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Li F, Lu D, Meng F, Tian C. Transcription Factor CgSte12 Regulates Pathogenicity by Affecting Appressorium Structural Development in the Anthracnose-Causing Fungus Colletotrichum gloeosporioides. PHYTOPATHOLOGY 2024:PHYTO12230484R. [PMID: 38748933 DOI: 10.1094/phyto-12-23-0484-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2024]
Abstract
Colletotrichum gloeosporioides is the causal agent of poplar anthracnose, which induces major economic losses and adversely affects the ecosystem services of poplar forests. The appressorium serves as a penetration structure for many pathogenic fungi, including C. gloeosporioides. The production of mucilage and the formation of penetration pegs are critically important for the appressorium-mediated penetration of host tissues. We previously found that CgPmk1 is a key protein involved in appressorium formation, penetration, and pathogenicity. Although CgSte12, which is a transcription factor that functions downstream of CgPmk1, regulates the formation of penetration pegs, its role in C. gloeosporioides appressorium development and pathogenicity has not been elucidated. Here, we developed C. gloeosporioides CgSTE12 mutants and characterized the molecular and cellular functions of CgSTE12. The results showed that mycelial growth and morphology were not affected in the CgSTE12 knockout mutants, which produced normal melanized appressoria. However, these mutants had less mucilage secreted around the appressoria, impaired appressorial cone formation, and the inability to form penetration pores and pegs, which ultimately led to a significant loss of pathogenicity. Our comparative transcriptome analysis revealed that CgSte12 controls the expression of genes involved in appressorium development and function, including genes encoding cutinases, NADPH oxidase, spermine biosynthesis-related proteins, ceramide biosynthesis-related proteins, fatty acid metabolism-related proteins, and glycerophospholipid metabolism-related proteins. Overall, our findings indicate that CgSte12 is a critical regulator of appressorium development and affects C. gloeosporioides pathogenicity by modulating the structural integrity of appressoria.
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Affiliation(s)
- Fuhan Li
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Dongxiao Lu
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Fanli Meng
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
| | - Chengming Tian
- The Key Laboratory for Silviculture and Conservation of Ministry of Education, College of Forestry, Beijing Forestry University, Beijing, China
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Michaelides M, Besirli CG, Yang Y, DE Guimaraes TAC, Wong SC, Huckfeldt RM, Comander JI, Sahel JA, Shah SM, Tee JJL, Kumaran N, Georgiadis A, Minnick P, Zeldin R, Naylor S, Xu J, Clark M, Anglade E, Wong P, Fleck PR, Fung A, Peluso C, Kalitzeos A, Georgiou M, Ripamonti C, Smith AJ, Ali RR, Forbes A, Bainbridge J. Phase 1/2 AAV5-hRKp.RPGR (Botaretigene Sparoparvovec) Gene Therapy: Safety and Efficacy in RPGR-Associated X-Linked Retinitis Pigmentosa. Am J Ophthalmol 2024; 267:122-134. [PMID: 38871269 DOI: 10.1016/j.ajo.2024.05.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 05/30/2024] [Accepted: 05/30/2024] [Indexed: 06/15/2024]
Abstract
PURPOSE To assess the safety and efficacy of AAV5-hRKp.RPGR in participants with retinitis pigmentosa GTPase regulator (RPGR)-associated X-linked retinitis pigmentosa (XLRP). DESIGN Open-label, phase 1/2 dose escalation/expansion study (ClinicalTrials.gov Identifier: NCT03252847). METHODS Males (≥5 years old) with XLRP-RPGR were evaluated. In the dose escalation phase, subretinal AAV5-hRKp.RPGR (low: 1.0 × 1011 vg/ml; intermediate: 2.0 × 1011 vg/ml; high: 4.0 × 1011 vg/ml) was administered to the poorer-seeing eye (n = 10). Dose confirmation (intermediate dose) was carried out in 3 pediatric participants. In the dose expansion phase, 36 participants were randomized 1:1:1 to immediate (low or intermediate dose) or deferred (control) treatment. The primary outcome was safety. Secondary efficacy outcomes included static perimetry, microperimetry, vision-guided mobility, best corrected visual acuity, and contrast sensitivity. Safety and efficacy outcomes were assessed for 52 weeks for immediate treatment participants and 26 weeks for control participants. RESULTS AAV5-hRKp.RPGR was safe and well tolerated, with no reported dose-limiting events. Most adverse events (AEs) were transient and related to the surgical procedure, resolving without intervention. Two serious AEs were reported with immediate treatment (retinal detachment, uveitis). A third serious AE (increased intraocular pressure) was reported outside the reporting period. All ocular inflammation-related AEs responded to corticosteroids. Treatment with AAV5-hRKp.RPGR resulted in improvements in retinal sensitivity and functional vision compared with the deferred group at Week 26; similar trends were observed at Week 52. CONCLUSIONS AAV5-hRKp.RPGR demonstrated an anticipated and manageable AE profile through 52 weeks. Safety and efficacy findings support investigation in a phase 3 trial.
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Affiliation(s)
- Michel Michaelides
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Moorfields Eye Hospital NHS Foundation Trust (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., N.K., A.K., M.G., J.B.), London, UK.
| | - Cagri G Besirli
- Kellogg Eye Center (C.G.B.), Ann Arbor, Michigan, USA; Janssen Pharmaceuticals (C.G.B.), Raritan, New Jersey, USA
| | - Yesa Yang
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Moorfields Eye Hospital NHS Foundation Trust (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., N.K., A.K., M.G., J.B.), London, UK
| | - Thales A C DE Guimaraes
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Moorfields Eye Hospital NHS Foundation Trust (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., N.K., A.K., M.G., J.B.), London, UK
| | - Sui Chien Wong
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Moorfields Eye Hospital NHS Foundation Trust (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., N.K., A.K., M.G., J.B.), London, UK; Great Ormond Street Hospital for Children NHS Foundation Trust (S.C.W.), London, UK
| | - Rachel M Huckfeldt
- Ocular Genomics Institute, Massachusetts Eye and Ear, Harvard Medical School (R.M.H., J.I.C.), Boston, Massachusetts, USA
| | - Jason I Comander
- Ocular Genomics Institute, Massachusetts Eye and Ear, Harvard Medical School (R.M.H., J.I.C.), Boston, Massachusetts, USA
| | - José-Alain Sahel
- UPMC Eye Center, University of Pittsburgh School of Medicine (J.-A.S., S.M.S.), Pittsburgh, Pennsylvania, USA
| | - Syed Mahmood Shah
- UPMC Eye Center, University of Pittsburgh School of Medicine (J.-A.S., S.M.S.), Pittsburgh, Pennsylvania, USA; Gundersen Health System (S.M.S., R.R.A.), La Crosse, Wisconsin, USA
| | - James J L Tee
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Moorfields Eye Hospital NHS Foundation Trust (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., N.K., A.K., M.G., J.B.), London, UK
| | - Neruban Kumaran
- Moorfields Eye Hospital NHS Foundation Trust (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., N.K., A.K., M.G., J.B.), London, UK; Guy's and St. Thomas' NHS Foundation Trust (N.K.), London, UK
| | | | - Pansy Minnick
- Janssen Pharmaceuticals (P.M., J.X., M.C., E.A., P.W., P.R.F., A.F., C.P.), Raritan, New Jersey, USA
| | - Robert Zeldin
- MeiraGTx (A.G., R.Z., S.N., A.F.), New York, New York, USA
| | - Stuart Naylor
- MeiraGTx (A.G., R.Z., S.N., A.F.), New York, New York, USA
| | - Jialin Xu
- Janssen Pharmaceuticals (P.M., J.X., M.C., E.A., P.W., P.R.F., A.F., C.P.), Raritan, New Jersey, USA
| | - Michael Clark
- Janssen Pharmaceuticals (P.M., J.X., M.C., E.A., P.W., P.R.F., A.F., C.P.), Raritan, New Jersey, USA
| | - Eddy Anglade
- Janssen Pharmaceuticals (P.M., J.X., M.C., E.A., P.W., P.R.F., A.F., C.P.), Raritan, New Jersey, USA
| | - Peggy Wong
- Janssen Pharmaceuticals (P.M., J.X., M.C., E.A., P.W., P.R.F., A.F., C.P.), Raritan, New Jersey, USA
| | - Penny R Fleck
- Janssen Pharmaceuticals (P.M., J.X., M.C., E.A., P.W., P.R.F., A.F., C.P.), Raritan, New Jersey, USA
| | - Albert Fung
- Janssen Pharmaceuticals (P.M., J.X., M.C., E.A., P.W., P.R.F., A.F., C.P.), Raritan, New Jersey, USA
| | - Colleen Peluso
- Janssen Pharmaceuticals (P.M., J.X., M.C., E.A., P.W., P.R.F., A.F., C.P.), Raritan, New Jersey, USA
| | - Angelos Kalitzeos
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Moorfields Eye Hospital NHS Foundation Trust (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., N.K., A.K., M.G., J.B.), London, UK
| | - Michalis Georgiou
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Moorfields Eye Hospital NHS Foundation Trust (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., N.K., A.K., M.G., J.B.), London, UK; Jones Eye Institute, University of Arkansas for Medical Sciences (M.G.), Little Rock, Arkansas, USA
| | | | - Alexander J Smith
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Centre for Gene Therapy and Regenerative Medicine, King's College London (A.J.S.), London, UK
| | - Robin R Ali
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Gundersen Health System (S.M.S., R.R.A.), La Crosse, Wisconsin, USA
| | | | - James Bainbridge
- From the UCL Institute of Ophthalmology (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., A.K., M.G., A.J.S., R.R.A., J.B.), London, UK; Moorfields Eye Hospital NHS Foundation Trust (M.M., Y.Y., T.A.C.G., S.C.W., J.J.L.T., N.K., A.K., M.G., J.B.), London, UK
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Baz-Redón N, Sánchez-Bellver L, Fernández-Cancio M, Rovira-Amigo S, Burgoyne T, Ranjit R, Aquino V, Toro-Barrios N, Carmona R, Polverino E, Cols M, Moreno-Galdó A, Camats-Tarruella N, Marfany G. Primary Ciliary Dyskinesia and Retinitis Pigmentosa: Novel RPGR Variant and Possible Modifier Gene. Cells 2024; 13:524. [PMID: 38534367 DOI: 10.3390/cells13060524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/09/2024] [Accepted: 03/13/2024] [Indexed: 03/28/2024] Open
Abstract
We report a novel RPGR missense variant co-segregated with a familial X-linked retinitis pigmentosa (XLRP) case. The brothers were hemizygous for this variant, but only the proband presented with primary ciliary dyskinesia (PCD). Thus, we aimed to elucidate the role of the RPGR variant and other modifier genes in the phenotypic variability observed in the family and its impact on motile cilia. The pathogenicity of the variant on the RPGR protein was evaluated by in vitro studies transiently transfecting the mutated RPGR gene, and immunofluorescence analysis on nasal brushing samples. Whole-exome sequencing was conducted to identify potential modifier variants. In vitro studies showed that the mutated RPGR protein could not localise to the cilium and impaired cilium formation. Accordingly, RPGR was abnormally distributed in the siblings' nasal brushing samples. In addition, a missense variant in CEP290 was identified. The concurrent RPGR variant influenced ciliary mislocalisation of the protein. We provide a comprehensive characterisation of motile cilia in this XLRP family, with only the proband presenting PCD symptoms. The variant's pathogenicity was confirmed, although it alone does not explain the respiratory symptoms. Finally, the CEP290 gene may be a potential modifier for respiratory symptoms in patients with RPGR mutations.
