1
|
Kurtz CC, Otis JP, Regan MD, Carey HV. How the gut and liver hibernate. Comp Biochem Physiol A Mol Integr Physiol 2020; 253:110875. [PMID: 33348019 DOI: 10.1016/j.cbpa.2020.110875] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/15/2020] [Accepted: 12/15/2020] [Indexed: 12/25/2022]
Abstract
For hibernating mammals, the transition from summer active to winter hibernation seasons come with significant remodeling at cellular, organ and whole organism levels. This review summarizes and synthesizes what is known about hibernation-related remodeling in the gastrointestinal tract of the thirteen-lined ground squirrel, including intestinal and hepatic physiology and the gut microbiota. Hibernation alters intestinal epithelial, immune and cell survival pathways in ways that point to a protective phenotype in the face of prolonged fasting and major fluctuations in nutrient and oxygen delivery during torpor-arousal cycles. The prolonged fasting associated with hibernation alters lipid metabolism and systemic cholesterol dynamics, with both the gut and liver participating in these changes. Fasting also affects the gut microbiota, altering the abundance, composition and diversity of gut microbes and impacting the metabolites they produce in ways that may influence hibernation-related traits in the host. Finally, interventional studies have demonstrated that the hibernation phenotype confers resistance to experimental ischemia-reperfusion injury in both gut and liver, suggesting potential therapeutic roadmaps. We propose that the plasticity inherent to hibernation biology may contribute to this stress tolerance, and in the spirit of August Krogh, makes hibernators particularly valuable for study to identify solutions to certain problems.
Collapse
Affiliation(s)
- Courtney C Kurtz
- Department of Biology, University of Wisconsin-Oshkosh, Oshkosh, WI, United States of America
| | - Jessica P Otis
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States of America
| | - Matthew D Regan
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Hannah V Carey
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, United States of America.
| |
Collapse
|
2
|
Tian T, Lindell SL, Kowalski C, Mangino MJ. Moesin functionality in hypothermic liver preservation injury. Cryobiology 2014; 69:34-40. [PMID: 24836372 DOI: 10.1016/j.cryobiol.2014.04.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 04/30/2014] [Accepted: 04/30/2014] [Indexed: 01/27/2023]
Abstract
The objective of this study was to determine how expression and functionality of the cytoskeletal linker protein moesin is involved in hepatic hypothermic preservation injury. Mouse livers were cold stored in University of Wisconsin (UW) solution and reperfused on an isolated perfused liver (IPL) device for one hour. Human hepatocytes (HepG2) and human or murine sinusoidal endothelial cells (SECs) were cold stored and rewarmed to induce hypothermic preservation injury. The cells were transfected with: wild type moesin, an siRNA duplex specific for moesin, and the moesin mutants T558D and T558A. Tissue and cell moesin expression and its binding to actin were determined by Western blot. Liver IPL functional outcomes deteriorated proportional to the length of cold storage, which correlated with moesin disassociation from the actin cytoskeleton. Cell viability (LDH and WST-8) in the cell models progressively declined with increasing preservation time, which also correlated with moesin disassociation. Transfection of a moesin containing plasmid or an siRNA duplex specific for moesin into HepG2 cells resulted in increased and decreased moesin expression, respectively. Overexpression of moesin protected while moesin knock-down potentiated preservation injury in the HepG2 cell model. Hepatocytes expressing the T558A (inactive) and T558D (active) moesin binding mutants demonstrated significantly more and less preservation injury, respectively. Cold storage time dependently caused hepatocyte detachment from the matrix and cell death, which was prevented by the T558D active moesin mutation. In conclusion, moesin is causally involved in hypothermic liver cell preservation injury through control of its active binding molecular functionality.
