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Al Harake SN, Abedin Y, Hatoum F, Nassar NZ, Ali A, Nassar A, Kanaan A, Bazzi S, Azar S, Harb F, Ghadieh HE. Involvement of a battery of investigated genes in lipid droplet pathophysiology and associated comorbidities. Adipocyte 2024; 13:2403380. [PMID: 39329369 PMCID: PMC11445895 DOI: 10.1080/21623945.2024.2403380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 08/29/2024] [Accepted: 09/05/2024] [Indexed: 09/28/2024] Open
Abstract
Lipid droplets (LDs) are highly specialized energy storage organelles involved in the maintenance of lipid homoeostasis by regulating lipid flux within white adipose tissue (WAT). The physiological function of adipocytes and LDs can be compromised by mutations in several genes, leading to NEFA-induced lipotoxicity, which ultimately manifests as metabolic complications, predominantly in the form of dyslipidemia, ectopic fat accumulation, and insulin resistance. In this review, we delineate the effects of mutations and deficiencies in genes - CIDEC, PPARG, BSCL2, AGPAT2, PLIN1, LIPE, LMNA, CAV1, CEACAM1, and INSR - involved in lipid droplet metabolism and their associated pathophysiological impairments, highlighting their roles in the development of lipodystrophies and metabolic dysfunction.
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Affiliation(s)
- Sami N. Al Harake
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Yasamin Abedin
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Fatema Hatoum
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Nour Zahraa Nassar
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Ali Ali
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Aline Nassar
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Amjad Kanaan
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Samer Bazzi
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Sami Azar
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Frederic Harb
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
| | - Hilda E. Ghadieh
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, Lebanon
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2
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Renard E, Thevenard-Berger A, Meyre D. Medical semiology of patients with monogenic obesity: A systematic review. Obes Rev 2024; 25:e13797. [PMID: 38956946 DOI: 10.1111/obr.13797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 03/20/2024] [Accepted: 06/19/2024] [Indexed: 07/04/2024]
Abstract
Patients with monogenic obesity display numerous medical features on top of hyperphagic obesity, but no study to date has provided an exhaustive description of their semiology. Two reviewers independently conducted a systematic review of MEDLINE, Embase, and Web of Science Core Collection databases from inception to January 2022 to identify studies that described symptoms of patients carrying pathogenic mutations in at least one of eight monogenic obesity genes (ADCY3, LEP, LEPR, MC3R, MC4R, MRAP2, PCSK1, and POMC). Of 5207 identified references, 269 were deemed eligible after title and abstract screening, full-text reading, and risk of bias and quality assessment. Data extraction included mutation spectrum and mode of inheritance, clinical presentation (e.g., anthropometry, energy intake and eating behaviors, digestive function, puberty and fertility, cognitive features, infectious diseases, morphological characteristics, chronic respiratory disease, and cardiovascular disease), biological characteristics (metabolic profile, endocrinology, hematology), radiological features, and treatments. The review provides an exhaustive description of mandatory, non-mandatory, and unique symptoms in heterozygous and homozygous carriers of mutation in eight monogenic obesity genes. This information is critical to help clinicians to orient genetic testing in subsets of patients with suspected monogenic obesity and provide actionable treatments (e.g., recombinant leptin and MC4R agonist).
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Affiliation(s)
- Emeline Renard
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, Nancy, France
- Department of Pediatrics, University Hospital of Nancy, Nancy, France
| | | | - David Meyre
- INSERM UMR_S 1256, Nutrition, Genetics, and Environmental Risk Exposure (NGERE), Faculty of Medicine of Nancy, University of Lorraine, Nancy, France
- Department of Molecular Medicine, Division of Biochemistry, Molecular Biology, and Nutrition, University Hospital of Nancy, Nancy, France
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
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3
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Soares RMV, da Silva MA, Campos JTADM, Lima JG. Familial partial lipodystrophy resulting from loss-of-function PPARγ pathogenic variants: phenotypic, clinical, and genetic features. Front Endocrinol (Lausanne) 2024; 15:1394102. [PMID: 39398333 PMCID: PMC11466747 DOI: 10.3389/fendo.2024.1394102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 09/10/2024] [Indexed: 10/15/2024] Open
Abstract
The PPARG gene encodes a member of a nuclear receptor superfamily known as peroxisome proliferator-activated gamma (PPARγ). PPARγ plays an essential role in adipogenesis, stimulating the differentiation of preadipocytes into adipocytes. Loss-of-function pathogenic variants in PPARG reduce the activity of the PPARγ receptor and can lead to severe metabolic consequences associated with familial partial lipodystrophy type 3 (FPLD3). This review focuses on recent scientific data related to FPLD3, including the role of PPARγ in adipose tissue metabolism and the phenotypic and clinical consequences of loss-of-function variants in the PPARG gene. The clinical features of 41 PPARG pathogenic variants associated with FPLD3 patients were reviewed, highlighting the genetic and clinical heterogeneity observed among 91 patients. Most of them were female, and the average age at the onset and diagnosis of lipoatrophy was 21 years and 33 years, respectively. Considering the metabolic profile, hypertriglyceridemia (91.9% of cases), diabetes (77%), hypertension (59.5%), polycystic ovary syndrome (58.2% of women), and metabolic-dysfunction-associated fatty liver disease (87,5%). We also discuss the current treatment for FPLD3. This review provides new data concerning the genetic and clinical heterogeneity in FPLD3 and highlights the importance of further understanding the genetics of this rare disease.
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Affiliation(s)
- Reivla Marques Vasconcelos Soares
- Department of Clinical Medicine, Hospital Universitário Onofre Lopes (HUOL), Federal University of Rio Grande do Norte (UFRN), Natal, RN, Brazil
| | - Monique Alvares da Silva
- Molecular Biology and Genomics Laboratory, Federal University of Rio Grande do Norte
(UFRN), Natal, RN, Brazil
| | - Julliane Tamara Araújo de Melo Campos
- Molecular Biology and Genomics Laboratory, Federal University of Rio Grande do Norte
(UFRN), Natal, RN, Brazil
- Department of Morphology (DMOR), Federal University of Rio Grande do Norte (UFRN), Natal, RN, Brazil
| | - Josivan Gomes Lima
- Department of Clinical Medicine, Hospital Universitário Onofre Lopes (HUOL), Federal University of Rio Grande do Norte (UFRN), Natal, RN, Brazil
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4
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Neikirk K, Kabugi K, Mungai M, Kula B, Smith N, Hinton AO. Ethnicity-related differences in mitochondrial regulation by insulin stimulation in diabetes. J Cell Physiol 2024; 239:e31317. [PMID: 38775168 PMCID: PMC11324399 DOI: 10.1002/jcp.31317] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 04/26/2024] [Accepted: 05/07/2024] [Indexed: 08/15/2024]
Abstract
Mitochondrial dysfunction has long been implicated in the development of insulin resistance, which is a hallmark of type 2 diabetes. However, recent studies reveal ethnicity-related differences in mitochondrial processes, underscoring the need for nuance in studying mitochondrial dysfunction and insulin sensitivity. Furthermore, the higher prevalence of type 2 diabetes among African Americans and individuals of African descent has brought attention to the role of ethnicity in disease susceptibility. In this review, which covers existing literature, genetic studies, and clinical data, we aim to elucidate the complex relationship between mitochondrial alterations and insulin stimulation by considering how mitochondrial dynamics, contact sites, pathways, and metabolomics may be differentially regulated across ethnicities, through mechanisms such as single nucleotide polymorphisms (SNPs). In addition to achieving a better understanding of insulin stimulation, future studies identifying novel regulators of mitochondrial structure and function could provide valuable insights into ethnicity-dependent insulin signaling and personalized care.
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Affiliation(s)
- Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Kinuthia Kabugi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Margaret Mungai
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Bartosz Kula
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, USA 14642
| | - Nathan Smith
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, USA 14642
| | - Antentor O. Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
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5
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Stone SI, Balasubramanyam A, Posey JE. Atypical Diabetes: What Have We Learned and What Does the Future Hold? Diabetes Care 2024; 47:770-781. [PMID: 38329838 PMCID: PMC11043229 DOI: 10.2337/dci23-0038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 11/21/2023] [Indexed: 02/10/2024]
Abstract
As our understanding of the pathophysiology of diabetes evolves, we increasingly recognize that many patients may have a form of diabetes that does not neatly fit with a diagnosis of either type 1 or type 2 diabetes. The discovery and description of these forms of "atypical diabetes" have led to major contributions to our collective understanding of the basic biology that drives insulin secretion, insulin resistance, and islet autoimmunity. These discoveries now pave the way to a better classification of diabetes based on distinct endotypes. In this review, we highlight the key biological and clinical insights that can be gained from studying known forms of atypical diabetes. Additionally, we provide a framework for identification of patients with atypical diabetes based on their clinical, metabolic, and molecular features. Helpful clinical and genetic resources for evaluating patients suspected of having atypical diabetes are provided. Therefore, appreciating the various endotypes associated with atypical diabetes will enhance diagnostic accuracy and facilitate targeted treatment decisions.
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Affiliation(s)
- Stephen I. Stone
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, Washington University School of Medicine, St. Louis, MO
| | - Ashok Balasubramanyam
- Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX
| | - Jennifer E. Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
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6
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Liu Z, Xin B, Smith IN, Sency V, Szekely J, Alkelai A, Shuldiner A, Efthymiou S, Rajabi F, Coury S, Brownstein CA, Rudnik-Schöneborn S, Bruel AL, Thevenon J, Zeidler S, Jayakar P, Schmidt A, Cremer K, Engels H, Peters SO, Zaki MS, Duan R, Zhu C, Xu Y, Gao C, Sepulveda-Morales T, Maroofian R, Alkhawaja IA, Khawaja M, Alhalasah H, Houlden H, Madden JA, Turchetti V, Marafi D, Agrawal PB, Schatz U, Rotenberg A, Rotenberg J, Mancini GMS, Bakhtiari S, Kruer M, Thiffault I, Hirsch S, Hempel M, Stühn LG, Haack TB, Posey JE, Lupski JR, Lee H, Sarn NB, Eng C, Gonzaga-Jauregui C, Zhang B, Wang H. Hemizygous variants in protein phosphatase 1 regulatory subunit 3F (PPP1R3F) are associated with a neurodevelopmental disorder characterized by developmental delay, intellectual disability and autistic features. Hum Mol Genet 2023; 32:2981-2995. [PMID: 37531237 PMCID: PMC10549786 DOI: 10.1093/hmg/ddad124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/20/2023] [Accepted: 07/26/2023] [Indexed: 08/04/2023] Open
Abstract
Protein phosphatase 1 regulatory subunit 3F (PPP1R3F) is a member of the glycogen targeting subunits (GTSs), which belong to the large group of regulatory subunits of protein phosphatase 1 (PP1), a major eukaryotic serine/threonine protein phosphatase that regulates diverse cellular processes. Here, we describe the identification of hemizygous variants in PPP1R3F associated with a novel X-linked recessive neurodevelopmental disorder in 13 unrelated individuals. This disorder is characterized by developmental delay, mild intellectual disability, neurobehavioral issues such as autism spectrum disorder, seizures and other neurological findings including tone, gait and cerebellar abnormalities. PPP1R3F variants segregated with disease in affected hemizygous males that inherited the variants from their heterozygous carrier mothers. We show that PPP1R3F is predominantly expressed in brain astrocytes and localizes to the endoplasmic reticulum in cells. Glycogen content in PPP1R3F knockout astrocytoma cells appears to be more sensitive to fluxes in extracellular glucose levels than in wild-type cells, suggesting that PPP1R3F functions in maintaining steady brain glycogen levels under changing glucose conditions. We performed functional studies on nine of the identified variants and observed defects in PP1 binding, protein stability, subcellular localization and regulation of glycogen metabolism in most of them. Collectively, the genetic and molecular data indicate that deleterious variants in PPP1R3F are associated with a new X-linked disorder of glycogen metabolism, highlighting the critical role of GTSs in neurological development. This research expands our understanding of neurodevelopmental disorders and the role of PP1 in brain development and proper function.
