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Song J, Choi SY. Arcuate Nucleus of the Hypothalamus: Anatomy, Physiology, and Diseases. Exp Neurobiol 2023; 32:371-386. [PMID: 38196133 PMCID: PMC10789173 DOI: 10.5607/en23040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 12/24/2023] [Accepted: 12/27/2023] [Indexed: 01/11/2024] Open
Abstract
The hypothalamus is part of the diencephalon and has several nuclei, one of which is the arcuate nucleus. The arcuate nucleus of hypothalamus (ARH) consists of neuroendocrine neurons and centrally-projecting neurons. The ARH is the center where the homeostasis of nutrition/metabolism and reproduction are maintained. As such, dysfunction of the ARH can lead to disorders of nutrition/metabolism and reproduction. Here, we review various types of neurons in the ARH and several genetic disorders caused by mutations in the ARH.
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Affiliation(s)
- Juhyun Song
- Department of Anatomy, Chonnam National University Medical School, Hwasun 58128, Korea
| | - Seok-Yong Choi
- Department of Biomedical Sciences, Chonnam National University Medical School, Hwasun 58128, Korea
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2
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Abstract
Obesity is a common complex trait that elevates the risk for various diseases, including type 2 diabetes and cardiovascular disease. A combination of environmental and genetic factors influences the pathogenesis of obesity. Advances in genomic technologies have driven the identification of multiple genetic loci associated with this disease, ranging from studying severe onset cases to investigating common multifactorial polygenic forms. Additionally, findings from epigenetic analyses of modifications to the genome that do not involve changes to the underlying DNA sequence have emerged as key signatures in the development of obesity. Such modifications can mediate the effects of environmental factors, including diet and lifestyle, on gene expression and clinical presentation. This review outlines what is known about the genetic and epigenetic contributors to obesity susceptibility, along with the albeit limited therapeutic options currently available. Furthermore, we delineate the potential mechanisms of actions through which epigenetic changes can mediate environmental influences and the related opportunities they present for future interventions in the management of obesity.
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Affiliation(s)
- Khanh Trang
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
| | - Struan F.A. Grant
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Division of Diabetes and Endocrinology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Department of Pediatrics, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 USA
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104 USA
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Abstract
Phosphoinositides (PIs) are phospholipids derived from phosphatidylinositol. PIs are regulated via reversible phosphorylation, which is directed by the opposing actions of PI kinases and phosphatases. PIs constitute a minor fraction of the total cellular lipid pool but play pleiotropic roles in multiple aspects of cell biology. Genetic mutations of PI regulatory enzymes have been identified in rare congenital developmental syndromes, including ciliopathies, and in numerous human diseases, such as cancer and metabolic and neurological disorders. Accordingly, PI regulatory enzymes have been targeted in the design of potential therapeutic interventions for human diseases. Recent advances place PIs as central regulators of membrane dynamics within functionally distinct subcellular compartments. This brief review focuses on the emerging role PIs play in regulating cell signaling within the primary cilium and in directing transfer of molecules at interorganelle membrane contact sites and identifies new roles for PIs in subcellular spaces.
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Affiliation(s)
- Elizabeth Michele Davies
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Christina Anne Mitchell
- Cancer Program, Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Victoria 3800, Australia
| | - Harald Alfred Stenmark
- Department of Molecular Cell Biology, Institute for Cancer Research. The Norwegian Radium Hospital, Montebello, N-0379 Oslo, Norway
- Centre for Cancer Cell Reprogramming, Faculty of Medicine, University of Oslo, Montebello, N-0379 Oslo, Norway
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DeMars KM, Ross MR, Starr A, McIntyre JC. Neuronal primary cilia integrate peripheral signals with metabolic drives. Front Physiol 2023; 14:1150232. [PMID: 37064917 PMCID: PMC10090425 DOI: 10.3389/fphys.2023.1150232] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 03/20/2023] [Indexed: 03/31/2023] Open
Abstract
Neuronal primary cilia have recently emerged as important contributors to the central regulation of energy homeostasis. As non-motile, microtubule-based organelles, primary cilia serve as signaling antennae for metabolic status. The impairment of ciliary structure or function can produce ciliopathies for which obesity is a hallmark phenotype and global ablation of cilia induces non-syndromic adiposity in mouse models. This organelle is not only a hub for metabolic signaling, but also for catecholamine neuromodulation that shapes neuronal circuitry in response to sensory input. The objective of this review is to highlight current research investigating the mechanisms of primary cilium-regulated metabolic drives for maintaining energy homeostasis.
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Affiliation(s)
- Kelly M. DeMars
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
| | - Madeleine R. Ross
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
- Summer Neuroscience Internship Program, University of Florida, Gainesville, FL, United States
| | - Alana Starr
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
| | - Jeremy C. McIntyre
- Department of Neuroscience, University of Florida, Gainesville, FL, United States
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Xu W, Xu M, Yin Q, Liu C, Cao Q, Deng Y, Liu S, He G. A novel homozygous TUB mutation associated with autosomal recessive retinitis pigmentosa in a consanguineous Chinese family. BMC Med Genomics 2023; 16:9. [PMID: 36650547 PMCID: PMC9847046 DOI: 10.1186/s12920-023-01430-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 01/04/2023] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Retinitis pigmentosa (RP) is the most common type of inherited retinopathy. At least 69 genes for RP have been identified. A significant proportion of RP, however, remains genetically unsolved. In this study, the genetic basis of a Chinese consanguineous family with presumed autosomal recessive retinitis pigmentosa (arRP) was investigated. METHODS Overall ophthalmic examinations, including funduscopy, decimal best-corrected visual acuity, axial length and electroretinography (ERG) were performed for the family. Genomic DNA from peripheral blood of the proband was subjected to whole exome sequencing. In silico predictions, structural modelling, and minigene assays were conducted to evaluate the pathogenicity of the variant. RESULTS A novel homozygous variant (NM_003320.4: c.1379A > G) in the TUB gene was identified as a candidate pathogenic variant in this parental consanguineous pedigree. This variant co-segregated with the disease in this pedigree and was absent in 118 ethnically matched healthy controls. It's an extremely rare variant that is neither deposited in population databases (1000 Genomes, ExAC, GnomAD, or Exome Variant Server) nor reported in the literature. Phylogenetic analysis indicated that the Asn residue at codon 460 of TUB is highly conserved across diverse species from tropicalis to humans. It was also completely conserved among the TUB, TULP1, TULP2, and TULP3 family proteins. Multiple bioinformatic algorithms predicted that this variant was deleterious. CONCLUSIONS A novel missense variant in TUB was identified, which was probably the pathogenic basis for arRP in this consanguineous family. This is the first report of a homozygous missense variant in TUB for RP.
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Affiliation(s)
- Wei Xu
- grid.477407.70000 0004 1806 9292Central Laboratory, Hunan Provincial People’s Hospital (the First Affiliated Hospital of Hunan Normal University), Changsha, 410000 China
| | - Ming Xu
- grid.464229.f0000 0004 1765 8757School of Medicine, Changsha Medical University, Changsha, 410219 China
| | - Qinqin Yin
- grid.477407.70000 0004 1806 9292Department of Ophthalmology, Hunan Provincial People’s Hospital (the First Affiliated Hospital of Hunan Normal University), Changsha, 410000 China
| | - Chuangyi Liu
- grid.477407.70000 0004 1806 9292Department of Ophthalmology, Hunan Provincial People’s Hospital (the First Affiliated Hospital of Hunan Normal University), Changsha, 410000 China
| | - Qiuxiang Cao
- grid.411427.50000 0001 0089 3695School of Life Sciences, Hunan Normal University, Changsha, 410081 China
| | - Yun Deng
- grid.411427.50000 0001 0089 3695School of Life Sciences, Hunan Normal University, Changsha, 410081 China
| | - Sulai Liu
- grid.477407.70000 0004 1806 9292Central Laboratory, Hunan Provincial People’s Hospital (the First Affiliated Hospital of Hunan Normal University), Changsha, 410000 China
| | - Guiyun He
- Department of Ophthalmology, Hunan Provincial People's Hospital (the First Affiliated Hospital of Hunan Normal University), Changsha, 410000, China.
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Ziccardi L, Niceta M, Stellacci E, Ciolfi A, Tatti M, Bruselles A, Mancini C, Barbano L, Cecchetti S, Costanzo E, Cappa M, Parravano M, Varano M, Tartaglia M, Cordeddu V. Biallelic Inactivating TUB Variants Cause Retinal Ciliopathy Impairing Biogenesis and the Structure of the Primary Cilium. Int J Mol Sci 2022; 23. [PMID: 36498982 DOI: 10.3390/ijms232314656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
Inherited retinal degeneration (IRD) represents a clinically variable and genetically heterogeneous group of disorders characterized by photoreceptor dysfunction. These diseases typically present with progressive severe vision loss and variable onset, ranging from birth to adulthood. Genomic sequencing has allowed to identify novel IRD-related genes, most of which encode proteins contributing to photoreceptor-cilia biogenesis and/or function. Despite these insights, knowledge gaps hamper a molecular diagnosis in one-third of IRD cases. By exome sequencing in a cohort of molecularly unsolved individuals with IRD, we identified a homozygous splice site variant affecting the transcript processing of TUB, encoding the first member of the Tubby family of bipartite transcription factors, in a sporadic case with retinal dystrophy. A truncating homozygous variant in this gene had previously been reported in a single family with three subjects sharing retinal dystrophy and obesity. The clinical assessment of the present patient documented a slightly increased body mass index and no changes in metabolic markers of obesity, but confirmed the occurrence of retinal detachment. In vitro studies using patient-derived fibroblasts showed the accelerated degradation of the encoded protein and aberrant cilium morphology and biogenesis. These findings definitely link impaired TUB function to retinal dystrophy and provide new data on the clinical characterization of this ultra-rare retinal ciliopathy.
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Thallmair V, Schultz L, Zhao W, Marrink SJ, Oliver D, Thallmair S. Two cooperative binding sites sensitize PI(4,5)P 2 recognition by the tubby domain. Sci Adv 2022; 8:eabp9471. [PMID: 36070381 PMCID: PMC9451155 DOI: 10.1126/sciadv.abp9471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 07/20/2022] [Indexed: 05/22/2023]
Abstract
Phosphoinositides (PIs) are lipid signaling molecules that operate by recruiting proteins to cellular membranes via PI recognition domains. The dominant PI of the plasma membrane is phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. One of only two PI(4,5)P2 recognition domains characterized in detail is the tubby domain. It is essential for targeting proteins into cilia involving reversible membrane association. However, the PI(4,5)P2 binding properties of tubby domains have remained enigmatic. Here, we used coarse-grained molecular dynamics simulations to explore PI(4,5)P2 binding by the prototypic tubby domain. The comparatively low PI(4,5)P2 affinity of the previously described canonical binding site is underpinned in a cooperative manner by a previously unknown, adjacent second binding site. Mutations in the previously unknown site impaired PI(4,5)P2-dependent plasma membrane localization in living cells and PI(4,5)P2 interaction in silico, emphasizing its importance for PI(4,5)P2 affinity. The two-ligand binding mode may serve to sharpen the membrane association-dissociation cycle of tubby-like proteins that underlies delivery of ciliary cargo.
