351
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Gonzalez B, Forcales SV, Perucho M. Second German-Catalan workshop on epigenetics & cancer. Epigenetics 2015; 10:352-9. [PMID: 25849957 DOI: 10.1080/15592294.2015.1023499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
The Second German-Catalan Workshop on Epigenetics and Cancer was held in Barcelona on November 19-21, 2014. The workshop brought together, for the second time, scientists from 2 German and 2 Catalan research institutions: the DKFZ, from Heidelberg, the CRCME, from Freiburg, and the IMPPC and PEBC/IDIBELL, both from Barcelona. The German-Catalan Workshops are intended to establish the framework for building a Research School to foster collaborations between researchers from the different institutions. Exchange programs for graduate students are among the activities of the future School. The topics presented and discussed in 33 talks were diverse and included work on DNA methylation, histone modifications, chromatin biology, characterization of imprinted regions in human tissues, non-coding RNAs, and epigenetic drug discovery. Among novel developments from the previous Workshop are the report of the epigenetics angle of the Warburg effect and the long-range trans-acting interaction of DNA methylation and of nucleosome remodeling. A shift in the view on DNA methylation became apparent by the realization of the intertwined interplay between hyper- and hypo-methylation in differentiation and cancer.
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Affiliation(s)
- Beatriz Gonzalez
- a Institute of Predictive and Personalized Medicine of Cancer (IMPPC); Campus Can Ruti ; Badalona , Barcelona , Spain
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352
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Reschen ME, Gaulton KJ, Lin D, Soilleux EJ, Morris AJ, Smyth SS, O'Callaghan CA. Lipid-induced epigenomic changes in human macrophages identify a coronary artery disease-associated variant that regulates PPAP2B Expression through Altered C/EBP-beta binding. PLoS Genet 2015; 11:e1005061. [PMID: 25835000 PMCID: PMC4383549 DOI: 10.1371/journal.pgen.1005061] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 02/09/2015] [Indexed: 01/17/2023] Open
Abstract
Genome-wide association studies (GWAS) have identified over 40 loci that affect risk of coronary artery disease (CAD) and the causal mechanisms at the majority of loci are unknown. Recent studies have suggested that many causal GWAS variants influence disease through altered transcriptional regulation in disease-relevant cell types. We explored changes in transcriptional regulation during a key pathophysiological event in CAD, the environmental lipid-induced transformation of macrophages to lipid-laden foam cells. We used a combination of open chromatin mapping with formaldehyde-assisted isolation of regulatory elements (FAIRE-seq) and enhancer and transcription factor mapping using chromatin immuno-precipitation (ChIP-seq) in primary human macrophages before and after exposure to atherogenic oxidized low-density lipoprotein (oxLDL), with resultant foam cell formation. OxLDL-induced foam cell formation was associated with changes in a subset of open chromatin and active enhancer sites that strongly correlated with expression changes of nearby genes. OxLDL-regulated enhancers were enriched for several transcription factors including C/EBP-beta, which has no previously documented role in foam cell formation. OxLDL exposure up-regulated C/EBP-beta expression and increased genomic binding events, most prominently around genes involved in inflammatory response pathways. Variants at CAD-associated loci were significantly and specifically enriched in the subset of chromatin sites altered by oxLDL exposure, including rs72664324 in an oxLDL-induced enhancer at the PPAP2B locus. OxLDL increased C/EBP beta binding to this site and C/EBP beta binding and enhancer activity were stronger with the protective A allele of rs72664324. In addition, expression of the PPAP2B protein product LPP3 was present in foam cells in human atherosclerotic plaques and oxLDL exposure up-regulated LPP3 in macrophages resulting in increased degradation of pro-inflammatory mediators. Our results demonstrate a genetic mechanism contributing to CAD risk at the PPAP2B locus and highlight the value of studying epigenetic changes in disease processes involving pathogenic environmental stimuli. Coronary artery disease is a complex disease where over 40 genomic loci contributing to genetic risk have been identified. However, identifying the precise variants, genomic elements and genes that mediate this risk at each locus has proved challenging. We hypothesized that some genetic risk variants may influence a key step in development of coronary artery disease, which occurs when macrophages encounter environmentally-derived lipid. These cells take up lipid and accumulate in atherosclerotic plaques in the walls of blood vessels where they contribute to the inflammatory atherosclerotic disease process. Therefore, we studied the effects of this lipid exposure on the genomic activity of these cells. Environmental lipid exposure triggered changes in transcriptional regulation and gene expression. Variants at coronary artery disease risk loci were enriched for genomic regions altered by lipid exposure. We studied one such risk variant rs72664324 in detail and found that it altered binding of the C/EBP-beta transcription factor and altered expression of the PPAP2B gene. PPAP2B encodes an enzyme that degrades pro-inflammatory substances. Our study demonstrates a hitherto unknown genetic mechanism underlying atherosclerotic heart disease and demonstrates the value of studying changes in transcriptional regulation in key disease processes involving environmental influences.
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Affiliation(s)
- Michael E. Reschen
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Kyle J. Gaulton
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Da Lin
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Elizabeth J. Soilleux
- Nuffield Department of Clinical Laboratory Sciences, University of Oxford and Department of Cellular Pathology, John Radcliffe Hospital, Oxford, United Kingdom
| | - Andrew J. Morris
- Division of Cardiovascular Medicine, The Gill Heart Institute, University of Kentucky, Lexington, Kentucky, United States of America
- Department of Veterans Affairs Medical Center, Lexington, Kentucky, United States of America
| | - Susan S. Smyth
- Division of Cardiovascular Medicine, The Gill Heart Institute, University of Kentucky, Lexington, Kentucky, United States of America
- Department of Veterans Affairs Medical Center, Lexington, Kentucky, United States of America
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353
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van der Meulen T, Huising MO. Role of transcription factors in the transdifferentiation of pancreatic islet cells. J Mol Endocrinol 2015; 54:R103-17. [PMID: 25791577 PMCID: PMC4373662 DOI: 10.1530/jme-14-0290] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The α and β cells act in concert to maintain blood glucose. The α cells release glucagon in response to low levels of glucose to stimulate glycogenolysis in the liver. In contrast, β cells release insulin in response to elevated levels of glucose to stimulate peripheral glucose disposal. Despite these opposing roles in glucose homeostasis, α and β cells are derived from a common progenitor and share many proteins important for glucose sensing and hormone secretion. Results from recent work have underlined these similarities between the two cell types by revealing that β-to-α as well as α-to-β transdifferentiation can take place under certain experimental circumstances. These exciting findings highlight unexpected plasticity of adult islets and offer hope of novel therapeutic paths to replenish β cells in diabetes. In this review, we focus on the transcription factor networks that establish and maintain pancreatic endocrine cell identity and how they may be perturbed to facilitate transdifferentiation.
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Affiliation(s)
- Talitha van der Meulen
- Department of NeurobiologyPhysiology and Behavior, College of Biological SciencesDepartment of Physiology and Membrane BiologySchool of Medicine, University of California, 193 Briggs Hall, One Shields Avenue, Davis, California 95616, USA
| | - Mark O Huising
- Department of NeurobiologyPhysiology and Behavior, College of Biological SciencesDepartment of Physiology and Membrane BiologySchool of Medicine, University of California, 193 Briggs Hall, One Shields Avenue, Davis, California 95616, USA Department of NeurobiologyPhysiology and Behavior, College of Biological SciencesDepartment of Physiology and Membrane BiologySchool of Medicine, University of California, 193 Briggs Hall, One Shields Avenue, Davis, California 95616, USA
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354
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Onengut-Gumuscu S, Chen WM, Burren O, Cooper NJ, Quinlan AR, Mychaleckyj JC, Farber E, Bonnie JK, Szpak M, Schofield E, Achuthan P, Guo H, Fortune MD, Stevens H, Walker NM, Ward LD, Kundaje A, Kellis M, Daly MJ, Barrett JC, Cooper JD, Deloukas P, Todd JA, Wallace C, Concannon P, Rich SS. Fine mapping of type 1 diabetes susceptibility loci and evidence for colocalization of causal variants with lymphoid gene enhancers. Nat Genet 2015; 47:381-6. [PMID: 25751624 PMCID: PMC4380767 DOI: 10.1038/ng.3245] [Citation(s) in RCA: 486] [Impact Index Per Article: 54.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 02/13/2015] [Indexed: 02/06/2023]
Abstract
Genetic studies of type 1 diabetes (T1D) have identified 50 susceptibility regions, finding major pathways contributing to risk, with some loci shared across immune disorders. To make genetic comparisons across autoimmune disorders as informative as possible, a dense genotyping array, the Immunochip, was developed, from which we identified four new T1D-associated regions (P < 5 × 10(-8)). A comparative analysis with 15 immune diseases showed that T1D is more similar genetically to other autoantibody-positive diseases, significantly most similar to juvenile idiopathic arthritis and significantly least similar to ulcerative colitis, and provided support for three additional new T1D risk loci. Using a Bayesian approach, we defined credible sets for the T1D-associated SNPs. The associated SNPs localized to enhancer sequences active in thymus, T and B cells, and CD34(+) stem cells. Enhancer-promoter interactions can now be analyzed in these cell types to identify which particular genes and regulatory sequences are causal.