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Affiliation(s)
- Zhigang Liu
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Baozhong Xin
- DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA
| | - Iris N Smith
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Valerie Sency
- DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA
| | - Julia Szekely
- DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA
| | - Anna Alkelai
- Regeneron Genetics Center, Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Alan Shuldiner
- Regeneron Genetics Center, Regeneron Pharmaceuticals, Tarrytown, NY 10591, USA
| | - Stephanie Efthymiou
- Department of Neuromuscular Disorders, University College London (UCL) Institute of Neurology, London WC1N 3BG, UK
| | - Farrah Rajabi
- Division of Genetics & Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Stephanie Coury
- Division of Genetics & Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Catherine A Brownstein
- Division of Genetics & Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
- The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA
| | | | - Ange-Line Bruel
- Inserm UMR1231 GAD, Génétique des Anomalies du Développement, Fédération Hospitalo-Universitaire Médecine Translationnelle et Anomalies du Développement (FHU TRANSLAD), CHU Dijon Bourgogne, Dijon 21000, France
- UF Innovation en diagnostic génomique des maladies rares, CHU Dijon Bourgogne, Dijon 21000, France
| | - Julien Thevenon
- Université Grenoble Alpes, Institute for Advanced Biosciences, Grenoble, France
| | - Shimriet Zeidler
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam 3015 GD, The Netherlands
| | - Parul Jayakar
- Division of Genetics and Metabolism, Nicklaus Children's Hospital, Miami, FL 33155, USA
| | - Axel Schmidt
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, 53105 Bonn, Germany
| | - Kirsten Cremer
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, 53105 Bonn, Germany
| | - Hartmut Engels
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, 53105 Bonn, Germany
| | - Sophia O Peters
- Institute of Human Genetics, University of Bonn, School of Medicine & University Hospital Bonn, 53105 Bonn, Germany
| | - Maha S Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Institute National Research Centre, Cairo 12622, Egypt
| | - Ruizhi Duan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Changlian Zhu
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, University of Gothenburg, Göteborg 417 56, Sweden
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Yiran Xu
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Chao Gao
- Department of Pediatric Rehabilitation Medicine, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou 450012, China
| | - Tania Sepulveda-Morales
- International Laboratory for Human Genome Research, Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de México, Juriquilla, Querétaro 76226, México
| | - Reza Maroofian
- Department of Neuromuscular Disorders, University College London (UCL) Institute of Neurology, London WC1N 3BG, UK
| | - Issam A Alkhawaja
- Al-Bashir Hospital, Pediatric Department, Pediatric Neurology Unit, Amman, Jordan
| | - Mariam Khawaja
- Prince Hamzah Hospital, Amman, Jordan
- Hospital Clínic and Fundació Hospital Sant Joan de Déu de Martorell/Barcelona, Barcelona, Spain
| | | | - Henry Houlden
- Department of Neuromuscular Disorders, University College London (UCL) Institute of Neurology, London WC1N 3BG, UK
| | - Jill A Madden
- Division of Genetics & Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
- The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA
| | - Valentina Turchetti
- Department of Neuromuscular Disorders, University College London (UCL) Institute of Neurology, London WC1N 3BG, UK
| | - Dana Marafi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pediatrics, Faculty of Medicine, Kuwait University, Kuwait City 13060, Kuwait
| | - Pankaj B Agrawal
- Division of Genetics & Genomics, Boston Children’s Hospital, Boston, MA 02115, USA
- The Manton Center for Orphan Disease Research, Boston Children's Hospital, Boston, MA 02115, USA
- Division of Neonatology, Department of Pediatrics, University of Miami School of Medicine and Jackson Health System, Miami, FL 33136, USA
| | - Ulrich Schatz
- Institute for Human Genetics, Medical University Innsbruck, Innsbruck 6020, Austria
| | | | | | - Grazia M S Mancini
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam 3015 GD, The Netherlands
| | - Somayeh Bakhtiari
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children’s Hospital, Phoenix, AZ 85016, USA
- Departments of Child Health, Neurology, and Cellular & Molecular Medicine, and Program in Genetics, University of Arizona College of Medicine–Phoenix, Phoenix, AZ 85004, USA
| | - Michael Kruer
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children’s Hospital, Phoenix, AZ 85016, USA
- Departments of Child Health, Neurology, and Cellular & Molecular Medicine, and Program in Genetics, University of Arizona College of Medicine–Phoenix, Phoenix, AZ 85004, USA
| | - Isabelle Thiffault
- Genomic Medicine Center, Children’s Mercy Kansas City, Children's Mercy Research Institute, Kansas City, MO 64108, USA
| | - Steffen Hirsch
- Institute if Human Genetics, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Maja Hempel
- Institute if Human Genetics, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Lara G Stühn
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, 72076 Tübingen, Germany
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Texas Children's Hospital, Houston, TX 77030, USA
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Hyunpil Lee
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Nicholas B Sarn
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Charis Eng
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Claudia Gonzaga-Jauregui
- International Laboratory for Human Genome Research, Laboratorio Internacional de Investigación sobre el Genoma Humano, Universidad Nacional Autónoma de México, Juriquilla, Querétaro 76226, México
| | - Bin Zhang
- Genomic Medicine Institute, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, USA
| | - Heng Wang
- DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA
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7
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Connally NJ, Nazeen S, Lee D, Shi H, Stamatoyannopoulos J, Chun S, Cotsapas C, Cassa CA, Sunyaev SR. The missing link between genetic association and regulatory function. eLife 2022; 11:e74970. [PMID: 36515579 PMCID: PMC9842386 DOI: 10.7554/elife.74970] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 12/02/2022] [Indexed: 12/15/2022] Open
Abstract
The genetic basis of most traits is highly polygenic and dominated by non-coding alleles. It is widely assumed that such alleles exert small regulatory effects on the expression of cis-linked genes. However, despite the availability of gene expression and epigenomic datasets, few variant-to-gene links have emerged. It is unclear whether these sparse results are due to limitations in available data and methods, or to deficiencies in the underlying assumed model. To better distinguish between these possibilities, we identified 220 gene-trait pairs in which protein-coding variants influence a complex trait or its Mendelian cognate. Despite the presence of expression quantitative trait loci near most GWAS associations, by applying a gene-based approach we found limited evidence that the baseline expression of trait-related genes explains GWAS associations, whether using colocalization methods (8% of genes implicated), transcription-wide association (2% of genes implicated), or a combination of regulatory annotations and distance (4% of genes implicated). These results contradict the hypothesis that most complex trait-associated variants coincide with homeostatic expression QTLs, suggesting that better models are needed. The field must confront this deficit and pursue this 'missing regulation.'
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Affiliation(s)
- Noah J Connally
- Department of Biomedical Informatics, Harvard Medical SchoolBostonUnited States
- Brigham and Women’s Hospital, Division of Genetics, Harvard Medical SchoolBostonUnited States
- Program in Medical and Population Genetics, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Sumaiya Nazeen
- Department of Biomedical Informatics, Harvard Medical SchoolBostonUnited States
- Brigham and Women’s Hospital, Division of Genetics, Harvard Medical SchoolBostonUnited States
- Brigham and Women’s Hospital, Department of Neurology, Harvard Medical SchoolBostonUnited States
| | - Daniel Lee
- Department of Biomedical Informatics, Harvard Medical SchoolBostonUnited States
- Brigham and Women’s Hospital, Division of Genetics, Harvard Medical SchoolBostonUnited States
- Program in Medical and Population Genetics, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Huwenbo Shi
- Program in Medical and Population Genetics, Broad Institute of MIT and HarvardCambridgeUnited States
- Department of Epidemiology, Harvard T.H. Chan School of Public HealthBostonUnited States
| | | | - Sung Chun
- Division of Pulmonary Medicine, Boston Children’s HospitalBostonUnited States
| | - Chris Cotsapas
- Program in Medical and Population Genetics, Broad Institute of MIT and HarvardCambridgeUnited States
- Department of Neurology, Yale Medical SchoolNew HavenUnited States
- Department of Genetics, Yale Medical SchoolNew HavenUnited States
| | - Christopher A Cassa
- Brigham and Women’s Hospital, Division of Genetics, Harvard Medical SchoolBostonUnited States
- Program in Medical and Population Genetics, Broad Institute of MIT and HarvardCambridgeUnited States
| | - Shamil R Sunyaev
- Department of Biomedical Informatics, Harvard Medical SchoolBostonUnited States
- Brigham and Women’s Hospital, Division of Genetics, Harvard Medical SchoolBostonUnited States
- Program in Medical and Population Genetics, Broad Institute of MIT and HarvardCambridgeUnited States
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8
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Bando H, Brinkmeier ML, Castinetti F, Fang Q, Lee MS, Saveanu A, Albarel F, Dupuis C, Brue T, Camper SA. Heterozygous variants in SIX3 and POU1F1 cause pituitary hormone deficiency in mouse and man. Hum Mol Genet 2022; 32:367-385. [PMID: 35951005 PMCID: PMC9851746 DOI: 10.1093/hmg/ddac192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/22/2022] [Accepted: 08/09/2022] [Indexed: 01/24/2023] Open
Abstract
Congenital hypopituitarism is a genetically heterogeneous condition that is part of a spectrum disorder that can include holoprosencephaly. Heterozygous mutations in SIX3 cause variable holoprosencephaly in humans and mice. We identified two children with neonatal hypopituitarism and thin pituitary stalk who were doubly heterozygous for rare, likely deleterious variants in the transcription factors SIX3 and POU1F1. We used genetically engineered mice to understand the disease pathophysiology. Pou1f1 loss-of-function heterozygotes are unaffected; Six3 heterozygotes have pituitary gland dysmorphology and incompletely ossified palate; and the Six3+/-; Pou1f1+/dw double heterozygote mice have a pronounced phenotype, including pituitary growth through the palate. The interaction of Pou1f1 and Six3 in mice supports the possibility of digenic pituitary disease in children. Disruption of Six3 expression in the oral ectoderm completely ablated anterior pituitary development, and deletion of Six3 in the neural ectoderm blocked the development of the pituitary stalk and both anterior and posterior pituitary lobes. Six3 is required in both oral and neural ectodermal tissues for the activation of signaling pathways and transcription factors necessary for pituitary cell fate. These studies clarify the mechanism of SIX3 action in pituitary development and provide support for a digenic basis for hypopituitarism.
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Affiliation(s)
| | | | - Frederic Castinetti
- Assistance Publique-Hôpitaux de Marseille (AP-HM), Department of Endocrinology, Hôpital de la Conception, Centre de Référence des Maladies Rares de l’hypophyse HYPO, Marseille, France,Aix-Marseille Université, Institut National de la Santé et de la Recherche Médicale (INSERM), U1251, Marseille Medical Genetics (MMG), Institut Marseille, Maladies Rares (MarMaRa), Marseille, France
| | - Qing Fang
- Department of Human Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Mi-Sun Lee
- Michigan Neuroscience Institute, Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Alexandru Saveanu
- Assistance Publique-Hôpitaux de Marseille (AP-HM), Department of Endocrinology, Hôpital de la Conception, Centre de Référence des Maladies Rares de l’hypophyse HYPO, Marseille, France,Aix-Marseille Université, Institut National de la Santé et de la Recherche Médicale (INSERM), U1251, Marseille Medical Genetics (MMG), Institut Marseille, Maladies Rares (MarMaRa), Marseille, France
| | - Frédérique Albarel
- Assistance Publique-Hôpitaux de Marseille (AP-HM), Department of Endocrinology, Hôpital de la Conception, Centre de Référence des Maladies Rares de l’hypophyse HYPO, Marseille, France,Aix-Marseille Université, Institut National de la Santé et de la Recherche Médicale (INSERM), U1251, Marseille Medical Genetics (MMG), Institut Marseille, Maladies Rares (MarMaRa), Marseille, France
| | - Clémentine Dupuis
- Department of Pediatrics, Centre Hospitalier Universitaire de Grenoble-Alpes, site Nord, Hôpital Couple Enfants, Grenoble, France
| | - Thierry Brue
- Assistance Publique-Hôpitaux de Marseille (AP-HM), Department of Endocrinology, Hôpital de la Conception, Centre de Référence des Maladies Rares de l’hypophyse HYPO, Marseille, France,Aix-Marseille Université, Institut National de la Santé et de la Recherche Médicale (INSERM), U1251, Marseille Medical Genetics (MMG), Institut Marseille, Maladies Rares (MarMaRa), Marseille, France
| | - Sally A Camper
- To whom correspondence should be addressed at: Department of Human Genetics, University of Michigan Medical School, 5704 Medical Science Building II, 1241 Catherine St., Ann Arbor, MI 48109, USA. Tel: +1-734-763-0682; Fax: +1-734-763-3784;
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9
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Okazaki A, Horpaopan S, Zhang Q, Randesi M, Ott J. Genotype Pattern Mining for Pairs of Interacting Variants Underlying Digenic Traits. Genes (Basel) 2021; 12:1160. [PMID: 34440333 PMCID: PMC8391494 DOI: 10.3390/genes12081160] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 07/23/2021] [Accepted: 07/27/2021] [Indexed: 12/15/2022] Open
Abstract
Some genetic diseases ("digenic traits") are due to the interaction between two DNA variants, which presumably reflects biochemical interactions. For example, certain forms of Retinitis Pigmentosa, a type of blindness, occur in the presence of two mutant variants, one each in the ROM1 and RDS genes, while the occurrence of only one such variant results in a normal phenotype. Detecting variant pairs underlying digenic traits by standard genetic methods is difficult and is downright impossible when individual variants alone have minimal effects. Frequent pattern mining (FPM) methods are known to detect patterns of items. We make use of FPM approaches to find pairs of genotypes (from different variants) that can discriminate between cases and controls. Our method is based on genotype patterns of length two, and permutation testing allows assigning p-values to genotype patterns, where the null hypothesis refers to equal pattern frequencies in cases and controls. We compare different interaction search approaches and their properties on the basis of published datasets. Our implementation of FPM to case-control studies is freely available.
