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Shimizu H, Hosseini-Alghaderi S, Woodcock SA, Baron M. Alternative mechanisms of Notch activation by partitioning into distinct endosomal domains. J Cell Biol 2024; 223:e202211041. [PMID: 38358349 PMCID: PMC10868400 DOI: 10.1083/jcb.202211041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 11/17/2023] [Accepted: 01/30/2024] [Indexed: 02/16/2024] Open
Abstract
Different membrane microdomain compositions provide unique environments that can regulate signaling receptor function. We identify microdomains on the endosome membrane of Drosophila endosomes, enriched in lipid-raft or clathrin/ESCRT-0, which are associated with Notch activation by distinct, ligand-independent mechanisms. Transfer of Notch between microdomains is regulated by Deltex and Suppressor of deltex ubiquitin ligases and is limited by a gate-keeper role for ESCRT complexes. Ubiquitination of Notch by Deltex recruits it to the clathrin/ESCRT-0 microdomain and enhances Notch activation by an ADAM10-independent/TRPML-dependent mechanism. This requirement for Deltex is bypassed by the downregulation of ESCRT-III. In contrast, while ESCRT-I depletion also activates Notch, it does so by an ADAM10-dependent/TRPML-independent mechanism and Notch is retained in the lipid raft-like microdomain. In the absence of such endosomal perturbation, different activating Notch mutations also localize to different microdomains and are activated by different mechanisms. Our findings demonstrate the interplay between Notch regulators, endosomal trafficking components, and Notch genetics, which defines membrane locations and activation mechanisms.
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Affiliation(s)
- Hideyuki Shimizu
- School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Samira Hosseini-Alghaderi
- School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Simon A. Woodcock
- School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Martin Baron
- School of Biological Sciences, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
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2
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Fu JL, Zheng SY, Wang Y, Hu XB, Xiao Y, Wang JM, Zhang L, Wang L, Nie Q, Hou M, Bai YY, Gan YW, Liang XM, Xie LL, Li DWC. HSP90β prevents aging-related cataract formation through regulation of the charged multivesicular body protein (CHMP4B) and p53. Proc Natl Acad Sci U S A 2023; 120:e2221522120. [PMID: 37487085 PMCID: PMC10400967 DOI: 10.1073/pnas.2221522120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 06/23/2023] [Indexed: 07/26/2023] Open
Abstract
Cataract is a leading ocular disease causing global blindness. The mechanism of cataractogenesis has not been well defined. Here, we demonstrate that the heat shock protein 90β (HSP90β) plays a fundamental role in suppressing cataractogenesis. HSP90β is the most dominant HSP in normal lens, and its constitutive high level of expression is largely derived from regulation by Sp1 family transcription factors. More importantly, HSP90β is significantly down-regulated in human cataract patients and in aging mouse lenses, whereas HSP90β silencing in zebrafish causes cataractogenesis, which can only be rescued by itself but not other HSP90 genes. Mechanistically, HSP90β can directly interact with CHMP4B, a newly-found client protein involved in control of cytokinesis. HSP90β silencing causes upregulation of CHMP4B and another client protein, the tumor suppressor p53. CHMP4B upregulation or overexpression induces excessive division of lens epithelial cells without proper differentiation. As a result, these cells were triggered to undergo apoptosis due to activation of the p53/Bak-Bim pathway, leading to cataractogenesis and microphthalmia. Silence of both HSP90β and CHMP4B restored normal phenotype of zebrafish eye. Together, our results reveal that HSP90β is a critical inhibitor of cataractogenesis through negative regulation of CHMP4B and the p53-Bak/Bim pathway.
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Affiliation(s)
- Jia-Ling Fu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Shu-Yu Zheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Yan Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Xue-Bin Hu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Yuan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Jing-Miao Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Lan Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Ling Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Qian Nie
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Min Hou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Yue-Yue Bai
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Yu-Wen Gan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Xing-Miao Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - Liu-Liu Xie
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
| | - David Wan-Cheng Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong510060, China
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3
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Rodríguez-Solana P, Arruti N, Nieves-Moreno M, Mena R, Rodríguez-Jiménez C, Guerrero-Carretero M, Acal JC, Blasco J, Peralta JM, Del Pozo Á, Montaño VEF, Dios-Blázquez LD, Fernández-Alcalde C, González-Atienza C, Sánchez-Cazorla E, Gómez-Cano MDLÁ, Delgado-Mora L, Noval S, Vallespín E. Whole Exome Sequencing of 20 Spanish Families: Candidate Genes for Non-Syndromic Pediatric Cataracts. Int J Mol Sci 2023; 24:11429. [PMID: 37511188 PMCID: PMC10380485 DOI: 10.3390/ijms241411429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 06/23/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Non-syndromic pediatric cataracts are defined as opacification of the crystalline lens that occurs during the first years of life without affecting other organs. Given that this disease is one of the most frequent causes of reversible blindness in childhood, the main objective of this study was to propose new responsible gene candidates that would allow a more targeted genetic approach and expand our genetic knowledge about the disease. We present a whole exome sequencing (WES) study of 20 Spanish families with non-syndromic pediatric cataracts and a previous negative result on an ophthalmology next-generation sequencing panel. After ophthalmological evaluation and collection of peripheral blood samples from these families, WES was performed. We were able to reach a genetic diagnosis in 10% of the families analyzed and found genes that could cause pediatric cataracts in 35% of the cohort. Of the variants found, 18.2% were classified as pathogenic, 9% as likely pathogenic, and 72.8% as variants of uncertain significance. However, we did not find conclusive results in 55% of the families studied, which suggests further studies are needed. The results of this WES study allow us to propose LONP1, ACACA, TRPM1, CLIC5, HSPE1, ODF1, PIKFYVE, and CHMP4A as potential candidates to further investigate for their role in pediatric cataracts, and AQP5 and locus 2q37 as causal genes.
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Affiliation(s)
- Patricia Rodríguez-Solana
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
| | - Natalia Arruti
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
- European Reference Network on Eye Diseases (ERN-EYE), La Paz University Hospital, 28046 Madrid, Spain
| | - María Nieves-Moreno
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
- European Reference Network on Eye Diseases (ERN-EYE), La Paz University Hospital, 28046 Madrid, Spain
| | - Rocío Mena
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
| | - Carmen Rodríguez-Jiménez
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
| | - Marta Guerrero-Carretero
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Juan Carlos Acal
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Joana Blasco
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Jesús M. Peralta
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Ángela Del Pozo
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
- Clinical Bioinformatics Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, CIBERER, La Paz University Hospital, 28046 Madrid, Spain;
| | - Victoria E. F. Montaño
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
| | - Lucía De Dios-Blázquez
- Clinical Bioinformatics Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, CIBERER, La Paz University Hospital, 28046 Madrid, Spain;
| | - Celia Fernández-Alcalde
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Carmen González-Atienza
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
| | - Eloísa Sánchez-Cazorla
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
| | - María de Los Ángeles Gómez-Cano
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
- Clinical Genetics Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, CIBERER, La Paz University Hospital, 28046 Madrid, Spain
| | - Luna Delgado-Mora
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
- Clinical Genetics Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, CIBERER, La Paz University Hospital, 28046 Madrid, Spain
| | - Susana Noval
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
- European Reference Network on Eye Diseases (ERN-EYE), La Paz University Hospital, 28046 Madrid, Spain
| | - Elena Vallespín
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
- European Reference Network on Eye Diseases (ERN-EYE), La Paz University Hospital, 28046 Madrid, Spain
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
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4
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Balka KR, Venkatraman R, Saunders TL, Shoppee A, Pang ES, Magill Z, Homman-Ludiye J, Huang C, Lane RM, York HM, Tan P, Schittenhelm RB, Arumugam S, Kile BT, O'Keeffe M, De Nardo D. Termination of STING responses is mediated via ESCRT-dependent degradation. EMBO J 2023:e112712. [PMID: 37139896 DOI: 10.15252/embj.2022112712] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 04/14/2023] [Accepted: 04/17/2023] [Indexed: 05/05/2023] Open
Abstract
cGAS-STING signalling is induced by detection of foreign or mislocalised host double-stranded (ds)DNA within the cytosol. STING acts as the major signalling hub, where it controls production of type I interferons and inflammatory cytokines. Basally, STING resides on the ER membrane. Following activation STING traffics to the Golgi to initiate downstream signalling and subsequently to endolysosomal compartments for degradation and termination of signalling. While STING is known to be degraded within lysosomes, the mechanisms controlling its delivery remain poorly defined. Here we utilised a proteomics-based approach to assess phosphorylation changes in primary murine macrophages following STING activation. This identified numerous phosphorylation events in proteins involved in intracellular and vesicular transport. We utilised high-temporal microscopy to track STING vesicular transport in live macrophages. We subsequently identified that the endosomal complexes required for transport (ESCRT) pathway detects ubiquitinated STING on vesicles, which facilitates the degradation of STING in murine macrophages. Disruption of ESCRT functionality greatly enhanced STING signalling and cytokine production, thus characterising a mechanism controlling effective termination of STING signalling.
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Affiliation(s)
- Katherine R Balka
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Rajan Venkatraman
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Tahnee L Saunders
- Ubiquitin Signalling Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Angus Shoppee
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
- Department of Biochemistry and Molecular Biology, Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Ee Shan Pang
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
- Department of Biochemistry and Molecular Biology, Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Zoe Magill
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
- Department of Biochemistry and Molecular Biology, Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Jihane Homman-Ludiye
- Monash Micro Imaging, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Cheng Huang
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
- Monash Proteomics and Metabolomics Facility, Monash University, Clayton, Vic., Australia
| | - Rachael M Lane
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Harrison M York
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Peck Tan
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
- Department of Biochemistry and Molecular Biology, Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Ralf B Schittenhelm
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
- Monash Proteomics and Metabolomics Facility, Monash University, Clayton, Vic., Australia
| | - Senthil Arumugam
- Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
- European Molecular Biological Laboratory Australia (EMBL Australia), Monash University, Clayton/Melbourne, Vic., Australia
| | - Benjamin T Kile
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Meredith O'Keeffe
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
- Department of Biochemistry and Molecular Biology, Cancer Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
| | - Dominic De Nardo
- Department of Biochemistry and Molecular Biology, Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Vic., Australia
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5
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Zhou Y, Bennett TM, White TW, Shiels A. Charged multivesicular body protein 4b forms complexes with gap junction proteins during lens fiber cell differentiation. FASEB J 2023; 37:e22801. [PMID: 36880430 PMCID: PMC10101236 DOI: 10.1096/fj.202201368rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 03/08/2023]
Abstract
Charged multivesicular body protein 4b (CHMP4B) is a core sub-unit of the endosomal sorting complex required for transport III (ESCRT-III) machinery that serves myriad remodeling and scission processes of biological membranes. Mutation of the human CHMP4B gene underlies rare forms of early-onset lens opacities or cataracts, and CHMP4B is required for lens growth and differentiation in mice. Here, we determine the sub-cellular distribution of CHMP4B in the lens and uncover a novel association with gap junction alpha-3 protein (GJA3) or connexin 46 (Cx46) and GJA8 or Cx50. Immunofluorescence confocal microscopy revealed that CHMP4B localized to cell membranes of elongated fiber cells in the outer cortex of the lens-where large gap junction plaques begin to form-particularly, on the broad faces of these flattened hexagon-like cells in cross-section. Dual immunofluorescence imaging showed that CHMP4B co-localized with gap junction plaques containing Cx46 and/or Cx50. When combined with the in situ proximity ligation assay, immunofluorescence confocal imaging indicated that CHMP4B lay in close physical proximity to Cx46 and Cx50. In Cx46-knockout (Cx46-KO) lenses, CHMP4B-membrane distribution was similar to that of wild-type, whereas, in Cx50-KO lenses, CHMP4B localization to fiber cell membranes was lost. Immunoprecipitation and immunoblotting analyses revealed that CHMP4B formed complexes with Cx46 and Cx50 in vitro. Collectively, our data suggest that CHMP4B forms plasma membrane complexes, either directly and/or indirectly, with gap junction proteins Cx46 and Cx50 that are often associated with "ball-and-socket" double-membrane junctions during lens fiber cell differentiation.
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Affiliation(s)
- Yuefang Zhou
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Thomas M. Bennett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Thomas W. White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, USA
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
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Karim S, Hussein IR, Schulten HJ, Alsaedi S, Mirza Z, Al-Qahtani M, Chaudhary A. Identification of Extremely Rare Pathogenic CNVs by Array CGH in Saudi Children with Developmental Delay, Congenital Malformations, and Intellectual Disability. CHILDREN 2023; 10:children10040662. [PMID: 37189911 DOI: 10.3390/children10040662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 03/15/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
Chromosomal imbalance is implicated in developmental delay (DD), congenital malformations (CM), and intellectual disability (ID), and, thus, precise identification of copy number variations (CNVs) is essential. We therefore aimed to investigate the genetic heterogeneity in Saudi children with DD/CM/ID. High-resolution array comparative genomic hybridization (array CGH) was used to detect disease-associated CNVs in 63 patients. Quantitative PCR was done to confirm the detected CNVs. Giemsa banding-based karyotyping was also performed. Array CGH identified chromosomal abnormalities in 24 patients; distinct pathogenic and/or variants of uncertain significance CNVs were found in 19 patients, and aneuploidy was found in 5 patients including 47,XXY (n = 2), 45,X (n = 2) and a patient with trisomy 18 who carried a balanced Robertsonian translocation. CNVs including 9p24p13, 16p13p11, 18p11 had gains/duplications and CNVs, including 3p23p14, 10q26, 11p15, 11q24q25, 13q21.1q32.1, 16p13.3p11.2, and 20q11.1q13.2, had losses/deletions only, while CNVs including 8q24, 11q12, 15q25q26, 16q21q23, and 22q11q13 were found with both gains or losses in different individuals. In contrast, standard karyotyping detected chromosomal abnormalities in ten patients. The diagnosis rate of array CGH (28%, 18/63 patients) was around two-fold higher than that of conventional karyotyping (15.87%, 10/63 patients). We herein report, for the first time, the extremely rare pathogenic CNVs in Saudi children with DD/CM/ID. The reported prevalence of CNVs in Saudi Arabia adds value to clinical cytogenetics.
