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van Baak MA, Mariman ECM. Obesity-induced and weight-loss-induced physiological factors affecting weight regain. Nat Rev Endocrinol 2023; 19:655-670. [PMID: 37696920 DOI: 10.1038/s41574-023-00887-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/27/2023] [Indexed: 09/13/2023]
Abstract
Weight regain after successful weight loss resulting from lifestyle interventions is a major challenge in the management of overweight and obesity. Knowledge of the causal mechanisms for weight regain can help researchers and clinicians to find effective strategies to tackle weight regain and reduce obesity-associated metabolic and cardiovascular complications. This Review summarizes the current understanding of a number of potential physiological mechanisms underlying weight regain after weight loss, including: the role of adipose tissue immune cells; hormonal and neuronal factors affecting hunger, satiety and reward; resting energy expenditure and adaptive thermogenesis; and lipid metabolism (lipolysis and lipid oxidation). We describe and discuss obesity-associated changes in these mechanisms, their persistence during weight loss and weight regain and their association with weight regain. Interventions to prevent or limit weight regain based on these factors, such as diet, exercise, pharmacotherapy and biomedical strategies, and current knowledge on the effectiveness of these interventions are also reviewed.
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Affiliation(s)
- Marleen A van Baak
- NUTRIM School for Nutrition and Translational Research in Metabolism, Department of Human Biology, Maastricht University, Maastricht, Netherlands.
| | - Edwin C M Mariman
- NUTRIM School for Nutrition and Translational Research in Metabolism, Department of Human Biology, Maastricht University, Maastricht, Netherlands
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2
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The effect of pre-resection obesity on post-resection body composition after 75% small bowel resection in rats. Sci Rep 2021; 11:13009. [PMID: 34155300 PMCID: PMC8217239 DOI: 10.1038/s41598-021-92510-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 06/03/2021] [Indexed: 11/08/2022] Open
Abstract
In patients with short bowel syndrome, an elevated pre-resection Body Mass Index may be protective of post-resection body composition. We hypothesized that rats with diet-induced obesity would lose less lean body mass after undergoing massive small bowel resection compared to non-obese rats. Rats (CD IGS; age = 2 mo; N = 80) were randomly assigned to either a high-fat (obese rats) or a low-fat diet (non-obese rats), and fed ad lib for six months. Each diet group then was randomized to either underwent a 75% distal small bowel resection (massive resection) or small bowel transection with re-anastomosis (sham resection). All rats then were fed ad lib with an intermediate-fat diet (25% of total calories) for two months. Body weight and quantitative magnetic resonance-determined body composition were monitored. Preoperative body weight was 884 ± 95 versus 741 ± 75 g, and preoperative percent body fat was 35.8 ± 3.9 versus 24.9 ± 4.6%; high-fat vs. low fat diet, respectively (p < 0.0001); preoperative diet type had no effect on lean mass. Regarding total body weight, massive resection produced an 18% versus 5% decrease in high-fat versus low-fat rats respectively, while sham resection produced a 2% decrease vs. a 7% increase, respectively (p < 0.0001, preoperative vs. necropsy data). Sham resection had no effect on lean mass; after massive resection, both high-fat and low-fat rats lost lean mass, but these changes were not different between the latter two rat groups. The high-fat diet and low-fat diet induced obesity and marginal obesity, respectively. The massive resection produced greater weight loss in high-fat rats compared to low-fat rats. The type of dietary preconditioning had no effect on lean mass loss after massive resection. A protective effect of pre-existing obesity on lean mass after massive intestinal resection was not demonstrated.
