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Dvoretskova E, Ho MC, Kittke V, Neuhaus F, Vitali I, Lam DD, Delgado I, Feng C, Torres M, Winkelmann J, Mayer C. Spatial enhancer activation influences inhibitory neuron identity during mouse embryonic development. Nat Neurosci 2024:10.1038/s41593-024-01611-9. [PMID: 38528203 DOI: 10.1038/s41593-024-01611-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 02/23/2024] [Indexed: 03/27/2024]
Abstract
The mammalian telencephalon contains distinct GABAergic projection neuron and interneuron types, originating in the germinal zone of the embryonic basal ganglia. How genetic information in the germinal zone determines cell types is unclear. Here we use a combination of in vivo CRISPR perturbation, lineage tracing and ChIP-sequencing analyses and show that the transcription factor MEIS2 favors the development of projection neurons by binding enhancer regions in projection-neuron-specific genes during mouse embryonic development. MEIS2 requires the presence of the homeodomain transcription factor DLX5 to direct its functional activity toward the appropriate binding sites. In interneuron precursors, the transcription factor LHX6 represses the MEIS2-DLX5-dependent activation of projection-neuron-specific enhancers. Mutations of Meis2 result in decreased activation of regulatory enhancers, affecting GABAergic differentiation. We propose a differential binding model where the binding of transcription factors at cis-regulatory elements determines differential gene expression programs regulating cell fate specification in the mouse ganglionic eminence.
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Affiliation(s)
- Elena Dvoretskova
- Max Planck Institute for Biological Intelligence, Martinsried, Germany
- Max Planck Institute of Neurobiology, Martinsried, Germany
| | - May C Ho
- Max Planck Institute for Biological Intelligence, Martinsried, Germany
- Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Volker Kittke
- Institute of Neurogenomics, Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Neuhererg, Germany
- TUM School of Medicine and Health, Institute of Human Genetics, Technical University of Munich, Munich, Germany
- DZPG (German Center for Mental Health), Munich, Germany
| | - Florian Neuhaus
- Max Planck Institute for Biological Intelligence, Martinsried, Germany
- Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Ilaria Vitali
- Max Planck Institute for Biological Intelligence, Martinsried, Germany
- Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Daniel D Lam
- Institute of Neurogenomics, Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Neuhererg, Germany
- TUM School of Medicine and Health, Institute of Human Genetics, Technical University of Munich, Munich, Germany
| | - Irene Delgado
- Cardiovascular Development Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
- Departamento de Genética, Fisiología y Microbiología, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain
| | - Chao Feng
- Max Planck Institute for Biological Intelligence, Martinsried, Germany
- Max Planck Institute of Neurobiology, Martinsried, Germany
| | - Miguel Torres
- Cardiovascular Development Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Juliane Winkelmann
- Institute of Neurogenomics, Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Neuhererg, Germany
- TUM School of Medicine and Health, Institute of Human Genetics, Technical University of Munich, Munich, Germany
- DZPG (German Center for Mental Health), Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Christian Mayer
- Max Planck Institute for Biological Intelligence, Martinsried, Germany.
- Max Planck Institute of Neurobiology, Martinsried, Germany.
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2
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Leu CL, Lam DD, Salminen AV, Wefers B, Becker L, Garrett L, Rozman J, Wurst W, de Angelis MH, Hölter SM, Winkelmann J, Williams RH. A patient-enriched MEIS1 coding variant causes a restless legs syndrome-like phenotype in mice. Sleep 2024:zsae015. [PMID: 38314840 DOI: 10.1093/sleep/zsae015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Indexed: 02/07/2024] Open
Abstract
Restless legs syndrome (RLS) is a neurological disorder characterized by uncomfortable or unpleasant sensations in the legs during rest periods. To relieve these sensations, patients move their legs, causing sleep disruption. While the pathogenesis of RLS has yet to be resolved, there is a strong genetic association to the MEIS1 gene. A missense variant in MEIS1 is enriched 7-fold in RLS patients compared to non-affected individuals. We generated a mouse line carrying this mutation (p.Arg272His/c.815G>A), referred to herein as Meis1R272H/R272H (Meis1 point mutation), to determine whether it would phenotypically resemble RLS. As women are more prone to RLS, driven partly by an increased risk of developing RLS during pregnancy, we focussed on female homozygous mice. We evaluated RLS-related outcomes, particularly sensorimotor behavior and sleep, in young and aged mice. Compared to non-carrier littermates, homozygous mice displayed very few differences. Significant hyperactivity occurred before the lights-on (rest) period in aged female mice, reflecting the age-dependent incidence of RLS. Sensory experiments involving tactile feedback (rotorod, wheel running, and hotplate) were only marginally different. Overall, RLS-like phenomena were not recapitulated except for the increased wake activity prior to rest. This is likely due to the focus on young mice. Nevertheless, the Meis1R272H mouse line is a potentially useful RLS model, carrying a clinically relevant variant and showing an age-dependent phenotype.
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Affiliation(s)
- Chia-Luen Leu
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Daniel D Lam
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Germany
| | - Aaro V Salminen
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Germany
| | - Benedikt Wefers
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Lore Becker
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, Neuherberg, Germany
| | - Lillian Garrett
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, Neuherberg, Germany
| | - Jan Rozman
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, Neuherberg, Germany
- German Center for Diabetes Research (DZD), Neuherberg
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6, avenue du Swing, 4367, Belvaux, Luxembourg
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- German Center for Neurodegenerative Diseases (DZNE), Site Munich, Germany
- Chair of Developmental Genetics, TUM School of Life Sciences, Technische Universität München, Freising, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Center Munich, Neuherberg, Germany
- Chair of Experimental Genetics, TUM School of Life Sciences, Technische Universität, München, Freising, Germany
- German Center for Diabetes Research (DZD), Neuherberg
| | - Sabine M Hölter
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Juliane Winkelmann
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Rhîannan H Williams
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
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Lam DD, Nikolic AA, Zhao C, Mirza-Schreiber N, Krężel W, Oexle K, Winkelmann J. Intronic elements associated with insomnia and restless legs syndrome exhibit cell type-specific epigenetic features contributing to MEIS1 regulation. Hum Mol Genet 2021; 31:1733-1746. [PMID: 34888668 DOI: 10.1093/hmg/ddab355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/25/2021] [Accepted: 12/05/2021] [Indexed: 12/13/2022] Open
Abstract
A highly evolutionarily conserved MEIS1 intronic region is strongly associated with restless legs syndrome (RLS) and insomnia. To understand its regulatory function, we dissected the region by analyzing chromatin accessibility, enhancer-promoter contacts, DNA methylation, and eQTLs in different human neural cell types and tissues. We observed specific activity with respect to cell type and developmental maturation, indicating a prominent role for distinct highly conserved intronic elements in forebrain inhibitory neuron differentiation. Two elements were hypomethylated in neural cells with higher MEIS1 expression, suggesting a role of enhancer demethylation in gene regulation. MEIS1 eQTLs showed a striking modular chromosomal distribution, with forebrain eQTLs clustering in intron 8/9. CRISPR interference targeting of individual elements in this region attenuated MEIS1 expression, revealing a complex regulatory interplay of distinct elements. In summary, we found that MEIS1 regulation is organized in a modular pattern. Disease-associated intronic regulatory elements control MEIS1 expression with cell type and maturation stage specificity, particularly in the inhibitory neuron lineage. The precise spatiotemporal activity of these elements likely contributes to the pathogenesis of insomnia and RLS.
