1
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Wang Y, Li Y, Li N, Li Y, Li H, Zhang D. Protective nutrition strategy in the acute phase of critical illness: why, what and how to protect. Front Nutr 2025; 12:1555311. [PMID: 40416376 PMCID: PMC12098084 DOI: 10.3389/fnut.2025.1555311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2025] [Accepted: 04/17/2025] [Indexed: 05/27/2025] Open
Abstract
Nutritional support is crucial for critically ill patients. Recent clinical studies suggest that both overfeeding during the acute phase of critical illness and overly conservative or delayed nutritional therapy can pose significant risks. Given substantial individual variability among critically ill patients, it is challenging to prescribe universally applicable and objective feeding strategies; Instead, we pointed out which nutritional interventions were harmful. We also summarized the reasons for protective nutrition, and elaborated the advantages of protective nutrition from three perspectives: gastrointestinal protection, nutritional protection and metabolic protection. In particular, it is emphasized that overfeeding will lead to metabolic disorders, such as mitochondrial dysfunction, autophagy inhibition, ketogenic inhibition, hyperglycemia, insulin resistance, etc. These detrimental processes can exacerbate one another, contributing to multiple organ dysfunction syndrome and poorer clinical outcomes. We also propose protective nutrition strategies comparable to lung protective ventilation strategies, which may benefit patients. Vigilant monitoring during nutritional implementation is also paramount, enhancing awareness of adverse events for early diagnosis and intervention to mitigate their harm.
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Affiliation(s)
| | | | | | | | | | - Dong Zhang
- Department of Critical Care Medicine, The First Hospital of Jilin University, Changchun, China
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2
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Ranea-Robles P, Lund C, Svendsen C, Gil C, Lund J, Kleinert M, Clemmensen C. Time-Resolved Effects of Short-term Overfeeding on Energy Balance in Mice. Diabetes 2025; 74:502-513. [PMID: 39787442 PMCID: PMC11926271 DOI: 10.2337/db24-0289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 01/06/2025] [Indexed: 01/12/2025]
Abstract
ARTICLE HIGHLIGHTS Intragastric overfeeding reveals insights into the homeostatic recovery from experimental weight gain. Protection against short-term, overfeeding-induced weight gain primarily involves a profound reduction in food intake and possibly an adaptive increase in energy expenditure. UCP1-mediated thermogenesis is not essential for homeostatic protection against short-term, overfeeding-induced weight gain.
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Affiliation(s)
- Pablo Ranea-Robles
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, Granada, Spain
- Centro de Investigación Biomédica, Universidad de Granada, Granada, Spain
- Instituto de Investigación Biosanitaria, Granada, Spain
| | - Camilla Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Charlotte Svendsen
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Cláudia Gil
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Jens Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Maximilian Kleinert
- German Center for Diabetes Research (DZD), Munich-Neuherberg, Germany
- Department of Molecular Physiology of Exercise and Nutrition, German Institute of Human Nutrition, Potsdam-Rehbruecke, Nuthetal, Germany
| | - Christoffer Clemmensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
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3
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Friedman MI, Sørensen TIA, Taubes G, Lund J, Ludwig DS. Trapped fat: Obesity pathogenesis as an intrinsic disorder in metabolic fuel partitioning. Obes Rev 2024; 25:e13795. [PMID: 38961319 DOI: 10.1111/obr.13795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 05/24/2024] [Accepted: 06/13/2024] [Indexed: 07/05/2024]
Abstract
Our understanding of the pathophysiology of obesity remains at best incomplete despite a century of research. During this time, two alternative perspectives have helped shape thinking about the etiology of the disorder. The currently prevailing view holds that excessive fat accumulation results because energy intake exceeds energy expenditure, with excessive food consumption being the primary cause of the imbalance. The other perspective attributes the initiating cause of obesity to intrinsic metabolic defects that shift fuel partitioning from pathways for mobilization and oxidation to those for synthesis and storage. The resulting reduction in fuel oxidation and trapping of energy in adipose tissue drives a compensatory increase in energy intake and, under some conditions, a decrease in expenditure. This theory of obesity pathogenesis has historically garnered relatively less attention despite its pedigree. Here, we present an updated comprehensive formulation of the fuel partitioning theory, focused on evidence gathered over the last 80 years from major animal models of obesity showing a redirection of fuel fluxes from oxidation to storage and accumulation of excess body fat with energy intake equal to or even less than that of lean animals. The aim is to inform current discussions about the etiology of obesity and by so doing, help lay new foundations for the design of more efficacious approaches to obesity research, treatment and prevention.
