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Hunger and Satiety Peptides: Is There a Pattern to Classify Patients with Prader-Willi Syndrome? J Clin Med 2021; 10:jcm10215170. [PMID: 34768690 PMCID: PMC8585040 DOI: 10.3390/jcm10215170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 10/29/2021] [Accepted: 11/02/2021] [Indexed: 11/16/2022] Open
Abstract
Hyperphagia is one of the main problems of patients with Prader-Willi syndrome (PWS) to cope with everyday life. The underlying mechanisms are not yet well understood. Gut-brain hormones are an interrelated network that may be at least partially involved. We aimed to study the hormonal profile of PWS patients in comparison with obese and healthy controls. Thirty adult PWS patients (15 men; age 27.5 ± 8.02 years; BMI 32.4 ± 8.14 kg/m2), 30 obese and 30 healthy controls were studied before and after eating a hypercaloric liquid diet. Plasma brain-derived neurotrophic factor (BDNF), leptin, total and active ghrelin, peptide YY (PYY), pancreatic polypeptide (PP), Glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and amylin were determined at times 0′, 30′, 60′ and 120′. Cluster analysis was used. When considering all peptides together, two clusters were established according to fasting hormonal standardized concentrations. Cluster 1 encompassed most of obese (25/30) and healthy controls (28/30). By contrast, the majority of patients with PWS were located in Cluster 2 (23/27) and presented a similar fasting profile with hyperghrelinemia, high levels of leptin, PYY, GIP and GLP-1, compared to Cluster 1; that may reflect a dysfunction of these hunger/satiety hormones. When peptide behavior over the time was considered, PP concentrations were not sustained postprandially from 60 min onwards in Cluster 2. BDNF and amylin did not help to differentiate the two clusters. Thus, cluster analysis could be a good tool to distinguish and characterize the differences in hormone responses between PWS and obese or healthy controls.
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Abstract
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by hyperphagia, hypotonia, learning disability, as well as a range of psychiatric conditions. The conservation of the PWS genetic interval on chromosome 15q11-q13 in human, and a cluster of genes on mouse chromosome 7, has facilitated the use of mice as animal models for PWS. Some models faithfully mimic the loss of all gene expression from the paternally inherited PWS genetic interval, whereas others target smaller regions or individual genes. Collectively, these models have provided insight into the mechanisms, many of which lead to alterations in hypothalamic function, underlying the core symptoms of PWS, including growth retardation, hyperphagia and metabolism, reproductive maturation and endophenotypes of relevance to behavioral and psychiatric problems. Here we review and summarize these studies.
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Affiliation(s)
- Simona Zahova
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Anthony R Isles
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom.
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Moose JE, Leets KA, Mate NA, Chisholm JD, Hougland JL. An overview of ghrelin O-acyltransferase inhibitors: a literature and patent review for 2010-2019. Expert Opin Ther Pat 2020; 30:581-593. [PMID: 32564644 DOI: 10.1080/13543776.2020.1776263] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION The peptide hormone ghrelin regulates physiological processes associated with energy homeostasis such as appetite, insulin signaling, glucose metabolism, and adiposity. Ghrelin has also been implicated in a growing number of neurological pathways involved in stress response and addiction behavior. For ghrelin to bind the growth hormone secretagogue receptor 1a (GHS-R1a) and activate signaling, the hormone must first be octanoylated on a specific serine side chain. This key transformation is performed by the enzyme ghrelin O-acyltransferase (GOAT), and therefore GOAT inhibitors may be useful in treating disorders related to ghrelin signaling such as diabetes, obesity, and related metabolic syndromes. AREAS COVERED This report covers ghrelin and GOAT as potential therapeutic targets and summarizes work on GOAT inhibitors through the end of 2019, highlighting recent successes with both peptidomimetics and small molecule GOAT inhibitors as potent modulators of GOAT-catalyzed ghrelin octanoylation. EXPERT OPINION A growing body of biochemical and structural knowledge regarding the ghrelin/GOAT system now enables multiple avenues for identifying and optimizing GOAT inhibitors. We are at the beginning of a new era with increased opportunities for leveraging ghrelin and GOAT in the understanding and treatment of multiple health conditions including diabetes, obesity, and addiction.
