrained in the ecology of many organisms, characterizing aspects of reproduction, development, hibernation, estivation, migration, and infrequent feeding habits. The challenge of long fasting episodes is the need to maintain physiological homeostasis while relying solely on endogenous resources. To meet that challenge, animals utilize an integrated repertoire of behavioral, physiological, and biochemical responses that reduce metabolic rates, maintain tissue structure and function, and thus enhance survival. We have synthesized in this review the integrative physiological, morphological, and biochemical responses, and their stages, that characterize natural fasting bouts. Underlying the capacity to survive extended fasts are behaviors and mechanisms that reduce metabolic expenditure and shift the dependency to lipid utilization. Hormonal regulation and immune capacity are altered by fasting; hormones that trigger digestion, elevate metabolism, and support immune performance become depressed, whereas hormones that enhance the utilization of endogenous substrates are elevated. The negative energy budget that accompanies fasting leads to the loss of body mass as fat stores are depleted and tissues undergo atrophy (i.e., loss of mass). Absolute rates of body mass loss scale allometrically among vertebrates. Tissues and organs vary in the degree of atrophy and downregulation of function, depending on the degree to which they are used during the fast. Fasting affects the population dynamics and activities of the gut microbiota, an interplay that impacts the host's fasting biology. Fasting-induced gene expression programs underlie the broad spectrum of integrated physiological mechanisms responsible for an animal's ability to survive long episodes of natural fasting.
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Affiliation(s)
- Stephen M Secor
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
| | - Hannah V Carey
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
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47
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Abstract
Many environmental conditions can constrain the ability of animals to obtain sufficient food energy, or transform that food energy into useful chemical forms. To survive extended periods under such conditions animals must suppress metabolic rate to conserve energy, water, or oxygen. Amongst small endotherms, this metabolic suppression is accompanied by and, in some cases, facilitated by a decrease in core body temperature-hibernation or daily torpor-though significant metabolic suppression can be achieved even with only modest cooling. Within some ectotherms, winter metabolic suppression exceeds the passive effects of cooling. During dry seasons, estivating ectotherms can reduce metabolism without changes in body temperature, conserving energy reserves, and reducing gas exchange and its inevitable loss of water vapor. This overview explores the similarities and differences of metabolic suppression among these states within adult animals (excluding developmental diapause), and integrates levels of organization from the whole animal to the genome, where possible. Several similarities among these states are highlighted, including patterns and regulation of metabolic balance, fuel use, and mitochondrial metabolism. Differences among models are also apparent, particularly in whether the metabolic suppression is intrinsic to the tissue or depends on the whole-animal response. While in these hypometabolic states, tissues from many animals are tolerant of hypoxia/anoxia, ischemia/reperfusion, and disuse. These natural models may, therefore, serve as valuable and instructive models for biomedical research.
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Affiliation(s)
- James F Staples
- Department of Biology, University of Western Ontario, London, Ontario, Canada
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48
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Anderson KJ, Vermillion KL, Jagtap P, Johnson JE, Griffin TJ, Andrews MT. Proteogenomic Analysis of a Hibernating Mammal Indicates Contribution of Skeletal Muscle Physiology to the Hibernation Phenotype. J Proteome Res 2016; 15:1253-61. [DOI: 10.1021/acs.jproteome.5b01138] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Kyle J. Anderson
- Department
of Biology, University of Minnesota Duluth, 1035 Kirby Drive, Duluth, Minnesota 55812, United States
| | - Katie L. Vermillion
- Department
of Biology, University of Minnesota Duluth, 1035 Kirby Drive, Duluth, Minnesota 55812, United States
| | - Pratik Jagtap
- Center
for Mass Spectrometry and Proteomics, University of Minnesota, 1479 Gortner
Avenue, St. Paul, Minnesota 55108, Unites States
- Department
of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 321 Church Streey South East, Minneapolis, Minnesota 55455, United States
| | - James E. Johnson
- Minnesota Supercomputing Institute, 512 Walter Library, 117 Pleasant Street South East, Minneapolis, Minnesota 55455, United States
| | - Timothy J. Griffin
- Center
for Mass Spectrometry and Proteomics, University of Minnesota, 1479 Gortner
Avenue, St. Paul, Minnesota 55108, Unites States
- Department
of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 321 Church Streey South East, Minneapolis, Minnesota 55455, United States
| | - Matthew T. Andrews
- Department
of Biology, University of Minnesota Duluth, 1035 Kirby Drive, Duluth, Minnesota 55812, United States
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Vermillion KL, Jagtap P, Johnson JE, Griffin TJ, Andrews MT. Characterizing Cardiac Molecular Mechanisms of Mammalian Hibernation via Quantitative Proteogenomics. J Proteome Res 2015; 14:4792-804. [DOI: 10.1021/acs.jproteome.5b00575] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Katie L. Vermillion
