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Madeo SF, Zagaroli L, Vandelli S, Calcaterra V, Crinò A, De Sanctis L, Faienza MF, Fintini D, Guazzarotti L, Licenziati MR, Mozzillo E, Pajno R, Scarano E, Street ME, Wasniewska M, Bocchini S, Bucolo C, Buganza R, Chiarito M, Corica D, Di Candia F, Francavilla R, Fratangeli N, Improda N, Morabito LA, Mozzato C, Rossi V, Schiavariello C, Farello G, Iughetti L, Salpietro V, Salvatoni A, Giordano M, Grugni G, Delvecchio M. Endocrine features of Prader-Willi syndrome: a narrative review focusing on genotype-phenotype correlation. Front Endocrinol (Lausanne) 2024; 15:1382583. [PMID: 38737552 PMCID: PMC11082343 DOI: 10.3389/fendo.2024.1382583] [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: 02/05/2024] [Accepted: 04/12/2024] [Indexed: 05/14/2024] Open
Abstract
Prader-Willi syndrome (PWS) is a complex genetic disorder caused by three different types of molecular genetic abnormalities. The most common defect is a deletion on the paternal 15q11-q13 chromosome, which is seen in about 60% of individuals. The next most common abnormality is maternal disomy 15, found in around 35% of cases, and a defect in the imprinting center that controls the activity of certain genes on chromosome 15, seen in 1-3% of cases. Individuals with PWS typically experience issues with the hypothalamic-pituitary axis, leading to excessive hunger (hyperphagia), severe obesity, various endocrine disorders, and intellectual disability. Differences in physical and behavioral characteristics between patients with PWS due to deletion versus those with maternal disomy are discussed in literature. Patients with maternal disomy tend to have more frequent neurodevelopmental problems, such as autistic traits and behavioral issues, and generally have higher IQ levels compared to those with deletion of the critical PWS region. This has led us to review the pertinent literature to investigate the possibility of establishing connections between the genetic abnormalities and the endocrine disorders experienced by PWS patients, in order to develop more targeted diagnostic and treatment protocols. In this review, we will review the current state of clinical studies focusing on endocrine disorders in individuals with PWS patients, with a specific focus on the various genetic causes. We will look at topics such as neonatal anthropometry, thyroid issues, adrenal problems, hypogonadism, bone metabolism abnormalities, metabolic syndrome resulting from severe obesity caused by hyperphagia, deficiencies in the GH/IGF-1 axis, and the corresponding responses to treatment.
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Affiliation(s)
- Simona F. Madeo
- Department of Medical and Surgical Sciences for Mother, Children and Adults, Pediatric Unit, University of Modena and Reggio Emilia, Modena, Italy
| | - Luca Zagaroli
- Department of Pediatrics, University of L’Aquila, L’Aquila, Italy
| | - Sara Vandelli
- Department of Medical and Surgical Sciences for Mother, Children and Adults, Post-Graduate School of Pediatrics, University of Modena and Reggio Emilia, Modena, Italy
| | - Valeria Calcaterra
- Department of Internal Medicine and Therapeutics, University of Pavia, Pavia, Italy
- Pediatric Department, Buzzi Children’s Hospital, Milano, Italy
| | - Antonino Crinò
- Center for Rare Diseases and Congenital Defects, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Luisa De Sanctis
- Pediatric Endocrinology, Regina Margherita Children Hospital – Department of Public Health and Pediatric Sciences, University of Torino, Torino, Italy
| | - Maria Felicia Faienza
- Pediatric Unit, Department of Precision and Regenerative Medicine and Ionian Area, University of Bari “Aldo Moro”, Bari, Italy
| | - Danilo Fintini
- Prader Willi Reference Center, Endocrinology and Diabetology Unit, Pediatric University Department, IRCCS Bambino Gesù Children Hospital, Rome, Italy
| | - Laura Guazzarotti
- Pediatric Endocrinology Unit, University Hospital of Padova, Padova, Italy
| | - Maria Rosaria Licenziati
- Neuro-endocrine Diseases and Obesity Unit, Department of Neurosciences, Santobono-Pausilipon Children’s Hospital, Naples, Italy
| | - Enza Mozzillo
- Department of Translational and Medical Science, Section of Pediatrics, University of Naples Federico II, Naples, Italy
| | - Roberta Pajno
- Pediatric Unit, IRCCS San Raffaele Institute, Milan, Italy
| | - Emanuela Scarano
- Pediatric Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Maria E. Street
- Department of Medicine and Surgery, University of Parma, Parma, Italy
- Department of Medicine and Surgery, University Hospital of Parma, Parma, Italy