Collapse
Affiliation(s)
- Tao Tian
- Department of Surgery, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298, United States
| | - Susanne L Lindell
- Department of Surgery, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298, United States
| | - Chris Kowalski
- Department of Surgery, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298, United States
| | - Martin J Mangino
- Department of Surgery, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298, United States; Department of Emergency Medicine, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298, United States; Department of Physiology and Biophysics, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, VA 23298, United States.
| |
Collapse
|
3
|
Storey KB, Heldmaier G, Rider MH. Mammalian Hibernation: Physiology, Cell Signaling, and Gene Controls on Metabolic Rate Depression. DORMANCY AND RESISTANCE IN HARSH ENVIRONMENTS 2010. [DOI: 10.1007/978-3-642-12422-8_13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
4
|
Zhu L, Hatakeyama J, Zhang B, Makdisi J, Ender C, Forte JG. Novel insights of the gastric gland organization revealed by chief cell specific expression of moesin. Am J Physiol Gastrointest Liver Physiol 2009; 296:G185-95. [PMID: 19074636 PMCID: PMC2643924 DOI: 10.1152/ajpgi.90597.2008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
ERM (ezrin, radixin, and moesin) proteins play critical roles in epithelial and endothelial cell polarity, among other functions. In gastric glands, ezrin is mainly expressed in acid-secreting parietal cells, but not in mucous neck cells or zymogenic chief cells. In looking for other ERM proteins, moesin was found lining the lumen of much of the gastric gland, but it was not expressed in parietal cells. No significant radixin expression was detected in the gastric glands. Moesin showed an increased gradient of expression from the neck to the base of the glands. In addition, the staining pattern of moesin revealed a branched morphology for the gastric lumen. This pattern of short branches extending from the glandular lumen was confirmed by using antibody against zonula occludens-1 (ZO-1) to stain tight junctions. With a mucous neck cell probe (lectin GSII, from Griffonia simplicifolia) and a chief cell marker (pepsinogen C), immunohistochemistry revealed that the mucous neck cells at the top of the glands do not express moesin, but, progressing toward the base, mucous cells showing decreased GSII staining had low or moderate level of moesin expression. The level of moesin expression continued to increase toward the base of the glands and reached a plateau in the base where chief cells and parietal cells abound. The level of pepsinogen expression also increased toward the base. Pepsinogen C was located on cytoplasmic granules and/or more generally distributed in chief cells, whereas moesin was exclusively expressed on the apical membrane. This is a clear demonstration of distinctive cellular expression of two ERM family members in the same tissue. The results provide the first evidence that moesin is involved in the cell biology of chief cells. Novel insights on gastric gland morphology revealed by the moesin and ZO-1 staining provide the basis for a model of cell maturation and migration within the gland.
Collapse
Affiliation(s)
- Lixin Zhu
- Department of Molecular and Cell Biology, University of California, Berkeley, California
| | - Jason Hatakeyama
- Department of Molecular and Cell Biology, University of California, Berkeley, California
| | - Bing Zhang
- Department of Molecular and Cell Biology, University of California, Berkeley, California
| | - Joy Makdisi
- Department of Molecular and Cell Biology, University of California, Berkeley, California
| | - Cody Ender
- Department of Molecular and Cell Biology, University of California, Berkeley, California
| | - John G. Forte
- Department of Molecular and Cell Biology, University of California, Berkeley, California
| |
Collapse
|
5
|
Epperson LE, Dahl TA, Martin SL. Quantitative Analysis of Liver Protein Expression During Hibernation in the Golden-mantled Ground Squirrel. Mol Cell Proteomics 2004; 3:920-33. [PMID: 15266006 DOI: 10.1074/mcp.m400042-mcp200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammals that enter deep hibernation experience extreme reductions in body temperature and in metabolic, respiratory, and heart rates for several weeks at a time. Survival of these extremes likely entails a highly regulated network of tissue- and time-specific gene expression patterns that remain largely unknown. To date, studies to identify differentially-expressed genes have employed a candidate gene approach or in a few cases broader unbiased screens at the RNA level. Here we use a proteomic approach to compare and identify differentially expressed liver proteins from two seasonal stages in the golden-mantled ground squirrel (summer and entrance into torpor) using two-dimensional gels followed by MS/MS. Eighty-four two-dimensional gel spots were found that quantitatively alter with the hibernation season, 68 of which gave unambiguous identifications based on similarity to sequences in the available mammalian database. Based on what is known of these proteins from prior research, they are involved in a variety of cellular processes including protein turnover, detoxification, purine biosynthesis, gluconeogenesis, lipid metabolism and mobility, ketone body formation, cell structure, and redox balance. A number of the enzymes found to change seasonally are known to be either rate-limiting or first enzymes in a metabolic pathway, indicating key roles in metabolic control. Functional roles are proposed to explain the changes seen in protein levels and their potential influence on the phenotype of hibernation.
