101
|
Severe Atherosclerosis and Hypercholesterolemia in Mice Lacking Both the Melanocortin Type 4 Receptor and Low Density Lipoprotein Receptor. PLoS One 2016; 11:e0167888. [PMID: 28030540 PMCID: PMC5193345 DOI: 10.1371/journal.pone.0167888] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 11/22/2016] [Indexed: 11/19/2022] Open
Abstract
Dysfunction of the melanocortin system can result in severe obesity accompanied with dyslipidemia and symptoms of the metabolic syndrome but the effect on vascular atherogenesis is not known. To study the impact of obesity and dyslipidemia on the cardiovascular system, we generated mice double-deficient for the melanocortin type 4 receptor (Mc4rmut mice) and the LDL receptor (Ldlr-/- mice). Mc4rmut mice develop obesity due to hyperphagia. Double-mutant mice (Mc4rmut;Ldlr-/-) exhibited massive increases in body weight, plasma cholesterol and triacylglycerol levels and developed atherosclerosis. Atherosclerotic lesion size was affected throughout the aortic root and brachiocephalic artery not only under semisynthetic, cholesterol-containing diet but also under cholesterol-free standard chow. The Mc4rmut mice developed a hepatic steatosis which contributes to increased plasma cholesterol levels even under cholesterol-free standard chow. Transcripts of cholesterol biosynthesis components and liver cholesterol levels did not significantly differ between wild-type and all mutant mouse strains but RNA sequencing data and biochemical measurements point to an altered bile acid elimination in Mc4rmut;Ldlr-/-. Therefore, the unchanged endogenous cholesterol biosynthesis together with a reduced hepatic VLDL and LDL-cholesterol clearance most likely led to increased plasma lipid levels and consequently to atherosclerosis in this animal model. Our data indicate that dysfunction of the melanocortin-regulated food intake and the resulting obesity significantly add to the proatherogenic lipoprotein profile caused by LDL receptor deficiency and, therefore, can be regarded as relevant risk factor for atherosclerosis.
Collapse
|
102
|
Contreras C, Nogueiras R, Diéguez C, Medina-Gómez G, López M. Hypothalamus and thermogenesis: Heating the BAT, browning the WAT. Mol Cell Endocrinol 2016; 438:107-115. [PMID: 27498420 DOI: 10.1016/j.mce.2016.08.002] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 07/30/2016] [Accepted: 08/01/2016] [Indexed: 12/20/2022]
Abstract
Brown adipose tissue (BAT) has been also considered as the main thermogenic organ responsible of maintenance body temperature through heat production. However, a new type of thermogenic fat has been characterized during the last years, the beige or brite fat, that is developed from white adipose tissue (WAT) in response to different stimuli by a process known as browning. The activities of brown and beige adipocytes ameliorate metabolic disease, including obesity in mice and correlate with leanness in humans. Many genes and pathways that regulate brown and beige adipocyte biology have now been identified, providing a variety of promising therapeutic targets for metabolic disease. The hypothalamus is the main central place orchestrating the outflow signals that drive the sympathetic nerve activity to BAT and WAT, controlling heat production and energy homeostasis. Recent data have revealed new hypothalamic molecular mechanisms, such as hypothalamic AMP-activated protein kinase (AMPK), that control both thermogenesis and browning. This review provides an overview of the factors influencing BAT and WAT thermogenesis, with special focus on the integration of peripheral information on hypothalamic circuits controlling thermoregulation.
Collapse
Affiliation(s)
- Cristina Contreras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain.
| | - Rubén Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain
| | - Carlos Diéguez
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain
| | - Gema Medina-Gómez
- Área de Bioquímica y Biología Molecular, Departamento de Ciencias Básicas de la Salud, Universidad Rey Juan Carlos, 28922, Alcorcón, Madrid, Spain
| | - Miguel López
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, Santiago de Compostela, 15782, Spain; CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, 15706, Spain.
| |
Collapse
|
103
|
Caron A, Richard D. Neuronal systems and circuits involved in the control of food intake and adaptive thermogenesis. Ann N Y Acad Sci 2016; 1391:35-53. [PMID: 27768821 DOI: 10.1111/nyas.13263] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 08/18/2016] [Accepted: 08/24/2016] [Indexed: 12/27/2022]
Abstract
With the still-growing prevalence of obesity worldwide, major efforts are made to understand the various behavioral, environmental, and genetic factors that promote excess fat gain. Obesity results from an imbalance between energy intake and energy expenditure, which emphasizes the importance of deciphering the mechanisms behind energy balance regulation to understand its physiopathology. The control of energy balance is assured by brain systems/circuits capable of generating adequate ingestive and thermogenic responses to maintain the stability of energy reserves, which implies a proper integration of the homeostatic signals that inform about the status of the energy stores. In this article, we overview the organization and functionality of key neuronal circuits or pathways involved in the control of food intake and energy expenditure. We review the role of the corticolimbic (executive and reward) and autonomic systems that integrate their activities to regulate energy balance. We also describe the mechanisms and pathways whereby homeostatic sensing is achieved in response to variations of homeostatic hormones, such as leptin, insulin, and ghrelin, while putting some emphasis on the prominent importance of the mechanistic target of the rapamycin signaling pathway in coordinating the homeostatic sensing process.
Collapse
Affiliation(s)
- Alexandre Caron
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec and Faculty of Medicine, Department of Medicine, Université Laval, Quebec City, Quebec, Canada
| | - Denis Richard
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec and Faculty of Medicine, Department of Medicine, Université Laval, Quebec City, Quebec, Canada
| |
Collapse
|
104
|
Abstract
Ovarian steroids, such as estradiol (E2), control a vastness of physiological processes, such as puberty, reproduction, growth, development and metabolic rate. In fact, physiological, pathological, pharmacological or genetically-induced estrogen deficiency causes increased appetite and reduced energy expenditure, promoting weight gain and ultimately leading to obesity. Remarkably, estrogen replacement reverts those effects. Interestingly, although a wealth of evidence has shown that E2 can directly modulate peripheral tissues to exert their metabolic actions, novel data gathered in recent years have shown that those effects are mainly central and occur in the hypothalamus. Here, we will review what is known about the actions of E2 on energy homeostasis, with particular focus on brown adipose tissue (BAT) thermogenesis.
Collapse
Affiliation(s)
- Miguel López
- Department of Physiology, Faculty of Medicine & CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria, 15782 Santiago de Compostela, Spain; CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Spain.
| | - Manuel Tena-Sempere
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Spain; Department of Cell Biology, Physiology and Immunology, University of Córdoba, Spain; Instituto Maimónides de Investigación Biomédica (IMIBIC)/Hospital Reina Sofía, 14004 Córdoba, Spain; FiDiPro Program, Department of Physiology, University of Turku, Kiinamyllynkatu 10, FIN-20520 Turku, Finland.
| |
Collapse
|
105
|
Nappi F, Barrea L, Di Somma C, Savanelli MC, Muscogiuri G, Orio F, Savastano S. Endocrine Aspects of Environmental "Obesogen" Pollutants. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 13:ijerph13080765. [PMID: 27483295 PMCID: PMC4997451 DOI: 10.3390/ijerph13080765] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Revised: 07/11/2016] [Accepted: 07/19/2016] [Indexed: 12/12/2022]
Abstract
Growing evidence suggests the causal link between the endocrine-disrupting chemicals (EDCs) and the global obesity epidemics, in the context in the so-called “obesogenic environment”. Dietary intake of contaminated foods and water, especially in association with unhealthy eating pattern, and inhalation of airborne pollutants represent the major sources of human exposure to EDCs. This is of particular concern in view of the potential impact of obesity on chronic non-transmissible diseases, such as type 2 diabetes, cardiovascular disease, and hormone-sensitive cancers. The key concept is the identification of adipose tissue not only as a preferential site of storage of EDCs, but also as an endocrine organ and, as such, susceptible to endocrine disruption. The timing of exposure to EDCs is critical to the outcome of that exposure, with early lifetime exposures (e.g., fetal or early postnatal) particularly detrimental because of their permanent effects on obesity later in life. Despite that the mechanisms operating in EDCs effects might vary enormously, this minireview is aimed to provide a general overview on the possible association between the pandemics of obesity and EDCs, briefly describing the endocrine mechanisms linking EDCs exposure and latent onset of obesity.
Collapse
Affiliation(s)
| | | | | | | | | | - Francesco Orio
- Department of Sports Science and Wellness, "Parthenope" University of Naples, 80133 Naples, Italy.
| | - Silvia Savastano
- Dipartimento di Medicina Clinica e Chirurgia, Unit of Endocrinology, Federico II University Medical School of Naples, Via Sergio Pansini 5, 80131 Naples, Italy.
| |
Collapse
|
106
|
Kühnen P, Clément K, Wiegand S, Blankenstein O, Gottesdiener K, Martini LL, Mai K, Blume-Peytavi U, Grüters A, Krude H. Proopiomelanocortin Deficiency Treated with a Melanocortin-4 Receptor Agonist. N Engl J Med 2016; 375:240-6. [PMID: 27468060 DOI: 10.1056/nejmoa1512693] [Citation(s) in RCA: 295] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Patients with rare defects in the gene encoding proopiomelanocortin (POMC) have extreme early-onset obesity, hyperphagia, hypopigmentation, and hypocortisolism, resulting from the lack of the proopiomelanocortin-derived peptides melanocyte-stimulating hormone and corticotropin. In such patients, adrenal insufficiency must be treated with hydrocortisone early in life. No effective pharmacologic treatments have been available for the hyperphagia and obesity that characterize the condition. In this investigator-initiated, open-label study, two patients with proopiomelanocortin deficiency were treated with setmelanotide, a new melanocortin-4 receptor agonist. The patients had a sustainable reduction in hunger and substantial weight loss (51.0 kg after 42 weeks in Patient 1 and 20.5 kg after 12 weeks in Patient 2).
Collapse
Affiliation(s)
- Peter Kühnen
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| | - Karine Clément
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| | - Susanna Wiegand
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| | - Oliver Blankenstein
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| | - Keith Gottesdiener
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| | - Lea L Martini
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| | - Knut Mai
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| | - Ulrike Blume-Peytavi
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| | - Annette Grüters
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| | - Heiko Krude
- From the Institute for Experimental Pediatric Endocrinology (P.K., O.B., H.K.), the Department of Pediatric Endocrinology and Diabetes (S.W., A.G.), the Department of Endocrinology, Diabetes, and Nutrition and Charité Center for Cardiovascular Research (K.M.), and the Department of Dermatology and Allergy, Clinical Research Center for Hair and Skin Science (U.B.-P.), Charité-Universitätsmedizin Berlin, and the Clinical Research Unit, Berlin Institute of Health (K.M.) - all in Berlin; the Institute of Cardiometabolism and Nutrition, Assistance Publique-Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, INSERM-Sorbonne University, Université Pierre et Marie Curie, Unité Mixte de Recherche Scientifique 1166, Paris (K.C., L.L.M.); and Rhythm Pharmaceuticals, Boston (K.G.)
| |
Collapse
|
107
|
Interactions between host genetics and gut microbiome in diabetes and metabolic syndrome. Mol Metab 2016; 5:795-803. [PMID: 27617202 PMCID: PMC5004229 DOI: 10.1016/j.molmet.2016.07.004] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 07/12/2016] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Diabetes, obesity, and the metabolic syndrome are multifactorial diseases dependent on a complex interaction of host genetics, diet, and other environmental factors. Increasing evidence places gut microbiota as important modulators of the crosstalk between diet and development of obesity and metabolic dysfunction. In addition, host genetics can have important impact on the composition and function of gut microbiota. Indeed, depending on the genetic background of the host, diet and other environmental factors may produce different changes in gut microbiota, have different impacts on host metabolism, and create different interactions between the microbiome and the host. SCOPE OF REVIEW In this review, we highlight how appropriate animal models can help dissect the complex interaction of host genetics with the gut microbiome and how diet can lead to different degrees of weight gain, levels of insulin resistance, and metabolic outcomes, such as diabetes, in different individuals. We also discuss the challenges of identifying specific disease-associated microbiota and the limitations of simple metrics, such as phylogenetic diversity or the ratio of Firmicutes to Bacteroidetes. MAJOR CONCLUSIONS Understanding these complex interactions will help in the development of novel treatments for microbiome-related metabolic diseases. This article is part of a special issue on microbiota.
