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Lu C, Li S, Jin M. Rapamycin Inhibits Light-Induced Necrosome Activation Occurring in Wild-Type, but not RPE65-Null, Mouse Retina. Invest Ophthalmol Vis Sci 2022; 63:19. [PMID: 36534385 PMCID: PMC9769341 DOI: 10.1167/iovs.63.13.19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose Both photodamage and aberrant visual cycle contribute to disease progress of many retinal degenerative disorders, whereas the signaling pathways causing photoreceptor death remain unclear. Here we investigated the effects of intense photo-stress on (1) necrosome activation in wild-type and RPE65-null mice, (2) interaction of p62/Sequestosome-1 with the necrosome proteins, and (3) the effects of rapamycin on photodamage-induced necrosome activation and retinal degeneration in wild-type mice. Methods Dark-adapted rd12 mice and 129S2/Sv mice with or without rapamycin treatment were exposed to 15,000 lux light for different times. Expression levels and subcellular localization of proteins were determined through immunoblot and immunohistochemical analyses. Cone sheaths were stained with peanut agglutinin. Correlation between photoreceptor degeneration and receptor-interacting protein kinase-1 (RIPK1) expression was assessed with Spearman's correlation analysis. Protein-protein interaction was analyzed by immunoprecipitation. Results Intense light caused rod and cone degeneration accompanied by a significant increase in RIPK1-RIPK3 expressions, mixed lineage kinase domain-like protein phosphorylation, damage-associated molecular patterns protein release, and inflammatory responses in wild-type mouse retina. The same intense light did not induce the necrosome activation in rd12 retina, but it did in rd12 mice that received 9-cis-retinal supply. RIPK1 expression levels are positively correlated with the degrees of rod and cone degeneration. Photodamage upregulated expression and interaction of the p62 autophagosome cargo protein with the necrosome proteins, whereas rapamycin treatment attenuated the light-induced necrosome activation and photoreceptor degeneration. Conclusions Necrosome activation contributed to photodamage-induced rod and cone degeneration. The visual cycle and autophagy are the important therapeutic targets to alleviate light-induced retinal necroptosis.
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Affiliation(s)
- Chunfeng Lu
- Neuroscience Center of Excellence, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana, United States
| | - Songhua Li
- Neuroscience Center of Excellence, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana, United States
| | - Minghao Jin
- Neuroscience Center of Excellence, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana, United States,Department of Ophthalmology, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana, United States
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Suzuki M, Tomita M. Genetic Variations of Vitamin A-Absorption and Storage-Related Genes, and Their Potential Contribution to Vitamin A Deficiency Risks Among Different Ethnic Groups. Front Nutr 2022; 9:861619. [PMID: 35571879 PMCID: PMC9096837 DOI: 10.3389/fnut.2022.861619] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 03/23/2022] [Indexed: 12/01/2022] Open
Abstract
Vitamin A, an essential fat-soluble micronutrient, plays a critical role in the body, by regulating vision, immune responses, and normal development, for instance. Vitamin A deficiency (VAD) is a major cause of xerophthalmia and increases the risk of death from infectious diseases. It is also emerging that prenatal exposure to VAD is associated with disease risks later in life. The overall prevalence of VAD has significantly declined over recent decades; however, the rate of VAD is still high in many low- and mid-income countries and even in high-income countries among specific ethnic/race groups. While VAD occurs when dietary intake is insufficient to meet demands, establishing a strong association between food insecurity and VAD, and vitamin A supplementation is the primary solution to treat VAD, genetic contributions have also been reported to effect serum vitamin A levels. In this review, we discuss genetic variations associated with vitamin A status and vitamin A bioactivity-associated genes, specifically those linked to uptake of the vitamin in the small intestine and its storage in the liver, as well as their potential contribution to vitamin A deficiency risks among different ethnic groups.
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Affiliation(s)
- Masako Suzuki
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, United States
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3
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Abstract
One of the most powerful and commonly used approaches for detecting local adaptation in the genome is the identification of extreme allele frequency differences between populations. In this article, we present a new maximum likelihood method for finding regions under positive selection. It is based on a Gaussian approximation to allele frequency changes and it incorporates admixture between populations. The method can analyze multiple populations simultaneously and retains power to detect selection signatures specific to ancestry components that are not representative of any extant populations. Using simulated data, we compare our method to related approaches, and show that it is orders of magnitude faster than the state-of-the-art, while retaining similar or higher power for most simulation scenarios. We also apply it to human genomic data and identify loci with extreme genetic differentiation between major geographic groups. Many of the genes identified are previously known selected loci relating to hair pigmentation and morphology, skin, and eye pigmentation. We also identify new candidate regions, including various selected loci in the Native American component of admixed Mexican-Americans. These involve diverse biological functions, such as immunity, fat distribution, food intake, vision, and hair development.
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Affiliation(s)
- Jade Yu Cheng
- Lundbeck GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Aaron J Stern
- Graduate Group in Computational Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Fernando Racimo
- Lundbeck GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
| | - Rasmus Nielsen
- Lundbeck GeoGenetics Centre, Globe Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, USA
- Department of Statistics, University of California, Berkeley, Berkeley, CA, USA
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Koster C, van den Hurk KT, Lewallen CF, Talib M, ten Brink JB, Boon CJF, Bergen AA. The Lrat -/- Rat: CRISPR/Cas9 Construction and Phenotyping of a New Animal Model for Retinitis Pigmentosa. Int J Mol Sci 2021; 22:ijms22137234. [PMID: 34281288 PMCID: PMC8267968 DOI: 10.3390/ijms22137234] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 11/16/2022] Open
Abstract
PURPOSE We developed and phenotyped a pigmented knockout rat model for lecithin retinol acyltransferase (LRAT) using CRISPR/Cas9. The introduced mutation (c.12delA) is based on a patient group harboring a homologous homozygous frameshift mutation in the LRAT gene (c.12delC), causing a dysfunctional visual (retinoid) cycle. METHODS The introduced mutation was confirmed by DNA and RNA sequencing. The expression of Lrat was determined on both the RNA and protein level in wildtype and knockout animals using RT-PCR and immunohistochemistry. The retinal structure and function, as well as the visual behavior of the Lrat-/- and control rats, were characterized using scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), electroretinography (ERG) and vision-based behavioral assays. RESULTS Wildtype animals had high Lrat mRNA expression in multiple tissues, including the eye and liver. In contrast, hardly any expression was detected in Lrat-/- animals. LRAT protein was abundantly present in wildtype animals and absent in Lrat-/- animals. Lrat-/- animals showed progressively reduced ERG potentials compared to wildtype controls from two weeks of age onwards. Vison-based behavioral assays confirmed reduced vision. Structural abnormalities, such as overall retinal thinning, were observed in Lrat-/- animals. The retinal thickness in knockout rats was decreased to roughly 80% by four months of age. No functional or structural differences were observed between wildtype and heterozygote animals. CONCLUSIONS Our Lrat-/- rat is a new animal model for retinal dystrophy, especially for the LRAT-subtype of early-onset retinal dystrophies. This model has advantages over the existing mouse models and the RCS rat strain and can be used for translational studies of retinal dystrophies.
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Affiliation(s)
- Céline Koster
- Department of Human Genetics Amsterdam, Section of Ophthalmogenetics, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands; (C.K.); (K.T.v.d.H.); (J.B.t.B.)
| | - Koen T. van den Hurk
- Department of Human Genetics Amsterdam, Section of Ophthalmogenetics, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands; (C.K.); (K.T.v.d.H.); (J.B.t.B.)
| | - Colby F. Lewallen
- Georgia Institute of Technology, G.W. Woodruff School of Mechanical Engineering, Atlanta, GA 30313, USA;
| | - Mays Talib
- Department of Ophthalmology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (M.T.); (C.J.F.B.)
| | - Jacoline B. ten Brink
- Department of Human Genetics Amsterdam, Section of Ophthalmogenetics, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands; (C.K.); (K.T.v.d.H.); (J.B.t.B.)
| | - Camiel J. F. Boon
- Department of Ophthalmology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands; (M.T.); (C.J.F.B.)
- Department of Ophthalmology, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands
| | - Arthur A. Bergen
- Department of Human Genetics Amsterdam, Section of Ophthalmogenetics, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands; (C.K.); (K.T.v.d.H.); (J.B.t.B.)
- Department of Ophthalmology, Amsterdam University Medical Centers (AUMC), University of Amsterdam (UvA), Location Meibergdreef, 1105 AZ Amsterdam, The Netherlands
- The Netherlands Institute for Neuroscience (NIN-KNAW), 1105 BA Amsterdam, The Netherlands
- Correspondence:
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Dewell TE, Gjoni K, Liu AZ, Libby ARG, Moore AT, So PL, Conklin BR. Transcription factor overexpression drives reliable differentiation of retinal pigment epithelium from human induced pluripotent stem cells. Stem Cell Res 2021; 53:102368. [PMID: 34087997 DOI: 10.1016/j.scr.2021.102368] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 02/10/2021] [Accepted: 04/21/2021] [Indexed: 12/13/2022] Open
Abstract
Age-related macular degeneration and genetic forms of blindness such as Best Disease and Retinitis Pigmentosa can be caused by degeneration of the Retinal Pigment Epithelium (RPE). RPE generated from patient-derived induced pluripotent stem cells (iPSCs) is valuable for both the study of disease mechanisms and development of therapeutic strategies. However, protocols to produce iPSC-derived RPE in vitro are often inefficient, labor-intensive, low-throughput, and highly variable between cell lines and within batches. Here, we report a robust, scalable method to generate iPSC-RPE using doxycycline-inducible expression of eye field transcription factors OTX2, PAX6 and MITF paired with RPE-permissive culture media. Doxycycline addition induces exogenous expression of these transcription factors in Best Disease patient- and wildtype iPSCs to efficiently produce monolayers of RPE with characteristic morphology and gene expression. Further, these RPE monolayers display functionality features including light absorption via pigmentation, polarity-driven fluid transport, and phagocytosis. With this method, we achieve a highly efficient and easily scalable differentiation without the need for mechanical isolation or enrichment methods, generating RPE cultures applicable for in vitro studies.
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Affiliation(s)
- Tessa E Dewell
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Ketrin Gjoni
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Angela Z Liu
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Ashley R G Libby
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA; Developmental and Stem Cell Biology Program, University of California, 1675 Owens St, San Francisco, CA 94158, USA
| | - Anthony T Moore
- UCSF Department of Ophthalmology, 10 Koret Way, San Francisco, CA 94143-0730, USA
| | - Po-Lin So
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA; Innovative Genomics Institute, 2151 Berkeley Way, Berkeley, CA 94720, USA; Gladstone Institutes Stem Cell Core, 1650 Owens Street, San Francisco, CA 94158, USA
| | - Bruce R Conklin
- Gladstone Institutes, 1650 Owens Street, San Francisco, CA 94158, USA; UCSF Department of Ophthalmology, 10 Koret Way, San Francisco, CA 94143-0730, USA; Innovative Genomics Institute, 2151 Berkeley Way, Berkeley, CA 94720, USA; UCSF Department of Medicine, 535 Mission Bay Blvd South, San Francisco, CA 94158, USA.
