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Koppes EA, Johnson MA, Moresco JJ, Luppi P, Lewis DW, Stolz DB, Diedrich JK, Yates JR, Wek RC, Watkins SC, Gollin SM, Park HJ, Drain P, Nicholls RD. Insulin secretion deficits in a Prader-Willi syndrome β-cell model are associated with a concerted downregulation of multiple endoplasmic reticulum chaperones. PLoS Genet 2023; 19:e1010710. [PMID: 37068109 PMCID: PMC10138222 DOI: 10.1371/journal.pgen.1010710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 04/27/2023] [Accepted: 03/21/2023] [Indexed: 04/18/2023] Open
Abstract
Prader-Willi syndrome (PWS) is a multisystem disorder with neurobehavioral, metabolic, and hormonal phenotypes, caused by loss of expression of a paternally-expressed imprinted gene cluster. Prior evidence from a PWS mouse model identified abnormal pancreatic islet development with retention of aged insulin and deficient insulin secretion. To determine the collective roles of PWS genes in β-cell biology, we used genome-editing to generate isogenic, clonal INS-1 insulinoma lines having 3.16 Mb deletions of the silent, maternal- (control) and active, paternal-allele (PWS). PWS β-cells demonstrated a significant cell autonomous reduction in basal and glucose-stimulated insulin secretion. Further, proteomic analyses revealed reduced levels of cellular and secreted hormones, including all insulin peptides and amylin, concomitant with reduction of at least ten endoplasmic reticulum (ER) chaperones, including GRP78 and GRP94. Critically, differentially expressed genes identified by whole transcriptome studies included reductions in levels of mRNAs encoding these secreted peptides and the group of ER chaperones. In contrast to the dosage compensation previously seen for ER chaperones in Grp78 or Grp94 gene knockouts or knockdown, compensation is precluded by the stress-independent deficiency of ER chaperones in PWS β-cells. Consistent with reduced ER chaperones levels, PWS INS-1 β-cells are more sensitive to ER stress, leading to earlier activation of all three arms of the unfolded protein response. Combined, the findings suggest that a chronic shortage of ER chaperones in PWS β-cells leads to a deficiency of protein folding and/or delay in ER transit of insulin and other cargo. In summary, our results illuminate the pathophysiological basis of pancreatic β-cell hormone deficits in PWS, with evolutionary implications for the multigenic PWS-domain, and indicate that PWS-imprinted genes coordinate concerted regulation of ER chaperone biosynthesis and β-cell secretory pathway function.
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Affiliation(s)
- Erik A Koppes
- Division of Genetic and Genomic Medicine, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Marie A Johnson
- Division of Genetic and Genomic Medicine, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - James J Moresco
- Department of Molecular Medicine and Neurobiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Patrizia Luppi
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Dale W Lewis
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania, United States of America
| | - Donna B Stolz
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Jolene K Diedrich
- Department of Molecular Medicine and Neurobiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - John R Yates
- Department of Molecular Medicine and Neurobiology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Ronald C Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Simon C Watkins
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Susanne M Gollin
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania, United States of America
| | - Hyun Jung Park
- Department of Human Genetics, University of Pittsburgh School of Public Health, Pittsburgh, Pennsylvania, United States of America
| | - Peter Drain
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Robert D Nicholls
- Division of Genetic and Genomic Medicine, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
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Qian Y, Xia F, Zuo Y, Zhong M, Yang L, Jiang Y, Zou C. Do patients with Prader-Willi syndrome have favorable glucose metabolism? Orphanet J Rare Dis 2022; 17:187. [PMID: 35525976 PMCID: PMC9077846 DOI: 10.1186/s13023-022-02344-3] [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: 01/08/2022] [Accepted: 04/26/2022] [Indexed: 11/26/2022] Open
Abstract
Background In recent years, more studies have observed that patients with Prader–Willi syndrome have lower insulin levels and lower insulin resistance than body mass index-matched controls, which may suggest protected glucose metabolism. Method The PubMed and Web of Science online databases were searched to identify relevant studies published in the English language using the terms “Prader–Willi syndrome” with “glucose”, “insulin”, “diabetes mellitus”, “fat”, “adipo*”, “ghrelin”, “oxytocin”, “irisin” or “autonomic nervous system”. Results The prevalence of impaired glucose intolerance, type 2 diabetes mellitus and some other obesity-associated complications in patients with Prader–Willi syndrome tends to be lower when compared to that in general obesity, which is consistent with the hypothetically protected glucose metabolism. Factors including adipose tissue, adiponectin, ghrelin, oxytocin, irisin, growth hormone and the autonomic nervous system possibly modulate insulin sensitivity in patients with Prader–Willi syndrome. Conclusion Although lower insulin levels, lower IR and protected glucose metabolism are widely reported in PWS patients, the causes are still mysterious. Based on existing knowledge, we cannot determine which factor is of utmost importance and what are the underlying mechanisms, and further research is in urgent need.