| | - Malgorzata Wasniewska
- Department of Human Pathology of Adulthood and Childhood, University of Messina, Messina, Italy
- Pediatric Unit, Gaetano Martino University Hospital of Messina, Messina, Italy
| | - Sarah Bocchini
- Prader Willi Reference Center, Endocrinology and Diabetology Unit, Pediatric University Department, IRCCS Bambino Gesù Children Hospital, Rome, Italy
| | - Carmen Bucolo
- Pediatric Unit, IRCCS San Raffaele Institute, Milan, Italy
| | - Raffaele Buganza
- Pediatric Endocrinology, Regina Margherita Children Hospital – Department of Public Health and Pediatric Sciences, University of Torino, Torino, Italy
| | - Mariangela Chiarito
- Pediatric Unit, Department of Precision and Regenerative Medicine and Ionian Area, University of Bari “Aldo Moro”, Bari, Italy
| | - Domenico Corica
- Department of Human Pathology of Adulthood and Childhood, University of Messina, Messina, Italy
- Pediatric Unit, Gaetano Martino University Hospital of Messina, Messina, Italy
| | - Francesca Di Candia
- Department of Translational and Medical Science, Section of Pediatrics, University of Naples Federico II, Naples, Italy
| | | | - Nadia Fratangeli
- Division of Auxology, Istituto Auxologico Italiano, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Verbania, Italy
| | - Nicola Improda
- Neuro-endocrine Diseases and Obesity Unit, Department of Neurosciences, Santobono-Pausilipon Children’s Hospital, Naples, Italy
| | | | - Chiara Mozzato
- Child and Women Health Department, University of Padova, Padova, Italy
| | - Virginia Rossi
- Pediatric Department, Buzzi Children’s Hospital, Milano, Italy
| | | | - Giovanni Farello
- Department of Clinical Medicine, Public Health, Life and Environmental Sciences, University of L’Aquila, L’Aquila, Italy
| | - Lorenzo Iughetti
- Department of Medical and Surgical Sciences for Mother, Children and Adults, Pediatric Unit, University of Modena and Reggio Emilia, Modena, Italy
| | - Vincenzo Salpietro
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L’Aquila, Italy
| | | | - Mara Giordano
- Laboratory of Genetics, Struttura Complessa a Direzione Universitaria (SCDU) Biochimica Clinica, Ospedale Maggiore della Carità, Novara, Italy
- Department of Health Sciences, University of Piemonte Orientale, Novara, Italy
| | - Graziano Grugni
- Division of Auxology, Istituto Auxologico Italiano, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Verbania, Italy
| | - Maurizio Delvecchio
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L’Aquila, Italy
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Reference Genes across Nine Brain Areas of Wild Type and Prader-Willi Syndrome Mice: Assessing Differences in Igfbp7, Pcsk1, Nhlh2 and Nlgn3 Expression. Int J Mol Sci 2022; 23:ijms23158729. [PMID: 35955861 PMCID: PMC9369261 DOI: 10.3390/ijms23158729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/18/2022] Open
Abstract
Prader−Willi syndrome (PWS) is a complex neurodevelopmental disorder caused by the deletion or inactivation of paternally expressed imprinted genes at the chromosomal region 15q11−q13. The PWS-critical region (PWScr) harbors tandemly repeated non-protein coding IPW-A exons hosting the intronic SNORD116 snoRNA gene array that is predominantly expressed in brain. Paternal deletion of PWScr is associated with key PWS symptoms in humans and growth retardation in mice (PWScr model). Dysregulation of the hypothalamic−pituitary axis (HPA) is thought to be causally involved in the PWS phenotype. Here we performed a comprehensive reverse transcription quantitative PCR (RT-qPCR) analysis across nine different brain regions of wild-type (WT) and PWScr mice to identify stably expressed reference genes. Four methods (Delta Ct, BestKeeper, Normfinder and Genorm) were applied to rank 11 selected reference gene candidates according to their expression stability. The resulting panel consists of the top three most stably expressed genes suitable for gene-expression profiling and comparative transcriptome analysis of WT and/or PWScr mouse brain regions. Using these reference genes, we revealed significant differences in the expression patterns of Igfbp7, Nlgn3 and three HPA associated genes: Pcsk1, Pcsk2 and Nhlh2 across investigated brain regions of wild-type and PWScr mice. Our results raise a reasonable doubt on the involvement of the Snord116 in posttranscriptional regulation of Nlgn3 and Nhlh2 genes. We provide a valuable tool for expression analysis of specific genes across different areas of the mouse brain and for comparative investigation of PWScr mouse models to discover and verify different regulatory pathways affecting this complex disorder.