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Affiliation(s)
- Noelia Baz-Redón
- Growth and Development Research Group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Laura Sánchez-Bellver
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Mónica Fernández-Cancio
- Growth and Development Research Group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Sandra Rovira-Amigo
- Growth and Development Research Group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Department of Paediatrics, Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain
| | - Thomas Burgoyne
- Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, London SW3 6NP, UK
- Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Rai Ranjit
- Royal Brompton Hospital, Guy's and St Thomas' NHS Foundation Trust, London SW3 6NP, UK
| | - Virginia Aquino
- Plataforma Andaluza de Medicina Computacional, Fundación Pública Andaluza Progreso y Salud, 41092 Sevilla, Spain
| | - Noemí Toro-Barrios
- Plataforma Andaluza de Medicina Computacional, Fundación Pública Andaluza Progreso y Salud, 41092 Sevilla, Spain
| | - Rosario Carmona
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Plataforma Andaluza de Medicina Computacional, Fundación Pública Andaluza Progreso y Salud, 41092 Sevilla, Spain
| | - Eva Polverino
- Pneumology Research Group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
- Pneumology Department, Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Maria Cols
- Paediatric Pulmonology Department and Cystic Fibrosis Unit, Hospital Sant Joan de Déu, 08950 Esplugues de Llobregat, Spain
| | - Antonio Moreno-Galdó
- Growth and Development Research Group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Department of Paediatrics, Vall d'Hebron Hospital Universitari, Vall d'Hebron Barcelona Hospital Campus, 08035 Barcelona, Spain
- Department of Paediatrics, Obstetrics, Gynecology, Preventive Medicine and Public Health, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | - Núria Camats-Tarruella
- Growth and Development Research Group, Vall d'Hebron Research Institute (VHIR), Hospital Universitari Vall d'Hebron, 08035 Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Gemma Marfany
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, 08028 Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, 08028 Barcelona, Spain
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Flax RG, Rosston P, Rocha C, Anderson B, Capener JL, Durcan TM, Drewry DH, Prinos P, Axtman AD. Illumination of understudied ciliary kinases. Front Mol Biosci 2024; 11:1352781. [PMID: 38523660 PMCID: PMC10958382 DOI: 10.3389/fmolb.2024.1352781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 01/29/2024] [Indexed: 03/26/2024] Open
Abstract
Cilia are cellular signaling hubs. Given that human kinases are central regulators of signaling, it is not surprising that kinases are key players in cilia biology. In fact, many kinases modulate ciliogenesis, which is the generation of cilia, and distinct ciliary pathways. Several of these kinases are understudied with few publications dedicated to the interrogation of their function. Recent efforts to develop chemical probes for members of the cyclin-dependent kinase like (CDKL), never in mitosis gene A (NIMA) related kinase (NEK), and tau tubulin kinase (TTBK) families either have delivered or are working toward delivery of high-quality chemical tools to characterize the roles that specific kinases play in ciliary processes. A better understanding of ciliary kinases may shed light on whether modulation of these targets will slow or halt disease onset or progression. For example, both understudied human kinases and some that are more well-studied play important ciliary roles in neurons and have been implicated in neurodevelopmental, neurodegenerative, and other neurological diseases. Similarly, subsets of human ciliary kinases are associated with cancer and oncological pathways. Finally, a group of genetic disorders characterized by defects in cilia called ciliopathies have associated gene mutations that impact kinase activity and function. This review highlights both progress related to the understanding of ciliary kinases as well as in chemical inhibitor development for a subset of these kinases. We emphasize known roles of ciliary kinases in diseases of the brain and malignancies and focus on a subset of poorly characterized kinases that regulate ciliary biology.
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Affiliation(s)
- Raymond G. Flax
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Peter Rosston
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Cecilia Rocha
- The Neuro’s Early Drug Discovery Unit (EDDU), McGill University, Montreal, QC, Canada
| | - Brian Anderson
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Jacob L. Capener
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Thomas M. Durcan
- The Neuro’s Early Drug Discovery Unit (EDDU), McGill University, Montreal, QC, Canada
| | - David H. Drewry
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- UNC Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Panagiotis Prinos
- Structural Genomics Consortium, University of Toronto, Toronto, ON, Canada
| | - Alison D. Axtman
- Structural Genomics Consortium, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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Kolkova Z, Durdik P, Holubekova V, Durdikova A, Jesenak M, Banovcin P. Identification of a novel RPGR mutation associated with retinitis pigmentosa and primary ciliary dyskinesia in a Slovak family: a case report. Front Pediatr 2024; 12:1339664. [PMID: 38333087 PMCID: PMC10850321 DOI: 10.3389/fped.2024.1339664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 01/10/2024] [Indexed: 02/10/2024] Open
Abstract
Background The mutations in the RPGR (retinitis pigmentosa GTPase regulator) gene are the most common cause of X-linked retinitis pigmentosa (XLRP), a rare genetic disorder affecting the photoreceptor cells in the retina. Several reported cases identified this gene as a genetic link between retinitis pigmentosa (RP) and primary ciliary dyskinesia (PCD), characterised by impaired ciliary function predominantly in the respiratory tract. Since different mutations in the same gene can result in various clinical manifestations, it is important to describe a correlation between the gene variant and the observed phenotype. Methods Two young brothers from a non-consanguineous Slovak family with diagnosed retinal dystrophy and recurrent respiratory infections were examined. Suspected PCD was diagnosed based on a PICADAR questionnaire, nasal nitric oxide analysis, transmission electron microscopy, high-speed video microscopy analysis, and genetic testing. Results We identified a novel frameshift RPGR mutation NM_001034853: c.309_310insA, p.Glu104Argfs*12, resulting in a complex X-linked phenotype combining PCD and RP. In our patients, this mutation was associated with normal ultrastructure of respiratory cilia, reduced ciliary epithelium, more aciliary respiratory epithelium, shorter cilia, and uncoordinated beating with a frequency at a lower limit of normal beating, explaining the clinical manifestation of PCD in our patients. Conclusion The identified novel pathogenic mutation in the RPGR gene expands the spectrum of genetic variants associated with the X-linked PCD phenotype overlapping with RP, highlighting the diversity of mutations contributing to the disorder. The described genotype-phenotype correlation can be useful in clinical practice to recognise a broader spectrum of PCD phenotypes as well as for future research focused on the genetic basis of PCD, gene interactions, the pathways implicated in PCD pathogenesis, and the role of RPGR protein for the proper functioning of cilia in various tissues throughout the body.
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Affiliation(s)
- Zuzana Kolkova
- Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| | - Peter Durdik
- Department of Pediatrics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
- Department of Pediatrics, University Hospital Martin, Martin, Slovakia
| | - Veronika Holubekova
- Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
| | - Anna Durdikova
- Department of Pediatrics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
- Department of Pediatrics, University Hospital Martin, Martin, Slovakia
| | - Milos Jesenak
- Department of Pediatrics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
- Department of Pediatrics, University Hospital Martin, Martin, Slovakia
- Department of Pulmonology and Phthisiology, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, University Hospital in Martin, Martin, Slovakia
- Department of Clinical Immunology and Allergology, University Hospital in Martin, Martin, Slovakia
| | - Peter Banovcin
- Department of Pediatrics, Jessenius Faculty of Medicine in Martin, Comenius University in Bratislava, Martin, Slovakia
- Department of Pediatrics, University Hospital Martin, Martin, Slovakia
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Han RC, Taylor LJ, Martinez-Fernandez de la Camara C, Henderson RH, Thompson DA, Cehajic-Kapetanovic J, MacLaren RE. Is RPGR-related retinal dystrophy associated with systemic disease? A case series. Ophthalmic Genet 2023; 44:577-584. [PMID: 36602268 DOI: 10.1080/13816810.2022.2163405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/30/2022] [Accepted: 12/23/2022] [Indexed: 01/06/2023]
Abstract
BACKGROUND Ciliopathies responsible for retinitis pigmentosa can also cause systemic manifestations. RPGR is a ciliary gene and pathogenic variants in RPGR cause a retinal ciliopathy, the commonest cause of X-linked recessive retinitis pigmentosa. The RPGR protein interacts with numerous other ciliary proteins present in the transition zone of both motile and sensory cilia, and may play an important role in regulating ciliary protein transport. There has been a growing, putative association of RPGR variants with systemic ciliopathies: mainly sino-respiratory infections and primary ciliary dyskinesia. MATERIALS AND METHODS Retrospective case series of patients with RPGR-RP presenting to Oxford Eye Hospital with systemic disease. RESULTS We report three children with RPGR-related rod-cone dystrophy, all of whom have mutations in the N-terminus of RPGR. Two cases co-presented with confirmed diagnoses of primary ciliary dyskinesia and one case with multiple sino-respiratory symptoms strongly suggestive of primary ciliary dyskinesia. These and all previously reported RPGR co-pathologies relate to ciliopathies and have no other systemic associations. CONCLUSIONS The link between RPGR variants and a systemic ciliopathy remains plausible, but currently unproven.
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Affiliation(s)
- Ruofan Connie Han
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Laura J Taylor
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Robert H Henderson
- Department of Ophthalmology, Great Ormond Street Children's Hospital, London, UK
| | - Dorothy A Thompson
- Department of Ophthalmology, Great Ormond Street Children's Hospital, London, UK
- Clinical and Academic Department of Ophthalmology, Great Ormond Street Hospital for Children, London, UK
| | - Jasmina Cehajic-Kapetanovic
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Robert E MacLaren
- Oxford Eye Hospital, John Radcliffe Hospital, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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7
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Wongchaisuwat N, Amato A, Lamborn AE, Yang P, Everett L, Pennesi ME. Retinitis pigmentosa GTPase regulator-related retinopathy and gene therapy. Saudi J Ophthalmol 2023; 37:276-286. [PMID: 38155670 PMCID: PMC10752277 DOI: 10.4103/sjopt.sjopt_168_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/14/2023] [Accepted: 08/16/2023] [Indexed: 12/30/2023] Open
Abstract
Retinitis pigmentosa GTPase regulator (RPGR)-related retinopathy is a retinal dystrophy inherited in a X-linked recessive manner that typically causes progressive visual loss starting in childhood with severe visual impairment by the fourth decade of life. It manifests as an early onset and severe form of retinitis pigmentosa. There are currently no effective treatments for RPGR-related retinopathy; however, there are multiple clinical trials in progress exploring gene augmentation therapy aimed at slowing down or halting the progression of disease and possibly restoring visual function. This review focuses on the molecular biology, clinical manifestations, and the recent progress of gene therapy clinical trials.
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Affiliation(s)
- Nida Wongchaisuwat
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
| | - Alessia Amato
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
| | - Andrew E. Lamborn
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
| | - Paul Yang
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
| | - Lesley Everett
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon, USA
| | - Mark E. Pennesi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, USA
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, Oregon, USA
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8
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Herrera JA, Dingle LA, Monetero MA, Venkateswaran RV, Blaikley JF, Granato F, Pearson S, Lawless C, Thornton DJ. Morphologically intact airways in lung fibrosis have an abnormal proteome. Respir Res 2023; 24:99. [PMID: 37005656 PMCID: PMC10066954 DOI: 10.1186/s12931-023-02400-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 03/16/2023] [Indexed: 04/04/2023] Open
Abstract
Honeycombing is a histological pattern consistent with Usual Interstitial Pneumonia (UIP). Honeycombing refers to cystic airways located at sites of dense fibrosis with marked mucus accumulation. Utilizing laser capture microdissection coupled mass spectrometry (LCM-MS), we interrogated the fibrotic honeycomb airway cells and fibrotic uninvolved airway cells (distant from honeycomb airways and morphologically intact) in specimens from 10 patients with UIP. Non-fibrotic airway cell specimens from 6 patients served as controls. Furthermore, we performed LCM-MS on the mucus plugs found in 6 patients with UIP and 6 patients with mucinous adenocarcinoma. The mass spectrometry data were subject to both qualitative and quantitative analysis and validated by immunohistochemistry. Surprisingly, fibrotic uninvolved airway cells share a similar protein profile to honeycomb airway cells, showing deregulation of the slit and roundabout receptor (Slit and Robo) pathway as the strongest category. We find that (BPI) fold-containing family B member 1 (BPIFB1) is the most significantly increased secretome-associated protein in UIP, whereas Mucin-5AC (MUC5AC) is the most significantly increased in mucinous adenocarcinoma. We conclude that fibrotic uninvolved airway cells share pathological features with fibrotic honeycomb airway cells. In addition, fibrotic honeycomb airway cells are enriched in mucin biogenesis proteins with a marked derangement in proteins essential for ciliogenesis. This unbiased spatial proteomic approach generates novel and testable hypotheses to decipher fibrosis progression.