Collapse
Affiliation(s)
- L Elaine Epperson
- Program in Molecular Biology, Department of Cell and Developmental Biology, University of Colorado School of Medicine, P.O. Box 6511, Mail Stop 8108, Aurora, CO 80045, USA
| | | | | |
Collapse
|
6
|
Storey KB, Storey JM. Metabolic rate depression in animals: transcriptional and translational controls. Biol Rev Camb Philos Soc 2004; 79:207-33. [PMID: 15005178 DOI: 10.1017/s1464793103006195] [Citation(s) in RCA: 427] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metabolic rate depression is an important survival strategy for many animal species and a common element of hibernation, torpor, aestivation, anaerobiosis, diapause, and anhydrobiosis. Studies of the biochemical mechanisms that regulate reversible transitions to and from hypometabolic states are identifying principles of regulatory control that are conserved across phylogenetic lines and that are broadly applied to the control of multiple cell functions. One such mechanism is reversible protein phosphorylation which is now known to contribute to the regulation of fuel metabolism, to ion channel arrest, and to the suppression of protein synthesis during hypometabolism. The present review focuses on two new areas of research in hypometabolism: (1) the role of differential gene expression in supplying protein products that adjust metabolism or protect cell functions for long-term survival, and (2) the mechanisms of protein life extension in hypometabolism involving inhibitory controls of transcription, translation and protein degradation. Control of translation examines reversible phosphorylation regulation of ribosomal initiation and elongation factors, the dissociation of polysomes and storage of mRNA transcripts during hypometabolism, and control over the translation of different mRNA types by differential sequestering of mRNA into polysome versus monosome fractions. The analysis draws primarily from current research on two animal models, hibernating mammals and anoxia-tolerant molluscs, with selected examples from multiple other sources.
Collapse
Affiliation(s)
- Kenneth B Storey
- College of Natural Sciences, Institute of Biochemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada K1S 5B6.
| | | |
Collapse
|
7
|
Carey HV, Andrews MT, Martin SL. Mammalian hibernation: cellular and molecular responses to depressed metabolism and low temperature. Physiol Rev 2003; 83:1153-81. [PMID: 14506303 DOI: 10.1152/physrev.00008.2003] [Citation(s) in RCA: 792] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Mammalian hibernators undergo a remarkable phenotypic switch that involves profound changes in physiology, morphology, and behavior in response to periods of unfavorable environmental conditions. The ability to hibernate is found throughout the class Mammalia and appears to involve differential expression of genes common to all mammals, rather than the induction of novel gene products unique to the hibernating state. The hibernation season is characterized by extended bouts of torpor, during which minimal body temperature (Tb) can fall as low as -2.9 degrees C and metabolism can be reduced to 1% of euthermic rates. Many global biochemical and physiological processes exploit low temperatures to lower reaction rates but retain the ability to resume full activity upon rewarming. Other critical functions must continue at physiologically relevant levels during torpor and be precisely regulated even at Tb values near 0 degrees C. Research using new tools of molecular and cellular biology is beginning to reveal how hibernators survive repeated cycles of torpor and arousal during the hibernation season. Comprehensive approaches that exploit advances in genomic and proteomic technologies are needed to further define the differentially expressed genes that distinguish the summer euthermic from winter hibernating states. Detailed understanding of hibernation from the molecular to organismal levels should enable the translation of this information to the development of a variety of hypothermic and hypometabolic strategies to improve outcomes for human and animal health.
