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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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Babbs RK, Beierle JA, Ruan QT, Kelliher JC, Chen MM, Feng AX, Kirkpatrick SL, Benitez FA, Rodriguez FA, Pierre JJ, Anandakumar J, Kumar V, Mulligan MK, Bryant CD. Cyfip1 Haploinsufficiency Increases Compulsive-Like Behavior and Modulates Palatable Food Intake in Mice: Dependence on Cyfip2 Genetic Background, Parent-of Origin, and Sex. G3 (BETHESDA, MD.) 2019; 9:3009-3022. [PMID: 31324746 PMCID: PMC6723122 DOI: 10.1534/g3.119.400470] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/18/2019] [Indexed: 12/11/2022]
Abstract
Binge eating (BE) is a heritable trait associated with eating disorders and involves episodes of rapid, large amounts of food consumption. We previously identified cytoplasmic FMR1-interacting protein 2 (Cyfip2) as a genetic factor underlying compulsive-like BE in mice. CYFIP2 is a homolog of CYFIP1 which is one of four paternally-deleted genes in patients with Type I Prader-Willi Syndrome (PWS), a neurodevelopmental disorder whereby 70% of cases involve paternal 15q11-q13 deletion. PWS symptoms include hyperphagia, obesity (if untreated), cognitive deficits, and obsessive-compulsive behaviors. We tested whether Cyfip1 haploinsufficiency (+/-) would enhance compulsive-like behavior and palatable food (PF) intake in a parental origin- and sex-dependent manner on two Cyfip2 genetic backgrounds, including the BE-prone C57BL/6N (Cyfip2N/N) background and the BE-resistant C57BL/6J (Cyfip2J/J) background. Cyfip1+/- mice showed increased compulsive-like behavior on both backgrounds and increased PF intake on the Cyfip2N/N background. In contrast, maternal Cyfip1 haploinsufficiency on the BE-resistant Cyfip2J/J background induced a robust escalation in PF intake in wild-type Cyfip1J/J males while having no effect in Cyfip1J/- males. Notably, induction of behavioral phenotypes in wild-type males following maternal Fmr1+/- has previously been reported. In the hypothalamus, there was a paternally-enhanced reduction in CYFIP1 protein whereas in the nucleus accumbens, there was a maternally-enhanced reduction in CYFIP1 protein. Nochange in FMR1 protein (FMRP) was observed in Cyfip1+/- mice, regardless of parental origin. To summarize, Cyfip1 haploinsufficiency increased compulsive-like behavior and induced genetic background-dependent, sex-dependent, and parent-of-origin-dependent effects on PF consumption and CYFIP1 expression that could have relevance for neurodevelopmental and neuropsychiatric disorders.
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Affiliation(s)
- Richard K Babbs
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
| | - Jacob A Beierle
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
- T32 NIGMS Training Program in Biomolecular Pharmacology
- Boston University's Transformative Training Program in Addiction Science (TTPAS), Biomedical Genetics, Boston University School of Medicine, Boston, MA 02118
| | - Qiu T Ruan
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
- T32 NIGMS Training Program in Biomolecular Pharmacology
- Boston University's Transformative Training Program in Addiction Science (TTPAS), Biomedical Genetics, Boston University School of Medicine, Boston, MA 02118
| | - Julia C Kelliher
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
| | - Melanie M Chen
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
| | - Ashley X Feng
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
| | - Stacey L Kirkpatrick
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
| | - Fabiola A Benitez
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
| | - Fred A Rodriguez
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
| | - Johanne J Pierre
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
| | - Jeya Anandakumar
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
| | - Vivek Kumar
- The Jackson Laboratory, 600 Main St., Bar Harbor, ME 04609, and
| | - Megan K Mulligan
- Department of Genetics, Genomics, and Informatics, University of Tennessee Health Science Center, 71 S. Manassas St, Memphis, TN 38163
| | - Camron D Bryant
- Laboratory of Addiction Genetics, Department of Pharmacology and Experimental Therapeutics and Psychiatry
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Genetic testing and PGD for unexplained recurrent fetal malformations with MAGEL2 gene mutation. SCIENCE CHINA-LIFE SCIENCES 2019; 62:886-894. [PMID: 31152388 DOI: 10.1007/s11427-019-9541-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 04/15/2019] [Indexed: 12/31/2022]
Abstract
Birth defects are caused by multiple factors, such as chromosome abnormality, environmental factors, and maternal factors. In this study, we focused on exploring the genetic causes of a non-consanguineous couple who suffered from four times of unsuccessful pregnancy due to unexplained recurrent fetal malformations with similar symptoms and normal chromosome copy number variations. Using trio-whole exome sequencing (trio-WES) for this couple and one of the affected fetuses, we found a mutation, c.1996delC on the maternal imprinted gene MAGEL2 that was carried by the affected fetus and husband, leading to Schaaf-Yang syndrome. To screen this mutation, we further performed preimplantation genetic diagnosis (PGD) strategy followed by a gene pedigree validation and pathogenicity analysis. After the transfer of a PGD-screened embryo, a normal newborn without previous abnormal symptoms was born (February 15, 2019). We present the first data that identified a pathogenic gene (MAGEL2 c.1996delC) in a fetus with Schaaf-Yang syndrome in the EAS (East Asian) database and overcame this genetic defect by using processed PGD for this couple based on the WES results.