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Affiliation(s)
- Jeremy A Herrera
- The Wellcome Centre for Cell-Matrix Research, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK.
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK.
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
| | - Lewis A Dingle
- Blond McIndoe Laboratories, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
| | - M Angeles Monetero
- Manchester University NHS Foundation Trust, Manchester, Greater Manchester, UK
| | - Rajamiyer V Venkateswaran
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
- Manchester University NHS Foundation Trust, Manchester, Greater Manchester, UK
| | - John F Blaikley
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
- Manchester University NHS Foundation Trust, Manchester, Greater Manchester, UK
| | - Felice Granato
- Manchester University NHS Foundation Trust, Manchester, Greater Manchester, UK
| | - Stella Pearson
- The Wellcome Centre for Cell-Matrix Research, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
- Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
| | - Craig Lawless
- The Wellcome Centre for Cell-Matrix Research, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
| | - David J Thornton
- The Wellcome Centre for Cell-Matrix Research, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
- Lydia Becker Institute of Immunology and Inflammation, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, Great Manchester, UK
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9
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Cellular and Molecular Mechanisms of Pathogenesis Underlying Inherited Retinal Dystrophies. Biomolecules 2023; 13:biom13020271. [PMID: 36830640 PMCID: PMC9953031 DOI: 10.3390/biom13020271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/23/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) are congenital retinal degenerative diseases that have various inheritance patterns, including dominant, recessive, X-linked, and mitochondrial. These diseases are most often the result of defects in rod and/or cone photoreceptor and retinal pigment epithelium function, development, or both. The genes associated with these diseases, when mutated, produce altered protein products that have downstream effects in pathways critical to vision, including phototransduction, the visual cycle, photoreceptor development, cellular respiration, and retinal homeostasis. The aim of this manuscript is to provide a comprehensive review of the underlying molecular mechanisms of pathogenesis of IRDs by delving into many of the genes associated with IRD development, their protein products, and the pathways interrupted by genetic mutation.
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10
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Appelbaum T, Aguirre GD, Beltran WA. Identification of circular RNAs hosted by the RPGR ORF15 genomic locus. RNA Biol 2023; 20:31-47. [PMID: 36593651 PMCID: PMC9817113 DOI: 10.1080/15476286.2022.2159165] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/23/2022] [Accepted: 12/07/2022] [Indexed: 01/04/2023] Open
Abstract
Mutations in the retina-specific isoform of the gene encoding retinitis pigmentosa GTPase regulator (RPGRorf15) cause X-linked retinitis pigmentosa, a severe and early onset inherited retinal degeneration. The underlying pathogenic mechanisms and variability in disease severity remain to be fully elucidated. The present study examines structural features of the ORF15 exonic region to provide new insights into the disease pathogenesis. Using canine and human RNA samples, we identified several novel RPGR ORF15-like linear RNA transcripts containing cryptic introns (exitrons) within the annotated exon ORF15. Furthermore, using outward-facing primers designed inside exitrons in the ORF15 exonic region, we found many of previously unidentified circular RNAs (circRNAs) that formed via back fusion of linear parts of the RPGRorf15 pre-mRNAs. These circRNAs (resistant to RNAse R treatment) were found in all studied cells and tissues. Notably, some circRNAs were present in cytoplasmic and polysomal RNA fractions. Although certain RPGR circRNAs may be cell type specific, we found some of the same circRNAs expressed in different cell types, suggesting similarities in their biogenesis and functions. Sequence analysis of RPGR circRNAs revealed several remarkable features, including identification of N6-methyladenosine (m6A) consensus sequence motifs and high prevalence of predictive microRNA binding sites pointing to the functional roles of these circRNAs. Our findings also illustrate the presence of non-canonical RPGR circRNA biogenesis pathways independent of the known back splicing mechanism. The obtained data on novel RPGR circRNAs further underline structural complexity of the RPGR ORF15 region and provide a potential molecular basis for the disease phenotypic heterogeneity.
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Affiliation(s)
- Tatyana Appelbaum
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gustavo D. Aguirre
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - William A. Beltran
- Division of Experimental Retinal Therapies, Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
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11
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Cehajic-Kapetanovic J, Martinez-Fernandez de la Camara C, Birtel J, Rehman S, McClements ME, Charbel Issa P, Lotery AJ, MacLaren RE. Impaired glutamylation of RPGR ORF15 underlies the cone-dominated phenotype associated with truncating distal ORF15 variants. Proc Natl Acad Sci U S A 2022; 119:e2208707119. [PMID: 36445968 PMCID: PMC9897430 DOI: 10.1073/pnas.2208707119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Pathogenic variants in the Retinitis pigmentosa GTPase regulator (RPGR) gene lead to a clinically severe form of X-linked retinal dystrophy. However, it remains unclear why some variants cause a predominant rod, while others result in a cone-dominated phenotype. Post-translational glutamylation of the photoreceptor-specific RPGRORF15 isoform by the TTLL5 enzyme is essential for its optimal function in photoreceptors, and loss of TTLL5 leads to retinal dystrophy with a cone phenotype. Here we show that RPGR retinal disease, studied in a single cohort of 116 male patients, leads to a clear progressive shift from rod- to cone-dominating phenotype as the RPGRORF15 variant location approaches the distal part of the Open Reading Frame 15 (ORF15) region. The rod photoreceptor involvement on the contrary diminishes along the RGPR sequence, and the variants associated with the cone only phenotype are located predominantly in the very distal part, including the C-terminal basic domain. Moreover, these distal truncating RPGRORF15 variants disrupt the interaction with TTLL5 and lead to a significant impairment of RPGR glutamylation. Thus, consistent with the phenotype of TTLL5 pathogenic variants, our study shows that RPGRORF15 variants, which disrupt its basic domain and the interaction with TTLL5, also impair RPGR glutamylation and lead to the cone phenotype. This has implications for ongoing gene therapy clinical trials where the application of RPGR with impaired glutamylation may be less effective in treating RGPR dystrophies and may even convert a rod-cone dystrophy into a cone dystrophy phenotype.
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Affiliation(s)
- Jasmina Cehajic-Kapetanovic
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
- 2To whom correspondence may be addressed.
| | - Cristina Martinez-Fernandez de la Camara
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
- 2To whom correspondence may be addressed.
| | - Johannes Birtel
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
- cDepartment of Ophthalmology, University of Bonn, 53127Bonn, Germany
| | - Salwah Rehman
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
| | - Michelle E. McClements
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
| | - Peter Charbel Issa
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
| | - Andrew J Lotery
- dClinical Neurosciences Research Group, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SO16 6YDSouthampton, United Kingdom
- eUniversity Hospital Southampton NHS Foundation Trust, SO16 6YDSouthampton, United Kingdom
| | - Robert E. MacLaren
- aNuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West WingOX3 9DU, United Kingdom
- bOxford Eye Hospital, Oxford University Hospitals The National Health Service Trust, John Radcliffe Hospital, West WingOX3 9DU, United Kingdom
- 2To whom correspondence may be addressed.
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12
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Martinez-Fernandez de la Camara C, Cehajic-Kapetanovic J, MacLaren RE. Emerging gene therapy products for RPGR-associated X-linked retinitis pigmentosa. Expert Opin Emerg Drugs 2022; 27:431-443. [PMID: 36562395 DOI: 10.1080/14728214.2022.2152003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 11/22/2022] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Mutations in the RPGR gene are responsible for one of the most prevalent and severe types of retinitis pigmentosa. Gene therapy has shown great promise to treat inherited retinal diseases, and currently, four RPGR gene therapy vectors are being evaluated in clinical trials. AREAS COVERED This manuscript reviews the gene therapy products that are in development for X-linked retinitis pigmentosa caused by mutations in RPGR, and the challenges that scientists and clinicians have faced. EXPERT OPINION The development of a gene therapy product for RPGR-associated retinal degeneration has been a great challenge due to the incomplete understanding of the underlying genetics and mechanism of action of RPGR, and on the other hand, due to the instability of the RPGR gene. Three of the four gene therapy vectors currently in clinical trials include a codon-optimized version of the human RPGR sequence, and the other vector contains a shortened version of the human RPGR. To date, the only Phase I/II results published in a peer-reviewed journal demonstrate a good safety profile and an improvement in the visual field using a codon optimized version of RPGRORF15.
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Affiliation(s)
- Cristina Martinez-Fernandez de la Camara
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing, Headley Way, OX3 9DU, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, West Wing, Headley Way, OX3 9DU, Oxford, UK
| | - Jasmina Cehajic-Kapetanovic
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing, Headley Way, OX3 9DU, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, West Wing, Headley Way, OX3 9DU, Oxford, UK
| | - Robert E MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5 & 6, West Wing, Headley Way, OX3 9DU, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, West Wing, Headley Way, OX3 9DU, Oxford, UK
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13
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Chahine Karam F, Loi TH, Ma A, Nash BM, Grigg JR, Parekh D, Riley LG, Farnsworth E, Bennetts B, Gonzalez-Cordero A, Jamieson RV. Human iPSC-Derived Retinal Organoids and Retinal Pigment Epithelium for Novel Intronic RPGR Variant Assessment for Therapy Suitability. J Pers Med 2022; 12:jpm12030502. [PMID: 35330501 PMCID: PMC8951517 DOI: 10.3390/jpm12030502] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 02/04/2023] Open
Abstract
The RPGR gene encodes Retinitis Pigmentosa GTPase Regulator, a known interactor with ciliary proteins, which is involved in maintaining healthy photoreceptor cells. Variants in RPGR are the main contributor to X-linked rod-cone dystrophy (RCD), and RPGR gene therapy approaches are in clinical trials. Hence, elucidation of the pathogenicity of novel RPGR variants is important for a patient therapy opportunity. Here, we describe a novel intronic RPGR variant, c.1415 − 9A>G, in a patient with RCD, which was classified as a variant of uncertain significance according to current clinical diagnostic criteria. The variant lay several base pairs intronic to the canonical splice acceptor site, raising suspicion of an RPGR RNA splicing abnormality and consequent protein dysfunction. To investigate disease causation in an appropriate disease model, induced pluripotent stem cells were generated from patient fibroblasts and differentiated to retinal pigment epithelium (iPSC-RPE) and retinal organoids (iPSC-RO). Abnormal RNA splicing of RPGR was demonstrated in patient fibroblasts, iPSC-RPE and iPSC-ROs, leading to a predicted frameshift and premature stop codon. Decreased RPGR expression was demonstrated in these cell types, with a striking loss of RPGR localization at the ciliary transitional zone, critically in the photoreceptor cilium of the patient iPSC-ROs. Mislocalisation of rhodopsin staining was present in the patient’s iPSC-RO rod photoreceptor cells, along with an abnormality of L/M opsin staining affecting cone photoreceptor cells and increased photoreceptor apoptosis. Additionally, patient iPSC-ROs displayed an increase in F-actin expression that was consistent with an abnormal actin regulation phenotype. Collectively, these studies indicate that the splicing abnormality caused by the c.1415 − 9A>G variant has an impact on RPGR function. This work has enabled the reclassification of this variant to pathogenic, allowing the consideration of patients with this variant having access to gene therapy clinical trials. In addition, we have identified biomarkers of disease suitable for the interrogation of other RPGR variants of uncertain significance.
