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Baxter MF, Borchert GA. Gene Therapy for Achromatopsia. Int J Mol Sci 2024; 25:9739. [PMID: 39273686 DOI: 10.3390/ijms25179739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 08/23/2024] [Accepted: 09/01/2024] [Indexed: 09/15/2024] Open
Abstract
Achromatopsia is the most common cone dysfunction syndrome, affecting 1 in 30,000 people. It is an autosomal recessive disorder with a heterogeneous genetic background with variants reported in CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6. Up to 90% of achromatopsia patients harbour mutations in CNGA3 or CNB3, which encode for the alpha and beta subunits of the cone cyclic nucleotide-gated (CNG) channel in cone-specific phototransduction. The condition presents at birth or early infancy with poor visual acuity, nystagmus, photophobia, and colour vision loss in all axes. Multimodal retinal imaging has provided insightful information to characterise achromatopsia patients based on their genotype. There is no FDA-approved treatment for achromatopsia; however, studies have reported several preclinical gene therapies with anatomical and functional improvements reported in vivo. There are currently five gene therapy clinical trials registered for human patients at the phase I/II stage and for CNGA3 or CNGB3 causing achromatopsia. This review aims to discuss the genetics of achromatopsia, genotypic and phenotypic correlations in multimodal retinal imaging, and the developments and challenges in gene therapy clinical trials.
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Affiliation(s)
- Megan F Baxter
- Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 9DU, UK
- School of Medicine and Dentistry, Griffith University, Gold Coast 4215, Australia
| | - Grace A Borchert
- School of Medicine and Dentistry, Griffith University, Gold Coast 4215, Australia
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Oxford Eye Hospital, Oxford University NHS Foundation Trust, Oxford OX3 9DU, UK
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Andersen MKG, Bertelsen M, Gundestrup S, Grønskov K, Kessel L. Phenotypic characteristics of Danish patients with achromatopsia. Acta Ophthalmol 2024; 102:e893-e905. [PMID: 38348755 DOI: 10.1111/aos.16656] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/20/2023] [Accepted: 01/27/2024] [Indexed: 08/07/2024]
Abstract
PURPOSE To describe the phenotype of Danish patients with genetically verified achromatopsia (ACHM) with special focus on signs of progression on structural or functional parameters, and possible genotype-phenotype correlations. METHODS Forty-eight patients were identified, with disease-causing variants in five different genes: CNGA3, CNGB3, GNAT2, PDE6C and PDE6H. Longitudinal evaluation was possible for 11 patients and 27 patients participated in a renewed in-depth phenotyping consisting of visual acuity assessment, optical coherence tomography (OCT), fundus autofluorescence, colour vision evaluation, contrast sensitivity, mesopic microperimetry and full-field electroretinography. Foveal morphology was evaluated based on OCT images for all 48 patients using a grading system based on the integrity of the hyperreflective photoreceptor band, the inner segment ellipsoid zone (ISe). Signs of progression were evaluated based on longitudinal data and correlation with age. RESULTS We found a statistically significant positive correlation between OCT grade and age (Spearman ρ = 0.62, p < 0.0001) and we observed changes in the foveal morphology in 2 of 11 patients with ≥5 years of follow-up. We did not find any convincing correlation between age and functional parameters (visual acuity, retinal sensitivity and contrast sensitivity) nor did we find correlation between structural and functional parameters, or any clear genotype-phenotype correlation. CONCLUSIONS Some patients with ACHM demonstrate signs of progressive foveal changes in OCT characteristics with increasing age. This is relevant in terms of possible new treatments. However, functional characteristics, such as visual acuity, remained stable despite changing foveal structure. Thus, seen from a patient perspective, ACHM can still be considered a non-progressive condition.
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Affiliation(s)
- Mette K G Andersen
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, Glostrup, Denmark
| | - Mette Bertelsen
- Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Svend Gundestrup
- Department of Multidisease, Copenhagen University Hospital, North Zealand, Denmark
| | - Karen Grønskov
- Department of Clinical Genetics, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Line Kessel
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet, Glostrup, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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Righetti G, Kempf M, Kohl S, Wissinger B, Kühlewein L, Stingl K, Stingl K. S-cone contribution to oscillatory potentials in patients with blue cone monochromacy. Doc Ophthalmol 2024; 149:11-21. [PMID: 38871951 PMCID: PMC11236933 DOI: 10.1007/s10633-024-09981-y] [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: 03/28/2024] [Accepted: 06/06/2024] [Indexed: 06/15/2024]
Abstract
PURPOSE The aim of this exploratory study is to investigate the role of S-cones in oscillatory potentials (OPs) generation by individuals with blue-cone monochromacy (BCM), retaining S-cones, and achromatopsia (ACHM), lacking cone functions. METHODS This retrospective study analyzed data from 39 ACHM patients, 20 BCM patients, and 26 controls. Central foveal thickness was obtained using spectral-domain optical coherence tomography, while amplitude and implicit time (IT) of a- and b-waves were extracted from the ISCEV Standard dark-adapted 3 cd.s.m-2 full-field ERG (ffERG). Time-frequency analysis of the same measurement enabled the extraction of OPs, providing insights into the dynamic characteristics of the recorded signal. RESULTS Both ACHM and BCM groups showed a significant reduction (p < .00001) of a- and b-wave amplitudes and ITs as well as the power of the OPs compared to the control groups. The comparison between ACHM and BCM didn't show any statistically significant differences in the electrophysiological parameters. The analysis of covariance revealed significantly reduced central foveal thickness in the BCM group compared to ACHM and controls (p < .00001), and in ACHM compared to controls (p < .00001), after age correction and Tukey post-hoc analysis. CONCLUSIONS S-cones do not significantly influence OPs, and the decline in OPs' power is not solely due to a reduced a-wave. This suggests a complex non-linear network influenced by photoreceptor inputs. Morphological changes don't correlate directly with functional alterations, prompting further exploration of OPs' function and physiological role.
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Affiliation(s)
- Giulia Righetti
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076, Tübingen, Germany.
| | - Melanie Kempf
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, 72076, Tübingen, Germany
| | - Susanne Kohl
- Molecular Genetics Laboratory, Center for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Center for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, 72076, Tübingen, Germany
| | - Laura Kühlewein
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076, Tübingen, Germany
- Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Katarina Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, 72076, Tübingen, Germany
| | - Krunoslav Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, 72076, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, 72076, Tübingen, Germany
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Nouri Z, Sarmadi A, Narrei S, Kianersi H, Kianersi F, Tabatabaiefar MA. Clinical characterizations and molecular genetic study of two co-segregating variants in PDZD7 and PDE6C genes leading simultaneously to non-syndromic hearing loss and achromatopsia. BMC Med Genomics 2024; 17:173. [PMID: 38956522 PMCID: PMC11218353 DOI: 10.1186/s12920-024-01942-3] [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: 10/08/2023] [Accepted: 06/19/2024] [Indexed: 07/04/2024] Open
Abstract
BACKGROUND Autosomal recessive non-syndromic hearing loss (NSHL) and cone dystrophies (CODs) are highly genetically and phenotypically heterogeneous disorders. In this study, we applied the whole exome sequencing (WES) to find the cause of HL and COD in an Iranian consanguineous family with three affected individuals. METHODS Three members from an Iranian consanguineous family who were suffering from NSHL and visual impairment were ascertained in this study. Comprehensive clinical evaluations and genetic analysis followed by bioinformatic and co-segregation studies were performed to diagnose the cause of these phenotypes. Data were collected from 2020 to 2022. RESULTS All cases showed congenital bilateral NSHL, decreased visual acuity, poor color discrimination, photophobia and macular atrophy. Moreover, cornea, iris and anterior vitreous were within normal limit in both eyes, decreased foveal sensitivity, central scotoma and generalized depression of visual field were seen in three cases. WES results showed two variants, a novel null variant (p.Trp548Ter) in the PDE6C gene causing COD type 4 (Achromatopsia) and a previously reported variant (p.Ile84Thr) in the PDZD7 gene causing NSHL. Both variants were found in the cis configuration on chromosome 10 with a genetic distance of about 8.3 cM, leading to their co-inheritance. However, two diseases could appear independently in subsequent generations due to crossover during meiosis. CONCLUSIONS Here, we could successfully determine the etiology of a seemingly complex phenotype in two adjacent genes. We identified a novel variant in the PDE6C gene, related to achromatopsia. Interestingly, this variant could cooperatively cause visual disorders: cone dystrophy and cone-rod dystrophy.