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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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Gstir R, Schafferer S, Scheideler M, Misslinger M, Griehl M, Daschil N, Humpel C, Obermair GJ, Schmuckermair C, Striessnig J, Flucher BE, Hüttenhofer A. Generation of a neuro-specific microarray reveals novel differentially expressed noncoding RNAs in mouse models for neurodegenerative diseases. RNA (NEW YORK, N.Y.) 2014; 20:1929-43. [PMID: 25344396 PMCID: PMC4238357 DOI: 10.1261/rna.047225.114] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 08/27/2014] [Indexed: 05/24/2023]
Abstract
We have generated a novel, neuro-specific ncRNA microarray, covering 1472 ncRNA species, to investigate their expression in different mouse models for central nervous system diseases. Thereby, we analyzed ncRNA expression in two mouse models with impaired calcium channel activity, implicated in Epilepsy or Parkinson's disease, respectively, as well as in a mouse model mimicking pathophysiological aspects of Alzheimer's disease. We identified well over a hundred differentially expressed ncRNAs, either from known classes of ncRNAs, such as miRNAs or snoRNAs or which represented entirely novel ncRNA species. Several differentially expressed ncRNAs in the calcium channel mouse models were assigned as miRNAs and target genes involved in calcium signaling, thus suggesting feedback regulation of miRNAs by calcium signaling. In the Alzheimer mouse model, we identified two snoRNAs, whose expression was deregulated prior to amyloid plaque formation. Interestingly, the presence of snoRNAs could be detected in cerebral spine fluid samples in humans, thus potentially serving as early diagnostic markers for Alzheimer's disease. In addition to known ncRNAs species, we also identified 63 differentially expressed, entirely novel ncRNA candidates, located in intronic or intergenic regions of the mouse genome, genomic locations, which previously have been shown to harbor the majority of functional ncRNAs.
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Affiliation(s)
- Ronald Gstir
- Division of Genomics and RNomics, Innsbruck Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Simon Schafferer
- Division of Genomics and RNomics, Innsbruck Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Marcel Scheideler
- RNA Biology Group, Institute for Genomics and Bioinformatics, Graz University of Technology, 8010 Graz, Austria
| | - Matthias Misslinger
- Division of Genomics and RNomics, Innsbruck Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Matthias Griehl
- Division of Genomics and RNomics, Innsbruck Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Nina Daschil
- Department of Psychiatry and Psychotherapy, University Clinic of General and Social Psychiatry, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Christian Humpel
- Department of Psychiatry and Psychotherapy, University Clinic of General and Social Psychiatry, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Gerald J Obermair
- Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Claudia Schmuckermair
- Pharmacology and Toxicology, Institute of Pharmacy, and Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Joerg Striessnig
- Pharmacology and Toxicology, Institute of Pharmacy, and Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Bernhard E Flucher
- Division of Physiology, Department of Physiology and Medical Physics, Innsbruck Medical University, 6020 Innsbruck, Austria
| | - Alexander Hüttenhofer
- Division of Genomics and RNomics, Innsbruck Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
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Genome-wide mapping of loci explaining variance in scrotal circumference in Nellore cattle. PLoS One 2014; 9:e88561. [PMID: 24558400 PMCID: PMC3928245 DOI: 10.1371/journal.pone.0088561] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Accepted: 01/07/2014] [Indexed: 12/21/2022] Open
Abstract
The reproductive performance of bulls has a high impact on the beef cattle industry. Scrotal circumference (SC) is the most recorded reproductive trait in beef herds, and is used as a major selection criterion to improve precocity and fertility. The characterization of genomic regions affecting SC can contribute to the identification of diagnostic markers for reproductive performance and uncover molecular mechanisms underlying complex aspects of bovine reproductive biology. In this paper, we report a genome-wide scan for chromosome segments explaining differences in SC, using data of 861 Nellore bulls (Bos indicus) genotyped for over 777,000 single nucleotide polymorphisms. Loci that excel from the genome background were identified on chromosomes 4, 6, 7, 10, 14, 18 and 21. The majority of these regions were previously found to be associated with reproductive and body size traits in cattle. The signal on chromosome 14 replicates the pleiotropic quantitative trait locus encompassing PLAG1 that affects male fertility in cattle and stature in several species. Based on intensive literature mining, SP4, MAGEL2, SH3RF2, PDE5A and SNAI2 are proposed as novel candidate genes for SC, as they affect growth and testicular size in other animal models. These findings contribute to linking reproductive phenotypes to gene functions, and may offer new insights on the molecular biology of male fertility.