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Affiliation(s)
- Atsuko Okazaki
- Department of Diagnostics and Therapeutics of Intractable Diseases, Juntendo University, Bunkyo-ku, Tokyo 113-8421, Japan;
- Laboratory of Statistical Genetics, Rockefeller University, New York, NY 10065, USA
| | - Sukanya Horpaopan
- Department of Anatomy, Faculty of Medical Science, Naresuan University, Phitsanulok 65000, Thailand;
| | - Qingrun Zhang
- Department of Mathematics and Statistics, University of Calgary, Calgary, AB T2N 1N4, Canada;
| | - Matthew Randesi
- Laboratory of the Biology of Addictive Diseases, Rockefeller University, New York, NY 10065, USA;
| | - Jurg Ott
- Laboratory of Statistical Genetics, Rockefeller University, New York, NY 10065, USA
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10
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Huang-Doran I, Kinzer AB, Jimenez-Linan M, Thackray K, Harris J, Adams CL, de Kerdanet M, Stears A, O’Rahilly S, Savage DB, Gorden P, Brown RJ, Semple RK. Ovarian Hyperandrogenism and Response to Gonadotropin-releasing Hormone Analogues in Primary Severe Insulin Resistance. J Clin Endocrinol Metab 2021; 106:2367-2383. [PMID: 33901270 PMCID: PMC8277216 DOI: 10.1210/clinem/dgab275] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Indexed: 01/26/2023]
Abstract
CONTEXT Insulin resistance (IR) is associated with polycystic ovaries and hyperandrogenism, but underpinning mechanisms are poorly understood and therapeutic options are limited. OBJECTIVE To characterize hyperandrogenemia and ovarian pathology in primary severe IR (SIR), using IR of defined molecular etiology to interrogate disease mechanism. To extend evaluation of gonadotropin-releasing hormone (GnRH) analogue therapy in SIR. METHODS Retrospective case note review in 2 SIR national referral centers. Female patients with SIR with documented serum total testosterone (TT) concentration. RESULTS Among 185 patients with lipodystrophy, 65 with primary insulin signaling disorders, and 29 with idiopathic SIR, serum TT ranged from undetectable to 1562 ng/dL (54.2 nmol/L; median 40.3 ng/dL [1.40 nmol/L]; n = 279) and free testosterone (FT) from undetectable to 18.0 ng/dL (0.625 nmol/L; median 0.705 ng/dL [0.0244 nmol/L]; n = 233). Higher TT but not FT in the insulin signaling subgroup was attributable to higher serum sex hormone-binding globulin (SHBG) concentration. Insulin correlated positively with SHBG in the insulin signaling subgroup, but negatively in lipodystrophy. In 8/9 patients with available ovarian tissue, histology was consistent with polycystic ovary syndrome (PCOS). In 6/6 patients treated with GnRH analogue therapy, gonadotropin suppression improved hyperandrogenic symptoms and reduced serum TT irrespective of SIR etiology. CONCLUSION SIR causes severe hyperandrogenemia and PCOS-like ovarian changes whether due to proximal insulin signaling or adipose development defects. A distinct relationship between IR and FT between the groups is mediated by SHBG. GnRH analogues are beneficial in a range of SIR subphenotypes.
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Affiliation(s)
- Isabel Huang-Doran
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
- National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
| | - Alexandra B Kinzer
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Mercedes Jimenez-Linan
- Histopathology Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Kerrie Thackray
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
- National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
| | - Julie Harris
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
- National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
| | - Claire L Adams
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
- National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
| | - Marc de Kerdanet
- Pediatric Endocrinology Unit, University Hospital, Rennes, France
| | - Anna Stears
- National Severe Insulin Resistance Service, Wolfson Diabetes & Endocrine Clinic, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Stephen O’Rahilly
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
- National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
| | - David B Savage
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
- National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, UK
| | - Phillip Gorden
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Rebecca J Brown
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH), Bethesda, MD, USA
- Rebecca J. Brown, Building 10-CRC, Room 6-5942, 10 Center Drive, Bethesda, MD, USA 20892.
| | - Robert K Semple
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, UK
- Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
- Correspondence: Robert K. Semple, Centre for Cardiovascular Science, Queen’s Medical Research Institute, University of Edinburgh, 47 Little France Crescent, Edinburgh, UK EH16 4TJ.
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11
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Cataldi S, Costa V, Ciccodicola A, Aprile M. PPARγ and Diabetes: Beyond the Genome and Towards Personalized Medicine. Curr Diab Rep 2021; 21:18. [PMID: 33866450 DOI: 10.1007/s11892-021-01385-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/25/2021] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW Full and partial synthetic agonists targeting the transcription factor PPARγ are contained in FDA-approved insulin-sensitizing drugs and used for the treatment of metabolic syndrome-related dysfunctions. Here, we discuss the association between PPARG genetic variants and drug efficacy, as well as the role of alternative splicing and post-translational modifications as contributors to the complexity of PPARγ signaling and to the effects of synthetic PPARγ ligands. RECENT FINDINGS PPARγ regulates the transcription of several target genes governing adipocyte differentiation and glucose and lipid metabolism, as well as insulin sensitivity and inflammatory pathways. These pleiotropic functions confer great relevance to PPARγ in physiological regulation of whole-body metabolism, as well as in the etiology of metabolic disorders. Accordingly, PPARG gene mutations, nucleotide variations, and post-translational modifications have been associated with adipose tissue disorders and the related risk of insulin resistance and type 2 diabetes (T2D). Moreover, PPARγ alternative splicing isoforms-generating dominant-negative isoforms mainly expressed in human adipose tissue-have been related to impaired PPARγ activity and adipose tissue dysfunctions. Thus, multiple regulatory levels that contribute to PPARγ signaling complexity may account for the beneficial as well as adverse effects of PPARγ agonists. Further targeted analyses, taking into account all these aspects, are needed for better deciphering the role of PPARγ in human pathophysiology, especially in insulin resistance and T2D. The therapeutic potential of full and partial PPARγ synthetic agonists underlines the clinical significance of this nuclear receptor. PPARG mutations, polymorphisms, alternative splicing isoforms, and post-translational modifications may contribute to the pathogenesis of metabolic disorders, also influencing the responsiveness of pharmacological therapy. Therefore, in the context of the current evidence-based trend to personalized diabetes management, we highlight the need to decipher the intricate regulation of PPARγ signaling to pave the way to tailored therapies in patients with insulin resistance and T2D.
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Affiliation(s)
- Simona Cataldi
- Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", CNR, Via P. Castellino 111, 80131, Naples, Italy
| | - Valerio Costa
- Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", CNR, Via P. Castellino 111, 80131, Naples, Italy
| | - Alfredo Ciccodicola
- Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", CNR, Via P. Castellino 111, 80131, Naples, Italy.
- Department of Science and Technology, University of Naples "Parthenope", 80131, Naples, Italy.
| | - Marianna Aprile
- Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", CNR, Via P. Castellino 111, 80131, Naples, Italy
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12
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Stone SI, Wegner DJ, Wambach JA, Cole FS, Urano F, Ornitz DM. Digenic Variants in the FGF21 Signaling Pathway Associated with Severe Insulin Resistance and Pseudoacromegaly. J Endocr Soc 2020; 4:bvaa138. [PMID: 33210059 PMCID: PMC7653638 DOI: 10.1210/jendso/bvaa138] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022] Open
Abstract
Insulin-mediated pseudoacromegaly (IMPA) is a rare disease of unknown etiology. Here we report a 12-year-old female with acanthosis nigricans, hirsutism, and acromegalic features characteristic of IMPA. The subject was noted to have normal growth hormone secretion, with extremely elevated insulin levels. Studies were undertaken to determine a potential genetic etiology for IMPA. The proband and her family members underwent whole exome sequencing. Functional studies were undertaken to validate the pathogenicity of candidate variant alleles. Whole exome sequencing identified monoallelic, predicted deleterious variants in genes that mediate fibroblast growth factor 21 (FGF21) signaling, FGFR1 and KLB, which were inherited in trans from each parent. FGF21 has multiple metabolic functions but no known role in human insulin resistance syndromes. Analysis of the function of the FGFR1 and KLB variants in vitro showed greatly attenuated ERK phosphorylation in response to FGF21, but not FGF2, suggesting that these variants act synergistically to inhibit endocrine FGF21 signaling but not canonical FGF2 signaling. Therefore, digenic variants in FGFR1 and KLB provide a potential explanation for the subject's severe insulin resistance and may represent a novel category of insulin resistance syndromes related to FGF21.
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Affiliation(s)
- Stephen I Stone
- Department of Pediatrics, Division of Pediatric Endocrinology & Diabetes, Washington University School of Medicine, St. Louis, Missouri, US
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, US
| | - Daniel J Wegner
- Department of Pediatrics, Division of Newborn Medicine, Washington University School of Medicine, St. Louis, Missouri, US
| | - Jennifer A Wambach
- Department of Pediatrics, Division of Newborn Medicine, Washington University School of Medicine, St. Louis, Missouri, US
| | - F Sessions Cole
- Department of Pediatrics, Division of Newborn Medicine, Washington University School of Medicine, St. Louis, Missouri, US
| | - Fumihiko Urano
- Department of Medicine, Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, St. Louis, Missouri, US
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, US
| | - David M Ornitz
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, US
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13
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Randesi M, Levran O, van den Brink W, Blanken P, van Ree JM, Ott J, Kreek MJ. Further evidence for the association of GAL, GALR1 and NPY1R variants with opioid dependence. Pharmacogenomics 2020; 21:903-917. [PMID: 32757697 PMCID: PMC7487975 DOI: 10.2217/pgs-2020-0045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Aim: Heroin addiction is a chronic, relapsing disease that has genetic and environmental, including drug-induced, contributions. Stress influences the development of addictions. This study was conducted to determine if variants in stress-related genes are associated with opioid dependence (OD). Patients & methods: One hundred and twenty variants in 26 genes were analyzed in 597 Dutch subjects. Patients included 281 OD in methadone maintenance with or without heroin-assisted treatment and 316 controls. Results: Twelve SNPs in seven genes showed a nominally significant association with OD. Experiment-wise significant associations (p < 0.05) were found for three SNP pairs, through an interaction effect: NPY1R/GAL rs4691910/rs1893679, NPY1R/GAL rs4691910/rs3136541 and GALR1/GAL rs9807208/rs3136541. Conclusion: This study lends more evidence to previous reports of association of stress-related variants with heroin dependence.