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3
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Milliken BT, Elfers C, Chepurny OG, Chichura KS, Sweet IR, Borner T, Hayes MR, De Jonghe BC, Holz GG, Roth CL, Doyle RP. Design and Evaluation of Peptide Dual-Agonists of GLP-1 and NPY2 Receptors for Glucoregulation and Weight Loss with Mitigated Nausea and Emesis. J Med Chem 2021; 64:1127-1138. [PMID: 33449689 PMCID: PMC7956155 DOI: 10.1021/acs.jmedchem.0c01783] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
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There is a critical unmet need for
therapeutics to treat the epidemic
of comorbidities associated with obesity and type 2 diabetes, ideally
devoid of nausea/emesis. This study developed monomeric peptide agonists
of glucagon-like peptide 1 receptor (GLP-1R) and neuropeptide Y2 receptor
(Y2-R) based on exendin-4 (Ex-4) and PYY3–36. A
novel peptide, GEP44, was obtained via in vitro receptor
screens, insulin secretion in islets, stability assays, and in vivo rat and shrew studies of glucoregulation, weight
loss, nausea, and emesis. GEP44 in lean and diet-induced obese rats
produced greater reduction in body weight compared to Ex-4 without
triggering nausea associated behavior. Studies in the shrew demonstrated
a near absence of emesis for GEP44 in contrast to Ex-4. Collectively,
these data demonstrate that targeting GLP-1R and Y2-R with chimeric
single peptides offers a route to new glucoregulatory treatments that
are well-tolerated and have improved weight loss when compared directly
to Ex-4.
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Affiliation(s)
- Brandon T Milliken
- Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244, United States
| | - Clinton Elfers
- Department of Pediatrics, Seattle Children's Hospital, University of Washington, Seattle, Washington 98105, United States
| | - Oleg G Chepurny
- Department of Medicine, State University of New York, Upstate Medical University, Syracuse, New York 13210, United States
| | - Kylie S Chichura
- Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244, United States
| | - Ian R Sweet
- Diabetes Research Institute, University of Washington, Seattle, Washington 98105, United States
| | - Tito Borner
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Matthew R Hayes
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Bart C De Jonghe
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - George G Holz
- Department of Medicine, State University of New York, Upstate Medical University, Syracuse, New York 13210, United States
| | - Christian L Roth
- Department of Pediatrics, Seattle Children's Hospital, University of Washington, Seattle, Washington 98105, United States
| | - Robert P Doyle
- Department of Chemistry, Syracuse University, 111 College Place, Syracuse, New York 13244, United States.,Department of Medicine, State University of New York, Upstate Medical University, Syracuse, New York 13210, United States
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4
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Zapata RC, Singh A, Pezeshki A, Avirineni BS, Patra S, Chelikani PK. Low-Protein Diets with Fixed Carbohydrate Content Promote Hyperphagia and Sympathetically Mediated Increase in Energy Expenditure. Mol Nutr Food Res 2019; 63:e1900088. [PMID: 31365786 DOI: 10.1002/mnfr.201900088] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 05/17/2019] [Indexed: 12/13/2022]
Abstract
SCOPE Dietary protein restriction elicits hyperphagia and increases energy expenditure; however, less is known of whether these responses are a consequence of increasing carbohydrate content. The effects of protein-diluted diets with fixed carbohydrate content on energy balance, hormones, and key markers of protein sensing and thermogenesis in tissues are determined. METHODS AND RESULTS Obesity-prone rats (n = 13-16 per group) are randomized to diets containing fixed carbohydrate (52% calories) and varying protein concentrations: 15% (control), 10% (mild protein restriction), 5% (moderate protein restriction) or 1% (severe protein restriction) protein calories, or protein-matched to 5% protein, for 21 days. Propranolol and ondansetron are administered to interrogate the roles of sympathetic and serotonergic systems, respectively, in diet-induced changes in energy expenditure. It is found that mild-to-moderate protein restriction promotes transient hyperphagia, whereas severe protein restriction induces hypophagia, with alterations in meal patterns. Protein restriction enhances energy expenditure that is partly attenuated by propranolol, but not ondansetron. Moderate to severe protein restriction decreases gains in body weight, lean and fat mass, decreased postprandial glucose and leptin, but increased fibroblast growth factor-21 concentrations. Protein-matching retains lean mass suggesting that intake of dietary protein, but not calories, is important for preserving lean mass. Notably, protein restriction increases the protein and/or transcript abundance of key amino acid sensing molecules in liver and intestine (PERK, eIF2α, ATF2, CHOP, 4EBP1, FGF21), and upregulated thermogenic markers (β2AR, Klotho, HADH, UCP-1) in brown adipose tissue. CONCLUSION Low-protein diets promote hyperphagia and sympathetically mediated increase in energy expenditure, prevent gains in tissue reserves, and concurrently upregulate hepatic and intestinal amino acid sensing intermediaries and thermogenic markers in brown adipose tissue.