Collapse
|
108
|
Namkung Y, Le Gouill C, Lukashova V, Kobayashi H, Hogue M, Khoury E, Song M, Bouvier M, Laporte SA. Monitoring G protein-coupled receptor and β-arrestin trafficking in live cells using enhanced bystander BRET. Nat Commun 2016; 7:12178. [PMID: 27397672 PMCID: PMC4942582 DOI: 10.1038/ncomms12178] [Citation(s) in RCA: 201] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 06/08/2016] [Indexed: 12/14/2022] Open
Abstract
Endocytosis and intracellular trafficking of receptors are pivotal to maintain physiological functions and drug action; however, robust quantitative approaches are lacking to study such processes in live cells. Here we present new bioluminescence resonance energy transfer (BRET) sensors to quantitatively monitor G protein-coupled receptors (GPCRs) and β-arrestin trafficking. These sensors are based on bystander BRET and use the naturally interacting chromophores luciferase (RLuc) and green fluorescent protein (rGFP) from Renilla. The versatility and robustness of this approach are exemplified by anchoring rGFP at the plasma membrane or in endosomes to generate high dynamic spectrometric BRET signals on ligand-promoted recruitment or sequestration of RLuc-tagged proteins to, or from, specific cell compartments, as well as sensitive subcellular BRET imaging for protein translocation visualization. These sensors are scalable to high-throughput formats and allow quantitative pharmacological studies of GPCR trafficking in real time, in live cells, revealing ligand-dependent biased trafficking of receptor/β-arrestin complexes. Cellular signaling processes often involve trafficking of receptors and other proteins between subcellular compartments. Here the authors demonstrate a method based on the concept of Enhanced bystander Bioluminescence Resonance Energy Transfer (EbBRET) that allows efficient real time monitoring of endocytosis and trafficking.
Collapse
Affiliation(s)
- Yoon Namkung
- Department of Medicine, Research Institute of the McGill University Health Center (RI-MUHC), McGill University, Montréal, Québec, Canada H4A 3J1
| | - Christian Le Gouill
- Department of Biochemistry and Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Québec, Canada H3C 1J4
| | - Viktoria Lukashova
- Department of Biochemistry and Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Québec, Canada H3C 1J4
| | - Hiroyuki Kobayashi
- Department of Biochemistry and Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Québec, Canada H3C 1J4
| | - Mireille Hogue
- Department of Biochemistry and Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Québec, Canada H3C 1J4
| | - Etienne Khoury
- Department of Medicine, Research Institute of the McGill University Health Center (RI-MUHC), McGill University, Montréal, Québec, Canada H4A 3J1
| | - Mideum Song
- Department of Medicine, Research Institute of the McGill University Health Center (RI-MUHC), McGill University, Montréal, Québec, Canada H4A 3J1
| | - Michel Bouvier
- Department of Biochemistry and Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montréal, Québec, Canada H3C 1J4
| | - Stéphane A Laporte
- Department of Medicine, Research Institute of the McGill University Health Center (RI-MUHC), McGill University, Montréal, Québec, Canada H4A 3J1.,Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada H3G 1Y6.,Department of Anatomy and Cell Biology, McGill University, Montréal, Québec, Canada H3A 0C7
| |
Collapse
|
109
|
Alliouachene S, Bilanges B, Chaussade C, Pearce W, Foukas LC, Scudamore CL, Moniz LS, Vanhaesebroeck B. Inactivation of class II PI3K-C2α induces leptin resistance, age-dependent insulin resistance and obesity in male mice. Diabetologia 2016; 59:1503-1512. [PMID: 27138914 PMCID: PMC4901096 DOI: 10.1007/s00125-016-3963-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 03/24/2016] [Indexed: 01/08/2023]
Abstract
AIMS/HYPOTHESIS While the class I phosphoinositide 3-kinases (PI3Ks) are well-documented positive regulators of metabolism, the involvement of class II PI3K isoforms (PI3K-C2α, -C2β and -C2γ) in metabolic regulation is just emerging. Organismal inactivation of PI3K-C2β increases insulin signalling and sensitivity, whereas PI3K-C2γ inactivation has a negative metabolic impact. In contrast, the role of PI3K-C2α in organismal metabolism remains unexplored. In this study, we investigated whether kinase inactivation of PI3K-C2α affects glucose metabolism in mice. METHODS We have generated and characterised a mouse line with a constitutive inactivating knock-in (KI) mutation in the kinase domain of the gene encoding PI3K-C2α (Pik3c2a). RESULTS While homozygosity for kinase-dead PI3K-C2α was embryonic lethal, heterozygous PI3K-C2α KI mice were viable and fertile, with no significant histopathological findings. However, male heterozygous mice showed early onset leptin resistance, with a defect in leptin signalling in the hypothalamus, correlating with a mild, age-dependent obesity, insulin resistance and glucose intolerance. Insulin signalling was unaffected in insulin target tissues of PI3K-C2α KI mice, in contrast to previous reports in which downregulation of PI3K-C2α in cell lines was shown to dampen insulin signalling. Interestingly, no metabolic phenotypes were detected in female PI3K-C2α KI mice at any age. CONCLUSIONS/INTERPRETATION Our data uncover a sex-dependent role for PI3K-C2α in the modulation of hypothalamic leptin action and systemic glucose homeostasis. ACCESS TO RESEARCH MATERIALS All reagents are available upon request.
Collapse
Affiliation(s)
- Samira Alliouachene
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK.
| | - Benoit Bilanges
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK.
| | - Claire Chaussade
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK
- Galderma R&D, Sophia Antipolis Cedex, France
| | - Wayne Pearce
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK
| | - Lazaros C Foukas
- Institute of Healthy Ageing and Department of Genetics, Evolution and Environment, University College London, London, UK
| | - Cheryl L Scudamore
- Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, Harwell, UK
| | - Larissa S Moniz
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK
| | - Bart Vanhaesebroeck
- UCL Cancer Institute, University College London, 72 Huntley Street, London, WC1E 6DD, UK.
| |
Collapse
|
110
|
Cropley JE, Eaton SA, Aiken A, Young PE, Giannoulatou E, Ho JWK, Buckland ME, Keam SP, Hutvagner G, Humphreys DT, Langley KG, Henstridge DC, Martin DIK, Febbraio MA, Suter CM. Male-lineage transmission of an acquired metabolic phenotype induced by grand-paternal obesity. Mol Metab 2016; 5:699-708. [PMID: 27656407 PMCID: PMC5021672 DOI: 10.1016/j.molmet.2016.06.008] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 06/14/2016] [Accepted: 06/16/2016] [Indexed: 12/22/2022] Open
Abstract
Objective Parental obesity can induce metabolic phenotypes in offspring independent of the inherited DNA sequence. Here we asked whether such non-genetic acquired metabolic traits can be passed on to a second generation that has never been exposed to obesity, even as germ cells. Methods We examined the F1, F2, and F3 a/a offspring derived from F0 matings of obese prediabetic Avy/a sires and lean a/a dams. After F0, only lean a/a mice were used for breeding. Results We found that F1 sons of obese founder males exhibited defects in glucose and lipid metabolism, but only upon a post-weaning dietary challenge. F1 males transmitted these defects to their own male progeny (F2) in the absence of the dietary challenge, but the phenotype was largely attenuated by F3. The sperm of F1 males exhibited changes in the abundance of several small RNA species, including the recently reported diet-responsive tRNA-derived fragments. Conclusions These data indicate that induced metabolic phenotypes may be propagated for a generation beyond any direct exposure to an inducing factor. This non-genetic inheritance likely occurs via the actions of sperm noncoding RNA. Paternal obesity induces latent defects in metabolism in F1 sons. Metabolic disease in F1 sons is exposed by short challenge with a Western diet. F1 sons transmit their phenotype to F2 grandsons in the absence of dietary challenge. F1 sperm exhibit changes to prominent small RNA species.
Collapse
Affiliation(s)
- Jennifer E Cropley
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia; Faculty of Medicine, University of New South Wales, Kensington, NSW, 2052, Australia.
| | - Sally A Eaton
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia; Faculty of Medicine, University of New South Wales, Kensington, NSW, 2052, Australia
| | - Alastair Aiken
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia
| | - Paul E Young
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia
| | - Eleni Giannoulatou
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia
| | - Joshua W K Ho
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia; Faculty of Medicine, University of New South Wales, Kensington, NSW, 2052, Australia
| | - Michael E Buckland
- Brain and Mind Research Institute, University of Sydney, Sydney, NSW, 2006, Australia
| | - Simon P Keam
- Faculty of Engineering and Information Technology, Centre of Health Technologies, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Gyorgy Hutvagner
- Faculty of Engineering and Information Technology, Centre of Health Technologies, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - David T Humphreys
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia
| | - Katherine G Langley
- Cellular and Molecular Metabolism Laboratory, Baker IDI Diabetes and Heart Research Institute, Melbourne, VIC, 3004, Australia
| | - Darren C Henstridge
- Cellular and Molecular Metabolism Laboratory, Baker IDI Diabetes and Heart Research Institute, Melbourne, VIC, 3004, Australia
| | - David I K Martin
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia; Children's Hospital Oakland Research Institute, Oakland, CA, 94609, USA
| | - Mark A Febbraio
- Diabetes and Metabolism Division, Garvan Institute of Medical Research, Darlinghurst, NSW, 2010, Australia
| | - Catherine M Suter
- Molecular, Structural and Computational Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, 2010, Australia; Faculty of Medicine, University of New South Wales, Kensington, NSW, 2052, Australia.
| |
Collapse
|
111
|
A Genome-Wide mQTL Analysis in Human Adipose Tissue Identifies Genetic Variants Associated with DNA Methylation, Gene Expression and Metabolic Traits. PLoS One 2016; 11:e0157776. [PMID: 27322064 PMCID: PMC4913906 DOI: 10.1371/journal.pone.0157776] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 06/03/2016] [Indexed: 01/17/2023] Open
Abstract
Little is known about the extent to which interactions between genetics and epigenetics may affect the risk of complex metabolic diseases and/or their intermediary phenotypes. We performed a genome-wide DNA methylation quantitative trait locus (mQTL) analysis in human adipose tissue of 119 men, where 592,794 single nucleotide polymorphisms (SNPs) were related to DNA methylation of 477,891 CpG sites, covering 99% of RefSeq genes. SNPs in significant mQTLs were further related to gene expression in adipose tissue and obesity related traits. We found 101,911 SNP-CpG pairs (mQTLs) in cis and 5,342 SNP-CpG pairs in trans showing significant associations between genotype and DNA methylation in adipose tissue after correction for multiple testing, where cis is defined as distance less than 500 kb between a SNP and CpG site. These mQTLs include reported obesity, lipid and type 2 diabetes loci, e.g. ADCY3/POMC, APOA5, CETP, FADS2, GCKR, SORT1 and LEPR. Significant mQTLs were overrepresented in intergenic regions meanwhile underrepresented in promoter regions and CpG islands. We further identified 635 SNPs in significant cis-mQTLs associated with expression of 86 genes in adipose tissue including CHRNA5, G6PC2, GPX7, RPL27A, THNSL2 and ZFP57. SNPs in significant mQTLs were also associated with body mass index (BMI), lipid traits and glucose and insulin levels in our study cohort and public available consortia data. Importantly, the Causal Inference Test (CIT) demonstrates how genetic variants mediate their effects on metabolic traits (e.g. BMI, cholesterol, high-density lipoprotein (HDL), hemoglobin A1c (HbA1c) and homeostatic model assessment of insulin resistance (HOMA-IR)) via altered DNA methylation in human adipose tissue. This study identifies genome-wide interactions between genetic and epigenetic variation in both cis and trans positions influencing gene expression in adipose tissue and in vivo (dys)metabolic traits associated with the development of obesity and diabetes.