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Affiliation(s)
- Suna Onengut-Gumuscu
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
- Department of Medicine, Division of Endocrinology, University of Virginia, Charlottesville, VA, USA
| | - Wei-Min Chen
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
- Department of Public Health Sciences, Division of Biostatistics and Epidemiology, University of Virginia, Charlottesville, VA, USA
| | - Oliver Burren
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | - Nick J. Cooper
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | - Aaron R. Quinlan
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
- Department of Public Health Sciences, Division of Biostatistics and Epidemiology, University of Virginia, Charlottesville, VA, USA
| | - Josyf C. Mychaleckyj
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
- Department of Public Health Sciences, Division of Biostatistics and Epidemiology, University of Virginia, Charlottesville, VA, USA
| | - Emily Farber
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
| | - Jessica K. Bonnie
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
| | - Michal Szpak
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
| | - Ellen Schofield
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | - Premanand Achuthan
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | - Hui Guo
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | - Mary D. Fortune
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | - Helen Stevens
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | - Neil M. Walker
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | - Luke D. Ward
- Department of Computer Science, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Anshul Kundaje
- Department of Computer Science, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA. Department of Genetics, Stanford University, Stanford, CA, USA
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Manolis Kellis
- Department of Computer Science, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Mark J. Daly
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, USA
| | | | - Jason D. Cooper
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | | | | | - John A. Todd
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
| | - Chris Wallace
- JDRF/Wellcome Trust Diabetes and Inflammation Laboratory, Department of Medical Genetics, Cambridge Institute for Medical Research, NIHR Biomedical Research Centre, University of Cambridge, Addenbrooke’s Hospital, Cambridge, CB2 0XY, UK
- MRC Biostatistics Unit, Institute of Public Health, University Forvie Site, Robinson Way, CB2 0SR, Cambridge, United Kingdom
| | - Patrick Concannon
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
| | - Stephen S. Rich
- Center for Public Health Genomics, University of Virginia, Charlottesville, VA, USA
- Department of Public Health Sciences, Division of Biostatistics and Epidemiology, University of Virginia, Charlottesville, VA, USA
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355
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Wang P, Fiaschi-Taesch NM, Vasavada RC, Scott DK, García-Ocaña A, Stewart AF. Diabetes mellitus--advances and challenges in human β-cell proliferation. Nat Rev Endocrinol 2015; 11:201-12. [PMID: 25687999 DOI: 10.1038/nrendo.2015.9] [Citation(s) in RCA: 157] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The treatment of diabetes mellitus represents one of the greatest medical challenges of our era. Diabetes results from a deficiency or functional impairment of insulin-producing β cells, alone or in combination with insulin resistance. It logically follows that the replacement or regeneration of β cells should reverse the progression of diabetes and, indeed, this seems to be the case in humans and rodents. This concept has prompted attempts in many laboratories to create new human β cells using stem-cell strategies to transdifferentiate or reprogramme non-β cells into β cells or to discover small molecules or other compounds that can induce proliferation of human β cells. This latter approach has shown promise, but has also proven particularly challenging to implement. In this Review, we discuss the physiology of normal human β-cell replication, the molecular mechanisms that regulate the cell cycle in human β cells, the upstream intracellular signalling pathways that connect them to cell surface receptors on β cells, the epigenetic mechanisms that control human β-cell proliferation and unbiased approaches for discovering novel molecules that can drive human β-cell proliferation. Finally, we discuss the potential and challenges of implementing strategies that replace or regenerate β cells.
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Affiliation(s)
- Peng Wang
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Nathalie M Fiaschi-Taesch
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Rupangi C Vasavada
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Donald K Scott
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Adolfo García-Ocaña
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Andrew F Stewart
- Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, Atran 5, Box 1152, 1 Gustave L. Levy Place, New York, NY 10029, USA
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356
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Jia S, Ivanov A, Blasevic D, Müller T, Purfürst B, Sun W, Chen W, Poy MN, Rajewsky N, Birchmeier C. Insm1 cooperates with Neurod1 and Foxa2 to maintain mature pancreatic β-cell function. EMBO J 2015; 34:1417-33. [PMID: 25828096 PMCID: PMC4492000 DOI: 10.15252/embj.201490819] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/10/2015] [Indexed: 12/25/2022] Open
Abstract
Key transcription factors control the gene expression program in mature pancreatic β-cells, but their integration into regulatory networks is little understood. Here, we show that Insm1, Neurod1 and Foxa2 directly interact and together bind regulatory sequences in the genome of mature pancreatic β-cells. We used Insm1 ablation in mature β-cells in mice and found pronounced deficits in insulin secretion and gene expression. Insm1-dependent genes identified previously in developing β-cells markedly differ from the ones identified in the adult. In particular, adult mutant β-cells resemble immature β-cells of newborn mice in gene expression and functional properties. We defined Insm1, Neurod1 and Foxa2 binding sites associated with genes deregulated in Insm1 mutant β-cells. Remarkably, combinatorial binding of Insm1, Neurod1 and Foxa2 but not binding of Insm1 alone explained a significant fraction of gene expression changes. Human genomic sequences corresponding to the murine sites occupied by Insm1/Neurod1/Foxa2 were enriched in single nucleotide polymorphisms associated with glycolytic traits. Thus, our data explain part of the mechanisms by which β-cells maintain maturity: Combinatorial Insm1/Neurod1/Foxa2 binding identifies regulatory sequences that maintain the mature gene expression program in β-cells, and disruption of this network results in functional failure.
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Affiliation(s)
- Shiqi Jia
- Developmental Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Andranik Ivanov
- Systems Biology of Gene Regulatory Elements, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Dinko Blasevic
- Developmental Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Thomas Müller
- Developmental Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Bettina Purfürst
- Electron Microscopy Platform, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Wei Sun
- Scientific Genomics Platform, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Wei Chen
- Scientific Genomics Platform, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Matthew N Poy
- Molecular Mechanisms of Metabolic Disease, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Nikolaus Rajewsky
- Systems Biology of Gene Regulatory Elements, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
| | - Carmen Birchmeier
- Developmental Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany
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357
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Epigenetic modifications and long noncoding RNAs influence pancreas development and function. Trends Genet 2015; 31:290-9. [PMID: 25812926 DOI: 10.1016/j.tig.2015.02.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 02/19/2015] [Accepted: 02/20/2015] [Indexed: 01/29/2023]
Abstract
Insulin-producing β cells within the pancreatic islet of Langerhans are responsible for maintaining glucose homeostasis; the loss or malfunction of β cells results in diabetes mellitus. Recent advances in cell purification strategies and sequencing technologies as well as novel molecular tools have revealed that epigenetic modifications and long noncoding RNAs (lncRNAs) represent an integral part of the transcriptional mechanisms regulating pancreas development and β cell function. Importantly, these findings have uncovered a new layer of gene regulation in the pancreas that can be exploited to enhance the restoration and/or repair of β cells to treat diabetes.
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358
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McKenna B, Guo M, Reynolds A, Hara M, Stein R. Dynamic recruitment of functionally distinct Swi/Snf chromatin remodeling complexes modulates Pdx1 activity in islet β cells. Cell Rep 2015; 10:2032-42. [PMID: 25801033 DOI: 10.1016/j.celrep.2015.02.054] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 01/21/2015] [Accepted: 02/23/2015] [Indexed: 02/03/2023] Open
Abstract
Pdx1 is a transcription factor of fundamental importance to pancreas formation and adult islet β cell function. However, little is known about the positive- and negative-acting coregulators recruited to mediate transcriptional control. Here, we isolated numerous Pdx1-interacting factors possessing a wide range of cellular functions linked with this protein, including, but not limited to, coregulators associated with transcriptional activation and repression, DNA damage response, and DNA replication. Because chromatin remodeling activities are essential to developmental lineage decisions and adult cell function, our analysis focused on investigating the influence of the Swi/Snf chromatin remodeler on Pdx1 action. The two mutually exclusive and indispensable Swi/Snf core ATPase subunits, Brg1 and Brm, distinctly affected target gene expression in β cells. Furthermore, physiological and pathophysiological conditions dynamically regulated Pdx1 binding to these Swi/Snf complexes in vivo. We discuss how context-dependent recruitment of coregulatory complexes by Pdx1 could impact pancreas cell development and adult islet β cell activity.
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Affiliation(s)
- Brian McKenna
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Min Guo
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Albert Reynolds
- Department of Cancer Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Manami Hara
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
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359
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Hnisz D, Schuijers J, Lin CY, Weintraub AS, Abraham BJ, Lee TI, Bradner JE, Young RA. Convergence of developmental and oncogenic signaling pathways at transcriptional super-enhancers. Mol Cell 2015; 58:362-70. [PMID: 25801169 DOI: 10.1016/j.molcel.2015.02.014] [Citation(s) in RCA: 346] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/17/2014] [Accepted: 02/05/2015] [Indexed: 12/19/2022]
Abstract
Super-enhancers and stretch enhancers (SEs) drive expression of genes that play prominent roles in normal and disease cells, but the functional importance of these clustered enhancer elements is poorly understood, so it is not clear why genes key to cell identity have evolved regulation by such elements. Here, we show that SEs consist of functional constituent units that concentrate multiple developmental signaling pathways at key pluripotency genes in embryonic stem cells and confer enhanced responsiveness to signaling of their associated genes. Cancer cells frequently acquire SEs at genes that promote tumorigenesis, and we show that these genes are especially sensitive to perturbation of oncogenic signaling pathways. Super-enhancers thus provide a platform for signaling pathways to regulate genes that control cell identity during development and tumorigenesis.
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Affiliation(s)
- Denes Hnisz
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Jurian Schuijers
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Charles Y Lin
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Abraham S Weintraub
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Brian J Abraham
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Tong Ihn Lee
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - James E Bradner
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Richard A Young
- Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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360
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Lenin R, Mohan V, Balasubramanyam M. SEAP activity serves for demonstrating ER stress induction by glucolipotoxicity as well as testing ER stress inhibitory potential of therapeutic agents. Mol Cell Biochem 2015; 404:271-9. [DOI: 10.1007/s11010-015-2387-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 03/05/2015] [Indexed: 01/06/2023]
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361
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Pott S, Lieb JD. What are super-enhancers? Nat Genet 2015; 47:8-12. [PMID: 25547603 DOI: 10.1038/ng.3167] [Citation(s) in RCA: 482] [Impact Index Per Article: 53.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 11/19/2014] [Indexed: 12/15/2022]
Abstract
The term 'super-enhancer' has been used to describe groups of putative enhancers in close genomic proximity with unusually high levels of Mediator binding, as measured by chromatin immunoprecipitation and sequencing (ChIP-seq). Here we review the identification and composition of super-enhancers, describe links between super-enhancers, gene regulation and disease, and discuss the functional significance of enhancer clustering. We also provide our perspective regarding the proposition that super-enhancers are a regulatory entity conceptually distinct from what was known before the introduction of the term. Our opinion is that there is not yet strong evidence that super-enhancers are a novel paradigm in gene regulation and that use of the term in this context is not currently justified. However, the term likely identifies strong enhancers that exhibit behaviors consistent with previous models and concepts of transcriptional regulation. In this respect, the super-enhancer definition is useful in identifying regulatory elements likely to control genes important for cell type specification.