Collapse
Affiliation(s)
- Hannah V Carey
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706, USA.
| | | | | |
Collapse
|
8
|
|
9
|
Epperson LE, Martin SL. Quantitative assessment of ground squirrel mRNA levels in multiple stages of hibernation. Physiol Genomics 2002; 10:93-102. [PMID: 12181366 DOI: 10.1152/physiolgenomics.00004.2002] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hibernators in torpor dramatically reduce their metabolic, respiratory, and heart rates and core body temperature. These extreme physiological conditions are frequently and rapidly reversed during the winter hibernation season via endogenous mechanisms. This phenotype must derive from regulated expression of the hibernator's genome; to identify its molecular components, a cDNA subtraction was used to enrich for seasonally upregulated mRNAs in liver of golden-mantled ground squirrels. The relative steady-state levels for seven mRNAs identified by this screen, plus five others, were measured and analyzed for seasonal and stage-specific differences using kinetic RT-PCR. Four mRNAs show seasonal upregulation in which all five winter stages differ significantly from and are higher than summer (alpha2-macroglobulin, apolipoprotein A1, cathepsin H, and thyroxine-binding globulin). One of these mRNAs, alpha2-macroglobulin, varies during the winter stages with significantly lower levels at late torpor. None of the 12 mRNAs increased during torpor. The implications for these newly recognized upregulated mRNAs for hibernation as well as more global issues of maintaining steady-state levels of mRNA during torpor are discussed.
Collapse
Affiliation(s)
- L Elaine Epperson
- Program in Molecular Biology, Department of Cellular and Structural Biology, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA
| | | |
Collapse
|
10
|
Van Breukelen F, Martin SL. Invited review: molecular adaptations in mammalian hibernators: unique adaptations or generalized responses? J Appl Physiol (1985) 2002; 92:2640-7. [PMID: 12015384 DOI: 10.1152/japplphysiol.01007.2001] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hibernators are unique among mammals in their ability to attain, withstand, and reverse low body temperatures. Hibernators repeatedly cycle between body temperatures near zero during torpor and 37 degrees C during euthermy. How do these mammals maintain cardiac function, cell integrity, blood fluidity, and energetic balance during their prolonged periods at low body temperature and avoid damage when they rewarm? Hibernation is often considered an example of a unique adaptation for low-temperature function in mammals. Although such adaptation is apparent at the level of whole animal physiology, it is surprisingly difficult to demonstrate clear examples of adaptations at the cellular and biochemical levels that improve function in the cold and are unique to hibernators. Instead of adaptation for improved function in the cold, the key molecular adaptations of hibernation may be to exploit the cold to depress most aspects of biochemical function and then rewarm without damage to restore optimal function of all systems. These capabilities are likely due to novel regulation of biochemical pathways shared by all mammals, including humans.
