51
|
Contreras RE, Schriever SC, Pfluger PT. Physiological and Epigenetic Features of Yoyo Dieting and Weight Control. Front Genet 2019; 10:1015. [PMID: 31921275 PMCID: PMC6917653 DOI: 10.3389/fgene.2019.01015] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/24/2019] [Indexed: 12/16/2022] Open
Abstract
Obesity and being overweight have become a worldwide epidemic affecting more than 1.9 billion adults and 340 million children. Efforts to curb this global health burden by developing effective long-term non-surgical weight loss interventions continue to fail due to weight regain after weight loss. Weight cycling, often referred to as Yoyo dieting, is driven by physiological counter-regulatory mechanisms that aim at preserving energy, i.e. decreased energy expenditure, increased energy intake, and impaired brain-periphery communication. Models based on genetically determined set points explained some of the weight control mechanisms, but exact molecular underpinnings remained elusive. Today, gene–environment interactions begin to emerge as likely drivers for the obesogenic memory effect associated with weight cycling. Here, epigenetic mechanisms, including histone modifications and DNA methylation, appear as likely factors that underpin long-lasting deleterious adaptations or an imprinted obesogenic memory to prevent weight loss maintenance. The first part summarizes our current knowledge on the physiology of weight cycling by discussing human and murine studies on the Yoyo-dieting phenomenon and physiological adaptations associated with weight loss and weight re-gain. The second part provides an overview on known associations between obesity and epigenetic modifications. We further interrogate the roles of epigenetic mechanisms in the CNS control of cognitive functions as well as reward and addictive behaviors, and subsequently discuss whether such mechanisms play a role in weight control. The final two parts describe major opportunities and challenges associated with studying epigenetic mechanisms in the CNS with its highly heterogenous cell populations, and provide a summary of recent technological advances that will help to delineate whether an obese memory is based upon epigenetic mechanisms.
Collapse
Affiliation(s)
- Raian E Contreras
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Centre for Diabetes Research (DZD), Neuherberg, Germany.,Neurobiology of Diabetes, TUM School of Medicine, Technische Universität München, Munich, Germany
| | - Sonja C Schriever
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Centre for Diabetes Research (DZD), Neuherberg, Germany
| | - Paul T Pfluger
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, Neuherberg, Germany.,Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Centre for Diabetes Research (DZD), Neuherberg, Germany.,Neurobiology of Diabetes, TUM School of Medicine, Technische Universität München, Munich, Germany
| |
Collapse
|
52
|
Izquierdo AG, Crujeiras AB, Casanueva FF, Carreira MC. Leptin, Obesity, and Leptin Resistance: Where Are We 25 Years Later? Nutrients 2019; 11:nu11112704. [PMID: 31717265 PMCID: PMC6893721 DOI: 10.3390/nu11112704] [Citation(s) in RCA: 243] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/27/2019] [Accepted: 10/31/2019] [Indexed: 12/14/2022] Open
Abstract
Leptin, a hormone that is capable of effectively reducing food intake and body weight, was initially considered for use in the treatment of obesity. However, obese subjects have since been found to have high levels of circulating leptin and to be insensitive to the exogenous administration of leptin. The inability of leptin to exert its anorexigenic effects in obese individuals, and therefore, the lack of clinical utility of leptin in obesity, is defined as leptin resistance. This phenomenon has not yet been adequately characterized. Elucidation of the molecular mechanisms underlying leptin resistance is of vital importance for the application of leptin as an effective treatment for obesity. Leptin must cross the blood–brain barrier (BBB) to reach the hypothalamus and exert its anorexigenic functions. The mechanisms involved in leptin transportation across the blood–brain barrier continue to be unclear, thereby preventing the clinical application of leptin in the treatment of obesity. In recent years, new strategies have been developed to recover the response to leptin in obesity. We have summarized these strategies in this review.