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Affiliation(s)
- Jacob E Moose
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Katelyn A Leets
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - Nilamber A Mate
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - John D Chisholm
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
| | - James L Hougland
- Department of Chemistry and BioInspired Syracuse, Syracuse University , Syracuse, NY, USA
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Zhang H, Li Q, Teng Y, Lin Y, Li S, Qin T, Chen L, Huang J, Zhai H, Yu Q, Xu G. Interleukin-27 decreases ghrelin production through signal transducer and activator of transcription 3-mechanistic target of rapamycin signaling. Acta Pharm Sin B 2020; 10:837-849. [PMID: 32528831 PMCID: PMC7280146 DOI: 10.1016/j.apsb.2019.12.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 11/06/2019] [Accepted: 11/19/2019] [Indexed: 01/19/2023] Open
Abstract
Interleukin-27 (IL-27), a heterodimeric cytokine, plays a protective role in diabetes. Ghrelin, a gastric hormone, provides a hunger signal to the central nervous system to stimulate food intake. The relationship between IL-27 and ghrelin is still unexplored. Here we investigated that signal transducer and activator of transcription 3 (STAT3)—mechanistic target of rapamycin (mTOR) signaling mediates the suppression of ghrelin induced by IL-27. Co-localization of interleukin 27 receptor subunit alpha (WSX-1) and ghrelin was observed in mouse and human gastric mucosa. Intracerebroventricular injection of IL-27 markedly suppressed ghrelin synthesis and secretion while stimulating STAT3–mTOR signaling in both C57BL/6J mice and high-fat diet-induced-obese mice. IL-27 inhibited the production of ghrelin in mHypoE-N42 cells. Inhibition of mTOR activity induced by mTOR siRNA or rapamycin blocked the suppression of ghrelin production induced by IL-27 in mHypoE-N42 cells. Stat 3 siRNA also abolished the inhibitory effect of IL-27 on ghrelin. IL-27 increased the interaction between STAT3 and mTOR in mHypoE-N42 cells. In conclusion, IL-27 suppresses ghrelin production through the STAT3-mTOR dependent mechanism.
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Maugham ML, Seim I, Thomas PB, Crisp GJ, Shah ET, Herington AC, Gregory LS, Nelson CC, Jeffery PL, Chopin LK. Limited short-term effects on human prostate cancer xenograft growth and epidermal growth factor receptor gene expression by the ghrelin receptor antagonist [D-Lys 3]-GHRP-6. Endocrine 2019; 64:393-405. [PMID: 30390209 DOI: 10.1007/s12020-018-1796-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 10/17/2018] [Indexed: 12/15/2022]
Abstract
PURPOSE The ghrelin axis regulates many physiological functions (including appetite, metabolism, and energy balance) and plays a role in disease processes. As ghrelin stimulates prostate cancer proliferation, the ghrelin receptor antagonist [D-Lys3]-GHRP-6 is a potential treatment for castrate-resistant prostate cancer and for preventing the metabolic consequences of androgen-targeted therapies. We therefore explored the effect of [D-Lys3]-GHRP-6 on PC3 prostate cancer xenograft growth. METHODS NOD/SCID mice with PC3 prostate cancer xenografts were administered 20 nmoles/mouse [D-Lys3]-GHRP-6 daily by intraperitoneal injection for 14 days and tumour volume and weight were measured. RNA sequencing of tumours was conducted to investigate expression changes following [D-Lys3]-GHRP-6 treatment. A second experiment, extending treatment time to 18 days and including a higher dose of [D-Lys3]-GHRP-6 (200 nmoles/mouse/day), was undertaken to ensure repeatability. RESULTS We demonstrate here that daily intraperitoneal injection of 20 nmoles/mouse [D-Lys3]-GHRP-6 reduces PC3 prostate cancer xenograft tumour volume and weight in NOD/SCID mice at two weeks post treatment initiation. RNA-sequencing revealed reduced expression of epidermal growth factor receptor (EGFR) in these tumours. Further experiments demonstrated that the effects of [D-Lys3]-GHRP-6 are transitory and lost after 18 days of treatment. CONCLUSIONS We show that [D-Lys3]-GHRP-6 has transitory effects on prostate xenograft tumours in mice, which rapidly develop an apparent resistance to the antagonist. Although further studies on [D-Lys3]-GHRP-6 are warranted, we suggest that daily treatment with the antagonist is not a suitable treatment for advanced prostate cancer.
