1
|
Lewis CTA, Melhedegaard EG, Ognjanovic MM, Olsen MS, Laitila J, Seaborne RAE, Gronset M, Zhang C, Iwamoto H, Hessel AL, Kuehn MN, Merino C, Amigo N, Frobert O, Giroud S, Staples JF, Goropashnaya AV, Fedorov VB, Barnes B, Toien O, Drew K, Sprenger RJ, Ochala J. Remodeling of skeletal muscle myosin metabolic states in hibernating mammals. eLife 2024; 13:RP94616. [PMID: 38752835 PMCID: PMC11098559 DOI: 10.7554/elife.94616] [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] [Indexed: 05/18/2024] Open
Abstract
Hibernation is a period of metabolic suppression utilized by many small and large mammal species to survive during winter periods. As the underlying cellular and molecular mechanisms remain incompletely understood, our study aimed to determine whether skeletal muscle myosin and its metabolic efficiency undergo alterations during hibernation to optimize energy utilization. We isolated muscle fibers from small hibernators, Ictidomys tridecemlineatus and Eliomys quercinus and larger hibernators, Ursus arctos and Ursus americanus. We then conducted loaded Mant-ATP chase experiments alongside X-ray diffraction to measure resting myosin dynamics and its ATP demand. In parallel, we performed multiple proteomics analyses. Our results showed a preservation of myosin structure in U. arctos and U. americanus during hibernation, whilst in I. tridecemlineatus and E. quercinus, changes in myosin metabolic states during torpor unexpectedly led to higher levels in energy expenditure of type II, fast-twitch muscle fibers at ambient lab temperatures (20 °C). Upon repeating loaded Mant-ATP chase experiments at 8 °C (near the body temperature of torpid animals), we found that myosin ATP consumption in type II muscle fibers was reduced by 77-107% during torpor compared to active periods. Additionally, we observed Myh2 hyper-phosphorylation during torpor in I. tridecemilineatus, which was predicted to stabilize the myosin molecule. This may act as a potential molecular mechanism mitigating myosin-associated increases in skeletal muscle energy expenditure during periods of torpor in response to cold exposure. Altogether, we demonstrate that resting myosin is altered in hibernating mammals, contributing to significant changes to the ATP consumption of skeletal muscle. Additionally, we observe that it is further altered in response to cold exposure and highlight myosin as a potentially contributor to skeletal muscle non-shivering thermogenesis.
Collapse
Affiliation(s)
| | | | - Marija M Ognjanovic
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
| | - Mathilde S Olsen
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
| | - Jenni Laitila
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
| | - Robert AE Seaborne
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
- Centre for Human and Applied Physiological Sciences, Faculty of Life Sciences & Medicine, King’s College LondonLondonUnited Kingdom
| | - Magnus Gronset
- Department of Cellular and Molecular Medicine, University of CopenhagenCopenhagenDenmark
| | - Changxin Zhang
- Department of Computational Medicine and Bioinformatics, University of MichiganAnn ArborUnited States
| | - Hiroyuki Iwamoto
- Spring-8, Japan Synchrotron Radiation Research InstituteHyogoJapan
| | - Anthony L Hessel
- Institute of Physiology II, University of MuensterMuensterGermany
- Accelerated Muscle Biotechnologies ConsultantsBostonUnited States
| | - Michel N Kuehn
- Institute of Physiology II, University of MuensterMuensterGermany
- Accelerated Muscle Biotechnologies ConsultantsBostonUnited States
| | | | | | - Ole Frobert
- Department of Clinical Medicine, Faculty of Health, Aarhus UniversityAarhusDenmark
- Faculty of Health, Department of Cardiology, Örebro UniversityÖrebroSweden
| | - Sylvain Giroud
- Energetics Lab, Department of Biology, Northern Michigan UniversityMarquetteUnited States
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Sciences, University of Veterinary Medicine ViennaViennaAustria
| | - James F Staples
- Department of Biology, University of Western OntarioLondonCanada
| | - Anna V Goropashnaya
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Vadim B Fedorov
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Brian Barnes
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Oivind Toien
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Kelly Drew
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska FairbanksFairbanksUnited States
| | - Ryan J Sprenger
- Department of Zoology, University of British ColumbiaVancouverCanada
| | - Julien Ochala
- Department of Biomedical Sciences, University of CopenhagenCopenhagenDenmark
| |
Collapse
|
2
|
Niu Y, Zhang X, Men S, Xu T, Zhang H, Li X, Storey KB, Chen Q. Effects of hibernation on two important contractile tissues in tibetan frogs, Nanorana parkeri: a perspective from transcriptomics and metabolomics approaches. BMC Genomics 2024; 25:454. [PMID: 38720264 PMCID: PMC11080311 DOI: 10.1186/s12864-024-10357-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 04/26/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND In response to seasonal cold and food shortage, the Xizang plateau frogs, Nanorana parkeri (Anura: Dicroglossidae), enter a reversible hypometabolic state where heart rate and oxygen consumption in skeletal muscle are strongly suppressed. However, the effect of winter hibernation on gene expression and metabolic profiling in these two tissues remains unknown. In the present study, we conducted transcriptomic and metabolomic analyses of heart and skeletal muscle from summer- and winter-collected N. parkeri to explore mechanisms involved in seasonal hibernation. RESULTS We identified 2407 differentially expressed genes (DEGs) in heart and 2938 DEGs in skeletal muscle. Enrichment analysis showed that shared DEGs in both tissues were enriched mainly in translation and metabolic processes. Of these, the expression of genes functionally categorized as "response to stress", "defense mechanisms", or "muscle contraction" were particularly associated with hibernation. Metabolomic analysis identified 24 and 22 differentially expressed metabolites (DEMs) in myocardium and skeletal muscle, respectively. In particular, pathway analysis showed that DEMs in myocardium were involved in the pentose phosphate pathway, glycerolipid metabolism, pyruvate metabolism, citrate cycle (TCA cycle), and glycolysis/gluconeogenesis. By contrast, DEMs in skeletal muscle were mainly involved in amino acid metabolism. CONCLUSIONS In summary, natural adaptations of myocardium and skeletal muscle in hibernating N. parkeri involved transcriptional alterations in translation, stress response, protective mechanisms, and muscle contraction processes as well as metabolic remodeling. This study provides new insights into the transcriptional and metabolic adjustments that aid winter survival of high-altitude frogs N. parkeri.
Collapse
Affiliation(s)
- Yonggang Niu
- School of Life Sciences, Dezhou University, Dezhou, 253023, Shandong, China.
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China.
| | - Xuejing Zhang
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China
| | - Shengkang Men
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China
| | - Tisen Xu
- School of Life Sciences, Dezhou University, Dezhou, 253023, Shandong, China
| | - Haiying Zhang
- School of Life Sciences, Dezhou University, Dezhou, 253023, Shandong, China
| | - Xiangyong Li
- School of Life Sciences, Dezhou University, Dezhou, 253023, Shandong, China
| | - Kenneth B Storey
- Department of Biology, Carleton University, Ottawa, ON, K1S 5B6, Canada
| | - Qiang Chen
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, Gansu, China.
| |
Collapse
|
3
|
Hutchinson AJ, Duffy BM, Rego LH, Staples JF. Paper towel shredding as a novel, affordable, noninvasive method for detecting arousals in hibernating rodents. Lab Anim (NY) 2024; 53:117-120. [PMID: 38637688 DOI: 10.1038/s41684-024-01362-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 03/18/2024] [Indexed: 04/20/2024]
Abstract
Many research groups explore the regulation of hibernation or compare the physiology of heterothermic mammals between the torpid and aroused, euthermic states. Current methods for monitoring torpor (for example, infrared cameras, body temperature or heart-rate telemetry, and motion sensing) are costly, require specialized techniques, and can be invasive. Here we present an alternate method for determining torpor-bout duration that is cost-effective, noninvasive and accurate: paper towel shredding. In the winter, euthermic thirteen-lined ground squirrels will shred paper towels placed in the cage, but torpid animals will not. The presence of a shredded paper towel, indicating an arousal from torpor, is easily evaluated during routine daily monitoring. In 12 animals over 52 days, this simple technique detected 59 arousals with 100% accuracy when compared with the body temperature telemetry of the same animals. Moreover, this novel method avoids some of the drawbacks of other cheap monitoring systems such as the sawdust technique.
Collapse
Affiliation(s)
- Amalie J Hutchinson
- Department of Biology, The University of Western Ontario, London, Ontario, Canada.
| | - Brynne M Duffy
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
| | - Lauren H Rego
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
| | - James F Staples
- Department of Biology, The University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
4
|
Lewis CTA, Melhedegaard EG, Ognjanovic MM, Olsen MS, Laitila J, Seaborne RAE, Gronset MN, Zhang C, Iwamoto H, Hessel AL, Kuehn MN, Merino C, Amigo N, Frobert O, Giroud S, Staples JF, Goropashnaya AV, Fedorov VB, Barnes BM, Toien O, Drew KL, Sprenger RJ, Ochala J. Remodelling of Skeletal Muscle Myosin Metabolic States in Hibernating Mammals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.14.566992. [PMID: 38014200 PMCID: PMC10680686 DOI: 10.1101/2023.11.14.566992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Hibernation is a period of metabolic suppression utilized by many small and large mammal species to survive during winter periods. As the underlying cellular and molecular mechanisms remain incompletely understood, our study aimed to determine whether skeletal muscle myosin and its metabolic efficiency undergo alterations during hibernation to optimize energy utilization. We isolated muscle fibers from small hibernators, Ictidomys tridecemlineatus and Eliomys quercinus and larger hibernators, Ursus arctos and Ursus americanus. We then conducted loaded Mant-ATP chase experiments alongside X-ray diffraction to measure resting myosin dynamics and its ATP demand. In parallel, we performed multiple proteomics analyses. Our results showed a preservation of myosin structure in U. arctos and U. americanus during hibernation, whilst in I. tridecemlineatus and E. quercinus, changes in myosin metabolic states during torpor unexpectedly led to higher levels in energy expenditure of type II, fast-twitch muscle fibers at ambient lab temperatures (20°C). Upon repeating loaded Mant-ATP chase experiments at 8°C (near the body temperature of torpid animals), we found that myosin ATP consumption in type II muscle fibers was reduced by 77-107% during torpor compared to active periods. Additionally, we observed Myh2 hyper-phosphorylation during torpor in I. tridecemilineatus, which was predicted to stabilize the myosin molecule. This may act as a potential molecular mechanism mitigating myosin-associated increases in skeletal muscle energy expenditure during periods of torpor in response to cold exposure. Altogether, we demonstrate that resting myosin is altered in hibernating mammals, contributing to significant changes to the ATP consumption of skeletal muscle. Additionally, we observe that it is further altered in response to cold exposure and highlight myosin as a potentially contributor to skeletal muscle non-shivering thermogenesis.