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Affiliation(s)
| | - Thorkild I A Sørensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
- Center for Childhood Health, Copenhagen, Denmark
| | | | - Jens Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - David S Ludwig
- New Balance Foundation Obesity Prevention Center, Boston Children's Hospital, Department of Pediatrics, Harvard Medical School, Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
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4
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Mahmoodi M, Mirzarazi Dahagi E, Nabavi M, Penalva YCM, Gosaine A, Murshed M, Couldwell S, Munter LM, Kaartinen MT. Circulating plasma fibronectin affects tissue insulin sensitivity, adipocyte differentiation, and transcriptional landscape of adipose tissue in mice. Physiol Rep 2024; 12:e16152. [PMID: 39054559 PMCID: PMC11272447 DOI: 10.14814/phy2.16152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Revised: 07/05/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
Plasma fibronectin (pFN) is a hepatocyte-derived circulating extracellular matrix protein that affects cell morphology, adipogenesis, and insulin signaling of adipocytes in vitro. In this study, we show pFN accrual to adipose tissue and its contribution to tissue homeostasis in mice. Hepatocyte-specific conditional Fn1 knockout mice (Fn1-/-ALB) show a decrease in adipose tissue FN levels and enhanced insulin sensitivity of subcutaneous (inguinal), visceral (epididymal) adipose tissue on a normal diet. Diet-induced obesity model of the Fn1-/-ALB mouse showed normal weight gain and whole-body fat mass, and normal adipose tissue depot volumes and unaltered circulating leptin and adiponectin levels. However, Fn1-/-ALB adipose depots showed significant alterations in adipocyte size and gene expression profiles. The inguinal adipose tissue on a normal diet, which had alterations in fatty acid metabolism and thermogenesis suggesting browning. The presence of increased beige adipocyte markers Ucp1 and Prdm16 supported this. In the inguinal fat, the obesogenic diet resulted in downregulation of the browning markers and changes in gene expression reflecting development, morphogenesis, and mesenchymal stem cell maintenance. Epididymal adipose tissue showed alterations in developmental and stem cell gene expression on both diets. The data suggests a role for pFN in adipose tissue insulin sensitivity and cell profiles.
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Affiliation(s)
- Mahdokht Mahmoodi
- Faculty of Dental Medicine and Oral Health Sciences (Biomedical Sciences)McGill UniversityMontrealQuebecCanada
| | - Elahe Mirzarazi Dahagi
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health SciencesMcGill UniversityMontrealQuebecCanada
| | - Mir‐Hamed Nabavi
- Faculty of Dental Medicine and Oral Health Sciences (Biomedical Sciences)McGill UniversityMontrealQuebecCanada
| | - Ylauna C. M. Penalva
- Department of Pharmacology & Therapeutics, Faculty of Medicine and Health SciencesMcGill UniversityMontrealQuebecCanada
- Centre de Recherche en Biologie Structurale (CRBS)McGill UniversityMontrealQuebecCanada
| | - Amrita Gosaine
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health SciencesMcGill UniversityMontrealQuebecCanada
| | - Monzur Murshed
- Faculty of Dental Medicine and Oral Health Sciences (Biomedical Sciences)McGill UniversityMontrealQuebecCanada
- Shriners Hospital for ChildrenMontrealQuebecCanada
| | - Sandrine Couldwell
- Faculty of Dental Medicine and Oral Health Sciences (Biomedical Sciences)McGill UniversityMontrealQuebecCanada
| | - Lisa M. Munter
- Department of Pharmacology & Therapeutics, Faculty of Medicine and Health SciencesMcGill UniversityMontrealQuebecCanada
- Centre de Recherche en Biologie Structurale (CRBS)McGill UniversityMontrealQuebecCanada
| | - Mari T. Kaartinen
- Faculty of Dental Medicine and Oral Health Sciences (Biomedical Sciences)McGill UniversityMontrealQuebecCanada
- Department of Anatomy and Cell Biology, Faculty of Medicine and Health SciencesMcGill UniversityMontrealQuebecCanada
- Department of Medicine (Division of Experimental Medicine), Faculty of Medicine and Health SciencesMcGill UniversityMontrealQuebecCanada
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5