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Affiliation(s)
- Veronika Thallmair
- Institute for Physiology and Pathophysiology, Philipps University Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
- DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps University Marburg, Marburg, Germany
| | - Lea Schultz
- Institute for Physiology and Pathophysiology, Philipps University Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
- DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps University Marburg, Marburg, Germany
| | - Wencai Zhao
- Institute for Physiology and Pathophysiology, Philipps University Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
- DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps University Marburg, Marburg, Germany
| | - Siewert J. Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, Netherlands
| | - Dominik Oliver
- Institute for Physiology and Pathophysiology, Philipps University Marburg, Deutschhausstr. 1-2, 35037 Marburg, Germany
- DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps University Marburg, Marburg, Germany
- Corresponding author. (S.T.); (D.O.)
| | - Sebastian Thallmair
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 7, 9747 AG Groningen, Netherlands
- Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, 60438 Frankfurt am Main, Germany
- Corresponding author. (S.T.); (D.O.)
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Wong A, Zhou A, Cao X, Mahaganapathy V, Azaro M, Gwin C, Wilson S, Buyske S, Bartlett CW, Flax JF, Brzustowicz LM, Xing J. MicroRNA and MicroRNA-Target Variants Associated with Autism Spectrum Disorder and Related Disorders. Genes (Basel) 2022; 13:genes13081329. [PMID: 35893067 PMCID: PMC9329941 DOI: 10.3390/genes13081329] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 07/19/2022] [Accepted: 07/22/2022] [Indexed: 12/13/2022] Open
Abstract
Autism spectrum disorder (ASD) is a childhood neurodevelopmental disorder with a complex and heterogeneous genetic etiology. MicroRNA (miRNA), a class of small non-coding RNAs, could regulate ASD risk genes post-transcriptionally and affect broad molecular pathways related to ASD and associated disorders. Using whole-genome sequencing, we analyzed 272 samples in 73 families in the New Jersey Language and Autism Genetics Study (NJLAGS) cohort. Families with at least one ASD patient were recruited and were further assessed for language impairment, reading impairment, and other associated phenotypes. A total of 5104 miRNA variants and 1,181,148 3′ untranslated region (3′ UTR) variants were identified in the dataset. After applying several filtering criteria, including population allele frequency, brain expression, miRNA functional regions, and inheritance patterns, we identified high-confidence variants in five brain-expressed miRNAs (targeting 326 genes) and 3′ UTR miRNA target regions of 152 genes. Some genes, such as SCP2 and UCGC, were identified in multiple families. Using Gene Ontology overrepresentation analysis and protein–protein interaction network analysis, we identified clusters of genes and pathways that are important for neurodevelopment. The miRNAs and miRNA target genes identified in this study are potentially involved in neurodevelopmental disorders and should be considered for further functional studies.
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Affiliation(s)
- Anthony Wong
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Anbo Zhou
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Xiaolong Cao
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Vaidhyanathan Mahaganapathy
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Marco Azaro
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Christine Gwin
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Sherri Wilson
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Steven Buyske
- Department of Statistics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA;
| | - Christopher W. Bartlett
- The Steve & Cindy Rasmussen Institute for Genomic Medicine, Battelle Center for Computational Biology, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43215, USA;
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Judy F. Flax
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Linda M. Brzustowicz
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
- Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Jinchuan Xing
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
- Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
- Correspondence:
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Rodríguez-López R, Gimeno-Ferrer F, do Santos DA, Ferrer-Bolufer I, Luján CG, Alcalá OZ, García-Banacloy A, Cogollos VB, Juan CS. Reviewed and updated Algorithm for Genetic Characterization of Syndromic Obesity Phenotypes. Curr Genomics 2022; 23:147-162. [PMID: 36777005 PMCID: PMC9878830 DOI: 10.2174/1389202923666220426093436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/30/2021] [Accepted: 02/01/2022] [Indexed: 11/22/2022] Open
Abstract
Background: Individuals with a phenotype of early-onset severe obesity associated with intellectual disability can have molecular diagnoses ranging from monogenic to complex genetic traits. Severe overweight is the major sign of a syndromic physical appearance and predicting the influence of a single gene and/or polygenic risk profile is extremely complicated among the majority of the cases. At present, considering rare monogenic bases as the principal etiology for the majority of obesity cases associated with intellectual disability is scientifically poor. The diversity of the molecular bases responsible for the two entities makes the appliance of the current routinely powerful genomics diagnostic tools essential. Objective: Clinical investigation of these difficult-to-diagnose patients requires pediatricians and neurologists to use optimized descriptions of signs and symptoms to improve genotype correlations. Methods: The use of modern integrated bioinformatics strategies which are conducted by experienced multidisciplinary clinical teams. Evaluation of the phenotype of the patient's family is also of importance. Results: The next step involves discarding the monogenic canonical obesity syndromes and considering infrequent unique molecular cases, and/or then polygenic bases. Adequate management of the application of the new technique and its diagnostic phases is essential for achieving good cost/efficiency balances. Conclusion: With the current clinical management, it is necessary to consider the potential coincidence of risk mutations for obesity in patients with genetic alterations that induce intellectual disability. In this review, we describe an updated algorithm for the molecular characterization and diagnosis of patients with a syndromic obesity phenotype.
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Affiliation(s)
- Raquel Rodríguez-López
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain;,Address correspondence to this author at the Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Avenida de las Tres Cruces no. 2 46014, Valencia, Spain; Tel: 0034 963 131 800 – 437317; Fax: 0034 963 131 979; E-mail:
| | - Fátima Gimeno-Ferrer
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - David Albuquerque do Santos
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - Irene Ferrer-Bolufer
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - Carola Guzmán Luján
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - Otilia Zomeño Alcalá
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - Amor García-Banacloy
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | | | - Carlos Sánchez Juan
- Endocrinology Service, General Hospital Consortium of Valencia, Valencia, Spain
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Abstract
A primary cilium, a hair-like protrusion of the plasma membrane, is a pivotal organelle for sensing external environmental signals and transducing intracellular signaling. An interesting linkage between cilia and obesity has been revealed by studies of the human genetic ciliopathies Bardet-Biedl syndrome and Alström syndrome, in which obesity is a principal manifestation. Mouse models of cell type-specific cilia dysgenesis have subsequently demonstrated that ciliary defects restricted to specific hypothalamic neurons are sufficient to induce obesity and hyperphagia. A potential mechanism underlying hypothalamic neuron cilia-related obesity is impaired ciliary localization of G protein-coupled receptors involved in the regulation of appetite and energy metabolism. A well-studied example of this is melanocortin 4 receptor (MC4R), mutations in which are the most common cause of human monogenic obesity. In the paraventricular hypothalamus neurons, a blockade of ciliary trafficking of MC4R as well as its downstream ciliary signaling leads to hyperphagia and weight gain. Another potential mechanism is reduced leptin signaling in hypothalamic neurons with defective cilia. Leptin receptors traffic to the periciliary area upon leptin stimulation. Moreover, defects in cilia formation hamper leptin signaling and actions in both developing and differentiated hypothalamic neurons. The list of obesity-linked ciliary proteins is expending and this supports a tight association between cilia and obesity. This article provides a brief review on the mechanism of how ciliary defects in hypothalamic neurons facilitate obesity.
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Affiliation(s)
- Chan Hee Lee
- Department of Biomedical Science, Hallym University, Chuncheon 24252, Korea
| | - Gil Myoung Kang
- Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul 05505, Korea
| | - Min-Seon Kim
- Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, Korea
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Xu HR, Liu Y, Yu TF, Hou ZH, Zheng JC, Chen J, Zhou YB, Chen M, Fu JD, Ma YZ, Wei WL, Xu ZS. Comprehensive Profiling of Tubby-Like Proteins in Soybean and Roles of the GmTLP8 Gene in Abiotic Stress Responses. Front Plant Sci 2022; 13:844545. [PMID: 35548296 PMCID: PMC9083326 DOI: 10.3389/fpls.2022.844545] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/15/2022] [Indexed: 05/24/2023]
Abstract
Tubby-like proteins (TLPs) are transcription factors that are widely present in eukaryotes and generally participate in growth and developmental processes. Using genome databases, a total of 22 putative TLP genes were identified in the soybean genome, and unevenly distributed across 13 chromosomes. Phylogenetic analysis demonstrated that the predicted GmTLP proteins were divided into five groups (I-V). Gene structure, protein motifs, and conserved domains were analyzed to identify differences and common features among the GmTLPs. A three-dimensional protein model was built to show the typical structure of TLPs. Analysis of publicly available gene expression data showed that GmTLP genes were differentially expressed in response to abiotic stresses. Based on those data, GmTLP8 was selected to further explore the role of TLPs in soybean drought and salt stress responses. GmTLP8 overexpressors had improved tolerance to drought and salt stresses, whereas the opposite was true of GmTLP8-RNAi lines. 3,3-diaminobenzidine and nitro blue tetrazolium staining and physiological indexes also showed that overexpression of GmTLP8 enhanced the tolerance of soybean to drought and salt stresses; in addition, downstream stress-responsive genes were upregulated in response to drought and salt stresses. This study provides new insights into the function of GmTLPs in response to abiotic stresses.
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Affiliation(s)
- Hong-Ru Xu
- College of Agriculture, Yangtze University/Hubei Collaborative Innovation Center for Grain Industry/Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education, Jingzhou, China
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
| | - Ying Liu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
| | - Tai-Fei Yu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
| | - Ze-Hao Hou
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
| | - Jia-Cheng Zheng
- College of Agronomy, Anhui Science and Technology University, Fengyang, China
| | - Jun Chen
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
| | - Yong-Bin Zhou
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
| | - Ming Chen
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
| | - Jin-Dong Fu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
| | - You-Zhi Ma
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
| | - Wen-Liang Wei
- College of Agriculture, Yangtze University/Hubei Collaborative Innovation Center for Grain Industry/Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education, Jingzhou, China
| | - Zhao-Shi Xu
- Institute of Crop Science, Chinese Academy of Agricultural Sciences (CAAS)/National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Beijing, China
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12
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Sakaguchi N, Suyama M. Pervasive occurrence of splice-site-creating mutations and their possible involvement in genetic disorders. NPJ Genom Med 2022; 7:22. [PMID: 35304488 DOI: 10.1038/s41525-022-00294-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 02/15/2022] [Indexed: 01/06/2023] Open
Abstract
The search for causative mutations in human genetic disorders has mainly focused on mutations that disrupt coding regions or splice sites. Recently, however, it has been reported that mutations creating splice sites can also cause a range of genetic disorders. In this study, we identified 5656 candidate splice-site-creating mutations (SCMs), of which 3942 are likely to be pathogenic, in 4054 genes responsible for genetic disorders. Reanalysis of exome data obtained from ciliopathy patients led us to identify 38 SCMs as candidate causative mutations. We estimate that, by focusing on SCMs, the increase in diagnosis rate is approximately 5.9–8.5% compared to the number of already known pathogenic variants. This finding suggests that SCMs are mutations worth focusing on in the search for causative mutations of genetic disorders.
