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Ma WX, Yuan PC, Zhang H, Kong LX, Lazarus M, Qu WM, Wang YQ, Huang ZL. Adenosine and P1 receptors: Key targets in the regulation of sleep, torpor, and hibernation. Front Pharmacol 2023; 14:1098976. [PMID: 36969831 PMCID: PMC10036772 DOI: 10.3389/fphar.2023.1098976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 02/27/2023] [Indexed: 03/12/2023] Open
Abstract
Graphical AbstractAdenosine mediates sleep, torpor and hibernation through P1 receptors. Recent reasearch has shown that P1 receptors play a vital role in the regulation of sleep-wake, torpor and hibernation-like states. In this review, we focus on the roles and neurobiological mechanisms of the CNS adenosine and P1 receptors in these three states. Among them, A1 and A2A receptors are key targets for sleep-wake regulation, A1Rs and A3Rs are very important for torpor induction, and activation of A1Rs is sufficient for hibernation-like state.
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Affiliation(s)
- Wei-Xiang Ma
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ping-Chuan Yuan
- Anhui Provincial Engineering Research Center for Polysaccharide Drugs, Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui, School of Pharmacy, Wannan Medical College, Wuhu, China
| | - Hui Zhang
- Anhui Provincial Engineering Research Center for Polysaccharide Drugs, Provincial Engineering Laboratory for Screening and Re-evaluation of Active Compounds of Herbal Medicines in Southern Anhui, School of Pharmacy, Wannan Medical College, Wuhu, China
| | - Ling-Xi Kong
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Michael Lazarus
- International Institute for Integrative Sleep Medicine (WPI-IIIS) and Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Wei-Min Qu
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Wei-Min Qu, ; Yi-Qun Wang, ; Zhi-Li Huang,
| | - Yi-Qun Wang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Wei-Min Qu, ; Yi-Qun Wang, ; Zhi-Li Huang,
| | - Zhi-Li Huang
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Department of Pharmacology, School of Basic Medical Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Wei-Min Qu, ; Yi-Qun Wang, ; Zhi-Li Huang,
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An Overview of the Implications for Perianesthesia Nurses in terms of Intraoperative Changes in Temperature and Factors Associated with Unintentional Postoperative Hypothermia. JOURNAL OF HEALTHCARE ENGINEERING 2022; 2022:6955870. [PMID: 35444780 PMCID: PMC9015883 DOI: 10.1155/2022/6955870] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/07/2022] [Accepted: 03/09/2022] [Indexed: 11/17/2022]
Abstract
Patients undergo surgery and anaesthesia on a daily basis across the United States and throughout the world. A major source of worry for these patients continues to be inadvertent hypothermia, once core temperature <36°C (96.8°F). Despite well-documented adverse physiological consequences, anaesthesia nurses continue to have a difficult task in keeping patient warmth pre-/peri-/post-surgical procedure. Thermostasis within postoperative patient necessitates the collaboration of many individuals. In order to provide safe and high-quality treatment, it is essential to use the most up-to-date data to guide therapeutic procedures targeted at achieving balance body temperature in surgical patients. Providing a review of the physiology of perioperative temperature variations and the comorbidities linked with accidental intraoperative hypothermia, this article will also provide preventive and treatment methods.
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Cerri M, Hitrec T, Luppi M, Amici R. Be cool to be far: Exploiting hibernation for space exploration. Neurosci Biobehav Rev 2021; 128:218-232. [PMID: 34144115 DOI: 10.1016/j.neubiorev.2021.03.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 01/08/2023]
Abstract
In mammals, torpor/hibernation is a state that is characterized by an active reduction in metabolic rate followed by a progressive decrease in body temperature. Torpor was successfully mimicked in non-hibernators by inhibiting the activity of neurons within the brainstem region of the Raphe Pallidus, or by activating the adenosine A1 receptors in the brain. This state, called synthetic torpor, may be exploited for many medical applications, and for space exploration, providing many benefits for biological adaptation to the space environment, among which an enhanced protection from cosmic rays. As regards the use of synthetic torpor in space, to fully evaluate the degree of physiological advantage provided by this state, it is strongly advisable to move from Earth-based experiments to 'in the field' tests, possibly on board the International Space Station.
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Affiliation(s)
- Matteo Cerri
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| | - Timna Hitrec
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| | - Marco Luppi
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| | - Roberto Amici
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
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Shimaoka H, Shiina T, Suzuki H, Horii Y, Horii K, Shimizu Y. Successful induction of deep hypothermia by isoflurane anesthesia and cooling in a non-hibernator, the rat. J Physiol Sci 2021; 71:10. [PMID: 33784982 PMCID: PMC10717611 DOI: 10.1186/s12576-021-00794-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 03/03/2021] [Indexed: 11/10/2022]
Abstract
The aim of the present study was to establish a novel method for inducing deep hypothermia in rats. Cooling rats anesthetized with isoflurane caused a time-dependent decrease in rectal temperature, but cardiac arrest occurred before their body temperature reached 20 °C when isoflurane inhalation was continued during the cooling process. Stopping inhalation of isoflurane when the rectal temperature reached 22.5 °C successfully induced deep hypothermia, although stopping the inhalation at 27.5 °C resulted in spontaneous recovery of rectal temperature. The hypothermic condition was able to be maintained for up to 6 h. A large number of c-Fos-positive cells were detected in the hypothalamus during hypothermia. Both the maintenance of and recovery from hypothermia caused organ injury, but the damage was transient and recovered within 1 week. These findings indicate that the established procedure is appropriate for inducing deep hypothermia without accompanying serious organ injury in rats.
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Affiliation(s)
- Hiroki Shimaoka
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan.
- Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, 1-1 Yanagido, Gifu, 501-1193, Japan.
| | - Hayato Suzuki
- Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Yuuki Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Kazuhiro Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
- Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, 1-1 Yanagido, Gifu, 501-1193, Japan
- Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
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Zhang Z, Reis FMCV, He Y, Park JW, DiVittorio JR, Sivakumar N, van Veen JE, Maesta-Pereira S, Shum M, Nichols I, Massa MG, Anderson S, Paul K, Liesa M, Ajijola OA, Xu Y, Adhikari A, Correa SM. Estrogen-sensitive medial preoptic area neurons coordinate torpor in mice. Nat Commun 2020; 11:6378. [PMID: 33311503 PMCID: PMC7732979 DOI: 10.1038/s41467-020-20050-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/12/2020] [Indexed: 12/15/2022] Open
Abstract
Homeotherms maintain a stable internal body temperature despite changing environments. During energy deficiency, some species can cease to defend their body temperature and enter a hypothermic and hypometabolic state known as torpor. Recent advances have revealed the medial preoptic area (MPA) as a key site for the regulation of torpor in mice. The MPA is estrogen-sensitive and estrogens also have potent effects on both temperature and metabolism. Here, we demonstrate that estrogen-sensitive neurons in the MPA can coordinate hypothermia and hypometabolism in mice. Selectively activating estrogen-sensitive MPA neurons was sufficient to drive a coordinated depression of metabolic rate and body temperature similar to torpor, as measured by body temperature, physical activity, indirect calorimetry, heart rate, and brain activity. Inducing torpor with a prolonged fast revealed larger and more variable calcium transients from estrogen-sensitive MPA neurons during bouts of hypothermia. Finally, whereas selective ablation of estrogen-sensitive MPA neurons demonstrated that these neurons are required for the full expression of fasting-induced torpor in both female and male mice, their effects on thermoregulation and torpor bout initiation exhibit differences across sex. Together, these findings suggest a role for estrogen-sensitive MPA neurons in directing the thermoregulatory and metabolic responses to energy deficiency.
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Affiliation(s)
- Zhi Zhang
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Fernando M C V Reis
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Yanlin He
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, LA, USA
| | - Jae W Park
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Johnathon R DiVittorio
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Nilla Sivakumar
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - J Edward van Veen
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Sandra Maesta-Pereira
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Michael Shum
- Division of Endocrinology, Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, CA, USA
| | - India Nichols
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Megan G Massa
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Shawn Anderson
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Ketema Paul
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Marc Liesa
- Division of Endocrinology, Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center, Department of Medicine, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Yong Xu
- USDA/ARS Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Avishek Adhikari
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
- Department of Psychology, University of California Los Angeles, Los Angeles, CA, USA
| | - Stephanie M Correa
- Department of Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA.
- Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA.
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Temperature-Dependent Alternative Splicing of Precursor mRNAs and Its Biological Significance: A Review Focused on Post-Transcriptional Regulation of a Cold Shock Protein Gene in Hibernating Mammals. Int J Mol Sci 2020; 21:ijms21207599. [PMID: 33066638 PMCID: PMC7590145 DOI: 10.3390/ijms21207599] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 01/18/2023] Open
Abstract
Multiple mRNA isoforms are often generated during processing such as alternative splicing of precursor mRNAs (pre-mRNA), resulting in a diversity of generated proteins. Alternative splicing is an essential mechanism for the functional complexity of eukaryotes. Temperature, which is involved in all life activities at various levels, is one of regulatory factors for controlling patterns of alternative splicing. Temperature-dependent alternative splicing is associated with various phenotypes such as flowering and circadian clock in plants and sex determination in poikilothermic animals. In some specific situations, temperature-dependent alternative splicing can be evoked even in homothermal animals. For example, the splicing pattern of mRNA for a cold shock protein, cold-inducible RNA-binding protein (CIRP or CIRBP), is changed in response to a marked drop in body temperature during hibernation of hamsters. In this review, we describe the current knowledge about mechanisms and functions of temperature-dependent alternative splicing in plants and animals. Then we discuss the physiological significance of hypothermia-induced alternative splicing of a cold shock protein gene in hibernating and non-hibernating animals.
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Horii Y, Shiina T, Uehara S, Nomura K, Shimaoka H, Horii K, Shimizu Y. Hypothermia induces changes in the alternative splicing pattern of cold-inducible RNA-binding protein transcripts in a non-hibernator, the mouse. Biomed Res 2020; 40:153-161. [PMID: 31413236 DOI: 10.2220/biomedres.40.153] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Cold-inducible RNA-binding protein (CIRBP) plays important roles in protection against harmful effects of cold temperature. We previously found that several splicing variants of CIRBP mRNA are constitutively expressed in the heart of non-hibernating euthermic hamsters and that one of the variants is predominantly expressed with remarkable reduction in the expression of other variants in hibernating hypothermic hamsters. The aim of this study was to determine whether the regulation of alternative splicing is a common function in a non-hibernator, the mouse. The expression of CIRBP mRNA was assessed by RT-PCR. In euthermic control mice, several splicing variants of CIRBP mRNA were detected in various organs. When hypothermia was induced in mice by using isoflurane anesthesia, the short form variant, which encodes full-length functional CIRBP, was predominantly detected. Keeping body temperature of anesthetized mice at 37°C prevented changes in the splicing pattern. Exposure of mice to a low temperature did not change the splicing pattern, suggesting that endogenous neuronal and/or humoral pathways activated in response to cold stimuli applied to the body surface play minor roles. In agreement with this, the shift in alternative splicing was reproduced in isolated leukocytes in vitro when they were incubated at 28°C. Since application of a TRPM8 or TRPA1 agonist at 37°C failed to promote the shift in the splicing pattern, it seems likely that cold-sensitive channels are not involved in the splicing regulation. Therefore, it is probable that a substantial reduction of temperature is a major cause of the regulation of alternative splicing of CIRBP transcripts. The regulatory system of CIRBP expression at the level of alternative splicing, which was originally discovered in the hibernating hamster, commonly exists in non-hibernators such as mice.
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Affiliation(s)
- Yuuki Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University.,Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, Gifu University
| | - Saki Uehara
- Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, Gifu University
| | - Kanako Nomura
- Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, Gifu University
| | - Hiroki Shimaoka
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University
| | - Kazuhiro Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University.,Laboratory of Veterinary Physiology, Faculty of Applied Biological Sciences, Gifu University.,Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University
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Horii Y, Shimaoka H, Horii K, Shiina T, Shimizu Y. Mild hypothermia causes a shift in the alternative splicing of cold-inducible RNA-binding protein transcripts in Syrian hamsters. Am J Physiol Regul Integr Comp Physiol 2019; 317:R240-R247. [PMID: 31188649 DOI: 10.1152/ajpregu.00012.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cold-shock proteins are thought to participate in the cold-tolerant nature of hibernating animals. We previously demonstrated that an alternative splicing may allow rapid induction of functional cold-inducible RNA-binding protein (CIRBP) in the hamster heart. The purpose of the present study was to determine the major cause of the alternative splicing in Syrian hamsters. RT-PCR analysis revealed that CIRBP mRNA is constitutively expressed in the heart, brain, lung, liver, and kidney of nonhibernating euthermic hamsters with several alternative splicing variants. In contrast, the short variant containing an open-reading frame for functional CIRBP was dominantly found in the hibernating animals. Keeping the animals in a cold and dark environment did not cause a shift in the alternative splicing. Induction of hypothermia by central administration of an adenosine A1-receptor agonist reproduced the shift in the splicing pattern. However, the agonist failed to shift the pattern when body temperature was kept at 37°C, suggesting that central adenosine A1 receptors are not directly linked to the shift of the alternative splicing. Rapid reduction of body temperature to 10°C by isoflurane anesthesia combined with cooling did not alter the splicing pattern, but maintenance of mild hypothermia (~28°C) for 2 h elicited the shift in the pattern. The results suggest that animals need to be maintained at mild hypothermia for an adequate duration to induce the shift in the alternative splicing. This is applicable to natural hibernation because hamsters entering hibernation show a gradual decrease in body temperature, being maintained at mild hypothermia for several hours.
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Affiliation(s)
- Yuuki Horii
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University , Gifu , Japan
| | - Hiroki Shimaoka
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University , Gifu , Japan
| | - Kazuhiro Horii
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University , Gifu , Japan
| | - Takahiko Shiina
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University , Gifu , Japan
| | - Yasutake Shimizu
- Laboratory of Physiology, Department of Basic Veterinary Science, The United Graduate School of Veterinary Sciences, Gifu University , Gifu , Japan.,Center for Highly Advanced Integration of Nano and Life Sciences (G-CHAIN), Gifu University , Gifu , Japan
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Hibernating astronauts-science or fiction? Pflugers Arch 2018; 471:819-828. [PMID: 30569200 PMCID: PMC6533228 DOI: 10.1007/s00424-018-2244-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 11/29/2018] [Accepted: 12/03/2018] [Indexed: 12/13/2022]
Abstract
For long-duration manned space missions to Mars and beyond, reduction of astronaut metabolism by torpor, the metabolic state during hibernation of animals, would be a game changer: Water and food intake could be reduced by up to 75% and thus reducing payload of the spacecraft. Metabolic rate reduction in natural torpor is linked to profound changes in biochemical processes, i.e., shift from glycolysis to lipolysis and ketone utilization, intensive but reversible alterations in organs like the brain and kidney, and in heart rate control via Ca2+. This state would prevent degenerative processes due to organ disuse and increase resistance against radiation defects. Neuro-endocrine factors have been identified as main targets to induce torpor although the exact mechanisms are not known yet. The widespread occurrence of torpor in mammals and examples of human hypometabolic states support the idea of human torpor and its beneficial applications in medicine and space exploration.
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Horii Y, Shiina T, Shimizu Y. The Mechanism Enabling Hibernation in Mammals. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1081:45-60. [PMID: 30288703 DOI: 10.1007/978-981-13-1244-1_3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Some rodents including squirrels and hamsters undergo hibernation. During hibernation, body temperature drops to only a few degrees above ambient temperature. The suppression of whole-body energy expenditure is associated with regulated, but not passive, reduction of cellular metabolism. The heart retains the ability to beat constantly, although body temperature drops to less than 10 °C during hibernation. Cardiac myocytes of hibernating mammals are characterized by reduced Ca2+ entry into the cell membrane and a concomitant enhancement of Ca2+ release from and reuptake by the sarcoplasmic reticulum. These adaptive changes would help in preventing excessive Ca2+ entry and its overload and in maintaining the resting levels of intracellular Ca2+. Adaptive changes in gene expression in the heart prior to hibernation may be indispensable for acquiring cold resistance. In addition, protective effects of cold-shock proteins are thought to have an important role. We recently reported the unique expression pattern of cold-inducible RNA-binding protein (CIRP) in the hearts of hibernating hamsters. The CIRP mRNA is constitutively expressed in the heart of a nonhibernating euthermic hamster with several different forms probably due to alternative splicing. The short product contained the complete open reading frame for full-length CIRP, while the long product had inserted sequences containing a stop codon, suggesting production of a C-terminal deletion isoform of CIRP. In contrast to nonhibernating hamsters, only the short product was found in hibernating animals. Thus, these results indicate that CIRP expression in the hamster heart is regulated at the level of alternative splicing, which would permit a rapid increment of functional CIRP when entering hibernation. We will summarize the current understanding of the cold-resistant property of the heart in hibernating animals.
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Affiliation(s)
- Yuuki Horii
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Takahiko Shiina
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan
| | - Yasutake Shimizu
- Department of Basic Veterinary Science, Laboratory of Physiology, The United Graduate School of Veterinary Sciences, Gifu University, Gifu, Japan.
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