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Bhalla K, Rosier K, Monnens Y, Meulemans S, Vervoort E, Thorrez L, Agostinis P, Meier DT, Rochtus A, Resnick JL, Creemers JWM. Similar metabolic pathways are affected in both Congenital Myasthenic Syndrome-22 and Prader-Willi Syndrome. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167175. [PMID: 38626828 DOI: 10.1016/j.bbadis.2024.167175] [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: 12/18/2023] [Revised: 04/11/2024] [Accepted: 04/12/2024] [Indexed: 04/26/2024]
Abstract
Loss of prolyl endopeptidase-like (PREPL) encoding a serine hydrolase with (thio)esterase activity leads to the recessive metabolic disorder Congenital Myasthenic Syndrome-22 (CMS22). It is characterized by severe neonatal hypotonia, feeding problems, growth retardation, and hyperphagia leading to rapid weight gain later in childhood. The phenotypic similarities with Prader-Willi syndrome (PWS) are striking, suggesting that similar pathways are affected. The aim of this study was to identify changes in the hypothalamic-pituitary axis in mouse models for both disorders and to examine mitochondrial function in skin fibroblasts of patients and knockout cell lines. We have demonstrated that Prepl is downregulated in the brains of neonatal PWS-IC-p/+m mice. In addition, the hypothalamic-pituitary axis is similarly affected in both Prepl-/- and PWS-IC-p/+m mice resulting in defective orexigenic signaling and growth retardation. Furthermore, we demonstrated that mitochondrial function is altered in PREPL knockout HEK293T cells and can be rescued with the supplementation of coenzyme Q10. Finally, PREPL-deficient and PWS patient skin fibroblasts display defective mitochondrial bioenergetics. The mitochondrial dysfunction in PWS fibroblasts can be rescued by overexpression of PREPL. In conclusion, we provide the first molecular parallels between CMS22 and PWS, raising the possibility that PREPL substrates might become therapeutic targets for treating both disorders.
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Affiliation(s)
- Kritika Bhalla
- Laboratory for Biochemical Neuroendocrinology, Department of Human genetics, KU Leuven, 3000 Leuven, Belgium
| | - Karen Rosier
- Laboratory for Biochemical Neuroendocrinology, Department of Human genetics, KU Leuven, 3000 Leuven, Belgium
| | - Yenthe Monnens
- Laboratory for Biochemical Neuroendocrinology, Department of Human genetics, KU Leuven, 3000 Leuven, Belgium
| | - Sandra Meulemans
- Laboratory for Biochemical Neuroendocrinology, Department of Human genetics, KU Leuven, 3000 Leuven, Belgium
| | - Ellen Vervoort
- Laboratory for Cell Death Research & Therapy, VIB, Department of Cellular and Molecular Medicine, Center for Cancer Biology, KU Leuven, 3000 Leuven, Belgium
| | - Lieven Thorrez
- Department of Development and Regeneration, KU Leuven Campus Kulak, 8500 Kortrijk, Belgium
| | - Patrizia Agostinis
- Laboratory for Cell Death Research & Therapy, VIB, Department of Cellular and Molecular Medicine, Center for Cancer Biology, KU Leuven, 3000 Leuven, Belgium
| | - Daniel T Meier
- Clinic of Endocrinology, Diabetes and Metabolism, University Hospital Basel, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Anne Rochtus
- Department of Development and Regeneration, UZ Leuven, 3000 Leuven, Belgium
| | - James L Resnick
- Department of Molecular genetics & Microbiology, College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - John W M Creemers
- Laboratory for Biochemical Neuroendocrinology, Department of Human genetics, KU Leuven, 3000 Leuven, Belgium.
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2
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Forrest MP, Penzes P. Mechanisms of copy number variants in neuropsychiatric disorders: From genes to therapeutics. Curr Opin Neurobiol 2023; 82:102750. [PMID: 37515924 PMCID: PMC10529795 DOI: 10.1016/j.conb.2023.102750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 06/01/2023] [Accepted: 06/27/2023] [Indexed: 07/31/2023]
Abstract
Copy number variants (CNVs) are genomic imbalances strongly linked to the aetiology of neuropsychiatric disorders such as schizophrenia and autism. By virtue of their large size, CNVs often contain many genes, providing a multi-genic view of disease processes that can be dissected in model systems. Thus, CNV research provides an important stepping stone towards understanding polygenic disease mechanisms, positioned between monogenic and polygenic risk models. In this review, we will outline hypothetical models for gene interactions occurring within CNVs and discuss different approaches used to study rodent and stem cell disease models. We highlight recent work showing that genetic and pharmacological strategies can be used to rescue important aspects of CNV-mediated pathophysiology, which often converges onto synaptic pathways. We propose that using a rescue approach in complete CNV models provides a new path forward for precise mechanistic understanding of complex disorders and a tangible route towards therapeutic development.
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Affiliation(s)
- Marc P Forrest
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Center for Autism and Neurodevelopment, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
| | - Peter Penzes
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Center for Autism and Neurodevelopment, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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3
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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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4
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Turner BRH, Mellor C, McElroy C, Bowen N, Gu W, Knill C, Itasaki N. Non-ubiquitous expression of core spliceosomal protein SmB/B' in chick and mouse embryos. Dev Dyn 2023; 252:276-293. [PMID: 36058892 PMCID: PMC10087933 DOI: 10.1002/dvdy.537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/02/2022] [Accepted: 08/25/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Although splicing is an integral part of the expression of many genes in our body, genetic syndromes with spliceosomal defects affect only specific tissues. To help understand the mechanism, we investigated the expression pattern of a core protein of the major spliceosome, SmB/B' (Small Nuclear Ribonucleoprotein Polypeptides B/B'), which is encoded by SNRPB. Loss-of-function mutations of SNRPB in humans cause cerebro-costo-mandibular syndrome (CCMS) characterized by rib gaps, micrognathia, cleft palate, and scoliosis. Our expression analysis focused on the affected structures as well as non-affected tissues, using chick and mouse embryos as model animals. RESULTS Embryos at young stages (gastrula) showed ubiquitous expression of SmB/B'. However, the level and pattern of expression became tissue-specific as differentiation proceeded. The regions relating to CCMS phenotypes such as cartilages of ribs and vertebrae and palatal mesenchyme express SmB/B' in the nucleus sporadically. However, cartilages that are not affected in CCMS also showed similar expressions. Another spliceosomal gene, SNRNP200, which mutations cause retinitis pigmentosa, was also prominently expressed in cartilages in addition to the retina. CONCLUSION The expression of SmB/B' is spatiotemporally regulated during embryogenesis despite the ubiquitous requirement of the spliceosome, however, the expression pattern is not strictly correlated with the phenotype presentation.
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Affiliation(s)
| | | | - Clara McElroy
- Faculty of Health Sciences, University of Bristol, Bristol, UK
| | - Natalie Bowen
- Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Wenjia Gu
- Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Chris Knill
- Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Nobue Itasaki
- Faculty of Health Sciences, University of Bristol, Bristol, UK
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Mechanisms of DNA methylation and histone modifications. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 197:51-92. [PMID: 37019597 DOI: 10.1016/bs.pmbts.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The field of genetics has expanded a lot in the past few decades due to the accessibility of human genome sequences, but still, the regulation of transcription cannot be explicated exclusively by the sequence of DNA of an individual. The coordination and crosstalk between chromatin factors which are conserved is indispensable for all living creatures. The regulation of gene expression has been dependent on the methylation of DNA, post-translational modifications of histones, effector proteins, chromatin remodeler enzymes that affect the chromatin structure and function, and other cellular activities such as DNA replication, DNA repair, proliferation and growth. The mutation and deletion of these factors can lead to human diseases. Various studies are being performed to identify and understand the gene regulatory mechanisms in the diseased state. The information from these high throughput screening studies is able to aid the treatment developments based on the epigenetics regulatory mechanisms. This book chapter will discourse on various modifications and their mechanisms that take place on histones and DNA that regulate the transcription of genes.
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Oztan O, Zyga O, Stafford DEJ, Parker KJ. Linking oxytocin and arginine vasopressin signaling abnormalities to social behavior impairments in Prader-Willi syndrome. Neurosci Biobehav Rev 2022; 142:104870. [PMID: 36113782 PMCID: PMC11024898 DOI: 10.1016/j.neubiorev.2022.104870] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 09/06/2022] [Accepted: 09/12/2022] [Indexed: 11/19/2022]
Abstract
Prader-Willi syndrome (PWS) is a genetic neurodevelopmental disorder. Global hypothalamic dysfunction is a core feature of PWS and has been implicated as a driver of many of PWS's phenotypic characteristics (e.g., hyperphagia-induced obesity, hypogonadism, short stature). Although the two neuropeptides (i.e., oxytocin [OXT] and arginine vasopressin [AVP]) most implicated in mammalian prosocial functioning are of hypothalamic origin, and social functioning is markedly impaired in PWS, there has been little consideration of how dysregulation of these neuropeptide signaling pathways may contribute to PWS's social behavior impairments. The present article addresses this gap in knowledge by providing a comprehensive review of the preclinical and clinical PWS literature-spanning endogenous neuropeptide measurement to exogenous neuropeptide administration studies-to better understand the roles of OXT and AVP signaling in this population. The preponderance of evidence indicates that OXT and AVP signaling are indeed dysregulated in PWS, and that these neuropeptide pathways may provide promising targets for therapeutic intervention in a patient population that currently lacks a pharmacological strategy for its debilitating social behavior symptoms.
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Affiliation(s)
- Ozge Oztan
- 1201 Welch Road, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - Olena Zyga
- 1201 Welch Road, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - Diane E J Stafford
- Center for Academic Medicine, 453 Quarry Road, Department of Pediatrics, Division of Pediatric Endocrinology, Stanford University, Palo Alto, CA 94304, USA
| | - Karen J Parker
- 1201 Welch Road, Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA; 300 Pasteur Drive, Department of Comparative Medicine, Stanford University, Stanford, CA 94305, USA.
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7
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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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8
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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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9
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Mian-Ling Z, Yun-Qi C, Chao-Chun Z. Prader-Willi Syndrome: Molecular Mechanism and Epigenetic Therapy. Curr Gene Ther 2021; 20:36-43. [PMID: 32329685 DOI: 10.2174/1566523220666200424085336] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 04/02/2020] [Accepted: 04/09/2020] [Indexed: 01/10/2023]
Abstract
Prader-Willi syndrome (PWS) is an imprinted neurodevelopmental disease characterized by cognitive impairments, developmental delay, hyperphagia, obesity, and sleep abnormalities. It is caused by a lack of expression of the paternally active genes in the PWS imprinting center on chromosome 15 (15q11.2-q13). Owing to the imprinted gene regulation, the same genes in the maternal chromosome, 15q11-q13, are intact in structure but repressed at the transcriptional level because of the epigenetic mechanism. The specific molecular defect underlying PWS provides an opportunity to explore epigenetic therapy to reactivate the expression of repressed PWS genes inherited from the maternal chromosome. The purpose of this review is to summarize the main advances in the molecular study of PWS and discuss current and future perspectives on the development of CRISPR/Cas9- mediated epigenome editing in the epigenetic therapy of PWS. Twelve studies on the molecular mechanism or epigenetic therapy of PWS were included in the review. Although our understanding of the molecular basis of PWS has changed fundamentally, there has been a little progress in the epigenetic therapy of PWS that targets its underlying genetic defects.