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Affiliation(s)
- Fidelle Chahine Karam
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
| | - To Ha Loi
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
| | - Alan Ma
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
- Department of Clinical Genetics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
| | - Benjamin M. Nash
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
- Sydney Genome Diagnostics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
| | - John R. Grigg
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
- Specialty of Ophthalmology, Faculty of Medicine and Health, University of Sydney, Sydney 2006, Australia
| | - Darshan Parekh
- Rare Diseases Functional Genomics Laboratory, Sydney Children’s Hospitals Network and Children’s Medical Research Institute, Westmead, Sydney 2145, Australia; (D.P.); (L.G.R.)
| | - Lisa G. Riley
- Rare Diseases Functional Genomics Laboratory, Sydney Children’s Hospitals Network and Children’s Medical Research Institute, Westmead, Sydney 2145, Australia; (D.P.); (L.G.R.)
- Specialty of Child and Adolescent Health, University of Sydney, Westmead, Sydney 2145, Australia
| | - Elizabeth Farnsworth
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
- Sydney Genome Diagnostics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
| | - Bruce Bennetts
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
- Sydney Genome Diagnostics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
| | - Anai Gonzalez-Cordero
- Stem Cell Medicine Group, Children’s Medical Research Institute, University of Sydney, Westmead, Sydney 2145, Australia;
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney 2006, Australia
| | - Robyn V. Jamieson
- Eye Genetics Research Unit, Children’s Medical Research Institute, Sydney Children’s Hospitals Network, Save Sight Institute, University of Sydney, Westmead, Sydney 2145, Australia; (F.C.K.); (T.H.L.); (A.M.); (B.M.N.); (J.R.G.)
- Department of Clinical Genetics, Western Sydney Genetics Program, Sydney Children’s Hospitals Network, Westmead, Sydney 2145, Australia
- Specialty of Genomic Medicine, Faculty of Medicine and Health, University of Sydney, Westmead, Sydney 2145, Australia; (E.F.); (B.B.)
- Correspondence: ; Tel.: +61-2-9687-2800; Fax: +61-2-9687-2120
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14
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Wang Y, Liu S, Zhai Y, Liu Y, Wan X, Wang W, Wang F, Sun X. Identification of a novel RPGR mutation associated with X-linked cone-rod dystrophy in a Chinese family. BMC Ophthalmol 2021; 21:401. [PMID: 34800980 PMCID: PMC8605601 DOI: 10.1186/s12886-021-02166-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 10/31/2021] [Indexed: 11/10/2022] Open
Abstract
Background Cone-rod dystrophy (CORD) is a group of inherited retinal dystrophies, characterized by decreased visual acuity, color vision defects, photophobia, and decreased sensitivity in the central visual field. Our study has identified a novel pathogenic variant associated with X-linked cone-rod dystrophy (XLCORD) in a Chinese family. Methods All six family members, including the proband, affected siblings, cousins and female carriers, have underwent thorough ophthalmic examinations. The whole exome sequencing was performed for the proband, followed by Sanger sequencing for spilt-sample validation. A mammalian expression vector (AAV-MCS) with mutated retinitis pigmentosa GTPase regulator (RPGR) sequence was expressed in HEK293 T cells. The mutated protein was verified by Western blotting and immunohistochemistry. Results A novel mutation in the RPGR gene (c.2383G > T, p.E795X) is identified to be responsible for CORD pathogenesis. Conclusions Our findings have expanded the spectrum of CORD-associated mutations in RPGR gene and serve as a basis for genetic diagnosis for X-linked CORD. Supplementary Information The online version contains supplementary material available at 10.1186/s12886-021-02166-0.
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Affiliation(s)
- Yafang Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai, 200080, China
| | - Shu Liu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai, 200080, China
| | - Yuanqi Zhai
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai, 200080, China
| | - Yang Liu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai, 200080, China
| | - Xiaoling Wan
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai, 200080, China
| | - Wenqiu Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai, 200080, China.
| | - Fenghua Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai, 200080, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, 100 Haining Road, Shanghai, 200080, China.,Shanghai Engineering Center for Visual Science and Photomedicine, 100 Haining Road, Shanghai, 200080, China.,National Clinical Research Center for Eye Diseases, 100 Haining Road, Shanghai, 200080, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, 100 Haining Road, Shanghai, 200080, China
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, 100 Haining Road, Shanghai, 200080, China.,Shanghai Key Laboratory of Ocular Fundus Diseases, 100 Haining Road, Shanghai, 200080, China.,Shanghai Engineering Center for Visual Science and Photomedicine, 100 Haining Road, Shanghai, 200080, China.,National Clinical Research Center for Eye Diseases, 100 Haining Road, Shanghai, 200080, China.,Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, 100 Haining Road, Shanghai, 200080, China
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15
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Nuzbrokh Y, Ragi SD, Tsang SH. Gene therapy for inherited retinal diseases. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1278. [PMID: 34532415 PMCID: PMC8421966 DOI: 10.21037/atm-20-4726] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 11/04/2020] [Indexed: 01/04/2023]
Abstract
Inherited retinal diseases (IRDs) are a genetically variable collection of devastating disorders that lead to significant visual impairment. Advances in genetic characterization over the past two decades have allowed identification of over 260 causative mutations associated with inherited retinal disorders. Thought to be incurable, gene supplementation therapy offers great promise in treating various forms of these blinding conditions. In gene replacement therapy, a disease-causing gene is replaced with a functional copy of the gene. These therapies are designed to slow disease progression and hopefully restore visual function. Gene therapies are typically delivered to target retinal cells by subretinal (SR) or intravitreal (IVT) injection. The historic Food and Drug Administration (FDA) approval of voretigene neparvovec for RPE65-associated Leber's congenital amaurosis (LCA) spurred tremendous optimism surrounding retinal gene therapy for various other monogenic IRDs. Novel disease-causing mutations continue to be discovered annually, and targeted genetic therapy is now under development in clinical and preclinical models for many IRDs. Numerous clinical trials for other IRDs are ongoing or have recently completed. Disorders being targeted for genetic therapy include retinitis pigmentosa (RP), choroideremia (CHM), achromatopsia (ACHM), Leber's hereditary optic neuropathy, usher syndrome (USH), X-linked retinoschisis, and Stargardt disease. Here, we provide an update of completed, ongoing, and planned clinical trials using gene supplementation strategies for retinal degenerative disorders.
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Affiliation(s)
- Yan Nuzbrokh
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY, USA.,Jonas Children's Vision Care, New York, NY, USA.,Renaissance School of Medicine at Stony Brook University, Stony Brook, New York, NY, USA
| | - Sara D Ragi
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY, USA.,Jonas Children's Vision Care, New York, NY, USA
| | - Stephen H Tsang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY, USA.,Jonas Children's Vision Care, New York, NY, USA.,Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY, USA
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Xiao YS, Liang J, Gao M, Sun JR, Liu Y, Chen JQ, Zhao XH, Wang YM, Chen YH, Wang YW, Wan XL, Luo XT, Sun XD. Deletion of prominin-1 in mice results in disrupted photoreceptor outer segment protein homeostasis. Int J Ophthalmol 2021; 14:1334-1344. [PMID: 34540608 PMCID: PMC8403851 DOI: 10.18240/ijo.2021.09.07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 04/21/2021] [Indexed: 11/23/2022] Open
Abstract
AIM To illustrate the underlying mechanism how prominin-1 (also known as Prom1) mutation contribute to progressive photoreceptor degeneration. METHODS A CRISPR-mediated Prom1 knockout (Prom1-KO) mice model in the C57BL/6 was generated and the photoreceptor degeneration phenotypes by means of structural and functional tests were demonstrated. Immunohistochemistry and immunoblot analysis were performed to reveal the localization and quantity of related outer segment (OS) proteins. RESULTS The Prom1-KO mice developed the photoreceptor degeneration phenotype including the decreased outer nuclear layer (ONL) thickness and compromised electroretinogram amplitude. Immunohistochemistry analysis revealed impaired trafficking of photoreceptor OS proteins. Immunoblot data demonstrated decreased photoreceptor OS proteins. CONCLUSION Prom1 deprivation causes progressive photoreceptor degeneration. Prom1 is essential for maintaining normal trafficking and normal quantity of photoreceptor OS proteins. The new light is shed on the pathogenic mechanism underlying photoreceptor degeneration caused by Prom1 mutation.
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Affiliation(s)
- Yu-Shu Xiao
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
| | - Jian Liang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
- Shanghai Key Laboratory of Fundus Diseases, Shanghai 200080, China
| | - Min Gao
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
| | - Jun-Ran Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
| | - Yang Liu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
| | - Jie-Qiong Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
| | - Xiao-Huan Zhao
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
| | - Yi-Min Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
| | - Yu-Hong Chen
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
| | - Yu-Wei Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
| | - Xiao-Ling Wan
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
- Shanghai Key Laboratory of Fundus Diseases, Shanghai 200080, China
| | - Xue-Ting Luo
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
- Shanghai Key Laboratory of Fundus Diseases, Shanghai 200080, China
| | - Xiao-Dong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, School of Medicine, Shanghai 200080, China
- Shanghai Key Laboratory of Fundus Diseases, Shanghai 200080, China
- Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai 200080, China
- National Clinical Research Center for Ophthalmic Diseases, Shanghai 200080, China
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Shah MH, Kumaran M, Chermakani P, Kader MA, Ramakrishnan R, Krishnadas SR, Devarajan B, Sundaresan P. Whole-exome sequencing identifies multiple pathogenic variants in a large South Indian family with primary open-angle glaucoma. Indian J Ophthalmol 2021; 69:2461-2468. [PMID: 34427245 PMCID: PMC8544095 DOI: 10.4103/ijo.ijo_3301_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Purpose: To identify the pathogenic variants associated with primary open-angle glaucoma (POAG) using whole-exome sequencing (WES) data of a large South Indian family. Methods: We recruited a large five-generation South Indian family (n = 84) with a positive family history of POAG (n = 19). All study participants had a comprehensive ocular evaluation. We performed WES for 16 samples (nine POAG and seven unaffected controls) since Sanger sequencing of the POAG candidate genes (MYOC, OPTN, and TBK1) showed no genetic variation. We used an in-house pipeline for prioritizing the pathogenic variants based on their segregation among the POAG individual. Results: We identified one novel and five low-frequency pathogenic variants with consistent co-segregation in all affected individuals. The variant c.G3719A in RPGR-interacting domain of RPGRIP1 that segregated heterozygously with the six POAG cases is distinct from variants causing photoreceptor dystrophies, reported affecting the RPGR protein complex signaling in primary cilia. The cilia in trabecular meshwork (TM) cells has been reported to mediate the intraocular pressure (IOP) sensation. Furthermore, we identified a novel c.A1295G variant in Rho guanine nucleotide exchange factors Gene 40 (ARHGEF40) and a likely pathogenic variant in the RPGR gene, suggesting that they may alter the RhoA activity essential for IOP regulation. Conclusion: Our study supports that low-frequency pathogenic variants in multiple genes and pathways probably affect Primary Open Angle Glaucoma’s pathogenesis in the large South Indian family. Furthermore, it requires larger case-controls to perform family-based association tests and to strengthen our analysis.