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Affiliation(s)
- Sebastian Pott
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
| | - Jason D Lieb
- Department of Human Genetics, University of Chicago, Chicago, Illinois, USA
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362
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Abstract
Type 2 diabetes (T2D) had long been referred to as the "geneticist's nightmare." Genome-wide association studies have fully confirmed the polygenic nature of T2D, demonstrating the role of many genes in T2D risk. The increasingly busier picture of T2D genetics is quite difficult to understand for the diabetes research community, which can create misunderstandings with geneticists, and can eventually limit both basic research and translational outcomes of these genetic discoveries. The present review wishes to lift the fog around genetics of T2D with the hope that it will foster integrated diabetes modeling approaches from genetic defects to personalized medicine.
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Affiliation(s)
- Amélie Bonnefond
- CNRS-UMR8199, Lille Pasteur Institute, Lille 59000, France; Lille University, Lille 59000, France; European Genomic Institute for Diabetes (EGID), Lille 59000, France
| | - Philippe Froguel
- CNRS-UMR8199, Lille Pasteur Institute, Lille 59000, France; Lille University, Lille 59000, France; European Genomic Institute for Diabetes (EGID), Lille 59000, France; Department of Genomics of Common Disease, School of Public Health, Imperial College London, Hammersmith Hospital, London W12 0NN, UK.
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363
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Heinz S, Romanoski CE, Benner C, Glass CK. The selection and function of cell type-specific enhancers. Nat Rev Mol Cell Biol 2015; 16:144-54. [PMID: 25650801 PMCID: PMC4517609 DOI: 10.1038/nrm3949] [Citation(s) in RCA: 670] [Impact Index Per Article: 74.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The human body contains several hundred cell types, all of which share the same genome. In metazoans, much of the regulatory code that drives cell type-specific gene expression is located in distal elements called enhancers. Although mammalian genomes contain millions of potential enhancers, only a small subset of them is active in a given cell type. Cell type-specific enhancer selection involves the binding of lineage-determining transcription factors that prime enhancers. Signal-dependent transcription factors bind to primed enhancers, which enables these broadly expressed factors to regulate gene expression in a cell type-specific manner. The expression of genes that specify cell type identity and function is associated with densely spaced clusters of active enhancers known as super-enhancers. The functions of enhancers and super-enhancers are influenced by, and affect, higher-order genomic organization.
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Affiliation(s)
| | | | | | - Christopher K. Glass
- Department of Cellular and Molecular Medicine, UC San Diego
- Department of Medicine, UC San Diego
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364
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Kundaje A, Meuleman W, Ernst J, Bilenky M, Yen A, Heravi-Moussavi A, Kheradpour P, Zhang Z, Wang J, Ziller MJ, Amin V, Whitaker JW, Schultz MD, Ward LD, Sarkar A, Quon G, Sandstrom RS, Eaton ML, Wu YC, Pfenning AR, Wang X, Claussnitzer M, Liu Y, Coarfa C, Harris RA, Shoresh N, Epstein CB, Gjoneska E, Leung D, Xie W, Hawkins RD, Lister R, Hong C, Gascard P, Mungall AJ, Moore R, Chuah E, Tam A, Canfield TK, Hansen RS, Kaul R, Sabo PJ, Bansal MS, Carles A, Dixon JR, Farh KH, Feizi S, Karlic R, Kim AR, Kulkarni A, Li D, Lowdon R, Elliott G, Mercer TR, Neph SJ, Onuchic V, Polak P, Rajagopal N, Ray P, Sallari RC, Siebenthall KT, Sinnott-Armstrong NA, Stevens M, Thurman RE, Wu J, Zhang B, Zhou X, Beaudet AE, Boyer LA, De Jager PL, Farnham PJ, Fisher SJ, Haussler D, Jones SJM, Li W, Marra MA, McManus MT, Sunyaev S, Thomson JA, Tlsty TD, Tsai LH, Wang W, Waterland RA, Zhang MQ, Chadwick LH, Bernstein BE, Costello JF, Ecker JR, Hirst M, Meissner A, Milosavljevic A, Ren B, Stamatoyannopoulos JA, Wang T, Kellis M. Integrative analysis of 111 reference human epigenomes. Nature 2015; 518:317-30. [PMID: 25693563 PMCID: PMC4530010 DOI: 10.1038/nature14248] [Citation(s) in RCA: 4182] [Impact Index Per Article: 464.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 01/21/2015] [Indexed: 02/06/2023]
Abstract
The reference human genome sequence set the stage for studies of genetic variation and its association with human disease, but epigenomic studies lack a similar reference. To address this need, the NIH Roadmap Epigenomics Consortium generated the largest collection so far of human epigenomes for primary cells and tissues. Here we describe the integrative analysis of 111 reference human epigenomes generated as part of the programme, profiled for histone modification patterns, DNA accessibility, DNA methylation and RNA expression. We establish global maps of regulatory elements, define regulatory modules of coordinated activity, and their likely activators and repressors. We show that disease- and trait-associated genetic variants are enriched in tissue-specific epigenomic marks, revealing biologically relevant cell types for diverse human traits, and providing a resource for interpreting the molecular basis of human disease. Our results demonstrate the central role of epigenomic information for understanding gene regulation, cellular differentiation and human disease.
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Affiliation(s)
- Anshul Kundaje
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [3] Department of Genetics, Department of Computer Science, 300 Pasteur Dr., Lane Building, L301, Stanford, California 94305-5120, USA
| | - Wouter Meuleman
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Jason Ernst
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [3] Department of Biological Chemistry, University of California, Los Angeles, 615 Charles E Young Dr South, Los Angeles, California 90095, USA
| | - Misha Bilenky
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Angela Yen
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Alireza Heravi-Moussavi
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Pouya Kheradpour
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Zhizhuo Zhang
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Jianrong Wang
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Michael J Ziller
- 1] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [2] Department of Stem Cell and Regenerative Biology, 7 Divinity Ave, Cambridge, Massachusetts 02138, USA
| | - Viren Amin
- Epigenome Center, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - John W Whitaker
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, Moores Cancer Center, Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Matthew D Schultz
- Genomic Analysis Laboratory, Howard Hughes Medical Institute &The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, California 92037, USA
| | - Lucas D Ward
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Abhishek Sarkar
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Gerald Quon
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Richard S Sandstrom
- Department of Genome Sciences, University of Washington, 3720 15th Ave. NE, Seattle, Washington 98195, USA
| | - Matthew L Eaton
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Yi-Chieh Wu
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Andreas R Pfenning
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Xinchen Wang
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [3] Biology Department, Massachusetts Institute of Technology, 31 Ames St, Cambridge, Massachusetts 02142, USA
| | - Melina Claussnitzer
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Yaping Liu
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Cristian Coarfa
- Epigenome Center, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - R Alan Harris
- Epigenome Center, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Noam Shoresh
- The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Charles B Epstein
- The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Elizabeta Gjoneska
- 1] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [2] The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St, Cambridge, Massachusetts 02139, USA
| | - Danny Leung
- 1] Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, Moores Cancer Center, Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA. [2] Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Wei Xie
- 1] Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, Moores Cancer Center, Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA. [2] Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - R David Hawkins
- 1] Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, Moores Cancer Center, Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA. [2] Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Ryan Lister
- Genomic Analysis Laboratory, Howard Hughes Medical Institute &The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, California 92037, USA
| | - Chibo Hong
- Department of Neurosurgery, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, 1450 3rd Street, San Francisco, California 94158, USA
| | - Philippe Gascard
- Department of Pathology, University of California San Francisco, 513 Parnassus Avenue, San Francisco, California 94143-0511, USA
| | - Andrew J Mungall
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Richard Moore
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Eric Chuah
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Angela Tam
- Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Theresa K Canfield
- Department of Genome Sciences, University of Washington, 3720 15th Ave. NE, Seattle, Washington 98195, USA
| | - R Scott Hansen
- Department of Medicine, Division of Medical Genetics, University of Washington, 2211 Elliot Avenue, Seattle, Washington 98121, USA
| | - Rajinder Kaul
- Department of Medicine, Division of Medical Genetics, University of Washington, 2211 Elliot Avenue, Seattle, Washington 98121, USA
| | - Peter J Sabo
- Department of Genome Sciences, University of Washington, 3720 15th Ave. NE, Seattle, Washington 98195, USA
| | - Mukul S Bansal
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [3] Department of Computer Science &Engineering, University of Connecticut, 371 Fairfield Way, Storrs, Connecticut 06269, USA
| | - Annaick Carles
- Department of Microbiology and Immunology and Centre for High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Jesse R Dixon
- 1] Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, Moores Cancer Center, Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA. [2] Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Kai-How Farh
- The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Soheil Feizi
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Rosa Karlic
- Bioinformatics Group, Department of Molecular Biology, Division of Biology, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia
| | - Ah-Ram Kim
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Ashwinikumar Kulkarni
- Department of Molecular and Cell Biology, Center for Systems Biology, The University of Texas, Dallas, NSERL, RL10, 800 W Campbell Road, Richardson, Texas 75080, USA
| | - Daofeng Li
- Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University in St Louis, 4444 Forest Park Ave, St Louis, Missouri 63108, USA