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Affiliation(s)
- Daniel D Lam
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Germany
| | - Ana Antic Nikolic
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Germany
| | - Chen Zhao
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Germany
| | - Nazanin Mirza-Schreiber
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Wojciech Krężel
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.,Institut de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Centre National de la Recherche Scientifique, UMR 7104, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Konrad Oexle
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Germany
| | - Juliane Winkelmann
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Germany.,Chair of Neurogenetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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Cathiard L, Fraulob V, Lam DD, Torres M, Winkelmann J, Krężel W. Investigation of dopaminergic signalling in Meis homeobox 1 (Meis1) deficient mice as an animal model of restless legs syndrome. J Sleep Res 2021; 30:e13311. [PMID: 34008292 DOI: 10.1111/jsr.13311] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 12/24/2022]
Abstract
Restless legs syndrome (RLS) is a common neurological disorder in which sensorimotor symptoms lead to sleep disturbances with substantial impact on life quality. RLS is caused by a combination of genetic and environmental factors, and Meis homeobox 1 (MEIS1) was identified as the main genetic risk factor. The efficacy of dopaminergic agonists, including dopamine D2 receptor (DRD2) agonists, for treating RLS led to the hypothesis of dopaminergic impairment. However, it remains unclear whether it is directly involved in the disease aetiology and what the role of MEIS1 is considering its developmental and postnatal expression in the striatum, a critical structure in motor control. We addressed the role of MEIS1 in striatal dopaminergic signalling in Meis1+/- mice, a valid animal model of RLS, and in Meis1Drd2 -/- mice carrying a somatic null mutation of Meis1 in Drd2+ neurones. Motor behaviours, pharmacological exploration of DRD2 signalling, and quantitative analyses of DRD2+ and DRD1+ expressing neurones were investigated. Although Meis1+/- mice displayed an RLS-like phenotype, including motor hyperactivity at the beginning of the rest phase, no reduction of dopaminoceptive neurones was observed in the striatum. Moreover, the null mutation of Meis1 in DRD2+ cells did not lead to RLS-like symptoms and dysfunction of the DRD2 pathway. These data indicate that MEIS1 does not modulate DRD2-dependent signalling in a cell-autonomous manner. Thus, the efficiency of D2 -like agonists may reflect the involvement of other dopaminergic receptors or normalisation of motor circuit abnormalities downstream from defects caused by MEIS1 dysfunction.
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Affiliation(s)
- Lucile Cathiard
- Institute of Genetics and Molecular and Cellular Biology, CNRS UMR7104, INSERM U1258, University of Strasbourg, Illkirch, France
| | - Valerie Fraulob
- Institute of Genetics and Molecular and Cellular Biology, CNRS UMR7104, INSERM U1258, University of Strasbourg, Illkirch, France
| | - Daniel D Lam
- Institute for Human Genetic, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Miguel Torres
- Cardiovascular Development Program, Centro Nacional de Investigaciones Cardiovasculares, CNIC, Madrid, Spain
| | - Juliane Winkelmann
- Institute for Human Genetic, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.,Chair for Neucgenetic, Klinikum rechts der Isar, Technische Universität München; Institute for Neurogenomics, Helmholtz Zentrum München; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Wojciech Krężel
- Institute of Genetics and Molecular and Cellular Biology, CNRS UMR7104, INSERM U1258, University of Strasbourg, Illkirch, France
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Na ES, Lam DD, Yokosawa E, Adams JM, Olson DP, Low MJ. Decreased sensitivity to the anorectic effects of leptin in mice that lack a Pomc-specific neural enhancer. PLoS One 2021; 15:e0244793. [PMID: 33382813 PMCID: PMC7775064 DOI: 10.1371/journal.pone.0244793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 11/24/2020] [Indexed: 11/18/2022] Open
Abstract
Enhancer redundancy has been postulated to provide a buffer for gene expression against genetic and environmental perturbations. While work in Drosophila has identified functionally overlapping enhancers, work in mammalian models has been limited. Recently, we have identified two partially redundant enhancers, nPE1 and nPE2, that drive proopiomelanocortin gene expression in the hypothalamus. Here we demonstrate that deletion of nPE1 produces mild obesity while knockout of nPE2 has no discernible metabolic phenotypes. Additionally, we show that acute leptin administration has significant effects on nPE1 knockout mice, with food intake and body weight change significantly impacted by peripheral leptin treatment. nPE1 knockout mice became less responsive to leptin treatment over time as percent body weight change increased over 2 week exposure to peripheral leptin. Both Pomc and Agrp mRNA were not differentially affected by chronic leptin treatment however we did see a decrease in Pomc and Agrp mRNA in both nPE1 and nPE2 knockout calorie restricted mice as compared to calorie restricted PBS-treated WT mice. Collectively, these data suggest dynamic regulation of Pomc by nPE1 such that mice with nPE1 knockout become less responsive to the anorectic effects of leptin treatment over time. Our results also support our earlier findings in which nPE2 may only be critical in adult mice that lack nPE1, indicating that these neural enhancers work synergistically to influence metabolism.
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Affiliation(s)
- Elisa S. Na
- Department of Psychology & Philosophy Texas Woman’s University, Denton, Texas, United States of America
- * E-mail: (ESN); (DDL)
| | - Daniel D. Lam
- Institute of Neurogenomics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
- Chair of Neurogenetics, Neurological Clinic and Polyclinic, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany
- * E-mail: (ESN); (DDL)
| | - Eva Yokosawa
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jessica M. Adams
- Division of Endocrinology, Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - David P. Olson
- Division of Endocrinology, Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Malcolm J. Low
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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Abstract
PURPOSE OF REVIEW To summarize the molecular and clinical findings of KMT2B-related dystonia (DYT-KMT2B), a newly identified genetic dystonia syndrome. RECENT FINDINGS Since first described in 2016, 66 different KMT2B-affecting variants, encompassing a set of frameshift, nonsense, splice-site, missense, and deletion mutations, have been reported in 76 patients. Most mutations are de novo and expected to mediate epigenetic dysregulation by inducing KMT2B haploinsufficiency. DYT-KMT2B is characterized phenotypically by limb-onset childhood dystonia that tends to spread progressively, resulting in generalized dystonia with cranio-cervical involvement. Co-occuring signs such as intellectual disability are frequently observed. Sustained response to deep brain stimulation (DBS), including restoration of independent ambulation, is seen in 93% (27/29) of patients. DYT-KMT2B is emerging as a prevalent monogenic dystonia. Childhood-onset dystonia presentations should prompt a search for KMT2B mutations, preferentially via next-generation-sequencing and genomic-array technologies, to enable specific counseling and treatment. Prospective multicenter studies are desirable to establish KMT2B mutational status as a DBS outcome predictor.
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Affiliation(s)
- Michael Zech
- Institut für Neurogenomik, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Munich, Neuherberg, Germany.,Institut für Humangenetik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | - Daniel D Lam
- Institut für Neurogenomik, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Munich, Neuherberg, Germany
| | - Juliane Winkelmann
- Institut für Neurogenomik, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764, Munich, Neuherberg, Germany. .,Institut für Humangenetik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany. .,Lehrstuhl für Neurogenetik, Technische Universität München, Munich, Germany. .,Munich Cluster for Systems Neurology, SyNergy, Munich, Germany.
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Khan K, Zech M, Morgan AT, Amor DJ, Skorvanek M, Khan TN, Hildebrand MS, Jackson VE, Scerri TS, Coleman M, Rigbye KA, Scheffer IE, Bahlo M, Wagner M, Lam DD, Berutti R, Havránková P, Fečíková A, Strom TM, Han V, Dosekova P, Gdovinova Z, Laccone F, Jameel M, Mooney MR, Baig SM, Jech R, Davis EE, Katsanis N, Winkelmann J. Recessive variants in ZNF142 cause a complex neurodevelopmental disorder with intellectual disability, speech impairment, seizures, and dystonia. Genet Med 2019; 21:2532-2542. [PMID: 31036918 PMCID: PMC6821592 DOI: 10.1038/s41436-019-0523-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 04/15/2019] [Indexed: 12/14/2022] Open
Abstract
PURPOSE The purpose of this study was to expand the genetic architecture of neurodevelopmental disorders, and to characterize the clinical features of a novel cohort of affected individuals with variants in ZNF142, a C2H2 domain-containing transcription factor. METHODS Four independent research centers used exome sequencing to elucidate the genetic basis of neurodevelopmental phenotypes in four unrelated families. Following bioinformatic filtering, query of control data sets, and secondary variant confirmation, we aggregated findings using an online data sharing platform. We performed in-depth clinical phenotyping in all affected individuals. RESULTS We identified seven affected females in four pedigrees with likely pathogenic variants in ZNF142 that segregate with recessive disease. Affected cases in three families harbor either nonsense or frameshifting likely pathogenic variants predicted to undergo nonsense mediated decay. One additional trio bears ultrarare missense variants in conserved regions of ZNF142 that are predicted to be damaging to protein function. We performed clinical comparisons across our cohort and noted consistent presence of intellectual disability and speech impairment, with variable manifestation of seizures, tremor, and dystonia. CONCLUSION Our aggregate data support a role for ZNF142 in nervous system development and add to the emergent list of zinc finger proteins that contribute to neurocognitive disorders.
