1
|
Ferrara PJ, Lang MJ, Johnson JM, Watanabe S, McLaughlin KL, Maschek JA, Verkerke AR, Siripoksup P, Chaix A, Cox JE, Fisher-Wellman KH, Funai K. Weight loss increases skeletal muscle mitochondrial energy efficiency in obese mice. LIFE METABOLISM 2023; 2:load014. [PMID: 37206438 PMCID: PMC10195096 DOI: 10.1093/lifemeta/load014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Weight loss from an overweight state is associated with a disproportionate decrease in whole-body energy expenditure that may contribute to the heightened risk for weight regain. Evidence suggests that this energetic mismatch originates from lean tissue. Although this phenomenon is well documented, the mechanisms have remained elusive. We hypothesized that increased mitochondrial energy efficiency in skeletal muscle is associated with reduced expenditure under weight loss. Wildtype (WT) male C57BL6/N mice were fed with high fat diet for 10 weeks, followed by a subset of mice that were maintained on the obesogenic diet (OB) or switched to standard chow to promote weight loss (WL) for additional 6 weeks. Mitochondrial energy efficiency was evaluated using high-resolution respirometry and fluorometry. Mass spectrometric analyses were employed to describe the mitochondrial proteome and lipidome. Weight loss promoted ~50% increase in the efficiency of oxidative phosphorylation (ATP produced per O2 consumed, or P/O) in skeletal muscle. However, weight loss did not appear to induce significant changes in mitochondrial proteome, nor any changes in respiratory supercomplex formation. Instead, it accelerated the remodeling of mitochondrial cardiolipin (CL) acyl-chains to increase tetralinoleoyl CL (TLCL) content, a species of lipids thought to be functionally critical for the respiratory enzymes. We further show that lowering TLCL by deleting the CL transacylase tafazzin was sufficient to reduce skeletal muscle P/O and protect mice from diet-induced weight gain. These findings implicate skeletal muscle mitochondrial efficiency as a novel mechanism by which weight loss reduces energy expenditure in obesity.
Collapse
Affiliation(s)
- Patrick J. Ferrara
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
| | - Marisa J. Lang
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
| | - Jordan M. Johnson
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
| | - Shinya Watanabe
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
| | - Kelsey L. McLaughlin
- East Carolina Diabetes & Obesity Institute, East Carolina University
- Department of Physiology, East Carolina University
| | - J. Alan Maschek
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
- Metabolomics Core Research Facility, University of Utah
| | - Anthony R.P. Verkerke
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
| | | | - Amandine Chaix
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
- Molecular Medicine Program, University of Utah
| | - James E. Cox
- Diabetes & Metabolism Research Center, University of Utah
- Metabolomics Core Research Facility, University of Utah
- Department of Biochemistry, University of Utah
| | - Kelsey H. Fisher-Wellman
- East Carolina Diabetes & Obesity Institute, East Carolina University
- Department of Physiology, East Carolina University
| | - Katsuhiko Funai
- Diabetes & Metabolism Research Center, University of Utah
- Department of Nutrition & Integrative Physiology, University of Utah
- Molecular Medicine Program, University of Utah
- Department of Biochemistry, University of Utah
| |
Collapse
|
2
|
Page AJ. Gastrointestinal Vagal Afferents and Food Intake: Relevance of Circadian Rhythms. Nutrients 2021; 13:nu13030844. [PMID: 33807524 PMCID: PMC7998414 DOI: 10.3390/nu13030844] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/25/2021] [Accepted: 03/03/2021] [Indexed: 01/20/2023] Open
Abstract
Gastrointestinal vagal afferents (VAs) play an important role in food intake regulation, providing the brain with information on the amount and nutrient composition of a meal. This is processed, eventually leading to meal termination. The response of gastric VAs, to food-related stimuli, is under circadian control and fluctuates depending on the time of day. These rhythms are highly correlated with meal size, with a nadir in VA sensitivity and increase in meal size during the dark phase and a peak in sensitivity and decrease in meal size during the light phase in mice. These rhythms are disrupted in diet-induced obesity and simulated shift work conditions and associated with disrupted food intake patterns. In diet-induced obesity the dampened responses during the light phase are not simply reversed by reverting back to a normal diet. However, time restricted feeding prevents loss of diurnal rhythms in VA signalling in high fat diet-fed mice and, therefore, provides a potential strategy to reset diurnal rhythms in VA signalling to a pre-obese phenotype. This review discusses the role of the circadian system in the regulation of gastrointestinal VA signals and the impact of factors, such as diet-induced obesity and shift work, on these rhythms.
Collapse
Affiliation(s)
- Amanda J. Page
- Adelaide Medical School, University of Adelaide, Adelaide, SA 5000, Australia; ; Tel.: +61-8-8128-4840
- Nutrition, Diabetes and Gut Health, Lifelong Health Theme, South Australian Health and Medical Research Institution (SAHMRI), Adelaide, SA 5000, Australia
| |
Collapse
|
3
|
Skowronski AA, LeDuc CA, Foo KS, Goffer Y, Burnett LC, Egli D, Leibel RL. Physiological consequences of transient hyperleptinemia during discrete developmental periods on body weight in mice. Sci Transl Med 2021; 12:12/524/eaax6629. [PMID: 31894105 DOI: 10.1126/scitranslmed.aax6629] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/29/2019] [Accepted: 12/06/2019] [Indexed: 12/27/2022]
Abstract
Leptin plays a role in central nervous system developmental programs and intercurrent physiological processes related to body fat regulation. The timing and neuromolecular mechanisms for these effects are relevant to the prevention and treatment of obesity. Factors implicated in a body weight "set point" including dietary fat, circulating leptin, and other adipokines tend to covary with adiposity and are difficult to disarticulate experimentally. To dissociate leptin effects from adiposity and diet, we created a transgenic mouse in which leptin expression is regulated by doxycycline exposure. Using this system, we investigated the physiological consequences of developmentally-timed transient hyperleptinemia on subsequent adiposity. We evaluated physiological effects of leptin elevation during adulthood (9 to 29 weeks old), "adolescence" (3 to 8 weeks old), and the immediate postnatal period [postnatal days 0 to 22 (P0 to P22)] on long-term adiposity and susceptibility to gain weight on high-fat diet (HFD) fed ad libitum. We found that inducing chronic hyperleptinemia in adult or "adolescent" mice did not alter body weight when excess leptin was discontinued, and upon later exposure to HFD, weight gain did not differ from controls. However, transient elevation of circulating leptin from P0 to P22 increased weight and fat gain in response to HFD, indicating greater susceptibility to obesity as adults. Thus, transient plasma leptin elevations-mimicking one aspect of transient adiposity-increased later susceptibility to diet-induced obesity, although these effects were restricted to a critical developmental (P0 to P22) time window. These findings may have clinical implications for weight management in infancy.
Collapse
Affiliation(s)
- Alicja A Skowronski
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Charles A LeDuc
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA.,Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Kylie S Foo
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Yossef Goffer
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Lisa C Burnett
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Dieter Egli
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA.,Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Obstetrics and Gynecology, and Columbia Stem Cell Initiative, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Rudolph L Leibel
- Division of Molecular Genetics, Department of Pediatrics, Vagelos College of Physicians and Surgeons, Columbia University Irving Medical Center, New York, NY 10032, USA. .,Naomi Berrie Diabetes Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| |
Collapse
|
4
|
Steckler R, Tamir S, Gutman R. Mice held at an environmental photic cycle oscillating at their tau-like period length do not show the high-fat diet-induced obesity that develops under the 24-hour photic cycle. Chronobiol Int 2021; 38:598-612. [PMID: 33455455 DOI: 10.1080/07420528.2020.1869029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Circadian disruptions precede high-fat diet (HFD)-induced obesity (DIO). Deviation of the endogenous circadian rhythm period length (tau) from 24 hours correlates with mice inter-strain DIO under the 24-hour light-dark cycle (T-cycle). Additionally, entrainment to a tau-resembling T-cycle attenuates DIO, to some extent, in muted mice. These phenomena suggest that entrainment to a 24-hour T-cycle promotes DIO beyond that expected from the HFD-induced metabolic disruptions. However, the hypothesis that entrainment to a tau-resembling T-cycle attenuates DIO has not been tested in wild-type mice. Therefore, we examined, in newborn female FVB/N mice, whether DIO found under their 'regular' 24-hour T-cycle is attenuated under a T-cycle oscillating at their tau-resembling period of 23.7 h, which is diverted from 24 hours by only 0.3 h. Compared to mice fed a low-fat diet, those fed an HFD under the 24-hour T-cycle showed a disrupted pattern of circadian locomotor activity prior to DIO onset. Both these phenomena were absent under the tau-like T-cycle. DIO developed under the 24-hour T-cycle despite similar caloric intake, and was associated with the lower locomotor activity of HFD-fed mice compared to the other mouse groups. These results demonstrated that DIO is secondary to HFD-induced circadian disruptions that are not harmonized by the strongest Zeitgeber (light-dark cycle) when oscillating at a period that diverts by as little as ca. 0.3-h from tau. More importantly, imposing a light-dark cycle oscillating at a tau-like period length, which enhances entrainment and presumably reinforces endogenous circadian rhythms, prevented HFD-induced circadian disruptions and enabled tighter control of energy homeostasis, as manifested by the absence of DIO, even under ad-lib HFD feeding. These results support the identification of tau-related biomarkers, which may be considered as risk-factors for DIO. Moreover, these findings may promote the development of clock-related pharmaceutical interventions that will reduce the gap between tau and 24 hours, and increase the robustness of the endogenous and entrained circadian rhythms. This will enable reducing DIO, even without caloric restriction or time-restricted feeding.