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Affiliation(s)
- Mohd Hussain Shah
- Department of Genetics, Aravind Medical Research Foundation, Madurai, India
| | - Manojkumar Kumaran
- Department of Bioinformatics, Aravind Medical Research Foundation, Madurai; School of Chemical and Biotechnology, SASTRA (Deemed to be University), Thanjavur, India
| | - Prakash Chermakani
- Department of Genetics, Aravind Medical Research Foundation; Department of Molecular Biology, Alagappa University, Karaikudi, Tamil Nadu, India
| | | | - R Ramakrishnan
- Glaucoma Clinic, Aravind Eye Hospital, Tirunelveli, India
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Li D, Hu M, Chen H, Wu X, Wei X, Lin H, Gao X, Wang H, Li M, Ong ACM, Yue Z, Sun L. An Nphp1 knockout mouse model targeting exon 2-20 demonstrates characteristic phenotypes of human Nephronophthisis. Hum Mol Genet 2021; 31:232-243. [PMID: 34415307 DOI: 10.1093/hmg/ddab239] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/30/2021] [Accepted: 08/12/2021] [Indexed: 11/13/2022] Open
Abstract
Nephronophthisis (NPH) is the most prevalent monogenetic disorder leading to end-stage renal failure (ESRD) in childhood. Mutations in Nphp1, encoding a cilia-localized protein, account for the majority of NPH cases. Despite its identification many years ago, Nphp1 deletions targeting exon 4 or exon 20 have not reproduced the histological features of human NPH in murine models. In this study, we deleted exon 2-20 of Nphp1 by CRISPR/Cas9 gene editing to create a near-total knockout (KO) mouse model (Nphp1del2-20/del2-20). Nphp1del2-20/del2-20 mice faithfully reproduced the renal and extrarenal phenotypes associated with human NPH, including renal cyst development, tubular basement membrane thickening, retinal degeneration and abnormal spermatogenesis. Importantly, Nphp1 re-expression using an adenoviral-associated-virus-9 (AAV9) vector could partially rescue both renal and retinal phenotypes in Nphp1del2-20/del2-20 mice. Our results reported the first relevant Nphp1 mouse model with renal phenotypes for human disease. It will be a valuable model for future studies of Nphp1 function and to develop novel treatments for this common childhood disease.
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Affiliation(s)
- Dantong Li
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Miaoyue Hu
- Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Huamu Chen
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Xiaohong Wu
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Xiaoya Wei
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Hongrong Lin
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Xuefei Gao
- Department of Physiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Haiyan Wang
- Department of Pediatrics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China
| | - Min Li
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Albert C M Ong
- Kidney Genetics Group, Academic Nephrology Unit, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield Medical School, Sheffield, UK
| | - Zhihui Yue
- Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Liangzhong Sun
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
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Li X, Alhasani RH, Cao Y, Zhou X, He Z, Zeng Z, Strang N, Shu X. Gypenosides Alleviate Cone Cell Death in a Zebrafish Model of Retinitis Pigmentosa. Antioxidants (Basel) 2021; 10:antiox10071050. [PMID: 34209942 PMCID: PMC8300748 DOI: 10.3390/antiox10071050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 06/09/2021] [Accepted: 06/22/2021] [Indexed: 01/05/2023] Open
Abstract
Retinitis pigmentosa (RP) is a group of visual disorders caused by mutations in over 70 genes. RP is characterized by initial degeneration of rod cells and late cone cell death, regardless of genetic abnormality. Rod cells are the main consumers of oxygen in the retina, and after the death of rod cells, the cone cells have to endure high levels of oxygen, which in turn leads to oxidative damage and cone degeneration. Gypenosides (Gyp) are major dammarane-type saponins of Gynostemma pentaphyllum that are known to reduce oxidative stress and inflammation. In this project we assessed the protective effect of Gyp against cone cell death in the rpgrip1 mutant zebrafish, which recapitulate the classical pathological features found in RP patients. Rpgrip1 mutant zebrafish were treated with Gyp (50 µg/g body weight) from two-months post fertilization (mpf) until 6 mpf. Gyp treatment resulted in a significant decrease in cone cell death compared to that of untreated mutant zebrafish. A markedly low level of reactive oxygen species and increased expression of antioxidant genes were detected in Gyp-incubated mutant zebrafish eyes compared to that of untreated mutant zebrafish. Similarly, the activities of catalase and superoxide dismutase and the level of glutathione were significantly increased in Gyp-treated mutant zebrafish eyes compared to that of untreated mutant zebrafish. Gyp treatment also decreased endoplasmic reticulum stress in rpgrip1 mutant eyes. Expression of proinflammatory cytokines was also significantly decreased in Gyp-treated mutant zebrafish eyes compared to that of untreated mutant zebrafish. Network pharmacology analysis demonstrated that the promotion of cone cell survival by Gyp is possibly mediated by multiple hub genes and associated signalling pathways. These data suggest treatment with Gyp will benefit RP patients.
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Affiliation(s)
- Xing Li
- School of Basic Medical Sciences, Shaoyang University, Shaoyang 422000, China; (X.L.); (Y.C.); (Z.H.)
| | - Reem Hasaballah Alhasani
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK; (R.H.A.); (X.Z.)
- Department of Biology, Faculty of Applied Science, Umm Al-Qura University, Makkah 21961, Saudi Arabia
| | - Yanqun Cao
- School of Basic Medical Sciences, Shaoyang University, Shaoyang 422000, China; (X.L.); (Y.C.); (Z.H.)
| | - Xinzhi Zhou
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK; (R.H.A.); (X.Z.)
| | - Zhiming He
- School of Basic Medical Sciences, Shaoyang University, Shaoyang 422000, China; (X.L.); (Y.C.); (Z.H.)
| | - Zhihong Zeng
- College of Biological and Environmental Engineering, Changsha University, Changsha 410022, China;
| | - Niall Strang
- Department of Vision Science, Glasgow Caledonian University, Glasgow G4 0BA, UK;
| | - Xinhua Shu
- School of Basic Medical Sciences, Shaoyang University, Shaoyang 422000, China; (X.L.); (Y.C.); (Z.H.)
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, UK; (R.H.A.); (X.Z.)
- Department of Vision Science, Glasgow Caledonian University, Glasgow G4 0BA, UK;
- Correspondence:
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20
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CgEnd3 Regulates Endocytosis, Appressorium Formation, and Virulence in the Poplar Anthracnose Fungus Colletotrichum gloeosporioides. Int J Mol Sci 2021; 22:ijms22084029. [PMID: 33919762 PMCID: PMC8103510 DOI: 10.3390/ijms22084029] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 01/23/2023] Open
Abstract
The hemibiotrophic ascomycete fungus Colletotrichum gloeosporioides is the causal agent of anthracnose on numerous plants, and it causes considerable economic losses worldwide. Endocytosis is an essential cellular process in eukaryotic cells, but its roles in C. gloeosporioides remain unknown. In our study, we identified an endocytosis-related protein, CgEnd3, and knocked it out via polyethylene glycol (PEG)-mediated protoplast transformation. The lack of CgEnd3 resulted in severe defects in endocytosis. C. gloeosporioides infects its host through a specialized structure called appressorium, and ΔCgEnd3 showed deficient appressorium formation, melanization, turgor pressure accumulation, penetration ability of appressorium, cellophane membrane penetration, and pathogenicity. CgEnd3 also affected oxidant adaptation and the expression of core effectors during the early stage of infection. CgEnd3 contains one EF hand domain and four calcium ion-binding sites, and it is involved in calcium signaling. A lack of CgEnd3 changed the responses to cell-wall integrity agents and fungicide fludioxonil. However, CgEnd3 regulated appressorium formation and endocytosis in a calcium signaling-independent manner. Taken together, these results demonstrate that CgEnd3 plays pleiotropic roles in endocytosis, calcium signaling, cell-wall integrity, appressorium formation, penetration, and pathogenicity in C. gloeosporioides, and it suggests that CgEnd3 or endocytosis-related genes function as promising antifungal targets.
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Hadalin V, Šuštar M, Volk M, Maver A, Sajovic J, Jarc-Vidmar M, Peterlin B, Hawlina M, Fakin A. Cone Dystrophy Associated with a Novel Variant in the Terminal Codon of the RPGR- ORF15. Genes (Basel) 2021; 12:genes12040499. [PMID: 33805381 PMCID: PMC8066792 DOI: 10.3390/genes12040499] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 12/30/2022] Open
Abstract
Mutations in RPGRORF15 are associated with rod-cone or cone/cone-rod dystrophy, the latter associated with mutations at the distal end. We describe the phenotype associated with a novel variant in the terminal codon of the RPGRORF15 c.3457T>A (Ter1153Lysext*38), which results in a C-terminal extension. Three male patients from two families were recruited, aged 31, 35, and 38 years. Genetic testing was performed by whole exome sequencing. Filtered variants were analysed according to the population frequency, ClinVar database, the variant’s putative impact, and predicted pathogenicity; and were classified according to the ACMG guidelines. Examination included visual acuity (Snellen), colour vision (Ishihara), visual field, fundus autofluorescence (FAF), optical coherence tomography (OCT), and electrophysiology. All patients were myopic, and had central scotoma and reduced colour vision. Visual acuities on better eyes were counting fingers, 0.3 and 0.05. Electrophysiology showed severely reduced cone-specific responses and macular dysfunction, while the rod-specific response was normal. FAF showed hyperautofluorescent ring centred at the fovea encompassing an area of photoreceptor loss approximately two optic discs in diameter (3462–6342 μm). Follow up after 2–11 years showed enlargement of the diameter (avg. 100 μm/year). The novel c.3457T>A (Ter1153Lysext*38) mutation in the terminal RPGRORF15 codon is associated with cone dystrophy, which corresponds to the previously described phenotypes associated with mutations in the distal end of the RPGRORF15. Minimal progression during follow-up years suggests a relatively stable disease after the initial loss of the central cones.
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Affiliation(s)
- Vlasta Hadalin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Maja Šuštar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Marija Volk
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Aleš Maver
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Jana Sajovic
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Martina Jarc-Vidmar
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Borut Peterlin
- Clinical Institute of Medical Genetics, University Medical Centre Ljubljana, Šlajmerjeva ulica 4, 1000 Ljubljana, Slovenia; (M.V.); (A.M.); (B.P.)
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, Grablovičeva 46, 1000 Ljubljana, Slovenia; (V.H.); (M.Š.); (J.S.); (M.J.-V.); (M.H.)
- Correspondence:
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Perrault I, Hanein S, Gérard X, Mounguengue N, Bouyakoub R, Zarhrate M, Fourrage C, Jabot-Hanin F, Bocquet B, Meunier I, Zanlonghi X, Kaplan J, Rozet JM. Whole Locus Sequencing Identifies a Prevalent Founder Deep Intronic RPGRIP1 Pathologic Variant in the French Leber Congenital Amaurosis Cohort. Genes (Basel) 2021; 12:genes12020287. [PMID: 33670832 PMCID: PMC7922592 DOI: 10.3390/genes12020287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/10/2021] [Accepted: 02/16/2021] [Indexed: 01/04/2023] Open
Abstract
Leber congenital amaurosis (LCA) encompasses the earliest and most severe retinal dystrophies and can occur as a non-syndromic or a syndromic disease. Molecular diagnosis in LCA is of particular importance in clinical decision-making and patient care since it can provide ocular and extraocular prognostics and identify patients eligible to develop gene-specific therapies. Routine high-throughput molecular testing in LCA yields 70%–80% of genetic diagnosis. In this study, we aimed to investigate the non-coding regions of one non-syndromic LCA gene, RPGRIP1, in a series of six families displaying one single disease allele after a gene-panel screening of 722 LCA families which identified 26 biallelic RPGRIP1 families. Using trio-based high-throughput whole locus sequencing (WLS) for second disease alleles, we identified a founder deep intronic mutation (NM_020366.3:c.1468-128T>G) in 3/6 families. We employed Sanger sequencing to search for the pathologic variant in unresolved LCA cases (106/722) and identified three additional families (two homozygous and one compound heterozygous with the NM_020366.3:c.930+77A>G deep intronic change). This makes the c.1468-128T>G the most frequent RPGRIP1 disease allele (8/60, 13%) in our cohort. Studying patient lymphoblasts, we show that the pathologic variant creates a donor splice-site and leads to the insertion of the pseudo-exon in the mRNA, which we were able to hamper using splice-switching antisense oligonucleotides (AONs), paving the way to therapies.