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Affiliation(s)
- Zhong Mian-Ling
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Chao Yun-Qi
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
| | - Zou Chao-Chun
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Zhejiang, China
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10
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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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Kummerfeld DM, Raabe CA, Brosius J, Mo D, Skryabin BV, Rozhdestvensky TS. A Comprehensive Review of Genetically Engineered Mouse Models for Prader-Willi Syndrome Research. Int J Mol Sci 2021; 22:3613. [PMID: 33807162 PMCID: PMC8037846 DOI: 10.3390/ijms22073613] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/26/2021] [Accepted: 03/28/2021] [Indexed: 02/05/2023] Open
Abstract
Prader-Willi syndrome (PWS) is a neurogenetic multifactorial disorder caused by the deletion or inactivation of paternally imprinted genes on human chromosome 15q11-q13. The affected homologous locus is on mouse chromosome 7C. The positional conservation and organization of genes including the imprinting pattern between mice and men implies similar physiological functions of this locus. Therefore, considerable efforts to recreate the pathogenesis of PWS have been accomplished in mouse models. We provide a summary of different mouse models that were generated for the analysis of PWS and discuss their impact on our current understanding of corresponding genes, their putative functions and the pathogenesis of PWS. Murine models of PWS unveiled the contribution of each affected gene to this multi-facetted disease, and also enabled the establishment of the minimal critical genomic region (PWScr) responsible for core symptoms, highlighting the importance of non-protein coding genes in the PWS locus. Although the underlying disease-causing mechanisms of PWS remain widely unresolved and existing mouse models do not fully capture the entire spectrum of the human PWS disorder, continuous improvements of genetically engineered mouse models have proven to be very powerful and valuable tools in PWS research.
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Affiliation(s)
- Delf-Magnus Kummerfeld
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
| | - Carsten A. Raabe
- Research Group Regulatory Mechanisms of Inflammation, Institute of Medical Biochemistry (ZMBE), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
- Institute of Experimental Pathology (ZMBE), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
| | - Juergen Brosius
- Institute of Experimental Pathology (ZMBE), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
- Institutes for Systems Genetics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Dingding Mo
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China;
| | - Boris V. Skryabin
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
| | - Timofey S. Rozhdestvensky
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
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Rong H, Yang W, Zhu H, Jiang B, Jiang J, Wang Y. Genomic imprinted genes in reciprocal hybrid endosperm of Brassica napus. BMC PLANT BIOLOGY 2021; 21:140. [PMID: 33726676 PMCID: PMC7968328 DOI: 10.1186/s12870-021-02908-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 02/28/2021] [Indexed: 05/06/2023]
Abstract
BACKGROUND Genomic imprinting results in the expression of parent-of-origin-specific alleles in the offspring. Brassica napus is an oil crop with research values in polyploidization. Identification of imprinted genes in B. napus will enrich the knowledge of genomic imprinting in dicotyledon plants. RESULTS In this study, we performed reciprocal crosses between B. napus L. cultivars Yangyou 6 (Y6) and Zhongshuang 11 (ZS11) to collect endosperm at 20 and 25 days after pollination (DAP) for RNA-seq. In total, we identified 297 imprinted genes, including 283 maternal expressed genes (MEGs) and 14 paternal expressed genes (PEGs) according to the SNPs between Y6 and ZS11. Only 36 genes (35 MEGs and 1 PEG) were continuously imprinted in 20 and 25 DAP endosperm. We found 15, 2, 5, 3, 10, and 25 imprinted genes in this study were also imprinted in Arabidopsis, rice, castor bean, maize, B. rapa, and other B. napus lines, respectively. Only 26 imprinted genes were specifically expressed in endosperm, while other genes were also expressed in root, stem, leaf and flower bud of B. napus. A total of 109 imprinted genes were clustered on rapeseed chromosomes. We found the LTR/Copia transposable elements (TEs) were most enriched in both upstream and downstream of the imprinted genes, and the TEs enriched around imprinted genes were more than non-imprinted genes. Moreover, the expression of 5 AGLs and 6 pectin-related genes in hybrid endosperm were significantly changed comparing with that in parent endosperm. CONCLUSION This research provided a comprehensive identification of imprinted genes in B. napus, and enriched the gene imprinting in dicotyledon plants, which would be useful in further researches on how gene imprinting regulates seed development.
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Affiliation(s)
- Hao Rong
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Wenjing Yang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Haotian Zhu
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Bo Jiang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Jinjin Jiang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
| | - Youping Wang
- Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, 225009 China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou, 225009 China
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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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Cataldi M, Arnaldi D, Tucci V, De Carli F, Patti G, Napoli F, Pace M, Maghnie M, Nobili L. Sleep disorders in Prader-Willi syndrome, evidence from animal models and humans. Sleep Med Rev 2021; 57:101432. [PMID: 33567377 DOI: 10.1016/j.smrv.2021.101432] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 02/06/2023]
Abstract
Prader-Willi Syndrome (PWS) is a complex genetic disorder with multiple cognitive, behavioral and endocrine dysfunctions. Sleep alterations and sleep disorders such as Sleep-disordered breathing and Central disorders of hypersomnolence are frequently recognized (either isolated or in comorbidity). The aim of the review is to highlight the pathophysiology and the clinical features of sleep disorders in PWS, providing the basis for early diagnosis and management. We reviewed the genetic features of the syndrome and the possible relationship with sleep alterations in animal models, and we described sleep phenotypes, diagnostic tools and therapeutic approaches in humans. Moreover, we performed a meta-analysis of cerebrospinal fluid orexin levels in patients with PWS; significantly lower levels of orexin were detected in PWS with respect to control subjects (although significantly higher than the ones of narcoleptic patients). Sleep disorders in humans with PWS are multifaceted and are often the result of different mechanisms. Since hypothalamic dysfunction seems to partially influence metabolic, respiratory and sleep/wake characteristics of this syndrome, additional studies are required in this framework.
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Affiliation(s)
- Matteo Cataldi
- Unit of Child Neuropsychiatry, Department of Medical and Surgical Neuroscience and Rehabilitation, IRCCS Istituto Giannina Gaslini, Genoa, Italy
| | - Dario Arnaldi
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Valter Tucci
- Genetics and Epigenetics of Behaviour Laboratory, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Fabrizio De Carli
- Institute of Bioimaging and Molecular Physiology, National Research Council, Genoa, Italy
| | - Giuseppa Patti
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; Department of Pediatrics, Istituto Giannina Gaslini, University of Genoa, Genoa, Italy
| | - Flavia Napoli
- Department of Pediatrics, Istituto Giannina Gaslini, University of Genoa, Genoa, Italy
| | - Marta Pace
- Genetics and Epigenetics of Behaviour Laboratory, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Mohamad Maghnie
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; Department of Pediatrics, Istituto Giannina Gaslini, University of Genoa, Genoa, Italy
| | - Lino Nobili
- Unit of Child Neuropsychiatry, Department of Medical and Surgical Neuroscience and Rehabilitation, IRCCS Istituto Giannina Gaslini, Genoa, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy.
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Abstract
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by hyperphagia, hypotonia, learning disability, as well as a range of psychiatric conditions. The conservation of the PWS genetic interval on chromosome 15q11-q13 in human, and a cluster of genes on mouse chromosome 7, has facilitated the use of mice as animal models for PWS. Some models faithfully mimic the loss of all gene expression from the paternally inherited PWS genetic interval, whereas others target smaller regions or individual genes. Collectively, these models have provided insight into the mechanisms, many of which lead to alterations in hypothalamic function, underlying the core symptoms of PWS, including growth retardation, hyperphagia and metabolism, reproductive maturation and endophenotypes of relevance to behavioral and psychiatric problems. Here we review and summarize these studies.
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Affiliation(s)
- Simona Zahova
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Anthony R Isles
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom.
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Hebras J, Marty V, Personnaz J, Mercier P, Krogh N, Nielsen H, Aguirrebengoa M, Seitz H, Pradere JP, Guiard BP, Cavaille J. Reassessment of the involvement of Snord115 in the serotonin 2c receptor pathway in a genetically relevant mouse model. eLife 2020; 9:60862. [PMID: 33016258 PMCID: PMC7673782 DOI: 10.7554/elife.60862] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022] Open
Abstract
SNORD115 has been proposed to promote the activity of serotonin (HTR2C) receptor via its ability to base pair with its pre-mRNA and regulate alternative RNA splicing and/or A-to-I RNA editing. Because SNORD115 genes are deleted in most patients with the Prader-Willi syndrome (PWS), diminished HTR2C receptor activity could contribute to the impaired emotional response and/or compulsive overeating characteristic of this disease. In order to test this appealing but never demonstrated hypothesis in vivo, we created a CRISPR/Cas9-mediated Snord115 knockout mouse. Surprisingly, we uncovered only modest region-specific alterations in Htr2c RNA editing profiles, while Htr2c alternative RNA splicing was unchanged. These subtle changes, whose functional relevance remains uncertain, were not accompanied by any discernible defects in anxio-depressive-like phenotypes. Energy balance and eating behavior were also normal, even after exposure to high-fat diet. Our study raises questions concerning the physiological role of SNORD115, notably its involvement in behavioural disturbance associated with PWS.