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Affiliation(s)
- Rizaldy C Zapata
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
| | - Arashdeep Singh
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
| | - Adel Pezeshki
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
| | - Bharath S Avirineni
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
| | - Souvik Patra
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
| | - Prasanth K Chelikani
- Department of Production Animal Health, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada.,Gastrointestinal Research Group, Snyder Institute for Chronic Diseases, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, T2N 4N1, Canada
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5
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Lu K, Chen X, Yan J, Li X, Huang C, Wan Q, Deng X, Zou Q. The Effect of Feeding Behavior on Hypothalamus in Obese Type 2 Diabetic Rats with Glucagon-like Peptide-1 Receptor Agonist Intervention. Obes Facts 2018; 11:181-194. [PMID: 29788009 PMCID: PMC6103358 DOI: 10.1159/000486316] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 12/13/2017] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE To investigate the utility of intravoxel incoherent motion-diffusion weighted imaging (IVIM-DWI) derived parameters in hypothalamus for monitoring the effect of Exendin-4 (Ex-4) intervention on the feeding behavior in obese diabetic rats within early feeding. METHODS 21 obese and 19 non-obese rats which were treated with streptozotocin injections were initially divided into an obese diabetes group (OD, n = 10), a non-obese diabetes group (D, n = 8), an obese group (O, n = 9) and a non-obese group (N, n = 9). Then, the rats in the 4 groups received subcutaneous injections of Ex-4, and feeding behavior was examined at 5, 35, 65, 95, and 125 min. The hypothalamic function was evaluated by IVIM-DWI. Finally, the relationship between the hypothalamic function and the amount of food intake was analyzed. RESULTS In comparison with the N group, the food intake significantly decreased in the O , OD, and D groups in response to Ex-4. Furthermore, a significant positive correlation was found between food intake and D values at different times from 5 to 125 min after Ex-4 intervention in all 4 groups. CONCLUSION A direct correlation between the change of hypothalamic function and feeding behavior was detected in OD rats with Ex-4 intervention in the early feeding period. The hypothalamic D value derived from IVIM-DWI is promising to reflect the dynamic change of hypothalamic function due to intervention.
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Affiliation(s)
- Ke Lu
- Department of Endocrinology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xiaoyan Chen
- Department of Endocrinology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
- *Dr. Xiaoyan Chen, Department of Endocrinology, First Affiliated Hospital of Guangzhou Medical University, 510120 Guangzhou, China,
| | - Jianhua Yan
- Department of Radiology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xinchun Li
- Department of MRI, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Chen Huang
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Qi Wan
- Department of MRI, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Xuelian Deng
- Department of Endocrinology, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Qiao Zou
- Department of MRI, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
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6
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Lutz TA. Gut hormones such as amylin and GLP-1 in the control of eating and energy expenditure. INTERNATIONAL JOURNAL OF OBESITY SUPPLEMENTS 2016; 6:S15-S21. [PMID: 28685025 DOI: 10.1038/ijosup.2016.4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The control of meal size is the best studied aspect of the control of energy balance, and manipulation of this system constitutes a promising target to treat obesity. A major part of this control system is based on gastrointestinal hormones such as glucagon-like peptide-1 (GLP-1) or amylin, which are released in response to a meal and which limit the size of an ongoing meal. Both amylin and GLP-1 have also been shown to increase energy expenditure in experimental rodents, but mechanistically we know much less how this effect may be mediated, which brain sites may be involved, and what the physiological relevance of these findings may be. Most studies indicate that the effect of peripheral amylin is centrally mediated via the area postrema, but other brain areas, such as the ventral tegmental area, may also be involved. GLP-1's effect on eating seems to be mainly mediated by vagal afferents projecting to the caudal hindbrain. Chronic exposure to amylin, GLP-1 or their analogs decrease food intake and body weight gain. Next to the induction of satiation, amylin may also constitute an adiposity signal and in fact interact with the adiposity signal leptin. Amylin analogs are under clinical consideration for their effect to reduce food intake and body weight in humans, and similar to rodents, amylin analogs seem to be particularly active when combined with leptin analogs.