Collapse
Affiliation(s)
- Rafi Steckler
- Laboratory of Integrative Physiology (LIP), The Department of Nutrition and Natural Products, MIGAL - Galilee Research Institute, Kiryat Shmona, Israel.,Department of Nutritional Sciences, Faculty of Sciences and Technology, Tel-Hai College, Upper Galilee, Israel
| | - Snait Tamir
- Department of Nutritional Sciences, Faculty of Sciences and Technology, Tel-Hai College, Upper Galilee, Israel.,Laboratory of Human Health and Nutrition Sciences, MIGAL - Galilee Research Institute, Kiryat Shmona, Israel
| | - Roee Gutman
- Laboratory of Integrative Physiology (LIP), The Department of Nutrition and Natural Products, MIGAL - Galilee Research Institute, Kiryat Shmona, Israel.,Department of Nutritional Sciences, Faculty of Sciences and Technology, Tel-Hai College, Upper Galilee, Israel.,Department of Animal Sciences, Faculty of Sciences and Technology, Tel-Hai College, Upper Galilee, Israel
| |
Collapse
|
5
|
Mazzone CM, Liang-Guallpa J, Li C, Wolcott NS, Boone MH, Southern M, Kobzar NP, Salgado IDA, Reddy DM, Sun F, Zhang Y, Li Y, Cui G, Krashes MJ. High-fat food biases hypothalamic and mesolimbic expression of consummatory drives. Nat Neurosci 2020; 23:1253-1266. [PMID: 32747789 PMCID: PMC7529959 DOI: 10.1038/s41593-020-0684-9] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 06/30/2020] [Indexed: 01/07/2023]
Abstract
Maintaining healthy body weight is increasingly difficult in our obesogenic environment. Dieting efforts are often overpowered by the internal drive to consume energy-dense foods. Although the selection of calorically rich substrates over healthier options is identifiable across species, the mechanisms behind this choice remain poorly understood. Using a passive devaluation paradigm, we found that exposure to high-fat diet (HFD) suppresses the intake of nutritionally balanced standard chow diet (SD) irrespective of age, sex, body mass accrual and functional leptin or melanocortin-4 receptor signaling. Longitudinal recordings revealed that this SD devaluation and subsequent shift toward HFD consumption is encoded at the level of hypothalamic agouti-related peptide neurons and mesolimbic dopamine signaling. Prior HFD consumption vastly diminished the capacity of SD to alleviate the negative valence associated with hunger and the rewarding properties of food discovery even after periods of HFD abstinence. These data reveal a neural basis behind the hardships of dieting.
Collapse
Affiliation(s)
- Christopher M Mazzone
- In Vivo Neurobiology Group, Neurobiology Laboratory, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health, Research Triangle Park, Durham, NC, USA
| | - Jing Liang-Guallpa
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD, USA
- National Institute on Drug Abuse (NIDA), National Institutes of Health, Baltimore, MD, USA
- NIH-Brown University Graduate Program in Neuroscience, Bethesda, MD, USA
| | - Chia Li
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD, USA
- National Institute on Drug Abuse (NIDA), National Institutes of Health, Baltimore, MD, USA
| | - Nora S Wolcott
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD, USA
| | - Montana H Boone
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD, USA
| | - Morgan Southern
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD, USA
| | - Nicholas P Kobzar
- In Vivo Neurobiology Group, Neurobiology Laboratory, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health, Research Triangle Park, Durham, NC, USA
| | - Isabel de Araujo Salgado
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD, USA
- National Institute on Drug Abuse (NIDA), National Institutes of Health, Baltimore, MD, USA
| | - Deepa M Reddy
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD, USA
| | - Fangmiao Sun
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
- PKU-IDG/McGovern Institute for Brain Research, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Chinese Institute for Brain Research, Beijing, China
| | - Yajun Zhang
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
- PKU-IDG/McGovern Institute for Brain Research, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Chinese Institute for Brain Research, Beijing, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
- PKU-IDG/McGovern Institute for Brain Research, Beijing, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
- Chinese Institute for Brain Research, Beijing, China
| | - Guohong Cui
- In Vivo Neurobiology Group, Neurobiology Laboratory, National Institute of Environmental Health Sciences (NIEHS), National Institutes of Health, Research Triangle Park, Durham, NC, USA.
| | - Michael J Krashes
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD, USA.
- National Institute on Drug Abuse (NIDA), National Institutes of Health, Baltimore, MD, USA.
| |
Collapse
|
6
|
Most J, Redman LM. Impact of calorie restriction on energy metabolism in humans. Exp Gerontol 2020; 133:110875. [DOI: 10.1016/j.exger.2020.110875] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/06/2020] [Accepted: 02/09/2020] [Indexed: 11/28/2022]
|
7
|
Izquierdo AG, Crujeiras AB, Casanueva FF, Carreira MC. Leptin, Obesity, and Leptin Resistance: Where Are We 25 Years Later? Nutrients 2019; 11:nu11112704. [PMID: 31717265 PMCID: PMC6893721 DOI: 10.3390/nu11112704] [Citation(s) in RCA: 243] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/27/2019] [Accepted: 10/31/2019] [Indexed: 12/14/2022] Open
Abstract
Leptin, a hormone that is capable of effectively reducing food intake and body weight, was initially considered for use in the treatment of obesity. However, obese subjects have since been found to have high levels of circulating leptin and to be insensitive to the exogenous administration of leptin. The inability of leptin to exert its anorexigenic effects in obese individuals, and therefore, the lack of clinical utility of leptin in obesity, is defined as leptin resistance. This phenomenon has not yet been adequately characterized. Elucidation of the molecular mechanisms underlying leptin resistance is of vital importance for the application of leptin as an effective treatment for obesity. Leptin must cross the blood–brain barrier (BBB) to reach the hypothalamus and exert its anorexigenic functions. The mechanisms involved in leptin transportation across the blood–brain barrier continue to be unclear, thereby preventing the clinical application of leptin in the treatment of obesity. In recent years, new strategies have been developed to recover the response to leptin in obesity. We have summarized these strategies in this review.
Collapse
Affiliation(s)
- Andrea G. Izquierdo
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Ana B. Crujeiras
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Felipe F. Casanueva
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Molecular Endocrinolgy, Universidad de Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
| | - Marcos C. Carreira
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
| |
Collapse
|
8
|
Zecharia D, Rauch M, Sharabi-Nov A, Tamir S, Gutman R. Postnatal administration of leptin antagonist mitigates susceptibility to obesity under high-fat diet in male αMUPA mice. Am J Physiol Endocrinol Metab 2019; 317:E783-E793. [PMID: 31454257 DOI: 10.1152/ajpendo.00099.2019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Perturbations in postnatal leptin signaling have been associated with altered susceptibility to diet-induced obesity (DIO) under high-fat-diet (HFD), albeit with contradicting evidence. Previous studies have shown that alpha murine urokinase-type plasminogen activator (αMUPA) mice have a higher and longer postnatal leptin surge compared with their wild types (WTs) as well as lower body weight and food intake under regular diet (RD). Here we explored αMUPA's propensity for DIO and the effect of attenuating postnatal leptin signaling with leptin antagonist (LA) on energy homeostasis under both RD and HFD. Four-day-old αMUPA pups were treated on alternate days until postnatal day 18 with either vehicle or LA (10 or 20 mg·day-1·kg-1) and weaned into RD or HFD. Compared with RD-fed αMUPA males, HFD-fed αMUPA males showed higher energy intake, even when corrected for body weight difference, and became hyperinsulinemic and obese. Additionally, HFD-fed αMUPA males gained body weight at a higher rate than their WTs mainly because of strain differences in energy expenditure. LA administration did not affect strain differences under RD but attenuated αMUPA's hyperinsulinemia and DIO under HFD, most likely by mediating energy expenditure. Together with our previous findings, these results suggest that αMUPA's leptin surge underlies its higher susceptibility to obesity under HFD, highlighting the role of leptin-related developmental processes in inducing obesity in a postweaning obesogenic environment, at least in αMUPA males. This study therefore supports the use of αMUPA mice for elucidating developmental mechanisms of obesity and the efficacy of early-life manipulations via leptin surge axis in attenuating DIO.
Collapse
Affiliation(s)
- Danielle Zecharia
- Laboratory of Integrative Physiology, MIGAL-Galilee Research Institute. Kiryat Shmona, Israel
- Department of Biotechnology, Faculty of Sciences and Technology, Tel-Hai College, Upper Galilee, Israel
| | - Maayan Rauch
- Laboratory of Integrative Physiology, MIGAL-Galilee Research Institute. Kiryat Shmona, Israel
| | - Adi Sharabi-Nov
- Research Wing, Ziv Medical Center, Zefat, Israel
- Department of Nutritional Sciences, Faculty of Sciences and Technology, Tel-Hai College, Upper Galilee, Israel
| | - Snait Tamir
- Department of Nutritional Sciences, Faculty of Sciences and Technology, Tel-Hai College, Upper Galilee, Israel
- Laboratory of Human Health and Nutrition Sciences, MIGAL-Galilee Research Institute, Kiryat Shmona, Israel
| | - Roee Gutman
- Laboratory of Integrative Physiology, MIGAL-Galilee Research Institute. Kiryat Shmona, Israel
- Department of Animal Sciences, Faculty of Sciences and Technology, Tel-Hai College, Upper Galilee, Israel
| |
Collapse
|
9
|
Zilberter T, Zilberter Y. Ketogenic Ratio Determines Metabolic Effects of Macronutrients and Prevents Interpretive Bias. Front Nutr 2018; 5:75. [PMID: 30214902 PMCID: PMC6125377 DOI: 10.3389/fnut.2018.00075] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 08/07/2018] [Indexed: 12/30/2022] Open
|
10
|
Skowronski AA, Ravussin Y, Leibel RL, LeDuc CA. Energy homeostasis in leptin deficient Lepob/ob mice. PLoS One 2017; 12:e0189784. [PMID: 29261744 PMCID: PMC5738099 DOI: 10.1371/journal.pone.0189784] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/03/2017] [Indexed: 01/28/2023] Open
Abstract
Maintenance of reduced body weight is associated both with reduced energy expenditure per unit metabolic mass and increased hunger in mice and humans. Lowered circulating leptin concentration, due to decreased fat mass, provides a primary signal for this response. However, leptin deficient (Lepob/ob) mice (and leptin receptor deficient Zucker rats) reduce energy expenditure following weight reduction by a necessarily non-leptin dependent mechanisms. To identify these mechanisms, Lepob/ob mice were fed ad libitum (AL group; n = 21) or restricted to 3 kilocalories of chow per day (CR group, n = 21). After losing 20% of initial weight (in approximately 2 weeks), the CR mice were stabilized at 80% of initial body weight for two weeks by titrated refeeding, and then released from food restriction. CR mice conserved energy (-17% below predicted based on body mass and composition during the day; -52% at night); and, when released to ad libitum feeding, CR mice regained fat and lean mass (to AL levels) within 5 weeks. CR mice did so while their ad libitum caloric intake was equal to that of the AL animals. While calorically restricted, the CR mice had a significantly lower respiratory exchange ratio (RER = 0.89) compared to AL (0.94); after release to ad libitum feeding, RER was significantly higher (1.03) than in the AL group (0.93), consistent with their anabolic state. These results confirm that, in congenitally leptin deficient animals, leptin is not required for compensatory reduction in energy expenditure accompanying weight loss, but suggest that the hyperphagia of the weight-reduced state is leptin-dependent.
