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Simcoe MJ, Shah A, Fan B, Choquet H, Weisschuh N, Waseem NH, Jiang C, Melles RB, Ritch R, Mahroo OA, Wissinger B, Jorgenson E, Wiggs JL, Garway-Heath DF, Hysi PG, Hammond CJ. Genome-Wide Association Study Identifies Two Common Loci Associated with Pigment Dispersion Syndrome/Pigmentary Glaucoma and Implicates Myopia in its Development. Ophthalmology 2022; 129:626-636. [PMID: 35031440 DOI: 10.1016/j.ophtha.2022.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 01/03/2022] [Accepted: 01/05/2022] [Indexed: 11/27/2022] Open
Abstract
PURPOSE To identify genetic variants associated with pigment dispersion syndrome (PDS) and pigmentary glaucoma (PG) in unrelated patients and to further understand the genetic and potentially causal relationships between PDS and associated risk factors. DESIGN A 2-stage genome-wide association meta-analysis with replication and subsequent in silico analyses including Mendelian randomization. PARTICIPANTS A total of 574 cases with PG or PDS and 52 627 controls of European descent. METHODS Genome-wide association analyses were performed in 4 cohorts and meta-analyzed in 3 stages: (1) a discovery meta-analysis was performed in 3 cohorts, (2) replication was performed in the fourth cohort, and (3) all 4 cohorts were meta-analyzed to increase statistical power. Two-sample Mendelian randomization was used to determine whether refractive error and intraocular pressure exert causal effects over PDS. MAIN OUTCOME MEASURES The association of genetic variants with PDS and whether myopia exerts causal effects over PDS. RESULTS Significant association was present at 2 novel loci for PDS/PG. These loci and follow-up analyses implicate the genes gamma secretase activator protein (GSAP) (lead single nucleotide polymorphism [SNP]: rs9641220, P = 6.0×10-10) and glutamate metabotropic receptor 5 (GRM5)/TYR (lead SNP: rs661177, P = 3.9×10-9) as important factors in disease risk. Mendelian randomization showed significant evidence that negative refractive error (myopia) exerts a direct causal effect over PDS (P = 8.86×10-7). CONCLUSIONS Common SNPs relating to the GSAP and GRM5/TYR genes are associated risk factors for the development of PDS and PG. Although myopia is a known risk factor, this study uses genetic data to demonstrate that myopia is, in part, a cause of PDS and PG.
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Affiliation(s)
- Mark J Simcoe
- Department of Ophthalmology, Kings College London, London, United Kingdom; Department of Twins Research and Genetic Epidemiology, Kings College London, London, United Kingdom; Institute of Ophthalmology, University College London, London, United Kingdom
| | - Ameet Shah
- Department of Ophthalmology, Royal Free Hospital NHS Foundation Trust, Pond Street, London, United Kingdom
| | - Baojian Fan
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts
| | - Hélène Choquet
- Division of Research, Kaiser Permanente Northern California, Oakland, California
| | - Nicole Weisschuh
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Naushin H Waseem
- Institute of Ophthalmology, University College London, London, United Kingdom
| | - Chen Jiang
- Division of Research, Kaiser Permanente Northern California, Oakland, California
| | - Ronald B Melles
- Kaiser Permanente Northern California, Department of Ophthalmology, Redwood City, California
| | - Robert Ritch
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary of Mount Sinai, New York, New York
| | - Omar A Mahroo
- Department of Ophthalmology, Kings College London, London, United Kingdom; Department of Twins Research and Genetic Epidemiology, Kings College London, London, United Kingdom; Institute of Ophthalmology, University College London, London, United Kingdom
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Eric Jorgenson
- Division of Research, Kaiser Permanente Northern California, Oakland, California
| | - Janey L Wiggs
- Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts
| | - David F Garway-Heath
- National Institute for Health Research Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
| | - Pirro G Hysi
- Department of Ophthalmology, Kings College London, London, United Kingdom; Department of Twins Research and Genetic Epidemiology, Kings College London, London, United Kingdom
| | - Christopher J Hammond
- Department of Ophthalmology, Kings College London, London, United Kingdom; Department of Twins Research and Genetic Epidemiology, Kings College London, London, United Kingdom.
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Usman S, Waseem NH, Nguyen TKN, Mohsin S, Jamal A, Teh MT, Waseem A. Vimentin Is at the Heart of Epithelial Mesenchymal Transition (EMT) Mediated Metastasis. Cancers (Basel) 2021; 13:4985. [PMID: 34638469 PMCID: PMC8507690 DOI: 10.3390/cancers13194985] [Citation(s) in RCA: 123] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 09/29/2021] [Accepted: 10/02/2021] [Indexed: 12/12/2022] Open
Abstract
Epithelial-mesenchymal transition (EMT) is a reversible plethora of molecular events where epithelial cells gain the phenotype of mesenchymal cells to invade the surrounding tissues. EMT is a physiological event during embryogenesis (type I) but also happens during fibrosis (type II) and cancer metastasis (type III). It is a multifaceted phenomenon governed by the activation of genes associated with cell migration, extracellular matrix degradation, DNA repair, and angiogenesis. The cancer cells employ EMT to acquire the ability to migrate, resist therapeutic agents and escape immunity. One of the key biomarkers of EMT is vimentin, a type III intermediate filament that is normally expressed in mesenchymal cells but is upregulated during cancer metastasis. This review highlights the pivotal role of vimentin in the key events during EMT and explains its role as a downstream as well as an upstream regulator in this highly complex process. This review also highlights the areas that require further research in exploring the role of vimentin in EMT. As a cytoskeletal protein, vimentin filaments support mechanical integrity of the migratory machinery, generation of directional force, focal adhesion modulation and extracellular attachment. As a viscoelastic scaffold, it gives stress-bearing ability and flexible support to the cell and its organelles. However, during EMT it modulates genes for EMT inducers such as Snail, Slug, Twist and ZEB1/2, as well as the key epigenetic factors. In addition, it suppresses cellular differentiation and upregulates their pluripotent potential by inducing genes associated with self-renewability, thus increasing the stemness of cancer stem cells, facilitating the tumour spread and making them more resistant to treatments. Several missense and frameshift mutations reported in vimentin in human cancers may also contribute towards the metastatic spread. Therefore, we propose that vimentin should be a therapeutic target using molecular technologies that will curb cancer growth and spread with reduced mortality and morbidity.
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Affiliation(s)
- Saima Usman
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Str., London E1 2AT, UK; (S.U.); (T.K.N.N.); (A.J.); (M.-T.T.)
| | - Naushin H. Waseem
- UCL Institute of Ophthalmology, 11-43 Bath Str., London EC1V 9EL, UK;
| | - Thuan Khanh Ngoc Nguyen
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Str., London E1 2AT, UK; (S.U.); (T.K.N.N.); (A.J.); (M.-T.T.)
| | - Sahar Mohsin
- Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 17666, United Arab Emirates;
| | - Ahmad Jamal
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Str., London E1 2AT, UK; (S.U.); (T.K.N.N.); (A.J.); (M.-T.T.)
| | - Muy-Teck Teh
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Str., London E1 2AT, UK; (S.U.); (T.K.N.N.); (A.J.); (M.-T.T.)
| | - Ahmad Waseem
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Turner Str., London E1 2AT, UK; (S.U.); (T.K.N.N.); (A.J.); (M.-T.T.)