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Liton PB, Boesze-Battaglia K, Boulton ME, Boya P, Ferguson TA, Ganley IG, Kauppinnen A, Laurie GW, Mizushima N, Morishita H, Russo R, Sadda J, Shyam R, Sinha D, Thompson DA, Zacks DN. AUTOPHAGY IN THE EYE: FROM PHYSIOLOGY TO PATHOPHYSOLOGY. AUTOPHAGY REPORTS 2023; 2:2178996. [PMID: 37034386 PMCID: PMC10078619 DOI: 10.1080/27694127.2023.2178996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 01/26/2023] [Indexed: 03/05/2023]
Abstract
Autophagy is a catabolic self-degradative pathway that promotes the degradation and recycling of intracellular material through the lysosomal compartment. Although first believed to function in conditions of nutritional stress, autophagy is emerging as a critical cellular pathway, involved in a variety of physiological and pathophysiological processes. Autophagy dysregulation is associated with an increasing number of diseases, including ocular diseases. On one hand, mutations in autophagy-related genes have been linked to cataracts, glaucoma, and corneal dystrophy; on the other hand, alterations in autophagy and lysosomal pathways are a common finding in essentially all diseases of the eye. Moreover, LC3-associated phagocytosis, a form of non-canonical autophagy, is critical in promoting visual cycle function. This review collects the latest understanding of autophagy in the context of the eye. We will review and discuss the respective roles of autophagy in the physiology and/or pathophysiology of each of the ocular tissues, its diurnal/circadian variation, as well as its involvement in diseases of the eye.
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Affiliation(s)
- Paloma B. Liton
- Departments of Ophthalmology & Pathology, Duke School of Medicine, Duke University, Durham, NC 27705, USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, University of Pennsylvania, School of Dental Medicine, Philadelphia, PA 19104, USA
| | - Michael E. Boulton
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham (UAB), Birmingham, AL, USA
| | - Patricia Boya
- Department of Neuroscience and Movement Science. Faculty of Science and Medicine, University of Fribourg, 1700 Fribourg, Switzerland
| | - Thomas A. Ferguson
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Ian G. Ganley
- MRC Protein Phosphorylation and Ubiquitylation Unit, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Anu Kauppinnen
- Faculty of Health and Sciences, School of Pharmacy, University of Eastern Finland, 70210 Kuopio, Finland
| | - Gordon W. Laurie
- Departments of Cell Biology, Ophthalmology and Biomedical Engineering, University of Virginia, Charlottesville, VA 22908, USA
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, 113-0033, Japan
| | - Hideaki Morishita
- Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, 113-0033, Japan
- Department of Physiology, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Rossella Russo
- Preclinical and Translational Pharmacology, Glaucoma Unit, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende, Italy
| | - Jaya Sadda
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Debasish Sinha
- Department of Ophthalmology, Cell Biology, and Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Debra A. Thompson
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
| | - David N. Zacks
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, MI, USA
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8
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Brennan L, Costello MJ, Hejtmancik JF, Menko AS, Riazuddin SA, Shiels A, Kantorow M. Autophagy Requirements for Eye Lens Differentiation and Transparency. Cells 2023; 12:475. [PMID: 36766820 PMCID: PMC9914699 DOI: 10.3390/cells12030475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/17/2023] [Accepted: 01/25/2023] [Indexed: 02/05/2023] Open
Abstract
Recent evidence points to autophagy as an essential cellular requirement for achieving the mature structure, homeostasis, and transparency of the lens. Collective evidence from multiple laboratories using chick, mouse, primate, and human model systems provides evidence that classic autophagy structures, ranging from double-membrane autophagosomes to single-membrane autolysosomes, are found throughout the lens in both undifferentiated lens epithelial cells and maturing lens fiber cells. Recently, key autophagy signaling pathways have been identified to initiate critical steps in the lens differentiation program, including the elimination of organelles to form the core lens organelle-free zone. Other recent studies using ex vivo lens culture demonstrate that the low oxygen environment of the lens drives HIF1a-induced autophagy via upregulation of essential mitophagy components to direct the specific elimination of the mitochondria, endoplasmic reticulum, and Golgi apparatus during lens fiber cell differentiation. Pioneering studies on the structural requirements for the elimination of nuclei during lens differentiation reveal the presence of an entirely novel structure associated with degrading lens nuclei termed the nuclear excisosome. Considerable evidence also indicates that autophagy is a requirement for lens homeostasis, differentiation, and transparency, since the mutation of key autophagy proteins results in human cataract formation.
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Affiliation(s)
- Lisa Brennan
- Department of Biomedical Science, Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33460, USA
| | - M. Joseph Costello
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - J. Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - A. Sue Menko
- Department of Pathology, Anatomy and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
- Department of Ophthalmology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - S. Amer Riazuddin
- The Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Marc Kantorow
- Department of Biomedical Science, Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33460, USA
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9
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Chang W, Zhao Y, Rayêe D, Xie Q, Suzuki M, Zheng D, Cvekl A. Dynamic changes in whole genome DNA methylation, chromatin and gene expression during mouse lens differentiation. Epigenetics Chromatin 2023; 16:4. [PMID: 36698218 PMCID: PMC9875507 DOI: 10.1186/s13072-023-00478-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 01/17/2023] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Cellular differentiation is marked by temporally and spatially coordinated gene expression regulated at multiple levels. DNA methylation represents a universal mechanism to control chromatin organization and its accessibility. Cytosine methylation of CpG dinucleotides regulates binding of methylation-sensitive DNA-binding transcription factors within regulatory regions of transcription, including promoters and distal enhancers. Ocular lens differentiation represents an advantageous model system to examine these processes as lens comprises only two cell types, the proliferating lens epithelium and postmitotic lens fiber cells all originating from the epithelium. RESULTS Using whole genome bisulfite sequencing (WGBS) and microdissected lenses, we investigated dynamics of DNA methylation and chromatin changes during mouse lens fiber and epithelium differentiation between embryos (E14.5) and newborns (P0.5). Histone H3.3 variant chromatin landscapes were also generated for both P0.5 lens epithelium and fibers by chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq). Tissue-specific features of DNA methylation patterns are demonstrated via comparative studies with embryonic stem (ES) cells and neural progenitor cells (NPCs) at Nanog, Pou5f1, Sox2, Pax6 and Six3 loci. Comparisons with ATAC-seq and RNA-seq data demonstrate that reduced methylation is associated with increased expression of fiber cell abundant genes, including crystallins, intermediate filament (Bfsp1 and Bfsp2) and gap junction proteins (Gja3 and Gja8), marked by high levels of histone H3.3 within their transcribed regions. Interestingly, Pax6-binding sites exhibited predominantly DNA hypomethylation in lens chromatin. In vitro binding of Pax6 proteins showed Pax6's ability to interact with sites containing one or two methylated CpG dinucleotides. CONCLUSIONS Our study has generated the first data on methylation changes between two different stages of mammalian lens development and linked these data with chromatin accessibility maps, presence of histone H3.3 and gene expression. Reduced DNA methylation correlates with expression of important genes involved in lens morphogenesis and lens fiber cell differentiation.
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Affiliation(s)
- William Chang
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Yilin Zhao
- Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Danielle Rayêe
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Qing Xie
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- University of California Santa Cruz, Santa Cruz, CA, 95064, USA
| | - Masako Suzuki
- Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Deyou Zheng
- Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
- Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Ales Cvekl
- Department of Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
- Genetics, Albert Einstein College of Medicine, Bronx, NY, 10461, USA.
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Beyer EC, Mathias RT, Berthoud VM. Loss of fiber cell communication may contribute to the development of cataracts of many different etiologies. Front Physiol 2022; 13:989524. [PMID: 36171977 PMCID: PMC9511111 DOI: 10.3389/fphys.2022.989524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
The lens is an avascular organ that is supported by an internal circulation of water and solutes. This circulation is driven by ion pumps, channels and transporters in epithelial cells and by ion channels in fiber cells and is maintained by fiber-fiber and fiber-epithelial cell communication. Gap junctional intercellular channels formed of connexin46 and connexin50 are critical components of this circulation as demonstrated by studies of connexin null mice and connexin mutant mice. Moreover, connexin mutants are one of the most common causes of autosomal dominant congenital cataracts. However, alterations of the lens circulation and coupling between lens fiber cells are much more prevalent, beyond the connexin mutant lenses. Intercellular coupling and levels of connexins are decreased with aging. Gap junction-mediated intercellular communication decreases in mice expressing mutant forms of several different lens proteins and in some mouse models of lens protein damage. These observations suggest that disruption of ionic homeostasis due to reduction of the lens circulation is a common component of the development of many different types of cataracts. The decrease in the lens circulation often reflects low levels of lens fiber cell connexins and/or functional gap junction channels.
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Affiliation(s)
- Eric C. Beyer
- Department of Pediatrics, University of Chicago, Chicago, IL, United States
- *Correspondence: Eric C. Beyer,
| | - Richard T. Mathias
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, NY, United States
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11
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Saleem RS, Siddiqui SN, Irshad S, Ashraf NM, Hamid A, Khan MAU, Khan MI, Micheal S. Targeted gene sequencing of FYCO1 identified a novel mutation in a Pakistani family for autosomal recessive congenital cataract. Mol Genet Genomic Med 2022; 10:e1985. [PMID: 35638468 PMCID: PMC9356559 DOI: 10.1002/mgg3.1985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/10/2022] [Accepted: 05/03/2022] [Indexed: 11/16/2022] Open
Abstract
Background Congenital cataract is causing one‐third of blindness worldwide. Congenital cataract is heterogeneous in its inheritance patterns. The current study is aimed to explore the unknown genetic causes underlying congenital cataracts. Methods Blood samples from affected and normal individuals of n = 25 Pakistani families identified with congenital cataracts were collected. Genomic DNA was extracted and Sanger sequencing was performed to identify novel pathogenic variants in the FYCO1 (MIM#607182) gene. Later structural bioinformatics tools and molecular dynamics simulations were performed to analyze the impact of these variants on protein structure and function. Results Sanger sequencing resulted in the identification of a novel splice site mutation (NM_024513.3: c.3151‐29_3151‐7del) segregating in an autosomal recessive manner. This novel variant was confirmed to be absent in the n = 300 population controls. Further, bioinformatics tools revealed the formation of a mutant protein with a loss of the Znf domain. In addition, we also found a previously known (c.4127 T > C; p.Leu1376Pro) mutation in four families. We also report a novel heterozygous variant (c.3419G > A; p.Arg1140Gln) in another family. Conclusions In conclusion, we report a novel deletion (NM_024513.3: c.3151‐29_3151‐7del) in one family and a frequent homozygous missense mutation (c.4127 T > C; p.Leu1376Pro) in four Pakistani families. The current research highlights the importance of autophagy in lens development and maintaining its transparency.
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Affiliation(s)
- Rani Saira Saleem
- School of Biochemistry and Biotechnology, University of Punjab, Lahore, Pakistan
| | - Sorath Noorani Siddiqui
- Department of Pediatric Ophthalmology and Strabismus, Al-Shifa Eye Trust Hospital, Rawalpindi, Pakistan
| | - Saba Irshad
- School of Biochemistry and Biotechnology, University of Punjab, Lahore, Pakistan
| | - Naeem Mahmood Ashraf
- Department of Biochemistry and Biotechnology, University of Gujrat, Punjab, Pakistan
| | - Arslan Hamid
- LIMES Institute, University of Bonn, Bonn, Germany
| | | | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Shazia Micheal
- Department of Clinical Genetics, AcademicMedical Centre, Amsterdam, The Netherlands
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12
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Mei S, Wu Y, Wang Y, Cui Y, Zhang M, Zhang T, Huang X, Yu S, Yu T, Zhao J. Disruption of PIKFYVE causes congenital cataract in human and zebrafish. eLife 2022; 11:71256. [PMID: 35023829 PMCID: PMC8758139 DOI: 10.7554/elife.71256] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 01/03/2022] [Indexed: 12/14/2022] Open
Abstract
Congenital cataract, an ocular disease predominantly occurring within the first decade of life, is one of the leading causes of blindness in children. However, the molecular mechanisms underlying the pathogenesis of congenital cataract remain incompletely defined. Through whole-exome sequencing of a Chinese family with congenital cataract, we identified a potential pathological variant (p.G1943E) in PIKFYVE, which is located in the PIP kinase domain of the PIKFYVE protein. We demonstrated that heterozygous/homozygous disruption of PIKFYVE kinase domain, instead of overexpression of PIKFYVEG1943E in zebrafish mimicked the cataract defect in human patients, suggesting that haploinsufficiency, rather than dominant-negative inhibition of PIKFYVE activity caused the disease. Phenotypical analysis of pikfyve zebrafish mutants revealed that loss of Pikfyve caused aberrant vacuolation (accumulation of Rab7+Lc3+ amphisomes) in lens cells, which was significantly alleviated by treatment with the V-ATPase inhibitor bafilomycin A1 (Baf-A1). Collectively, we identified PIKFYVE as a novel causative gene for congenital cataract and pinpointed the potential application of Baf-A1 for the treatment of congenital cataract caused by PIKFYVE deficiency.
