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Wang SE, Xiong Y, Jang MA, Park KS, Donahue M, Velez J, Jin J, Jiang YH. Newly developed oral bioavailable EHMT2 inhibitor as a potential epigenetic therapy for Prader-Willi syndrome. Mol Ther 2024; 32:2662-2675. [PMID: 38796700 DOI: 10.1016/j.ymthe.2024.05.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 03/29/2024] [Accepted: 05/23/2024] [Indexed: 05/28/2024] Open
Abstract
Prader-Willi syndrome (PWS) is the prototypic genomic disorder resulting from deficiency of paternally expressed genes in the human chromosome 15q11-q13 region. The unique molecular mechanism involving epigenetic modifications renders PWS as the most attractive candidate to explore a proof-of-concept of epigenetic therapy in humans. The premise is that epigenetic modulations could reactivate the repressed PWS candidate genes from the maternal chromosome and offer therapeutic benefit. Our prior study identifies an EHMT2/G9a inhibitor, UNC0642, that reactivates the expression of PWS genes via reduction of H3K9me2. However, low brain permeability and poor oral bioavailability of UNC0642 preclude its advancement into translational studies in humans. In this study, a newly developed inhibitor, MS152, modified from the structure of UNC0642, has better brain penetration and greater potency and selectivity against EHMT2/G9a. MS152 reactivated maternally silenced PWS genes in PWS patient fibroblasts and in brain and liver tissues of PWS mouse models. Importantly, the molecular efficacy of oral administration is comparable with the intraperitoneal route. MS152 treatment in newborns ameliorates the perinatal lethality and poor growth, maintaining reactivation in a PWS mouse model at postnatal 90 days. Our findings provide strong support for MS152 as a first-in-class inhibitor to advance the epigenetic therapy of PWS in humans.
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Affiliation(s)
- Sung Eun Wang
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven CT 06520, USA
| | - Yan Xiong
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences, Oncological Sciences and Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Mi-Ae Jang
- Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, South Korea
| | - Kwang-Su Park
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences, Oncological Sciences and Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Meaghan Donahue
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven CT 06520, USA
| | - Julia Velez
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences, Oncological Sciences and Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Jian Jin
- Mount Sinai Center for Therapeutics Discovery, Departments of Pharmacological Sciences, Oncological Sciences and Neuroscience, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
| | - Yong-Hui Jiang
- Department of Genetics, Yale University School of Medicine, 333 Cedar Street, New Haven CT 06520, USA; Department of Neuroscience, Yale University School of Medicine, 333 Cedar Street, New Haven CT 06520, USA; Department of Pediatrics, Yale University School of Medicine, 333 Cedar Street, New Haven CT 06520, USA.
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2
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Gutierrez Fugón OJ, Sharifi O, Heath N, Soto DC, Gomez JA, Yasui DH, Mendiola AJP, O'Geen H, Beitnere U, Tomkova M, Haghani V, Dillon G, Segal DJ, LaSalle JM. Integration of CTCF loops, methylome, and transcriptome in differentiating LUHMES as a model for imprinting dynamics of the 15q11-q13 locus in human neurons. Hum Mol Genet 2024:ddae111. [PMID: 39045627 DOI: 10.1093/hmg/ddae111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 06/30/2024] [Accepted: 07/17/2024] [Indexed: 07/25/2024] Open
Abstract
Human cell line models, including the neuronal precursor line LUHMES, are important for investigating developmental transcriptional dynamics within imprinted regions, particularly the 15q11-q13 Angelman (AS) and Prader-Willi (PWS) syndrome locus. AS results from loss of maternal UBE3A in neurons, where the paternal allele is silenced by a convergent antisense transcript UBE3A-ATS, a lncRNA that terminates at PWAR1 in non-neurons. qRT-PCR analysis confirmed the exclusive and progressive increase in UBE3A-ATS in differentiating LUHMES neurons, validating their use for studying UBE3A silencing. Genome-wide transcriptome analyses revealed changes to 11 834 genes during neuronal differentiation, including the upregulation of most genes within the 15q11-q13 locus. To identify dynamic changes in chromatin loops linked to transcriptional activity, we performed a HiChIP validated by 4C, which identified two neuron-specific CTCF loops between MAGEL2-SNRPN and PWAR1-UBE3A. To determine if allele-specific differentially methylated regions (DMR) may be associated with CTCF loop anchors, whole genome long-read nanopore sequencing was performed. We identified a paternally hypomethylated DMR near the SNRPN upstream loop anchor exclusive to neurons and a paternally hypermethylated DMR near the PWAR1 CTCF anchor exclusive to undifferentiated cells, consistent with increases in neuronal transcription. Additionally, DMRs near CTCF loop anchors were observed in both cell types, indicative of allele-specific differences in chromatin loops regulating imprinted transcription. These results provide an integrated view of the 15q11-q13 epigenetic landscape during LUHMES neuronal differentiation, underscoring the complex interplay of transcription, chromatin looping, and DNA methylation. They also provide insights for future therapeutic approaches for AS and PWS.
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Affiliation(s)
- Orangel J Gutierrez Fugón
- Genome Center, Department of Biochemistry and Molecular Medicine, University of California Davis, 451 Health Sciences Dr., Davis, CA 95616, United States
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, 1275 Med Science Dr, Davis, CA 95616, United States
| | - Osman Sharifi
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, 1275 Med Science Dr, Davis, CA 95616, United States
| | - Nicholas Heath
- Genome Center, Department of Biochemistry and Molecular Medicine, University of California Davis, 451 Health Sciences Dr., Davis, CA 95616, United States
| | - Daniela C Soto
- Genome Center, Department of Biochemistry and Molecular Medicine, University of California Davis, 451 Health Sciences Dr., Davis, CA 95616, United States
- Department of Psychiatry and Biobehavioral Sciences, University of California Los Angeles, 757 Westwood Plaza #4, Los Angeles, CA 90095, United States
| | - J Antonio Gomez
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, 1275 Med Science Dr, Davis, CA 95616, United States
- Department of Natural Science, Seaver College, Pepperdine University, 24255 Pacific Coast Hwy, Malibu, CA 90263, United States
| | - Dag H Yasui
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, 1275 Med Science Dr, Davis, CA 95616, United States
| | - Aron Judd P Mendiola
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, 1275 Med Science Dr, Davis, CA 95616, United States
| | - Henriette O'Geen
- Genome Center, Department of Biochemistry and Molecular Medicine, University of California Davis, 451 Health Sciences Dr., Davis, CA 95616, United States
| | - Ulrika Beitnere
- Genome Center, Department of Biochemistry and Molecular Medicine, University of California Davis, 451 Health Sciences Dr., Davis, CA 95616, United States
- Max Delbrück Center for Molecular Medicine, Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Marketa Tomkova
- Genome Center, Department of Biochemistry and Molecular Medicine, University of California Davis, 451 Health Sciences Dr., Davis, CA 95616, United States
- Ludwig Cancer Research Center, University of Oxford, Old Road Campus Research Build, Roosevelt Dr, Headington, Oxford OX3 7DQ, United Kingdom
| | - Viktoria Haghani
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, 1275 Med Science Dr, Davis, CA 95616, United States
| | - Greg Dillon
- Genetics and Neurodevelopmental Disorders Unit, Biogen, 225 Binney Street Cambridge, MA 02142 United States
| | - David J Segal
- Genome Center, Department of Biochemistry and Molecular Medicine, University of California Davis, 451 Health Sciences Dr., Davis, CA 95616, United States
| | - Janine M LaSalle
- Department of Medical Microbiology and Immunology, School of Medicine, University of California Davis, 1275 Med Science Dr, Davis, CA 95616, United States
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Rohm D, Black JB, McCutcheon SR, Barrera A, Morone DJ, Nuttle X, de Esch CE, Tai DJ, Talkowski ME, Iglesias N, Gersbach CA. Activation of the imprinted Prader-Willi Syndrome locus by CRISPR-based epigenome editing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.03.583177. [PMID: 38496583 PMCID: PMC10942373 DOI: 10.1101/2024.03.03.583177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Epigenome editing with DNA-targeting technologies such as CRISPR-dCas9 can be used to dissect gene regulatory mechanisms and potentially treat associated disorders. For example, Prader-Willi Syndrome (PWS) is caused by loss of paternally expressed imprinted genes on chromosome 15q11.2-q13.3, although the maternal allele is intact but epigenetically silenced. Using CRISPR repression and activation screens in human induced pluripotent stem cells (iPSCs), we identified genomic elements that control expression of the PWS gene SNRPN from the paternal and maternal chromosomes. We showed that either targeted transcriptional activation or DNA demethylation can activate the silenced maternal SNRPN and downstream PWS transcripts. However, these two approaches function at unique regions, preferentially activating different transcript variants and involving distinct epigenetic reprogramming mechanisms. Remarkably, transient expression of the targeted demethylase leads to stable, long-term maternal SNRPN expression in PWS iPSCs. This work uncovers targeted epigenetic manipulations to reprogram a disease-associated imprinted locus and suggests possible therapeutic interventions.
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Affiliation(s)
- Dahlia Rohm
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Center for Advanced Genomic Technologies, Duke University, Durham, NC 27708, USA
| | - Joshua B. Black
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Center for Advanced Genomic Technologies, Duke University, Durham, NC 27708, USA
| | - Sean R. McCutcheon
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Center for Advanced Genomic Technologies, Duke University, Durham, NC 27708, USA
| | - Alejandro Barrera
- Center for Advanced Genomic Technologies, Duke University, Durham, NC 27708, USA
- Department of Biostatistics and Bioinformatics, Duke University, Durham, NC 27708, USA
| | - Daniel J. Morone
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Center for Advanced Genomic Technologies, Duke University, Durham, NC 27708, USA
| | - Xander Nuttle
- Center for Genomic Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Celine E. de Esch
- Center for Genomic Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Derek J.C. Tai
- Center for Genomic Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Michael E. Talkowski
- Center for Genomic Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA
- Program in Medical and Population Genetics and Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Nahid Iglesias
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Center for Advanced Genomic Technologies, Duke University, Durham, NC 27708, USA
| | - Charles A. Gersbach
- Department of Biomedical Engineering, Duke University, Durham, NC 27708, USA
- Center for Advanced Genomic Technologies, Duke University, Durham, NC 27708, USA
- Department of Surgery, Duke University Medical Center, Durham, NC 27710, USA
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4
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Wang SE, Jiang YH. Novel epigenetic molecular therapies for imprinting disorders. Mol Psychiatry 2023; 28:3182-3193. [PMID: 37626134 PMCID: PMC10618104 DOI: 10.1038/s41380-023-02208-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 07/21/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023]
Abstract
Genomic imprinting disorders are caused by the disruption of genomic imprinting processes leading to a deficit or increase of an active allele. Their unique molecular mechanisms underlying imprinted genes offer an opportunity to investigate epigenetic-based therapy for reactivation of an inactive allele or reduction of an active allele. Current treatments are based on managing symptoms, not targeting the molecular mechanisms underlying imprinting disorders. Here, we highlight molecular approaches of therapeutic candidates in preclinical and clinical studies for individual imprinting disorders. These include the significant progress of discovery and testing of small molecules, antisense oligonucleotides, and CRISPR mediated genome editing approaches as new therapeutic strategies. We discuss the significant challenges of translating these promising therapies from the preclinical stage to the clinic, especially for genome editing based approaches.
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Affiliation(s)
- Sung Eun Wang
- Department of Genetics, Yale University School of Medicine, 333 Cedar street, New Haven, CT, 06520, USA
| | - Yong-Hui Jiang
- Department of Genetics, Yale University School of Medicine, 333 Cedar street, New Haven, CT, 06520, USA.
- Department of Neuroscience, Yale University School of Medicine, 333 Cedar street, New Haven, CT, 06520, USA.
- Department of Pediatrics, Yale University School of Medicine, 333 Cedar street, New Haven, CT, 06520, USA.
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5
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Punt AM, Judson MC, Sidorov MS, Williams BN, Johnson NS, Belder S, den Hertog D, Davis CR, Feygin MS, Lang PF, Jolfaei MA, Curran PJ, van IJcken WF, Elgersma Y, Philpot BD. Molecular and behavioral consequences of Ube3a gene overdosage in mice. JCI Insight 2022; 7:158953. [PMID: 36134658 PMCID: PMC9675564 DOI: 10.1172/jci.insight.158953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 08/17/2022] [Indexed: 12/01/2022] Open
Abstract
Chromosome 15q11.2-q13.1 duplication syndrome (Dup15q syndrome) is a severe neurodevelopmental disorder characterized by intellectual disability, impaired motor coordination, and autism spectrum disorder. Chromosomal multiplication of the UBE3A gene is presumed to be the primary driver of Dup15q pathophysiology, given that UBE3A exhibits maternal monoallelic expression in neurons and that maternal duplications typically yield far more severe neurodevelopmental outcomes than paternal duplications. However, studies into the pathogenic effects of UBE3A overexpression in mice have yielded conflicting results. Here, we investigated the neurodevelopmental impact of Ube3a gene overdosage using bacterial artificial chromosome-based transgenic mouse models (Ube3aOE) that recapitulate the increases in Ube3a copy number most often observed in Dup15q. In contrast to previously published Ube3a overexpression models, Ube3aOE mice were indistinguishable from wild-type controls on a number of molecular and behavioral measures, despite suffering increased mortality when challenged with seizures, a phenotype reminiscent of sudden unexpected death in epilepsy. Collectively, our data support a model wherein pathogenic synergy between UBE3A and other overexpressed 15q11.2-q13.1 genes is required for full penetrance of Dup15q syndrome phenotypes.