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Affiliation(s)
- Jade Hebras
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Virginie Marty
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Jean Personnaz
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1048, Institut National de la Santé et de la Recherche Médicale (INSERM), France Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université de Toulouse Université Paul Sabatier, Toulouse, France
| | - Pascale Mercier
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Centre National de la Recherche Scientifique UMR5089, Toulouse, France
| | - Nicolai Krogh
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Henrik Nielsen
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Marion Aguirrebengoa
- LBCMCP, Centre de Biologie Intégrative (CBI), CNRS, Université de Toulouse, Toulouse, France
| | - Hervé Seitz
- IGH (CNRS and University of Montpellier), Montpellier, France
| | - Jean-Phillipe Pradere
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1048, Institut National de la Santé et de la Recherche Médicale (INSERM), France Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université de Toulouse Université Paul Sabatier, Toulouse, France
| | - Bruno P Guiard
- Centre de Recherches sur la Cognition Animale (CRCA), Centre de Biologie Intégrative (CBI), Centre National de la Recherche Scientifique, Université de Toulouse, Toulouse, France
| | - Jérôme Cavaille
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, Toulouse, France
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17
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Chung MS, Langouët M, Chamberlain SJ, Carmichael GG. Prader-Willi syndrome: reflections on seminal studies and future therapies. Open Biol 2020; 10:200195. [PMID: 32961075 PMCID: PMC7536080 DOI: 10.1098/rsob.200195] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/02/2020] [Indexed: 12/13/2022] Open
Abstract
Prader-Willi syndrome (PWS) is caused by the loss of function of the paternally inherited 15q11-q13 locus. This region is governed by genomic imprinting, a phenomenon in which genes are expressed exclusively from one parental allele. The genomic imprinting of the 15q11-q13 locus is established in the germline and is largely controlled by a bipartite imprinting centre. One part, termed the Prader-Willi syndrome imprinting center (PWS-IC), comprises a CpG island that is unmethylated on the paternal allele and methylated on the maternal allele. The second part, termed the Angelman syndrome imprinting centre, is required to silence the PWS_IC in the maternal germline. The loss of the paternal contribution of the imprinted 15q11-q13 locus most frequently occurs owing to a large deletion of the entire imprinted region but can also occur through maternal uniparental disomy or an imprinting defect. While PWS is considered a contiguous gene syndrome based on large-deletion and uniparental disomy patients, the lack of expression of only non-coding RNA transcripts from the SNURF-SNRPN/SNHG14 may be the primary cause of PWS. Patients with small atypical deletions of the paternal SNORD116 cluster alone appear to have most of the PWS related clinical phenotypes. The loss of the maternal contribution of the 15q11-q13 locus causes a separate and distinct condition called Angelman syndrome. Importantly, while much has been learned about the regulation and expression of genes and transcripts deriving from the 15q11-q13 locus, there remains much to be learned about how these genes and transcripts contribute at the molecular level to the clinical traits and developmental aspects of PWS that have been observed.
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Affiliation(s)
| | | | | | - Gordon G. Carmichael
- Department of Genetics and Genome Sciences, UCONN Health, 400 Farmington Avenue, Farmington, CT 06030, USA
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18
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Germain ND, Levine ES, Chamberlain SJ. IPSC Models of Chromosome 15Q Imprinting Disorders: From Disease Modeling to Therapeutic Strategies. ADVANCES IN NEUROBIOLOGY 2020; 25:55-77. [PMID: 32578144 DOI: 10.1007/978-3-030-45493-7_3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The chromosome 15q11-q13 region of the human genome is regulated by genomic imprinting, an epigenetic phenomenon in which genes are expressed exclusively from one parental allele. Several genes within the 15q11-q13 region are expressed exclusively from the paternally inherited chromosome 15. At least one gene UBE3A, shows exclusive expression of the maternal allele, but this allele-specific expression is restricted to neurons. The appropriate regulation of imprinted gene expression across chromosome 15q11-q13 has important implications for human disease. Three different neurodevelopmental disorders result from aberrant expression of imprinted genes in this region: Prader-Willi syndrome (PWS), Angelman syndrome (AS), and 15q duplication syndrome.
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Affiliation(s)
- Noelle D Germain
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, CT, USA
| | - Eric S Levine
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, USA.
| | - Stormy J Chamberlain
- Department of Genetics and Genome Sciences, University of Connecticut School of Medicine, Farmington, CT, USA
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Adhikari A, Copping NA, Onaga B, Pride MC, Coulson RL, Yang M, Yasui DH, LaSalle JM, Silverman JL. Cognitive deficits in the Snord116 deletion mouse model for Prader-Willi syndrome. Neurobiol Learn Mem 2019; 165:106874. [PMID: 29800646 PMCID: PMC6520209 DOI: 10.1016/j.nlm.2018.05.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/24/2018] [Accepted: 05/16/2018] [Indexed: 01/12/2023]
Abstract
Prader-Willi syndrome (PWS) is an imprinted neurodevelopmental disease caused by a loss of paternal genes on chromosome 15q11-q13. It is characterized by cognitive impairments, developmental delay, sleep abnormalities, and hyperphagia often leading to obesity. Clinical research has shown that a lack of expression of SNORD116, a paternally expressed imprinted gene cluster that encodes multiple copies of a small nucleolar RNA (snoRNA) in both humans and mice, is most likely responsible for many PWS symptoms seen in humans. The majority of previous research using PWS preclinical models focused on characterization of the hyperphagic and metabolic phenotypes. However, a crucial understudied clinical phenotype is cognitive impairments and thus we investigated the learning and memory abilities using a model of PWS, with a heterozygous deletion in Snord116. We utilized the novel object recognition task, which doesn't require external motivation, or exhaustive swim training. Automated findings were further confirmed with manual scoring by a highly trained blinded investigator. We discovered deficits in Snord116+/- mutant mice in the novel object recognition, location memory and tone cue fear conditioning assays when compared to age-, sex- matched, littermate control Snord116+/+ mice. Further, we confirmed that despite physical neo-natal developmental delays, Snord116+/- mice had normal exploratory and motor abilities. These results show that the Snord116+/- deletion murine model is a valuable preclinical model for investigating learning and memory impairments in individuals with PWS without common confounding phenotypes.
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Affiliation(s)
- Anna Adhikari
- MIND Institute, University of California, Davis School of Medicine, Department of Psychiatry and Behavioral Sciences, Sacramento, CA, USA
| | - Nycole A Copping
- MIND Institute, University of California, Davis School of Medicine, Department of Psychiatry and Behavioral Sciences, Sacramento, CA, USA
| | - Beth Onaga
- MIND Institute, University of California, Davis School of Medicine, Department of Psychiatry and Behavioral Sciences, Sacramento, CA, USA
| | - Michael C Pride
- MIND Institute, University of California, Davis School of Medicine, Department of Psychiatry and Behavioral Sciences, Sacramento, CA, USA
| | - Rochelle L Coulson
- MIND Institute, Genome Center, UC Davis School of Medicine, Department of Medical Microbiology and Immunology, Davis, CA, USA
| | - Mu Yang
- Department of Psychiatry and Institute for Genomic Medicine, New York, NY, USA
| | - Dag H Yasui
- MIND Institute, Genome Center, UC Davis School of Medicine, Department of Medical Microbiology and Immunology, Davis, CA, USA
| | - Janine M LaSalle
- MIND Institute, Genome Center, UC Davis School of Medicine, Department of Medical Microbiology and Immunology, Davis, CA, USA
| | - Jill L Silverman
- MIND Institute, University of California, Davis School of Medicine, Department of Psychiatry and Behavioral Sciences, Sacramento, CA, USA.
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20
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The diverse roles of DNA methylation in mammalian development and disease. Nat Rev Mol Cell Biol 2019; 20:590-607. [PMID: 31399642 DOI: 10.1038/s41580-019-0159-6] [Citation(s) in RCA: 1159] [Impact Index Per Article: 231.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2019] [Indexed: 12/22/2022]
Abstract
DNA methylation is of paramount importance for mammalian embryonic development. DNA methylation has numerous functions: it is implicated in the repression of transposons and genes, but is also associated with actively transcribed gene bodies and, in some cases, with gene activation per se. In recent years, sensitive technologies have been developed that allow the interrogation of DNA methylation patterns from a small number of cells. The use of these technologies has greatly improved our knowledge of DNA methylation dynamics and heterogeneity in embryos and in specific tissues. Combined with genetic analyses, it is increasingly apparent that regulation of DNA methylation erasure and (re-)establishment varies considerably between different developmental stages. In this Review, we discuss the mechanisms and functions of DNA methylation and demethylation in both mice and humans at CpG-rich promoters, gene bodies and transposable elements. We highlight the dynamic erasure and re-establishment of DNA methylation in embryonic, germline and somatic cell development. Finally, we provide insights into DNA methylation gained from studying genetic diseases.
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Lewis MW, Vargas-Franco D, Morse DA, Resnick JL. A mouse model of Angelman syndrome imprinting defects. Hum Mol Genet 2019; 28:220-229. [PMID: 30260400 DOI: 10.1093/hmg/ddy345] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 09/21/2018] [Indexed: 02/07/2023] Open
Abstract
Angelman syndrome, Prader-Will syndrome and Dup15q syndrome map to a cluster of imprinted genes located at 15q11-q13. Imprinting at this domain is regulated by an imprinting control region consisting of two distinct elements, the Angelman syndrome imprinting center (AS-IC) and the Prader-Willi syndrome imprinting center (PWS-IC). Individuals inheriting deletions of the AS-IC exhibit reduced expression of the maternally expressed UBE3A gene and biallelic expression of paternal-only genes. We have previously demonstrated that AS-IC activity partly consists of providing transcription across the PWS-IC in oocytes, and that these transcripts are necessary for maternal imprinting of Snrpn. Here we report a novel mouse mutation that truncates transcripts prior to transiting the PWS-IC and results in a domain-wide imprinting defect. These results confirm a transcription-based model for imprint setting at this domain. The imprinting defect can be preempted by removal of the transcriptional block in oocytes, but not by its removal in early embryos. Imprinting defect mice exhibit several traits often found in individuals with Angelman syndrome imprinting defects.
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Affiliation(s)
- Michael W Lewis
- Department of Molecular Genetics and Microbiology College of Medicine University of Florida, Gainsvile, FL, USA
| | - Dorianmarie Vargas-Franco
- Department of Molecular Genetics and Microbiology College of Medicine University of Florida, Gainsvile, FL, USA
| | - Deborah A Morse
- Department of Molecular Genetics and Microbiology College of Medicine University of Florida, Gainsvile, FL, USA
| | - James L Resnick
- Department of Molecular Genetics and Microbiology College of Medicine University of Florida, Gainsvile, FL, USA
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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: 29] [Impact Index Per Article: 5.8] [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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23
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Carias KV, Wevrick R. Preclinical Testing in Translational Animal Models of Prader-Willi Syndrome: Overview and Gap Analysis. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2019; 13:344-358. [PMID: 30989085 PMCID: PMC6447752 DOI: 10.1016/j.omtm.2019.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder causing endocrine, musculoskeletal, and neurological dysfunction. PWS is caused by the inactivation of contiguous genes, complicating the development of targeted therapeutics. Clinical trials are now underway in PWS, with more trials to be implemented in the next few years. PWS-like endophenotypes are recapitulated in gene-targeted mice in which the function of one or more PWS genes is disrupted. These animal models can guide priorities for clinical trials or provide information about efficacy of a compound within the context of the specific disease. We now review the current status of preclinical studies that measure the effect of therapeutics on PWS-like endophenotypes. Seven categories of therapeutics (oxytocin and related compounds, K+-ATP channel agonists, melanocortin 4 receptor agonists, incretin mimetics and/or GLP-1 receptor agonists, cannabinoids, ghrelin agents, and Caralluma fimbriata [cactus] extract) have been tested for their effect on endophenotypes in both PWS animal models and clinical trials. Many other therapeutics have been tested in clinical trials, but not preclinical models of PWS or vice versa. Fostering dialogs among investigators performing preclinical validation of animal models and those implementing clinical studies will accelerate the discovery and translation of therapies into clinical practice in PWS.