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Affiliation(s)
- T A Lutz
- Institute of Veterinary Physiology, Vetsuisse Faculty University of Zurich, Zurich, Switzerland.,Zurich Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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7
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Reidelberger R, Haver A, Anders K, Apenteng B, Lanio C. Effects of solid-phase extraction of plasma in measuring gut metabolic hormones in fasted and fed blood of lean and diet-induced obese rats. Physiol Rep 2016; 4:4/10/e12800. [PMID: 27207785 PMCID: PMC4886168 DOI: 10.14814/phy2.12800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 04/26/2016] [Indexed: 12/25/2022] Open
Abstract
Glucagon‐like peptide‐1 (GLP‐1), peptide YY (3‐36) [PYY(3‐36)], amylin, ghrelin, insulin, and leptin are thought to act as hormonal signals from periphery to brain to control food intake. Here, we determined the effects of solid‐phase extraction of plasma in measuring these hormones in blood of lean and diet‐induced obese rats. Individual enzyme‐linked immunoassays and a multiplex assay were used to measure active GLP‐1, total PYY, active amylin, active ghrelin, insulin, leptin, and total GIP in response to (1) addition of known amounts of the peptides to lean and obese plasma, (2) a large meal in lean and obese rats, and (3) intravenous infusions of anorexigenic doses of GLP‐1, PYY(3‐36), amylin, and leptin in lean rats. Extraction of lean and obese plasma prior to assays produced consistent recoveries across assays for GLP‐1, PYY, amylin, ghrelin, and insulin, reflecting losses inherent to the extraction procedure. Plasma extraction prior to assays generally revealed larger meal‐induced changes in plasma GLP‐1, PYY, amylin, ghrelin, and insulin in lean and obese rats. Plasma extraction and the multiplex assay were used to compare plasma levels of GLP‐1, PYY, and amylin after a large meal with plasma levels produced by IV infusions of anorexigenic doses of GLP‐1, PYY(3‐36), and amylin. Infusions produced dose‐dependent increases in plasma peptide levels, which were well above their postprandial levels. These results do not support the hypothesis that postprandial plasma levels of GLP‐1, PYY(3‐36), and amylin are sufficient to decrease food intake by an endocrine mechanism.