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Affiliation(s)
- Zahra Nouri
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
- Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Akram Sarmadi
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
- Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sina Narrei
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
- Department of Research and Development, Harmonic Medical Genetics Lab, Isfahan, Iran
| | - Hamidreza Kianersi
- Isfahan Eye Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Farzan Kianersi
- Department of Ophthalmology, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Amin Tabatabaiefar
- Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
- Pediatric Inherited Diseases Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
- University of Medical Sciences, Isfahan, 81746-73461, Iran.
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Georgiou M, Robson AG, Fujinami K, de Guimarães TAC, Fujinami-Yokokawa Y, Daich Varela M, Pontikos N, Kalitzeos A, Mahroo OA, Webster AR, Michaelides M. Phenotyping and genotyping inherited retinal diseases: Molecular genetics, clinical and imaging features, and therapeutics of macular dystrophies, cone and cone-rod dystrophies, rod-cone dystrophies, Leber congenital amaurosis, and cone dysfunction syndromes. Prog Retin Eye Res 2024; 100:101244. [PMID: 38278208 DOI: 10.1016/j.preteyeres.2024.101244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Inherited retinal diseases (IRD) are a leading cause of blindness in the working age population and in children. The scope of this review is to familiarise clinicians and scientists with the current landscape of molecular genetics, clinical phenotype, retinal imaging and therapeutic prospects/completed trials in IRD. Herein we present in a comprehensive and concise manner: (i) macular dystrophies (Stargardt disease (ABCA4), X-linked retinoschisis (RS1), Best disease (BEST1), PRPH2-associated pattern dystrophy, Sorsby fundus dystrophy (TIMP3), and autosomal dominant drusen (EFEMP1)), (ii) cone and cone-rod dystrophies (GUCA1A, PRPH2, ABCA4, KCNV2 and RPGR), (iii) predominant rod or rod-cone dystrophies (retinitis pigmentosa, enhanced S-Cone syndrome (NR2E3), Bietti crystalline corneoretinal dystrophy (CYP4V2)), (iv) Leber congenital amaurosis/early-onset severe retinal dystrophy (GUCY2D, CEP290, CRB1, RDH12, RPE65, TULP1, AIPL1 and NMNAT1), (v) cone dysfunction syndromes (achromatopsia (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2, ATF6), X-linked cone dysfunction with myopia and dichromacy (Bornholm Eye disease; OPN1LW/OPN1MW array), oligocone trichromacy, and blue-cone monochromatism (OPN1LW/OPN1MW array)). Whilst we use the aforementioned classical phenotypic groupings, a key feature of IRD is that it is characterised by tremendous heterogeneity and variable expressivity, with several of the above genes associated with a range of phenotypes.
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Affiliation(s)
- Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Kaoru Fujinami
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
| | - Thales A C de Guimarães
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan.
| | - Malena Daich Varela
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Nikolas Pontikos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Angelos Kalitzeos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Section of Ophthalmology, King s College London, St Thomas Hospital Campus, London, United Kingdom; Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, United Kingdom; Department of Translational Ophthalmology, Wills Eye Hospital, Philadelphia, PA, USA.
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Karas BF, Terez KR, Mowla S, Battula N, Flannery KP, Gural BM, Aboussleman G, Mubin N, Manzini MC. Removal of pomt1 in zebrafish leads to loss of α-dystroglycan glycosylation and dystroglycanopathy phenotypes. Hum Mol Genet 2024; 33:709-723. [PMID: 38272461 PMCID: PMC11000664 DOI: 10.1093/hmg/ddae006] [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: 07/11/2023] [Revised: 11/28/2023] [Accepted: 12/22/2023] [Indexed: 01/27/2024] Open
Abstract
Biallelic mutations in Protein O-mannosyltransferase 1 (POMT1) are among the most common causes of a severe group of congenital muscular dystrophies (CMDs) known as dystroglycanopathies. POMT1 is a glycosyltransferase responsible for the attachment of a functional glycan mediating interactions between the transmembrane glycoprotein dystroglycan and its binding partners in the extracellular matrix (ECM). Disruptions in these cell-ECM interactions lead to multiple developmental defects causing brain and eye malformations in addition to CMD. Removing Pomt1 in the mouse leads to early embryonic death due to the essential role of dystroglycan during placental formation in rodents. Here, we characterized and validated a model of pomt1 loss of function in the zebrafish showing that developmental defects found in individuals affected by dystroglycanopathies can be recapitulated in the fish. We also discovered that pomt1 mRNA provided by the mother in the oocyte supports dystroglycan glycosylation during the first few weeks of development. Muscle disease, retinal synapse formation deficits, and axon guidance defects can only be uncovered during the first week post fertilization by generating knock-out embryos from knock-out mothers. Conversely, maternal pomt1 from heterozygous mothers was sufficient to sustain muscle, eye, and brain development only leading to loss of photoreceptor synapses at 30 days post fertilization. Our findings show that it is important to define the contribution of maternal mRNA while developing zebrafish models of dystroglycanopathies and that offspring generated from heterozygous and knock-out mothers can be used to differentiate the role of dystroglycan glycosylation in tissue formation and maintenance.
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Affiliation(s)
- Brittany F Karas
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University-Robert Wood Johnson Medical School, 89 French Street, New Brunswick, NJ 08901, United States
| | - Kristin R Terez
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University-Robert Wood Johnson Medical School, 89 French Street, New Brunswick, NJ 08901, United States
| | - Shorbon Mowla
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University-Robert Wood Johnson Medical School, 89 French Street, New Brunswick, NJ 08901, United States
| | - Namarata Battula
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University-Robert Wood Johnson Medical School, 89 French Street, New Brunswick, NJ 08901, United States
| | - Kyle P Flannery
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University-Robert Wood Johnson Medical School, 89 French Street, New Brunswick, NJ 08901, United States
| | - Brian M Gural
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University-Robert Wood Johnson Medical School, 89 French Street, New Brunswick, NJ 08901, United States
| | - Grace Aboussleman
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University-Robert Wood Johnson Medical School, 89 French Street, New Brunswick, NJ 08901, United States
| | - Numa Mubin
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University-Robert Wood Johnson Medical School, 89 French Street, New Brunswick, NJ 08901, United States
| | - M Chiara Manzini
- Department of Neuroscience and Cell Biology, Child Health Institute of New Jersey, Rutgers University-Robert Wood Johnson Medical School, 89 French Street, New Brunswick, NJ 08901, United States
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Wu S, Yu Y, Wang Y, Zhang L, Fang X, Ye P, Ma J. Novel ATF6 homozygous variant in a Chinese patient with achromatopsia. Ophthalmic Genet 2024; 45:153-158. [PMID: 38419580 DOI: 10.1080/13816810.2024.2322643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/19/2024] [Indexed: 03/02/2024]
Abstract
BACKGROUND ATF6-associated Achromatopsia (ACHM) is a rare autosomal recessive disorder characterized by reduction of visual acuity, photophobia, nystagmus, and poor color vision. METHODS Detailed ophthalmological examinations were performed in a Chinese patient with ACHM. Whole exome sequencing and Sanger sequencing were performed to detect the disease-causing gene in the patient. RESULTS A 6-year-old girl presented photophobia, low vision and reduced color discrimination. Small yellow lesion in the macula of both eyes was observed. FAF demonstrated hypofluorescence in the macular fovea. OCT images revealed interruption of ellipsoid and interdigitation zone in the foveal area and a loss of the foveal pit. ERG showed relatively normal rod responses and unrecordable cone responses. Sequencing result identified a novel splicing variant c.354 + 6T>C in the ATF6 gene (NM_007348.4). CONCLUSIONS We reported detailed clinical features and genetic analysis of a new Chinese ATF6-associated patient with ACHM.