| | - Rebecca Lowdon
- Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University in St Louis, 4444 Forest Park Ave, St Louis, Missouri 63108, USA
| | - GiNell Elliott
- Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University in St Louis, 4444 Forest Park Ave, St Louis, Missouri 63108, USA
| | - Tim R Mercer
- Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Shane J Neph
- Department of Genome Sciences, University of Washington, 3720 15th Ave. NE, Seattle, Washington 98195, USA
| | - Vitor Onuchic
- Epigenome Center, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Paz Polak
- 1] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [2] Brigham &Women's Hospital, 75 Francis Street, Boston, Massachusetts 02115, USA
| | - Nisha Rajagopal
- 1] Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, Moores Cancer Center, Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA. [2] Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Pradipta Ray
- Department of Molecular and Cell Biology, Center for Systems Biology, The University of Texas, Dallas, NSERL, RL10, 800 W Campbell Road, Richardson, Texas 75080, USA
| | - Richard C Sallari
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Kyle T Siebenthall
- Department of Genome Sciences, University of Washington, 3720 15th Ave. NE, Seattle, Washington 98195, USA
| | - Nicholas A Sinnott-Armstrong
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
| | - Michael Stevens
- 1] Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University in St Louis, 4444 Forest Park Ave, St Louis, Missouri 63108, USA. [2] Department of Computer Science and Engineeering, Washington University in St. Louis, St. Louis, Missouri 63130, USA
| | - Robert E Thurman
- Department of Genome Sciences, University of Washington, 3720 15th Ave. NE, Seattle, Washington 98195, USA
| | - Jie Wu
- 1] Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York 11794-3600, USA. [2] Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Bo Zhang
- Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University in St Louis, 4444 Forest Park Ave, St Louis, Missouri 63108, USA
| | - Xin Zhou
- Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University in St Louis, 4444 Forest Park Ave, St Louis, Missouri 63108, USA
| | - Arthur E Beaudet
- Molecular and Human Genetics Department, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Laurie A Boyer
- Biology Department, Massachusetts Institute of Technology, 31 Ames St, Cambridge, Massachusetts 02142, USA
| | - Philip L De Jager
- 1] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [2] Brigham &Women's Hospital, 75 Francis Street, Boston, Massachusetts 02115, USA. [3] Harvard Medical School, 25 Shattuck St, Boston, Massachusetts 02115, USA
| | - Peggy J Farnham
- Department of Biochemistry, Keck School of Medicine, University of Southern California, 1450 Biggy Street, Los Angeles, California 90089-9601, USA
| | - Susan J Fisher
- ObGyn, Reproductive Sciences, University of California San Francisco, 35 Medical Center Way, San Francisco, California 94143, USA
| | - David Haussler
- Center for Biomolecular Sciences and Engineering, University of Santa Cruz, 1156 High Street, Santa Cruz, California 95064, USA
| | - Steven J M Jones
- 1] Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada. [2] Department of Molecular Biology and Biochemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada. [3] Department of Medical Genetics, University of British Columbia, 2329 West Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Wei Li
- Dan L. Duncan Cancer Center, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA
| | - Marco A Marra
- 1] Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada. [2] Department of Medical Genetics, University of British Columbia, 2329 West Mall, Vancouver, BC, Canada, V6T 1Z4
| | - Michael T McManus
- Department of Microbiology and Immunology, Diabetes Center, University of California, San Francisco, 513 Parnassus Ave, San Francisco, California 94143-0534, USA
| | - Shamil Sunyaev
- 1] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [2] Brigham &Women's Hospital, 75 Francis Street, Boston, Massachusetts 02115, USA. [3] Harvard Medical School, 25 Shattuck St, Boston, Massachusetts 02115, USA
| | - James A Thomson
- 1] University of Wisconsin, Madison, Wisconsin 53715, USA. [2] Morgridge Institute for Research, 330 N. Orchard Street, Madison, Wisconsin 53707, USA
| | - Thea D Tlsty
- Department of Pathology, University of California San Francisco, 513 Parnassus Avenue, San Francisco, California 94143-0511, USA
| | - Li-Huei Tsai
- 1] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [2] The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 43 Vassar St, Cambridge, Massachusetts 02139, USA
| | - Wei Wang
- Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, Moores Cancer Center, Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - Robert A Waterland
- USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, 1100 Bates Street, Houston, Texas 77030, USA
| | - Michael Q Zhang
- 1] Department of Molecular and Cell Biology, Center for Systems Biology, The University of Texas, Dallas, NSERL, RL10, 800 W Campbell Road, Richardson, Texas 75080, USA. [2] Bioinformatics Division, Center for Synthetic and Systems Biology, TNLIST, Tsinghua University, Beijing 100084, China
| | - Lisa H Chadwick
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, Research Triangle Park, North Carolina 27709, USA
| | - Bradley E Bernstein
- 1] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [2] Massachusetts General Hospital, 55 Fruit St, Boston, Massachusetts 02114, USA. [3] Howard Hughes Medical Institute, 4000 Jones Bridge Road, Chevy Chase, Maryland 20815-6789, USA
| | - Joseph F Costello
- Department of Neurosurgery, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, 1450 3rd Street, San Francisco, California 94158, USA
| | - Joseph R Ecker
- Genomic Analysis Laboratory, Howard Hughes Medical Institute &The Salk Institute for Biological Studies, 10010 N. Torrey Pines Road, La Jolla, California 92037, USA
| | - Martin Hirst
- 1] Canada's Michael Smith Genome Sciences Centre, BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada. [2] Department of Microbiology and Immunology and Centre for High-Throughput Biology, University of British Columbia, 2125 East Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Alexander Meissner
- 1] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA. [2] Department of Stem Cell and Regenerative Biology, 7 Divinity Ave, Cambridge, Massachusetts 02138, USA
| | | | - Bing Ren
- 1] Department of Cellular and Molecular Medicine, Institute of Genomic Medicine, Moores Cancer Center, Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA. [2] Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, California 92093, USA
| | - John A Stamatoyannopoulos
- Department of Genome Sciences, University of Washington, 3720 15th Ave. NE, Seattle, Washington 98195, USA
| | - Ting Wang
- Department of Genetics, Center for Genome Sciences and Systems Biology, Washington University in St Louis, 4444 Forest Park Ave, St Louis, Missouri 63108, USA
| | - Manolis Kellis
- 1] Computer Science and Artificial Intelligence Lab, Massachusetts Institute of Technology, 32 Vassar St, Cambridge, Massachusetts 02139, USA. [2] The Broad Institute of Harvard and MIT, 415 Main Street, Cambridge, Massachusetts 02142, USA
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365
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Saisho Y. β-cell dysfunction: Its critical role in prevention and management of type 2 diabetes. World J Diabetes 2015; 6:109-124. [PMID: 25685282 PMCID: PMC4317303 DOI: 10.4239/wjd.v6.i1.109] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 08/17/2014] [Accepted: 12/01/2014] [Indexed: 02/05/2023] Open
Abstract
Type 2 diabetes (T2DM) is characterized by insulin resistance and β-cell dysfunction. Although, in contrast to type 1 diabetes, insulin resistance is assumed to be a major pathophysiological feature of T2DM, T2DM never develops unless β-cells fail to compensate insulin resistance. Recent studies have revealed that a deficit of β-cell functional mass is an essential component of the pathophysiology of T2DM, implying that β-cell deficit is a common feature of both type 1 and type 2 diabetes. β-cell dysfunction is present at the diagnosis of T2DM and progressively worsens with disease duration. β-cell dysfunction is associated with worsening of glycemic control and treatment failure; thus, it is important to preserve or recover β-cell functional mass in the management of T2DM. Since β-cell regenerative capacity appears somewhat limited in humans, reducing β-cell workload appears to be the most effective way to preserve β-cell functional mass to date, underpinning the importance of lifestyle modification and weight loss for the treatment and prevention of T2DM. This review summarizes the current knowledge on β-cell functional mass in T2DM and discusses the treatment strategy for T2DM.
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366
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Xie R, Carrano AC, Sander M. A systems view of epigenetic networks regulating pancreas development and β-cell function. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2015; 7:1-11. [PMID: 25644779 DOI: 10.1002/wsbm.1287] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 11/20/2014] [Accepted: 12/03/2014] [Indexed: 01/08/2023]
Abstract
The development of the pancreas and determination of endocrine cell fate are controlled by a highly complex interplay of signaling events and transcriptional networks. It is now known that an interconnected epigenetic program is also required to drive these processes. Recent studies using genome-wide approaches have implicated epigenetic regulators, such as DNA and histone-modifying enzymes and noncoding RNAs, to play critical roles in pancreas development and the maintenance of cell identity and function. Furthermore, genome-wide analyses have implicated epigenetic changes as a casual factor in the pathogenesis of diabetes. In the future, genomic approaches to further our understanding of the role of epigenetics in endocrine cell development and function will be useful for devising strategies to produce or manipulate β-cells for therapies of diabetes.
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Affiliation(s)
- Ruiyu Xie
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, Sanford Consortium for Regenerative Medicine, University of California - San Diego, La Jolla, CA, USA
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Satterlee JS, Beckel-Mitchener A, Little R, Procaccini D, Rutter JL, Lossie AC. Neuroepigenomics: Resources, Obstacles, and Opportunities. NEUROEPIGENETICS 2015; 1:2-13. [PMID: 25722961 PMCID: PMC4337407 DOI: 10.1016/j.nepig.2014.10.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Long-lived post-mitotic cells, such as the majority of human neurons, must respond effectively to ongoing changes in neuronal stimulation or microenvironmental cues through transcriptional and epigenomic regulation of gene expression. The role of epigenomic regulation in neuronal function is of fundamental interest to the neuroscience community, as these types of studies have transformed our understanding of gene regulation in post-mitotic cells. This perspective article highlights many of the resources available to researchers interested in neuroepigenomic investigations and discusses some of the current obstacles and opportunities in neuroepigenomics.