- Department
of Biology, University of Minnesota Duluth, 1035 Kirby Drive, Duluth, Minnesota 55812, United States
| | - Pratik Jagtap
- Center
for Mass Spectrometry and Proteomics, University of Minnesota, 1479 Gortner
Avenue, St. Paul, Minnesota 55108, United States
- Department
of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 321 Church St SE, Minneapolis, Minnesota 55455, United States
| | - James E. Johnson
- Minnesota Supercomputing Institute, 512 Walter Library 117 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Timothy J. Griffin
- Center
for Mass Spectrometry and Proteomics, University of Minnesota, 1479 Gortner
Avenue, St. Paul, Minnesota 55108, United States
- Department
of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 321 Church St SE, Minneapolis, Minnesota 55455, United States
| | - Matthew T. Andrews
- Department
of Biology, University of Minnesota Duluth, 1035 Kirby Drive, Duluth, Minnesota 55812, United States
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Field KA, Johnson JS, Lilley TM, Reeder SM, Rogers EJ, Behr MJ, Reeder DM. The White-Nose Syndrome Transcriptome: Activation of Anti-fungal Host Responses in Wing Tissue of Hibernating Little Brown Myotis. PLoS Pathog 2015; 11:e1005168. [PMID: 26426272 PMCID: PMC4591128 DOI: 10.1371/journal.ppat.1005168] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 08/25/2015] [Indexed: 01/08/2023] Open
Abstract
White-nose syndrome (WNS) in North American bats is caused by an invasive cutaneous infection by the psychrophilic fungus Pseudogymnoascus destructans (Pd). We compared transcriptome-wide changes in gene expression using RNA-Seq on wing skin tissue from hibernating little brown myotis (Myotis lucifugus) with WNS to bats without Pd exposure. We found that WNS caused significant changes in gene expression in hibernating bats including pathways involved in inflammation, wound healing, and metabolism. Local acute inflammatory responses were initiated by fungal invasion. Gene expression was increased for inflammatory cytokines, including interleukins (IL) IL-1β, IL-6, IL-17C, IL-20, IL-23A, IL-24, and G-CSF and chemokines, such as Ccl2 and Ccl20. This pattern of gene expression changes demonstrates that WNS is accompanied by an innate anti-fungal host response similar to that caused by cutaneous Candida albicans infections. However, despite the apparent production of appropriate chemokines, immune cells such as neutrophils and T cells do not appear to be recruited. We observed upregulation of acute inflammatory genes, including prostaglandin G/H synthase 2 (cyclooxygenase-2), that generate eicosanoids and other nociception mediators. We also observed differences in Pd gene expression that suggest host-pathogen interactions that might determine WNS progression. We identified several classes of potential virulence factors that are expressed in Pd during WNS, including secreted proteases that may mediate tissue invasion. These results demonstrate that hibernation does not prevent a local inflammatory response to Pd infection but that recruitment of leukocytes to the site of infection does not occur. The putative virulence factors may provide novel targets for treatment or prevention of WNS. These observations support a dual role for inflammation during WNS; inflammatory responses provide protection but excessive inflammation may contribute to mortality, either by affecting torpor behavior or causing damage upon emergence in the spring. White-nose syndrome is the most devastating epizootic wildlife disease of mammals in history, having killed millions of hibernating bats in North America since 2007. We have used next-generation RNA sequencing to provide a survey of the gene expression changes that accompany this disease in the skin of bats infected with the causative fungus. We identified possible new mechanisms that may either provide protection or contribute to mortality, including inflammatory immune responses. Contrary to expectations that hibernation represents a period of dormancy, we found that gene expression pathways were responsive to the environment. We also examined which genes were expressed in the pathogen and identified several classes of genes that could contribute to the virulence of this disease. Gene expression changes in the host were associated with local inflammation despite the fact that the bats were hibernating. However, we found that hibernating bats with white-nose syndrome lack some of the responses known to defend other mammals from fungal infection. We propose that bats could be protected from white-nose syndrome if these responses could be established prior to hibernation or if treatments could block the virulence factors expressed by the pathogen.
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Affiliation(s)
- Kenneth A. Field
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania, United States of America
- * E-mail:
| | - Joseph S. Johnson
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania, United States of America
| | - Thomas M. Lilley
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania, United States of America
| | - Sophia M. Reeder
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania, United States of America
| | - Elizabeth J. Rogers
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania, United States of America
| | - Melissa J. Behr
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - DeeAnn M. Reeder
- Department of Biology, Bucknell University, Lewisburg, Pennsylvania, United States of America
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