Collapse
|
112
|
Ferguson LR, De Caterina R, Görman U, Allayee H, Kohlmeier M, Prasad C, Choi MS, Curi R, de Luis DA, Gil Á, Kang JX, Martin RL, Milagro FI, Nicoletti CF, Nonino CB, Ordovas JM, Parslow VR, Portillo MP, Santos JL, Serhan CN, Simopoulos AP, Velázquez-Arellano A, Zulet MA, Martinez JA. Guide and Position of the International Society of Nutrigenetics/Nutrigenomics on Personalised Nutrition: Part 1 - Fields of Precision Nutrition. Lifestyle Genom 2016; 9:12-27. [DOI: 10.1159/000445350] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
113
|
Pepin É, Al-Mass A, Attané C, Zhang K, Lamontagne J, Lussier R, Madiraju SRM, Joly E, Ruderman NB, Sladek R, Prentki M, Peyot ML. Pancreatic β-Cell Dysfunction in Diet-Induced Obese Mice: Roles of AMP-Kinase, Protein Kinase Cε, Mitochondrial and Cholesterol Metabolism, and Alterations in Gene Expression. PLoS One 2016; 11:e0153017. [PMID: 27043434 PMCID: PMC4820227 DOI: 10.1371/journal.pone.0153017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/22/2016] [Indexed: 12/27/2022] Open
Abstract
Diet induced obese (DIO) mice can be stratified according to their weight gain in response to high fat diet as low responders (LDR) and high responders (HDR). This allows the study of β-cell failure and the transitions to prediabetes (LDR) and early diabetes (HDR). C57BL/6N mice were fed for 8 weeks with a normal chow diet (ND) or a high fat diet and stratified as LDR and HDR. Freshly isolated islets from ND, LDR and HDR mice were studied ex-vivo for mitochondrial metabolism, AMPK activity and signalling, the expression and activity of key enzymes of energy metabolism, cholesterol synthesis, and mRNA profiling. Severely compromised glucose-induced insulin secretion in HDR islets, as compared to ND and LDR islets, was associated with suppressed AMP-kinase activity. HDR islets also showed reduced acetyl-CoA carboxylase activity and enhanced activity of 3-hydroxy-3-methylglutaryl-CoA reductase, which led respectively to elevated fatty acid oxidation and increased cholesterol biosynthesis. HDR islets also displayed mitochondrial membrane hyperpolarization and reduced ATP turnover in the presence of elevated glucose. Expression of protein kinase Cε, which reduces both lipolysis and production of signals for insulin secretion, was elevated in DIO islets. Genes whose expression increased or decreased by more than 1.2-fold were minor between LDR and ND islets (17 differentially expressed), but were prominent between HDR and ND islets (1508 differentially expressed). In HDR islets, particularly affected genes were related to cell cycle and proliferation, AMPK signaling, mitochondrial metabolism and cholesterol metabolism. In conclusion, chronically reduced AMPK activity, mitochondrial dysfunction, elevated cholesterol biosynthesis in islets, and substantial alterations in gene expression accompany β-cell failure in HDR islets. The β-cell compensation process in the prediabetic state (LDR) is largely independent of transcriptional adaptive changes, whereas the transition to early diabetes (HDR) is associated with major alterations in gene expression.
Collapse
Affiliation(s)
- Émilie Pepin
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Anfal Al-Mass
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
- Departments of Medicine and Human Genetics, McGill University, Montreal, Québec, Canada
| | - Camille Attané
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Kezhuo Zhang
- Departments of Medicine and Human Genetics, McGill University, Montreal, Québec, Canada
| | - Julien Lamontagne
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Roxane Lussier
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - S. R. Murthy Madiraju
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Erik Joly
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
| | - Neil B. Ruderman
- Departments of Medicine and Physiology and Biophysics, Boston University School of Medicine and Diabetes Unit, Boston Medical Center, Boston, MA, United States of America
| | - Robert Sladek
- Departments of Medicine and Human Genetics, McGill University, Montreal, Québec, Canada
| | - Marc Prentki
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
- Departments of Nutrition, Biochemistry and Molecular Medicine, Faculty of Medicine, University of Montréal, Montreal, Québec, Canada
- * E-mail: (MP); (MLP)
| | - Marie-Line Peyot
- Montreal Diabetes Research Center and Centre de Recherche du CHUM, Montréal, Québec, Canada
- * E-mail: (MP); (MLP)
| |
Collapse
|
114
|
Guglielmi V, Floris R, D'Adamo M, Garaci F, Novelli G, Sbraccia P. Massive obesity and hyperphagia in posterior bilateral periventricular heterotopias: case report. BMC MEDICAL GENETICS 2016; 17:18. [PMID: 26956990 PMCID: PMC4784440 DOI: 10.1186/s12881-016-0282-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 03/01/2016] [Indexed: 11/18/2022]
Abstract
Background Bilateral posterior periventricular nodular heterotopia PNH is a complex malformation of cortical development with imaging features distinguishing it from classic bilateral PNH associated with filamin (FLNA) mutations. It distinctively consists of variably sized nodules of neurons along the trigones and temporal or occipital horns of the lateral ventricles and spectrum of developmental disorders of the mid-/hindbrain. This association suggests that pPNH is part of a more diffuse process of posterior or infrasylvian brain developmental abnormalities other than just a disorder of neuronal migration. Case presentation This report describes the first case of an Italian young girl featuring pPNH and severe hyperphagic obesity. At the time of our first examination at age 3 years of age she was severely obese (body mass index, BMI 45.9 Kg/m2) and food-seeking behavior in the free-living situation was reported by the relatives. She showed normal linear growth and cognition, but mildly dysmorphic facial traits including deeply-set eyes, prominent zygomatic bones, downturned mouth corners and low-set ears. Over the years, the patient progressively developed further massive weight gain (at age 9 years, her BMI was 60.4 Kg/m2) and hyperphagia was confirmed by an ad libitum test meal. During follow-up, she presented limitations in walking capacity and in physical functioning due to the disabling obesity. On the basis of distinctive neuro-radiological findings pPNH was diagnosed, in absence of history of seizures. Conclusion The present case may contribute to the expansion of the phenotypic expressions of this distinctive complex malformation.
Collapse
Affiliation(s)
- Valeria Guglielmi
- Department of Systems Medicine, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy.,Obesity Center, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Roberto Floris
- Diagnostic Imaging, University Hospital Policlinico Tor Vergata, University of Rome "Tor Vergata", Rome, Italy.,Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Monica D'Adamo
- Department of Systems Medicine, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy.,Obesity Center, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Francesco Garaci
- Diagnostic Imaging, University Hospital Policlinico Tor Vergata, University of Rome "Tor Vergata", Rome, Italy.,Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
| | - Giuseppe Novelli
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy.,Medical Genetics Unit, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Paolo Sbraccia
- Department of Systems Medicine, University of Rome "Tor Vergata", Via Montpellier 1, 00133, Rome, Italy. .,Obesity Center, University Hospital Policlinico Tor Vergata, Rome, Italy.
| |
Collapse
|
115
|
Hansen PG, Skov LR, Jespersen AM, Skov KL, Schmidt K. Apples versus brownies: A field experiment in rearranging conference snacking buffets to reduce short-term energy intake. ACTA ACUST UNITED AC 2016. [DOI: 10.1080/15378020.2016.1129227] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
116
|
Ramos-Molina B, Martin MG, Lindberg I. PCSK1 Variants and Human Obesity. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2016; 140:47-74. [PMID: 27288825 DOI: 10.1016/bs.pmbts.2015.12.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PCSK1, encoding prohormone convertase 1/3 (PC1/3), was one of the first genes linked to monogenic early-onset obesity. PC1/3 is a protease involved in the biosynthetic processing of a variety of neuropeptides and prohormones in endocrine tissues. PC1/3 activity is essential for the activating cleavage of many peptide hormone precursors implicated in the regulation of food ingestion, glucose homeostasis, and energy homeostasis, for example, proopiomelanocortin, proinsulin, proglucagon, and proghrelin. A large number of genome-wide association studies in a variety of different populations have now firmly established a link between three PCSK1 polymorphisms frequent in the population and increased risk of obesity. Human subjects with PC1/3 deficiency, a rare autosomal-recessive disorder caused by the presence of loss-of-function mutations in both alleles, are obese and display a complex set of endocrinopathies. Increasing numbers of genetic diagnoses of infants with persistent diarrhea has recently led to the finding of many novel PCSK1 mutations. PCSK1-deficient infants experience severe intestinal malabsorption during the first years of life, requiring controlled nutrition; these children then become hyperphagic, with associated obesity. The biochemical characterization of novel loss-of-function PCSK1 mutations has resulted in the discovery of new pathological mechanisms affecting the cell biology of the endocrine cell beyond simple loss of enzyme activity, for example, dominant-negative effects of certain mutants on wild-type PC1/3 protein, and activation of the cellular unfolded protein response by endoplasmic reticulum-retained mutants. A better understanding of these molecular and cellular pathologies may illuminate possible treatments for the complex endocrinopathy of PCSK1 deficiency, including obesity.
Collapse
Affiliation(s)
- B Ramos-Molina
- Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - M G Martin
- Department of Pediatrics, Division of Gastroenterology and Nutrition, Mattel Children's Hospital and the David Geffen School of Medicine, Los Angeles, CA, United States of America
| | - I Lindberg
- Department of Anatomy and Neurobiology, University of Maryland, Baltimore, MD, United States of America.
| |
Collapse
|
117
|
Rehman Khan A, Awan FR. Leptin Resistance: A Possible Interface Between Obesity and Pulmonary-Related Disorders. Int J Endocrinol Metab 2016; 14:e32586. [PMID: 27279832 PMCID: PMC4896114 DOI: 10.5812/ijem.32586] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 12/01/2015] [Accepted: 01/03/2016] [Indexed: 01/09/2023] Open
Abstract
CONTEXT Under normal physiological conditions, leptin regulates body weight by creating a balance between food intake and energy expenditure. However, in obesity, serum leptin levels increase and become defective to retain energy balance. EVIDENCE ACQUISITION Elevated serum leptin levels are regarded as an established marker of obesity. It is also reported that obese asthmatic patients have maximum serum leptin levels compared to other groups such as non-obese asthmatics, and normal obese and non obese subjects without asthma. In addition to having an appetite suppressing effect, leptin also regulates certain acute-phase protein expressions including α-1 antitrypsin (A1AT) in the liver. RESULTS A1AT is a protease inhibitor that counterbalances the activity of the neutrophil elastase (NE) enzyme. A1AT reductions in obese-leptin resistant subjects lead to increased NE activity. The overactivity of NE degrades lung tissue proteins, which may lead to pulmonary disorders including asthma. CONCLUSIONS On the basis of prior studies, it could be hypothesized that, in obese asthmatic patients, the highest degree of leptin failure/resistance might lead to the creation of an imbalance between NE and its inhibitor A1AT. To ascertain this, large scale prospective studies are warranted to assess the comparative serum leptin and A1AT levels and NE activity in asthmatic non-obese and obese patients, simultaneously. Such studies might help to devise novel interventional therapies for the treatment of pulmonary-related problems including asthma, chronic obstructive pulmonary disorder (COPD), and other lung defects in susceptible obese subjects in the future.