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Recommendations for the investigation of animal models of Prader-Willi syndrome. Mamm Genome 2013; 24:165-78. [PMID: 23609791 DOI: 10.1007/s00335-013-9454-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 03/11/2013] [Indexed: 12/28/2022]
Abstract
Prader-Willi syndrome (PWS) occurs in about 1 in 15,000 individuals and is a contiguous gene disorder causing developmental disability, hyperphagia usually with obesity, and behavioral problems, including an increased incidence of psychiatric illness. The genomic imprinting that regulates allele-specific expression of PWS candidate genes, the fact that multiple genes are typically inactivated, and the presence of many genes that produce functional RNAs rather than proteins has complicated the identification of the underlying genetic pathophysiology of PWS. Over 30 genetically modified mouse strains that have been developed and characterized have been instrumental in elucidating the genetic and epigenetic mechanisms for the regulation of PWS genes and in discovering their physiological functions. In 2011, a PWS Animal Models Working Group (AMWG) was established to generate discussions and facilitate exchange of ideas regarding the best use of PWS animal models. Here, we summarize the goals of the AMWG, describe current animal models of PWS, and make recommendations for strategies to maximize the utility of animal models and for the development and use of new animal models of PWS.
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Henson BJ, Zhu W, Hardaway K, Wetzel JL, Stefan M, Albers KM, Nicholls RD. Transcriptional and post-transcriptional regulation of SPAST, the gene most frequently mutated in hereditary spastic paraplegia. PLoS One 2012; 7:e36505. [PMID: 22574173 PMCID: PMC3344893 DOI: 10.1371/journal.pone.0036505] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 04/02/2012] [Indexed: 01/01/2023] Open
Abstract
Hereditary spastic paraplegias (HSPs) comprise a group of neurodegenerative disorders that are characterized by progressive spasticity of the lower extremities, due to axonal degeneration in the corticospinal motor tracts. HSPs are genetically heterogeneous and show autosomal dominant inheritance in ∼70–80% of cases, with additional cases being recessive or X-linked. The most common type of HSP is SPG4 with mutations in the SPAST gene, encoding spastin, which occurs in 40% of dominantly inherited cases and in ∼10% of sporadic cases. Both loss-of-function and dominant-negative mutation mechanisms have been described for SPG4, suggesting that precise or stoichiometric levels of spastin are necessary for biological function. Therefore, we hypothesized that regulatory mechanisms controlling expression of SPAST are important determinants of spastin biology, and if altered, could contribute to the development and progression of the disease. To examine the transcriptional and post-transcriptional regulation of SPAST, we used molecular phylogenetic methods to identify conserved sequences for putative transcription factor binding sites and miRNA targeting motifs in the SPAST promoter and 3′-UTR, respectively. By a variety of molecular methods, we demonstrate that SPAST transcription is positively regulated by NRF1 and SOX11. Furthermore, we show that miR-96 and miR-182 negatively regulate SPAST by effects on mRNA stability and protein level. These transcriptional and miRNA regulatory mechanisms provide new functional targets for mutation screening and therapeutic targeting in HSP.
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Affiliation(s)
- Brian J. Henson
- Birth Defects Laboratories, Division of Medical Genetics, Department of Pediatrics, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania, United States of America
| | - Wan Zhu
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, United States of America
| | - Kelsey Hardaway
- Birth Defects Laboratories, Division of Medical Genetics, Department of Pediatrics, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania, United States of America
| | - Jaime L. Wetzel
- Birth Defects Laboratories, Division of Medical Genetics, Department of Pediatrics, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania, United States of America
| | - Mihaela Stefan
- Birth Defects Laboratories, Division of Medical Genetics, Department of Pediatrics, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania, United States of America
| | - Kathryn M. Albers
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Robert D. Nicholls
- Birth Defects Laboratories, Division of Medical Genetics, Department of Pediatrics, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, Pennsylvania, United States of America
- Department of Human Genetics, University of Pittsburgh Graduate School of Public Health, Pittsburgh, Pennsylvania, United States of America
- * E-mail:
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Yasui DH, Scoles HA, Horike SI, Meguro-Horike M, Dunaway KW, Schroeder DI, Lasalle JM. 15q11.2-13.3 chromatin analysis reveals epigenetic regulation of CHRNA7 with deficiencies in Rett and autism brain. Hum Mol Genet 2011; 20:4311-23. [PMID: 21840925 DOI: 10.1093/hmg/ddr357] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Copy number variations (CNVs) within human 15q11.2-13.3 show reduced penetrance and variable expressivity in a range of neurologic disorders. Therefore, characterizing 15q11.2-13.3 chromatin structure is important for understanding the regulation of this locus during normal neuronal development. Deletion of the Prader-Willi imprinting center (PWS-IC) within 15q11.2-13.3 disrupts long-range imprinted gene expression resulting in Prader-Willi syndrome. Previous results establish that MeCP2 binds to the PWS-IC and is required for optimal expression of distal GABRB3 and UBE3A. To examine the hypothesis that MeCP2 facilitates 15q11.2-13.3 transcription by linking the PWS-IC with distant elements, chromosome capture conformation on chip (4C) analysis was performed in human SH-SY5Y neuroblastoma cells. SH-SY5Y neurons had 2.84-fold fewer 15q11.2-13.3 PWS-IC chromatin interactions than undifferentiated SH-SY5Y neuroblasts, revealing developmental chromatin de-condensation of the locus. Out of 68 PWS-IC interactions with15q11.2-13.3 identified by 4C analysis and 62 15q11.2-13.3 MeCP2-binding sites identified by previous ChIP-chip studies, only five sites showed overlap. Remarkably, two of these overlapping PWS-IC- and MeCP2-bound sites mapped to sites flanking CHRNA7 (cholinergic receptor nicotinic alpha 7) encoding the cholinergic receptor, nicotinic, alpha 7. PWS-IC interaction with CHRNA7 in neurons was independently confirmed by fluorescent in situ hybridization analysis. Subsequent quantitative transcriptional analyses of frontal cortex from Rett syndrome and autism patients revealed significantly reduced CHRNA7 expression compared with controls. Together, these results suggest that transcription of CHRNA7 is modulated by chromatin interactions with the PWS-IC. Thus, loss of long-range chromatin interactions within 15q11.2-13.3 may contribute to multiple human neurodevelopmental disorders.