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Affiliation(s)
- Shaoyi Mei
- Shenzhen Eye Institute, Shenzhen Eye Hospital Affiliated to Jinan University, Shenzhen, China
| | - Yi Wu
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Yan Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yubo Cui
- Department of Ophthalmology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The first Affiliated Hospital, Southern University of Science and Technology), Shenzhen, China
| | - Miao Zhang
- Shenzhen Eye Institute, Shenzhen Eye Hospital Affiliated to Jinan University, Shenzhen, China
| | - Tong Zhang
- Shenzhen Eye Institute, Shenzhen Eye Hospital Affiliated to Jinan University, Shenzhen, China
| | - Xiaosheng Huang
- Shenzhen Eye Institute, Shenzhen Eye Hospital Affiliated to Jinan University, Shenzhen, China
| | - Sejie Yu
- Department of Ophthalmology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The first Affiliated Hospital, Southern University of Science and Technology), Shenzhen, China
| | - Tao Yu
- Shenzhen Key Laboratory for Neuronal Structural Biology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, China
| | - Jun Zhao
- Department of Ophthalmology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The first Affiliated Hospital, Southern University of Science and Technology), Shenzhen, China
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13
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Wang X, Wang D, Wang Q, Huang W, Dongye M, Zhang X, Lin D, Lin Z, Li J, Hu W, Li X, Lin X, Zhong Q, Chen W, Lin H. Broadening the Mutation Spectrum in GJA8 and CHMP4B: Novel Missense Variants and the Associated Phenotypes in Six Chinese Han Congenital Cataracts Families. Front Med (Lausanne) 2021; 8:713284. [PMID: 34722561 PMCID: PMC8554029 DOI: 10.3389/fmed.2021.713284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 09/21/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: To broaden the mutation and phenotype spectrum of the GJA8 and CHMP4B genes and to reveal genotype-phenotype correlations in a cohort of Chinese patients with congenital cataracts (CCs). Methods: Six Chinese Han families with CCs inherited in an autosomal dominant (AD) pattern were recruited for this study. All patients underwent full ocular examinations. Genomic DNA was extracted from the leukocytes of peripheral blood collected from all available patients and their unaffected family members. Whole-exome sequencing (WES) was performed on all probands and at least one of their parents. Candidate variants were further confirmed by Sanger sequencing. Bioinformatic analysis with several computational predictive programs was performed to assess the impacts of the candidate variants on the structure and function of the proteins. Results: Four heterozygous candidate variants in three different genes (CRYBB2, GJA8, and CHMP4B) were identified in affected individuals from the six families, including two novel missense variants (GJA8: c.64G > C/p. G22R, and CHMP4B: c.587C > G/p. S196C), one missense mutation (CRYBB2: c.562C > T/p. R188C), and one small deletion (GJA8: c.426_440delGCTGGAGGGGACCCT/p.143_147delLEGTL). The three missense mutations were predicted as deleterious in all four computational prediction programs. In the homologous model, the GJA8: p.143_147delLEGTL mutation showed a sequence deletion of five amino acids at the cytoplasmic loop of the Cx50 protein, close to the third transmembrane domain. Patients carrying mutations in the same gene showed similar cataract phenotypes at a young age, including total cataracts, Y-sutural with fetal nuclear cataracts, and subcapsular cataracts. Conclusion: This study further expands the mutation spectrum and genotype-phenotype correlation of CRYBB2, GJA8, and CHMP4B underlying CCs. This study sheds light on the importance of comparing congenital cataract phenotypes in patients at the same age stage. It offers clues for the pathogenesis of CCs and allows for an early prenatal diagnosis for families carrying these genetic variants.
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Affiliation(s)
- Xun Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Dongni Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qiwei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Weiming Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Meimei Dongye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xulin Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Duoru Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zhuoling Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Weiling Hu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaoyan Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaoshan Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qiuping Zhong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Weirong Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Haotian Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.,Center for Precision Medicine, Sun Yat-sen University, Guangzhou, China
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14
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Placidi G, Campa CC. Deliver on Time or Pay the Fine: Scheduling in Membrane Trafficking. Int J Mol Sci 2021; 22:11773. [PMID: 34769203 PMCID: PMC8583995 DOI: 10.3390/ijms222111773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/23/2021] [Accepted: 10/27/2021] [Indexed: 12/12/2022] Open
Abstract
Membrane trafficking is all about time. Automation in such a biological process is crucial to ensure management and delivery of cellular cargoes with spatiotemporal precision. Shared molecular regulators and differential engagement of trafficking components improve robustness of molecular sorting. Sequential recruitment of low affinity protein complexes ensures directionality of the process and, concomitantly, serves as a kinetic proofreading mechanism to discriminate cargoes from the whole endocytosed material. This strategy helps cells to minimize losses and operating errors in membrane trafficking, thereby matching the appealed deadline. Here, we summarize the molecular pathways of molecular sorting, focusing on their timing and efficacy. We also highlight experimental procedures and genetic approaches to robustly probe these pathways, in order to guide mechanistic studies at the interface between biochemistry and quantitative biology.
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Affiliation(s)
- Giampaolo Placidi
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov.le 142, km 3.95, 10060 Candiolo, Italy;
- Candiolo Cancer Institute, FPO-IRCCS, Str. Prov.le 142, km 3.95, 10060 Candiolo, Italy
| | - Carlo C. Campa
- Italian Institute for Genomic Medicine, c/o IRCCS, Str. Prov.le 142, km 3.95, 10060 Candiolo, Italy;
- Candiolo Cancer Institute, FPO-IRCCS, Str. Prov.le 142, km 3.95, 10060 Candiolo, Italy
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15
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Shiels A, Hejtmancik JF. Inherited cataracts: Genetic mechanisms and pathways new and old. Exp Eye Res 2021; 209:108662. [PMID: 34126080 PMCID: PMC8595562 DOI: 10.1016/j.exer.2021.108662] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/13/2021] [Accepted: 06/01/2021] [Indexed: 12/15/2022]
Abstract
Cataract(s) is the clinical equivalent of lens opacity and is caused by light scattering either by high molecular weight protein aggregates in lens cells or disruption of the lens microarchitecture itself. Genetic mutations underlying inherited cataract can provide insight into the biological processes and pathways critical for lens homeostasis and transparency, classically including the lens crystallins, connexins, membrane proteins or components, and intermediate filament proteins. More recently, cataract genes have been expanded to include newly identified biological processes such as chaperone or protein degradation components, transcription or growth factors, channels active in the lens circulation, and collagen and extracellular matrix components. Cataracts can be classified by age, and in general congenital cataracts are caused by severe mutations resulting in major damage to lens proteins, while age related cataracts are associated with variants that merely destabilize proteins thereby increasing susceptibility to environmental insults over time. Thus there might be separate pathways to opacity for congenital and age-related cataracts whereby congenital cataracts induce the unfolded protein response (UPR) and apoptosis to destroy the lens microarchitecture, while in age related cataract high molecular weight (HMW) aggregates formed by denatured crystallins bound by α-crystallin result in light scattering without severe damage to the lens microarchitecture.
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Affiliation(s)
- Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892-1860, USA.
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16
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Adding Some "Splice" to Stress Eating: Autophagy, ESCRT and Alternative Splicing Orchestrate the Cellular Stress Response. Genes (Basel) 2021; 12:genes12081196. [PMID: 34440370 PMCID: PMC8393842 DOI: 10.3390/genes12081196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 12/12/2022] Open
Abstract
Autophagy is a widely studied self-renewal pathway that is essential for degrading damaged cellular organelles or recycling biomolecules to maintain cellular homeostasis, particularly under cellular stress. This pathway initiates with formation of an autophagosome, which is a double-membrane structure that envelopes cytosolic components and fuses with a lysosome to facilitate degradation of the contents. The endosomal sorting complexes required for transport (ESCRT) proteins play an integral role in controlling autophagosome fusion events and disruption to this machinery leads to autophagosome accumulation. Given the central role of autophagy in maintaining cellular health, it is unsurprising that dysfunction of this process is associated with many human maladies including cancer and neurodegenerative diseases. The cell can also rapidly respond to cellular stress through alternative pre-mRNA splicing that enables adaptive changes to the cell's proteome in response to stress. Thus, alternative pre-mRNA splicing of genes that are involved in autophagy adds another layer of complexity to the cell's stress response. Consequently, the dysregulation of alternative splicing of genes associated with autophagy and ESCRT may also precipitate disease states by either reducing the ability of the cell to respond to stress or triggering a maladaptive response that is pathogenic. In this review, we summarize the diverse roles of the ESCRT machinery and alternative splicing in regulating autophagy and how their dysfunction can have implications for human disease.
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17
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Sun P, Lu Q, Li Z, Qin N, Jiang Y, Ma H, Jin G, Yu H, Dai J. Assessment of prognostic prediction models for gastric cancer using genomic and transcriptomic profiles. Meta Gene 2021. [DOI: 10.1016/j.mgene.2021.100890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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18
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Rodger C, Flex E, Allison RJ, Sanchis-Juan A, Hasenahuer MA, Cecchetti S, French CE, Edgar JR, Carpentieri G, Ciolfi A, Pantaleoni F, Bruselles A, Onesimo R, Zampino G, Marcon F, Siniscalchi E, Lees M, Krishnakumar D, McCann E, Yosifova D, Jarvis J, Kruer MC, Marks W, Campbell J, Allen LE, Gustincich S, Raymond FL, Tartaglia M, Reid E. De Novo VPS4A Mutations Cause Multisystem Disease with Abnormal Neurodevelopment. Am J Hum Genet 2020; 107:1129-1148. [PMID: 33186545 PMCID: PMC7820634 DOI: 10.1016/j.ajhg.2020.10.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/26/2020] [Indexed: 11/30/2022] Open
Abstract
The endosomal sorting complexes required for transport (ESCRTs) are essential for multiple membrane modeling and membrane-independent cellular processes. Here we describe six unrelated individuals with de novo missense variants affecting the ATPase domain of VPS4A, a critical enzyme regulating ESCRT function. Probands had structural brain abnormalities, severe neurodevelopmental delay, cataracts, growth impairment, and anemia. In cultured cells, overexpression of VPS4A mutants caused enlarged endosomal vacuoles resembling those induced by expression of known dominant-negative ATPase-defective forms of VPS4A. Proband-derived fibroblasts had enlarged endosomal structures with abnormal accumulation of the ESCRT protein IST1 on the limiting membrane. VPS4A function was also required for normal endosomal morphology and IST1 localization in iPSC-derived human neurons. Mutations affected other ESCRT-dependent cellular processes, including regulation of centrosome number, primary cilium morphology, nuclear membrane morphology, chromosome segregation, mitotic spindle formation, and cell cycle progression. We thus characterize a distinct multisystem disorder caused by mutations affecting VPS4A and demonstrate that its normal function is required for multiple human developmental and cellular processes.
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Affiliation(s)
- Catherine Rodger
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK; Department of Medical Genetics, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Elisabetta Flex
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Rachel J Allison
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK; Department of Medical Genetics, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Alba Sanchis-Juan
- Department of Haematology, NHS Blood and Transplant Centre, University of Cambridge, Cambridge CB2 0XY, UK; NIHR BioResource, Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Marcia A Hasenahuer
- Department of Medical Genetics, University of Cambridge, Cambridge CB2 0QQ, UK; European Molecular Biology Laboratory - European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Serena Cecchetti
- Microscopy Area, Core Facilities, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Courtney E French
- Department of Medical Genetics, University of Cambridge, Cambridge CB2 0QQ, UK
| | - James R Edgar
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK; Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
| | - Giovanna Carpentieri
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 00161, Italy; Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Andrea Ciolfi
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Francesca Pantaleoni
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy
| | - Alessandro Bruselles
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Roberta Onesimo
- Fondazione Policlinico Universitario A. Gemelli-IRCCS, Rome 00168, Italy
| | - Giuseppe Zampino
- Fondazione Policlinico Universitario A. Gemelli-IRCCS, Rome 00168, Italy; Università Cattolica del Sacro Cuore, Rome 00168, Italy
| | - Francesca Marcon
- Unit of Mechanisms, Biomarkers and Models, Department of Environment and Health, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Ester Siniscalchi
- Unit of Mechanisms, Biomarkers and Models, Department of Environment and Health, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Melissa Lees
- Department of Clinical Genetics, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Deepa Krishnakumar
- Department of Paediatric Neurology, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK
| | - Emma McCann
- Department of Clinical Genetics, Liverpool Women's Hospital, Liverpool L8 7SS, UK
| | - Dragana Yosifova
- Department of Medical Genetics, Guys' and St Thomas' NHS Foundation Trust, London SE1 9RT, UK
| | - Joanna Jarvis
- Clinical Genetics, Birmingham Women's and Children's NHS Foundation Trust, Birmingham B15 2TG, UK
| | | | - Warren Marks
- Cook Children's Medical Centre, Fort Worth, TX 76104, USA
| | - Jonathan Campbell
- Colchester Hospital, East Suffolk and North Essex NHS Foundation Trust, Essex CO4 5JL, UK
| | - Louise E Allen
- Ophthalmology Department, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK
| | - Stefano Gustincich
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova 16163, Italy; Area of Neuroscience, SISSA, Trieste 34136, Italy
| | - F Lucy Raymond
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK; Department of Medical Genetics, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Rome 00146, Italy.
| | - Evan Reid
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK; Department of Medical Genetics, University of Cambridge, Cambridge CB2 0QQ, UK.