Collapse
Affiliation(s)
- Abdul Rehman Khan
- Diabetes and Cardio-Metabolic Disorders Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
- Obesity and Diabetes Research Laboratory, Department of Chemistry, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan
- Corresponding author: Abdul Rehman Khan, Obesity and Diabetes Research Laboratory, Department of Chemistry, University of Azad Jammu and Kashmir, Muzaffarabad, Pakistan. Tel: +92-3335742975, E-mail:
| | - Fazli Rabbi Awan
- Diabetes and Cardio-Metabolic Disorders Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
| |
Collapse
|
118
|
Stark R, Reichenbach A, Andrews ZB. Hypothalamic carnitine metabolism integrates nutrient and hormonal feedback to regulate energy homeostasis. Mol Cell Endocrinol 2015; 418 Pt 1:9-16. [PMID: 26261054 DOI: 10.1016/j.mce.2015.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Revised: 07/31/2015] [Accepted: 08/03/2015] [Indexed: 01/11/2023]
Abstract
The maintenance of energy homeostasis requires the hypothalamic integration of nutrient feedback cues, such as glucose, fatty acids, amino acids, and metabolic hormones such as insulin, leptin and ghrelin. Although hypothalamic neurons are critical to maintain energy homeostasis research efforts have focused on feedback mechanisms in isolation, such as glucose alone, fatty acids alone or single hormones. However this seems rather too simplistic considering the range of nutrient and endocrine changes associated with different metabolic states, such as starvation (negative energy balance) or diet-induced obesity (positive energy balance). In order to understand how neurons integrate multiple nutrient or hormonal signals, we need to identify and examine potential intracellular convergence points or common molecular targets that have the ability to sense glucose, fatty acids, amino acids and hormones. In this review, we focus on the role of carnitine metabolism in neurons regulating energy homeostasis. Hypothalamic carnitine metabolism represents a novel means for neurons to facilitate and control both nutrient and hormonal feedback. In terms of nutrient regulation, carnitine metabolism regulates hypothalamic fatty acid sensing through the actions of CPT1 and has an underappreciated role in glucose sensing since carnitine metabolism also buffers mitochondrial matrix levels of acetyl-CoA, an allosteric inhibitor of pyruvate dehydrogenase and hence glucose metabolism. Studies also show that hypothalamic CPT1 activity also controls hormonal feedback. We hypothesis that hypothalamic carnitine metabolism represents a key molecular target that can concurrently integrate nutrient and hormonal information, which is critical to maintain energy homeostasis. We also suggest this is relevant to broader neuroendocrine research as it predicts that hormonal signaling in the brain varies depending on current nutrient status. Indeed, the metabolic action of ghrelin, leptin or insulin at POMC or NPY neurons may depend on appropriate nutrient-sensing in these neurons and we hypothesize carnitine metabolism is critical in the integrative processing. Future research is required to examine the neuron-specific effects of carnitine metabolism on concurrent nutrient- and hormonal-sensing in AgRP and POMC neurons.
Collapse
Affiliation(s)
- Romana Stark
- Department of Physiology, Monash University, Clayton, Victoria 3183, Australia
| | - Alex Reichenbach
- Department of Physiology, Monash University, Clayton, Victoria 3183, Australia
| | - Zane B Andrews
- Department of Physiology, Monash University, Clayton, Victoria 3183, Australia.
| |
Collapse
|
119
|
Yumuk V, Tsigos C, Fried M, Schindler K, Busetto L, Micic D, Toplak H. European Guidelines for Obesity Management in Adults. Obes Facts 2015; 8:402-24. [PMID: 26641646 PMCID: PMC5644856 DOI: 10.1159/000442721] [Citation(s) in RCA: 750] [Impact Index Per Article: 83.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 11/24/2015] [Indexed: 02/06/2023] Open
Abstract
Obesity is a chronic metabolic disease characterised by an increase of body fat stores. It is a gateway to ill health, and it has become one of the leading causes of disability and death, affecting not only adults but also children and adolescents worldwide. In clinical practice, the body fatness is estimated by BMI, and the accumulation of intra-abdominal fat (marker for higher metabolic and cardiovascular disease risk) can be assessed by waist circumference. Complex interactions between biological, behavioural, social and environmental factors are involved in regulation of energy balance and fat stores. A comprehensive history, physical examination and laboratory assessment relevant to the patient's obesity should be obtained. Appropriate goals of weight management emphasise realistic weight loss to achieve a reduction in health risks and should include promotion of weight loss, maintenance and prevention of weight regain. Management of co-morbidities and improving quality of life of obese patients are also included in treatment aims. Balanced hypocaloric diets result in clinically meaningful weight loss regardless of which macronutrients they emphasise. Aerobic training is the optimal mode of exercise for reducing fat mass while a programme including resistance training is needed for increasing lean mass in middle-aged and overweight/obese individuals. Cognitive behavioural therapy directly addresses behaviours that require change for successful weight loss and weight loss maintenance. Pharmacotherapy can help patients to maintain compliance and ameliorate obesity-related health risks. Surgery is the most effective treatment for morbid obesity in terms of long-term weight loss. A comprehensive obesity management can only be accomplished by a multidisciplinary obesity management team. We conclude that physicians have a responsibility to recognise obesity as a disease and help obese patients with appropriate prevention and treatment. Treatment should be based on good clinical care, and evidence-based interventions; should focus on realistic goals and lifelong multidisciplinary management.
Collapse
Affiliation(s)
- Volkan Yumuk
- Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, Istanbul University Cerrahpasa Medical Faculty, Istanbul, Turkey
| | - Constantine Tsigos
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - Martin Fried
- Clinical Center for Minimally Invasive and Bariatric Surgery, ISCARE Lighthouse, Prague and 1st Medical Faculty, Charles University, Prague, Czech Republic
| | - Karin Schindler
- Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - Luca Busetto
- Department of Medicine, Padova University Hospital – Bariatric Unit, University of Padova, Padova, Italy
| | - Dragan Micic
- Centre for Metabolic Disorders in Endocrinology, Institute of Endocrinology, Diabetes and Diseases of Metabolism, Clinical Center of Serbia, Belgrade, Serbia
| | - Hermann Toplak
- Department of Medicine, Institute for Diabetes and Metabolism, Medical University, Graz, Austria
| |
Collapse
|
120
|
Melanocortin-4 receptor gene variants are not associated with binge-eating behavior in nonobese patients with eating disorders. Psychiatr Genet 2015; 25:35-8. [PMID: 25419636 DOI: 10.1097/ypg.0000000000000065] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We aimed to determine whether variability in the melanocortin-4 receptor (MC4R) gene, predisposing to hyperphagia and obesity, may also be present in nonobese patients with binge-eating behavior or be related to anthropometric or psychopathological parameters in these patients. The coding region of the MC4R gene was sequenced in nonobese patients with binge-eating behavior diagnosed with bulimia nervosa or binge-eating disorder (n=77); individuals with severe early-onset obesity (n=170); and lean women with anorexia nervosa (n=20). A psychometric evaluation (Eating Disorders Inventory-2 and Symptom Checklist 90 Revised inventories) was carried out for all the patients with eating disorders. In the obesity group, 10 different variants were identified, whereas in the binge-eating patients, only two individuals with bulimia nervosa were found to carry the I251L polymorphism, which did not correlate with weight, BMI, or psychopathological features. We found no evidence that mutations in the MC4R gene are associated with binge-eating behavior in nonobese eating disorder patients.
Collapse
|
121
|
Curtis D. Practical Experience of the Application of a Weighted Burden Test to Whole Exome Sequence Data for Obesity and Schizophrenia. Ann Hum Genet 2015; 80:38-49. [PMID: 26474449 PMCID: PMC4833177 DOI: 10.1111/ahg.12135] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
For biological and statistical reasons it makes sense to combine information from variants at the level of the gene. One may wish to give more weight to variants which are rare and those that are more likely to affect function. A combined weighting scheme, implemented in the SCOREASSOC program, was applied to whole exome sequence data for 1392 subjects with schizophrenia and 982 with obesity from the UK10K project. Results conformed fairly well with null hypothesis expectations and no individual gene was strongly implicated. However, a number of the higher ranked genes appear plausible candidates as being involved in one or other phenotype and may warrant further investigation. These include MC4R, NLGN2, CRP, DONSON, GTF3A, IL36B, ADCYAP1R1, ARSA, DLG1, SIK2, SLAIN1, UBE2Q2, ZNF507, CRHR1, MUSK, NSF, SNORD115, GDF3 and HIBADH. Some individual variants in these genes have different frequencies between cohorts and could be genotyped in additional subjects. For other genes, there is a general excess of variants at many different sites so attempts at replication would be more difficult. Overall, the weighted burden test provides a convenient method for using sequence data to highlight genes of interest.
Collapse
Affiliation(s)
- David Curtis
- UCL Genetics Institute, UCL, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | | |
Collapse
|
122
|
Williams EP, Mesidor M, Winters K, Dubbert PM, Wyatt SB. Overweight and Obesity: Prevalence, Consequences, and Causes of a Growing Public Health Problem. Curr Obes Rep 2015; 4:363-70. [PMID: 26627494 DOI: 10.1007/s13679-015-0169-4] [Citation(s) in RCA: 503] [Impact Index Per Article: 55.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
This review considers a variety of perspectives on overweight and obesity (OW/obesity), including measurement and classification; prevalence and changes in prevalence in recent years; genetic, biological, medical, individual, and social correlates of OW/obesity; and treatment approaches. Despite increased attention, OW/obesity is escalating in prevalence worldwide, and the causes are exceedingly complex. A range of innovative studies, including basic research on gut microflora, dietary composition, pharmacologic interventions, and surgical procedures, is generating findings with potential for future prevention and treatment of OW/obesity. Social system changes such as school programs and the awareness of the roles of personal, family, health provider, and cultural experiences related to OW/obesity have also gained traction for vital prevention and treatment efforts over the past decade.
Collapse
Affiliation(s)
- Ellen P Williams
- University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
| | - Marie Mesidor
- Health Promotion & Disease Prevention Program, Central Arkansas Veterans Healthcare System, 4300 West 7th Street, Little Rock, AR, 72205, USA.
| | - Karen Winters
- University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
| | - Patricia M Dubbert
- South Central Veterans Affairs Mental Illness Research, Education & Clinical Center, Little Rock Geriatric Research, Education & Clinical Center, University of Arkansas for Medical Sciences, 2200 Fort Roots Drive, North Little Rock, AR, 72114, USA.
| | - Sharon B Wyatt
- University of Mississippi Medical Center, 2500 North State Street, Jackson, MS, 39216, USA.
| |
Collapse
|
123
|
Abstract
Pediatric obesity is highly prevalent in developed countries globally (and worsening in developing countries) and threatens to shorten the lifespan of the current generation. At highest risk for weight-related comorbidities including Type 2 diabetes mellitus, non-alcoholic fatty liver disease and dyslipidemia is a sub-set of children with severe obesity, often defined as a body mass index (BMI) percentile ≥99th percentile for age and sex. The pathophysiology of severe obesity in childhood is complex, resulting from the dynamic interplay of a myriad of individual and societal factors including genetic predisposition and health behaviors contributing to energy imbalance. Approximately 4–6% of children have severe obesity, representing a common scenario encountered by providers, and intervention is critical to halt ongoing weight gain and, when possible, reverse the trend. Clinical approaches promoting behavioral weight loss may result in modest, albeit clinically significant, reductions in BMI; however, such changes are often difficult to maintain long-term. Data regarding the impact of targeted pharmacotherapy including agents such as orlistat are limited in the pediatric population and again only suggest modest results. However, increasing evidence suggest that surgical treatment, as an adjunct to ongoing lifestyle changes, may be a promising option in carefully-screened adolescents with severe obesity and weight-related comorbidities who are motivated to adhere to the long-term treatment needs.