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Waseem NH, Low S, Shah AZ, Avisetti D, Ostergaard P, Simpson M, Niemiec KA, Martin-Martin B, Aldehlawi H, Usman S, Lee PS, Khawaja AP, Ruddle JB, Shah A, Sackey E, Day A, Jiang Y, Swinfield G, Viswanathan A, Alfano G, Chakarova C, Cordell HJ, Garway-Heath DF, Khaw PT, Bhattacharya SS, Waseem A, Foster PJ. Mutations in SPATA13/ASEF2 cause primary angle closure glaucoma. PLoS Genet 2020; 16:e1008721. [PMID: 32339198 PMCID: PMC7233598 DOI: 10.1371/journal.pgen.1008721] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 05/18/2020] [Accepted: 03/17/2020] [Indexed: 11/18/2022] Open
Abstract
Current estimates suggest 50% of glaucoma blindness worldwide is caused by primary angle-closure glaucoma (PACG) but the causative gene is not known. We used genetic linkage and whole genome sequencing to identify Spermatogenesis Associated Protein 13, SPATA13 (NM_001166271; NP_001159743, SPATA13 isoform I), also known as ASEF2 (Adenomatous polyposis coli-stimulated guanine nucleotide exchange factor 2), as the causal gene for PACG in a large seven-generation white British family showing variable expression and incomplete penetrance. The 9 bp deletion, c.1432_1440del; p.478_480del was present in all affected individuals with angle-closure disease. We show ubiquitous expression of this transcript in cell lines derived from human tissues and in iris, retina, retinal pigment and ciliary epithelia, cornea and lens. We also identified eight additional mutations in SPATA13 in a cohort of 189 unrelated PACS/PAC/PACG samples. This gene encodes a 1277 residue protein which localises to the nucleus with partial co-localisation with nuclear speckles. In cells undergoing mitosis SPATA13 isoform I becomes part of the kinetochore complex co-localising with two kinetochore markers, polo like kinase 1 (PLK-1) and centrosome-associated protein E (CENP-E). The 9 bp deletion reported in this study increases the RAC1-dependent guanine nucleotide exchange factors (GEF) activity. The increase in GEF activity was also observed in three other variants identified in this study. Taken together, our data suggest that SPATA13 is involved in the regulation of mitosis and the mutations dysregulate GEF activity affecting homeostasis in tissues where it is highly expressed, influencing PACG pathogenesis.
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Affiliation(s)
- Naushin H. Waseem
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
| | - Sancy Low
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
- Department of Ophthalmology, St. Thomas’ Hospital, Westminster Bridge Road, London, United Kingdom
| | - Amna Z. Shah
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
| | - Deepa Avisetti
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Queen Mary University of London, London, United Kingdom
| | - Pia Ostergaard
- Medical Genetics Unit, St. George’s University of London, Cranmer Terrace, London, United Kingdom
| | - Michael Simpson
- Genetics and Molecular Medicine, King’s College London, Great Maze Pond, London, United Kingdom
| | - Katarzyna A. Niemiec
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Queen Mary University of London, London, United Kingdom
| | - Belen Martin-Martin
- Blizard Advanced Light Microscopy, Blizard Institute, Queen Mary University of London, London, United Kingdom
| | - Hebah Aldehlawi
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Queen Mary University of London, London, United Kingdom
| | - Saima Usman
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Queen Mary University of London, London, United Kingdom
| | - Pak Sang Lee
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
| | - Anthony P. Khawaja
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
| | - Jonathan B. Ruddle
- Department of Ophthalmology, University of Melbourne, Victoria, Australia
| | - Ameet Shah
- Department of Ophthalmology, Royal Free Hospital NHS Foundation Trust, Pond Street, London, United Kingdom
| | - Ege Sackey
- Medical Genetics Unit, St. George’s University of London, Cranmer Terrace, London, United Kingdom
| | - Alexander Day
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Yuzhen Jiang
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Geoff Swinfield
- Society of Genealogists, Goswell Road, London, United Kingdom
| | - Ananth Viswanathan
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
| | - Giovanna Alfano
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
| | | | - Heather J. Cordell
- Institute of Genetic Medicine, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - David F. Garway-Heath
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
| | - Peng T. Khaw
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
| | - Shomi S. Bhattacharya
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
| | - Ahmad Waseem
- Centre for Oral Immunobiology and Regenerative Medicine, Institute of Dentistry, Queen Mary University of London, London, United Kingdom
| | - Paul J. Foster
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
- UCL Institute of Ophthalmology, Bath Street, London, United Kingdom
- * E-mail:
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Alfano G, Waseem NH, Webster AR, Bhattacharya SS. Identification and characterization of the VAX2 p.Leu139Arg variant: possible involvement of VAX2 in cone dystrophy. Ophthalmic Genet 2019; 39:539-543. [PMID: 29947570 DOI: 10.1080/13816810.2018.1484927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
OBJECTIVE This study was undertaken with the objective to investigate the potential involvement of VAX2 in retinal degeneration. METHODS A cohort of macular and cone dystrophy patients (n = 70) was screened for variant identification. Polymerase chain reaction (PCR) products were purified using ExoSAP-IT. Direct sequencing of PCR products was performed using BigDye 3.1 on the ABI 3730 DNA Analyzer and analyzed using DNASTAR software tool. Search for known variant was performed using the following platforms: 1000 Genomes Project, Ensembl, UCSC, ExAc, and dbSNP. The VAX2 mutants were generated using the GeneArt® Site-Directed Mutagenesis kit. In vitro analysis was performed in hTERTRPE-1 (RPE-1) cell line. Cells were photographed using a Zeiss AXIOVERT S100 microscope. Images were analyzed using Photoshop CS4 software. RESULTS Here, we report the identification of a heterozygous non-synonymous variant (c.416T>G; p.Leu139Arg) in one cone dystrophy proband. Functional characterization of this variant in vitro revealed an aberrant phenotype seen as protein mislocalization to cytoplasm/nucleus and aggregates undergoing degradation or forming aggresomes. The cellular phenotype suggests protein loss-of-function. Analysis of the VAX2 p.Leu139Met, a variant present in the normal population, showed a phenotype similar to the wild-type, further supporting the hypothesis for the Leucine 139 to Arginine change to be damaging. CONCLUSIONS This study raises the interesting possibility for evaluating VAX2 as a candidate gene for cone dystrophy.
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Affiliation(s)
| | | | - Andrew R Webster
- a Institute of Ophthalmology , UCL , London , UK.,b Moorfields Eye Hospital , London , UK
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5
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Vishal M, Sharma A, Kaurani L, Alfano G, Mookherjee S, Narta K, Agrawal J, Bhattacharya I, Roychoudhury S, Ray J, Waseem NH, Bhattacharya SS, Basu A, Sen A, Ray K, Mukhopadhyay A. Genetic association and stress mediated down-regulation in trabecular meshwork implicates MPP7 as a novel candidate gene in primary open angle glaucoma. BMC Med Genomics 2016; 9:15. [PMID: 27001270 PMCID: PMC4802647 DOI: 10.1186/s12920-016-0177-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 03/11/2016] [Indexed: 12/04/2022] Open
Abstract
Background Glaucoma is the largest cause of irreversible blindness affecting more than 60 million people globally. The disease is defined as a gradual loss of peripheral vision due to death of Retinal Ganglion Cells (RGC). The RGC death is largely influenced by the rate of aqueous humor production by ciliary processes and its passage through the trabecular meshwork (TM) in the anterior part of the eye. Primary open angle glaucoma (POAG), the most common subtype, is a genetically complex disease. Multiple genes and many loci have been reported to be involved in POAG but taken together they explain less than 10 % of the patients from a genetic perspective warranting more studies in different world populations. The purpose of this study was to perform genome-wide search for common variants associated with POAG in an east-Indian population. Methods The study recruited 746 POAG cases and 697 controls distributed into discovery and validation cohorts. In the discovery phase, genome-wide genotype data was generated on Illumina Infinium 660 W-Quad platform and the significant SNPs were genotyped using Illumina GGGT assay in the second phase. Logistic regression was used to test association in the discovery phase to adjust for population sub-structure and chi-square test was used for association analysis in validation phase. Publicly available expression dataset for trabecular meshwork was used to check for expression of the candidate gene under cyclic mechanical stress. Western blot and immunofluorescence experiments were performed in human TM cells and murine eye, respectively to check for expression of the candidate gene. Results Meta-analysis of discovery and validation phase data revealed the association of rs7916852 in MPP7 gene (p = 5.7x10−7) with POAG. We have shown abundant expression of MPP7 in the HTM cells. Expression analysis shows that upon cyclic mechanical stress MPP7 was significantly down-regulated in HTM (Fold change: 2.6; p = 0.018). MPP7 protein expression was also found to be enriched in the ciliary processes of the murine eye. Conclusion Using a genome-wide approach we have identified MPP7 as a novel candidate gene for POAG with evidence of its expression in relevant ocular tissues and dysregulation under mechanical stress possibly mimicking the disease scenario. Electronic supplementary material The online version of this article (doi:10.1186/s12920-016-0177-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Mansi Vishal
- Molecular and Human Genetics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India.,Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India
| | - Anchal Sharma
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India
| | - Lalit Kaurani
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India
| | | | - Suddhasil Mookherjee
- Molecular and Human Genetics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India
| | - Kiran Narta
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India
| | - Jyoti Agrawal
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India
| | | | - Susanta Roychoudhury
- Cancer Biology and Inflammatory disorder division, CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India
| | - Jharna Ray
- S. N. Pradhan Centre for Neurosciences, University of Calcutta, Kolkata, 700019, India
| | | | | | - Analabha Basu
- National Institute of Biomedical Genomics, Kalyani, 741251, India
| | | | - Kunal Ray
- Molecular and Human Genetics Division, CSIR-Indian Institute of Chemical Biology, Kolkata, 700032, India. .,Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India.