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Affiliation(s)
- Kamal Khan
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA.,Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan.,Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Michael Zech
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany.,Institut für Humangenetik, Technische Universität München, Munich, Germany
| | - Angela T Morgan
- Murdoch Children's Research Institute and University of Melbourne Department of Paediatrics, Royal Children's Hospital, Parkville, Australia
| | - David J Amor
- Murdoch Children's Research Institute and University of Melbourne Department of Paediatrics, Royal Children's Hospital, Parkville, Australia
| | - Matej Skorvanek
- Department of Neurology, P.J. Safarik University, Kosice, Slovak Republic.,Department of Neurology, University Hospital of L. Pasteur, Kosice, Slovak Republic
| | - Tahir N Khan
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA.,Department of Biological Sciences, National University of Medical Sciences, Rawalpindi, Pakistan
| | - Michael S Hildebrand
- Murdoch Children's Research Institute and University of Melbourne Department of Paediatrics, Royal Children's Hospital, Parkville, Australia.,Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC, Australia
| | - Victoria E Jackson
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, and University of Melbourne Department of Medical Biology and School of Mathematics and Statistics, Parkville, VIC, Australia
| | - Thomas S Scerri
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, and University of Melbourne Department of Medical Biology and School of Mathematics and Statistics, Parkville, VIC, Australia
| | - Matthew Coleman
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC, Australia
| | - Kristin A Rigbye
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC, Australia
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, VIC, Australia.,University of Melbourne Department of Paediatrics, Royal Children's Hospital, and Florey and Murdoch Children's Research Institute, Parkville, VIC, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, and University of Melbourne Department of Medical Biology and School of Mathematics and Statistics, Parkville, VIC, Australia
| | - Matias Wagner
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany.,Institut für Humangenetik, Technische Universität München, Munich, Germany
| | - Daniel D Lam
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany
| | - Riccardo Berutti
- Institut für Humangenetik, Helmholtz Zentrum München, Munich, Germany
| | - Petra Havránková
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, Czech Republic
| | - Anna Fečíková
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, Czech Republic
| | - Tim M Strom
- Institut für Humangenetik, Technische Universität München, Munich, Germany.,Institut für Humangenetik, Helmholtz Zentrum München, Munich, Germany
| | - Vladimir Han
- Department of Neurology, P.J. Safarik University, Kosice, Slovak Republic.,Department of Neurology, University Hospital of L. Pasteur, Kosice, Slovak Republic
| | - Petra Dosekova
- Department of Neurology, P.J. Safarik University, Kosice, Slovak Republic.,Department of Neurology, University Hospital of L. Pasteur, Kosice, Slovak Republic
| | - Zuzana Gdovinova
- Department of Neurology, P.J. Safarik University, Kosice, Slovak Republic.,Department of Neurology, University Hospital of L. Pasteur, Kosice, Slovak Republic
| | - Franco Laccone
- Institute of Medical Genetics, Medical School of Vienna, Vienna, Austria
| | - Muhammad Jameel
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
| | - Marie R Mooney
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA
| | - Shahid M Baig
- Human Molecular Genetics Laboratory, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan.,Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Robert Jech
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, Czech Republic
| | - Erica E Davis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, USA.
| | - Juliane Winkelmann
- Institute of Neurogenomics, Helmholtz Zentrum München, Munich, Germany. .,Institut für Humangenetik, Technische Universität München, Munich, Germany. .,Lehrstuhl für Neurogenetik, Technische Universität München, Munich, Germany. .,Munich Cluster for Systems Neurology, SyNergy, Munich, Germany.
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8
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Zech M, Lam DD, Weber S, Berutti R, Poláková K, Havránková P, Fečíková A, Strom TM, Růžička E, Jech R, Winkelmann J. A unique de novo gain-of-function variant in CAMK4 associated with intellectual disability and hyperkinetic movement disorder. Cold Spring Harb Mol Case Stud 2018; 4:mcs.a003293. [PMID: 30262571 PMCID: PMC6318768 DOI: 10.1101/mcs.a003293] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 09/04/2018] [Indexed: 01/12/2023] Open
Abstract
Calcium/calmodulin-dependent protein kinases (CaMKs) are key mediators of calcium signaling and underpin neuronal health. Although widely studied, the contribution of CaMKs to Mendelian disease is rather enigmatic. Here, we describe an unusual neurodevelopmental phenotype, characterized by milestone delay, intellectual disability, autism, ataxia, and mixed hyperkinetic movement disorder including severe generalized dystonia, in a proband who remained etiologically undiagnosed despite exhaustive testing. We performed trio whole-exome sequencing to identify a de novo essential splice-site variant (c.981+1G>A) in CAMK4, encoding CaMKIV. Through in silico evaluation and cDNA analyses, we demonstrated that c.981+1G>A alters CAMK4 pre-mRNA processing and results in a stable mRNA transcript containing a 77-nt out-of-frame deletion and a premature termination codon within the last exon. The expected protein, p.Lys303Serfs*28, exhibits selective loss of the carboxy-terminal regulatory domain of CaMKIV and bears striking structural resemblance to previously reported synthetic mutants that confer constitutive CaMKIV activity. Biochemical studies in proband-derived cells confirmed an activating effect of c.981+1G>A and indicated that variant-induced excessive CaMKIV signaling is sensitive to pharmacological manipulation. Additionally, we found that variants predicted to cause selective depletion of CaMKIV's regulatory domain are unobserved in diverse catalogs of human variation, thus revealing that c.981+1G>A is a unique molecular event. We propose that our proband's phenotype is explainable by a dominant CAMK4 splice-disrupting mutation that acts through a gain-of-function mechanism. Our findings highlight the importance of CAMK4 in human neurodevelopment, provide a foundation for future clinical research of CAMK4, and suggest the CaMKIV signaling pathway as a potential drug target in neurological disease.
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Affiliation(s)
- Michael Zech
- Institut für Neurogenomik, Helmholtz Zentrum München, Munich, 85764, Germany.,Klinik und Poliklinik für Neurologie, Klinikum rechts der Isar, Technische Universität München, Munich, 81675, Germany
| | - Daniel D Lam
- Institut für Neurogenomik, Helmholtz Zentrum München, Munich, 85764, Germany
| | - Sandrina Weber
- Institut für Neurogenomik, Helmholtz Zentrum München, Munich, 85764, Germany
| | - Riccardo Berutti
- Institut für Humangenetik, Helmholtz Zentrum München, Munich, 85764, Germany
| | - Kamila Poláková
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, 120 00, Czech Republic
| | - Petra Havránková
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, 120 00, Czech Republic
| | - Anna Fečíková
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, 120 00, Czech Republic
| | - Tim M Strom
- Institut für Humangenetik, Helmholtz Zentrum München, Munich, 85764, Germany.,Institut für Humangenetik, Technische Universität München, Munich, 81675, Germany
| | - Evžen Růžička
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, 120 00, Czech Republic
| | - Robert Jech
- Department of Neurology and Center of Clinical Neuroscience, First Faculty of Medicine, Charles University and General Faculty Hospital, Prague, 120 00, Czech Republic
| | - Juliane Winkelmann
- Institut für Neurogenomik, Helmholtz Zentrum München, Munich, 85764, Germany.,Institut für Humangenetik, Technische Universität München, Munich, 81675, Germany.,Lehrstuhl für Neurogenetik, Technische Universität München, Munich, 80333, Germany.,Munich Cluster for Systems Neurology, SyNergy, Munich, 81377, Germany
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9
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Abstract
Obesity results from the consumption of food in excess of bodily energy requirements, with the excess energy stored as adipose tissue. Sequelae of obesity, such as heart disease and type 2 diabetes, consistently rank among the top causes of death worldwide. The global prevalence of obesity highlights the urgency of understanding the mechanisms regulating hunger and satiety. Appetite, defined as the motivational drive to obtain food, is regulated by a complex neurocircuitry which integrates a variety of interoceptive signals to gauge nutritional state and guide appropriate levels of food-seeking. Here we review key recent developments in the identification of cell groups, neural circuits, endogenous and exogenous substances, and intracellular signaling pathways which drive hunger and satiety. We also consider particularly promising pharmacological targets for appetite modulation.