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Affiliation(s)
- Michelle L Maugham
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Skeletal Biology and Forensic Anthropology Research Laboratory, Cancer Program, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Inge Seim
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Integrative Biology Laboratory, College of Life Sciences, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Patrick B Thomas
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Gabrielle J Crisp
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Esha T Shah
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Adrian C Herington
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Laura S Gregory
- Skeletal Biology and Forensic Anthropology Research Laboratory, Cancer Program, School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Colleen C Nelson
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Penny L Jeffery
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Lisa K Chopin
- Ghrelin Research Group, Institute of Health and Biomedical Innovation, Translational Research Institute and School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia.
- Australian Prostate Cancer Research Centre - Queensland, Princess Alexandra Hospital, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.
- Comparative and Endocrine Biology Laboratory, Institute of Health and Biomedical Innovation, Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.
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Carias KV, Wevrick R. Preclinical Testing in Translational Animal Models of Prader-Willi Syndrome: Overview and Gap Analysis. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 13:344-358. [PMID: 30989085 PMCID: PMC6447752 DOI: 10.1016/j.omtm.2019.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder causing endocrine, musculoskeletal, and neurological dysfunction. PWS is caused by the inactivation of contiguous genes, complicating the development of targeted therapeutics. Clinical trials are now underway in PWS, with more trials to be implemented in the next few years. PWS-like endophenotypes are recapitulated in gene-targeted mice in which the function of one or more PWS genes is disrupted. These animal models can guide priorities for clinical trials or provide information about efficacy of a compound within the context of the specific disease. We now review the current status of preclinical studies that measure the effect of therapeutics on PWS-like endophenotypes. Seven categories of therapeutics (oxytocin and related compounds, K+-ATP channel agonists, melanocortin 4 receptor agonists, incretin mimetics and/or GLP-1 receptor agonists, cannabinoids, ghrelin agents, and Caralluma fimbriata [cactus] extract) have been tested for their effect on endophenotypes in both PWS animal models and clinical trials. Many other therapeutics have been tested in clinical trials, but not preclinical models of PWS or vice versa. Fostering dialogs among investigators performing preclinical validation of animal models and those implementing clinical studies will accelerate the discovery and translation of therapies into clinical practice in PWS.
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Affiliation(s)
- K Vanessa Carias
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Rachel Wevrick
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
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8
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Rodriguez JA, Bruggeman EC, Mani BK, Osborne-Lawrence S, Lord CC, Roseman HF, Viroslav HL, Vijayaraghavan P, Metzger NP, Gupta D, Shankar K, Pietra C, Liu C, Zigman JM. Ghrelin Receptor Agonist Rescues Excess Neonatal Mortality in a Prader-Willi Syndrome Mouse Model. Endocrinology 2018; 159:4006-4022. [PMID: 30380028 PMCID: PMC6260060 DOI: 10.1210/en.2018-00801] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 10/24/2018] [Indexed: 12/18/2022]
Abstract
In the current study, we sought to determine the significance of the ghrelin system in Prader-Willi Syndrome (PWS). PWS is characterized by hypotonia and difficulty feeding in neonates and hyperphagia and obesity beginning later in childhood. Other features include low GH, neonatal hypoglycemia, hypogonadism, and accelerated mortality. Although the hyperphagia and obesity in PWS have been attributed to elevated levels of the orexigenic hormone ghrelin, this link has never been firmly established, nor have ghrelin's potentially protective actions to increase GH secretion, blood glucose, and survival been investigated in a PWS context. In the current study, we show that placing Snord116del mice modeling PWS on ghrelin-deficient or ghrelin receptor [GH secretagogue receptor (GHSR)]-deficient backgrounds does not impact their characteristically reduced body weight, lower plasma IGF-1, delayed sexual maturation, or increased mortality in the period prior to weaning. However, blood glucose was further reduced in male Snord116del pups on a ghrelin-deficient background, and percentage body weight gain and percentage fat mass were further reduced in male Snord116del pups on a GHSR-deficient background. Strikingly, 2 weeks of daily administration of the GHSR agonist HM01 to Snord116del neonates markedly improved survival, resulting in a nearly complete rescue of the excess mortality owing to loss of the paternal Snord116 gene. These data support further exploration of the therapeutic potential of GHSR agonist administration in limiting PWS mortality, especially during the period characterized by failure to thrive.