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Affiliation(s)
- K Vanessa Carias
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
| | - Rachel Wevrick
- Department of Medical Genetics, University of Alberta, Edmonton, AB, Canada
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Saito T, Hara S, Kato T, Tamano M, Muramatsu A, Asahara H, Takada S. A tandem repeat array in IG-DMR is essential for imprinting of paternal allele at the Dlk1-Dio3 domain during embryonic development. Hum Mol Genet 2019; 27:3283-3292. [PMID: 29931170 DOI: 10.1093/hmg/ddy235] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 06/18/2018] [Indexed: 12/27/2022] Open
Abstract
Genomic imprinting is a phenomenon that causes parent-origin-specific monoallelic expression of a small subset of genes, known as imprinted genes, by parentally inherited epigenetic marks. Imprinted genes at the delta-like homolog 1 gene (Dlk1)-type III iodothyronine deiodinase gene (Dio3) imprinted domain, regulated by intergenic differentially methylated region (IG-DMR), are essential for normal development of late embryonic stages. Although the functions of IG-DMR have been reported by generating knockout mice, molecular details of the regulatory mechanisms are not fully understood as the specific sequence(s) of IG-DMR have not been identified. Here, we generated mutant mice by deleting a 216 bp tandem repeated sequence in IG-DMR, which comprised seven repeats of 24 bp motifs, by genome editing technologies. The mutant mice showed that paternal transmission of the deletion allele, but not maternal transmission, induces severe growth retardation and perinatal lethality, possibly due to placental defects. Embryos with a paternally transmitted deletion allele showed biallelic expression of maternally expressed genes and repression of paternally expressed genes. DNA methylation status also showed loss of methylation at IG-DMR and Gtl2-DMR, indicating that the tandem repeat sequence of IG-DMR is one of the functional sequences of IG-DMR, which is required for maintaining DNA methylation imprints of paternal allele at IG-DMR.
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Affiliation(s)
- Takeshi Saito
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, Japan.,Department of Systems BioMedicine, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Satoshi Hara
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Tomoko Kato
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, Japan.,Regenerative Medicine Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Moe Tamano
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Akari Muramatsu
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, Japan
| | - Hiroshi Asahara
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, Japan.,Department of Systems BioMedicine, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
| | - Shuji Takada
- Department of Systems BioMedicine, National Research Institute for Child Health and Development, Tokyo, Japan
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25
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Butler MG, Miller JL, Forster JL. Prader-Willi Syndrome - Clinical Genetics, Diagnosis and Treatment Approaches: An Update. Curr Pediatr Rev 2019; 15:207-244. [PMID: 31333129 PMCID: PMC7040524 DOI: 10.2174/1573396315666190716120925] [Citation(s) in RCA: 177] [Impact Index Per Article: 35.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Prader-Willi Syndrome (PWS) is a neurodevelopmental genomic imprinting disorder with lack of expression of genes inherited from the paternal chromosome 15q11-q13 region usually from paternal 15q11-q13 deletions (about 60%) or maternal uniparental disomy 15 or both 15s from the mother (about 35%). An imprinting center controls the expression of imprinted genes in the chromosome 15q11-q13 region. Key findings include infantile hypotonia, a poor suck, failure to thrive and hypogonadism/hypogenitalism. Short stature and small hands/feet due to growth and other hormone deficiencies, hyperphagia and marked obesity occur in early childhood, if uncontrolled. Cognitive and behavioral problems (tantrums, compulsions, compulsive skin picking) are common. OBJECTIVE Hyperphagia and obesity with related complications are major causes of morbidity and mortality in PWS. This report will describe an accurate diagnosis with determination of specific genetic subtypes, appropriate medical management and best practice treatment approaches. METHODS AND RESULTS An extensive literature review was undertaken related to genetics, clinical findings and laboratory testing, clinical and behavioral assessments and summary of updated health-related information addressing the importance of early PWS diagnosis and treatment. A searchable, bulleted and formatted list of topics is provided utilizing a Table of Contents approach for the clinical practitioner. CONCLUSION Physicians and other health care providers can use this review with clinical, genetic and treatment summaries divided into sections pertinent in the context of clinical practice. Frequently asked questions by clinicians, families and other interested participants or providers will be addressed.
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Affiliation(s)
- Merlin G Butler
- Departments of Psychiatry & Behavioral Sciences and Pediatrics, University of Kansas Medical Center, Kansas City, KS, United States
| | - Jennifer L Miller
- Department of Pediatrics, University of Florida School of Medicine, Gainesville, FL, United States
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26
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Mertsch S, Schlicht K, Melkonyan H, Schlatt S, Thanos S. snRPN controls the ability of neurons to regenerate axons. Restor Neurol Neurosci 2018; 36:31-43. [PMID: 29439367 DOI: 10.3233/rnn-170780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Retinal ganglion cells (RGCs) of mammals lose the ability to regenerate injured axons during postnatal maturation, but little is known about the underlying molecular mechanisms. OBJECTIVE It remains of particular importance to understand the mechanisms of axonal regeneration to develop new therapeutic approaches for nerve injuries. METHODS Retinas from newborn to adult monkeys (Callithrix jacchus)1 were obtained immediately after death and cultured in vitro. Growths of axons were monitored using microscopy and time-lapse video cinematography. Immunohistochemistry, Western blotting, qRT-PCR, and genomics were performed to characterize molecules associated with axonal regeneration and growth. A genomic screen was performed by using retinal explants versus native and non-regenerative explants obtained from eye cadavers on the day of birth, and hybridizing the mRNA with cross-reacting cDNA on conventional human microarrays. Followed the genomic screen, siRNA experiments were conducted to identify the functional involvement of identified candidates. RESULTS Neuron-specific human ribonucleoprotein N (snRPN) was found to be a potential regulator of impaired axonal regeneration during neuronal maturation in these animals. In particular, up-regulation of snRPN was observed during retinal maturation, coinciding with a decline in regenerative ability. Axon regeneration was reactivated in snRPN-knockout retinal ex vivo explants of adult monkey. CONCLUSION These results suggest that coordinated snRPN-driven activities within the neuron-specific ribonucleoprotein complex regulate the regenerative ability of RGCs in primates, thereby highlighting a potential new role for snRPN within neurons and the possibility of novel postinjury therapies.
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Affiliation(s)
- Sonja Mertsch
- Institute of Experimental Ophthalmology and DFG-Excellence Center, Cells in Motion (CiM, area C.4), School of Medicine, University of Münster, Münster, Germany.,Department of Ophthalmology, Laboratory of Experimental Ophthalmology, University Clinic Duesseldorf, Duesseldorf, Germany
| | - Katrin Schlicht
- Institute of Experimental Ophthalmology and DFG-Excellence Center, Cells in Motion (CiM, area C.4), School of Medicine, University of Münster, Münster, Germany
| | - Harutyun Melkonyan
- Institute of Experimental Ophthalmology and DFG-Excellence Center, Cells in Motion (CiM, area C.4), School of Medicine, University of Münster, Münster, Germany
| | - Stefan Schlatt
- Institute of Regenerative Medicine (CeRA) and DFG-Excellence Center, Cells in Motion (CiM, area A.2), School of Medicine, University of Münster, Münster, Germany
| | - Solon Thanos
- Institute of Experimental Ophthalmology and DFG-Excellence Center, Cells in Motion (CiM, area C.4), School of Medicine, University of Münster, Münster, Germany
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Welden JR, Zhang Z, Duncan MJ, Falaleeva M, Wells T, Stamm S. The posterior pituitary expresses the serotonin receptor 2C. Neurosci Lett 2018; 684:132-139. [PMID: 29969651 DOI: 10.1016/j.neulet.2018.06.051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/19/2018] [Accepted: 06/27/2018] [Indexed: 10/28/2022]
Abstract
The serotonin receptor 2C (5HT2C) is an important drug target to treat obesity and depression. Its pre-mRNA undergoes alternative splicing, encoding a short RNA1 isoform that is localized intracellularly and a full-length isoform (RNA2) that can reach the cell membrane. These splicing isoforms are deregulated in Prader-Willi syndrome (PWS), due to the loss of a trans-acting regulatory RNA, SNORD115. Here we show that the 5HT2C mRNA is expressed in the posterior pituitary, suggesting that 5HT2C mRNA is generated in the hypothalamus and subsequently conveyed by axonal transport. In the pituitary, the ratio of 5HT2C isoforms is regulated by feeding, and can be manipulated using a splice-site changing oligonucleotide injected into the blood. The pituitary expression of the 5HT2C mRNA may constitute a previously unknown mechanism whereby serotonin in the circulation or drugs targeting the 5HT2C might induce side-effects. Finally, the deregulation of 5HT2C splicing isoforms in PWS could contribute to the known hormonal imbalances.
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Affiliation(s)
- Justin R Welden
- Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40503, United States
| | - Zhaiyi Zhang
- Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40503, United States
| | - Marilyn J Duncan
- Dept. of Neuroscience, University of Kentucky College of Medicine, Lexington, KY, 40536, United States
| | - Marina Falaleeva
- Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40503, United States
| | - Timothy Wells
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, United Kingdom
| | - Stefan Stamm
- Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY, 40503, United States.
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Wanowska E, Kubiak MR, Rosikiewicz W, Makałowska I, Szcześniak MW. Natural antisense transcripts in diseases: From modes of action to targeted therapies. WILEY INTERDISCIPLINARY REVIEWS. RNA 2018; 9:e1461. [PMID: 29341438 PMCID: PMC5838512 DOI: 10.1002/wrna.1461] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 11/28/2017] [Accepted: 11/29/2017] [Indexed: 12/16/2022]
Abstract
Antisense transcription is a widespread phenomenon in mammalian genomes, leading to production of RNAs molecules referred to as natural antisense transcripts (NATs). NATs apply diverse transcriptional and post-transcriptional regulatory mechanisms to carry out a wide variety of biological roles that are important for the normal functioning of living cells, but their dysfunctions can be associated with human diseases. In this review, we attempt to provide a molecular basis for the involvement of NATs in the etiology of human disorders such as cancers and neurodegenerative and cardiovascular diseases. We also discuss the pros and cons of oligonucleotide-based therapies targeted against NATs, and we comment on state-of-the-art progress in this promising area of clinical research. WIREs RNA 2018, 9:e1461. doi: 10.1002/wrna.1461 This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Interactions with Proteins and Other Molecules > Small Molecule-RNA Interactions.