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Affiliation(s)
- Shijing Wu
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yinhui Yu
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yao Wang
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Zhejiang University, Hangzhou, Zhejiang, China
| | - Li Zhang
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Zhejiang University, Hangzhou, Zhejiang, China
| | - Xiaoyun Fang
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Zhejiang University, Hangzhou, Zhejiang, China
| | - Panpan Ye
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jian Ma
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang Provincial Key Laboratory of Ophthalmology, Zhejiang Provincial Clinical Research Center for Eye Diseases, Zhejiang Provincial Engineering Institute on Eye Diseases, Zhejiang University, Hangzhou, Zhejiang, China
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Grissim G, Walesa A, Follett HM, Higgins BP, Goetschel K, Heitkotter H, Carroll J. Longitudinal Assessment of OCT-Based Measures of Foveal Cone Structure in Achromatopsia. Invest Ophthalmol Vis Sci 2024; 65:16. [PMID: 38587442 PMCID: PMC11005076 DOI: 10.1167/iovs.65.4.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 03/24/2024] [Indexed: 04/09/2024] Open
Abstract
Purpose Achromatopsia (ACHM) is an autosomal recessive retinal disease associated with reduced or absent cone function. There is debate regarding the extent to which cone structure shows progressive degeneration in patients with ACHM. Here, we used optical coherence tomography (OCT) images to evaluate outer nuclear layer (ONL) thickness and ellipsoid zone (EZ) integrity over time in individuals with ACHM. Methods Sixty-three individuals with genetically confirmed ACHM with follow-up ranging from about 6 months to 10 years were imaged using either Bioptigen or Cirrus OCT. Foveal cone structure was evaluated by assessing EZ integrity and ONL thickness. Results A total of 470 OCT images were graded, 243 OD and 227 OS. The baseline distribution of EZ grades was highly symmetrical between eyes (P = 0.99) and there was no significant interocular difference in baseline ONL thickness (P = 0.12). The EZ grade remained unchanged over the follow-up period for 60 of 63 individuals. Foveal ONL thickness showed a clinically significant change in only 1 of the 61 individuals analyzed, although detailed adaptive optics imaging revealed no changes in cone density in this individual. Conclusions ACHM appears to be a generally stable condition, at least over the follow-up period assessed here. As cones are the cellular targets for emerging gene therapies, stable EZ and ONL thickness demonstrate therapeutic potential for ACHM, although other aspects of the visual system need to be considered when determining the best timing for therapeutic intervention.
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Affiliation(s)
- Garrett Grissim
- School of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Ashleigh Walesa
- Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Hannah M. Follett
- Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Brian P. Higgins
- Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Kaitlin Goetschel
- Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Heather Heitkotter
- Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Joseph Carroll
- Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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Yang Z, Yan L, Zhang W, Qi J, An W, Yao K. Dyschromatopsia: a comprehensive analysis of mechanisms and cutting-edge treatments for color vision deficiency. Front Neurosci 2024; 18:1265630. [PMID: 38298913 PMCID: PMC10828017 DOI: 10.3389/fnins.2024.1265630] [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: 07/23/2023] [Accepted: 01/02/2024] [Indexed: 02/02/2024] Open
Abstract
Color blindness is a retinal disease that mainly manifests as a color vision disorder, characterized by achromatopsia, red-green color blindness, and blue-yellow color blindness. With the development of technology and progress in theory, extensive research has been conducted on the genetic basis of color blindness, and various approaches have been explored for its treatment. This article aims to provide a comprehensive review of recent advances in understanding the pathological mechanism, clinical symptoms, and treatment options for color blindness. Additionally, we discuss the various treatment approaches that have been developed to address color blindness, including gene therapy, pharmacological interventions, and visual aids. Furthermore, we highlight the promising results from clinical trials of these treatments, as well as the ongoing challenges that must be addressed to achieve effective and long-lasting therapeutic outcomes. Overall, this review provides valuable insights into the current state of research on color blindness, with the intention of informing further investigation and development of effective treatments for this disease.
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Affiliation(s)
- Zihao Yang
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
- College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
| | - Lin Yan
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
- College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
| | - Wenliang Zhang
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
- College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
| | - Jia Qi
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
- College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
| | - Wenjing An
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
- College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
| | - Kai Yao
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
- College of Life Sciences and Health, Wuhan University of Science and Technology, Wuhan, China
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Zhang SX, Wang JJ, Starr CR, Lee EJ, Park KS, Zhylkibayev A, Medina A, Lin JH, Gorbatyuk M. The endoplasmic reticulum: Homeostasis and crosstalk in retinal health and disease. Prog Retin Eye Res 2024; 98:101231. [PMID: 38092262 PMCID: PMC11056313 DOI: 10.1016/j.preteyeres.2023.101231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 12/19/2023]
Abstract
The endoplasmic reticulum (ER) is the largest intracellular organelle carrying out a broad range of important cellular functions including protein biosynthesis, folding, and trafficking, lipid and sterol biosynthesis, carbohydrate metabolism, and calcium storage and gated release. In addition, the ER makes close contact with multiple intracellular organelles such as mitochondria and the plasma membrane to actively regulate the biogenesis, remodeling, and function of these organelles. Therefore, maintaining a homeostatic and functional ER is critical for the survival and function of cells. This vital process is implemented through well-orchestrated signaling pathways of the unfolded protein response (UPR). The UPR is activated when misfolded or unfolded proteins accumulate in the ER, a condition known as ER stress, and functions to restore ER homeostasis thus promoting cell survival. However, prolonged activation or dysregulation of the UPR can lead to cell death and other detrimental events such as inflammation and oxidative stress; these processes are implicated in the pathogenesis of many human diseases including retinal disorders. In this review manuscript, we discuss the unique features of the ER and ER stress signaling in the retina and retinal neurons and describe recent advances in the research to uncover the role of ER stress signaling in neurodegenerative retinal diseases including age-related macular degeneration, inherited retinal degeneration, achromatopsia and cone diseases, and diabetic retinopathy. In some chapters, we highlight the complex interactions between the ER and other intracellular organelles focusing on mitochondria and illustrate how ER stress signaling regulates common cellular stress pathways such as autophagy. We also touch upon the integrated stress response in retinal degeneration and diabetic retinopathy. Finally, we provide an update on the current development of pharmacological agents targeting the UPR response and discuss some unresolved questions and knowledge gaps to be addressed by future research.