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Affiliation(s)
- Isabelle Perrault
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
- Correspondence:
| | - Sylvain Hanein
- Translational Genetics, Institute of Genetic Diseases, INSERM UMR1163, Imagine and Paris Descartes University, 75015 Paris, France;
| | - Xavier Gérard
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| | - Nelson Mounguengue
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| | - Ryme Bouyakoub
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
| | - Mohammed Zarhrate
- Genomics Platform, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France;
| | - Cécile Fourrage
- Bioinformatic Platform, Institute of Genetic Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (C.F.); (F.J.-H.)
| | - Fabienne Jabot-Hanin
- Bioinformatic Platform, Institute of Genetic Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (C.F.); (F.J.-H.)
- Bioinformatics Core Facility, Université Paris Descartes-Structure Fédérative de Recherche Necker, INSERM US24/CNRS UMS3633, 75015 Paris, France
| | - Béatrice Bocquet
- Centre de Référence des Affections Sensorielles Génétiques, Institut des Neurosciences de Montpellier, CHU-Saint Eloi Montpellier, 34091 Montpellier, France; (B.B.); (I.M.)
| | - Isabelle Meunier
- Centre de Référence des Affections Sensorielles Génétiques, Institut des Neurosciences de Montpellier, CHU-Saint Eloi Montpellier, 34091 Montpellier, France; (B.B.); (I.M.)
- National Reference Centre for Inherited Sensory Diseases, Univ Montpellier, CHU, 34091 Montpellier, France
| | - Xavier Zanlonghi
- Eye Clinic Jules Verne, 44300 Nantes, France;
- CHU, 35000 Rennes, France
| | - Josseline Kaplan
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
- Ophthalmology Department, University Hospital Henri Mondor, APHP, 94000 Créteil, France
| | - Jean-Michel Rozet
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetics Diseases, Imagine and Paris Descartes University, 75015 Paris, France; (X.G.); (N.M.); (R.B.); (J.K.); (J.-M.R.)
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23
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Zou X, Fang S, Wu S, Li H, Sun Z, Zhu T, Wei X, Sui R. Detailed comparison of phenotype between male patients carrying variants in exons 1-14 and ORF15 of RPGR. Exp Eye Res 2020; 198:108147. [PMID: 32702353 DOI: 10.1016/j.exer.2020.108147] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 07/05/2020] [Accepted: 07/08/2020] [Indexed: 12/19/2022]
Abstract
PURPOSE To compare disease severity in detail between patients carrying variants in exons 1-14 and ORF15 of retinitis pigmentosa GTPase regulator (RPGR). METHODS Systematic next-generation sequencing data analysis, Sanger sequencing validation and segregation analysis were utilised to identify the pathogenic variants. Detailed ophthalmic examinations, including electroretinograms, fundus photography, fundus autofluorescence and optical coherence tomography were performed. Statistical analysis, including age adjustment and comparison, were performed based on cross-sectional level to compare disease severity between variants in the two RPGR variant groups. RESULTS Sixty-two variants were identified in RPGR in 86 patients from 77 unrelated families. Twenty-nine (37.7%) had variants in RPGR-exons 1-14 (group 1) and 48 (62.3%) in RPGR-ORF15 (group 2). Eighty-four patients were diagnosed with X-linked retinitis pigmentosa and only two patients with cone-rod dystrophy. LogMAR visual acuity increased 0.035 and 0.022 each year on average in group 1 and group 2, respectively. Group 2 patients had better visual acuity with a mean logMAR difference of 0.4378, which is significant after age adjustment (P < 0.01). Neither the value of log (ellipsoid zone width) nor central retinal thickness was significantly correlated with variant grouping after considering the effect of the age variable (P = 0.56 and 0.40, respectively). Spherical refractive error did not differ significantly between the two variant groups (P = 0.17). Patterns of autofluorescence included a hyperfluorescent ring at the posterior pole, diffuse hyperfluorescence in the macular area, and dark macular autofluorescence with or without fovea hyperfluorescence. The age and proportion of fundus autofluorescence patterns between the two variant groups were significantly different (P < 0.01). CONCLUSIONS Patients with variants in exons 1-14 retained less visual acuity than patients with ORF15 variants and deteriorated faster. However, the ellipsoid zone widths, central retinal thickness and refractions were comparable between the two groups. Autofluorescence pattern relates to the age and the variant grouping.
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Affiliation(s)
- Xuan Zou
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Sha Fang
- School of Statistics, Capital University of Economics and Business, Beijing, 100070, China
| | - Shijing Wu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Hui Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Zixi Sun
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Tian Zhu
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Xing Wei
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Ruifang Sui
- Department of Ophthalmology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China.
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De La Camara CMF, Cehajic-Kapetanovic J, MacLaren RE. RPGR gene therapy presents challenges in cloning the coding sequence. Expert Opin Biol Ther 2020; 20:63-71. [PMID: 31612744 PMCID: PMC7104355 DOI: 10.1080/14712598.2020.1680635] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction: Currently, there are three Phase I/II clinical trials based on gene therapy ongoing to test different AAV.RPGR or deleted RPGR vectors on patients affected by X-linked retinitis pigmentosa. These three vectors differ in the adeno-associated viral (AAV) vector capsid used, and the coding sequences: two contain codon optimized versions of RPGR which give the full-length protein, whilst the third uses a wild-type sequence that contains a large deletion encoding part of the functional domain of the RPGR protein.Areas covered: This review approaches the different studies that have led to the initiation of three different clinical trials for RPGR related X-linked retinitis pigmentosa.Expert opinion: The development of a gene therapy vector to deliver a normal copy of the RPGR gene into the photoreceptors has presented a challenge for the scientific community. The instability of its sequence and the fact that its function is not well understood can lead to the production of a nonfunctional or deleterious protein for the human retina. Since the RPGR protein undergoes post-translational glutamylation in the protein domain that may be particularly affected by gene instability, a functional assay of glutamylation is essential to verify the correct coding sequence.
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Affiliation(s)
- Cristina Martinez-Fernandez De La Camara
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, John Radcliffe Hospital, Headley Way, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Headley Way, UK
| | - Jasmina Cehajic-Kapetanovic
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, John Radcliffe Hospital, Headley Way, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Headley Way, UK
| | - Robert E. MacLaren
- Department of Clinical Neurosciences, Nuffield Laboratory of Ophthalmology, University of Oxford, John Radcliffe Hospital, Headley Way, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Headley Way, UK
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25
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Zhang Z, Dai H, Wang L, Tao T, Xu J, Sun X, Yang L, Li G. Novel mutations of RPGR in Chinese families with X-linked retinitis pigmentosa. BMC Ophthalmol 2019; 19:240. [PMID: 31775781 PMCID: PMC6882249 DOI: 10.1186/s12886-019-1250-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/18/2019] [Indexed: 12/15/2022] Open
Abstract
Background RP (retinitis pigmentosa) is a group of hereditary retinal degenerative diseases. XLRP is a relatively severe subtype of RP. Thus, it is necessary to identify genes and mutations in patients who present with X-linked retinitis pigmentosa. Methods Genomic DNA was extracted from peripheral blood. The coding regions and intron-exon boundaries of the retinitis pigmentosa GTPase regulator (RPGR) and RP2 genes were amplified by PCR and then sequenced directly. Ophthalmic examinations were performed to identify affected individuals from two families and to characterize the phenotype of the disease. Results Mutation screening demonstrated two novel nonsense mutations (c.1541C > G; p.S514X and c.2833G > T; p.E945X) in the RPGR gene. The clinical manifestation of family 1 with mutations in exon 13 was mild. Genotype-phenotype correlation analysis suggested that patients with mutations close to the downstream region of ORF15 in family 2 manifested an early loss of cone function. Family 2 carried a nonsense mutation in ORF15 that appeared to have a semi-dominant pattern of inheritance. All male patients and two female carriers in family 2 manifested pathological myopia (PM), indicating that there may be a distinctive X-linked genotype-phenotype correlation between RP and PM. Conclusions We identified two novel mutations of the RPGR gene, which broadens the spectrum of RPGR mutations and the phenotypic spectrum of the disease in Chinese families.
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Affiliation(s)
- Zhimeng Zhang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Hehua Dai
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Lei Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Tianchang Tao
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Jing Xu
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Xiaowei Sun
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Liping Yang
- Department of Ophthalmology, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Peking University Third Hospital, Beijing, People's Republic of China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China.
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26
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Takahashi VKL, Xu CL, Takiuti JT, Apatoff MBL, Duong JK, Mahajan VB, Tsang SH. Comparison of structural progression between ciliopathy and non-ciliopathy associated with autosomal recessive retinitis pigmentosa. Orphanet J Rare Dis 2019; 14:187. [PMID: 31370859 PMCID: PMC6676605 DOI: 10.1186/s13023-019-1163-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 07/22/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND To evaluate and compare the progression of ciliopathy and non-ciliopathy autosomal recessive Retinitis Pigmentosa patients (arRP) by measuring the constriction of hyperautofluorescent rings in fundus autofluorescence (FAF) images and the progressive shortening of the ellipsoid zone line width obtained by spectral-domain optical coherence tomography (SD-OCT). RESULTS For the ciliopathy group, the estimated mean shortening of the ellipsoid zone line was 259 μm per year and the ring area decreased at a rate of 2.46 mm2 per year. For the non-ciliopathy group, the estimated mean shortening of the ellipsoid zone line was 84 μm per year and the ring area decreased at a rate of 0.7 mm2 per year. CONCLUSIONS Our study was able to quantify and compare the loss of EZ line width and short-wavelength autofluorescence (SW-AF) ring constriction progression over time for ciliopathy and non-ciliopathy arRP genes. These results may serve as a basis for modeling RP disease progression, and furthermore, they could potentially be used as endpoints in clinical trials seeking to promote cone and rod survival in RP patients.
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Affiliation(s)
- Vitor K L Takahashi
- Department of Ophthalmology, Columbia University, New York, NY, USA.,Jonas Children's Vision Care, and the Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Columbia Stem Cell Initiative, Institute of Human Nutrition, Columbia University, New York, NY, USA.,Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil
| | - Christine L Xu
- Department of Ophthalmology, Columbia University, New York, NY, USA.,Jonas Children's Vision Care, and the Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Columbia Stem Cell Initiative, Institute of Human Nutrition, Columbia University, New York, NY, USA
| | - Júlia T Takiuti
- Department of Ophthalmology, Columbia University, New York, NY, USA.,Jonas Children's Vision Care, and the Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Columbia Stem Cell Initiative, Institute of Human Nutrition, Columbia University, New York, NY, USA.,Division of Ophthalmology, University of São Paulo Medical School, São Paulo, Brazil
| | - Mary Ben L Apatoff
- Department of Ophthalmology, Columbia University, New York, NY, USA.,Jonas Children's Vision Care, and the Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Columbia Stem Cell Initiative, Institute of Human Nutrition, Columbia University, New York, NY, USA
| | - Jimmy K Duong
- Department of Biostatistics, Columbia University, New York, NY, USA
| | - Vinit B Mahajan
- Byers Eye Institute, Omics Laboratory, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, USA.,Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Stephen H Tsang
- Department of Ophthalmology, Columbia University, New York, NY, USA. .,Jonas Children's Vision Care, and the Bernard & Shirlee Brown Glaucoma Laboratory, Departments of Ophthalmology, Pathology & Cell Biology, Columbia Stem Cell Initiative, Institute of Human Nutrition, Columbia University, New York, NY, USA. .,Department of Pathology & Cell Biology, Stem Cell Initiative (CSCI), Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, NY, USA. .,Harkness Eye Institute, Columbia University Medical Center, 635 West 165th Street, Box 212, New York, NY, 10032, USA.