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Affiliation(s)
- Matthew Randesi
- Laboratory of The Biology of Addictive Diseases, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA,Author for correspondence:
| | - Orna Levran
- Laboratory of The Biology of Addictive Diseases, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Wim van den Brink
- Department of Psychiatry, Amsterdam Institute for Addiction Research, Academic Medical Center, University of Amsterdam, PO Box 22660, 1100DD Amsterdam, The Netherlands
| | - Peter Blanken
- Parnassia Addiction Research Centre (Brijder Addiction Treatment), PO Box 53002, 2505 AA The Hague, The Netherlands
| | - Jan M van Ree
- Brain Center Rudolf Magnus, University Medical Center, Utrecht University, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
| | - Jurg Ott
- Laboratory of Statistical Genetics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Mary J Kreek
- Laboratory of The Biology of Addictive Diseases, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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14
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Ahn B, Wan S, Jaiswal N, Vega RB, Ayer DE, Titchenell PM, Han X, Won KJ, Kelly DP. MondoA drives muscle lipid accumulation and insulin resistance. JCI Insight 2019; 5:129119. [PMID: 31287806 PMCID: PMC6693825 DOI: 10.1172/jci.insight.129119] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 06/27/2019] [Indexed: 12/22/2022] Open
Abstract
Obesity-related insulin resistance is associated with intramyocellular lipid accumulation in skeletal muscle. We hypothesized that in contrast to current dogma, this linkage is related to an upstream mechanism that coordinately regulates both processes. We demonstrate that the muscle-enriched transcription factor MondoA is glucose/fructose responsive in human skeletal myotubes and directs the transcription of genes in cellular metabolic pathways involved in diversion of energy substrate from a catabolic fate into nutrient storage pathways including fatty acid desaturation and elongation, triacylglyeride (TAG) biosynthesis, glycogen storage, and hexosamine biosynthesis. MondoA also reduces myocyte glucose uptake by suppressing insulin signaling. Mice with muscle-specific MondoA deficiency were partially protected from insulin resistance and muscle TAG accumulation in the context of diet-induced obesity. These results identify MondoA as a nutrient-regulated transcription factor that under normal physiological conditions serves a dynamic checkpoint function to prevent excess energy substrate flux into muscle catabolic pathways when myocyte nutrient balance is positive. However, in conditions of chronic caloric excess, this mechanism becomes persistently activated leading to progressive myocyte lipid storage and insulin resistance.
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Affiliation(s)
| | - Shibiao Wan
- Institute for Diabetes, Obesity and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Natasha Jaiswal
- Institute for Diabetes, Obesity and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rick B. Vega
- Center for Metabolic Origins of Disease, Sanford Burnham Prebys Medical Discovery Institute at Lake Nona, Orlando, Florida, USA
| | - Donald E. Ayer
- Department of Oncological Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, USA
| | - Paul M. Titchenell
- Institute for Diabetes, Obesity and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies, Departments of Medicine and Biochemistry, University of Texas Health-San Antonio, San Antonio, Texas, USA
| | - Kyoung Jae Won
- Institute for Diabetes, Obesity and Metabolism, Department of Medicine, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, USA
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15
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Broekema M, Savage D, Monajemi H, Kalkhoven E. Gene-gene and gene-environment interactions in lipodystrophy: Lessons learned from natural PPARγ mutants. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:715-732. [DOI: 10.1016/j.bbalip.2019.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 01/13/2019] [Accepted: 02/02/2019] [Indexed: 12/13/2022]
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16
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Karpe F, Vasan SK, Humphreys SM, Miller J, Cheeseman J, Dennis AL, Neville MJ. Cohort Profile: The Oxford Biobank. Int J Epidemiol 2019; 47:21-21g. [PMID: 29040543 PMCID: PMC5837504 DOI: 10.1093/ije/dyx132] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2017] [Indexed: 11/18/2022] Open
Affiliation(s)
- Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford.,Oxford National Institute for Health Research, Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Senthil K Vasan
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford
| | - Sandy M Humphreys
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford.,Oxford National Institute for Health Research, Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - John Miller
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford.,Oxford National Institute for Health Research, Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Jane Cheeseman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford.,Oxford National Institute for Health Research, Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - A Louise Dennis
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford.,Oxford National Institute for Health Research, Biomedical Research Centre, Churchill Hospital, Oxford, UK
| | - Matt J Neville
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford.,Oxford National Institute for Health Research, Biomedical Research Centre, Churchill Hospital, Oxford, UK
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17
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Saul MC, Seward CH, Troy JM, Zhang H, Sloofman LG, Lu X, Weisner PA, Caetano-Anolles D, Sun H, Zhao SD, Chandrasekaran S, Sinha S, Stubbs L. Transcriptional regulatory dynamics drive coordinated metabolic and neural response to social challenge in mice. Genome Res 2017; 27:959-972. [PMID: 28356321 PMCID: PMC5453329 DOI: 10.1101/gr.214221.116] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 03/24/2017] [Indexed: 12/22/2022]
Abstract
Agonistic encounters are powerful effectors of future behavior, and the ability to learn from this type of social challenge is an essential adaptive trait. We recently identified a conserved transcriptional program defining the response to social challenge across animal species, highly enriched in transcription factor (TF), energy metabolism, and developmental signaling genes. To understand the trajectory of this program and to uncover the most important regulatory influences controlling this response, we integrated gene expression data with the chromatin landscape in the hypothalamus, frontal cortex, and amygdala of socially challenged mice over time. The expression data revealed a complex spatiotemporal patterning of events starting with neural signaling molecules in the frontal cortex and ending in the modulation of developmental factors in the amygdala and hypothalamus, underpinned by a systems-wide shift in expression of energy metabolism-related genes. The transcriptional signals were correlated with significant shifts in chromatin accessibility and a network of challenge-associated TFs. Among these, the conserved metabolic and developmental regulator ESRRA was highlighted for an especially early and important regulatory role. Cell-type deconvolution analysis attributed the differential metabolic and developmental signals in this social context primarily to oligodendrocytes and neurons, respectively, and we show that ESRRA is expressed in both cell types. Localizing ESRRA binding sites in cortical chromatin, we show that this nuclear receptor binds both differentially expressed energy-related and neurodevelopmental TF genes. These data link metabolic and neurodevelopmental signaling to social challenge, and identify key regulatory drivers of this process with unprecedented tissue and temporal resolution.
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Affiliation(s)
- Michael C Saul
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Christopher H Seward
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Joseph M Troy
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Illinois Informatics Institute, Urbana, Illinois 61801, USA
| | - Huimin Zhang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Laura G Sloofman
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Xiaochen Lu
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Patricia A Weisner
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Derek Caetano-Anolles
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Hao Sun
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sihai Dave Zhao
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Statistics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Sriram Chandrasekaran
- Harvard Society of Fellows, Harvard University, Cambridge, Massachusetts 02138, USA
- Faculty of Arts and Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA
| | - Saurabh Sinha
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Computer Science
- Department of Entomology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Lisa Stubbs
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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18
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Hivert MF, Scholtens DM, Allard C, Nodzenski M, Bouchard L, Brisson D, Lowe LP, McDowell I, Reddy T, Dastani Z, Richards JB, Hayes MG, Lowe WL. Genetic determinants of adiponectin regulation revealed by pregnancy. Obesity (Silver Spring) 2017; 25:935-944. [PMID: 28317342 PMCID: PMC5404994 DOI: 10.1002/oby.21805] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Revised: 12/25/2016] [Accepted: 01/18/2017] [Indexed: 11/10/2022]
Abstract
OBJECTIVE This study investigated genetic determinants of adiponectin during pregnancy to reveal novel biology of adipocyte regulation. METHODS A genome-wide association study was conducted in 1,322 pregnant women from the Hyperglycemia and Adverse Pregnancy Outcome Study with adiponectin measured at ∼28 weeks of gestation. Variants reaching P < 5×10-5 for de novo genotyping in two replication cohorts (Genetics of Glycemic regulation in Gestation and Growth N = 522; ECOGENE-21 N = 174) were selected. RESULTS In the combined meta-analysis, the maternal T allele of rs900400 located on chr3q25 (near LEKR1/CCNL1) was associated with lower maternal adiponectin (β ± standard error [SE] = -0.18 ± 0.03 standard deviation [SD] of adiponectin per risk allele; P = 1.5 ×10-8 ; N = 2,004; multivariable adjusted models). In contrast, rs900400 showed only nominal association with adiponectin in a large sample of nonpregnant women (β ± SE = -0.012 ± 0.006; P = 0.05; N = 16,678 women from the ADIPOgen consortium). The offspring rs900400 T risk allele was associated with greater neonatal skinfold thickness (β ±SE = 0.19 ± 0.04 SD per risk allele; P = 4.1×10-8 ; N = 1,489) and higher cord blood leptin (β ± SE = 0.28 ± 0.05 log-leptin per risk allele; P = 8.2 ×10-9 ; N = 502), but not with cord blood adiponectin (P = 0.23; N = 495). The T allele of rs900400 was associated with higher expression of TIPARP in adipocytes. CONCLUSIONS These investigations of adipokines during pregnancy and early life suggest that rs900400 has a role in adipocyte function.
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Affiliation(s)
- Marie-France Hivert
- Department of Population Medicine, Harvard Pilgrim Health Care Institute, Harvard Medical School, Boston, MA, USA
- Diabetes Unit, Massachusetts General Hospital, Boston, MA, USA
- Department of Medicine, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Denise M. Scholtens
- Department of Preventive Medicine, Division of Biostatistics, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Catherine Allard
- Department of Mathematics, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Michael Nodzenski
- Department of Preventive Medicine, Division of Biostatistics, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Luigi Bouchard
- Department of Biochemistry, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Diane Brisson
- Department of Medicine, Université de Montréal, ECOGENE-21 and Lipid Clinic, Chicoutimi, QC, Canada
| | - Lynn P. Lowe
- Department of Preventive Medicine, Division of Epidemiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Ian McDowell
- Department of Biostatistics and Bioinformatics, Duke Institute for Genome Sciences and Policy, Durham, NC, USA
| | - Tim Reddy
- Department of Biostatistics and Bioinformatics, Duke Institute for Genome Sciences and Policy, Durham, NC, USA
| | - Zari Dastani
- Department of Internal Medicine, Centre for Clinical Epidemiology, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC, Canada
| | - J. Brent Richards
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC, Canada
- Department of Twin Research, King’s College London, London, UK
| | - M. Geoffrey Hayes
- Division of Endocrinology, Metabolism and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - William L. Lowe
- Division of Endocrinology, Metabolism and Molecular Medicine, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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19
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Achermann JC, Schwabe J, Fairall L, Chatterjee K. Genetic disorders of nuclear receptors. J Clin Invest 2017; 127:1181-1192. [PMID: 28368288 DOI: 10.1172/jci88892] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Following the first isolation of nuclear receptor (NR) genes, genetic disorders caused by NR gene mutations were initially discovered by a candidate gene approach based on their known roles in endocrine pathways and physiologic processes. Subsequently, the identification of disorders has been informed by phenotypes associated with gene disruption in animal models or by genetic linkage studies. More recently, whole exome sequencing has associated pathogenic genetic variants with unexpected, often multisystem, human phenotypes. To date, defects in 20 of 48 human NR genes have been associated with human disorders, with different mutations mediating phenotypes of varying severity or several distinct conditions being associated with different changes in the same gene. Studies of individuals with deleterious genetic variants can elucidate novel roles of human NRs, validating them as targets for drug development or providing new insights into structure-function relationships. Importantly, human genetic discoveries enable definitive disease diagnosis and can provide opportunities to therapeutically manage affected individuals. Here we review germline changes in human NR genes associated with "monogenic" conditions, including a discussion of the structural basis of mutations that cause distinctive changes in NR function and the molecular mechanisms mediating pathogenesis.