Collapse
Affiliation(s)
- Alicja A. Skowronski
- Institute of Human Nutrition, Columbia University, New York City, New York, United States of America
- Department of Medicine, Columbia University, New York City, New York, United States of America
| | - Yann Ravussin
- Department of Medicine, Columbia University, New York City, New York, United States of America
| | - Rudolph L. Leibel
- Institute of Human Nutrition, Columbia University, New York City, New York, United States of America
- Department of Pediatrics, Columbia University, New York City, New York, United States of America
- Obesity Research Core, Columbia University, New York City, New York, United States of America
| | - Charles A. LeDuc
- Department of Pediatrics, Columbia University, New York City, New York, United States of America
- Obesity Research Core, Columbia University, New York City, New York, United States of America
- * E-mail:
| |
Collapse
|
11
|
Belenchia AM, Johnson SA, Kieschnick AC, Rosenfeld CS, Peterson CA. Time Course of Vitamin D Depletion and Repletion in Reproductive-age Female C57BL/6 Mice. Comp Med 2017; 67:483-490. [PMID: 29212579 PMCID: PMC5713162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 03/01/2016] [Accepted: 04/28/2017] [Indexed: 06/07/2023]
Abstract
The use of animal models in vitamin D deficiency (VDD) research, particularly in regard to maternal deficits, has increased dramatically, yet these studies may be confounded due to ill-conceived experimental timelines. We conducted 2 experiments to (1) characterize the time course of VDD induction and repletion and (2) explore the long-term consequences of VDD on calcium homeostasis and body composition in reproductive-age female mice. Eight-week-old female C57BL/6 mice were randomized to receive either a vitamin D sufficient (VDS) or VDD diet; serum was collected weekly. At week 4, VDD mice were switched to VDS diet, and serum was collected weekly until week 8. Another group of same-age female mice was maintained on VDD diet for 40 wk. Body weights and serum were collected every 2 wk until week 40, when body composition was measured by using echoMRI. Mice did not become VDD until week 3 of the VDD diet and, after decreasing slightly at 4 wk, serum 25-hydroxyvitamin D remained unchanged through 40 wk. Vitamin D repletion to 25-hydroxyvitamin D concentrations considered adequate by the Institute of Medicine took 2 to 3 wk. Prolonged VDD in mice was marked by hypocalcemia and hyperparathyroidism and led to proportional decreases in both lean and fat mass. These data provide guidance in the design of studies using mice as a maternal VDD model, especially those exploring its effects on the developmental origins of health and disease and highlight the importance of monitoring and controlling the calciotropic effects of diet-induced VDD. This study also shows that prolonged VDD in reproductive-age female C57BL/6 mice induces metabolically meaningful changes in absolute, but not relative, body composition.
Collapse
Affiliation(s)
- Anthony M Belenchia
- Departments of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri
| | - Sarah A Johnson
- Departments of Biomedical Sciences, Bond Life Sciences Center, University of Missouri, Columbia, Missouri
| | - Alyssa C Kieschnick
- Departments of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri
| | - Cheryl S Rosenfeld
- Departments of Biomedical Sciences, Bond Life Sciences Center, University of Missouri, Columbia, Missouri
| | - Catherine A Peterson
- Departments of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri;,
| |
Collapse
|
12
|
|
13
|
Yu YH. Making sense of metabolic obesity and hedonic obesity. J Diabetes 2017; 9:656-666. [PMID: 28093902 DOI: 10.1111/1753-0407.12529] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 01/01/2023] Open
Abstract
Body weight is neither stationary nor does it change unidirectionally. Rather, body weight usually oscillates up and down around a set point. Two types of forces determine the direction of weight changes. Forces that push body weight away from the set point are defined as non-homeostatic and are governed by multiple mechanisms, including, but not limited to, hedonic regulation of food intake. Forces that restore the set point weight are defined as homeostatic, and they operate through mechanisms that regulate short-term energy balance driven by hunger and satiation and long-term energy balance driven by changes in adiposity. In the normal physiological state, the deviation of body weight from the set point is usually small and temporary, and is constantly corrected by homeostatic forces. Metabolic obesity develops when body weight set point is shifted to an abnormally high level and the obese body weight becomes metabolically defended. In hedonic obesity, the obese body weight is maintained by consistent overeating due to impairments in the reward system, although the set point is not elevated. Adaptive increases in energy expenditure are elicited in hedonic obesity because body weight is elevated above the set point. Neither subtype of obesity undergoes spontaneous resolution unless the underlying disorders are corrected. In this review, the need for both appropriate patient stratification and tailored treatments is discussed in the context of the new framework of metabolic and hedonic obesity.
Collapse
Affiliation(s)
- Yi-Hao Yu
- Department of Endocrinology, Greenwich Hospital and Northeast Medical Group, Yale-New Haven Health System, Greenwich, Connecticut, USA
| |
Collapse
|
14
|
Almundarij TI, Gavini CK, Novak CM. Suppressed sympathetic outflow to skeletal muscle, muscle thermogenesis, and activity energy expenditure with calorie restriction. Physiol Rep 2017; 5:5/4/e13171. [PMID: 28242830 PMCID: PMC5328781 DOI: 10.14814/phy2.13171] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 01/29/2017] [Indexed: 12/21/2022] Open
Abstract
During weight loss, adaptive thermogenesis occurs where energy expenditure (EE) is suppressed beyond that predicted for the smaller body size. Here, we investigated the contributions of resting and nonresting EE to the reduced total EE seen after 3 weeks of 50% calorie restriction (CR) in rats, focusing on activity‐associated EE, muscle thermogenesis, and sympathetic outflow. Prolonged food restriction resulted in a 42% reduction in daily EE, through a 40% decrease in resting EE, and a 48% decline in nonresting EE. These decreases in EE were significant even when the reductions in body weight and lean mass were taken into account. Along with a decreased caloric need for low‐to‐moderate‐intensity treadmill activity with 50% CR, baseline and activity‐related muscle thermogenesis were also suppressed, though the ability to increase muscle thermogenesis above baseline levels was not compromised. When sympathetic drive was measured by assessing norepinephrine turnover (NETO), 50% CR was found to decrease NETO in three of the four muscle groups examined, whereas elevated NETO was found in white adipose tissue of food‐restricted rats. Central activation of melanocortin 4 receptors in the ventromedial hypothalamus stimulated this pathway, enhancing activity EE; this was not compromised by 50% CR. These data suggest that suppressed activity EE contributes to adaptive thermogenesis during energy restriction. This may stem from decreased sympathetic drive to skeletal muscle, increasing locomotor efficiency and reducing skeletal muscle thermogenesis. The capacity to increase activity EE in response to central stimuli is retained, however, presenting a potential target for preventing weight regain.
Collapse
Affiliation(s)
- Tariq I Almundarij
- College of Agriculture and Veterinary Medicine, Al Qassim University, Buraydah, Al-Qassim Province, Saudi Arabia.,Department of Biological Sciences, Kent State University, Kent, Ohio
| | - Chaitanya K Gavini
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois.,School of Biomedical Sciences, Kent State University, Kent, Ohio
| | - Colleen M Novak
- Department of Biological Sciences, Kent State University, Kent, Ohio .,School of Biomedical Sciences, Kent State University, Kent, Ohio
| |
Collapse
|
15
|
Weight Perturbation Alters Leptin Signal Transduction in a Region-Specific Manner throughout the Brain. PLoS One 2017; 12:e0168226. [PMID: 28107353 PMCID: PMC5249166 DOI: 10.1371/journal.pone.0168226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2016] [Accepted: 11/28/2016] [Indexed: 01/02/2023] Open
Abstract
Diet-induced obesity (DIO) resulting from consumption of a high fat diet (HFD) attenuates normal neuronal responses to leptin and may contribute to the metabolic defense of an acquired higher body weight in humans; the molecular bases for the persistence of this defense are unknown. We measured the responses of 23 brain regions to exogenous leptin in 4 different groups of weight- and/or diet-perturbed mice. Responses to leptin were assessed by quantifying pSTAT3 levels in brain nuclei 30 minutes following 3 mg/kg intraperitoneal leptin. HFD attenuated leptin sensing throughout the brain, but weight loss did not restore central leptin signaling to control levels in several brain regions important in energy homeostasis, including the arcuate and dorsomedial hypothalamic nuclei. Effects of diet on leptin signaling varied by brain region, with results dependent on the method of weight loss (restriction of calories of HFD, ad lib intake of standard mouse chow). High fat diet attenuates leptin signaling throughout the brain, but some brain regions maintain their ability to sense leptin. Weight loss restores leptin sensing to some degree in most (but not all) brain regions, while other brain regions display hypersensitivity to leptin following weight loss. Normal leptin sensing was restored in several brain regions, with the pattern of restoration dependent on the method of weight loss.
Collapse
|
16
|
Burnett LC, Skowronski AA, Rausch R, LeDuc CA, Leibel RL. Determination of the half-life of circulating leptin in the mouse. Int J Obes (Lond) 2016; 41:355-359. [PMID: 28025576 PMCID: PMC5340585 DOI: 10.1038/ijo.2016.238] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/16/2016] [Accepted: 12/11/2016] [Indexed: 01/01/2023]
Abstract
Background The adipokine hormone, leptin, is a major component of body weight homeostasis. Numerous studies have been performed administering recombinant mouse leptin as an experimental reagent; however, the half life of circulating leptin following exogenous administration of recombinant mouse leptin has not been carefully evaluated. Methods Exogenous leptin was administered (3 mg leptin/kg body weight) to ten week old fasted non-obese male mice and plasma was serially collected at seven time points; plasma leptin concentration was measured by ELISA at each time point to estimate the circulating half life of mouse leptin. Results Under the physiological circumstances tested, the half life of mouse leptin was 40.2 (+/− 2.2) minutes. Circulating leptin concentrations up to one hour following exogenous leptin administration were 170-fold higher than endogenous levels at fasting. Conclusions The half life of mouse leptin was determined to be 40.2 minutes. These results should be useful in planning and interpreting experiments employing exogenous leptin. The unphysiological elevations in circulating leptin resulting from widely used dosing regimens for exogenous leptin are likely to confound inferences regarding some aspects of the hormone’s clinical biology.