Collapse
Affiliation(s)
- Edmond P. Wickham
- Departments of Internal Medicine and Pediatrics, Virginia Commonwealth University, Richmond VA 23298
| | - Mark D. DeBoer
- Division of Pediatric Endocrinology, Department of Pediatrics, University of Virginia, Charlottesville, VA 22908,Author to whom correspondence should be addressed: Mark D. DeBoer, MD, MSc., MCR, P.O. Box 800386, Charlottesville, VA 22908, Phone: 434-924-9833, Fax: 434-924-9181,
| |
Collapse
|
124
|
Grandone A, Marzuillo P, Cirillo G, Squitieri R, Tolone S, Miraglia del Giudice E, Perrone L, Tolone C. FTO Polymorphism rs9939609 Contributes to Weight Changes in Children With Celiac Disease on Gluten-Free Diet. J Pediatr Gastroenterol Nutr 2015. [PMID: 26222659 DOI: 10.1097/mpg.0000000000000724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVES Studies of adults and children with celiac disease have reported an increased risk of overweight during gluten-free diet (GFD). The fat mass and obesity-associated gene (FTO) variant rs9939609 has been associated with increased risk of developing obesity in children and adults. METHODS In our study, we analyzed the effect of this variant on weight gain in a cohort of 280 children with celiac disease on GFD. RESULTS We found that after a mean follow-up time of 3.0 years on GFD, FTO polymorphism influenced significantly the mean change in body mass index z score (P = 0.01). CONCLUSIONS We conclude that the FTO gene contributes to determine weight changes in children with celiac disease on GFD.
Collapse
Affiliation(s)
- Anna Grandone
- *Department of the Woman, Child and of General and Specialized Surgery †Department of General Surgery, Second University of Naples, Naples, Italy
| | | | | | | | | | | | | | | |
Collapse
|
125
|
Abstract
One-third of North American children are overweight or obese. Pathologic obesity accounts for only a small percentage of these cases. The vast majority are the result of a complex interaction of genetic and hormonal, nutritional, physical activity, and physical and social environmental factors. Obesity increases the risk for various cardiometabolic, pulmonary, and psychosocial complications for children, which often continues into adulthood. Multidisciplinary care, focusing on family-centered behavior change, is an evidence-based, essential part of the treatment, along with pharmacologic and surgical options for more complex cases. Prevention and early intervention strategies are key to reversing the obesity epidemic.
Collapse
Affiliation(s)
- Muskaan Gurnani
- Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - Catherine Birken
- Division of Paediatric Medicine, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
| | - Jill Hamilton
- Division of Endocrinology, Department of Paediatrics, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada.
| |
Collapse
|
126
|
Montgomery Sklar E. Body Image, Weight, and Self-Concept in Men. Am J Lifestyle Med 2015; 11:252-258. [PMID: 30202340 DOI: 10.1177/1559827615594351] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 06/04/2015] [Accepted: 06/05/2015] [Indexed: 11/16/2022] Open
Abstract
In the traditional debate between biological and environmental determinants of body weight, the body has most often been explored in terms of its anatomical, genetic, or hormonal influences on personality, experience, and behavior. While obesity has been identified as a threat to our public health, correlating attitudes toward body image and self-concept have been explored within women to a limited extent, and even less so in relation to men. Consequently, men's body image will be discussed in light of current literature reveals for women. For men, as for women, as the social pressure to attain an "ideal" physique increases, the discrepancy between that ideal and one's body increases as well. This dynamic is more readily recognized for women than for men. As men are socialized not to discuss their body image concerns, negative self-concept and esteem may reinforce behaviors resulting in weight gain. In recent years, the proliferation of media has served to reinforce messaging related to one's body. This review of existing data and literature suggests that body image and self-concept are related to body weight in men (as with women) and need to be addressed as part of healthy weight management practices.
Collapse
|
127
|
Gervasini G, Gamero-Villarroel C. Discussing the putative role of obesity-associated genes in the etiopathogenesis of eating disorders. Pharmacogenomics 2015; 16:1287-1305. [DOI: 10.2217/pgs.15.77] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
In addition to the identification of mutations clearly related to Mendelian forms of obesity; genome-wide association studies and follow-up studies have in the last years pinpointed several loci associated with BMI. These genetic alterations are located in or near genes expressed in the hypothalamus that are involved in the regulation of eating behavior. Accordingly, it seems plausible that these SNPs, or others located in related genes, could also help develop aberrant conduct patterns that favor the establishment of eating disorders should other susceptibility factors or personality dimensions be present. However, and somewhat surprisingly, with few exceptions such as BDNF, the great majority of the genes governing these pathways remain untested in patients with anorexia nervosa, bulimia nervosa or binge-eating disorder. In the present work, we review the few existing studies, but also indications and biological concepts that point to these genes in the CNS as good candidates for association studies with eating disorder patients.
Collapse
Affiliation(s)
- Guillermo Gervasini
- Department of Medical & Surgical Therapeutics, Division of Pharmacology, Medical School, University of Extremadura, Av. Elvas s/n, E-06005, Badajoz, Spain
| | - Carmen Gamero-Villarroel
- Department of Medical & Surgical Therapeutics, Division of Pharmacology, Medical School, University of Extremadura, Av. Elvas s/n, E-06005, Badajoz, Spain
| |
Collapse
|
128
|
Hall JE, do Carmo JM, da Silva AA, Wang Z, Hall ME. Obesity-induced hypertension: interaction of neurohumoral and renal mechanisms. Circ Res 2015; 116:991-1006. [PMID: 25767285 DOI: 10.1161/circresaha.116.305697] [Citation(s) in RCA: 713] [Impact Index Per Article: 79.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Excess weight gain, especially when associated with increased visceral adiposity, is a major cause of hypertension, accounting for 65% to 75% of the risk for human primary (essential) hypertension. Increased renal tubular sodium reabsorption impairs pressure natriuresis and plays an important role in initiating obesity hypertension. The mediators of abnormal kidney function and increased blood pressure during development of obesity hypertension include (1) physical compression of the kidneys by fat in and around the kidneys, (2) activation of the renin-angiotensin-aldosterone system, and (3) increased sympathetic nervous system activity. Activation of the renin-angiotensin-aldosterone system is likely due, in part, to renal compression, as well as sympathetic nervous system activation. However, obesity also causes mineralocorticoid receptor activation independent of aldosterone or angiotensin II. The mechanisms for sympathetic nervous system activation in obesity have not been fully elucidated but may require leptin and activation of the brain melanocortin system. With prolonged obesity and development of target organ injury, especially renal injury, obesity-associated hypertension becomes more difficult to control, often requiring multiple antihypertensive drugs and treatment of other risk factors, including dyslipidemia, insulin resistance and diabetes mellitus, and inflammation. Unless effective antiobesity drugs are developed, the effect of obesity on hypertension and related cardiovascular, renal and metabolic disorders is likely to become even more important in the future as the prevalence of obesity continues to increase.
Collapse
Affiliation(s)
- John E Hall
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson.
| | - Jussara M do Carmo
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson
| | - Alexandre A da Silva
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson
| | - Zhen Wang
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson
| | - Michael E Hall
- From the Departments of Physiology and Biophysics (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), Medicine (M.E.H.), Mississippi Center for Obesity Research (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), and Cardiovascular-Renal Research Center (J.E.H., J.M.d.C., A.A.d.S., Z.W., M.E.H.), University of Mississippi Medical Center, Jackson
| |
Collapse
|
129
|
Lemus MB, Bayliss JA, Lockie SH, Santos VV, Reichenbach A, Stark R, Andrews ZB. A stereological analysis of NPY, POMC, Orexin, GFAP astrocyte, and Iba1 microglia cell number and volume in diet-induced obese male mice. Endocrinology 2015; 156:1701-13. [PMID: 25742051 DOI: 10.1210/en.2014-1961] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The hypothalamic arcuate nucleus (ARC) contains 2 key neural populations, neuropeptide Y (NPY) and proopiomelanocortin (POMC), and, together with orexin neurons in the lateral hypothalamus, plays an integral role in energy homeostasis. However, no studies have examined total neuronal number and volume after high-fat diet (HFD) exposure using sophisticated stereology. We used design-based stereology to estimate NPY and POMC neuronal number and volume, as well as glial fibrillary acidic protein (astrocyte marker) and ionized calcium-binding adapter molecule 1 (microglia marker) cell number in the ARC; as well as orexin neurons in the lateral hypothalamus. Stereological analysis indicated approximately 8000 NPY and approximately 9000 POMC neurons in the ARC, and approximately 7500 orexin neurons in the lateral hypothalamus. HFD exposure did not affect total neuronal number in any population. However, HFD significantly increased average NPY cell volume and affected NPY and POMC cell volume distribution. HFD reduced orexin cell volume but had a bimodal effect on volume distribution with increased cells at relatively small volumes and decreased cells with relatively large volumes. ARC glial fibrillary acidic protein cells increased after 2 months on a HFD, although no significant difference after 6 months on chow diet or HFD was observed. No differences in ARC ionized calcium-binding adapter molecule 1 cell number were observed in any group. Thus, HFD affects ARC NPY or POMC neuronal cell volume number not cell number. Our results demonstrate the importance of stereology to perform robust unbiased analysis of cell number and volume. These data should be an empirical baseline reference to which future studies are compared.
Collapse
Affiliation(s)
- Moyra B Lemus
- Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | | | | | | | | | | | | |
Collapse
|
130
|
Thameem F, Voruganti VS, Blangero J, Comuzzie AG, Abboud HE. Evaluation of neurotrophic tyrosine receptor kinase 2 (NTRK2) as a positional candidate gene for variation in estimated glomerular filtration rate (eGFR) in Mexican American participants of San Antonio Family Heart study. J Biomed Sci 2015; 22:23. [PMID: 25885044 PMCID: PMC4383052 DOI: 10.1186/s12929-015-0123-5] [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: 09/03/2014] [Accepted: 02/26/2015] [Indexed: 01/09/2023] Open
Abstract
Background The estimated glomerular filtration rate (eGFR) is a well-known measure of kidney function and is commonly used for the diagnosis and management of patients with chronic kidney disease. The inter-individual variation in eGFR has significant genetic component. However, the identification of underlying genetic susceptibility variants has been challenging. In an attempt to identify and characterize susceptibility genetic variant(s) we previously identified the strongest evidence for linkage of eGFR occurring on chromosome 9q21 in the Mexican American participants of San Antonio Family Heart Study (SAFHS). The objective of the present study was to examine whether the common genetic variants in Neurotrophic Tyrosine Receptor Kinase 2 (NTRK2), a positional candidate gene on 9q21, contribute to variation in eGFR. Results Twelve tagging single nucleotide polymorphisms (SNPs) across the NTRK2 gene region were selected (r2 ≥ 0.80, minor allele frequency of ≥ 0.05) from the Hapmap database. SNPs were genotyped by TaqMan assay in the 848 Mexican American subjects participated in the SAFHS. Association analysis between the genotypes and eGFR (estimated by the Modification of Diet in Renal Disease equation) were performed by measured genotype approach as implemented in the program SOLAR. Of the 12 common genetic variants examined, the rs1036915 (located in 3′UTR) and rs1187274 (located in intron-14), present in perfect linkage disequilibrium, exhibited an association (P = 0.017) with eGFR after accounting for the effects of age, sex, diabetes, diabetes duration, systolic blood pressure and blood pressure medication. The carriers of minor allele of rs1036915 (G; 38%) had increased eGFR (104 ± 25 ml/min/1.73 m2) in comparison to the carriers of major allele A (98 ± 25 ml/min/1.73 m2). Conclusion Together, our results suggest for the first time that the genetic variants in NTRK2 may regulate eGFR.