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20
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Pulit SL, Karaderi T, Lindgren CM. Sexual dimorphisms in genetic loci linked to body fat distribution. Biosci Rep 2017; 37:BSR20160184. [PMID: 28073971 PMCID: PMC5291139 DOI: 10.1042/bsr20160184] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/07/2017] [Accepted: 01/10/2017] [Indexed: 01/02/2023] Open
Abstract
Obesity is a chronic condition associated with increased morbidity and mortality and is a risk factor for a number of other diseases including type 2 diabetes and cardiovascular disease. Obesity confers an enormous, costly burden on both individuals and public health more broadly. Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes. Body fat distribution is distinct from overall obesity in measurement, but studies of body fat distribution can yield insights into the risk factors for and causes of overall obesity. Sexual dimorphism in body fat distribution is present throughout life. Though sexual dimorphism is subtle in early stages of life, it is attenuated in puberty and during menopause. This phenomenon could be, at least in part, due to the influence of sex hormones on the trait. Findings from recent large genome-wide association studies (GWAS) for various measures of body fat distribution (including waist-to-hip ratio, hip or waist circumference, trunk fat percentage and the ratio of android and gynoid fat percentage) emphasize the strong sexual dimorphism in the genetic regulation of fat distribution traits. Importantly, sexual dimorphism is not observed for overall obesity (as assessed by body mass index or total fat percentage). Notably, the genetic loci associated with body fat distribution, which show sexual dimorphism, are located near genes that are expressed in adipose tissues and/or adipose cells. Considering the epidemiological and genetic evidence, sexual dimorphism is a prominent feature of body fat distribution. Research that specifically focuses on sexual dimorphism in fat distribution can provide novel insights into human physiology and into the development of obesity and its comorbidities, as well as yield biological clues that will aid in the improvement of disease prevention and treatment.
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Affiliation(s)
- Sara L Pulit
- Department of Neurology, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Tugce Karaderi
- Department of Biological Sciences, Faculty of Arts and Sciences, Eastern Mediterranean University, Famagusta, Cyprus
| | - Cecilia M Lindgren
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, U.K.
- Wellcome Trust Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, U.K
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21
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Wafer R, Tandon P, Minchin JEN. The Role of Peroxisome Proliferator-Activated Receptor Gamma ( PPARG) in Adipogenesis: Applying Knowledge from the Fish Aquaculture Industry to Biomedical Research. Front Endocrinol (Lausanne) 2017; 8:102. [PMID: 28588550 PMCID: PMC5438977 DOI: 10.3389/fendo.2017.00102] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 05/01/2017] [Indexed: 12/13/2022] Open
Abstract
The tropical freshwater zebrafish has recently emerged as a valuable model organism for the study of adipose tissue biology and obesity-related disease. The strengths of the zebrafish model system are its wealth of genetic mutants, transgenic tools, and amenability to high-resolution imaging of cell dynamics within live animals. However, zebrafish adipose research is at a nascent stage and many gaps exist in our understanding of zebrafish adipose physiology and metabolism. By contrast, adipose research within other, closely related, teleost species has a rich and extensive history, owing to the economic importance of these fish as a food source. Here, we compare and contrast knowledge on peroxisome proliferator-activated receptor gamma (PPARG)-mediated adipogenesis derived from both biomedical and aquaculture literatures. We first concentrate on the biomedical literature to (i) briefly review PPARG-mediated adipogenesis in mammals, before (ii) reviewing Pparg-mediated adipogenesis in zebrafish. Finally, we (iii) mine the aquaculture literature to compare and contrast Pparg-mediated adipogenesis in aquaculturally relevant teleosts. Our goal is to highlight evolutionary similarities and differences in adipose biology that will inform our understanding of the role of adipose tissue in obesity and related disease.
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Affiliation(s)
- Rebecca Wafer
- BHF Centre for Cardiovascular Science, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Panna Tandon
- BHF Centre for Cardiovascular Science, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - James E. N. Minchin
- BHF Centre for Cardiovascular Science, The Queen’s Medical Research Institute, University of Edinburgh, Edinburgh, UK
- *Correspondence: James E. N. Minchin,
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22
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Rank L, Veith S, Gwosch EC, Demgenski J, Ganz M, Jongmans MC, Vogel C, Fischbach A, Buerger S, Fischer JMF, Zubel T, Stier A, Renner C, Schmalz M, Beneke S, Groettrup M, Kuiper RP, Bürkle A, Ferrando-May E, Mangerich A. Analyzing structure-function relationships of artificial and cancer-associated PARP1 variants by reconstituting TALEN-generated HeLa PARP1 knock-out cells. Nucleic Acids Res 2016; 44:10386-10405. [PMID: 27694308 PMCID: PMC5137445 DOI: 10.1093/nar/gkw859] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 09/05/2016] [Accepted: 09/16/2016] [Indexed: 12/17/2022] Open
Abstract
Genotoxic stress activates PARP1, resulting in the post-translational modification of proteins with poly(ADP-ribose) (PAR). We genetically deleted PARP1 in one of the most widely used human cell systems, i.e. HeLa cells, via TALEN-mediated gene targeting. After comprehensive characterization of these cells during genotoxic stress, we analyzed structure–function relationships of PARP1 by reconstituting PARP1 KO cells with a series of PARP1 variants. Firstly, we verified that the PARP1\E988K mutant exhibits mono-ADP-ribosylation activity and we demonstrate that the PARP1\L713F mutant is constitutively active in cells. Secondly, both mutants exhibit distinct recruitment kinetics to sites of laser-induced DNA damage, which can potentially be attributed to non-covalent PARP1–PAR interaction via several PAR binding motifs. Thirdly, both mutants had distinct functional consequences in cellular patho-physiology, i.e. PARP1\L713F expression triggered apoptosis, whereas PARP1\E988K reconstitution caused a DNA-damage-induced G2 arrest. Importantly, both effects could be rescued by PARP inhibitor treatment, indicating distinct cellular consequences of constitutive PARylation and mono(ADP-ribosyl)ation. Finally, we demonstrate that the cancer-associated PARP1 SNP variant (V762A) as well as a newly identified inherited PARP1 mutation (F304L\V762A) present in a patient with pediatric colorectal carcinoma exhibit altered biochemical and cellular properties, thereby potentially supporting human carcinogenesis. Together, we establish a novel cellular model for PARylation research, by revealing strong structure–function relationships of natural and artificial PARP1 variants.
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Affiliation(s)
- Lisa Rank
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Sebastian Veith
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.,Research Training Group 1331, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Eva C Gwosch
- Bioimaging Center, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Janine Demgenski
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Magdalena Ganz
- Bioimaging Center, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Marjolijn C Jongmans
- Department of Human Genetics, Radboud University Medical Center Nijmegen, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands.,Department of Medical Genetics, University Medical Center Utrecht, Utrecht, The Netherland
| | - Christopher Vogel
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Arthur Fischbach
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Stefanie Buerger
- FlowKon FACS Facility, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Jan M F Fischer
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Tabea Zubel
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.,Konstanz Research School Chemical Biology, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Anna Stier
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Christina Renner
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Michael Schmalz
- Center of Applied Photonics, Department of Physics, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Sascha Beneke
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.,Ecotoxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Marcus Groettrup
- FlowKon FACS Facility, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany.,Immunology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Roland P Kuiper
- Department of Human Genetics, Radboud University Medical Center Nijmegen, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Alexander Bürkle
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Elisa Ferrando-May
- Bioimaging Center, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
| | - Aswin Mangerich
- Molecular Toxicology Group, Department of Biology, University of Konstanz, D-78457 Konstanz, Germany
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23
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Goldsworthy M, Bai Y, Li CM, Ge H, Lamas E, Hilton H, Esapa CT, Baker D, Baron W, Juan T, Véniant MM, Lloyd DJ, Cox RD. Haploinsufficiency of the Insulin Receptor in the Presence of a Splice-Site Mutation in Ppp2r2a Results in a Novel Digenic Mouse Model of Type 2 Diabetes. Diabetes 2016; 65:1434-46. [PMID: 26868295 PMCID: PMC5947768 DOI: 10.2337/db15-1276] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 02/07/2016] [Indexed: 12/16/2022]
Abstract
Insulin resistance in mice typically does not manifest as diabetes due to multiple compensatory mechanisms. Here, we present a novel digenic model of type 2 diabetes in mice heterozygous for a null allele of the insulin receptor and an N-ethyl-N-nitrosourea-induced alternative splice mutation in the regulatory protein phosphatase 2A (PP2A) subunit PPP2R2A. Inheritance of either allele independently results in insulin resistance but not overt diabetes. Doubly heterozygous mice exhibit progressive hyperglycemia, hyperinsulinemia, and impaired glucose tolerance from 12 weeks of age without significant increase in body weight. Alternative splicing of Ppp2r2a decreased PPP2R2A protein levels. This reduction in PPP2R2A containing PP2A phosphatase holoenzyme was associated with decreased serine/threonine protein kinase AKT protein levels. Ultimately, reduced insulin-stimulated phosphorylated AKT levels were observed, a result that was confirmed in Hepa1-6, C2C12, and differentiated 3T3-L1 cells knocked down using Ppp2r2a small interfering RNAs. Altered AKT signaling and expression of gluconeogenic genes in the fed state contributed to an insulin resistance and hyperglycemia phenotype. This model demonstrates how genetic changes with individually small phenotypic effects interact to cause diabetes and how differences in expression of hypomorphic alleles of PPP2R2A and potentially other regulatory proteins have deleterious effects and may therefore be relevant in determining diabetes risk.
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Affiliation(s)
| | - Ying Bai
- Diabetes Group, Medical Research Council Harwell, Oxfordshire, U.K
| | - Chi-Ming Li
- Genome Analysis Unit, Amgen Inc., Thousand Oaks, CA
| | - Huanying Ge
- Genome Analysis Unit, Amgen Inc., Thousand Oaks, CA
| | - Edwin Lamas
- Genome Analysis Unit, Amgen Inc., Thousand Oaks, CA
| | - Helen Hilton
- Protein Core Facility, Medical Research Council Harwell, Oxfordshire, U.K
| | | | - Dan Baker
- Genome Analysis Unit, Amgen Inc., Thousand Oaks, CA
| | - Will Baron
- Genome Analysis Unit, Amgen Inc., Thousand Oaks, CA
| | - Todd Juan
- Genome Analysis Unit, Amgen Inc., Thousand Oaks, CA
| | | | - David J Lloyd
- Department of Metabolic Disorders, Amgen Inc., Thousand Oaks, CA
| | - Roger D Cox
- Diabetes Group, Medical Research Council Harwell, Oxfordshire, U.K.
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24
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Li A, Meyre D. Jumping on the Train of Personalized Medicine: A Primer for Non-Geneticist Clinicians: Part 2. Fundamental Concepts in Genetic Epidemiology. ACTA ACUST UNITED AC 2014; 10:101-117. [PMID: 25598767 PMCID: PMC4287874 DOI: 10.2174/1573400510666140319235334] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 02/07/2014] [Accepted: 04/18/2014] [Indexed: 12/12/2022]
Abstract
With the decrease in sequencing costs, personalized genome sequencing will eventually become common in medical practice. We therefore write this series of three reviews to help non-geneticist clinicians to jump into the fast-moving field of personalized medicine. In the first article of this series, we reviewed the fundamental concepts in molecular genetics. In this second article, we cover the key concepts and methods in genetic epidemiology including the classification of genetic disorders, study designs and their implementation, genetic marker selection, genotyping and sequencing technologies, gene identification strategies, data analyses and data interpretation. This review will help the reader critically appraise a genetic association study. In the next article, we will discuss the clinical applications of genetic epidemiology in the personalized medicine area.
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Affiliation(s)
- Aihua Li
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON L8N 3Z5, Canada
| | - David Meyre
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON L8N 3Z5, Canada
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25
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Anguria P, Kitinya J, Ntuli S, Carmichael T. The role of heredity in pterygium development. Int J Ophthalmol 2014; 7:563-73. [PMID: 24967209 DOI: 10.3980/j.issn.2222-3959.2014.03.31] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 03/01/2014] [Indexed: 11/02/2022] Open
Abstract
Several risk factors, which include heredity, ultra-violet (UV) light and chronic inflammation, contribute to pterygium development. However, there is no report integrating these factors in the pathogenesis of pterygium. The aim of this review is to describe the connection between heredity, UV, and inflammation in pterygium development. Existing reports indicate that sunlight exposure is the main factor in pterygium occurrence by inducing growth factor production or chronic inflammation or DNA damage. Heredity may be a factor. Our studies on factors in pterygium occurrence and recurrence identify that heredity is crucial for pterygium to develop, and that sunlight is only a trigger, and that chronic inflammation promotes pterygium enlargement. We propose that genetic factors may interfere with the control of fibrovascular proliferation while UV light or (sunlight) most likely only triggers pterygium development by inducing growth factors which promote vibrant fibrovascular proliferation in predisposed individuals. It also just triggers inflammation and collagenolysis, which may be promoters of the enlargement of the fibrovascular mass. Pterygium probably occurs in the presence of exuberant collagen production and profuse neovascularisation.