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6
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Dewett D, Lam-Kamath K, Poupault C, Khurana H, Rister J. Mechanisms of vitamin A metabolism and deficiency in the mammalian and fly visual system. Dev Biol 2021; 476:68-78. [PMID: 33774009 DOI: 10.1016/j.ydbio.2021.03.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/18/2021] [Accepted: 03/20/2021] [Indexed: 10/21/2022]
Abstract
Vitamin A deficiency can cause human pathologies that range from blindness to embryonic malformations. This diversity is due to the lack of two major vitamin A metabolites with very different functions: the chromophore 11-cis-retinal (vitamin A aldehyde) is a critical component of the visual pigment that mediates phototransduction, while the signaling molecule all-trans-retinoic acid regulates the development of various tissues and is required for the function of the immune system. Since animals cannot synthesize vitamin A de novo, they must obtain it either as preformed vitamin A from animal products or as carotenoid precursors from plant sources. Due to its essential role in the visual system, acute vitamin A deprivation impairs photoreceptor function and causes night blindness (poor vision under dim light conditions), while chronic deprivation results in retinal dystrophies and photoreceptor cell death. Chronic vitamin A deficiency is the leading cause of preventable childhood blindness according to the World Health Organization. Due to the requirement of vitamin A for retinoic acid signaling in development and in the immune system, vitamin A deficiency also causes increased mortality in children and pregnant women in developing countries. Drosophila melanogaster is an excellent model to study the effects of vitamin A deprivation on the eye because vitamin A is not essential for Drosophila development and chronic deficiency does not cause lethality. Moreover, genetic screens in Drosophila have identified evolutionarily conserved factors that mediate the production of vitamin A and its cellular uptake. Here, we review our current knowledge about the role of vitamin A in the visual system of mammals and Drosophila melanogaster. We compare the molecular mechanisms that mediate the uptake of dietary vitamin A precursors and the metabolism of vitamin A, as well as the consequences of vitamin A deficiency for the structure and function of the eye.
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Affiliation(s)
- Deepshe Dewett
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, USA
| | - Khanh Lam-Kamath
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, USA
| | - Clara Poupault
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, USA
| | - Heena Khurana
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, USA
| | - Jens Rister
- Department of Biology, Integrated Sciences Complex, University of Massachusetts Boston, Boston, USA.
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7
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Artero-Castro A, Long K, Bassett A, Ávila-Fernandez A, Cortón M, Vidal-Puig A, Jendelova P, Rodriguez-Jimenez FJ, Clemente E, Ayuso C, Erceg S. Gene Correction Recovers Phagocytosis in Retinal Pigment Epithelium Derived from Retinitis Pigmentosa-Human-Induced Pluripotent Stem Cells. Int J Mol Sci 2021; 22:ijms22042092. [PMID: 33672445 PMCID: PMC7923278 DOI: 10.3390/ijms22042092] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/12/2021] [Accepted: 02/15/2021] [Indexed: 12/30/2022] Open
Abstract
Hereditary retinal dystrophies (HRD) represent a significant cause of blindness, affecting mostly retinal pigment epithelium (RPE) and photoreceptors (PRs), and currently suffer from a lack of effective treatments. Highly specialized RPE and PR cells interact mutually in the functional retina, therefore primary HRD affecting one cell type leading to a secondary HRD in the other cells. Phagocytosis is one of the primary functions of the RPE and studies have discovered that mutations in the phagocytosis-associated gene Mer tyrosine kinase receptor (MERTK) lead to primary RPE dystrophy. Treatment strategies for this rare disease include the replacement of diseased RPE with healthy autologous RPE to prevent PR degeneration. The generation and directed differentiation of patient-derived human-induced pluripotent stem cells (hiPSCs) may provide a means to generate autologous therapeutically-relevant adult cells, including RPE and PR. However, the continued presence of the MERTK gene mutation in patient-derived hiPSCs represents a significant drawback. Recently, we reported the generation of a hiPSC model of MERTK-associated Retinitis Pigmentosa (RP) that recapitulates disease phenotype and the subsequent creation of gene-corrected RP-hiPSCs using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9. In this study, we differentiated gene-corrected RP-hiPSCs into RPE and found that these cells had recovered both wild-type MERTK protein expression and the lost phagocytosis of fluorescently-labeled photoreceptor outer segments observed in uncorrected RP-hiPSC-RPE. These findings provide proof-of-principle for the utility of gene-corrected hiPSCs as an unlimited cell source for personalized cell therapy of rare vision disorders.
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Affiliation(s)
- Ana Artero-Castro
- Stem Cells Therapies in Neurodegenerative Diseases Lab, Centro de Investigación Principe Felipe (CIPF), 46012 Valencia, Spain; (A.A.-C.); (F.J.R.-J.); (E.C.)
| | - Kathleen Long
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK; (K.L.); (A.B.)
| | - Andrew Bassett
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK; (K.L.); (A.B.)
| | - Almudena Ávila-Fernandez
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz, (IIS-FJD, UAM), 28040 Madrid, Spain; (A.Á.-F.); (M.C.); (C.A.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, 28040 Madrid, Spain
| | - Marta Cortón
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz, (IIS-FJD, UAM), 28040 Madrid, Spain; (A.Á.-F.); (M.C.); (C.A.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, 28040 Madrid, Spain
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Wellcome Trust MRC Institute of Metabolic Science, University of Cambridge, Addenbrooke’s Hospital, Cambridge CB2 0QQ, UK;
| | - Pavla Jendelova
- Institute of Experimental Medicine, Department of Neuroregeneration, Czech Academy of Science, 14220 Prague, Czech Republic;
| | - Francisco Javier Rodriguez-Jimenez
- Stem Cells Therapies in Neurodegenerative Diseases Lab, Centro de Investigación Principe Felipe (CIPF), 46012 Valencia, Spain; (A.A.-C.); (F.J.R.-J.); (E.C.)
| | - Eleonora Clemente
- Stem Cells Therapies in Neurodegenerative Diseases Lab, Centro de Investigación Principe Felipe (CIPF), 46012 Valencia, Spain; (A.A.-C.); (F.J.R.-J.); (E.C.)
| | - Carmen Ayuso
- Department of Genetics and Genomics, IIS-Fundación Jiménez Díaz, (IIS-FJD, UAM), 28040 Madrid, Spain; (A.Á.-F.); (M.C.); (C.A.)
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, 28040 Madrid, Spain
| | - Slaven Erceg
- Stem Cells Therapies in Neurodegenerative Diseases Lab, Centro de Investigación Principe Felipe (CIPF), 46012 Valencia, Spain; (A.A.-C.); (F.J.R.-J.); (E.C.)
- Institute of Experimental Medicine, Department of Neuroregeneration, Czech Academy of Science, 14220 Prague, Czech Republic;
- National Stem Cell Bank-Valencia Node, Proteomics, Genotyping and Cell Line Platform, PRB3, ISCIII, Research Centre Principe Felipe, c/ Eduardo Primo Yúfera 3, 46012 Valencia, Spain
- Correspondence: ; Tel.: +34-963-289-680 (ext. 1102)
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8
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Teino I, Matvere A, Pook M, Varik I, Pajusaar L, Uudeküll K, Vaher H, Trei A, Kristjuhan A, Org T, Maimets T. Impact of AHR Ligand TCDD on Human Embryonic Stem Cells and Early Differentiation. Int J Mol Sci 2020; 21:E9052. [PMID: 33260776 PMCID: PMC7731104 DOI: 10.3390/ijms21239052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/20/2020] [Accepted: 11/26/2020] [Indexed: 12/17/2022] Open
Abstract
Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor, which mediates the effects of a variety of environmental stimuli in multiple tissues. Recent advances in AHR biology have underlined its importance in cells with high developmental potency, including pluripotent stem cells. Nonetheless, there is little data on AHR expression and its role during the initial stages of stem cell differentiation. The purpose of this study was to investigate the temporal pattern of AHR expression during directed differentiation of human embryonic stem cells (hESC) into neural progenitor, early mesoderm and definitive endoderm cells. Additionally, we investigated the effect of the AHR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the gene expression profile in hESCs and differentiated cells by RNA-seq, accompanied by identification of AHR binding sites by ChIP-seq and epigenetic landscape analysis by ATAC-seq. We showed that AHR is differentially regulated in distinct lineages. We provided evidence that TCDD alters gene expression patterns in hESCs and during early differentiation. Additionally, we identified novel potential AHR target genes, which expand our understanding on the role of this protein in different cell types.
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Affiliation(s)
- Indrek Teino
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
| | - Antti Matvere
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
| | - Martin Pook
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
| | - Inge Varik
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
| | - Laura Pajusaar
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
| | - Keyt Uudeküll
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
| | - Helen Vaher
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
| | - Annika Trei
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
| | - Arnold Kristjuhan
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
| | - Tõnis Org
- Chair of Biotechnology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia;
- Institute of Genomics, University of Tartu, Riia 23b, 51010 Tartu, Estonia
| | - Toivo Maimets
- Chair of Cell Biology, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia; (A.M.); (M.P.); (I.V.); (L.P.); (K.U.); (H.V.); (A.T.); (A.K.); (T.M.)
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Abstract
Degenerative retinal disease is the major cause of sight loss in the developed world and currently there is a lack of effective treatments. As the loss of vision is directly the result of the loss of retinal cells, effective cell replacement through stem-cell-based therapies may have the potential to treat a great number of retinal diseases whatever their underlying etiology. The eye is an ideal organ to develop cell therapies as it is immune privileged, and modern surgical techniques enable precise delivery of cells to the retina. Furthermore, a range of noninvasive diagnostic tests and high-resolution imaging techniques facilitate the evaluation of any therapeutic intervention. In this review, we evaluate the progress to date of current cell therapy strategies for retinal repair, focusing on transplantation of pluripotent stem-cell-derived retinal pigment epithelium (RPE) and photoreceptor cells.
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Affiliation(s)
- Emma L West
- Division of Molecular Therapy, UCL Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Joana Ribeiro
- Division of Molecular Therapy, UCL Institute of Ophthalmology, London EC1V 9EL, United Kingdom
| | - Robin R Ali
- Division of Molecular Therapy, UCL Institute of Ophthalmology, London EC1V 9EL, United Kingdom.,Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan 48105, USA
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10
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Talib M, Boon CJF. Retinal Dystrophies and the Road to Treatment: Clinical Requirements and Considerations. Asia Pac J Ophthalmol (Phila) 2020; 9:159-179. [PMID: 32511120 PMCID: PMC7299224 DOI: 10.1097/apo.0000000000000290] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/01/2020] [Indexed: 12/15/2022] Open
Abstract
: Retinal dystrophies (RDs) comprise relatively rare but devastating causes of progressive vision loss. They represent a spectrum of diseases with marked genetic and clinical heterogeneity. Mutations in the same gene may lead to different diagnoses, for example, retinitis pigmentosa or cone dystrophy. Conversely, mutations in different genes may lead to the same phenotype. The age at symptom onset, and the rate and characteristics of peripheral and central vision decline, may vary widely per disease group and even within families. For most RD cases, no effective treatment is currently available. However, preclinical studies and phase I/II/III gene therapy trials are ongoing for several RD subtypes, and recently the first retinal gene therapy has been approved by the US Food and Drug Administration for RPE65-associated RDs: voretigene neparvovec-rzyl (Luxturna). With the rapid advances in gene therapy studies, insight into the phenotypic spectrum and long-term disease course is crucial information for several RD types. The vast clinical heterogeneity presents another important challenge in the evaluation of potential efficacy in future treatment trials, and in establishing treatment candidacy criteria. This perspective describes these challenges, providing detailed clinical descriptions of several forms of RD that are caused by genes of interest for ongoing and future gene or cell-based therapy trials. Several ongoing and future treatment options will be described.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden, The Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden, The Netherlands
- Department of Ophthalmology, Amsterdam UMC, Academic Medical Center, University of Amsterdam. Amsterdam, The Netherlands
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11
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Sirbu IO, Chiş AR, Moise AR. Role of carotenoids and retinoids during heart development. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158636. [PMID: 31978553 DOI: 10.1016/j.bbalip.2020.158636] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/15/2020] [Accepted: 01/16/2020] [Indexed: 02/08/2023]
Abstract
The nutritional requirements of the developing embryo are complex. In the case of dietary vitamin A (retinol, retinyl esters and provitamin A carotenoids), maternal derived nutrients serve as precursors to signaling molecules such as retinoic acid, which is required for embryonic patterning and organogenesis. Despite variations in the composition and levels of maternal vitamin A, embryonic tissues need to generate a precise amount of retinoic acid to avoid congenital malformations. Here, we summarize recent findings regarding the role and metabolism of vitamin A during heart development and we survey the association of genes known to affect retinoid metabolism or signaling with various inherited disorders. A better understanding of the roles of vitamin A in the heart and of the factors that affect retinoid metabolism and signaling can help design strategies to meet nutritional needs and to prevent birth defects and disorders associated with altered retinoid metabolism. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.