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Affiliation(s)
- Elżbieta Wanowska
- Institute of Antropology, Laboratory of Integrative GenomicsAdam Mickiewicz UniversityPoznanPoland
| | - Magdalena Regina Kubiak
- Institute of Antropology, Laboratory of Integrative GenomicsAdam Mickiewicz UniversityPoznanPoland
| | - Wojciech Rosikiewicz
- Institute of Antropology, Laboratory of Integrative GenomicsAdam Mickiewicz UniversityPoznanPoland
| | - Izabela Makałowska
- Institute of Antropology, Laboratory of Integrative GenomicsAdam Mickiewicz UniversityPoznanPoland
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29
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Nonclinical data supporting orphan medicinal product designations: lessons from rare neurological conditions. Drug Discov Today 2018; 23:26-48. [DOI: 10.1016/j.drudis.2017.09.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/01/2017] [Accepted: 09/27/2017] [Indexed: 12/14/2022]
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30
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Albuquerque D, Manco L, González LM, Gervasini G, Benito GM, González JR, Rodríguez-López R. Polymorphisms in the SNRPN gene are associated with obesity susceptibility in a Spanish population. J Gene Med 2017; 19. [PMID: 28387446 DOI: 10.1002/jgm.2956] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Revised: 03/15/2017] [Accepted: 04/04/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND SNRPN, which codes for the RNA-binding SmN protein, is a candidate gene for Prader-Willi syndrome. One characteristic of this neuroendocrine disorder is hyperphagia resulting in extreme obesity later in life. In the present study, we aimed to assess whether variability within this gene could be implicated in obesity susceptibility. METHODS A case-control study was performed including 265 unrelated patients with nonsyndromic and early-onset severe obesity, belonging to high-risk obesity families from Spanish ancestry; 184 healthy control individuals were included representative of the same genetic background and sex-matched. Forty-nine single nucleotide polymorphisms (SNPs) spanning the entire SNRPN gene were selected and genotyped using the Sequenom MassARRAY platform (Sequenom Inc., San Diego, CA, USA). RESULTS The four SNPs, rs12905653, rs752874, rs1391516 and rs2047433, were found to be nominally associated with obesity (p < 0.03). The diversity haplotype distribution among cases and controls identified the combination rs12905653-T/rs8028366-A/rs4028395-T as being strongly and inversely associated with obesity (odds ratio = 0.49; p = 0.0006). A genetic risk score was built based on rs12905653, rs1391516 and rs2047433 SNPs and each unit increase in genetic risk score increased the obesity risk by 49% (odds ratio = 1.49, 95% confidence interval = 1.24-1.80). CONCLUSIONS To our knowledge, this is the first study reporting an association between variability in the SNRPN gene and the risk of being obese. Interestingly, it was the major allele of each SNP that was found to be associated with the risk of weight gain. Further studies analyzing this locus and the possible additive deleterious capability of SNP combinations could be useful for demonstrating the development of obesity.
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Affiliation(s)
- David Albuquerque
- Research Center for Anthropology and Health (CIAS), University of Coimbra, Coimbra, Portugal.,Genomics Group, Fundación Investigación Hospital General Universitario de Valencia, Valencia, Spain
| | - Licínio Manco
- Research Center for Anthropology and Health (CIAS), University of Coimbra, Coimbra, Portugal
| | - Luz M González
- Genomics Group, Fundación Investigación Hospital General Universitario de Valencia, Valencia, Spain
| | - Guillermo Gervasini
- Department of Medical & Surgical Therapeutics, Division of Pharmacology, Medical School, University of Extremadura, Badajoz, Spain
| | - Goitzane Marcaida Benito
- Genomics Group, Fundación Investigación Hospital General Universitario de Valencia, Valencia, Spain.,Laboratory of Molecular Genetics, Clinical Analysis Service, Hospital Universitario General de Valencia, Valencia, Spain
| | - Juan R González
- ISGlobal, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.,CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain.,Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Raquel Rodríguez-López
- Genomics Group, Fundación Investigación Hospital General Universitario de Valencia, Valencia, Spain.,Laboratory of Molecular Genetics, Clinical Analysis Service, Hospital Universitario General de Valencia, Valencia, Spain
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31
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Cavaillé J. Box C/D small nucleolar RNA genes and the Prader-Willi syndrome: a complex interplay. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [PMID: 28296064 DOI: 10.1002/wrna.1417] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/11/2017] [Accepted: 01/13/2017] [Indexed: 12/22/2022]
Abstract
The nucleolus of mammalian cells contains hundreds of box C/D small nucleolar RNAs (SNORDs). Through their ability to base pair with ribosomal RNA precursors, most play important roles in the synthesis and/or activity of ribosomes, either by guiding sequence-specific 2'-O-methylations or by facilitating RNA folding and cleavages. A growing number of SNORD genes with elusive functions have been discovered recently. Intriguingly, the vast majority of them are located in two large, imprinted gene clusters at human chromosome region 15q11q13 (the SNURF-SNRPN domain) and at 14q32 (the DLK1-DIO3 domain) where they are expressed, respectively, only from the paternally and maternally inherited alleles. These placental mammal-specific SNORD genes have many features of the canonical SNORDs that guide 2'-O-methylations, yet they lack obvious complementarity with ribosomal RNAs and, surprisingly, they are processed from large, tandemly repeated genes expressed preferentially in the brain. This review summarizes our understanding of the biology of these peculiar SNORD genes, focusing particularly on SNORD115 and SNORD116 in the SNURF-SNRPN domain. It examines the growing evidence that altered levels of these SNORDs and/or their host-gene transcripts may be a primary cause of Prader-Willi syndrome (PWS; a rare disorder characterized by overeating and obesity) as well as abnormalities in signaling through the 5-HT2C serotonin receptor. Finally, the hypothesis that PWS may be a ribosomopathy (ribosomal disease) is also discussed. WIREs RNA 2017, 8:e1417. doi: 10.1002/wrna.1417 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Jérôme Cavaillé
- Laboratoire de Biologie Moléculaire Eucaryote, Université de Toulouse; UPS and CNRS, LMBE, Toulouse, France
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Golding DM, Rees DJ, Davies JR, Relkovic D, Furby HV, Guschina IA, Hopkins AL, Davies JS, Resnick JL, Isles AR, Wells T. Paradoxical leanness in the imprinting-centre deletion mouse model for Prader-Willi syndrome. J Endocrinol 2017; 232:123-135. [PMID: 27799465 PMCID: PMC5118940 DOI: 10.1530/joe-16-0367] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 10/31/2016] [Indexed: 01/09/2023]
Abstract
Prader-Willi syndrome (PWS), a neurodevelopmental disorder caused by loss of paternal gene expression from 15q11-q13, is characterised by growth retardation, hyperphagia and obesity. However, as single gene mutation mouse models for this condition display an incomplete spectrum of the PWS phenotype, we have characterised the metabolic impairment in a mouse model for 'full' PWS, in which deletion of the imprinting centre (IC) abolishes paternal gene expression from the entire PWS cluster. We show that PWS-ICdel mice displayed postnatal growth retardation, with reduced body weight, hyperghrelinaemia and marked abdominal leanness; proportionate retroperitoneal, epididymal/omental and inguinal white adipose tissue (WAT) weights being reduced by 82%, 84% and 67%, respectively. PWS-ICdel mice also displayed a 48% reduction in proportionate interscapular brown adipose tissue (isBAT) weight with significant 'beiging' of abdominal WAT, and a 2°C increase in interscapular surface body temperature. Maintenance of PWS-ICdel mice under thermoneutral conditions (30°C) suppressed the thermogenic activity in PWS-ICdel males, but failed to elevate the abdominal WAT weight, possibly due to a normalisation of caloric intake. Interestingly, PWS-ICdel mice also showed exaggerated food hoarding behaviour with standard and high-fat diets, but despite becoming hyperphagic when switched to a high-fat diet, PWS-ICdel mice failed to gain weight. This evidence indicates that, unlike humans with PWS, loss of paternal gene expression from the PWS cluster in mice results in abdominal leanness. Although reduced subcutaneous insulation may lead to exaggerated heat loss and thermogenesis, abdominal leanness is likely to arise from a reduced lipid storage capacity rather than increased energy utilisation in BAT.
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Affiliation(s)
| | - Daniel J Rees
- Institute of Life SciencesCollege of Medicine, Swansea University, Swansea, UK
| | - Jennifer R Davies
- Behavioural Genetics GroupMRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine & Psychology, Cardiff University, Cardiff, UK
| | - Dinko Relkovic
- Behavioural Genetics GroupMRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine & Psychology, Cardiff University, Cardiff, UK
| | - Hannah V Furby
- Behavioural Genetics GroupMRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine & Psychology, Cardiff University, Cardiff, UK
| | | | | | - Jeffrey S Davies
- Institute of Life SciencesCollege of Medicine, Swansea University, Swansea, UK
| | - James L Resnick
- Center for Mammalian GeneticsUniversity of Florida, College of Medicine, Gainesville, Florida, USA
| | - Anthony R Isles
- Behavioural Genetics GroupMRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine & Psychology, Cardiff University, Cardiff, UK
| | - Timothy Wells
- School of BiosciencesCardiff University, Cardiff, UK
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Garfield AS, Davies JR, Burke LK, Furby HV, Wilkinson LS, Heisler LK, Isles AR. Increased alternate splicing of Htr2c in a mouse model for Prader-Willi syndrome leads disruption of 5HT 2C receptor mediated appetite. Mol Brain 2016; 9:95. [PMID: 27931246 PMCID: PMC5144496 DOI: 10.1186/s13041-016-0277-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 11/30/2016] [Indexed: 12/21/2022] Open
Abstract
Alternate splicing of serotonin (5-hydroxytryptamine; 5-HT) 2C receptor (5-HT2CR) pre-RNA is negatively regulated by the small nucleolar RNA, Snord115, loss of which is observed in nearly all individuals with Prader-Willi Syndrome (PWS), a multigenic disorder characterised by hyperphagia and obesity. Given the role of the 5-HT2CR in the regulation of ingestive behaviour we investigated the pathophysiological implications of Snord115 deficiency on 5-HT2CR regulated appetite in a genotypically relevant PWS mouse model (PWS-IC). Specifically, we demonstrate that loss of Snord115 expression is associated with increased levels of hypothalamic truncated 5-HT2CR pre-mRNA. The 5-HT2CR promotes appetite suppression via engagement of the central melanocortin system. Pro-opiomelancortin (Pomc) mRNA levels within the arcuate nucleus of the hypothalamus (ARC) were reduced in PWS-IC mice. We then went on to assess the functional consequences of these molecular changes, demonstrating that PWS-IC mice are unresponsive to an anorectic doses of a 5-HT2CR agonist and that this is associated with attenuated activation of POMC neurons within the ARC. These data provide new insight into the significance of Htr2c pre-mRNA processing to the physiological regulation of appetite and potentially the pathological manifestation of hyperphagia in PWS. Furthermore, these findings have translational relevance for individuals with PWS who may seek to control appetite with another 5-HT2CR agonist, the new obesity treatment lorcaserin.