Collapse
Affiliation(s)
- L C Burnett
- Columbia University Institute of Human Nutrition, New York, NY, USA.,Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA
| | - A A Skowronski
- Columbia University Institute of Human Nutrition, New York, NY, USA.,Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA
| | - R Rausch
- Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA
| | - C A LeDuc
- Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA.,New York Obesity Research Center, New York, NY, USA
| | - R L Leibel
- Columbia University Department of Pediatrics, Division of Molecular Genetics, New York, NY, USA.,Naomi Berrie Diabetes Center, New York, NY, USA.,New York Obesity Research Center, New York, NY, USA
| |
Collapse
|
17
|
Chhabra KH, Adams JM, Jones GL, Yamashita M, Schlapschy M, Skerra A, Rubinstein M, Low MJ. Reprogramming the body weight set point by a reciprocal interaction of hypothalamic leptin sensitivity and Pomc gene expression reverts extreme obesity. Mol Metab 2016; 5:869-881. [PMID: 27689000 PMCID: PMC5034612 DOI: 10.1016/j.molmet.2016.07.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 07/29/2016] [Indexed: 12/26/2022] Open
Abstract
Objective A major challenge for obesity treatment is the maintenance of reduced body weight. Diet-induced obese mice are resistant to achieving normoweight once the obesogenic conditions are reversed, in part because lowered circulating leptin leads to a reduction in metabolic rate and a rebound of hyperphagia that defend the previously elevated body weight set point. Because hypothalamic POMC is a central leptin target, we investigated whether changes in circulating leptin modify Pomc expression to maintain normal energy balance in genetically predisposed obese mice. Methods Mice with reversible Pomc silencing in the arcuate nucleus (ArcPomc−/−) become morbidly obese eating low-fat chow. We measured body composition, food intake, plasma leptin, and leptin sensitivity in ArcPomc−/− mice weight-matched to littermate controls by calorie restriction, either from weaning or after developing obesity. Pomc was reactivated by tamoxifen-dependent Cre recombinase transgenes. Long acting PASylated leptin was administered to weight-reduced ArcPomc−/− mice to mimic the super-elevated leptin levels of obese mice. Results ArcPomc−/− mice had increased adiposity and leptin levels shortly after weaning. Despite chronic calorie restriction to achieve normoweight, ArcPomc−/− mice remained moderately hyperleptinemic and resistant to exogenous leptin's effects to reduce weight and food intake. However, subsequent Pomc reactivation in weight-matched ArcPomc−/− mice normalized plasma leptin, leptin sensitivity, adiposity, and food intake. In contrast, extreme hyperleptinemia induced by PASylated leptin blocked the full restoration of hypothalamic Pomc expression in calorie restricted ArcPomc−/− mice, which consequently regained 30% of their lost body weight and attained a metabolic steady state similar to that of tamoxifen treated obese ArcPomc−/− mice. Conclusions Pomc reactivation in previously obese, calorie-restricted ArcPomc−/− mice normalized energy homeostasis, suggesting that their body weight set point was restored to control levels. In contrast, massively obese and hyperleptinemic ArcPomc−/− mice or those weight-matched and treated with PASylated leptin to maintain extreme hyperleptinemia prior to Pomc reactivation converged to an intermediate set point relative to lean control and obese ArcPomc−/− mice. We conclude that restoration of hypothalamic leptin sensitivity and Pomc expression is necessary for obese ArcPomc−/− mice to achieve and sustain normal metabolic homeostasis; whereas deficits in either parameter set a maladaptive allostatic balance that defends increased adiposity and body weight. Hypothalamic POMC-deficiency increases adiposity and induces leptin resistance. PASylated leptin blocks the normalization of Pomc expression, weight and adiposity. Interactions of leptin sensitivity and Pomc expression dictate body weight set point.
Collapse
Affiliation(s)
- Kavaljit H Chhabra
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Jessica M Adams
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Graham L Jones
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Miho Yamashita
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Martin Schlapschy
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising (Weihenstephan), Germany
| | - Arne Skerra
- Lehrstuhl für Biologische Chemie, Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354 Freising (Weihenstephan), Germany
| | - Marcelo Rubinstein
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina; Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA.
| |
Collapse
|
18
|
Ploj K, Benthem L, Kakol-Palm D, Gennemark P, Andersson L, Bjursell M, Börjesson J, Kärrberg L, Månsson M, Antonsson M, Johansson A, Iverson S, Carlsson B, Turnbull A, Lindén D. Effects of a novel potent melanin-concentrating hormone receptor 1 antagonist, AZD1979, on body weight homeostasis in mice and dogs. Br J Pharmacol 2016; 173:2739-51. [PMID: 27400775 DOI: 10.1111/bph.13548] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 06/13/2016] [Accepted: 07/01/2016] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Melanin-concentrating hormone (MCH) is an orexigen, and while rodents express one MCH receptor (MCH1 receptor), humans, non-human primates and dogs express two MCH receptors (MCH1 and MCH2 ). MCH1 receptor antagonists have been developed for the treatment of obesity and lower body weight in rodents. However, the mechanisms for the body weight loss and whether MCH1 receptor antagonism can lower body weight in species expressing both MCH receptors are not fully understood. EXPERIMENTAL APPROACH A novel recently identified potent MCH1 receptor antagonist, AZD1979, was studied in wild type and Mchr1 knockout (KO) mice and by using pair-feeding and indirect calorimetry in diet-induced obese (DIO) mice. The effect of AZD1979 on body weight was also studied in beagle dogs. KEY RESULTS AZD1979 bound to MCH1 receptors in the CNS and dose-dependently reduced body weight in DIO mice leading to improved homeostasis model assessment-index of insulin sensitivity. AZD1979 did not affect food intake or body weight in Mchr1 KO mice demonstrating specificity for the MCH1 receptor mechanism. In DIO mice, initial AZD1979-mediated body weight loss was driven by decreased food intake, but an additional component of preserved energy expenditure was apparent in pair-feeding and indirect calorimetry studies. AZD1979 also dose-dependently reduced body weight in dogs. CONCLUSION AND IMPLICATIONS AZD1979 is a novel potent MCH1 receptor antagonist that affects both food intake and energy expenditure. That AZD1979 also lowers body weight in a species expressing both MCH receptors holds promise for the use of MCH1 receptor antagonists for the treatment of human obesity.
Collapse
Affiliation(s)
- Karolina Ploj
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden.,Drug Safety & Metabolism, AstraZeneca Mölndal, Sweden
| | - Lambertus Benthem
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden
| | - Dorota Kakol-Palm
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden
| | - Peter Gennemark
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden
| | - Liselotte Andersson
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden.,Drug Safety & Metabolism, AstraZeneca Mölndal, Sweden
| | - Mikael Bjursell
- Discovery Sciences Transgenics, AstraZeneca, Mölndal, Sweden
| | - Jenny Börjesson
- Discovery Sciences Transgenics, AstraZeneca, Mölndal, Sweden
| | - Lillevi Kärrberg
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden.,Drug Safety & Metabolism, AstraZeneca Mölndal, Sweden
| | | | - Madeleine Antonsson
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden
| | - Anders Johansson
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden
| | | | - Björn Carlsson
- Early Clinical Development, AstraZeneca, Mölndal, Sweden
| | - Andrew Turnbull
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden
| | - Daniel Lindén
- Cardiovascular & Metabolic Diseases innovative Medicines (CVMD iMed), AstraZeneca Mölndal, Sweden
| |
Collapse
|
19
|
Münzberg H, Qualls-Creekmore E, Yu S, Morrison CD, Berthoud HR. Hedonics Act in Unison with the Homeostatic System to Unconsciously Control Body Weight. Front Nutr 2016; 3:6. [PMID: 26913284 PMCID: PMC4753312 DOI: 10.3389/fnut.2016.00006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 02/01/2016] [Indexed: 12/22/2022] Open
Affiliation(s)
- Heike Münzberg
- Pennington Biomedical Research Center, Louisiana State University System , Baton Rouge, LA , USA
| | - Emily Qualls-Creekmore
- Pennington Biomedical Research Center, Louisiana State University System , Baton Rouge, LA , USA
| | - Sangho Yu
- Pennington Biomedical Research Center, Louisiana State University System , Baton Rouge, LA , USA
| | - Christopher D Morrison
- Pennington Biomedical Research Center, Louisiana State University System , Baton Rouge, LA , USA
| | - Hans-Rudolf Berthoud
- Pennington Biomedical Research Center, Louisiana State University System , Baton Rouge, LA , USA
| |
Collapse
|
20
|
Bolze F, Morath V, Bast A, Rink N, Schlapschy M, Mocek S, Skerra A, Klingenspor M. Long-Acting PASylated Leptin Ameliorates Obesity by Promoting Satiety and Preventing Hypometabolism in Leptin-Deficient Lep(ob/ob) Mice. Endocrinology 2016; 157:233-44. [PMID: 26492472 DOI: 10.1210/en.2015-1519] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Body weight loss of Lep(ob/ob) mice in response to leptin is larger than expected from the reduction in energy intake alone, suggesting a thermogenic action of unknown magnitude. We exploited the superior pharmacological properties of a novel long-acting leptin prepared via PASylation to study the contribution of its anorexigenic and thermogenic effects. PASylation, the genetic fusion of leptin with a conformationally disordered polypeptide comprising 600 Pro/Ala/Ser (PAS) residues, provides a superior way to increase the hydrodynamic volume of the fusion protein, thus retarding kidney filtration and extending plasma half-life. Here a single PAS(600)-leptin injection (300 pmol/g) resulted in a maximal weight reduction of 21% 6 days after application. The negative energy balance of 300 kJ/(4 d) was driven by a decrease in energy intake, whereas energy expenditure remained stable. Mice that were food restricted to the same extent showed an energy deficit of only 220 kJ/(4 d) owing to recurring torpor bouts. Therefore, the anorexigenic effect of PAS(600)-leptin contributes 75% to weight loss, whereas the thermogenic action accounts for 25% by preventing hypometabolism. In a second experiment, just four injections of PAS(600)-leptin (100 pmol/g) administered in 5- to 6-day intervals rectified the Lep(ob/ob) phenotype. In total, 16 nmol of PAS(600)-leptin per mouse triggered a weight loss of 43% within 20 days and normalized hypothermia and glucose homeostasis as well as hepatic steatosis. The beneficial properties of PAS(600)-leptin are substantiated by a comparison with previous studies in which approximately 400 nmol (∼25-fold) unmodified leptin was mandatory to achieve similar improvements.