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Affiliation(s)
- Dag H Yasui
- Department of Medical Microbiology and Immunology, Genome Center, University of California Davis School of Medicine, One Shields Avenue, Davis, CA 95616, USA.
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Stefan M, Simmons RA, Bertera S, Trucco M, Esni F, Drain P, Nicholls RD. Global deficits in development, function, and gene expression in the endocrine pancreas in a deletion mouse model of Prader-Willi syndrome. Am J Physiol Endocrinol Metab 2011; 300:E909-22. [PMID: 21343540 PMCID: PMC3093973 DOI: 10.1152/ajpendo.00185.2010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Prader-Willi syndrome (PWS) is a multisystem disorder caused by genetic loss of function of a cluster of imprinted, paternally expressed genes. Neonatal failure to thrive in PWS is followed by childhood-onset hyperphagia and obesity among other endocrine and behavioral abnormalities. PWS is typically assumed to be caused by an unknown hypothalamic-pituitary dysfunction, but the underlying pathogenesis remains unknown. A transgenic deletion mouse model (TgPWS) has severe failure to thrive, with very low levels of plasma insulin and glucagon in fetal and neonatal life prior to and following onset of progressive hypoglycemia. In this study, we tested the hypothesis that primary deficits in pancreatic islet development or function may play a fundamental role in the TgPWS neonatal phenotype. Major pancreatic islet hormones (insulin, glucagon) were decreased in TgPWS mice, consistent with plasma levels. Immunohistochemical analysis of the pancreas demonstrated disrupted morphology of TgPWS islets, with reduced α- and β-cell mass arising from an increase in apoptosis. Furthermore, in vivo and in vitro studies show that the rate of insulin secretion is significantly impaired in TgPWS β-cells. In TgPWS pancreas, mRNA levels for genes encoding all pancreatic hormones, other secretory factors, and the ISL1 transcription factor are upregulated by either a compensatory response to plasma hormone deficiencies or a primary effect of a deleted gene. Our findings identify a cluster of imprinted genes required for the development, survival, coordinate regulation of genes encoding hormones, and secretory function of pancreatic endocrine cells, which may underlie the neonatal phenotype of the TgPWS mouse model.
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Affiliation(s)
- Mihaela Stefan
- Dept. of Pediatrics, Children's Hospital of Pittsburgh of UPMC, Rangos Research Bldg., 4401 Penn Ave., Pittsburgh, PA 15224, USA
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Ding F, Li HH, Li J, Myers RM, Francke U. Neonatal maternal deprivation response and developmental changes in gene expression revealed by hypothalamic gene expression profiling in mice. PLoS One 2010; 5:e9402. [PMID: 20195375 PMCID: PMC2827556 DOI: 10.1371/journal.pone.0009402] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Accepted: 01/14/2010] [Indexed: 02/07/2023] Open
Abstract
Neonatal feeding problems are observed in several genetic diseases including Prader-Willi syndrome (PWS). Later in life, individuals with PWS develop hyperphagia and obesity due to lack of appetite control. We hypothesized that failure to thrive in infancy and later-onset hyperphagia are related and could be due to a defect in the hypothalamus. In this study, we performed gene expression microarray analysis of the hypothalamic response to maternal deprivation in neonatal wild-type and Snord116del mice, a mouse model for PWS in which a cluster of imprinted C/D box snoRNAs is deleted. The neonatal starvation response in both strains was dramatically different from that reported in adult rodents. Genes that are affected by adult starvation showed no expression change in the hypothalamus of 5 day-old pups after 6 hours of maternal deprivation. Unlike in adult rodents, expression levels of Nanos2 and Pdk4 were increased, and those of Pgpep1, Ndp, Brms1l, Mett10d, and Snx1 were decreased after neonatal deprivation. In addition, we compared hypothalamic gene expression profiles at postnatal days 5 and 13 and observed significant developmental changes. Notably, the gene expression profiles of Snord116del deletion mice and wild-type littermates were very similar at all time points and conditions, arguing against a role of Snord116 in feeding regulation in the neonatal period.