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Affiliation(s)
- Ioan Ovidiu Sirbu
- Biochemistry Department, Victor Babes University of Medicine and Pharmacy, Eftimie Murgu Nr. 2, 300041 Timisoara, Romania; Timisoara Institute of Complex Systems, V. Lucaciu 18, 300044 Timisoara, Romania.
| | - Aimée Rodica Chiş
- Biochemistry Department, Victor Babes University of Medicine and Pharmacy, Eftimie Murgu Nr. 2, 300041 Timisoara, Romania
| | - Alexander Radu Moise
- Medical Sciences Division, Northern Ontario School of Medicine, Sudbury, ON P3E 2C6, Canada; Department of Chemistry and Biochemistry, Biology and Biomolecular Sciences Program, Laurentian University, Sudbury, ON P3E 2C6, Canada.
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12
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Widjaja-Adhi MAK, Golczak M. The molecular aspects of absorption and metabolism of carotenoids and retinoids in vertebrates. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158571. [PMID: 31770587 DOI: 10.1016/j.bbalip.2019.158571] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/04/2019] [Accepted: 11/07/2019] [Indexed: 02/08/2023]
Abstract
Vitamin A is an essential nutrient necessary for numerous basic physiological functions, including reproduction and development, immune cell differentiation and communication, as well as the perception of light. To evade the dire consequences of vitamin A deficiency, vertebrates have evolved specialized metabolic pathways that enable the absorption, transport, and storage of vitamin A acquired from dietary sources as preformed retinoids or provitamin A carotenoids. This evolutionary advantage requires a complex interplay between numerous specialized retinoid-transport proteins, receptors, and enzymes. Recent advances in molecular and structural biology resulted in a rapid expansion of our understanding of these processes at the molecular level. This progress opened new avenues for the therapeutic manipulation of retinoid homeostasis. In this review, we summarize current research related to the biochemistry of carotenoid and retinoid-processing proteins with special emphasis on the structural aspects of their physiological actions. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.
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Affiliation(s)
- Made Airanthi K Widjaja-Adhi
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States of America
| | - Marcin Golczak
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States of America; Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH, United States of America.
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13
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Gauthier ME, Roy S, Cantin L, Salesse C. Comparison between the enzymatic activity, structure and substrate binding of mouse and human lecithin retinol acyltransferase. Biochem Biophys Res Commun 2019; 519:832-7. [PMID: 31561851 DOI: 10.1016/j.bbrc.2019.09.061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 09/15/2019] [Indexed: 11/22/2022]
Abstract
Lecithin retinol acyltransferase (LRAT) is involved in the visual cycle where it catalyzes the formation of all-trans retinyl ester. The mouse animal model has been widely used to study LRAT. Primary sequence alignment shows 80% identity and 90% similarity between human and mouse LRAT. However, human LRAT has a proline at position 173 (hLRAT (P173)) while an arginine can be found at this position for the mouse protein (mLRAT (R173)). Moreover, residue 173 is important for the human protein since a substitution mutation of this residue to a leucine (P173L-hLRAT) caused night blindness in a patient. The present study was thus undertaken to determine whether mouse and human LRAT have a similar enzymatic activity, structure and substrate binding affinity using a truncated form of LRAT (tLRAT). The enzymatic activity and binding affinity to the substrate, all-trans retinol, of mtLRAT (R173) were found to be 2.7- and 3.9-fold lower, respectively, than that of htLRAT (P173). Moreover, the enzymatic activity of P173L-htLRAT is 6.3-fold lower compared to that of htLRAT (P173). Furthermore, a significant difference was observed between the intrinsic fluorescence emission as well as between the circular dichroism spectra of mtLRAT (R173) and htLRAT (P173). In addition, mtLRAT proteins are less thermostable than htLRAT proteins, which suggests that structural differences exist between the mouse and human proteins. Altogether, these data strongly suggest that the much lower catalytic activity of mtLRAT (R173) compared to that of htLRAT (P173) mostly results from differences between their structure, predominantly revealed by their dissimilar thermal stability, as well as their efficiency to bind all-trans retinol. Therefore, conclusions regarding the behavior of human LRAT based on measurements performed with mouse LRAT must be made with caution. Also, the much lower enzymatic activity of P173L-htLRAT compared to that of htLRAT (P173) might explain the night blindness of a patient carrying this mutation.
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14
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Abstract
The retina is the light sensitive part of the eye and nervous tissue that have been used extensively to characterize the function of the central nervous system. The retina has a central position both in fundamental biology and in the physiopathology of neurodegenerative diseases. We address the contribution of functional genomics to the understanding of retinal biology by reviewing key events in their historical perspective as an introduction to major findings that were obtained through the study of the retina using genomics, transcriptomics and proteomics. We illustrate our purpose by showing that most of the genes of interest for retinal development and those involved in inherited retinal degenerations have a restricted expression to the retina and most particularly to photoreceptors cells. We show that the exponential growth of data generated by functional genomics is a future challenge not only in terms of storage but also in terms of accessibility to the scientific community of retinal biologists in the future. Finally, we emphasize on novel perspectives that emerge from the development of redox-proteomics, the new frontier in retinal biology.
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Affiliation(s)
- Frédéric Blond
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
| | - Thierry Léveillard
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
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15
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Talib M, van Schooneveld MJ, van Duuren RJG, Van Cauwenbergh C, Ten Brink JB, De Baere E, Florijn RJ, Schalij-Delfos NE, Leroy BP, Bergen AA, Boon CJF. Long-Term Follow-Up of Retinal Degenerations Associated With LRAT Mutations and Their Comparability to Phenotypes Associated With RPE65 Mutations. Transl Vis Sci Technol 2019; 8:24. [PMID: 31448181 PMCID: PMC6703192 DOI: 10.1167/tvst.8.4.24] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [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: 07/12/2018] [Accepted: 04/09/2019] [Indexed: 12/12/2022] Open
Abstract
Purpose To investigate the natural history in patients with LRAT-associated retinal degenerations (RDs), in the advent of clinical trials testing treatment options. Methods A retrospective cohort of 13 patients with LRAT-RDs. Results Twelve patients from a genetic isolate carried a homozygous c.12del mutation. One unrelated patient carried a homozygous c.326G>T mutation. The mean follow-up time was 25.3 years (SD 15.2; range 4.8–53.5). The first symptom was nyctalopia (n = 11), central vision loss (n = 1), or light-gazing (n = 1), and was noticed in the first decade of life. Seven patients (54%) reached low vision (visual acuity < 20/67), four of whom reaching blindness (visual acuity < 20/400), respectively, at mean ages of 49.9 (SE 5.4) and 59.9 (SE 3.1) years. The fundus appearance was variable. Retinal white dots were seen in six patients (46%). Full-field electroretinograms (n = 11) were nondetectable (n = 2; ages 31–60), reduced in a nonspecified pattern (n = 2; ages 11–54), or showed rod–cone (n = 6; ages 38–48) or cone–rod (n = 1; age 29) dysfunction. Optical coherence tomography (n = 4) showed retinal thinning but relative preservation of the (para-)foveal outer retinal layers in the second (n = 1) and sixth decade of life (n = 2), and profound chorioretinal degeneration from the eighth decade of life (n = 1). Conclusions LRAT-associated phenotypes in this cohort were variable and unusual, but generally milder than those seen in RPE65-associated disease, and may be particularly amenable to treatment. The window of therapeutic opportunity can be extended in patients with a mild phenotype. Translational Relevance Knowledge of the natural history of LRAT-RDs is essential in determining the window of opportunity in ongoing and future clinical trials for novel therapeutic options.
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Affiliation(s)
- Mays Talib
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Mary J van Schooneveld
- Department of Ophthalmology, Academic Medical Center, Amsterdam, the Netherlands.,Bartiméus, Diagnostic Center for Complex Visual Disorders, Zeist, the Netherlands
| | - Roos J G van Duuren
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Caroline Van Cauwenbergh
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Jacoline B Ten Brink
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, the Netherlands
| | - Elfride De Baere
- Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Ralph J Florijn
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, the Netherlands
| | | | - Bart P Leroy
- Department of Ophthalmology, Ghent University and Ghent University Hospital, Ghent, Belgium.,Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium.,Ophthalmic Genetics & Visual Electrophysiology, Division of Ophthalmology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Arthur A Bergen
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, the Netherlands.,The Netherlands Institute for Neuroscience (NIN-KNAW), Amsterdam, the Netherlands
| | - Camiel J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands.,Department of Ophthalmology, Academic Medical Center, Amsterdam, the Netherlands
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16
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Nedelec B, Rozet JM, Fares Taie L. Genetic architecture of retinoic-acid signaling-associated ocular developmental defects. Hum Genet 2019; 138:937-955. [DOI: 10.1007/s00439-019-02052-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 07/23/2019] [Indexed: 12/14/2022]
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17
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Daruwalla A, Choi EH, Palczewski K, Kiser PD. Structural biology of 11- cis-retinaldehyde production in the classical visual cycle. Biochem J 2018; 475:3171-88. [PMID: 30352831 DOI: 10.1042/BCJ20180193] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/20/2018] [Accepted: 09/26/2018] [Indexed: 12/21/2022]
Abstract
The vitamin A derivative 11-cis-retinaldehyde plays a pivotal role in vertebrate vision by serving as the chromophore of rod and cone visual pigments. In the initial step of vision, a photon is absorbed by this chromophore resulting in its isomerization to an all-trans state and consequent activation of the visual pigment and phototransduction cascade. Spent chromophore is released from the pigments through hydrolysis. Subsequent photon detection requires the delivery of regenerated 11-cis-retinaldehyde to the visual pigment. This trans-cis conversion is achieved through a process known as the visual cycle. In this review, we will discuss the enzymes, binding proteins and transporters that enable the visual pigment renewal process with a focus on advances made during the past decade in our understanding of their structural biology.
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18
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Yang F, Ma H, Butler MR, Ding XQ. Deficiency of type 2 iodothyronine deiodinase reduces necroptosis activity and oxidative stress responses in retinas of Leber congenital amaurosis model mice. FASEB J 2018; 32:fj201800484RR. [PMID: 29874126 PMCID: PMC6181634 DOI: 10.1096/fj.201800484rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 05/14/2018] [Indexed: 02/06/2023]
Abstract
Thyroid hormone (TH) signaling has been shown to regulate cone photoreceptor viability. Suppression of TH signaling with antithyroid drug treatment or by targeting iodothyronine deiodinases and TH receptors preserves cones in mouse models of retinal degeneration, including the Leber congenital amaurosis Rpe65-deficient mice. This work investigates the cellular mechanisms underlying how suppressing TH signaling preserves cones in Rpe65-deficient mice, using mice deficient in type 2 iodothyronine deiodinase (Dio2), the enzyme that converts the prohormone thyroxine to the active hormone triiodothyronine (T3). Deficiency of Dio2 improved cone survival and function in Rpe65-/- and Rpe65-deficiency on a cone dominant background ( Rpe65-/-/ Nrl-/-) mice. Analysis of cell death pathways revealed that receptor-interacting serine/threonine-protein kinase (RIPK)/necroptosis activity was increased in Rpe65-/-/ Nrl-/- retinas, and Dio2 deficiency reversed the alterations. Cell-stress analysis showed that the cellular oxidative stress responses were increased in Rpe65-/-/ Nrl-/- retinas, and Dio2 deficiency abolished the elevations. Similarly, antithyroid drug treatment resulted in reduced RIPK/necroptosis activity and oxidative stress responses in Rpe65-/-/ Nrl-/- retinas. Moreover, treatment with T3 significantly induced RIPK/necroptosis activity and oxidative stress responses in the retina. This work shows that suppression of TH signaling reduces cellular RIPK/necroptosis activity and oxidative stress responses in degenerating retinas, suggesting a mechanism underlying the observed cone preservation.-Yang, F., Ma, H., Butler, M. R., Ding, X.-Q. Deficiency of type 2 iodothyronine deiodinase reduces necroptosis activity and oxidative stress responses in retinas of Leber congenital amaurosis model mice.