Collapse
|
5
|
Abid MSR, Bredahl EC, Clifton AD, Qiu H, Andrews MT, Checco JW. Proteomic Identification of Seasonally Expressed Proteins Contributing to Heart Function and the Avoidance of Skeletal Muscle Disuse Atrophy in a Hibernating Mammal. J Proteome Res 2024; 23:215-225. [PMID: 38117800 PMCID: PMC10843731 DOI: 10.1021/acs.jproteome.3c00540] [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] [Indexed: 12/22/2023]
Abstract
Hibernation in the thirteen-lined ground squirrel (Ictidomys tridecemlineatus) takes place over 4-6 months and is characterized by multiday bouts of hypothermic torpor (5-7 °C core body temperature) that are regularly interrupted every 1-2 weeks by brief (12-24 h) normothermic active periods called interbout arousals. Our goal was to gain insight into the molecular mechanisms that underlie the hibernator's ability to preserve heart function and avoid the deleterious effects of skeletal muscle disuse atrophy over prolonged periods of inactivity, starvation, and near-freezing body temperatures. To achieve this goal, we performed organelle enrichment of heart and skeletal muscle at five seasonal time points followed by LC-MS-based label-free quantitative proteomics. In both organs, we saw an increase in the levels of many proteins as ground squirrels transition from an active state to a prehibernation state in the fall. Interestingly, seasonal abundance patterns identified DHRS7C, SRL, TRIM72, RTN2, and MPZ as potential protein candidates for mitigating disuse atrophy in skeletal muscle, and ex vivo contractile mechanics analysis revealed no deleterious effects in the ground squirrel's muscles despite prolonged sedentary activity. Overall, an increased understanding of protein abundance in hibernators may enable novel therapeutic strategies to treat muscle disuse atrophy and heart disease in humans.
Collapse
Affiliation(s)
- Md Shadman Ridwan Abid
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, United States
| | - Eric C. Bredahl
- Department of Exercise Science and Pre-Health Professions, Creighton University, Omaha, NE, 68178, United States
| | - Ashley D. Clifton
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, United States
| | - Haowen Qiu
- Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE, 68588, United States
- The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, NE, 68588, United States
| | - Matthew T. Andrews
- School of Natural Resources, University of Nebraska-Lincoln, Lincoln, NE, 68583, United States
| | - James W. Checco
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE, 68588, United States
- The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, NE, 68588, United States
| |
Collapse
|
6
|
Staples JF, Mathers KE, Duffy BM. Mitochondrial Metabolism in Hibernation: Regulation and Implications. Physiology (Bethesda) 2022; 37:0. [PMID: 35658625 DOI: 10.1152/physiol.00006.2022] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Hibernators rapidly and reversibly suppress mitochondrial respiration and whole animal metabolism. Posttranslational modifications likely regulate these mitochondrial changes, which may help conserve energy in winter. These modifications are affected by reactive oxygen species (ROS), so suppressing mitochondrial ROS production may also be important for hibernators, just as it is important for surviving ischemia-reperfusion injury.
Collapse
Affiliation(s)
- James F Staples
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Katherine E Mathers
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| | - Brynne M Duffy
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
7
|
Fan C, Liu Y, Wang Y, Zhang A, Xie W, Zhang H, Weng Q, Xu M. Expression of glycogenic genes in the oviduct of Chinese brown frog (Rana dybowskii) during pre-brumation. Theriogenology 2022; 185:78-87. [DOI: 10.1016/j.theriogenology.2022.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/07/2022] [Accepted: 03/07/2022] [Indexed: 10/18/2022]
|
8
|
Integrative transcription start site analysis and physiological phenotyping reveal torpor-specific expression program in mouse skeletal muscle. Commun Biol 2021; 4:1290. [PMID: 34782710 PMCID: PMC8592991 DOI: 10.1038/s42003-021-02819-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 10/28/2021] [Indexed: 11/30/2022] Open
Abstract
Mice enter an active hypometabolic state, called daily torpor when they experience a lowered caloric intake under cold ambient temperature. During torpor, the oxygen consumption rate in some animals drops to less than 30% of the normal rate without harming the body. This safe but severe reduction in metabolism is attractive for various clinical applications; however, the mechanism and molecules involved are unclear. Therefore, here we systematically analyzed the gene expression landscape on the level of the RNA transcription start sites in mouse skeletal muscles under various metabolic states to identify torpor-specific transcribed regulatory patterns. We analyzed the soleus muscles from 38 mice in torpid and non-torpid conditions and identified 287 torpor-specific promoters out of 12,862 detected promoters. Furthermore, we found that the transcription factor ATF3 is highly expressed during torpor deprivation and its binding motif is enriched in torpor-specific promoters. Atf3 was also highly expressed in the heart and brown adipose tissue during torpor and systemically knocking out Atf3 affected the torpor phenotype. Our results demonstrate that mouse torpor combined with powerful genetic tools is useful for studying active hypometabolism.
Collapse
|
9
|
Stable suppression of skeletal muscle fructose-1,6-bisphosphatase during ground squirrel hibernation: Potential implications of reversible acetylation as a regulatory mechanism. Cryobiology 2021; 102:97-103. [PMID: 34274341 DOI: 10.1016/j.cryobiol.2021.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 07/09/2021] [Accepted: 07/13/2021] [Indexed: 11/21/2022]
Abstract
Mammalian hibernation is a period that involves substantial metabolic change in order to promote survival in harsh conditions, with animals typically relying on non-carbohydrate fuel stores during long bouts of torpor. However, the use and maintenance of carbohydrate fuel stores remains important during periods of arousal from torpor as well as when exiting hibernation. Gluconeogenesis plays a key role in maintaining glucose stores; however, little is known about this process within the muscles of hibernating mammals. Here, we used 13-lined ground squirrels (Ictidomys tridecemlineatus) as our model for mammalian hibernation, and showed that skeletal muscle fructose-1,6-bisphosphatase (FBPase; EC 3.1.3.11), the rate-limiting enzyme for the gluconeogenic pathway, was suppressed during torpor as compared to the euthermic control. A physical assessment of partially purified FBPase via exposure to increasing concentrations of the denaturant urea indicated that FBPase from the two conditions were structurally distinct. Western blot analysis suggests that the kinetic and physical differences between euthermic and torpid FBPase may be derived from differential acetylation, whereby increased acetylation of the torpid enzyme makes FBPase more rigid and less active. This study increases our understanding of skeletal muscle carbohydrate metabolism during mammalian hibernation and sets forth a potentially novel mechanism for the regulation of FBPase during environmental stress.
Collapse
|
10
|
Gillen AE, Fu R, Riemondy KA, Jager J, Fang B, Lazar MA, Martin SL. Liver Transcriptome Dynamics During Hibernation Are Shaped by a Shifting Balance Between Transcription and RNA Stability. Front Physiol 2021; 12:662132. [PMID: 34093224 PMCID: PMC8176218 DOI: 10.3389/fphys.2021.662132] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/26/2021] [Indexed: 12/12/2022] Open
Abstract
Hibernators dramatically lower metabolism to save energy while fasting for months. Prolonged fasting challenges metabolic homeostasis, yet small-bodied hibernators emerge each spring ready to resume all aspects of active life, including immediate reproduction. The liver is the body’s metabolic hub, processing and detoxifying macromolecules to provide essential fuels to brain, muscle and other organs throughout the body. Here we quantify changes in liver gene expression across several distinct physiological states of hibernation in 13-lined ground squirrels, using RNA-seq to measure the steady-state transcriptome and GRO-seq to measure transcription for the first time in a hibernator. Our data capture key timepoints in both the seasonal and torpor-arousal cycles of hibernation. Strong positive correlation between transcription and the transcriptome indicates that transcriptional control dominates the known seasonal reprogramming of metabolic gene expression in liver for hibernation. During the torpor-arousal cycle, however, discordance develops between transcription and the steady-state transcriptome by at least two mechanisms: 1) although not transcribed during torpor, some transcripts are unusually stable across the torpor bout; and 2) unexpectedly, on some genes, our data suggest continuing, slow elongation with a failure to terminate transcription across the torpor bout. While the steady-state RNAs corresponding to these read through transcripts did not increase during torpor, they did increase shortly after rewarming despite their simultaneously low transcription. Both of these mechanisms would assure the immediate availability of functional transcripts upon rewarming. Integration of transcriptional, post-transcriptional and RNA stability control mechanisms, all demonstrated in these data, likely initiate a serial gene expression program across the short euthermic period that restores the tissue and prepares the animal for the next bout of torpor.