| | - Arijit Mukhopadhyay
- Genomics & Molecular Medicine, CSIR-Institute of Genomics & Integrative Biology, Mathura Road (near Sukhdev Vihar), New Delhi, 110025, India. .,Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India. .,UCL Institute of Ophthalmology, London, EC1V 9EL, UK.
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6
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Ratnapriya R, Zhan X, Fariss RN, Branham KE, Zipprer D, Chakarova CF, Sergeev YV, Campos MM, Othman M, Friedman JS, Maminishkis A, Waseem NH, Brooks M, Rajasimha HK, Edwards AO, Lotery A, Klein BE, Truitt BJ, Li B, Schaumberg DA, Morgan DJ, Morrison MA, Souied E, Tsironi EE, Grassmann F, Fishman GA, Silvestri G, Scholl HPN, Kim IK, Ramke J, Tuo J, Merriam JE, Merriam JC, Park KH, Olson LM, Farrer LA, Johnson MP, Peachey NS, Lathrop M, Baron RV, Igo RP, Klein R, Hagstrom SA, Kamatani Y, Martin TM, Jiang Y, Conley Y, Sahel JA, Zack DJ, Chan CC, Pericak-Vance MA, Jacobson SG, Gorin MB, Klein ML, Allikmets R, Iyengar SK, Weber BH, Haines JL, Léveillard T, Deangelis MM, Stambolian D, Weeks DE, Bhattacharya SS, Chew EY, Heckenlively JR, Abecasis GR, Swaroop A. Rare and common variants in extracellular matrix gene Fibrillin 2 (FBN2) are associated with macular degeneration. Hum Mol Genet 2014; 23:5827-37. [PMID: 24899048 DOI: 10.1093/hmg/ddu276] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Neurodegenerative diseases affecting the macula constitute a major cause of incurable vision loss and exhibit considerable clinical and genetic heterogeneity, from early-onset monogenic disease to multifactorial late-onset age-related macular degeneration (AMD). As part of our continued efforts to define genetic causes of macular degeneration, we performed whole exome sequencing in four individuals of a two-generation family with autosomal dominant maculopathy and identified a rare variant p.Glu1144Lys in Fibrillin 2 (FBN2), a glycoprotein of the elastin-rich extracellular matrix (ECM). Sanger sequencing validated the segregation of this variant in the complete pedigree, including two additional affected and one unaffected individual. Sequencing of 192 maculopathy patients revealed additional rare variants, predicted to disrupt FBN2 function. We then undertook additional studies to explore the relationship of FBN2 to macular disease. We show that FBN2 localizes to Bruch's membrane and its expression appears to be reduced in aging and AMD eyes, prompting us to examine its relationship with AMD. We detect suggestive association of a common FBN2 non-synonymous variant, rs154001 (p.Val965Ile) with AMD in 10 337 cases and 11 174 controls (OR = 1.10; P-value = 3.79 × 10(-5)). Thus, it appears that rare and common variants in a single gene--FBN2--can contribute to Mendelian and complex forms of macular degeneration. Our studies provide genetic evidence for a key role of elastin microfibers and Bruch's membrane in maintaining blood-retina homeostasis and establish the importance of studying orphan diseases for understanding more common clinical phenotypes.
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Affiliation(s)
| | - Xiaowei Zhan
- Center for Statistical Genetics, Department of Biostatistics and
| | | | - Kari E Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48109, USA
| | - David Zipprer
- Neurobiology Neurodegeneration and Repair Laboratory
| | - Christina F Chakarova
- Department of Genetics, UCL-Institute of Ophthalmology, Bath Street, London EC1V 9EL, UK
| | | | | | - Mohammad Othman
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48109, USA
| | | | | | - Naushin H Waseem
- Department of Genetics, UCL-Institute of Ophthalmology, Bath Street, London EC1V 9EL, UK
| | | | | | - Albert O Edwards
- Institute for Molecular Biology, University of Oregon and Oregon Retina, Eugene, OR 97401, USA
| | - Andrew Lotery
- Faculty of Medicine, Clinical and Experimental Sciences, University of Southampton, Southampton SO16 6YD, UK
| | - Barbara E Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and, Public Health, Madison, WI 53726, USA
| | - Barbara J Truitt
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Bingshan Li
- Center for Human Genetics Research, Vanderbilt University, Nashville, TN 37232, USA
| | - Debra A Schaumberg
- Division of Preventive Medicine, Brigham and Women's Hospital, Boston, MA 02215, USA, Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA
| | - Denise J Morgan
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA
| | - Margaux A Morrison
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA
| | - Eric Souied
- Hôpital Intercommunal de Créteil, Hôpital Henri Mondor - Université Paris Est Créteil 94000, France
| | - Evangelia E Tsironi
- Department of Ophthalmology, University of Thessaly School of Medicine, Larissa, Greece
| | - Felix Grassmann
- Institute of Human Genetics, University of Regensburg, Regensburg 93053, Germany
| | - Gerald A Fishman
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | | | - Hendrik P N Scholl
- Wilmer Eye Institute, Johns Hopkins University, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | - Ivana K Kim
- Retina Service and Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
| | - Jacqueline Ramke
- The Fred Hollows Foundation, Auckland, New Zealand, School of Social Sciences, University of New South Wales, Sydney, Australia
| | | | | | | | - Kyu Hyung Park
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul 463-707, Republic of Korea
| | - Lana M Olson
- Center for Human Genetics Research, Vanderbilt University, Nashville, TN 37232, USA
| | - Lindsay A Farrer
- Departments of Medicine (Section of Biomedical Genetics), Ophthalmology and Biostatistics, Neurology, Epidemiology, Boston University Schools of Medicine and Public Health, Boston, MA 02215, USA
| | | | - Neal S Peachey
- Cleveland Clinic Foundation, Cole Eye Institute, Cleveland, OH 44195, USA, Louis Stokes Cleveland VA Medical Center, Cleveland, OH 44195, USA
| | - Mark Lathrop
- Department of Genetics, Institut de la Vision - Inserm Université Pierre et Marie Curie UMR-S 968, Paris, France
| | | | - Robert P Igo
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ronald Klein
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and, Public Health, Madison, WI 53726, USA
| | | | - Yoichiro Kamatani
- Department of Genetics, Institut de la Vision - Inserm Université Pierre et Marie Curie UMR-S 968, Paris, France
| | - Tammy M Martin
- Oregon Health & Science University, Portland, OR 97239, USA
| | - Yingda Jiang
- Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Yvette Conley
- Health Promotion and Development, School of Nursing, 440 Victoria Building, 3500 Victoria St, Pittsburgh, PA 15261, USA
| | - Jose-Alan Sahel
- Department of Genetics, Institut de la Vision - Inserm Université Pierre et Marie Curie UMR-S 968, Paris, France
| | - Donald J Zack
- Wilmer Eye Institute, Johns Hopkins University, 600 N. Wolfe Street, Baltimore, MD 21287, USA
| | | | - Margaret A Pericak-Vance
- Bascom Palmer Eye Institute and Human Genomics, University of Miami Miller School of Medicine, Miami, FL 33125, USA
| | - Samuel G Jacobson
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael B Gorin
- Department of Ophthalmology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Michael L Klein
- Macular Degeneration Center, Casey Eye Institute, Oregon Health and Science, University, Portland, OR 97201, USA
| | - Rando Allikmets
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, USA
| | - Sudha K Iyengar
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Bernhard H Weber
- Institute of Human Genetics, University of Regensburg, Regensburg 93053, Germany
| | - Jonathan L Haines
- Center for Human Genetics Research, Vanderbilt University, Nashville, TN 37232, USA
| | - Thierry Léveillard
- Department of Genetics, Institut de la Vision - Inserm Université Pierre et Marie Curie UMR-S 968, Paris, France
| | - Margaret M Deangelis
- Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA
| | - Dwight Stambolian
- Department of Ophthalmology, and Department of Genetics, University of Pennsylvania, Philadelphia, PA 9104, USA
| | - Daniel E Weeks
- Department of Human Genetics and Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Shomi S Bhattacharya