Collapse
Affiliation(s)
- Farook Thameem
- Division of Nephrology, Department of Medicine, The University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA. .,Department of Biochemistry, Faculty of Medicine, Kuwait University, Safat, 13110, Kuwait.
| | - V Saroja Voruganti
- Department of Nutrition, University of North Carolina at Chapel Hill, Kannapolis, NC, 28081, USA. .,UNC Nutrition Research Institute, University of North Carolina at Chapel Hill, Kannapolis, NC, 28081, USA.
| | - John Blangero
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, 78227, USA.
| | - Anthony G Comuzzie
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, 78227, USA.
| | - Hanna E Abboud
- Division of Nephrology, Department of Medicine, The University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA. .,South Texas Veterans Healthcare System, San Antonio, TX, 78229, USA.
| |
Collapse
|
131
|
Contreras C, Gonzalez F, Fernø J, Diéguez C, Rahmouni K, Nogueiras R, López M. The brain and brown fat. Ann Med 2015; 47:150-68. [PMID: 24915455 PMCID: PMC4438385 DOI: 10.3109/07853890.2014.919727] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Accepted: 04/25/2014] [Indexed: 02/06/2023] Open
Abstract
Brown adipose tissue (BAT) is a specialized organ responsible for thermogenesis, a process required for maintaining body temperature. BAT is regulated by the sympathetic nervous system (SNS), which activates lipolysis and mitochondrial uncoupling in brown adipocytes. For many years, BAT was considered to be important only in small mammals and newborn humans, but recent data have shown that BAT is also functional in adult humans. On the basis of this evidence, extensive research has been focused on BAT function, where new molecules, such as irisin and bone morphogenetic proteins, particularly BMP7 and BMP8B, as well as novel central factors and new regulatory mechanisms, such as orexins and the canonical ventomedial nucleus of the hypothalamus (VMH) AMP- activated protein kinase (AMPK)-SNS-BAT axis, have been discovered and emerged as potential drug targets to combat obesity. In this review we provide an overview of the complex central regulation of BAT and how different neuronal cell populations co-ordinately work to maintain energy homeostasis.
Collapse
Affiliation(s)
- Cristina Contreras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria , Santiago de Compostela, 15782 , Spain
| | | | | | | | | | | | | |
Collapse
|
132
|
Alan BE, Cengel Kultur SE. Change in metabolic parameters and weight in response to risperidone monotherapy in young children with nonpsychotic disorders: a prospective open-label study. Child Adolesc Ment Health 2015; 20:20-25. [PMID: 32680333 DOI: 10.1111/camh.12033] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/20/2013] [Indexed: 12/30/2022]
Abstract
BACKGROUND This study investigates changes in metabolic parameters in prepubertal children after 14-16 weeks of treatment with low-dose risperidone. METHOD Thirty-one children (mean age 5.46 ± 1.98 years) were treated with risperidone (0.25-1 mg/day; 0.01-0.07 mg/kg/day). Patients were excluded if they were using any medication other than risperidone or were diagnosed with any medical problem in addition to a non-psychotic disorder. RESULTS Weight (Δ: 2.51 ± 1.94 kg), height (Δ: 0.03 ± 0.04 cm), BMI (Δ: 0.82 ± 1.4), BMI percentile (Δ: 9.72 ± 16.40), BMI z-score (Δ: 0.33 ± 1.03), triglyceride (Δ: 1.50 ± 23.97 mg/dl), very low density lipoprotein (Δ: 2.99 ± 4.76 mg/dl), insulin (Δ: 3.07 ± 3.38 mIU/ml), and leptin (Δ: 3.02 ± 4.69 ng/ml) were significantly increased (p < .05). CONCLUSION The metabolic side effects of risperidone must be carefully monitored in prepubertal children.
Collapse
Affiliation(s)
- Burcu Ersoz Alan
- Child and Adolescent Psychiatry Clinic, Dr. Sami Ulus Women and Children's Health and Diseases Training and Research Hospital, Telsizler/Altindag, Ankara, 06080, Turkey
| | - S Ebru Cengel Kultur
- School of Medicine, Department of Child and Adolescent Psychiatry, Hacettepe University, Sihhiye, Ankara, Turkey
| |
Collapse
|
133
|
Ceccarini G, Maffei M, Vitti P, Santini F. Fuel homeostasis and locomotor behavior: role of leptin and melanocortin pathways. J Endocrinol Invest 2015; 38:125-31. [PMID: 25501840 DOI: 10.1007/s40618-014-0225-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 12/01/2014] [Indexed: 11/26/2022]
Abstract
BACKGROUND While it is now accepted that genes and their products affect food intake, the concept that locomotor behavior or the propensity for physical activity is controlled by neuro hum oral regulators is frequently underappreciated. In mammals, complex interactions have developed to allow the cross-talk between fuel homeostasis and physical activity. AIM The aim of this review is to provide a synopsis of the influence of the leptin-melanocortin pathway, a well-studied pivotal player in body weight regulation, on locomotor behaviors. CONCLUSIONS In rodents, reductions in leptin levels that physiologically occur following acute food deprivation or a reduction of the fat mass consequent to prolonged caloric restrictions are associated with a decrease in total locomotor activity and simultaneous increase in food-anticipatory activity, a locomotor behavior which reflects a foraging attitude. These actions can be prevented by leptin administration and are at least partially mediated by the neurons of the melanocortin pathway. In humans, twin studies have attributed to genetic factors approximately 50% of the variance of physical activity. An elevated number of the genes or loci which may affect physical activity are involved in body weight homeostasis. Polymorphisms of the melanocortin-4 and leptin receptors have repeatedly been associated with the level of physical activity. Unraveling the complexity of the regulation of locomotor behavior and the interconnections with the pathways involved in energy homeostasis may help explain the substantial individual variability in physical activities in humans and disentangle the harmful effects of sedentary lifestyle, which may be distinct from the detrimental effects of obesity.
Collapse
Affiliation(s)
- G Ceccarini
- Obesity Center at the Endocrine Unit, University Hospital of Pisa, Pisa, Italy.
| | - M Maffei
- Obesity Center at the Endocrine Unit, University Hospital of Pisa, Pisa, Italy
- National Research Council, Institute of Clinical Physiology, Pisa, Italy
| | - P Vitti
- Obesity Center at the Endocrine Unit, University Hospital of Pisa, Pisa, Italy
| | - F Santini
- Obesity Center at the Endocrine Unit, University Hospital of Pisa, Pisa, Italy.
| |
Collapse
|
134
|
Doulla M, McIntyre AD, Hegele RA, Gallego PH. A novel MC4R mutation associated with childhood-onset obesity: A case report. Paediatr Child Health 2015; 19:515-8. [PMID: 25587224 DOI: 10.1093/pch/19.10.515] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/01/2014] [Indexed: 11/12/2022] Open
Abstract
The melanocortin-4-receptor gene (MC4R) is a key regulator of energy homeostasis, food intake and body weight. MC4R gene mutations are associated with early-onset severe obesity. Most patients are heterozygotes, with some reports of homozygotes and compound heterozygotes. The authors report a case involving an eight-year-old girl with progressive weight gain from infancy, body mass index 44 kg/m(2) (>97th percentile), hyperphagia, hyperinsulinemia and increased linear growth. There was no phenotype of morbid obesity in the parents or sibling. Coding regions and intron-exon boundaries of the genes encoding leptin, leptin receptor, pro-opiomelanocortin and MC4R were analyzed. Two heterozygous coding mutations in the MCR4 gene (S94N and C293R) were detected, of which the second has not been previously reported. The mutations were on opposite chromosomes, confirming compound heterozygosity. The molecular findings and clinical features associated with this novel MC4R mutation are described. The authors emphasize that rare mutations can be found in some patients with severe childhood-onset obesity.
Collapse
Affiliation(s)
- Manpreet Doulla
- Department of Pediatrics, Schulich School of Medicine and Dentistry, Western University
| | - Adam D McIntyre
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University
| | - Robert A Hegele
- Robarts Research Institute, Schulich School of Medicine and Dentistry, Western University
| | - Patricia H Gallego
- Department of Pediatrics, Pediatric Endocrinology Section, London Health Sciences Centre, Children's Hospital, London, Ontario
| |
Collapse
|
135
|
Sasaki T. Age-Associated Weight Gain, Leptin, and SIRT1: A Possible Role for Hypothalamic SIRT1 in the Prevention of Weight Gain and Aging through Modulation of Leptin Sensitivity. Front Endocrinol (Lausanne) 2015; 6:109. [PMID: 26236282 PMCID: PMC4504171 DOI: 10.3389/fendo.2015.00109] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 07/01/2015] [Indexed: 12/14/2022] Open
Abstract
The hypothalamus is the principal regulator of body weight and energy balance. It modulates both energy intake and energy expenditure by sensing the energy status of the body through neural inputs from the periphery as well as direct humoral inputs. Leptin, an adipokine, is one of the humoral factors responsible for alerting the hypothalamus that enough energy is stored in the periphery. Plasma leptin levels are positively linked to adiposity; leptin suppress energy intake and stimulates energy expenditure. However, prolonged increases in plasma leptin levels due to obesity cause leptin resistance, affecting both leptin access to hypothalamic neurons and leptin signal transduction within hypothalamic neurons. Decreased sensing of peripheral energy status through leptin may lead to a positive energy balance and gradual gains in weight and adiposity, further worsening leptin resistance. Leptin resistance, increased adiposity, and weight gain are all associated with aging in both humans and animals. Central insulin resistance is associated with similar observations. Therefore, improving the action of humoral factors in the hypothalamus may prevent gradual weight gain, especially during middle age. SIRT1 is a NAD(+)-dependent protein deacetylase with numerous substrates, including histones, transcription factors, co-factors, and various enzymes. SIRT1 improves both leptin sensitivity and insulin sensitivity by decreasing the levels of several molecules that impair leptin and insulin signal transduction. SIRT1 and NAD(+) levels decrease with age in the hypothalamus; increased hypothalamic SIRT1 levels prevent age-associated weight gain and improve leptin sensitivity in mice. Therefore, preventing the age-dependent loss of SIRT1 function in the hypothalamus could improve the action of humoral factors in the hypothalamus as well as central regulation of energy balance.
Collapse
Affiliation(s)
- Tsutomu Sasaki
- Laboratory for Metabolic Signaling, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Japan
- *Correspondence: Tsutomu Sasaki, Laboratory for Metabolic Signaling, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma 371-8512, Japan,
| |
Collapse
|
136
|
Meisel SF, Beeken RJ, van Jaarsveld CH, Wardle J. The Association of FTO SNP rs9939609 with Weight Gain at University. Obes Facts 2015; 8:243-51. [PMID: 26138810 PMCID: PMC4959463 DOI: 10.1159/000434733] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 05/04/2015] [Indexed: 12/30/2022] Open
Abstract
AIM We tested the hypothesis that the obesity-associated FTO SNP rs9939609 would be associated with clinically significant weight gain (≥ 5% of initial body weight) in the first year of university; a time identified as high risk for weight gain. METHODS We collected anthropometric data from university students (n = 1,411, mean age: 22.4 ± 2.5 years, 49.1% male) at the beginning and end of the academic year. DNA was analysed for FTO rs9939609. Associations of FTO genotype with BMI at baseline were analysed using ANCOVA, and with risk of 5% weight gain over follow-up with logistic regression; both analyses adjusting for age and sex. The alpha level was reduced to 0.0125 to account for multiple testing. RESULTS Using an additive model, FTO status was not associated with higher BMI at baseline (22.2 vs. 21.9 kg/m2, p = 0.059). Dropout was high but unrelated to genotype. Among the 310 (21.9%) completing follow-up, those with AT genotypes had twice the odds of ≥ 5% weight gain compared with TTs (OR = 2.05, 95% CI = 1.05-4.01, p = 0.036), but this was no longer significant after Bonferroni correction. There was a trend for AA carriers for ≥ 5% weight gain compared with TT carriers (p = 0.089), but sample size was small. CONCLUSION This study provides nominal evidence for the genetic susceptibility hypothesis, but findings need to be replicated.