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Affiliation(s)
- Peter Anguria
- Department of Neurosciences, Division of Ophthalmology, University of the Witwatersrand Johannesburg, 7 York Road, Park Town 2193, South Africa
| | - James Kitinya
- Department of Anatomic Pathology, University of Limpopo Polokwane Campus, Private Bag X9316 Polokwane 0700, South Africa
| | - Sam Ntuli
- Department of Public Health Medicine, University of Limpopo Polokwane Campus, Private Bag X9316 Polokwane 0700, South Africa
| | - Trevor Carmichael
- Department of Neurosciences, Division of Ophthalmology, University of the Witwatersrand Johannesburg, 7 York Road, Park Town 2193, South Africa
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26
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Sobrino Crespo C, Perianes Cachero A, Puebla Jiménez L, Barrios V, Arilla Ferreiro E. Peptides and food intake. Front Endocrinol (Lausanne) 2014; 5:58. [PMID: 24795698 PMCID: PMC4005944 DOI: 10.3389/fendo.2014.00058] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 04/09/2014] [Indexed: 12/19/2022] Open
Abstract
The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food intake, whereas the other subpopulation coexpresses pro-opiomelanocortin (POMC) and cocaine and amphetamine-regulated transcript that inhibits food intake. AgRP antagonizes the effects of the POMC product, α-melanocyte-stimulating hormone (α-MSH). Both populations project to areas important in the regulation of food intake, including the hypothalamic paraventricular nucleus, which also receives important inputs from other hypothalamic nuclei.
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Affiliation(s)
- Carmen Sobrino Crespo
- Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Spain
| | - Aránzazu Perianes Cachero
- Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Spain
| | - Lilian Puebla Jiménez
- Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Spain
| | - Vicente Barrios
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Eduardo Arilla Ferreiro
- Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Spain
- *Correspondence: Eduardo Arilla Ferreiro, Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Madrid E-28871, Spain e-mail:
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27
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Vafiadaki E, Arvanitis DA, Sanoudou D, Kranias EG. Identification of a protein phosphatase-1/phospholamban complex that is regulated by cAMP-dependent phosphorylation. PLoS One 2013; 8:e80867. [PMID: 24244723 PMCID: PMC3828283 DOI: 10.1371/journal.pone.0080867] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 10/17/2013] [Indexed: 11/19/2022] Open
Abstract
In human and experimental heart failure, the activity of the type 1 phosphatase is significantly increased, associated with dephosphorylation of phospholamban, inhibition of the sarco(endo)plasmic reticulum Ca2+ transport ATPase (SERCA2a) and depressed function. In the current study, we investigated the molecular mechanisms controlling protein phosphatase-1 activity. Using recombinant proteins and complementary in vitro binding studies, we identified a multi-protein complex centered on protein phosphatase-1 that includes its muscle specific glycogen-targeting subunit GM and substrate phospholamban. GM interacts directly with phospholamban and this association is mediated by the cytosolic regions of the proteins. Our findings suggest the involvement of GM in mediating formation of the phosphatase-1/GM/phospholamban complex through the direct and independent interactions of GM with both protein phosphatase-1 and phospholamban. Importantly, the protein phosphatase-1/GM/phospholamban complex dissociates upon protein kinase A phosphorylation, indicating its significance in the β-adrenergic signalling axis. Moreover, protein phosphatase-1 activity is regulated by two binding partners, inhibitor-1 and the small heat shock protein 20, Hsp20. Indeed, human genetic variants of inhibitor-1 (G147D) or Hsp20 (P20L) result in reduced binding and inhibition of protein phosphatase-1, suggesting aberrant enzymatic regulation in human carriers. These findings provide insights into the mechanisms underlying fine-tuned regulation of protein phosphatase-1 and its impact on the SERCA2/phospholamban interactome in cardiac function.
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Affiliation(s)
- Elizabeth Vafiadaki
- Molecular Biology Division, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Demetrios A. Arvanitis
- Molecular Biology Division, Biomedical Research Foundation, Academy of Athens, Athens, Greece
| | - Despina Sanoudou
- Molecular Biology Division, Biomedical Research Foundation, Academy of Athens, Athens, Greece
- Department of Pharmacology, Medical School, University of Athens, Greece
| | - Evangelia G. Kranias
- Molecular Biology Division, Biomedical Research Foundation, Academy of Athens, Athens, Greece
- Department of Pharmacology and Cell Biophysics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
- * E-mail:
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Cooper DN, Krawczak M, Polychronakos C, Tyler-Smith C, Kehrer-Sawatzki H. Where genotype is not predictive of phenotype: towards an understanding of the molecular basis of reduced penetrance in human inherited disease. Hum Genet 2013; 132:1077-130. [PMID: 23820649 PMCID: PMC3778950 DOI: 10.1007/s00439-013-1331-2] [Citation(s) in RCA: 423] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 06/15/2013] [Indexed: 02/06/2023]
Abstract
Some individuals with a particular disease-causing mutation or genotype fail to express most if not all features of the disease in question, a phenomenon that is known as 'reduced (or incomplete) penetrance'. Reduced penetrance is not uncommon; indeed, there are many known examples of 'disease-causing mutations' that fail to cause disease in at least a proportion of the individuals who carry them. Reduced penetrance may therefore explain not only why genetic diseases are occasionally transmitted through unaffected parents, but also why healthy individuals can harbour quite large numbers of potentially disadvantageous variants in their genomes without suffering any obvious ill effects. Reduced penetrance can be a function of the specific mutation(s) involved or of allele dosage. It may also result from differential allelic expression, copy number variation or the modulating influence of additional genetic variants in cis or in trans. The penetrance of some pathogenic genotypes is known to be age- and/or sex-dependent. Variable penetrance may also reflect the action of unlinked modifier genes, epigenetic changes or environmental factors. At least in some cases, complete penetrance appears to require the presence of one or more genetic variants at other loci. In this review, we summarize the evidence for reduced penetrance being a widespread phenomenon in human genetics and explore some of the molecular mechanisms that may help to explain this enigmatic characteristic of human inherited disease.
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Affiliation(s)
- David N. Cooper
- Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, CF14 4XN UK
| | - Michael Krawczak
- Institute of Medical Informatics and Statistics, Christian-Albrechts University, 24105 Kiel, Germany
| | | | - Chris Tyler-Smith
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK
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Abstract
Digenic inheritance (DI) is the simplest form of inheritance for genetically complex diseases. By contrast with the thousands of reports that mutations in single genes cause human diseases, there are only dozens of human disease phenotypes with evidence for DI in some pedigrees. The advent of high-throughput sequencing (HTS) has made it simpler to identify monogenic disease causes and could similarly simplify proving DI because one can simultaneously find mutations in two genes in the same sample. However, through 2012, I could find only one example of human DI in which HTS was used; in that example, HTS found only the second of the two genes. To explore the gap between expectation and reality, I tried to collect all examples of human DI with a narrow definition and characterise them according to the types of evidence collected, and whether there has been replication. Two strong trends are that knowledge of candidate genes and knowledge of protein–protein interactions (PPIs) have been helpful in most published examples of human DI. By contrast, the positional method of genetic linkage analysis, has been mostly unsuccessful in identifying genes underlying human DI. Based on the empirical data, I suggest that combining HTS with growing networks of established PPIs may expedite future discoveries of human DI and strengthen the evidence for them.
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Snyder EE, Walts B, Pérusse L, Chagnon YC, Weisnagel SJ, Rankinen T, Bouchard C. The Human Obesity Gene Map: The 2003 Update. ACTA ACUST UNITED AC 2012; 12:369-439. [PMID: 15044658 DOI: 10.1038/oby.2004.47] [Citation(s) in RCA: 207] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This is the tenth update of the human obesity gene map, incorporating published results up to the end of October 2003 and continuing the previous format. Evidence from single-gene mutation obesity cases, Mendelian disorders exhibiting obesity as a clinical feature, quantitative trait loci (QTLs) from human genome-wide scans and animal crossbreeding experiments, and association and linkage studies with candidate genes and other markers is reviewed. Transgenic and knockout murine models relevant to obesity are also incorporated (N = 55). As of October 2003, 41 Mendelian syndromes relevant to human obesity have been mapped to a genomic region, and causal genes or strong candidates have been identified for most of these syndromes. QTLs reported from animal models currently number 183. There are 208 human QTLs for obesity phenotypes from genome-wide scans and candidate regions in targeted studies. A total of 35 genomic regions harbor QTLs replicated among two to five studies. Attempts to relate DNA sequence variation in specific genes to obesity phenotypes continue to grow, with 272 studies reporting positive associations with 90 candidate genes. Fifteen such candidate genes are supported by at least five positive studies. The obesity gene map shows putative loci on all chromosomes except Y. Overall, more than 430 genes, markers, and chromosomal regions have been associated or linked with human obesity phenotypes. The electronic version of the map with links to useful sites can be found at http://obesitygene.pbrc.edu.
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Affiliation(s)
- Eric E Snyder
- Human Genomics Laboratory, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana 70808-4124, USA
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Rice GM, Raca G, Jakielski KJ, Laffin JJ, Iyama-Kurtycz CM, Hartley SL, Sprague RE, Heintzelman AT, Shriberg LD. Phenotype of FOXP2 haploinsufficiency in a mother and son. Am J Med Genet A 2011; 158A:174-81. [PMID: 22106036 DOI: 10.1002/ajmg.a.34354] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Accepted: 09/22/2011] [Indexed: 12/18/2022]
Abstract
Disruptions in FOXP2, a transcription factor, are the only known monogenic cause of speech and language impairment. We report on clinical findings for two new individuals with a submicroscopic deletion of FOXP2: a boy with severe apraxia of speech and his currently moderately affected mother. A 1.57 Mb deletion on chromosome 7q31 was detected by array comparative genomic hybridization (aCGH). In addition to FOXP2, the patients' deletion involves two other genes, MDFIC and PPP1R3A, neither of which has been associated with speech or language disorders. Thus, findings for these two family members provide informative phenotypic information on FOXP2 haploinsufficiency. Evaluation by a clinical geneticist indicated no major congenital anomalies or dysmorphic features. Evaluations by a clinical psychologist and occupational therapist indicated cognitive-linguistic processing and sensorimotor control deficits, but did not support a diagnosis of autism spectrum disorder. Evaluation by clinical and research speech pathologists confirmed that both patients' speech deficits met contemporary criteria for apraxia of speech. Notably, the patients were not able to laugh, cough, or sneeze spontaneously, replicating findings reported for two other FOXP2 cases and a potential diagnostic sign of nonsyndromic apraxia of speech. Speech severity findings for the boy were not consistent with the hypothesis that loss of maternal FOXP2 should be relatively benign. Better understanding of the behavioral phenotype of FOXP2 disruptions will aid identification of patients, toward an eventual understanding of the pathophysiology of syndromic and nonsyndromic apraxia of speech.
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Semple RK, Savage DB, Cochran EK, Gorden P, O'Rahilly S. Genetic syndromes of severe insulin resistance. Endocr Rev 2011; 32:498-514. [PMID: 21536711 DOI: 10.1210/er.2010-0020] [Citation(s) in RCA: 217] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Insulin resistance is among the most prevalent endocrine derangements in the world, and it is closely associated with major diseases of global reach including diabetes mellitus, atherosclerosis, nonalcoholic fatty liver disease, and ovulatory dysfunction. It is most commonly found in those with obesity but may also occur in an unusually severe form in rare patients with monogenic defects. Such patients may loosely be grouped into those with primary disorders of insulin signaling and those with defects in adipose tissue development or function (lipodystrophy). The severe insulin resistance of both subgroups puts patients at risk of accelerated complications and poses severe challenges in clinical management. However, the clinical disorders produced by different genetic defects are often biochemically and clinically distinct and are associated with distinct risks of complications. This means that optimal management of affected patients should take into account the specific natural history of each condition. In clinical practice, they are often underdiagnosed, however, with low rates of identification of the underlying genetic defect, a problem compounded by confusing and overlapping nomenclature and classification. We now review recent developments in understanding of genetic forms of severe insulin resistance and/or lipodystrophy and suggest a revised classification based on growing knowledge of the underlying pathophysiology.