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13
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Chadha A, Paniagua AE, Williams DS. Comparison of Ciliary Targeting of Two Rhodopsin-Like GPCRs: Role of C-Terminal Localization Sequences in Relation to Cilium Type. J Neurosci 2021; 41:7514-31. [PMID: 34301828 DOI: 10.1523/JNEUROSCI.0357-21.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 05/20/2021] [Accepted: 06/16/2021] [Indexed: 11/21/2022] Open
Abstract
Primary cilia exhibit a distinct complement of proteins, including G-protein-coupled receptors (GPCRs) that mediate sensory and developmental signals. The localization of GPCRs to the ciliary membrane involves ciliary localization sequences (CLSs), but it is not known how CLSs might relate to cilium type. Here, we studied the localization of two rhodopsin (RHO)-like GPCRs, somatostatin receptor (SSTR3) and RHO, in three types of cilia, from inner medullary collecting duct (IMCD3) cells, hTERT-RPE1 cells (possessing pocket cilia), and rod photoreceptors (whose cilia grow into elaborate phototransductive outer segments). SSTR3 was localized specifically to all three types of cilia, whereas RHO showed more selectivity for the photoreceptor cilium. Focusing on C-terminal CLSs, we characterized a novel CLS in the SSTR3 C terminus, which was required for the robust ciliary localization of SSTR3. Replacing the C terminus of RHO with this SSTR3 CLS-enhanced ciliary localization, compared with full-length RHO in IMCD3 and hTERT-RPE1 cells. Addition of the SSTR3 CLS to the single transmembrane protein CD8A enabled ciliary localization. In hTERT-RPE1 cells, a partial SSTR3 CLS added to CD8A effected specific localization to the periciliary (pocket) membrane, demonstrating C-terminal localization sequence targeting to this domain. Using retinas from mice, including both sexes, we show that deletion of the C terminus of RHO reduced the rod outer segment localization and that addition of the SSTR3 C-terminal CLS to the truncated RHO partly rescued this mislocalization. Overall, the study details elements of the different C termini of SSTR3 and RHO that are major effectors in determining specificity of cilium (or pericilium) localization among different types of cilia.SIGNIFICANCE STATEMENT The localization of G-protein-coupled receptors to primary cilia is key to many types of signal transduction. After characterizing a novel C-terminal CLS in SSTR3, we investigated how SSTR3 and RHO localization to the cilium relates to C-terminal CLSs and to cilium type. We found that the SSTR3 C-terminal CLS was effective in three different types of cilia, but the RHO C terminus showed a clear localization preference for the highly elaborate photoreceptor cilium. When added to CD8A, part of the SSTR3 CLS promoted specific periciliary membrane localization in hTERT-RPE1 cells, demonstrating an effective CLS for this domain. Thus, we demonstrate that elements of the C termini of SSTR3 and RHO determine different localization patterns among different types of cilia.
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14
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Powell DR, Revelli JP, Doree DD, DaCosta CM, Desai U, Shadoan MK, Rodriguez L, Mullens M, Yang QM, Ding ZM, Kirkpatrick LL, Vogel P, Zambrowicz B, Sands AT, Platt KA, Hansen GM, Brommage R. High-Throughput Screening of Mouse Gene Knockouts Identifies Established and Novel High Body Fat Phenotypes. Diabetes Metab Syndr Obes 2021; 14:3753-3785. [PMID: 34483672 PMCID: PMC8409770 DOI: 10.2147/dmso.s322083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/04/2021] [Indexed: 01/05/2023] Open
Abstract
PURPOSE Obesity is a major public health problem. Understanding which genes contribute to obesity may better predict individual risk and allow development of new therapies. Because obesity of a mouse gene knockout (KO) line predicts an association of the orthologous human gene with obesity, we reviewed data from the Lexicon Genome5000TM high throughput phenotypic screen (HTS) of mouse gene KOs to identify KO lines with high body fat. MATERIALS AND METHODS KO lines were generated using homologous recombination or gene trapping technologies. HTS body composition analyses were performed on adult wild-type and homozygous KO littermate mice from 3758 druggable mouse genes having a human ortholog. Body composition was measured by either DXA or QMR on chow-fed cohorts from all 3758 KO lines and was measured by QMR on independent high fat diet-fed cohorts from 2488 of these KO lines. Where possible, comparisons were made to HTS data from the International Mouse Phenotyping Consortium (IMPC). RESULTS Body fat data are presented for 75 KO lines. Of 46 KO lines where independent external published and/or IMPC KO lines are reported as obese, 43 had increased body fat. For the remaining 29 novel high body fat KO lines, Ksr2 and G2e3 are supported by data from additional independent KO cohorts, 6 (Asnsd1, Srpk2, Dpp8, Cxxc4, Tenm3 and Kiss1) are supported by data from additional internal cohorts, and the remaining 21 including Tle4, Ak5, Ntm, Tusc3, Ankk1, Mfap3l, Prok2 and Prokr2 were studied with HTS cohorts only. CONCLUSION These data support the finding of high body fat in 43 independent external published and/or IMPC KO lines. A novel obese phenotype was identified in 29 additional KO lines, with 27 still lacking the external confirmation now provided for Ksr2 and G2e3 KO mice. Undoubtedly, many mammalian obesity genes remain to be identified and characterized.
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Affiliation(s)
- David R Powell
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Jean-Pierre Revelli
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Deon D Doree
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Christopher M DaCosta
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Urvi Desai
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Melanie K Shadoan
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Lawrence Rodriguez
- Department of Information Technology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Michael Mullens
- Department of Information Technology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Qi M Yang
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Zhi-Ming Ding
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Laura L Kirkpatrick
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Peter Vogel
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Brian Zambrowicz
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
- Department of Information Technology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Arthur T Sands
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
- Department of Information Technology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Kenneth A Platt
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Gwenn M Hansen
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Robert Brommage
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
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15
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Chalmers J, Tung YCL, Liu CH, O'Kane CJ, O'Rahilly S, Yeo GSH. A multicomponent screen for feeding behaviour and nutritional status in Drosophila to interrogate mammalian appetite-related genes. Mol Metab 2021; 43:101127. [PMID: 33242659 PMCID: PMC7753202 DOI: 10.1016/j.molmet.2020.101127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVE More than 300 genetic variants have been robustly associated with measures of human adiposity. Highly penetrant mutations causing human obesity do so largely by disrupting satiety pathways in the brain and increasing food intake. Most of the common obesity-predisposing variants are in, or near, genes expressed highly in the brain, but little is known of their function. Exploring the biology of these genes at scale in mammalian systems is challenging. We sought to establish and validate the use of a multicomponent screen for feeding behaviour phenotypes, taking advantage of the tractable model organism Drosophila melanogaster. METHODS We validated a screen for feeding behaviour in Drosophila by comparing results after disrupting the expression of centrally expressed genes that influence energy balance in flies to those of 10 control genes. We then used this screen to explore the effects of disrupted expression of genes either a) implicated in energy homeostasis through human genome-wide association studies (GWAS) or b) expressed and nutritionally responsive in specific populations of hypothalamic neurons with a known role in feeding/fasting. RESULTS Using data from the validation study to classify responses, we studied 53 Drosophila orthologues of genes implicated by human GWAS in body mass index and found that 15 significantly influenced feeding behaviour or energy homeostasis in the Drosophila screen. We then studied 50 Drosophila homologues of 47 murine genes reciprocally nutritionally regulated in POMC and agouti-related peptide neurons. Seven of these 50 genes were found by our screen to influence feeding behaviour in flies. CONCLUSION We demonstrated the utility of Drosophila as a tractable model organism in a high-throughput genetic screen for food intake phenotypes. This simple, cost-efficient strategy is ideal for high-throughput interrogation of genes implicated in feeding behaviour and obesity in mammals and will facilitate the process of reaching a functional understanding of obesity pathogenesis.
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Affiliation(s)
- J Chalmers
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | - Y C L Tung
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | - C H Liu
- Department of Physiology, Development and Neuroscience, Cambridge University, Downing St, Cambridge, CB2 3EG, UK.
| | - C J O'Kane
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, UK.
| | - S O'Rahilly
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | - G S H Yeo
- Medical Research Council (MRC) Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
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Remez L, Cohen B, Nevet MJ, Rizel L, Ben-Yosef T. TULP1 and TUB Are Required for Specific Localization of PRCD to Photoreceptor Outer Segments. Int J Mol Sci 2020; 21:E8677. [PMID: 33213002 DOI: 10.3390/ijms21228677] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/11/2020] [Accepted: 11/16/2020] [Indexed: 11/28/2022] Open
Abstract
Photoreceptor disc component (PRCD) is a small protein which is exclusively localized to photoreceptor outer segments, and is involved in the formation of photoreceptor outer segment discs. Mutations in PRCD are associated with retinal degeneration in humans, mice, and dogs. The purpose of this work was to identify PRCD-binding proteins in the retina. PRCD protein-protein interactions were identified when implementing the Ras recruitment system (RRS), a cytoplasmic-based yeast two-hybrid system, on a bovine retina cDNA library. An interaction between PRCD and tubby-like protein 1 (TULP1) was identified. Co-immunoprecipitation in transfected mammalian cells confirmed that PRCD interacts with TULP1, as well as with its homolog, TUB. These interactions were mediated by TULP1 and TUB highly conserved C-terminal tubby domain. PRCD localization was altered in the retinas of TULP1- and TUB-deficient mice. These results show that TULP1 and TUB, which are involved in the vesicular trafficking of several photoreceptor proteins from the inner segment to the outer segment, are also required for PRCD exclusive localization to photoreceptor outer segment discs.
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17
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Yang XR, Benson MD, MacDonald IM, Innes AM. A diagnostic approach to syndromic retinal dystrophies with intellectual disability. Am J Med Genet C Semin Med Genet 2020; 184:538-570. [PMID: 32918368 DOI: 10.1002/ajmg.c.31834] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/30/2020] [Accepted: 08/05/2020] [Indexed: 12/20/2022]
Abstract
Inherited retinal dystrophies are a group of monogenic disorders that, as a whole, contribute significantly to the burden of ocular disease in both pediatric and adult patients. In their syndromic forms, retinal dystrophies can be observed in association with intellectual disability, frequently alongside other systemic manifestations. There are now over 80 genes implicated in syndromic retinal dystrophies with intellectual disability. Identifying and accurately characterizing these disorders allows the clinician to narrow the differential diagnosis, evaluate for relevant associated features, arrive at a timely and accurate diagnosis, and address both sight-threatening ocular manifestations and morbidity-causing systemic manifestations. The co-occurrence of retinal dystrophy and intellectual disability in an individual can be challenging to investigate, diagnose, and counsel given the considerable phenotypic and genotypic heterogeneity that exists within this broad group of disorders. We performed a review of the current literature and propose an algorithm to facilitate the evaluation, and clinical and mechanistic classification, of these individuals.
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Affiliation(s)
- Xiao-Ru Yang
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Matthew D Benson
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada
| | - Ian M MacDonald
- Department of Ophthalmology, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Genetics, University of Alberta, Edmonton, Alberta, Canada
| | - A Micheil Innes
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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18
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Abstract
Phosphatidylinositol and its phosphorylated derivatives, the phosphoinositides, play many important roles in all eukaryotic cells. These include modulation of physical properties of membranes, activation or inhibition of membrane-associated proteins, recruitment of peripheral membrane proteins that act as effectors, and control of membrane trafficking. They also serve as precursors for important second messengers, inositol (1,4,5) trisphosphate and diacylglycerol. Animal models and human diseases involving defects in phosphoinositide regulatory pathways have revealed their importance for function in the mammalian retina and retinal pigmented epithelium. New technologies for localizing, measuring and genetically manipulating them are revealing new information about their importance for the function and health of the vertebrate retina.