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Affiliation(s)
- A. Mattijs Punt
- Department of Clinical Genetics and Department of Neuroscience and
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC, Rotterdam, Netherlands
| | - Matthew C. Judson
- Neuroscience Center, Department of Cell Biology and Physiology, and the Carolina Institute for Developmental Disabilities and
| | - Michael S. Sidorov
- Neuroscience Center, Department of Cell Biology and Physiology, and the Carolina Institute for Developmental Disabilities and
| | - Brittany N. Williams
- Neuroscience Center, Department of Cell Biology and Physiology, and the Carolina Institute for Developmental Disabilities and
| | - Naomi S. Johnson
- Neuroscience Center, Department of Cell Biology and Physiology, and the Carolina Institute for Developmental Disabilities and
| | - Sabine Belder
- Department of Clinical Genetics and Department of Neuroscience and
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC, Rotterdam, Netherlands
| | - Dion den Hertog
- Department of Clinical Genetics and Department of Neuroscience and
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC, Rotterdam, Netherlands
| | - Courtney R. Davis
- Neuroscience Center, Department of Cell Biology and Physiology, and the Carolina Institute for Developmental Disabilities and
| | - Maximillian S. Feygin
- Neuroscience Center, Department of Cell Biology and Physiology, and the Carolina Institute for Developmental Disabilities and
| | - Patrick F. Lang
- Neuroscience Center, Department of Cell Biology and Physiology, and the Carolina Institute for Developmental Disabilities and
| | - Mehrnoush Aghadavoud Jolfaei
- Department of Clinical Genetics and Department of Neuroscience and
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC, Rotterdam, Netherlands
| | - Patrick J. Curran
- Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | | | - Ype Elgersma
- Department of Clinical Genetics and Department of Neuroscience and
- ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus MC, Rotterdam, Netherlands
| | - Benjamin D. Philpot
- Neuroscience Center, Department of Cell Biology and Physiology, and the Carolina Institute for Developmental Disabilities and
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Abstract
In mammals, parthenogenesis is limited because of problems arising from genomic imprinting. Here, we report live mammalian offspring derived from single unfertilized eggs. This was achieved by the targeted DNA methylation rewriting of seven imprinting control regions. By designing guide RNAs with protospacer adjacent motif (PAM) sequences matching one allele but not the other, dCas9-Dnmt3a or dCpf1-Tet1 enables targeted DNA methylation editing in an allele-specific manner. The success of parthenogenesis in mammals opens many opportunities in agriculture, research, and medicine. In mammals, a new life starts with the fusion of an oocyte and a sperm cell. Parthenogenesis, a way of generating offspring solely from female gametes, is limited because of problems arising from genomic imprinting. Here, we report live mammalian offspring derived from single unfertilized oocytes, which was achieved by targeted DNA methylation rewriting of seven imprinting control regions. Oocyte coinjection of catalytically inactive Cas9 (dCas9)-Dnmt3a or dCpf1-Tet1 messenger RNA (mRNA) with single-guide RNAs (sgRNAs) targeting specific regions induced de novo methylation or demethylation, respectively, of the targeted region. Following parthenogenetic activation, these edited regions showed maintenance of methylation as naturally established regions during early preimplantation development. The transfer of modified parthenogenetic embryos into foster mothers resulted in significantly extended development and finally in the generation of viable full-term offspring. These data demonstrate that parthenogenesis can be achieved by targeted epigenetic rewriting of multiple critical imprinting control regions.
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Fanis P, Morrou M, Tomazou M, Michailidou K, Spyrou GM, Toumba M, Skordis N, Neocleous V, Phylactou LA. Methylation status of hypothalamic Mkrn3 promoter across puberty. Front Endocrinol (Lausanne) 2022; 13:1075341. [PMID: 36714607 PMCID: PMC9880154 DOI: 10.3389/fendo.2022.1075341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/20/2022] [Indexed: 01/15/2023] Open
Abstract
Makorin RING finger protein 3 (MKRN3) is an important factor located on chromosome 15 in the imprinting region associated with Prader-Willi syndrome. Imprinted MKRN3 is expressed in hypothalamic regions essential for the onset of puberty and mutations in the gene have been found in patients with central precocious puberty. The pubertal process is largely controlled by epigenetic mechanisms that include, among other things, DNA methylation at CpG dinucleotides of puberty-related genes. In the present study, we investigated the methylation status of the Mkrn3 promoter in the hypothalamus of the female mouse before, during and after puberty. Initially, we mapped the 32 CpG dinucleotides in the promoter, the 5'UTR and the first 50 nucleotides of the coding region of the Mkrn3 gene. Moreover, we identified a short CpG island region (CpG islet) located within the promoter. Methylation analysis using bisulfite sequencing revealed that CpG dinucleotides were methylated regardless of developmental stage, with the lowest levels of methylation being found within the CpG islet region. In addition, the CpG islet region showed significantly lower methylation levels at the pre-pubertal stage when compared with the pubertal or post-pubertal stage. Finally, in silico analysis of transcription factor binding sites on the Mkrn3 CpG islet identified the recruitment of 29 transcriptional regulators of which 14 were transcriptional repressors. Our findings demonstrate the characterization and differential methylation of the CpG dinucleotides located in the Mkrn3 promoter that could influence the transcriptional activity in pre-pubertal compared to pubertal or post-pubertal period. Further studies are needed to clarify the possible mechanisms and effects of differential methylation of the Mkrn3 promoter.
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Affiliation(s)
- Pavlos Fanis
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Maria Morrou
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Marios Tomazou
- Department of Bioinformatics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Kyriaki Michailidou
- Biostatistics Unit, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - George M. Spyrou
- Department of Bioinformatics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Meropi Toumba
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- Child Endocrine Care, Department of Pediatrics, Aretaeio Hospital, Nicosia, Cyprus
| | - Nicos Skordis
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- Division of Pediatric Endocrinology, Paedi Center for Specialized Pediatrics, Nicosia, Cyprus
- Medical School, University of Nicosia, Nicosia, Cyprus
| | - Vassos Neocleous
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Leonidas A. Phylactou
- Department of Molecular Genetics, Function and Therapy, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- *Correspondence: Leonidas A. Phylactou,
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Wang T, Li J, Yang L, Wu M, Ma Q. The Role of Long Non-coding RNAs in Human Imprinting Disorders: Prospective Therapeutic Targets. Front Cell Dev Biol 2021; 9:730014. [PMID: 34760887 PMCID: PMC8573313 DOI: 10.3389/fcell.2021.730014] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/23/2021] [Indexed: 12/26/2022] Open
Abstract
Genomic imprinting is a term used for an intergenerational epigenetic inheritance and involves a subset of genes expressed in a parent-of-origin-dependent way. Imprinted genes are expressed preferentially from either the paternally or maternally inherited allele. Long non-coding RNAs play essential roles in regulating this allele-specific expression. In several well-studied imprinting clusters, long non-coding RNAs have been found to be essential in regulating temporal- and spatial-specific establishment and maintenance of imprinting patterns. Furthermore, recent insights into the epigenetic pathological mechanisms underlying human genomic imprinting disorders suggest that allele-specific expressed imprinted long non-coding RNAs serve as an upstream regulator of the expression of other protein-coding or non-coding imprinted genes in the same cluster. Aberrantly expressed long non-coding RNAs result in bi-allelic expression or silencing of neighboring imprinted genes. Here, we review the emerging roles of long non-coding RNAs in regulating the expression of imprinted genes, especially in human imprinting disorders, and discuss three strategies targeting the central long non-coding RNA UBE3A-ATS for the purpose of developing therapies for the imprinting disorders Prader-Willi syndrome and Angelman syndrome. In summary, a better understanding of long non-coding RNA-related mechanisms is key to the development of potential therapeutic targets for human imprinting disorders.
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Affiliation(s)
- Tingxuan Wang
- Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Jianjian Li
- Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Liuyi Yang
- Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Manyin Wu
- Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Qing Ma
- Shenzhen Key Laboratory of Synthetic Genomics, Guangdong Provincial Key Laboratory of Synthetic Genomics, CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
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Ruiz de la Cruz M, de la Cruz Montoya AH, Rojas Jiménez EA, Martínez Gregorio H, Díaz Velásquez CE, Paredes de la Vega J, de la Cruz Hernández-Hernández F, Vaca Paniagua F. Cis-Acting Factors Causing Secondary Epimutations: Impact on the Risk for Cancer and Other Diseases. Cancers (Basel) 2021; 13:cancers13194807. [PMID: 34638292 PMCID: PMC8508567 DOI: 10.3390/cancers13194807] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 08/09/2021] [Accepted: 08/15/2021] [Indexed: 12/25/2022] Open
Abstract
Epigenetics affects gene expression and contributes to disease development by alterations known as epimutations. Hypermethylation that results in transcriptional silencing of tumor suppressor genes has been described in patients with hereditary cancers and without pathogenic variants in the coding region of cancer susceptibility genes. Although somatic promoter hypermethylation of these genes can occur in later stages of the carcinogenic process, constitutional methylation can be a crucial event during the first steps of tumorigenesis, accelerating tumor development. Primary epimutations originate independently of changes in the DNA sequence, while secondary epimutations are a consequence of a mutation in a cis or trans-acting factor. Secondary epimutations have a genetic basis in cis of the promoter regions of genes involved in familial cancers. This highlights epimutations as a novel carcinogenic mechanism whose contribution to human diseases is underestimated by the scarcity of the variants described. In this review, we provide an overview of secondary epimutations and present evidence of their impact on cancer. We propose the necessity for genetic screening of loci associated with secondary epimutations in familial cancer as part of prevention programs to improve molecular diagnosis, secondary prevention, and reduce the mortality of these diseases.
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Affiliation(s)
- Miguel Ruiz de la Cruz
- Laboratorio Nacional en Salud, Diagnóstico Molecular y Efecto Ambiental en Enfermedades Crónico-Degenerativas, Facultad de Estudios Superiores Iztacala, Tlalnepantla 54090, Mexico; (M.R.d.l.C.); (E.A.R.J.); (H.M.G.); (C.E.D.V.); (J.P.d.l.V.)
- Avenida Instituto Politécnico Nacional # 2508, Colonia San Pedro Zacatenco, Delegación Gustavo A. Madero, C.P. Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City 07360, Mexico;
| | | | - Ernesto Arturo Rojas Jiménez
- Laboratorio Nacional en Salud, Diagnóstico Molecular y Efecto Ambiental en Enfermedades Crónico-Degenerativas, Facultad de Estudios Superiores Iztacala, Tlalnepantla 54090, Mexico; (M.R.d.l.C.); (E.A.R.J.); (H.M.G.); (C.E.D.V.); (J.P.d.l.V.)
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, UNAM, Tlalnepantla 54090, Mexico;
| | - Héctor Martínez Gregorio
- Laboratorio Nacional en Salud, Diagnóstico Molecular y Efecto Ambiental en Enfermedades Crónico-Degenerativas, Facultad de Estudios Superiores Iztacala, Tlalnepantla 54090, Mexico; (M.R.d.l.C.); (E.A.R.J.); (H.M.G.); (C.E.D.V.); (J.P.d.l.V.)
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, UNAM, Tlalnepantla 54090, Mexico;
| | - Clara Estela Díaz Velásquez
- Laboratorio Nacional en Salud, Diagnóstico Molecular y Efecto Ambiental en Enfermedades Crónico-Degenerativas, Facultad de Estudios Superiores Iztacala, Tlalnepantla 54090, Mexico; (M.R.d.l.C.); (E.A.R.J.); (H.M.G.); (C.E.D.V.); (J.P.d.l.V.)
| | - Jimena Paredes de la Vega
- Laboratorio Nacional en Salud, Diagnóstico Molecular y Efecto Ambiental en Enfermedades Crónico-Degenerativas, Facultad de Estudios Superiores Iztacala, Tlalnepantla 54090, Mexico; (M.R.d.l.C.); (E.A.R.J.); (H.M.G.); (C.E.D.V.); (J.P.d.l.V.)
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, UNAM, Tlalnepantla 54090, Mexico;
| | - Fidel de la Cruz Hernández-Hernández
- Avenida Instituto Politécnico Nacional # 2508, Colonia San Pedro Zacatenco, Delegación Gustavo A. Madero, C.P. Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), Mexico City 07360, Mexico;
| | - Felipe Vaca Paniagua
- Laboratorio Nacional en Salud, Diagnóstico Molecular y Efecto Ambiental en Enfermedades Crónico-Degenerativas, Facultad de Estudios Superiores Iztacala, Tlalnepantla 54090, Mexico; (M.R.d.l.C.); (E.A.R.J.); (H.M.G.); (C.E.D.V.); (J.P.d.l.V.)
- Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, UNAM, Tlalnepantla 54090, Mexico;
- Subdirección de Investigación Básica, Instituto Nacional de Cancerología, Ciudad de México 14080, Mexico
- Correspondence: ; Tel.: +52-55-5623-1333 (ext. 39788)
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10
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Fetit R, Hillary RF, Price DJ, Lawrie SM. The neuropathology of autism: A systematic review of post-mortem studies of autism and related disorders. Neurosci Biobehav Rev 2021; 129:35-62. [PMID: 34273379 DOI: 10.1016/j.neubiorev.2021.07.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/13/2021] [Accepted: 07/10/2021] [Indexed: 02/07/2023]
Abstract
Post-mortem studies allow for the direct investigation of brain tissue in those with autism and related disorders. Several review articles have focused on aspects of post-mortem abnormalities but none has brought together the entire post-mortem literature. Here, we systematically review the evidence from post-mortem studies of autism, and of related disorders that present with autistic features. The literature consists of a small body of studies with small sample sizes, but several remarkably consistent findings are evident. Cortical layering is largely undisturbed, but there are consistent reductions in minicolumn numbers and aberrant myelination. Transcriptomics repeatedly implicate abberant synaptic, metabolic, proliferation, apoptosis and immune pathways. Sufficient replicated evidence is available to implicate non-coding RNA, aberrant epigenetic profiles, GABAergic, glutamatergic and glial dysfunction in autism pathogenesis. Overall, the cerebellum and frontal cortex are most consistently implicated, sometimes revealing distinct region-specific alterations. The literature on related disorders such as Rett syndrome, Fragile X and copy number variations (CNVs) predisposing to autism is particularly small and inconclusive. Larger studies, matched for gender, developmental stage, co-morbidities and drug treatment are required.