Collapse
Affiliation(s)
- Austin E Gillen
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, United States
| | - Rui Fu
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, United States
| | - Kent A Riemondy
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, United States
| | - Jennifer Jager
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.,Division of Endocrinology, Diabetes, and Metabolism, Department of Genetics, and The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Bin Fang
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.,Division of Endocrinology, Diabetes, and Metabolism, Department of Genetics, and The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Mitchell A Lazar
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, and The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.,Division of Endocrinology, Diabetes, and Metabolism, Department of Genetics, and The Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Sandra L Martin
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO, United States.,Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO, United States
| |
Collapse
|
11
|
Tessier SN, Breedon SA, Storey KB. Modulating Nrf2 transcription factor activity: Revealing the regulatory mechanisms of antioxidant defenses during hibernation in 13-lined ground squirrels. Cell Biochem Funct 2021; 39:623-635. [PMID: 33624895 DOI: 10.1002/cbf.3627] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 11/09/2022]
Abstract
Mammalian hibernators undergo major behavioural, physiological and biochemical changes to survive hypothermia, ischaemia-reperfusion and finite fuel reserves during days or weeks of continuous torpor. During hibernation, the 13-lined ground squirrel (Ictidomys tridecemlineatus) undergoes a global suppression of energetically expensive processes such as transcription and translation, while selectively upregulating certain genes/proteins to mitigate torpor-related damage. Antioxidant defenses are critical for preventing damage caused by reactive oxygen species (ROS) during torpor and arousal, and Nrf2 is a critical regulator of these antioxidant genes. This study analysed the relative protein expression levels of Nrf2, KEAP1, small Mafs (MafF, MafK and MafG) and catalase and the regulation of Nrf2 transcription factors by post-translational modifications (PTMs) and protein-protein interactions with a negative regulator (KEAP1) during hibernation. It was found that a significant increase in MafK during late torpor predicated an increase in relative Nrf2 and catalase levels seen in arousal. Additionally, Nrf2-KEAP1 protein-protein interactions and Nrf2 PTMs, including serine phosphorylation and lysine acetylation, were responsive to cycles of torpor-arousal with peak responses occurring during arousal. These peaks seen during arousal correspond to a surge in oxygen consumption, which causes increased ROS production. Thus, these regulatory mechanisms could be important during hibernation because they provide mechanisms for mitigating the deleterious effects of oxidative stress by modifying Nrf2 expression and function in an energetically inexpensive manner.
Collapse
Affiliation(s)
- Shannon N Tessier
- Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada.,BioMEMS Resource Center & Center for Engineering in Medicine and Surgery, Massachusetts General Hospital & Harvard Medical School, Charlestown, Massachusetts, USA
| | - Sarah A Breedon
- Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Kenneth B Storey
- Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada
| |
Collapse
|
12
|
Mohr SM, Bagriantsev SN, Gracheva EO. Cellular, Molecular, and Physiological Adaptations of Hibernation: The Solution to Environmental Challenges. Annu Rev Cell Dev Biol 2020; 36:315-338. [PMID: 32897760 DOI: 10.1146/annurev-cellbio-012820-095945] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Thriving in times of resource scarcity requires an incredible flexibility of behavioral, physiological, cellular, and molecular functions that must change within a relatively short time. Hibernation is a collection of physiological strategies that allows animals to inhabit inhospitable environments, where they experience extreme thermal challenges and scarcity of food and water. Many different kinds of animals employ hibernation, and there is a spectrum of hibernation phenotypes. Here, we focus on obligatory mammalian hibernators to identify the unique challenges they face and the adaptations that allow hibernators to overcome them. This includes the cellular and molecular strategies used to combat low environmental and body temperatures and lack of food and water. We discuss metabolic, neuronal, and hormonal cues that regulate hibernation and how they are thought to be coordinated by internal clocks. Last, we touch on questions that are left to be addressed in the field of hibernation research. Studies from the last century and more recent work reveal that hibernation is not simply a passive reduction in body temperature and vital parameters but rather an active process seasonally regulated at the molecular, cellular, and organismal levels.
Collapse
Affiliation(s)
- Sarah M Mohr
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA; .,Department of Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut 06510, USA;
| | - Sviatoslav N Bagriantsev
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA;
| | - Elena O Gracheva
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA; .,Department of Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, Connecticut 06510, USA;
| |
Collapse
|
13
|
Transcriptional changes in muscle of hibernating arctic ground squirrels (Urocitellus parryii): implications for attenuation of disuse muscle atrophy. Sci Rep 2020; 10:9010. [PMID: 32488149 PMCID: PMC7265340 DOI: 10.1038/s41598-020-66030-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Accepted: 05/11/2020] [Indexed: 01/10/2023] Open
Abstract
Physical inactivity generates muscle atrophy in most mammalian species. In contrast, hibernating mammals demonstrate limited muscle loss over the prolonged intervals of immobility during winter, which suggests that they have adaptive mechanisms to reduce disuse muscle atrophy. To identify transcriptional programs that underlie molecular mechanisms attenuating muscle loss, we conducted a large-scale gene expression profiling in quadriceps muscle of arctic ground squirrels, comparing hibernating (late in a torpor and during torpor re-entry after arousal) and summer active animals using next generation sequencing of the transcriptome. Gene set enrichment analysis showed a coordinated up-regulation of genes involved in all stages of protein biosynthesis and ribosome biogenesis during both stages of hibernation that suggests induction of translation during interbout arousals. Elevated proportion of down-regulated genes involved in apoptosis, NFKB signaling as well as significant under expression of atrogenes, upstream regulators (FOXO1, FOXO3, NFKB1A), key components of the ubiquitin proteasome pathway (FBXO32, TRIM63, CBLB), and overexpression of PPARGC1B inhibiting proteolysis imply suppression of protein degradation in muscle during arousals. The induction of protein biosynthesis and decrease in protein catabolism likely contribute to the attenuation of disuse muscle atrophy through prolonged periods of immobility of hibernation.
Collapse
|
14
|
Chazarin B, Storey KB, Ziemianin A, Chanon S, Plumel M, Chery I, Durand C, Evans AL, Arnemo JM, Zedrosser A, Swenson JE, Gauquelin-Koch G, Simon C, Blanc S, Lefai E, Bertile F. Metabolic reprogramming involving glycolysis in the hibernating brown bear skeletal muscle. Front Zool 2019; 16:12. [PMID: 31080489 PMCID: PMC6503430 DOI: 10.1186/s12983-019-0312-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/08/2019] [Indexed: 12/17/2022] Open
Abstract
Background In mammals, the hibernating state is characterized by biochemical adjustments, which include metabolic rate depression and a shift in the primary fuel oxidized from carbohydrates to lipids. A number of studies of hibernating species report an upregulation of the levels and/or activity of lipid oxidizing enzymes in muscles during torpor, with a concomitant downregulation for glycolytic enzymes. However, other studies provide contrasting data about the regulation of fuel utilization in skeletal muscles during hibernation. Bears hibernate with only moderate hypothermia but with a drop in metabolic rate down to ~ 25% of basal metabolism. To gain insights into how fuel metabolism is regulated in hibernating bear skeletal muscles, we examined the vastus lateralis proteome and other changes elicited in brown bears during hibernation. Results We show that bear muscle metabolic reorganization is in line with a suppression of ATP turnover. Regulation of muscle enzyme expression and activity, as well as of circulating metabolite profiles, highlighted a preference for lipid substrates during hibernation, although the data suggested that muscular lipid oxidation levels decreased due to metabolic rate depression. Our data also supported maintenance of muscle glycolysis that could be fuelled from liver gluconeogenesis and mobilization of muscle glycogen stores. During hibernation, our data also suggest that carbohydrate metabolism in bear muscle, as well as protein sparing, could be controlled, in part, by actions of n-3 polyunsaturated fatty acids like docosahexaenoic acid. Conclusions Our work shows that molecular mechanisms in hibernating bear skeletal muscle, which appear consistent with a hypometabolic state, likely contribute to energy and protein savings. Maintenance of glycolysis could help to sustain muscle functionality for situations such as an unexpected exit from hibernation that would require a rapid increase in ATP production for muscle contraction. The molecular data we report here for skeletal muscles of bears hibernating at near normal body temperature represent a signature of muscle preservation despite atrophying conditions.
Collapse
Affiliation(s)
- Blandine Chazarin
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France.,10Centre National d'Etudes Spatiales, CNES, F-75001 Paris, France
| | - Kenneth B Storey
- 2Department of Biology, Carleton University, Ottawa, ON K1S 5B6 Canada
| | - Anna Ziemianin
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France.,10Centre National d'Etudes Spatiales, CNES, F-75001 Paris, France
| | - Stéphanie Chanon
- 3CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Marine Plumel
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Isabelle Chery
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Christine Durand
- 3CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Alina L Evans
- 4Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, NO-2480 Koppang, Norway
| | - Jon M Arnemo
- 4Department of Forestry and Wildlife Management, Inland Norway University of Applied Sciences, Campus Evenstad, NO-2480 Koppang, Norway.,5Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden
| | - Andreas Zedrosser
- 6Department of Environmental and Health Studies, University College of Southeast Norway, N-3800 Bø, Telemark Norway.,7Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, A-1180 Vienna, Austria
| | - Jon E Swenson
- 8Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, NO-1432 Ås, Norway.,9Norwegian Institute for Nature Research, NO-7485 Trondheim, Norway
| | | | - Chantal Simon
- 3CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France
| | - Stephane Blanc
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Etienne Lefai
- 3CarMen Laboratory, INSERM 1060, INRA 1397, University of Lyon, F-69600 Oullins, France.,Université d'Auvergne, INRA, UNH UMR1019, F-63122 Saint-Genès Champanelle, France
| | - Fabrice Bertile
- 1Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| |
Collapse
|
15
|
Gehrke S, Rice S, Stefanoni D, Wilkerson RB, Nemkov T, Reisz JA, Hansen KC, Lucas A, Cabrales P, Drew K, D'Alessandro A. Red Blood Cell Metabolic Responses to Torpor and Arousal in the Hibernator Arctic Ground Squirrel. J Proteome Res 2019; 18:1827-1841. [PMID: 30793910 DOI: 10.1021/acs.jproteome.9b00018] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Arctic ground squirrels provide a unique model to investigate metabolic responses to hibernation in mammals. During winter months these rodents are exposed to severe hypothermia, prolonged fasting, and hypoxemia. In the light of their role in oxygen transport/off-loading and owing to the absence of nuclei and organelles (and thus de novo protein synthesis capacity), mature red blood cells have evolved metabolic programs to counteract physiological or pathological hypoxemia. However, red blood cell metabolism in hibernation has not yet been investigated. Here we employed targeted and untargeted metabolomics approaches to investigate erythrocyte metabolism during entrance to torpor to arousal, with a high resolution of the intermediate time points. We report that torpor and arousal promote metabolism through glycolysis and pentose phosphate pathway, respectively, consistent with previous models of oxygen-dependent metabolic modulation in mature erythrocytes. Erythrocytes from hibernating squirrels showed up to 100-fold lower levels of biomarkers of reperfusion injury, such as the pro-inflammatory dicarboxylate succinate. Altered tryptophan metabolism during torpor was here correlated to the accumulation of potentially neurotoxic catabolites kynurenine, quinolinate, and picolinate. Arousal was accompanied by alterations of sulfur metabolism, including sudden spikes in a metabolite putatively identified as thiorphan (level 1 confidence)-a potent inhibitor of several metalloproteases that play a crucial role in nociception and inflammatory complication to reperfusion secondary to ischemia or hemorrhage. Preliminary studies in rats showed that intravenous injection of thiorphan prior to resuscitation mitigates metabolic and cytokine markers of reperfusion injury, etiological contributors to inflammatory complications after shock.