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Affiliation(s)
- Sarah X Zhang
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States.
| | - Josh J Wang
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Christopher R Starr
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Eun-Jin Lee
- Department of Ophthalmology and Byers Eye Institute, Stanford University, Stanford, CA, United States; VA Palo Alto Healthcare System, Palo Alto, CA, United States; Department of Pathology, Stanford University, Stanford, CA, United States
| | - Karen Sophia Park
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Assylbek Zhylkibayev
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Andy Medina
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Jonathan H Lin
- Department of Ophthalmology and Byers Eye Institute, Stanford University, Stanford, CA, United States; VA Palo Alto Healthcare System, Palo Alto, CA, United States; Department of Pathology, Stanford University, Stanford, CA, United States
| | - Marina Gorbatyuk
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
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Solaki M, Wissinger B, Kohl S, Reuter P. Functional evaluation allows ACMG/AMP-based re-classification of CNGA3 variants associated with achromatopsia. Genet Med 2023; 25:100979. [PMID: 37689994 DOI: 10.1016/j.gim.2023.100979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/30/2023] [Accepted: 08/30/2023] [Indexed: 09/11/2023] Open
Abstract
PURPOSE CNGA3 encoding the main subunit of the cyclic nucleotide-gated ion channel in cone photoreceptors is one of the major disease-associated genes for achromatopsia. Most CNGA3 variants are missense variants with the majority being functionally uncharacterized and therefore hampering genetic diagnosis. In light of potential gene therapy, objective variant pathogenicity assessment is essential. METHODS We established a medium-throughput aequorin-based luminescence bioassay allowing mutant CNGA3 channel function assessment via quantification of CNGA3 channel-mediated calcium influx in a cell culture system, thereby enabling American College of Medical Genetics and Genomics/Association for Molecular Pathology-based variant re-classification. RESULTS We provide functional read-out obtained for 150 yet uncharacterized CNGA3 missense substitutions of which 55 were previously categorized as variants of uncertain significance (VUS) identifying 25 as functionally normal and 125 as functionally abnormal. These data enabled the American College of Medical Genetics and Genomics/ Association for Molecular Pathology-based variant re-classification of 52/55 VUS as either benign, likely benign, or likely pathogenic reaching a VUS re-classification rate of 94.5%. CONCLUSION Our aequorin-based bioassay allows functionally ensured clinical variant interpretation for 150 CNGA3 missense variants enabling and supporting VUS re-classification and assuring molecular diagnosis to patients affected by CNGA3-associated achromatopsia, hereby identifying patients eligible for future gene therapy trials on this disease.
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Affiliation(s)
- Maria Solaki
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
| | - Peggy Reuter
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany.
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12
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Zheng Y, Sun C, Zhang X, Ruzycki PA, Chen S. Missense mutations in CRX homeodomain cause dominant retinopathies through two distinct mechanisms. eLife 2023; 12:RP87147. [PMID: 37963072 PMCID: PMC10645426 DOI: 10.7554/elife.87147] [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] [Indexed: 11/16/2023] Open
Abstract
Homeodomain transcription factors (HD TFs) are instrumental to vertebrate development. Mutations in HD TFs have been linked to human diseases, but their pathogenic mechanisms remain elusive. Here, we use Cone-Rod Homeobox (CRX) as a model to decipher the disease-causing mechanisms of two HD mutations, p.E80A and p.K88N, that produce severe dominant retinopathies. Through integrated analysis of molecular and functional evidence in vitro and in knock-in mouse models, we uncover two novel gain-of-function mechanisms: p.E80A increases CRX-mediated transactivation of canonical CRX target genes in developing photoreceptors; p.K88N alters CRX DNA-binding specificity resulting in binding at ectopic sites and severe perturbation of CRX target gene expression. Both mechanisms produce novel retinal morphological defects and hinder photoreceptor maturation distinct from loss-of-function models. This study reveals the distinct roles of E80 and K88 residues in CRX HD regulatory functions and emphasizes the importance of transcriptional precision in normal development.
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Affiliation(s)
- Yiqiao Zheng
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
| | - Chi Sun
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
| | - Xiaodong Zhang
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
| | - Philip A Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Genetics, Washington University in St LouisSaint LouisUnited States
| | - Shiming Chen
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Ophthalmology and Visual Sciences, Washington University in St LouisSaint LouisUnited States
- Department of Developmental Biology, Washington University in St LouisSaint LouisUnited States
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13
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Lee EJ, Diaz-Aguilar MS, Min H, Choi J, Valdez Duran DA, Grandjean JM, Wiseman RL, Kroeger H, Lin JH. Mitochondria and Endoplasmic Reticulum Stress in Retinal Organoids from Patients with Vision Loss. THE AMERICAN JOURNAL OF PATHOLOGY 2023; 193:1721-1739. [PMID: 36535406 PMCID: PMC10616714 DOI: 10.1016/j.ajpath.2022.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/10/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022]
Abstract
Activating transcription factor 6 (ATF6), a key regulator of the unfolded protein response, plays a key role in endoplasmic reticulum function and protein homeostasis. Variants of ATF6 that abrogate transcriptional activity cause morphologic and molecular defects in cones, clinically manifesting as the human vision loss disease achromatopsia (ACHM). ATF6 is expressed in all retinal cells. However, the effect of disease-associated ATF6 variants on other retinal cell types remains unclear. Herein, this was investigated by analyzing bulk RNA-sequencing transcriptomes from retinal organoids generated from patients with ACHM, carrying homozygous loss-of-function ATF6 variants. Marked dysregulation in mitochondrial respiratory complex gene expression and disrupted mitochondrial morphology in ACHM retinal organoids were identified. This indicated that loss of ATF6 leads to previously unappreciated mitochondrial defects in the retina. Next, gene expression from control and ACHM retinal organoids were compared with transcriptome profiles of seven major retinal cell types generated from recent single-cell transcriptomic maps of nondiseased human retina. This indicated pronounced down-regulation of cone genes and up-regulation in Müller glia genes, with no significant effects on other retinal cells. Overall, the current analysis of ACHM patient retinal organoids identified new cellular and molecular phenotypes in addition to cone dysfunction: activation of Müller cells, increased endoplasmic reticulum stress, disrupted mitochondrial structure, and elevated respiratory chain activity gene expression.
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Affiliation(s)
- Eun-Jin Lee
- Department of Ophthalmology, Stanford University, Stanford, California; Department of Pathology, VA Palo Alto Healthcare System, Palo Alto, California; Department of Pathology, Stanford University, Stanford, California
| | - Monica S Diaz-Aguilar
- Department of Ophthalmology, Stanford University, Stanford, California; Department of Pathology, VA Palo Alto Healthcare System, Palo Alto, California; Department of Pathology, Stanford University, Stanford, California; Department of Medicine, Rush University Medical College, Chicago, Illinois
| | - Hyejung Min
- Department of Pathology, VA Palo Alto Healthcare System, Palo Alto, California; Department of Pathology, Stanford University, Stanford, California
| | - Jihee Choi
- Department of Pathology, Stanford University, Stanford, California
| | | | - Julia M Grandjean
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California
| | - R Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California
| | - Heike Kroeger
- Department of Cellular Biology, University of Georgia, Athens, Georgia
| | - Jonathan H Lin
- Department of Ophthalmology, Stanford University, Stanford, California; Department of Pathology, VA Palo Alto Healthcare System, Palo Alto, California; Department of Pathology, Stanford University, Stanford, California.