Collapse
Affiliation(s)
- Susanne F. Meisel
- Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, UK
- *Susanne Meisel, PhD, Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, Gower Street, London WC1E 6BT, UK,
| | - Rebecca J. Beeken
- Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, UK
| | | | - Jane Wardle
- Cancer Research UK Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, UK
| |
Collapse
|
137
|
Abstract
Although food intake is necessary to provide energy for all bodily activities, considering food intake as a motivated behavior is complex. Rather than being a simple unconditioned reflex to energy need, eating is mediated by diverse factors. These include homeostatic signals such as those related to body fat stores, to food available and being eaten, and to circulating energy-rich compounds like glucose and fatty acids. Eating is also greatly influenced by non-homeostatic signals that convey information related to learning and experience, hedonics, stress, the social situation, opportunity, and many other factors. Recent developments identifying the intricate nature of the relationships between homeostatic and non-homeostatic influences significantly add to the complexity underlying the neural basis of the motivation to eat. The future of research in the field of food intake would seem to lie in the identification of the neural circuitry and interactions between homeostatic and non-homeostatic influences.
Collapse
|
138
|
Role of ADHD symptoms as a contributing factor to obesity in patients with MC4R mutations. Med Hypotheses 2015; 84:4-7. [DOI: 10.1016/j.mehy.2014.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 10/27/2014] [Accepted: 11/06/2014] [Indexed: 02/04/2023]
|
139
|
DeNicola E, Aburizaiza OS, Siddique A, Khwaja H, Carpenter DO. Obesity and public health in the Kingdom of Saudi Arabia. REVIEWS ON ENVIRONMENTAL HEALTH 2015; 30:191-205. [PMID: 26351801 DOI: 10.1515/reveh-2015-0008] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/13/2015] [Indexed: 06/05/2023]
Abstract
Overweight and obesity are now a global epidemic, with more than one in five people qualifying as obese worldwide. These conditions are accompanied by excessive rates of non-communicable diseases (NCDs) related to overweight, like type 2 diabetes mellitus, hypertension, and cardiovascular diseases. Saudi Arabia, which has become increasingly westernized over the past few decades now has one of the highest prevalence rates of overweight and obesity, even in children. This puts the population at great risk for increased rates of NCD mortality. Competing cultures is partly to blame, as the combination of persisting traditional Saudi cultural practices, modern cultural changes, and economic prosperity has created an obesogenic environment that promotes unhealthy eating, sedentary lifestyles, and weight gain. Overweight and obesity are more prevalent in Saudi women than in Saudi men. Interventions targeting the environment are needed in order to promote greater health through healthy eating decisions and increased physical activity or exercise (especially for women).
Collapse
|
140
|
Montagne L, Raimondo A, Delobel B, Duban-Bedu B, Noblet FS, Dechaume A, Bersten DC, Meyre D, Whitelaw ML, Froguel P, Bonnefond A. Identification of two novel loss-of-function SIM1 mutations in two overweight children with developmental delay. Obesity (Silver Spring) 2014; 22:2621-4. [PMID: 25234154 DOI: 10.1002/oby.20886] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 08/14/2014] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Several deletions of chromosome 6q, including SIM1, were reported in obese patients with developmental delay. Furthermore, rare loss-of-function SIM1 mutations were shown to contribute to severe obesity, yet the role of these mutations in developmental delay remained unclear. Here, SIM1 in children with neurodevelopmental abnormalities was screened and the functional effect of the identified mutations was investigated. METHODS SIM1 was sequenced in 283 children presenting with developmental delay and at least overweight. The effect of the identified mutations on SIM1 transcriptional activity in stable human cell lines was assessed using luciferase gene reporter assays. RESULTS Two novel mutations (c.886A>G/p.R296G and c.925A>G/p.S309G) in two boys with variable degrees of cognitive deficits and weight issues were identified. The child mutated for p.R296G presented with a generally more severe phenotype than the p.S309G carrier (obesity, compulsive eating, neonatal hypotonia versus overweight only), while both mutations had strong loss-of-function effects on SIM1 transcriptional activity. CONCLUSIONS Severe loss-of-function SIM1 mutations can be associated with a spectrum of developmental delay phenotypes and obesity. Our data suggest that SIM1 sequencing should be performed more systematically in patients with developmental delay, even in the absence of severe obesity. These results deserve further SIM1 screening studies.
Collapse
Affiliation(s)
- Louise Montagne
- European Genomic Institute for Diabetes, Lille, France. Correspondence: Philippe Froguel ; CNRS-UMR8199, Lille Pasteur Institute, Lille, France; Lille 2 University, Lille, France; Department of Pediatrics, Saint Antoine Pediatric Hospital, Saint Vincent de Paul Hospital, Catholic University of Lille, Lille, France
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
141
|
Leptin deficient ob/ob mice and diet-induced obese mice responded differently to Roux-en-Y bypass surgery. Int J Obes (Lond) 2014; 39:798-805. [PMID: 25349056 DOI: 10.1038/ijo.2014.189] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/08/2014] [Accepted: 10/18/2014] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Weight regain contributes to the therapeutic failure in 15-20% of type 2 diabetic patients after Roux-en-Y gastric bypass surgery (RYGB), and the mechanism remains largely unknown. This study was conducted to explore the mechanism of weight regain. RESEARCH DESIGN Wild-type (WT) diet-induced obese (DIO) mice were used to mimic human obesity, and ob/ob mice were used for leptin deficiency-induced obesity. Two groups of mice were compared in weight regain for 10 months after RYGB. Weight loss, food intake, fecal energy loss and energy expenditure were monitored in the study of weight regain. Fasting insulin, insulin tolerance and homeostatic model assessment-insulin resistance were tested for insulin sensitivity under the weight regain. Weight loss from RYGB and calorie restriction was compared for the impact in insulin sensitivity. RESULTS In WT mice, RYGB induced a sustained weight loss and insulin sensitization over the sham operation in this 10-month study. However, RYGB failed to generate the same effects in leptin-deficient ob/ob mice, which suffered a weight regain over the pre-surgery level. In ob/ob mice, body weight was reduced by RYGB transiently in the first week, recovered in the second week and increased over the baseline thereafter. Weight loss was induced by RYGB relative to that of sham mice, but the loss was not sufficient to keep body weight below the pre-surgery levels. In addition, insulin sensitivity was not improved by the weight loss. The response to RYGB was improved in ob/ob mice by 2 weeks of leptin treatment. Weight loss from calorie restriction had an equivalent effect on insulin sensitization compared with that of RYGB. CONCLUSION Those data demonstrate that ob/ob mice and DIO mice responded differently to RYGB surgery, suggesting that leptin may be one of the factors required for RYGB to prevent weight regain and diabetes recurrence.
Collapse
|
142
|
Scheepers LEJM, Penders J, Mbakwa CA, Thijs C, Mommers M, Arts ICW. The intestinal microbiota composition and weight development in children: the KOALA Birth Cohort Study. Int J Obes (Lond) 2014; 39:16-25. [PMID: 25298274 DOI: 10.1038/ijo.2014.178] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 09/04/2014] [Accepted: 09/24/2014] [Indexed: 12/17/2022]
Abstract
OBJECTIVE To investigate whether the intestinal microbiota composition in early infancy is associated with subsequent weight development in children. METHODS Analyses were conducted within the KOALA Birth Cohort Study (n = 2834). This cohort originates from two recruitments groups: pregnant women with a conventional lifestyle (no selection based on lifestyle) and pregnant women recruited through alternative channels (organic shops, anthroposophic clinicians/midwives, Steiner schools and relevant magazines). From 909 one-month-old infants, fecal samples were collected and analyzed by quantitative PCR targeting bifidobacteria, Bacteroides fragilis group, Clostridium difficile, Escherichia coli, Lactobacilli and total bacteria counts. Between the ages of 1 and 10 years, parent-reported weight and height was collected at 7 time points. Age- and gender-standardized body mass index (BMI) z-scores were calculated. Data were analyzed using generalized estimating equation. RESULTS Colonization with B. fragilis group was borderline significantly associated with a higher BMI z-score of 0.15 (95% confidence interval (CI): -0.02 to 0.31), in the conventional subcohort. After stratification for fiber intake (P(forinteraction) = 0.003), colonization with B. fragilis group was associated with a 0.34 higher BMI z-score among children with a low-fiber intake in this subcohort (95% CI: 0.17-0.53). Higher counts among colonized children were positively associated with BMI z-score only in children within the conventional subcohort and a high-fiber diet (BMI z-score 0.08; 95% CI: 0.01-0.14), but inversely associated in children with a low-fiber diet (BMI z-score -0.05; 95% CI: -0.10 to 0.00), and in children recruited through alternative channels (BMI z-score -0.10; 95% CI: -0.17 to -0.03). The other bacteria were not associated with BMI z-scores, regardless of subcohort. CONCLUSION Using a targeted approach, we conclude that the intestinal microbiota, particularly the B. fragilis group, is associated with childhood weight development. To identify the potential impact of additional bacterial taxa, further prospective studies applying an unconstrained in-depth characterization of the microbiota are needed.
Collapse
Affiliation(s)
- L E J M Scheepers
- Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, The Netherlands
| | - J Penders
- 1] Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, The Netherlands [2] Department of Medical Microbiology, Maastricht University Medical Centre, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht, The Netherlands
| | - C A Mbakwa
- Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, The Netherlands
| | - C Thijs
- Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, The Netherlands
| | - M Mommers
- Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, The Netherlands
| | - I C W Arts
- 1] Department of Epidemiology, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, The Netherlands [2] Department of Epidemiology, Maastricht University, CARIM School for Cardiovascular Diseases, Maastricht, The Netherlands
| |
Collapse
|
143
|
da Silva AA, do Carmo JM, Dubinion JH, Bassi M, Mokhtarpouriani K, Hamza SM, Hall JE. Chronic central nervous system MC3/4R blockade attenuates hypertension induced by nitric oxide synthase inhibition but not by angiotensin II infusion. Hypertension 2014; 65:171-7. [PMID: 25287400 DOI: 10.1161/hypertensionaha.114.03999] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We examined whether central melanocortin 3 and 4 receptor (MC3/4R) blockade attenuates the blood pressure (BP) responses to chronic L-NAME or angiotensin II (Ang II) infusion in Sprague-Dawley rats implanted with telemetry transmitters, venous catheters, and intracerebroventricular cannula into the lateral ventricle. After 5 days of control measurements, L-NAME (10 μg/kg/min IV, groups 1 and 2) or Ang II (10 ng/kg/min IV, groups 3 and 4) were infused for 24 days, and starting on day 7 of L-NAME or Ang II infusion, the MC3/4R antagonist SHU-9119 (24 nmol/d, n=6/group; groups 1 and 3) or vehicle (saline 0.5 μL/h, n=6/group; groups 2 and 4) was infused intracerebroventricularly for 10 days. A control normotensive group also received SHU-9119 for 10 days (n=5). L-NAME and Ang II increased BP by 40±3 and 56±5 mm Hg, respectively, although heart rate was slightly reduced. MC3/4R blockade doubled food intake and reduced heart rate (≈40 to ≈50 bpm) in all groups. MC3/4R blockade caused only a small reduction in BP in normotensive group (4 mm Hg) and no change in rats receiving Ang II, although markedly reducing BP by 21±4 mm Hg in L-NAME-treated rats. After SHU-9119 infusion was stopped, food intake, heart rate, and BP gradually returned to values observed before SHU-9119 infusion was started. Ganglionic blockade at the end of L-NAME or Ang II infusion caused similar BP reduction in both groups. These results suggest that the brain MC3/4R contributes, at least in part, to the hypertension induced by chronic L-NAME infusion but not by Ang II.