Collapse
Affiliation(s)
- Sarah Gehrke
- Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , Colorado 80045 , United States
| | - Sarah Rice
- Department of Chemistry and Biochemistry , University of Alaska Fairbanks , Fairbanks , Alaska 99775 , United States
| | - Davide Stefanoni
- Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , Colorado 80045 , United States
| | - Rebecca B Wilkerson
- Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , Colorado 80045 , United States
| | - Travis Nemkov
- Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , Colorado 80045 , United States
| | - Julie A Reisz
- Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , Colorado 80045 , United States
| | - Kirk C Hansen
- Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , Colorado 80045 , United States
| | - Alfredo Lucas
- Department of Bioengineering , University of California San Diego , La Jolla , California 92093 , United States
| | - Pedro Cabrales
- Department of Bioengineering , University of California San Diego , La Jolla , California 92093 , United States
| | - Kelly Drew
- Department of Chemistry and Biochemistry , University of Alaska Fairbanks , Fairbanks , Alaska 99775 , United States
| | - Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics , University of Colorado Denver - Anschutz Medical Campus , Aurora , Colorado 80045 , United States
| |
Collapse
|
16
|
Nespolo RF, Gaitan-Espitia JD, Quintero-Galvis JF, Fernandez FV, Silva AX, Molina C, Storey KB, Bozinovic F. A functional transcriptomic analysis in the relict marsupial Dromiciops gliroides
reveals adaptive regulation of protective functions during hibernation. Mol Ecol 2018; 27:4489-4500. [DOI: 10.1111/mec.14876] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 09/05/2018] [Accepted: 09/07/2018] [Indexed: 12/20/2022]
Affiliation(s)
- Roberto F. Nespolo
- Instituto de Ciencias Ambientales y Evolutivas; Facultad de Ciencias; Universidad Austral de Chile; Valdivia Chile
- Departamento de Ecología; Center of Applied Ecology and Sustainability (CAPES); Facultad de Ciencias Biológicas; Pontificia Universidad Católica de Chile; Santiago Chile
- Millennium Institute for Integrative Biology (iBio); Santiago Chile
| | - Juan Diego Gaitan-Espitia
- The Swire Institute of Marine Science and School of Biological Sciences; The University of Hong Kong; Hong Kong SAR China
- CSIRO Oceans & Atmosphere; Hobart Tasmania Australia
| | - Julian F. Quintero-Galvis
- Instituto de Ciencias Ambientales y Evolutivas; Facultad de Ciencias; Universidad Austral de Chile; Valdivia Chile
| | - Fernanda V. Fernandez
- Instituto de Fisiología; Facultad de Medicina; Universidad Austral de Chile; Valdivia Chile
| | - Andrea X. Silva
- AUSTRALomics, Vicerrectoría de Investigación, Desarrollo y Creación Artística; Universidad Austral de Chile; Valdivia Chile
| | - Cristian Molina
- AUSTRALomics, Vicerrectoría de Investigación, Desarrollo y Creación Artística; Universidad Austral de Chile; Valdivia Chile
| | - Kenneth B. Storey
- Department of Biology and Institute of Biochemistry; Carleton University; Ottawa Ontario Canada
| | - Francisco Bozinovic
- Departamento de Ecología; Center of Applied Ecology and Sustainability (CAPES); Facultad de Ciencias Biológicas; Pontificia Universidad Católica de Chile; Santiago Chile
| |
Collapse
|
17
|
Wiersma M, Beuren TMA, de Vrij EL, Reitsema VA, Bruintjes JJ, Bouma HR, Brundel BJJM, Henning RH. Torpor-arousal cycles in Syrian hamster heart are associated with transient activation of the protein quality control system. Comp Biochem Physiol B Biochem Mol Biol 2018; 223:23-28. [PMID: 29894736 DOI: 10.1016/j.cbpb.2018.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/28/2018] [Accepted: 06/04/2018] [Indexed: 12/14/2022]
Abstract
Hibernation consists of torpor, with marked suppression of metabolism and physiological functions, alternated with arousal periods featuring their full restoration. The heart is particularly challenged, exemplified by its rate reduction from 400 to 5-10 beats per minute during torpor in Syrian hamsters. In addition, during arousals, the heart needs to accommodate the very rapid return to normal function, which lead to our hypothesis that cardiac function during hibernation is supported by maintenance of protein homeostasis through adaptations in the protein quality control (PQC) system. Hereto, we examined autophagy, the endoplasmic reticulum (ER) unfolded protein (UPRER) response and the heat shock response (HSR) in Syrian hamster hearts during torpor and arousal. Transition from torpor to arousal (1.5 h) was associated with stimulation of the PQC system during early arousal, demonstrated by induction of autophagosomes, as shown by an increase in LC3B-II protein abundance, likely related to the activation of the UPRER during late torpor in response to proteotoxic stress. The HSR was not activated during torpor or arousal. Our results demonstrate activation of the cardiac PQC system - particularly autophagosomal degradation - in early arousal in response to cardiac stress, to clear excess aberrant or damaged proteins, being gradually formed during the torpor bout and/or the rapid increase in heart rate during the transition from torpor to arousal. This mechanism may enable the large gain in cardiac function during the transition from torpor to arousal, which may hold promise to further understand 'hibernation' of cardiomyocytes in human heart disease.
Collapse
Affiliation(s)
- Marit Wiersma
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands; Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands.
| | - Thais M A Beuren
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands; Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Edwin L de Vrij
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands; Department of Surgery, Martini Hospital, Groningen, The Netherlands
| | - Vera A Reitsema
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Jantje J Bruintjes
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Hjalmar R Bouma
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands; Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Bianca J J M Brundel
- Department of Physiology, Amsterdam Cardiovascular Sciences, VU University Medical Center, Amsterdam, The Netherlands; Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| | - Robert H Henning
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, The Netherlands
| |
Collapse
|
18
|
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.
Collapse
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
| |
Collapse
|
19
|
D'Alessandro A, Nemkov T, Bogren LK, Martin SL, Hansen KC. Comfortably Numb and Back: Plasma Metabolomics Reveals Biochemical Adaptations in the Hibernating 13-Lined Ground Squirrel. J Proteome Res 2016; 16:958-969. [PMID: 27991798 DOI: 10.1021/acs.jproteome.6b00884] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Hibernation is an evolutionary adaptation that affords some mammals the ability to exploit the cold to achieve extreme metabolic depression (torpor) while avoiding ischemia/reperfusion or hemorrhagic shock injuries. Hibernators cycle periodically out of torpor, restoring high metabolic activity. If understood at the molecular level, the adaptations underlying torpor-arousal cycles may be leveraged for translational applications in critical fields such as intensive care medicine. Here, we monitored 266 metabolites to investigate the metabolic adaptations to hibernation in plasma from 13-lined ground squirrels (57 animals, 9 time points). Results indicate that the periodic arousals foster the removal of potentially toxic oxidative stress-related metabolites, which accumulate in plasma during torpor while replenishing reservoirs of circulating catabolic substrates (free fatty acids and amino acids). Specifically, we identified metabolic fluctuations of basic amino acids lysine and arginine, one-carbon metabolism intermediates, and sulfur-containing metabolites methionine, cysteine, and cystathionine. Conversely, reperfusion injury markers such as succinate/fumarate remained relatively stable across cycles. Considering the cycles of these metabolites with the hibernator's cycling metabolic activity together with their well-established role as substrates for the production of hydrogen sulfide (H2S), we hypothesize that these metabolic fluctuations function as a biological clock regulating torpor to arousal transitions and resistance to reperfusion during arousal.
Collapse
Affiliation(s)
- Angelo D'Alessandro
- Department of Biochemistry and Molecular Genetics and ‡Department of Cell and Developmental Biology, University of Colorado Denver - Anschutz Medical Campus , Aurora, Colorado 80045, United States
| | - Travis Nemkov
- Department of Biochemistry and Molecular Genetics and ‡Department of Cell and Developmental Biology, University of Colorado Denver - Anschutz Medical Campus , Aurora, Colorado 80045, United States
| | - Lori K Bogren
- Department of Biochemistry and Molecular Genetics and ‡Department of Cell and Developmental Biology, University of Colorado Denver - Anschutz Medical Campus , Aurora, Colorado 80045, United States
| | - Sandra L Martin
- Department of Biochemistry and Molecular Genetics and ‡Department of Cell and Developmental Biology, University of Colorado Denver - Anschutz Medical Campus , Aurora, Colorado 80045, United States
| | - Kirk C Hansen
- Department of Biochemistry and Molecular Genetics and ‡Department of Cell and Developmental Biology, University of Colorado Denver - Anschutz Medical Campus , Aurora, Colorado 80045, United States
| |
Collapse
|
20
|
Schieber AMP, Ayres JS. Thermoregulation as a disease tolerance defense strategy. Pathog Dis 2016; 74:ftw106. [PMID: 27815313 PMCID: PMC5975229 DOI: 10.1093/femspd/ftw106] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/03/2016] [Accepted: 11/02/2016] [Indexed: 12/28/2022] Open
Abstract
Physiological responses that occur during infection are most often thought of in terms of effectors of microbial destruction through the execution of resistance mechanisms, due to a direct action of the microbe, or are maladaptive consequences of host-pathogen interplay. However, an examination of the cellular and organ-level consequences of one such response, thermoregulation that leads to fever or hypothermia, reveals that these actions cannot be readily explained within the traditional paradigms of microbial killing or maladaptive consequences of host-pathogen interactions. In this review, the concept of disease tolerance is applied to thermoregulation during infection, inflammation and trauma, and we discuss the physiological consequences of thermoregulation during disease including tissue susceptibility to damage, inflammation, behavior and toxin neutralization.