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Affiliation(s)
- Roger Reidelberger
- Department of Biomedical Sciences, Creighton University, Omaha, Nebraska VA Research Service, VA Nebraska Western Iowa Health Care System, Omaha, Nebraska
| | - Alvin Haver
- Department of Biomedical Sciences, Creighton University, Omaha, Nebraska VA Research Service, VA Nebraska Western Iowa Health Care System, Omaha, Nebraska
| | - Krista Anders
- Department of Biomedical Sciences, Creighton University, Omaha, Nebraska
| | - Bettye Apenteng
- Department of Biomedical Sciences, Creighton University, Omaha, Nebraska
| | - Craig Lanio
- EMD Millipore Corp., Billerica, Massachusetts
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8
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Hay DL, Chen S, Lutz TA, Parkes DG, Roth JD. Amylin: Pharmacology, Physiology, and Clinical Potential. Pharmacol Rev 2016; 67:564-600. [PMID: 26071095 DOI: 10.1124/pr.115.010629] [Citation(s) in RCA: 231] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Amylin is a pancreatic β-cell hormone that produces effects in several different organ systems. Here, we review the literature in rodents and in humans on amylin research since its discovery as a hormone about 25 years ago. Amylin is a 37-amino-acid peptide that activates its specific receptors, which are multisubunit G protein-coupled receptors resulting from the coexpression of a core receptor protein with receptor activity-modifying proteins, resulting in multiple receptor subtypes. Amylin's major role is as a glucoregulatory hormone, and it is an important regulator of energy metabolism in health and disease. Other amylin actions have also been reported, such as on the cardiovascular system or on bone. Amylin acts principally in the circumventricular organs of the central nervous system and functionally interacts with other metabolically active hormones such as cholecystokinin, leptin, and estradiol. The amylin-based peptide, pramlintide, is used clinically to treat type 1 and type 2 diabetes. Clinical studies in obesity have shown that amylin agonists could also be useful for weight loss, especially in combination with other agents.
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Affiliation(s)
- Debbie L Hay
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
| | - Steve Chen
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
| | - Thomas A Lutz
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
| | - David G Parkes
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
| | - Jonathan D Roth
- School of Biological Sciences, Maurice Wilkins Centre for Molecular Biodiscovery and Centre for Brain Research, University of Auckland, Auckland, New Zealand (D.L.H.); Amylin Pharmaceuticals LLC, San Diego, California (S.C., D.G.P.); Institute of Veterinary Physiology, Institute of Laboratory Animal Sciences and Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland (T.A.L.); and Intercept Pharmaceuticals, Inc., San Diego, California (J.D.R.)
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9
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Yanala UR, Reidelberger RD, Thompson JS, Shostrom VK, Carlson MA. Effect of proximal versus distal 50% enterectomy on nutritional parameters in rats preconditioned with a high-fat diet or regular chow. Sci Rep 2015; 5:17331. [PMID: 26612764 PMCID: PMC4661515 DOI: 10.1038/srep17331] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 10/29/2015] [Indexed: 12/13/2022] Open
Abstract
Obesity may protect against the nutritional consequences of short bowel syndrome. We hypothesized that rats preconditioned with an obesogenic diet would have better outcomes after surgical induction of short bowel syndrome compared to rats on regular chow. Rats were fed a high-fat diet or regular rat chow for six months, and then underwent 50% proximal, 50% distal, or sham enterectomy. Food intake, weight, and body composition were monitored before and for 4 weeks after surgery. The high-fat diet consistently produced obesity (>25% body fat). All procedures induced weight loss, but there was no discernable difference between resection vs. sham resection. Rats on the high-fat diet had a greater post-resection loss of body fat compared to rats on chow (36 vs. 26 g, respectively). There was a nonsignificant trend of less lean mass loss in the former compared to the latter rats (16 vs. 33 g, respectively). Enterectomy moderated serum ghrelin, GIP, PPY, insulin, and leptin. Intestinal adaptation was not different between obese vs. non-obese rats. Rats preconditioned with the high-fat diet may have had better retention of lean body mass after a surgical procedure compared to rats on chow. The effect of 50% enterectomy was less than expected.