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Affiliation(s)
- Lora K Heisler
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen AB25 2ZD, UK.
| | - Daniel D Lam
- Neurologische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, 81675 Munich, Germany; Institut für Neurogenomik, Helmholtz Zentrum München, 85764 Munich, Germany
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10
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Chhabra KH, Adams JM, Fagel B, Lam DD, Qi N, Rubinstein M, Low MJ. Hypothalamic POMC Deficiency Improves Glucose Tolerance Despite Insulin Resistance by Increasing Glycosuria. Diabetes 2016; 65:660-72. [PMID: 26467632 PMCID: PMC4764146 DOI: 10.2337/db15-0804] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 10/07/2015] [Indexed: 12/18/2022]
Abstract
Hypothalamic proopiomelanocortin (POMC) is essential for the physiological regulation of energy balance; however, its role in glucose homeostasis remains less clear. We show that hypothalamic arcuate nucleus (Arc)POMC-deficient mice, which develop severe obesity and insulin resistance, unexpectedly exhibit improved glucose tolerance and remain protected from hyperglycemia. To explain these paradoxical phenotypes, we hypothesized that an insulin-independent pathway is responsible for the enhanced glucose tolerance. Indeed, the mutant mice demonstrated increased glucose effectiveness and exaggerated glycosuria relative to wild-type littermate controls at comparable blood glucose concentrations. Central administration of the melanocortin receptor agonist melanotan II in mutant mice reversed alterations in glucose tolerance and glycosuria, whereas, conversely, administration of the antagonist Agouti-related peptide (Agrp) to wild-type mice enhanced glucose tolerance. The glycosuria of ArcPOMC-deficient mice was due to decreased levels of renal GLUT 2 (rGLUT2) but not sodium-glucose cotransporter 2 and was associated with reduced renal catecholamine content. Epinephrine treatment abolished the genotype differences in glucose tolerance and rGLUT2 levels, suggesting that reduced renal sympathetic nervous system (SNS) activity is the underlying mechanism for the observed glycosuria and improved glucose tolerance in ArcPOMC-deficient mice. Therefore, the ArcPOMC-SNS-rGLUT2 axis is potentially an insulin-independent therapeutic target to control diabetes.
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Affiliation(s)
- Kavaljit H Chhabra
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI
| | - Jessica M Adams
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI
| | - Brian Fagel
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI
| | - Daniel D Lam
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI
| | - Nathan Qi
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
| | - Marcelo Rubinstein
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI
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11
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Burke LK, Doslikova B, D'Agostino G, Greenwald-Yarnell M, Georgescu T, Chianese R, Martinez de Morentin PB, Ogunnowo-Bada E, Cansell C, Valencia-Torres L, Garfield AS, Apergis-Schoute J, Lam DD, Speakman JR, Rubinstein M, Low MJ, Rochford JJ, Myers MG, Evans ML, Heisler LK. Sex difference in physical activity, energy expenditure and obesity driven by a subpopulation of hypothalamic POMC neurons. Mol Metab 2016; 5:245-252. [PMID: 26977396 PMCID: PMC4770275 DOI: 10.1016/j.molmet.2016.01.005] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Obesity is one of the primary healthcare challenges of the 21st century. Signals relaying information regarding energy needs are integrated within the brain to influence body weight. Central among these integration nodes are the brain pro-opiomelanocortin (POMC) peptides, perturbations of which disrupt energy balance and promote severe obesity. However, POMC neurons are neurochemically diverse and the crucial source of POMC peptides that regulate energy homeostasis and body weight remains to be fully clarified. METHODS Given that a 5-hydroxytryptamine 2c receptor (5-HT2CR) agonist is a current obesity medication and 5-HT2CR agonist's effects on appetite are primarily mediated via POMC neurons, we hypothesized that a critical source of POMC regulating food intake and body weight is specifically synthesized in cells containing 5-HT2CRs. To exclusively manipulate Pomc synthesis only within 5-HT2CR containing cells, we generated a novel 5-HT 2C R (CRE) mouse line and intercrossed it with Cre recombinase-dependent and hypothalamic specific reactivatable Pomc (NEO) mice to restrict Pomc synthesis to the subset of hypothalamic cells containing 5-HT2CRs. This provided a means to clarify the specific contribution of a defined subgroup of POMC peptides in energy balance and body weight. RESULTS Here we transform genetically programed obese and hyperinsulinemic male mice lacking hypothalamic Pomc with increased appetite, reduced physical activity and compromised brown adipose tissue (BAT) into lean, healthy mice via targeted restoration of Pomc function only within 5-HT2CR expressing cells. Remarkably, the same metabolic transformation does not occur in females, who despite corrected feeding behavior and normalized insulin levels remain physically inactive, have lower energy expenditure, compromised BAT and develop obesity. CONCLUSIONS These data provide support for the functional heterogeneity of hypothalamic POMC neurons, revealing that Pomc expression within 5-HT2CR expressing neurons is sufficient to regulate energy intake and insulin sensitivity in male and female mice. However, an unexpected sex difference in the function of this subset of POMC neurons was identified with regard to energy expenditure. We reveal that a large sex difference in physical activity, energy expenditure and the development of obesity is driven by this subpopulation, which constitutes approximately 40% of all POMC neurons in the hypothalamic arcuate nucleus. This may have broad implications for strategies utilized to combat obesity, which at present largely ignore the sex of the obese individual.
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Affiliation(s)
- Luke K Burke
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK; Department of Medicine and Institute of Metabolic Science, University of Cambridge, Wellcome Trust/Medical Research Council, Cambridge, UK; Department of Pharmacology, University of Cambridge, Cambridge, UK
| | | | - Giuseppe D'Agostino
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK; Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Megan Greenwald-Yarnell
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Teodora Georgescu
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Raffaella Chianese
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | | | - Emmanuel Ogunnowo-Bada
- Department of Medicine and Institute of Metabolic Science, University of Cambridge, Wellcome Trust/Medical Research Council, Cambridge, UK
| | - Celine Cansell
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Lourdes Valencia-Torres
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK; Department of Pharmacology, University of Cambridge, Cambridge, UK
| | | | | | - Daniel D Lam
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - John R Speakman
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, UK; State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Marcelo Rubinstein
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, 1428, Buenos Aires, Argentina
| | - Malcolm J Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Justin J Rochford
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Martin G Myers
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA
| | - Mark L Evans
- Department of Medicine and Institute of Metabolic Science, University of Cambridge, Wellcome Trust/Medical Research Council, Cambridge, UK.
| | - Lora K Heisler
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK.