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14
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Kugler SA, Valmaggia C, Sturm V, Schorderet DF, Todorova MG. Analysis of Suspected Achromatopsia by Multimodal Diagnostic Testing. Klin Monbl Augenheilkd 2023; 240:1158-1173. [PMID: 37714190 DOI: 10.1055/a-2176-4233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023]
Abstract
BACKGROUND Achromatopsia (ACHM) as a hereditary cone disease might manifest in a stationary and progressive manner. The proper clinical and genetic diagnosis may allow an individual prognosis, accurate genetic counselling, and the optimal choice of low vision aids. The primary aim of the study was to determine the spectrum of clinical and genetic diagnostics required to characterize the ACHM. METHODS A retrospective analysis was performed in 8 patients from non-related families (5 ♀,3 ♂); age at diagnosis: 3 - 56 y, mean 18.13 (SD ± 18.22). Clinical phenotyping, supported by colour vision test, fundus photography-, autofluorescence- (FAF), infra-red- (IR), OCT imaging and electroretinography provided information on the current status and the course of the disease over the years. In addition, genetic examinations were performed with ACHM relevant testing (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H and the transcription factor ATF6). RESULTS All patients suffered photophobia and reduced visual acuity (mean: 0.16 [SD ± 0.08]). Nystagmus was identified in 7 from 8 subjects and in one patient a head-turn right helped to reduce the nystagmus amplitude. Colour vision testing confirmed complete achromatopsia in 7 out of 8 patients. Electrophysiology found severely reduced photopic- but also scotopic responses. Thinning and interruption of the inner segment ellipsoid (ISe) line within the macula but also FAF- and IR abnormalities in the fovea and/or parafovea were characteristic in all ACHM patients. Identification of pathogenic mutations in 7 patients helped to confirm the diagnosis of ACHM (3 adults, 4 children; 3 ♀ and 4 ♂). Achromatopsia was linked to CNGA3 (2 ♀, 1 ♂) and CNGB3 variants (2 ♀, 3 ♂). The youngest patient (♀, 10 y) had 3 different CNGB3 variants on different alleles. In a patient (♂, 29 y) carrying 2 pathogenic digenic-triallelic CNGA3- and CNGB3-mutations, a severe progression of ISe discontinuity to coloboma-like macular atrophy was observed during the 12-year follow-up. The oldest female (67 y) showed a compound homozygous CNGA3- and heterozygous CNGB3-, as well as a heterozygous GUCY2D variants. The destruction of her ISe line was significantly enlarged and represented a progressive cone-rod phenotype in comparison to other ACHM patients. In a patient (♂, 45 y) carrying a pathogenic CNGB3 and USH2 mutation, a severe macular oedema and a rod-cone phenotype was observed. In addition, two variants in C2ORF71 considered as VOS were found. One patient showed the rare ATF6 mutation, where a severe coloboma-like macular atrophy was observed on the left eye as early as at the age of three years. CONCLUSION Combining multimodal ophthalmological diagnostics and molecular genetics when evaluating patients with ACHM helps in characterizing the disease and associated modifiers, and is therefore strongly recommended for such patients.
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Affiliation(s)
- Sylvia A Kugler
- Department of Ophthalmology, Cantonal Hospital St. Gallen, Switzerland
| | - Christophe Valmaggia
- Department of Ophthalmology, Cantonal Hospital St. Gallen, Switzerland
- Department of Ophthalmology, University of Zürich, Switzerland
| | - Veit Sturm
- Department of Ophthalmology, University of Zürich, Switzerland
- Ophthalmology, Eye Center Rosengarten, Arbon, Switzerland
| | - Daniel F Schorderet
- Faculty of Biology and Medicine, University of Lausanne and Faculty of Life Sciences, École polytechnique fédérale de Lausanne, Switzerland
| | - Margarita G Todorova
- Department of Ophthalmology, Cantonal Hospital St. Gallen, Switzerland
- Department of Ophthalmology, University of Zürich, Switzerland
- Department of Ophthalmology, University Hospital Basel, Switzerland
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15
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Wang H, Liu Z, Zhang Y, Tao D, Li L. Achromatopsia Showing Compound Heterozygous Mutations in ATF6 by Whole Exome Sequencing: A Rare Case Report. J Pediatr Ophthalmol Strabismus 2023; 60:e65-e69. [PMID: 37747165 DOI: 10.3928/01913913-20230814-02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Achromatopsia, inherited in an autosomal recessive manner, is a rare condition featured by dysfunction of cone photoreceptors responsible for high-acuity vision in daylight. To date, its pathogenesis and genetic mechanism are still not well defined due to the rarity of cases. In this study, the authors describe a patient with achromatopsia who was diagnosed based on the combination of whole exome sequencing, ocular examination, fundus photography, and fundus fluorescein angiography. A 1-year-old girl presented due to absence of the foveal reflex, severe photophobia, and pigment mottling. Fundus photography and fundus fluorescein angiography were performed on admission. Blood samples were extracted from the proband and her parents. Whole exome sequencing detected two ATF6 variants (c.533C>A and c.82+1G>T), which were confirmed through Sanger sequencing. According to the American College of Medical Genetics guidelines, both c.533C>A and c.82+1G>T variants in ATF6 were predicted as pathogenic mutations (PVS1, PM2, PM3). The patient was diagnosed as having achromatopsia with pathogenicity of ATF6 variants (c.533C>A and c.82+1G>T). [J Pediatr Ophthalmol Strabismus. 2023;60(5):e65-e69.].
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16
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Zheng Y, Sun C, Zhang X, Ruzycki PA, Chen S. Missense mutations in CRX homeodomain cause dominant retinopathies through two distinct mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.01.526652. [PMID: 36778408 PMCID: PMC9915647 DOI: 10.1101/2023.02.01.526652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Homeodomain transcription factors (HD TFs) are instrumental to vertebrate development. Mutations in HD TFs have been linked to human diseases, but their pathogenic mechanisms remain elusive. Here we use Cone-Rod Homeobox (CRX) as a model to decipher the disease-causing mechanisms of two HD mutations, p.E80A and p.K88N, that produce severe dominant retinopathies. Through integrated analysis of molecular and functional evidence in vitro and in knock-in mouse models, we uncover two novel gain-of-function mechanisms: p.E80A increases CRX-mediated transactivation of canonical CRX target genes in developing photoreceptors; p.K88N alters CRX DNA-binding specificity resulting in binding at ectopic sites and severe perturbation of CRX target gene expression. Both mechanisms produce novel retinal morphological defects and hinder photoreceptor maturation distinct from loss-of-function models. This study reveals the distinct roles of E80 and K88 residues in CRX HD regulatory functions and emphasizes the importance of transcriptional precision in normal development.
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Affiliation(s)
- Yiqiao Zheng
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Chi Sun
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Xiaodong Zhang
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Philip A. Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Genetics, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Shiming Chen
- Molecular Genetic and Genomics Graduate Program, Division of Biological and Biomedical Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Ophthalmology and Visual Sciences, Washington University in St Louis, Saint Louis, Missouri, USA
- Department of Developmental Biology, Washington University in St Louis, Saint Louis, Missouri, USA
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Genetic and Clinical Characterization of Danish Achromatopsia Patients. Genes (Basel) 2023; 14:genes14030690. [PMID: 36980963 PMCID: PMC10048638 DOI: 10.3390/genes14030690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/16/2023] Open
Abstract
Achromatopsia is a rare congenital condition with cone photoreceptor dysfunction causing color blindness, reduced vision, nystagmus and photophobia. New treatments are being developed, but the current evidence is still conflicting regarding possible progression over time, and there is no clear genotype-phenotype correlation. This natural history study aimed to further explore the course of disease and potential clinical differences between various genotypes. The retrospective design allowed for the study of a large cohort with a long follow-up. Patients were identified from the Danish national registries. If not already available, genetic analysis was offered to the patient. Clinical data from 1945–2022 were retrieved from medical records and included best-corrected visual acuity (BCVA), color vision, refractive error, nystagmus, visual fields and fundoscopic findings. We identified variants believed to be disease causing in five of the known achromatopsia genes: CNGA3; CNGB3; GNAT2; PDE6C and PDE6H; and novel variants were identified in CNGB3 and PDE6C. Progressive deterioration of BCVA only attributable to achromatopsia was found in three of 58 patients. Progressive phenotype was seen with variants in CNGB3 and PDE6C. The results indicate that myopia could be more frequently occurring with variants in GNAT2, PDE6C and PDE6H and support the evidence that achromatopsia is a predominantly stationary condition with respect to BCVA. Although a clear genotype-phenotype correlation can still not be concluded, there may be differences in phenotypical characteristics with variants in different genes.