Collapse
Affiliation(s)
- Andrea G. Izquierdo
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Ana B. Crujeiras
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Felipe F. Casanueva
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Molecular Endocrinolgy, Universidad de Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
| | - Marcos C. Carreira
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
| |
Collapse
|
53
|
Stemmer K, Müller TD, DiMarchi RD, Pfluger PT, Tschöp MH. CNS-targeting pharmacological interventions for the metabolic syndrome. J Clin Invest 2019; 129:4058-4071. [PMID: 31380808 DOI: 10.1172/jci129195] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The metabolic syndrome (MetS) encompasses medical conditions such as obesity, hyperglycemia, high blood pressure, and dyslipidemia that are major drivers for the ever-increasing prevalence of type 2 diabetes, cardiovascular diseases, and certain types of cancer. At the core of clinical strategies against the MetS is weight loss, induced by bariatric surgery, lifestyle changes based on calorie reduction and exercise, or pharmacology. This Review summarizes the past, current, and future efforts of targeting the MetS by pharmacological agents. Major emphasis is given to drugs that target the CNS as a key denominator for obesity and its comorbid sequelae.
Collapse
Affiliation(s)
- Kerstin Stemmer
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Timo D Müller
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | | | - Paul T Pfluger
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity, Helmholtz Zentrum München, Neuherberg, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany.,Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| |
Collapse
|
54
|
Comeras LB, Herzog H, Tasan RO. Neuropeptides at the crossroad of fear and hunger: a special focus on neuropeptide Y. Ann N Y Acad Sci 2019; 1455:59-80. [PMID: 31271235 PMCID: PMC6899945 DOI: 10.1111/nyas.14179] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/15/2019] [Accepted: 06/03/2019] [Indexed: 12/11/2022]
Abstract
Survival in a natural environment forces an individual into constantly adapting purposive behavior. Specified interoceptive neurons monitor metabolic and physiological balance and activate dedicated brain circuits to satisfy essential needs, such as hunger, thirst, thermoregulation, fear, or anxiety. Neuropeptides are multifaceted, central components within such life‐sustaining programs. For instance, nutritional depletion results in a drop in glucose levels, release of hormones, and activation of hypothalamic and brainstem neurons. These neurons, in turn, release several neuropeptides that increase food‐seeking behavior and promote food intake. Similarly, internal and external threats activate neuronal pathways of avoidance and defensive behavior. Interestingly, specific nuclei of the hypothalamus and extended amygdala are activated by both hunger and fear. Here, we introduce the relevant neuropeptides and describe their function in feeding and emotional‐affective behaviors. We further highlight specific pathways and microcircuits, where neuropeptides may interact to identify prevailing homeostatic needs and direct respective compensatory behaviors. A specific focus will be on neuropeptide Y, since it is known for its pivotal role in metabolic and emotional pathways. We hypothesize that the orexigenic and anorexigenic properties of specific neuropeptides are related to their ability to inhibit fear and anxiety.
Collapse
Affiliation(s)
- Lucas B Comeras
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| | - Herbert Herzog
- Neuroscience Division, Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - Ramon O Tasan
- Department of Pharmacology, Medical University Innsbruck, Innsbruck, Austria
| |
Collapse
|
55
|
Ip MSM, Mokhlesi B. Activating Leptin Receptors in the Central Nervous System Using Intranasal Leptin. A Novel Therapeutic Target for Sleep-disordered Breathing. Am J Respir Crit Care Med 2019; 199:689-691. [PMID: 30365343 PMCID: PMC6423110 DOI: 10.1164/rccm.201810-1925ed] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Mary S M Ip
- 1 Queen Mary Hospital University of Hong Kong Hong Kong S.A.R., China and
| | - Babak Mokhlesi
- 2 Sleep Disorders Center University of Chicago Chicago, Illinois
| |
Collapse
|
56
|
Harrison L, Pfuhlmann K, Schriever SC, Pfluger PT. Profound weight loss induces reactive astrogliosis in the arcuate nucleus of obese mice. Mol Metab 2019; 24:149-155. [PMID: 30979678 PMCID: PMC6977167 DOI: 10.1016/j.molmet.2019.03.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 03/27/2019] [Accepted: 03/28/2019] [Indexed: 11/12/2022] Open
Abstract
Objective Obesity has been linked to an inflammation like state in the hypothalamus, mainly characterized by reactive gliosis (RG) of astrocytes and microglia. Here, using two diet models or pharmacological treatment, we assessed the effects of mild and drastic weight loss on RG, in the context of high-fat diet (HFD) induced obesity. Methods We subjected HFD-induced obese (DIO) male C57BL/6J mice to a weight loss intervention with a switch to standard chow, calorie restriction (CR), or treatment with the Glp1 receptor agonist Exendin-4 (EX4). The severity of RG was estimated by an ordinal scoring system based on fluorescence intensities of glial fibrillary acidic protein, ionized calcium-binding adapter molecule 1 positive (Iba1), cell numbers, and morphological characteristics. Results In contrast to previous reports, DIO mice fed chronically with HFD showed no differences in microglial or astrocytic RG, compared to chow controls. Moreover, mild or profound weight loss had no impact on microglial RG. However, astrocyte RG was increased in CR and EX4 groups compared to chow fed animals and strongly correlated to body weight loss. Profound weight loss by either CR or EX4 was further linked to increased levels of circulating non-esterified free fatty acids. Conclusions Overall, our data demonstrate that in a chronically obese state, astrocyte and microglial RG is indifferent from that observed in age-matched chow controls. Nonetheless, profound acute weight loss can induce astrocyte RG in the hypothalamic arcuate nucleus, possibly due to increased circulating NEFAs. This suggests that astrocytes may sense acute changes to both the dietary environment and body weight. Acute weight loss induces reactive gliosis in arcuate nucleus residing astrocytes. Reactive gliosis after chronic high-fat diet is comparable to chow fed litter mates. Observed gliosis coincides with increased circulating non-esterified fatty acids.