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Affiliation(s)
- Yanjie Qian
- Department of Endocrinology, The Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, No 3333 Binsheng Road, Hangzhou, 310051, China
| | - Fangling Xia
- Department of Endocrinology, The Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, No 3333 Binsheng Road, Hangzhou, 310051, China
| | - Yiming Zuo
- Department of Endocrinology, The Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, No 3333 Binsheng Road, Hangzhou, 310051, China
| | - Mianling Zhong
- Department of Endocrinology, The Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, No 3333 Binsheng Road, Hangzhou, 310051, China
| | - Lili Yang
- Department of Endocrinology, The Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, No 3333 Binsheng Road, Hangzhou, 310051, China
| | - Yonghui Jiang
- Department of Genetics, Yale University School of Medicine, New Haven, USA
| | - Chaochun Zou
- Department of Endocrinology, The Children's Hospital of Zhejiang University School of Medicine, National Clinical Research Center for Child Health, No 3333 Binsheng Road, Hangzhou, 310051, China.
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3
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Kummerfeld DM, Raabe CA, Brosius J, Mo D, Skryabin BV, Rozhdestvensky TS. A Comprehensive Review of Genetically Engineered Mouse Models for Prader-Willi Syndrome Research. Int J Mol Sci 2021; 22:3613. [PMID: 33807162 PMCID: PMC8037846 DOI: 10.3390/ijms22073613] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/26/2021] [Accepted: 03/28/2021] [Indexed: 02/05/2023] Open
Abstract
Prader-Willi syndrome (PWS) is a neurogenetic multifactorial disorder caused by the deletion or inactivation of paternally imprinted genes on human chromosome 15q11-q13. The affected homologous locus is on mouse chromosome 7C. The positional conservation and organization of genes including the imprinting pattern between mice and men implies similar physiological functions of this locus. Therefore, considerable efforts to recreate the pathogenesis of PWS have been accomplished in mouse models. We provide a summary of different mouse models that were generated for the analysis of PWS and discuss their impact on our current understanding of corresponding genes, their putative functions and the pathogenesis of PWS. Murine models of PWS unveiled the contribution of each affected gene to this multi-facetted disease, and also enabled the establishment of the minimal critical genomic region (PWScr) responsible for core symptoms, highlighting the importance of non-protein coding genes in the PWS locus. Although the underlying disease-causing mechanisms of PWS remain widely unresolved and existing mouse models do not fully capture the entire spectrum of the human PWS disorder, continuous improvements of genetically engineered mouse models have proven to be very powerful and valuable tools in PWS research.