Collapse
Affiliation(s)
- Alexandria M Palaferri Schieber
- The Salk Institute for Biological Studies, Immunobiology and Microbial Pathogenesis, 10010 North Torrey Pines Road, San DIego CA, USA
| | - Janelle S Ayres
- The Salk Institute for Biological Studies, Immunobiology and Microbial Pathogenesis, 10010 North Torrey Pines Road, San DIego CA, USA
| |
Collapse
|
21
|
Abstract
Hibernation is characterized by prolonged periods of inactivity with concomitantly low nutrient intake, conditions that would typically result in muscle atrophy combined with a loss of oxidative fibers. Yet, hibernators consistently emerge from winter with very little atrophy, frequently accompanied by a slight shift in fiber ratios to more oxidative fiber types. Preservation of muscle morphology is combined with down-regulation of glycolytic pathways and increased reliance on lipid metabolism instead. Furthermore, while rates of protein synthesis are reduced during hibernation, balance is maintained by correspondingly low rates of protein degradation. Proposed mechanisms include a number of signaling pathways and transcription factors that lead to increased oxidative fiber expression, enhanced protein synthesis and reduced protein degradation, ultimately resulting in minimal loss of skeletal muscle protein and oxidative capacity. The functional significance of these outcomes is maintenance of skeletal muscle strength and fatigue resistance, which enables hibernating animals to resume active behaviors such as predator avoidance, foraging and mating immediately following terminal arousal in the spring.
Collapse
Affiliation(s)
- Clark J Cotton
- Department of Biology, College of St Benedict/St John's University, Collegeville, MN 56321, USA
| |
Collapse
|
22
|
Reilly BD, Franklin CE. Prevention of muscle wasting and osteoporosis: the value of examining novel animal models. J Exp Biol 2016; 219:2582-95. [DOI: 10.1242/jeb.128348] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
ABSTRACT
Bone mass and skeletal muscle mass are controlled by factors such as genetics, diet and nutrition, growth factors and mechanical stimuli. Whereas increased mechanical loading of the musculoskeletal system stimulates an increase in the mass and strength of skeletal muscle and bone, reduced mechanical loading and disuse rapidly promote a decrease in musculoskeletal mass, strength and ultimately performance (i.e. muscle atrophy and osteoporosis). In stark contrast to artificially immobilised laboratory mammals, animals that experience natural, prolonged bouts of disuse and reduced mechanical loading, such as hibernating mammals and aestivating frogs, consistently exhibit limited or no change in musculoskeletal performance. What factors modulate skeletal muscle and bone mass, and what physiological and molecular mechanisms protect against losses of muscle and bone during dormancy and following arousal? Understanding the events that occur in different organisms that undergo natural periods of prolonged disuse and suffer negligible musculoskeletal deterioration could not only reveal novel regulatory factors but also might lead to new therapeutic options. Here, we review recent work from a diverse array of species that has revealed novel information regarding physiological and molecular mechanisms that dormant animals may use to conserve musculoskeletal mass despite prolonged inactivity. By highlighting some of the differences and similarities in musculoskeletal biology between vertebrates that experience disparate modes of dormancy, it is hoped that this Review will stimulate new insights and ideas for future studies regarding the regulation of atrophy and osteoporosis in both natural and clinical models of muscle and bone disuse.
Collapse
Affiliation(s)
- Beau D. Reilly
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Craig E. Franklin
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| |
Collapse
|
23
|
Arendt T, Stieler JT, Holzer M. Tau and tauopathies. Brain Res Bull 2016; 126:238-292. [DOI: 10.1016/j.brainresbull.2016.08.018] [Citation(s) in RCA: 333] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/31/2016] [Accepted: 08/31/2016] [Indexed: 12/11/2022]
|
24
|
Fu W, Hu H, Dang K, Chang H, Du B, Wu X, Gao Y. Remarkable preservation of Ca(2+) homeostasis and inhibition of apoptosis contribute to anti-muscle atrophy effect in hibernating Daurian ground squirrels. Sci Rep 2016; 6:27020. [PMID: 27256167 PMCID: PMC4891705 DOI: 10.1038/srep27020] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/12/2016] [Indexed: 01/16/2023] Open
Abstract
The underlying mechanisms that hibernators deviated from muscle atrophy during prolonged hibernating inactivity remain elusive. This study tested the hypothesis that the maintenance of intracellular Ca2+ homeostasis and inhibition of apoptosis would be responsible for preventing muscle atrophy in hibernating Daurian ground squirrels. The results showed that intracellular Ca2+ homeostasis was maintained in soleus and extensor digitorum longus (EDL) in hibernation and post-hibernation, while cytosolic Ca2+ was overloaded in gastrocnemius (GAS) in hibernation with a recovery in post-hibernation. The Ca2+ overload was also observed in interbout arousals in all three type muscles. Besides, the Bax/Bcl-2 ratio was unchanged in transcriptional level among pre-hibernation, hibernation and interbout arousals, and reduced to a minimum in post-hibernation. Furthermore, the Bax/Bcl-2 ratio in protein level was reduced in hibernation but recovered in interbout arousals. Although cytochrome C was increased in GAS and EDL in post-hibernation, no apoptosis was observed by TUNEL assay. These findings suggested that the intracellular Ca2+ homeostasis in hibernation might be regulated by the cytosolic Ca2+ overload during interbout arousals, which were likely responsible for preventing muscle atrophy via inhibition of apoptosis. Moreover, the muscle-specificity indicated that the different mechanisms against disuse-induced atrophy might be involved in different muscles in hibernation.
Collapse
Affiliation(s)
- Weiwei Fu
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an 710069, China
| | - Huanxin Hu
- National Research Center for Veterinary Medicine, Luo Yang 471003, China
| | - Kai Dang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an 710069, China
| | - Hui Chang
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an 710069, China
| | - Bei Du
- Shaanxi Institute of International Trade and Commerce, Xian Yang 712046, China
| | - Xue Wu
- Department of Burns and Cutaneous Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
| | - Yunfang Gao
- Key Laboratory of Resource Biology and Biotechnology in Western China (Northwest University), Ministry of Education, Xi'an 710069, China
| |
Collapse
|
25
|
Wu CW, Biggar KK, Luu BE, Szereszewski KE, Storey KB. Analysis of microRNA expression during the torpor-arousal cycle of a mammalian hibernator, the 13-lined ground squirrel. Physiol Genomics 2016; 48:388-96. [PMID: 27084747 DOI: 10.1152/physiolgenomics.00005.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/04/2016] [Indexed: 01/06/2023] Open
Abstract
Hibernation is a highly regulated stress response that is utilized by some mammals to survive harsh winter conditions and involves a complex metabolic reprogramming at the cellular level to maintain tissue protections at low temperature. In this study, we profiled the expression of 117 conserved microRNAs in the heart, muscle, and liver of the 13-lined ground squirrel (Ictidomys tridecemlineatus) across four stages of the torpor-arousal cycle (euthermia, early torpor, late torpor, and interbout arousal) by real-time PCR. We found significant differential regulation of numerous microRNAs that were both tissue specific and torpor stage specific. Among the most significant regulated microRNAs was miR-208b, a positive regulator of muscle development that was found to be upregulated by fivefold in the heart during late torpor (13-fold during arousal), while decreased by 3.7-fold in the skeletal muscle, implicating a potential regulatory role in the development of cardiac hypertrophy and skeletal muscle atrophy in the ground squirrels during torpor. In addition, the insulin resistance marker miR-181a was upregulated by 5.7-fold in the liver during early torpor, which supports previous suggestions of hyperinsulinemia in hibernators during the early stages of the hibernation cycle. Although microRNA expression profiles were largely unique between the three tissues, GO annotation analysis revealed that the putative targets of upregulated microRNAs tend to enrich toward suppression of progrowth-related processes in all three tissues. These findings implicate microRNAs in the regulation of both tissue-specific processes and general suppression of cell growth during hibernation.
Collapse
Affiliation(s)
- Cheng-Wei Wu
- Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Kyle K Biggar
- Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Bryan E Luu
- Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Kama E Szereszewski
- Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada
| | - Kenneth B Storey
- Institute of Biochemistry and Department of Biology, Carleton University, Ottawa, Ontario, Canada
| |
Collapse
|
26
|
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.
Collapse
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
| |
Collapse
|
27
|
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.
Collapse
Affiliation(s)
- James F Staples
- Department of Biology, University of Western Ontario, London, Ontario, Canada
| |
Collapse
|
28
|
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
| |
Collapse
|
29
|
Hecht AM, Braun BC, Krause E, Voigt CC, Greenwood AD, Czirják GÁ. Plasma proteomic analysis of active and torpid greater mouse-eared bats (Myotis myotis). Sci Rep 2015; 5:16604. [PMID: 26586174 PMCID: PMC4653738 DOI: 10.1038/srep16604] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 10/15/2015] [Indexed: 11/21/2022] Open
Abstract
Hibernation is a physiological adaptation to overcome extreme environmental conditions. It is characterized by prolonged periods of torpor interrupted by temporary arousals during winter. During torpor, body functions are suppressed and restored rapidly to almost pre-hibernation levels during arousal. Although molecular studies have been performed on hibernating rodents and bears, it is unclear how generalizable the results are among hibernating species with different physiology such as bats. As targeted blood proteomic analysis are lacking in small hibernators, we investigated the general plasma proteomic profile of European Myotis myotis and hibernation associated changes between torpid and active individuals by two-dimensional gel electrophoresis. Results revealed an alternation of proteins involved in transport, fuel switching, innate immunity and blood coagulation between the two physiological states. The results suggest that metabolic changes during hibernation are associated with plasma proteomic changes. Further characterization of the proteomic plasma profile identified transport proteins, coagulation proteins and complement factors and detected a high abundance of alpha-fetoprotein. We were able to establish for the first time a basic myotid bat plasma proteomic profile and further demonstrated a modulated protein expression during torpor in Myotis myotis, indicating both novel physiological pathways in bats in general, and during hibernation in particular.