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Affiliation(s)
- Juan A Rodriguez
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Emily C Bruggeman
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Bharath K Mani
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Sherri Osborne-Lawrence
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Caleb C Lord
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Henry F Roseman
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Hannah L Viroslav
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Prasanna Vijayaraghavan
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Nathan P Metzger
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Deepali Gupta
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | - Kripa Shankar
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
| | | | - Chen Liu
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas
| | - Jeffrey M Zigman
- Division of Hypothalamic Research, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
- Division of Endocrinology, Department of Internal Medicine, UT Southwestern Medical Center, Dallas, Texas
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, Texas
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Polex-Wolf J, Lam BY, Larder R, Tadross J, Rimmington D, Bosch F, Cenzano VJ, Ayuso E, Ma MK, Rainbow K, Coll AP, O’Rahilly S, Yeo GS. Hypothalamic loss of Snord116 recapitulates the hyperphagia of Prader-Willi syndrome. J Clin Invest 2018; 128:960-969. [PMID: 29376887 PMCID: PMC5824864 DOI: 10.1172/jci97007] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 12/05/2017] [Indexed: 12/20/2022] Open
Abstract
Profound hyperphagia is a major disabling feature of Prader-Willi syndrome (PWS). Characterization of the mechanisms that underlie PWS-associated hyperphagia has been slowed by the paucity of animal models with increased food intake or obesity. Mice with a microdeletion encompassing the Snord116 cluster of noncoding RNAs encoded within the Prader-Willi minimal deletion critical region have previously been reported to show growth retardation and hyperphagia. Here, consistent with previous reports, we observed growth retardation in Snord116+/-P mice with a congenital paternal Snord116 deletion. However, these mice neither displayed increased food intake nor had reduced hypothalamic expression of the proprotein convertase 1 gene PCSK1 or its upstream regulator NHLH2, which have recently been suggested to be key mediators of PWS pathogenesis. Specifically, we disrupted Snord116 expression in the mediobasal hypothalamus in Snord116fl mice via bilateral stereotaxic injections of a Cre-expressing adeno-associated virus (AAV). While the Cre-injected mice had no change in measured energy expenditure, they became hyperphagic between 9 and 10 weeks after injection, with a subset of animals developing marked obesity. In conclusion, we show that selective disruption of Snord116 expression in the mediobasal hypothalamus models the hyperphagia of PWS.
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Affiliation(s)
- Joseph Polex-Wolf
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Brian Y.H. Lam
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Rachel Larder
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - John Tadross
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Debra Rimmington
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Fàtima Bosch
- Center of Animal Biotechnology and Gene Therapy and Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain, and Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Verónica Jiménez Cenzano
- Center of Animal Biotechnology and Gene Therapy and Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain, and Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Eduard Ayuso
- Center of Animal Biotechnology and Gene Therapy and Department of Biochemistry and Molecular Biology, School of Veterinary Medicine, Universitat Autònoma de Barcelona, Bellaterra, Spain, and Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Marcella K.L. Ma
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Kara Rainbow
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Anthony P. Coll
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Stephen O’Rahilly
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
| | - Giles S.H. Yeo
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust–MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, United Kingdom
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Rodriguez JA, Zigman JM. Hypothalamic loss of Snord116 and Prader-Willi syndrome hyperphagia: the buck stops here? J Clin Invest 2018; 128:900-902. [PMID: 29376891 DOI: 10.1172/jci99725] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Hyperphagia and obesity are the best-known manifestations of Prader-Willi syndrome (PWS) and are responsible for most of the overall morbidity and mortality associated with the disease. Yet these PWS symptoms remain poorly understood and without effective pharmacologic therapies. Mouse models attempting to recapitulate both the genetic alterations and marked hyperphagia plus obesity of PWS have been enigmatic, leading to skepticism about the use of mouse models to investigate PWS. In this issue of the JCI, Polex-Wolf and colleagues challenge the skeptics by successfully inducing hyperphagia following bilateral mediobasal hypothalamic deletion of the Snord116 gene from adult mice. Obesity also resulted, although only in a subset of mice. While this approach represents an exciting advance, highlighting a pathologic effect of loss of mediobasal hypothalamic Snord116 expression on the development of PWS's hallmark symptoms, the variability in the body-weight and body composition responses to this site-selective gene deletion raises several questions.