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Analysis of Tumor-Infiltrating T-Cell Transcriptomes Reveal a Unique Genetic Signature across Different Types of Cancer. Int J Mol Sci 2022; 23:ijms231911065. [PMID: 36232369 PMCID: PMC9569723 DOI: 10.3390/ijms231911065] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/09/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022] Open
Abstract
CD8+ and CD4+ T-cells play a key role in cellular immune responses against cancer by cytotoxic responses and effector lineages differentiation, respectively. These subsets have been found in different types of cancer; however, it is unclear whether tumor-infiltrating T-cell subsets exhibit similar transcriptome profiling across different types of cancer in comparison with healthy tissue-resident T-cells. Thus, we analyzed the single cell transcriptome of five tumor-infiltrating CD4-T, CD8-T and Treg cells obtained from different types of cancer to identify specific pathways for each subset in malignant environments. An in silico analysis was performed from single-cell RNA-sequencing data available in public repositories (Gene Expression Omnibus) including breast cancer, melanoma, colorectal cancer, lung cancer and head and neck cancer. After dimensionality reduction, clustering and selection of the different subpopulations from malignant and nonmalignant datasets, common genes across different types of cancer were identified and compared to nonmalignant genes for each T-cell subset to identify specific pathways. Exclusive pathways in CD4+ cells, CD8+ cells and Tregs, and common pathways for the tumor-infiltrating T-cell subsets were identified. Finally, the identified pathways were compared with RNAseq and proteomic data obtained from T-cell subsets cultured under malignant environments and we observed that cytokine signaling, especially Th2-type cytokine, was the top overrepresented pathway in Tregs from malignant samples.
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Triantafylla M, Papageorgiou E, Thomas MG, McLean R, Kohl S, Sheth V, Tu Z, Proudlock FA, Gottlob I. Longitudinal Evaluation of Changes in Retinal Architecture Using Optical Coherence Tomography in Achromatopsia. Invest Ophthalmol Vis Sci 2022; 63:6. [PMID: 35930270 PMCID: PMC9363676 DOI: 10.1167/iovs.63.9.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose This prospective study investigates longitudinal changes in retinal structure in patients with achromatopsia (ACHM) using optical coherence tomography (OCT). Methods Seventeen patients (five adults, 12 children) with genetically confirmed CNGA3- or CNGB3-associated ACHM underwent ocular examination and OCT over a follow-up period of between 2 and 9.33 years (mean = 5.7 years). Foveal tomograms were qualitatively graded and were segmented for quantitative analysis: central macular thickness (CMt), outer nuclear layer thickness (ONLt), and size of the foveal hyporeflective zone (vertical HRZ thickness: HRZt and horizontal HRZ width: HRZw) were measured. Data were analyzed using linear mixed regression models. Both age and visit were included into the models, to explore the possibility that the rate of disease progression depends on patient age. Results Fifteen of 17 patients (88%) showed longitudinal changes in retinal structure over the follow-up period. The most common patterns of progression was development of ellipsoid zone (EZ) disruption and HRZ. There was a significant increase in HRZt (P = 0.01) and HRZw (P = 0.001) between visits and no significant change in CMt and ONLt. Retinal parameters showed no difference in changes by genetic mutation (CNGA3 (n = 11), CNGB3 (n = 6)). Conclusions This study demonstrates clear longitudinal changes in foveal structure mainly in children, but also in adults with ACHM, over a long follow-up period. The longitudinal foveal changes suggest that treatment at an earlier age should be favored.
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Affiliation(s)
- Magdalini Triantafylla
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, United Kingdom
| | - Eleni Papageorgiou
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, United Kingdom
| | - Mervyn G. Thomas
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, United Kingdom
| | - Rebecca McLean
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, United Kingdom
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Department for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Viral Sheth
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, United Kingdom
| | - Zhanhan Tu
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, United Kingdom
| | - Frank A. Proudlock
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, United Kingdom
| | - Irene Gottlob
- Ulverscroft Eye Unit, Neuroscience, Psychology and Behaviour, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, University of Leicester, United Kingdom
- Department of Neurology, Cooper University Hospital, Cooper Neurological Institute, Cooper Medical School of Rowan University, Camden, New Jersey, United States
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Zebrafish and inherited photoreceptor disease: Models and insights. Prog Retin Eye Res 2022; 91:101096. [PMID: 35811244 DOI: 10.1016/j.preteyeres.2022.101096] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 06/20/2022] [Accepted: 06/23/2022] [Indexed: 11/21/2022]
Abstract
Photoreceptor dysfunctions and degenerative diseases are significant causes of vision loss in patients, with few effective treatments available. Targeted interventions to prevent or reverse photoreceptor-related vision loss are not possible without a thorough understanding of the underlying mechanism leading to disease, which is exceedingly difficult to accomplish in the human system. Cone diseases are particularly challenging to model, as some popular genetically modifiable model animals are nocturnal with a rod-dominant visual system and cones that have dissimilarities to human cones. As a result, cone diseases, which affect visual acuity, colour perception, and central vision in patients, are generally poorly understood in terms of pathology and mechanism. Zebrafish (Danio rerio) provide the opportunity to model photoreceptor diseases in a diurnal vertebrate with a cone-rich retina which develops many macular degeneration-like pathologies. Zebrafish undergo external development, allowing early-onset retinal diseases to be detected and studied, and many ophthalmic tools are available for zebrafish visual assessment during development and adulthood. There are numerous zebrafish models of photoreceptor disease, spanning the various types of photoreceptor disease (developmental, rod, cone, and mixed photoreceptor diseases) and genetic/molecular cause. In this review, we explore the features of zebrafish that make them uniquely poised to model cone diseases, summarize the established zebrafish models of inherited photoreceptor disease, and discuss how disease in these models compares to the human presentation, where applicable. Further, we highlight the contributions of these zebrafish models to our understanding of photoreceptor biology and disease, and discuss future directions for utilising and investigating these diverse models.
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Solaki M, Baumann B, Reuter P, Andreasson S, Audo I, Ayuso C, Balousha G, Benedicenti F, Birch D, Bitoun P, Blain D, Bocquet B, Branham K, Català-Mora J, De Baere E, Dollfus H, Falana M, Giorda R, Golovleva I, Gottlob I, Heckenlively JR, Jacobson SG, Jones K, Jägle H, Janecke AR, Kellner U, Liskova P, Lorenz B, Martorell-Sampol L, Messias A, Meunier I, Belga Ottoni Porto F, Papageorgiou E, Plomp AS, de Ravel TJL, Reiff CM, Renner AB, Rosenberg T, Rudolph G, Salati R, Sener EC, Sieving PA, Stanzial F, Traboulsi EI, Tsang SH, Varsanyi B, Weleber RG, Zobor D, Stingl K, Wissinger B, Kohl S. Comprehensive variant spectrum of the CNGA3 gene in patients affected by achromatopsia. Hum Mutat 2022; 43:832-858. [PMID: 35332618 DOI: 10.1002/humu.24371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 02/23/2022] [Accepted: 03/22/2022] [Indexed: 11/06/2022]
Abstract
Achromatopsia (ACHM) is a congenital cone photoreceptor disorder characterized by impaired color discrimination, low visual acuity, photosensitivity, and nystagmus. To date, six genes have been associated with ACHM (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6), the majority of these being implicated in the cone phototransduction cascade. CNGA3 encodes the CNGA3 subunit of the cyclic nucleotide-gated ion channel in cone photoreceptors and is one of the major disease-associated genes for ACHM. Herein, we provide a comprehensive overview of the CNGA3 variant spectrum in a cohort of 1060 genetically confirmed ACHM patients, 385 (36.3%) of these carrying "likely disease-causing" variants in CNGA3. Compiling our own genetic data with those reported in the literature and in public databases, we further extend the CNGA3 variant spectrum to a total of 316 variants, 244 of which we interpreted as "likely disease-causing" according to ACMG/AMP criteria. We report 48 novel "likely disease-causing" variants, 24 of which are missense substitutions underlining the predominant role of this mutation class in the CNGA3 variant spectrum. In addition, we provide extensive in silico analyses and summarize reported functional data of previously analyzed missense, nonsense and splicing variants to further advance the pathogenicity assessment of the identified variants.