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19
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Tamargo-Gómez I, Fernández ÁF, Mariño G. Pathogenic Single Nucleotide Polymorphisms on Autophagy-Related Genes. Int J Mol Sci 2020; 21:ijms21218196. [PMID: 33147747 PMCID: PMC7672651 DOI: 10.3390/ijms21218196] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 02/06/2023] Open
Abstract
In recent years, the study of single nucleotide polymorphisms (SNPs) has gained increasing importance in biomedical research, as they can either be at the molecular origin of a determined disorder or directly affect the efficiency of a given treatment. In this regard, sequence variations in genes involved in pro-survival cellular pathways are commonly associated with pathologies, as the alteration of these routes compromises cellular homeostasis. This is the case of autophagy, an evolutionarily conserved pathway that counteracts extracellular and intracellular stressors by mediating the turnover of cytosolic components through lysosomal degradation. Accordingly, autophagy dysregulation has been extensively described in a wide range of human pathologies, including cancer, neurodegeneration, or inflammatory alterations. Thus, it is not surprising that pathogenic gene variants in genes encoding crucial effectors of the autophagosome/lysosome axis are increasingly being identified. In this review, we present a comprehensive list of clinically relevant SNPs in autophagy-related genes, highlighting the scope and relevance of autophagy alterations in human disease.
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Affiliation(s)
- Isaac Tamargo-Gómez
- Instituto de Investigación Sanitaria del Principado de Asturias, 33011 Oviedo, Spain;
- Departamento de Biología Funcional, Universidad de Oviedo, 33011 Oviedo, Spain
| | - Álvaro F. Fernández
- Instituto de Investigación Sanitaria del Principado de Asturias, 33011 Oviedo, Spain;
- Departamento de Biología Funcional, Universidad de Oviedo, 33011 Oviedo, Spain
- Correspondence: (Á.F.F.); (G.M.); Tel.: +34-985652416 (G.M.)
| | - Guillermo Mariño
- Instituto de Investigación Sanitaria del Principado de Asturias, 33011 Oviedo, Spain;
- Departamento de Biología Funcional, Universidad de Oviedo, 33011 Oviedo, Spain
- Correspondence: (Á.F.F.); (G.M.); Tel.: +34-985652416 (G.M.)
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20
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Davies BA, Morton LO, Jefferson JR, Rozeveld CN, Doskey LC, LaRusso NF, Katzmann DJ. Polarized human cholangiocytes release distinct populations of apical and basolateral small extracellular vesicles. Mol Biol Cell 2020; 31:2463-2474. [PMID: 32845745 PMCID: PMC7851850 DOI: 10.1091/mbc.e19-03-0133] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Intercellular communication is critical for organismal homeostasis, and defects can contribute to human disease states. Polarized epithelial cells execute distinct signaling agendas via apical and basolateral surfaces to communicate with different cell types. Small extracellular vesicles (sEVs), including exosomes and small microvesicles, represent an understudied form of intercellular communication in polarized cells. Human cholangiocytes, epithelial cells lining bile ducts, were cultured as polarized epithelia in a Transwell system as a model with which to study polarized sEV communication. Characterization of isolated apically and basolaterally released EVs revealed enrichment in sEVs. However, differences in apical and basolateral sEV composition and numbers were observed. Genetic or pharmacological perturbation of cellular machinery involved in the biogenesis of intralumenal vesicles at endosomes (the source of exosomes) revealed general and domain-specific effects on sEV biogenesis/release. Additionally, analyses of signaling revealed distinct profiles of activation depending on sEV population, target cell, and the function of the endosomal sorting complex required for transport (ESCRT)-associated factor ALG-2–interacting protein X (ALIX) within the donor cells. These results support the conclusion that polarized cholangiocytes release distinct sEV pools to mediate communication via their apical and basolateral domains and suggest that defective ESCRT function may contribute to disease states through altered sEV signaling.
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Affiliation(s)
- Brian A Davies
- Biochemistry and Molecular Biology Department, Mayo Clinic, Rochester, MN 55905
| | - Leslie O Morton
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
| | - John R Jefferson
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905.,Chemistry Department, Luther College, Decorah, IA 52101
| | - Cody N Rozeveld
- Biochemistry and Molecular Biology Department, Mayo Clinic, Rochester, MN 55905.,Mayo Clinic Graduate School of Biomedical Science, Mayo Clinic, Rochester, MN 55905
| | - Luke C Doskey
- Biochemistry and Molecular Biology Department, Mayo Clinic, Rochester, MN 55905.,Mayo Clinic Graduate School of Biomedical Science, Mayo Clinic, Rochester, MN 55905
| | - Nicholas F LaRusso
- Biochemistry and Molecular Biology Department, Mayo Clinic, Rochester, MN 55905.,Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN 55905
| | - David J Katzmann
- Biochemistry and Molecular Biology Department, Mayo Clinic, Rochester, MN 55905.,Mayo Clinic Graduate School of Biomedical Science, Mayo Clinic, Rochester, MN 55905
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21
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Jung E, Choi TI, Lee JE, Kim CH, Kim J. ESCRT subunit CHMP4B localizes to primary cilia and is required for the structural integrity of the ciliary membrane. FASEB J 2019; 34:1331-1344. [PMID: 31914703 DOI: 10.1096/fj.201901778r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 09/30/2019] [Accepted: 11/14/2019] [Indexed: 12/14/2022]
Abstract
Proteins specialized in the detection, generation, or stabilization of membrane curvature play important roles in establishing various morphologies of cells and cellular organelles. Primary cilia are cellular organelles that protrude from the cell surface using a microtubule-based cytoskeleton called the axoneme as a structural support. It is unclear whether the integrity of the high curvature of the ciliary membrane depends on membrane curvature-related proteins. Charged Multivesicular Body Protein 4B (CHMP4B), a subunit of the endosomal sorting complexes required for transport (ESCRT), can stabilize membrane curvature. Here we show that CHMP4B is involved in the assembly and maintenance of primary cilia. CHMP4B was localized to primary cilia in mammalian cells. Knockdown of CHMP4B interfered with cilium assembly and also caused fragmentation of preexisting cilia. By contrast, cilium formation was unaffected by the interruption of the ESCRT-dependent endocytic degradation pathway. Morpholino (MO)-mediated CHMP4B depletion in zebrafish embryos induced characteristic phenotypes of ciliary defects such as curved body axis, hydrocephalus, otolith malformation, and kidney cyst. Our study reveals a new role for the multifunctional protein CHMP4B as a key factor in maintaining the structural integrity of primary cilia.
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Affiliation(s)
- Eunji Jung
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology, Daejeon, Korea
| | - Tae-Ik Choi
- Department of Biology, Chungnam National University, Daejeon, Korea
| | - Ji-Eun Lee
- Department of Health Sciences and Technology, Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Seoul, Korea
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon, Korea
| | - Joon Kim
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology, Daejeon, Korea.,Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Korea
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22
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Molecular genetics of congenital cataracts. Exp Eye Res 2019; 191:107872. [PMID: 31770519 DOI: 10.1016/j.exer.2019.107872] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 11/12/2019] [Accepted: 11/13/2019] [Indexed: 12/18/2022]
Abstract
Congenital cataracts, the most common cause of visual impairment and blindness in children worldwide, have diverse etiologies. According to statistics analysis, about one quarter of congenital cataracts caused by genetic defects. Various mutations of more than one hundred genes have been identified in hereditary cataracts so far. In this review, we briefly summarize recent developments about the genetics, molecular mechanisms, and treatments of congenital cataracts. The studies of these pathogenic mutations and molecular genetics is making it possible for us to comprehend the underlying mechanisms of cataractogenesis and providing new insights into the preventive, diagnostic and therapeutic approaches of cataracts.
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23
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Abstract
Cataract, the clinical correlate of opacity or light scattering in the eye lens, is usually caused by the presence of high-molecular-weight (HMW) protein aggregates or disruption of the lens microarchitecture. In general, genes involved in inherited cataracts reflect important processes and pathways in the lens including lens crystallins, connexins, growth factors, membrane proteins, intermediate filament proteins, and chaperones. Usually, mutations causing severe damage to proteins cause congenital cataracts, while milder variants increasing susceptibility to environmental insults are associated with age-related cataracts. These may have different pathogenic mechanisms: Congenital cataracts induce the unfolded protein response and apoptosis. By contrast, denatured crystallins in age-related cataracts are bound by α-crystallin and form light-scattering HMW aggregates. New therapeutic approaches to age-related cataracts use chemical chaperones to solubilize HMW aggregates, while attempts are being made to regenerate lenses using endogenous stem cells to treat congenital cataracts.
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Affiliation(s)
- Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA;
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-1860, USA;
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24
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Zhou Y, Bennett TM, Shiels A. A charged multivesicular body protein (CHMP4B) is required for lens growth and differentiation. Differentiation 2019; 109:16-27. [PMID: 31404815 PMCID: PMC6815251 DOI: 10.1016/j.diff.2019.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 10/26/2022]
Abstract
Charged multivesicular body protein 4B (CHMP4B) functions as a core component of the endosome sorting complex required for transport-III (ESCRT-III) machinery that facilitates diverse membrane remodeling and scission processes in eukaryotes. Mutations in the human CHMP4B gene underlie rare, inherited forms of early-onset lens opacities or cataract. Here we have characterized the lens phenotypes of mutant (knock-in) mice harboring a human cataract-associated mutation (p.D129V) in CHMP4B (Chmp4b-mutant) and conditional knockdown mice deficient in lens CHMP4B (Chmp4b-CKD). In situ hybridization localized Chmp4b transcripts to lens epithelial cells and elongating fiber cells at the lens equator. Heterozygous Chmp4b-mutant (D/V) mice were viable and fertile with lenses grossly similar to those of wild-type. However, homozygous Chmp4b-mutant (V/V) mice died by embryonic day 15.5 (E15.5) with grossly abnormal eye and brain histology. Chmp4b-CKD mice displayed variable degrees of lens dysmorphology including lens ablation. Immuno-localization of aquaporin-0 (AQP0) revealed lens fiber cell degeneration in homozygous Chmp4b-mutant (V/V) mouse embryos and in embryonic and postnatal Chmp4b-CKD mice. DNA fragmentation (TUNEL) analysis revealed global cell death in homozygous Chmp4b-mutant (V/V) embryos, whereas, cell death was confined to the lens of Chmp4b-CKD mice. Immuno-localization of the monocyte/macrophage marker macrosialin (CD68) suggested that severe lens degeneration in Chmp4b-CKD mice resulted in an ocular immune cell response. Collectively, these mouse data suggest that (1) heterozygous, germ-line mutations in Chmp4b may not manifest as cataract, (2) homozygous, germ-line mutations in Chmp4b are embryonic lethal, and (3) conditional loss of Chmp4b results in arrest of lens growth and differentiation.
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Affiliation(s)
- Yuefang Zhou
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Thomas M Bennett
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA.
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25
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Weatherbee BAT, Barton JR, Siddam AD, Anand D, Lachke SA. Molecular characterization of the human lens epithelium-derived cell line SRA01/04. Exp Eye Res 2019; 188:107787. [PMID: 31479653 DOI: 10.1016/j.exer.2019.107787] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 08/26/2019] [Accepted: 08/30/2019] [Indexed: 12/18/2022]
Abstract
Cataract-associated gene discovery in human and animal models have informed on key aspects of human lens development, homeostasis and pathology. Additionally, in vitro models such as the culture of permanent human lens epithelium-derived cell lines (LECs) have also been utilized to understand the molecular biology of lens cells. However, these resources remain uncharacterized, specifically regarding their global gene expression and suitability to model lens cell biology. Therefore, we sought to molecularly characterize gene expression in the human LEC, SRA01/04, which is commonly used in lens studies. We first performed short tandem repeat (STR) analysis and validated SRA01/04 LEC for its human origin, as recommended by the eye research community. Next, we used Illumina HumanHT-12 v3.0 Expression BeadChip arrays to gain insights into the global gene expression profile of SRA01/04. Comparative analysis of SRA01/04 microarray data was performed using other resources such as the lens expression database iSyTE (integrated Systems Tool for Eye gene discovery), the cataract gene database Cat-Map and the published lens literature. This analysis showed that SRA01/04 significantly expresses >40% of the top iSyTE lens-enriched genes (313 out of 749) across different developmental stages. Further, SRA01/04 also significantly expresses ~53% (168 out of 318) of cataract-associated genes in Cat-Map. We also performed comparative gene expression analysis between SRA01/04 cells and the previously validated mouse LEC 21EM15. To gain insight into whether SRA01/04 reflects epithelial or fiber cell characteristics, we compared its gene expression profile to previously reported differentially expressed genes in isolated mouse lens epithelial and fiber cells. This analysis suggests that SRA01/04 has reduced expression of several fiber cell-enriched genes. In agreement with these findings, cell culture analysis demonstrates that SRA01/04 has reduced potential to initiate spontaneous lentoid body formation compared to 21EM15 cells. Next, to independently validate SRA01/04 microarray gene expression, we subjected several candidate genes to RT-PCR and RT-qPCR assays. This analysis demonstrates that SRA01/04 supports expression of many key genes associated with lens development and cataract, including CRYAB, CRYBB2, CRYGS, DKK3, EPHA2, ETV5, GJA1, HSPB1, INPPL1, ITGB1, PAX6, PVRL3, SFRP1, SPARC, TDRD7, and VIM, among others, and therefore can be relevant for understanding the mechanistic basis of these factors. At the same time, SRA01/04 cells do not exhibit robust expression of several genes known to be important to lens biology and cataract such as ALDH1A1, COL4A6, CP, CRYBA4, FOXE3, HMX1, HSF4, MAF, MEIS1, PITX3, PRX, SIX3, and TRPM3, among many others. Therefore, the present study offers a rich transcript-level resource for case-by-case evaluation of the potential advantages and limitations of SRA01/04 cells prior to their use in downstream investigations. In sum, these data show that the human LEC, SRA01/04, exhibits lens epithelial cell-like character reflected in the expression of several lens-enriched and cataract-associated genes, and therefore can be considered as a useful in vitro resource when combined with in vivo studies to gain insight into specific aspects of human lens epithelial cells.