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12
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Lam DD, Attard CA, Mercer AJ, Myers MG, Rubinstein M, Low MJ. Conditional expression of Pomc in the Lepr-positive subpopulation of POMC neurons is sufficient for normal energy homeostasis and metabolism. Endocrinology 2015; 156:1292-302. [PMID: 25594696 PMCID: PMC4399319 DOI: 10.1210/en.2014-1373] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Peptides derived from the proopiomelanocortin (POMC) precursor are critical for the normal regulation of many physiological parameters, and POMC deficiency results in severe obesity and metabolic dysfunction. Conversely, augmentation of central nervous system melanocortin function is a promising therapeutic avenue for obesity and diabetes but is confounded by detrimental cardiovascular effects including hypertension. Because the hypothalamic population of POMC-expressing neurons is neurochemically and neuroanatomically heterogeneous, there is interest in the possible dissociation of functionally distinct POMC neuron subpopulations. We used a Cre recombinase-dependent and hypothalamus-specific reactivatable PomcNEO allele to restrict Pomc expression to hypothalamic neurons expressing leptin receptor (Lepr) in mice. In contrast to mice with total hypothalamic Pomc deficiency, which are severely obese, mice with Lepr-restricted Pomc expression displayed fully normal body weight, food consumption, glucose homeostasis, and locomotor activity. Thus, Lepr+ POMC neurons, which constitute approximately two-thirds of the total POMC neuron population, are sufficient for normal regulation of these parameters. This functional dissociation approach represents a promising avenue for isolating therapeutically relevant POMC neuron subpopulations.
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Affiliation(s)
- Daniel D Lam
- Department of Molecular and Integrative Physiology (D.D.L., C.A.A., A.J.M., M.R., M.J.L.), and Department of Internal Medicine (M.G.M.), Division of Metabolism, Endocrinology, and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan 48105; and Instituto de Investigaciones en Ingeniería Genética y Biología Molecular (M.R.), Consejo Nacional de Investigaciones Científicas y Técnicas and Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
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13
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Lam DD, de Souza FSJ, Nasif S, Yamashita M, López-Leal R, Otero-Corchon V, Meece K, Sampath H, Mercer AJ, Wardlaw SL, Rubinstein M, Low MJ. Partially redundant enhancers cooperatively maintain Mammalian pomc expression above a critical functional threshold. PLoS Genet 2015; 11:e1004935. [PMID: 25671638 PMCID: PMC4335486 DOI: 10.1371/journal.pgen.1004935] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 12/02/2014] [Indexed: 11/29/2022] Open
Abstract
Cell-specific expression of many genes is conveyed by multiple enhancers, with each individual enhancer controlling a particular expression domain. In contrast, multiple enhancers drive similar expression patterns of some genes involved in embryonic development, suggesting regulatory redundancy. Work in Drosophila has indicated that functionally overlapping enhancers canalize development by buffering gene expression against environmental and genetic disturbances. However, little is known about regulatory redundancy in vertebrates and in genes mainly expressed during adulthood. Here we study nPE1 and nPE2, two phylogenetically conserved mammalian enhancers that drive expression of the proopiomelanocortin gene (Pomc) to the same set of hypothalamic neurons. The simultaneous deletion of both enhancers abolished Pomc expression at all ages and induced a profound metabolic dysfunction including early-onset extreme obesity. Targeted inactivation of either nPE1 or nPE2 led to very low levels of Pomc expression during early embryonic development indicating that both enhancers function synergistically. In adult mice, however, Pomc expression is controlled additively by both enhancers, with nPE1 being responsible for ∼80% and nPE2 for ∼20% of Pomc transcription. Consequently, nPE1 knockout mice exhibit mild obesity whereas nPE2-deficient mice maintain a normal body weight. These results suggest that nPE2-driven Pomc expression is compensated by nPE1 at later stages of development, essentially rescuing the earlier phenotype of nPE2 deficiency. Together, these results reveal that cooperative interactions between the enhancers confer robustness of Pomc expression against gene regulatory disturbances and preclude deleterious metabolic phenotypes caused by Pomc deficiency in adulthood. Thus, our study demonstrates that enhancer redundancy can be used by genes that control adult physiology in mammals and underlines the potential significance of regulatory sequence mutations in common diseases. The stability of animal form and function in the face of genetic and environmental variation relies on consistent gene expression. Multiple enhancers, each specifying a unique regulatory domain, control the precise spatiotemporal expression of many genes. However, in some genes apparently redundant enhancers regulate expression in overlapping cell-specific patterns. Although this arrangement has been shown to be important for developmental robustness in invertebrates, the role of apparently redundant enhancers in vertebrate species and in genes functioning in adulthood is poorly understood. Here, we show that expression of the mammalian Pomc gene is controlled in a tissue-specific manner by two such apparently redundant enhancers. We used targeted deletion of the individual enhancers to delineate their respective contributions to Pomc expression in the brain. Since Pomc expression from its intact locus exceeds the sum of the individual enhancer contributions to Pomc mRNA levels in embryonic mice, we infer a synergistic action between the enhancers during development. In contrast, the interaction between the enhancers is additive in adult mice. Deletion of both enhancers simultaneously almost completely abolished Pomc expression and the mutant mice displayed extreme obesity and metabolic dysfunction, while deletion of the individual enhancers had a modest or no phenotypic effect. Together, our results demonstrate that the two enhancers cooperatively maintain Pomc expression above a critical functional threshold.
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Affiliation(s)
- Daniel D. Lam
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Flavio S. J. de Souza
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Sofia Nasif
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Miho Yamashita
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | | | - Veronica Otero-Corchon
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Kana Meece
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, United States of America
| | - Harini Sampath
- Center for Research on Occupational and Environmental Toxicology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Aaron J. Mercer
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Sharon L. Wardlaw
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, United States of America
| | - Marcelo Rubinstein
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Instituto de Investigaciones en Ingeniería Genética y Biología Molecular, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Malcolm J. Low
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
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14
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Osundiji MA, Lam DD, Shaw J, Yueh CY, Markkula SP, Hurst P, Colliva C, Roda A, Heisler LK, Evans ML. Brain glucose sensors play a significant role in the regulation of pancreatic glucose-stimulated insulin secretion. Diabetes 2012; 61:321-8. [PMID: 22210318 PMCID: PMC3266403 DOI: 10.2337/db11-1050] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 11/10/2011] [Indexed: 11/13/2022]
Abstract
As patients decline from health to type 2 diabetes, glucose-stimulated insulin secretion (GSIS) typically becomes impaired. Although GSIS is driven predominantly by direct sensing of a rise in blood glucose by pancreatic β-cells, there is growing evidence that hypothalamic neurons control other aspects of peripheral glucose metabolism. Here we investigated the role of the brain in the modulation of GSIS. To examine the effects of increasing or decreasing hypothalamic glucose sensing on glucose tolerance and insulin secretion, glucose or inhibitors of glucokinase, respectively, were infused into the third ventricle during intravenous glucose tolerance tests (IVGTTs). Glucose-infused rats displayed improved glucose handling, particularly within the first few minutes of the IVGTT, with a significantly lower area under the excursion curve within the first 10 min (AUC0-10). This was explained by increased insulin secretion. In contrast, infusion of the glucokinase inhibitors glucosamine or mannoheptulose worsened glucose tolerance and decreased GSIS in the first few minutes of IVGTT. Our data suggest a role for brain glucose sensors in the regulation of GSIS, particularly during the early phase. We propose that pharmacological agents targeting hypothalamic glucose-sensing pathways may represent novel therapeutic strategies for enhancing early phase insulin secretion in type 2 diabetes.