- Department of Genetics, UCL-Institute of Ophthalmology, Bath Street, London EC1V 9EL, UK
| | - Emily Y Chew
- Clinical Trials Branch, Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48109, USA
| | | | - Anand Swaroop
- Neurobiology Neurodegeneration and Repair Laboratory,
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7
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Borman AD, Pearce LR, Mackay DS, Nagel-Wolfrum K, Davidson AE, Henderson R, Garg S, Waseem NH, Webster AR, Plagnol V, Wolfrum U, Farooqi IS, Moore AT. A homozygous mutation in the TUB gene associated with retinal dystrophy and obesity. Hum Mutat 2013; 35:289-93. [PMID: 24375934 PMCID: PMC4284018 DOI: 10.1002/humu.22482] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 11/04/2013] [Indexed: 01/30/2023]
Abstract
Inherited retinal dystrophies are a major cause of childhood blindness. Here, we describe the identification of a homozygous frameshift mutation (c.1194_1195delAG, p.Arg398Serfs*9) in TUB in a child from a consanguineous UK Caucasian family investigated using autozygosity mapping and whole-exome sequencing. The proband presented with obesity, night blindness, decreased visual acuity, and electrophysiological features of a rod cone dystrophy. The mutation was also found in two of the proband's siblings with retinal dystrophy and resulted in mislocalization of the truncated protein. In contrast to known forms of retinal dystrophy, including those caused by mutations in the tubby-like protein TULP-1, loss of function of TUB in the proband and two affected family members was associated with early-onset obesity, consistent with an additional role for TUB in energy homeostasis.
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Affiliation(s)
- Arundhati Dev Borman
- Moorfield's Eye Hospital, London, EC1C 2PD, UK; Institute of Ophthalmology, London, EC1V 9EL, UK
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8
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Davidson AE, Schwarz N, Zelinger L, Stern-Schneider G, Shoemark A, Spitzbarth B, Gross M, Laxer U, Sosna J, Sergouniotis PI, Waseem NH, Wilson R, Kahn RA, Plagnol V, Wolfrum U, Banin E, Hardcastle AJ, Cheetham ME, Sharon D, Webster AR. Mutations in ARL2BP, encoding ADP-ribosylation-factor-like 2 binding protein, cause autosomal-recessive retinitis pigmentosa. Am J Hum Genet 2013; 93:321-9. [PMID: 23849777 DOI: 10.1016/j.ajhg.2013.06.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 05/03/2013] [Accepted: 06/04/2013] [Indexed: 01/01/2023] Open
Abstract
Retinitis pigmentosa (RP) is a genetically heterogeneous retinal degeneration characterized by photoreceptor death, which results in visual failure. Here, we used a combination of homozygosity mapping and exome sequencing to identify mutations in ARL2BP, which encodes an effector protein of the small GTPases ARL2 and ARL3, as causative for autosomal-recessive RP (RP66). In a family affected by RP and situs inversus, a homozygous, splice-acceptor mutation, c.101-1G>C, which alters pre-mRNA splicing of ARLBP2 in blood RNA, was identified. In another family, a homozygous c.134T>G (p.Met45Arg) mutation was identified. In the mouse retina, ARL2BP localized to the basal body and cilium-associated centriole of photoreceptors and the periciliary extension of the inner segment. Depletion of ARL2BP caused cilia shortening. Moreover, depletion of ARL2, but not ARL3, caused displacement of ARL2BP from the basal body, suggesting that ARL2 is vital for recruiting or anchoring ARL2BP at the base of the cilium. This hypothesis is supported by the finding that the p.Met45Arg amino acid substitution reduced binding to ARL2 and caused the loss of ARL2BP localization at the basal body in ciliated nasal epithelial cells. These data demonstrate a role for ARL2BP and ARL2 in primary cilia function and that this role is essential for normal photoreceptor maintenance and function.
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Davidson AE, Sergouniotis PI, Mackay DS, Wright GA, Waseem NH, Michaelides M, Holder GE, Robson AG, Moore AT, Plagnol V, Webster AR. RP1L1 variants are associated with a spectrum of inherited retinal diseases including retinitis pigmentosa and occult macular dystrophy. Hum Mutat 2013; 34:506-14. [PMID: 23281133 DOI: 10.1002/humu.22264] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 12/05/2012] [Indexed: 11/09/2022]
Abstract
In one consanguineous family with retinitis pigmentosa (RP), a condition characterized by progressive visual loss due to retinal degeneration, homozygosity mapping, and candidate gene sequencing suggested a novel locus. Exome sequencing identified a homozygous frameshifting mutation, c.601delG, p.Lys203Argfs*28, in RP1L1 encoding RP 1-like1, a photoreceptor-specific protein. A screen of a further 285 unrelated individuals with autosomal recessive RP identified an additional proband, homozygous for a missense variant, c.1637G>C, p.Ser546Thr, in RP1L1. A distinct retinal disorder, occult macular dystrophy (OCMD) solely affects the central retinal cone photoreceptors and has previously been reported to be associated with variants in the same gene. The association between mutations in RP1L1 and the disorder OCMD was explored by screening a cohort of 28 unrelated individuals with the condition; 10 were found to harbor rare (minor allele frequency ≤0.5% in the 1,000 genomes dataset) heterozygous RP1L1 missense variants. Analysis of family members revealed many unaffected relatives harboring the same variant. Linkage analysis excluded the possibility of a recessive mode of inheritance, and sequencing of RP1, a photoreceptor protein that interacts with RP1L1, excluded a digenic mechanism involving this gene. These findings imply an important and diverse role for RP1L1 in human retinal physiology and disease.
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Affiliation(s)
- Alice E Davidson
- University College London Institute of Ophthalmology, London, UK
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10
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Rose AM, Shah AZ, Waseem NH, Chakarova CF, Alfano G, Coussa RG, Ajlan R, Koenekoop RK, Bhattacharya SS. Expression of PRPF31 and TFPT: regulation in health and retinal disease. Hum Mol Genet 2012; 21:4126-37. [PMID: 22723017 DOI: 10.1093/hmg/dds242] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
PRPF31, a gene located at chromosome 19q13.4, encodes the ubiquitous splicing factor PRPF31. The gene lies in a head-to-head arrangement with TFPT, a poorly characterized gene with a role in cellular apoptosis. Mutations in PRPF31 have been implicated in autosomal dominant retinitis pigmentosa (adRP), a frequent and important cause of blindness worldwide. Disease associated with PRPF31 mutations is unusual, in that there is often non-penetrance of the disease phenotype in affected families, caused by differential expression of PRPF31. This study aimed to characterize the basic promoter elements of PRPF31 and TFPT. Luciferase reporter constructs were made, using genomic DNA from an asymptomatic individual with a heterozygous deletion of the entire putative promoter region. Fragments were tested by the dual-luciferase reporter assay in HeLa and RPE-1 cell lines. A comparison was made between the promoter regions of symptomatic and asymptomatic mutation-carrying individuals. A patient (CAN493) with adRP was identified, harbouring a regulatory region mutation; both alleles were assayed by the dual-luciferase reporter assay. Luciferase assays led to the identification of core promoters for both PRPF31 and TFPT; despite their shared gene architecture, the two genes appear to be controlled by slightly different regulatory regions. One functional polymorphism was identified in the PRPF31 promoter that increased transcriptional activation. The change was not, however, consistent with the observed symptomatic-asymptomatic phenotypes in a family affected by PRPF31-adRP. Analysis of the mutant promoter fragment from CAN493 showed a >50% reduction in promoter activity, suggesting a disease mechanism of functional haploinsufficiency-the first report of this disease mechanism in adRP.