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Affiliation(s)
- Fan Yang
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Hongwei Ma
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Michael R. Butler
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Xi-Qin Ding
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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19
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Affiliation(s)
- Rehan M. Hussain
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Ninel Z. Gregori
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Thomas A. Ciulla
- Department of Ophthalmology, Retina Service, Midwest Eye Institute, Indianapolis, IN, USA
- Retina Service, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Byron L. Lam
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
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20
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Abstract
Genetic mouse models mimicking human diseases have been developed and utilized for retinal research in various topics, involving anatomy, physiology, biochemistry, and pathology. The main reasons why mouse models are important for retinal research include that rodents share a key retinal homology with humans and that genetic manipulation is relatively easily applicable for mice. Here, we describe genetic mouse models, which are categorized with functions in the retina and relationship with human diseases.
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Affiliation(s)
- Akiko Maeda
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Tadao Maeda
- Research Division, Kobe Research Institute, HEALIOS K.K., Kobe, Japan.
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21
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Scholl HPN, Strauss RW, Singh MS, Dalkara D, Roska B, Picaud S, Sahel JA. Emerging therapies for inherited retinal degeneration. Sci Transl Med 2017; 8:368rv6. [PMID: 27928030 DOI: 10.1126/scitranslmed.aaf2838] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 11/17/2016] [Indexed: 12/13/2022]
Abstract
Inherited retinal degenerative diseases, a genetically and phenotypically heterogeneous group of disorders, affect the function of photoreceptor cells and are among the leading causes of blindness. Recent advances in molecular genetics and cell biology are elucidating the pathophysiological mechanisms underlying these disorders and are helping to identify new therapeutic approaches, such as gene therapy, stem cell therapy, and optogenetics. Several of these approaches have entered the clinical phase of development. Artificial replacement of dying photoreceptor cells using retinal prostheses has received regulatory approval. Precise retinal imaging and testing of visual function are facilitating more efficient clinical trial design. In individual patients, disease stage will determine whether the therapeutic strategy should comprise photoreceptor cell rescue to delay or arrest vision loss or retinal replacement for vision restoration.
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Affiliation(s)
- Hendrik P N Scholl
- Department of Ophthalmology, University of Basel, 4056 Basel, Switzerland. .,Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Rupert W Strauss
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA.,Moorfields Eye Hospital, London EC1V 2PD, U.K.,UCL Institute of Ophthalmology, University College London, London EC1V 9EL, U.K.,Department of Ophthalmology, Medical University Graz, Graz, Austria.,Department of Ophthalmology, Johannes Kepler University Linz, 4021 Linz, Austria
| | - Mandeep S Singh
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Deniz Dalkara
- INSERM, UMR S 968, 75012 Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Institut de la Vision, Paris, France.,CNRS, UMR 7210, 75012 Paris, France
| | - Botond Roska
- Department of Ophthalmology, University of Basel, 4056 Basel, Switzerland.,Neural Circuit Laboratories, Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Serge Picaud
- INSERM, UMR S 968, 75012 Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Institut de la Vision, Paris, France.,CNRS, UMR 7210, 75012 Paris, France
| | - José-Alain Sahel
- INSERM, UMR S 968, 75012 Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Institut de la Vision, Paris, France.,CNRS, UMR 7210, 75012 Paris, France.,Fondation Ophtalmologique Adolphe de Rothschild, 75019 Paris, France.,Centre d'Investigation Clinique 1423, INSERM-Center Hospitalier National d'Ophtalmologie des Quinze-Vingts, 75012 Paris, France.,Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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22
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Abstract
Sight depends on the intimate association between photoreceptors and pigment epithelial cells. The evolutionary origin of this cellular tandem can be traced back to the emergence of bilateral animals, at least 450 million years ago, as they define the minimal unit of the ancestral prototypic eye. Phototransduction is a demanding process from the energetic and homeostatic points of view, and not surprisingly photoreceptive cells are particularly susceptible to damage and degeneration. Here, we will examine the different ancillary roles that the pigmented cells play in the physiology and homeostasis of photoreceptors, linking each one of these processes to the most common hereditary retinal diseases. We will discuss the challenges and opportunities of recent therapeutic advances based on cell and gene replacement. The transition from animal models to clinical trials will be addressed for each one of the different therapeutic strategies with a special focus on those depending on retinal-pigmented epithelial cells. Finally, we will discuss the potential impact of combining CRISPR technologies with gene and cell therapy approaches, which - in the frame of the personalized medicine revolution - may constitute a leap forward in the treatment of retinal dystrophies.
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Affiliation(s)
- Joaquín Letelier
- a Centro Andaluz de Biología del Desarrollo (CSIC/UPO/JA) , Seville , Spain
| | - Paola Bovolenta
- b Centro de Biología Molecular "Severo Ochoa," (CSIC/UAM) and CIBERER, ISCIII , Madrid , Spain
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23
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Abstract
Vitamin A (all-trans-retinol) is metabolized to the visual chromophore (11-cis-retinal) in the eyes and to all-trans-retinoic acid, a hormone like compound, in most tissues. A key enzyme in retinoid metabolism is lecithin:retinol acyltransferase (LRAT), which catalyzes the esterification of vitamin A. The importance of LRAT is indicated by pathogenic missense and nonsense mutations, which cause devastating blinding diseases. Retinoid-based chromophore replacement therapy has been proposed as treatment for these types of blindness based on studies in LRAT null mice. Here, we analyzed the structural and biochemical basis for retinal pathology caused by mutations in the human LRAT gene. Most LRAT missense mutations associated with retinal degeneration are localized within the catalytic domain, whereas E14L substitution is localized in an N-terminal α-helix, which has been implicated in interaction with the phospholipid bilayer. To elucidate the biochemical consequences of this mutation, we determined LRAT(E14L)'s enzymatic properties, protein stability, and impact on ocular retinoid metabolism. Bicistronic expression of LRAT(E14L) and enhanced green fluorescence protein revealed instability and accelerated proteosomal degradation of this mutant isoform. Surprisingly, instability of LRAT(E14L) did not abrogate the production of the visual chromophore in a cell-based assay. Instead, expression of LRAT(E14L) led to a rapid increase in cellular levels of retinoic acid upon retinoid supplementation. Thus, our study unveils the potential role of retinoic acid in the pathology of a degenerative retinal disease with important implications for the use of retinoid-based therapeutics in affected patients.
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Affiliation(s)
- Sylwia Chelstowska
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106, United States
- Laboratory of Hematology and Flow Cytometry, Department of Hematology, Military Institute of Medicine, Warsaw 04141, Poland
| | | | - Josie A. Silvaroli
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Marcin Golczak
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio 44106, United States
- Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, United States
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24
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Broadgate S, Yu J, Downes SM, Halford S. Unravelling the genetics of inherited retinal dystrophies: Past, present and future. Prog Retin Eye Res 2017; 59:53-96. [PMID: 28363849 DOI: 10.1016/j.preteyeres.2017.03.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 02/07/2023]
Abstract
The identification of the genes underlying monogenic diseases has been of interest to clinicians and scientists for many years. Using inherited retinal dystrophies as an example of monogenic disease we describe the history of molecular genetic techniques that have been pivotal in the discovery of disease causing genes. The methods that were developed in the 1970's and 80's are still in use today but have been refined and improved. These techniques enabled the concept of the Human Genome Project to be envisaged and ultimately realised. When the successful conclusion of the project was announced in 2003 many new tools and, as importantly, many collaborations had been developed that facilitated a rapid identification of disease genes. In the post-human genome project era advances in computing power and the clever use of the properties of DNA replication has allowed the development of next-generation sequencing technologies. These methods have revolutionised the identification of disease genes because for the first time there is no need to define the position of the gene in the genome. The use of next generation sequencing in a diagnostic setting has allowed many more patients with an inherited retinal dystrophy to obtain a molecular diagnosis for their disease. The identification of novel genes that have a role in the development or maintenance of retinal function is opening up avenues of research which will lead to the development of new pharmacological and gene therapy approaches. Neither of which can be used unless the defective gene and protein is known. The continued development of sequencing technologies also holds great promise for the advent of truly personalised medicine.
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Affiliation(s)
- Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Jing Yu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Susan M Downes
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, OX3 9DU, UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
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25
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Shin Y, Moiseyev G, Chakraborty D, Ma JX. A Dominant Mutation in Rpe65, D477G, Delays Dark Adaptation and Disturbs the Visual Cycle in the Mutant Knock-In Mice. Am J Pathol 2016; 187:517-527. [PMID: 28041994 DOI: 10.1016/j.ajpath.2016.11.004] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 11/01/2016] [Accepted: 11/03/2016] [Indexed: 01/09/2023]
Abstract
RPE65 is an indispensable component of the retinoid visual cycle in vertebrates, through which the visual chromophore 11-cis-retinal (11-cis-RAL) is generated to maintain normal vision. Various blinding conditions in humans, such as Leber congenital amaurosis and retinitis pigmentosa (RP), are attributed to either homozygous or compound heterozygous mutations in RPE65. Herein, we investigated D477G missense mutation, an unprecedented dominant-acting mutation of RPE65 identified in patients with autosomal dominant RP. We generated a D477G knock-in (KI) mouse and characterized its phenotypes. Although RPE65 protein levels were decreased in heterozygous KI mice, their scotopic, maximal, and photopic electroretinography responses were comparable to those of wild-type (WT) mice in stationary condition. As shown by high-performance liquid chromatography analysis, levels of 11-cis-RAL in fully dark-adapted heterozygous KI mice were similar to that in WT mice. However, kinetics of 11-cis-RAL regeneration after light exposure were significantly slower in heterozygous KI mice compared with WT and RPE65 heterozygous knockout mice. Furthermore, heterozygous KI mice exhibited lower A-wave recovery compared with WT mice after photobleaching, suggesting a delayed dark adaptation. Taken together, these observations suggest that D477G acts as a dominant-negative mutant of RPE65 that delays chromophore regeneration. The KI mice provide a useful model for further understanding of the pathogenesis of RP associated with this RPE65 mutant and for the development of therapeutic strategies.
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Affiliation(s)
- Younghwa Shin
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Gennadiy Moiseyev
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Dibyendu Chakraborty
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
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Chelstowska S, Widjaja-Adhi MA, Silvaroli JA, Golczak M. Molecular Basis for Vitamin A Uptake and Storage in Vertebrates. Nutrients 2016; 8:E676. [PMID: 27792183 DOI: 10.3390/nu8110676] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 09/30/2016] [Accepted: 10/18/2016] [Indexed: 01/27/2023] Open
Abstract
The ability to store and distribute vitamin A inside the body is the main evolutionary adaptation that allows vertebrates to maintain retinoid functions during nutritional deficiencies and to acquire new metabolic pathways enabling light-independent production of 11-cis retinoids. These processes greatly depend on enzymes that esterify vitamin A as well as associated retinoid binding proteins. Although the significance of retinyl esters for vitamin A homeostasis is well established, until recently, the molecular basis for the retinol esterification enzymatic activity was unknown. In this review, we will look at retinoid absorption through the prism of current biochemical and structural studies on vitamin A esterifying enzymes. We describe molecular adaptations that enable retinoid storage and delineate mechanisms in which mutations found in selective proteins might influence vitamin A homeostasis in affected patients.
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Abstract
Leber congenital amaurosis (LCA) is a group of severe inherited retinal dystrophies that lead to early childhood blindness. In the last decade, interest in LCA has increased as advances in genetics have been applied to better identify, classify, and treat LCA. To date, 23 LCA genes have been identified. Gene replacement in the RPE65 form of LCA represents a major advance in treatment, although limitations have been recognized. In this article, we review the clinical and genetic features of LCA and evaluate the evidence available for gene therapy in RPE65 disease.