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Affiliation(s)
- Mayowa A. Osundiji
- Department of Medicine, University of Cambridge Metabolic Research Laboratories, and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge, U.K
| | - Daniel D. Lam
- Department of Pharmacology, University of Cambridge, Cambridge, U.K
| | - Jill Shaw
- Department of Medicine, University of Cambridge Metabolic Research Laboratories, and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge, U.K
- Department of Pharmacology, University of Cambridge, Cambridge, U.K
| | - Chen-Yu Yueh
- Department of Medicine, University of Cambridge Metabolic Research Laboratories, and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge, U.K
- Department of Family Medicine, Chang Gung Memorial Hospital at Chiayi, Chang Gung Institute of Technology, Chiayi, Taiwan
| | - S. Pauliina Markkula
- Department of Medicine, University of Cambridge Metabolic Research Laboratories, and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge, U.K
| | - Paul Hurst
- Department of Medicine, University of Cambridge Metabolic Research Laboratories, and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge, U.K
| | - Carolina Colliva
- Department of Pharmaceutical Sciences, University of Bologna, Bologna, Italy
| | - Aldo Roda
- Department of Pharmaceutical Sciences, University of Bologna, Bologna, Italy
| | - Lora K. Heisler
- Department of Pharmacology, University of Cambridge, Cambridge, U.K
| | - Mark L. Evans
- Department of Medicine, University of Cambridge Metabolic Research Laboratories, and National Institute for Health Research, Cambridge Biomedical Research Centre, Cambridge, U.K
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15
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Zhou L, Yueh CY, Lam DD, Shaw J, Osundiji M, Garfield AS, Evans M, Heisler LK. Glucokinase inhibitor glucosamine stimulates feeding and activates hypothalamic neuropeptide Y and orexin neurons. Behav Brain Res 2011; 222:274-8. [PMID: 21440571 PMCID: PMC3133639 DOI: 10.1016/j.bbr.2011.03.043] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Revised: 03/16/2011] [Accepted: 03/17/2011] [Indexed: 12/05/2022]
Abstract
Maintaining glucose levels within the appropriate physiological range is necessary for survival. The identification of specific neuronal populations, within discreet brain regions, sensitive to changes in glucose concentration has led to the hypothesis of a central glucose-sensing system capable of directly modulating feeding behaviour. Glucokinase (GK) has been identified as a glucose-sensor responsible for detecting such changes both within the brain and the periphery. We previously reported that antagonism of centrally expressed GK by administration of glucosamine (GSN) was sufficient to induce protective glucoprivic feeding in rats. Here we examine a neurochemical mechanism underlying this effect and report that GSN stimulated food intake is highly correlated with the induction of the neuronal activation marker cFOS within two nuclei with a demonstrated role in central glucose sensing and appetite, the arcuate nucleus of the hypothalamus (ARC) and lateral hypothalamic area (LHA). Furthermore, GSN stimulated cFOS within the ARC was observed in orexigenic neurons expressing the endogenous melanocortin receptor antagonist agouti-related peptide (AgRP) and neuropeptide Y (NPY), but not those expressing the anorectic endogenous melanocortin receptor agonist alpha-melanocyte stimulating hormone (α-MSH). In the LHA, GSN stimulated cFOS was found within arousal and feeding associated orexin/hypocretin (ORX), but not orexigenic melanin-concentrating hormone (MCH) expressing neurons. Our data suggest that GK within these specific feeding and arousal related populations of AgRP/NPY and ORX neurons may play a modulatory role in the sensing of and appetitive response to hypoglycaemia.
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Affiliation(s)
- Ligang Zhou
- Department of Pharmacology, University of Cambridge, Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
- Department of Endocrinology, Shuguang Hospital, Shanghai University of TCM, China
| | - Chen-Yu Yueh
- Institute of Metabolic Science, Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK
- Department of Family Medicine, Chang Gung Memorial Hospital at Chiayi, Taiwan; Chang Gung Institute of Technology, Taiwan
| | - Daniel D. Lam
- Department of Pharmacology, University of Cambridge, Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Jill Shaw
- Institute of Metabolic Science, Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Mayowa Osundiji
- Institute of Metabolic Science, Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Alastair S. Garfield
- Department of Pharmacology, University of Cambridge, Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Mark Evans
- Institute of Metabolic Science, Department of Medicine, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Lora K. Heisler
- Department of Pharmacology, University of Cambridge, Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
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16
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Lam DD, Leinninger GM, Louis GW, Garfield AS, Marston OJ, Leshan RL, Scheller EL, Christensen L, Donato J, Xia J, Evans ML, Elias C, Dalley JW, Burdakov DI, Myers MG, Heisler LK. Leptin does not directly affect CNS serotonin neurons to influence appetite. Cell Metab 2011; 13:584-91. [PMID: 21531340 PMCID: PMC3087147 DOI: 10.1016/j.cmet.2011.03.016] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 12/28/2010] [Accepted: 03/18/2011] [Indexed: 01/11/2023]
Abstract
Serotonin (5-HT) and leptin play important roles in the modulation of energy balance. Here we investigated mechanisms by which leptin might interact with CNS 5-HT pathways to influence appetite. Although some leptin receptor (LepRb) neurons lie close to 5-HT neurons in the dorsal raphe (DR), 5-HT neurons do not express LepRb. Indeed, while leptin hyperpolarizes some non-5-HT DR neurons, leptin does not alter the activity of DR 5-HT neurons. Furthermore, 5-HT depletion does not impair the anorectic effects of leptin. The serotonin transporter-cre allele (Sert(cre)) is expressed in 5-HT (and developmentally in some non-5-HT) neurons. While Sert(cre) promotes LepRb excision in a few LepRb neurons in the hypothalamus, it is not active in DR LepRb neurons, and neuron-specific Sert(cre)-mediated LepRb inactivation in mice does not alter body weight or adiposity. Thus, leptin does not directly influence 5-HT neurons and does not meaningfully modulate important appetite-related determinants via 5-HT neuron function.
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Affiliation(s)
- Daniel D. Lam
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | - Gina M. Leinninger
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Gwendolyn W. Louis
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Oliver J. Marston
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | - Rebecca L. Leshan
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Erica L. Scheller
- School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lyndsay Christensen
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jose Donato
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9077, USA
| | - Jing Xia
- Behavioural and Clinical Neuroscience Institute and Department of Experimental Psychology, University of Cambridge, Cambridge CB2 1PD, UK
| | - Mark L. Evans
- Institute of Metabolic Science, University of Cambridge, Cambridge CB2 1PD, UK
| | - Carol Elias
- Division of Hypothalamic Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390-9077, USA
| | - Jeffrey W. Dalley
- Behavioural and Clinical Neuroscience Institute and Department of Experimental Psychology, University of Cambridge, Cambridge CB2 1PD, UK
- Department of Psychiatry, University of Cambridge, Cambridge CB2 1PD, UK
| | - Denis I. Burdakov
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
| | - Martin G. Myers
- Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Lora K. Heisler
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK
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17
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Lam DD, Garfield AS, Marston OJ, Shaw J, Heisler LK. Brain serotonin system in the coordination of food intake and body weight. Pharmacol Biochem Behav 2010; 97:84-91. [PMID: 20837046 DOI: 10.1016/j.pbb.2010.09.003] [Citation(s) in RCA: 179] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 08/02/2010] [Accepted: 09/06/2010] [Indexed: 11/30/2022]
Abstract
An inverse relationship between brain serotonin and food intake and body weight has been known for more than 30 years. Specifically, augmentation of brain serotonin inhibits food intake, while depletion of brain serotonin promotes hyperphagia and weight gain. Through the decades, serotonin receptors have been identified and their function in the serotonergic regulation of food intake clarified. Recent refined genetic studies now indicate that a primary mechanism through which serotonin influences appetite and body weight is via serotonin 2C receptor (5-HT(2C)R) and serotonin 1B receptor (5-HT(1B)R) influencing the activity of endogenous melanocortin receptor agonists and antagonists at the melanocortin 4 receptor (MC4R). However, other mechanisms are also possible and the challenge of future research is to delineate them in the complete elucidation of the complex neurocircuitry underlying the serotonergic control of appetite and body weight.