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Affiliation(s)
- Ujwal R Yanala
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Surgery, VA-Nebraska Western Iowa Health Care System, Omaha, NE 68105
| | - Roger D Reidelberger
- Department of Surgery, VA-Nebraska Western Iowa Health Care System, Omaha, NE 68105.,Department of Biomedical Sciences, Creighton University, Omaha, NE 68178
| | - Jon S Thompson
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198
| | - Valerie K Shostrom
- Department of Biostatistics, University of Nebraska Medical Center, Omaha, NE 68198
| | - Mark A Carlson
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198.,Department of Surgery, VA-Nebraska Western Iowa Health Care System, Omaha, NE 68105.,Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198
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10
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Gennemark P, Hjorth S, Gabrielsson J. Modeling energy intake by adding homeostatic feedback and drug intervention. J Pharmacokinet Pharmacodyn 2014; 42:79-96. [PMID: 25388764 DOI: 10.1007/s10928-014-9399-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 11/03/2014] [Indexed: 12/19/2022]
Abstract
Energy intake (EI) is a pivotal biomarker used in quantification approaches to metabolic disease processes such as obesity, diabetes, and growth disorders. Eating behavior is however under both short-term and long-term control. This control system manifests itself as tolerance and rebound phenomena in EI, when challenged by drug treatment or diet restriction. The paper describes a model with the capability to capture physiological counter-regulatory feedback actions triggered by energy imbalances. This feedback is general as it handles tolerance to both increases and decreases in EI, and works in both acute and chronic settings. A drug mechanism function inhibits (or stimulates) EI. The deviation of EI relative to a reference level (set-point) serves as input to a non-linear appetite control signal which in turn impacts EI in parallel to the drug intervention. Three examples demonstrate the potential usefulness of the model in both acute and chronic dosing situations. The model shifts the predicted concentration-response relationship rightwardly at lower concentrations, in contrast to models that do not handle functional adaptation. A fourth example further shows that the model may qualitatively explain differences in rate and extent of adaptation in observed EI and its concomitants in both rodents and humans.
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11
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Madsbad S. The role of glucagon-like peptide-1 impairment in obesity and potential therapeutic implications. Diabetes Obes Metab 2014; 16:9-21. [PMID: 23617798 DOI: 10.1111/dom.12119] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/19/2013] [Accepted: 04/19/2013] [Indexed: 12/20/2022]
Abstract
The hormone glucagon-like peptide-1 (GLP-1) is released from the gut in response to food intake. It acts as a satiety signal, leading to reduced food intake, and also as a regulator of gastric emptying. Furthermore, GLP-1 functions as an incretin hormone, stimulating insulin release and inhibiting glucagon secretion from the pancreas in response to food ingestion. Evidence suggests that the action or effect of GLP-1 may be impaired in obese subjects, even in those with normal glucose tolerance. GLP-1 impairment may help explain the increased gastric emptying and decreased satiety signalling seen in obesity. Incretin impairment, probably associated with reduced insulinotropic potency of GLP-1, is also characteristic of type 2 diabetes (T2D). Therefore, it is possible that incretin impairment may contribute to the pathophysiological bridge between obesity and T2D. This review summarises current knowledge about the pathophysiology and consequences of GLP-1 and incretin impairment in obesity, and examines the evidence for an incretin-related link between obesity and T2D. It also considers the current literature surrounding the novel use of GLP-1 receptor agonists as a treatment for obesity in patients with normoglycaemia, prediabetes and T2D.
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Affiliation(s)
- S Madsbad
- Department of Endocrinology, Hvidovre University Hospital, Hvidovre, Denmark
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12
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13
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Abstract
Peptide hormones and proteins control body weight and glucose homeostasis by engaging peripheral and central metabolic signalling pathways responsible for the maintenance of body weight and euglycaemia. The development of obesity, often in association with type 2 diabetes mellitus (T2DM), reflects a dysregulation of metabolic, anorectic and orexigenic pathways in multiple organs. Notably, therapeutic attempts to normalize body weight and glycaemia with single agents alone have generally been disappointing. The success of bariatric surgery, together with emerging data from preclinical studies, illustrates the rationale and feasibility of using two or more agonists, or single co-agonists, for the treatment of obesity and T2DM. Here, we review advances in the science of co-agonist therapy, and highlight promising areas and challenges in co-agonist development. We describe mechanisms of action for combinations of glucagon-like peptide 1, glucagon, gastric inhibitory polypeptide, gastrin, islet amyloid polypeptide and leptin, which enhance weight loss whilst preserving glucoregulatory efficacy in experimental models of obesity and T2DM. Although substantial progress has been achieved in preclinical studies, the putative success and safety of co-agonist therapy for the treatment of patients with obesity and T2DM remains uncertain and requires extensive additional clinical validation.