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Affiliation(s)
- Maria Solaki
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Britta Baumann
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Peggy Reuter
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Sten Andreasson
- Department of Ophthalmology, University Hospital Lund, Lund, Sweden
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- CHNO des Quinze-Vingts, Centre de Référence Maladies Rares REFERET, and INSERM-DGOS CIC1423, Paris, France
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria - Fundación Jiménez Díaz University Hospital - Universidad Autónoma de Madrid (IIS-FJD, UAM), Madrid, Spain
- Center for Biomedical Network Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Ghassan Balousha
- Department of Pathology and Histology, Faculty of Medicine, Al-Quds University, Eastern Jerusalem, Palestine
| | - Francesco Benedicenti
- Clinical Genetics Service and South Tyrol Coordination Center for Rare Diseases, Department of Pediatrics, Regional Hospital of Bolzano, Bolzano, Italy
| | - David Birch
- Retina Foundation of the Southwest, Dallas, Texas, USA
| | - Pierre Bitoun
- Genetique Medicale, CHU Paris Nord, Hopital Jean Verdier, Bondy Cedex, France
| | | | - Beatrice Bocquet
- National Reference Centre for Inherited Sensory Diseases, Institute for Neurosciences of Montpellier (INM), University of Montpellier, INSERM, Montpellier, France
| | - Kari Branham
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA
| | - Jaume Català-Mora
- Unitat de Distròfies Hereditàries de Retina Hospital Sant Joan de Déu, Barcelona, Esplugues de Llobregat, Spain
| | - Elfride De Baere
- Department of Biomolecular Medicine, Center for Medical Genetics, Ghent University and Ghent University Hospital, Ghent, Belgium
| | - Helene Dollfus
- CARGO, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- U-1112, Inserm, Faculté de Médecine, Université de Strasbourg, Strasbourg, France
| | - Mohammed Falana
- Department of Pathology and Histology, Faculty of Medicine, Al-Quds University, Eastern Jerusalem, Palestine
| | - Roberto Giorda
- Molecular Biology Laboratory, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
| | - Irina Golovleva
- Department of Medical Biosciences/Medical and Clinical Genetics, University of Umea, Umea, Sweden
| | - Irene Gottlob
- The University of Leicester Ulverscroft Eye Unit, Leicester Royal Infirmary, Leicester, UK
| | - John R Heckenlively
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, USA
| | - Samuel G Jacobson
- Department of Ophthalmology, Perelman School of Medicine, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kaylie Jones
- Retina Foundation of the Southwest, Dallas, Texas, USA
| | - Herbert Jägle
- Department of Ophthalmology, University of Regensburg, Regensburg, Germany
| | - Andreas R Janecke
- Institute of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Ulrich Kellner
- Zentrum für Seltene Netzhauterkrankungen, AugenZentrum Siegburg, MVZ Augenärztliches Diagnostik- und Therapiecentrum Siegburg GmbH, Siegburg, Germany
- RetinaScience, Bonn, 53192, Germany
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig University Giessen, Giessen, Germany
- Department of Ophthalmology, Universitaetsklinikum Bonn, Bonn, Germany
| | | | - André Messias
- Department of Ophthalmology, Otorhinolaryngology, and Head and Neck Surgery, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Isabelle Meunier
- National Reference Centre for Inherited Sensory Diseases, Montpellier University Hospital, University of Montpellier, Montpellier, France
- Sensgene Care Network, France
| | | | - Eleni Papageorgiou
- Department of Ophthalmology, University Hospital of Larissa, Mezourlo, Larissa, Greece
| | - Astrid S Plomp
- Department of Human Genetics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Thomy J L de Ravel
- Centre for Medical Genetics, University Hospital Brussels, Brussels, Belgium
| | | | | | - Thomas Rosenberg
- Department of Ophthalmology, National Eye Clinic, Glostrup Hospital, Glostrup, Denmark
| | - Günther Rudolph
- University Eye Hospital, Ludwig Maximilians University, Munich, Germany
| | - Roberto Salati
- Scientific Institute, IRCCS Eugenio Medea, Pediatric Ophthalmology Unit, Bosisio Parini, Lecco, Italy
| | - E Cumhur Sener
- Strabismus and Pediatric Ophthalmology, Private Practice, Ankara, Turkey
| | - Paul A Sieving
- Center for Ocular Regenerative Therapy, School of Medicine, University of California Davis, Sacramento, USA
| | - Franco Stanzial
- Clinical Genetics Service and South Tyrol Coordination Center for Rare Diseases, Department of Pediatrics, Regional Hospital of Bolzano, Bolzano, Italy
| | - Elias I Traboulsi
- Center for Genetic Eye Diseases, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA
| | - Stephen H Tsang
- Department of Ophthalmology, Pathology and Cell Biology, College of Physicians and Surgeons, Columbia Stem Cell Initiative, Columbia University, New York City, New York, USA
| | - Balázs Varsanyi
- Department of Ophthalmology, Medical School, University of Pécs and Ganglion Medical Center, Pécs, Pécs, Hungary
| | - Richard G Weleber
- Oregon Health & Science University, Ophthalmic Genetics Service of the Casey Eye Institute, 515 SW Campus Drive, 97239, Portland, Oregon, USA
| | - Ditta Zobor
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Hospital Tübingen, Tübingen, Germany
- Department of Ophthalmology, Semmelweis University Budapest, Budapest, Hungary
| | - Katarina Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tübingen, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany
| | - Bernd Wissinger
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
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22
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Aweidah H, Salameh M, Yahalom C, Blumenfeld A, Macarov M, Weisschuh N, Kohl S, Banin E, Sharon D. A deep intronic substitution in CNGB3 is one of the major causes of achromatopsia among Jewish patients. Mol Vis 2021; 27:588-600. [PMID: 34703197 PMCID: PMC8477987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 09/20/2021] [Indexed: 11/27/2022] Open
Abstract
PURPOSE Although most (or even all) genes that can cause achromatopsia (ACHM) when mutated are known, some patients are still negative for mutations even after screening the coding sequence of all known genes. Our aim was to characterize the genetic and clinical aspects of a deep intronic (c.1663-1205G>A, IVS14-1205G>A) CNGB3 variant. METHODS Clinical evaluation included visual acuity testing, refractive error, a full clinical eye exam, full-field electroretinography (ffERG), color vision testing, and retinal imaging. Genetic analysis of CNGB3 exons, as well as part of intron 14, was performed by Sanger sequencing of PCR products. RESULTS Screening for the CNGB3 c.1663-1205G>A variant revealed 17 patients belonging to 12 unrelated families who were either homozygous for this variant (7 cases, 5 families) or heterozygous in combination with another heterozygous known CNGB3 mutation (10 cases, 7 families). All patients were diagnosed with cone-dominated disease, mainly complete ACHM. In all cases, the disease had an early, congenital onset. Visual acuity was markedly impaired, ranging between 0.07 and 0.32 on the Early Treatment Diabetic Retinopathy Study (ETDRS) scale (logarithm of the minimum angle of resolution [LogMAR] +1.18 to +0.50), with a mean visual acuity of 0.15 ETDRS (LogMAR +0.80). Additional typical signs of ACHM, including impaired color vision, light aversion, and nystagmus, were also noted in all patients. As is common in ACHM, fundus exams were largely unremarkable in most patients, with mild foveal RPE changes seen in some cases at older ages. ERG was available for 14 out of 17 patients, and in all of them-including infants from the age of 6 months-cone responses were nondetectable. In a few cases, rod involvement was also evident, with a mild reduction of amplitudes. Optical coherence tomography (OCT) imaging showed irregularity of the ellipsoid zone in the foveal area in some patients. CONCLUSIONS CNGB3 is the most common cause of ACHM in patients of European descent; this is mainly due to a panethnic founder mutation, c.1148del. Here, we report on an intronic CNGB3 variant that is more frequent than the c.1148del mutation in our cohort of Jewish patients. Among our ACHM cohort, 63.7% of patients had biallelic CNGA3 mutations and 26.4% had biallelic CNGB3 mutations. The phenotype of patients harboring the intronic mutation falls largely within the spectrum commonly seen in ACHM. Since gene therapy for CNGB3 is currently under investigation, these patients might benefit from this promising therapy. Given that this variant is not detectable by current commonly used genetic testing platforms, these patients could easily be missed.