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Affiliation(s)
- Delf-Magnus Kummerfeld
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
| | - Carsten A. Raabe
- Research Group Regulatory Mechanisms of Inflammation, Institute of Medical Biochemistry (ZMBE), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
- Institute of Experimental Pathology (ZMBE), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
| | - Juergen Brosius
- Institute of Experimental Pathology (ZMBE), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
- Institutes for Systems Genetics, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Dingding Mo
- School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055, China;
| | - Boris V. Skryabin
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
| | - Timofey S. Rozhdestvensky
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Von-Esmarch-Str. 56, D-48149 Muenster, Germany;
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Abstract
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder characterized by hyperphagia, hypotonia, learning disability, as well as a range of psychiatric conditions. The conservation of the PWS genetic interval on chromosome 15q11-q13 in human, and a cluster of genes on mouse chromosome 7, has facilitated the use of mice as animal models for PWS. Some models faithfully mimic the loss of all gene expression from the paternally inherited PWS genetic interval, whereas others target smaller regions or individual genes. Collectively, these models have provided insight into the mechanisms, many of which lead to alterations in hypothalamic function, underlying the core symptoms of PWS, including growth retardation, hyperphagia and metabolism, reproductive maturation and endophenotypes of relevance to behavioral and psychiatric problems. Here we review and summarize these studies.
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Affiliation(s)
- Simona Zahova
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - Anthony R Isles
- Neuroscience and Mental Health Research Institute, School of Medicine, Cardiff University, Cardiff, United Kingdom.
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Samaha G, Wade CM, Beatty J, Lyons LA, Fleeman LM, Haase B. Mapping the genetic basis of diabetes mellitus in the Australian Burmese cat (Felis catus). Sci Rep 2020; 10:19194. [PMID: 33154479 PMCID: PMC7644637 DOI: 10.1038/s41598-020-76166-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/22/2020] [Indexed: 12/30/2022] Open
Abstract
Diabetes mellitus, a common endocrinopathy affecting domestic cats, shares many clinical and pathologic features with type 2 diabetes in humans. In Australia and Europe, diabetes mellitus is almost four times more common among Burmese cats than in other breeds. As a genetically isolated population, the diabetic Australian Burmese cat provides a spontaneous genetic model for studying diabetes mellitus in humans. Studying complex diseases in pedigreed breeds facilitates tighter control of confounding factors including population stratification, allelic frequencies and environmental heterogeneity. We used the feline SNV array and whole genome sequence data to undertake a genome wide-association study and runs of homozygosity analysis, of a case–control cohort of Australian and European Burmese cats. Our results identified diabetes-associated haplotypes across chromosomes A3, B1 and E1 and selective sweeps across the Burmese breed on chromosomes B1, B3, D1 and D4. The locus on chromosome B1, common to both analyses, revealed coding and splice region variants in candidate genes, ANK1, EPHX2 and LOX2, implicated in diabetes mellitus and lipid dysregulation. Mapping this condition in Burmese cats has revealed a polygenic spectrum, implicating loci linked to pancreatic beta cell dysfunction, lipid dysregulation and insulin resistance in the pathogenesis of diabetes mellitus in the Burmese cat.
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Affiliation(s)
- Georgina Samaha
- Faculty of Science, Sydney School of Veterinary Science, University of Sydney, Sydney, NSW, Australia.
| | - Claire M Wade
- School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, Australia
| | - Julia Beatty
- Faculty of Science, Sydney School of Veterinary Science, University of Sydney, Sydney, NSW, Australia.,Department of Infectious Diseases and Public Health, City University of Hong Kong, Kowloon, Hong Kong SAR, People's Republic of China
| | - Leslie A Lyons
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO, USA
| | | | - Bianca Haase
- Faculty of Science, Sydney School of Veterinary Science, University of Sydney, Sydney, NSW, Australia
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6
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Crespi BJ. Why and How Imprinted Genes Drive Fetal Programming. Front Endocrinol (Lausanne) 2020; 10:940. [PMID: 32117048 PMCID: PMC7025584 DOI: 10.3389/fendo.2019.00940] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 12/27/2019] [Indexed: 02/06/2023] Open
Abstract
Imprinted genes mediate fetal and childhood growth and development, and early growth patterns drive fetal programming effects. However, predictions and evidence from the kinship theory of imprinting have yet to be directly integrated with data on fetal programming and risks of metabolic disease. I first define paternal-gene and maternal-gene optima with regard to early human growth and development. Next, I review salient evidence with regard to imprinted gene effects on birth weight, body composition, trajectories of feeding and growth, and timing of developmental stages, to evaluate why and how imprinted gene expression influences risks of metabolic disease in later life. I find that metabolic disease risks derive primarily from maternal gene biases that lead to reduced placental efficacy, low birth weight, low relative muscle mass, high relative white fat, increased abdominal adiposity, reduced pancreatic β-cell mass that promotes insulin resistance, reduced appetite and infant sucking efficacy, catch-up fat deposition from family foods after weaning, and early puberty. Paternal gene biases, by contrast, may contribute to metabolic disease via lower rates of brown fat thermiogenesis, and through favoring more rapid postnatal catch-up growth after intrauterine growth restriction from environmental causes. These disease risks can be alleviated through dietary and pharmacological alterations that selectively target imprinted gene expression and relevant metabolic pathways. The kinship theory of imprinting, and mother-offspring conflict more generally, provide a clear predictive framework for guiding future research on fetal programming and metabolic disease.
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Affiliation(s)
- Bernard J. Crespi
- Department of Biological Sciences and Human Evolutionary Studies Program, Simon Fraser University, Burnaby, BC, Canada
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7
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Burnett LC, Hubner G, LeDuc CA, Morabito MV, Carli JFM, Leibel RL. Loss of the imprinted, non-coding Snord116 gene cluster in the interval deleted in the Prader Willi syndrome results in murine neuronal and endocrine pancreatic developmental phenotypes. Hum Mol Genet 2018; 26:4606-4616. [PMID: 28973544 DOI: 10.1093/hmg/ddx342] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/18/2017] [Indexed: 01/06/2023] Open
Abstract
Global neurodevelopmental delay is a prominent characteristic of individuals with Prader-Willi syndrome (PWS). The neuromolecular bases for these delays are unknown. We identified neuroanatomical changes in the brains of mice deficient for a gene in the minimal critical deletion region for PWS (Snord116p-/m+). In Snord116p-/m+ mice, reduced primary forebrain neuron cell body size is apparent in embryonic day 15.5 fetuses, and persists until postnatal day 30 in cerebellar Purkinje neurons. Snord116 is a snoRNA gene cluster of unknown function that can localize to the nucleolus. In cerebellar Purkinje neurons from postnatal day 30 Snord116p-/m+ mice the reduction in neuronal cell body size was associated with decreased neuronal nucleolar size. We also identified developmental changes in the endocrine pancreas of Snord116p-/m+ animals that persist into adulthood. Mice lacking Snord116 have smaller pancreatic islets; within the islet the percentage of δ-cells is increased, while the percentage of α-cells is reduced. The α-cell markers, Sst and Hhex, are upregulated in Snord116p-/m+ isolated islets while Ins1, Ins2, Pdx1, Nkx6-1, and Pax6 are downregulated. There is a 3-fold increase in the percentage of polyhormonal cells in the neonatal pancreata of Snord116p-/m+ mice, due primarily to an increase in cells co-positive with somatostatin. Snord116 may play a role in islet cell lineage specification. The Snord116 gene cluster is important for developmental processes in the brain as well as the endocrine pancreas.
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Affiliation(s)
- Lisa Cole Burnett
- Institute of Human Nutrition.,Division of Molecular Genetics, Department of Pediatrics, Columbia University, New York, NY 10027, USA.,Naomi Berrie Diabetes Center, Russ Berrie Medical Science Pavillion, New York, NY 10032, USA
| | | | - Charles A LeDuc
- Division of Molecular Genetics, Department of Pediatrics, Columbia University, New York, NY 10027, USA.,Naomi Berrie Diabetes Center, Russ Berrie Medical Science Pavillion, New York, NY 10032, USA.,New York Obesity Research Center, Russ Berrie Medical Science Pavillion, New York, NY 10032, USA
| | - Michael V Morabito
- Division of Molecular Genetics, Department of Pediatrics, Columbia University, New York, NY 10027, USA.,Naomi Berrie Diabetes Center, Russ Berrie Medical Science Pavillion, New York, NY 10032, USA
| | - Jayne F Martin Carli
- Division of Molecular Genetics, Department of Pediatrics, Columbia University, New York, NY 10027, USA.,Naomi Berrie Diabetes Center, Russ Berrie Medical Science Pavillion, New York, NY 10032, USA.,Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10027, USA
| | - Rudolph L Leibel
- Division of Molecular Genetics, Department of Pediatrics, Columbia University, New York, NY 10027, USA.,Naomi Berrie Diabetes Center, Russ Berrie Medical Science Pavillion, New York, NY 10032, USA.,New York Obesity Research Center, Russ Berrie Medical Science Pavillion, New York, NY 10032, USA
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8
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Spatiotemporal Expression and Molecular Characterization of miR-344b and miR-344c in the Developing Mouse Brain. Neural Plast 2016; 2016:1951250. [PMID: 27034842 PMCID: PMC4791505 DOI: 10.1155/2016/1951250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 02/01/2016] [Indexed: 01/14/2023] Open
Abstract
MicroRNAs (miRNAs) are small noncoding RNA known to regulate brain development. The expression of two novel miRNAs, namely, miR-344b and miR-344c, was characterized during mouse brain developmental stages in this study. In situ hybridization analysis showed that miR-344b and miR-344c were expressed in the germinal layer during embryonic brain developmental stages. In contrast, miR-344b was not detectable in the adult brain while miR-344c was expressed exclusively in the adult olfactory bulb and cerebellar granular layer. Stem-loop RT-qPCR analysis of whole brain RNAs showed that expression of the miR-344b and miR-344c was increased as brain developed throughout the embryonic stage and maintained at adulthood. Further investigation showed that these miRNAs were expressed in adult organs, where miR-344b and miR-344c were highly expressed in pancreas and brain, respectively. Bioinformatics analysis suggested miR-344b and miR-344c targeted Olig2 and Otx2 mRNAs, respectively. However, luciferase experiments demonstrated that these miRNAs did not target Olig2 and Otx2 mRNAs. Further investigation on the locality of miR-344b and miR-344c showed that both miRNAs were localized in nuclei of immature neurons. In conclusion, miR-344b and miR-344c were expressed spatiotemporally during mouse brain developmental stages.
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9
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Davies JR, Humby T, Dwyer DM, Garfield AS, Furby H, Wilkinson LS, Wells T, Isles AR. Calorie seeking, but not hedonic response, contributes to hyperphagia in a mouse model for Prader-Willi syndrome. Eur J Neurosci 2015; 42:2105-13. [PMID: 26040449 PMCID: PMC4949663 DOI: 10.1111/ejn.12972] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/29/2015] [Accepted: 05/29/2015] [Indexed: 12/25/2022]
Abstract
Prader–Willi syndrome (PWS) is a neurodevelopmental disorder caused by deletion or inactivation of paternally expressed imprinted genes on human chromosome 15q11‐q13, the most recognised feature of which is hyperphagia. This is thought to arise as a consequence of abnormalities in both the physiological drive for food and the rewarding properties of food. Although a number of mouse models for PWS exist, the underlying variables dictating maladaptive feeding remain unknown. Here, feeding behaviour in a mouse model in which the imprinting centre (IC) of the syntenic PWS interval has been deleted (PWSICdel mice) is characterised. It is demonstrated that PWSICdel mice show hyperghrelinaemia and increased consumption of food both following overnight fasting and when made more palatable with sucrose. However, hyperphagia in PWSICdel mice was not accompanied by any changes in reactivity to the hedonic properties of palatable food (sucrose or saccharin), as measured by lick‐cluster size. Nevertheless, overall consumption by PWSICdel mice for non‐caloric saccharin in the licking test was significantly reduced. Combined with converging findings from a continuous reinforcement schedule, these data indicate that PWSICdel mice show a marked heightened sensitivity to the calorific value of food. Overall, these data indicate that any impact of the rewarding properties of food on the hyperphagia seen in PWSICdel mice is driven primarily by calorie content and is unlikely to involve hedonic processes. This has important implications for understanding the neural systems underlying the feeding phenotype of PWS and the contribution of imprinted genes to abnormal feeding behaviour more generally.
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Affiliation(s)
- Jennifer R Davies
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Medicine, Cardiff University, Cardiff, UK
| | - Trevor Humby
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Psychology, Cardiff University, Cardiff, UK
| | - Dominic M Dwyer
- School of Psychology, Cardiff University, Cardiff, UK.,School of Psychology, University of New South Wales, Sydney, NSW, Australia
| | | | - Hannah Furby
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Medicine, Cardiff University, Cardiff, UK.,School of Biosciences, Cardiff University, Cardiff, UK
| | - Lawrence S Wilkinson
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Medicine, Cardiff University, Cardiff, UK.,School of Psychology, Cardiff University, Cardiff, UK
| | - Timothy Wells
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Anthony R Isles
- Behavioural Genetics Group, MRC Centre for Neuropsychiatric Genetics and Genomics, Neuroscience and Mental Health Research Institute, Cardiff University, Hadyn Ellis Building, Cardiff, CF24 4HQ, UK.,School of Medicine, Cardiff University, Cardiff, UK
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10
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Cleaton MA, Edwards CA, Ferguson-Smith AC. Phenotypic Outcomes of Imprinted Gene Models in Mice: Elucidation of Pre- and Postnatal Functions of Imprinted Genes. Annu Rev Genomics Hum Genet 2014; 15:93-126. [DOI: 10.1146/annurev-genom-091212-153441] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Carol A. Edwards
- Department of Genetics, University of Cambridge, Cambridge CB2 3EG, United Kingdom;
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11
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Harrington RA, Weinstein DA, Miller JL. Hypoglycemia in Prader-Willi syndrome. Am J Med Genet A 2014; 164A:1127-9. [PMID: 24458695 DOI: 10.1002/ajmg.a.36405] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 11/27/2013] [Indexed: 11/06/2022]
Abstract
Although mouse models of Prader-Willi syndrome (PWS) suggest that hypoglycemia may be part of this syndrome, review of the literature shows little evidence that it is an issue in humans with PWS. Both adrenal and growth hormone deficiency can be seen in PWS, and both of these hormone deficiencies are associated with increased risk for hypoglycemia. We reviewed medical records for patients with PWS seen at the University of Florida Prader-Willi Program. Children were 2 months to 5 years of age. We recorded the presence, degree, and persistence of hypoglycemia, age of first occurrence, genetic diagnosis, and gestational age. Repeated hypoglycemia was determined if individuals had multiple blood glucose (BG) values <50 mg/dl before 1 month old, or BG levels <50 mg/dl once and additional BG values <70 mg/dl after 1 year of age. Of 95 patient charts reviewed, 12 (12.6%) had recorded hypoglycemia. Six of 12 patients with hypoglycemia had documented BG levels <40 mg/dl. Seven had their first episode of hypoglycemia within the first day of life. Of these seven individuals, five had BG <40 mg/dl. Repeated hypoglycemia was noted in 10 patients (83% of all patients with hypoglycemia). Only two with hypoglycemia had documented adrenal insufficiency. Our study suggests that infants with PWS may be predisposed to hypoglycemia from birth. Additional investigation is necessary to confirm our findings and define the cause of hypoglycemia. If the presence of hypoglycemia is confirmed, early detection and treatment may result in improved neurocognitive outcomes.
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Affiliation(s)
- Rena A Harrington
- Pediatric Endocrinology, University of Florida, Gainesville, Florida
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12
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Nallar SC, Kalvakolanu DV. Regulation of snoRNAs in cancer: close encounters with interferon. J Interferon Cytokine Res 2013; 33:189-98. [PMID: 23570385 DOI: 10.1089/jir.2012.0106] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The interferon (IFN) family of cytokines regulates many cellular processes, such as transcription, translation, post-translational modifications, and protein degradation. IFNs induce growth inhibition and/or cell death, depending on the cell type, by employing different proteins. This review describes a novel growth-suppressive pathway employed by IFNs that affects rRNA levels. Maturation of rRNA involves numerous noncoding small regulatory RNA-guided processes. These regulatory RNAs, called small nucleolar RNA (snoRNAs), function as a ribonucleoprotein particle (RNP) in the nucleolus. The biogenesis of snoRNPs is dependent on core protein and assembly factors. Our laboratory recently isolated a growth-suppressive protein gene associated with retinoid-IFN-induced mortality (GRIM)-1 using a genetic screen. IFN-inducible GRIM-1 (SHQ1) is an assembly factor that controls one arm of the snoRNP machinery. GRIM-1 inhibits sno/scaRNP formation to induce growth suppression via reduction in mature rRNA levels. Loss of GRIM-1 observed in certain cancers implicates it to be a novel tumor suppressor. Certain snoRNAs have been reported to act as either oncogenes or tumor suppressors in vitro. Recent studies have shown that certain sno/scaRNAs are further processed into micro RNA-like molecules to control translation of protein-coding RNAs. We present a model as to how these small regulatory RNAs influence cell growth and a potential role for GRIM-1 in this process.
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Affiliation(s)
- Shreeram C Nallar
- Department of Microbiology & Immunology, Greenebaum Cancer Center, University of Maryland School of Medicine , Baltimore, MD 21201, USA
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13
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Lost miRNA surveillance of Notch, IGFR pathway—road to sarcomagenesis. Tumour Biol 2013; 35:483-92. [DOI: 10.1007/s13277-013-1068-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 07/29/2013] [Indexed: 12/16/2022] Open
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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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Bervini S, Herzog H. Mouse models of Prader-Willi Syndrome: a systematic review. Front Neuroendocrinol 2013; 34:107-19. [PMID: 23391702 DOI: 10.1016/j.yfrne.2013.01.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 01/21/2013] [Accepted: 01/23/2013] [Indexed: 11/28/2022]
Abstract
Prader-Willi Syndrome (PWS) is a neurodevelopmental genetic disorder caused by loss of expression of imprinted, paternally inherited genes on chromosome 15q11q13. This imprinted gene cluster has its homologous region on mouse chromosome 7C. The extremely well conserved synteny between the human and the murine regions gave origin to the generation of mouse models for PWS, which facilitated investigations of the role and function of single genes or gene clusters in the pathogenesis of this disease. In this review we will describe which mouse models have been generated so far and how they were developed; we will focus on the consequences of single genes' (or gene clusters') loss of expression on the phenotype, highlighting the similarities to the human PWS features. PWS mouse models have brought major improvements in our knowledge about this complex condition, although the mechanisms implicated in its pathogenesis still remain not fully understood.
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Affiliation(s)
- Sandrina Bervini
- Neuroscience Research Program, The Garvan Institute of Medical Research, 384 Victoria Street, Sydney-Darlinghurst, NSW 2010, Australia
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Bowerman M, Swoboda KJ, Michalski JP, Wang GS, Reeks C, Beauvais A, Murphy K, Woulfe J, Screaton RA, Scott FW, Kothary R. Glucose metabolism and pancreatic defects in spinal muscular atrophy. Ann Neurol 2012; 72:256-68. [PMID: 22926856 DOI: 10.1002/ana.23582] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Spinal muscular atrophy (SMA) is the number 1 genetic killer of young children. It is caused by mutation or deletion of the survival motor neuron 1 (SMN1) gene. Although SMA is primarily a motor neuron disease, metabolism abnormalities such as metabolic acidosis, abnormal fatty acid metabolism, hyperlipidemia, and hyperglycemia have been reported in SMA patients. We thus initiated an in-depth analysis of glucose metabolism in SMA. METHODS Glucose metabolism and pancreas development were investigated in the Smn(2B/-) intermediate SMA mouse model and type I SMA patients. RESULTS Here, we demonstrate in an SMA mouse model a dramatic cell fate imbalance within pancreatic islets, with a predominance of glucagon-producing α cells at the expense of insulin-producing β cells. These SMA mice display fasting hyperglycemia, hyperglucagonemia, and glucose resistance. We demonstrate similar abnormalities in pancreatic islets from deceased children with the severe infantile form of SMA in association with supportive evidence of glucose intolerance in at least a subset of such children. INTERPRETATION Our results indicate that defects in glucose metabolism may play an important contributory role in SMA pathogenesis.
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Tugwood JD, Kelsall J, Coverley LC, Westwood FR, Haque K, Huby RDJ. Fibrodysplasia Induced in Dog Skin by a Matrix Metalloproteinase (MMP) Inhibitor—A Mechanistic Analysis. Toxicol Sci 2012; 127:236-45. [DOI: 10.1093/toxsci/kfs075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Abstract
OBJECTIVE Prader-Willi syndrome (PWS) is a genetic neurodevelopmental disorder with several nutritional phases during childhood proceeding from poor feeding, through normal eating without and with obesity, to hyperphagia and life-threatening obesity, with variable ages of onset. We investigated whether differences in appetite hormones may explain the development of abnormal eating behaviour in young children with PWS. SUBJECTS In this cross-sectional study, children with PWS (n=42) and controls (n=9) aged 7 months-5 years were recruited. Mothers were interviewed regarding eating behaviour, and body mass index (BMI) was calculated. Fasting plasma samples were assayed for insulin, leptin, glucose, peptide YY (PYY), ghrelin and pancreatic polypeptide (PP). RESULTS There was no significant relationship between eating behaviour in PWS subjects and the levels of any hormones or insulin resistance, independent of age. Fasting plasma leptin levels were significantly higher (mean ± s.d.: 22.6 ± 12.5 vs 1.97 ± 0.79 ng ml(-1), P=0.005), and PP levels were significantly lower (22.6 ± 12.5 vs 69.8 ± 43.8 pmol l(-1), P<0.001) in the PWS group compared with the controls, and this was independent of age, BMI, insulin resistance or IGF-1 levels. However, there was no significant difference in plasma insulin, insulin resistance or ghrelin levels between groups, though PYY declined more rapidly with age but not BMI in PWS subjects. CONCLUSION Even under the age of 5 years, PWS is associated with low levels of anorexigenic PP, as in older children and adults. Hyperghrelinaemia or hypoinsulinaemia was not seen in these young children with PWS. Change in these appetite hormones was not associated with the timing of the transition to the characteristic hyperphagic phase. However, abnormal and/or delayed development or sensitivity of the effector pathways of these appetitive hormones (for example, parasympathetic and central nervous system) may interact with low PP levels, and later hyperghrelinaemia or hypoinsulinaemia, to contribute to hyperphagia in PWS.
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Maj M, Ilhan A, Neziri D, Gartner W, Berggard T, Attems J, Base W, Wagner L. Age related changes in pancreatic beta cells: A putative extra-cerebral site of Alzheimer’s pathology. World J Diabetes 2011; 2:49-53. [PMID: 21537460 PMCID: PMC3083907 DOI: 10.4239/wjd.v2.i4.49] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 03/29/2011] [Accepted: 04/05/2011] [Indexed: 02/05/2023] Open
Abstract
Frequent concomitant manifestation of type 2 diabetes mellitus (T2DM) and Alzheimer’s disease (AD) has been recently demonstrated by epidemiological studies. This might be due to functional similarities between β-cells and neurons, such as secretion on demand of highly specific molecules in a tightly controlled fashion. An additional similarity represents the age-related alteration of hyperphosphorylated tau in AD patients. Similarly, alterations have been identified in β-cells of T2DM patients. The islet amyloid polypeptide has been associated with β-cell apoptosis. As a consequence of increasing age, the accumulation of highly modified proteins together with decreased regenerative potential might lead to increasing rates of apoptosis. Moreover, reduction of β-cell replication capabilities results in reduction of β-cell mass in mammals, simultaneously with impaired glucose tolerance. The new challenge is to learn much more about age-related protein modifications. This can lead to new treatment strategies for reducing the incidence of T2DM and AD.
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Affiliation(s)
- Magdalena Maj
- Magdalena Maj, Aysegul Ilhan, Dashurie Neziri, Wolfgang Gartner, Department of Internal Medicine III, Division of Nephrology and Dialysis, Medical University of Vienna, 1090 Vienna, Austria
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