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Affiliation(s)
- Daniel D Lam
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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18
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Przydzial MJ, Garfield AS, Lam DD, Moore SP, Evans ML, Heisler LK. Nutritional state influences Nociceptin/Orphanin FQ peptide receptor expression in the dorsal raphe nucleus. Behav Brain Res 2010; 206:313-7. [PMID: 19765615 PMCID: PMC2783909 DOI: 10.1016/j.bbr.2009.09.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2008] [Revised: 08/26/2009] [Accepted: 09/11/2009] [Indexed: 11/28/2022]
Abstract
Agonists of the nociceptin/orphanin FQ (N/OFQ) peptide (NOP) receptor stimulate food intake. Concordantly, neuroanatomical localization of NOP receptor mRNA has revealed it to be highly expressed in brain regions associated with the regulation of energy balance. However, the specific mechanisms and neurochemical pathways through which physiological N/OFQ influences appetite are not well understood. To investigate this, we examined nutritional state-associated changes in NOP receptor mRNA levels throughout the rostrocaudal extent of the rat brain using in situ hybridization histochemistry (ISHH) and quantitative densitometry analysis. We observed a significant downregulation of NOP receptor mRNA in the dorsal raphe nucleus (DRN) of fasted rats compared to free-feeding rats. In contrast, no difference in NOP receptor mRNA expression was observed in the supraoptic, parventricular, ventromedial, arcuate or dorsomedial nuclei of the hypothalamus, the red nucleus, the locus coeruleus or the hypoglossal nucleus in the fasted or fed state. These data suggest that the endogenous N/OFQ system is responsive to changes in energy balance and that NOP receptors specifically within the DRN may be physiologically relevant to N/OFQ's effects on appetite.
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Affiliation(s)
| | | | - Daniel D. Lam
- Department of Pharmacology, University of Cambridge,
Cambridge, CB2 1PD, UK
| | - Stephen P. Moore
- Metabolic Research Laboratories, Institute of Metabolic
Science, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 2QQ,
UK
| | - Mark L. Evans
- Metabolic Research Laboratories, Institute of Metabolic
Science, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 2QQ,
UK
| | - Lora K. Heisler
- Department of Pharmacology, University of Cambridge,
Cambridge, CB2 1PD, UK
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19
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Garfield AS, Lam DD, Marston OJ, Przydzial MJ, Heisler LK. Role of central melanocortin pathways in energy homeostasis. Trends Endocrinol Metab 2009; 20:203-15. [PMID: 19541496 DOI: 10.1016/j.tem.2009.02.002] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2008] [Revised: 02/06/2009] [Accepted: 02/06/2009] [Indexed: 02/07/2023]
Abstract
The rise in the global prevalence of human obesity has emphasized the need for a greater understanding of the physiological mechanisms that underlie energy homeostasis. Numerous circulating nutritional cues and central neuromodulatory signals are integrated within the brain to regulate both short- and long-term nutritional state. The central melanocortin system represents a crucial point of convergence for these signals and, thus, has a fundamental role in regulating body weight. The melanocortin ligands, synthesized in discrete neuronal populations within the hypothalamus and brainstem, modulate downstream homeostatic signalling via their action at central melanocortin-3 and -4 receptors. Intimately involved in both ingestive behaviour and energy expenditure, the melanocortin system has garnered much interest as a potential therapeutic target for human obesity.
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Affiliation(s)
- Alastair S Garfield
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
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20
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Lam DD, Zhou L, Vegge A, Xiu PY, Christensen BT, Osundiji MA, Yueh CY, Evans ML, Heisler LK. Distribution and neurochemical characterization of neurons within the nucleus of the solitary tract responsive to serotonin agonist-induced hypophagia. Behav Brain Res 2009; 196:139-43. [PMID: 18762217 PMCID: PMC2614086 DOI: 10.1016/j.bbr.2008.07.039] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 07/25/2008] [Accepted: 07/29/2008] [Indexed: 11/28/2022]
Abstract
Pharmacological compounds enhancing serotonergic tone significantly decrease food intake and are among the most clinically efficacious treatments for obesity. However, the central mechanisms through which serotonergic compounds modulate feeding behavior have not been fully defined. The primary relay center receiving visceral gastrointestinal information in the central nervous system is the nucleus of the solitary tract (NTS) in the caudal brainstem. Here we investigated whether the classic anorectic serotonin receptor agonist m-chloro-phenylpiperazine (mCPP) enhances the activity of metabolically sensitive NTS neurons. Using c-fos immunoreactivity (FOS-IR) as a marker of neuronal activation in rats, we observed that mCPP significantly and dose-dependently activated a discrete population of caudal NTS neurons at the level of the area postrema (AP). In particular, this pattern of FOS-IR induction was consistent with the location of catecholamine-containing neurons. Dual-labeling performed with FOS-IR and the catecholamine biosynthetic enzyme tyrosine hydroxylase (TH) revealed that mCPP induced FOS-IR in 83.7% of TH-IR containing neurons in the NTS at the level of the AP. The degree of activation of TH neurons was strongly negatively correlated with food intake. Moreover, this activation was specific to catecholamine neurons, with negligible induction of cocaine- and amphetamine-regulated transcript (CART), cholecystokinin (CCK), glucagon-like peptide 1 (GLP-1), or neurotensin neurons. NTS catecholaminergic neurons relay visceral gastrointestinal signals to both the lateral hypothalamus (LHA) and paraventricular nucleus of the hypothalamus (PVH), where these signals are integrated into autonomic and hormonal responses regulating food intake. The data presented here identify a novel mechanism through which a serotonin receptor agonist acting in the caudal brainstem may regulate ingestive behavior.
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Affiliation(s)
- Daniel D. Lam
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Ligang Zhou
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Andreas Vegge
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
- Department of Veterinary Pathobiology, Faculty of Life Sciences, University of Copenhagen, Dyrlaegevej 88, 1870 Frederiksberg, Denmark
| | - Philip Y. Xiu
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
| | - Britt T. Christensen
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
- Department of Veterinary Pathobiology, Faculty of Life Sciences, University of Copenhagen, Dyrlaegevej 88, 1870 Frederiksberg, Denmark
| | - Mayowa A. Osundiji
- Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
| | - Chen-yu Yueh
- Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
- College of Medicine, Chang Gung University, Chang Gung Memorial Hospital, Chiayi, Taiwan, ROC
| | - Mark L. Evans
- Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke’s Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
| | - Lora K. Heisler
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, UK
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21
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Kumar KG, Trevaskis JL, Lam DD, Sutton GM, Koza RA, Chouljenko VN, Kousoulas KG, Rogers PM, Kesterson RA, Thearle M, Ferrante AW, Mynatt RL, Burris TP, Dong JZ, Halem HA, Culler MD, Heisler LK, Stephens JM, Butler AA. Identification of adropin as a secreted factor linking dietary macronutrient intake with energy homeostasis and lipid metabolism. Cell Metab 2008; 8:468-81. [PMID: 19041763 PMCID: PMC2746325 DOI: 10.1016/j.cmet.2008.10.011] [Citation(s) in RCA: 298] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 04/23/2008] [Accepted: 10/29/2008] [Indexed: 12/15/2022]
Abstract
Obesity and nutrient homeostasis are linked by mechanisms that are not fully elucidated. Here we describe a secreted protein, adropin, encoded by a gene, Energy Homeostasis Associated (Enho), expressed in liver and brain. Liver Enho expression is regulated by nutrition: lean C57BL/6J mice fed high-fat diet (HFD) exhibited a rapid increase, while fasting reduced expression compared to controls. However, liver Enho expression declines with diet-induced obesity (DIO) associated with 3 months of HFD or with genetically induced obesity, suggesting an association with metabolic disorders in the obese state. In DIO mice, transgenic overexpression or systemic adropin treatment attenuated hepatosteatosis and insulin resistance independently of effects on adiposity or food intake. Adropin regulated expression of hepatic lipogenic genes and adipose tissue peroxisome proliferator-activated receptor gamma, a major regulator of lipogenesis. Adropin may therefore be a factor governing glucose and lipid homeostasis, which protects against hepatosteatosis and hyperinsulinemia associated with obesity.