Collapse
Affiliation(s)
- Florian Bolze
- Lehrstuhl für Molekulare Ernährungsmedizin (F.B., A.B., N.R., S.M., M.K.), Else Kröner-Fresenius Center and ZIEL-Research Center for Nutrition and Food Science, and Munich Center for Integrated Protein Science and Lehrstuhl für Biologische Chemie (V.M., M.S., A.S.), Technische Universität München, 85350 Freising-Weihenstephan, Germany; and XL-protein GmbH (A.S.), 85354 Freising, Germany
| | - Volker Morath
- Lehrstuhl für Molekulare Ernährungsmedizin (F.B., A.B., N.R., S.M., M.K.), Else Kröner-Fresenius Center and ZIEL-Research Center for Nutrition and Food Science, and Munich Center for Integrated Protein Science and Lehrstuhl für Biologische Chemie (V.M., M.S., A.S.), Technische Universität München, 85350 Freising-Weihenstephan, Germany; and XL-protein GmbH (A.S.), 85354 Freising, Germany
| | - Andrea Bast
- Lehrstuhl für Molekulare Ernährungsmedizin (F.B., A.B., N.R., S.M., M.K.), Else Kröner-Fresenius Center and ZIEL-Research Center for Nutrition and Food Science, and Munich Center for Integrated Protein Science and Lehrstuhl für Biologische Chemie (V.M., M.S., A.S.), Technische Universität München, 85350 Freising-Weihenstephan, Germany; and XL-protein GmbH (A.S.), 85354 Freising, Germany
| | - Nadine Rink
- Lehrstuhl für Molekulare Ernährungsmedizin (F.B., A.B., N.R., S.M., M.K.), Else Kröner-Fresenius Center and ZIEL-Research Center for Nutrition and Food Science, and Munich Center for Integrated Protein Science and Lehrstuhl für Biologische Chemie (V.M., M.S., A.S.), Technische Universität München, 85350 Freising-Weihenstephan, Germany; and XL-protein GmbH (A.S.), 85354 Freising, Germany
| | - Martin Schlapschy
- Lehrstuhl für Molekulare Ernährungsmedizin (F.B., A.B., N.R., S.M., M.K.), Else Kröner-Fresenius Center and ZIEL-Research Center for Nutrition and Food Science, and Munich Center for Integrated Protein Science and Lehrstuhl für Biologische Chemie (V.M., M.S., A.S.), Technische Universität München, 85350 Freising-Weihenstephan, Germany; and XL-protein GmbH (A.S.), 85354 Freising, Germany
| | - Sabine Mocek
- Lehrstuhl für Molekulare Ernährungsmedizin (F.B., A.B., N.R., S.M., M.K.), Else Kröner-Fresenius Center and ZIEL-Research Center for Nutrition and Food Science, and Munich Center for Integrated Protein Science and Lehrstuhl für Biologische Chemie (V.M., M.S., A.S.), Technische Universität München, 85350 Freising-Weihenstephan, Germany; and XL-protein GmbH (A.S.), 85354 Freising, Germany
| | - Arne Skerra
- Lehrstuhl für Molekulare Ernährungsmedizin (F.B., A.B., N.R., S.M., M.K.), Else Kröner-Fresenius Center and ZIEL-Research Center for Nutrition and Food Science, and Munich Center for Integrated Protein Science and Lehrstuhl für Biologische Chemie (V.M., M.S., A.S.), Technische Universität München, 85350 Freising-Weihenstephan, Germany; and XL-protein GmbH (A.S.), 85354 Freising, Germany
| | - Martin Klingenspor
- Lehrstuhl für Molekulare Ernährungsmedizin (F.B., A.B., N.R., S.M., M.K.), Else Kröner-Fresenius Center and ZIEL-Research Center for Nutrition and Food Science, and Munich Center for Integrated Protein Science and Lehrstuhl für Biologische Chemie (V.M., M.S., A.S.), Technische Universität München, 85350 Freising-Weihenstephan, Germany; and XL-protein GmbH (A.S.), 85354 Freising, Germany
| |
Collapse
|
21
|
Santoro A, Mattace Raso G, Meli R. Drug targeting of leptin resistance. Life Sci 2015; 140:64-74. [DOI: 10.1016/j.lfs.2015.05.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/06/2015] [Accepted: 05/13/2015] [Indexed: 12/21/2022]
|
22
|
Méquinion M, Chauveau C, Viltart O. The use of animal models to decipher physiological and neurobiological alterations of anorexia nervosa patients. Front Endocrinol (Lausanne) 2015; 6:68. [PMID: 26042085 PMCID: PMC4436882 DOI: 10.3389/fendo.2015.00068] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Accepted: 04/15/2015] [Indexed: 12/18/2022] Open
Abstract
Extensive studies were performed to decipher the mechanisms regulating feeding due to the worldwide obesity pandemy and its complications. The data obtained might be adapted to another disorder related to alteration of food intake, the restrictive anorexia nervosa. This multifactorial disease with a complex and unknown etiology is considered as an awful eating disorder since the chronic refusal to eat leads to severe, and sometimes, irreversible complications for the whole organism, until death. There is an urgent need to better understand the different aspects of the disease to develop novel approaches complementary to the usual psychological therapies. For this purpose, the use of pertinent animal models becomes a necessity. We present here the various rodent models described in the literature that might be used to dissect central and peripheral mechanisms involved in the adaptation to deficient energy supplies and/or the maintenance of physiological alterations on the long term. Data obtained from the spontaneous or engineered genetic models permit to better apprehend the implication of one signaling system (hormone, neuropeptide, neurotransmitter) in the development of several symptoms observed in anorexia nervosa. As example, mutations in the ghrelin, serotonin, dopamine pathways lead to alterations that mimic the phenotype, but compensatory mechanisms often occur rendering necessary the use of more selective gene strategies. Until now, environmental animal models based on one or several inducing factors like diet restriction, stress, or physical activity mimicked more extensively central and peripheral alterations decribed in anorexia nervosa. They bring significant data on feeding behavior, energy expenditure, and central circuit alterations. Animal models are described and criticized on the basis of the criteria of validity for anorexia nervosa.
Collapse
Affiliation(s)
- Mathieu Méquinion
- INSERM UMR-S1172, Development and Plasticity of Postnatal Brain, Lille, France
| | - Christophe Chauveau
- Pathophysiology of Inflammatory Bone Diseases, EA 4490, University of the Littoral Opal Coast, Boulogne sur Mer, France
| | - Odile Viltart
- INSERM UMR-S1172, Early stages of Parkinson diseases, University Lille 1, Lille, France
| |
Collapse
|
23
|
Yu YH, Vasselli JR, Zhang Y, Mechanick JI, Korner J, Peterli R. Metabolic vs. hedonic obesity: a conceptual distinction and its clinical implications. Obes Rev 2015; 16:234-47. [PMID: 25588316 PMCID: PMC5053237 DOI: 10.1111/obr.12246] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 11/19/2014] [Accepted: 11/19/2014] [Indexed: 01/01/2023]
Abstract
Body weight is determined via both metabolic and hedonic mechanisms. Metabolic regulation of body weight centres around the 'body weight set point', which is programmed by energy balance circuitry in the hypothalamus and other specific brain regions. The metabolic body weight set point has a genetic basis, but exposure to an obesogenic environment may elicit allostatic responses and upward drift of the set point, leading to a higher maintained body weight. However, an elevated steady-state body weight may also be achieved without an alteration of the metabolic set point, via sustained hedonic over-eating, which is governed by the reward system of the brain and can override homeostatic metabolic signals. While hedonic signals are potent influences in determining food intake, metabolic regulation involves the active control of both food intake and energy expenditure. When overweight is due to elevation of the metabolic set point ('metabolic obesity'), energy expenditure theoretically falls onto the standard energy-mass regression line. In contrast, when a steady-state weight is above the metabolic set point due to hedonic over-eating ('hedonic obesity'), a persistent compensatory increase in energy expenditure per unit metabolic mass may be demonstrable. Recognition of the two types of obesity may lead to more effective treatment and prevention of obesity.
Collapse
Affiliation(s)
- Y-H Yu
- Weight Loss and Diabetes Center, Greenwich Hospital, Greenwich, CT, USA; Endocrinology Associates of Greenwich, Northeast Medical Group, Yale New-Haven Health System, Greenwich, CT, USA
| | | | | | | | | | | |
Collapse
|
24
|
Keijer J, Hoevenaars FPM, Nieuwenhuizen A, van Schothorst EM. Nutrigenomics of body weight regulation: a rationale for careful dissection of individual contributors. Nutrients 2014; 6:4531-51. [PMID: 25338273 PMCID: PMC4210933 DOI: 10.3390/nu6104531] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 09/29/2014] [Accepted: 10/13/2014] [Indexed: 01/09/2023] Open
Abstract
Body weight stability may imply active regulation towards a certain physiological condition, a body weight setpoint. This interpretation is ill at odds with the world-wide increase in overweight and obesity. Until now, a body weight setpoint has remained elusive and the setpoint theory did not provide practical clues for body weight reduction interventions. For this an alternative theoretical model is necessary, which is available as the settling point model. The settling point model postulates that there is little active regulation towards a predefined body weight, but that body weight settles based on the resultant of a number of contributors, represented by the individual's genetic predisposition, in interaction with environmental and socioeconomic factors, such as diet and lifestyle. This review refines the settling point model and argues that by taking body weight regulation from a settling point perspective, the road will be opened to careful dissection of the various contributors to establishment of body weight and its regulation. This is both necessary and useful. Nutrigenomic technologies may help to delineate contributors to body weight settling. Understanding how and to which extent the different contributors influence body weight will allow the design of weight loss and weight maintenance interventions, which hopefully are more successful than those that are currently available.