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Affiliation(s)
- Feng Ding
- Department of Genetics, Stanford University, Stanford, California, United States of America
| | - Hong Hua Li
- Department of Genetics, Stanford University, Stanford, California, United States of America
| | - Jun Li
- Department of Genetics, Stanford University, Stanford, California, United States of America
| | - Richard M. Myers
- Department of Genetics, Stanford University, Stanford, California, United States of America
| | - Uta Francke
- Department of Genetics, Stanford University, Stanford, California, United States of America
- * E-mail:
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Chan WK, Bhalla AD, Le Hir H, Nguyen LS, Huang L, Gécz J, Wilkinson MF. A UPF3-mediated regulatory switch that maintains RNA surveillance. Nat Struct Mol Biol 2009; 16:747-53. [PMID: 19503078 DOI: 10.1038/nsmb.1612] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Accepted: 04/24/2009] [Indexed: 02/05/2023]
Abstract
Nonsense-mediated decay (NMD) is an RNA decay pathway that downregulates aberrant mRNAs and a subset of normal mRNAs. The regulation of NMD is poorly understood. Here we identify a regulatory mechanism acting on two related UPF (up-frameshift) factors crucial for NMD: UPF3A and UPF3B. This regulatory mechanism, which reduces the level of UPF3A in response to the presence of UPF3B, is relieved in individuals harboring UPF3B mutations, leading to strongly increased steady-state levels of UPF3A. UPF3A compensates for the loss of UPF3B by regulating several NMD target transcripts, but it can also impair NMD, as it competes with the stronger NMD activator UPF3B for binding to the essential NMD factor UPF2. This deleterious effect of UPF3A protein is prevented by its destabilization using a conserved UPF3B-dependent mechanism. Together, our results suggest that UPF3A levels are tightly regulated by a post-transcriptional switch to maintain appropriate levels of NMD substrates in cells containing different levels of UPF3B.
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Affiliation(s)
- Wai-Kin Chan
- Department of Biochemistry and Molecular Biology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
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Goytain A, Hines RM, Quamme GA. Functional characterization of NIPA2, a selective Mg2+ transporter. Am J Physiol Cell Physiol 2008; 295:C944-53. [PMID: 18667602 DOI: 10.1152/ajpcell.00091.2008] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We used microarray analysis to identify renal cell transcripts that were upregulated with low magnesium. One transcript, identified as NIPA2 (nonimprinted in Prader-Willi/Angelman syndrome) subtype 2, was increased over twofold relative to cells cultured in normal magnesium. The deduced sequence comprises 129 amino acids with 8 predicted transmembrane regions. As the secondary structure of NIPA2 conformed to a membrane transport protein, we expressed it in Xenopus oocytes and determined that it mediated Mg(2+) uptake with two-electrode voltage-clamp and fluorescence studies. Mg(2+) transport was electrogenic, voltage dependent, and saturable, demonstrating a Michaelis affinity constant of 0.31 mM. Unlike other reported Mg(2+) transporters, NIPA2 was very selective for the Mg(2+) cation. NIPA2 mRNA is found in many tissues but particularly abundant in renal cells. With the use of immunofluorescence, it was shown that NIPA2 protein was normally localized to the early endosomes and plasma membrane and was recruited to the plasma membrane in response to low extracellular magnesium. We conclude that NIPA2 plays a role in magnesium metabolism and regulation of renal magnesium conservation.
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Affiliation(s)
- Angela Goytain
- Department of Medicine, Vancouver Hospital, Koerner Pavilion, 2211 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 1Z37
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Bittel DC, Kibiryeva N, Butler MG. Whole genome microarray analysis of gene expression in subjects with fragile X syndrome. Genet Med 2007; 9:464-72. [PMID: 17666893 PMCID: PMC5453801 DOI: 10.1097/gim.0b013e3180ca9a9a] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE Fragile X syndrome, the most common inherited form of human mental retardation, arises as a consequence of a large expansion of a CGG trinucleotide repeat in 5' untranslated region of the fragile X mental retardation 1 (FMR1) gene located on the X chromosome. Although the FMR1 gene was cloned 15 years ago, the mechanisms that cause fragile X syndrome remain to be elucidated. Multiple studies have identified proteins that potentially interact with FMRP, the product of FMR1, and differentially expressed genes in an Fmr1 knockout mouse. To assess the impact of fragile X syndrome on gene expression in humans and to attempt to identify disturbed genes and gene interactive pathways relevant to fragile X syndrome, we performed gene expression microarray analysis using RNA isolated from lymphoblastoid cells derived from males with fragile X syndrome with and similarly aged control males. METHODS We used whole genome microarrays consisting of 57,000 probes to analyze global changes to the transcriptome in readily available lymphoblastoid cell lines derived from males with fragile X syndrome and healthy comparison males with normal intelligence. We verified the differential expression of several of these genes with known biological function relevant to fragile X syndrome using quantitative reverse transcription polymerase chain reaction using RNA from lymphoblastoid cells from fragile X syndrome and control males as well as RNA from human brain tissue (frontal cortex) of other affected fragile X syndrome males. RESULTS We identified more than 90 genes that had significant differences in probe intensity of at least 1.5-fold with a false discovery rate of 5% in cells from males with fragile X syndrome relative to comparison males. The list of 90 differentially expressed genes contained an overrepresentation of genes involved in signaling (e.g., UNC13B [-3.3-fold change in expression in lymphoblasts by quantitative reverse transcription polymerase chain reaction), GABRD [+2.0-fold change] EEF1A2 [+4.3-fold change]), morphogenesis (e.g., MAP1B [-7.5-fold change], ACCN1 [-8.0-fold change]), and neurodevelopment and function (e.g., PPP1R9B [+3.5-fold change], HES1 [+2.8-fold change]). CONCLUSIONS These genes may represent members of candidate networks disturbed by the loss of FMR1 and consequently fragile X mental retardation protein function, thus lending support for altered fragile X mental retardation protein function resulting in an abnormal transcriptome. Further analyses of the genes, especially those that have been identified in multiple studies, are warranted to develop a more integrated description of the alterations in gene processing that lead to fragile X syndrome.