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Affiliation(s)
- Maan Alkharashi
- a Boston Children's Hospital, Harvard Medical School , Boston , MA , USA.,b Department of Ophthalmology , King Saud University , Riyadh , Saudi Arabia
| | - Anne B Fulton
- b Department of Ophthalmology , King Saud University , Riyadh , Saudi Arabia
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Abstract
Recent progress in molecular understanding of the retinoid cycle in mammalian retina stems from painstaking biochemical reconstitution studies supported by natural or engineered animal models with known genetic lesions and studies of humans with specific genetic blinding diseases. Structural and membrane biology have been used to detect critical retinal enzymes and proteins and their substrates and ligands, placing them in a cellular context. These studies have been supplemented by analytical chemistry methods that have identified small molecules by their spectral characteristics, often in conjunction with the evaluation of models of animal retinal disease. It is from this background that rational therapeutic interventions to correct genetic defects or environmental insults are identified. Thus, most presently accepted modulators of the retinoid cycle already have demonstrated promising results in animal models of retinal degeneration. These encouraging signs indicate that some human blinding diseases can be alleviated by pharmacological interventions.
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Affiliation(s)
- Philip D Kiser
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106 ; Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio 44106
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106
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Abstract
Lecithin:retinol acyltransferase (LRAT) catalyzes the acyl transfer from the sn-1 position of phosphatidylcholine (PC) to all-trans-retinol, creating fatty acid retinyl esters (palmitoyl, stearoyl, and some unsaturated derivatives). In the eye, these retinyl esters are substrates for the 65 kDa retinoid isomerase (RPE65). LRAT is well characterized biochemically, and recent structural data from closely related family members of the NlpC/P60 superfamily and a chimeric protein have established its catalytic mechanism. Mutations in the LRAT gene are responsible for approximately 1% of reported cases of Leber congenital amaurosis (LCA). Lack of functional LRAT, expressed in the retinal pigmented epithelium (RPE), results in loss of the visual chromophore and photoreceptor degeneration. LCA is a rare hereditary retinal dystrophy with an early onset associated with mutations in one of 21 known genes. Protocols have been devised to identify therapeutics that compensate for mutations in RPE65, also associated with LCA. The same protocols can be adapted to combat dystrophies associated with LRAT. Improvement in the visual function of clinical recipients of therapy with recombinant adeno-associated virus (rAAV) vectors incorporating the RPE65 gene provides a proof of concept for LRAT, which functions in the same cell type and metabolic pathway as RPE65. In parallel, a clinical trial that employs oral 9-cis-retinyl acetate to replace the missing chromophore in RPE65 and LRAT causative disease has proven to be effective and free of adverse effects. This article summarizes the biochemistry of LRAT and examines chromophore replacement as a treatment for LCA caused by LRAT mutations.
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Affiliation(s)
- Avery E Sears
- Cleveland Center for Membrane and Structural Biology, Department of Pharmacology, School of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Krzysztof Palczewski
- Cleveland Center for Membrane and Structural Biology, Department of Pharmacology, School of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
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Wen B, Li S, Li H, Chen Y, Ma X, Wang J, Lu F, Qu J, Hou L. Microphthalmia-associated transcription factor regulates the visual cycle genes Rlbp1 and Rdh5 in the retinal pigment epithelium. Sci Rep 2016; 6:21208. [PMID: 26876013 PMCID: PMC4753414 DOI: 10.1038/srep21208] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 01/19/2016] [Indexed: 12/14/2022] Open
Abstract
Regeneration of the visual pigment by cells of the retinal pigment epithelium (RPE) is fundamental to vision. Here we show that the microphthalmia-associated transcription factor, MITF, which plays a central role in the development and function of RPE cells, regulates the expression of two visual cycle genes, Rlbp1 which encodes retinaldehyde binding protein-1 (RLBP1), and Rdh5, which encodes retinol dehydrogenase-5 (RDH5). First, we found that Rlbp1 and Rdh5 are downregulated in optic cups and presumptive RPEs of Mitf-deficient mouse embryos. Second, experimental manipulation of MITF levels in human RPE cells in culture leads to corresponding modulations of the endogenous levels of RLBP1 and RDH5. Third, the retinal degeneration associated with the disruption of the visual cycle in Mitf-deficient mice can be partially corrected both structurally and functionally by an exogenous supply of 9-cis-retinal. We conclude that the expression of Rlbp1 and Rdh5 critically depends on functional Mitf in the RPE and suggest that MITF has an important role in controlling retinoid processing in the RPE.
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Affiliation(s)
- Bin Wen
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science of Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou, 325003, China
| | - Shuang Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003, China
| | - Huirong Li
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003, China
| | - Yu Chen
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003, China
| | - Xiaoyin Ma
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003, China
| | - Jing Wang
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003, China
| | - Fan Lu
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science of Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou, 325003, China
| | - Jia Qu
- State Key Laboratory Cultivation Base and Key Laboratory of Vision Science of Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou, 325003, China
| | - Ling Hou
- Laboratory of Developmental Cell Biology and Disease, School of Ophthalmology and Optometry and Eye Hospital, Wenzhou Medical University, Wenzhou, 325003, China.,State Key Laboratory Cultivation Base and Key Laboratory of Vision Science of Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology, Wenzhou Medical University, Wenzhou, 325003, China
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Soens ZT, Li Y, Zhao L, Eblimit A, Dharmat R, Li Y, Chen Y, Naqeeb M, Fajardo N, Lopez I, Sun Z, Koenekoop RK, Chen R. Hypomorphic mutations identified in the candidate Leber congenital amaurosis gene CLUAP1. Genet Med 2016; 18:1044-51. [PMID: 26820066 DOI: 10.1038/gim.2015.205] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 12/04/2015] [Indexed: 12/11/2022] Open
Abstract
Purpose Leber congenital amaurosis (LCA) is an early-onset form of retinal degeneration and six of the 22 known LCA disease genes encode photoreceptor ciliary proteins. Despite the identification of 22 LCA disease genes, the genetic basis of approximately 30% of LCA patients remains unknown. We sought to investigate the cause of disease in the remaining 30% by examining cilia-associated genes. Methods Whole-exome sequencing was performed on an LCA cohort of 212 unsolved probands previously screened for mutations in known retinal disease genes. Immunohistochemistry using mouse retinas was used to confirm protein localization and zebrafish were used to perform rescue experiments. Results A homozygous nonsynonymous mutation was found in a single proband in CLUAP1, a gene required for ciliogenesis and cilia maintenance. Cluap1 knockout zebrafish exhibit photoreceptor cell death as early as five days post fertilization and rescue experiments revealed that our proband’s mutation is significantly hypomorphic. Conclusion Consistent with the knowledge that CLUAP1 plays an important role in cilia function and that cilia are critical to photoreceptor function, our results indicate that hypomorphic mutations in CLUAP1 can result in dysfunctional photoreceptors without systemic abnormalities. This represents the first report linking mutations in CLUAP1 to human disease and establishes CLUAP1 as a candidate LCA gene.
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Scholl HPN, Moore AT, Koenekoop RK, Wen Y, Fishman GA, van den Born LI, Bittner A, Bowles K, Fletcher EC, Collison FT, Dagnelie G, Degli Eposti S, Michaelides M, Saperstein DA, Schuchard RA, Barnes C, Zein W, Zobor D, Birch DG, Mendola JD, Zrenner E. Safety and Proof-of-Concept Study of Oral QLT091001 in Retinitis Pigmentosa Due to Inherited Deficiencies of Retinal Pigment Epithelial 65 Protein (RPE65) or Lecithin:Retinol Acyltransferase (LRAT). PLoS One 2015; 10:e0143846. [PMID: 26656277 PMCID: PMC4687523 DOI: 10.1371/journal.pone.0143846] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [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: 06/17/2015] [Accepted: 10/29/2015] [Indexed: 11/30/2022] Open
Abstract
Restoring vision in inherited retinal degenerations remains an unmet medical need. In mice exhibiting a genetically engineered block of the visual cycle, vision was recently successfully restored by oral administration of 9-cis-retinyl acetate (QLT091001). Safety and visual outcomes of a once-daily oral dose of 40 mg/m2/day QLT091001 for 7 consecutive days was investigated in an international, multi-center, open-label, proof-of-concept study in 18 patients with RPE65- or LRAT-related retinitis pigmentosa. Eight of 18 patients (44%) showed a ≥20% increase and 4 of 18 (22%) showed a ≥40% increase in functional retinal area determined from Goldmann visual fields; 12 (67%) and 5 (28%) of 18 patients showed a ≥5 and ≥10 ETDRS letter score increase of visual acuity, respectively, in one or both eyes at two or more visits within 2 months of treatment. In two patients who underwent fMRI, a significant positive response was measured to stimuli of medium contrast, moving, pattern targets in both left and right hemispheres of the occipital cortex. There were no serious adverse events. Treatment-related adverse events were transient and the most common included headache, photophobia, nausea, vomiting, and minor biochemical abnormalities. Measuring the outer segment length of the photoreceptor layer with high-definition optical coherence tomography was highly predictive of treatment responses with responders having a significantly larger baseline outer segment thickness (11.7 ± 4.8 μm, mean ± 95% CI) than non-responders (3.5 ± 1.2 μm). This structure-function relationship suggests that treatment with QLT091001 is more likely to be efficacious if there is sufficient photoreceptor integrity.
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Affiliation(s)
- Hendrik P. N. Scholl
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
- * E-mail:
| | - Anthony T. Moore
- Moorfields Eye Hospital and Institute of Ophthalmology, University College London, London, United Kingdom
- Dept. of Ophthalmology, University of California San Francisco, San Francisco, CA, United States of America
| | | | - Yuquan Wen
- Retina Foundation of the Southwest, Dallas, TX, United States of America
- Baylor Visual Function Center, Baylor University Medical Center, Dallas, TX, United States of America
| | - Gerald A. Fishman
- Chicago Lighthouse, Pangere Center for Inherited Retinal Diseases, Chicago, IL, United States of America
| | | | - Ava Bittner
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
- Nova Southeastern University, College of Optometry, Fort Lauderdale, FL, United States of America
| | - Kristen Bowles
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
- College of Optometry, University of Houston, Houston, TX, United States of America
| | - Emily C. Fletcher
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
- Gloucester Royal NHS Foundation Trust, Gloucester Royal Hospitals, Gloucester, United Kingdom
| | - Frederick T. Collison
- Chicago Lighthouse, Pangere Center for Inherited Retinal Diseases, Chicago, IL, United States of America
| | - Gislin Dagnelie
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, United States of America
| | - Simona Degli Eposti
- Moorfields Eye Hospital and Institute of Ophthalmology, University College London, London, United Kingdom
| | - Michel Michaelides
- Moorfields Eye Hospital and Institute of Ophthalmology, University College London, London, United Kingdom
| | - David A. Saperstein
- Vitreoretinal Associates of Washington, Seattle, WA, United States of America
- QLT Inc., Vancouver, Canada
| | - Ronald A. Schuchard
- QLT Inc., Vancouver, Canada
- Stanford Univ School of Medicine, Palo Alto, CA, United States of America
| | - Claire Barnes
- QLT Inc., Vancouver, Canada
- VA Palo Alto Health Care System, Palo Alto, CA, United States of America
| | - Wadih Zein
- Division of Epidemiology and Clinical Research, National Eye Institute, National Institutes of Health, Bethesda, MD, United States of America
| | - Ditta Zobor
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - David G. Birch
- Retina Foundation of the Southwest, Dallas, TX, United States of America
- Ophthalmology, UT Southwestern, Dallas, TX, United States of America
| | | | - Eberhart Zrenner
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
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Wen Y, Birch DG. Outer Segment Thickness Predicts Visual Field Response to QLT091001 in Patients with RPE65 or LRAT Mutations. Transl Vis Sci Technol 2015; 4:8. [PMID: 26448901 DOI: 10.1167/tvst.4.5.8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 08/17/2015] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine whether the degree of change in Goldmann visual fields (GVFs) following oral administration of QLT091001 was related to baseline measures of retinal structure. METHODS Oral QLT091001 was administered once daily for 7 days in all study patients. Comprehensive ophthalmic testing, including spectral-domain optical coherence tomography (SD-OCT), was conducted in 14 patients with Leber congenital amaurosis (LCA) and 18 patients with retinitis pigmentosa (RP) at seven international sites. Average thickness of the outer segment (OS) layer was calculated over central 20°. Both eyes of each subject were evaluated separately. RESULTS Nineteen of 28 eyes (68%) with LCA and 13 of 36 eyes (36%) with RP responded to QLT091001. Among these responders, the average baseline thickness of the OS layer (central 20°) was 13.5 μm in the LCA cohort and 11.7 μm in the RP cohort. Nonresponders had average baseline OS thickness of less than 4.6 μm in both cohorts. The OS thickness in the central 20° was significantly shorter in nonresponders than responders in the LCA cohort (P = 0.01, t-test) and in the RP cohort (P = 0.02, Wilcoxon rank sum test). The OS thickness in the central 20° did not change significantly from baseline during the first 2 months (P = 0.09, t-test, paired). CONCLUSIONS The present findings suggest that there is a close parallel between the thickness of the photoreceptor layer and the potential for functional improvement in these patients. TRANSLATIONAL RELEVANCE SD-OCT thickness in the central retina may be useful for predicting the visual field response in the peripheral retina to QLT091001. (https://clinicaltrials.gov/ct2/show/NCT01014052 number, NCT01014052).