Collapse
Affiliation(s)
- Jaap Keijer
- Human and Animal Physiology, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands.
| | - Femke P M Hoevenaars
- Human and Animal Physiology, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands.
| | - Arie Nieuwenhuizen
- Human and Animal Physiology, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands.
| | - Evert M van Schothorst
- Human and Animal Physiology, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands.
| |
Collapse
|
25
|
Abstract
Mammals regulate fat mass so that increases or reductions in adipose tissue mass activate responses that favor return to one's previous weight. A reduction in fat mass activates a system that increases food intake and reduces energy expenditure; conversely, overfeeding and rapid adipose tissue expansion reduces food intake and increases energy expenditure. With the identification of leptin nearly two decades ago, the central circuit that defends against reductions in body fat was revealed. However, the systems that defend against rapid expansion of fat mass remain largely unknown. Here we review the physiology of the overfed state and evidence for a distinct regulatory system, which unlike the leptin-mediated system, we propose primarily measures a functional aspect of adipose tissue and not total mass per se.
Collapse
Affiliation(s)
- Yann Ravussin
- Department of Medicine, Columbia University, 1150 St. Nicholas Ave, New York, NY 10032, USA; Naomi Berrie Diabetes Center, Columbia University, 1150 St. Nicholas Ave, New York, NY 10032, USA
| | - Rudolph L Leibel
- Naomi Berrie Diabetes Center, Columbia University, 1150 St. Nicholas Ave, New York, NY 10032, USA; Department of Pediatrics, Columbia University, 1150 St. Nicholas Ave, New York, NY 10032, USA
| | - Anthony W Ferrante
- Department of Medicine, Columbia University, 1150 St. Nicholas Ave, New York, NY 10032, USA; Naomi Berrie Diabetes Center, Columbia University, 1150 St. Nicholas Ave, New York, NY 10032, USA.
| |
Collapse
|
26
|
Abstract
The hyperphagia, low sympathetic nervous system tone, and decreased circulating concentrations of bioactive thyroid hormones that are common to states of congenital leptin deficiency and hypoleptinemia following and during weight loss suggest that the major physiological function of leptin is to signal states of negative energy balance and decreased energy stores. In weight-reduced humans, these phenotypes together with pronounced hypometabolism and increased parasympathetic nervous system tone create the optimal circumstance for weight regain. Based on the weight loss induced by leptin administration in states of leptin deficiency (obese) and observed similarity of phenotypes in states of congenital and dietary-induced states of hypoleptinemia (reduced obese), it has been suggested that exogenous leptin could potentially be useful in initiating, promoting, and sustaining weight reduction. However, the responses of human beings to exogenous leptin administration are dependent not only on extant energy stores but also on energy balance. Leptin administration to humans at usual weight has little, if any, effect on body weight while leptin administration during weight loss mitigates hunger, especially if given in supraphysiological doses during severe caloric restriction. Leptin repletion is most effective following weight loss by dietary restriction. In this state of weight stability but reduced energy stores, leptin at least partially reverses many of the metabolic, autonomic, neuroendocrine, and behavioral adaptations that favor weight regain. The major physiological function of leptin is to signal states of negative energy balance and decreased energy stores. Leptin, and pharmacotherapies affecting leptin signaling pathways, is likely to be most useful in sustaining weight loss.
Collapse
Affiliation(s)
- Michael Rosenbaum
- Division of Molecular GeneticsDepartments of Pediatrics and Medicine, College of Physicians and Surgeons, Columbia University, Russ Berrie Medical Science Pavilion, 6th Floor, 1150 St Nicholas Avenue, New York, New York 10032, USA
| | - Rudolph L Leibel
- Division of Molecular GeneticsDepartments of Pediatrics and Medicine, College of Physicians and Surgeons, Columbia University, Russ Berrie Medical Science Pavilion, 6th Floor, 1150 St Nicholas Avenue, New York, New York 10032, USA
| |
Collapse
|
27
|
Berkseth KE, Guyenet SJ, Melhorn SJ, Lee D, Thaler JP, Schur EA, Schwartz MW. Hypothalamic gliosis associated with high-fat diet feeding is reversible in mice: a combined immunohistochemical and magnetic resonance imaging study. Endocrinology 2014; 155:2858-67. [PMID: 24914942 PMCID: PMC4098007 DOI: 10.1210/en.2014-1121] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Gliosis, the activation of astrocyte and microglial cell populations, is a hallmark of central nervous system injury and is detectable using either immunohistochemistry or in vivo magnetic resonance imaging (MRI). Obesity in rodents and humans is associated with gliosis of the arcuate nucleus, a key hypothalamic region for the regulation of energy homeostasis and adiposity, but whether this response is permanent or reversible is unknown. Here we combine terminal immunohistochemistry analysis with serial, noninvasive MRI to characterize the progression and reversibility of hypothalamic gliosis in high-fat diet (HFD)-fed mice. The effects of HFD feeding for 16 weeks to increase body weight and adiposity relative to chow were nearly normalized after the return to chow feeding for an additional 4 weeks in the diet-reversal group. Mice maintained on the HFD for the full 20-week study period experienced continued weight gain associated with the expected increases of astrocyte and microglial activation in the arcuate nucleus, but these changes were not observed in the diet-reversal group. The proopiomelanocortin neuron number did not differ between groups. Although MRI demonstrated a positive correlation between body weight, adiposity, and the gliosis-associated T2 signal in the mediobasal hypothalamus, it did not detect the reversal of gliosis among the HFD-fed mice after the return to chow diet. We conclude that hypothalamic gliosis associated with 16-week HFD feeding is largely reversible in rodents, consistent with the reversal of the HFD-induced obesity phenotype, and extend published evidence regarding the utility of MRI as a tool for studying obesity-associated hypothalamic gliosis in vivo.
Collapse
Affiliation(s)
- Kathryn E Berkseth
- Diabetes and Obesity Center of Excellence (K.E.B., S.J.G., J.P.T., M.W.S.) and Departments of Medicine (E.A.S., S.J.M.) and Radiology (D.L.), University of Washington, Seattle, Washington 98109
| | | | | | | | | | | | | |
Collapse
|
28
|
Skowronski AA, Morabito MV, Mueller BR, Lee S, Hjorth S, Lehmann A, Watanabe K, Zeltser LM, Ravussin Y, Rosenbaum M, LeDuc CA, Leibel RL. Effects of a novel MC4R agonist on maintenance of reduced body weight in diet-induced obese mice. Obesity (Silver Spring) 2014; 22:1287-95. [PMID: 24318934 PMCID: PMC4008720 DOI: 10.1002/oby.20678] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 11/26/2013] [Accepted: 12/04/2013] [Indexed: 01/23/2023]
Abstract
OBJECTIVE The physiology of the weight-reduced (WR) state suggests that pharmacologic agents affecting energy homeostasis may have greater efficacy in WR individuals. Our aim was to establish a protocol that allows for evaluation of efficacy of weight maintenance agents and to assess the effectiveness of AZD2820, a novel melanocortin 4 receptor (MC4R) agonist in such a paradigm. METHODS MC4R agonist was administered in stratified doses to mice who were either fed high-fat diet ad libitum (AL) throughout the study; or stabilized at a 20% reduced body weight (BW), administered the drug for 4 weeks, and thereafter released from caloric restriction while continuing to receive the drug (WR). RESULTS After release of WR mice to AL feeding, the high-dose group (53.4 nmol/day) regained 12.4% less BW than their vehicle-treated controls since the beginning of drug treatment. In WR mice, 10.8 nmol/day of the agonist was sufficient to maintain these animals at 95.1% of initial BW versus 53.4 nmol/day required to maintain the BW of AL animals (94.5%). CONCLUSIONS In the WR state, the MC4R agonist was comparably efficacious to a five-fold higher dose in the AL state. This protocol provides a model for evaluating the mechanisms and quantitative efficacy of weight-maintenance strategies and agents.
Collapse
Affiliation(s)
- Alicja A. Skowronski
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
| | - Michael V. Morabito
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
| | - Bridget R. Mueller
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
| | - Samuel Lee
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
| | - Stephan Hjorth
- AstraZeneca, R&D Disease Area Diabetes/Obesity, Mölndal, Sweden
| | - Anders Lehmann
- AstraZeneca, R&D Disease Area Diabetes/Obesity, Mölndal, Sweden
| | - Kazuhisa Watanabe
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
| | - Lori M. Zeltser
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
| | - Yann Ravussin
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
| | - Michael Rosenbaum
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
| | - Charles A. LeDuc
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
| | - Rudolph L. Leibel
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, NY
- Corresponding author: Naomi Berrie Diabetes Center, Columbia University, 1150 St. Nicholas Ave, New York, NY 10032,
| |
Collapse
|
29
|
Effects of chronic leptin infusion on subsequent body weight and composition in mice: Can body weight set point be reset? Mol Metab 2014; 3:432-40. [PMID: 24944902 PMCID: PMC4060284 DOI: 10.1016/j.molmet.2014.02.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 02/20/2014] [Accepted: 02/24/2014] [Indexed: 11/22/2022] Open
Abstract
Circulating leptin concentrations correlate with fat mass and signal the status of somatic energy stores to the brain. Previous studies suggest that diet-induced elevations of body weight increase body weight “set-point”. To assess whether chronic hyperleptinemia is responsible for this shift in defended body weight, we elevated circulating leptin concentrations in lean mice to those comparable to diet-induced obese mice for eighteen weeks. We hypothesized that following cessation of leptin infusion, a higher body weight would be defended. Compared to saline-infused controls, leptin-infused mice had elevated circulating leptin concentrations, gained less weight, yet had similar metabolic rates. Following cessation of leptin administration, leptin-infused mice gained some weight yet plateaued at 5–10% below controls. These results suggest that, unlike mice rendered hyperleptinemic by diet-induced weight gain, leptin-infused mice do not subsequently “defend” a higher body weight, suggesting that hyperleptinemia per se does not mimic the CNS consequences of chronic weight gain.
Collapse
|
30
|
Roujeau C, Jockers R, Dam J. New pharmacological perspectives for the leptin receptor in the treatment of obesity. Front Endocrinol (Lausanne) 2014; 5:167. [PMID: 25352831 PMCID: PMC4195360 DOI: 10.3389/fendo.2014.00167] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 09/26/2014] [Indexed: 12/24/2022] Open
Abstract
After its discovery in 1994, leptin became the great hope as an anti-obesity treatment based on its ability to reduce food intake and increase energy expenditure. However, treating obese people with exogenous leptin was unsuccessful in most cases since most of them present already high circulating leptin levels to which they do not respond anymore defining the so-called state of "leptin resistance." Indeed, leptin therapy is unsuccessful to lower body weight in commonly obese people but effective in people with rare single gene mutations of the leptin gene. Consequently, treatment of obese people with leptin was given less attention and the focus of obesity research shifted toward the prevention and reversal of the state of leptin resistance. Many of these new promising approaches aim to restore or sensitize the impaired function of the leptin receptor by pharmacological means. The current review will focus on the different emerging therapeutic strategies in obesity research that are related to leptin and its receptor.