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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: 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: 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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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: 1.8] [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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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: 13] [Impact Index Per Article: 3.3] [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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Bratkovič T, Božič J, Rogelj B. Functional diversity of small nucleolar RNAs. Nucleic Acids Res 2020; 48:1627-1651. [PMID: 31828325 PMCID: PMC7038934 DOI: 10.1093/nar/gkz1140] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 11/17/2019] [Accepted: 12/05/2019] [Indexed: 12/22/2022] Open
Abstract
Small nucleolar RNAs (snoRNAs) are short non-protein-coding RNAs with a long-recognized role in tuning ribosomal and spliceosomal function by guiding ribose methylation and pseudouridylation at targeted nucleotide residues of ribosomal and small nuclear RNAs, respectively. SnoRNAs are increasingly being implicated in regulation of new types of post-transcriptional processes, for example rRNA acetylation, modulation of splicing patterns, control of mRNA abundance and translational efficiency, or they themselves are processed to shorter stable RNA species that seem to be the principal or alternative bioactive isoform. Intriguingly, some display unusual cellular localization under exogenous stimuli, or tissue-specific distribution. Here, we discuss the new and unforeseen roles attributed to snoRNAs, focusing on the presumed mechanisms of action. Furthermore, we review the experimental approaches to study snoRNA function, including high resolution RNA:protein and RNA:RNA interaction mapping, techniques for analyzing modifications on targeted RNAs, and cellular and animal models used in snoRNA biology research.
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Affiliation(s)
- Tomaž Bratkovič
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva cesta 7, SI1000 Ljubljana, Slovenia
| | - Janja Božič
- Jozef Stefan Institute, Department of Biotechnology, Jamova cesta 39, SI1000 Ljubljana, Slovenia.,Biomedical Research Institute BRIS, Puhova ulica 10, SI1000 Ljubljana, Slovenia
| | - Boris Rogelj
- University of Ljubljana, Faculty of Pharmacy, Aškerčeva cesta 7, SI1000 Ljubljana, Slovenia.,Jozef Stefan Institute, Department of Biotechnology, Jamova cesta 39, SI1000 Ljubljana, Slovenia.,Biomedical Research Institute BRIS, Puhova ulica 10, SI1000 Ljubljana, Slovenia.,University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, SI1000 Ljubljana, Slovenia
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Skryabin BV, Kummerfeld DM, Gubar L, Seeger B, Kaiser H, Stegemann A, Roth J, Meuth SG, Pavenstädt H, Sherwood J, Pap T, Wedlich-Söldner R, Sunderkötter C, Schwartz YB, Brosius J, Rozhdestvensky TS. Pervasive head-to-tail insertions of DNA templates mask desired CRISPR-Cas9-mediated genome editing events. SCIENCE ADVANCES 2020; 6:eaax2941. [PMID: 32095517 PMCID: PMC7015686 DOI: 10.1126/sciadv.aax2941] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 11/25/2019] [Indexed: 02/05/2023]
Abstract
CRISPR-Cas9-mediated homology-directed DNA repair is the method of choice for precise gene editing in a wide range of model organisms, including mouse and human. Broad use by the biomedical community refined the method, making it more efficient and sequence specific. Nevertheless, the rapidly evolving technique still contains pitfalls. During the generation of six different conditional knockout mouse models, we discovered that frequently (sometimes solely) homology-directed repair and/or nonhomologous end joining mechanisms caused multiple unwanted head-to-tail insertions of donor DNA templates. Disturbingly, conventionally applied PCR analysis, in most cases, failed to identify these multiple integration events, which led to a high rate of falsely claimed precisely edited alleles. We caution that comprehensive analysis of modified alleles is essential and offer practical solutions to correctly identify precisely edited chromosomes.