Collapse
Affiliation(s)
- Alexander M. Hecht
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
| | - Beate C. Braun
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
| | - Eberhard Krause
- Leibniz Institute for Molecular Pharmacology, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Christian C. Voigt
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
- Department of Animal Behaviour, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany
| | - Alex D. Greenwood
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
- Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163 Berlin, Germany
| | - Gábor Á. Czirják
- Leibniz Institute for Zoo and Wildlife Research, Alfred-Kowalke-Straße 17, 10315 Berlin, Germany
| |
Collapse
|
30
|
Karimpour-Fard A, Epperson LE, Hunter LE. A survey of computational tools for downstream analysis of proteomic and other omic datasets. Hum Genomics 2015; 9:28. [PMID: 26510531 PMCID: PMC4624643 DOI: 10.1186/s40246-015-0050-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 10/06/2015] [Indexed: 12/19/2022] Open
Abstract
Proteomics is an expanding area of research into biological systems with significance for biomedical and therapeutic applications ranging from understanding the molecular basis of diseases to testing new treatments, studying the toxicity of drugs, or biotechnological improvements in agriculture. Progress in proteomic technologies and growing interest has resulted in rapid accumulation of proteomic data, and consequently, a great number of tools have become available. In this paper, we review the well-known and ready-to-use tools for classification, clustering and validation, interpretation, and generation of biological information from experimental data. We suggest some rules of thumb for the reader on choosing the best suitable learning method for a particular dataset and conclude with pathway and functional analysis and then provide information about submitting final results to a repository.
Collapse
Affiliation(s)
- Anis Karimpour-Fard
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, 80045, USA.
| | - L Elaine Epperson
- Integrated Center for Genes, Environment, and Health, National Jewish Health, Denver, CO, 80206, USA
| | - Lawrence E Hunter
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| |
Collapse
|
31
|
van Breukelen F, Martin SL. The Hibernation Continuum: Physiological and Molecular Aspects of Metabolic Plasticity in Mammals. Physiology (Bethesda) 2015; 30:273-81. [DOI: 10.1152/physiol.00010.2015] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mammals are often considered to be masters of homeostasis, with the ability to maintain a constant internal milieu, despite marked changes in the environment; however, many species exhibit striking physiological and biochemical plasticity in the face of environmental fluctuations. Here, we review metabolic depression and body temperature fluctuation in mammals, with a focus on the extreme example of hibernation in small-bodied eutherian species. Careful exploitation of the phenotypic plasticity of mammals with metabolic flexibility may provide the key to unlocking the molecular secrets of orchestrating and surviving reversible metabolic depression in less plastic species, including humans.
Collapse
Affiliation(s)
| | - Sandra L. Martin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| |
Collapse
|
32
|
Proteomics approaches shed new light on hibernation physiology. J Comp Physiol B 2015; 185:607-27. [PMID: 25976608 DOI: 10.1007/s00360-015-0905-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 03/11/2015] [Accepted: 04/19/2015] [Indexed: 10/23/2022]
Abstract
The broad phylogenetic distribution and rapid phenotypic transitions of mammalian hibernators imply that hibernation is accomplished by differential expression of common genes. Traditional candidate gene approaches have thus far explained little of the molecular mechanisms underlying hibernation, likely due to (1) incomplete and imprecise sampling of a complex phenotype, and (2) the forming of hypotheses about which genes might be important based on studies of model organisms incapable of such dynamic physiology. Unbiased screening approaches, such as proteomics, offer an alternative means to discover the cellular underpinnings that permit successful hibernation and may reveal previously overlooked, important pathways. Here, we review the findings that have emerged from proteomics studies of hibernation. One striking feature is the stability of the proteome, especially across the extreme physiological shifts of torpor-arousal cycles during hibernation. This has led to subsequent investigations of the role of post-translational protein modifications in altering protein activity without energetically wasteful removal and rebuilding of protein pools. Another unexpected finding is the paucity of universal proteomic adjustments across organ systems in response to the extreme metabolic fluctuations despite the universality of their physiological challenges; rather each organ appears to respond in a unique, tissue-specific manner. Additional research is needed to extend and synthesize these results before it will be possible to address the whole body physiology of hibernation.
Collapse
|
33
|
Fedorov VB, Goropashnaya AV, Stewart NC, Tøien Ø, Chang C, Wang H, Yan J, Showe LC, Showe MK, Barnes BM. Comparative functional genomics of adaptation to muscular disuse in hibernating mammals. Mol Ecol 2014; 23:5524-37. [PMID: 25314618 PMCID: PMC4245363 DOI: 10.1111/mec.12963] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 09/24/2014] [Accepted: 10/03/2014] [Indexed: 01/04/2023]
Abstract
Hibernation is an energy-saving adaptation that involves a profound suppression of physical activity that can continue for 6-8 months in highly seasonal environments. While immobility and disuse generate muscle loss in most mammalian species, in contrast, hibernating bears and ground squirrels demonstrate limited muscle atrophy over the prolonged periods of physical inactivity during winter, suggesting that hibernating mammals have adaptive mechanisms to prevent disuse muscle atrophy. To identify common transcriptional programmes that underlie molecular mechanisms preventing muscle loss, we conducted a large-scale gene expression screen in hind limb muscles comparing hibernating and summer-active black bears and arctic ground squirrels using custom 9600 probe cDNA microarrays. A molecular pathway analysis showed an elevated proportion of overexpressed genes involved in all stages of protein biosynthesis and ribosome biogenesis in muscle of both species during torpor of hibernation that suggests induction of translation at different hibernation states. The induction of protein biosynthesis probably contributes to attenuation of disuse muscle atrophy through the prolonged periods of immobility of hibernation. The lack of directional changes in genes of protein catabolic pathways does not support the importance of metabolic suppression for preserving muscle mass during winter. Coordinated reduction in multiple genes involved in oxidation-reduction and glucose metabolism detected in both species is consistent with metabolic suppression and lower energy demand in skeletal muscle during inactivity of hibernation.
Collapse
Affiliation(s)
- Vadim B. Fedorov
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Anna V. Goropashnaya
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Nathan C. Stewart
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Øivind Tøien
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Celia Chang
- Systems and Computational Biology Center, the Wistar Institute, Philadelphia, PA 19104, USA
| | - Haifang Wang
- CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes of Biological Sciences, 320 Yue Yang Road, Shanghai, 200031, China
| | - Jun Yan
- CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes of Biological Sciences, 320 Yue Yang Road, Shanghai, 200031, China
| | - Louise C. Showe
- Systems and Computational Biology Center, the Wistar Institute, Philadelphia, PA 19104, USA
| | - Michael K. Showe
- Systems and Computational Biology Center, the Wistar Institute, Philadelphia, PA 19104, USA
| | - Brian M. Barnes
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| |
Collapse
|
34
|
Bogren LK, Murphy CJ, Johnston EL, Sinha N, Serkova NJ, Drew KL. 1H-NMR metabolomic biomarkers of poor outcome after hemorrhagic shock are absent in hibernators. PLoS One 2014; 9:e107493. [PMID: 25211248 PMCID: PMC4161479 DOI: 10.1371/journal.pone.0107493] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 08/12/2014] [Indexed: 11/20/2022] Open
Abstract
Background Hemorrhagic shock (HS) following trauma is a leading cause of death among persons under the age of 40. During HS the body undergoes systemic warm ischemia followed by reperfusion during medical intervention. Ischemia/reperfusion (I/R) results in a disruption of cellular metabolic processes that ultimately lead to tissue and organ dysfunction or failure. Resistance to I/R injury is a characteristic of hibernating mammals. The present study sought to identify circulating metabolites in the rat as biomarkers for metabolic alterations associated with poor outcome after HS. Arctic ground squirrels (AGS), a hibernating species that resists I/R injury independent of decreased body temperature (warm I/R), was used as a negative control. Methodology/principal findings Male Sprague-Dawley rats and AGS were subject to HS by withdrawing blood to a mean arterial pressure (MAP) of 35 mmHg and maintaining the low MAP for 20 min before reperfusing with Ringers. The animals’ temperature was maintained at 37±0.5°C for the duration of the experiment. Plasma samples were taken immediately before hemorrhage and three hours after reperfusion. Hydrophilic and lipid metabolites from plasma were then analyzed via 1H–NMR from unprocessed plasma and lipid extracts, respectively. Rats, susceptible to I/R injury, had a qualitative shift in their hydrophilic metabolic fingerprint including differential activation of glucose and anaerobic metabolism and had alterations in several metabolites during I/R indicative of metabolic adjustments and organ damage. In contrast, I/R injury resistant AGS, regardless of season or body temperature, maintained a stable metabolic homeostasis revealed by a qualitative 1H–NMR metabolic profile with few changes in quantified metabolites during HS-induced global I/R. Conclusions/significance An increase in circulating metabolites indicative of anaerobic metabolism and activation of glycolytic pathways is associated with poor prognosis after HS in rats. These same biomarkers are absent in AGS after HS with warm I/R.
Collapse
Affiliation(s)
- Lori K. Bogren
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, United States of America
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States of America
- * E-mail:
| | - Carl J. Murphy
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, United States of America
| | - Erin L. Johnston
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, United States of America
| | - Neeraj Sinha
- Centre of Biomedical Research, SGPGIMS Campus, Lucknow, Uttar Pradesh, India
| | - Natalie J. Serkova
- Department of Anesthesiology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America
- University of Colorado Cancer Center, University of Colorado Anschutz Medical Campus, Aurora, CO, United States of America
| | - Kelly L. Drew
- Department of Chemistry and Biochemistry, University of Alaska Fairbanks, Fairbanks, AK, United States of America
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK, United States of America
| |
Collapse
|
35
|
Martin SL. Intrinsic circannual rhythm controls protein dynamics in a hibernator to support rapid heat production. Temperature (Austin) 2014; 1:80-1. [PMID: 27581746 PMCID: PMC4977172 DOI: 10.4161/temp.29627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/16/2014] [Accepted: 06/17/2014] [Indexed: 11/21/2022] Open
Abstract
A proteomics screen of brown adipose tissue in 13-lined ground squirrels reveals protein changes underlying the extreme recruitment and activity cycles characteristic of this organ in small eutherian hibernators. Protein changes precede changes in physiology, indicating endogenous timing rather than ambient temperature controls the annual recruitment-atrophy cycle in this obligate hibernator.