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Affiliation(s)
- Rana Fetit
- Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.
| | - Robert F Hillary
- Centre for Genomic and Experimental Medicine, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - David J Price
- Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Stephen M Lawrie
- Division of Psychiatry, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH10 5HF, UK; Patrick Wild Centre, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, EH10 5HF, UK
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11
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Pellikaan K, van Woerden GM, Kleinendorst L, Rosenberg AGW, Horsthemke B, Grosser C, van Zutven LJCM, van Rossum EFC, van der Lely AJ, Resnick JL, Brüggenwirth HT, van Haelst MM, de Graaff LCG. The Diagnostic Journey of a Patient with Prader-Willi-Like Syndrome and a Unique Homozygous SNURF-SNRPN Variant; Bio-Molecular Analysis and Review of the Literature. Genes (Basel) 2021; 12:genes12060875. [PMID: 34200226 PMCID: PMC8227738 DOI: 10.3390/genes12060875] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 12/11/2022] Open
Abstract
Prader–Willi syndrome (PWS) is a rare genetic condition characterized by hypotonia, intellectual disability, and hypothalamic dysfunction, causing pituitary hormone deficiencies and hyperphagia, ultimately leading to obesity. PWS is most often caused by the loss of expression of a cluster of genes on chromosome 15q11.2-13. Patients with Prader–Willi-like syndrome (PWLS) display features of the PWS phenotype without a classical PWS genetic defect. We describe a 46-year-old patient with PWLS, including hypotonia, intellectual disability, hyperphagia, and pituitary hormone deficiencies. Routine genetic tests for PWS were normal, but a homozygous missense variant NM_003097.3(SNRPN):c.193C>T, p.(Arg65Trp) was identified. Single nucleotide polymorphism array showed several large regions of homozygosity, caused by high-grade consanguinity between the parents. Our functional analysis, the ‘Pipeline for Rapid in silico, in vivo, in vitro Screening of Mutations’ (PRiSM) screen, showed that overexpression of SNRPN-p.Arg65Trp had a dominant negative effect, strongly suggesting pathogenicity. However, it could not be confirmed that the variant was responsible for the phenotype of the patient. In conclusion, we present a unique homozygous missense variant in SNURF-SNRPN in a patient with PWLS. We describe the diagnostic trajectory of this patient and the possible contributors to her phenotype in light of the current literature on the genotype–phenotype relationship in PWS.
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Affiliation(s)
- Karlijn Pellikaan
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Centre Rotterdam, 3015 GD Rotterdam, The Netherlands; (K.P.); (A.G.W.R.); (E.F.C.v.R.); (A.J.v.d.L.)
- Dutch Centre of Reference for Prader-Willi Syndrome, 3015 GD Rotterdam, The Netherlands
| | - Geeske M. van Woerden
- Department of Neuroscience, Erasmus University Medical Centre, 3015 GD Rotterdam, The Netherlands;
- The ENCORE Expertise Centre for Neurodevelopmental Disorders, Erasmus University Medical Centre, 3015 GD Rotterdam, The Netherlands
- Department of Clinical Genetics, Erasmus University Medical Centre, 3015 GD Rotterdam, The Netherlands; (L.J.C.M.v.Z.); (H.T.B.)
| | - Lotte Kleinendorst
- Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, 1081 HV Amsterdam, The Netherlands; (L.K.); (M.M.v.H.)
| | - Anna G. W. Rosenberg
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Centre Rotterdam, 3015 GD Rotterdam, The Netherlands; (K.P.); (A.G.W.R.); (E.F.C.v.R.); (A.J.v.d.L.)
- Dutch Centre of Reference for Prader-Willi Syndrome, 3015 GD Rotterdam, The Netherlands
| | - Bernhard Horsthemke
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; (B.H.); (C.G.)
| | - Christian Grosser
- Institute of Human Genetics, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany; (B.H.); (C.G.)
- Praxis für Humangenetik Tübingen, 72076 Tuebingen, Germany
| | - Laura J. C. M. van Zutven
- Department of Clinical Genetics, Erasmus University Medical Centre, 3015 GD Rotterdam, The Netherlands; (L.J.C.M.v.Z.); (H.T.B.)
| | - Elisabeth F. C. van Rossum
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Centre Rotterdam, 3015 GD Rotterdam, The Netherlands; (K.P.); (A.G.W.R.); (E.F.C.v.R.); (A.J.v.d.L.)
- Obesity Center CGG, Erasmus MC, University Medical Centre Rotterdam, 3015 GD Rotterdam, The Netherlands
| | - Aart J. van der Lely
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Centre Rotterdam, 3015 GD Rotterdam, The Netherlands; (K.P.); (A.G.W.R.); (E.F.C.v.R.); (A.J.v.d.L.)
| | - James L. Resnick
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA;
| | - Hennie T. Brüggenwirth
- Department of Clinical Genetics, Erasmus University Medical Centre, 3015 GD Rotterdam, The Netherlands; (L.J.C.M.v.Z.); (H.T.B.)
| | - Mieke M. van Haelst
- Department of Clinical Genetics, Amsterdam UMC, University of Amsterdam, 1081 HV Amsterdam, The Netherlands; (L.K.); (M.M.v.H.)
| | - Laura C. G. de Graaff
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, University Medical Centre Rotterdam, 3015 GD Rotterdam, The Netherlands; (K.P.); (A.G.W.R.); (E.F.C.v.R.); (A.J.v.d.L.)
- Dutch Centre of Reference for Prader-Willi Syndrome, 3015 GD Rotterdam, The Netherlands
- The ENCORE Expertise Centre for Neurodevelopmental Disorders, Erasmus University Medical Centre, 3015 GD Rotterdam, The Netherlands
- Academic Centre for Growth Disorders, Erasmus MC Rotterdam, 3015 GD Rotterdam, The Netherlands
- Correspondence: ; Tel.: +31-618843010
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12
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Mendiola AJP, LaSalle JM. Epigenetics in Prader-Willi Syndrome. Front Genet 2021; 12:624581. [PMID: 33659026 PMCID: PMC7917289 DOI: 10.3389/fgene.2021.624581] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 01/18/2021] [Indexed: 11/16/2022] Open
Abstract
Prader-Willi Syndrome (PWS) is a rare neurodevelopmental disorder that affects approximately 1 in 20,000 individuals worldwide. Symptom progression in PWS is classically characterized by two nutritional stages. Stage 1 is hypotonia characterized by poor muscle tone that leads to poor feeding behavior causing failure to thrive in early neonatal life. Stage 2 is followed by the development of extreme hyperphagia, also known as insatiable eating and fixation on food that often leads to obesity in early childhood. Other major features of PWS include obsessive-compulsive and hoarding behaviors, intellectual disability, and sleep abnormalities. PWS is genetic disorder mapping to imprinted 15q11.2-q13.3 locus, specifically at the paternally expressed SNORD116 locus of small nucleolar RNAs and noncoding host gene transcripts. SNORD116 is processed into several noncoding components and is hypothesized to orchestrate diurnal changes in metabolism through epigenetics, according to functional studies. Here, we review the current status of epigenetic mechanisms in PWS, with an emphasis on an emerging role for SNORD116 in circadian and sleep phenotypes. We also summarize current ongoing therapeutic strategies, as well as potential implications for more common human metabolic and psychiatric disorders.
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Affiliation(s)
| | - Janine M. LaSalle
- Department of Medical Microbiology and Immunology, Genome Center, MIND Institute, University of California, Davis, Davis, CA, United States
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13
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Sadikovic B, Levy MA, Kerkhof J, Aref-Eshghi E, Schenkel L, Stuart A, McConkey H, Henneman P, Venema A, Schwartz CE, Stevenson RE, Skinner SA, DuPont BR, Fletcher RS, Balci TB, Siu VM, Granadillo JL, Masters J, Kadour M, Friez MJ, van Haelst MM, Mannens MMAM, Louie RJ, Lee JA, Tedder ML, Alders M. Clinical epigenomics: genome-wide DNA methylation analysis for the diagnosis of Mendelian disorders. Genet Med 2021; 23:1065-1074. [PMID: 33547396 PMCID: PMC8187150 DOI: 10.1038/s41436-020-01096-4] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/29/2020] [Accepted: 12/31/2020] [Indexed: 01/23/2023] Open
Abstract
Purpose We describe the clinical implementation of genome-wide DNA methylation analysis in rare disorders across the EpiSign diagnostic laboratory network and the assessment of results and clinical impact in the first subjects tested. Methods We outline the logistics and data flow between an integrated network of clinical diagnostics laboratories in Europe, the United States, and Canada. We describe the clinical validation of EpiSign using 211 specimens and assess the test performance and diagnostic yield in the first 207 subjects tested involving two patient subgroups: the targeted cohort (subjects with previous ambiguous/inconclusive genetic findings including genetic variants of unknown clinical significance) and the screening cohort (subjects with clinical findings consistent with hereditary neurodevelopmental syndromes and no previous conclusive genetic findings). Results Among the 207 subjects tested, 57 (27.6%) were positive for a diagnostic episignature including 48/136 (35.3%) in the targeted cohort and 8/71 (11.3%) in the screening cohort, with 4/207 (1.9%) remaining inconclusive after EpiSign analysis. Conclusion This study describes the implementation of diagnostic clinical genomic DNA methylation testing in patients with rare disorders. It provides strong evidence of clinical utility of EpiSign analysis, including the ability to provide conclusive findings in the majority of subjects tested.
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Affiliation(s)
- Bekim Sadikovic
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada. .,Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada.
| | - Michael A Levy
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - Jennifer Kerkhof
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - Erfan Aref-Eshghi
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - Laila Schenkel
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - Alan Stuart
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - Haley McConkey
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - Peter Henneman
- Amsterdam University Medical Center, University of Amsterdam, Department of Clinical Genetics, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands
| | - Andrea Venema
- Amsterdam University Medical Center, University of Amsterdam, Department of Clinical Genetics, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands
| | | | | | | | | | | | - Tugce B Balci
- Department of Pediatrics, Division of Medical Genetics, Western University, London, ON, Canada.,Medical Genetics Program of Southwestern Ontario, London Health Sciences Centre, London, ON, Canada
| | - Victoria Mok Siu
- Department of Pediatrics, Division of Medical Genetics, Western University, London, ON, Canada.,Medical Genetics Program of Southwestern Ontario, London Health Sciences Centre, London, ON, Canada
| | - Jorge L Granadillo
- Division of Genetics and Genomic Medicine, Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Jennefer Masters
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | - Mike Kadour
- Molecular Genetics Laboratory, Molecular Diagnostics Division, London Health Sciences Centre, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Western University, London, ON, Canada
| | | | - Mieke M van Haelst
- Amsterdam University Medical Center, University of Amsterdam, Department of Clinical Genetics, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands
| | - Marcel M A M Mannens
- Amsterdam University Medical Center, University of Amsterdam, Department of Clinical Genetics, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands
| | | | | | | | - Marielle Alders
- Amsterdam University Medical Center, University of Amsterdam, Department of Clinical Genetics, Amsterdam Reproduction and Development Research Institute, Amsterdam, The Netherlands.
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14
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Javed S, Selliah T, Lee YJ, Huang WH. Dosage-sensitive genes in autism spectrum disorders: From neurobiology to therapy. Neurosci Biobehav Rev 2020; 118:538-567. [PMID: 32858083 DOI: 10.1016/j.neubiorev.2020.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/26/2020] [Accepted: 08/17/2020] [Indexed: 12/24/2022]
Abstract
Autism spectrum disorders (ASDs) are a group of heterogenous neurodevelopmental disorders affecting 1 in 59 children. Syndromic ASDs are commonly associated with chromosomal rearrangements or dosage imbalance involving a single gene. Many of these genes are dosage-sensitive and regulate transcription, protein homeostasis, and synaptic function in the brain. Despite vastly different molecular perturbations, syndromic ASDs share core symptoms including social dysfunction and repetitive behavior. However, each ASD subtype has a unique pathogenic mechanism and combination of comorbidities that require individual attention. We have learned a great deal about how these dosage-sensitive genes control brain development and behaviors from genetically-engineered mice. Here we describe the clinical features of eight monogenic neurodevelopmental disorders caused by dosage imbalance of four genes, as well as recent advances in using genetic mouse models to understand their pathogenic mechanisms and develop intervention strategies. We propose that applying newly developed quantitative molecular and neuroscience technologies will advance our understanding of the unique neurobiology of each disorder and enable the development of personalized therapy.
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Affiliation(s)
- Sehrish Javed
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Tharushan Selliah
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Yu-Ju Lee
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Wei-Hsiang Huang
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.
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15
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Molecular-Genetic Diagnostics of Angelman Syndrome – The Bulgarian Experience. ACTA MEDICA BULGARICA 2020. [DOI: 10.2478/amb-2020-0002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
Objective: The aim of the study was to determine the molecular mechanisms of mutagenesis in Bulgarian patients with Angelman syndrome (AS). AS is a severe neurodevelopmental disorder caused by loss of expression in brain of the maternally inherited UBE3A gene as a result of various 15q11.2-q13 alterations.
Material and Methods: In total 24 patients (11 boys, 13 girls) from 22 unrelated families with suspected clinical diagnosis AS were analysed. We used methylation specific PCR, multiplex ligation-dependent probe amplification, methylation sensitive MLPA, and direct sequencing of the UBE3A gene.
Results: In 9 families (41%) pathogenic mutations were detected, which confirmed the clinical diagnosis on а molecular-genetic level. In 4 (44%) of these families we found 15q11-q13 region deletion with breakpoints BP1-BP3 or BP2-BP3. In 1 (11%) of the families we found imprinting defect: deletion of the AS-SRO regulatory region (part of the PWS-AS imprinting center). In 1 (11%) of the families we detected a rare finding – paternal uniparental disomy of chromosome 15. In 3 (33%) of the families diff erent point mutations in the UBE3A gene were detected: two novel missence mutations c.488T > C; p.Leu163Ser and c.1832A > T; p.Gln611Leu, and one known frameshift mutation c.2576_2579delAAGA; p.Lys859Argfs*4.