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Affiliation(s)
- Boris V Skryabin
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Muenster, Germany
| | - Delf-Magnus Kummerfeld
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Muenster, Germany
| | - Leonid Gubar
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Muenster, Germany
| | - Birte Seeger
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Muenster, Germany
| | - Helena Kaiser
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Muenster, Germany
| | - Anja Stegemann
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Muenster, Germany
| | - Johannes Roth
- Institute of Immunology, University Hospital Muenster, Muenster, Germany
| | - Sven G Meuth
- Clinic of Neurology with Institute of Translational Neurology, University Hospital Muenster, Muenster, Germany
| | | | - Joanna Sherwood
- Institute of Experimental Musculoskeletal Medicine (IMM), University Hospital Muenster, Muenster, Germany
| | - Thomas Pap
- Institute of Experimental Musculoskeletal Medicine (IMM), University Hospital Muenster, Muenster, Germany
| | | | - Cord Sunderkötter
- Department of Dermatology and Venereology, University Hospital Halle, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Yuri B Schwartz
- Department of Molecular Biology, Umeå University, 901 87 Umeå, Sweden
| | - Juergen Brosius
- Institute of Experimental Pathology (ZMBE), University of Muenster, Muenster, Germany.,Institutes for Systems Genetics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Timofey S Rozhdestvensky
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Muenster, Germany
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Ectopic expression of Snord115 in choroid plexus interferes with editing but not splicing of 5-Ht2c receptor pre-mRNA in mice. Sci Rep 2019; 9:4300. [PMID: 30862860 PMCID: PMC6414643 DOI: 10.1038/s41598-019-39940-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/01/2019] [Indexed: 01/01/2023] Open
Abstract
Serotonin 5-HT2C receptor is a G-protein coupled excitatory receptor that regulates several biochemical pathways and has been implicated in obesity, mental state, sleep cycles, autism, neuropsychiatric disorders and neurodegenerative diseases. The activity of 5-HT2CR is regulated via alternative splicing and A to I editing of exon Vb of its pre-mRNA. Snord115 is a small nucleolar RNA that is expressed in mouse neurons and displays an 18-nucleotide base complementary to exon Vb of 5-HT2CR pre-mRNA. For almost two decades this putative guide element of Snord115 has wandered like a ghost through the literature in attempts to elucidate the biological significance of this complementarity. In mice, Snord115 is expressed in neurons and absent in the choroid plexus where, in contrast, 5-Ht2cr mRNA is highly abundant. Here we report the analysis of 5-Ht2cr pre-mRNA posttranscriptional processing via RNA deep sequencing in a mouse model that ectopically expresses Snord115 in the choroid plexus. In contrast to previous reports, our analysis demonstrated that Snord115 does not control alternative splicing of 5-Ht2cr pre-mRNA in vivo. We identified a modest, yet statistically significant reduction of 5-Ht2cr pre-mRNA A to I editing at the major A, B, C and D sites. We suggest that Snord115 and exon Vb of 5Ht2cr pre-mRNA form a double-stranded structure that is subject to ADAR-mediated A to I editing. To the best of our knowledge, this is the first comprehensive Snord115 gain-of-function analysis based on in vivo mouse models.