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Affiliation(s)
- Anna M Rose
- Department of Genetics, UCL Institute of Ophthalmology, London EC1V 9EL, UK.
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11
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Maubaret CG, Vaclavik V, Mukhopadhyay R, Waseem NH, Churchill A, Holder GE, Moore AT, Bhattacharya SS, Webster AR. Autosomal dominant retinitis pigmentosa with intrafamilial variability and incomplete penetrance in two families carrying mutations in PRPF8. Invest Ophthalmol Vis Sci 2011; 52:9304-9. [PMID: 22039234 DOI: 10.1167/iovs.11-8372] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The aim of this study was to report detailed genotype/phenotype correlation in two British autosomal dominant retinitis pigmentosa (adRP) families with recently described mutations in PRPF8. METHODS Ten affected members from the two families (excluded for PRPF31 mutations) were assessed clinically. Seven subjects had fundus photography; some had electrophysiology, autofluorescence imaging, and visual field testing. Linkage analysis was performed from genomic DNA in one family. RNA was extracted from lymphocytes of the proband from both families, reverse transcribed into cDNA and subsequently screened for mutations in PRPF8. Segregation of mutations in each family was tested by direct genomic sequencing of the specific exons carrying the mutation. RESULTS All affected members complained of nyctalopia with variable age of onset. In the first family, there was marked variation in the clinical phenotype among affected individuals ranging from severe rod-cone dystrophy to a 67-year-old patient with a normal retinal appearance and mild rod dysfunction on scotopic electroretinography (ERG). The second family demonstrated similar variability and a history of a nonpenetrant individual. Linkage analysis in the first family showed strong evidence for linkage to markers on chromosome 17p implicating PRPF8 as a candidate gene. A c.6353 C>T change causing a nonconservative missense mutation p.S2118F was found in exon 38 of PRPF8 by direct sequencing of the cDNA. The mutation c.6930G>C (p.R2310S) was found in the second family. CONCLUSIONS This is the first report of marked intrafamilial variability associated with mutations in the PRPF8 gene, including incomplete penetrance. PRPF8 mutations should be suspected in patients with adRP and variable expressivity.
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Affiliation(s)
- Cécilia G Maubaret
- Institute of Ophthalmology, University College London, and Moorfields Eye Hospital, London, United Kingdom
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12
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Rose AM, Mukhopadhyay R, Webster AR, Bhattacharya SS, Waseem NH. A 112 kb deletion in chromosome 19q13.42 leads to retinitis pigmentosa. Invest Ophthalmol Vis Sci 2011; 52:6597-603. [PMID: 21715351 DOI: 10.1167/iovs.11-7861] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE. This study sets out to identify novel mutations in PRPF31 in a cohort of autosomal dominant retinitis pigmentosa (adRP) patients with a history of nonpenetrance in the family. METHODS. Twenty-one patients with history of nonpenetrant autosomal dominant retinitis pigmentosa were selected; all underwent full ophthalmic examination. Multiplex ligation-dependent probe analysis (MLPA) was performed and, where a deletion was found, further family members were recruited. An individual suspected to harbor a large deletion was used as a positive control. Analysis of single nucleotide polymorphisms in the upstream region was used to determine the extent of the deletion, and the breakpoint was then characterized by PCR and sequencing. RESULTS. In one family, multiplex ligation-dependent probe analysis revealed a novel large deletion in 19q13.4 encompassing exons 1 to 13 of the PRPF31 gene. The mutation was characterized as a deletion of 112 kilobase (kb), encompassing over 90% of PRPF31 and five upstream genes: TFPT, OSCAR, NDUFA3, TARM-1, and VSTM-1. The breakpoint in the positive control family was also characterized. The mechanism of deletion in both families was Alu-mediated nonallelic homologous recombination. CONCLUSIONS. This study describes two large deletions, one in a previously reported family and one in a new family: the latter represents the largest deletion yet described on chromosome 19 and the first report of the involvement of VSTM-1. Remarkably, heterozygous deletion of this large region (encompassing six genes) produces little or no other clinical disease besides retinitis pigmentosa.
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Affiliation(s)
- Anna M Rose
- Department of Genetics, UCL Institute of Ophthalmology, London, United Kingdom.
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13
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Berry V, Francis PJ, Prescott Q, Waseem NH, Moore AT, Bhattacharya SS. A novel 1-bp deletion in PITX3 causing congenital posterior polar cataract. Mol Vis 2011; 17:1249-53. [PMID: 21633712 PMCID: PMC3103741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Accepted: 05/02/2011] [Indexed: 11/16/2022] Open
Abstract
PURPOSE Cataracts are the most common cause of blindness worldwide. Inherited cataract is a clinically and genetically heterogeneous disease. Here we report a novel mutation in the paired-like homeodomain 3 (PITX3) gene segregating in a four generation English family with an isolated autosomal dominant posterior polar cataract. METHODS A genome-wide linkage was performed by means of single nucleotide polymorphism (SNP) and microsatellite markers. Linkage analyses were performed with the GeneHunter and MLINK programs. Direct sequencing of PCR products was performed to detect mutation in the gene, using the BigDye version 3.1 and analyzed using Sequence analysis version 5.2. RESULTS Genome-wide linkage analysis with SNP markers, identified a disease-haplotype interval on chromosome 10q. Two point positive logarithm of odds (LOD) scores was obtained with markers D10S205 (Z=3.10 at θ=0.00), flanked by markers D10S1709 and D10S543, which harbors the homeobox gene PITX3. Sequence analysis of PITX3 revealed a 1-bp deletion that cosegregated with all the affected members of this family which resulted in a frameshift in codon 181 and likely to produce an aberrant protein consisting of 127 additional residues. CONCLUSIONS The 542delC is a novel mutation in PITX3 causing an isolated posterior polar cataract.
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Affiliation(s)
- Vanita Berry
- Department of Genetics, Institute of Ophthalmology, University College London, London, UK
| | - Peter J. Francis
- Casey Eye Institute, Oregon Health and Science University, Portland, OR
| | - Quincy Prescott
- Department of Genetics, Institute of Ophthalmology, University College London, London, UK
| | - Naushin H. Waseem
- Department of Genetics, Institute of Ophthalmology, University College London, London, UK
| | | | - Shomi S. Bhattacharya
- Department of Genetics, Institute of Ophthalmology, University College London, London, UK
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14
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Audo I, Bujakowska K, Mohand-Saïd S, Lancelot ME, Moskova-Doumanova V, Waseem NH, Antonio A, Sahel JA, Bhattacharya SS, Zeitz C. Prevalence and novelty of PRPF31 mutations in French autosomal dominant rod-cone dystrophy patients and a review of published reports. BMC Med Genet 2010; 11:145. [PMID: 20939871 PMCID: PMC2984399 DOI: 10.1186/1471-2350-11-145] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 10/12/2010] [Indexed: 12/01/2022]
Abstract
Background Rod-cone dystrophies are heterogeneous group of inherited retinal disorders both clinically and genetically characterized by photoreceptor degeneration. The mode of inheritance can be autosomal dominant, autosomal recessive or X-linked. The purpose of this study was to identify mutations in one of the genes, PRPF31, in French patients with autosomal dominant RP, to perform genotype-phenotype correlations of those patients, to determine the prevalence of PRPF31 mutations in this cohort and to review previously identified PRPF31 mutations from other cohorts. Methods Detailed phenotypic characterization was performed including precise family history, best corrected visual acuity using the ETDRS chart, slit lamp examination, kinetic and static perimetry, full field and multifocal ERG, fundus autofluorescence imaging and optic coherence tomography. For genetic diagnosis, genomic DNA of ninety families was isolated by standard methods. The coding exons and flanking intronic regions of PRPF31 were PCR amplified, purified and sequenced in the index patient. Results We showed for the first time that 6.7% cases of a French adRP cohort have a PRPF31 mutation. We identified in total six mutations, which were all novel and not detected in ethnically matched controls. The mutation spectrum from our cohort comprises frameshift and splice site mutations. Co-segregation analysis in available family members revealed that each index patient and all affected family members showed a heterozygous mutation. In five families incomplete penetrance was observed. Most patients showed classical signs of RP with relatively preserved central vision and visual field. Conclusion Our studies extended the mutation spectrum of PRPF31 and as previously reported in other populations, it is a major cause of adRP in France.