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Affiliation(s)
- John S. Satterlee
- National Institute on Drug Abuse (NIDA), Division of Basic Neurobiology and Behavioral Research, 6001 Executive Boulevard, Bethesda, MD 20850, USA
| | - Andrea Beckel-Mitchener
- National Institute on Mental Health (NIMH), Division of Neuroscience and Basic Behavioral Science, 6001 Executive Boulevard Bethesda, MD 20892-9641, USA
| | - Roger Little
- National Institute on Drug Abuse (NIDA), Division of Basic Neurobiology and Behavioral Research, 6001 Executive Boulevard, Bethesda, MD 20850, USA
| | - Dena Procaccini
- National Institute on Drug Abuse (NIDA), Division of Basic Neurobiology and Behavioral Research, 6001 Executive Boulevard, Bethesda, MD 20850, USA
| | - Joni L. Rutter
- National Institute on Drug Abuse (NIDA), Division of Basic Neurobiology and Behavioral Research, 6001 Executive Boulevard, Bethesda, MD 20850, USA
| | - Amy C. Lossie
- Office of Behavioral and Social Sciences Research (OBSSR), Division of Program Coordination, Planning, and Strategic Initiatives, Office of the Director/National Institutes of Health (NIH), 31 Center Drive, Bethesda, MD 20892, USA
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368
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Schierding W, O’Sullivan JM. Connecting SNPs in Diabetes: A Spatial Analysis of Meta-GWAS Loci. Front Endocrinol (Lausanne) 2015; 6:102. [PMID: 26191039 PMCID: PMC4490250 DOI: 10.3389/fendo.2015.00102] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/13/2015] [Indexed: 11/23/2022] Open
Abstract
Meta-analyses of genome-wide association studies (GWAS) have improved our understanding of the genetic foundations of a number of diseases, including diabetes. However, single nucleotide polymorphisms (SNPs) that are identified by GWAS, especially those that fall outside of gene regions, do not always clearly link to the underlying biology. Despite this, these SNPs have often been validated through re-sequencing efforts as not just tag SNPs, but as causative SNPs, and so must play a role in disease development or progression. In this study, we show how the 3D genome (spatial connections) and trans-expression Quantitative Trait Loci connect diabetes loci from different GWAS meta-analyses, informing the backbone of regulatory networks. Our findings include a three-way functional-spatial connection between the TM6SF2, CTRB1-BCAR1, and CELSR2-PSRC1 loci (rs201189528, rs7202844, and rs7202844, respectively) connected through the KCNIP3 and BCAR1/BCAR3 loci, respectively. These spatial hubs serve as an example of how loci in genes with little biological connection to disease come together to contribute to the diabetes phenotype.
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Affiliation(s)
| | - Justin M. O’Sullivan
- Liggins Institute, University of Auckland, Auckland, New Zealand
- Gravida: National Centre for Growth and Development, University of Auckland, Auckland, New Zealand
- *Correspondence: Justin M. O’Sullivan, The Liggins Institute, University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand,
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369
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Abstract
Systems models of the ways transcription factor networks operate and evolve are essential for understanding cell identity, developmental commitment and regulatory variation. Terminologies from different techniques and disciplines may need to be adapted or put aside to make and test these models effectively.
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370
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Kluth O, Matzke D, Schulze G, Schwenk RW, Joost HG, Schürmann A. Differential transcriptome analysis of diabetes-resistant and -sensitive mouse islets reveals significant overlap with human diabetes susceptibility genes. Diabetes 2014; 63:4230-8. [PMID: 25053586 DOI: 10.2337/db14-0425] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Type 2 diabetes in humans and in obese mice is polygenic. In recent genome-wide association studies, genetic markers explaining a small portion of the genetic contribution to the disease were discovered. However, functional evidence linking these genes with the pathogenesis of diabetes is scarce. We performed RNA sequencing-based transcriptomics of islets from two obese mouse strains, a diabetes-susceptible (NZO) and a diabetes-resistant (B6-ob/ob) mouse, after a short glucose challenge and compared these results with human data. Alignment of 2,328 differentially expressed genes to 106 human diabetes candidate genes revealed an overlap of 20 genes, including TCF7L2, IGFBP2, CDKN2A, CDKN2B, GRB10, and PRC1. The data provide a functional validation of human diabetes candidate genes, including those involved in regulating islet cell recovery and proliferation, and identify additional candidates that could be involved in human β-cell failure.
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Affiliation(s)
- Oliver Kluth
- Department of Experimental Diabetology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany German Center for Diabetes Research, Neuherberg, Germany
| | - Daniela Matzke
- Department of Experimental Diabetology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany German Center for Diabetes Research, Neuherberg, Germany
| | - Gunnar Schulze
- Department of Experimental Diabetology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany German Center for Diabetes Research, Neuherberg, Germany
| | - Robert W Schwenk
- Department of Experimental Diabetology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany German Center for Diabetes Research, Neuherberg, Germany
| | - Hans-Georg Joost
- German Center for Diabetes Research, Neuherberg, Germany Department of Pharmacology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany
| | - Annette Schürmann
- Department of Experimental Diabetology, German Institute of Human Nutrition, Potsdam-Rehbruecke, Germany
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371
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Alenkvist I, Dyachok O, Tian G, Li J, Mehrabanfar S, Jin Y, Birnir B, Tengholm A, Welsh M. Absence of Shb impairs insulin secretion by elevated FAK activity in pancreatic islets. J Endocrinol 2014; 223:267-75. [PMID: 25274988 DOI: 10.1530/joe-14-0531] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The Src homology-2 domain containing protein B (SHB) has previously been shown to function as a pleiotropic adapter protein, conveying signals from receptor tyrosine kinases to intracellular signaling intermediates. The overexpression of Shb in β-cells promotes β-cell proliferation by increased insulin receptor substrate (IRS) and focal adhesion kinase (FAK) activity, whereas Shb deficiency causes moderate glucose intolerance and impaired first-peak insulin secretion. Using an array of techniques, including live-cell imaging, patch-clamping, immunoblotting, and semi-quantitative PCR, we presently investigated the causes of the abnormal insulin secretory characteristics in Shb-knockout mice. Shb-knockout islets displayed an abnormal signaling signature with increased activities of FAK, IRS, and AKT. β-catenin protein expression was elevated and it showed increased nuclear localization. However, there were no major alterations in the gene expression of various proteins involved in the β-cell secretory machinery. Nor was Shb deficiency associated with changes in glucose-induced ATP generation or cytoplasmic Ca(2+) handling. In contrast, the glucose-induced rise in cAMP, known to be important for the insulin secretory response, was delayed in the Shb-knockout compared with WT control. Inhibition of FAK increased the submembrane cAMP concentration, implicating FAK activity in the regulation of insulin exocytosis. In conclusion, Shb deficiency causes a chronic increase in β-cell FAK activity that perturbs the normal insulin secretory characteristics of β-cells, suggesting multi-faceted effects of FAK on insulin secretion depending on the mechanism of FAK activation.
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Affiliation(s)
- Ida Alenkvist
- Department of Medical Cell BiologyUppsala University, Box 571, Husargatan 3, 75123 Uppsala, SwedenDepartment of NeuroscienceUppsala University, Uppsala, Sweden
| | - Oleg Dyachok
- Department of Medical Cell BiologyUppsala University, Box 571, Husargatan 3, 75123 Uppsala, SwedenDepartment of NeuroscienceUppsala University, Uppsala, Sweden
| | - Geng Tian
- Department of Medical Cell BiologyUppsala University, Box 571, Husargatan 3, 75123 Uppsala, SwedenDepartment of NeuroscienceUppsala University, Uppsala, Sweden
| | - Jia Li
- Department of Medical Cell BiologyUppsala University, Box 571, Husargatan 3, 75123 Uppsala, SwedenDepartment of NeuroscienceUppsala University, Uppsala, Sweden
| | - Saba Mehrabanfar
- Department of Medical Cell BiologyUppsala University, Box 571, Husargatan 3, 75123 Uppsala, SwedenDepartment of NeuroscienceUppsala University, Uppsala, Sweden
| | - Yang Jin
- Department of Medical Cell BiologyUppsala University, Box 571, Husargatan 3, 75123 Uppsala, SwedenDepartment of NeuroscienceUppsala University, Uppsala, Sweden
| | - Bryndis Birnir
- Department of Medical Cell BiologyUppsala University, Box 571, Husargatan 3, 75123 Uppsala, SwedenDepartment of NeuroscienceUppsala University, Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell BiologyUppsala University, Box 571, Husargatan 3, 75123 Uppsala, SwedenDepartment of NeuroscienceUppsala University, Uppsala, Sweden
| | - Michael Welsh
- Department of Medical Cell BiologyUppsala University, Box 571, Husargatan 3, 75123 Uppsala, SwedenDepartment of NeuroscienceUppsala University, Uppsala, Sweden
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372
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Olsson AH, Volkov P, Bacos K, Dayeh T, Hall E, Nilsson EA, Ladenvall C, Rönn T, Ling C. Genome-wide associations between genetic and epigenetic variation influence mRNA expression and insulin secretion in human pancreatic islets. PLoS Genet 2014; 10:e1004735. [PMID: 25375650 PMCID: PMC4222689 DOI: 10.1371/journal.pgen.1004735] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 09/05/2014] [Indexed: 12/29/2022] Open
Abstract
Genetic and epigenetic mechanisms may interact and together affect biological processes and disease development. However, most previous studies have investigated genetic and epigenetic mechanisms independently, and studies examining their interactions throughout the human genome are lacking. To identify genetic loci that interact with the epigenome, we performed the first genome-wide DNA methylation quantitative trait locus (mQTL) analysis in human pancreatic islets. We related 574,553 single nucleotide polymorphisms (SNPs) with genome-wide DNA methylation data of 468,787 CpG sites targeting 99% of RefSeq genes in islets from 89 donors. We identified 67,438 SNP-CpG pairs in cis, corresponding to 36,783 SNPs (6.4% of tested SNPs) and 11,735 CpG sites (2.5% of tested CpGs), and 2,562 significant SNP-CpG pairs in trans, corresponding to 1,465 SNPs (0.3% of tested SNPs) and 383 CpG sites (0.08% of tested CpGs), showing significant associations after correction for multiple testing. These include reported diabetes loci, e.g. ADCY5, KCNJ11, HLA-DQA1, INS, PDX1 and GRB10. CpGs of significant cis-mQTLs were overrepresented in the gene body and outside of CpG islands. Follow-up analyses further identified mQTLs associated with gene expression and insulin secretion in human islets. Causal inference test (CIT) identified SNP-CpG pairs where DNA methylation in human islets is the potential mediator of the genetic association with gene expression or insulin secretion. Functional analyses further demonstrated that identified candidate genes (GPX7, GSTT1 and SNX19) directly affect key biological processes such as proliferation and apoptosis in pancreatic β-cells. Finally, we found direct correlations between DNA methylation of 22,773 (4.9%) CpGs with mRNA expression of 4,876 genes, where 90% of the correlations were negative when CpGs were located in the region surrounding transcription start site. Our study demonstrates for the first time how genome-wide genetic and epigenetic variation interacts to influence gene expression, islet function and potential diabetes risk in humans. Inter-individual variation in genetics and epigenetics affects biological processes and disease susceptibility. However, most studies have investigated genetic and epigenetic mechanisms independently and to uncover novel mechanisms affecting disease susceptibility there is a highlighted need to study interactions between these factors on a genome-wide scale. To identify novel loci affecting islet function and potentially diabetes, we performed the first genome-wide methylation quantitative trait locus (mQTL) analysis in human pancreatic islets including DNA methylation of 468,787 CpG sites located throughout the genome. Our results showed that DNA methylation of 11,735 CpGs in 4,504 unique genes is regulated by genetic factors located in cis (67,438 SNP-CpG pairs). Furthermore, significant mQTLs cover previously reported diabetes loci including KCNJ11, INS, HLA, PDX1 and GRB10. We also found mQTLs associated with gene expression and insulin secretion in human islets. By performing causality inference tests (CIT), we identified CpGs where DNA methylation potentially mediates the genetic impact on gene expression and insulin secretion. Our functional follow-up experiments further demonstrated that identified mQTLs/genes (GPX7, GSTT1 and SNX19) directly affect pancreatic β-cell function. Together, our study provides a detailed map of genome-wide associations between genetic and epigenetic variation, which affect gene expression and insulin secretion in human pancreatic islets.