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Affiliation(s)
- Robert K Semple
- Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom.
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Gurnell M. 'Striking the Right Balance' in Targeting PPARgamma in the Metabolic Syndrome: Novel Insights from Human Genetic Studies. PPAR Res 2011; 2007:83593. [PMID: 17389771 PMCID: PMC1847466 DOI: 10.1155/2007/83593] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2006] [Revised: 12/13/2006] [Accepted: 12/13/2006] [Indexed: 12/03/2022] Open
Abstract
At a time when the twin epidemics of obesity and type 2 diabetes threaten to engulf even the most well-resourced Western healthcare systems, the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) has emerged as a
bona fide therapeutic target for treating human metabolic disease. The novel insulin-sensitizing antidiabetic thiazolidinediones (TZDs, e.g., rosiglitazone, pioglitazone), which are licensed for use in the treatment of type 2 diabetes, are high-affinity PPARγ ligands, whose beneficial effects extend beyond improvement in glycaemic control to include amelioration of dyslipidaemia, lowering of blood pressure, and favourable modulation of macrophage lipid handling and inflammatory responses. However, a major drawback to the clinical use of exisiting TZDs is weight gain, reflecting both enhanced adipogenesis and fluid retention, neither of which is desirable in a population that is already overweight and prone to cardiovascular disease. Accordingly, the “search is on” to identify the next generation of PPARγ modulators that will promote maximal clinical benefit by targeting specific facets of the metabolic syndrome (glucose intolerance/diabetes, dyslipidaemia, and hypertension), while simultaneously avoiding undesirable side effects of PPARγ activation (e.g., weight gain). This paper outlines the important clinical and laboratory observations made in human subjects harboring genetic variations in PPARγ that support such a therapeutic strategy.
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Affiliation(s)
- Mark Gurnell
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK
- *Mark Gurnell:
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Barak Y, Kim S. Genetic manipulations of PPARs: effects on obesity and metabolic disease. PPAR Res 2011; 2007:12781. [PMID: 17389768 PMCID: PMC1791068 DOI: 10.1155/2007/12781] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 11/10/2006] [Accepted: 11/16/2006] [Indexed: 12/18/2022] Open
Abstract
The interest in genetic manipulations of PPARs is as old as their discovery as receptors of ligands with beneficial clinical activities. Considering the effects of PPAR ligands on critical aspects of systemic physiology, including obesity, lipid metabolism, insulin resistance, and diabetes, gene knockout (KO) in mice is the ideal platform for both hypothesis testing and discovery of new PPAR functions in vivo. With the fervent pursuit of the magic bullet to eradicate the obesity epidemic, special emphasis has been placed on the impacts of PPARs on obesity and its associated diseases. As detailed in this review, understanding how PPARs regulate gene expression and basic metabolic pathways is a necessary intermediate en route to deciphering their effects on obesity. Over a decade and dozens of genetic modifications of PPARs into this effort, valuable lessons have been learned, but we are left with more questions to be answered. These lessons and future prospects are the subject of this review.
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Affiliation(s)
- Yaacov Barak
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
- *Yaacov Barak:
| | - Suyeon Kim
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
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35
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[Paediatric obesities: from childhood to adolescence]. An Pediatr (Barc) 2011; 75:63.e1-23. [PMID: 21602112 DOI: 10.1016/j.anpedi.2011.03.018] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 03/22/2011] [Indexed: 12/14/2022] Open
Abstract
Obesity, as in every western country, is currently the most prevalent chronic disease in childhood in Spain. This has led to obesity being one of the most common consultations in general paediatrics and, particularly, in paediatric endocrinology. Furthermore, obesity associated comorbidities are increasing in prevalence in children and adolescents. It is widely accepted that this increase in the prevalence of obesity is derived from an imbalance between energy intake and expenditure, associated to the lifestyle in western countries. However, there is increasing evidence of the role of individual and familial genetic background in the risk of developing obesity. The pathophysiological basis of the mechanisms responsible for the control of appetite and energy expenditure are being discovered on the basis of the increasing known cases of human monogenic, syndromic and endocrine obesity. Thus it is no longer appropriate to talk about obesity but rather about «obesities», as their pathophysiological bases differ and they require different diagnostic and management approaches. In 2011, the paediatrician must be aware of this issue and focus the clinical history and physical examination towards these specific clinical sign and symptoms, to better manage the available diagnostic and therapeutic resources when faced with a child with obesity.
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Costa V, Gallo MA, Letizia F, Aprile M, Casamassimi A, Ciccodicola A. PPARG: Gene Expression Regulation and Next-Generation Sequencing for Unsolved Issues. PPAR Res 2010; 2010:409168. [PMID: 20871817 PMCID: PMC2943117 DOI: 10.1155/2010/409168] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Accepted: 07/08/2010] [Indexed: 01/01/2023] Open
Abstract
Peroxisome proliferator-activated receptor gamma (PPARγ) is one of the most extensively studied ligand-inducible transcription factors (TFs), able to modulate its transcriptional activity through conformational changes. It is of particular interest because of its pleiotropic functions: it plays a crucial role in the expression of key genes involved in adipogenesis, lipid and glucid metabolism, atherosclerosis, inflammation, and cancer. Its protein isoforms, the wide number of PPARγ target genes, ligands, and coregulators contribute to determine the complexity of its function. In addition, the presence of genetic variants is likely to affect expression levels of target genes although the impact of PPARG gene variations on the expression of target genes is not fully understood. The introduction of massively parallel sequencing platforms-in the Next Generation Sequencing (NGS) era-has revolutionized the way of investigating the genetic causes of inherited diseases. In this context, DNA-Seq for identifying-within both coding and regulatory regions of PPARG gene-novel nucleotide variations and haplotypes associated to human diseases, ChIP-Seq for defining a PPARγ binding map, and RNA-Seq for unraveling the wide and intricate gene pathways regulated by PPARG, represent incredible steps toward the understanding of PPARγ in health and disease.
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Affiliation(s)
- Valerio Costa
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
| | | | - Francesca Letizia
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
| | - Marianna Aprile
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
| | - Amelia Casamassimi
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
- Department of General Pathology, 1st School of Medicine, Second University of Naples, 80138 Naples, Italy
| | - Alfredo Ciccodicola
- Institute of Genetics and Biophysics “Adriano Buzzati-Traverso” (IGB), CNR, 80131 Naples, Italy
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Bennett CE, Nsengimana J, Bostock JA, Cymbalista C, Futers TS, Knight BL, McCormack LJ, Prasad UK, Riches K, Rolton D, Scarrott T, Barrett JH, Carter AM. CCAAT/enhancer binding protein alpha, beta and delta gene variants: associations with obesity related phenotypes in the Leeds Family Study. Diab Vasc Dis Res 2010; 7:195-203. [PMID: 20460359 DOI: 10.1177/1479164110366274] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
OBJECTIVE To identify novel polymorphisms in the genes encoding the transcription factors CCAAT/enhancer binding protein alpha, beta and delta ( CEBPA, CEBPB, CEBPD) and investigate associations between polymorphisms and obesity-related phenotypes. METHODS Denaturing high-performance liquid chromatography (HPLC) was used to screen for novel gene variants and polymorphisms were genotyped in stored DNA from participants of the Leeds Family Study (537 subjects from 89 families). Genotype and haplotype analyses were carried out in STATA and PBAT, respectively. RESULTS Twenty-five polymorphisms were identified; 11 in CEBPA, 12 in CEBPB and 2 in CEBPD. Several allelic variants were associated at a nominal 5% level with waist-to-hip ratio (-919G>A in CEBPA, -412G>T and 646C>T in CEBPB), leptin (1558G>A in CEBPA, -1051A>G and 1383T>- in CEBPB) and adiponectin (1382G>T and 1903G>T in CEBPB). Effects of CEBPA and CEBPB allelic variants were independent, but variants within each gene were in linkage disequilibrium. Several associations were observed between other obesity-related traits and allelic variants in CEBPA and CEBPB, but not CEBPD. CONCLUSION These findings suggest that common allelic variants in CEBPA and CEBPB could influence abdominal obesity and related metabolic abnormalities associated with type 2 diabetes and cardiovascular disease in healthy White Northern European families, although results require independent confirmation.
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Affiliation(s)
- Claire E Bennett
- Division of Cardiovascular and Diabetes Research, Leeds Institute of Genetics, Health and Therapeutics, University of Leeds, UK
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Castañeda TR, Tong J, Datta R, Culler M, Tschöp MH. Ghrelin in the regulation of body weight and metabolism. Front Neuroendocrinol 2010; 31:44-60. [PMID: 19896496 DOI: 10.1016/j.yfrne.2009.10.008] [Citation(s) in RCA: 243] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2009] [Revised: 10/26/2009] [Accepted: 10/26/2009] [Indexed: 12/25/2022]
Abstract
Ghrelin, a peptide hormone predominantly produced by the stomach, was isolated as the endogenous ligand for the growth hormone secretagogue receptor. Ghrelin is a potent stimulator of growth hormone (GH) secretion and is the only circulatory hormone known to potently enhance feeding and weight gain and to regulate energy homeostasis following central and systemic administration. Therapeutic intervention with ghrelin in catabolic situations may induce a combination of enhanced food intake, increased gastric emptying and nutrient storage, coupled with an increase in GH thereby linking nutrient partitioning with growth and repair processes. These qualities have fostered the idea that ghrelin-based compounds may have therapeutic utility in treating malnutrition and wasting induced by various sub-acute and chronic disorders. Conversely, compounds that inhibit ghrelin action may be useful for the prevention or treatment of metabolic syndrome components such as obesity, impaired lipid metabolism or insulin resistance. In recent years, the effects of ghrelin on glucose homeostasis, memory function and gastrointestinal motility have attracted considerable amount of attention and revealed novel therapeutic targets in treating a wide range of pathologic conditions. Furthermore, discovery of ghrelin O-acyltransferase has also opened new research opportunities that could lead to major understanding of ghrelin physiology. This review summarizes the current knowledge on ghrelin synthesis, secretion, mechanism of action and biological functions with an additional focus on potential for ghrelin-based pharmacotherapies.
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Affiliation(s)
- T R Castañeda
- Dept. of Physiology and Pharmacology, Center for Diabetes and Endocrine Research, College of Medicine, University of Toledo, Toledo, OH, USA
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Suliman SG, Stanik J, McCulloch LJ, Wilson N, Edghill EL, Misovicova N, Gasperikova D, Sandrikova V, Elliott KS, Barak L, Ellard S, Volpi EV, Klimes I, Gloyn AL. Severe insulin resistance and intrauterine growth deficiency associated with haploinsufficiency for INSR and CHN2: new insights into synergistic pathways involved in growth and metabolism. Diabetes 2009; 58:2954-61. [PMID: 19720790 PMCID: PMC2780873 DOI: 10.2337/db09-0787] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Digenic causes of human disease are rarely reported. Insulin via its receptor, which is encoded by INSR, plays a key role in both metabolic and growth signaling pathways. Heterozygous INSR mutations are the most common cause of monogenic insulin resistance. However, growth retardation is only reported with homozygous or compound heterozygous mutations. We describe a novel translocation [t(7,19)(p15.2;p13.2)] cosegregating with insulin resistance and pre- and postnatal growth deficiency. Chromosome translocations present a unique opportunity to identify modifying loci; therefore, our objective was to determine the mutational mechanism resulting in this complex phenotype. RESEARCH DESIGN AND METHODS Breakpoint mapping was performed by fluorescence in situ hybridization (FISH) on patient chromosomes. Sequencing and gene expression studies of disrupted and adjacent genes were performed on patient-derived tissues. RESULTS Affected individuals had increased insulin, C-peptide, insulin-to-C-peptide ratio, and adiponectin levels consistent with an insulin receptoropathy. FISH mapping established that the translocation breakpoints disrupt INSR on chromosome 19p15.2 and CHN2 on chromosome 7p13.2. Sequencing demonstrated INSR haploinsufficiency accounting for elevated insulin levels and dysglycemia. CHN2 encoding beta-2 chimerin was shown to be expressed in insulin-sensitive tissues, and its disruption was shown to result in decreased gene expression in patient-derived adipose tissue. CONCLUSIONS We present a likely digenic cause of insulin resistance and growth deficiency resulting from the combined heterozygous disruption of INSR and CHN2, implicating CHN2 for the first time as a key element of proximal insulin signaling in vivo.