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Costa RA, Ferreira IR, Cintra HA, Gomes LHF, Guida LDC. Genotype-Phenotype Relationships and Endocrine Findings in Prader-Willi Syndrome. Front Endocrinol (Lausanne) 2019; 10:864. [PMID: 31920975 PMCID: PMC6923197 DOI: 10.3389/fendo.2019.00864] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 11/26/2019] [Indexed: 12/13/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a complex imprinting disorder related to genomic errors that inactivate paternally-inherited genes on chromosome 15q11-q13 with severe implications on endocrine, cognitive and neurologic systems, metabolism, and behavior. The absence of expression of one or more genes at the PWS critical region contributes to different phenotypes. There are three molecular mechanisms of occurrence: paternal deletion of the 15q11-q13 region; maternal uniparental disomy 15; or imprinting defects. Although there is a clinical diagnostic consensus criteria, DNA methylation status must be confirmed through genetic testing. The endocrine system can be the most affected in PWS, and growth hormone replacement therapy provides improvement in growth, body composition, and behavioral and physical attributes. A key feature of the syndrome is the hypothalamic dysfunction that may be the basis of several endocrine symptoms. Clinical and molecular complexity in PWS enhances the importance of genetic diagnosis in therapeutic definition and genetic counseling. So far, no single gene mutation has been described to contribute to this genetic disorder or related to any exclusive symptoms. Here we proposed to review individually disrupted genes within the PWS critical region and their reported clinical phenotypes related to the syndrome. While genes such as MKRN3, MAGEL2, NDN, or SNORD115 do not address the full spectrum of PWS symptoms and are less likely to have causal implications in PWS major clinical signs, SNORD116 has emerged as a critical, and possibly, a determinant candidate in PWS, in the recent years. Besides that, the understanding of the biology of the PWS SNORD genes is fairly low at the present. These non-coding RNAs exhibit all the hallmarks of RNA methylation guides and can be incorporated into ribonucleoprotein complexes with possible hypothalamic and endocrine functions. Also, DNA conservation between SNORD sequences across placental mammals strongly suggests that they have a functional role as RNA entities on an evolutionary basis. The broad clinical spectrum observed in PWS and the absence of a clear genotype-phenotype specific correlation imply that the numerous genes involved in the syndrome have an additive deleterious effect on different phenotypes when deficiently expressed.
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Coulson RL, Powell WT, Yasui DH, Dileep G, Resnick J, LaSalle JM. Prader-Willi locus Snord116 RNA processing requires an active endogenous allele and neuron-specific splicing by Rbfox3/NeuN. Hum Mol Genet 2018; 27:4051-4060. [PMID: 30124848 PMCID: PMC6240740 DOI: 10.1093/hmg/ddy296] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/10/2018] [Accepted: 07/03/2018] [Indexed: 12/18/2022] Open
Abstract
Prader-Willi syndrome (PWS), an imprinted neurodevelopmental disorder characterized by metabolic, sleep and neuropsychiatric features, is caused by the loss of paternal SNORD116, containing only non-coding RNAs (ncRNAs). The primary SNORD116 transcript is processed into small nucleolar RNAs (snoRNAs), which localize to nucleoli, and their spliced host gene 116HG, which is retained at its site of transcription. While functional complementation of the SNORD116 ncRNAs is a desirable goal for treating PWS, the mechanistic requirements of SNORD116 RNA processing are poorly understood. Here we developed and tested a novel transgenic mouse which ubiquitously expresses Snord116 on both a wild-type and a Snord116 paternal deletion (Snord116+/-) background. Interestingly, while the Snord116 transgene was ubiquitously expressed in multiple tissues, splicing of the transgene and production of snoRNAs was limited to brain tissues. Knockdown of Rbfox3, encoding neuron-specific splicing factor neuronal nuclei (NeuN) in Snord116+/--derived neurons, reduced splicing of the transgene in neurons. RNA fluorescence in situ hybridization for 116HG revealed a single significantly larger signal in transgenic mice, demonstrating colocalization of transgenic and endogenous 116HG RNAs. Similarly, significantly increased snoRNA levels were detected in transgenic neuronal nucleoli, indicating that transgenic Snord116 snoRNAs were effectively processed and localized. In contrast, neither transgenic 116HG nor snoRNAs were detectable in either non-neuronal tissues or Snord116+/- neurons. Together, these results demonstrate that exogenous expression and neuron-specific splicing of the Snord116 locus are insufficient to rescue the genetic deficiency of Snord116 paternal deletion. Elucidating the mechanisms regulating Snord116 processing and localization is essential to develop effective gene replacement therapies for PWS.