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27
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Zhang X, Shahani U, Reilly J, Shu X. Disease mechanisms and neuroprotection by tauroursodeoxycholic acid in Rpgr knockout mice. J Cell Physiol 2019; 234:18801-18812. [PMID: 30924157 DOI: 10.1002/jcp.28519] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/22/2019] [Accepted: 03/06/2019] [Indexed: 12/16/2022]
Abstract
Mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene are the predominant cause of retinitis pigmentosa. RPGR plays a critical role as a scaffold protein in the regulation of protein trafficking from the basal body to the axoneme, where the cargoes are transported to the outer segments (OSs) of photoreceptors. This trafficking process is controlled directly by intraflagellar transport complexes and regulated by the RPGR protein complex, although the precise mechanisms have yet to be defined. We used an Rpgr conditional knockout (cko) mouse model to investigate the disease mechanisms during retinal degeneration and to evaluate the protective effects of tauroursodeoxycholic acid (TUDCA). Rhodopsin, cone opsins and transducin were mislocalized in Rpgr cko photoreceptors, while localization of NPHP4 to connecting cilia was absent, suggesting that RPGR is required for ciliary protein trafficking. Microglia were activated in advance of retinal degeneration in Rpgr cko mouse retinas. TUDCA treatment suppressed microglial activation and inflammation and prevented photoreceptor degeneration in Rpgr cko mice. Our data demonstrated that TUDCA has therapeutic potential for RPGR-associated RP patients.
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Affiliation(s)
- Xun Zhang
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, Scotland
| | - Uma Shahani
- Department of Vision Science, Glasgow Caledonian University, Glasgow, Scotland
| | - James Reilly
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, Scotland
| | - Xinhua Shu
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, Scotland.,Department of Vision Science, Glasgow Caledonian University, Glasgow, Scotland
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28
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Jamshidi F, Place EM, Mehrotra S, Navarro-Gomez D, Maher M, Branham KE, Valkanas E, Cherry TJ, Lek M, MacArthur D, Pierce EA, Bujakowska KM. Contribution of noncoding pathogenic variants to RPGRIP1-mediated inherited retinal degeneration. Genet Med 2018; 21:694-704. [PMID: 30072743 PMCID: PMC6399075 DOI: 10.1038/s41436-018-0104-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/15/2018] [Indexed: 11/22/2022] Open
Abstract
Purpose: With the advent of gene therapies for inherited retinal degenerations (IRDs), genetic diagnostics will have an increasing role in clinical decision-making. Yet the genetic cause of disease cannot be identified using exon-based sequencing for a significant portion of patients. We hypothesized that non-coding mutations contribute significantly to the genetic causality of IRDs and evaluated patients with single coding mutations in RPGRIP1 to test this hypothesis. Methods: IRD families underwent targeted panel sequencing. Unsolved cases were explored by whole exome and genome sequencing looking for additional mutations. Candidate mutations were then validated by Sanger sequencing, quantitative PCR, and in vitro splicing assays in two cell lines analyzed through amplicon sequencing. Results: Among 1722 families, three had biallelic loss of function mutations in RPGRIP1 while seven had a single disruptive coding mutation. Whole exome and genome sequencing revealed potential non-coding mutations in these seven families. In six, the non-coding mutations were shown to lead to loss of function in vitro. Conclusion: Non-coding mutations were identified in 6 of 7 families with single coding mutations in RPGRIP1. The results suggest that non-coding mutations contribute significantly to the genetic causality of IRDs and RPGRIP1–mediated IRDs are more common than previously thought.
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Affiliation(s)
- Farzad Jamshidi
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Emily M Place
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Sudeep Mehrotra
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Daniel Navarro-Gomez
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Mathew Maher
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Kari E Branham
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Elise Valkanas
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Boston, Massachusetts, USA
| | - Timothy J Cherry
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute and University of Washington, Department of Pediatrics, Seattle, Washington, USA
| | - Monkol Lek
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Boston, Massachusetts, USA.,Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Daniel MacArthur
- Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Boston, Massachusetts, USA.,Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Eric A Pierce
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA.
| | - Kinga M Bujakowska
- Ocular Genomics Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA.
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29
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Patnaik SR, Zhang X, Biswas L, Akhtar S, Zhou X, Kusuluri DK, Reilly J, May-Simera H, Chalmers S, McCarron JG, Shu X. RPGR protein complex regulates proteasome activity and mediates store-operated calcium entry. Oncotarget 2018; 9:23183-23197. [PMID: 29796181 PMCID: PMC5955404 DOI: 10.18632/oncotarget.25259] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 04/07/2018] [Indexed: 11/25/2022] Open
Abstract
Ciliopathies are a group of genetically heterogeneous disorders, characterized by defects in cilia genesis or maintenance. Mutations in the RPGR gene and its interacting partners, RPGRIP1 and RPGRIP1L, cause ciliopathies, but the function of their proteins remains unclear. Here we show that knockdown (KD) of RPGR, RPGRIP1 or RPGRIP1L in hTERT-RPE1 cells results in abnormal actin cytoskeleton organization. The actin cytoskeleton rearrangement is regulated by the small GTPase RhoA via the planar cell polarity (PCP) pathway. RhoA activity was upregulated in the absence of RPGR, RPGRIP1 or RPGRIP1L proteins. In RPGR, RPGRIP1 or RPGRIP1L KD cells, we observed increased levels of DVl2 and DVl3 proteins, the core components of the PCP pathway, due to impaired proteasomal activity. RPGR, RPGRIP1 or RPGRIP1L KD cells treated with thapsigargin (TG), an inhibitor of sarcoendoplasmic reticulum Ca2+- ATPases, showed impaired store-operated Ca2+ entry (SOCE), which is mediated by STIM1 and Orai1 proteins. STIM1 was not localized to the ER-PM junction upon ER store depletion in RPGR, RPGRIP1 or RPGRIP1L KD cells. Our results demonstrate that the RPGR protein complex is required for regulating proteasomal activity and for modulating SOCE, which may contribute to the ciliopathy phenotype.
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Affiliation(s)
- Sarita Rani Patnaik
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
- Institute of Molecular Physiology, Johannes Gutenberg-Universität Mainz, D-55128 Mainz, Germany
| | - Xun Zhang
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
| | - Lincoln Biswas
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
| | - Saeed Akhtar
- Cornea Research Chair, Department of Optometry, King Saud University, Riyadh 11433, Kingdom of Saudi Arabia
| | - Xinzhi Zhou
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
| | - Deva Krupakar Kusuluri
- Institute of Molecular Physiology, Johannes Gutenberg-Universität Mainz, D-55128 Mainz, Germany
| | - James Reilly
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
| | - Helen May-Simera
- Institute of Molecular Physiology, Johannes Gutenberg-Universität Mainz, D-55128 Mainz, Germany
| | - Susan Chalmers
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, Scotland
| | - John G. McCarron
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0RE, Scotland
| | - Xinhua Shu
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland
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30
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Martinez-Fernandez De La Camara C, Nanda A, Salvetti AP, Fischer MD, MacLaren RE. Gene therapy for the treatment of X-linked retinitis pigmentosa. Expert Opin Orphan Drugs 2018; 6:167-177. [PMID: 30057863 PMCID: PMC6059358 DOI: 10.1080/21678707.2018.1444476] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
INTRODUCTION X-linked retinitis pigmentosa caused by mutations in the retinitis pigmentosa GTPase regulator (RPGR) gene is the most common form of recessive RP. The phenotype is characterised by its severity and rapid disease progression. Gene therapy using adeno-associated viral vectors is currently the most promising therapeutic approach. However, the construction of a stable vector encoding the full-length RPGR transcript has previously proven to be a limiting step towards gene therapy clinical trials. Recently however, a codon optimised version of RPGR has been shown to increase the stability and fidelity of the sequence, conferring a therapeutic effect in murine and canine animal models. AREAS COVERED This manuscript reviews the natural history of X-linked retinitis pigmentosa and the research performed from the discovery of the causative gene, RPGR, to the preclinical testing of potential therapies that have led to the initiation of three clinical trials. EXPERT OPINION X-linked retinitis pigmentosa is an amenable disease to be treated by gene therapy. Codon optimisation has overcome the challenge of designing an RPGR vector without mutations, and with a therapeutic effect in different animal models. With the RPGR gene therapy clinical trials still in the early stages, the confirmation of the safety, tolerability and potency of the therapy is still ongoing.
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Affiliation(s)
| | - Anika Nanda
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Oxford, UK
| | - Anna Paola Salvetti
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Sacco Hospital, University of Milan, Milano, Italy
| | - M. Dominik Fischer
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Centre for Ophthalmology Tübingen, University Eye Hospital, Tübingen, Germany
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford, UK
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, John Radcliffe Hospital, Oxford, UK
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31
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Eblimit A, Agrawal SA, Thomas K, Anastassov IA, Abulikemu T, Moayedi Y, Mardon G, Chen R. Conditional loss of Spata7 in photoreceptors causes progressive retinal degeneration in mice. Exp Eye Res 2018; 166:120-130. [PMID: 29100828 PMCID: PMC5756513 DOI: 10.1016/j.exer.2017.10.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 10/10/2017] [Accepted: 10/13/2017] [Indexed: 12/31/2022]
Abstract
The mammalian retina consists of multiple cell layers including photoreceptor cells, which are light sensing neurons that play essential functions in the visual process. Previously, we identified mutations in SPATA7, encoding spermatogenesis associated protein 7, in families with Leber Congenital Amaurosis (LCA) and juvenile Retinitis Pigmentosa (RP), and showed that Spata7 null mice recapitulate the human disease phenotype of retinal degeneration. SPATA7 is expressed in the connecting cilium of photoreceptor (PR) cells in the mouse retina, as well as in retinal pigment epithelium (RPE) cells, but the functional role of Spata7 in the RPE remains unknown. To investigate whether Spata7 is required in PRs, the RPE, or both, we conditionally knocked out Spata7 in photoreceptors and RPE cells using Crx-Cre and Best1-Cre transgenic mouse lines, respectively. In Spata7 photoreceptor-specific conditional (cKO) mice, both rod and cone photoreceptor dysfunction and degeneration is observed, characterized by progressive thinning of the outer nuclear layer and reduced response to light; however, RPE-specific deletion of Spata7 does not impair retinal function or cell survival. Furthermore, our findings show that both Rhodopsin and RPGRIP1 are mislocalized in the Spata7Flox/-; Crx-Cre cKO mice, suggesting that loss of Spata7 in photoreceptors alone can result in altered trafficking of these proteins in the connecting cilium. Together, our findings suggest that loss of Spata7 in photoreceptors alone is sufficient to cause photoreceptor degeneration, but its function in the RPE is not required for photoreceptor survival; therefore, loss of Spata7 in photoreceptors alters both rod and cone function and survival, consistent with the clinical phenotypes observed in LCA and RP patients with mutations in SPATA7.
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Affiliation(s)
- Aiden Eblimit
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA
| | - Smriti Akshay Agrawal
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA
| | - Kandace Thomas
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA
| | - Ivan Assenov Anastassov
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030-3411, USA
| | - Tajiguli Abulikemu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA; The Key Laboratory of Plant Resources and Chemistry of Arid Zone, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, Xinjiang, 830011, China
| | | | - Graeme Mardon
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030-3411, USA.
| | - Rui Chen
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX 77030-3411, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030-3411, USA.