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Affiliation(s)
- Alastair S Garfield
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.,Present address: Cardiovascular and Metabolic Disease, Pfizer, Cambridge, MA, 02139, USA
| | - Jennifer R Davies
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine and Pscyhology, Cardiff University, Cardiff, UK
| | - Luke K Burke
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Hannah V Furby
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine and Pscyhology, Cardiff University, Cardiff, UK
| | - Lawrence S Wilkinson
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine and Pscyhology, Cardiff University, Cardiff, UK
| | - Lora K Heisler
- Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
| | - Anthony R Isles
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Schools of Medicine and Pscyhology, Cardiff University, Cardiff, UK.
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Cheon CK. Genetics of Prader-Willi syndrome and Prader-Will-Like syndrome. Ann Pediatr Endocrinol Metab 2016; 21:126-135. [PMID: 27777904 PMCID: PMC5073158 DOI: 10.6065/apem.2016.21.3.126] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 09/30/2016] [Indexed: 11/29/2022] Open
Abstract
The Prader-Willi syndrome (PWS) is a human imprinting disorder resulting from genomic alterations that inactivate imprinted, paternally expressed genes in human chromosome region 15q11-q13. This genetic condition appears to be a contiguous gene syndrome caused by the loss of at least 2 of a number of genes expressed exclusively from the paternal allele, including SNRPN, MKRN3, MAGEL2, NDN and several snoRNAs, but it is not yet well known which specific genes in this region are associated with this syndrome. Prader-Will-Like syndrome (PWLS) share features of the PWS phenotype and the gene functions disrupted in PWLS are likely to lie in genetic pathways that are important for the development of PWS phenotype. However, the genetic basis of these rare disorders differs and the absence of a correct diagnosis may worsen the prognosis of these individuals due to the endocrine-metabolic malfunctioning associated with the PWS. Therefore, clinicians face a challenge in determining when to request the specific molecular test used to identify patients with classical PWS because the signs and symptoms of PWS are common to other syndromes such as PWLS. This review aims to provide an overview of current knowledge relating to the genetics of PWS and PWLS, with an emphasis on identification of patients that may benefit from further investigation and genetic screening.
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Affiliation(s)
- Chong Kun Cheon
- Division of Pediatric Endocrinology and Metabolism, Department of Pediatrics, Pusan National University Children's Hospital, Pusan National University School of Medicine, Yangsan, Korea
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Voon HPJ, Gibbons RJ. Maintaining memory of silencing at imprinted differentially methylated regions. Cell Mol Life Sci 2016; 73:1871-9. [PMID: 26883803 PMCID: PMC4819931 DOI: 10.1007/s00018-016-2157-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 02/04/2016] [Indexed: 01/09/2023]
Abstract
Imprinted genes are an exceptional cluster of genes which are expressed in a parent-of-origin dependent fashion. This allele-specific expression is dependent on differential DNA methylation which is established in the parental germlines in a sex-specific manner. The DNA methylation imprint is accompanied by heterochromatin modifications which must be continuously maintained through development. This review summarises the factors which are important for protecting the epigenetic modifications at imprinted differentially methylated regions (DMRs), including PGC7, ZFP57 and the ATRX/Daxx/H3.3 complex. We discuss how these factors maintain heterochromatin silencing, not only at imprinted DMRs, but also other heterochromatic regions in the genome.
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Affiliation(s)
- Hsiao P J Voon
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, 3800, Australia
| | - Richard J Gibbons
- University of Oxford, Oxford, UK.
- MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford, OX3 9DS, UK.
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Spikol ED, Laverriere CE, Robnett M, Carter G, Wolfe E, Glasgow E. Zebrafish Models of Prader-Willi Syndrome: Fast Track to Pharmacotherapeutics. Diseases 2016; 4. [PMID: 27857842 PMCID: PMC5110251 DOI: 10.3390/diseases4010013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a rare genetic neurodevelopmental disorder characterized by an insatiable appetite, leading to chronic overeating and obesity. Additional features include short stature, intellectual disability, behavioral problems and incomplete sexual development. Although significant progress has been made in understanding the genetic basis of PWS, the mechanisms underlying the pathogenesis of the disorder remain poorly understood. Treatment for PWS consists mainly of palliative therapies; curative therapies are sorely needed. Zebrafish, Danio rerio, represent a promising way forward for elucidating physiological problems such as obesity and identifying new pharmacotherapeutic options for PWS. Over the last decade, an increased appreciation for the highly conserved biology among vertebrates and the ability to perform high-throughput drug screening has seen an explosion in the use of zebrafish for disease modeling and drug discovery. Here, we review recent advances in developing zebrafish models of human disease. Aspects of zebrafish genetics and physiology that are relevant to PWS will be discussed, and the advantages and disadvantages of zebrafish models will be contrasted with current animal models for this syndrome. Finally, we will present a paradigm for drug screening in zebrafish that is potentially the fastest route for identifying and delivering curative pharmacotherapies to PWS patients.
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Butler MG, Manzardo AM, Forster JL. Prader-Willi Syndrome: Clinical Genetics and Diagnostic Aspects with Treatment Approaches. Curr Pediatr Rev 2016; 12:136-66. [PMID: 26592417 PMCID: PMC6742515 DOI: 10.2174/1573396312666151123115250] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 11/22/2022]
Abstract
BACKGROUND Prader-Willi syndrome (PWS) is a neuro-developmental genetic disorder due to lack of expression of genes inherited from the paternal chromosome 15q11-q13 region with three main genetic subtypes. These include paternal 15q11-q13 deletion (about 70% of cases), maternal uniparental disomy 15 or both 15s from the mother (20-30% of cases), and defects in the imprinting center (1-3%) which controls the expression of imprinted genes in this chromosome region. Clinical manifestations include infantile hypotonia with a poor suck resulting in failure to thrive, short stature, small hands/feet and hypogonadism/hypogenitalism due to growth and other hormone deficiencies, hyperphagia and excessive weight gain with obesity and cognitive and behavioral problems including obsessive compulsions, tantrums and self-injury. The phenotype is likely related to hypothalamic dysfunction. OBJECTIVE Hyperphagia and obesity with related complications are major causes of morbidity and mortality in PWS requiring accurate diagnosis, appropriate medical management and treatment; the major objective of our report. METHODS AND RESULTS An extensive review of the literature was undertaken including genetics, clinical and behavioral aspects, and updated health-related information addressing the importance of early diagnosis and treatment of individuals with Prader-Willi syndrome. A searchable, bulleted and formatted list of topics related to this obesity syndrome was provided utilizing a Table of Contents approach for the clinical practitioner. CONCLUSIONS Physicians and other health care providers can use this review with clinical, genetic and treatment summaries divided into sections that are pertinent in the context of clinical practice. Finally, frequently asked questions by clinicians, families and other interested participants will be addressed.
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Affiliation(s)
- Merlin G Butler
- University of Kansas Medical Center, Department of Psychiatry and Behavioral Sciences, 3901 Rainbow Boulevard, MS 4015, Kansas City, Kansas 66160, USA.
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Fujimoto I, Hasegawa K, Fujiwara K, Yamada M, Yoshikawa K. Necdin controls EGFR signaling linked to astrocyte differentiation in primary cortical progenitor cells. Cell Signal 2015; 28:94-107. [PMID: 26655377 DOI: 10.1016/j.cellsig.2015.11.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/23/2015] [Accepted: 11/30/2015] [Indexed: 11/26/2022]
Abstract
Cellular signaling mediated by the EGF receptor (EGFR) plays a key role in controlling proliferation and differentiation of cortical progenitor cells (CPCs). However, regulatory mechanisms of EGFR signaling in CPCs remain largely unknown. Here we demonstrate that necdin, a MAGE (melanoma antigen) family protein, interacts with EGFR in primary CPCs and represses its downstream signaling linked to astrocyte differentiation. EGFR was autophosphorylated and interacted with necdin in EGF-stimulated CPCs. Necdin bound to autophosphorylated EGFR via its tyrosine kinase domain. EGF-induced phosphorylation of ERK was enhanced in necdin-null CPCs, where the interaction between EGFR and the adaptor protein Grb2 was strengthened, suggesting that endogenous necdin suppresses the EGFR/ERK signaling pathway in CPCs. In necdin-null CPCs, astrocyte differentiation induced by the gliogenic cytokine cardiotrophin-1 was significantly accelerated in the presence of EGF, and inhibition of EGFR/ERK signaling abolished the acceleration. Furthermore, necdin strongly suppressed astrocyte differentiation induced by overexpression of EGFR or its ligand binding-defective mutant equivalent to a glioblastoma-associated EGFR variant. These results suggest that necdin acts as an intrinsic suppressor of the EGFR/ERK signaling pathway in EGF-responsive CPCs to restrain astroglial development in a cell-autonomous manner.
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Affiliation(s)
- Izumi Fujimoto
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Koichi Hasegawa
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Kazushiro Fujiwara
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Masashi Yamada
- Laboratory of Extracellular Matrix Biochemistry, Institute for Protein Research, Osaka University, Osaka, Japan
| | - Kazuaki Yoshikawa
- Laboratory of Regulation of Neuronal Development, Institute for Protein Research, Osaka University, Osaka, Japan.
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Strogantsev R, Krueger F, Yamazawa K, Shi H, Gould P, Goldman-Roberts M, McEwen K, Sun B, Pedersen R, Ferguson-Smith AC. Allele-specific binding of ZFP57 in the epigenetic regulation of imprinted and non-imprinted monoallelic expression. Genome Biol 2015; 16:112. [PMID: 26025256 PMCID: PMC4491874 DOI: 10.1186/s13059-015-0672-7] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/11/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Selective maintenance of genomic epigenetic imprints during pre-implantation development is required for parental origin-specific expression of imprinted genes. The Kruppel-like zinc finger protein ZFP57 acts as a factor necessary for maintaining the DNA methylation memory at multiple imprinting control regions in early mouse embryos and embryonic stem (ES) cells. Maternal-zygotic deletion of ZFP57 in mice presents a highly penetrant phenotype with no animals surviving to birth. Additionally, several cases of human transient neonatal diabetes are associated with somatic mutations in the ZFP57 coding sequence. RESULTS Here, we comprehensively map sequence-specific ZFP57 binding sites in an allele-specific manner using hybrid ES cell lines from reciprocal crosses between C57BL/6J and Cast/EiJ mice, assigning allele specificity to approximately two-thirds of all binding sites. While half of these are biallelic and include endogenous retrovirus (ERV) targets, the rest show monoallelic binding based either on parental origin or on genetic background of the allele. Parental-origin allele-specific binding is methylation-dependent and maps only to imprinting control differentially methylated regions (DMRs) established in the germline. We identify a novel imprinted gene, Fkbp6, which has a critical function in mouse male germ cell development. Genetic background-specific sequence differences also influence ZFP57 binding, as genetic variation that disrupts the consensus binding motif and its methylation is often associated with monoallelic expression of neighboring genes. CONCLUSIONS The work described here uncovers further roles for ZFP57-mediated regulation of genomic imprinting and identifies a novel mechanism for genetically determined monoallelic gene expression.