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Affiliation(s)
- K Ganesh Kumar
- Neuropeptides Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA
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22
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Lam DD, Przydzial MJ, Ridley SH, Yeo GSH, Rochford JJ, O'Rahilly S, Heisler LK. Serotonin 5-HT2C receptor agonist promotes hypophagia via downstream activation of melanocortin 4 receptors. Endocrinology 2008; 149:1323-8. [PMID: 18039773 PMCID: PMC2275368 DOI: 10.1210/en.2007-1321] [Citation(s) in RCA: 210] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The neurotransmitter serotonin (5-hydroxytryptamine) is a well-established modulator of energy balance. Both pharmacological and genetic evidence implicate the serotonin 2C receptor (5-HT(2C)R) as a critical receptor mediator of serotonin's effects on ingestive behavior. Here we characterized the effect of the novel and selective 5-HT(2C)R agonist BVT.X on energy balance in obese and lean mice and report that BVT.X significantly reduces acute food intake without altering locomotor activity or oxygen consumption. In an effort to elucidate the mechanism of this effect, we examined the chemical phenotype of 5-HT(2C)R-expressing neurons in a critical brain region affecting feeding behavior, the arcuate nucleus of the hypothalamus. We show that 5-HT(2C)Rs are coexpressed with neurons containing proopiomelanocortin, known to potently affect appetite, in the arcuate nucleus of the hypothalamus of the mouse. We then demonstrate that prolonged infusion with BVT.X in obese mice significantly increases Pomc mRNA and reduces body weight, percent body fat, and initial food intake. To evaluate the functional importance of melanocortin circuitry in the effect of BVT.X on ingestive behavior, we assessed mice with disrupted melanocortin pathways. We report that mice lacking the melanocortin 4 receptor are not responsive to BVT.X-induced hypophagia, demonstrating that melanocortins acting on melanocortin 4 receptor are a requisite downstream pathway for 5-HT(2C)R agonists to exert effects on food intake. The data presented here not only indicate that the novel 5-HT(2C)R agonist BVT.X warrants further investigation as a treatment for obesity but also elucidate specific neuronal pathways potently affecting energy balance through which 5-HT(2C)R agonists regulate ingestive behavior.
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MESH Headings
- Adipose Tissue/drug effects
- Adipose Tissue/metabolism
- Animals
- Appetite Depressants/pharmacology
- Appetite Regulation/drug effects
- Appetite Regulation/physiology
- Disease Models, Animal
- Eating/drug effects
- Eating/physiology
- Energy Metabolism/drug effects
- Energy Metabolism/physiology
- Feeding and Eating Disorders/etiology
- Feeding and Eating Disorders/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Obese
- Motor Activity/drug effects
- Motor Activity/physiology
- Oxygen Consumption/drug effects
- Oxygen Consumption/physiology
- Pro-Opiomelanocortin/metabolism
- RNA, Messenger/metabolism
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Receptor, Serotonin, 5-HT2C/metabolism
- Serotonin/metabolism
- Serotonin 5-HT2 Receptor Agonists
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Affiliation(s)
- Daniel D Lam
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
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23
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Zhou L, Sutton GM, Rochford JJ, Semple RK, Lam DD, Oksanen L, Thornton-Jones ZD, Clifton PG, Yueh CY, Evans ML, McCrimmon R, Elmquist JK, Butler AA, Heisler LK. Serotonin 2C receptor agonists improve type 2 diabetes via melanocortin-4 receptor signaling pathways. Cell Metab 2007; 6:398-405. [PMID: 17983585 PMCID: PMC2075535 DOI: 10.1016/j.cmet.2007.10.008] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 08/16/2007] [Accepted: 10/15/2007] [Indexed: 11/18/2022]
Abstract
The burden of type 2 diabetes and its associated premature morbidity and mortality is rapidly growing, and the need for novel efficacious treatments is pressing. We report here that serotonin 2C receptor (5-HT(2C)R) agonists, typically investigated for their anorectic properties, significantly improve glucose tolerance and reduce plasma insulin in murine models of obesity and type 2 diabetes. Importantly, 5-HT(2C)R agonist-induced improvements in glucose homeostasis occurred at concentrations of agonist that had no effect on ingestive behavior, energy expenditure, locomotor activity, body weight, or fat mass. We determined that this primary effect on glucose homeostasis requires downstream activation of melanocortin-4 receptors (MC4Rs), but not MC3Rs. These findings suggest that pharmacological targeting of 5-HT(2C)Rs may enhance glucose tolerance independently of alterations in body weight and that this may prove an effective and mechanistically novel strategy in the treatment of type 2 diabetes.
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MESH Headings
- Absorptiometry, Photon
- Animals
- Blotting, Western
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Gene Expression/drug effects
- Glucose/metabolism
- Glucose Intolerance
- Glucose Tolerance Test
- Homeostasis/drug effects
- Immunohistochemistry
- Insulin/blood
- Male
- Mice
- Mice, Knockout
- Mice, Obese
- Neurons/drug effects
- Neurons/metabolism
- Piperazines/pharmacology
- Polymerase Chain Reaction
- Pro-Opiomelanocortin/genetics
- Receptor, Melanocortin, Type 4/chemistry
- Receptor, Melanocortin, Type 4/metabolism
- Receptor, Melanocortin, Type 4/physiology
- Serotonin 5-HT2 Receptor Agonists
- Serotonin Receptor Agonists/pharmacology
- Signal Transduction/drug effects
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Affiliation(s)
- Ligang Zhou
- Department of Clinical Biochemistry, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Gregory M. Sutton
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA
| | - Justin J. Rochford
- Department of Clinical Biochemistry, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
| | - Robert K. Semple
- Department of Clinical Biochemistry, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
| | - Daniel D. Lam
- Department of Clinical Biochemistry, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
| | - Laura J. Oksanen
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | | | - Peter G. Clifton
- Department of Psychology, Sussex University, Brighton BN1 9QG, UK
| | - Chen-Yu Yueh
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
| | - Mark L. Evans
- Department of Medicine, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
| | - Rory J. McCrimmon
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Joel K. Elmquist
- Division of Hypothalamic Research and the Departments of Internal Medicine and Pharmacology, The University of Texas Southwestern Medical Center, Dallas, TX 75390-9051, USA
| | - Andrew A. Butler
- Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA
| | - Lora K. Heisler
- Department of Clinical Biochemistry, Addenbrooke's Hospital, University of Cambridge, Cambridge CB2 2QQ, UK
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24
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Abstract
The neurotransmitter serotonin is an important regulator of energy balance. In the brain, serotonergic fibres from midbrain raphe nuclei project to key feeding centres, where serotonin acts on specific receptors to modulate the activity of various downstream neuropeptide systems and autonomic pathways and thus affects ingestive behaviour and energy expenditure. Serotonin, released by intestinal enterochromaffin cells, also appears to regulate energy homeostasis through peripheral mechanisms. Serotonergic effects on energy balance lead to secondary effects on glucose homeostasis, based on a well-established link between obesity and insulin resistance. However, serotonergic pathways may also directly affect glucose homeostasis through regulation of autonomic efferents and/or action on peripheral tissues. Several serotonergic compounds have been evaluated for clinical use in the treatment of obesity and type 2 diabetes; results of these trials are discussed here. Finally, future directions in the elucidation of serotonergic metabolic regulation are discussed.
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Affiliation(s)
- Daniel D Lam
- Department of Clinical Biochemistry, Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 2QQ, UK
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25
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Lam DD, Farooqi IS, Heisler LK. Melanocortin receptors as targets in the treatment of obesity. Curr Top Med Chem 2007; 7:1085-1097. [PMID: 17584129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The central melanocortin system plays a critical role in energy homeostasis. It is well established that melanocortin-containing neurons are nutritionally regulated and that genetic alterations in the melanocortin system produce profound effects on food intake, energy expenditure, and body weight. Within the brain, melanocortin-producing neurons originate in the arcuate nucleus of the hypothalamus (ARC) and the nucleus of the solitary tract (NTS) in the brainstem and project to various nuclei modulating energy balance. A large body of pharmacological and genetic evidence implicates the central melanocortin 4 receptors (MC4Rs) in the effects of melanocortin peptides on ingestive behaviour, energy expenditure, and body weight. Preclinical studies with endogenous and synthetic melanocortin ligands demonstrate that they produce potent effects on food intake and energy expenditure. Clinical studies thus far have been somewhat less successful and have been hampered by the induction of side effects, which present obstacles to the development of successful therapeutic agents. However, various promising strategies are being pursued to overcome these limitations, including the synthesis of more selective and potent melanocortin analogs.
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Affiliation(s)
- Daniel D Lam
- Department of Clinical Biochemistry, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
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