Conclusion: The obtained results helped us to develop a systematic diagnostic algorithm in order to provide proper diagnosis for the patients with AS. Combining excellent knowledge of the molecular mechanisms of mutagenesis and proper molecular-genetic testing approaches is a cornerstone in the management of AS patients, ensuring AS families would receive both adequate genetic counseling and prophylaxis of the disease in the future.
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16
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Nechin J, Tunstall E, Raymond N, Hamagami N, Pathmanabhan C, Forestier S, Davis TL. Hemimethylation of CpG dyads is characteristic of secondary DMRs associated with imprinted loci and correlates with 5-hydroxymethylcytosine at paternally methylated sequences. Epigenetics Chromatin 2019; 12:64. [PMID: 31623686 PMCID: PMC6796366 DOI: 10.1186/s13072-019-0309-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 10/09/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In mammals, the regulation of imprinted genes is controlled by differential methylation at imprinting control regions which acquire parent of origin-specific methylation patterns during gametogenesis and retain differences in allelic methylation status throughout fertilization and subsequent somatic cell divisions. In addition, many imprinted genes acquire differential methylation during post-implantation development; these secondary differentially methylated regions appear necessary to maintain the imprinted expression state of individual genes. Despite the requirement for both types of differentially methylated sequence elements to achieve proper expression across imprinting clusters, methylation patterns are more labile at secondary differentially methylated regions. To understand the nature of this variability, we analyzed CpG dyad methylation patterns at both paternally and maternally methylated imprinted loci within multiple imprinting clusters. RESULTS We determined that both paternally and maternally methylated secondary differentially methylated regions associated with imprinted genes display high levels of hemimethylation, 29-49%, in comparison to imprinting control regions which exhibited 8-12% hemimethylation. To explore how hemimethylation could arise, we assessed the differentially methylated regions for the presence of 5-hydroxymethylcytosine which could cause methylation to be lost via either passive and/or active demethylation mechanisms. We found enrichment of 5-hydroxymethylcytosine at paternally methylated secondary differentially methylated regions, but not at the maternally methylated sites we analyzed in this study. CONCLUSIONS We found high levels of hemimethylation to be a generalizable characteristic of secondary differentially methylated regions associated with imprinted genes. We propose that 5-hydroxymethylcytosine enrichment may be responsible for the variability in methylation status at paternally methylated secondary differentially methylated regions associated with imprinted genes. We further suggest that the high incidence of hemimethylation at secondary differentially methylated regions must be counteracted by continuous methylation acquisition at these loci.
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Affiliation(s)
- Julianna Nechin
- Department of Biology, Bryn Mawr College, 101 N. Merion Avenue, Bryn Mawr, PA, 19010-2899, USA
| | - Emma Tunstall
- Department of Biology, Bryn Mawr College, 101 N. Merion Avenue, Bryn Mawr, PA, 19010-2899, USA
| | - Naideline Raymond
- Department of Biology, Bryn Mawr College, 101 N. Merion Avenue, Bryn Mawr, PA, 19010-2899, USA
| | - Nicole Hamagami
- Department of Biology, Bryn Mawr College, 101 N. Merion Avenue, Bryn Mawr, PA, 19010-2899, USA
| | - Chris Pathmanabhan
- Department of Biology, Bryn Mawr College, 101 N. Merion Avenue, Bryn Mawr, PA, 19010-2899, USA
| | - Samantha Forestier
- Department of Biology, Bryn Mawr College, 101 N. Merion Avenue, Bryn Mawr, PA, 19010-2899, USA
| | - Tamara L Davis
- Department of Biology, Bryn Mawr College, 101 N. Merion Avenue, Bryn Mawr, PA, 19010-2899, USA.
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17
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Kim Y, Wang SE, Jiang YH. Epigenetic therapy of Prader-Willi syndrome. Transl Res 2019; 208:105-118. [PMID: 30904443 PMCID: PMC6527448 DOI: 10.1016/j.trsl.2019.02.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 02/25/2019] [Accepted: 02/26/2019] [Indexed: 01/05/2023]
Abstract
Prader-Willi syndrome (PWS) is a complex and multisystem neurobehavioral disorder. The molecular mechanism of PWS is deficiency of paternally expressed gene gene or genes from the chromosome 15q11-q13. Due to imprinted gene regulation, the same genes in the maternal chromosome 15q11-q13 are structurally intact but transcriptionally repressed by an epigenetic mechanism. The unique molecular defect underlying PWS renders an exciting opportunity to explore epigenetic-based therapy to reactivate the expression of repressed PWS genes from the maternal chromosome. Inactivation of H3K9m3 methyltransferase SETDB1 and zinc finger protein ZNF274 results in reactivation of SNRPN and SNORD116 cluster from the maternal chromosomes in PWS patient iPSCs and iPSC-derived neurons, respectively. High content screening of small molecule libraries using cells derived from transgenic mice carrying the SNRPN-EGFP fusion protein has discovered that inhibitors of EHMT2/G9a, a histone 3 lysine 9 methyltransferase, are capable of reactivating expression of paternally expressed SNRPN and SNORD116 from the maternal chromosome, both in cultured PWS patient-derived fibroblasts and in a PWS mouse model. Treatment with an EMHT2/G9a inhibitor also rescues perinatal lethality and failure to thrive phenotypes in a PWS mouse model. These findings present the first evidence to support a proof-of-principle for epigenetic-based therapy for the PWS in humans.
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Affiliation(s)
- Yuna Kim
- Department of Pediatrics, Duke University of School of Medicine, Durham, North Carolina
| | - Sung Eun Wang
- Department of Pediatrics, Duke University of School of Medicine, Durham, North Carolina
| | - Yong-Hui Jiang
- Department of Pediatrics, Duke University of School of Medicine, Durham, North Carolina; Department of Neurobiology, Duke University of School of Medicine, Durham, North Carolina; Department of Program in Genetics and Genomics, Duke University of School of Medicine, Durham, North Carolina; Department of Program in Cellular and Molecular Biology, Duke University of School of Medicine, Durham, North Carolina.
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18
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Hartin SN, Hossain WA, Francis D, Godler DE, Barkataki S, Butler MG. Analysis of the Prader-Willi syndrome imprinting center using droplet digital PCR and next-generation whole-exome sequencing. Mol Genet Genomic Med 2019; 7:e00575. [PMID: 30793526 PMCID: PMC6465664 DOI: 10.1002/mgg3.575] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 12/13/2018] [Accepted: 01/02/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Detailed analysis of imprinting center (IC) defects in individuals with Prader-Willi syndrome (PWS) is not readily available beyond chromosomal microarray (MA) analysis, and such testing is important for a more accurate diagnosis and recurrence risks. This is the first feasibility study of newly developed droplet digital polymerase chain reaction (ddPCR) examining DNA copy number differences in the PWS IC region of those with IC defects. METHODS The study cohort included 17 individuals without 15q11-q13 deletions or maternal disomy but with IC defects as determined by genotype analysis showing biparental inheritance. Seven sets of parents and two healthy, unrelated controls were also analyzed. RESULTS Copy number differences were distinguished by comparing the number of positive droplets detected by IC probes to those from a chromosome 15 reference probe, GABRβ3. The ddPCR findings were compared to results from other methods including MA, and whole-exome sequencing (WES) with 100% concordance. The study also estimated the frequency of IC microdeletions and identified gene variants by WES that may impact phenotypes including CPT2 and NTRK1 genes. CONCLUSION Droplet digital polymerase chain reaction is a cost-effective method that can be used to confirm the presence of microdeletions in PWS with impact on genetic counseling and recurrence risks for families.
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Affiliation(s)
- Samantha N. Hartin
- Departments of Psychiatry & Behavioral Sciences and PediatricsUniversity of Kansas Medical CenterKansas CityKansas
| | - Waheeda A. Hossain
- Departments of Psychiatry & Behavioral Sciences and PediatricsUniversity of Kansas Medical CenterKansas CityKansas
| | - David Francis
- Cyto‐molecular Diagnostic Research LaboratoryRoyal Children's Hospital, Victorian Clinical Genetics Services and Murdoch Children's Research InstituteMelbourneVictoriaAustralia
| | - David E. Godler
- Cyto‐molecular Diagnostic Research LaboratoryRoyal Children's Hospital, Victorian Clinical Genetics Services and Murdoch Children's Research InstituteMelbourneVictoriaAustralia
| | | | - Merlin G. Butler
- Departments of Psychiatry & Behavioral Sciences and PediatricsUniversity of Kansas Medical CenterKansas CityKansas
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19
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Lorgen-Ritchie M, Murray AD, Ferguson-Smith AC, Richards M, Horgan GW, Phillips LH, Hoad G, Gall I, Harrison K, McNeill G, Ito M, Haggarty P. Imprinting methylation in SNRPN and MEST1 in adult blood predicts cognitive ability. PLoS One 2019; 14:e0211799. [PMID: 30707743 PMCID: PMC6358095 DOI: 10.1371/journal.pone.0211799] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 01/21/2019] [Indexed: 01/01/2023] Open
Abstract
Genomic imprinting is important for normal brain development and aberrant imprinting has been associated with impaired cognition. We studied the imprinting status in selected imprints (H19, IGF2, SNRPN, PEG3, MEST1, NESPAS, KvDMR, IG-DMR and ZAC1) by pyrosequencing in blood samples from longitudinal cohorts born in 1936 (n = 485) and 1921 (n = 223), and anterior hippocampus, posterior hippocampus, periventricular white matter, and thalamus from brains donated to the Aberdeen Brain Bank (n = 4). MEST1 imprint methylation was related to childhood cognitive ability score (-0.416 95% CI -0.792,-0.041; p = 0.030), with the strongest effect evident in males (-0.929 95% CI -1.531,-0.326; p = 0.003). SNRPN imprint methylation was also related to childhood cognitive ability (+0.335 95%CI 0.008,0.663; p = 0.045). A significant association was also observed for SNRPN methylation and adult crystallised cognitive ability (+0.262 95%CI 0.007,0.517; p = 0.044). Further testing of significant findings in a second cohort from the same region, but born in 1921, resulted in similar effect sizes and greater significance when the cohorts were combined (MEST1; -0.371 95% CI -0.677,-0.065; p = 0.017; SNRPN; +0.361 95% CI 0.079,0.643; p = 0.012). For SNRPN and MEST1 and four other imprints the methylation levels in blood and in the five brain regions were similar. Methylation of the paternally expressed, maternally methylated genes SNRPN and MEST1 in adult blood was associated with cognitive ability in childhood. This is consistent with the known importance of the SNRPN containing 15q11-q13 and the MEST1 containing 7q31-34 regions in cognitive function. These findings, and their sex specific nature in MEST1, point to new mechanisms through which complex phenotypes such as cognitive ability may be inherited. These mechanisms are potentially relevant to both the heritable and non-heritable components of cognitive ability. The process of epigenetic imprinting—within SNRPN and MEST1 in particular—and the factors that influence it, are worthy of further study in relation to the determinants of cognitive ability.
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Affiliation(s)
- Marlene Lorgen-Ritchie
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Alison D. Murray
- Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Marcus Richards
- MRC Unit for Lifelong Health and Ageing, University College London, London, United Kingdom
| | - Graham W. Horgan
- Biomathematics and Statistics Scotland, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Gwen Hoad
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Ishbel Gall
- Department of Pathology, N.H.S. Grampian, Aberdeen, United Kingdom
| | - Kristina Harrison
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Geraldine McNeill
- Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Mitsuteru Ito
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Paul Haggarty
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
- * E-mail:
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20
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Lorgen-Ritchie M, Murray AD, Ferguson-Smith AC, Richards M, Horgan GW, Phillips LH, Hoad G, Gall I, Harrison K, McNeill G, Ito M, Haggarty P. Imprinting methylation in SNRPN and MEST1 in adult blood predicts cognitive ability. PLoS One 2019; 14:e0211799. [PMID: 30707743 PMCID: PMC6358095 DOI: 10.1371/journal.pone.0211799 10.1371/journal.pone.0215422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Genomic imprinting is important for normal brain development and aberrant imprinting has been associated with impaired cognition. We studied the imprinting status in selected imprints (H19, IGF2, SNRPN, PEG3, MEST1, NESPAS, KvDMR, IG-DMR and ZAC1) by pyrosequencing in blood samples from longitudinal cohorts born in 1936 (n = 485) and 1921 (n = 223), and anterior hippocampus, posterior hippocampus, periventricular white matter, and thalamus from brains donated to the Aberdeen Brain Bank (n = 4). MEST1 imprint methylation was related to childhood cognitive ability score (-0.416 95% CI -0.792,-0.041; p = 0.030), with the strongest effect evident in males (-0.929 95% CI -1.531,-0.326; p = 0.003). SNRPN imprint methylation was also related to childhood cognitive ability (+0.335 95%CI 0.008,0.663; p = 0.045). A significant association was also observed for SNRPN methylation and adult crystallised cognitive ability (+0.262 95%CI 0.007,0.517; p = 0.044). Further testing of significant findings in a second cohort from the same region, but born in 1921, resulted in similar effect sizes and greater significance when the cohorts were combined (MEST1; -0.371 95% CI -0.677,-0.065; p = 0.017; SNRPN; +0.361 95% CI 0.079,0.643; p = 0.012). For SNRPN and MEST1 and four other imprints the methylation levels in blood and in the five brain regions were similar. Methylation of the paternally expressed, maternally methylated genes SNRPN and MEST1 in adult blood was associated with cognitive ability in childhood. This is consistent with the known importance of the SNRPN containing 15q11-q13 and the MEST1 containing 7q31-34 regions in cognitive function. These findings, and their sex specific nature in MEST1, point to new mechanisms through which complex phenotypes such as cognitive ability may be inherited. These mechanisms are potentially relevant to both the heritable and non-heritable components of cognitive ability. The process of epigenetic imprinting-within SNRPN and MEST1 in particular-and the factors that influence it, are worthy of further study in relation to the determinants of cognitive ability.