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Affiliation(s)
- Ruslan Strogantsev
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3EG, UK. .,Present address: Epigenetics ISP, Babraham Institute, Cambridge, CB22 3AT, UK.
| | - Felix Krueger
- Bioinformatics Department, Babraham Institute, Cambridge, CB22 3AT, UK.
| | - Kazuki Yamazawa
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3EG, UK.
| | - Hui Shi
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3EG, UK.
| | - Poppy Gould
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3EG, UK.
| | - Megan Goldman-Roberts
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3EG, UK.
| | - Kirsten McEwen
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3EG, UK.
| | - Bowen Sun
- The Anne McLaren Laboratory for Regenerative Medicine, University of Cambridge, Cambridge, CB2 0SZ, UK.
| | - Roger Pedersen
- The Anne McLaren Laboratory for Regenerative Medicine, University of Cambridge, Cambridge, CB2 0SZ, UK.
| | - Anne C Ferguson-Smith
- Department of Physiology Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3EG, UK. .,Present address: Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK.
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Kishimoto R, Tamada K, Liu X, Okubo H, Ise S, Ohta H, Ruf S, Nakatani J, Kohno N, Spitz F, Takumi T. Model mice for 15q11-13 duplication syndrome exhibit late-onset obesity and altered lipid metabolism. Hum Mol Genet 2015; 24:4559-72. [PMID: 26002101 DOI: 10.1093/hmg/ddv187] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 05/18/2015] [Indexed: 12/27/2022] Open
Abstract
Copy number variations on human chromosome 15q11-q13 have been implicated in several neurodevelopmental disorders. A paternal loss or duplication of the Prader-Willi syndrome/Angelman syndrome (PWS/AS) region confers a risk of obesity, although the mechanism remains a mystery due to a lack of an animal model that accurately recreates the obesity phenotype. We performed detailed analyses of mice with duplication of PWS/AS locus (6 Mb) generated by chromosome engineering and found that animals with a paternal duplication of this region (patDp/+) show late-onset obesity, high sensitivity for high-fat diet, high levels of blood leptin and insulin without an increase in food intake. We show that prior to becoming obese, young patDp/+ mice already had enlarged white adipocytes. Transcriptome analysis of adipose tissue revealed an up-regulation of Secreted frizzled-related protein 5 (Sfrp5), known to promote adipogenesis. We additionally generated a new mouse model of paternal duplication focusing on a 3 Mb region (3 Mb patDp/+) within the PWS/AS locus. These mice recapitulate the obese phenotypes including expansion of visceral adipose tissue. Our results suggest paternally expressed genes in PWS/AS locus play a significant role for the obesity and identify new potential targets for future research and treatment of obesity.
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Affiliation(s)
- Rui Kishimoto
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan, Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Kota Tamada
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan, Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - Xiaoxi Liu
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Hiroko Okubo
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Satoko Ise
- Banyu Tsukuba Research Institute, Tsukuba, Ibaraki 300-2611, Japan
| | - Hisashi Ohta
- Banyu Tsukuba Research Institute, Tsukuba, Ibaraki 300-2611, Japan
| | - Sandra Ruf
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Jin Nakatani
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Ohtsu, Shiga 520-2192, Japan and
| | - Nobuoki Kohno
- Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan
| | - François Spitz
- Developmental Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Toru Takumi
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan, Graduate School of Biomedical Sciences, Hiroshima University, Minami, Hiroshima 734-8553, Japan, JST, CREST, Tokyo, Japan
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Iyer J, Girirajan S. Gene discovery and functional assessment of rare copy-number variants in neurodevelopmental disorders. Brief Funct Genomics 2015; 14:315-28. [DOI: 10.1093/bfgp/elv018] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Varmuza S, Miri K. What does genetics tell us about imprinting and the placenta connection? Cell Mol Life Sci 2015; 72:51-72. [PMID: 25194419 PMCID: PMC11114082 DOI: 10.1007/s00018-014-1714-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Revised: 08/25/2014] [Accepted: 08/27/2014] [Indexed: 01/07/2023]
Abstract
Genomic imprinting is an epigenetic gene silencing phenomenon that is specific to eutherians in the vertebrate lineage. The acquisition of both placentation and genomic imprinting has spurred interest in the possible evolutionary link for many years. In this review we examine the genetic evidence and find that while many imprinted domains are anchored by genes required for proper placenta development in a parent of origin fashion, an equal number of imprinted genes have no apparent function that depends on imprinting. Examination of recent data from studies of molecular and genetic mechanisms points to a maternal control of the selection and maintenance of imprint marks, reinforcing the importance of the oocyte in the healthy development of the placenta and fetus.
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Affiliation(s)
- Susannah Varmuza
- Department of Cell and Systems Biology, University of Toronto, 611-25 Harbord Street, Toronto, M5S 3G5, Canada,
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43
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Angelman syndrome imprinting center encodes a transcriptional promoter. Proc Natl Acad Sci U S A 2014; 112:6871-5. [PMID: 25378697 DOI: 10.1073/pnas.1411261111] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Clusters of imprinted genes are often controlled by an imprinting center that is necessary for allele-specific gene expression and to reprogram parent-of-origin information between generations. An imprinted domain at 15q11-q13 is responsible for both Angelman syndrome (AS) and Prader-Willi syndrome (PWS), two clinically distinct neurodevelopmental disorders. Angelman syndrome arises from the lack of maternal contribution from the locus, whereas Prader-Willi syndrome results from the absence of paternally expressed genes. In some rare cases of PWS and AS, small deletions may lead to incorrect parent-of-origin allele identity. DNA sequences common to these deletions define a bipartite imprinting center for the AS-PWS locus. The PWS-smallest region of deletion overlap (SRO) element of the imprinting center activates expression of genes from the paternal allele. The AS-SRO element generates maternal allele identity by epigenetically inactivating the PWS-SRO in oocytes so that paternal genes are silenced on the future maternal allele. Here we have investigated functional activities of the AS-SRO, the element necessary for maternal allele identity. We find that, in humans, the AS-SRO is an oocyte-specific promoter that generates transcripts that transit the PWS-SRO. Similar upstream promoters were detected in bovine oocytes. This result is consistent with a model in which imprinting centers become DNA methylated and acquire maternal allele identity in oocytes in response to transiting transcription.
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Brant JO, Riva A, Resnick JL, Yang TP. Influence of the Prader-Willi syndrome imprinting center on the DNA methylation landscape in the mouse brain. Epigenetics 2014; 9:1540-56. [PMID: 25482058 PMCID: PMC4623435 DOI: 10.4161/15592294.2014.969667] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/23/2014] [Accepted: 08/25/2014] [Indexed: 11/19/2022] Open
Abstract
Reduced representation bisulfite sequencing (RRBS) was used to analyze DNA methylation patterns across the mouse brain genome in mice carrying a deletion of the Prader-Willi syndrome imprinting center (PWS-IC) on either the maternally- or paternally-inherited chromosome. Within the ~3.7 Mb imprinted Angelman/Prader-Willi syndrome (AS/PWS) domain, 254 CpG sites were interrogated for changes in methylation due to PWS-IC deletion. Paternally-inherited deletion of the PWS-IC increased methylation levels ~2-fold at each CpG site (compared to wild-type controls) at differentially methylated regions (DMRs) associated with 5' CpG island promoters of paternally-expressed genes; these methylation changes extended, to a variable degree, into the adjacent CpG island shores. Maternal PWS-IC deletion yielded little or no changes in methylation at these DMRs, and methylation of CpG sites outside of promoter DMRs also was unchanged upon maternal or paternal PWS-IC deletion. Using stringent ascertainment criteria, ~750,000 additional CpG sites were also interrogated across the entire mouse genome. This analysis identified 26 loci outside of the imprinted AS/PWS domain showing altered DNA methylation levels of ≥25% upon PWS-IC deletion. Curiously, altered methylation at 9 of these loci was a consequence of maternal PWS-IC deletion (maternal PWS-IC deletion by itself is not known to be associated with a phenotype in either humans or mice), and 10 of these loci exhibited the same changes in methylation irrespective of the parental origin of the PWS-IC deletion. These results suggest that the PWS-IC may affect DNA methylation at these loci by directly interacting with them, or may affect methylation at these loci through indirect downstream effects due to PWS-IC deletion. They further suggest the PWS-IC may have a previously uncharacterized function outside of the imprinted AS/PWS domain.