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15
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Riazuddin SA, Iqbal M, Wang Y, Masuda T, Chen Y, Bowne S, Sullivan LS, Waseem NH, Bhattacharya S, Daiger SP, Zhang K, Khan SN, Riazuddin S, Hejtmancik JF, Sieving PA, Zack DJ, Katsanis N. A splice-site mutation in a retina-specific exon of BBS8 causes nonsyndromic retinitis pigmentosa. Am J Hum Genet 2010; 86:805-12. [PMID: 20451172 DOI: 10.1016/j.ajhg.2010.04.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 03/28/2010] [Accepted: 04/09/2010] [Indexed: 10/19/2022] Open
Abstract
Tissue-specific alternative splicing is an important mechanism for providing spatiotemporal protein diversity. Here we show that an in-frame splice mutation in BBS8, one of the genes involved in pleiotropic Bardet-Biedl syndrome (BBS), is sufficient to cause nonsyndromic retinitis pigmentosa (RP). A genome-wide scan of a consanguineous RP pedigree mapped the trait to a 5.6 Mb region; subsequent systematic sequencing of candidate transcripts identified a homozygous splice-site mutation in a previously unknown BBS8 exon. The allele segregated with the disorder, was absent from controls, was completely invariant across evolution, and was predicted to lead to the elimination of a 10 amino acid sequence from the protein. Subsequent studies showed the exon to be expressed exclusively in the retina and enriched significantly in the photoreceptor layer. Importantly, we found this exon to represent the major BBS8 mRNA species in the mammalian photoreceptor, suggesting that the encoded 10 amino acids play a pivotal role in the function of BBS8 in this organ. Understanding the role of this additional sequence might therefore inform the mechanism of retinal degeneration in patients with syndromic BBS or other related ciliopathies.
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16
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Waseem NH, Vaclavik V, Webster A, Jenkins SA, Bird AC, Bhattacharya SS. Mutations in the gene coding for the pre-mRNA splicing factor, PRPF31, in patients with autosomal dominant retinitis pigmentosa. Invest Ophthalmol Vis Sci 2007; 48:1330-4. [PMID: 17325180 DOI: 10.1167/iovs.06-0963] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Retinitis pigmentosa is a clinically and genetically heterogeneous disorder. It is characterized by progressive degeneration of the peripheral retina, leading to night blindness and loss of the peripheral visual field. PRPF31 is one of four pre-mRNA splicing factors identified as causing autosomal dominant retinitis pigmentosa, with incomplete penetrance being the unique feature associated with mutations in this gene. The purpose of this study was to identify PRPF31 mutations in a cohort of 118 cases of autosomal dominant retinitis pigmentosa and determine the genotype-phenotype correlation emerging from the spectrum of mutations in this gene. METHODS Probands with autosomal dominant retinitis pigmentosa underwent ophthalmic evaluation. Blood samples were obtained, genomic DNA was isolated, and PRPF31 exons along with adjacent splice junctions were amplified by PCR and screened by direct sequencing. RESULTS In the 118 individuals with autosomal dominant retinitis pigmentosa, six mutations were identified, of which four were novel. One previously known splice site mutation was identified in two other apparently unrelated families. CONCLUSIONS Mutations in PRPF31 causing adRP were present in nearly 5% of a mixed U.K. population. The age of onset and the severity of the disease varied with different mutations. In addition, individuals carrying the same mutation showed a range of phenotypic variation, suggesting the involvement of other modifying genes.
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Affiliation(s)
- Naushin H Waseem
- Department of Molecular Genetics, Institute of Ophthalmology, University College London, London, United Kingdom
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17
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Tschernutter M, Jenkins SA, Waseem NH, Saihan Z, Holder GE, Bird AC, Bhattacharya SS, Ali RR, Webster AR. Clinical characterisation of a family with retinal dystrophy caused by mutation in the Mertk gene. Br J Ophthalmol 2006; 90:718-23. [PMID: 16714263 PMCID: PMC1860205 DOI: 10.1136/bjo.2005.084897] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIM MERTK, a tyrosine kinase receptor protein expressed by the retinal pigment epithelium (RPE), is mutated in both rodent models and humans affected by retinal disease. This study reports a survey of families for Mertk mutations and describes the phenotype exhibited by one family. METHODS 96 probands with retinal dystrophy, consistent with autosomal recessive segregation, were screened by direct sequencing. A family homozygous for a likely null allele was investigated clinically. RESULTS A novel frame shifting deletion was identified in one of 96 probands. Other polymorphisms were detected. The deletion allele occurred on both chromosomes of four affected family members. Electrophysiology demonstrated early loss of scotopic and macular function with later loss of photopic function. Visual acuities and visual fields were preserved into the second decade. Perception of light vision was present in a patient in the fourth decade. A "bull's eye" appearance and a hyperautofluorescent lesion at the central macula were consistent clinical findings. CONCLUSIONS Mutations in Mertk are a rare cause of ARRP in humans. The study extends the phenotypic characteristics of this retinal dystrophy and shows distinctive clinical signs that may improve its clinical identification. The moderate severity and presence of autofluorescence implies that outer segment phagocytosis is not entirely absent.
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Affiliation(s)
- M Tschernutter
- Institute of Ophthalmology, Bath Street, London EC1V 9EL, UK
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18
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Waseem A, Karsten U, Leigh IM, Purkis P, Waseem NH, Lane EB. Conformational Changes in the Rod Domain of Human Keratin 8 following Heterotypic Association with Keratin 18 and Its Implication for Filament Stability†. Biochemistry 2004; 43:1283-95. [PMID: 14756564 DOI: 10.1021/bi035072s] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Keratin intermediate filaments are heteropolymers of type I and type II polypeptides that constitute the bulk of the epithelial cytoskeleton. We microinjected seven keratin monoclonal antibodies into human epithelial cells, and two of them, only A45-B/B3 and LP3K, caused the formation of keratin aggregates. The keratin filaments in human epithelial cells were also disrupted by a monovalent A45-B/B3 Fab fragment, suggesting that the binding of the antibody, rather than cross-linking, collapses the filaments. Immunoblotting and ELISA experiments suggested that the antibody reacted weakly with recombinant K8 but did not react with recombinant K18 at all. However, the antibody reactivity increased substantially when a mixture of the two keratin polypeptides, either recombinant or derived from MCF-7, was used. The epitopes of 15 monoclonal antibodies recognizing human K8 were characterized by their reactivity with recombinant fragments of K8. Reactivity of antibody A45-B/B3 with fragments of K8 in the presence of K18 revealed that the antibody recognizes an epitope in the rod domain of K8, between residues 313 and 332, on the amino-terminal side of the stutter in helix 2B, which is involved in heterotypic association. The data suggest that this region of K8 undergoes a conformational change following interaction with the complementary K18 either to expose the epitope or to increase its affinity for the antibody. Taken together, the data highlight the role of this epitope in heterotypic association and in filament stabilization.
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Affiliation(s)
- Ahmad Waseem
- Programme in Oral Oncology, Oral Diseases Research Centre, Bart's and The London, Queen Mary's School of Medicine and Dentistry, London, UK.