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Affiliation(s)
- Marlene Lorgen-Ritchie
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Alison D. Murray
- Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Marcus Richards
- MRC Unit for Lifelong Health and Ageing, University College London, London, United Kingdom
| | - Graham W. Horgan
- Biomathematics and Statistics Scotland, University of Aberdeen, Aberdeen, United Kingdom
| | | | - Gwen Hoad
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Ishbel Gall
- Department of Pathology, N.H.S. Grampian, Aberdeen, United Kingdom
| | - Kristina Harrison
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
| | - Geraldine McNeill
- Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Mitsuteru Ito
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Paul Haggarty
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, United Kingdom
- * E-mail:
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21
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A bipartite boundary element restricts UBE3A imprinting to mature neurons. Proc Natl Acad Sci U S A 2019; 116:2181-2186. [PMID: 30674673 DOI: 10.1073/pnas.1815279116] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Angelman syndrome (AS) is a severe neurodevelopmental disorder caused by the loss of function from the maternal allele of UBE3A, a gene encoding an E3 ubiquitin ligase. UBE3A is only expressed from the maternally inherited allele in mature human neurons due to tissue-specific genomic imprinting. Imprinted expression of UBE3A is restricted to neurons by expression of UBE3A antisense transcript (UBE3A-ATS) from the paternally inherited allele, which silences the paternal allele of UBE3A in cis However, the mechanism restricting UBE3A-ATS expression and UBE3A imprinting to neurons is not understood. We used CRISPR/Cas9-mediated genome editing to functionally define a bipartite boundary element critical for neuron-specific expression of UBE3A-ATS in humans. Removal of this element led to up-regulation of UBE3A-ATS without repressing paternal UBE3A However, increasing expression of UBE3A-ATS in the absence of the boundary element resulted in full repression of paternal UBE3A, demonstrating that UBE3A imprinting requires both the loss of function from the boundary element as well as the up-regulation of UBE3A-ATS These results suggest that manipulation of the competition between UBE3A-ATS and UBE3A may provide a potential therapeutic approach for AS.
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22
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Langouët M, Glatt-Deeley HR, Chung MS, Dupont-Thibert CM, Mathieux E, Banda EC, Stoddard CE, Crandall L, Lalande M. Zinc finger protein 274 regulates imprinted expression of transcripts in Prader-Willi syndrome neurons. Hum Mol Genet 2019; 27:505-515. [PMID: 29228278 DOI: 10.1093/hmg/ddx420] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 12/01/2017] [Indexed: 01/09/2023] Open
Abstract
Prader-Willi syndrome (PWS) is characterized by neonatal hypotonia, developmental delay and hyperphagia/obesity and is caused by the absence of paternal contribution to chromosome 15q11-q13. Using induced pluripotent stem cell (iPSC) models of PWS, we previously discovered an epigenetic complex that is comprised of the zinc-finger protein ZNF274 and the SET domain bifurcated 1 (SETDB1) histone H3 lysine 9 (H3K9) methyltransferase and that silences the maternal alleles at the PWS locus. Here, we have knocked out ZNF274 and rescued the expression of silent maternal alleles in neurons derived from PWS iPSC lines, without affecting DNA methylation at the PWS-Imprinting Center (PWS-IC). This suggests that the ZNF274 complex is a separate imprinting mark that represses maternal PWS gene expression in neurons and is a potential target for future therapeutic applications to rescue the PWS phenotype.
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Affiliation(s)
- Maéva Langouët
- Department of Genetics and Genome Sciences, School of Medicine
| | | | - Michael S Chung
- Department of Genetics and Genome Sciences, School of Medicine
| | | | - Elodie Mathieux
- Department of Genetics and Genome Sciences, School of Medicine
| | - Erin C Banda
- Department of Genetics and Genome Sciences, School of Medicine
| | | | - Leann Crandall
- Department of Genetics and Genome Sciences, School of Medicine
| | - Marc Lalande
- Department of Genetics and Genome Sciences, School of Medicine.,Institute for Systems Genomics, University of Connecticut, Farmington, CT 06030-6403, USA
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23
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Coulson RL, Powell WT, Yasui DH, Dileep G, Resnick J, LaSalle JM. Prader-Willi locus Snord116 RNA processing requires an active endogenous allele and neuron-specific splicing by Rbfox3/NeuN. Hum Mol Genet 2018; 27:4051-4060. [PMID: 30124848 PMCID: PMC6240740 DOI: 10.1093/hmg/ddy296] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/10/2018] [Accepted: 07/03/2018] [Indexed: 12/18/2022] Open
Abstract
Prader-Willi syndrome (PWS), an imprinted neurodevelopmental disorder characterized by metabolic, sleep and neuropsychiatric features, is caused by the loss of paternal SNORD116, containing only non-coding RNAs (ncRNAs). The primary SNORD116 transcript is processed into small nucleolar RNAs (snoRNAs), which localize to nucleoli, and their spliced host gene 116HG, which is retained at its site of transcription. While functional complementation of the SNORD116 ncRNAs is a desirable goal for treating PWS, the mechanistic requirements of SNORD116 RNA processing are poorly understood. Here we developed and tested a novel transgenic mouse which ubiquitously expresses Snord116 on both a wild-type and a Snord116 paternal deletion (Snord116+/-) background. Interestingly, while the Snord116 transgene was ubiquitously expressed in multiple tissues, splicing of the transgene and production of snoRNAs was limited to brain tissues. Knockdown of Rbfox3, encoding neuron-specific splicing factor neuronal nuclei (NeuN) in Snord116+/--derived neurons, reduced splicing of the transgene in neurons. RNA fluorescence in situ hybridization for 116HG revealed a single significantly larger signal in transgenic mice, demonstrating colocalization of transgenic and endogenous 116HG RNAs. Similarly, significantly increased snoRNA levels were detected in transgenic neuronal nucleoli, indicating that transgenic Snord116 snoRNAs were effectively processed and localized. In contrast, neither transgenic 116HG nor snoRNAs were detectable in either non-neuronal tissues or Snord116+/- neurons. Together, these results demonstrate that exogenous expression and neuron-specific splicing of the Snord116 locus are insufficient to rescue the genetic deficiency of Snord116 paternal deletion. Elucidating the mechanisms regulating Snord116 processing and localization is essential to develop effective gene replacement therapies for PWS.
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Affiliation(s)
- Rochelle L Coulson
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
| | - Weston T Powell
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
| | - Dag H Yasui
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
| | - Gayathri Dileep
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
| | - James Resnick
- Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Janine M LaSalle
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
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24
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Andrews SV, Sheppard B, Windham GC, Schieve LA, Schendel DE, Croen LA, Chopra P, Alisch RS, Newschaffer CJ, Warren ST, Feinberg AP, Fallin MD, Ladd-Acosta C. Case-control meta-analysis of blood DNA methylation and autism spectrum disorder. Mol Autism 2018; 9:40. [PMID: 29988321 PMCID: PMC6022498 DOI: 10.1186/s13229-018-0224-6] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/21/2018] [Indexed: 11/10/2022] Open
Abstract
Background Several reports have suggested a role for epigenetic mechanisms in ASD etiology. Epigenome-wide association studies (EWAS) in autism spectrum disorder (ASD) may shed light on particular biological mechanisms. However, studies of ASD cases versus controls have been limited by post-mortem timing and severely small sample sizes. Reports from in-life sampling of blood or saliva have also been very limited in sample size and/or genomic coverage. We present the largest case-control EWAS for ASD to date, combining data from population-based case-control and case-sibling pair studies. Methods DNA from 968 blood samples from children in the Study to Explore Early Development (SEED 1) was used to generate epigenome-wide array DNA methylation (DNAm) data at 485,512 CpG sites for 453 cases and 515 controls, using the Illumina 450K Beadchip. The Simons Simplex Collection (SSC) provided 450K array DNAm data on an additional 343 cases and their unaffected siblings. We performed EWAS meta-analysis across results from the two data sets, with adjustment for sex and surrogate variables that reflect major sources of biological variation and technical confounding such as cell type, batch, and ancestry. We compared top EWAS results to those from a previous brain-based analysis. We also tested for enrichment of ASD EWAS CpGs for being targets of meQTL associations using available SNP genotype data in the SEED sample. Findings In this meta-analysis of blood-based DNA from 796 cases and 858 controls, no single CpG met a Bonferroni discovery threshold of p < 1.12 × 10− 7. Seven CpGs showed differences at p < 1 × 10− 5 and 48 at 1 × 10− 4. Of the top 7, 5 showed brain-based ASD associations as well, often with larger effect sizes, and the top 48 overall showed modest concordance (r = 0.31) in direction of effect with cerebellum samples. Finally, we observed suggestive evidence for enrichment of CpG sites controlled by SNPs (meQTL targets) among the EWAS CpG hits, which was consistent across EWAS and meQTL discovery p value thresholds. Conclusions No single CpG site showed a large enough DNAm difference between cases and controls to achieve epigenome-wide significance in this sample size. However, our results suggest the potential to observe disease associations from blood-based samples. Among the seven sites achieving suggestive statistical significance, we observed consistent, and stronger, effects at the same sites among brain samples. Discovery-oriented EWAS for ASD using blood samples will likely need even larger samples and unified genetic data to further understand DNAm differences in ASD. Electronic supplementary material The online version of this article (10.1186/s13229-018-0224-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shan V Andrews
- 1Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205 USA.,2Wendy Klag Center for Autism and Developmental Disabilities, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, W6509, Baltimore, MD 21205 USA
| | - Brooke Sheppard
- 1Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205 USA.,2Wendy Klag Center for Autism and Developmental Disabilities, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, W6509, Baltimore, MD 21205 USA
| | - Gayle C Windham
- 3California Department of Public Health, Environmental Health Investigations Branch, 850 Marina Bay Parkway, Richmond, CA 94804 USA
| | - Laura A Schieve
- 4National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, MS E-86, 1600 Clifton Road, Atlanta, GA 30333 USA
| | - Diana E Schendel
- 5Deparment of Public Health, Section of Epidemiology, Aarhus University, Aarhus, Denmark.,6Department of Economics and Business, National Centre for Register-based Research, Aarhus University, Aarhus, Denmark.,7Lundbeck Foundation Initiative for Integrative Psychiatric Research, iPSYCH, Aarhus, Denmark
| | - Lisa A Croen
- 8Kaiser Permanente Division of Research, 2000 Broadway, Oakland, CA 94612 USA
| | - Pankaj Chopra
- 9Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322 USA
| | - Reid S Alisch
- 10Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd, Madison, WI 53719 USA
| | - Craig J Newschaffer
- 11Department of Epidemiology and Biostatistics, Drexel University School of Public Health, 3215 Market Street, Philadelphia, PA 19104 USA.,A.J. Drexel Autism Institute, 3020 Market Street Suite 560, Philadelphia, PA 19104 USA
| | - Stephen T Warren
- 9Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322 USA.,13Department of Biochemistry, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322 USA.,14Department of Pediatrics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322 USA
| | - Andrew P Feinberg
- 15Center for Epigenetics, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, MD 21205 USA.,16Department of Medicine, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, MD 21205 USA
| | - M Daniele Fallin
- 2Wendy Klag Center for Autism and Developmental Disabilities, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, W6509, Baltimore, MD 21205 USA.,15Center for Epigenetics, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, MD 21205 USA.,17Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, 624 N. Broadway, HH850, Baltimore, MD 21205 USA
| | - Christine Ladd-Acosta
- 1Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD 21205 USA.,2Wendy Klag Center for Autism and Developmental Disabilities, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, W6509, Baltimore, MD 21205 USA
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25
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Hartin SN, Hossain WA, Weisensel N, Butler MG. Three siblings with Prader-Willi syndrome caused by imprinting center microdeletions and review. Am J Med Genet A 2018; 176:886-895. [PMID: 29437285 PMCID: PMC6688622 DOI: 10.1002/ajmg.a.38627] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 12/21/2017] [Accepted: 01/16/2018] [Indexed: 12/14/2022]
Abstract
Prader-Willi syndrome (PWS) is a complex genetic imprinting disorder characterized by childhood obesity, short stature, hypogonadism/hypogenitalism, hypotonia, cognitive impairment, and behavioral problems. Usually PWS occurs sporadically due to the loss of paternally expressed genes on chromosome 15 with the majority of individuals having the 15q11-q13 region deleted. Examples of familial PWS have been reported but rarely. To date 13 families have been reported with more than one child with PWS and without a 15q11-q13 deletion secondary to a chromosome 15 translocation, inversion, or uniparental maternal disomy 15. Ten of those 13 families were shown to carry microdeletions in the PWS imprinting center. The microdeletions were found to be of paternal origin in nine of the ten cases in which family studies were carried out. Using a variety of techniques, the microdeletions were identified in regions within the complex SNRPN gene locus encompassing the PWS imprinting center. Here, we report the clinical and genetic findings in three adult siblings with PWS caused by a microdeletion in the chromosome 15 imprinting center inherited from an unaffected father that controls the activity of genes in the 15q11-q13 region and summarize the 13 reported cases in the literature.