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Affiliation(s)
- Douglas C Bittel
- Children's Mercy Hospitals and Clinics and University of Missouri-Kansas City School of Medicine, Kansas City, Missouri 64108, USA
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Nowicki ST, Tassone F, Ono MY, Ferranti J, Croquette MF, Goodlin-Jones B, Hagerman RJ. The Prader-Willi phenotype of fragile X syndrome. J Dev Behav Pediatr 2007; 28:133-8. [PMID: 17435464 DOI: 10.1097/01.dbp.0000267563.18952.c9] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The Prader-Willi phenotype (PWP) of fragile X syndrome (FXS) is associated with obesity and hyperphagia similar to Prader-Willi syndrome (PWS), but without cytogenetic or methylation abnormalities at 15q11-13. Thirteen cases of PWP and FXS are reported here that were identified by obesity and hyperphagia. Delayed puberty was seen in 5 of 9 cases who had entered puberty, a small penis or testicles in seven of 13 cases, and infant hypotonia and/or a poor suck in seven of 13 cases. Autism spectrum disorder occurred in 10 of 13 cases, and autism was diagnosed in seven of 13 cases. We investigated cytoplasmic interacting FMR1 protein (CYFIP) expression, which is a protein that interacts with FMR1 protein (FMRP) because the gene for CYFIP is located at 15q11-13. CYFIP mRNA levels were significantly reduced in our patients with the PWP and FXS compared to individuals without FXS (p < .001) and also individuals with FXS without PWP (p = .03).
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Affiliation(s)
- Stephen T Nowicki
- Department of Pediatrics, University of California at Davis Medical Center, Sacramento, California 95817, USA
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16
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Bittel DC, Kibiryeva N, Sell SM, Strong TV, Butler MG. Whole genome microarray analysis of gene expression in Prader-Willi syndrome. Am J Med Genet A 2007; 143A:430-42. [PMID: 17236194 PMCID: PMC5467864 DOI: 10.1002/ajmg.a.31606] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Prader-Willi syndrome (PWS) is caused by loss of function of paternally expressed genes in the 15q11-q13 region and a paucity of data exists on transcriptome variation. To further characterize genetic alterations in this classic obesity syndrome using whole genome microarrays to analyze gene expression, microarray and quantitative RT-PCR analysis were performed using RNA isolated from lymphoblastoid cells from PWS male subjects (four with 15q11-q13 deletion and three with UPD) and three age and cognition matched nonsyndromic comparison males. Of more than 47,000 probes examined in the microarray, 23,383 were detectable and 323 had significantly different expression in the PWS lymphoblastoid cells relative to comparison cells, 14 of which were related to neurodevelopment and function. As expected, there was no evidence of expression of paternally expressed genes from the 15q11-q13 region (e.g., SNRPN) in the PWS cells. Alterations in expression of serotonin receptor genes (e.g., HTR2B) and genes involved in eating behavior and obesity (ADIPOR2, MC2R, HCRT, OXTR) were noted. Other genes of interest with reduced expression in PWS subjects included STAR (a key regulator of steroid synthesis) and SAG (an arrestin family member which desensitizes G-protein-coupled receptors). Quantitative RT-PCR for SAG, OXTR, STAR, HCRT, and HTR2B using RNA isolated from their lymphoblastoid cells and available brain tissue (frontal cortex) from separate individuals with PWS and control subjects and normalized to GAPD gene expression levels validated our microarray gene expression data. Our analysis identified previously unappreciated changes in gene expression which may contribute to the clinical manifestations seen in PWS.