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19
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Waseem NH, Bagnall R, Green PM, Giannelli F. Mutation detection in factor VIII cDNA from lymphocytes of hemophilia A patients by solid phase fluorescent chemical cleavage of mismatch. Methods Mol Biol 2002; 187:109-23. [PMID: 12013738 DOI: 10.1385/1-59259-273-2:109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Affiliation(s)
- Naushin H Waseem
- Division of Medical and Molecular Genetics, GKT School of Medicine, Guy's Hospital, London
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Woods AL, Hall PA, Shepherd NA, Hanby AM, Waseem NH, Lane DP, Levison DA. The assessment of proliferating cell nuclear antigen (PCNA)immunostaining in primary gastrointestinal lymphomas and its relationship to histological grade, S + G2 + M phase fraction (flow cytometric analysis) and prognosis. Histopathology 2002; 41:165-71. [PMID: 12405950 DOI: 10.1046/j.1365-2559.2002.14894.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- A L Woods
- Department of Histopathology, UMDS, Guy's Hospital, London, UK
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21
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Ola A, Waga S, Ellison V, Stillman B, McGurk M, Leigh IM, Waseem NH, Waseem A. Human-Saccharomyces cerevisiae proliferating cell nuclear antigen hybrids: oligomeric structure and functional characterization using in vitro DNA replication. J Biol Chem 2001; 276:10168-77. [PMID: 11094057 DOI: 10.1074/jbc.m008929200] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The proliferating cell nuclear antigen (PCNA) is a highly conserved protein required for the assembly of the DNA polymerase delta (pol delta) holoenzyme. Because PCNAs from Saccharomyces cerevisiae and human do not complement each other using in vitro or in vivo assays, hybrids of the two proteins would help identify region(s) involved in the assembly of the pol delta holoenzyme. Two mutants of human PCNA, HU1 (D21E) and HU3 (D120E), and six hybrids of human and S. cerevisiae PCNA, HC1, HC5, CH2, CH3, CH4, and CH5, were prepared by swapping corresponding regions between the two proteins. In solution, all PCNA assembled into trimers, albeit to different extents. These PCNA variants were tested for stimulation of pol delta and in vitro replication of M13 and SV40 DNA as well as to stimulate the ATPase activity of replication factor C (RF-C). Our data suggest that in addition to the interdomain connecting loop and C terminus, an additional site in the N terminus is required for pol delta interaction. PCNA mutants and hybrids that stimulated pol delta and RF-C were deficient in M13 and SV40 DNA replication assays, indicating that PCNA-induced pol delta stimulation and RF-C-mediated loading are not sufficient for coordinated DNA synthesis at a replication fork.
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Affiliation(s)
- A Ola
- Head and Neck Cancer Research Program, Guys, King's, and St. Thomas' Dental Institute, Guy's Campus, King's College London, London SE1 9RT, United Kingdom
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22
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Bagnall RD, Waseem NH, Green PM, Colvin B, Lee C, Giannelli F. Creation of a novel donor splice site in intron 1 of the factor VIII gene leads to activation of a 191 bp cryptic exon in two haemophilia A patients. Br J Haematol 1999; 107:766-71. [PMID: 10606882 DOI: 10.1046/j.1365-2141.1999.01767.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We have constructed a confidential U.K. database of haemophilia A mutations and pedigrees by characterizing the gene defect of one index patient in each U.K. family. Mutations were identified by screening all coding regions of the factor VIII (FVIII) mRNA, using solid-phase fluorescent chemical cleavage of mismatch and examining additional non-coding regions of the gene. Here we report two haemophilia A patients (UK 114 FVIII:C 2% and UK 243 FVIII:C < 1%) with an abnormal FVIII mRNA due to an A to G point mutation, 1.4 kb downstream from exon 1 in the FVIII gene. This mutation creates a new donor splice site in intron 1 and leads to insertion of a 191 bp novel exon in the mRNA. Haplotype analysis suggests that the mutation may have originated in a common ancestor of the two patients, who further illustrate how mRNA analysis allows higher efficiency of haemophilia A mutation detection, because their mutation would not have been identified by direct analysis of the factor VIII gene.
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Affiliation(s)
- R D Bagnall
- Division of Medical and Molecular Genetics, Guy's, King's and St Thomas's School of Medicine, London
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23
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Green PM, Waseem NH, Bagnall RD, Giannelli F. Mutation analysis and genetic service: the construction and use of national confidential databases of mutations and pedigrees. Genet Test 1999; 1:181-8. [PMID: 10464644 DOI: 10.1089/gte.1997.1.181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The development of rapid mutation screening procedures allows the detection of mutations in large populations. This is particularly useful for inherited diseases of high mutational heterogeneity, such as haemophilia A and B, because the analysis of the very many different natural mutants clearly defines the features that are important to the function of the relevant gene and gene product. Furthermore, the characterization of the mutation in an index person from each affected family may lead to the construction of confidential databases of mutations and pedigrees that allow optimization of genetic service. We report how, motivated by the aforementioned concepts, we have planned and introduced in the UK a national strategy to optimize genetic service in both haemophilias and, in particular, we describe the principles that have guided us.
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Affiliation(s)
- P M Green
- Division of Medical & Molecular Genetics, United Medical School of Guy's Hospital, London
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Waseem NH, Bagnall R, Green PM, Giannelli F. Start of UK confidential haemophilia A database: analysis of 142 patients by solid phase fluorescent chemical cleavage of mismatch. Haemophilia Centres. Thromb Haemost 1999; 81:900-5. [PMID: 10404764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
A national strategy for optimising genetic services in haemophilia A has been initiated in the UK. Solid phase fluorescent chemical cleavage of mismatch is used to screen the entire coding region of factor VIII in six segments: four amplified from the trace of mRNA in blood lymphocytes and two from genomic DNA for the 3.4 kb exon 14 and flanking intron sequences. These segments are analysed in two threefold multiplexes so that the genes of 18 patients can be screened in a single ABI 377 gel. The promoter and polyadenylation signal region are amplified and sequenced directly. We have analysed 142 unrelated patients and identified 141 factor VIII mutations and one Normandy type von Willebrand homozygote. The former mutations include 89 missense, 10 nonsense, 5 frameshift, one 24 bp deletion and one splice signal defect. These comprise 71 different changes, of which 39 have not been previously observed.
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Affiliation(s)
- N H Waseem
- Division of Medical and Molecular Genetics, Guy's Hospital, London, UK
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25
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Abstract
Keratins are a family of highly homologous proteins expressed as pairs of acidic and basic forms which make intermediate filaments in epithelial cells. Keratin 13 (K13) is the major acidic keratin, which together with K4, its basic partner, is expressed in the suprabasal layers of non-cornified stratified epithelia. The mechanism which allows mucosal-specific expression of this keratin remains unknown. To provide insight into the tissue-specific expression, we have isolated the human K13 gene by screening a chromosome 17 library with a specific K13 cRNA probe. Sequence analysis of unidirectional deletions produced by transposon Tn3 has revealed that the gene is 4601 nucleotides long and contains seven introns and eight exons. When driven by the CMV promoter, the gene produced K13 protein in MCF-7 cells, which normally do not express this protein. Two transcription-start sites were identified, the major being at 61 and the minor at 63 nucleotides upstream of ATG. The upstream sequence contained a TATA box and several other putative transcription factor binding sites. A single copy of the K13 gene was detected in the human genome by Southern hybridisation and polymerase chain reaction. K13 mRNA shows differential expression in cultured keratinocytes, and in A431 cells the RNA levels remained independent of calcium concentrations in the culture medium. Characterisation of the human K13 gene will facilitate elucidation of the molecular mechanism regulating K13 expression in mucosal tissues.
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Affiliation(s)
- A Waseem
- Department of Craniofacial Development, Guy's Dental School, Floor 28, Guy's Tower, London Bridge, London, SE1 9RT, UK.