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Affiliation(s)
| | - Joshua R Barton
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Archana D Siddam
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA; Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, 19716, USA.
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26
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Chen P, Chen H, Pan XJ, Tang SZ, Xia YJ, Zhang H. Novel mutations in CRYBB1/CRYBB2 identified by targeted exome sequencing in Chinese families with congenital cataract. Int J Ophthalmol 2018; 11:1577-1582. [PMID: 30364188 PMCID: PMC6192965 DOI: 10.18240/ijo.2018.10.01] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 05/08/2018] [Indexed: 11/23/2022] Open
Abstract
AIM To summarize the phenotypes and identify the underlying genetic cause of the CRYBB1 and CRYBB2 gene responsible for congenital cataract in two Chinese families. METHODS Detailed family histories and clinical data were collected from patients during an ophthalmologic examination. Of 523 inheritable genetic vision system-related genes were captured and sequenced by targeted next-generation sequencing, and the results were confirmed by Sanger sequencing. The possible functional impacts of an amino acid substitution were performed with PolyPhen-2 and SIFT predictions. RESULTS The patients in the two families were affected with congenital cataract. Sixty-five (FAMILY-1) and sixty-two (FAMILY-2) single-nucleotide polymorphisms and indels were selected by recommended filtering criteria. Segregation was then analyzed by applying Sanger sequencing with the family members. A heterozygous CRYBB1 mutation in exon 4 (c.347T>C, p.L116P) was identified in sixteen patients in FAMILY-1. A heterozygous CRYBB2 mutation in exon 5 (c.355G>A, p.G119R) was identified in three patients in FAMILY-2. Each mutation co-segregated with the affected individuals and did not exist in unaffected family members and 200 unrelated normal controls. The mutation was predicted to be highly conservative and to be deleterious by both PolyPhen-2 and SIFT. CONCLUSION The CRYBB1 mutation (c.347T>C) and CRYBB2 mutation (c.355G>A) are novel in patients with congenital cataract. We summarize the variable phenotypes among the patients, which expanded the phenotypic spectrum of congenital cataract in a different ethnic background.
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Affiliation(s)
- Peng Chen
- Qingdao University, Qingdao 266071, Shandong Province, China
| | - Hao Chen
- Qingdao University, Qingdao 266071, Shandong Province, China
| | - Xiao-Jing Pan
- Shandong Eye Institute, Qingdao 266071, Shandong Province, China
| | - Su-Zhen Tang
- Qingdao University, Qingdao 266071, Shandong Province, China
| | - Yu-Jun Xia
- Qingdao University, Qingdao 266071, Shandong Province, China
| | - Hui Zhang
- Jinan Second People's Hospital, Jinan 250022, Shandong Province, China
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27
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Zhou Z, Li L, Lu L, Min L. Identification of a missense mutation in MIP gene via mutation analysis of a Guangxi Zhuang ethnic pedigree with congenital nuclear cataracts. Exp Ther Med 2018; 16:3256-3260. [PMID: 30214549 DOI: 10.3892/etm.2018.6557] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 06/29/2018] [Indexed: 01/04/2023] Open
Abstract
At present, congenital cataract is the world's leading cause of blindness among children. The aim of the present study was to determine and analyze the genetic disorder associated with a congenital nuclear cataract in a three-generation family of Guangxi Zhuang ethnicity. A total of 3 affected individuals and 5 unaffected family members underwent appropriate comprehensive medical examinations, mainly of the eyes. The white blood cells of the family members were collected and genomic DNA was extracted from 100 healthy individuals, as the control group. The sequences of candidate genes were determined by polymerase chain reaction amplification followed by direct sequencing. The functional consequences of the mutation were analysed with biology software. A missense mutation (c.97C>T) was found in exon 1 of major intrinsic protein of lens fiber (MIP) gene. Therefore, the arginine of the highly conserved codon 33 was changed to cysteine. This mutation was identified in the affected family members, but not identified in unaffected family members or the 100 normal controls. The mutation in the MIP gene is the genetic cause of the congenital cataract in the ethnic Guangxi Zhuang family.
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Affiliation(s)
- Zhou Zhou
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, P.R. China
| | - Li Li
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, P.R. China
| | - Lu Lu
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, P.R. China
| | - Li Min
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, Guangxi 530021, P.R. China
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28
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Reis LM, Semina EV. Genetic landscape of isolated pediatric cataracts: extreme heterogeneity and variable inheritance patterns within genes. Hum Genet 2018; 138:847-863. [PMID: 30187164 DOI: 10.1007/s00439-018-1932-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 08/29/2018] [Indexed: 12/12/2022]
Abstract
Pediatric cataract represents an important cause of pediatric visual impairment. While both genetic and environmental causes for pediatric cataract are known, a large proportion remains idiopathic. The purpose of this review is to discuss genes involved in isolated pediatric cataract, with a focus on variable inheritance patterns within genes. Mutations in over 52 genes are known to cause isolated pediatric cataract, with a major contribution from genes encoding for crystallins, transcription factors, membrane proteins, and cytoskeletal proteins. Interestingly, both dominant and recessive inheritance patterns have been reported for mutations in 13 different cataract genes. For some genes, dominant and recessive alleles represent distinct types of mutations, but for many, especially missense variants, there are no clear patterns to distinguish between dominant and recessive alleles. Further research into the functional effects of these mutations, as well as additional data on the frequency of the identified variants, is needed to clarify variant pathogenicity. Exome sequencing continues to be successful in identifying novel genes associated with congenital cataract but is hindered by the extreme genetic heterogeneity of this condition. The large number of idiopathic cases suggests that more genes and potentially novel mechanisms of gene disruption remain to be identified.
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Affiliation(s)
- Linda M Reis
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA
| | - Elena V Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin, Milwaukee, WI, 53226, USA. .,Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, 53226, USA.
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29
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Arii J, Watanabe M, Maeda F, Tokai-Nishizumi N, Chihara T, Miura M, Maruzuru Y, Koyanagi N, Kato A, Kawaguchi Y. ESCRT-III mediates budding across the inner nuclear membrane and regulates its integrity. Nat Commun 2018; 9:3379. [PMID: 30139939 PMCID: PMC6107581 DOI: 10.1038/s41467-018-05889-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 07/28/2018] [Indexed: 11/30/2022] Open
Abstract
Vesicle-mediated nucleocytoplasmic transport is a nuclear pore-independent mechanism for the nuclear export of macromolecular complexes, but the molecular basis for this transport remains largely unknown. Here we show that endosomal sorting complex required for transport-III (ESCRT-III) is recruited to the inner nuclear membrane (INM) during the nuclear export of herpes simplex virus 1 (HSV-1). Scission during HSV-1 budding through the INM is prevented by depletion of ESCRT-III proteins. Interestingly, in uninfected human cells, the depletion of ESCRT-III proteins induces aberrant INM proliferation. Our results show that HSV-1 expropriates the ESCRT-III machinery in infected cells for scission of the INM to produce vesicles containing progeny virus nucleocapsids. In uninfected cells, ESCRT-III regulates INM integrity by downregulating excess INM. The endosomal sorting complex required for transport-III (ESCRT-III) has been implicated in the packaging of HIV and HSV-1 viruses in the cytoplasm. Here the authors show that ESCRT-III proteins are required for the transport of HSV-1 nucleocapsids from nucleoplasm to cytosol through the nuclear envelope and confirm that the same mechanism is also used for the nucleocytoplasmic transport of RNP in Drosophila cells.
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Affiliation(s)
- Jun Arii
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Mizuki Watanabe
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Fumio Maeda
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Noriko Tokai-Nishizumi
- Microscope Core Laboratory, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Takahiro Chihara
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.,Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8526, Japan
| | - Masayuki Miura
- Department of Genetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Yuhei Maruzuru
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Naoto Koyanagi
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Akihisa Kato
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan
| | - Yasushi Kawaguchi
- Division of Molecular Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan. .,Department of Infectious Disease Control, International Research Center for Infectious Diseases, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo, 108-8639, Japan.
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Zhang XH, Da Wang J, Jia HY, Zhang JS, Li Y, Xiong Y, Li J, Li XX, Huang Y, Zhu GY, Rong SS, Wormstone M, Wan XH. Mutation profiles of congenital cataract genes in 21 northern Chinese families. Mol Vis 2018; 24:471-477. [PMID: 30078984 PMCID: PMC6054834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 07/18/2018] [Indexed: 11/29/2022] Open
Abstract
PURPOSE To identify disease-causing gene mutations in 21 northern Chinese families with congenital cataracts. METHODS Medical record collection and ophthalmologic examinations were conducted for 21 families with congenital cataracts. A volume of 5 ml of peripheral blood was drawn from each participant for genomic DNA isolation. Thirty-four known candidate genes for congenital cataracts were analyzed in the probands of 21 families with targeted next-generation sequencing (NGS). Bioinformatics analysis of the sequence variants was performed through computational predictive programs. Sanger sequencing was used to perform the cosegregation analysis. Genotyping and haplotype analyses were performed in two patients with a p.V44M mutation in the GJA8 gene. RESULTS Twelve disease-causing mutations were detected in 13 of the 21 patients, and the mutation detection rate was 61.9%. The 12 gene mutations included one nonsense, one splice site, seven missense, and three insert and deletion (INDELs) mutations. Four mutations were novel. Of the 13 patients with pathogenic gene mutations, five (38.5%) were affected by mutations in lens crystallin genes, three (23%) were affected by mutations in connexin genes, three (23%) were affected by mutations in transcription factor genes, one (7.7%) was affected by a mutation in a transmembrane transporter gene, and one (7.7%) was affected by a mutation in a chromatin-modifying protein gene. Two families carried the p.V44M mutation in the GJA8 gene. Haplotype analysis revealed a chromosome region of 475 kb containing the mutation in the GJA8 gene was harbored by two families. CONCLUSIONS Compared with traditional Sanger sequencing, targeted NGS for genetic testing of congenital cataracts markedly increases the mutation detection rate and is cost-effective. The p.V44M mutation in the GJA8 gene was the most common mutation and was due to a founder effect within the Chinese cohort studied. The results of this study expand the gene mutation spectrum of congenital cataracts.
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Affiliation(s)
- Xiao Hui Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University; Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
| | - Jin Da Wang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University; Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
| | - Hong Yan Jia
- Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, China
| | - Jing Shang Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University; Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
| | - Yang Li
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University; Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
| | - Ying Xiong
- Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, China
| | - Jing Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, China
| | - Xiao Xia Li
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University; Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
| | - Yao Huang
- Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University, Beijing Key Laboratory of Ophthalmology and Visual Sciences, Beijing, China
| | - Gu Yu Zhu
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University; Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
| | - Shi Song Rong
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear, Boston, MA
| | - Michael Wormstone
- School of Biological Sciences, Norwich Research Park, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Xiu Hua Wan
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University; Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
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31
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Javadiyan S, Craig JE, Souzeau E, Sharma S, Lower KM, Mackey DA, Staffieri SE, Elder JE, Taranath D, Straga T, Black J, Pater J, Casey T, Hewitt AW, Burdon KP. High-Throughput Genetic Screening of 51 Pediatric Cataract Genes Identifies Causative Mutations in Inherited Pediatric Cataract in South Eastern Australia. G3 (BETHESDA, MD.) 2017; 7:3257-3268. [PMID: 28839118 PMCID: PMC5633377 DOI: 10.1534/g3.117.300109] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 08/15/2017] [Indexed: 01/09/2023]
Abstract
Pediatric cataract is a leading cause of childhood blindness. This study aimed to determine the genetic cause of pediatric cataract in Australian families by screening known disease-associated genes using massively parallel sequencing technology. We sequenced 51 previously reported pediatric cataract genes in 33 affected individuals with a family history (cases with previously known or published mutations were excluded) using the Ion Torrent Personal Genome Machine. Variants were prioritized for validation if they were predicted to alter the protein sequence and were absent or rare with minor allele frequency <1% in public databases. Confirmed mutations were assessed for segregation with the phenotype in all available family members. All identified novel or previously reported cataract-causing mutations were screened in 326 unrelated Australian controls. We detected 11 novel mutations in GJA3, GJA8, CRYAA, CRYBB2, CRYGS, CRYGA, GCNT2, CRYGA, and MIP; and three previously reported cataract-causing mutations in GJA8, CRYAA, and CRYBB2 The most commonly mutated genes were those coding for gap junctions and crystallin proteins. Including previous reports of pediatric cataract-associated mutations in our Australian cohort, known genes account for >60% of familial pediatric cataract in Australia, indicating that still more causative genes remain to be identified.