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Affiliation(s)
- Douglas C. Bittel
- Children’s Mercy Hospitals and Clinics, University of Missouri-Kansas City, School of Medicine, Kansas City, MO
| | - Nataliya Kibiryeva
- Children’s Mercy Hospitals and Clinics, University of Missouri-Kansas City, School of Medicine, Kansas City, MO
| | | | | | - Merlin G. Butler
- Children’s Mercy Hospitals and Clinics, University of Missouri-Kansas City, School of Medicine, Kansas City, MO
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Bittel DC, Kibiryeva N, McNulty SG, Driscoll DJ, Butler MG, White RA. Whole genome microarray analysis of gene expression in an imprinting center deletion mouse model of Prader-Willi syndrome. Am J Med Genet A 2007; 143A:422-9. [PMID: 17036336 PMCID: PMC5453790 DOI: 10.1002/ajmg.a.31504] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Prader-Willi syndrome (PWS) is caused by loss of paternally expressed genes in the 15q11-q13 region. To further characterize alterations in gene expression in this classical obesity syndrome we used whole genome microarrays to study a PWS mouse model resulting from a paternally derived imprinting center (IC) deletion (PWS IC deletion). These mice die generally within 2-3 days of life (reflective of failure to thrive in infants with PWS) and therefore, the analysis was performed on RNA extracted from the whole brain of PWS IC deletion mice and normal littermates at less than 24 hr after birth. Of more than 45,000 probes examined, 26,471 (59%) were detected for further analysis, and 69 had a significant change in expression of at least 1.5-fold and a false discovery rate (FDR) of 5%. Eight of the genes with differential expression were imprinted and from the PWS critical region (PWSCR). The three genes with the highest expression in the PWS IC mice were pro-opiomelanocortin (Pomc) and two transcripts of unknown function. Pomc knockout mice have been shown to develop obesity. Therefore, elevated Pomc RNA in PWS IC deletion neonatal mice may be an important genetic factor in the survival of these mice as it may affect eating behavior. Interestingly, Mc5r, a melanocortin receptor known to directly respond to Pomc expression changes, was upregulated as well. Mc5r is known to be involved with thermoregulation which is reportedly abnormal in PWS infants. These observations support a role for Pomc and the network of genes involved in regulating energy homeostasis in the early clinical findings of failure to thrive observed in PWS. Other notable patterns include three previously unstudied transcripts that are expressed only from the paternal allele under regulatory control of the IC and include AK013560, BB3144814, and BB182944 (whose genes are located in the mouse PWSCR on chromosome 7B). As expected, all the known paternally expressed genes from the PWSCR had detection signals below the threshold in the PWS IC deletion mice but were clearly detectable in control littermates. Several of the genes in this study were further examined by quantitative reverse transcription-PCR (RT-PCR) to confirm their expression status. Further analysis of gene expression in these mice may lead to novel pathways affected in PWS. These results, along with other recent reports, suggest that the cumulative effect of modest changes in expression of many genes, especially genes involved in energy metabolism, contribute to the failure to thrive of infants with PWS.
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Affiliation(s)
- Douglas C. Bittel
- Children’s Mercy Hospitals and Clinics and University of Missouri-Kansas City, School of Medicine, Kansas City, Missouri
| | - Nataliya Kibiryeva
- Children’s Mercy Hospitals and Clinics and University of Missouri-Kansas City, School of Medicine, Kansas City, Missouri
| | - Steven G. McNulty
- Children’s Mercy Hospitals and Clinics and University of Missouri-Kansas City, School of Medicine, Kansas City, Missouri
| | - Daniel J. Driscoll
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Merlin G. Butler
- Children’s Mercy Hospitals and Clinics and University of Missouri-Kansas City, School of Medicine, Kansas City, Missouri
| | - Robert A. White
- Children’s Mercy Hospitals and Clinics and University of Missouri-Kansas City, School of Medicine, Kansas City, Missouri
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Stefan M, Claiborn KC, Stasiek E, Chai JH, Ohta T, Longnecker R, Greally JM, Nicholls RD. Genetic mapping of putative Chrna7 and Luzp2 neuronal transcriptional enhancers due to impact of a transgene-insertion and 6.8 Mb deletion in a mouse model of Prader-Willi and Angelman syndromes. BMC Genomics 2005; 6:157. [PMID: 16280085 PMCID: PMC1322230 DOI: 10.1186/1471-2164-6-157] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Accepted: 11/09/2005] [Indexed: 02/03/2023] Open
Abstract
Background Prader-Willi and Angelman syndrome (PWS and AS) patients typically have an ~5 Mb deletion of human chromosome 15q11-q13, of opposite parental origin. A mouse model of PWS and AS has a transgenic insertion-deletion (TgPWS/TgAS) of chromosome 7B/C subsequent to paternal or maternal inheritance, respectively. In this study, we define the deletion endpoints and examine the impact on expression of flanking genes. Results Using molecular and cytological methods we demonstrate that 13 imprinted and 11 non-imprinted genes are included in the TgPWS/TgAS deletion. Normal expression levels were found in TgPWS brain for genes extending 9.1- or 5.6-Mb centromeric or telomeric of the deletion, respectively. Our molecular cytological studies map the proximal deletion breakpoint between the Luzp2 and Siglec-H loci, and we show that overall mRNA levels of Luzp2 in TgPWS and TgAS brain are significantly reduced by 17%. Intriguingly, 5' Chrna7 shows 1.7-fold decreased levels in TgPWS and TgAS brain whereas there is a ≥15-fold increase in expression in neonatal liver and spleen of these mouse models. By isolating a Chrna7-Tg fusion transcript from TgAS mice, we mapped the telomeric deletion breakpoint in Chrna7 intron 4. Conclusion Based on the extent of the deletion, TgPWS/TgAS mice are models for PWS/AS class I deletions. Other than for the first gene promoters immediately outside the deletion, since genes extending 5.6–9.1 Mb away from each end of the deletion show normal expression levels in TgPWS brain, this indicates that the transgene array does not induce silencing and there are no additional linked rearrangements. Using gene expression, non-coding conserved sequence (NCCS) and synteny data, we have genetically mapped a putative Luzp2 neuronal enhancer responsible for ~33% of allelic transcriptional activity. The Chrna7 results are explained by hypothesizing loss of an essential neuronal transcriptional enhancer required for ~80% of allelic Chrna7 promoter activity, while the Chrna7 promoter is upregulated in B lymphocytes by the transgene immunoglobulin enhancer. The mapping of a putative Chrna7 neuronal enhancer inside the deletion has significant implications for understanding the transcriptional regulation of this schizophrenia-susceptibility candidate gene.
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Affiliation(s)
- Mihaela Stefan
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Pediatrics, Children's Hospital of Pittsburgh, 3460 Fifth Avenue, Pittsburgh, PA 15213
| | - Kathryn C Claiborn
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Edyta Stasiek
- Division of Hematology, Department of Medicine, Albert Einstein College of Medicine, The Bronx, USA
| | - Jing-Hua Chai
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tohru Ohta
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
- Health Science University of Hokkaido, Hokkaido, Japan
| | - Richard Longnecker
- Department of Microbiology and Immunology, Feinberg School of Medicine, Northwestern University, Ward 6-231, 303 East Chicago Ave, Chicago, IL 60611, USA
| | - John M Greally
- Division of Hematology, Department of Medicine, Albert Einstein College of Medicine, The Bronx, USA
| | - Robert D Nicholls
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Birth Defects Laboratories, Children's Hospital of Pittsburgh, Room 2109 Rangos Research Center, 3460 Fifth Avenue, Pittsburgh, PA 15213, USA
- Department of Pediatrics, Children's Hospital of Pittsburgh, 3460 Fifth Avenue, Pittsburgh, PA 15213
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Stefan M, Ji H, Simmons RA, Cummings DE, Ahima RS, Friedman MI, Nicholls RD. Hormonal and metabolic defects in a prader-willi syndrome mouse model with neonatal failure to thrive. Endocrinology 2005; 146:4377-85. [PMID: 16002520 DOI: 10.1210/en.2005-0371] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Prader-Willi syndrome (PWS) has a biphasic clinical phenotype with failure to thrive in the neonatal period followed by hyperphagia and severe obesity commencing in childhood among other endocrinological and neurobehavioral abnormalities. The syndrome results from loss of function of several clustered, paternally expressed genes in chromosome 15q11-q13. PWS is assumed to result from a hypothalamic defect, but the pathophysiological basis of the disorder is unknown. We hypothesize that a fetal developmental abnormality in PWS leads to the neonatal phenotype, whereas the adult phenotype results from a failure in compensatory mechanisms. To address this hypothesis and better characterize the neonatal failure to thrive phenotype during postnatal life, we studied a transgenic deletion PWS (TgPWS) mouse model that shares similarities with the first stage of the human syndrome. TgPWS mice have fetal and neonatal growth retardation associated with profoundly reduced insulin and glucagon levels. Consistent with growth retardation, TgPWS mice have deregulated liver expression of IGF system components, as revealed by quantitative gene expression studies. Lethality in TgPWS mice appears to result from severe hypoglycemia after postnatal d 2 after depletion of liver glycogen stores. Consistent with hypoglycemia, TgPWS mice appear to have increased fat oxidation. Ghrelin levels increase in TgPWS reciprocally with the falling glucose levels, suggesting that the rise in ghrelin reported in PWS patients may be secondary to a perceived energy deficiency. Together, the data reveal defects in endocrine pancreatic function as well as glucose and hepatic energy metabolism that may underlie the neonatal phenotype of PWS.
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Affiliation(s)
- M Stefan
- Center for Neurobiology and Behavior, Department of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia 19104-6140, USA
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Abstract
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder that arises from lack of expression of paternally inherited genes known to be imprinted and located in the chromosome 15q11-q13 region. PWS is considered the most common syndromal cause of life-threatening obesity and is estimated at 1 in 10,000 to 20,000 individuals. A de novo paternally derived chromosome 15q11-q13 deletion is the cause of PWS in about 70% of cases, and maternal disomy 15 accounts for about 25% of cases. The remaining cases of PWS result either from genomic imprinting defects (microdeletions or epimutations) of the imprinting centre in the 15q11-q13 region or from chromosome 15 translocations. Here, we describe the clinical presentation of PWS, review the current understanding of causative cytogenetic and molecular genetic mechanisms, and discuss future directions for research.
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Affiliation(s)
- Douglas C Bittel
- Section of Medical Genetics and Molecular Medicine, Children's Mercy Hospitals and Clinics, and University of Missouri-Kansas City School of Medicine, 2401 Gillham Rd, Kansas City, MO 64108, USA.
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