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Waseem A, White K, Waseem NH. Identification of a novel keratin epitope: evidence for association between non-helical sub-domains L12 during filament assembly. Int J Biochem Cell Biol 1997; 29:971-83. [PMID: 9375377 DOI: 10.1016/s1357-2725(97)00055-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Keratin filaments in simple epithelial cells are heteropolymers of keratin 8 (K8) and keratin 18 (K18) polypeptides. The assembly of these polypeptides into intermediate filaments is a complex multi-stage phenomenon that involves several levels of associations. These molecular associations are not very well characterized. Monoclonal antibodies (MAbs) with defined specificities can be used to probe these associations and to isolate various intermediates in the assembly pathway. Here we describe the specificity of a MAb LE65 that has been widely used in keratin expression studies. We report that the MAb LE65 does not recognize individual keratin polypeptides but it instead reacts with a complex of K8 with K18. The MAb also did not react with complexes of K8 or K18 with other keratins. By allowing the antibody to react with complexes reconstituted from keratin fragments plus the complementary keratin, we have mapped the MAb LE65 epitope on the L12 sub-domains of K18, residues 214-231, and K8, residues 234-265, which must associate together to achieve antibody binding. These results suggest that the non-helical linkers, L12, of complementary keratins associate directly during filament assembly. This would explain why microinjection of MAb LE65 has been shown to disrupt keratin filaments. Furthermore, it may also help to explain the mechanism of filament disruption in some skin blistering syndromes induced by spontaneous mutations in the L12 region.
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Affiliation(s)
- A Waseem
- Department of Craniofacial Development, UMDS, Guy's Hospital, London, U.K
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Abstract
Five monoclonal antibodies raised against rat PCNA cross-reacted with a similar protein in the fission yeast Schizosaccharomyces pombe. One of these was used to screen an S.pombe cDNA expression library. An incomplete cDNA was isolated and used to screen a genomic library, identifying a single gene, designated pcn1+ (proliferating cell nuclear antigen). The gene encodes a protein of 260 amino acids, with a deduced sequence 52% identical to human and rat PCNAs, which are 98.5% identical to each other. The budding yeast PCNA homologue POL30 is only 35% identical to the human and rat proteins. Pcn1 has a region near the C-terminus of particularly high homology to higher eukaryotic PCNA proteins. pcn1+ is essential for viability and delta pcn1 cells undergo aberrant DNA replication before cell cycle arrest. Overproduction of the protein leads to cell cycle delay in G2. Disruption of pcn1+ is complemented by the human PCNA gene, demonstrating that these genes are functional homologues.
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Affiliation(s)
- N H Waseem
- CRC Cell Transformation Research Group, University of Dundee, UK
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Wilkins BS, Harris S, Waseem NH, Lane DP, Jones DB. A study of cell proliferation in formalin-fixed, wax-embedded bone marrow trephine biopsies using the monoclonal antibody PC10, reactive with proliferating cell nuclear antigen (PCNA). J Pathol 1992; 166:45-52. [PMID: 1347081 DOI: 10.1002/path.1711660108] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We have investigated proliferation in bone marrow trephine biopsies from 32 patients with normal or abnormal haemopoiesis, using the monoclonal antibody PC10, which detects proliferating cell nuclear antigen (PCNA), together with immunohistochemical markers of haemopoietic cell lineage. PCNA immunostaining revealed the pattern of proliferation within individual haemopoietic lineages in normal marrow. Two unexpected observations were made: of erythroid cells, only pro-erythroblasts and occasional early normoblasts reacted, and positivity of megakaryocytes was unrelated to nuclear lobulation or CD61 expression. The pathological cases represented conditions in which haemopoiesis is increased (reactive hyperplasia, chronic granulocytic leukaemia, myeloproliferative and myelodysplastic syndromes, megaloblastic anaemia). Increases in the number, and disturbances of the spatial organization, of PCNA-expressing cells were present to a variable extent in all cases. Sheets of PCNA-positive megaloblastoid erythrocytes were frequently found in myelodysplastic and myeloproliferative tissue, associated with marked disturbances in the spatial organization of all haemopoietic lineages. Cases of megaloblastic anaemia due to vitamin B12/folate deficiency also demonstrated greatly increased erythroid PCNA expression, with positivity in some giant metamyelocytes. In addition to reflecting increased proliferation, elevated PCNA expression in some bone marrow pathologies may be due to altered kinetics of the protein induced by disturbances in growth factor production.
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Affiliation(s)
- B S Wilkins
- University Department of Pathology, Southampton General Hospital, U.K
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Woods AL, Hall PA, Shepherd NA, Hanby AM, Waseem NH, Lane DP, Levison DA. The assessment of proliferating cell nuclear antigen (PCNA) immunostaining in primary gastrointestinal lymphomas and its relationship to histological grade, S+G2+M phase fraction (flow cytometric analysis) and prognosis. Histopathology 1991; 19:21-7. [PMID: 1680784 DOI: 10.1111/j.1365-2559.1991.tb00890.x] [Citation(s) in RCA: 170] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PCNA is a nuclear protein that is synthesized in late G1 and S phases of the cell cycle and is, therefore, correlated with the cell proliferative state. A new monoclonal antibody (PC10) to genetically engineered PCNA has been shown to label proliferating cells in formalin-fixed paraffin-embedded normal human tissues. Previous studies in lymphomas, using various markers of cell proliferation, have shown a strong correlation between indices of cell proliferation and histological grade. These studies have shown that within each histological subtype there is often a wide range of proliferative indices and that these may be of some prognostic significance. Thirty-one gastrointestinal lymphomas were studied. Our results show that there is a good correlation between PC10 index and histological grade of tumour (0.01 P greater than P greater than 0.001) and also a significant relationship between PC10 index and S+G2+M phase fraction as measured by flow cytometric analysis (r2 = 0.62; P less than 0.01). Twenty-three cases were available for survival analysis. In these cases a high PC10 score correlated with poor survival (P = 0.04). Based on this series, it appears that there is a significant relationship between PC10 index and histological grade, and between PC10 index and S+G2+M phase as measured by flow cytometric analysis. In addition, our results suggest that a high PC10 index is an adverse prognostic factor in primary gastrointestinal lymphoma.
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Affiliation(s)
- A L Woods
- Department of Histopathology, UMDS, Guy's Hospital, London, UK
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Yu CC, Hall PA, Fletcher CD, Camplejohn RS, Waseem NH, Lane DP, Levison DA. Haemangiopericytomas: the prognostic value of immunohistochemical staining with a monoclonal antibody to proliferating cell nuclear antigen (PCNA). Histopathology 1991; 19:29-33. [PMID: 1680785 DOI: 10.1111/j.1365-2559.1991.tb00891.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Forty-two cases of haemangiopericytoma were studied retrospectively using immunohistochemical staining with PC10, a monoclonal antibody to PCNA. The percentage of tumour cells with positive staining for PCNA was found to correlate well with histological grading. Clinical follow-up data were available in 25 adults and showed no known deaths in 11 cases with a low proportion (less than 14%) of positive cells. Out of 14 cases with a high number (greater than or equal to 14%) of positive cells, seven patients are known to have died, two had metastases, and in a further two there have been multiple recurrences of tumour. DNA flow cytometry was performed on 26 cases but this showed no correlation with PC10 staining or clinical outcome. Staining with PC10 may be of particular value in the identification of patients at greatest risk of rapid tumour metastasis and early death.
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Affiliation(s)
- C C Yu
- Department of Histopathology, UMDS, Guy's Hospital, London, UK
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Waseem NH, Lane DP. Monoclonal antibody analysis of the proliferating cell nuclear antigen (PCNA). Structural conservation and the detection of a nucleolar form. J Cell Sci 1990; 96 ( Pt 1):121-9. [PMID: 1695635 DOI: 10.1242/jcs.96.1.121] [Citation(s) in RCA: 511] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The proliferating cell nuclear antigen, PCNA, has recently been identified as the polymerase delta accessory protein. PCNA is essential for cellular DNA synthesis and is also required for the in vitro replication of simian virus 40 (SV40) DNA where it acts to coordinate leading and lagging strand synthesis at the replication fork. The cDNA for rat PCNA was cloned into a series of bacterial expression vectors and the resulting protein used to immunize mice. Eleven new monoclonal antibodies to PCNA have been isolated and characterized. Some of the antibodies recognize epitopes conserved from man to fission yeast. Immunocytochemical analysis of primate epithelial cell lines showed that the antibodies recognized antigenically distinct forms of PCNA and that these forms were localized to different compartments of the nucleus. One antibody reacted exclusively with PCNA in the nucleolus. These results suggest that the PCNA protein may fulfil several separate roles in the cell nucleus associated with changes in its antigenic structure.
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Affiliation(s)
- N H Waseem
- ICRF Clare Hall Laboratories, Potters Bar, Herts, UK
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