Collapse
Affiliation(s)
- Sandra L Martin
- Department of Cell and Developmental Biology; University of Colorado School of Medicine; Aurora, CO USA
| |
Collapse
|
36
|
Hindle AG, Grabek KR, Epperson LE, Karimpour-Fard A, Martin SL. Metabolic changes associated with the long winter fast dominate the liver proteome in 13-lined ground squirrels. Physiol Genomics 2014; 46:348-61. [PMID: 24642758 DOI: 10.1152/physiolgenomics.00190.2013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Small-bodied hibernators partition the year between active homeothermy and hibernating heterothermy accompanied by fasting. To define molecular events underlying hibernation that are both dependent and independent of fasting, we analyzed the liver proteome among two active and four hibernation states in 13-lined ground squirrels. We also examined fall animals transitioning between fed homeothermy and fasting heterothermy. Significantly enriched pathways differing between activity and hibernation were biased toward metabolic enzymes, concordant with the fuel shifts accompanying fasting physiology. Although metabolic reprogramming to support fasting dominated these data, arousing (rewarming) animals had the most distinct proteome among the hibernation states. Instead of a dominant metabolic enzyme signature, torpor-arousal cycles featured differences in plasma proteins and intracellular membrane traffic and its regulation. Phosphorylated NSFL1C, a membrane regulator, exhibited this torpor-arousal cycle pattern; its role in autophagosome formation may promote utilization of local substrates upon metabolic reactivation in arousal. Fall animals transitioning to hibernation lagged in their proteomic adjustment, indicating that the liver is more responsive than preparatory to the metabolic reprogramming of hibernation. Specifically, torpor use had little impact on the fall liver proteome, consistent with a dominant role of nutritional status. In contrast to our prediction of reprogramming the transition between activity and hibernation by gene expression and then within-hibernation transitions by posttranslational modification (PTM), we found extremely limited evidence of reversible PTMs within torpor-arousal cycles. Rather, acetylation contributed to seasonal differences, being highest in winter (specifically in torpor), consistent with fasting physiology and decreased abundance of the mitochondrial deacetylase, SIRT3.
Collapse
Affiliation(s)
- Allyson G Hindle
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Katharine R Grabek
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado; Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, Colorado; and
| | - L Elaine Epperson
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Anis Karimpour-Fard
- Center for Computational Pharmacology University of Colorado School of Medicine, Aurora, Colorado
| | - Sandra L Martin
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado; Human Medical Genetics and Genomics Program, University of Colorado School of Medicine, Aurora, Colorado; and
| |
Collapse
|
37
|
Hindle AG, Martin SL. Intrinsic circannual regulation of brown adipose tissue form and function in tune with hibernation. Am J Physiol Endocrinol Metab 2014; 306:E284-99. [PMID: 24326419 PMCID: PMC3920013 DOI: 10.1152/ajpendo.00431.2013] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Winter hibernators repeatedly cycle between cold torpor and rewarming supported by nonshivering thermogenesis in brown adipose tissue (BAT). In contrast, summer animals are homeotherms, undergoing reproduction, growth, and fattening. This life history confers variability to BAT recruitment and activity. To address the components underlying prewinter enhancement and winter activation, we interrogated the BAT proteome in 13-lined ground squirrels among three summer and five winter states. We also examined mixed physiology in fall and spring individuals to test for ambient temperature and seasonal effects, as well as the timing of seasonal transitions. BAT form and function differ circannually in these animals, as evidenced by morphology and proteome dynamics. This intrinsic pattern distinguished homeothermic groups and early vs. late winter hibernators. Homeothermic variation derived from postemergence delay in growth and substrate biosynthesis. The heterothermic proteome varied less despite extreme winter physiological shifts and was optimized to exploit lipids by enhanced fatty acid binding, β-oxidation, and mitochondrial protein translocation. Surprisingly, ambient temperature did not affect the BAT proteome during transition seasons; rather, the pronounced summer-winter shift preceded environmental changes and phenotypic progression. During fall transition, differential regulation of two fatty acid binding proteins provides further evidence of recruitment and separates proteomic preparation from successful hibernation. Abundance of FABP4 correlates with torpor bout length throughout the year, clarifying its potential function in hibernation. Metabolically active BAT is a target for treating human obesity and metabolic disorders. Understanding the hibernator's extreme and seasonally distinct recruitment and activation control strategies offers untapped potential to identify novel, therapeutically relevant regulatory pathways.
Collapse
Affiliation(s)
- Allyson G Hindle
- Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | | |
Collapse
|
38
|
Zhang Y, Pan YH, Yin Q, Yang T, Dong D, Liao CC, Zhang S. Critical roles of mitochondria in brain activities of torpid Myotis ricketti bats revealed by a proteomic approach. J Proteomics 2014; 105:266-84. [PMID: 24434588 DOI: 10.1016/j.jprot.2014.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 12/31/2013] [Accepted: 01/04/2014] [Indexed: 01/21/2023]
Abstract
UNLABELLED Bats are the only mammals that fly and hibernate. Little is known about their overall metabolism in the brain during hibernation. In this study, brain proteins of torpid and active Myotis ricketti bats were fractionated and compared using a proteomic approach. Results showed that 21% (23 proteins) of identified proteins with significant expression changes were associated with amino acid metabolism and proteostasis. The expression levels of proteins involved in energy metabolism (15 proteins), cytoskeletal structure (18 proteins), and stress response (13 proteins) were also significantly altered in torpid bats. Over 30% (34 proteins) of differentially expressed proteins were associated with mitochondrial functions. Various post-translational modifications (PTMs) on PDHB, DLD, and ARG1 were detected, suggesting that bats use PTMs to regulate protein functions during torpor. Antioxidation and stress responses in torpid bats were similar to those of hibernated squirrels, suggesting a common strategy adopted by small hibernators against brain dysfunction. Since many amino acids that metabolize in mitochondria modulate neuronal transmissions, results of this study reveal pivotal roles of mitochondria in neural communication, metabolic regulation, and brain cell survival during bat hibernation. This article is part of a Special Issue entitled: Proteomics of non-model organisms. BIOLOGICAL SIGNIFICANCE This study reveals the mechanisms used by bats to regulate brain activities during torpor. These mechanisms include post-translational modifications and differential expression of proteins involved in mitochondrial electron transport, anaerobic glycolysis, TCA cycle efflux, cytoskeletal plasticity, amino acid metabolism, vesicle structure, antioxidation defense, stress response, and proteostasis. Our study provides insights in metabolic regulation of flying mammals during torpor and common strategies used by small hibernators in response to hibernation. This article is part of a Special Issue entitled: Proteomics of non-model organisms.
Collapse
Affiliation(s)
- Yijian Zhang
- Laboratory of Molecular Ecology and Evolution, Institute for Advanced Studies in Multidisciplinary Science and Technology, East China Normal University, Shanghai 200062, China
| | - Yi-Hsuan Pan
- Laboratory of Molecular Ecology and Evolution, Institute for Advanced Studies in Multidisciplinary Science and Technology, East China Normal University, Shanghai 200062, China
| | - Qiuyuan Yin
- Laboratory of Molecular Ecology and Evolution, Institute for Advanced Studies in Multidisciplinary Science and Technology, East China Normal University, Shanghai 200062, China
| | - Tianxiao Yang
- Laboratory of Molecular Ecology and Evolution, Institute for Advanced Studies in Multidisciplinary Science and Technology, East China Normal University, Shanghai 200062, China
| | - Dong Dong
- Laboratory of Molecular Ecology and Evolution, Institute for Advanced Studies in Multidisciplinary Science and Technology, East China Normal University, Shanghai 200062, China
| | - Chen-Chung Liao
- Proteomic Research Center, National Yang-Ming University, Taipei 11221, Taiwan.
| | - Shuyi Zhang
- Laboratory of Molecular Ecology and Evolution, Institute for Advanced Studies in Multidisciplinary Science and Technology, East China Normal University, Shanghai 200062, China.
| |
Collapse
|
39
|
Substrate-specific changes in mitochondrial respiration in skeletal and cardiac muscle of hibernating thirteen-lined ground squirrels. J Comp Physiol B 2014; 184:401-14. [PMID: 24408585 DOI: 10.1007/s00360-013-0799-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 12/20/2013] [Accepted: 12/29/2013] [Indexed: 10/25/2022]
Abstract
During torpor, the metabolic rate (MR) of thirteen-lined ground squirrels (Ictidomys tridecemlineatus) is considerably lower relative to euthermia, resulting in part from temperature-independent mitochondrial metabolic suppression in liver and skeletal muscle, which together account for ~40% of basal MR. Although heart accounts for very little (<0.5%) of basal MR, in the present study, we showed that respiration rates were decreased up to 60% during torpor in both subsarcolemmal (SS) and intermyofibrillar (IM) mitochondria from cardiac muscle. We further demonstrated pronounced seasonal (summer vs. winter [i.e., interbout] euthermia) changes in respiration rates in both mitochondrial subpopulations in this tissue, consistent with a shift in fuel use away from carbohydrates and proteins and towards fatty acids and ketones. By contrast, these seasonal changes in respiration rates were not observed in either SS or IM mitochondria isolated from hind limb skeletal muscle. Both populations of skeletal muscle mitochondria, however, did exhibit metabolic suppression during torpor, and this suppression was 2- to 3-fold greater in IM mitochondria, which provide ATP for Ca(2+)- and myosin ATPases, the activities of which are likely quite low in skeletal muscle during torpor because animals are immobile. Finally, these changes in mitochondrial respiration rates were still evident when standardized to citrate synthase activity rather than to total mitochondrial protein.