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Affiliation(s)
- Anders H. Olsson
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Petr Volkov
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Karl Bacos
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Tasnim Dayeh
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Elin Hall
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Emma A. Nilsson
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Claes Ladenvall
- Department of Clinical Sciences, Diabetes and Endocrinology, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Tina Rönn
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
| | - Charlotte Ling
- Department of Clinical Sciences, Epigenetics and Diabetes, Lund University Diabetes Centre, Clinical Research Centre, Malmö, Sweden
- * E-mail:
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373
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Abstract
Gene enhancer elements are noncoding segments of DNA that play a central role in regulating transcriptional programs that control development, cell identity, and evolutionary processes. Recent studies have shown that noncoding single nucleotide polymorphisms (SNPs) that have been associated with risk for numerous common diseases through genome-wide association studies frequently lie in cell-type-specific enhancer elements. These enhancer variants probably influence transcriptional output, thereby offering a mechanistic basis to explain their association with risk for many common diseases. This review focuses on the identification and interpretation of disease-susceptibility variants that influence enhancer function. We discuss strategies for prioritizing the study of functional enhancer SNPs over those likely to be benign, review experimental and computational approaches to identifying the gene targets of enhancer variants, and highlight efforts to quantify the impact of enhancer variants on target transcript levels and cellular phenotypes. These studies are beginning to provide insights into the mechanistic basis of many common diseases, as well as into how we might translate this knowledge for improved disease diagnosis, prevention and treatments. Finally, we highlight five major challenges often associated with interpreting enhancer variants, and discuss recent technical advances that may help to surmount these challenges.
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Affiliation(s)
- Olivia Corradin
- />Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44122 USA
| | - Peter C Scacheri
- />Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44122 USA
- />Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106 USA
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374
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Parnell LD, Blokker BA, Dashti HS, Nesbeth PD, Cooper BE, Ma Y, Lee YC, Hou R, Lai CQ, Richardson K, Ordovás JM. CardioGxE, a catalog of gene-environment interactions for cardiometabolic traits. BioData Min 2014; 7:21. [PMID: 25368670 PMCID: PMC4217104 DOI: 10.1186/1756-0381-7-21] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 10/18/2014] [Indexed: 12/29/2022] Open
Abstract
Background Genetic understanding of complex traits has developed immensely over the past decade but remains hampered by incomplete descriptions of contribution to phenotypic variance. Gene-environment (GxE) interactions are one of these contributors and in the guise of diet and physical activity are important modulators of cardiometabolic phenotypes and ensuing diseases. Results We mined the scientific literature to collect GxE interactions from 386 publications for blood lipids, glycemic traits, obesity anthropometrics, vascular measures, inflammation and metabolic syndrome, and introduce CardioGxE, a gene-environment interaction resource. We then analyzed the genes and SNPs supporting cardiometabolic GxEs in order to demonstrate utility of GxE SNPs and to discern characteristics of these important genetic variants. We were able to draw many observations from our extensive analysis of GxEs. 1) The CardioGxE SNPs showed little overlap with variants identified by main effect GWAS, indicating the importance of environmental interactions with genetic factors on cardiometabolic traits. 2) These GxE SNPs were enriched in adaptation to climatic and geographical features, with implications on energy homeostasis and response to physical activity. 3) Comparison to gene networks responding to plasma cholesterol-lowering or regression of atherosclerotic plaques showed that GxE genes have a greater role in those responses, particularly through high-energy diets and fat intake, than do GWAS-identified genes for the same traits. Other aspects of the CardioGxE dataset were explored. Conclusions Overall, we demonstrate that SNPs supporting cardiometabolic GxE interactions often exhibit transcriptional effects or are under positive selection. Still, not all such SNPs can be assigned potential functional or regulatory roles often because data are lacking in specific cell types or from treatments that approximate the environmental factor of the GxE. With research on metabolic related complex disease risk embarking on genome-wide GxE interaction tests, CardioGxE will be a useful resource.
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Affiliation(s)
- Laurence D Parnell
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - Britt A Blokker
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - Hassan S Dashti
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - Paula-Dene Nesbeth
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - Brittany Elle Cooper
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - Yiyi Ma
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - Yu-Chi Lee
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - Ruixue Hou
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - Chao-Qiang Lai
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - Kris Richardson
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
| | - José M Ordovás
- JM-USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111, USA
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375
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Pdx1 and USF transcription factors co-ordinately regulate Alx3 gene expression in pancreatic β-cells. Biochem J 2014; 463:287-96. [DOI: 10.1042/bj20140643] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We investigated the transcriptional mechanisms regulating the expression of Alx3 in pancreatic islets. We found that the transcriptional transactivation of Alx3 in β-cells requires the co-operation of the islet-specific homeoprotein Pdx1 with the transcription factors USF1 and USF2.
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376
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Global genomic and transcriptomic analysis of human pancreatic islets reveals novel genes influencing glucose metabolism. Proc Natl Acad Sci U S A 2014; 111:13924-9. [PMID: 25201977 DOI: 10.1073/pnas.1402665111] [Citation(s) in RCA: 335] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Genetic variation can modulate gene expression, and thereby phenotypic variation and susceptibility to complex diseases such as type 2 diabetes (T2D). Here we harnessed the potential of DNA and RNA sequencing in human pancreatic islets from 89 deceased donors to identify genes of potential importance in the pathogenesis of T2D. We present a catalog of genetic variants regulating gene expression (eQTL) and exon use (sQTL), including many long noncoding RNAs, which are enriched in known T2D-associated loci. Of 35 eQTL genes, whose expression differed between normoglycemic and hyperglycemic individuals, siRNA of tetraspanin 33 (TSPAN33), 5'-nucleotidase, ecto (NT5E), transmembrane emp24 protein transport domain containing 6 (TMED6), and p21 protein activated kinase 7 (PAK7) in INS1 cells resulted in reduced glucose-stimulated insulin secretion. In addition, we provide a genome-wide catalog of allelic expression imbalance, which is also enriched in known T2D-associated loci. Notably, allelic imbalance in paternally expressed gene 3 (PEG3) was associated with its promoter methylation and T2D status. Finally, RNA editing events were less common in islets than previously suggested in other tissues. Taken together, this study provides new insights into the complexity of gene regulation in human pancreatic islets and better understanding of how genetic variation can influence glucose metabolism.