Collapse
Affiliation(s)
- Alexandre A da Silva
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Center of Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson.
| | - Jussara M do Carmo
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Center of Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson
| | - John H Dubinion
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Center of Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson
| | - Mirian Bassi
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Center of Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson
| | - Kasra Mokhtarpouriani
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Center of Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson
| | - Shereen M Hamza
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Center of Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson
| | - John E Hall
- From the Department of Physiology and Biophysics, Mississippi Center for Obesity Research, Center of Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson
| |
Collapse
|
144
|
Abstract
Heritability of obesity and body weight variation is high. Molecular genetic studies have led to the identification of mutations in a few genes, with a major effect on obesity (major genes and monogenic forms). Analyses of these genes have helped to unravel important pathways and have created a more profound understanding of body weight regulation. For most individuals, a polygenic basis is relevant for the genetic predisposition to obesity. Small effect sizes are conveyed by the polygenic variants. Hence, only if a number of these variants is harboured, a sizeable phenotypic effect is detectable. Most, if not all, of the genes relevant to weight regulation are expressed in the hypothalamus. This underscores the major role of this region of the brain in body weight regulation.
Collapse
Affiliation(s)
- Anke Hinney
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, Essen, Germany.
| | - Anna-Lena Volckmar
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, Essen, Germany.
| | - Jochen Antel
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, Essen, Germany.
| |
Collapse
|
145
|
Monge-Roffarello B, Labbe SM, Roy MC, Lemay ML, Coneggo E, Samson P, Lanfray D, Richard D. The PVH as a site of CB1-mediated stimulation of thermogenesis by MC4R agonism in male rats. Endocrinology 2014; 155:3448-58. [PMID: 24949658 DOI: 10.1210/en.2013-2092] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The present study was designed to investigate the involvement of the cannabinoid receptor 1 (CB1) in the stimulating effects of the melanocortin-4 receptor (MC4R) agonism on whole-body and brown adipose tissue (BAT) thermogenesis. In a first series of experiments, whole-body and BAT thermogenesis were investigated in rats infused in the third ventricle of the brain with the MC4R agonist melanotan II (MTII) and the CB1 agonist δ9-tetrahydrocannabinol (δ(9)-THC) or the CB1 antagonist AM251. Whole-body thermogenesis was measured by indirect calorimetry and BAT thermogenesis assessed from interscapular BAT (iBAT) temperature. δ(9)-THC blunted the effects of MTII on energy expenditure and iBAT temperature, whereas AM251 tended to potentiate the MTII effects. δ(9)-THC also blocked the stimulating effect of MTII on (14)C-bromopalmitate and (3)H-deoxyglucose uptakes in iBAT. Additionally, δ(9)-THC attenuated the stimulating effect of MTII on the expression of peroxisome proliferator-activated receptor-γ coactivator 1-α (Pgc1α), type II iodothyronine deiodinase (Dio2), carnitine palmitoyltransferase 1B (Cpt1b), and uncoupling protein 1 (Ucp1). In a second series of experiments, we addressed the involvement of the paraventricular hypothalamic nucleus (PVH) in the CB1-mediated effects of MTII on iBAT thermogenesis, which were assessed following the infusion of MTII in the PVH and δ(9)-THC or AM251 in the fourth ventricle of the brain. We demonstrated the ability of δ(9)-THC to blunt MTII-induced iBAT temperature elevation. δ(9)-THC also blocked the PVH effect of MTII on (14)C-bromopalmitate uptake as well as on Pgc1α and Dio2 expression in iBAT. Altogether the results of this study demonstrate the involvement of the PVH in the CB1-mediated stimulating effects of the MC4R agonist MTII on whole-body and BAT thermogenesis.
Collapse
MESH Headings
- Adipose Tissue, Brown/metabolism
- Animals
- Male
- Paraventricular Hypothalamic Nucleus/metabolism
- Peptides, Cyclic/metabolism
- Piperidines
- Pyrazoles
- Rats
- Rats, Wistar
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptor, Melanocortin, Type 4/agonists
- Receptor, Melanocortin, Type 4/metabolism
- Thermogenesis
- alpha-MSH/analogs & derivatives
- alpha-MSH/metabolism
Collapse
Affiliation(s)
- Boris Monge-Roffarello
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Canada G1V 4G5
| | | | | | | | | | | | | | | |
Collapse
|
146
|
Giovaninni NP, Fuly JT, Moraes LI, Coutinho TN, Trarbach EB, Jorge AADL, Costalonga EF. Study of the association between 3111T/C polymorphism of the CLOCK gene and the presence of overweight in schoolchildren. J Pediatr (Rio J) 2014; 90:500-5. [PMID: 24818524 DOI: 10.1016/j.jped.2014.01.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 11/20/2013] [Accepted: 01/21/2014] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVES To evaluate the association between 3111T/C polymorphism of the CLOCK gene and the presence of obesity and sleep duration in children aged 6-13 years. In adults, this genetic variant has been associated with duration of sleep, ghrelin levels, weight, and eating habits. Although short sleep duration has been linked to obesity in children, no study has aimed to identify the possible molecular mechanisms of this association to date. METHODS Weight, height, and circumferences were transformed into Z-scores for age and gender. Genotyping was performed using TaqMan methodology. A questionnaire regarding hours of sleep was provided to parents. The appropriate statistical tests were performed. RESULTS This study evaluated 370 children (45% males, 55% females, mean age 8.5 ± 1.5 years). The prevalence of overweight was 18%. The duration of sleep was, on average, 9.7hours, and was inversely related to age (p<0.001). Genotype distribution was: 4% CC, 31% CT, and 65% TT. There was a trend toward higher prevalence of overweight in children who slept less than nine hours (23%) when compared to those who slept more than ten hours (16%, p=0.06). Genotype was not significantly correlated to any of the assessed outcomes. CONCLUSIONS The CLOCK 3111T/C polymorphism was not significantly associated with overweight or sleep duration in children in this city.
Collapse
Affiliation(s)
| | - Jeanne T Fuly
- Universidade Vila Velha (UVV), Vila Velha, ES, Brazil
| | | | | | | | | | | |
Collapse
|
147
|
Abstract
Obesity among children, adolescents and adults has emerged as one of the most serious public health concerns in the 21st century. The worldwide prevalence of childhood obesity has increased remarkably over the past 3 decades. The growing prevalence of childhood obesity has also led to appearance of obesity-related comorbid disease entities at an early age. Childhood obesity can adversely affect nearly every organ system and often causes serious consequences, including hypertension, dyslipidemia, insulin resistance, dysglycemia, fatty liver disease and psychosocial complications. It is also a major contributor to increasing healthcare expenditures. For all these reasons, it is important to prevent childhood obesity as well as to identify overweight and obese children at an early stage so they can begin treatment and attain and maintain a healthy weight. At present, pharmacotherapy options for treatment of pediatric obesity are very limited. Therefore, establishing a comprehensive management program that emphasizes appropriate nutrition, exercise and behavioral modification is crucial. The physician's role should expand beyond the clinical setting to the community to serve as a role model and to advocate for prevention and early treatment of obesity.
Collapse
Affiliation(s)
- Neslihan Koyuncuoğlu Güngör
- Louisiana State University Health Sciences Center-Shreveport, Department of Pediatric Endocrinology, Shreveport, LA, USA
,* Address for Correspondence: Louisiana State University Health Sciences Center-Shreveport, Department of Pediatric Endocrinology, Shreveport, LA, USA GSM: +1 312 6756070 E-mail:
| |
Collapse
|
148
|
Study of the association between 3111T/C polymorphism of the CLOCK gene and the presence of overweight in schoolchildren. JORNAL DE PEDIATRIA (VERSÃO EM PORTUGUÊS) 2014. [DOI: 10.1016/j.jpedp.2014.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
149
|
Mason K, Page L, Balikcioglu PG. Screening for hormonal, monogenic, and syndromic disorders in obese infants and children. Pediatr Ann 2014; 43:e218-24. [PMID: 25198446 PMCID: PMC4369917 DOI: 10.3928/00904481-20140825-08] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The prevalence of pediatric obesity in the United States is nearly 17%. Most cases are "exogenous", resulting from excess energy intake relative to energy expenditure over a prolonged period of time. However, some cases of obesity are "endogenous", associated with hormonal, genetic, or syndromic disorders such as hypothyroidism, Cushing's syndrome, growth hormone deficiency, defective leptin signaling, mutations in the melanocortin 4 receptor, and Prader-Willi and Bardet-Biedl syndromes. This article reviews the hormonal, monogenic, and syndromic causes of childhood obesity and identifies critical features that distinguish "endogenous" obesity disorders from the more common exogenous obesity. Findings that raise suspicion for endogenous obesity include onset in infancy, lack of satiety, poor linear growth, dysmorphic features, and cognitive dysfunction. Selection and interpretation of appropriate laboratory tests and indications for subspecialist referral are also discussed.
Collapse
|
150
|
Delhanty PJD, Bouw E, Huisman M, Vervenne RML, Themmen APN, van der Lely AJ, van den Akker ELT. Functional characterization of a new human melanocortin-4 receptor homozygous mutation (N72K) that is associated with early-onset obesity. Mol Biol Rep 2014; 41:7967-72. [PMID: 25163632 DOI: 10.1007/s11033-014-3691-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 08/21/2014] [Indexed: 01/31/2023]
Abstract
The melanocortin 4 receptor (MC4R) is expressed in the hypothalamus and is essential for regulation of appetite and energy expenditure. MC4R dysfunction in humans causes hyperphagia, impaired satiety and obesity. We have identified a novel c.216C>A (N72 K) homozygous mutation in MC4R in a girl with severe obesity. The patient presented with early-onset obesity and hyperphagia indicating an effect of the homozygous mutation on her phenotype. In silico analyses indicate a damaging effect on receptor function, and the mutation is unusual in occurring in the first intra-cellular loop of the receptor. Site-directed mutagenesis was used to generate plasmid constructs expressing wild-type and mutant MC4R. These were transfected into HEK293 cells and assessed for cAMP responsiveness to α-MSH. Cells expressing N-terminal HA and C-terminal GFP-tagged MC4R were assessed by immunofluorescence confocal microscopy and flow cytometry for correct cell-surface localization. The maximal response of the mutant MC4R to α-MSH was decreased to 20 ± 1 % of the wild type receptor response, and the EC50 was increased from 16.5 ± 5.4 nM to 37.0 ± 8.3 nM. Localization of N- and C-terminally tagged MC4R by confocal microscopy and flow cytometry showed aberrant retention of the mutant receptor in the cytoplasm. Our data describe a rare homozygous inactivating mutation in the first intra-cellular loop of MC4R that markedly impairs its function and is associated with early-onset obesity and hyperphagia.
Collapse
Affiliation(s)
- Patric J D Delhanty
- Departments of Internal Medicine and Pediatric Endocrinology, Erasmus MC, Rotterdam, The Netherlands,
| | | | | | | | | | | | | |
Collapse
|