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Possa-Paranhos IC, Butts J, Pyszka E, Nelson C, Cho D, Sweeney P. Neuroanatomical dissection of the MC3R circuitry regulating energy rheostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.22.590573. [PMID: 38712101 PMCID: PMC11071362 DOI: 10.1101/2024.04.22.590573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Although mammals resist both acute weight loss and weight gain, the neural circuitry mediating bi-directional defense against weight change is incompletely understood. Global constitutive deletion of the melanocortin-3-receptor (MC3R) impairs the behavioral response to both anorexic and orexigenic stimuli, with MC3R knockout mice demonstrating increased weight gain following anabolic challenges and increased weight loss following anorexic challenges (i.e. impaired energy rheostasis). However, the brain regions mediating this phenotype remain incompletely understood. Here, we utilized MC3R floxed mice and viral injections of Cre-recombinase to selectively delete MC3R from medial hypothalamus (MH) in adult mice. Behavioral assays were performed on these animals to test the role of MC3R in MH in the acute response to orexigenic and anorexic challenges. Complementary chemogenetic approaches were used in MC3R-Cre mice to localize and characterize the specific medial hypothalamic brain regions mediating the role of MC3R in energy homeostasis. Finally, we performed RNAscope in situ hybridization to map changes in the mRNA expression of MC3R, POMC, and AgRP following energy rheostatic challenges. Our results demonstrate that MC3R deletion in MH increased feeding and weight gain following acute high fat diet feeding in males, and enhanced the anorexic effects of semaglutide, in a sexually dimorphic manner. Additionally, activation of DMH MC3R neurons increased energy expenditure and locomotion. Together, these results demonstrate that MC3R mediated effects on energy rheostasis result from the loss of MC3R signaling in the medial hypothalamus of adult animals and suggest an important role for DMH MC3R signaling in energy rheostasis.
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Affiliation(s)
| | - Jared Butts
- University of Illinois Urbana-Champaign, Department of Molecular and Integrative Physiology
- University of Illinois Urbana-Champaign Neuroscience Program
| | - Emma Pyszka
- University of Illinois Urbana-Champaign, Department of Molecular and Integrative Physiology
| | - Christina Nelson
- University of Illinois Urbana-Champaign, Department of Molecular and Integrative Physiology
| | - Dajin Cho
- University of Illinois Urbana-Champaign, Department of Molecular and Integrative Physiology
- University of Illinois Urbana-Champaign Neuroscience Program
| | - Patrick Sweeney
- University of Illinois Urbana-Champaign, Department of Molecular and Integrative Physiology
- University of Illinois Urbana-Champaign Neuroscience Program
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6
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Lund C, Ranea-Robles P, Falk S, Rausch DM, Skovbjerg G, Vibe-Petersen VK, Krauth N, Skytte JL, Vana V, Roostalu U, Pers TH, Lund J, Clemmensen C. Protection against overfeeding-induced weight gain is preserved in obesity but does not require FGF21 or MC4R. Nat Commun 2024; 15:1192. [PMID: 38331907 PMCID: PMC10853283 DOI: 10.1038/s41467-024-45223-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 01/18/2024] [Indexed: 02/10/2024] Open
Abstract
Overfeeding triggers homeostatic compensatory mechanisms that counteract weight gain. Here, we show that both lean and diet-induced obese (DIO) male mice exhibit a potent and prolonged inhibition of voluntary food intake following overfeeding-induced weight gain. We reveal that FGF21 is dispensable for this defense against weight gain. Targeted proteomics unveiled novel circulating factors linked to overfeeding, including the protease legumain (LGMN). Administration of recombinant LGMN lowers body weight and food intake in DIO mice. The protection against weight gain is also associated with reduced vascularization in the hypothalamus and sustained reductions in the expression of the orexigenic neuropeptide genes, Npy and Agrp, suggesting a role for hypothalamic signaling in this homeostatic recovery from overfeeding. Overfeeding of melanocortin 4 receptor (MC4R) KO mice shows that these mice can suppress voluntary food intake and counteract the enforced weight gain, although their rate of weight recovery is impaired. Collectively, these findings demonstrate that the defense against overfeeding-induced weight gain remains intact in obesity and involves mechanisms independent of both FGF21 and MC4R.