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Affiliation(s)
- Yuquan Wen
- Retina Foundation of the Southwest, Dallas, TX, USA
| | - David G Birch
- Retina Foundation of the Southwest, Dallas, TX, USA ; Ophthalmology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Veleri S, Lazar CH, Chang B, Sieving PA, Banin E, Swaroop A. Biology and therapy of inherited retinal degenerative disease: insights from mouse models. Dis Model Mech 2015; 8:109-29. [PMID: 25650393 PMCID: PMC4314777 DOI: 10.1242/dmm.017913] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases.
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Affiliation(s)
- Shobi Veleri
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Csilla H Lazar
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano Sciences, Babes-Bolyai-University, Cluj-Napoca, 400271, Romania
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
| | - Paul A Sieving
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eyal Banin
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA. Center for Retinal and Macular Degenerations, Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Nikopoulos K, Avila-Fernandez A, Corton M, Lopez-Molina MI, Perez-Carro R, Bontadelli L, Di Gioia SA, Zurita O, Garcia-Sandoval B, Rivolta C, Ayuso C. Identification of two novel mutations in CDHR1 in consanguineous Spanish families with autosomal recessive retinal dystrophy. Sci Rep 2015; 5:13902. [PMID: 26350383 DOI: 10.1038/srep13902] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 08/11/2015] [Indexed: 11/22/2022] Open
Abstract
Inherited retinal dystrophies present extensive phenotypic and genetic heterogeneity, posing a challenge for patients’ molecular and clinical diagnoses. In this study, we wanted to clinically characterize and investigate the molecular etiology of an atypical form of autosomal recessive retinal dystrophy in two consanguineous Spanish families. Affected members of the respective families exhibited an array of clinical features including reduced visual acuity, photophobia, defective color vision, reduced or absent ERG responses, macular atrophy and pigmentary deposits in the peripheral retina. Genetic investigation included autozygosity mapping coupled with exome sequencing in the first family, whereas autozygome-guided candidate gene screening was performed by means of Sanger DNA sequencing in the second family. Our approach revealed nucleotide changes in CDHR1; a homozygous missense variant (c.1720C > G, p.P574A) and a homozygous single base transition (c.1485 + 2T > C) affecting the canonical 5’ splice site of intron 13, respectively. Both changes co-segregated with the disease and were absent among cohorts of unrelated control individuals. To date, only five mutations in CDHR1 have been identified, all resulting in premature stop codons leading to mRNA nonsense mediated decay. Our work reports two previously unidentified homozygous mutations in CDHR1 further expanding the mutational spectrum of this gene.
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Jelani M, Jeon M, Rahman OU, Rahim F, Naeem M, Kang C. Whole-exome sequencing identifies a novel LRAT mutation underlying retinitis punctata albescens in a consanguineous Pakistani family. Genes Genomics 2015; 37:845-9. [DOI: 10.1007/s13258-015-0311-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Abstract
Cones are photoreceptor cells used for bright light and color vision. Retinoids are vitamin A derivatives, one of which is the 11-cis aldehyde form that serves as the chromophore for both cone and rod visual pigments. In the visual disease, Type 2 Leber congenital amaurosis (LCA2), 11-cis-retinal generation is inhibited or abolished. Work by others has shown that patients with LCA2 have symptoms consistent with degenerating cones. In mouse models for LCA2, early cone degeneration is readily apparent: cone opsins and other proteins associated with the outer segment are delocalized and cell numbers decline rapidly within the first month. Rods would appear normal morphologically and functionally, if not for the absence of chromophore. Supplementation of mouse models of LCA2 with cis-retinoids has been shown to slow loss of cone photoreceptor cells if mice were maintained in darkness. Thus, 11-cis-retinal appears not only to have a role in the light response reaction but also to promote proper trafficking of the cone opsins and maintain viable cones.
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Affiliation(s)
- Masahiro Kono
- Department of Ophthalmology, Albert Florens Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.
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Conte I, Hadfield KD, Barbato S, Carrella S, Pizzo M, Bhat RS, Carissimo A, Karali M, Porter LF, Urquhart J, Hateley S, O'Sullivan J, Manson FD, Neuhauss SC, Banfi S, Black GC. MiR-204 is responsible for inherited retinal dystrophy associated with ocular coloboma. Proc Natl Acad Sci U S A 2015; 112:E3236-45. [PMID: 26056285 DOI: 10.1073/pnas.1401464112] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Ocular developmental disorders, including the group classified as microphthalmia, anophthalmia, and coloboma (MAC) and inherited retinal dystrophies, collectively represent leading causes of hereditary blindness. Characterized by extreme genetic and clinical heterogeneity, the separate groups share many common genetic causes, in particular relating to pathways controlling retinal and retinal pigment epithelial maintenance. To understand these shared pathways and delineate the overlap between these groups, we investigated the genetic cause of an autosomal dominantly inherited condition of retinal dystrophy and bilateral coloboma, present in varying degrees in a large, five-generation family. By linkage analysis and exome sequencing, we identified a previously undescribed heterozygous mutation, n.37 C > T, in the seed region of microRNA-204 (miR-204), which segregates with the disease in all affected individuals. We demonstrated that this mutation determines significant alterations of miR-204 targeting capabilities via in vitro assays, including transcriptome analysis. In vivo injection, in medaka fish (Oryzias latipes), of the mutated miR-204 caused a phenotype consistent with that observed in the family, including photoreceptor alterations with reduced numbers of both cones and rods as a result of increased apoptosis, thereby confirming the pathogenic effect of the n.37 C > T mutation. Finally, knockdown assays in medaka fish demonstrated that miR-204 is necessary for normal photoreceptor function. Overall, these data highlight the importance of miR-204 in the regulation of ocular development and maintenance and provide the first evidence, to our knowledge, of its contribution to eye disease, likely through a gain-of-function mechanism.
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Abstract
Retinal dystrophies (RDs) are degenerative diseases of the retina which have marked clinical and genetic heterogeneity. Common presentations among these disorders include night or colour blindness, tunnel vision and subsequent progression to complete blindness. The known causative disease genes have a variety of developmental and functional roles with mutations in more than 120 genes shown to be responsible for the phenotypes. In addition, mutations within the same gene have been shown to cause different disease phenotypes, even amongst affected individuals within the same family highlighting further levels of complexity. The known disease genes encode proteins involved in retinal cellular structures, phototransduction, the visual cycle, and photoreceptor structure or gene regulation. This review aims to demonstrate the high degree of genetic complexity in both the causative disease genes and their associated phenotypes, highlighting the more common clinical manifestation of retinitis pigmentosa (RP). The review also provides insight to recent advances in genomic molecular diagnosis and gene and cell-based therapies for the RDs.
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Affiliation(s)
- Benjamin M Nash
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
| | - Dale C Wright
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
| | - John R Grigg
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
| | - Bruce Bennetts
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
| | - Robyn V Jamieson
- 1 Eye Genetics Research Group, Children's Medical Research Institute, University of Sydney, The Children's Hospital at Westmead and Save Sight Institute, Sydney, NSW, Australia ; 2 Sydney Genome Diagnostics, The Children's Hospital at Westmead, Sydney, NSW, Australia ; 3 Discipline of Paediatrics and Child Health, Sydney Medical School, University of Sydney, NSW, Australia
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Yücel-Yılmaz D, Tarlan B, Kıratlı H, Ozgül RK. Genome-wide homozygosity mapping in families with leber congenital amaurosis identifies mutations in AIPL1 and RDH12 genes. DNA Cell Biol 2015; 33:876-83. [PMID: 25148430 DOI: 10.1089/dna.2014.2554] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Leber congenital amaurosis (LCA) causes severe visual impairment and blindness very early in life. Mutant alleles of several genes acting in different pathways, of which all have critical roles for normal retinal function, were involved in LCA development. The purpose of this study was to use genome-wide genotyping to identify LCA-causing loci in two Turkish families. Genome-wide genotyping and haplotype analysis were performed for prioritization of candidate genes for mutation screening in families with LCA. Identified informative critical choromosomal regions obtained by homozygosity mapping from the families were searched for overlapping of any LCA causative genes. Corresponding clinical phenotypes of the patients with identified mutations were evaluated. In this study, two families were shown to be linked to two different LCA loci covering retinol dehydrogenase 12 (RDH12) and aryl-hydrocarbon-interacting protein-like1 (AIPL1) genes. Mutation screening revealed a novel p.Gln141* mutation in the AIPL1 gene and a previously described p.Thr49Met mutation in the RDH12 gene in a homozygous state. Our patients with the RDH12 mutation had the distinct macular coloboma sign, and the patient with the AIPL1 mutation developed microphthalmia and severe widespread retinal pigment epithelial atrophy, in contrast to previously reported cases. It is currently evident that mutation screening needs to be done in at least 18 genes known to be associated with LCA. Thus, homozygosity mapping is an alternative technique to improve the molecular diagnosis in LCA, which is a group of genetically and clinically heterogeneous diseases causing retinal degeneration. The patients without mutation in known genes may further be analyzed by using next-generation sequencing.
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Affiliation(s)
- Didem Yücel-Yılmaz
- 1 Metabolism Unit, Department of Pediatrics, Institute of Child Health, Hacettepe University , Ankara, Turkey
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41
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Garcia-Cazorla À, Mochel F, Lamari F, Saudubray JM. The clinical spectrum of inherited diseases involved in the synthesis and remodeling of complex lipids. A tentative overview. J Inherit Metab Dis 2015; 38:19-40. [PMID: 25413954 DOI: 10.1007/s10545-014-9776-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/16/2014] [Accepted: 09/23/2014] [Indexed: 12/19/2022]
Abstract
Over one hundred diseases related to inherited defects of complex lipids synthesis and remodeling are now reported. Most of them were described within the last 5 years. New descriptions and phenotypes are expanding rapidly. While the associated clinical phenotype is currently difficult to outline, with only a few patients identified, it appears that all organs and systems may be affected. The main clinical presentations can be divided into (1) Diseases affecting the central and peripheral nervous system. Complex lipid synthesis disorders produce prominent motor manifestations due to upper and/or lower motoneuron degeneration. Motor signs are often complex, associated with other neurological and extra-neurological signs. Three neurological phenotypes, spastic paraparesis, neurodegeneration with brain iron accumulation and peripheral neuropathies, deserve special attention. Many apparently well clinically defined syndromes are not distinct entities, but rather clusters on a continuous spectrum, like for the PNPLA6-associated diseases, extending from Boucher-Neuhauser syndrome via Gordon Holmes syndrome to spastic ataxia and pure hereditary spastic paraplegia; (2) Muscular/cardiac presentations; (3) Skin symptoms mostly represented by syndromic (neurocutaneous) and non syndromic ichthyosis; (4) Retinal dystrophies with syndromic and non syndromic retinitis pigmentosa, Leber congenital amaurosis, cone rod dystrophy, Stargardt disease; (5) Congenital bone dysplasia and segmental overgrowth disorders with congenital lipomatosis; (6) Liver presentations characterized mainly by transient neonatal cholestatic jaundice and non alcoholic liver steatosis with hypertriglyceridemia; and (7) Renal and immune presentations. Lipidomics and molecular functional studies could help to elucidate the mechanism(s) of dominant versus recessive inheritance observed for the same gene in a growing number of these disorders.