Collapse
Affiliation(s)
- Frank Van Breukelen
- Department of Cellular and Structural Biology, University of Colorado School of Medicine, Denver, Colorado 80262, USA
| | | |
Collapse
|
11
|
Affiliation(s)
- Kenneth B. Storey
- Institute of Biochemistry, College of Natural Sciences, Carleton University, Ottawa, Ontario, Canada
| |
Collapse
|
12
|
Bretscher A, Chambers D, Nguyen R, Reczek D. ERM-Merlin and EBP50 protein families in plasma membrane organization and function. Annu Rev Cell Dev Biol 2001; 16:113-43. [PMID: 11031232 DOI: 10.1146/annurev.cellbio.16.1.113] [Citation(s) in RCA: 290] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ezrin-radixin-moesin (ERM) family of proteins have emerged as key regulatory molecules in linking F-actin to specific membrane proteins, especially in cell surface structures. Merlin, the product of the NF2 tumor suppressor gene, has sequence similarity to ERM proteins and binds to some of the same membrane proteins, but lacks a C-terminal F-actin binding site. In this review we discuss how ERM proteins and merlin are negatively regulated by an intramolecular association between their N- and C-terminal domains. Activation of at least ERM proteins can be accomplished by C-terminal phosphorylation in the presence of PIP2. We also discuss membrane proteins to which ERM and merlin bind, including those making an indirect linkage through the PDZ-containing adaptor molecules EBP50 and E3KARP. Finally, the function of these proteins in cortical structure, endocytic traffic, signal transduction, and growth control is discussed.
Collapse
Affiliation(s)
- A Bretscher
- Department of Molecular Biology and Genetics, Biotechnology Building, Cornell University, Ithaca, New York 14853, USA.
| | | | | | | |
Collapse
|
13
|
Abstract
A cDNA library prepared from heart of hibernating golden-mantled ground squirrels, Spermophilus lateralis, was differentially screened to clone genes that were up-regulated during hibernation. Two differentially expressed clones were found after three rounds of screening and were confirmed as up-regulated by Northern blotting. Clone Ang6 encoded a polypeptide with 116 amino acids that was identified as the ventricular isoform of myosin light chain 1 (MLC1(v)). Clone Ang19 coded for 274 amino acid residues of the mitochondrially encoded protein subunit 2 of NADH-ubiquinone oxidoreductase (ND2). Both proteins showed high amino acid sequence identity with their human counterparts, 97.5% for MLC1(v) and 66% for ND2. Northern blot hybridization revealed differential expression of these genes in multiple organs during hibernation. Transcript levels of both were approximately twofold higher in heart and three- to fourfold higher in skeletal muscle of hibernating, versus euthermic, animals. ND2 was also up-regulated in hibernator liver. Hibernation-induced up-regulation of MLC1(v) suggests that a restructuring of myosin subunit composition could contribute to changes in muscle contractility needed for hypothermic function, whereas changes in ND subunit composition may affect the function of the electron transport chain during hibernation.
Collapse
Affiliation(s)
- A Fahlman
- Institute of Biochemistry and Department of Biology, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada
| | | | | |
Collapse
|
14
|
|
15
|
Abstract
The purpose of this study was to characterize changes in gene expression in the brain of a seasonal hibernator, the golden-mantled ground squirrel, Spermophilus lateralis, during the hibernation season. Very little information is available on molecular changes that correlate with hibernation state, and what has been done focused mainly on seasonal changes in peripheral tissues. We produced over 4000 reverse transcription-PCR products from euthermic and hibernating brain and compared them using differential display. Twenty-nine of the most promising were examined by Northern analysis. Although some small differences were observed across hibernation states, none of the 29 had significant changes. However, a more direct approach, investigating expression of putative hibernation-responsive genes by Northern analysis, revealed an increase in expression of transcription factors c-fos, junB, and c-Jun, but not junD, commencing during late torpor and peaking during the arousal phase of individual hibernation bouts. In contrast, prostaglandin D2 synthase declined during late torpor and arousal but returned to a high level on return to euthermia. Other genes that have putative roles in mammalian sleep or specific brain functions, including somatostatin, enkephalin, growth-associated protein 43, glutamate acid decarboxylases 65/67, histidine decarboxylase, and a sleep-related transcript SD464 did not change significantly during individual hibernation bouts. We also observed no decline in total RNA or total mRNA during torpor; such a decline had been previously hypothesized. Therefore, it appears that the dramatic changes in body temperature and other physiological variables that accompany hibernation involve only modest reprogramming of gene expression or steady-state mRNA levels.
Collapse
|