Collapse
Affiliation(s)
- Luke Harrison
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, 85764, Neuherberg, Germany; Institute for Diabetes and Obesity, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany; Division of Metabolic Diseases, Technische Universität München, 80333, Munich, Germany
| | - Katrin Pfuhlmann
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, 85764, Neuherberg, Germany; Institute for Diabetes and Obesity, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany; Division of Metabolic Diseases, Technische Universität München, 80333, Munich, Germany
| | - Sonja C Schriever
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, 85764, Neuherberg, Germany; Institute for Diabetes and Obesity, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany
| | - Paul T Pfluger
- Research Unit Neurobiology of Diabetes, Helmholtz Zentrum München, 85764, Neuherberg, Germany; Institute for Diabetes and Obesity, Helmholtz Zentrum München, 85764, Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764, Neuherberg, Germany.
| |
Collapse
|
57
|
Yoo S, Cha D, Kim DW, Hoang TV, Blackshaw S. Tanycyte-Independent Control of Hypothalamic Leptin Signaling. Front Neurosci 2019; 13:240. [PMID: 30941008 PMCID: PMC6433882 DOI: 10.3389/fnins.2019.00240] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/01/2019] [Indexed: 12/29/2022] Open
Abstract
Leptin is secreted by adipocytes to regulate appetite and body weight. Recent studies have reported that tanycytes actively transport circulating leptin across the brain barrier into the hypothalamus, and are required for normal levels of hypothalamic leptin signaling. However, direct evidence for leptin receptor (LepR) expression is lacking, and the effect of tanycyte-specific deletion of LepR has not been investigated. In this study, we analyze the expression and function of the tanycytic LepR in mice. Using single-molecule fluorescent in situ hybridization (smfISH), RT-qPCR, single-cell RNA sequencing (scRNA-Seq), and selective deletion of the LepR in tanycytes, we are unable to detect expression of LepR in the tanycytes. Tanycyte-specific deletion of LepR likewise did not affect leptin-induced pSTAT3 expression in hypothalamic neurons, regardless of whether leptin was delivered by intraperitoneal or intracerebroventricular injection. Finally, we use activity-regulated scRNA-Seq (act-Seq) to comprehensively profile leptin-induced changes in gene expression in all cell types in mediobasal hypothalamus. Clear evidence for leptin signaling is only seen in endothelial cells and subsets of neurons, although virtually all cell types show leptin-induced changes in gene expression. We thus conclude that LepR expression in tanycytes is either absent or undetectably low, that tanycytes do not directly regulate hypothalamic leptin signaling through a LepR-dependent mechanism, and that leptin regulates gene expression in diverse hypothalamic cell types through both direct and indirect mechanisms.
Collapse
Affiliation(s)
- Sooyeon Yoo
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - David Cha
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Dong Won Kim
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Thanh V Hoang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Seth Blackshaw
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States.,Department of Ophthalmology, Johns Hopkins University, Baltimore, MD, United States.,Department of Neurology, Johns Hopkins University, Baltimore, MD, United States.,Center for Human Systems Biology, Johns Hopkins University, Baltimore, MD, United States.,School of Medicine, Institute for Cell Engineering, Johns Hopkins University, Baltimore, MD, United States
| |
Collapse
|