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Affiliation(s)
- Samantha N. Hartin
- Departments of Psychiatry and Behavioral Sciences and
Pediatrics, University of Kansas Medical Center, Kansas City, Kansas
| | - Waheeda A. Hossain
- Departments of Psychiatry and Behavioral Sciences and
Pediatrics, University of Kansas Medical Center, Kansas City, Kansas
| | | | - Merlin G. Butler
- Departments of Psychiatry and Behavioral Sciences and
Pediatrics, University of Kansas Medical Center, Kansas City, Kansas
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26
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Cowley M, Skaar DA, Jima DD, Maguire RL, Hudson KM, Park SS, Sorrow P, Hoyo C. Effects of Cadmium Exposure on DNA Methylation at Imprinting Control Regions and Genome-Wide in Mothers and Newborn Children. ENVIRONMENTAL HEALTH PERSPECTIVES 2018; 126:037003. [PMID: 29529597 PMCID: PMC6071808 DOI: 10.1289/ehp2085] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 01/30/2018] [Accepted: 01/30/2018] [Indexed: 05/21/2023]
Abstract
BACKGROUND Imprinted genes are defined by their preferential expression from one of the two parental alleles. This unique mode of gene expression is dependent on allele-specific DNA methylation profiles established at regulatory sequences called imprinting control regions (ICRs). These loci have been used as biosensors to study how environmental exposures affect methylation and transcription. However, a critical unanswered question is whether they are more, less, or equally sensitive to environmental stressors as the rest of the genome. OBJECTIVES Using cadmium exposure in humans as a model, we aimed to determine the relative sensitivity of ICRs to perturbation of methylation compared to similar, nonimprinted loci in the genome. METHODS We assayed DNA methylation genome-wide using bisulfite sequencing of 19 newborn cord blood and 20 maternal blood samples selected on the basis of maternal blood cadmium levels. Differentially methylated regions (DMRs) associated with cadmium exposure were identified. RESULTS In newborn cord blood and maternal blood, 641 and 1,945 cadmium-associated DMRs were identified, respectively. DMRs were more common at the 15 maternally methylated ICRs than at similar nonimprinted loci in newborn cord blood (p=5.64×10-8) and maternal blood (p=6.22×10-14), suggesting a higher sensitivity for ICRs to cadmium. Genome-wide, Enrichr analysis indicated that the top three functional categories for genes that overlapped DMRs in maternal blood were body mass index (BMI) (p=2.0×10-5), blood pressure (p=3.8×10-5), and body weight (p=0.0014). In newborn cord blood, the top three functional categories were BMI, atrial fibrillation, and hypertension, although associations were not significant after correction for multiple testing (p=0.098). These findings suggest that epigenetic changes may contribute to the etiology of cadmium-associated diseases. CONCLUSIONS We analyzed cord blood and maternal blood DNA methylation profiles genome-wide at nucleotide resolution in individuals selected for high and low blood cadmium levels in the first trimester. Our findings suggest that ICRs may be hot spots for perturbation by cadmium, motivating further study of these loci to investigate potential mechanisms of cadmium action. https://doi.org/10.1289/EHP2085.
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Affiliation(s)
- Michael Cowley
- Center for Human Health and the Environment and Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina, USA
- W.M. Keck Center for Behavioral Biology , North Carolina State University , Raleigh, North Carolina, USA
| | - David A Skaar
- Center for Human Health and the Environment and Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina, USA
| | - Dereje D Jima
- Center for Human Health and the Environment and Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina, USA
- Bioinformatics Research Center, North Carolina State University , Raleigh, North Carolina, USA
| | - Rachel L Maguire
- Center for Human Health and the Environment and Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina, USA
| | - Kathleen M Hudson
- Center for Human Health and the Environment and Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina, USA
| | - Sarah S Park
- Center for Human Health and the Environment and Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina, USA
| | - Patricia Sorrow
- Center for Human Health and the Environment and Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina, USA
| | - Cathrine Hoyo
- Center for Human Health and the Environment and Department of Biological Sciences, North Carolina State University , Raleigh, North Carolina, USA
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27
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Lozano-Ureña A, Montalbán-Loro R, Ferguson-Smith AC, Ferrón SR. Genomic Imprinting and the Regulation of Postnatal Neurogenesis. Brain Plast 2017; 3:89-98. [PMID: 29765862 PMCID: PMC5928554 DOI: 10.3233/bpl-160041] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Most genes required for mammalian development are expressed from both maternally and paternally inherited chromosomal homologues. However, there are a small number of genes known as “imprinted genes” that only express a single allele from one parent, which is repressed on the gene from the other parent. Imprinted genes are dependent on epigenetic mechanisms such as DNA methylation and post-translational modifications of the DNA-associated histone proteins to establish and maintain their parental identity. In the brain, multiple transcripts have been identified which show parental origin-specific expression biases. However, the mechanistic relationship with canonical imprinting is unknown. Recent studies on the postnatal neurogenic niches raise many intriguing questions concerning the role of genomic imprinting and gene dosage during postnatal neurogenesis, including how imprinted genes operate in concert with signalling cues to contribute to newborn neurons’ formation during adulthood. Here we have gathered the current knowledge on the imprinting process in the neurogenic niches. We also review the phenotypes associated with genetic mutations at particular imprinted loci in order to consider the impact of imprinted genes in the maintenance and/or differentiation of the neural stem cell pool in vivo and during brain tumour formation.
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Affiliation(s)
- Anna Lozano-Ureña
- ERI BiotecMed Departamento de Biología Celular, Universidad de Valencia, Spain
| | | | | | - Sacri R Ferrón
- ERI BiotecMed Departamento de Biología Celular, Universidad de Valencia, Spain
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Okuno H, Nakabayashi K, Abe K, Ando T, Sanosaka T, Kohyama J, Akamatsu W, Ohyama M, Takahashi T, Kosaki K, Okano H. Changeability of the fully methylated status of the 15q11.2 region in induced pluripotent stem cells derived from a patient with Prader-Willi syndrome. Congenit Anom (Kyoto) 2017; 57:96-103. [PMID: 28004416 DOI: 10.1111/cga.12206] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 12/13/2016] [Accepted: 12/18/2016] [Indexed: 12/12/2022]
Abstract
Prader-Will syndrome (PWS) is characterized by hyperphagia, growth hormone deficiency and central hypogonadism caused by the dysfunction of the hypothalamus. Patients with PWS present with methylation abnormalities of the PWS-imprinting control region in chromosome 15q11.2, subject to parent-of-origin-specific methylation and controlling the parent-of-origin-specific expression of other paternally expressed genes flanking the region. In theory, the reversal of hypermethylation in the hypothalamic cells could be a promising strategy for the treatment of PWS patients, since cardinal symptoms of PWS patients are correlated with dysfunction of the hypothalamus. The genome-wide methylation status dramatically changes during the reprograming of somatic cells into induced pluripotent stem cells (iPSCs) and during the in vitro culture of iPSCs. Here, we tested the methylation status of the chromosome 15q11.2 region in iPSCs from a PWS patient using pyrosequencing and a more detailed method of genome-wide DNA methylation profiling to reveal whether iPSCs with a partially unmethylated status for the chromosome 15q11.2 region exhibit global methylation aberrations. As a result, we were able to show that a fully methylated status for chromosome 15q11.2 in a PWS patient could be reversed to a partially unmethylated status in at least some of the PWS-iPSC lines. Genome-wide DNA methylation profiling revealed that the partial unmethylation occurred at differentially methylated regions located in chromosome 15q11.2, but not at other differentially methylated regions associated with genome imprinting. The present data potentially opens a door to cell-based therapy for PWS patients and, possibly, patients with other disorders associated with genomic imprinting.
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Affiliation(s)
- Hironobu Okuno
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Kazuhiko Nakabayashi
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Kousei Abe
- Department of Maternal-Fetal Biology, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Takayuki Ando
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Tsukasa Sanosaka
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Jun Kohyama
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Wado Akamatsu
- Center for Genomic and Regenerative Medicine, Juntendo University School of Medicine, Tokyo, Japan
| | - Manabu Ohyama
- Department of Dermatology, Kyorin University School of Medicine, Tokyo, Japan
| | - Takao Takahashi
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
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Epigenetic Control of Gene Expression in Maize. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 328:25-48. [DOI: 10.1016/bs.ircmb.2016.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Targeting the histone methyltransferase G9a activates imprinted genes and improves survival of a mouse model of Prader-Willi syndrome. Nat Med 2016; 23:213-222. [PMID: 28024084 DOI: 10.1038/nm.4257] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 11/29/2016] [Indexed: 12/13/2022]
Abstract
Prader-Willi syndrome (PWS) is an imprinting disorder caused by a deficiency of paternally expressed gene(s) in the 15q11-q13 chromosomal region. The regulation of imprinted gene expression in this region is coordinated by an imprinting center (PWS-IC). In individuals with PWS, genes responsible for PWS on the maternal chromosome are present, but repressed epigenetically, which provides an opportunity for the use of epigenetic therapy to restore expression from the maternal copies of PWS-associated genes. Through a high-content screen (HCS) of >9,000 small molecules, we discovered that UNC0638 and UNC0642-two selective inhibitors of euchromatic histone lysine N-methyltransferase-2 (EHMT2, also known as G9a)-activated the maternal (m) copy of candidate genes underlying PWS, including the SnoRNA cluster SNORD116, in cells from humans with PWS and also from a mouse model of PWS carrying a paternal (p) deletion from small nuclear ribonucleoprotein N (Snrpn (S)) to ubiquitin protein ligase E3A (Ube3a (U)) (mouse model referred to hereafter as m+/pΔS-U). Both UNC0642 and UNC0638 caused a selective reduction of the dimethylation of histone H3 lysine 9 (H3K9me2) at PWS-IC, without changing DNA methylation, when analyzed by bisulfite genomic sequencing. This indicates that histone modification is essential for the imprinting of candidate genes underlying PWS. UNC0642 displayed therapeutic effects in the PWS mouse model by improving the survival and the growth of m+/pΔS-U newborn pups. This study provides the first proof of principle for an epigenetics-based therapy for PWS.
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Dunaway KW, Islam MS, Coulson RL, Lopez SJ, Vogel Ciernia A, Chu RG, Yasui DH, Pessah IN, Lott P, Mordaunt C, Meguro-Horike M, Horike SI, Korf I, LaSalle JM. Cumulative Impact of Polychlorinated Biphenyl and Large Chromosomal Duplications on DNA Methylation, Chromatin, and Expression of Autism Candidate Genes. Cell Rep 2016; 17:3035-3048. [PMID: 27974215 PMCID: PMC5206988 DOI: 10.1016/j.celrep.2016.11.058] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/14/2016] [Accepted: 11/20/2016] [Indexed: 12/17/2022] Open
Abstract
Rare variants enriched for functions in chromatin regulation and neuronal synapses have been linked to autism. How chromatin and DNA methylation interact with environmental exposures at synaptic genes in autism etiologies is currently unclear. Using whole-genome bisulfite sequencing in brain tissue and a neuronal cell culture model carrying a 15q11.2-q13.3 maternal duplication, we find that significant global DNA hypomethylation is enriched over autism candidate genes and affects gene expression. The cumulative effect of multiple chromosomal duplications and exposure to the pervasive persistent organic pollutant PCB 95 altered methylation of more than 1,000 genes. Hypomethylated genes were enriched for H2A.Z, increased maternal UBE3A in Dup15q corresponded to reduced levels of RING1B, and bivalently modified H2A.Z was altered by PCB 95 and duplication. These results demonstrate the compounding effects of genetic and environmental insults on the neuronal methylome that converge upon dysregulation of chromatin and synaptic genes.
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Affiliation(s)
- Keith W Dunaway
- Medical Microbiology and Immunology, UC Davis, Davis, CA 95616, USA; Genome Center, UC Davis, Davis, CA 95616, USA; MIND Institute, UC Davis, Davis, CA 95616, USA; Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA
| | - M Saharul Islam
- Medical Microbiology and Immunology, UC Davis, Davis, CA 95616, USA; Genome Center, UC Davis, Davis, CA 95616, USA; MIND Institute, UC Davis, Davis, CA 95616, USA; Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA
| | - Rochelle L Coulson
- Medical Microbiology and Immunology, UC Davis, Davis, CA 95616, USA; Genome Center, UC Davis, Davis, CA 95616, USA; MIND Institute, UC Davis, Davis, CA 95616, USA; Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA
| | - S Jesse Lopez
- Medical Microbiology and Immunology, UC Davis, Davis, CA 95616, USA; Genome Center, UC Davis, Davis, CA 95616, USA; MIND Institute, UC Davis, Davis, CA 95616, USA; Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA
| | - Annie Vogel Ciernia
- Medical Microbiology and Immunology, UC Davis, Davis, CA 95616, USA; Genome Center, UC Davis, Davis, CA 95616, USA; MIND Institute, UC Davis, Davis, CA 95616, USA; Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA
| | - Roy G Chu
- Medical Microbiology and Immunology, UC Davis, Davis, CA 95616, USA; Genome Center, UC Davis, Davis, CA 95616, USA; MIND Institute, UC Davis, Davis, CA 95616, USA; Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA
| | - Dag H Yasui
- Medical Microbiology and Immunology, UC Davis, Davis, CA 95616, USA; Genome Center, UC Davis, Davis, CA 95616, USA; MIND Institute, UC Davis, Davis, CA 95616, USA; Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA
| | - Isaac N Pessah
- Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA; Veterinary Molecular Biosciences, UC Davis, Davis, CA 95616, USA
| | - Paul Lott
- Genome Center, UC Davis, Davis, CA 95616, USA
| | - Charles Mordaunt
- Medical Microbiology and Immunology, UC Davis, Davis, CA 95616, USA; Genome Center, UC Davis, Davis, CA 95616, USA; MIND Institute, UC Davis, Davis, CA 95616, USA; Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA
| | - Makiko Meguro-Horike
- Advanced Science Research Center, Kanazawa University, 13-1 Takaramachi, Kanazawa 920-8640, Japan
| | - Shin-Ichi Horike
- Advanced Science Research Center, Kanazawa University, 13-1 Takaramachi, Kanazawa 920-8640, Japan
| | - Ian Korf
- Genome Center, UC Davis, Davis, CA 95616, USA
| | - Janine M LaSalle
- Medical Microbiology and Immunology, UC Davis, Davis, CA 95616, USA; Genome Center, UC Davis, Davis, CA 95616, USA; MIND Institute, UC Davis, Davis, CA 95616, USA; Center for Children's Environmental Health, UC Davis, Davis, CA 95616, USA.