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Affiliation(s)
- Shari Javadiyan
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Jamie E Craig
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Emmanuelle Souzeau
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Shiwani Sharma
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Karen M Lower
- Department of Haematology and Genetic Pathology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - David A Mackey
- Centre for Ophthalmology and Visual Science, University of Western Australia, Lions Eye Institute, Perth, Western Australia 6009, Australia
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria 3002, Australia
- Department of Surgery, University of Melbourne, Victoria 3010, Australia
| | - Sandra E Staffieri
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria 3002, Australia
- Department of Surgery, University of Melbourne, Victoria 3010, Australia
- Department of Ophthalmology, Royal Children's Hospital, Melbourne, Victoria 3052, Australia
| | - James E Elder
- Department of Surgery, University of Melbourne, Victoria 3010, Australia
- Department of Ophthalmology, Royal Children's Hospital, Melbourne, Victoria 3052, Australia
| | - Deepa Taranath
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
| | - Tania Straga
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
| | - Joanna Black
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
| | - John Pater
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
| | - Theresa Casey
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
| | - Alex W Hewitt
- Department of Surgery, University of Melbourne, Victoria 3010, Australia
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, South Australia 5006, Australia
- Department of Paediatrics, University of Melbourne, Victoria 3010, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Kathryn P Burdon
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, South Australia 5042, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania 7000, Australia
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32
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Horner DS, Pasini ME, Beltrame M, Mastrodonato V, Morelli E, Vaccari T. ESCRT genes and regulation of developmental signaling. Semin Cell Dev Biol 2017; 74:29-39. [PMID: 28847745 DOI: 10.1016/j.semcdb.2017.08.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 08/06/2017] [Accepted: 08/18/2017] [Indexed: 11/30/2022]
Abstract
ESCRT (Endosomal Sorting Complex Required for Transport) proteins have been shown to control an increasing number of membrane-associated processes. Some of these, and prominently regulation of receptor trafficking, profoundly shape signal transduction. Evidence in fungi, plants and multiple animal models support the emerging concept that ESCRTs are main actors in coordination of signaling with the changes in cells and tissues occurring during development and homeostasis. Consistent with their pleiotropic function, ESCRTs are regulated in multiple ways to tailor signaling to developmental and homeostatic needs. ESCRT activity is crucial to correct execution of developmental programs, especially at key transitions, allowing eukaryotes to thrive and preventing appearance of congenital defects.
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Affiliation(s)
- David S Horner
- Dipartimento di Bioscienze, Universita' degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Maria E Pasini
- Dipartimento di Bioscienze, Universita' degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Monica Beltrame
- Dipartimento di Bioscienze, Universita' degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy
| | - Valeria Mastrodonato
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milano, Italy
| | - Elena Morelli
- IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milano, Italy
| | - Thomas Vaccari
- Dipartimento di Bioscienze, Universita' degli Studi di Milano, Via Celoria 26, 20133 Milano, Italy; IFOM, The FIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milano, Italy.
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33
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Shen C, Wang J, Wu X, Wang F, Liu Y, Guo X, Zhang L, Cao Y, Cao X, Ma H. Next-generation sequencing for D47N mutation in Cx50 analysis associated with autosomal dominant congenital cataract in a six-generation Chinese family. BMC Ophthalmol 2017; 17:73. [PMID: 28526010 PMCID: PMC5437554 DOI: 10.1186/s12886-017-0476-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 05/15/2017] [Indexed: 11/26/2022] Open
Abstract
Background Congenital cataract is the most frequent cause of blindness during infancy or early childhood. To date, more than 40 loci associated with congenital cataract have been identified, including at least 26 genes on different chromosomes associated with inherited cataract. This present study aimed to identify the genetic mutation in a six-generation Chinese family affected with congenital cataract. Methods A detailed six-generation Chinese cataract family history and clinical data of the family members were recorded. A total of 27 family members, including 14 affected and 13 unaffected individuals were recruited. Whole exome sequencing was performed to determine the disease-causing mutation. Sanger sequencing was used to confirm the results. Results A known missense mutation, c. 139G > A (p. D47N), in Cx50 was identified. This mutation co-segregated with all affected individuals and was not observed in the unaffected family members or in 100 unrelated controls. The homology modeling showed that the structure of the mutant protein was different with that wild-type Cx50. Conclusions The missense mutation c.139G > A in GJA8 gene is associated with autosomal dominant congenital cataract in a six-generation Chinese family. The result of this present study provides further evidence that the p. D47N mutation in CX50 is a hot-spot mutation.
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Affiliation(s)
- Chao Shen
- Department of Clinical Diagnosis, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China
| | - Jingbing Wang
- Department of Clinical Diagnosis, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China
| | - Xiaotang Wu
- Department of Clinical Diagnosis, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China
| | - Fuchao Wang
- Department of Clinical Diagnosis, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China
| | - Yang Liu
- Department of Ophthalmology, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China
| | - Xiaoying Guo
- Department of Clinical Diagnosis, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China
| | - Lina Zhang
- Department of Clinical Diagnosis, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China
| | - Yanfei Cao
- Department of Clinical Diagnosis, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China
| | - Xiuhua Cao
- Department of Clinical Diagnosis, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China
| | - Hongxing Ma
- Department of Clinical Diagnosis, General Hospital of Daqing Oil Field, Daqing, Heilongjiang Province, People's Republic of China.
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Javadiyan S, Craig JE, Sharma S, Lower KM, Casey T, Haan E, Souzeau E, Burdon KP. Novel missense mutation in the bZIP transcription factor, MAF, associated with congenital cataract, developmental delay, seizures and hearing loss (Aymé-Gripp syndrome). BMC MEDICAL GENETICS 2017; 18:52. [PMID: 28482824 PMCID: PMC5422868 DOI: 10.1186/s12881-017-0414-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 04/28/2017] [Indexed: 01/24/2023]
Abstract
Background Cataract is a major cause of severe visual impairment in childhood. The purpose of this study was to determine the genetic cause of syndromic congenital cataract in an Australian mother and son. Method Fifty-one genes associated with congenital cataract were sequenced in the proband using a custom Ampliseq library on the Ion Torrent Personal Genome Machine (PGM). Reads were aligned against the human genome (hg19) and variants were annotated. Variants were prioritised for validation by Sanger sequencing if they were novel, rare or previously reported to be associated with paediatric cataract and were predicted to be protein changing. Variants were assessed for segregation with the phenotype in the affected mother. Result A novel likely pathogenic variant was identified in the transactivation domain of the MAF gene (c.176C > G, p.(Pro59Arg)) in the proband and his affected mother., but was absent in 326 unrelated controls and absent from public variant databases. Conclusion The MAF variant is the likely cause of the congenital cataract, Asperger syndrome, seizures, hearing loss and facial characteristics in the proband, providinga diagnosis of Aymé-Gripp syndrome for the family. Electronic supplementary material The online version of this article (doi:10.1186/s12881-017-0414-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shari Javadiyan
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, Australia.
| | - Jamie E Craig
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, Australia
| | - Shiwani Sharma
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, Australia
| | - Karen M Lower
- Department of Haematology and Genetic Pathology, School of Medicine, Flinders University, Adelaide, Australia
| | - Theresa Casey
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, Australia
| | - Eric Haan
- SA Clinical Genetics Service, SA Pathology (at Women's and Children's Hospital), Adelaide, Australia.,School of Medicine, University of Adelaide, Adelaide, Australia
| | - Emmanuelle Souzeau
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, Australia
| | - Kathryn P Burdon
- Department of Ophthalmology, School of Medicine, Flinders University, Adelaide, Australia.,Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
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35
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Messina-Baas O, Cuevas-Covarrubias SA. Inherited Congenital Cataract: A Guide to Suspect the Genetic Etiology in the Cataract Genesis. Mol Syndromol 2017; 8:58-78. [PMID: 28611546 DOI: 10.1159/000455752] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2016] [Indexed: 01/23/2023] Open
Abstract
Cataracts are the principal cause of treatable blindness worldwide. Inherited congenital cataract (CC) shows all types of inheritance patterns in a syndromic and nonsyndromic form. There are more than 100 genes associated with cataract with a predominance of autosomal dominant inheritance. A cataract is defined as an opacity of the lens producing a variation of the refractive index of the lens. This variation derives from modifications in the lens structure resulting in light scattering, frequently a consequence of a significant concentration of high-molecular-weight protein aggregates. The aim of this review is to introduce a guide to identify the gene involved in inherited CC. Due to the manifold clinical and genetic heterogeneity, we discarded the cataract phenotype as a cardinal sign; a 4-group classification with the genes implicated in inherited CC is proposed. We consider that this classification will assist in identifying the probable gene involved in inherited CC.
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36
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Dang FT, Yang FY, Yang YQ, Ge XL, Chen D, Zhang L, Yu XP, Gu F, Zhu YH. A novel mutation of p.F32I in GJA8 in human dominant congenital cataracts. Int J Ophthalmol 2016; 9:1561-1567. [PMID: 27990357 DOI: 10.18240/ijo.2016.11.05] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 06/16/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To identify a causative mutation in a three-generation family with autosomal dominant congenital total cataract and dissect the molecular consequence of the identified mutation. METHODS Clinical and ophthalmological examinations were performed on the affected and unaffected family members. Mutation were screened in recruited family members by polymerase chain reaction (PCR) of the two reported genes (CRYAA and GJA8) which were linked to human total cataracts and direct sequencing of the PCR product. The molecular consequences of the identified mutation was dissected. The plasmids carrying wild-type and mutant mouse ORF of Gja8, coding for connexin 50 (Cx50), were generated and ectopic expressed in 293 cells. Recombinant protein expression and cellular localization of recombinated Cx50 were assessed by confocal microscopy. RESULTS Clinical and ophthalmological examinations were performed on the affected and unaffected family members. Mutation were screened in recruited family members by PCR of the two reported genes (CRYAA and GJA8) which were linked to human total cataracts and direct sequencing of the PCR product. The molecular consequences of the identified mutation was dissected. The plasmids carrying wild-type and mutant mouse ORF of Gja8, coding for Cx50, were generated and ectopic expressed in 293 cells. Recombinant protein expression and cellular localization of recombinated Cx50 were assessed by confocal microscopy. CONCLUSION This study has identified a novel cataract mutation in GJA8, which adds a novel mutation to the existing spectrum of Cx50 mutations with cataract. The molecular consequences of p.F32I mutation in GJA8 exclude instability and the mislocalization of mutant Cx50 protein.
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Affiliation(s)
- Feng-Tao Dang
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Fa-Yu Yang
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou 325027, Zhejiang Province, China
| | - Ye-Qin Yang
- School of Nursing, Wenzhou Medical University, Wenzhou 325000, Zhejiang Province, China
| | - Xiang-Lian Ge
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou 325027, Zhejiang Province, China
| | - Ding Chen
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou 325027, Zhejiang Province, China
| | - Liu Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian Province, China
| | - Xin-Ping Yu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou 325027, Zhejiang Province, China
| | - Feng Gu
- School of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou 325027, Zhejiang Province, China
| | - Yi-Hua Zhu
- Department of Ophthalmology, the First Affiliated Hospital of Fujian Medical University, Fuzhou 350005, Fujian Province, China
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Sidjanin DJ, Park AK, Ronchetti A, Martins J, Jackson WT. TBC1D20 mediates autophagy as a key regulator of autophagosome maturation. Autophagy 2016; 12:1759-1775. [PMID: 27487390 DOI: 10.1080/15548627.2016.1199300] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In humans, loss of TBC1D20 (TBC1 domain family, member 20) protein function causes Warburg Micro syndrome 4 (WARBM4), an autosomal recessive disorder characterized by congenital eye, brain, and genital abnormalities. TBC1D20-deficient mice exhibit ocular abnormalities and male infertility. TBC1D20 is a ubiquitously expressed member of the family of GTPase-activating proteins (GAPs) that increase the intrinsically slow GTP-hydrolysis rate of small RAB-GTPases when bound to GTP. Biochemical studies have established TBC1D20 as a GAP for RAB1B and RAB2A. However, the cellular role of TBC1D20 still remains elusive, and there is little information about how the functional loss of TBC1D20 causes clinical manifestations in WARBM4-affected children. Here we evaluate the role of TBC1D20 in cells carrying a null mutant allele, as well as TBC1D20-deficient mice, which display eye and testicular abnormalities. We demonstrate that TBC1D20, via its RAB1B GAP function, is a key regulator of autophagosome maturation, a process required for maintenance of autophagic flux and degradation of autophagic cargo. Our results provide evidence that TBC1D20-mediated autophagosome maturation maintains lens transparency by mediating the removal of damaged proteins and organelles from lens fiber cells. Additionally, our results show that in the testes TBC1D20-mediated maturation of autophagosomes is required for autophagic flux, but is also required for the formation of acrosomes. Furthermore TBC1D20-deficient mice, while not mimicking severe developmental brain abnormalities identified in WARBM4 affected children, display disrupted neuronal autophagic flux resulting in adult-onset motor dysfunction. In summary, we show that TBC1D20 has an essential role in the maturation of autophagosomes and a defect in TBC1D20 function results in eye, testicular, and neuronal abnormalities in mice implicating disrupted autophagy as a mechanism that contributes to WARBM4 pathogenesis.