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Key Words
- AS, Angelman Syndrome
- AS-IC, Angelman Syndrome Imprinting Center
- AS-SRO, Angelman Syndrome Shortest Region of deletion Overlap
- BGS, Sodium Bisulfite Genomic Sequencing
- BISSCA, Bisulfite Sequencing Comparative Analysis
- CGI, CpG Island
- DH, DNase I Hypersensitive
- DMR, Differentially Methylated Region
- DNA methylation
- EtOH, Ethanol
- GO, gene ontology
- IC, Imprinting Center
- ICR, Imprinting Control Region
- IPA, Ingenuity Pathway Analysis ®
- PWS, Prader-Willi Syndrome
- PWS-IC, Prader-Willi Syndrome Imprinting Center
- PWS-SRO, Prader-Willi Syndrome Shortest Region of deletion Overlap
- RRBS, Reduced Representation Bisulfite Sequencing
- SDS, Sodium Dodecyl Sulfate
- SLIM, Sliding Linear Model
- TBE, Tris/Borate/EDTA
- Tris, Trisaminomethane
- UTR, untranslated region
- angelman syndrome
- genomic imprinting
- imprinting center
- lncRNA, long non-coding RNA
- mat, maternally-inherited allele
- pat, paternally-inherited allele
- prader-Willi syndrome
- reduced representation bisulfite sequencing
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Affiliation(s)
- Jason O Brant
- Department of Biochemistry and Molecular Biology; University of Florida; Gainesville, FL USA
- Center for Epigenetics; University of Florida; Gainesville, FL USA
| | - Alberto Riva
- Department of Molecular Genetics and Microbiology; University of Florida; Gainesville, FL USA
- Genetics Institute; University of Florida; Gainesville, FL USA
| | - James L Resnick
- Department of Molecular Genetics and Microbiology; University of Florida; Gainesville, FL USA
- Center for Epigenetics; University of Florida; Gainesville, FL USA
- Genetics Institute; University of Florida; Gainesville, FL USA
| | - Thomas P Yang
- Department of Biochemistry and Molecular Biology; University of Florida; Gainesville, FL USA
- Center for Epigenetics; University of Florida; Gainesville, FL USA
- Genetics Institute; University of Florida; Gainesville, FL USA
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Restricted development of mouse triploid fetuses with disorganized expression of imprinted genes. ZYGOTE 2014; 23:874-84. [DOI: 10.1017/s0967199414000550] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
SummaryEukaryotic species commonly contain a diploid complement of chromosomes. The diploid state appears to be advantageous for mammals because it enables sexual reproduction and facilitates genetic recombination. Nonetheless, the effects of DNA ploidy on mammalian ontogeny have yet to be understood. The present study shows phenotypic features and expression patterns of imprinted genes in tripronucleate diandric and digynic triploid (DAT and DGT) mouse fetuses on embryonic day 10.5 (E10.5). Measurement of crown–rump length revealed that the length of DGT fetuses (1.87 ± 0.13 mm; mean ± standard error of the mean) was much smaller than that of diploid fetuses (4.81 ± 0.05 mm). However, no significant difference was observed in the crown–rump length between diploid and DAT fetuses (3.86 ± 0.43 mm). In DGT fetuses, the expression level of paternally expressed genes, Igf2, Dlk1, Ndn, and Peg3, remained significantly reduced and that of maternally expressed genes, Igf2r and Grb10, increased. Additionally, in DAT fetuses, the Igf2 mRNA expression level was approximately twice that in diploid fetuses, as expected. These results provide the first demonstration that imprinted genes in mouse triploid fetuses show distinctive expression patterns independent of the number of parental-origin haploid sets. These data suggest that both DNA ploidy and asymmetrical functions of parental genomes separately influence mammalian ontogeny.
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Cleaton MA, Edwards CA, Ferguson-Smith AC. Phenotypic Outcomes of Imprinted Gene Models in Mice: Elucidation of Pre- and Postnatal Functions of Imprinted Genes. Annu Rev Genomics Hum Genet 2014; 15:93-126. [DOI: 10.1146/annurev-genom-091212-153441] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Carol A. Edwards
- Department of Genetics, University of Cambridge, Cambridge CB2 3EG, United Kingdom;
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47
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Lorenc A, Linnenbrink M, Montero I, Schilhabel MB, Tautz D. Genetic differentiation of hypothalamus parentally biased transcripts in populations of the house mouse implicate the Prader-Willi syndrome imprinted region as a possible source of behavioral divergence. Mol Biol Evol 2014; 31:3240-9. [PMID: 25172960 PMCID: PMC4245819 DOI: 10.1093/molbev/msu257] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Parentally biased expression of transcripts (genomic imprinting) in adult tissues, including the brain, can influence and possibly drive the evolution of behavioral traits. We have previously found that paternally determined cues are involved in population-specific mate choice decisions between two populations of the Western house mouse (Mus musculus domesticus). Here, we ask whether this could be mediated by genomically imprinted transcripts that are subject to fast differentiation between these populations. We focus on three organs that are of special relevance for mate choice and behavior: The vomeronasal organ (VNO), the hypothalamus, and the liver. To first identify candidate transcripts at a genome-wide scale, we used reciprocal crosses between M. m. domesticus and M. m. musculus inbred strains and RNA sequencing of the respective tissues. Using a false discovery cutoff derived from mock reciprocal cross comparisons, we find a total of 66 imprinted transcripts, 13 of which have previously not been described as imprinted. The largest number of imprinted transcripts were found in the hypothalamus; fewer were found in the VNO, and the least were found in the liver. To assess molecular differentiation and imprinting in the wild-derived M. m. domesticus populations, we sequenced the RNA of the hypothalamus from individuals of these populations. This confirmed the presence of the above identified transcripts also in wild populations and allowed us to search for those that show a high genetic differentiation between these populations. Our results identify the Ube3a–Snrpn imprinted region on chromosome 7 as a region that encompasses the largest number of previously not described transcripts with paternal expression bias, several of which are at the same time highly differentiated. For four of these, we confirmed their imprinting status via single nucleotide polymorphism-specific pyrosequencing assays with RNA from reciprocal crosses. In addition, we find the paternally expressed Peg13 transcript within the Trappc9 gene region on chromosome 15 to be highly differentiated. Interestingly, both regions have been implicated in Prader–Willi nervous system disorder phenotypes in humans. We suggest that these genomically imprinted regions are candidates for influencing the population-specific mate-choice in mice.
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Affiliation(s)
- Anna Lorenc
- Max-Planck Institute for Evolutionary Biology, Department Evolutionary Genetics, Plön, Germany
| | - Miriam Linnenbrink
- Max-Planck Institute for Evolutionary Biology, Department Evolutionary Genetics, Plön, Germany
| | - Inka Montero
- Max-Planck Institute for Evolutionary Biology, Department Evolutionary Genetics, Plön, Germany
| | - Markus B Schilhabel
- Institute of Clinical Molecular Biology, Christian-Albrechts-University, Kiel, Germany
| | - Diethard Tautz
- Max-Planck Institute for Evolutionary Biology, Department Evolutionary Genetics, Plön, Germany
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48
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Matarazzo V, Muscatelli F. Natural breaking of the maternal silence at the mouse and human imprinted Prader-Willi locus: A whisper with functional consequences. Rare Dis 2013; 1:e27228. [PMID: 25003016 PMCID: PMC3978896 DOI: 10.4161/rdis.27228] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 11/15/2013] [Accepted: 11/15/2013] [Indexed: 12/22/2022] Open
Abstract
Genomic imprinting is a normal process of epigenetic regulation leading some autosomal genes to be expressed from one parental allele only, the other parental allele being silenced. The reasons why this mechanism has been selected throughout evolution are not clear; however, expression dosage is critical for imprinted genes. There is a paradox between the fact that genomic imprinting is a robust mechanism controlling the expression of specific genes and the fact that this mechanism is based on epigenetic regulation that, per se, should present some flexibility. The robustness has been well studied, revealing the epigenetic modifications at the imprinted locus, but the flexibility has been poorly investigated.
Prader-Willi syndrome is the best-studied disease involving imprinted genes caused by the absence of expression of paternally inherited alleles of genes located in the human 15q11-q13 region. Until now, the silencing of the maternally inherited alleles was like a dogma. Rieusset et al. showed that in absence of the paternal Ndn allele, in Ndn +m/-p mice, the maternal Ndn allele is expressed at an extremely low level with a high degree of non-genetic heterogeneity. In about 50% of these mutant mice, this stochastic expression reduces birth lethality and severity of the breathing deficiency, correlated with a reduction in the loss of serotonergic neurons. Furthermore, using several mouse models, they reveal a competition between non-imprinted Ndn promoters, which results in monoallelic (paternal or maternal) Ndn expression, suggesting that Ndn monoallelic expression occurs in the absence of imprinting regulation. Importantly, specific expression of the maternal NDN allele is also detected in post-mortem brain samples of PWS individuals. Here, similar expression of the Magel2 maternal allele is reported in Magel2 +m/-p mice, suggesting that this loss of imprinting can be extended to other PWS genes. These data reveal an unexpected epigenetic flexibility of PWS imprinted genes that could be exploited to reactivate the functional but dormant maternal alleles in PWS.
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MacDonald WA, Mann MRW. Epigenetic regulation of genomic imprinting from germ line to preimplantation. Mol Reprod Dev 2013; 81:126-40. [PMID: 23893518 DOI: 10.1002/mrd.22220] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Accepted: 07/20/2013] [Indexed: 01/25/2023]
Abstract
Genomic imprinting is an epigenetic process that distinguishes parental alleles, resulting in parent-specific expression of a gene or cluster of genes. Imprints are acquired during gametogenesis when genome-wide epigenetic remodeling occurs. These imprints must then be maintained during preimplantation development, when another wave of genome-wide epigenetic remodeling takes place. Thus, for imprints to persist as parent-specific epigenetic marks, coordinated factors and processes must be involved to both recognize an imprint and protect it from genome-wide remodeling. Parent-specific DNA methylation has long been recognized as a primary epigenetic mark demarcating a genomic imprint. Recent work has advanced our understanding of how and when parent-specific DNA methylation is erased and acquired in the germ line as well as maintained during preimplantation development. Epigenetic factors have also been identified that are recruited to imprinted regions to protect them from genome-wide DNA demethylation during preimplantation development. Intriguingly, asynchrony in epigenetic reprogramming appears to be a recurrent theme with asynchronous acquisition between male and female germ lines, between different imprinted genes, and between the two parental alleles of a gene. Here, we review recent advancements and discuss how they impact our current understanding of the epigenetic regulation of genomic imprinting.
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Affiliation(s)
- William A MacDonald
- Departments of Obstetrics & Gynecology, and Biochemistry, University of Western Ontario, Schulich School of Medicine and Dentistry, London, Ontario, Canada; Children's Health Research Institute, London, Ontario, Canada
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Yazdi PG, Su H, Ghimbovschi S, Fan W, Coskun PE, Nalbandian A, Knoblach S, Resnick JL, Hoffman E, Wallace DC, Kimonis VE. Differential gene expression reveals mitochondrial dysfunction in an imprinting center deletion mouse model of Prader-Willi syndrome. Clin Transl Sci 2013; 6:347-55. [PMID: 24127921 DOI: 10.1111/cts.12083] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a genetic disorder caused by deficiency of imprinted gene expression from the paternal chromosome 15q11-15q13 and clinically characterized by neonatal hypotonia, short stature, cognitive impairment, hypogonadism, hyperphagia, morbid obesity, and diabetes. Previous clinical studies suggest that a defect in energy metabolism may be involved in the pathogenesis of PWS. We focused our attention on the genes associated with energy metabolism and found that there were 95 and 66 mitochondrial genes differentially expressed in PWS muscle and brain, respectively. Assessment of enzyme activities of mitochondrial oxidative phosphorylation complexes in the brain, heart, liver, and muscle were assessed. We found the enzyme activities of the cardiac mitochondrial complexes II+III were up-regulated in the PWS imprinting center deletion mice compared to the wild-type littermates. These studies suggest that differential gene expression, especially of the mitochondrial genes may contribute to the pathophysiology of PWS.
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Affiliation(s)
- Puya G Yazdi
- Division of Genetics and Metabolism, Department of Pediatrics, University of California, Irvine, California, USA
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