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Affiliation(s)
- Camilla Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Pablo Ranea-Robles
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Sarah Falk
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Dylan M Rausch
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Grethe Skovbjerg
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
- Gubra ApS, Hørsholm, Denmark
| | | | - Nathalie Krauth
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | | | - Vasiliki Vana
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | | | - Tune H Pers
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Jens Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Christoffer Clemmensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark.
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7
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Snieckute G, Ryder L, Vind AC, Wu Z, Arendrup FS, Stoneley M, Chamois S, Martinez-Val A, Leleu M, Dreos R, Russell A, Gay DM, Genzor AV, Choi BSY, Basse AL, Sass F, Dall M, Dollet LCM, Blasius M, Willis AE, Lund AH, Treebak JT, Olsen JV, Poulsen SS, Pownall ME, Jensen BAH, Clemmensen C, Gerhart-Hines Z, Gatfield D, Bekker-Jensen S. ROS-induced ribosome impairment underlies ZAKα-mediated metabolic decline in obesity and aging. Science 2023; 382:eadf3208. [PMID: 38060659 DOI: 10.1126/science.adf3208] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 11/03/2023] [Indexed: 12/18/2023]
Abstract
The ribotoxic stress response (RSR) is a signaling pathway in which the p38- and c-Jun N-terminal kinase (JNK)-activating mitogen-activated protein kinase kinase kinase (MAP3K) ZAKα senses stalling and/or collision of ribosomes. Here, we show that reactive oxygen species (ROS)-generating agents trigger ribosomal impairment and ZAKα activation. Conversely, zebrafish larvae deficient for ZAKα are protected from ROS-induced pathology. Livers of mice fed a ROS-generating diet exhibit ZAKα-activating changes in ribosomal elongation dynamics. Highlighting a role for the RSR in metabolic regulation, ZAK-knockout mice are protected from developing high-fat high-sugar (HFHS) diet-induced blood glucose intolerance and liver steatosis. Finally, ZAK ablation slows animals from developing the hallmarks of metabolic aging. Our work highlights ROS-induced ribosomal impairment as a physiological activation signal for ZAKα that underlies metabolic adaptation in obesity and aging.
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Affiliation(s)
- Goda Snieckute
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Laura Ryder
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Anna Constance Vind
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Zhenzhen Wu
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | | | - Mark Stoneley
- MRC Toxicology Unit, University of Cambridge, Cambridge CB2 1QR, UK
| | - Sébastien Chamois
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Ana Martinez-Val
- Mass Spectrometry for Quantitative Proteomics, Proteomics Program, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Marion Leleu
- Bioinformatics Competence Center, Ecole Polytechnique Fédérale de Lausanne and University of Lausanne, CH-1015 Lausanne, Switzerland
| | - René Dreos
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | | | - David Michael Gay
- Biotech Research and Innovation Center, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Aitana Victoria Genzor
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Beatrice So-Yun Choi
- Department of Biomedical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Astrid Linde Basse
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Frederike Sass
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Morten Dall
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Lucile Chantal Marie Dollet
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Melanie Blasius
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Cambridge CB2 1QR, UK
| | - Anders H Lund
- Biotech Research and Innovation Center, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Jonas T Treebak
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Jesper Velgaard Olsen
- Mass Spectrometry for Quantitative Proteomics, Proteomics Program, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen N, Denmark
| | - Steen Seier Poulsen
- Department of Biomedical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | | | | | - Christoffer Clemmensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Zach Gerhart-Hines
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - David Gatfield
- Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland
| | - Simon Bekker-Jensen
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Center for Gene Expression, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
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8
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Speakman JR, Hall KD. Models of body weight and fatness regulation. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220231. [PMID: 37661735 PMCID: PMC10475878 DOI: 10.1098/rstb.2022.0231] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 07/13/2023] [Indexed: 09/05/2023] Open
Abstract
Body weight and fatness appear to be regulated phenomena. Several different theoretical models are available to capture the essence of this idea. These include the set-point, dynamic equilibrium, adiposity force, control theory-settling point, Hall-Guo, operation point and dual intervention point (DIP) models. The set-point model posits a single reference point around which levels of fat are regulated. The dynamic equilibrium model suggests that the apparent regulation of body fat around a reference point is an illusion owing to the necessary impacts of weight change on energy expenditure. Control theory focuses on the importance of feedback gain and suggests set-point and dynamic equilibrium are ends of a continuum of feedback gain. Control theory models have also been called 'settling point' models. The Hall-Guo, operation point and DIP models also bring together the set-point and dynamic equilibrium ideas into a single framework. The DIP proposes a zone of indifference where dynamic equilibrium 'regulation' predominates, bounded by upper and lower intervention points beyond which physiological mechanisms are activated. The drifty gene hypothesis is an idea explaining where this individual variation in the upper intervention point might come from. We conclude that further experiments to test between the models are sorely required. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.