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Affiliation(s)
- D J Sidjanin
- a Department of Cell Biology, Neurobiology, and Anatomy , Human and Molecular Genetics Center, Medical College of Wisconsin , Milwaukee , WI , USA
| | - Anna K Park
- a Department of Cell Biology, Neurobiology, and Anatomy , Human and Molecular Genetics Center, Medical College of Wisconsin , Milwaukee , WI , USA
| | - Adam Ronchetti
- a Department of Cell Biology, Neurobiology, and Anatomy , Human and Molecular Genetics Center, Medical College of Wisconsin , Milwaukee , WI , USA
| | - Jamaria Martins
- b Microbiology and Molecular Genetics, Human and Molecular Genetics Center, Medical College of Wisconsin , Milwaukee , WI , USA
| | - William T Jackson
- c Department of Microbiology and Immunology , University of Maryland School of Medicine , Baltimore , MD , USA
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Chen JH, Huang C, Zhang B, Yin S, Liang J, Xu C, Huang Y, Cen LP, Ng TK, Zheng C, Zhang S, Chen H, Pang CP, Zhang M. Mutations of RagA GTPase in mTORC1 Pathway Are Associated with Autosomal Dominant Cataracts. PLoS Genet 2016; 12:e1006090. [PMID: 27294265 PMCID: PMC4905677 DOI: 10.1371/journal.pgen.1006090] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 05/09/2016] [Indexed: 01/15/2023] Open
Abstract
Cataracts are a significant public health problem with no proven methods for prevention. Discovery of novel disease mechanisms to delineate new therapeutic targets is of importance in cataract prevention and therapy. Herein, we report that mutations in the RagA GTPase (RRAGA), a key regulator of the mechanistic rapamycin complex 1 (mTORC1), are associated with autosomal dominant cataracts. We performed whole exome sequencing in a family with autosomal dominant juvenile-onset cataracts, and identified a novel p.Leu60Arg mutation in RRAGA that co-segregated with the disease, after filtering against the dbSNP database, and at least 123,000 control chromosomes from public and in-house exome databases. In a follow-up direct screening of RRAGA in another 22 families and 142 unrelated patients with congenital or juvenile-onset cataracts, RRAGA was found to be mutated in two unrelated patients (p.Leu60Arg and c.-16G>A respectively). Functional studies in human lens epithelial cells revealed that the RRAGA mutations exerted deleterious effects on mTORC1 signaling, including increased relocation of RRAGA to the lysosomes, up-regulated mTORC1 phosphorylation, down-regulated autophagy, altered cell growth or compromised promoter activity. These data indicate that the RRAGA mutations, associated with autosomal dominant cataracts, play a role in the disease by acting through disruption of mTORC1 signaling. A group of guanine nucleotide-binding molecules called Rag GTPases are known to play a crucial role in regulation of mTORC1 signaling cascade. In the current study, whole exome sequencing has led to the identification of the RagA GTPase (RRAGA) gene for cataracts and we proceeded to study properties of the RRAGA protein. We captured and sequenced the whole exome for four affected patients from a family with autosomal dominant juvenile-onset posterior cataracts, and found a novel rare mutation in RagA GTPase (RRAGA). To validate this finding, we then sequenced more families and patients, and observed RRAGA mutations in unrelated patients with related phenotypes, suggesting that RRAGA could be mutated in congenital and juvenile-onset cataracts. We further demonstrated supporting evidence that in human lens epithelial cells the RRAGA mutations exerted deleterious effects on relocation of RRAGA to the lysosomes, mTORC1 phosphorylation, autophagy and cell growth. This study gives important new insight into the roles of RRAGA and mTROC1 signaling in the etiology of cataracts.
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Affiliation(s)
- Jian-Huan Chen
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
- Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - Chukai Huang
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Bining Zhang
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Shengjie Yin
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Jiajian Liang
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Ciyan Xu
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Yuqiang Huang
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Ling-Ping Cen
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Tsz-Kin Ng
- Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - Ce Zheng
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Shaobin Zhang
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Haoyu Chen
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
| | - Chi-Pui Pang
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
- Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
- * E-mail: (CPP); (MZ)
| | - Mingzhi Zhang
- Joint Shantou International Eye Center, Shantou University & the Chinese University of Hong Kong, Shantou, China
- * E-mail: (CPP); (MZ)
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Javadiyan S, Craig JE, Souzeau E, Sharma S, Lower KM, Pater J, Casey T, Hodson T, Burdon KP. Recurrent mutation in the crystallin alpha A gene associated with inherited paediatric cataract. BMC Res Notes 2016; 9:83. [PMID: 26867756 PMCID: PMC4750205 DOI: 10.1186/s13104-016-1890-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 01/27/2016] [Indexed: 12/18/2022] Open
Abstract
Background Cataract is a major cause of childhood blindness worldwide. The purpose of this study was to determine the genetic cause of paediatric cataract in a South Australian family with a bilateral lamellar paediatric cataract displaying variable phenotypes. Case presentation Fifty-one genes implicated in congenital cataract in human or mouse were sequenced in an affected individual from an Australian (Caucasian) family using a custom Ampliseq library on the Ion Torrent Personal Genome Machine. Reads were mapped against the human genome (hg19) and variants called with the Torrent Suite software. Variants were annotated to dbSNP 137 using Ion Reporter (IR 1.6.2) and were prioritised for validation if they were novel or rare and were predicted to be protein changing. We identified a previously reported oligomerization disrupting mutation, c.62G > A (p.R21Q), in the Crystallin alpha A (CRYAA) gene segregating in this three generation family. No other novel or rare coding mutations were detected in the known cataract genes sequenced. Microsatellite markers were used to compare the haplotypes between the family reported here and a previously published family with the same segregating mutation. Haplotype analysis indicated a potential common ancestry between the two South Australian families with this mutation. The work strengthens the genotype-phenotype correlations between this functional mutation in the crystallin alpha A (CRYAA) gene and paediatric cataract. Conclusion The p.R21Q mutation is the most likely cause of paediatric cataract in this family. The recurrence of this mutation in paediatric cataract families is likely due to a familial relationship. Electronic supplementary material The online version of this article (doi:10.1186/s13104-016-1890-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shari Javadiyan
- Department of Ophthalmology, School of Medicine, Flinders Medical Centre, Flinders University, Rm 4D 111.1, Flinders Dr, Bedford Park, Adelaide, 5042, Australia.
| | - Jamie E Craig
- Department of Ophthalmology, School of Medicine, Flinders Medical Centre, Flinders University, Rm 4D 111.1, Flinders Dr, Bedford Park, Adelaide, 5042, Australia.
| | - Emmanuelle Souzeau
- Department of Ophthalmology, School of Medicine, Flinders Medical Centre, Flinders University, Rm 4D 111.1, Flinders Dr, Bedford Park, Adelaide, 5042, Australia.
| | - Shiwani Sharma
- Department of Ophthalmology, School of Medicine, Flinders Medical Centre, Flinders University, Rm 4D 111.1, Flinders Dr, Bedford Park, Adelaide, 5042, Australia.
| | - Karen M Lower
- Department of Haematology and Genetic Pathology, School of Medicine, Flinders University, Adelaide, Australia.
| | - John Pater
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, Australia.
| | - Theresa Casey
- Ophthalmology Department, Women's and Children's Hospital, Adelaide, Australia.
| | | | - Kathryn P Burdon
- Department of Ophthalmology, School of Medicine, Flinders Medical Centre, Flinders University, Rm 4D 111.1, Flinders Dr, Bedford Park, Adelaide, 5042, Australia. .,Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.
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Ye X, Zhang G, Dong N, Meng Y. Human pituitary homeobox-3 gene in congenital cataract in a Chinese family. Int J Clin Exp Med 2015; 8:22435-9. [PMID: 26885225 PMCID: PMC4730011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Accepted: 11/23/2015] [Indexed: 06/05/2023]
Abstract
OBJECTIVES Congenital cataract is the common cause of world blindness. It is generally inherited as an autosomal recessive trait and has various phenotypes. This study aimed to explore the gene responsible for autosomal recessive congenital cataract in a Chinese family, and to investigate the functional and cellular consequences of the mutation. METHODS A four-generation Chinese family with autosomal recessive congenital cataract was included in the study. A genome wide scan and linkage analysis were performed in the chromosomal region of Pituitary homeobox 3 (PITX3) to identify the linked region of the genome. And sequence analysis of PITX3 gene was also investigated using BigDye Terminator mix 3.0 and SeqScape Software 2.5. RESULTS The genome wide scan and linkage analysis identified a disease-haplotype interva. The maximum logarithm of odds LOD score was (Zmax) 3.11 at marker D10S1693 (θmax=0.00), flanked by D10S1680 and D10S467, which included the PITX3 gene. Sequencing revealed a splice site mutation, G→A, at D10S1680 and D10S467, which co-segregated with all the affected members of this family. CONCLUSIONS The 543delG is a novel mutation in PITX3 causing an autosomal recessive congenital cataract.
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Affiliation(s)
- Xiangyu Ye
- Department of Ophthalmology, Affiliated Xiamen Eye Center, Eye Institute of Xiamen University Xiamen, Fujian, China
| | - Guangbin Zhang
- Department of Ophthalmology, Affiliated Xiamen Eye Center, Eye Institute of Xiamen University Xiamen, Fujian, China
| | - Nuo Dong
- Department of Ophthalmology, Affiliated Xiamen Eye Center, Eye Institute of Xiamen University Xiamen, Fujian, China
| | - Yan Meng
- Department of Ophthalmology, Affiliated Xiamen Eye Center, Eye Institute of Xiamen University Xiamen, Fujian, China
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Morishita H, Mizushima N. Autophagy in the lens. Exp Eye Res 2015; 144:22-8. [PMID: 26302409 DOI: 10.1016/j.exer.2015.08.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 07/30/2015] [Accepted: 08/18/2015] [Indexed: 10/23/2022]
Abstract
The lens of the eye is a transparent tissue composed of lens fiber cells that differentiate from lens epithelial cells and degrade all cytoplasmic organelles during terminal differentiation. Autophagy is a major intracellular degradation system in which cytoplasmic proteins and organelles are degraded in the lysosome. Although autophagy is constitutively activated in the lens and has been proposed to be involved in lens organelle degradation, its precise role is not well understood. Recent genetic studies in mice have demonstrated that autophagy is critically important for intracellular quality control in the lens but can be dispensable for lens organelle degradation. Here, we review recent findings on the roles of autophagy and lysosomes in organelle degradation and intracellular quality control in the lens, and discuss their possible involvement in the development of human cataract.
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Affiliation(s)
- Hideaki Morishita
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.
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Abstract
Lens opacities or cataract(s) represent a universally important cause of visual impairment and blindness. Typically, cataract is acquired with aging as a complex disorder involving environmental and genetic risk factors. Cataract may also be inherited with an early onset either in association with other ocular and/or systemic abnormalities or as an isolated lens phenotype. Here we briefly review recent advances in gene discovery for inherited and age-related forms of cataract that are providing new insights into lens development and aging.
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Exome Sequencing and Epigenetic Analysis of Twins Who Are Discordant for Congenital Cataract. Twin Res Hum Genet 2015; 18:393-8. [PMID: 26045100 DOI: 10.1017/thg.2015.34] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE To further understand genetic factors that contribute to congenital cataracts, we sought to identify early post-twinning mutational and epigenetic events that may account for the discordant phenotypes of a twin pair. METHODS A patient with a congenital cataract and her twin sister were assessed for genetic factors that might contribute to their discordant phenotypes by mutation screening of 11 candidate genes (CRYGC, CRYGD, CRYAA, CRYAB, CRYBA1, CRYBB1, CRYBB2, MIP, HSF4, GJA3, and GJA8), exome analysis followed by Sanger sequencing of 10 additional candidate genes (PLEKHO2, FRYL, RBP3, P2RX2, GSR, TRAM1, VEGFA, NARS2, CADPS, and TEKT4), and promoter methylation analysis of five representative genes (TRAM1, CRYAA, HSF4, VEGFA, GJA3, DCT) plus one additional candidate gene (FTL). RESULTS Mutation screening revealed no gene mutation differences between the patient and her twin sister for the 11 candidate genes. Exome sequencing analysis revealed variations between the twins in 442 genes, 10 of which are expressed in the eye. However, these differential variants could not be confirmed by Sanger sequencing. Furthermore, epigenetic discordance was not detected in the twin pair. CONCLUSIONS The genomic DNA mutational and epigenetic events assessed in this study could not explain the discordance in the development of phenotypic differences between the twin pair, suggesting the possible involvement of somatic mutations or environmental factors. Identification of possible causes requires further research.
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A novel Cx50 (GJA8) p.H277Y mutation associated with autosomal dominant congenital cataract identified with targeted next-generation sequencing. Graefes Arch Clin Exp Ophthalmol 2015; 253:915-24. [PMID: 25947639 DOI: 10.1007/s00417-015-3019-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 04/06/2015] [Accepted: 04/08/2015] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND To unravel the molecular genetic background responsible for autosomal dominant congenital pulverulent nuclear cataracts in a four-generation Chinese family. METHODS Family history data were collected, ophthalmological examinations were performed, and genomic DNA was extracted from peripheral blood of the family members. The candidate genes were captured and sequenced by targeted next-generation sequencing, and the results were confirmed by Sanger sequencing. The structure modelling of the protein was displayed based on Swiss-Model Server, and its possible changes in the secondary structure were predicted using Antheprot 2000 software. The chemical dissimilarity and possible functional impact of an amino acid substitution were performed with Grantham score, PolyPhen-2, and SIFT predictions. Protein distributions were assessed by confocal microscopy. RESULTS A novel heterozygous c.829C > T transition that led to the substitution of a highly conserved histidine by tyrosine at codon 277 (p.H277Y) in the coding region of connexin50 (Cx50, GJA8) was identified. Bioinformatics analysis showed that the mutation likely altered the secondary structure of the protein by replacing the helix of the COOH-terminal portion with a turn. The mutation was predicted to be moderately conservative by Grantham score and to be deleterious by both PolyPhen-2 and SIFT with consistent results. In addition, when expressed in COS1 cells, the mutation led to protein accumulation and caused changes in Cx 50 protein localization pattern. CONCLUSIONS This is a novel missense mutation [c.829C > T, (p.H277Y)] identified in exon 2 of Cx50. Our findings expand the spectrum of Cx50 mutations that are associated with autosomal dominant congenital pulverulent nuclear cataract.