Collapse
Affiliation(s)
- Clara Roujeau
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Ralf Jockers
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Julie Dam
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
- *Correspondence: Julie Dam, Institut Cochin, 22 rue Méchain, 75014, Paris, France e-mail:
| |
Collapse
|
31
|
Kentish SJ, O'Donnell TA, Frisby CL, Li H, Wittert GA, Page AJ. Altered gastric vagal mechanosensitivity in diet-induced obesity persists on return to normal chow and is accompanied by increased food intake. Int J Obes (Lond) 2013; 38:636-42. [PMID: 23897220 DOI: 10.1038/ijo.2013.138] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 07/10/2013] [Accepted: 07/20/2013] [Indexed: 11/09/2022]
Abstract
BACKGROUND AND AIMS Gastric vagal afferents convey satiety signals in response to mechanical stimuli. The sensitivity of these afferents is decreased in diet-induced obesity. Leptin, secreted from gastric epithelial cells, potentiates the response of vagal afferents to mechanical stimuli in lean mice, but has an inhibitory effect in high-fat diet (HFD)-induced obese mice. We sought to determine whether changes in vagal afferent function and response to leptin in obesity were reversible by returning obese mice consuming a HFD to standard laboratory chow diet (SLD). METHODS Eight-week-old female C57BL/6 mice were either fed a SLD (N=20) or HFD (N=20) for 24 weeks. A third group was fed a HFD for 12 weeks and then a SLD for a further 12 weeks (RFD, N=18). An in vitro gastro-oesophageal vagal afferent preparation was used to determine the mechanosensitivity of gastric vagal afferents and the modulatory effect of leptin (0.1-10 nM) was examined. Retrograde tracing and quantitative RT-PCR were used to determine the expression of leptin receptor (LepR) messenger RNA (mRNA) in whole nodose and specific cell bodies traced from the stomach. RESULTS After 24 weeks, both the HFD and RFD mice had increased body weight, gonadal fat mass, plasma leptin, plasma insulin and daily energy consumption compared with the SLD mice. The HFD and RFD mice had reduced tension receptor mechanosensitivity and leptin further inhibited responses to tension in HFD, RFD but not SLD mice. Mucosal receptors from both the SLD and RFD mice were potentiated by leptin, an effect not seen in HFD mice. LepR expression was unchanged in the whole nodose, but was reduced in the mucosal afferents of the HFD and RFD mice. CONCLUSION Disruption of gastric vagal afferent function by HFD-induced obesity is only partially reversible by dietary change, which provides a potential mechanism preventing maintenance of weight loss.
Collapse
Affiliation(s)
- S J Kentish
- Nerve-Gut Research Laboratory, Hanson Institute, Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia
| | | | - C L Frisby
- Royal Adelaide Hospital, Adelaide, SA, Australia
| | - H Li
- Nerve-Gut Research Laboratory, Hanson Institute, Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - G A Wittert
- Nerve-Gut Research Laboratory, Hanson Institute, Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia
| | - A J Page
- 1] Nerve-Gut Research Laboratory, Hanson Institute, Discipline of Medicine, University of Adelaide, Adelaide, SA, Australia [2] Royal Adelaide Hospital, Adelaide, SA, Australia
| |
Collapse
|
32
|
Relationships between dietary macronutrients and adult neurogenesis in the regulation of energy metabolism. Br J Nutr 2013; 109:1573-89. [PMID: 23433235 DOI: 10.1017/s000711451200579x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Of the environmental factors which have an impact on body weight, nutrients are most influential. Within normal limits, hypothalamic and related neuronal populations correct perturbations in energy metabolism, to return the body to its nutritional set-point, either through direct response to nutrients or indirectly via peripheral appetite signals. Excessive intake of certain macronutrients, such as simple carbohydrates and SFA, can lead to obesity and attendant metabolic dysfunction, also reflected in alterations in structural plasticity, and, intriguingly,neurogenesis, in some of these brain regions. Neurogenesis, previously thought to occur only in the embryo, is now known to take place in the adult brain, dependent on numerous stimulating and inhibiting factors, including dietary components. Because of classic associations between neurogenesis and the hippocampus, in learning and cognition, this brain region has also been the focus of attention in the study of links between diet and neurogenesis. Recently, however, a more complete picture of this relationship has been building: not only has the hypothalamus been shown to satisfy the criteria for a neurogenic niche, but appetite-related mediators, including circulating hormones, such as leptin and ghrelin, pro-inflammatory cytokines and the endocannabinoid intracellular messengers, are also being examined for their potential role in mediating neurogenic responses to macronutrients. The present review draws together these observations and investigates whether n-3 PUFA may exert their attenuating effects on body weight through the stimulation of adult neurogenesis. Exploration of the effects of nutraceuticals on neurogenic brain regions may encourage the development of new rational therapies in the fight against obesity.
Collapse
|
33
|
|
34
|
Cordoba-Chacon J, Gahete MD, Pozo-Salas AI, Moreno-Herrera A, Castaño JP, Kineman RD, Luque RM. Peripubertal-onset but not adult-onset obesity increases IGF-I and drives development of lean mass, which may lessen the metabolic impairment in adult obesity. Am J Physiol Endocrinol Metab 2012; 303:E1151-7. [PMID: 22932784 PMCID: PMC3774069 DOI: 10.1152/ajpendo.00340.2012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
It has been suggested that adult metabolic dysfunction may be more severe in individuals who become obese as children compared with those who become obese later in life. To determine whether adult metabolic function differs if diet-induced weight gain occurs during the peripubertal age vs. if excess weight gain occurs after puberty, male C57Bl/6J mice were fed a low-fat (LF; 10% kcal from fat) or high-fat (HF; 60% kcal from fat) diet starting during the peripubertal period (pHF; 4 wk of age) or as adults (aHF; 12 wk of age). Both pHF and aHF mice were hyperinsulinemic and hyperglycemic, and both showed impaired glucose tolerance and insulin resistance compared with their LF-fed controls. However, despite a longer time on diet, pHF mice were relatively more insulin sensitive than aHF mice, which was associated with higher lean mass and circulating IGF-I levels. In addition, HF feeding had an overall stimulatory effect on circulating corticosterone levels; however, this rise was associated only with elevated plasma ACTH in the aHF mice. Despite the belief that adult metabolic dysfunction may be more severe in individuals who become obese as children, data generated using a diet-induced obese mouse model suggest that adult metabolic dysfunction associated with peripubertal onset of obesity is not worse than that associated with adult-onset obesity.
Collapse
Affiliation(s)
- Jose Cordoba-Chacon
- Department of Cell Biology, Physiology, and Immunology, Instituto Maimónides de Investigación Biomédica de Córdoba/Hospital Universitario Reina Sofia, University of Cordoba Centro de Investigacion Biomedica en Red Fisiopatologia de Obesidad y Nutricion, Córdoba, Spain
| | | | | | | | | | | | | |
Collapse
|
35
|
Muñoz R, Carmody JS, Stylopoulos N, Davis P, Kaplan LM. Isolated duodenal exclusion increases energy expenditure and improves glucose homeostasis in diet-induced obese rats. Am J Physiol Regul Integr Comp Physiol 2012; 303:R985-93. [PMID: 22972837 DOI: 10.1152/ajpregu.00262.2012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Roux-en-Y gastric bypass (RYGB) in rodent models reduces food intake (FI), increases resting energy expenditure (EE), and improves glycemic control. We have shown that mimicking the duodenal component of RYGB by implantation of a 10-cm endoluminal sleeve device (ELS-10) induces weight loss and improves glycemic control in diet-induced obese (DIO) rats. We sought to determine the mechanisms and structural requirements of these effects. We examined the effects of ELS-10 devices implanted in male DIO rats on body weight, food intake (FI), meal patterns, total and resting EE, and multiple parameters of glucose homeostasis, comparing them with sham-operated (SO) rats and with SO rats weight matched to the ELS-10-treated group. To determine the extent of duodenal exclusion required to influence metabolic outcomes, we compared the effects of implanting 10-, 4-, or 1-cm ELS devices. ELS-10 rats exhibited 13% higher total and 9% higher resting EE than SO controls. ELS-10 rats also exhibited enhanced postprandial GLP-1 secretion and improved glucose tolerance and insulin sensitivity out of proportion to the effects of weight loss alone. Implantation of 4- or 1-cm ELS devices had no effect on EE and limited effects on glucose homeostasis. Complete duodenal exclusion with ELS-10 induces weight loss by decreasing FI and increasing EE and improves glycemic control through weight loss-independent mechanisms. Thus signals originating in the proximal small intestine appear to exert a direct influence on the physiological regulation of EE and glucose homeostasis. Their selective manipulation could provide effective new therapies for obesity and diabetes that mimic the benefits of RYGB.
Collapse
Affiliation(s)
- Rodrigo Muñoz
- Obesity, Metabolism & Nutritional Institute and Gastrointestinal Unit, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02129, USA
| | | | | | | | | |
Collapse
|
36
|
Ravussin Y, Gutman R, LeDuc CA, Leibel RL. Estimating energy expenditure in mice using an energy balance technique. Int J Obes (Lond) 2012; 37:399-403. [PMID: 22751256 DOI: 10.1038/ijo.2012.105] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To compare, in mice, the accuracy of estimates of energy expenditure (EE) using an energy balance technique (TEEbal: food energy intake and body composition change) vs indirect calorimetry (TEEIC). SUBJECTS In 32 male C57BL/6J mice, EE was estimated using an energy balance (caloric intake minus change in body energy stores) method over a 37-day period. EE was also measured in the same animals by indirect calorimetry. These measures were compared. RESULTS The two methods were highly correlated (r(2)=0.87: TEEbal=1.07*TEEIC-0.22, P<0.0001). By Bland-Altman analysis, TEEbal estimates were slightly higher (4.6±1.5%; P<0.05) than TEEIC estimates (Bias=0.55 kcal per 24 h). CONCLUSION TEEbal can be performed in 'home cages' and provides an accurate integrated long-term measurement of EE while minimizing potentially confounding stress that may accompany the use of indirect calorimetry systems. The technique can also be used to assess long-term energy intake.