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MESH Headings
- Adult
- Age of Onset
- Antigens, CD/genetics
- Biomarkers/blood
- Blood Glucose/metabolism
- C-Peptide/blood
- Chromosome Mapping
- Chromosomes, Human, Pair 19
- Chromosomes, Human, Pair 7
- DNA-Binding Proteins/genetics
- Diabetes Mellitus/genetics
- Diabetes Mellitus/metabolism
- Female
- Fetal Growth Retardation/genetics
- Fetal Growth Retardation/metabolism
- Gene Expression Regulation
- Growth Disorders/genetics
- Growth Disorders/metabolism
- Haplotypes
- Humans
- In Situ Hybridization, Fluorescence
- Insulin/blood
- Insulin/metabolism
- Insulin Resistance
- Male
- Pregnancy
- Receptor, Insulin/genetics
- Receptors, Steroid/genetics
- Receptors, Thyroid Hormone/genetics
- Sequence Analysis, DNA
- Signal Transduction
- Translocation, Genetic
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Affiliation(s)
- Sara G.I. Suliman
- Oxford Centre for Diabetes, Endocrinology & Metabolism, University of Oxford, Oxford, U.K
| | - Juraj Stanik
- DIABGENE and Diabetes Laboratory, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic
- Children Diabetes Centre at 1st Paediatric Department, Comenius University School of Medicine, Bratislava, Slovak Republic
| | - Laura J. McCulloch
- Oxford Centre for Diabetes, Endocrinology & Metabolism, University of Oxford, Oxford, U.K
| | - Natalie Wilson
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, U.K
| | - Emma L. Edghill
- Institute of Biomedical and Clinical Sciences, Peninsula Medical School, Exeter, U.K
| | - Nadezda Misovicova
- Clinical Genetics, Jessenius School of Medicine, Martin, Slovak Republic
| | - Daniela Gasperikova
- DIABGENE and Diabetes Laboratory, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Vilja Sandrikova
- Paediatric Endocrinology Outpatient Clinic, Prievidza Hospital, Prievidza, Slovak Republic
| | | | - Lubomir Barak
- Children Diabetes Centre at 1st Paediatric Department, Comenius University School of Medicine, Bratislava, Slovak Republic
| | - Sian Ellard
- Institute of Biomedical and Clinical Sciences, Peninsula Medical School, Exeter, U.K
- Department of Molecular Genetics, Royal Devon & Exeter National Health Service Trust, Exeter, U.K
| | - Emanuela V. Volpi
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, U.K
| | - Iwar Klimes
- DIABGENE and Diabetes Laboratory, Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovak Republic
| | - Anna L. Gloyn
- Oxford Centre for Diabetes, Endocrinology & Metabolism, University of Oxford, Oxford, U.K
- Corresponding author: Anna L. Gloyn,
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Jeninga EH, Gurnell M, Kalkhoven E. Functional implications of genetic variation in human PPARgamma. Trends Endocrinol Metab 2009; 20:380-7. [PMID: 19748282 DOI: 10.1016/j.tem.2009.04.005] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2009] [Revised: 04/15/2009] [Accepted: 04/15/2009] [Indexed: 12/25/2022]
Abstract
The peroxisome proliferator-activated receptor gamma (PPARgamma) plays a key role in the regulation of lipid and glucose metabolism. Human genetic evidence supporting this view comes from the study of both common (e.g. the Pro12Ala polymorphism) and rare (loss-of-function mutations) variants in the gene encoding PPARgamma. Indeed, patients harbouring mutant PPARgamma exhibit familial partial lipodystrophy type 3 and an extreme monogenic form of the metabolic syndrome. The recent elucidation of the crystal structure of the full-length PPARgamma-RXRalpha heterodimer bound to DNA has shed new light on the functional consequences of these genetic PPARgamma alterations and provides novel insights as to why different perturbations of receptor function unite in a common pathway of metabolic dysfunction.
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Affiliation(s)
- Ellen H Jeninga
- Department of Metabolic and Endocrine Diseases, UMC Utrecht, Lundlaan 6, 3584 EA Utrecht, The Netherlands
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41
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Festuccia WT, Deshaies Y. Depot specificities of PPARγ ligand actions on lipid and glucose metabolism and their implication in PPARγ-mediated body fat redistribution. ACTA ACUST UNITED AC 2009. [DOI: 10.2217/clp.09.45] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Nohara A, Kobayashi J, Mabuchi H. Retinoid X receptor heterodimer variants and cardiovascular risk factors. J Atheroscler Thromb 2009; 16:303-18. [PMID: 19672026 DOI: 10.5551/jat.no786] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Nuclear receptors are transcription factors that can be activated by specific ligands. Recent progress has shown that retinoid X receptor (RXR) and its heterodimerization partners, including peroxisome proliferator-activated receptors, regulate many important genes involved in energy homeostasis and atherosclerosis, and should be promising therapeutic targets of metabolic syndrome. RXR heterodimers regulate a number of complex cellular processes, and genetic studies of RXR heterodimers have provided important clinical information in addition to knowledge gained from basic research. Genetic variants of RXR heterodimers were screened and investigated, and some variants were shown to have a considerable impact on metabolic disorders, including phenotypic components of familial combined hyperlipidemia. The combined efforts of basic and clinical science regarding nuclear receptors have achieved significant progress in unraveling the inextricably linked control system of energy expenditure, lipid and glucose homeostasis, inflammation, and atherosclerosis.This review summarizes the current understanding regarding RXR heterodimers based on their human genetic variants, which will provide new clues to uncover the background of multifactorial disease, such as metabolic syndrome or familial combined hyperlipidemia.
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Affiliation(s)
- Atsushi Nohara
- Departments of Lipidology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
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Bottomley WE, Soos MA, Adams C, Guran T, Howlett TA, Mackie A, Miell J, Monson JP, Temple R, Tenenbaum-Rakover Y, Tymms J, Savage DB, Semple RK, O'Rahilly S, Barroso I. IRS2 variants and syndromes of severe insulin resistance. Diabetologia 2009; 52:1208-11. [PMID: 19377890 PMCID: PMC2680062 DOI: 10.1007/s00125-009-1345-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 02/16/2009] [Indexed: 10/20/2022]
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Abstract
The nuclear hormone receptor peroxisome proliferator activated receptor gamma (PPARγ) is an important transcription factor regulating adipocyte differentiation, lipid and glucose homeostasis, and insulin sensitivity. Numerous genetic mutations of PPARγ have been identified and these mutations positively or negatively regulate insulin sensitivity. Among these, a relatively common polymorphism of PPARγ, Pro12Ala of PPARγ2, the isoform expressed only in adipose tissue has been shown to be associated with lower body mass index, enhanced insulin sensitivity, and resistance to the risk of type 2 diabetes in human subjects carrying this mutation. Subsequent studies in different ethnic populations, however, have revealed conflicting results, suggesting a complex interaction between the PPARγ2 Pro12Ala polymorphism and environmental factors such as the ratio of dietary unsaturated fatty acids to saturated fatty acids and/or between the PPARγ2 Pro12Ala polymorphism and genetic factors such as polymorphic mutations in other genes. In addition, this polymorphic mutation in PPARγ2 is associated with other aspects of human diseases, including cancers, polycystic ovary syndrome, Alzheimer disease and aging. This review will highlight findings from recent studies.
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Ferguson LR. Dissecting the Nutrigenomics, Diabetes, and Gastrointestinal Disease Interface: From Risk Assessment to Health Intervention. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2008; 12:237-44. [DOI: 10.1089/omi.2008.0044] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Tan GD, Savage DB, Fielding BA, Collins J, Hodson L, Humphreys SM, O'Rahilly S, Chatterjee K, Frayn KN, Karpe F. Fatty acid metabolism in patients with PPARgamma mutations. J Clin Endocrinol Metab 2008; 93:4462-70. [PMID: 18713822 DOI: 10.1210/jc.2007-2356] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
CONTEXT PPARG mutations may cause insulin resistance and dyslipidemia, but little is known about the mechanisms of the abnormalities of lipid metabolism. OBJECTIVE We hypothesized that in PPARG mutations, abnormal adipose tissue triglyceride storage causes insulin resistance. DESIGN, PATIENTS, AND MAIN OUTCOME MEASURES Whole-body and adipose tissue-specific metabolic phenotyping through arteriovenous blood sampling was made before and after a mixed meal including 13C-palmitic acid. Studies were performed in a 32-yr-old male with partial lipodystrophy and type 2 diabetes, heterozygous for the PPARG P467L mutation and in an apparently phenotypically normal 32-yr-old male heterozygous for the PPARG n.AAA553T mutation. Comparator groups were age- and sex-matched healthy participants (n=10) and type 2 diabetes sex-matched participants (n=6). RESULTS The P467L patient had elevated unmodulated fasting and postprandial plasma nonesterified fatty acid (NEFA) concentrations, despite a low adipose tissue NEFA output. Instead, NEFA appeared to originate directly from triglyceride-rich lipoproteins: 13C-palmitic acid accumulated rapidly in the NEFA fraction, as a sign of impaired fatty acid trapping in tissues. In contrast to the Pparg haploinsufficient mouse, the patient with n.AAA553T mutation did not exhibit paradoxically insulin sensitive and showed a mostly normal metabolic pattern. CONCLUSIONS The lipodystrophic PPARG P467L phenotype include excessive and uncontrolled generation of NEFA directly from triglyceride-rich lipoproteins, explaining high systemic NEFA concentrations, whereas the human PPARG haploinsufficiency is metabolically almost normal.
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Affiliation(s)
- Garry D Tan
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, Oxford OX3 7LJ, United Kingdom
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Genetics and aetiology of Pagetic disorders of bone. Arch Biochem Biophys 2008; 473:172-82. [DOI: 10.1016/j.abb.2008.02.045] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 02/27/2008] [Accepted: 02/28/2008] [Indexed: 12/20/2022]
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Chatterjee VKK. Nuclear receptors and human disease: resistance to thyroid hormone and lipodystrophic insulin resistance. ANNALES D'ENDOCRINOLOGIE 2008; 69:103-6. [PMID: 18430406 DOI: 10.1016/j.ando.2008.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- V K K Chatterjee
- Metabolic Research Laboratories, Level 4, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, United Kingdom.
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Abstract
Lack of adipose tissue, either complete or partial, is the hallmark of disorders known as lipodystrophies. Patients with lipodystrophies suffer from metabolic complications similar to those associated with obesity, including insulin resistance, type 2 diabetes, hypertriglyceridemia, and hepatic steatosis. The loss of body fat in inherited lipodystrophies can be caused by defects in the development and/or differentiation of adipose tissue as a consequence of mutations in a number of genes, including PPARG (encoding a nuclear hormone receptor), AGPAT2 (encoding an enzyme involved in the biosynthesis of triglyceride and phospholipids), AKT2 (encoding a protein involved in insulin signal transduction), and BSCL2 (encoding seipin, whose role in the adipocyte biology remains unclear). The loss of body fat can also be caused by the premature death of adipocytes due to mutations in lamin A/C, nuclear lamina proteins, and ZMPSTE24, which modifies the prelamin A post-translationally. In this review, we focus on the molecular basis of inherited lipodystrophies as they relate to adipocyte biology and their associated phenotypic manifestations.
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Affiliation(s)
- Anil K Agarwal
- Division of Nutrition and Metabolic Diseases, Department of Internal Medicine and the Center for Human Nutrition, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9052, USA
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Abstract
The authors discuss a new study showing that carriers of the mutation PPP1R3A show decreased muscle glycogen levels.
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Affiliation(s)
- Leif Groop
- Department of Clinical Sciences, Diabetes andEndocrinology Research Unit, Lund UniversityDiabetes Centre, Lund University, Malmoe, Sweden.
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