Collapse
|
40
|
Hindle AG, Martin SL. Cytoskeletal regulation dominates temperature-sensitive proteomic changes of hibernation in forebrain of 13-lined ground squirrels. PLoS One 2013; 8:e71627. [PMID: 23951209 PMCID: PMC3739743 DOI: 10.1371/journal.pone.0071627] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 07/01/2013] [Indexed: 12/17/2022] Open
Abstract
13-lined ground squirrels, Ictidomys tridecemlineatus, are obligate hibernators that transition annually between summer homeothermy and winter heterothermy – wherein they exploit episodic torpor bouts. Despite cerebral ischemia during torpor and rapid reperfusion during arousal, hibernator brains resist damage and the animals emerge neurologically intact each spring. We hypothesized that protein changes in the brain underlie winter neuroprotection. To identify candidate proteins, we applied a sensitive 2D gel electrophoresis method to quantify protein differences among forebrain extracts prepared from ground squirrels in two summer, four winter and fall transition states. Proteins that differed among groups were identified using LC-MS/MS. Only 84 protein spots varied significantly among the defined states of hibernation. Protein changes in the forebrain proteome fell largely into two reciprocal patterns with a strong body temperature dependence. The importance of body temperature was tested in animals from the fall; these fall animals use torpor sporadically with body temperatures mirroring ambient temperatures between 4 and 21°C as they navigate the transition between summer homeothermy and winter heterothermy. Unlike cold-torpid fall ground squirrels, warm-torpid individuals strongly resembled the homeotherms, indicating that the changes observed in torpid hibernators are defined by body temperature, not torpor per se. Metabolic enzymes were largely unchanged despite varied metabolic activity across annual and torpor-arousal cycles. Instead, the majority of the observed changes were cytoskeletal proteins and their regulators. While cytoskeletal structural proteins tended to differ seasonally, i.e., between summer homeothermy and winter heterothermy, their regulatory proteins were more strongly affected by body temperature. Changes in the abundance of various isoforms of the microtubule assembly and disassembly regulatory proteins dihydropyrimidinase-related protein and stathmin suggested mechanisms for rapid cytoskeletal reorganization on return to euthermy during torpor-arousal cycles.
Collapse
Affiliation(s)
- Allyson G Hindle
- Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado, USA.
| | | |
Collapse
|
41
|
Arendt T, Bullmann T. Neuronal plasticity in hibernation and the proposed role of the microtubule-associated protein tau as a "master switch" regulating synaptic gain in neuronal networks. Am J Physiol Regul Integr Comp Physiol 2013; 305:R478-89. [PMID: 23824962 DOI: 10.1152/ajpregu.00117.2013] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present paper provides an overview of adaptive changes in brain structure and learning abilities during hibernation as a behavioral strategy used by several mammalian species to minimize energy expenditure under current or anticipated inhospitable environmental conditions. One cellular mechanism that contributes to the regulated suppression of metabolism and thermogenesis during hibernation is reversible phosphorylation of enzymes and proteins, which limits rates of flux through metabolic pathways. Reversible phosphorylation during hibernation also affects synaptic membrane proteins, a process known to be involved in synaptic plasticity. This mechanism of reversible protein phosphorylation also affects the microtubule-associated protein tau, thereby generating a condition that in the adult human brain is associated with aggregation of tau protein to paired helical filaments (PHFs), as observed in Alzheimer's disease. Here, we put forward the concept that phosphorylation of tau is a neuroprotective mechanism to escape NMDA-mediated hyperexcitability of neurons that would otherwise occur during slow gradual cooling of the brain. Phosphorylation of tau and its subsequent targeting to subsynaptic sites might, thus, work as a kind of "master switch," regulating NMDA receptor-mediated synaptic gain in a wide array of neuronal networks, thereby enabling entry into torpor. If this condition lasts too long, however, it may eventually turn into a pathological trigger, driving a cascade of events leading to neurodegeneration, as in Alzheimer's disease or other "tauopathies".
Collapse
Affiliation(s)
- Thomas Arendt
- Paul Flechsig Institute of Brain Research, Universität Leipzig, Germany.
| | | |
Collapse
|
42
|
Reilly BD, Schlipalius DI, Cramp RL, Ebert PR, Franklin CE. Frogs and estivation: transcriptional insights into metabolism and cell survival in a natural model of extended muscle disuse. Physiol Genomics 2013; 45:377-88. [PMID: 23548685 DOI: 10.1152/physiolgenomics.00163.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Green-striped burrowing frogs (Cyclorana alboguttata) survive in arid environments by burrowing underground and entering into a deep, prolonged metabolic depression known as estivation. Throughout estivation, C. alboguttata is immobilized within a cast-like cocoon of shed skin and ceases feeding and moving. Remarkably, these frogs exhibit very little muscle atrophy despite extended disuse and fasting. Little is known about the transcriptional regulation of estivation or associated mechanisms that may minimize degradative pathways of atrophy. To investigate transcriptional pathways associated with metabolic depression and maintenance of muscle function in estivating burrowing frogs, we assembled a skeletal muscle transcriptome using next-generation short read sequencing and compared gene expression patterns between active and 4 mo estivating C. alboguttata. This identified a complex suite of gene expression changes that occur in muscle during estivation and provides evidence that estivation in burrowing frogs involves transcriptional regulation of genes associated with cytoskeletal remodeling, avoidance of oxidative stress, energy metabolism, the cell stress response, and apoptotic signaling. In particular, the expression levels of genes encoding cell cycle and prosurvival proteins, such as serine/threonine-protein kinase Chk1, cell division protein kinase 2, survivin, and vesicular overexpressed in cancer prosurvival protein 1, were upregulated during estivation. These data suggest that estivating C. alboguttata are able to regulate the expression of genes in several major cellular pathways critical to the survival and viability of cells, thus preserving muscle function while avoiding the deleterious consequences often seen in laboratory models of muscle disuse.
Collapse
Affiliation(s)
- Beau D Reilly
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia.
| | | | | | | | | |
Collapse
|
43
|
Andres-Mateos E, Mejias R, Soleimani A, Lin BM, Burks TN, Marx R, Lin B, Zellars RC, Zhang Y, Huso DL, Marr TG, Leinwand LA, Merriman DK, Cohn RD. Impaired skeletal muscle regeneration in the absence of fibrosis during hibernation in 13-lined ground squirrels. PLoS One 2012; 7:e48884. [PMID: 23155423 PMCID: PMC3498346 DOI: 10.1371/journal.pone.0048884] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2012] [Accepted: 10/02/2012] [Indexed: 02/06/2023] Open
Abstract
Skeletal muscle atrophy can occur as a consequence of immobilization and/or starvation in the majority of vertebrates studied. In contrast, hibernating mammals are protected against the loss of muscle mass despite long periods of inactivity and lack of food intake. Resident muscle-specific stem cells (satellite cells) are known to be activated by muscle injury and their activation contributes to the regeneration of muscle, but whether satellite cells play a role in hibernation is unknown. In the hibernating 13-lined ground squirrel we show that muscles ablated of satellite cells were still protected against atrophy, demonstrating that satellite cells are not involved in the maintenance of skeletal muscle during hibernation. Additionally, hibernating skeletal muscle showed extremely slow regeneration in response to injury, due to repression of satellite cell activation and myoblast differentiation caused by a fine-tuned interplay of p21, myostatin, MAPK, and Wnt signaling pathways. Interestingly, despite long periods of inflammation and lack of efficient regeneration, injured skeletal muscle from hibernating animals did not develop fibrosis and was capable of complete recovery when animals emerged naturally from hibernation. We propose that hibernating squirrels represent a new model system that permits evaluation of impaired skeletal muscle remodeling in the absence of formation of tissue fibrosis.
Collapse
Affiliation(s)
- Eva Andres-Mateos
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Rebeca Mejias
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Arshia Soleimani
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Brian M. Lin
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Tyesha N. Burks
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Ruth Marx
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Benjamin Lin
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Richard C. Zellars
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - Yonggang Zhang
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins School of Medicine, Baltimore, Maryland, United States of America
| | - David L. Huso
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Tom G. Marr
- Hiberna Corporation, Boulder, Colorado, United States of America
| | - Leslie A. Leinwand
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, United States of America
| | - Dana K. Merriman
- Department of Biology and Microbiology, University of Wisconsin, Oshkosh, Wisconsin, United States of America
| | - Ronald D. Cohn
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| |
Collapse
|
44
|
Jani A, Orlicky DJ, Karimpour-Fard A, Epperson LE, Russell RL, Hunter LE, Martin SL. Kidney proteome changes provide evidence for a dynamic metabolism and regional redistribution of plasma proteins during torpor-arousal cycles of hibernation. Physiol Genomics 2012; 44:717-27. [PMID: 22643061 DOI: 10.1152/physiolgenomics.00010.2012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Hibernating ground squirrels maintain homeostasis despite extreme physiological challenges. In winter, these circannual hibernators fast for months while cycling between prolonged periods of low blood flow and body temperature, known as torpor, and short interbout arousals (IBA), where more typical mammalian parameters are rapidly restored. Here we examined the kidney proteome for changes that support the dramatically different physiological demands of the hibernator's year. We identified proteins in 150 two-dimensional gel spots that altered by at least 1.5-fold using liquid chromatography and tandem mass spectrometry. These data successfully classified individuals by physiological state and revealed three dynamic patterns of relative protein abundance that dominated the hibernating kidney: 1) a large group of proteins generally involved with capturing and storing energy were most abundant in summer; 2) a select subset of these also increased during each arousal from torpor; and 3) 14 spots increased in torpor and early arousal were enriched for plasma proteins that enter cells via the endocytic pathway. Immunohistochemistry identified α(2)-macroglobulin and albumin in kidney blood vessels during late torpor and early arousal; both exhibited regional heterogeneity consistent with highly localized control of blood flow in the glomeruli. Furthermore, albumin, but not α(2)-macroglobulin, was detected in the proximal tubules during torpor and early arousal but not in IBA or summer animals. Taken together, our findings indicate that normal glomerular filtration barriers remain intact throughout torpor-arousal cycles but endocytosis, and hence renal function, is compromised at low body temperature during torpor and then recovers with rewarming during arousal.
Collapse
Affiliation(s)
- Alkesh Jani
- Division of Renal Diseases and Hypertension, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | | | | | | | | | | | | |
Collapse
|