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Affiliation(s)
- Juan A Rodriguez
- Division of Hypothalamic Research, Department of Internal Medicine
| | - Jeffrey M Zigman
- Division of Hypothalamic Research, Department of Internal Medicine.,Division of Endocrinology and Metabolism, Department of Internal Medicine, and.,Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Abstract
Ghrelin and motilin are released from gastrointestinal endocrine cells during hunger, to act through G protein-coupled receptors that have closely related amino acid sequences. The actions of ghrelin are more complex than motilin because ghrelin also exists outside the GI tract, it is processed to des-acyl ghrelin which has activity, ghrelin can exist in truncated forms and retain activity, the ghrelin receptor can have constitutive activity and is subject to biased agonism and finally additional ghrelin-like and des-acyl ghrelin receptors are proposed. Both ghrelin and motilin can stimulate gastric emptying, acting via different pathways, perhaps influenced by biased agonism at the receptors, but research is revealing additional pathways of activity. For example, it is becoming apparent that reduction of nausea may be a key therapeutic target for ghrelin receptor agonists and perhaps for compounds that modulate the constitutive activity of the ghrelin receptor. Reduction of nausea may be the mechanism through which gastroparesis symptoms are reduced. Intriguingly, a potential ability of motilin to influence nausea is also becoming apparent. Ghrelin interacts with digestive function through its effects on appetite, and ghrelin antagonists may have a place in treating Prader-Willi syndrome. Unlike motilin, ghrelin receptor agonists also have the potential to treat constipation by acting at the lumbosacral defecation centres. In conclusion, agonists of both ghrelin and motilin receptors hold potential as treatments for specific subsets of digestive system disorders.
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Cavaillé J. Box C/D small nucleolar RNA genes and the Prader-Willi syndrome: a complex interplay. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [PMID: 28296064 DOI: 10.1002/wrna.1417] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 12/22/2022]
Abstract
The nucleolus of mammalian cells contains hundreds of box C/D small nucleolar RNAs (SNORDs). Through their ability to base pair with ribosomal RNA precursors, most play important roles in the synthesis and/or activity of ribosomes, either by guiding sequence-specific 2'-O-methylations or by facilitating RNA folding and cleavages. A growing number of SNORD genes with elusive functions have been discovered recently. Intriguingly, the vast majority of them are located in two large, imprinted gene clusters at human chromosome region 15q11q13 (the SNURF-SNRPN domain) and at 14q32 (the DLK1-DIO3 domain) where they are expressed, respectively, only from the paternally and maternally inherited alleles. These placental mammal-specific SNORD genes have many features of the canonical SNORDs that guide 2'-O-methylations, yet they lack obvious complementarity with ribosomal RNAs and, surprisingly, they are processed from large, tandemly repeated genes expressed preferentially in the brain. This review summarizes our understanding of the biology of these peculiar SNORD genes, focusing particularly on SNORD115 and SNORD116 in the SNURF-SNRPN domain. It examines the growing evidence that altered levels of these SNORDs and/or their host-gene transcripts may be a primary cause of Prader-Willi syndrome (PWS; a rare disorder characterized by overeating and obesity) as well as abnormalities in signaling through the 5-HT2C serotonin receptor. Finally, the hypothesis that PWS may be a ribosomopathy (ribosomal disease) is also discussed. WIREs RNA 2017, 8:e1417. doi: 10.1002/wrna.1417 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Jérôme Cavaillé
- Laboratoire de Biologie Moléculaire Eucaryote, Université de Toulouse; UPS and CNRS, LMBE, Toulouse, France
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Hong X, Zhang H, Liang H, Li D, Huang J, Li Z, Jiang S, Zhang W, Xu G. Exendin-4 decreases ghrelin levels through mTOR signaling. Mol Cell Endocrinol 2016; 437:201-212. [PMID: 27569528 DOI: 10.1016/j.mce.2016.08.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/11/2016] [Accepted: 08/24/2016] [Indexed: 12/13/2022]
Abstract
Exendin-4 (EX-4), a long-acting glucagon-like peptide-1 receptor (GLP-1R) agonist, regulates feeding behavior through its ability to inhibit gastric emptying. Ghrelin, a gastric hormone, provides a hunger signal to the central nervous system to stimulate appetite. Here, we report that EX-4 suppresses ghrelin production through the mTORC1-dependent mechanism. Central administration of EX-4 reduces gastric, hypothalamic and plasma ghrelin in both C57BL/6J mice and diet induced obese mice. These changes were associated with a significant increase in mTORC1 activity. Both GLP-1 and EX-4 suppressed the expression and secretion of ghrelin in cultured mHypoE-42 cells, a hypothalamic cell line. These effects were associated with significant changes in mTOR signaling. Inhibition of mTORC1 activity by mTOR siRNA or rapamycin abolished the suppression of ghrelin production induced by GLP-1 and EX-4 in mHypoE-42 cells. Our results identify mTORC1 as a critical signaling pathway for the downregulation of ghrelin induced by activation of GLP-1R.