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Thakur A, Mackin SJ, Irwin RE, O’Neill KM, Pollin G, Walsh C. Widespread recovery of methylation at gametic imprints in hypomethylated mouse stem cells following rescue with DNMT3A2. Epigenetics Chromatin 2016; 9:53. [PMID: 27895716 PMCID: PMC5118886 DOI: 10.1186/s13072-016-0104-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 11/08/2016] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Imprinted loci are paradigms of epigenetic regulation and are associated with a number of genetic disorders in human. A key characteristic of imprints is the presence of a gametic differentially methylated region (gDMR). Previous studies have indicated that DNA methylation lost from gDMRs could not be restored by DNMT1, or the de novo enzymes DNMT3A or 3B in stem cells, indicating that imprinted regions must instead undergo passage through the germline for reprogramming. However, previous studies were non-quantitative, were unclear on the requirement for DNMT3A/B and showed some inconsistencies. In addition, new putative gDMR has recently been described, along with an improved delineation of the existing gDMR locations. We therefore aimed to re-examine the dependence of methylation at gDMRs on the activities of the methyltransferases in mouse embryonic stem cells (ESCs). RESULTS We examined the most complete current set of imprinted gDMRs that could be assessed using quantitative pyrosequencing assays in two types of ESCs: those lacking DNMT1 (1KO) and cells lacking a combination of DNMT3A and DNMT3B (3abKO). We further verified results using clonal analysis and combined bisulfite and restriction analysis. Our results showed that loss of methylation was approximately equivalent in both cell types. 1KO cells rescued with a cDNA-expressing DNMT1 could not restore methylation at the imprinted gDMRs, confirming some previous observations. However, nearly all gDMRs were remethylated in 3abKO cells rescued with a DNMT3A2 expression construct (3abKO + 3a2). Transcriptional activity at the H19/Igf2 locus also tracked with the methylation pattern, confirming functional reprogramming in the latter. CONCLUSIONS These results suggested (1) a vital role for DNMT3A/B in methylation maintenance at imprints, (2) that loss of DNMT1 and DNMT3A/B had equivalent effects, (3) that rescue with DNMT3A2 can restore imprints in these cells. This may provide a useful system in which to explore factors influencing imprint reprogramming.
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Affiliation(s)
- Avinash Thakur
- Genomic Medicine Research Group, Biomedical Sciences Research Institute, Centre for Molecular Biosciences, University of Ulster, Coleraine, BT52 1SA UK
- Terry Fox Laboratory, BC Cancer Agency, 675 W 10th Ave, Vancouver, BC V5Z 1G1 Canada
| | - Sarah-Jayne Mackin
- Genomic Medicine Research Group, Biomedical Sciences Research Institute, Centre for Molecular Biosciences, University of Ulster, Coleraine, BT52 1SA UK
| | - Rachelle E. Irwin
- Genomic Medicine Research Group, Biomedical Sciences Research Institute, Centre for Molecular Biosciences, University of Ulster, Coleraine, BT52 1SA UK
| | - Karla M. O’Neill
- Genomic Medicine Research Group, Biomedical Sciences Research Institute, Centre for Molecular Biosciences, University of Ulster, Coleraine, BT52 1SA UK
- Centre for Experimental Medicine, The Wellcome-Wolfson Institute for Experimental Medicine, Queen’s University Belfast, 97 Lisburn Road, Belfast, BT9 7AE UK
| | - Gareth Pollin
- Genomic Medicine Research Group, Biomedical Sciences Research Institute, Centre for Molecular Biosciences, University of Ulster, Coleraine, BT52 1SA UK
| | - Colum Walsh
- Genomic Medicine Research Group, Biomedical Sciences Research Institute, Centre for Molecular Biosciences, University of Ulster, Coleraine, BT52 1SA UK
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Buiting K, Williams C, Horsthemke B. Angelman syndrome — insights into a rare neurogenetic disorder. Nat Rev Neurol 2016; 12:584-93. [DOI: 10.1038/nrneurol.2016.133] [Citation(s) in RCA: 199] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Massah S, Beischlag TV, Prefontaine GG. Epigenetic events regulating monoallelic gene expression. Crit Rev Biochem Mol Biol 2015; 50:337-58. [PMID: 26155735 DOI: 10.3109/10409238.2015.1064350] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
In mammals, generally it is assumed that the genes inherited from each parent are expressed to similar levels. However, it is now apparent that in non-sex chromosomes, 6-10% of genes are selected for monoallelic expression. Monoallelic expression or allelic exclusion is established either in an imprinted (parent-of-origin) or a stochastic manner. The stochastic model explains random selection while the imprinted model describes parent-of-origin specific selection of alleles for expression. Allelic exclusion occurs during X chromosome inactivation, parent-of-origin expression of imprinted genes and stochastic monoallelic expression of cell surface molecules, clustered protocadherin (PCDH) genes. Mis-regulation or loss of allelic exclusion contributes to developmental diseases. Epigenetic mechanisms are fundamental players that determine this type of expression despite a homogenous genetic background. DNA methylation and histone modifications are two mediators of the epigenetic phenomena. The majority of DNA methylation is found on cytosines of the CpG dinucleotide in mammals. Several covalent modifications of histones change the electrostatic forces between DNA and histones modifying gene expression. Long-range chromatin interactions organize chromatin into transcriptionally permissive and prohibitive regions leading to simultaneous regulation of gene expression and repression. Non-coding RNAs (ncRNAs) are also players in regulating gene expression. Together, these epigenetic mechanisms fine-tune gene expression levels essential for normal development and survival. In this review, first we discuss what is known about monoallelic gene expression. Then, we focus on the molecular mechanisms that regulate expression of three monoallelically expressed gene classes: the X-linked genes, selected imprinted genes and PCDH genes.
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Affiliation(s)
- Shabnam Massah
- a The Faculty of Health Sciences , Simon Fraser University , Burnaby , BC , Canada
| | - Timothy V Beischlag
- a The Faculty of Health Sciences , Simon Fraser University , Burnaby , BC , Canada
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MacDonald WA, Sachani SS, White CR, Mann MRW. A role for chromatin topology in imprinted domain regulation. Biochem Cell Biol 2015. [PMID: 26222733 DOI: 10.1139/bcb-2015-0032] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Recently, many advancements in genome-wide chromatin topology and nuclear architecture have unveiled the complex and hidden world of the nucleus, where chromatin is organized into discrete neighbourhoods with coordinated gene expression. This includes the active and inactive X chromosomes. Using X chromosome inactivation as a working model, we utilized publicly available datasets together with a literature review to gain insight into topologically associated domains, lamin-associated domains, nucleolar-associating domains, scaffold/matrix attachment regions, and nucleoporin-associated chromatin and their role in regulating monoallelic expression. Furthermore, we comprehensively review for the first time the role of chromatin topology and nuclear architecture in the regulation of genomic imprinting. We propose that chromatin topology and nuclear architecture are important regulatory mechanisms for directing gene expression within imprinted domains. Furthermore, we predict that dynamic changes in chromatin topology and nuclear architecture play roles in tissue-specific imprint domain regulation during early development and differentiation.
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Affiliation(s)
- William A MacDonald
- a Departments of Obstetrics & Gynecology, and Biochemistry, University of Western Ontario, Schulich School of Medicine and Dentistry, London, Ontario, Canada.,b Children's Health Research Institute, 4th Floor, Victoria Research Laboratories, A4-130a, 800 Commissioners Rd E, London, ON N6C 2V5, Canada
| | - Saqib S Sachani
- a Departments of Obstetrics & Gynecology, and Biochemistry, University of Western Ontario, Schulich School of Medicine and Dentistry, London, Ontario, Canada.,b Children's Health Research Institute, 4th Floor, Victoria Research Laboratories, A4-130a, 800 Commissioners Rd E, London, ON N6C 2V5, Canada
| | - Carlee R White
- a Departments of Obstetrics & Gynecology, and Biochemistry, University of Western Ontario, Schulich School of Medicine and Dentistry, London, Ontario, Canada.,b Children's Health Research Institute, 4th Floor, Victoria Research Laboratories, A4-130a, 800 Commissioners Rd E, London, ON N6C 2V5, Canada
| | - Mellissa R W Mann
- a Departments of Obstetrics & Gynecology, and Biochemistry, University of Western Ontario, Schulich School of Medicine and Dentistry, London, Ontario, Canada.,b Children's Health Research Institute, 4th Floor, Victoria Research Laboratories, A4-130a, 800 Commissioners Rd E, London, ON N6C 2V5, Canada
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Ospelt C, Gay S. Epigenetics in rheumatology. Rheumatology (Oxford) 2015. [DOI: 10.1016/b978-0-323-09138-1.00018-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Judson MC, Sosa-Pagan JO, Del Cid WA, Han JE, Philpot BD. Allelic specificity of Ube3a expression in the mouse brain during postnatal development. J Comp Neurol 2014; 522:1874-96. [PMID: 24254964 DOI: 10.1002/cne.23507] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 10/30/2013] [Accepted: 11/15/2013] [Indexed: 12/23/2022]
Abstract
Genetic alterations of the maternal UBE3A allele result in Angelman syndrome (AS), a neurodevelopmental disorder characterized by severe developmental delay, lack of speech, and difficulty with movement and balance. The combined effects of maternal UBE3A mutation and cell type-specific epigenetic silencing of paternal UBE3A are hypothesized to result in a complete loss of functional UBE3A protein in neurons. However, the allelic specificity of UBE3A expression in neurons and other cell types in the brain has yet to be characterized throughout development, including the early postnatal period when AS phenotypes emerge. Here we define maternal and paternal allele-specific Ube3a protein expression throughout postnatal brain development in the mouse, a species that exhibits orthologous epigenetic silencing of paternal Ube3a in neurons and AS-like behavioral phenotypes subsequent to maternal Ube3a deletion. We find that neurons downregulate paternal Ube3a protein expression as they mature and, with the exception of neurons born from postnatal stem cell niches, do not express detectable paternal Ube3a beyond the first postnatal week. By contrast, neurons express maternal Ube3a throughout postnatal development, during which time localization of the protein becomes increasingly nuclear. Unlike neurons, astrocytes and oligodendrotyes biallelically express Ube3a. Notably, mature oligodendrocytes emerge as the predominant Ube3a-expressing glial cell type in the cortex and white matter tracts during postnatal development. These findings demonstrate the spatiotemporal characteristics of allele-specific Ube3a expression in key brain cell types, thereby improving our understanding of the developmental parameters of paternal Ube3a silencing and the cellular basis of AS.
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Affiliation(s)
- Matthew C Judson
- Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, 27599
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Huang HS, Yoon BJ, Brooks S, Bakal R, Berrios J, Larsen RS, Wallace ML, Han JE, Chung EH, Zylka MJ, Philpot BD. Snx14 regulates neuronal excitability, promotes synaptic transmission, and is imprinted in the brain of mice. PLoS One 2014; 9:e98383. [PMID: 24859318 PMCID: PMC4032282 DOI: 10.1371/journal.pone.0098383] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/02/2014] [Indexed: 01/04/2023] Open
Abstract
Genomic imprinting describes an epigenetic process through which genes can be expressed in a parent-of-origin-specific manner. The monoallelic expression of imprinted genes renders them particularly susceptible to disease causing mutations. A large proportion of imprinted genes are expressed in the brain, but little is known about their functions. Indeed, it has proven difficult to identify cell type-specific imprinted genes due to the heterogeneity of cell types within the brain. Here we used laser capture microdissection of visual cortical neurons and found evidence that sorting nexin 14 (Snx14) is a neuronally imprinted gene in mice. SNX14 protein levels are high in the brain and progressively increase during neuronal development and maturation. Snx14 knockdown reduces intrinsic excitability and severely impairs both excitatory and inhibitory synaptic transmission. These data reveal a role for monoallelic Snx14 expression in maintaining normal neuronal excitability and synaptic transmission.
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Affiliation(s)
- Hsien-Sung Huang
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Bong-June Yoon
- Division of Life Sciences, Korea University, Seoul, Korea
| | - Sherian Brooks
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Robert Bakal
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Janet Berrios
- Curriculum in Neurobiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, Unites States of America
| | - Rylan S. Larsen
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Michael L. Wallace
- Curriculum in Neurobiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, Unites States of America
| | - Ji Eun Han
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Eui Hwan Chung
- Department of Biology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Mark J. Zylka
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
- Curriculum in Neurobiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, Unites States of America
- Neuroscience Center, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Benjamin D. Philpot
- Department of Cell Biology & Physiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
- Curriculum in Neurobiology, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, Unites States of America
- Neuroscience Center, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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McNally B, Linder M, Valdes R. Epigenetic primer for diagnostic applications: a window into personalized medicine. Per Med 2014; 11:323-337. [DOI: 10.2217/pme.14.21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Epigenetic testing, primarily in the form of DNA methylation analysis, is currently being used in healthcare settings to help identify and manage disease conditions and to develop and select drugs that specifically target epigenetic machinery. Yet, the clinical application of epigenetic analysis is still in its infancy. With a number of large-scale national and international epigenomic consortia projects in progress to identify tissue-specific epigenomes in normal and disease conditions, we are now poised for a new era of understanding disease processes based upon genetic changes that do not involve alterations to the DNA sequence. The developing epigenetic knowledge base will significantly advance the practice of personalized medicine and precision therapeutics. In this article, we provide a primer on the fundamentals of epigenetics with an emphasis on DNA methylation and review the prospective uses of epigenetic testing in advancing healthcare.