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Affiliation(s)
- Àngels Garcia-Cazorla
- Department of Neurology, Neurometabolic Unit, Hospital Sant Joan de Déu and CIBERER, ISCIII, Barcelona, Spain,
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42
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Eblimit A, Nguyen TMT, Chen Y, Esteve-Rudd J, Zhong H, Letteboer S, Van Reeuwijk J, Simons DL, Ding Q, Wu KM, Li Y, Van Beersum S, Moayedi Y, Xu H, Pickard P, Wang K, Gan L, Wu SM, Williams DS, Mardon G, Roepman R, Chen R. Spata7 is a retinal ciliopathy gene critical for correct RPGRIP1 localization and protein trafficking in the retina. Hum Mol Genet 2014; 24:1584-601. [PMID: 25398945 DOI: 10.1093/hmg/ddu573] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Leber congenital amaurosis (LCA) and juvenile retinitis pigmentosa (RP) are severe hereditary diseases that causes visual impairment in infants and children. SPATA7 has recently been identified as the LCA3 and juvenile RP gene in humans, whose function in the retina remains elusive. Here, we show that SPATA7 localizes at the primary cilium of cells and at the connecting cilium (CC) of photoreceptor cells, indicating that SPATA7 is a ciliary protein. In addition, SPATA7 directly interacts with the retinitis pigmentosa GTPase regulator interacting protein 1 (RPGRIP1), a key connecting cilium protein that has also been linked to LCA. In the retina of Spata7 null mutant mice, a substantial reduction of RPGRIP1 levels at the CC of photoreceptor cells is observed, suggesting that SPATA7 is required for the stable assembly and localization of the ciliary RPGRIP1 protein complex. Furthermore, our results pinpoint a role of this complex in protein trafficking across the CC to the outer segments, as we identified that rhodopsin accumulates in the inner segments and around the nucleus of photoreceptors. This accumulation then likely triggers the apoptosis of rod photoreceptors that was observed. Loss of Spata7 function in mice indeed results in a juvenile RP-like phenotype, characterized by progressive degeneration of photoreceptor cells and a strongly decreased light response. Together, these results indicate that SPATA7 functions as a key member of a retinal ciliopathy-associated protein complex, and that apoptosis of rod photoreceptor cells triggered by protein mislocalization is likely the mechanism of disease progression in LCA3/ juvenile RP patients.
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Affiliation(s)
| | - Thanh-Minh T Nguyen
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525, The Netherlands
| | - Yiyun Chen
- HGSC, Department of Molecular and Human Genetics
| | - Julian Esteve-Rudd
- Jules Stein Eye Institute, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Hua Zhong
- Department of Pathology and Immunology
| | - Stef Letteboer
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525, The Netherlands
| | - Jeroen Van Reeuwijk
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525, The Netherlands
| | - David L Simons
- Department of Neuroscience and Department of Ophthalmology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qian Ding
- Department of Ophthalmology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Ka Man Wu
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525, The Netherlands
| | - Yumei Li
- HGSC, Department of Molecular and Human Genetics
| | - Sylvia Van Beersum
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525, The Netherlands
| | | | - Huidan Xu
- HGSC, Department of Molecular and Human Genetics
| | | | - Keqing Wang
- HGSC, Department of Molecular and Human Genetics
| | - Lin Gan
- Department of Ophthalmology, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Samuel M Wu
- Department of Neuroscience and Department of Ophthalmology, Baylor College of Medicine, Houston, TX 77030, USA
| | - David S Williams
- Jules Stein Eye Institute, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
| | - Graeme Mardon
- Department of Molecular and Human Genetics, Department of Pathology and Immunology, Department of Neuroscience and Department of Ophthalmology, Baylor College of Medicine, Houston, TX 77030, USA,
| | - Ronald Roepman
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525, The Netherlands,
| | - Rui Chen
- HGSC, Department of Molecular and Human Genetics,
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43
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Koenekoop RK, Sui R, Sallum J, van den Born LI, Ajlan R, Khan A, den Hollander AI, Cremers FPM, Mendola JD, Bittner AK, Dagnelie G, Schuchard RA, Saperstein DA. Oral 9-cis retinoid for childhood blindness due to Leber congenital amaurosis caused by RPE65 or LRAT mutations: an open-label phase 1b trial. Lancet 2014; 384:1513-20. [PMID: 25030840 DOI: 10.1016/s0140-6736(14)60153-7] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Leber congenital amaurosis, caused by mutations in RPE65 and LRAT, is a severe form of inherited retinal degeneration leading to blindness. We aimed to assess replacement of the missing chromophore 11-cis retinal with oral QLT091001 (synthetic 9-cis-retinyl acetate) in these patients. METHODS In our open-label, prospective, phase 1b trial, we enrolled patients (aged ≥6 years) with Leber congenital amaurosis and RPE65 or LRAT mutations at McGill University's Montreal Children's Hospital. Patients received 7 days of oral QLT091001 (10-40 mg/m(2) per day). We assessed patients at baseline and days 7, 9, 14, and 30, and then 2 months and every 2 months thereafter for up to 2·2 years for safety outcomes and visual function endpoints including Goldmann visual fields (GVF), visual acuity, and functional MRI assessment. We regarded patients as having an improvement in vision if we noted at least a 20% improvement in retinal area on GVF compared with baseline or a visual acuity improvement of five or more letters compared with baseline in two consecutive study visits (or any improvement from no vision at baseline). This study is registered with ClinicalTrials.gov, number NCT01014052. FINDINGS Between December, 2009, and June, 2011, we enrolled and treated 14 patients aged 6-38 years who were followed up until March, 2012. Ten (71%) of 14 patients had an improvement in GVF areas (mean increase in retinal area of 28-683%). Six (43%) patients had an improvement in visual acuity (mean increase of 2-30 letters). Self-reported or parent-reported improvements in activities of daily living supported these findings. After 2 years, 11 (79%) patients had returned to their baseline GVF retinal area and ten (71%) had returned to baseline visual acuity letter values. Thus, three (21%) patients had a sustained GVF response and four (30%) had a sustained visual acuity response. Four patients had functional MRI scans, which correlated with visual response or absence of response to treatment. No serious adverse events occurred, although we noted transient headaches (11 patients), photophobia (11 patients), reduction in serum HDL concentrations (four patients), and increases in serum triglycerides (eight patients) and aspartate aminotransferase concentrations (two patients). INTERPRETATION Non-invasive oral QLT091001 therapy is well tolerated, and can rapidly improve visual function in some patients with Leber congenital amaurosis and RPE65 and LRAT mutations. FUNDING QLT, Foundation Fighting Blindness Canada, CIHR, FRSQ, Reseau Vision.
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Affiliation(s)
- Robert K Koenekoop
- McGill Ocular Genetics Laboratory and Paediatric Ophthalmology, Montreal Children's Hospital, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, McGill University Health Centre, Montreal, Quebec, Canada.
| | - Ruifang Sui
- Ophthalmology, Peking Union Medical College Hospital, Beijing, China
| | - Juliana Sallum
- Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
| | | | - Radwan Ajlan
- McGill Ocular Genetics Laboratory and Paediatric Ophthalmology, Montreal Children's Hospital, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Ayesha Khan
- McGill Ocular Genetics Laboratory and Paediatric Ophthalmology, Montreal Children's Hospital, Departments of Paediatric Surgery, Human Genetics and Ophthalmology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Anneke I den Hollander
- Department of Ophthalmology, Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Frans P M Cremers
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Janine D Mendola
- McGill Vision Research Unit and Department of Ophthalmology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Ava K Bittner
- The Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Gislin Dagnelie
- The Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, USA
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Abstract
Visual transduction is the process in the eye whereby absorption of light in the retina is translated into electrical signals that ultimately reach the brain. The first challenge presented by visual transduction is to understand its molecular basis. We know that maintenance of vision is a continuous process requiring the activation and subsequent restoration of a vitamin A-derived chromophore through a series of chemical reactions catalyzed by enzymes in the retina and retinal pigment epithelium (RPE). Diverse biochemical approaches that identified key proteins and reactions were essential to achieve a mechanistic understanding of these visual processes. The three-dimensional arrangements of these enzymes' polypeptide chains provide invaluable insights into their mechanisms of action. A wealth of information has already been obtained by solving high-resolution crystal structures of both rhodopsin and the retinoid isomerase from pigment RPE (RPE65). Rhodopsin, which is activated by photoisomerization of its 11-cis-retinylidene chromophore, is a prototypical member of a large family of membrane-bound proteins called G protein-coupled receptors (GPCRs). RPE65 is a retinoid isomerase critical for regeneration of the chromophore. Electron microscopy (EM) and atomic force microscopy have provided insights into how certain proteins are assembled to form much larger structures such as rod photoreceptor cell outer segment membranes. A second challenge of visual transduction is to use this knowledge to devise therapeutic approaches that can prevent or reverse conditions leading to blindness. Imaging modalities like optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) applied to appropriate animal models as well as human retinal imaging have been employed to characterize blinding diseases, monitor their progression, and evaluate the success of therapeutic agents. Lately two-photon (2-PO) imaging, together with biochemical assays, are revealing functional aspects of vision at a new molecular level. These multidisciplinary approaches combined with suitable animal models and inbred mutant species can be especially helpful in translating provocative cell and tissue culture findings into therapeutic options for further development in animals and eventually in humans. A host of different approaches and techniques is required for substantial progress in understanding fundamental properties of the visual system.
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Affiliation(s)
- Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, United States
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45
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Abstract
Inherited retinal degenerations (IRDs) encompass a large group of clinically and genetically heterogeneous diseases that affect approximately 1 in 3000 people (>2 million people worldwide) (Bessant DA, Ali RR, Bhattacharya SS. 2001. Molecular genetics and prospects for therapy of the inherited retinal dystrophies. Curr Opin Genet Dev 11: 307-316.). IRDs may be inherited as Mendelian traits or through mitochondrial DNA, and may affect the entire retina (e.g., rod-cone dystrophy, also known as retinitis pigmentosa, cone dystrophy, cone-rod dystrophy, choroideremia, Usher syndrome, and Bardet-Bidel syndrome) or be restricted to the macula (e.g., Stargardt disease, Best disease, and Sorsby fundus dystrophy), ultimately leading to blindness. IRDs are a major cause of severe vision loss, with profound impact on patients and society. Although IRDs remain untreatable today, significant progress toward therapeutic strategies for IRDs has marked the past two decades. This progress has been based on better understanding of the pathophysiological pathways of these diseases and on technological advances.