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377
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Fogarty MP, Cannon ME, Vadlamudi S, Gaulton KJ, Mohlke KL. Identification of a regulatory variant that binds FOXA1 and FOXA2 at the CDC123/CAMK1D type 2 diabetes GWAS locus. PLoS Genet 2014; 10:e1004633. [PMID: 25211022 PMCID: PMC4161327 DOI: 10.1371/journal.pgen.1004633] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 07/28/2014] [Indexed: 12/28/2022] Open
Abstract
Many of the type 2 diabetes loci identified through genome-wide association studies localize to non-protein-coding intronic and intergenic regions and likely contain variants that regulate gene transcription. The CDC123/CAMK1D type 2 diabetes association signal on chromosome 10 spans an intergenic region between CDC123 and CAMK1D and also overlaps the CDC123 3'UTR. To gain insight into the molecular mechanisms underlying the association signal, we used open chromatin, histone modifications and transcription factor ChIP-seq data sets from type 2 diabetes-relevant cell types to identify SNPs overlapping predicted regulatory regions. Two regions containing type 2 diabetes-associated variants were tested for enhancer activity using luciferase reporter assays. One SNP, rs11257655, displayed allelic differences in transcriptional enhancer activity in 832/13 and MIN6 insulinoma cells as well as in human HepG2 hepatocellular carcinoma cells. The rs11257655 risk allele T showed greater transcriptional activity than the non-risk allele C in all cell types tested. Using electromobility shift and supershift assays we demonstrated that the rs11257655 risk allele showed allele-specific binding to FOXA1 and FOXA2. We validated FOXA1 and FOXA2 enrichment at the rs11257655 risk allele using allele-specific ChIP in human islets. These results suggest that rs11257655 affects transcriptional activity through altered binding of a protein complex that includes FOXA1 and FOXA2, providing a potential molecular mechanism at this GWAS locus.
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Affiliation(s)
- Marie P. Fogarty
- Department of Genetics, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Maren E. Cannon
- Department of Genetics, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Swarooparani Vadlamudi
- Department of Genetics, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kyle J. Gaulton
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Karen L. Mohlke
- Department of Genetics, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
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378
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Hara K, Shojima N, Hosoe J, Kadowaki T. Genetic architecture of type 2 diabetes. Biochem Biophys Res Commun 2014; 452:213-20. [PMID: 25111817 DOI: 10.1016/j.bbrc.2014.08.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 08/04/2014] [Indexed: 02/07/2023]
Abstract
Genome-wide association studies (GWAS) have identified over 70 loci associated with type 2 diabetes (T2D). Most genetic variants associated with T2D are common variants with modest effects on T2D and are shared with major ancestry groups. To what extent the genetic component of T2D can be explained by common variants relies upon the shape of the genetic architecture of T2D. Fine mapping utilizing populations with different patterns of linkage disequilibrium and functional annotation derived from experiments in relevant tissues are mandatory to track down causal variants responsible for the pathogenesis of T2D.
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Affiliation(s)
- Kazuo Hara
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Nobuhiro Shojima
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Jun Hosoe
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
| | - Takashi Kadowaki
- The Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
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379
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Johnson ME, Schug J, Wells AD, Kaestner KH, Grant SFA. Genome-wide analyses of ChIP-Seq derived FOXA2 DNA occupancy in liver points to genetic networks underpinning multiple complex traits. J Clin Endocrinol Metab 2014; 99:E1580-5. [PMID: 24878043 PMCID: PMC4121035 DOI: 10.1210/jc.2013-4503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Forkhead Box A2 (FOXA2) exerts an influence on glucose homeostasis via activity in the liver. In addition, a key genome-wide association study (GWAS) recently demonstrated that genetic variation, namely rs6048205, at the FOXA2 locus is robustly associated with fasting glucose levels. Our hypothesis was that this DNA-binding protein regulates the expression of a set of molecular pathways critical to endocrine traits. METHODS Drawing on our laboratory and bioinformatic experience with chromatin immunoprecipitation followed by massively parallel sequencing, we analyzed our existing FOXA2 chromatin immunoprecipitation followed by massively parallel sequencing data generated in human liver, using the algorithm hypergeometric optimization of motif enrichment, to gain insight into its global genomic binding pattern from a disease perspective. RESULTS We performed a pathway analysis of the gene list using the gene set enrichment analysis algorithm, which yielded a number of significant annotations. Motivated by the fact that the FOXA2 locus has been implicated by GWAS, we cross-referenced the occupancy sites with the National Institutes of Health GWAS catalog and found strong evidence for the enrichment of loci implicated in endocrine, neuropsychiatric, cardiovascular, and cancer trait categories, but interestingly there was no evidence for enrichment for inflammation related traits. Intriguingly, a FOXA2 occupancy site coincided with rs6048205, suggesting that this variant confers its effect, at least partially, via a perturbation of a FOXA2 feedback mechanism. CONCLUSION Our data strongly suggest that FOXA2 is acting as a master regulator of key pathways that are enriched for loci implicated by GWAS for most trait categories, with the clear exception of inflammation, suggesting that this factor exerts its effect in this context via noninflammatory processes.
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Affiliation(s)
- Matthew E Johnson
- Division of Human Genetics (M.E.J., S.F.A.G.) and Department of Pathology and Laboratory Medicine (A.D.W.), The Children's Hospital of Philadelphia, and Department of Genetics and Institute of Diabetes, Obesity, and Metabolism (J.S., K.H.K., S.F.A.G.), and Department of Pediatrics (S.F.A.G.), Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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380
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Affiliation(s)
- T M Frayling
- Genetics of Complex Traits, Institute of Biomedical and Clinical Science, Peninsula Medical School, Exeter, UK
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381
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Thomsen SK, Gloyn AL. The pancreatic β cell: recent insights from human genetics. Trends Endocrinol Metab 2014; 25:425-34. [PMID: 24986330 PMCID: PMC4229643 DOI: 10.1016/j.tem.2014.05.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 05/02/2014] [Accepted: 05/07/2014] [Indexed: 12/14/2022]
Abstract
Diabetes mellitus is a metabolic disease characterised by relative or absolute pancreatic β cell dysfunction. Genetic variants implicated in disease risk can be identified by studying affected individuals. To understand the mechanisms driving genetic associations, variants must be translated through causative transcripts to biological insights. Studies into the genetic basis of Mendelian forms of diabetes have successfully identified genes involved in both β cell function and pancreatic development. For type 2 diabetes (T2D), genome-wide association studies (GWASs) are uncovering an ever-increasing number of susceptibility variants that exert their effect through β cell dysfunction, but translation to mechanistic understanding has in most cases been slow. Improved annotations of the islet genome and advances in whole-genome and -exome sequencing (WHS and WES) have facilitated recent progress.
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Affiliation(s)
- Soren K Thomsen
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Headington, OX3 7LE, UK
| | - Anna L Gloyn
- Oxford Centre for Diabetes, Endocrinology, and Metabolism, University of Oxford, Headington, OX3 7LE, UK; Oxford National Institute for Health Research (NIHR) Biomedical Research Centre, Churchill Hospital, Headington, OX3 7LE, UK.
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Benner C, van der Meulen T, Cacéres E, Tigyi K, Donaldson CJ, Huising MO. The transcriptional landscape of mouse beta cells compared to human beta cells reveals notable species differences in long non-coding RNA and protein-coding gene expression. BMC Genomics 2014; 15:620. [PMID: 25051960 PMCID: PMC4124169 DOI: 10.1186/1471-2164-15-620] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 07/10/2014] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Insulin producing beta cell and glucagon producing alpha cells are colocalized in pancreatic islets in an arrangement that facilitates the coordinated release of the two principal hormones that regulate glucose homeostasis and prevent both hypoglycemia and diabetes. However, this intricate organization has also complicated the determination of the cellular source(s) of the expression of genes that are detected in the islet. This reflects a significant gap in our understanding of mouse islet physiology, which reduces the effectiveness by which mice model human islet disease. RESULTS To overcome this challenge, we generated a bitransgenic reporter mouse that faithfully labels all beta and alpha cells in mouse islets to enable FACS-based purification and the generation of comprehensive transcriptomes of both populations. This facilitates systematic comparison across thousands of genes between the two major endocrine cell types of the islets of Langerhans whose principal hormones are of cardinal importance for glucose homeostasis. Our data leveraged against similar data for human beta cells reveal a core common beta cell transcriptome of 9900+ genes. Against the backdrop of overall similar beta cell transcriptomes, we describe marked differences in the repertoire of receptors and long non-coding RNAs between mouse and human beta cells. CONCLUSIONS The comprehensive mouse alpha and beta cell transcriptomes complemented by the comparison of the global (dis)similarities between mouse and human beta cells represent invaluable resources to boost the accuracy by which rodent models offer guidance in finding cures for human diabetes.
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Affiliation(s)
- Christopher Benner
- />Razzavi Newman Integrated Genomics and Bioinformatics Core, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Talitha van der Meulen
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Elena Cacéres
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Kristof Tigyi
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Cynthia J Donaldson
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
| | - Mark O Huising
- />Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037 USA
- />Department of Neurobiology, Physiology & Behavior, University of California, One Shields Avenue, 180 Briggs Hall, Davis, CA 95616 USA
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383
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Esguerra JLS, Eliasson L. Functional implications of long non-coding RNAs in the pancreatic islets of Langerhans. Front Genet 2014; 5:209. [PMID: 25071836 PMCID: PMC4083688 DOI: 10.3389/fgene.2014.00209] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 06/19/2014] [Indexed: 12/14/2022] Open
Abstract
Type-2 diabetes (T2D) is a complex disease characterized by insulin resistance in target tissues and impaired insulin release from pancreatic beta cells. As central tissue of glucose homeostasis, the pancreatic islet continues to be an important focus of research to understand the pathophysiology of the disease. The increased access to human pancreatic islets has resulted in improved knowledge of islet function, and together with advances in RNA sequencing and related technologies, revealed the transcriptional and epigenetic landscape of human islet cells. The discovery of thousands of long non-coding RNA (lncRNA) transcripts highly enriched in the pancreatic islet and/or specifically expressed in the beta-cells, points to yet another layer of gene regulation of many hitherto unknown mechanistic principles governing islet cell functions. Here we review fundamental islet physiology and propose functional implications of the lncRNAs in islet development and endocrine cell functions. We also take into account important differences between rodent and human islets in terms of morphology and function, and suggest how species-specific lncRNAs may partly influence gene regulation to define the unique phenotypic identity of an organism and the functions of its constituent cells. The implication of primate-specific lncRNAs will be far-reaching in all aspects of diabetes research, but most importantly in the identification and development of novel targets to improve pancreatic islet cell functions as a therapeutic approach to treat T2D.