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19
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Godisela KK, Reddy SS, Reddy PY, Kumar CU, Reddy VS, Ayyagari R, Reddy GB. Role of sorbitol-mediated cellular stress response in obesity-associated retinal degeneration. Arch Biochem Biophys 2020; 679:108207. [PMID: 31760123 DOI: 10.1016/j.abb.2019.108207] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 11/16/2019] [Accepted: 11/20/2019] [Indexed: 02/07/2023]
Abstract
PURPOSE Obesity is a global health problem associated with several diseases including ocular complications. Earlier we reported progressive retinal degeneration because of obesity in a spontaneous obese rat (WNIN/Ob) model. In the current study, we examined the molecular mechanisms leading to retinal degeneration in WNIN/Ob rat. METHODS Sorbitol was estimated by the fluorometric method in the retina of WNIN/Ob rats at different age (3-, 6- and 12- months), along with their respective lean rats. Immunoblotting was performed in the retina to assess the status of the insulin signaling pathway, ER stress and cellular stress (p38MAPK and ERK1/2). Human SK-N-SH cells were treated with 0.5 and 1.0 M sorbitol for 30 min to study insulin signaling, ER stress, and cellular stress. TUNEL assay was done to measure apoptosis. The retinal function in the rats was determined by electroretinogram. RESULTS A gradual but significantly higher intracellular sorbitol accumulation was observed in the retina of obese rats from 3- to 12-months. The cellular osmotic stress has activated the insulin signaling mechanism without activating AKT and also triggered ER stress. Both the stresses activated the ERK and p38MAPK signaling causing apoptosis in the retina leading to retinal degeneration. Retinal dysfunction was confirmed by altered scotopic and photopic electroretinogram responses. These in vivo results were mimicked in SK-N-SH cells when exposed to sorbitol in vitro. CONCLUSIONS These results suggest cellular stress due to sorbitol accumulation impairing the ER function, thereby leading to progressive retinal degeneration under obese conditions.
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Affiliation(s)
- Kishore K Godisela
- Biochemistry Division, National Institute of Nutrition, Hyderabad, India
| | | | - P Yadagiri Reddy
- Biochemistry Division, National Institute of Nutrition, Hyderabad, India
| | - Ch Uday Kumar
- Biochemistry Division, National Institute of Nutrition, Hyderabad, India
| | - V Sudhakar Reddy
- Biochemistry Division, National Institute of Nutrition, Hyderabad, India
| | - Radha Ayyagari
- Shiley Eye Institute, University of California San Diego, La Jolla, CA, USA
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20
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Powell DR, Doree DD, DaCosta CM, Platt KA, Hansen GM, van Sligtenhorst I, Ding ZM, Revelli JP, Brommage R. Obesity of G2e3 Knockout Mice Suggests That Obesity-Associated Variants Near Human G2E3 Decrease G2E3 Activity. Diabetes Metab Syndr Obes 2020; 13:2641-2652. [PMID: 32801815 PMCID: PMC7394505 DOI: 10.2147/dmso.s259546] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/02/2020] [Indexed: 12/12/2022] Open
Abstract
PURPOSE In humans, single nucleotide polymorphisms (SNPs) near the adjacent protein kinase D1 (PRKD1) and G2/M-phase-specific E3 ubiquitin protein ligase (G2E3) genes on chromosome 14 are associated with obesity. To date, no published evidence links inactivation of either gene to changes in body fat. These two genes are also adjacent on mouse chromosome 12. Because obesity genes are highly conserved between humans and mice, we analyzed body fat in adult G2e3 and Prkd1 knockout (KO) mice to determine whether inactivating either gene leads to obesity in mice and, by inference, probably in humans. METHODS The G2e3 and Prkd1 KO lines were generated by gene trapping and by homologous recombination methodologies, respectively. Body fat was measured by DEXA in adult mice fed chow from weaning and by QMR in a separate cohort of mice fed high-fat diet (HFD) from weaning. Glucose homeostasis was evaluated with oral glucose tolerance tests (OGTTs) performed on adult mice fed HFD from weaning. RESULTS Body fat was increased in multiple cohorts of G2e3 KO mice relative to their wild-type (WT) littermates. When data from all G2e3 KO (n=32) and WT (n=31) mice were compared, KO mice showed increases of 11% in body weight (P<0.01), 65% in body fat (P<0.001), 48% in % body fat (P<0.001), and an insignificant 3% decrease in lean body mass. G2e3 KO mice were also glucose intolerant during an OGTT (P<0.05). In contrast, Prkd1 KO and WT mice had comparable body fat levels and glucose tolerance. CONCLUSION Significant obesity and glucose intolerance were observed in G2e3, but not Prkd1, KO mice. The conservation of obesity genes between mice and humans strongly suggests that the obesity-associated SNPs located near the human G2E3 and PRKD1 genes are linked to variants that decrease the amount of functional human G2E3.
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Affiliation(s)
- David R Powell
- Lexicon Pharmaceuticals Inc, The Woodlands, TX, 77381, USA
- Correspondence: David R Powell Lexicon Pharmaceuticals Inc., 8800 Technology Forest Place, The Woodlands, TX77381, USATel +1 281 863 3060Fax +1 281 863 8115 Email
| | - Deon D Doree
- Lexicon Pharmaceuticals Inc, The Woodlands, TX, 77381, USA
| | | | | | - Gwenn M Hansen
- Lexicon Pharmaceuticals Inc, The Woodlands, TX, 77381, USA
| | | | - Zhi-Ming Ding
- Lexicon Pharmaceuticals Inc, The Woodlands, TX, 77381, USA
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Abstract
Obesity and excess weight are a pandemic phenomenon in the modern world. Childhood and adolescent obesity often ends up in obesity in adults. The costs of obesity and its consequences are staggering for any society, crippling for countries in development. Childhood obesity is also widespread in Macedonia. Metabolic syndrome, dyslipidemia and carbohydrate intolerance are found in significant numbers. Parents and grandparents are often obese. Some of the children are either dysmorphic, or slightly retarded. We have already described patients with Prader-Willi syndrome, Bardet-Biedl syndrome or WAGR syndrome. A genetic screening for mutations in monogenic obesity in children with early, rapid-onset or severe obesity, severe hyperphagia, hypogonadism, intestinal dysfunction, hypopigmentation of hair and skin, postprandial hypoglycaemia, diabetes insipidus, abnormal leptin level and coexistence of lean and obese siblings in the family discovers many genetic forms of obesity. There are about 30 monogenic forms of obesity. In addition, obesity is different in ethnic groups, and the types of monogenic obesity differ. In brief, an increasing number of genes and genetic mechanisms in children continue to be discovered. This sheds new light on the molecular mechanisms of obesity and potentially gives a target for new forms of treatment.
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22
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Wang L, De Solis AJ, Goffer Y, Birkenbach KE, Engle SE, Tanis R, Levenson JM, Li X, Rausch R, Purohit M, Lee JY, Tan J, De Rosa MC, Doege CA, Aaron HL, Martins GJ, Brüning JC, Egli D, Costa R, Berbari N, Leibel RL, Stratigopoulos G. Ciliary gene RPGRIP1L is required for hypothalamic arcuate neuron development. JCI Insight 2019; 4:e123337. [PMID: 30728336 PMCID: PMC6413800 DOI: 10.1172/jci.insight.123337] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 01/03/2019] [Indexed: 12/16/2022] Open
Abstract
Intronic polymorphisms in the α-ketoglutarate-dependent dioxygenase gene (FTO) that are highly associated with increased body weight have been implicated in the transcriptional control of a nearby ciliary gene, retinitis pigmentosa GTPase regulator-interacting protein-1 like (RPGRIP1L). Previous studies have shown that congenital Rpgrip1l hypomorphism in murine proopiomelanocortin (Pomc) neurons causes obesity by increasing food intake. Here, we show by congenital and adult-onset Rpgrip1l deletion in Pomc-expressing neurons that the hyperphagia and obesity are likely due to neurodevelopmental effects that are characterized by a reduction in the Pomc/Neuropeptide Y (Npy) neuronal number ratio and marked increases in arcuate hypothalamic-paraventricular hypothalamic (ARH-PVH) axonal projections. Biallelic RPGRIP1L mutations result in fewer cilia-positive human induced pluripotent stem cell-derived (iPSC-derived) neurons and blunted responses to Sonic Hedgehog (SHH). Isogenic human ARH-like embryonic stem cell-derived (ESc-derived) neurons homozygous for the obesity-risk alleles at rs8050136 or rs1421085 have decreased RPGRIP1L expression and have lower numbers of POMC neurons. RPGRIP1L overexpression increases POMC cell number. These findings suggest that apparently functional intronic polymorphisms affect hypothalamic RPGRIP1L expression and impact development of POMC neurons and their derivatives, leading to hyperphagia and increased adiposity.
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Affiliation(s)
- Liheng Wang
- Naomi Berrie Diabetes Center and Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Alain J. De Solis
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
| | - Yossef Goffer
- Naomi Berrie Diabetes Center & Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, New York, USA
| | - Kathryn E. Birkenbach
- Naomi Berrie Diabetes Center & Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, New York, USA
| | - Staci E. Engle
- Department of Biology, Indiana University-Purdue University, Indianapolis, Indiana, USA
| | - Ross Tanis
- University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Jacob M. Levenson
- University of Central Florida College of Medicine, Orlando, Florida, USA
| | - Xueting Li
- Institute of Human Nutrition graduate program, Columbia University, New York, New York, USA
| | - Richard Rausch
- Naomi Berrie Diabetes Center & Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, New York, USA
| | - Manika Purohit
- Zuckerman Institute, Columbia University, New York, New York, USA
| | - Jen-Yi Lee
- Cancer Research Laboratory Molecular Imaging Center, University of California, Berkeley, 94720, USA
| | - Jerica Tan
- Naomi Berrie Diabetes Center, Columbia Stem Cell Initiative, Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Maria Caterina De Rosa
- Naomi Berrie Diabetes Center, Columbia Stem Cell Initiative, Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Claudia A. Doege
- Naomi Berrie Diabetes Center, Columbia Stem Cell Initiative, Department of Pathology and Cell Biology, Columbia University, New York, New York, USA
| | - Holly L. Aaron
- Cancer Research Laboratory Molecular Imaging Center, University of California, Berkeley, 94720, USA
| | | | - Jens C. Brüning
- Department of Neuronal Control of Metabolism, Max Planck Institute for Metabolism Research, Cologne, Germany
- Center for Endocrinology, Diabetes and Preventive Medicine (CEDP), University Hospital Cologne, Cologne, Germany
- Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
- National Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Dieter Egli
- Naomi Berrie Diabetes Center & Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, New York, USA
| | - Rui Costa
- Zuckerman Institute, Columbia University, New York, New York, USA
| | - Nicolas Berbari
- Department of Biology, Indiana University-Purdue University, Indianapolis, Indiana, USA
| | - Rudolph L. Leibel
- Naomi Berrie Diabetes Center & Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, New York, USA
| | - George Stratigopoulos
- Naomi Berrie Diabetes Center & Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, New York, USA
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Tam V, Turcotte M, Meyre D. Established and emerging strategies to crack the genetic code of obesity. Obes Rev 2019; 20:212-240. [PMID: 30353704 DOI: 10.1111/obr.12770] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/11/2022]
Abstract
Tremendous progress has been made in the genetic elucidation of obesity over the past two decades, driven largely by technological, methodological and organizational innovations. Current strategies for identifying obesity-predisposing loci/genes, including cytogenetics, linkage analysis, homozygosity mapping, admixture mapping, candidate gene studies, genome-wide association studies, custom genotyping arrays, whole-exome sequencing and targeted exome sequencing, have achieved differing levels of success, and the identified loci in aggregate explain only a modest fraction of the estimated heritability of obesity. This review outlines the successes and limitations of these approaches and proposes novel strategies, including the use of exceptionally large sample sizes, the study of diverse ethnic groups and deep phenotypes and the application of innovative methods and study designs, to identify the remaining obesity-predisposing genes. The use of both established and emerging strategies has the potential to crack the genetic code of obesity in the not-too-distant future. The resulting knowledge is likely to yield improvements in obesity prediction, prevention and care.
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Affiliation(s)
- V Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - M Turcotte
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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Han S, Miyoshi K, Shikada S, Amano G, Wang Y, Yoshimura T, Katayama T. TULP3 is required for localization of membrane-associated proteins ARL13B and INPP5E to primary cilia. Biochem Biophys Res Commun 2019; 509:227-234. [PMID: 30583862 DOI: 10.1016/j.bbrc.2018.12.109] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 12/14/2018] [Indexed: 01/24/2023]
Abstract
The primary cilia are known as biosensors that transduce signals through the ciliary membrane proteins in vertebrate cells. The ciliary membrane contains transmembrane proteins and membrane-associated proteins. Tubby-like protein 3 (TULP3), a member of the tubby family, has been shown to interact with the intraflagellar transport-A complex (IFT-A) and to be involved in the ciliary localization of transmembrane proteins, although its role in the ciliary entry of membrane-associated proteins has remained unclear. Here, to determine whether TULP3 is required for the localization of ciliary membrane-associated proteins, we generated and analyzed TULP3-knockout (KO) hTERT RPE-1 (RPE1) cells. Immunofluorescence analysis demonstrated that ciliary formation was downregulated in TULP3-KO cells and that membrane-associated proteins, ADP-ribosylation factor-like 13B (ARL13B) and inositol polyphosphate-5-phosphatase E (INPP5E), failed to localize to primary cilia in TULP3-KO cells. These defects in the localization of ARL13B and INPP5E in TULP3-KO cells were rescued by the exogenous expression of wild-type TULP3, but not that of mutant TULP3 lacking the ability to bind IFT-A. In addition, the expression of TUB protein, another member of the tubby family whose endogenous expression is absent in RPE1 cells, also rescued the defective ciliary localization of ARL13B and INPP5E in TULP3-KO cells, suggesting that there is functional redundancy between TULP3 and TUB. Our findings indicate that TULP3 participates in ciliogenesis, and targets membrane-associated proteins to primary cilia via binding to IFT-A.
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Affiliation(s)
- Sarina Han
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Ko Miyoshi
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan.
| | - Sho Shikada
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Genki Amano
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Yinshengzhuoma Wang
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Takeshi Yoshimura
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Taiichi Katayama
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
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25
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Mizobuchi K, Katagiri S, Hayashi T, Yoshitake K, Fujinami K, Kuniyoshi K, Mishima R, Tsunoda K, Iwata T, Nakano T. Clinical findings of end-stage retinitis pigmentosa with a homozygous PDE6A variant (p.R653X). Am J Ophthalmol Case Rep 2019; 13:110-5. [PMID: 30619975 DOI: 10.1016/j.ajoc.2018.12.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 11/24/2018] [Accepted: 12/17/2018] [Indexed: 12/16/2022] Open
Abstract
Purpose To report clinical and genetic features of a Japanese patient with end-stage retinitis pigmentosa (RP) caused by a homozygous PDE6A variant. Methods We performed comprehensive ophthalmic examinations. Whole exome sequencing analysis was used to investigate the RP patient with parental consanguinity. The pedigree included 4 RP patients in the two generations, which suggests presumed pseudo-autosomal dominant inheritance. Results A PDE6A variant (p.R653X) was identified to be homozygous and disease-causing in the patient. Homozygosity mapping revealed the homozygous region including the variant and confirmation of autosomal recessive inheritance. The patient reported night blindness at 4 years of age and exhibited typical RP fundus appearance with macula involvement during the follow-up period from at the age of 52–69 years. At the age of 52, the patient exhibited a loss of visual acuity and had severely constricted visual fields, with a further gradual deterioration of her vision until she was 69 years old. At the age of 69, funduscopy showed severe chorioretinal degeneration in the area from the posterior pole to the peripheral retina. Conclusions and Importance This is the first report that the PDE6A variant (p.R653X) has been identified as one of the causes of autosomal recessive RP in the Japanese population. Longitudinal natural history/end-stage findings demonstrated early-onset and a severe RP phenotype with macula involvement when the patient was in her 50s and severe chorioretinal degenerations in her late 60s.
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Hearn T. ALMS1 and Alström syndrome: a recessive form of metabolic, neurosensory and cardiac deficits. J Mol Med (Berl) 2018; 97:1-17. [PMID: 30421101 PMCID: PMC6327082 DOI: 10.1007/s00109-018-1714-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/25/2018] [Accepted: 10/30/2018] [Indexed: 12/12/2022]
Abstract
Alström syndrome (AS) is characterised by metabolic deficits, retinal dystrophy, sensorineural hearing loss, dilated cardiomyopathy and multi-organ fibrosis. Elucidating the function of the mutated gene, ALMS1, is critical for the development of specific treatments and may uncover pathways relevant to a range of other disorders including common forms of obesity and type 2 diabetes. Interest in ALMS1 is heightened by the recent discovery of its involvement in neonatal cardiomyocyte cell cycle arrest, a process with potential relevance to regenerative medicine. ALMS1 encodes a ~ 0.5 megadalton protein that localises to the base of centrioles. Some studies have suggested a role for this protein in maintaining centriole-nucleated sensory organelles termed primary cilia, and AS is now considered to belong to the growing class of human genetic disorders linked to ciliary dysfunction (ciliopathies). However, mechanistic details are lacking, and recent studies have implicated ALMS1 in several processes including endosomal trafficking, actin organisation, maintenance of centrosome cohesion and transcription. In line with a more complex picture, multiple isoforms of the protein likely exist and non-centrosomal sites of localisation have been reported. This review outlines the evidence for both ciliary and extra-ciliary functions of ALMS1.
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Affiliation(s)
- Tom Hearn
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, UK.
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27
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Abstract
In this review, we describe the extraordinary population of Greenland, which differs from large outbred populations of Europe and Asia, both in terms of population history and living conditions. Many years in isolation, small population size and an extreme environment have shaped the genetic composition of the Greenlandic population. The unique genetic background combined with the transition from a traditional Inuit lifestyle and diet, to a more Westernized lifestyle, has led to an increase in the prevalence of metabolic conditions like obesity, where the prevalence from 1993 to 2010 has increased from 16.4% to 19.4% among men, and from 13.0% to 25.4% among women, type 2 diabetes and cardiovascular diseases. The genetic susceptibility to metabolic conditions has been explored in Greenlanders, as well as other isolated populations, taking advantage of population-genetic properties of these populations. During the last 10 years, these studies have provided examples of loci showing evidence of positive selection, due to adaption to Arctic climate and Inuit diet, including TBC1D4 and FADS/CPT1A, and have facilitated the discovery of several loci associated with metabolic phenotypes. Most recently, the c.2433-1G>A loss-of-function variant in ADCY3 associated with obesity and type 2 diabetes was described. This locus has provided novel biological insights, as it has been shown that reduced ADCY3 function causes obesity through disrupted function in primary cilia. Future studies of isolated populations will likely provide further genetic as well as biological insights.
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Affiliation(s)
- M K Andersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - T Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Qin C, Li J, Tang K. The Paraventricular Nucleus of the Hypothalamus: Development, Function, and Human Diseases. Endocrinology 2018; 159:3458-3472. [PMID: 30052854 DOI: 10.1210/en.2018-00453] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 07/16/2018] [Indexed: 02/08/2023]
Abstract
The paraventricular nucleus of the hypothalamus (PVH), located in the ventral diencephalon adjacent to the third ventricle, is a highly conserved brain region present in species from zebrafish to humans. The PVH is composed of three main types of neurons, magnocellular, parvocellular, and long-projecting neurons, which play imperative roles in the regulation of energy balance and various endocrinological activities. In this review, we focus mainly on recent findings about the early development of the hypothalamus and the PVH, the functions of the PVH in the modulation of energy homeostasis and in the hypothalamus-pituitary system, and human diseases associated with the PVH, such as obesity, short stature, hypertension, and diabetes insipidus. Thus, the investigations of the PVH will benefit not only understanding of the development of the central nervous system but also the etiology of and therapy for human diseases.
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Affiliation(s)
- Cheng Qin
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, China
| | - Jiaheng Li
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, China
| | - Ke Tang
- Institute of Life Science, Nanchang University, Nanchang, Jiangxi, China
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, Guangdong, China
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29
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Saeed S, Arslan M, Froguel P. Genetics of Obesity in Consanguineous Populations: Toward Precision Medicine and the Discovery of Novel Obesity Genes. Obesity (Silver Spring) 2018; 26:474-484. [PMID: 29464904 DOI: 10.1002/oby.22064] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 09/05/2017] [Accepted: 09/30/2017] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Consanguinity has been instrumental in the elucidation of many Mendelian genetic diseases. Here, the unique advantage of consanguineous populations was considered in the quest for genes causing obesity. METHODS PubMed was searched for articles relevant to consanguinity and obesity published between 1995 and 2016. Some earlier articles of interest were also consulted. RESULTS Although obesity is the most heritable disorder, even in outbred populations, only 2% to 5% of severe obesity cases have so far been proven to be caused by single gene mutations. In some highly consanguineous populations, a remarkably higher proportion of obesity cases because of known and novel monogenic variants has been identified (up to 30%). CONCLUSIONS Combining the power conferred by consanguinity with current large-capacity sequencing techniques should bring new genetic factors and molecular mechanisms to the fore, unveiling a large part of the yet-elusive neurohumoral circuitry involved in the regulation of energy homeostasis and appetite. Importantly, the undertaking of such initiatives is destined to unfold novel targets for the development of precision medicine relevant to different forms of obesity.
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Affiliation(s)
- Sadia Saeed
- Department of Genomics of Common Disease, Imperial College London, London, UK
- CNRS, Pasteur Institute of Lille, University of Lille, Lille, France
| | - Muhammad Arslan
- Centre for Research in Molecular Medicine, The University of Lahore, Lahore, Pakistan
- Department of Biological Sciences, Forman Christian College, Lahore, Pakistan
| | - Philippe Froguel
- Department of Genomics of Common Disease, Imperial College London, London, UK
- CNRS, Pasteur Institute of Lille, University of Lille, Lille, France
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30
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Wang M, Xu Z, Kong Y. The tubby-like proteins kingdom in animals and plants. Gene 2018; 642:16-25. [DOI: 10.1016/j.gene.2017.10.077] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 08/15/2017] [Accepted: 10/27/2017] [Indexed: 11/28/2022]
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da Fonseca ACP, Mastronardi C, Johar A, Arcos-Burgos M, Paz-Filho G. Genetics of non-syndromic childhood obesity and the use of high-throughput DNA sequencing technologies. J Diabetes Complications 2017; 31:1549-1561. [PMID: 28735903 DOI: 10.1016/j.jdiacomp.2017.04.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 04/18/2017] [Accepted: 04/19/2017] [Indexed: 12/12/2022]
Abstract
BACKGROUND Childhood obesity is a serious public health problem associated with the development of several chronic diseases, such as type 2 diabetes mellitus, dyslipidemia, and hypertension. The elevated prevalence of obesity is mostly due to inadequate diet and lifestyle, but it is also influenced by genetic factors. OBJECTIVES To review recent advances in the field of the genetics of obesity. We summarize the list of genes associated with the rare non-syndromic forms of obesity, and explain their function. Furthermore, we discuss the technologies that are available for the genetic diagnosis of obesity. RESULTS Several studies reported that single gene variants cause Mendelian forms of obesity, determined by mutations of major effect in single genes. Rare, non-syndromic forms of obesity are a result of loss-of-function mutations in genes that act on the development and function of the hypothalamus or the leptin-melanocortin pathway. These variants disrupt enzymes and receptors that play a role in energy homeostasis, resulting in severe early-onset obesity and endocrine dysfunctions. Different approaches and technologies have been used to understand the genetic background of obesity. Currently, whole genome and whole exome sequencing are important diagnostic tools to identify new genes and variants associated with severe obesity, but other approaches are also useful at individual or population levels, such as linkage analysis, candidate gene sequencing, chromosomal microarray analysis, and genome-wide association studies. CONCLUSIONS The understanding of the genetic causes of obesity and the usefulness and limitations of the genetic diagnostic approaches can contribute to the development of new personalized therapeutic targets against obesity.
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Affiliation(s)
| | - Claudio Mastronardi
- Institute of Translational Medicine, Universidad del Rosario, Bogota, Colombia
| | - Angad Johar
- Department of Genome Sciences, John Curtin School of Medical Research, The Australian National University, Australia.
| | | | - Gilberto Paz-Filho
- Department of Genome Sciences, John Curtin School of Medical Research, The Australian National University, Australia.
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32
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Nies VJM, Struik D, Wolfs MGM, Rensen SS, Szalowska E, Unmehopa UA, Fluiter K, van der Meer TP, Hajmousa G, Buurman WA, Greve JW, Rezaee F, Shiri-Sverdlov R, Vonk RJ, Swaab DF, Wolffenbuttel BHR, Jonker JW, van Vliet-Ostaptchouk JV. TUB gene expression in hypothalamus and adipose tissue and its association with obesity in humans. Int J Obes (Lond) 2017; 42:376-383. [PMID: 28852204 DOI: 10.1038/ijo.2017.214] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/21/2017] [Accepted: 07/30/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND/OBJECTIVES Mutations in the Tubby gene (TUB) cause late-onset obesity and insulin resistance in mice and syndromic obesity in humans. Although TUB gene function has not yet been fully elucidated, studies in rodents indicate that TUB is involved in the hypothalamic pathways regulating food intake and adiposity. Aside from the function in central nervous system, TUB has also been implicated in energy metabolism in adipose tissue in rodents. We aimed to determine the expression and distribution patterns of TUB in man as well as its potential association with obesity. SUBJECTS/METHODS In situ hybridization was used to localize the hypothalamic regions and cells expressing TUB mRNA. Using RT-PCR, we determined the mRNA expression level of the two TUB gene alternative splicing isoforms, the short and the long transcript variants, in the hypothalami of 12 obese and 12 normal-weight subjects, and in biopsies from visceral (VAT) and subcutaneous (SAT) adipose tissues from 53 severely obese and 24 non-obese control subjects, and correlated TUB expression with parameters of obesity and metabolic health. RESULTS Expression of both TUB transcripts was detected in the hypothalamus, whereas only the short TUB isoform was found in both VAT and SAT. TUB mRNA was detected in several hypothalamic regions involved in body weight regulation, including the nucleus basalis of Meynert and the paraventricular, supraoptic and tuberomammillary nuclei. We found no difference in the hypothalamic TUB expression between obese and control groups, whereas the level of TUB mRNA was significantly lower in adipose tissue of obese subjects as compared to controls. Also, TUB expression was negatively correlated with indices of body weight and obesity in a fat-depot-specific manner. CONCLUSIONS Our results indicate high expression of TUB in the hypothalamus, especially in areas involved in body weight regulation, and the correlation between TUB expression in adipose tissue and obesity. These findings suggest a role for TUB in human obesity.
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Affiliation(s)
- V J M Nies
- Section of Molecular Metabolism and Nutrition, Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - D Struik
- Section of Molecular Metabolism and Nutrition, Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - M G M Wolfs
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - S S Rensen
- Department of General Surgery, Maastricht University Medical Center, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands
| | - E Szalowska
- Centre for Medical Biomics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - U A Unmehopa
- Department of Endocrinology & Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - K Fluiter
- Department of Genome Analysis, Academic Medical Center, Amsterdam, The Netherlands
| | - T P van der Meer
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - G Hajmousa
- Cardiovascular Regenerative Medicine, Department Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - W A Buurman
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - J W Greve
- Department of Surgery, Zuyderland Medical Center Heerlen; Dutch Obesity Clinic South, Heerlen, The Netherlands
| | - F Rezaee
- Centre for Medical Biomics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - R Shiri-Sverdlov
- Departments of Molecular Genetics, School of Nutrition & Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - R J Vonk
- Centre for Medical Biomics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - D F Swaab
- Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - B H R Wolffenbuttel
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - J W Jonker
- Section of Molecular Metabolism and Nutrition, Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - J V van Vliet-Ostaptchouk
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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Kaur Y, de Souza RJ, Gibson WT, Meyre D. A systematic review of genetic syndromes with obesity. Obes Rev 2017; 18:603-634. [PMID: 28346723 DOI: 10.1111/obr.12531] [Citation(s) in RCA: 104] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/01/2017] [Accepted: 02/02/2017] [Indexed: 11/29/2022]
Abstract
Syndromic monogenic obesity typically follows Mendelian patterns of inheritance and involves the co-presentation of other characteristics, such as mental retardation, dysmorphic features and organ-specific abnormalities. Previous reviews on obesity have reported 20 to 30 syndromes but no systematic review has yet been conducted on syndromic obesity. We searched seven databases using terms such as 'obesity', 'syndrome' and 'gene' to conduct a systematic review of literature on syndromic obesity. Our literature search identified 13,719 references. After abstract and full-text review, 119 relevant papers were eligible, and 42 papers were identified through additional searches. Our analysis of these 161 papers found that 79 obesity syndromes have been reported in literature. Of the 79 syndromes, 19 have been fully genetically elucidated, 11 have been partially elucidated, 27 have been mapped to a chromosomal region and for the remaining 22, neither the gene(s) nor the chromosomal location(s) have yet been identified. Interestingly, 54.4% of the syndromes have not been assigned a name, whereas 13.9% have more than one name. We report on organizational inconsistencies (e.g. naming discrepancies and syndrome classification) and provide suggestions for improvements. Overall, this review illustrates the need for increased clinical and genetic research on syndromes with obesity.
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Affiliation(s)
- Y Kaur
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - R J de Souza
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada
| | - W T Gibson
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada.,British Columbia Children's Hospital Research Institute, Vancouver, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Canada
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Pigeyre M, Yazdi FT, Kaur Y, Meyre D. Recent progress in genetics, epigenetics and metagenomics unveils the pathophysiology of human obesity. Clin Sci (Lond) 2016; 130:943-86. [PMID: 27154742 DOI: 10.1042/CS20160136] [Citation(s) in RCA: 227] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 02/24/2016] [Indexed: 12/19/2022]
Abstract
In high-, middle- and low-income countries, the rising prevalence of obesity is the underlying cause of numerous health complications and increased mortality. Being a complex and heritable disorder, obesity results from the interplay between genetic susceptibility, epigenetics, metagenomics and the environment. Attempts at understanding the genetic basis of obesity have identified numerous genes associated with syndromic monogenic, non-syndromic monogenic, oligogenic and polygenic obesity. The genetics of leanness are also considered relevant as it mirrors some of obesity's aetiologies. In this report, we summarize ten genetically elucidated obesity syndromes, some of which are involved in ciliary functioning. We comprehensively review 11 monogenic obesity genes identified to date and their role in energy maintenance as part of the leptin-melanocortin pathway. With the emergence of genome-wide association studies over the last decade, 227 genetic variants involved in different biological pathways (central nervous system, food sensing and digestion, adipocyte differentiation, insulin signalling, lipid metabolism, muscle and liver biology, gut microbiota) have been associated with polygenic obesity. Advances in obligatory and facilitated epigenetic variation, and gene-environment interaction studies have partly accounted for the missing heritability of obesity and provided additional insight into its aetiology. The role of gut microbiota in obesity pathophysiology, as well as the 12 genes associated with lipodystrophies is discussed. Furthermore, in an attempt to improve future studies and merge the gap between research and clinical practice, we provide suggestions on how high-throughput '-omic' data can be integrated in order to get closer to the new age of personalized medicine.
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Styne DM, Arslanian SA, Connor EL, Farooqi IS, Murad MH, Silverstein JH, Yanovski JA. Pediatric Obesity-Assessment, Treatment, and Prevention: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab 2017; 102:709-757. [PMID: 28359099 PMCID: PMC6283429 DOI: 10.1210/jc.2016-2573] [Citation(s) in RCA: 609] [Impact Index Per Article: 87.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/10/2016] [Indexed: 02/06/2023]
Abstract
COSPONSORING ASSOCIATIONS The European Society of Endocrinology and the Pediatric Endocrine Society. This guideline was funded by the Endocrine Society. OBJECTIVE To formulate clinical practice guidelines for the assessment, treatment, and prevention of pediatric obesity. PARTICIPANTS The participants include an Endocrine Society-appointed Task Force of 6 experts, a methodologist, and a medical writer. EVIDENCE This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The Task Force commissioned 2 systematic reviews and used the best available evidence from other published systematic reviews and individual studies. CONSENSUS PROCESS One group meeting, several conference calls, and e-mail communications enabled consensus. Endocrine Society committees and members and co-sponsoring organizations reviewed and commented on preliminary drafts of this guideline. CONCLUSION Pediatric obesity remains an ongoing serious international health concern affecting ∼17% of US children and adolescents, threatening their adult health and longevity. Pediatric obesity has its basis in genetic susceptibilities influenced by a permissive environment starting in utero and extending through childhood and adolescence. Endocrine etiologies for obesity are rare and usually are accompanied by attenuated growth patterns. Pediatric comorbidities are common and long-term health complications often result; screening for comorbidities of obesity should be applied in a hierarchal, logical manner for early identification before more serious complications result. Genetic screening for rare syndromes is indicated only in the presence of specific historical or physical features. The psychological toll of pediatric obesity on the individual and family necessitates screening for mental health issues and counseling as indicated. The prevention of pediatric obesity by promoting healthful diet, activity, and environment should be a primary goal, as achieving effective, long-lasting results with lifestyle modification once obesity occurs is difficult. Although some behavioral and pharmacotherapy studies report modest success, additional research into accessible and effective methods for preventing and treating pediatric obesity is needed. The use of weight loss medications during childhood and adolescence should be restricted to clinical trials. Increasing evidence demonstrates the effectiveness of bariatric surgery in the most seriously affected mature teenagers who have failed lifestyle modification, but the use of surgery requires experienced teams with resources for long-term follow-up. Adolescents undergoing lifestyle therapy, medication regimens, or bariatric surgery for obesity will need cohesive planning to help them effectively transition to adult care, with continued necessary monitoring, support, and intervention. Transition programs for obesity are an uncharted area requiring further research for efficacy. Despite a significant increase in research on pediatric obesity since the initial publication of these guidelines 8 years ago, further study is needed of the genetic and biological factors that increase the risk of weight gain and influence the response to therapeutic interventions. Also needed are more studies to better understand the genetic and biological factors that cause an obese individual to manifest one comorbidity vs another or to be free of comorbidities. Furthermore, continued investigation into the most effective methods of preventing and treating obesity and into methods for changing environmental and economic factors that will lead to worldwide cultural changes in diet and activity should be priorities. Particular attention to determining ways to effect systemic changes in food environments and total daily mobility, as well as methods for sustaining healthy body mass index changes, is of importance.
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Affiliation(s)
- Dennis M Styne
- University of California Davis, Sacramento, California 95817
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36
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Abstract
Obesity is a complex, heritable trait influenced by the interplay of genetics, epigenetics, metagenomics and the environment. With the increasing access to high precision diagnostic tools for genetic investigations, numerous genes influencing the phenotype have been identified, especially in early onset severe obesity. This review summarizes the current knowledge on the known genetic causes of obesity and the available therapeutic options. Furthermore, we discuss the role and potential mechanism of epigenetic changes that may be involved as mediators of the environmental influences and that may provide future opportunities for intervention.
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Affiliation(s)
- Vidhu V Thaker
- Division of Molecular Genetics, Department of Pediatrics, Columbia University Medical Center, New York, NY
- Harvard Medical School, Boston, MA
- Division of Endocrinology, Boston Children's Hospital, Boston, MA
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Dong Y, Cai X, Wu Y, Liu Y, Deng L, Chen H. Insights from Genetic Model Systems of Retinal Degeneration: Role of Epsins in Retinal Angiogenesis and VEGFR2 Signaling. J Nat Sci 2017; 3:e281. [PMID: 28191500 PMCID: PMC5303005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The retina is a light sensitive tissue that contains specialized photoreceptor cells called rods and cones which process visual signals. These signals are relayed to the brain through interneurons and the fibers of the optic nerve. The retina is susceptible to a variety of degenerative diseases, including age-related macular degeneration (AMD), diabetic retinopathy (DR), retinitis pigmentosa (RP) and other inherited retinal degenerations. In order to reveal the mechanism underlying these diseases and to find methods for the prevention/treatment of retinal degeneration, animal models have been generated to mimic human eye diseases. In this paper, several well-characterized and commonly used animal models are reviewed. Of particular interest are the contributions of these models to our understanding of the mechanisms of retinal degeneration and thereby providing novel treatment options including gene therapy, stem cell therapy, nanomedicine, and CRISPR/Cas9 genome editing. Role of newly-identified adaptor protein epsins from our laboratory is discussed in retinal angiogenesis and VEGFR2 signaling.
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Affiliation(s)
- Yunzhou Dong
- Vascular Biology Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Xue Cai
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Yong Wu
- Department of Internal Medicine, Charles R. Drew University of Medicine & Sciences, University of California School of Medicine, Los Angeles, CA 90059, USA
| | - Yanjun Liu
- Department of Internal Medicine, Charles R. Drew University of Medicine & Sciences, University of California School of Medicine, Los Angeles, CA 90059, USA
| | - Lin Deng
- Department of Biological Chemistry & Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Hong Chen
- Vascular Biology Program, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
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Ignatieva EV, Afonnikov DA, Saik OV, Rogaev EI, Kolchanov NA. A compendium of human genes regulating feeding behavior and body weight, its functional characterization and identification of GWAS genes involved in brain-specific PPI network. BMC Genet 2016; 17:158. [PMID: 28105929 PMCID: PMC5249002 DOI: 10.1186/s12863-016-0466-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background Obesity is heritable. It predisposes to many diseases. The objectives of this study were to create a compendium of genes relevant to feeding behavior (FB) and/or body weight (BW) regulation; to construct and to analyze networks formed by associations between genes/proteins; and to identify the most significant genes, biological processes/pathways, and tissues/organs involved in BW regulation. Results The compendium of genes controlling FB or BW includes 578 human genes. Candidate genes were identified from various sources, including previously published original research and review articles, GWAS meta-analyses, and OMIM (Online Mendelian Inheritance in Man). All genes were ranked according to knowledge about their biological role in body weight regulation and classified according to expression patterns or functional characteristics. Substantial and overrepresented numbers of genes from the compendium encoded cell surface receptors, signaling molecules (hormones, neuropeptides, cytokines), transcription factors, signal transduction proteins, cilium and BBSome components, and lipid binding proteins or were present in the brain-specific list of tissue-enriched genes identified with TSEA tool. We identified 27 pathways from KEGG, REACTOME and BIOCARTA whose genes were overrepresented in the compendium. Networks formed by physical interactions or homological relationships between proteins or interactions between proteins involved in biochemical/signaling pathways were reconstructed and analyzed. Subnetworks and clusters identified by the MCODE tool included genes/proteins associated with cilium morphogenesis, signal transduction proteins (particularly, G protein–coupled receptors, kinases or proteins involved in response to insulin stimulus) and transcription regulation (particularly nuclear receptors). We ranked GWAS genes according to the number of neighbors in three networks and revealed 22 GWAS genes involved in the brain-specific PPI network. On the base of the most reliable PPIs functioning in the brain tissue, new regulatory schemes interpreting relevance to BW regulation are proposed for three GWAS genes (ETV5, LRP1B, and NDUFS3). Conclusions A compendium comprising 578 human genes controlling FB or BW was designed, and the most significant functional groups of genes, biological processes/pathways, and tissues/organs involved in BW regulation were revealed. We ranked genes from the GWAS meta-analysis set according to the number and quality of associations in the networks and then according to their involvement in the brain-specific PPI network and proposed new regulatory schemes involving three GWAS genes (ETV5, LRP1B, and NDUFS3) in BW regulation. The compendium is expected to be useful for pathology risk estimation and for design of new pharmacological approaches in the treatment of human obesity. Electronic supplementary material The online version of this article (doi:10.1186/s12863-016-0466-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elena V Ignatieva
- Center for Brain Neurobiology and Neurogenetics, The Federal Research Center Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia. .,Novosibirsk State University, Novosibirsk, 630090, Russia. .,Laboratory of Evolutionary Bioinformatics and Theoretical Genetics, The Federal Research Center Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.
| | - Dmitry A Afonnikov
- Center for Brain Neurobiology and Neurogenetics, The Federal Research Center Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.,Novosibirsk State University, Novosibirsk, 630090, Russia.,Laboratory of Evolutionary Bioinformatics and Theoretical Genetics, The Federal Research Center Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Olga V Saik
- Center for Brain Neurobiology and Neurogenetics, The Federal Research Center Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Evgeny I Rogaev
- Center for Brain Neurobiology and Neurogenetics, The Federal Research Center Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.,BNRI, Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA, 15604, USA
| | - Nikolay A Kolchanov
- Novosibirsk State University, Novosibirsk, 630090, Russia.,Department of Systems Biology, The Federal Research Center Institute of Cytology and Genetics of Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia
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39
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Abstract
Obesity results from a synergistic relationship between genes and the environment. The phenotypic expression of genetic factors involved in obesity is variable, allowing to distinguish several clinical pictures of obesity. Monogenic obesity is described as rare and severe early-onset obesity with abnormal feeding behavior and endocrine disorders. This is mainly due to autosomal recessive mutations in genes of the leptin-melanocortin pathway which plays a key role in the hypothalamic control of food intake. Melanocortin 4 receptor(MC4R)-linked obesity is characterized by the variable severity of obesity and no notable additional phenotypes. Mutations in the MC4R gene are involved in 2-3% of obese children and adults; the majority of these are heterozygous. Syndromic obesity is associated with mental retardation, dysmorphic features, and organ-specific developmental abnormalities. Additional genes participating in the development of hypothalamus and central nervous system have been regularly identified. But to date, not all involved genes have been identified so far. New diagnostic tools, such as whole-exome sequencing, will probably help to identify other genes. Managing these patients is challenging. Indeed, specific treatments are available only for specific types of monogenic obesity, such as leptin deficiency. Data on bariatric surgery are limited and controversial. New molecules acting on the leptin-melanocortin pathway are currently being developed.
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Affiliation(s)
- Hélène Huvenne
- GHICL, Saint-Vincent de Paul Hospital, Department of Pediatrics, Lille, France
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40
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Abstract
Since 2007, discovery of genetic variants associated with general obesity and fat distribution has advanced tremendously through genome-wide association studies (GWAS). Currently, the number of robustly associated loci is 190. Even though these loci explain <3 % of the variance, they have provided us a still emerging picture of genomic localization, frequency and effect size spectra, and hints of functional implications. The translation into biological knowledge has turned out to be an immense task. However, in silico enrichment analyses of genes involved in specific pathways or expressed in specific tissues have the power to suggest biological mechanisms underlying obesity. Inspired by this, we highlight genes in five loci potentially mechanistically linked to leptin-receptor trafficking and signaling in primary cilia. The clinical application of genetic knowledge as prediction, prevention, or treatment strategies is unfortunately still far from reality. Thus, despite major advances, further research is warranted to solve one of the greatest health problems in modern society.
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Affiliation(s)
- Mette Korre Andersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 1, 2.sal, 2100, Copenhagen, Denmark.
| | - Camilla Helene Sandholt
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 1, 2.sal, 2100, Copenhagen, Denmark.
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Cai X, Chen L, McGinnis JF. Correlation of ER stress and retinal degeneration in tubby mice. Exp Eye Res 2015; 140:130-138. [PMID: 26325328 DOI: 10.1016/j.exer.2015.08.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 07/09/2015] [Accepted: 08/25/2015] [Indexed: 11/17/2022]
Abstract
Mutation of the Tub gene results in the mislocalization of photoreceptor-specific proteins and eventually retinal degeneration. However, the exact mechanism underlying the retinal degeneration remains largely unknown. In this study, we discovered that the expression of endoplasmic reticulum (ER) stress markers, IRE1, ATF6, eIF2α, GRP78/BiP, and XBP-1, is up regulated during tubby retinal development. The dynamics of the expression of these genes are time-dependent and coincided with the time-course of photoreceptor death. Our data also demonstrated that ER stress triggers apoptosis via down-regulation of Bcl2, up-regulation of CHOP and the activation of NF-кB signaling.
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Affiliation(s)
- Xue Cai
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States.
| | - Lijuan Chen
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States
| | - James F McGinnis
- Department of Ophthalmology, Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States; Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States; Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States.
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42
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Alsters SIM, Goldstone AP, Buxton JL, Zekavati A, Sosinsky A, Yiorkas AM, Holder S, Klaber RE, Bridges N, van Haelst MM, le Roux CW, Walley AJ, Walters RG, Mueller M, Blakemore AIF. Truncating Homozygous Mutation of Carboxypeptidase E (CPE) in a Morbidly Obese Female with Type 2 Diabetes Mellitus, Intellectual Disability and Hypogonadotrophic Hypogonadism. PLoS One 2015; 10:e0131417. [PMID: 26120850 PMCID: PMC4485893 DOI: 10.1371/journal.pone.0131417] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 06/02/2015] [Indexed: 01/25/2023] Open
Abstract
Carboxypeptidase E is a peptide processing enzyme, involved in cleaving numerous peptide precursors, including neuropeptides and hormones involved in appetite control and glucose metabolism. Exome sequencing of a morbidly obese female from a consanguineous family revealed homozygosity for a truncating mutation of the CPE gene (c.76_98del; p.E26RfsX68). Analysis detected no CPE expression in whole blood-derived RNA from the proband, consistent with nonsense-mediated decay. The morbid obesity, intellectual disability, abnormal glucose homeostasis and hypogonadotrophic hypogonadism seen in this individual recapitulates phenotypes in the previously described fat/fat and Cpe knockout mouse models, evidencing the importance of this peptide/hormone-processing enzyme in regulating body weight, metabolism, and brain and reproductive function in humans.
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Affiliation(s)
- Suzanne I. M. Alsters
- Section of Investigative Medicine, Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Anthony P. Goldstone
- Imperial Centre for Endocrinology, Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, United Kingdom
- Centre for Neuropsychopharmacology and Computational, Cognitive and Clinical Neuroimaging Laboratory, Division of Brain Sciences, Department of Medicine, Imperial College London, Hammersmith Hospital, London, United Kingdom
- Metabolic and Molecular Imaging Group, MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, United Kingdom
- * E-mail: (AG); (AB)
| | - Jessica L. Buxton
- Section of Investigative Medicine, Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
- Centre for Cardiovascular Genetics, UCL Institute of Cardiovascular Science, London, United Kingdom
| | - Anna Zekavati
- NIHR Imperial BRC Genomics Facility, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Alona Sosinsky
- NIHR Imperial BRC Genomics Facility, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Andrianos M. Yiorkas
- Section of Investigative Medicine, Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
| | - Susan Holder
- NW Thames Regional Genetics Service, Kennedy Galton Centre, North West London Hospitals NHS Trust, Northwick Park Hospital, Harrow, United Kingdom
| | - Robert E. Klaber
- Department of Paediatrics, Imperial College Healthcare NHS Trust, St Mary's Hospital, London, United Kingdom
| | - Nicola Bridges
- Department of Paediatric Endocrinology, Chelsea and Westminster Hospital, London, United Kingdom
| | - Mieke M. van Haelst
- Department of Medical Genetics, Wilhelmina Children’s Hospital, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Carel W. le Roux
- Section of Investigative Medicine, Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
- Diabetes Complications Research Centre, Conway Institute, School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Andrew J. Walley
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, United Kingdom
| | - Robin G. Walters
- Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, University of Oxford, Oxford, United Kingdom
| | - Michael Mueller
- NIHR Imperial BRC Genomics Facility, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Alexandra I. F. Blakemore
- Section of Investigative Medicine, Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Imperial College London, London, United Kingdom
- * E-mail: (AG); (AB)
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43
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Marfany G, Gonzàlez-Duarte R. Clinical applications of high-throughput genetic diagnosis in inherited retinal dystrophies: Present challenges and future directions. World J Med Genet 2015; 5:14-22. [DOI: 10.5496/wjmg.v5.i2.14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 12/30/2014] [Accepted: 02/09/2015] [Indexed: 02/06/2023] Open
Abstract
The advent of next generation sequencing (NGS) techniques has greatly simplified the molecular diagnosis and gene identification in very rare and highly heterogeneous Mendelian disorders. Over the last two years, these approaches, especially whole exome sequencing (WES), alone or combined with homozygosity mapping and linkage analysis, have proved to be successful in the identification of more than 25 new causative retinal dystrophy genes. NGS-approaches have also identified a wealth of new mutations in previously reported genes and have provided more comprehensive information concerning the landscape of genotype-phenotype correlations and the genetic complexity/diversity of human control populations. Although whole genome sequencing is far more informative than WES, the functional meaning of the genetic variants identified by the latter can be more easily interpreted, and final diagnosis of inherited retinal dystrophies is extremely successful, reaching 80%, particularly for recessive cases. Even considering the present limitations of WES, the reductions in costs and time, the continual technical improvements, the implementation of refined bioinformatic tools and the unbiased comprehensive genetic information it provides, make WES a very promising diagnostic tool for routine clinical and genetic diagnosis in the future.
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44
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Haliloglu B, Bereket A. Hypothalamic obesity in children: pathophysiology to clinical management. J Pediatr Endocrinol Metab 2015; 28:503-13. [PMID: 25781673 DOI: 10.1515/jpem-2014-0512] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 01/29/2015] [Indexed: 12/22/2022]
Abstract
Hypothalamic obesity (HyOb) is a complex neuroendocrine disorder caused by damage to the hypothalamus, which results in disruption of energy regulation. The key hypothalamic areas of energy regulation are the ARC (arcuate nucleus), the VMH (ventromedial hypothalamus), the PVN (paraventriculer nuclei) and the LHA (lateral hypothalamic area). These pathways can be disrupted mechanically by hypothalamic tumors, neurosurgery, inflammatory disorders, radiotherapy and trauma or functionally as such seen in genetic diseases. Rapid weight gain and severe obesity are the most striking features of HyOb and caused by hyperphagia, reduced basal metabolic rate (BMR) and decreased physical activity. HyOb is usually unresponsive to diet and exercise. Although, GLP-1 and its anologs seem to be a new agent, there is still no curative treatment. Thus, prevention is of prime importance and the clinicians should be alert and vigilant in patients at risk for development of HyOb.
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Abstract
Metabolic disease encompasses several disorders including obesity, type 2 diabetes, and dyslipidemia. Recently, the incidence of metabolic disease has drastically increased, driven primarily by a worldwide obesity epidemic. Transgenerational inheritance remains controversial, but has been proposed to contribute to human metabolic disease risk based on a growing number of proof-of-principle studies in model organisms ranging from Caenorhabditis elegans to Mus musculus to Sus scrofa. Collectively, these studies demonstrate that heritable risk is epigenetically transmitted from parent to offspring over multiple generations in the absence of a continued exposure to the triggering stimuli. A diverse assortment of initial triggers can induce transgenerational inheritance including high-fat or high-sugar diets, low-protein diets, various toxins, and ancestral genetic variants. Although the mechanistic basis underlying the transgenerational inheritance of disease risk remains largely unknown, putative molecules mediating transmission include small RNAs, histone modifications, and DNA methylation. Due to the considerable impact of metabolic disease on human health, it is critical to better understand the role of transgenerational inheritance of metabolic disease risk to open new avenues for therapeutic intervention and improve upon the current methods for clinical diagnoses and treatment.
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Affiliation(s)
- Rachel Stegemann
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, United States
| | - David A Buchner
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH 44106, United States; Department of Biological Chemistry, Case Western Reserve University, Cleveland, OH 44106, United States.
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46
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Abstract
Obesity is a major public health concern. This condition results from a constant and complex interplay between predisposing genes and environmental stimuli. Current attempts to manage obesity have been moderately effective and a better understanding of the etiology of obesity is required for the development of more successful and personalized prevention and treatment options. To that effect, mouse models have been an essential tool in expanding our understanding of obesity, due to the availability of their complete genome sequence, genetically identified and defined strains, various tools for genetic manipulation and the accessibility of target tissues for obesity that are not easily attainable from humans. Our knowledge of monogenic obesity in humans greatly benefited from the mouse obesity genetics field. Genes underlying highly penetrant forms of monogenic obesity are part of the leptin-melanocortin pathway in the hypothalamus. Recently, hypothesis-generating genome-wide association studies for polygenic obesity traits in humans have led to the identification of 119 common gene variants with modest effect, most of them having an unknown function. These discoveries have led to novel animal models and have illuminated new biologic pathways. Integrated mouse-human genetic approaches have firmly established new obesity candidate genes. Innovative strategies recently developed by scientists are described in this review to accelerate the identification of causal genes and deepen our understanding of obesity etiology. An exhaustive dissection of the molecular roots of obesity may ultimately help to tackle the growing obesity epidemic worldwide.
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Affiliation(s)
- Fereshteh T. Yazdi
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada
| | - Susanne M. Clee
- Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - David Meyre
- Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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47
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Abstract
Heritability of obesity and body weight variation is high. Molecular genetic studies have led to the identification of mutations in a few genes, with a major effect on obesity (major genes and monogenic forms). Analyses of these genes have helped to unravel important pathways and have created a more profound understanding of body weight regulation. For most individuals, a polygenic basis is relevant for the genetic predisposition to obesity. Small effect sizes are conveyed by the polygenic variants. Hence, only if a number of these variants is harboured, a sizeable phenotypic effect is detectable. Most, if not all, of the genes relevant to weight regulation are expressed in the hypothalamus. This underscores the major role of this region of the brain in body weight regulation.
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Affiliation(s)
- Anke Hinney
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, Essen, Germany.
| | - Anna-Lena Volckmar
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, Essen, Germany.
| | - Jochen Antel
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Universitätsklinikum Essen, Essen, Germany.
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48
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Abstract
The heritability of obesity has long been appreciated and the genetics of obesity has been the focus of intensive study for decades. Early studies elucidating genetic factors involved in rare monogenic and syndromic forms of extreme obesity focused attention on dysfunction of hypothalamic leptin-related pathways in the control of food intake as a major contributor. Subsequent genome-wide association studies of common genetic variants identified novel loci that are involved in more common forms of obesity across populations of diverse ethnicities and ages. The subsequent search for factors contributing to the heritability of obesity not explained by these 2 approaches ("missing heritability") has revealed additional rare variants, copy number variants, and epigenetic changes that contribute. Although clinical applications of these findings have been limited to date, the increasing understanding of the interplay of these genetic factors with environmental conditions, such as the increased availability of high calorie foods and decreased energy expenditure of sedentary lifestyles, promises to accelerate the translation of genetic findings into more successful preventive and therapeutic interventions.
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Affiliation(s)
- Jill Waalen
- The Scripps Research Institute and the Scripps Translational Science Institute, La Jolla, California.
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49
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Jacobson SG, Cideciyan AV, Huang WC, Sumaroka A, Roman AJ, Schwartz SB, Luo X, Sheplock R, Dauber JM, Swider M, Stone EM. TULP1 mutations causing early-onset retinal degeneration: preserved but insensitive macular cones. Invest Ophthalmol Vis Sci 2014; 55:5354-64. [PMID: 25074776 DOI: 10.1167/iovs.14-14570] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate visual function and outer and inner retinal structure in the rare form of retinal degeneration (RD) caused by TULP1 (tubby-like protein 1) mutations. METHODS Retinal degeneration patients with TULP1 mutations (n = 5; age range, 5-36 years) were studied by kinetic and chromatic static perimetry, en face autofluorescence imaging, and spectral-domain optical coherence tomography (OCT) scans. Outer and inner retinal laminar thickness were measured and mapped across the central retina. Comparisons were made with results from patients with RD associated with four ciliopathy genotypes (MAK, RPGR, BBS1, and USH2A). RESULTS The TULP1-RD patients were severely affected already in the first decade of life and there was rapidly progressive visual loss. No evidence of rod function was present at any age. Small central islands showed melanized retinal pigment epithelium by autofluorescence imaging and well-preserved photoreceptor laminar thickness by OCT imaging. There was extracentral loss of laminar architecture and increased inner retinal thickening. Structure-function relationships in residual foveal cone islands were made in TULP1-RD patients and in other retinopathies considered ciliopathies. Patients with TULP1-RD, unlike the others, had greater dysfunction for the degree of foveal structural preservation. CONCLUSIONS Retinal degeneration with TULP1 mutations leads to a small central island of residual foveal cones at early ages. These cones are less sensitive than expected from the residual structure. The human phenotype is consistent with experimental evidence in the Tulp1 knockout mouse model that visual dysfunction could be complicated by abnormal processes proximal to cone outer segments.
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Affiliation(s)
- Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Wei Chieh Huang
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alejandro J Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Sharon B Schwartz
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Xunda Luo
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Rebecca Sheplock
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Joanna M Dauber
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Malgorzata Swider
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Edwin M Stone
- Department of Ophthalmology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States Howard Hughes Medical Institute, Iowa City, Iowa, United States
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Abstract
PURPOSE To highlight major advancements in ocular genetics from the year 2013. DESIGN Literature review. METHODS A literature search was conducted on PubMed to identify articles pertaining to genetic influences on human eye diseases. This review focuses on manuscripts published in print or online in the English language between January 1, 2013 and December 31, 2013. A total of 120 papers from 2013 were included in this review. RESULTS Significant progress has been made in our understanding of the genetic basis of a broad group of ocular disorders, including glaucoma, age-related macular degeneration, cataract, diabetic retinopathy, keratoconus, Fuchs' endothelial dystrophy, and refractive error. CONCLUSIONS The latest next-generation sequencing technologies have become extremely effective tools for identifying gene mutations associated with ocular disease. These technological advancements have also paved the way for utilization of genetic information in clinical practice, including disease diagnosis, prediction of treatment response and molecular interventions guided by gene-based knowledge.
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Affiliation(s)
- Inas F Aboobakar
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - R Rand Allingham
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
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