Collapse
Affiliation(s)
- Y Ravussin
- Division of Molecular Genetics and Naomi Berrie Diabetes Center, Columbia University, New York, NY 10032, USA
| | | | | | | |
Collapse
|
37
|
Ravussin Y, LeDuc CA, Watanabe K, Leibel RL. Effects of ambient temperature on adaptive thermogenesis during maintenance of reduced body weight in mice. Am J Physiol Regul Integr Comp Physiol 2012; 303:R438-48. [PMID: 22761182 DOI: 10.1152/ajpregu.00092.2012] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We showed previously that, at ambient room temperature (22°C), mice maintained at 20% below their initial body weight by calorie restriction expend energy at a rate below that which can be accounted for by the decrease of fat and fat-free mass. Food-restricted rodents may become torpid at subthermoneutral temperatures, a possible confounding factor when using mice as human models in obesity research. We examined the bioenergetic, hormonal, and behavioral responses to maintenance of a 20% body weight reduction in singly housed C57BL/6J +/+ and Lep(ob) mice housed at both 22°C and 30°C. Weight-reduced high-fat-fed diet mice (HFD-WR) showed similar quantitative reductions in energy expenditure-adjusted for body mass and composition-at both 22°C and 30°C: -1.4 kcal/24 h and -1.6 kcal/24 h below predicted, respectively, and neither group entered torpor. In contrast, weight-reduced Lep(ob) mice (OB-WR) housed at 22°C became torpid in the late lights-off period (0200-0500) but did not when housed at 30°C. These studies indicate that mice with an intact leptin axis display similar decreases in "absolute" energy expenditure in response to weight reduction at both 22°C and 30°C ambient temperature. More importantly, the "percent" decrease in total energy expenditure observed in the HFD-WR compared with AL mice is much greater at 30°C (-19%) than at 22°C (-10%). Basal energy expenditure demands are ∼45% lower in mice housed at 30°C vs. 22°C, since the mice housed at thermoneutrality do not allocate extra energy for heat production. The higher total energy expenditure of mice housed at 22°C due to these increased thermogenic demands may mask physiologically relevant changes in energy expenditure showing that ambient temperature must be carefully considered when quantifying energy metabolism in both rodents and humans.
Collapse
Affiliation(s)
- Yann Ravussin
- Department of Pediatrics, Division of Molecular Genetics, Columbia University, College of Physicians and Surgeons, New York, New York, USA
| | | | | | | |
Collapse
|
38
|
Ravussin Y, Koren O, Spor A, LeDuc C, Gutman R, Stombaugh J, Knight R, Ley RE, Leibel RL. Responses of gut microbiota to diet composition and weight loss in lean and obese mice. Obesity (Silver Spring) 2012; 20:738-47. [PMID: 21593810 PMCID: PMC3871199 DOI: 10.1038/oby.2011.111] [Citation(s) in RCA: 304] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Maintenance of a reduced body weight is accompanied by a decrease in energy expenditure beyond that accounted for by reduced body mass and composition, as well as by an increased drive to eat. These effects appear to be due--in part--to reductions in circulating leptin concentrations due to loss of body fat. Gut microbiota have been implicated in the regulation of body weight. The effects of weight loss on qualitative aspects of gut microbiota have been studied in humans and mice, but these studies have been confounded by concurrent changes in diet composition, which influence microbial community composition. We studied the impact of 20% weight loss on the microbiota of diet-induced obese (DIO: 60% calories fat) mice on a high-fat diet (HFD). Weight-reduced DIO (DIO-WR) mice had the same body weight and composition as control (CON) ad-libitum (AL) fed mice being fed a control diet (10% calories fat), allowing a direct comparison of diet and weight-perturbation effects. Microbial community composition was assessed by pyrosequencing 16S rRNA genes derived from the ceca of sacrificed animals. There was a strong effect of diet composition on the diversity and composition of the microbiota. The relative abundance of specific members of the microbiota was correlated with circulating leptin concentrations and gene expression levels of inflammation markers in subcutaneous white adipose tissue in all mice. Together, these results suggest that both host adiposity and diet composition impact microbiota composition, possibly through leptin-mediated regulation of mucus production and/or inflammatory processes that alter the gut habitat.
Collapse
Affiliation(s)
- Yann Ravussin
- Division of Molecular Genetics and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Omry Koren
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | - Ayme Spor
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | - Charles LeDuc
- Division of Molecular Genetics and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Roee Gutman
- Division of Molecular Genetics and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Jesse Stombaugh
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, USA
| | - Rob Knight
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado, USA
- Howard Hughes Medical Institute, Boulder, Colorado, USA
| | - Ruth E. Ley
- Department of Microbiology, Cornell University, Ithaca, New York, USA
| | - Rudolph L. Leibel
- Division of Molecular Genetics and Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| |
Collapse
|
39
|
Hambly C, Duncan JS, Archer ZA, Moar KM, Mercer JG, Speakman JR. Repletion of TNFα or leptin in calorically restricted mice suppresses post-restriction hyperphagia. Dis Model Mech 2012; 5:83-94. [PMID: 21954068 PMCID: PMC3255546 DOI: 10.1242/dmm.007781] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 08/02/2011] [Indexed: 11/30/2022] Open
Abstract
The causes of post-restriction hyperphagia (PRH) represent a target for drug-based therapies to prevent obesity. However, the factors causing PRH are poorly understood. We show that, in mice, the extent of PRH was independent of the time under restriction, but depended on its severity, suggesting that PRH was driven by signals from altered body composition. Signals related to fat mass were important drivers. Circulating levels of leptin and TNFα were significantly depleted following caloric restriction (CR). We experimentally repleted their levels to match those of controls, and found that in both treatment groups the level of PRH was significantly blunted. These data establish a role for TNFα and leptin in the non-pathological regulation of energy homeostasis. Signals from adipose tissue, including but not limited to leptin and TNFα, regulate PRH and might be targets for therapies that support people engaged in CR to reduce obesity.
Collapse
Affiliation(s)
- Catherine Hambly
- Aberdeen Centre for Energy Regulation and Obesity (ACERO), Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen AB21 9SB, Scotland, UK
- ACERO, Institute of Biological and Environmental Science, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| | - Jacqueline S. Duncan
- Aberdeen Centre for Energy Regulation and Obesity (ACERO), Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen AB21 9SB, Scotland, UK
| | - Zoë A. Archer
- Aberdeen Centre for Energy Regulation and Obesity (ACERO), Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen AB21 9SB, Scotland, UK
| | - Kim M. Moar
- Aberdeen Centre for Energy Regulation and Obesity (ACERO), Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen AB21 9SB, Scotland, UK
| | - Julian G. Mercer
- Aberdeen Centre for Energy Regulation and Obesity (ACERO), Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen AB21 9SB, Scotland, UK
| | - John R. Speakman
- Aberdeen Centre for Energy Regulation and Obesity (ACERO), Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen AB21 9SB, Scotland, UK
- ACERO, Institute of Biological and Environmental Science, University of Aberdeen, Aberdeen, AB24 2TZ, Scotland, UK
| |
Collapse
|
40
|
Thaler JP, Yi CX, Schur EA, Guyenet SJ, Hwang BH, Dietrich MO, Zhao X, Sarruf DA, Izgur V, Maravilla KR, Nguyen HT, Fischer JD, Matsen ME, Wisse BE, Morton GJ, Horvath TL, Baskin DG, Tschöp MH, Schwartz MW. Obesity is associated with hypothalamic injury in rodents and humans. J Clin Invest 2011; 122:153-62. [PMID: 22201683 DOI: 10.1172/jci59660] [Citation(s) in RCA: 1288] [Impact Index Per Article: 99.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Accepted: 11/02/2011] [Indexed: 01/21/2023] Open
Abstract
Rodent models of obesity induced by consuming high-fat diet (HFD) are characterized by inflammation both in peripheral tissues and in hypothalamic areas critical for energy homeostasis. Here we report that unlike inflammation in peripheral tissues, which develops as a consequence of obesity, hypothalamic inflammatory signaling was evident in both rats and mice within 1 to 3 days of HFD onset, prior to substantial weight gain. Furthermore, both reactive gliosis and markers suggestive of neuron injury were evident in the hypothalamic arcuate nucleus of rats and mice within the first week of HFD feeding. Although these responses temporarily subsided, suggesting that neuroprotective mechanisms may initially limit the damage, with continued HFD feeding, inflammation and gliosis returned permanently to the mediobasal hypothalamus. Consistent with these data in rodents, we found evidence of increased gliosis in the mediobasal hypothalamus of obese humans, as assessed by MRI. These findings collectively suggest that, in both humans and rodent models, obesity is associated with neuronal injury in a brain area crucial for body weight control.
Collapse
Affiliation(s)
- Joshua P Thaler
- Division of Metabolism, Endocrinology and Nutrition, Diabetes and Obesity Center of Excellence, University of Washington, Seattle, Washington 98109, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Tam CS, Lecoultre V, Ravussin E. Novel strategy for the use of leptin for obesity therapy. Expert Opin Biol Ther 2011; 11:1677-85. [PMID: 21910668 DOI: 10.1517/14712598.2011.619974] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Obesity is a chronic disease and a major global health challenge. Apart from bariatric surgery, which is costly and not without risk, there are currently no successful long-term treatment options for obesity. The history of pharmacological agents for obesity has been turbulent with many examples of drugs being removed from the market due to significant side effects. Orlistat and sibutramine (the latest drugs on the market) provide only modest weight loss and are both associated with high attrition rates due to intolerable side effects. Furthermore, sibutramine was recently withdrawn from the market. There is a need for the development of safe and efficacious drug treatments for obesity. AREAS COVERED This review covers the history of leptin therapy as an orphan drug, leptin-replacement therapy as a treatment for obesity, preclinical studies showing the efficacy of leptin/amylin combination and finally, the very promising early clinical findings using pramlintide/meteleptin combination therapy in overweight to obese individuals. EXPERT OPINION Combination pharmacological therapy, such as pramlintide/metreleptin, for the treatment of obesity is very promising and is supported by encouraging weight loss results and improvement in metabolic makers in early-phase clinical studies. However, the latest randomized clinical trial on pramlintide/metreleptin was recently stopped due to safety concerns.
Collapse
Affiliation(s)
- Charmaine S Tam
- Human Physiology, Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
| | | | | |
Collapse
|