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SIPA1L3 identified by linkage analysis and whole-exome sequencing as a novel gene for autosomal recessive congenital cataract. Eur J Hum Genet 2015; 23:1627-33. [PMID: 25804400 DOI: 10.1038/ejhg.2015.46] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 12/25/2022] Open
Abstract
Congenital cataract (CC) is one of the most important causes for blindness or visual impairment in infancy. A substantial proportion of isolated CCs has monogenic causes. The disease is genetically heterogeneous, and all Mendelian modes of inheritance have been reported. We mapped a locus for isolated CC on 19p13.1-q13.2 in a distantly consanguineous German family with two sisters affected by dense white cataracts. Whole-exome sequencing identified a homozygous nonsense variant c.4489C>T (p.(R1497*)) in SIPA1L3 (signal-induced proliferation-associated 1 like 3) in both affected children. SIPA1L3 encodes a GTPase-activating protein (GAP), which interacts with small GTPases of the Rap family via its Rap-GAP-domain. The suggested role of Rap GTPases in cell growth, differentiation and organization of the cytoskeleton in the human lens, and lens-enriched expression of the murine ortholog gene Sipa1l3 in embryonic mice indicates that this gene is crucial for early lens development. Our results provide evidence that sequence variants in human SIPA1L3 cause autosomal recessive isolated CC and give new insight into the molecular pathogenesis underlying human cataracts.
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46
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Song Z, Wang L, Liu Y, Xiao W. A novel nonsense mutation in the MIP gene linked to congenital posterior polar cataracts in a Chinese family. PLoS One 2015; 10:e0119296. [PMID: 25803033 PMCID: PMC4372439 DOI: 10.1371/journal.pone.0119296] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 01/12/2015] [Indexed: 11/19/2022] Open
Abstract
Purpose To detect the causative mutation for congenital posterior polar cataracts in a five-generation Chinese family and further explore the potential pathogenesis of this disease. Methods Coding exons, with flanking sequences of five candidate genes, were screened using direct DNA sequencing. The identified mutations were confirmed by restriction fragment length polymorphism (RFLP) analysis. A full-length wild-type or an Y219* mutant aquaporin0 (AQP0) fused with an N-terminal FLAG tag, was transfected into HEK293T cells. For co-localization studies, FLAG-WT-AQP0 and Myc-Y219*-AQP0 constructs were co-transfected. Quantitative real-time RT-PCR, western blotting and immunofluorescence studies were performed to determine protein expression levels and sub-cellular localization, respectively. Results We identified a novel nonsense mutation in MIP (c.657 C>G; p.Y219*) (major intrinsic protein gene) that segregates with congenital posterior polar cataract in a Chinese family. This mutation altered a highly conserved tyrosine to a stop codon (Y219*) within AQP0.When FLAG-WT-AQP0 and FLAG-Y219*-AQP0 expression constructs were singly transfected into HEK 293T cells, mRNA expression showed no significant difference between the wild-type and the mutant, while Y219*-AQP0 protein expression was significantly lower than that of wild-type AQP0. Wild-type AQP0 predominantly localized to the plasma membrane, while the mutated protein was abundant within the cytoplasm of HEK293T cells. However, when FLAG-WT-AQP0 andMyc-MU-AQP0were co-expressed, both proteins showed high fluorescence in the cytoplasm. Conclusions The novel nonsense mutation in the MIP gene (c.657 C>G) identified in a Chinese family may cause posterior polar cataracts. The dominant negative effect of the mutated protein on the wild-type protein interfered with the trafficking of wild-type protein to the cell membrane and both the mutant and wild-type protein were trapped in the cytoplasm. Consequently, both wild-type and mutant protein lost their function as a water channel on the cell membrane, and may result in a cataract phenotype. Our data also expands the spectrum of known MIP mutations.
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Affiliation(s)
- Zixun Song
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Lianqing Wang
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, P. R. China
| | - Yaping Liu
- Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, P. R. China
| | - Wei Xiao
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
- * E-mail:
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Hu B, Jiang D, Chen Y, Wei L, Zhang S, Zhao F, Ni R, Lu C, Wan C. High CHMP4B expression is associated with accelerated cell proliferation and resistance to doxorubicin in hepatocellular carcinoma. Tumour Biol 2015; 36:2569-81. [PMID: 25874485 DOI: 10.1007/s13277-014-2873-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 11/18/2014] [Indexed: 01/17/2023] Open
Abstract
Charged multivesicular body protein 4B (CHMP4B), a subunit of the endosomal sorting complex required for transport (ESCRT)-III complex, plays an important part in cytokinetic membrane abscission and the late stage of mitotic cell division. In this study, we explored the prognostic significance of CHMP4B in human hepatocellular carcinoma (HCC) and its impact on the physiology of HCC cells. Western blot and immunohistochemistrical analyses showed that CHMP4B was significantly upregulated in HCC tissues, compared with adjacent non-tumorous tissues. Meanwhile, clinicopathological analysis revealed that high CHMP4B expression was correlated with multiple clinicopathological variables, including AFP, cirrhosis, AJCC stage, Ki-67 expression, and poor prognosis. More importantly, univariate and multivariate survival analyses demonstrated that CHMP4B served as an independent prognostic factor for survival of HCC patients. Using HCC cell cultures, we found that the expression of CHMP4B was progressively upregulated after the release from serum starvation. To verify whether CHMP4B could regulate the proliferation of HCC cells, CHMP4B was knocked down through the transfection of CHMP4B-siRNA oligos. Flow cytometry and CCK-8 assays indicated that interference of CHMP4B led to cell cycle arrest and proliferative impairment of HCC cells. Additionally, depletion of CHMP4B expression could increase the sensitivity to doxorubicin in HepG2 and Huh7 cells. Taken together, our results implied that CHMP4B could be a promising prognostic biomarker as well as a potential therapeutic target of HCC.
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Affiliation(s)
- Baoying Hu
- Basic Medical Research Centre, Medical College, Nantong University, Nantong, 226001, China
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Terrell AM, Anand D, Smith SF, Dang CA, Waters SM, Pathania M, Beebe DC, Lachke SA. Molecular characterization of mouse lens epithelial cell lines and their suitability to study RNA granules and cataract associated genes. Exp Eye Res 2014; 131:42-55. [PMID: 25530357 DOI: 10.1016/j.exer.2014.12.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 12/02/2014] [Accepted: 12/18/2014] [Indexed: 01/10/2023]
Abstract
The discovery of cytosolic RNA granule (RG) component proteins associated with human cataract has initiated investigations on post-transcriptional mechanisms of gene expression control in the lens. Application of established mouse lens epithelial cell lines (LECs) can provide rapid insights on RG function in lens cells, especially because mouse mutants in several RG components are not available. However, although these LECs represent potential reagents for such analyses, they are uncharacterized for lens gene expression or RG formation. Therefore, a detailed molecular and cellular characterization of three permanent mouse LECs 17EM15, 21EM15 and αTN4 is performed in this study. Comparative analysis between microarray gene expression datasets on LEC 21EM15 and iSyTE lens tissue demonstrates that 30% of top 200 iSyTE identified lens-enriched genes are expressed in these cells. Majority of these candidates are independently validated to either have lens expression, function or linkage to cataract. Moreover, analysis of microarray data with genes described in Cat-Map, an online database of cataract associated genes and loci, demonstrates that 131 genes linked to cataract loci are expressed in 21EM15 cells. Furthermore, gene expression in LECs is compared to isolated lens epithelium or fiber cells by qRT-PCR and by comparative analyses with publically available epithelium or fiber-specific microarray and RNA-seq (sequencing) datasets. Expression of select candidate genes was validated by regular and real-time quantitative RT-PCR. Expression of lens epithelium-enriched genes Foxe3, Pax6, Anxa4 and Mcm4 is up-regulated in LEC lines, compared to isolated lens fiber cells. Moreover, similar to isolated lens epithelium, all three LECs exhibit down-regulation of fiber cell-expressed genes Crybb1, Mip and Prox1 when compared to fiber cells. These data indicate that the LEC lines exhibit greater similarity to lens epithelium than to fiber cells. Compared to non-lens cell line NIH3T3, LECs exhibit significantly enriched expression of transcription factors with important function in the lens, namely Pax6, Foxe3 and Prox1. In addition to these genes, all three LECs also express key lens- and cataract-associated genes, namely Dkk3, Epha2, Hsf4, Jag1, Mab21l1, Meis1, Pknox1, Pou2f1, Sfrp1, Sparc, Tdrd7 and Trpm3. Additionally, 21EM15 microarrays indicate expression of Chmp4b, Cryab and Tcfap2a among others important genes. Immunostaining with makers for Processing bodies (P-bodies) and Stress granules (SGs) demonstrates that these classes of RGs are robustly expressed in all three LECs. Moreover, under conditions of stress, 17EM15 and αTN4 exhibit significantly higher numbers of P-bodies and SGs compared to NIH3T3 cells. In sum, these data indicate that mouse LECs 21EM15, 17EM15 and αTN4 express key lens or cataract genes, are similar to lens epithelium than fiber cells, and exhibit high levels of P-bodies and SGs, indicating their suitability for investigating gene expression control and RG function in lens-derived cells.
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Affiliation(s)
- Anne M Terrell
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Sylvie F Smith
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Christine A Dang
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Stephanie M Waters
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Mallika Pathania
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - David C Beebe
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, MO, USA
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, USA; Center for Bioinformatics & Computational Biology, University of Delaware, Newark, DE, USA.
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Chen JH, Qiu J, Chen H, Pang CP, Zhang M. Rapid and cost-effective molecular diagnosis using exome sequencing of one proband with autosomal dominant congenital cataract. Eye (Lond) 2014; 28:1511-6. [PMID: 25301372 DOI: 10.1038/eye.2014.158] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 03/02/2014] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Due to high genetic heterogeneity, to exclude known mutations and map novel mutations in autosomal dominant congenital cataract (ADCC) using conventional candidate gene screening requires laborious laboratory work. We attempted to use a cost-effective exome sequencing strategy to identify disease-causing mutations in an ADCC pedigree. METHODS An ADCC pedigree affected by nuclear cataract and 200 unrelated senile cataract controls were recruited and given comprehensive ophthalmic examination. Whole exome of the proband of the family was captured by the Illumina TruSeq Exome Enrichment Kit, followed by sequencing using Illumina HiSeq 2000 sequencer. Validation was performed by direct sequencing. RESULTS The whole exome, including all exons of known ADCC disease-causing genes, was screened for possible disease-causing mutations. A recurrent missense mutation c.773C>T (p.S258F) in exon 2 of the gap junction protein alpha 8 gene (GJA8) was identified in the proband with nuclear cataract. The result was confirmed by direct sequencing. The mutation showed complete co-segregation with the disease phenotype in the family but was not observed in unrelated unaffected controls. CONCLUSION By successfully sequencing whole exome of only one proband and identifying a GJA8 mutation in one ADCC pedigree, the current study demonstrated that exome sequencing could serve as a rapid, robust, and cost-effective approach in clinical diagnosis and disease-causing gene discovery for ADCC.
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Affiliation(s)
- J-H Chen
- 1] Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China [2] Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - J Qiu
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
| | - H Chen
- 1] Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China [2] Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - C P Pang
- 1] Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China [2] Department of Ophthalmology and Visual Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - M Zhang
- Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, China
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A novel MIP gene mutation analysis in a Chinese family affected with congenital progressive punctate cataract. PLoS One 2014; 9:e102733. [PMID: 25033405 PMCID: PMC4102541 DOI: 10.1371/journal.pone.0102733] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 06/23/2014] [Indexed: 02/01/2023] Open
Abstract
Congenital cataracts are one of the leading causes of visual impairment and blindness in children, and genetic factors play an important role in their development. This study aimed to identify the genetic defects associated with autosomal dominant congenital progressive punctate cataracts in a Chinese family and to explore the potential pathogenesis. Detailed family history and clinical data were recorded, and all the family members’ blood samples were collected for DNA extraction. Linkage analysis was performed by microsatellite markers that are associated with punctate cataracts, and logarithm (base 10) of odds (LOD) scores were calculated using the LINKAGE program. Positive two-point LOD scores were obtained at markers D12S1622 (Zmax = 2.71 at θ = 0.0), D12S1724 (Zmax = 2.71 at θ = 0.0), and D12S90 (Zmax = 2.71 at θ = 0.0), which flank the major intrinsic protein of lens fiber (MIP) gene on chromosomal region 12q13. Direct sequencing of the encoding region of the MIP gene revealed a novel mutation (G>D) in exon 4 at nucleotide 644, which caused a substitution of glycine to aspartic acid at codon 215 (p.G215D) for the MIP protein. The mutation cosegregated with all patients with congenital progressive punctate cataracts, but it was absent in the healthy members. Bioinformatics analysis predicted that the mutation affects the function of the MIP protein. The wild type (WT) and G215D mutant of MIP were transfected with green fluorescent protein (GFP) into Hela cells separately, and it was found that the G215D mutant was aberrantly located in the cytoplasm instead of in the plasma membrane. In summary, our study presented genetic and functional evidence linking the new MIP mutation of G215D to autosomal dominant congenital cataracts, which adds to the list of MIP mutations linked to congenital progressive punctate cataracts.
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