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Affiliation(s)
- Hamzah Aweidah
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Manar Salameh
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Claudia Yahalom
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Anat Blumenfeld
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Michal Macarov
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Nicole Weisschuh
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
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23
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Patterson EJ, Langlo CS, Georgiou M, Kalitzeos A, Pennesi ME, Neitz J, Hardcastle AJ, Neitz M, Michaelides M, Carroll J. Comparing Retinal Structure in Patients with Achromatopsia and Blue Cone Monochromacy Using OCT. OPHTHALMOLOGY SCIENCE 2021; 1:100047. [PMID: 36186895 PMCID: PMC9521040 DOI: 10.1016/j.xops.2021.100047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 07/01/2021] [Accepted: 07/20/2021] [Indexed: 01/12/2023]
Abstract
Purpose To compare foveal hypoplasia and the appearance of the ellipsoid zone (EZ) at the fovea in patients with genetically confirmed achromatopsia (ACHM) and blue cone monochromacy (BCM). Design Retrospective, multi-center observational study. Subjects Molecularly confirmed patients with ACHM (n = 89) and BCM (n = 33). Methods We analyzed high-resolution spectral domain optical coherence tomography (SD-OCT) images of the macula from aforementioned patients with BCM. Three observers independently graded SD-OCT images for foveal hypoplasia (i.e. retention of one or more inner retinal layers at the fovea) and four observers judged the integrity of the EZ at the fovea, based on an established grading scheme. These measures were compared with previously published data from the ACHM patients. Main Outcome Measures Presence of foveal hypoplasia and EZ grade. Results Foveal hypoplasia was significantly more prevalent in ACHM than in BCM (p<0.001). In addition, we observed a significant difference in the distribution of EZ grades between ACHM and BCM, with grade II EZ being by far the most common phenotype in BCM (61% of patients). In contrast, ACHM patients had a relatively equal prevalence of EZ grades I, II, and IV. Interestingly, grade IV EZ was 2.6 times more prevalent in ACHM compared to BCM, while grade V EZ (macular atrophy) was present in 3% of both the ACHM and BCM cohorts. Conclusions The higher incidence of foveal hypoplasia in ACHM than BCM supports a role for cone activity in foveal development. Although there are differences in EZ grades between these conditions, the degree of overlap suggests EZ grade is not sufficient for definitive diagnosis, in contrast to previous reports. Analysis of additional OCT features in similar cohorts may reveal differences with greater diagnostic value. Finally, the extent to which foveal hypoplasia or EZ grade is prognostic for therapeutic potential in either group remains to be seen, but motivates further study.
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Key Words
- achromatopsia
- blue cone monochromacy
- cone
- ellipsoid zone
- fovea
- foveal hypoplasia
- hyper-reflective band
- imaging
- oct
- photoreceptor
- sd-oct
- x-linked cone dysfunction
- achm, achromatopsia
- bcm, blue cone monochromacy
- elm, external limiting membrane
- erg, electroretinography
- ez, ellipsoid zone
- lcr, locus control region
- lrp, longitudinal reflectivity profile
- npv, negative predictive value
- ppv, positive predictive value
- sd-oct, spectral-domain oct
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Affiliation(s)
- Emily J. Patterson
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | | | - Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Mark E. Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon
| | - Jay Neitz
- Ophthalmology, University of Washington, Seattle, Washington
| | - Alison J. Hardcastle
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Maureen Neitz
- Ophthalmology, University of Washington, Seattle, Washington
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital, London, United Kingdom
| | - Joseph Carroll
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin
- Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
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24
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Yang C, Georgiou M, Atkinson R, Collin J, Al-Aama J, Nagaraja-Grellscheid S, Johnson C, Ali R, Armstrong L, Mozaffari-Jovin S, Lako M. Pre-mRNA Processing Factors and Retinitis Pigmentosa: RNA Splicing and Beyond. Front Cell Dev Biol 2021; 9:700276. [PMID: 34395430 PMCID: PMC8355544 DOI: 10.3389/fcell.2021.700276] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/09/2021] [Indexed: 12/20/2022] Open
Abstract
Retinitis pigmentosa (RP) is the most common inherited retinal disease characterized by progressive degeneration of photoreceptors and/or retinal pigment epithelium that eventually results in blindness. Mutations in pre-mRNA processing factors (PRPF3, 4, 6, 8, 31, SNRNP200, and RP9) have been linked to 15–20% of autosomal dominant RP (adRP) cases. Current evidence indicates that PRPF mutations cause retinal specific global spliceosome dysregulation, leading to mis-splicing of numerous genes that are involved in a variety of retina-specific functions and/or general biological processes, including phototransduction, retinol metabolism, photoreceptor disk morphogenesis, retinal cell polarity, ciliogenesis, cytoskeleton and tight junction organization, waste disposal, inflammation, and apoptosis. Importantly, additional PRPF functions beyond RNA splicing have been documented recently, suggesting a more complex mechanism underlying PRPF-RPs driven disease pathogenesis. The current review focuses on the key RP-PRPF genes, depicting the current understanding of their roles in RNA splicing, impact of their mutations on retinal cell’s transcriptome and phenome, discussed in the context of model species including yeast, zebrafish, and mice. Importantly, information on PRPF functions beyond RNA splicing are discussed, aiming at a holistic investigation of PRPF-RP pathogenesis. Finally, work performed in human patient-specific lab models and developing gene and cell-based replacement therapies for the treatment of PRPF-RPs are thoroughly discussed to allow the reader to get a deeper understanding of the disease mechanisms, which we believe will facilitate the establishment of novel and better therapeutic strategies for PRPF-RP patients.
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Affiliation(s)
- Chunbo Yang
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Maria Georgiou
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Robert Atkinson
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Joseph Collin
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jumana Al-Aama
- Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Colin Johnson
- Leeds Institute of Molecular Medicine, University of Leeds, Leeds, United Kingdom
| | - Robin Ali
- King's College London, London, United Kingdom
| | - Lyle Armstrong
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Sina Mozaffari-Jovin
- Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Majlinda Lako
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
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25
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Wang NK, Liu PK, Kong Y, Levi SR, Huang WC, Hsu CW, Wang HH, Chen N, Tseng YJ, Quinn PMJ, Tai MH, Lin CS, