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Gao F, Zhang W, Cao M, Liu X, Han T, He W, Shi B, Gu Z. Maternal supplementation with konjac glucomannan improves maternal microbiota for healthier offspring during lactation. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:3736-3748. [PMID: 38234014 DOI: 10.1002/jsfa.13258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/19/2023] [Accepted: 01/01/2024] [Indexed: 01/19/2024]
Abstract
BACKGROUND The maternal diet during gestation and lactation affects the health of the offspring. Konjac glucomannan (KGM) is a significantly functional polysaccharide in food research, possessing both antioxidant and prebiotic properties. However, the mechanisms of how KGM regulates maternal nutrition remain insufficient and limited. This study aimed to investigate maternal supplementation with KGM during late gestation and lactation to benefit both maternal and offspring generations. RESULTS Our findings indicate that KGM improves serum low density lipoprotein cholesterol (LDL-C) and antioxidant capacity. Furthermore, the KGM group displayed a significant increase in the feed intake-related hormones neuropeptide tyrosine (NPY), Ghrelin, and adenosine monophosphate-activated kinase (AMPK) levels. KGM modified the relative abundance of Clostridium, Candidatus Saccharimonas, unclassified Firmicutes, and unclassified Christensenellaceae in sow feces. Acetate, valerate, and isobutyrate were also improved in the feces of sows in the KGM group. These are potential target bacterial genera that may modulate the host's health. Furthermore, Spearman's correlation analysis unveiled significant correlations between the altered bacteria genus and feed intake-related hormones. More importantly, KGM reduced interleukin-6 (IL-6) levels in milk, further improved IL-10 levels, and reduced zonulin levels in the serum of offspring. CONCLUSION In conclusion, maternal dietary supplementation with KGM during late gestation and lactation improves maternal nutritional status by modifying maternal microbial and increasing lactation feed intake, which benefits the anti-inflammatory capacity of the offspring serum. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Feng Gao
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Wentao Zhang
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Mingming Cao
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Xinyu Liu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Tingting Han
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Wei He
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Baoming Shi
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
| | - Zhigang Gu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, China
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Kamata T, Yamada S, Sekijima T. Differential AMPK-mediated metabolic regulation observed in hibernation-style polymorphisms in Siberian chipmunks. Front Physiol 2023; 14:1220058. [PMID: 37664438 PMCID: PMC10468594 DOI: 10.3389/fphys.2023.1220058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/07/2023] [Indexed: 09/05/2023] Open
Abstract
Hibernation is a unique physiological phenomenon allowing extreme hypothermia in endothermic mammals. Hypometabolism and hypothermia tolerance in hibernating animals have been investigated with particular interest; recently, studies of cultured cells and manipulation of the nervous system have made it possible to reproduce physiological states related to hypothermia induction. However, much remains unknown about the periodic regulation of hibernation. In particular, the physiological mechanisms facilitating the switch from an active state to a hibernation period, including behavioral changes and the acquisition of hypothermia tolerance remain to be elucidated. AMPK is a protein known to play a central role not only in feeding behavior but also in metabolic regulation in response to starvation. Our previous research has revealed that chipmunks activate AMPK in the brain during hibernation. However, whether AMPK is activated during winter in non-hibernating animals is unknown. Previous comparative studies between hibernating and non-hibernating animals have often been conducted between different species, consequently it has been impossible to account for the effects of phylogenetic differences. Our long-term monitoring of siberian chipmunks, has revealed intraspecific variation between those individuals that hibernate annually and those that never become hypothermic. Apparent differences were found between hibernating and non-hibernating types with seasonal changes in lifespan and blood HP levels. By comparing seasonal changes in AMPK activity between these polymorphisms, we clarified the relationship between hibernation and AMPK regulation. In hibernating types, phosphorylation of p-AMPK and p-ACC was enhanced throughout the brain during hibernation, indicating that AMPK-mediated metabolic regulation is activated. In non-hibernating types, AMPK and ACC were not seasonally activated. In addition, AMPK activation in the hypothalamus had already begun during high Tb before hibernation. Changes in AMPK activity in the brain during hibernation may be driven by circannual rhythms, suggesting a hibernation-regulatory mechanism involving AMPK activation independent of Tb. The differences in brain AMPK regulation between hibernators and non-hibernators revealed in this study were based on a single species thus did not involve phylogenetic differences, thereby supporting the importance of brain temperature-independent AMPK activation in regulating seasonal metabolism in hibernating animals.
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Affiliation(s)
- Taito Kamata
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
- Faculty of Agriculture, Niigata University, Niigata, Japan
| | - Shintaro Yamada
- Graduate School of Science and Technology, Niigata University, Niigata, Japan
- Institute of Biomedical Science, Kansai Medical University, Osaka, Japan
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Junkins MS, Bagriantsev SN, Gracheva EO. Towards understanding the neural origins of hibernation. J Exp Biol 2022; 225:273864. [PMID: 34982152 DOI: 10.1242/jeb.229542] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hibernators thrive under harsh environmental conditions instead of initiating canonical behavioral and physiological responses to promote survival. Although the physiological changes that occur during hibernation have been comprehensively researched, the role of the nervous system in this process remains relatively underexplored. In this Review, we adopt the perspective that the nervous system plays an active, essential role in facilitating and supporting hibernation. Accumulating evidence strongly suggests that the hypothalamus enters a quiescent state in which powerful drives to thermoregulate, eat and drink are suppressed. Similarly, cardiovascular and pulmonary reflexes originating in the brainstem are altered to permit the profoundly slow heart and breathing rates observed during torpor. The mechanisms underlying these changes to the hypothalamus and brainstem are not currently known, but several neuromodulatory systems have been implicated in the induction and maintenance of hibernation. The intersection of these findings with modern neuroscience approaches, such as optogenetics and in vivo calcium imaging, has opened several exciting avenues for hibernation research.
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Affiliation(s)
- Madeleine S Junkins
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.,Department of Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Sviatoslav N Bagriantsev
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
| | - Elena O Gracheva
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.,Department of Neuroscience and Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA
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Klevezal GA, Lobkov VA, Shchepotkin DV. Hibernation Records on the Surface of Rodent Incisors: Intraspecific Variations and Interspecific Differences. BIOL BULL+ 2021. [DOI: 10.1134/s1062359021090089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Chen S, Liu X, Peng C, Tan C, Sun H, Liu H, Zhang Y, Wu P, Cui C, Liu C, Yang D, Li Z, Lu J, Guan J, Ke X, Wang R, Bo X, Xu X, Han J, Liu J. The phytochemical hyperforin triggers thermogenesis in adipose tissue via a Dlat-AMPK signaling axis to curb obesity. Cell Metab 2021; 33:565-580.e7. [PMID: 33657393 DOI: 10.1016/j.cmet.2021.02.007] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 10/22/2020] [Accepted: 02/08/2021] [Indexed: 12/15/2022]
Abstract
Stimulation of adipose tissue thermogenesis is regarded as a promising avenue in the treatment of obesity. However, pharmacologic engagement of this process has proven difficult. Using the Connectivity Map (CMap) approach, we identified the phytochemical hyperforin (HPF) as an anti-obesity agent. We found that HPF efficiently promoted thermogenesis by stimulating AMPK and PGC-1α via a Ucp1-dependent pathway. Using LiP-SMap (limited proteolysis-mass spectrometry) combined with a microscale thermophoresis assay and molecular docking analysis, we confirmed dihydrolipoamide S-acetyltransferase (Dlat) as a direct molecular target of HPF. Ablation of Dlat significantly attenuated HPF-mediated adipose tissue browning both in vitro and in vivo. Furthermore, genome-wide association study analysis indicated that a variation in DLAT is significantly associated with obesity in humans. These findings suggest that HPF is a promising lead compound in the pursuit of a pharmacological approach to promote energy expenditure in the treatment of obesity.
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Affiliation(s)
- Suzhen Chen
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China; Department of Otolaryngology Head and Neck Surgery & Center of Sleep Medicine, Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China.
| | - Xiaoxiao Liu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, China
| | - Chao Peng
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Science, Shanghai 201210, China
| | - Chang Tan
- Department of Chemistry, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China
| | - Honglin Sun
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China
| | - He Liu
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China
| | - Yao Zhang
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China
| | - Ping Wu
- National Facility for Protein Science in Shanghai, Zhangjiang Lab, Shanghai Advanced Research Institute, Chinese Academy of Science, Shanghai 201210, China
| | - Can Cui
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Chuchu Liu
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China
| | - Di Yang
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China
| | - Zhiqiang Li
- Affiliated Hospital of Qingdao University and Biomedical Sciences Institute of Qingdao University, Qingdao University, Qingdao, China
| | - Junxi Lu
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China
| | - Jian Guan
- Department of Otolaryngology Head and Neck Surgery & Center of Sleep Medicine, Shanghai Key Laboratory of Sleep Disordered Breathing, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China
| | - Xisong Ke
- Center for Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Renxiao Wang
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Xiaohai Bo
- Department of Chemistry, Shanghai Normal University, 100 Guilin Road, Shanghai 200234, China
| | - Xiaojun Xu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 210009, China.
| | - Junfeng Han
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China.
| | - Junli Liu
- Shanghai Diabetes Institute, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 200233 Shanghai, China.
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Kinnunen SME, Mänttäri SK, Saarela SYO. Expression of AMPK, SIRT1, and ACC Differs between Winter- and Summer-Acclimatized Djungarian Hamsters. Physiol Biochem Zool 2017; 90:605-612. [DOI: 10.1086/694295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Heim AB, Chung D, Florant GL, Chicco AJ. Tissue-specific seasonal changes in mitochondrial function of a mammalian hibernator. Am J Physiol Regul Integr Comp Physiol 2017; 313:R180-R190. [DOI: 10.1152/ajpregu.00427.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 05/03/2017] [Accepted: 05/25/2017] [Indexed: 01/09/2023]
Abstract
Mammalian hibernators, such as golden-mantled ground squirrels ( Callospermophilus lateralis; GMGS), cease to feed while reducing metabolic rate and body temperature during winter months, surviving exclusively on endogenous fuels stored before hibernation. We hypothesized that mitochondria, the cellular sites of oxidative metabolism, undergo tissue-specific seasonal adjustments in carbohydrate and fatty acid utilization to facilitate or complement this remarkable phenotype. To address this, we performed high-resolution respirometry of mitochondria isolated from GMGS liver, heart, skeletal muscle, and brown adipose tissue (BAT) sampled during summer (active), fall (prehibernation), and winter (hibernation) seasons using multisubstrate titration protocols. Mitochondrial phospholipid composition was examined as a postulated intrinsic modulator of respiratory function across tissues and seasons. Respirometry revealed seasonal variations in mitochondrial oxidative phosphorylation capacity, substrate utilization, and coupling efficiency that reflected the distinct functions and metabolic demands of the tissues they support. A consistent finding across tissues was a greater influence of fatty acids (palmitoylcarnitine) on respiratory parameters during the prehibernation and hibernation seasons. In particular, fatty acids had a greater suppressive effect on pyruvate-supported oxidative phosphorylation in heart, muscle, and liver mitochondria and enhanced uncoupled respiration in BAT and muscle mitochondria in the colder seasons. Seasonal variations in the mitochondrial membrane composition reflected changes in the supply and utilization of polyunsaturated fatty acids but were generally mild and inconsistent with functional variations. In conclusion, mitochondria respond to seasonal variations in physical activity, temperature, and nutrient availability in a tissue-specific manner that complements circannual shifts in the bioenergetic and thermoregulatory demands of mammalian hibernators.
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Affiliation(s)
- Ashley B. Heim
- Department of Biology, Colorado State University, Fort Collins, Colorado
| | - Dillon Chung
- Department of Zoology, University of British Colombia, Vancouver, British Columbia, Canada; and
| | - Gregory L. Florant
- Department of Biology, Colorado State University, Fort Collins, Colorado
| | - Adam J. Chicco
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado
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Abstract
Extended bouts of fasting are ingrained in the ecology of many organisms, characterizing aspects of reproduction, development, hibernation, estivation, migration, and infrequent feeding habits. The challenge of long fasting episodes is the need to maintain physiological homeostasis while relying solely on endogenous resources. To meet that challenge, animals utilize an integrated repertoire of behavioral, physiological, and biochemical responses that reduce metabolic rates, maintain tissue structure and function, and thus enhance survival. We have synthesized in this review the integrative physiological, morphological, and biochemical responses, and their stages, that characterize natural fasting bouts. Underlying the capacity to survive extended fasts are behaviors and mechanisms that reduce metabolic expenditure and shift the dependency to lipid utilization. Hormonal regulation and immune capacity are altered by fasting; hormones that trigger digestion, elevate metabolism, and support immune performance become depressed, whereas hormones that enhance the utilization of endogenous substrates are elevated. The negative energy budget that accompanies fasting leads to the loss of body mass as fat stores are depleted and tissues undergo atrophy (i.e., loss of mass). Absolute rates of body mass loss scale allometrically among vertebrates. Tissues and organs vary in the degree of atrophy and downregulation of function, depending on the degree to which they are used during the fast. Fasting affects the population dynamics and activities of the gut microbiota, an interplay that impacts the host's fasting biology. Fasting-induced gene expression programs underlie the broad spectrum of integrated physiological mechanisms responsible for an animal's ability to survive long episodes of natural fasting.
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Affiliation(s)
- Stephen M Secor
- Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama, USA
| | - Hannah V Carey
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
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9
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Kinnunen S, Mänttäri S, Herzig KH, Nieminen P, Mustonen AM, Saarela S. Effects of wintertime fasting and seasonal adaptation on AMPK and ACC in hypothalamus, adipose tissue and liver of the raccoon dog (Nyctereutes procyonoides). Comp Biochem Physiol A Mol Integr Physiol 2015; 192:44-51. [PMID: 26603554 DOI: 10.1016/j.cbpa.2015.11.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 11/11/2015] [Accepted: 11/16/2015] [Indexed: 12/25/2022]
Abstract
The raccoon dog (Nyctereutes procyonoides) is a canid with autumnal fattening and passive wintering strategy. We examined the effects of wintertime fasting and seasonality on AMP-activated protein kinase (AMPK), a regulator of metabolism, and its target, acetyl-CoA carboxylase (ACC) on the species. Twelve farmed raccoon dogs (eleven females/one male) were divided into two groups: half were fasted for ten weeks in December-March (winter fasted) and the others were fed ad libitum (winter fed). A third group (autumn fed, eight females) was fed ad libitum and sampled in December. Total AMPK, ACC and their phosphorylated forms (pAMPK, pACC) were measured from hypothalamus, liver, intra-abdominal (iWAT) and subcutaneous white adipose tissues (sWAT). The fasted animals lost 32% and the fed 20% of their body mass. Hypothalamic AMPK expression was lower and pACC levels higher in the winter groups compared to the autumn fed group. Liver pAMPK was lower in the winter fasted group, with consistently decreased ACC and pACC. AMPK and pAMPK were down-regulated in sWAT and iWAT of both winter groups, with a parallel decline in pACC in sWAT. The responses of AMPK and ACC to fasting were dissimilar to the effects observed previously in non-seasonal mammals and hibernators. Differences between the winter fed and autumn fed groups indicate that the functions of AMPK and ACC could be regulated in a season-dependent manner. Furthermore, the distinctive effects of prolonged fasting and seasonal adaptation on AMPK-ACC pathway could contribute to the wintering strategy of the raccoon dog.
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Affiliation(s)
- Sanni Kinnunen
- Department of Biology, University of Oulu, P.O. Box 3000, FI-90014, University of Oulu, Finland.
| | - Satu Mänttäri
- Finnish Institute of Occupational Health, Aapistie 1, FI-90220 Oulu, Finland
| | - Karl-Heinz Herzig
- Institute of Biomedicine, Biocenter Oulu, P.O. Box 5000, FI-90014, University of Oulu, Finland; Medical Research Center Oulu and Oulu University Hospital, Kajaanintie 50, FI-90220 Oulu, Finland
| | - Petteri Nieminen
- Institute of Biomedicine/Anatomy, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland; Department of Biology, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - Anne-Mari Mustonen
- Institute of Biomedicine/Anatomy, School of Medicine, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland; Department of Biology, Faculty of Science and Forestry, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - Seppo Saarela
- Department of Biology, University of Oulu, P.O. Box 3000, FI-90014, University of Oulu, Finland
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Induction of a Torpor-Like State by 5'-AMP Does Not Depend on H2S Production. PLoS One 2015; 10:e0136113. [PMID: 26295351 PMCID: PMC4546583 DOI: 10.1371/journal.pone.0136113] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 07/29/2015] [Indexed: 01/11/2023] Open
Abstract
Background Therapeutic hypothermia is used to reduce ischemia/reperfusion injury (IRI) during organ transplantation and major surgery, but does not fully prevent organ injury. Interestingly, hibernating animals undergo repetitive periods of low body temperature called ‘torpor’ without signs of organ injury. Recently, we identified an essential role of hydrogen sulfide (H2S) in entrance into torpor and preservation of kidney integrity during hibernation. A torpor-like state can be induced pharmacologically by injecting 5’-Adenosine monophosphate (5’-AMP). The mechanism by which 5’-AMP leads to the induction of a torpor-like state, and the role of H2S herein, remains to be unraveled. Therefore, we investigated whether induction of a torpor-like state by 5-AMP depends on H2S production. Methods To study the role of H2S on the induction of torpor, amino-oxyacetic acid (AOAA), a non-specific inhibitor of H2S, was administered before injection with 5'-AMP to block endogenous H2S production in Syrian hamster. To assess the role of H2S on maintenance of torpor induced by 5’-AMP, additional animals were injected with AOAA during torpor. Key Results During the torpor-like state induced by 5’-AMP, the expression of H2S- synthesizing enzymes in the kidneys and plasma levels of H2S were increased. Blockade of these enzymes inhibited the rise in the plasma level of H2S, but neither precluded torpor nor induced arousal. Remarkably, blockade of endogenous H2S production was associated with increased renal injury. Conclusions Induction of a torpor-like state by 5’-AMP does not depend on H2S, although production of H2S seems to attenuate renal injury. Unraveling the mechanisms by which 5’-AMP reduces the metabolism without organ injury may allow optimization of current strategies to limit (hypothermic) IRI and improve outcome following organ transplantation, major cardiac and brain surgery.
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Doherty AH, Florant GL, Donahue SW. Endocrine regulation of bone and energy metabolism in hibernating mammals. Integr Comp Biol 2014; 54:463-83. [PMID: 24556365 DOI: 10.1093/icb/icu001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Precise coordination among organs is required to maintain homeostasis throughout hibernation. This is particularly true in balancing bone remodeling processes (bone formation and resorption) in hibernators experiencing nutritional deprivation and extreme physical inactivity, two factors normally leading to pronounced bone loss in non-hibernating mammals. In recent years, important relationships between bone, fat, reproductive, and brain tissues have come to light. These systems share interconnected regulatory mechanisms of energy metabolism that potentially protect the skeleton during hibernation. This review focuses on the endocrine and neuroendocrine regulation of bone/fat/energy metabolism in hibernators. Hibernators appear to have unique mechanisms that protect musculoskeletal tissues while catabolizing their abundant stores of fat. Furthermore, the bone remodeling processes that normally cause disuse-induced bone loss in non-hibernators are compared to bone remodeling processes in hibernators, and possible adaptations of the bone signaling pathways that protect the skeleton during hibernation are discussed. Understanding the biological mechanisms that allow hibernators to survive the prolonged disuse and fasting associated with extreme environmental challenges will provide critical information regarding the limit of convergence in mammalian systems and of skeletal plasticity, and may contribute valuable insight into the etiology and treatment of human diseases.
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Affiliation(s)
- Alison H Doherty
- *Department of Biology, Colorado State University, Fort Collins, CO 80523-1620, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523-1620, USA*Department of Biology, Colorado State University, Fort Collins, CO 80523-1620, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523-1620, USA
| | - Gregory L Florant
- *Department of Biology, Colorado State University, Fort Collins, CO 80523-1620, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523-1620, USA
| | - Seth W Donahue
- *Department of Biology, Colorado State University, Fort Collins, CO 80523-1620, USA; Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523-1620, USA
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12
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Body temperature patterns and use of torpor in an alpine glirid species, woolly dormouse. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s13364-013-0154-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Bouma HR, Verhaag EM, Otis JP, Heldmaier G, Swoap SJ, Strijkstra AM, Henning RH, Carey HV. Induction of torpor: mimicking natural metabolic suppression for biomedical applications. J Cell Physiol 2012; 227:1285-90. [PMID: 21618525 DOI: 10.1002/jcp.22850] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mammalian hibernation consists of periods of depressed metabolism and reduced body temperature called "torpor" that are interspersed by normothermic arousal periods. Numerous cellular processes are halted during torpor, including transcription, translation, and ion homeostasis. Hibernators are able to survive long periods of low blood flow and body temperature followed by rewarming and reperfusion without overt signs of organ injury, which makes these animals excellent models for application of natural protective mechanisms to human medicine. This review examines efforts to induce torpor-like states in non-hibernating species using pharmacological compounds. Elucidating the underlying mechanisms of natural and pharmacologically induced torpor will speed the development of new clinical approaches to treat a variety of trauma and stress states in humans.
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Affiliation(s)
- Hjalmar R Bouma
- Department of Clinical Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
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Florant GL, Healy JE. The regulation of food intake in mammalian hibernators: a review. J Comp Physiol B 2011; 182:451-67. [PMID: 22080368 DOI: 10.1007/s00360-011-0630-y] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Revised: 10/20/2011] [Accepted: 10/29/2011] [Indexed: 12/20/2022]
Abstract
One of the most profound hallmarks of mammalian hibernation is the dramatic reduction in food intake during the winter months. Several species of hibernator completely cease food intake (aphagia) for nearly 7 months regardless of ambient temperature and in many cases, whether or not food is available to them. Food intake regulation has been studied in mammals that hibernate for over 50 years and still little is known about the physiological mechanisms that control this important behavior in hibernators. It is well known from lesion experiments in non-hibernators that the hypothalamus is the main brain region controlling food intake and therefore body mass. In hibernators, the regulation of food intake and body mass is presumably governed by a circannual rhythm since there is a clear seasonal rhythm to food intake: animals increase food intake in the summer and early autumn, food intake declines in autumn and actually ceases in winter in many species, and resumes again in spring as food becomes available in the environment. Changes in circulating hormones (e.g., leptin, insulin, and ghrelin), nutrients (glucose, and free fatty acids), and cellular enzymes such as AMP-activated protein kinase (AMPK) have been shown to determine the activity of neurons involved in the food intake pathway. Thus, it appears likely that the food intake pathway is controlled by a variety of inputs, but is also acted upon by upstream regulators that are presumably rhythmic in nature. Current research examining the molecular mechanisms and integration of environmental signals (e.g., temperature and light) with these molecular mechanisms will hopefully shed light on how animals can turn off food intake and survive without eating for months on end.
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Affiliation(s)
- Gregory L Florant
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA.
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15
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Tanida M, Yamamoto N. Central AMP-activated protein kinase affects sympathetic nerve activity in rats. Neurosci Lett 2011; 503:167-70. [PMID: 21893163 DOI: 10.1016/j.neulet.2011.08.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 07/21/2011] [Accepted: 08/09/2011] [Indexed: 02/02/2023]
Abstract
In this study, we examined the effect of intracerebroventricular (ICV) injection of 5-aminoimidazole-4-carboxamide 1-beta-d-ribofuranoside (AICAR), an AMP-activated protein kinase (AMPK) activator, or compound C (CC), an AMPK inhibitor, on the activity of sympathetic nerves innervating the adrenal gland and kidney in urethane-anesthetized rats to elucidate the role of AMPK in sympathetic nervous system function. We found that an ICV injection of AICAR or CC significantly stimulated renal sympathetic nerve activity (RSNA) and adrenal sympathetic nerve activity (ASNA) in a dose-dependent manner. Following this, we examined the role of AMPK on the sympatho-excitation caused by leptin injection. Pretreatment with AICAR or CC eliminated the leptin-induced increase in RSNA, however, neither pretreatment with AICAR or CC affected the leptin-induced increase in ASNA. Our data suggest that AMPK may regulate the sympathetic nerve system, and that the stimulating effect of leptin on sympathetic nerve activity in kidney may depend on central AMPK.
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Affiliation(s)
- Mamoru Tanida
- Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga 525-8577, Japan.
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Ju TC, Chen HM, Lin JT, Chang CP, Chang WC, Kang JJ, Sun CP, Tao MH, Tu PH, Chang C, Dickson DW, Chern Y. Nuclear translocation of AMPK-alpha1 potentiates striatal neurodegeneration in Huntington's disease. ACTA ACUST UNITED AC 2011; 194:209-27. [PMID: 21768291 PMCID: PMC3144412 DOI: 10.1083/jcb.201105010] [Citation(s) in RCA: 151] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Adenosine monophosphate-activated protein kinase (AMPK) is a major energy sensor that maintains cellular energy homeostasis. Huntington's disease (HD) is a neurodegenerative disorder caused by the expansion of CAG repeats in the huntingtin (Htt) gene. In this paper, we report that activation of the α1 isoform of AMPK (AMPK-α1) occurred in striatal neurons of humans and mice with HD. Overactivation of AMPK in the striatum caused brain atrophy, facilitated neuronal loss, and increased formation of Htt aggregates in a transgenic mouse model (R6/2) of HD. Such nuclear accumulation of AMPK-α1 was activity dependent. Prevention of nuclear translocation or inactivation of AMPK-α1 ameliorated cell death and down-regulation of Bcl2 caused by mutant Htt (mHtt). Conversely, enhanced expression of Bcl2 protected striatal cells from the toxicity evoked by mHtt and AMPK overactivation. These data demonstrate that aberrant activation of AMPK-α1 in the nuclei of striatal cells represents a new toxic pathway induced by mHtt.
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Affiliation(s)
- Tz-Chuen Ju
- Institute of Neuroscience and 2 Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang Ming University, Taipei 112, Taiwan
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Li J, Benashski S, McCullough LD. Post-stroke hypothermia provides neuroprotection through inhibition of AMP-activated protein kinase. J Neurotrauma 2011; 28:1281-8. [PMID: 21446786 DOI: 10.1089/neu.2011.1751] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Hypothermia is robustly protective in pre-clinical models of both global and focal ischemia, as well as in patients after cardiac arrest. Although the mechanism for hypothermic neuroprotection remains unknown, reducing metabolic drive may play a role. Capitalizing on the beneficial effects of hypothermia while avoiding detrimental effects such as infection will be the key to moving this therapy forward as a treatment for stroke. AMPK is a master energy sensor that monitors levels of key energy metabolites. AMPK is activated via phosphorylation (pAMPK) when cellular energy levels are low, such as that seen during ischemia. AMPK activation appears to be detrimental in experimental stroke, likely via exacerbating ischemia-induced metabolic failure. We tested the hypothesis that hypothermia reduces AMPK activation. First, it was found that hypothermia reduced infarct after middle cerebral artery occlusion. Second, induced hypothermia reduced brain pAMPK in both sham control and stroke mice. Third, hypothermic neuroprotection was ameliorated after administration of compound C, an AMPK inhibitor. Finally, deletion of one of the catalytic isoforms of AMPK completely reversed the effect of hypothermia on stroke outcome after both acute and chronic survival. These effects were mediated by a reduction in AMPK activation rather than a reduction in LKB1, an upstream AMPK kinase. In summary, these studies provide evidence that hypothermia exerts its protective effect in part by inhibiting AMPK activation in experimental focal stroke. This suggests that AMPK represents a potentially important biological target for stroke treatment.
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Affiliation(s)
- Jun Li
- Department of Neuroscience, University of Connecticut Health Center, Farmington, CT 06030, USA
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Otis JP, Raybould HE, Carey HV. Cholecystokinin activation of central satiety centers changes seasonally in a mammalian hibernator. Gen Comp Endocrinol 2011; 171:269-74. [PMID: 21362421 PMCID: PMC4441800 DOI: 10.1016/j.ygcen.2011.02.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 02/09/2011] [Accepted: 02/22/2011] [Indexed: 12/24/2022]
Abstract
Hibernators that rely on lipids during winter exhibit profound changes in food intake over the annual cycle. The mechanisms that regulate appetite changes in seasonal hibernators remain unclear, but likely consist of complex interactions between gut hormones, adipokines, and central processing centers. We hypothesized that seasonal changes in the sensitivity of neurons in the nucleus tractus solitarius (NTS) to the gut hormone cholecystokinin (CCK) may contribute to appetite regulation in ground squirrels. Spring (SPR), late summer (SUM), and winter euthermic hibernating (HIB) 13-lined ground squirrels (Ictidomys tridecemlineatus) were treated with intraperitoneal CCK (100 μg/kg) or vehicle (CON) for 3h and Fos expression in the NTS was quantified. In CON squirrels, numbers of Fos-positive neurons in HIB were low compared to SPR and SUM. CCK treatment increased Fos-positive neurons in the NTS at the levels of the area postrema (AP) and pre AP during all seasons and at the level of the rostral AP in HIB squirrels. The highest absolute levels of Fos-positive neurons were found in SPR CCK squirrels, but the highest relative increase from CON was found in HIB CCK squirrels. Fold-changes in Fos-positive neurons in SUM were intermediate between SPR and HIB. Thus, CCK sensitivity falls from SPR to SUM suggesting that seasonal changes in sensitivity of NTS neurons to vagally-derived CCK may influence appetite in the active phase of the annual cycle in hibernating squirrels. Enhanced sensitivity to CCK signaling in NTS neurons of hibernators indicates that changes in gut-brain signaling may contribute to seasonal changes in food intake during the annual cycle.
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Affiliation(s)
- Jessica P. Otis
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Dr., Madison, WI 53706, USA
| | - Helen E. Raybould
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California-Davis, 1321 Haring Hall, Davis, CA 95616, USA
| | - Hannah V. Carey
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Dr., Madison, WI 53706, USA
- Corresponding author: Fax: +1 608 263 3926. (H.V. Carey)
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Xu P, Siegel PB, Denbow DM. AICAR and Compound C regulate food intake independently of AMP-activated protein kinase in lines of chickens selected for high or low body weight. Comp Biochem Physiol A Mol Integr Physiol 2011; 159:401-12. [PMID: 21530673 DOI: 10.1016/j.cbpa.2011.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 04/08/2011] [Accepted: 04/12/2011] [Indexed: 02/07/2023]
Abstract
AMP-activated protein kinase (AMPK) functions to maintain cellular and body energy balance. Our aim was to investigate the effect of intracerebroventricular (ICV) administration of AMPK stimulator AICAR and AMPK inhibitor Compound C on food intake in lines of chickens that had undergone long-term selection from a common founder population for high (HWS) or low (LWS) body weight. AICAR caused a quadratic dose-dependent decrease in food intake in LWS but not HWS chicks. Compound C caused a quadratic dose-dependent increase in food intake in HWS but not in LWS chicks. Key aspects of the AMPK pathway, including upstream kinases mRNA expression, AMPK subunit α mRNA expression and phosphorylation, and a downstream target acetyl CoA carboxylase (ACC) phosphorylation were not affected by either AICAR or Compound C in either line. The exception was a significant inhibitory effect of AICAR on ACC phosphorylation ratio due to increased total ACC protein content without changing phosphorylated ACC protein levels. Thus, the anorexigenic effect of AICAR in LWS chicks and orexigenic effect of Compound C in HWS chicks resulted from activation or inhibition of other kinase pathways separate from AMPK. These results suggest genetic variation in feeding response for central AICAR and Compound C in chickens, which may contribute to the different body weights between the HWS and LWS lines.