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Affiliation(s)
- John R. Speakman
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong Province, 518055, People's Republic of China
- School of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, AB24 2TZ, UK
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, People's Republic of China
- China Medical University, Shenyang, Liaoning Province, 110122, People's Republic of China
| | - Kevin D. Hall
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
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9
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Lund J, Clemmensen C. Physiological protection against weight gain: evidence from overfeeding studies and future directions. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220229. [PMID: 37482786 PMCID: PMC10363696 DOI: 10.1098/rstb.2022.0229] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 04/24/2023] [Indexed: 07/25/2023] Open
Abstract
Body weight is under physiological regulation. When body fat mass decreases, a series of responses are triggered to promote weight regain by increasing food intake and decreasing energy expenditure. Analogous, in response to experimental overfeeding, excessive weight gain is counteracted by a reduction in food intake and possibly by an increase in energy expenditure. While low blood leptin and other hormones defend against weight loss, the signals that oppose overfeeding-induced fat mass expansion are still unknown. In this article, we discuss insights gained from overfeeding interventions in humans and intragastric overfeeding studies in rodents. We summarize the knowledge on the relative contributions of energy intake, energy expenditure and energy excretion to the physiological defence against overfeeding-induced weight gain. Furthermore, we explore literature supporting the existence of unidentified endocrine and non-endocrine pathways that defend against weight gain. Finally, we discuss the physiological drivers of constitutional thinness and suggest that overfeeding of individuals with constitutional thinness represents a gateway to understand the physiology of weight gain resistance in humans. Experimental overfeeding, combined with modern multi-omics techniques, has the potential to unveil the long-sought signalling pathways that protect against weight gain. Discovering these mechanisms could give rise to new treatments for obesity. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part I)'.
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Affiliation(s)
- Jens Lund
- Novo Nordisk Foundation Center for Basic Metabolic Research. Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Christoffer Clemmensen
- Novo Nordisk Foundation Center for Basic Metabolic Research. Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
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10
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Recent Advances in the Knowledge of the Mechanisms of Leptin Physiology and Actions in Neurological and Metabolic Pathologies. Int J Mol Sci 2023; 24:ijms24021422. [PMID: 36674935 PMCID: PMC9860943 DOI: 10.3390/ijms24021422] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/05/2023] [Accepted: 01/07/2023] [Indexed: 01/13/2023] Open
Abstract
Excess body weight is frequently associated with low-grade inflammation. Evidence indicates a relationship between obesity and cancer, as well as with other diseases, such as diabetes and non-alcoholic fatty liver disease, in which inflammation and the actions of various adipokines play a role in the pathological mechanisms involved in these disorders. Leptin is mainly produced by adipose tissue in proportion to fat stores, but it is also synthesized in other organs, where leptin receptors are expressed. This hormone performs numerous actions in the brain, mainly related to the control of energy homeostasis. It is also involved in neurogenesis and neuroprotection, and central leptin resistance is related to some neurological disorders, e.g., Parkinson's and Alzheimer's diseases. In peripheral tissues, leptin is implicated in the regulation of metabolism, as well as of bone density and muscle mass. All these actions can be affected by changes in leptin levels and the mechanisms associated with resistance to this hormone. This review will present recent advances in the molecular mechanisms of leptin action and their underlying roles in pathological situations, which may be of interest for revealing new approaches for the treatment of diseases where the actions of this adipokine might be compromised.
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