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Affiliation(s)
- José-Alain Sahel
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Paris, F-75012, France INSERM, U968, Paris, F-75012, France CNRS, UMR 7210, Paris, F-75012, France Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France Fondation Ophtalmologique Adolphe de Rothschild, Paris, F-75019, France Académie des Sciences-Institut de France, Paris, F-75006, France Institute of Ophthalmology-University College London, London EC1V 9EL, United Kingdom
| | - Katia Marazova
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Paris, F-75012, France INSERM, U968, Paris, F-75012, France CNRS, UMR 7210, Paris, F-75012, France
| | - Isabelle Audo
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Paris, F-75012, France INSERM, U968, Paris, F-75012, France CNRS, UMR 7210, Paris, F-75012, France Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France Institute of Ophthalmology-University College London, London EC1V 9EL, United Kingdom
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46
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Abstract
Inherited retinal dystrophies are Mendelian neurodegenerative conditions classified as pigmentary retinopathies, macular dystrophies and others. Over a 21-year period, from 1990 to 2011, we have screened in Montpellier 107 genes in 609 families and have identified a causal mutation in 68.5% of them. Following a gene candidate approach, we established that RPE65, the isomerohydrolase of the visual cycle, is responsible for severe childhood blindness (Leber congenital amaurosis or early onset retinal dystrophy). In an ongoing study, we screened the genes in a series of 283 families with dominant retinitis pigmentosa and we have estimated that 80% of the families have a mutation in a known gene. A similar study is currently undergoing for autosomal recessive retinitis pigmentosa. Finally, we have identified IMPG1 as a responsible gene for rare cases of macular vitelliform dystrophy with a dominant or recessive inheritance.
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Affiliation(s)
- Christian P Hamel
- Inserm U.1051, institut des neurosciences de Montpellier, hôpital Saint-Éloi, BP 74103, 80, rue Augustin-Fliche, 34091 Montpellier cedex 5, France.
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47
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Abstract
Rhodopsin is the light receptor in rod photoreceptor cells of the retina that initiates scotopic vision. In the dark, rhodopsin is bound to the chromophore 11-cis retinal, which locks the receptor in an inactive state. The maintenance of an inactive rhodopsin in the dark is critical for rod photoreceptor cells to remain highly sensitive. Perturbations by mutation or the absence of 11-cis retinal can cause rhodopsin to become constitutively active, which leads to the desensitization of photoreceptor cells and, in some instances, retinal degeneration. Constitutive activity can arise in rhodopsin by various mechanisms and can cause a variety of inherited retinal diseases including Leber congenital amaurosis, congenital night blindness, and retinitis pigmentosa. In this review, the molecular and structural properties of different constitutively active forms of rhodopsin are overviewed, and the possibility that constitutive activity can arise from different active-state conformations is discussed.
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Affiliation(s)
- Paul Shin-Hyun Park
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, USA.
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48
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Maeda T, Lee MJ, Palczewska G, Marsili S, Tesar PJ, Palczewski K, Takahashi M, Maeda A. Retinal pigmented epithelial cells obtained from human induced pluripotent stem cells possess functional visual cycle enzymes in vitro and in vivo. J Biol Chem 2013; 288:34484-93. [PMID: 24129572 DOI: 10.1074/jbc.m113.518571] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [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: 12/29/2022] Open
Abstract
Differentiated retinal pigmented epithelial (RPE) cells have been obtained from human induced pluripotent stem (hiPS) cells. However, the visual (retinoid) cycle in hiPS-RPE cells has not been adequately examined. Here we determined the expression of functional visual cycle enzymes in hiPS-RPE cells compared with that of isolated wild-type mouse primary RPE (mpRPE) cells in vitro and in vivo. hiPS-RPE cells appeared morphologically similar to mpRPE cells. Notably, expression of certain visual cycle proteins was maintained during cell culture of hiPS-RPE cells, whereas expression of these same molecules rapidly decreased in mpRPE cells. Production of the visual chromophore, 11-cis-retinal, and retinosome formation also were documented in hiPS-RPE cells in vitro. When mpRPE cells with luciferase activity were transplanted into the subretinal space of mice, bioluminance intensity was preserved for >3 months. Additionally, transplantation of mpRPE into blind Lrat(-/-) and Rpe65(-/-) mice resulted in the recovery of visual function, including increased electrographic signaling and endogenous 11-cis-retinal production. Finally, when hiPS-RPE cells were transplanted into the subretinal space of Lrat(-/-) and Rpe65(-/-) mice, their vision improved as well. Moreover, histological analyses of these eyes displayed replacement of dysfunctional RPE cells by hiPS-RPE cells. Together, our results show that hiPS-RPE cells can exhibit a functional visual cycle in vitro and in vivo. These cells could provide potential treatment options for certain blinding retinal degenerative diseases.
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Affiliation(s)
- Tadao Maeda
- From the Departments of Ophthalmology and Visual Sciences
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49
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Mackay DS, Borman AD, Sui R, van den Born LI, Berson EL, Ocaka LA, Davidson AE, Heckenlively JR, Branham K, Ren H, Lopez I, Maria M, Azam M, Henkes A, Blokland E, Qamar R, Webster AR, Cremers FPM, Moore AT, Koenekoop RK, Andreasson S, de Baere E, Bennett J, Chader GJ, Berger W, Golovleva I, Greenberg J, den Hollander AI, Klaver CCW, Klevering BJ, Lorenz B, Preising MN, Ramsear R, Roberts L, Roepman R, Rohrschneider K, Wissinger B. Screening of a large cohort of leber congenital amaurosis and retinitis pigmentosa patients identifies novel LCA5 mutations and new genotype-phenotype correlations. Hum Mutat 2013; 34:1537-1546. [PMID: 23946133 DOI: 10.1002/humu.22398] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Accepted: 08/05/2013] [Indexed: 11/11/2022]
Abstract
This study was undertaken to investigate the prevalence of sequence variants in LCA5 in patients with Leber congenital amaurosis (LCA), early-onset retinal dystrophy (EORD), and autosomal recessive retinitis pigmentosa (arRP); to delineate the ocular phenotypes; and to provide an overview of all published LCA5 variants in an online database. Patients underwent standard ophthalmic evaluations after providing informed consent. In selected patients, optical coherence tomography (OCT) and fundus autofluorescence imaging were possible. DNA samples from 797 unrelated patients with LCA and 211 with the various types of retinitis pigmentosa (RP) were screened by Sanger sequence analysis of all LCA5 exons and intron/exon junctions. Some LCA patients were prescreened by APEX technology or selected based on homozygosity mapping. In silico analyses were performed to assess the pathogenicity of the variants. Segregation analysis was performed where possible. Published and novel LCA5 variants were collected, amended for their correct nomenclature, and listed in a Leiden Open Variation Database (LOVD). Sequence analysis identified 18 new probands with 19 different LCA5 variants. Seventeen of the 19 LCA5 variants were novel. Except for two missense variants and one splice site variant, all variants were protein-truncating mutations. Most patients expressed a severe phenotype, typical of LCA. However, some LCA subjects had better vision and intact inner segment/outer segment (IS/OS) junctions on OCT imaging. In two families with LCA5 variants, the phenotype was more compatible with EORD with affected individuals displaying preserved islands of retinal pigment epithelium. One of the families with a milder phenotype harbored a homozygous splice site mutation; a second family was found to have a combination of a stop mutation and a missense mutation. This is the largest LCA5 study to date. We sequenced 1,008 patients (797 with LCA, 211 with arRP) and identified 18 probands with LCA5 mutations. Mutations in LCA5 are a rare cause of childhood retinal dystrophy accounting for ∼2% of disease in this cohort, and the majority of LCA5 mutations are likely null. The LCA5 protein truncating mutations are predominantly associated with LCA. However, in two families with the milder EORD, the LCA5 gene analysis revealed a homozygous splice site mutation in one and a stop mutation in combination with a missense mutation in a second family, suggesting that this milder phenotype is due to residual function of lebercilin and expanding the currently known phenotypic spectrum to include the milder early onset RP. Some patients have remaining foveal cone structures (intact IS/OS junctions on OCT imaging) and remaining visual acuities, which may bode well for upcoming treatment trials.
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Affiliation(s)
- Donna S Mackay
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Arundhati Dev Borman
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK.,Moorfields Eye Hospital, London, UK
| | - Ruifang Sui
- Ophthalmology, Peking Union Med College Hosp, Beijing, China
| | | | - Eliot L Berson
- Berman-Gund Laboratory for the Study of Retinal Degenerations, Harvard Medical School, Massachusetts Eye and Ear, Boston, Massachusetts, USA
| | - Louise A Ocaka
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Alice E Davidson
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - John R Heckenlively
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan
| | - Kari Branham
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan
| | - Huanan Ren
- McGill Ocular Genetics Laboratory, Departments of Pediatric Surgery, Human Genetics and Ophthalmology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Irma Lopez
- McGill Ocular Genetics Laboratory, Departments of Pediatric Surgery, Human Genetics and Ophthalmology, McGill University Health Centre, Montreal, Quebec, Canada
| | - Maleeha Maria
- Department of Human Genetics, Radboud University Medical Centre, and Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands.,Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Maleeha Azam
- Department of Human Genetics, Radboud University Medical Centre, and Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands.,Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Arjen Henkes
- Department of Human Genetics, Radboud University Medical Centre, and Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Ellen Blokland
- Department of Human Genetics, Radboud University Medical Centre, and Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Raheel Qamar
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan.,Al-Nafees Medical College & Hospital, Isra University, Islamabad, Pakistan
| | - Andrew R Webster
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK.,Moorfields Eye Hospital, London, UK
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Centre, and Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Anthony T Moore
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK.,Moorfields Eye Hospital, London, UK
| | - Robert K Koenekoop
- McGill Ocular Genetics Laboratory, Departments of Pediatric Surgery, Human Genetics and Ophthalmology, McGill University Health Centre, Montreal, Quebec, Canada
| | | | - Sten Andreasson
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Elfride de Baere
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Jean Bennett
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Gerald J Chader
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Wolfgang Berger
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Irina Golovleva
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Jacquie Greenberg
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | | | | | - B Jeroen Klevering
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Birgit Lorenz
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Markus N Preising
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Raj Ramsear
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Lisa Roberts
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | - Ronald Roepman
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
| | | | - Bernd Wissinger
- Department of Human Genetics, Institute of Ophthalmology, UCL, London, UK
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50
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Wang X, Wang H, Sun V, Tuan HF, Keser V, Wang K, Ren H, Lopez I, Zaneveld JE, Siddiqui S, Bowles S, Khan A, Salvo J, Jacobson SG, Iannaccone A, Wang F, Birch D, Heckenlively JR, Fishman GA, Traboulsi EI, Li Y, Wheaton D, Koenekoop RK, Chen R. Comprehensive molecular diagnosis of 179 Leber congenital amaurosis and juvenile retinitis pigmentosa patients by targeted next generation sequencing. J Med Genet 2013; 50:674-88. [PMID: 23847139 DOI: 10.1136/jmedgenet-2013-101558] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND Leber congenital amaurosis (LCA) and juvenile retinitis pigmentosa (RP) are inherited retinal diseases that cause early onset severe visual impairment. An accurate molecular diagnosis can refine the clinical diagnosis and allow gene specific treatments. METHODS We developed a capture panel that enriches the exonic DNA of 163 known retinal disease genes. Using this panel, we performed targeted next generation sequencing (NGS) for a large cohort of 179 unrelated and prescreened patients with the clinical diagnosis of LCA or juvenile RP. Systematic NGS data analysis, Sanger sequencing validation, and segregation analysis were utilised to identify the pathogenic mutations. Patients were revisited to examine the potential phenotypic ambiguity at the time of initial diagnosis. RESULTS Pathogenic mutations for 72 patients (40%) were identified, including 45 novel mutations. Of these 72 patients, 58 carried mutations in known LCA or juvenile RP genes and exhibited corresponding phenotypes, while 14 carried mutations in retinal disease genes that were not consistent with their initial clinical diagnosis. We revisited patients in the latter case and found that homozygous mutations in PRPH2 can cause LCA/juvenile RP. Guided by the molecular diagnosis, we reclassified the clinical diagnosis in two patients. CONCLUSIONS We have identified a novel gene and a large number of novel mutations that are associated with LCA/juvenile RP. Our results highlight the importance of molecular diagnosis as an integral part of clinical diagnosis.
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Affiliation(s)
- Xia Wang
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
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