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Affiliation(s)
- Jonathan L S Esguerra
- Islet Cell Exocytosis, Department of Clinical Sciences-Malmö, Lund University Diabetes Centre, Lund University Malmö, Sweden
| | - Lena Eliasson
- Islet Cell Exocytosis, Department of Clinical Sciences-Malmö, Lund University Diabetes Centre, Lund University Malmö, Sweden
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384
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Kameswaran V, Kaestner KH. The Missing lnc(RNA) between the pancreatic β-cell and diabetes. Front Genet 2014; 5:200. [PMID: 25071830 PMCID: PMC4077016 DOI: 10.3389/fgene.2014.00200] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 06/15/2014] [Indexed: 01/15/2023] Open
Abstract
Diabetes mellitus represents a group of complex metabolic diseases that result in impaired glucose homeostasis, which includes destruction of β-cells or the failure of these insulin-secreting cells to compensate for increased metabolic demand. Despite a strong interest in characterizing the transcriptome of the different human islet cell types to understand the molecular basis of diabetes, very little attention has been paid to the role of long non-coding RNAs (lncRNAs) and their contribution to this disease. Here we summarize the growing evidence for the potential role of these lncRNAs in β-cell function and dysregulation in diabetes, with a focus on imprinted genomic loci.
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Affiliation(s)
- Vasumathi Kameswaran
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
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385
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Pullen TJ, Rutter GA. Roles of lncRNAs in pancreatic beta cell identity and diabetes susceptibility. Front Genet 2014; 5:193. [PMID: 25071823 PMCID: PMC4076741 DOI: 10.3389/fgene.2014.00193] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 06/12/2014] [Indexed: 01/09/2023] Open
Abstract
Type 2 diabetes usually ensues from the inability of pancreatic beta cells to compensate for incipient insulin resistance. The loss of beta cell mass, function, and potentially beta cell identity contribute to this dysfunction to extents which are debated. In recent years, long non-coding RNAs (lncRNAs) have emerged as potentially providing a novel level of gene regulation implicating critical cellular processes such as pluripotency and differentiation. With over 1000 lncRNAs now identified in beta cells, there is growing evidence for their involvement in the above processes in these cells. While functional evidence on individual islet lncRNAs is still scarce, we discuss how lncRNAs could contribute to type 2 diabetes susceptibility, particularly at loci identified through genome-wide association studies as affecting disease risk.
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Affiliation(s)
- Timothy J Pullen
- Section of Cell Biology, Department of Medicine, Imperial Centre for Translational and Experimental Medicine, Imperial College London London, UK
| | - Guy A Rutter
- Section of Cell Biology, Department of Medicine, Imperial Centre for Translational and Experimental Medicine, Imperial College London London, UK
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386
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387
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Chia DJ. Minireview: mechanisms of growth hormone-mediated gene regulation. Mol Endocrinol 2014; 28:1012-25. [PMID: 24825400 DOI: 10.1210/me.2014-1099] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
GH exerts a diverse array of physiological actions that include prominent roles in growth and metabolism, with a major contribution via stimulating IGF-1 synthesis. GH achieves its effects by influencing gene expression profiles, and Igf1 is a key transcriptional target of GH signaling in liver and other tissues. This review examines the mechanisms of GH-mediated gene regulation that begin with signal transduction pathways activated downstream of the GH receptor and continue with chromatin events at target genes and additionally encompasses the topics of negative regulation and cross talk with other cellular inputs. The transcription factor, signal transducer and activator of transcription 5b, is regarded as the major signaling pathway by which GH achieves its physiological effects, including in stimulating Igf1 gene transcription in liver. Recent studies exploring the mechanisms of how activated signal transducer and activator of transcription 5b accomplishes this are highlighted, which begin to characterize epigenetic features at regulatory domains of the Igf1 locus. Further research in this field offers promise to better understand the GH-IGF-1 axis in normal physiology and disease and to identify strategies to manipulate the axis to improve human health.
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Affiliation(s)
- Dennis J Chia
- Department of Pediatrics, Icahn School of Medicine at Mt Sinai, New York, New York 10029
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388
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Das SK, Sharma NK. Expression quantitative trait analyses to identify causal genetic variants for type 2 diabetes susceptibility. World J Diabetes 2014; 5:97-114. [PMID: 24748924 PMCID: PMC3990322 DOI: 10.4239/wjd.v5.i2.97] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 02/21/2014] [Accepted: 03/14/2014] [Indexed: 02/05/2023] Open
Abstract
Type 2 diabetes (T2D) is a common metabolic disorder which is caused by multiple genetic perturbations affecting different biological pathways. Identifying genetic factors modulating the susceptibility of this complex heterogeneous metabolic phenotype in different ethnic and racial groups remains challenging. Despite recent success, the functional role of the T2D susceptibility variants implicated by genome-wide association studies (GWAS) remains largely unknown. Genetic dissection of transcript abundance or expression quantitative trait (eQTL) analysis unravels the genomic architecture of regulatory variants. Availability of eQTL information from tissues relevant for glucose homeostasis in humans opens a new avenue to prioritize GWAS-implicated variants that may be involved in triggering a causal chain of events leading to T2D. In this article, we review the progress made in the field of eQTL research and knowledge gained from those studies in understanding transcription regulatory mechanisms in human subjects. We highlight several novel approaches that can integrate eQTL analysis with multiple layers of biological information to identify ethnic-specific causal variants and gene-environment interactions relevant to T2D pathogenesis. Finally, we discuss how the eQTL analysis mediated search for “missing heritability” may lead us to novel biological and molecular mechanisms involved in susceptibility to T2D.
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389
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Call for data analysis papers. Nat Genet 2014. [DOI: 10.1038/ng.2914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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390
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Avrahami D, Kaestner KH. A cistrome roadmap for understanding pancreatic islet biology. Nat Genet 2014; 46:95-6. [PMID: 24473321 PMCID: PMC5351417 DOI: 10.1038/ng.2880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although dozens of common variants have been associated with increased risk of type 2 diabetes (T2D), the mechanisms by which these variants increase disease susceptibility are largely unknown. A new study mapping the human pancreatic islet cistrome provides a roadmap for exploring the effects of these variants and suggests that altered enhancer function might be a common contributor to the genetic risk of T2D.
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Affiliation(s)
- Dana Avrahami
- Department of Genetics and the Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Klaus H Kaestner
- Department of Genetics and the Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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391
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Johnson ME, Zhao J, Schug J, Deliard S, Xia Q, Guy VC, Sainz J, Kaestner KH, Wells AD, Grant SFA. Two novel type 2 diabetes loci revealed through integration of TCF7L2 DNA occupancy and SNP association data. BMJ Open Diabetes Res Care 2014; 2:e000052. [PMID: 25469308 PMCID: PMC4250976 DOI: 10.1136/bmjdrc-2014-000052] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 09/04/2014] [Accepted: 10/03/2014] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND The transcription factor 7-like 2 (TCF7L2) locus is strongly implicated in the pathogenesis of type 2 diabetes (T2D). We previously mapped the genomic regions bound by TCF7L2 using ChIP (chromatin immunoprecipitation)-seq in the colorectal carcinoma cell line, HCT116, revealing an unexpected highly significant over-representation of genome-wide association studies (GWAS) loci associated primarily with endocrine (in particular T2D) and cardiovascular traits. METHODS In order to further explore if this observed phenomenon occurs in other cell lines, we carried out ChIP-seq in HepG2 cells and leveraged ENCODE data for five additional cell lines. Given that only a minority of the predicted genetic component to most complex traits has been identified to date, plus our GWAS-related observations with respect to TCF7L2 occupancy, we investigated if restricting association analyses to the genes yielded from this approach, in order to reduce the constraints of multiple testing, could reveal novel T2D loci. RESULTS We found strong evidence for the continued enrichment of endocrine and cardiovascular GWAS categories, with additional support for cancer. When investigating all the known GWAS loci bound by TCF7L2 in the shortest gene list, derived from HCT116, the coronary artery disease-associated variant, rs46522 at the UBE2Z-GIP-ATP5G1-SNF8 locus, yielded significant association with T2D within DIAGRAM. Furthermore, when we analyzed tag-SNPs (single nucleotide polymorphisms) in genes not previously implicated by GWAS but bound by TCF7L2 within 5 kb, we observed a significant association of rs4780476 within CPPED1 in DIAGRAM. CONCLUSIONS ChIP-seq data generated with this GWAS-implicated transcription factor provided a biologically plausible method to limit multiple testing in the assessment of genome-wide genotyping data to uncover two novel T2D-associated loci.
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Affiliation(s)
- Matthew E Johnson
- Division of Human Genetics , The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania , USA
| | - Jianhua Zhao
- Division of Human Genetics , The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania , USA
| | - Jonathan Schug
- Department of Genetics and Institute of Diabetes, Obesity and Metabolism , Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania , USA
| | - Sandra Deliard
- Division of Human Genetics , The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania , USA
| | - Qianghua Xia
- Division of Human Genetics , The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania , USA
| | - Vanessa C Guy
- Division of Human Genetics , The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania , USA
| | - Jesus Sainz
- Institute of Biomedicine and Biotechnology of Cantabria (IBBTEC), Spanish National Research Council (CSIC) , Santander , Spain
| | - Klaus H Kaestner
- Department of Genetics and Institute of Diabetes, Obesity and Metabolism , Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania , USA
| | - Andrew D Wells
- Pathology and Laboratory Medicine , Children's Hospital of Philadelphia , Philadelphia, Pennsylvania , USA
| | - Struan F A Grant
- Division of Human Genetics , The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania , USA ; Department of Genetics and Institute of Diabetes, Obesity and Metabolism , Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania , USA ; Department of Pediatrics , Perelman School of Medicine, University of Pennsylvania , Philadelphia, Pennsylvania , USA
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