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Affiliation(s)
- Xiaosi Hong
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Heng Zhang
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Hongbin Liang
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Danjie Li
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Jiana Huang
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Zhi Li
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China
| | - Sibo Jiang
- Departments of Pharmaceutics, University of Florida, 6550 Sanger Rd, Orlando, FL 32827, USA
| | - Weizhen Zhang
- Shenzhen University Diabetes Center, Shenzhen University Health Science Center, Shenzhen, Guangdong, China; Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA.
| | - Geyang Xu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong, 510632, China.
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14
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Davies JR, Humby T, Dwyer DM, Garfield AS, Furby H, Wilkinson LS, Wells T, Isles AR. Calorie seeking, but not hedonic response, contributes to hyperphagia in a mouse model for Prader-Willi syndrome. Eur J Neurosci 2015; 42:2105-13. [PMID: 26040449 PMCID: PMC4949663 DOI: 10.1111/ejn.12972] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/29/2015] [Accepted: 05/29/2015] [Indexed: 12/25/2022]
Abstract
Prader–Willi syndrome (PWS) is a neurodevelopmental disorder caused by deletion or inactivation of paternally expressed imprinted genes on human chromosome 15q11‐q13, the most recognised feature of which is hyperphagia. This is thought to arise as a consequence of abnormalities in both the physiological drive for food and the rewarding properties of food. Although a number of mouse models for PWS exist, the underlying variables dictating maladaptive feeding remain unknown. Here, feeding behaviour in a mouse model in which the imprinting centre (IC) of the syntenic PWS interval has been deleted (PWSICdel mice) is characterised. It is demonstrated that PWSICdel mice show hyperghrelinaemia and increased consumption of food both following overnight fasting and when made more palatable with sucrose. However, hyperphagia in PWSICdel mice was not accompanied by any changes in reactivity to the hedonic properties of palatable food (sucrose or saccharin), as measured by lick‐cluster size. Nevertheless, overall consumption by PWSICdel mice for non‐caloric saccharin in the licking test was significantly reduced. Combined with converging findings from a continuous reinforcement schedule, these data indicate that PWSICdel mice show a marked heightened sensitivity to the calorific value of food. Overall, these data indicate that any impact of the rewarding properties of food on the hyperphagia seen in PWSICdel mice is driven primarily by calorie content and is unlikely to involve hedonic processes. This has important implications for understanding the neural systems underlying the feeding phenotype of PWS and the contribution of imprinted genes to abnormal feeding behaviour more generally.
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Affiliation(s)
- Jennifer R Davies
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Medicine, Cardiff University, Cardiff, UK
| | - Trevor Humby
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Psychology, Cardiff University, Cardiff, UK
| | - Dominic M Dwyer
- School of Psychology, Cardiff University, Cardiff, UK.,School of Psychology, University of New South Wales, Sydney, NSW, Australia
| | | | - Hannah Furby
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Medicine, Cardiff University, Cardiff, UK.,School of Biosciences, Cardiff University, Cardiff, UK
| | - Lawrence S Wilkinson
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Medicine, Cardiff University, Cardiff, UK.,School of Psychology, Cardiff University, Cardiff, UK
| | - Timothy Wells
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Anthony R Isles
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Medicine, Cardiff University, Cardiff, UK
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15
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Kishimoto R, Tamada K, Liu X, Okubo H, Ise S, Ohta H, Ruf S, Nakatani J, Kohno N, Spitz F, Takumi T. Model mice for 15q11-13 duplication syndrome exhibit late-onset obesity and altered lipid metabolism. Hum Mol Genet 2015; 24:4559-72. [PMID: 26002101 DOI: 10.1093/hmg/ddv187] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 05/18/2015] [Indexed: 12/27/2022] Open
Abstract
Copy number variations on human chromosome 15q11-q13 have been implicated in several neurodevelopmental disorders. A paternal loss or duplication of the Prader-Willi syndrome/Angelman syndrome (PWS/AS) region confers a risk of obesity, although the mechanism remains a mystery due to a lack of an animal model that accurately recreates the obesity phenotype. We performed detailed analyses of mice with duplication of PWS/AS locus (6 Mb) generated by chromosome engineering and found that animals with a paternal duplication of this region (patDp/+) show late-onset obesity, high sensitivity for high-fat diet, high levels of blood leptin and insulin without an increase in food intake. We show that prior to becoming obese, young patDp/+ mice already had enlarged white adipocytes. Transcriptome analysis of adipose tissue revealed an up-regulation of Secreted frizzled-related protein 5 (Sfrp5), known to promote adipogenesis. We additionally generated a new mouse model of paternal duplication focusing on a 3 Mb region (3 Mb patDp/+) within the PWS/AS locus. These mice recapitulate the obese phenotypes including expansion of visceral adipose tissue. Our results suggest paternally expressed genes in PWS/AS locus play a significant role for the obesity and identify new potential targets for future research and treatment of obesity.