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32
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Rpgrip1 is required for rod outer segment development and ciliary protein trafficking in zebrafish. Sci Rep 2017; 7:16881. [PMID: 29203866 PMCID: PMC5715152 DOI: 10.1038/s41598-017-12838-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 09/14/2017] [Indexed: 12/23/2022] Open
Abstract
Mutations in the RPGR-interacting protein 1 (RPGRIP1) gene cause recessive Leber congenital amaurosis (LCA), juvenile retinitis pigmentosa (RP) and cone-rod dystrophy. RPGRIP1 interacts with other retinal disease-causing proteins and has been proposed to have a role in ciliary protein transport; however, its function remains elusive. Here, we describe a new zebrafish model carrying a nonsense mutation in the rpgrip1 gene. Rpgrip1homozygous mutants do not form rod outer segments and display mislocalization of rhodopsin, suggesting a role for RPGRIP1 in rhodopsin-bearing vesicle trafficking. Furthermore, Rab8, the key regulator of rhodopsin ciliary trafficking, was mislocalized in photoreceptor cells of rpgrip1 mutants. The degeneration of rod cells is early onset, followed by the death of cone cells. These phenotypes are similar to that observed in LCA and juvenile RP patients. Our data indicate RPGRIP1 is necessary for rod outer segment development through regulating ciliary protein trafficking. The rpgrip1 mutant zebrafish may provide a platform for developing therapeutic treatments for RP patients.
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May-Simera H, Nagel-Wolfrum K, Wolfrum U. Cilia - The sensory antennae in the eye. Prog Retin Eye Res 2017; 60:144-180. [PMID: 28504201 DOI: 10.1016/j.preteyeres.2017.05.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 05/04/2017] [Accepted: 05/08/2017] [Indexed: 12/21/2022]
Abstract
Cilia are hair-like projections found on almost all cells in the human body. Originally believed to function merely in motility, the function of solitary non-motile (primary) cilia was long overlooked. Recent research has demonstrated that primary cilia function as signalling hubs that sense environmental cues and are pivotal for organ development and function, tissue hoemoestasis, and maintenance of human health. Cilia share a common anatomy and their diverse functional features are achieved by evolutionarily conserved functional modules, organized into sub-compartments. Defects in these functional modules are responsible for a rapidly growing list of human diseases collectively termed ciliopathies. Ocular pathogenesis is common in virtually all classes of syndromic ciliopathies, and disruptions in cilia genes have been found to be causative in a growing number of non-syndromic retinal dystrophies. This review will address what is currently known about cilia contribution to visual function. We will focus on the molecular and cellular functions of ciliary proteins and their role in the photoreceptor sensory cilia and their visual phenotypes. We also highlight other ciliated cell types in tissues of the eye (e.g. lens, RPE and Müller glia cells) discussing their possible contribution to disease progression. Progress in basic research on the cilia function in the eye is paving the way for therapeutic options for retinal ciliopathies. In the final section we describe the latest advancements in gene therapy, read-through of non-sense mutations and stem cell therapy, all being adopted to treat cilia dysfunction in the retina.
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Affiliation(s)
- Helen May-Simera
- Institute of Molecular Physiology, Cilia Biology, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Kerstin Nagel-Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany.
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Glaviano A, Smith AJ, Blanco A, McLoughlin S, Cederlund ML, Heffernan T, Sapetto-Rebow B, Alvarez Y, Yin J, Kennedy BN. A method for isolation of cone photoreceptors from adult zebrafish retinae. BMC Neurosci 2016; 17:71. [PMID: 27821066 PMCID: PMC5100264 DOI: 10.1186/s12868-016-0307-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 10/31/2016] [Indexed: 11/08/2022] Open
Abstract
Background Cone photoreceptors are specialised sensory retinal neurons responsible for photopic vision, colour perception and visual acuity. Retinal degenerative diseases are a heterogeneous group of eye diseases in which the most severe vision loss typically arises from cone photoreceptor dysfunction or degeneration. Establishing a method to purify cone photoreceptors from retinal tissue can accelerate the identification of key molecular determinants that underlie cone photoreceptor development, survival and function. The work herein describes a new method to purify enhanced green fluorescent protein (EGFP)-labelled cone photoreceptors from adult retina of Tg(3.2gnat2:EGFP) zebrafish. Results Methods for dissecting adult zebrafish retinae, cell dissociation, cell sorting, RNA isolation and RNA quality control were optimised. The dissociation protocol, carried out with ~30 retinae from adult zebrafish, yielded approximately 6 × 106 cells. Flow cytometry cell sorting subsequently distinguished 1 × 106 EGFP+ cells and 4 × 106 EGFP− cells. Electropherograms confirmed downstream isolation of high-quality RNA with RNA integrity number (RIN) >7.6 and RNA concentration >5.7 ng/µl obtained from both populations. Reverse Transcriptase-PCR confirmed that the EGFP-positive cell populations express known genetic markers of cone photoreceptors that were not expressed in the EGFP-negative cell population whereas a rod opsin amplicon was only detected in the EGFP-negative retinal cell population. Conclusions This work describes a valuable adult zebrafish cone photoreceptor isolation methodology enabling future identification of cone photoreceptor-enriched genes, proteins and signalling networks responsible for their development, survival and function. In addition, this advancement facilitates the identification of novel candidate genes for inherited human blindness.
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Affiliation(s)
- Antonino Glaviano
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland
| | - Andrew J Smith
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland
| | - Alfonso Blanco
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland
| | - Sarah McLoughlin
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland
| | - Maria L Cederlund
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland
| | - Theresa Heffernan
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland
| | - Beata Sapetto-Rebow
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland
| | - Yolanda Alvarez
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland
| | - Jun Yin
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland
| | - Breandán N Kennedy
- UCD School of Biomolecular & Biomedical Science, UCD Conway Institute, University College Dublin, Dublin, D04 V1W8, Ireland.
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Retinal transcriptome sequencing sheds light on the adaptation to nocturnal and diurnal lifestyles in raptors. Sci Rep 2016; 6:33578. [PMID: 27645106 PMCID: PMC5028738 DOI: 10.1038/srep33578] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 08/31/2016] [Indexed: 01/06/2023] Open
Abstract
Owls (Strigiformes) represent a fascinating group of birds that are the ecological night-time counterparts to diurnal raptors (Accipitriformes). The nocturnality of owls, unusual within birds, has favored an exceptional visual system that is highly tuned for hunting at night, yet the molecular basis for this adaptation is lacking. Here, using a comparative evolutionary analysis of 120 vision genes obtained by retinal transcriptome sequencing, we found strong positive selection for low-light vision genes in owls, which contributes to their remarkable nocturnal vision. Not surprisingly, we detected gene loss of the violet/ultraviolet-sensitive opsin (SWS1) in all owls we studied, but two other color vision genes, the red-sensitive LWS and the blue-sensitive SWS2, were found to be under strong positive selection, which may be linked to the spectral tunings of these genes toward maximizing photon absorption in crepuscular conditions. We also detected the only other positively selected genes associated with motion detection in falcons and positively selected genes associated with bright-light vision and eye protection in other diurnal raptors (Accipitriformes). Our results suggest the adaptive evolution of vision genes reflect differentiated activity time and distinct hunting behaviors.
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Appelbaum T, Becker D, Santana E, Aguirre GD. Molecular studies of phenotype variation in canine RPGR-XLPRA1. Mol Vis 2016; 22:319-31. [PMID: 27122963 PMCID: PMC4830396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 04/07/2016] [Indexed: 11/02/2022] Open
Abstract
PURPOSE Canine X-linked progressive retinal atrophy 1 (XLPRA1) caused by a mutation in retinitis pigmentosa (RP) GTPase regulator (RPGR) exon ORF15 showed significant variability in disease onset in a colony of dogs that all inherited the same mutant X chromosome. Defective protein trafficking has been detected in XLPRA1 before any discernible degeneration of the photoreceptors. We hypothesized that the severity of the photoreceptor degeneration in affected dogs may be associated with defects in genes involved in ciliary trafficking. To this end, we examined six genes as potential disease modifiers. We also examined the expression levels of 24 genes involved in ciliary trafficking (seven), visual pathway (five), neuronal maintenance genes (six), and cellular stress response (six) to evaluate their possible involvement in early stages of the disease. METHODS Samples from a pedigree derived from a single XLPRA1-affected male dog outcrossed to unrelated healthy mix-bred or purebred females were used for immunohistochemistry (IHC), western blot, mutational and haplotype analysis, and gene expression (GE). Cell-specific markers were used to examine retinal remodeling in the disease. Single nucleotide polymorphisms (SNPs) spanning the entire RPGR interacting and protein trafficking genes (RAB8A, RPGRIP1L, CEP290, CC2D2A, DFNB31, and RAB11B) were genotyped in the pedigree. Quantitative real-time PCR (qRT-PCR) was used to examine the expression of a total of 24 genes, including the six genes listed. RESULTS Examination of cryosections from XLPRA1-affected animals of similar age (3-4 years) with different disease severity phenotype revealed mislocalization of opsins and upregulation of the Müller cell gliosis marker GFAP. Four to ten haplotypes per gene were identified in RAB8A, RPGRIP1L, CEP290, CC2D2A, DFNB31, and RAB11B for further assessment as potential genetic modifiers of XLPRA1. No correlation was found between the haplotypes and disease severity. During mutational analysis, several new variants, including a single intronic mutation in RAB8A and three mutations in exon 3 of DFNB31 were described (c.970G>A (V324I), c.978T>C (G326=), and c.985G>A (A329T)). Expression analysis of stress response genes in 16-week-old predisease XLPRA1 retinas revealed upregulation of GFAP but not HSPA5, DDIT3, HSPA4, HSP90B1, or HIF1A. Western blot analysis confirmed GFAP upregulation. In the same predisease group, no significant differences were found in the expression of 18 selected genes (RHO, OPN1LW, OPN1MW, RLBP1, RPGRORF15, RAB8A, RPGRIP1L, CEP290, CC2D2A, DFNB31, RAB11B, CRX, RCVRN, PVALB, CALB1, FGFR1, NTRK2, and NTRK3) involved in neuronal function. CONCLUSIONS Lack of association between haplotypes of RAB8A, RPGRIP1L, CEP290, CC2D2A, DFNB31, and RAB11B and the disease phenotype suggests that these genes are not genetic modifiers of XLPRA1. Upregulation of GFAP, an established indicator of the Müller cell gliosis, manifests as an important early feature of the disease.
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Falk N, Lösl M, Schröder N, Gießl A. Specialized Cilia in Mammalian Sensory Systems. Cells 2015; 4:500-19. [PMID: 26378583 PMCID: PMC4588048 DOI: 10.3390/cells4030500] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 08/04/2015] [Accepted: 09/09/2015] [Indexed: 02/01/2023] Open
Abstract
Cilia and flagella are highly conserved and important microtubule-based organelles that project from the surface of eukaryotic cells and act as antennae to sense extracellular signals. Moreover, cilia have emerged as key players in numerous physiological, developmental, and sensory processes such as hearing, olfaction, and photoreception. Genetic defects in ciliary proteins responsible for cilia formation, maintenance, or function underlie a wide array of human diseases like deafness, anosmia, and retinal degeneration in sensory systems. Impairment of more than one sensory organ results in numerous syndromic ciliary disorders like the autosomal recessive genetic diseases Bardet-Biedl and Usher syndrome. Here we describe the structure and distinct functional roles of cilia in sensory organs like the inner ear, the olfactory epithelium, and the retina of the mouse. The spectrum of ciliary function in fundamental cellular processes highlights the importance of elucidating ciliopathy-related proteins in order to find novel potential therapies.
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Affiliation(s)
- Nathalie Falk
- Department of Biology, Animal Physiology, University of Erlangen-Nuremberg, 91058 Erlangen, Germany.
| | - Marlene Lösl
- Department of Biology, Animal Physiology, University of Erlangen-Nuremberg, 91058 Erlangen, Germany.
| | - Nadja Schröder
- Department of Biology, Animal Physiology, University of Erlangen-Nuremberg, 91058 Erlangen, Germany.
| | - Andreas Gießl
- Department of Biology, Animal Physiology, University of Erlangen-Nuremberg, 91058 Erlangen, Germany.
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