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Affiliation(s)
| | - Mark Linder
- PGXL Laboratories, Louisville, KY 40202, USA
- Department of Pathology & Laboratory Medicine, University of Louisville School of Medicine, MDR Building, 511 S Flloyd Street, Room 222, Louisville KY 40292, USA
| | - Roland Valdes
- PGXL Laboratories, Louisville, KY 40202, USA
- Department of Pathology & Laboratory Medicine, University of Louisville School of Medicine, MDR Building, 511 S Flloyd Street, Room 222, Louisville KY 40292, USA
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Chopra P, Papale LA, White ATJ, Hatch A, Brown RM, Garthwaite MA, Roseboom PH, Golos TG, Warren ST, Alisch RS. Array-based assay detects genome-wide 5-mC and 5-hmC in the brains of humans, non-human primates, and mice. BMC Genomics 2014; 15:131. [PMID: 24524199 PMCID: PMC3930898 DOI: 10.1186/1471-2164-15-131] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 02/05/2014] [Indexed: 11/12/2022] Open
Abstract
Background Methylation on the fifth position of cytosine (5-mC) is an essential epigenetic mark that is linked to both normal neurodevelopment and neurological diseases. The recent identification of another modified form of cytosine, 5-hydroxymethylcytosine (5-hmC), in both stem cells and post-mitotic neurons, raises new questions as to the role of this base in mediating epigenetic effects. Genomic studies of these marks using model systems are limited, particularly with array-based tools, because the standard method of detecting DNA methylation cannot distinguish between 5-mC and 5-hmC and most methods have been developed to only survey the human genome. Results We show that non-human data generated using the optimization of a widely used human DNA methylation array, designed only to detect 5-mC, reproducibly distinguishes tissue types within and between chimpanzee, rhesus, and mouse, with correlations near the human DNA level (R2 > 0.99). Genome-wide methylation analysis, using this approach, reveals 6,102 differentially methylated loci between rhesus placental and fetal tissues with pathways analysis significantly overrepresented for developmental processes. Restricting the analysis to oncogenes and tumor suppressor genes finds 76 differentially methylated loci, suggesting that rhesus placental tissue carries a cancer epigenetic signature. Similarly, adapting the assay to detect 5-hmC finds highly reproducible 5-hmC levels within human, rhesus, and mouse brain tissue that is species-specific with a hierarchical abundance among the three species (human > rhesus >> mouse). Annotation of 5-hmC with respect to gene structure reveals a significant prevalence in the 3'UTR and an association with chromatin-related ontological terms, suggesting an epigenetic feedback loop mechanism for 5-hmC. Conclusions Together, these data show that this array-based methylation assay is generalizable to all mammals for the detection of both 5-mC and 5-hmC, greatly improving the utility of mammalian model systems to study the role of epigenetics in human health, disease, and evolution.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Reid S Alisch
- Department of Psychiatry, University of Wisconsin-Madison, 6001 Research Park Blvd,, Madison, Wisconsin 53719, USA.
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Abstract
Bipolar disorder is a common, complex genetic disorder, but the mode of transmission remains to be discovered. Many researchers assume that common genomic variants carry some risk for manifesting the disease. The research community has celebrated the first genome-wide significant associations between common single nucleotide polymorphisms (SNPs) and bipolar disorder. Currently, attempts are under way to translate these findings into clinical practice, genetic counseling, and predictive testing. However, some experts remain cautious. After all, common variants explain only a very small percentage of the genetic risk, and functional consequences of the discovered SNPs are inconclusive. Furthermore, the associated SNPs are not disease specific, and the majority of individuals with a "risk" allele are healthy. On the other hand, population-based genome-wide studies in psychiatric disorders have rediscovered rare structural variants and mutations in genes, which were previously known to cause genetic syndromes and monogenic Mendelian disorders. In many Mendelian syndromes, psychiatric symptoms are prevalent. Although these conditions do not fit the classic description of any specific psychiatric disorder, they often show nonspecific psychiatric symptoms that cross diagnostic boundaries, including intellectual disability, behavioral abnormalities, mood disorders, anxiety disorders, attention deficit, impulse control deficit, and psychosis. Although testing for chromosomal disorders and monogenic Mendelian disorders is well established, testing for common variants is still controversial. The standard concept of genetic testing includes at least three broad criteria that need to be fulfilled before new genetic tests should be introduced: analytical validity, clinical validity, and clinical utility. These criteria are currently not fulfilled for common genomic variants in psychiatric disorders. Further work is clearly needed before genetic testing for common variants in psychiatric disorders should be established.
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Affiliation(s)
- Berit Kerner
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA
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Zhu L, Wang X, Li XL, Towers A, Cao X, Wang P, Bowman R, Yang H, Goldstein J, Li YJ, Jiang YH. Epigenetic dysregulation of SHANK3 in brain tissues from individuals with autism spectrum disorders. Hum Mol Genet 2013; 23:1563-78. [PMID: 24186872 DOI: 10.1093/hmg/ddt547] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The molecular basis for the majority of cases of autism spectrum disorders (ASD) remains unknown. We tested the hypothesis that ASD have an epigenetic cause by performing DNA methylation profiling of five CpG islands (CGI-1 to CGI-5) in the SHANK3 gene in postmortem brain tissues from 54 ASD patients and 43 controls. We found significantly increased overall DNA methylation (epimutation) in three intragenic CGIs (CGI-2, CGI-3 and CGI-4). The increased methylation was clustered in the CGI-2 and CGI-4 in ∼15% of ASD brain tissues. SHANK3 has an extensive array of mRNA splice variants resulting from combinations of five intragenic promoters and alternative splicing of coding exons. Altered expression and alternative splicing of SHANK3 isoforms were observed in brain tissues with increased methylation of SHANK3 CGIs in ASD brain tissues. A DNA methylation inhibitor modified the methylation of CGIs and altered the isoform-specific expression of SHANK3 in cultured cells. This study is the first to find altered methylation patterns in SHANK3 in ASD brain samples. Our finding provides evidence to support an alternative approach to investigating the molecular basis of ASD. The ability to alter the epigenetic modification and expression of SHANK3 by environmental factors suggests that SHANK3 may be a valuable biomarker for dissecting the role of gene and environment interaction in the etiology of ASD.
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Powell WT, Coulson RL, Crary FK, Wong SS, Ach RA, Tsang P, Alice Yamada N, Yasui DH, Lasalle JM. A Prader-Willi locus lncRNA cloud modulates diurnal genes and energy expenditure. Hum Mol Genet 2013; 22:4318-28. [PMID: 23771028 PMCID: PMC3792690 DOI: 10.1093/hmg/ddt281] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Prader–Willi syndrome (PWS), a genetic disorder of obesity, intellectual disability and sleep abnormalities, is caused by loss of non-coding RNAs on paternal chromosome 15q11-q13. The imprinted minimal PWS locus encompasses a long non-coding RNA (lncRNA) transcript processed into multiple SNORD116 small nucleolar RNAs and the spliced exons of the host gene, 116HG. However, both the molecular function and the disease relevance of the spliced lncRNA 116HG are unknown. Here, we show that 116HG forms a subnuclear RNA cloud that co-purifies with the transcriptional activator RBBP5 and active metabolic genes, remains tethered to the site of its transcription and increases in size in post-natal neurons and during sleep. Snord116del mice lacking 116HG exhibited increased energy expenditure corresponding to the dysregulation of diurnally expressed Mtor and circadian genes Clock, Cry1 and Per2. These combined genomic and metabolic analyses demonstrate that 116HG regulates the diurnal energy expenditure of the brain. These novel molecular insights into the energy imbalance in PWS should lead to improved therapies and understanding of lncRNA roles in complex neurodevelopmental and metabolic disorders.
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Affiliation(s)
- Weston T Powell
- Medical Microbiology and Immunology, Genome Center, MIND Institute, University of California, Davis, CA 95616, USA
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LaSalle JM, Powell WT, Yasui DH. Epigenetic layers and players underlying neurodevelopment. Trends Neurosci 2013; 36:460-70. [PMID: 23731492 DOI: 10.1016/j.tins.2013.05.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Revised: 05/02/2013] [Accepted: 05/03/2013] [Indexed: 12/22/2022]
Abstract
Epigenetic mechanisms convey information above and beyond the sequence of DNA, so it is predicted that they are critical in the complex regulation of brain development and explain the long-lived effects of environmental cues on pre- and early post-natal brain development. Neurons have a complex epigenetic landscape that changes dynamically with transcriptional activity in early life. Here, we summarize progress in our understanding of the discrete layers of the dynamic methylome, chromatin proteome, noncoding RNAs, chromatin loops, and long-range interactions in neuronal development and maturation. Many neurodevelopmental disorders have genetic alterations in these epigenetic modifications or regulators, and these human genetics lessons have demonstrated the importance of these epigenetic players and the epigenetic layers that transcriptional events lay down in the early brain.
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Affiliation(s)
- Janine M LaSalle
- Medical Microbiology and Immunology, Genome Center, MIND Institute, University of California, Davis, CA, USA.
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Regulatory elements associated with paternally-expressed genes in the imprinted murine Angelman/Prader-Willi syndrome domain. PLoS One 2013; 8:e52390. [PMID: 23390487 PMCID: PMC3563663 DOI: 10.1371/journal.pone.0052390] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 11/13/2012] [Indexed: 11/19/2022] Open
Abstract
The Angelman/Prader-Willi syndrome (AS/PWS) domain contains at least 8 imprinted genes regulated by a bipartite imprinting center (IC) associated with the SNRPN gene. One component of the IC, the PWS-IC, governs the paternal epigenotype and expression of paternal genes. The mechanisms by which imprinting and expression of paternal genes within the AS/PWS domain – such as MKRN3 and NDN – are regulated by the PWS-IC are unclear. The syntenic region in the mouse is organized and imprinted similarly to the human domain with the murine PWS-IC defined by a 6 kb interval within the Snrpn locus that includes the promoter. To identify regulatory elements that may mediate PWS-IC function, we mapped the location and allele-specificity of DNase I hypersensitive (DH) sites within the PWS-IC in brain cells, then identified transcription factor binding sites within a subset of these DH sites. Six major paternal-specific DH sites were detected in the Snrpn gene, five of which map within the 6 kb PWS-IC. We postulate these five DH sites represent functional components of the murine PWS-IC. Analysis of transcription factor binding within multiple DH sites detected nuclear respiratory factors (NRF's) and YY1 specifically on the paternal allele. NRF's and YY1 were also detected in the paternal promoter region of the murine Mrkn3 and Ndn genes. These results suggest that NRF's and YY1 may facilitate PWS-IC function and coordinately regulate expression of paternal genes. The presence of NRF's also suggests a link between transcriptional regulation within the AS/PWS domain and regulation of respiration. 3C analyses indicated Mkrn3 lies in close proximity to the PWS-IC on the paternal chromosome, evidence that the PWS-IC functions by allele-specific interaction with its distal target genes. This could occur by allele-specific co-localization of the PWS-IC and its target genes to transcription factories containing NRF's and YY1.
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Chamberlain SJ. RNAs of the human chromosome 15q11-q13 imprinted region. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012. [PMID: 23208756 DOI: 10.1002/wrna.1150] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The human chromosome 15q11-q13 region hosts a wide variety of coding and noncoding RNAs, and is also the site of nearly every imaginable type of RNA processing. To deepen the intrigue, the transcripts in the human chromosome 15q11-q13 region are subject to regulation by genomic imprinting, and some of these transcripts are imprinted in a tissue-specific manner. As the region is critically important for three human neurogenetic disorders, Angelman syndrome, Prader-Willi syndrome, and 15q duplication syndrome, there is intense interest in understanding the types of RNA and RNA processing that occurs among the imprinted genes. This review summarizes what is known about the various RNAs within the imprinted domain, including a novel type of RNA that was only very recently identified.
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Affiliation(s)
- Stormy J Chamberlain
- Department of Genetics and Developmental Biology, University of Connecticut Health Center, Farmington, CT, USA.
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Kranz TM, Ekawardhani S, Lin MK, Witzmann SR, Streit F, Schuelter U, Bauer H, Henseler D, Turner JD, Muller CP, Reif A, Schote AB, Meyer J. The chromosome 15q14 locus for bipolar disorder and schizophrenia: is C15orf53 a major candidate gene? J Psychiatr Res 2012; 46:1414-20. [PMID: 22944046 DOI: 10.1016/j.jpsychires.2012.08.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 06/10/2012] [Accepted: 08/10/2012] [Indexed: 10/27/2022]
Abstract
Bipolar disorder (BD) and schizophrenia are complexly inherited and highly heritable disorders with currently unknown etiologies. Recently, two independent genome-wide association studies for BD identified a small region on chromosome 15q14-15.1, pointing to a locus close to the gene C15orf53. Previously, this genomic region was also found to co-segregate with periodic catatonia (SCZD10, OMIM %605419), an unsystematic schizophrenia according to Leonhard's classification, in several multiplex families, thus pointing to overlapping etiologies of both conditions. A susceptibility locus on chromosome 15q14-15.1 was narrowed down to a 4.38 Mb region in these affected families followed by mutation and segregation analyses of C15orf53. Association analysis of individuals affected by BD and/or SCZD10 (n = 274) and controls (n = 230) and expression analyses in distinct post-mortem human limbic brain tissues were conducted. C15orf53 revealed no mutations in our SCZD10 family members, but segregation of two common haplotypes was found. No association of identified haplotypes was found in our case-control samples. Gene expression could be demonstrated for immune-system-derived cells but not for the post-mortem human limbic brain tissue. Our results indicate that C15orf53 is probably neither causative for the etiology of BD nor for SCZD10 in our samples.
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Affiliation(s)
- Thorsten M Kranz
- Department of Neurobehavioral Genetics, Institute of Psychobiology, University of Trier, Johanniterufer 15, 54290 Trier, Germany.
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Quantitative, high-resolution CpG methylation assays on the pyrosequencingplatform. Epigenomics 2012. [DOI: 10.1017/cbo9780511777271.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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49
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Askree SH, Dharamrup S, Hjelm LN, Coffee B. Parent-of-Origin Testing for 15q11-q13 Gains by Quantitative DNA Methylation Analysis. J Mol Diagn 2012; 14:192-8. [DOI: 10.1016/j.jmoldx.2012.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 01/10/2012] [Accepted: 01/30/2012] [Indexed: 10/28/2022] Open
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50
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Temporal and developmental requirements for the Prader-Willi imprinting center. Proc Natl Acad Sci U S A 2012; 109:3446-50. [PMID: 22331910 DOI: 10.1073/pnas.1115057109] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Imprinted gene expression associated with Prader-Willi syndrome (PWS) and Angelman syndrome (AS) is controlled by two imprinting centers (ICs), the PWS-IC and the AS-IC. The PWS-IC operates in cis to activate transcription of genes that are expressed exclusively from the paternal allele. We have created a conditional allele of the PWS-IC to investigate its developmental activity. Deletion of the paternal PWS-IC in the embryo before implantation abolishes expression of the paternal-only genes in the neonatal brain. Surprisingly, deletion of the PWS-IC in early brain progenitors does not affect the subsequent imprinted status of PWS/AS genes in the newborn brain. These results indicate that the PWS-IC functions to protect the paternal epigenotype at the epiblast stage of development but is dispensable thereafter.
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