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Affiliation(s)
- Rui Kishimoto
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan, Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Kota Tamada
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan, Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Xiaoxi Liu
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Hiroko Okubo
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Satoko Ise
- Banyu Tsukuba Research Institute, Tsukuba, Ibaraki 300-2611, Japan
| | - Hisashi Ohta
- Banyu Tsukuba Research Institute, Tsukuba, Ibaraki 300-2611, Japan
| | - Sandra Ruf
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jin Nakatani
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Ohtsu, Shiga 520-2192, Japan and
| | - Nobuoki Kohno
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - François Spitz
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Toru Takumi
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan, Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan, JST, CREST, Tokyo, Japan
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16
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Kern A, Grande C, Smith RG. Apo-Ghrelin Receptor (apo-GHSR1a) Regulates Dopamine Signaling in the Brain. Front Endocrinol (Lausanne) 2014; 5:129. [PMID: 25183960 PMCID: PMC4135303 DOI: 10.3389/fendo.2014.00129] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 07/18/2014] [Indexed: 12/29/2022] Open
Abstract
The orexigenic peptide hormone ghrelin is synthesized in the stomach and its receptor growth hormone secretagogue receptor (GHSR1a) is expressed mainly in the central nervous system (CNS). In this review, we confine our discussion to the physiological role of GHSR1a in the brain. Paradoxically, despite broad expression of GHSR1a in the CNS, other than trace amounts in the hypothalamus, ghrelin is undetectable in the brain. In our efforts to elucidate the function of the ligand-free ghrelin receptor (apo-GHSR1a), we identified subsets of neurons that co-express GHSR1a and dopamine receptors. In this review, we focus on interactions between apo-GHSR1a and dopamine-2 receptor (DRD2) and formation of GHSR1a:DRD2 heteromers in hypothalamic neurons that regulate appetite, and discuss implications for the treatment of Prader-Willi syndrome (PWS). GHSR1a antagonists of distinct chemical structures, a quinazolinone and a triazole, respectively, enhance and inhibit dopamine signaling through GHSR1a:DRD2 heteromers by an allosteric mechanism. This finding illustrates a potential strategy for designing the next generation of drugs for treating eating disorders as well as psychiatric disorders caused by abnormal dopamine signaling. Treatment with a GHSR1a antagonist that enhances dopamine/DRD2 activity in GHSR1a:DRD2 expressing hypothalamic neurons has the potential to inhibit the uncontrollable hyperphagia associated with PWS. DRD2 antagonists are prescribed for treating schizophrenia, but these block dopamine signaling in all DRD2 expressing neurons and are associated with adverse side effects, including enhanced appetite and excessive weight gain. A GHSR1a antagonist of structural class that allosterically blocks dopamine/DRD2 action in GHSR1a:DRD2 expressing neurons would have no effect on neurons expressing DRD2 alone; therefore, the side effects of DRD2 antagonists would potentially be reduced thereby enhancing patient compliance.
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Affiliation(s)
- Andras Kern
- Department of Metabolism and Aging, Scripps Research Institute Florida, Jupiter, FL, USA
| | - Cristina Grande
- Department of Metabolism and Aging, Scripps Research Institute Florida, Jupiter, FL, USA
| | - Roy G. Smith
- Department of Metabolism and Aging, Scripps Research Institute Florida, Jupiter, FL, USA
- *Correspondence: Roy G. Smith, Department of Metabolism and Aging, Scripps Research Institute Florida, 130 Scripps Way #3B3, Jupiter, FL 33458, USA e-mail:
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