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Affiliation(s)
- Pingwen Xu
- Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0306, USA
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Healy JE, Gearhart CN, Bateman JL, Handa RJ, Florant GL. AMPK and ACCchange with fasting and physiological condition in euthermic and hibernating golden-mantled ground squirrels (Callospermophilus lateralis). Comp Biochem Physiol A Mol Integr Physiol 2011; 159:322-31. [PMID: 21473923 DOI: 10.1016/j.cbpa.2011.03.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Revised: 03/25/2011] [Accepted: 03/28/2011] [Indexed: 10/18/2022]
Abstract
AMP-activated protein kinase (AMPK) is a cellular energy sensor that responds to low endogenous energy by stimulating fatty acid oxidation (through inactivation of acetyl-CoA carboxylase (ACC)) and food intake. Fasting generally stimulates phosphorylation of AMPK (pAMPK) and ACC (pACC), but it is unclear how AMPK and ACC react to a long-term fast (i.e. hibernation). We performed Western blots for total and pAMPK and pACC on tissues from a species of hibernator (Callospermophilus lateralis) after short-term summer fasting (1-5 days) and long-term winter fasting (3 months). Winter animals were sacrificed during hibernation at low body temperature (torpid, T(b)~5°C) or at normal high T(b)(euthermic, T(b)~37°C). We found a general increase in pAMPK in most tissues (liver, muscle, and white adipose tissue (WAT), but not hypothalamus) and pACC in all tissues after a short-term summer fast. Response of AMPK and ACC to a long-term winter fast differed by tissue-in liver, there was no difference in total or pAMPK or pACC between groups, but in muscle, WAT and BAT, euthermic GMGS had lower relative abundance of pAMPK and pACC than torpid animals. Therefore, AMPK may be an important energy sensor at all points in hibernator's circannual cycles of food intake and T(b).
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Affiliation(s)
- Jessica E Healy
- Department of Biology, Colorado State University, Fort Collins, CO, USA.
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Healy JE, Bateman JL, Ostrom CE, Florant GL. Peripheral ghrelin stimulates feeding behavior and positive energy balance in a sciurid hibernator. Horm Behav 2011; 59:512-9. [PMID: 21310157 PMCID: PMC3081408 DOI: 10.1016/j.yhbeh.2011.01.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Revised: 01/17/2011] [Accepted: 01/31/2011] [Indexed: 01/23/2023]
Abstract
Hibernators exhibit a robust circannual cycle of body mass gain and loss primarily mediated by food intake, but the pathways controlling food intake in these animals have not been fully elucidated. Ghrelin is an orexigenic hormone that increases feeding in all mammals studied so far, but has not until recently been studied in hibernators. In other mammals, ghrelin stimulates feeding through phosphorylation and activation of AMP-activated protein kinase (AMPK). Activation of AMPK phosphorylates and deactivates acetyl Co-A carboxylase (ACC), a committed step in fatty acid synthesis. In order to determine the effects of exogenous ghrelin on food intake and metabolic factors (i.e. non-esterified fatty acids (NEFAs), and hypothalamic AMPK and ACC) in hibernators, ghrelin was peripherally injected into ground squirrels in all four seasons. Changes in food intake and body mass were recorded over a 2-6 hour period post injections, and squirrels were euthanized. Brains and blood were removed, and Western blots were performed to determine changes in phosphorylation of hypothalamic AMPK and ACC. A colorimetric assay was used to determine changes in concentration of serum NEFAs. We found that food intake, body mass, and locomotor activity significantly increased with ghrelin injections versus saline-injected controls, even in animals injected during their aphagic winter season. Injected ghrelin was correlated with increased phosphorylation of AMPK, but didn't have an effect on ACC in winter. Ghrelin-injected animals also had increased levels of serum NEFAs compared with saline controls. This study is the first to show an effect of injected ghrelin on a hibernator.
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Affiliation(s)
- Jessica E Healy
- Department of Biology, Colorado State University, Fort Collins, CO 85023, USA.
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Knight K. AMPK ACTIVATOR ACTIVATES HIBERNATOR'S APPETITE. J Exp Biol 2010. [DOI: 10.1242/jeb.046672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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