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Affiliation(s)
- Rochelle L Coulson
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
| | - Weston T Powell
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
| | - Dag H Yasui
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
| | - Gayathri Dileep
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
| | - James Resnick
- Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Janine M LaSalle
- Microbiology and Immunology, Genome Center, and MIND Institute, UC Davis School of Medicine, Davis, CA, USA
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11
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Bratkovič T, Modic M, Camargo Ortega G, Drukker M, Rogelj B. Neuronal differentiation induces SNORD115 expression and is accompanied by post-transcriptional changes of serotonin receptor 2c mRNA. Sci Rep 2018; 8:5101. [PMID: 29572515 PMCID: PMC5865145 DOI: 10.1038/s41598-018-23293-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 03/09/2018] [Indexed: 12/13/2022] Open
Abstract
The serotonin neurotransmitter system is widespread in the brain and implicated in modulation of neuronal responses to other neurotransmitters. Among 14 serotonin receptor subtypes, 5-HT2cR plays a pivotal role in controlling neuronal network excitability. Serotonergic activity conveyed through receptor 5-HT2cR is regulated post-transcriptionally via two mechanisms, alternative splicing and A-to-I RNA editing. Brain-specific small nucleolar RNA SNORD115 harbours a phylogenetically conserved 18-nucleotide antisense element with perfect complementarity to the region of 5ht2c primary transcript that undergoes post-transcriptional changes. Previous 5ht2c minigene studies have implicated SNORD115 in fine-tuning of both post-transcriptional events. We monitored post-transcriptional changes of endogenous 5ht2c transcripts during neuronal differentiation. Both SNORD115 and 5ht2c were upregulated upon neuronal commitment. We detected increased 5ht2c alternative exon Vb inclusion already at the stage of neuronal progenitors, and more extensive A-to-I editing of non-targeted sites A and B compared to adjacent adenosines at sites E, C and D throughout differentiation. As the extent of editing is known to positively correlate with exon Vb usage while it reduces receptor functionality, our data support the model where SNORD115 directly promotes alternative exon inclusion without the requirement for conversion of key adenosines to inosines, thereby favouring production of full-length receptor isoforms with higher potency.
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Affiliation(s)
- Tomaž Bratkovič
- University of Ljubljana, Faculty of Pharmacy, Department of Pharmaceutical Biology, Aškerčeva 7, 1000, Ljubljana, Slovenia
| | - Miha Modic
- Institute of Stem Cell Research and the Induced Pluripotent Stem Cell Core Facility, Helmholtz Center Munich, 85764, Neuherberg, Germany
| | - Germán Camargo Ortega
- Institute of Stem Cell Research and the Induced Pluripotent Stem Cell Core Facility, Helmholtz Center Munich, 85764, Neuherberg, Germany.,Physiological Genomics, Biomedical Center, Ludwig-Maximilian University Munich, Munich, Germany
| | - Micha Drukker
- Institute of Stem Cell Research and the Induced Pluripotent Stem Cell Core Facility, Helmholtz Center Munich, 85764, Neuherberg, Germany
| | - Boris Rogelj
- Jozef Stefan Institute, Department of Biotechnology, Jamova 39, 1000, Ljubljana, Slovenia. .,Biomedical Research Institute BRIS, Puhova 10, 1000, Ljubljana, Slovenia. .,University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, 1000, Ljubljana, Slovenia.
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12
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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: 57] [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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Lassi G, Maggi S, Balzani E, Cosentini I, Garcia-Garcia C, Tucci V. Working-for-Food Behaviors: A Preclinical Study in Prader-Willi Mutant Mice. Genetics 2016; 204:1129-1138. [PMID: 27672097 PMCID: PMC5105846 DOI: 10.1534/genetics.116.192286] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/14/2016] [Indexed: 12/31/2022] Open
Abstract
Abnormal feeding behavior is one of the main symptoms of Prader-Willi syndrome (PWS). By studying a PWS mouse mutant line, which carries a paternally inherited deletion of the small nucleolar RNA 116 (Snord116), we observed significant changes in working-for-food behavioral responses at various timescales. In particular, we report that PWS mutant mice show a significant delay compared to wild-type littermate controls in responding to both hour-scale and seconds-to-minutes-scale time intervals. This timing shift in mutant mice is associated with better performance in the working-for-food task, and results in better decision making in these mutant mice. The results of our study reveal a novel aspect of the organization of feeding behavior, and advance the understanding of the interplay between the metabolic functions and cognitive mechanisms of PWS.