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Affiliation(s)
- Sharon A Sadry
- Department of Medicine, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue TCP5-1004, Toronto M5G 1X5, ON, Canada
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14
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Srinivasan M, Mahmood S, Patel MS. Metabolic programming effects initiated in the suckling period predisposing for adult-onset obesity cannot be reversed by calorie restriction. Am J Physiol Endocrinol Metab 2013; 304:E486-94. [PMID: 23249696 PMCID: PMC3602662 DOI: 10.1152/ajpendo.00519.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Neonatal rats reared on high-carbohydrate (HC) milk formula developed chronic hyperinsulinemia and adult-onset obesity due to programming of islets and the hypothalamic energy circuitry. In this study, calorie restriction by pair-feeding was imposed on HC male rats (HC/PF) to normalize food intake similar to that of mother-fed (MF) rats from weaning until postnatal day 140. A group of HC/PF rats was switched over to ad libitum feeding (HC/PF/AL) from days 90 to 140. Pair-feeding reduced body weight gains and serum insulin and leptin levels in HC/PF rats compared with HC rats, but these parameters were restored to HC levels in the HC/PF/AL rats after ad libitum feeding. Interestingly, the heightened insulin secretory response of isolated islets from adult HC/PF and HC/PF/ AL rats to glucose, acetylcholine, and oxymetazoline were not significantly different from the responses of islets from HC rats. Similarly, the expression of neuropeptide Y and proopiomelanocortin in the hypothalamus was not significantly different among HC, HC/PF, and HC/PF/AL rats. Expression of the leptin receptor in the hypothalami from the HC, HC/PF, and HC/PF/AL rats mirrored that of serum leptin, whereas suppressor of cytokine signaling 3 (Socs3) expression remained high in these three groups. The results indicate that, although calorie restriction resulted in reduction in body weight gain and normalized the serum hormonal pattern, the programed predisposition for the hypersecretory capacity of islets and the hypothalamic hyperphagic response in the HC rats could not be permanently overcome by the pair-feeding imposed on HC rats.
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Affiliation(s)
- Malathi Srinivasan
- Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA
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Lutz TA. The interaction of amylin with other hormones in the control of eating. Diabetes Obes Metab 2013; 15:99-111. [PMID: 22862822 DOI: 10.1111/j.1463-1326.2012.01670.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Revised: 07/20/2012] [Accepted: 07/28/2012] [Indexed: 11/30/2022]
Abstract
Twenty years of research established amylin as an important control of energy homeostasis. Amylin controls nutrient and energy fluxes by reducing energy intake, by modulating nutrient utilization via an inhibition of postprandial glucagon secretion and by increasing energy disposal via a prevention of compensatory decreases of energy expenditure in weight reduced individuals. Like many other gastrointestinal hormones, amylin is secreted in response to meals and it reduces eating by promoting meal-ending satiation. Not surprisingly, amylin interacts with many of these hormones to control eating. These interactions seem to occur at different levels because amylin seems to mediate the eating inhibitory effect of some of these gastrointestinal hormones, and the combination of some of these hormones seems to lead to a stronger reduction in eating than single hormones alone. Amylin's effect on eating is thought to be mediated by a stimulation of specific amylin receptors in the area postrema. Secondary brain sites that were defined to mediate amylin action - and hence potential additional sites of interaction with other hormones - include the nucleus of the solitary tract, the lateral parabrachial nucleus, the lateral hypothalamic area and other hypothalamic nuclei. The focus of this review is to summarize the current knowledge of amylin interactions in the control of eating. In most cases, these interactions have only been studied at a descriptive rather than a mechanistic level and despite the clear knowledge on primary sites of amylin action, the interaction sites between amylin and other hormones are often unknown.
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Affiliation(s)
- T A Lutz
- Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland.
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