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Affiliation(s)
- Glenda Lassi
- Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Silvia Maggi
- Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Edoardo Balzani
- Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Ilaria Cosentini
- Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Celina Garcia-Garcia
- Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Valter Tucci
- Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, 16163 Genova, Italy
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Hassan M, Butler MG. Prader-Willi syndrome and atypical submicroscopic 15q11-q13 deletions with or without imprinting defects. Eur J Med Genet 2016; 59:584-589. [PMID: 27659713 DOI: 10.1016/j.ejmg.2016.09.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 09/12/2016] [Accepted: 09/17/2016] [Indexed: 12/24/2022]
Abstract
We report a 20 year follow up on a Caucasian female, now 26 years of age, with Prader-Willi syndrome (PWS) harboring an atypical 15q11-q13 submicroscopic deletion of 100-200 kb in size first detected in 1996 involving the imprinting center, SNRPN gene and surrounding region. PWS is a rare complex disorder caused by the loss of paternally expressed genes in the 15q11-q13 region. With high resolution chromosomal microarray and methylation - specific MLPA analysis, we updated the genetic findings on our patient and found a 209,819bp deletion including the SNURF-SNRPN gene complex which includes the imprinting center and the SNORD116 region. We compared with four other similarly reported individuals in the literature with atypical submicroscopic deletions within this region but without imprinting center involvement to better characterize the specific genetic lesions causing PWS clinical findings. Clinically, our patient met the diagnostic criteria of PWS including infantile hypotonia, a poor suck with feeding difficulties, global developmental delays and later food foraging, childhood obesity, small hands and skin picking. Small atypical deletions of comparable sizes were seen in the 15q11-q13 region in all five cases and similar behavioral/physical characteristics were found despite an imprinting defect in our patient. These results further support an overlapping critical deletion region involving the non-coding snoRNA SNORD116 in common in the five individuals playing a key role in contributing to the PWS phenotype.
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Affiliation(s)
- Maaz Hassan
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA; Department of Pediatrics, University of Kansas Medical Center, Kansas City, KS, USA
| | - Merlin G Butler
- Department of Psychiatry & Behavioral Sciences, University of Kansas Medical Center, Kansas City, KS, USA; Department of Pediatrics, University of Kansas Medical Center, Kansas City, KS, USA.
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15
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BC1 RNA motifs required for dendritic transport in vivo. Sci Rep 2016; 6:28300. [PMID: 27350115 PMCID: PMC4923876 DOI: 10.1038/srep28300] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 05/20/2016] [Indexed: 12/26/2022] Open
Abstract
BC1 RNA is a small brain specific non-protein coding RNA. It is transported from the cell body into dendrites where it is involved in the fine-tuning translational control. Due to its compactness and established secondary structure, BC1 RNA is an ideal model for investigating the motifs necessary for dendritic localization. Previously, microinjection of in vitro transcribed BC1 RNA mutants into the soma of cultured primary neurons suggested the importance of RNA motifs for dendritic targeting. These ex vivo experiments identified a single bulged nucleotide (U22) and a putative K-turn (GA motif) structure required for dendritic localization or distal transport, respectively. We generated six transgenic mouse lines (three founders each) containing neuronally expressing BC1 RNA variants on a BC1 RNA knockout mouse background. In contrast to ex vivo data, we did not find indications of reduction or abolition of dendritic BC1 RNA localization in the mutants devoid of the GA motif or the bulged nucleotide. We confirmed the ex vivo data, which showed that the triloop terminal sequence had no consequence on dendritic transport. Interestingly, changing the triloop supporting structure completely abolished dendritic localization of BC1 RNA. We propose a novel RNA motif important for dendritic transport in vivo.
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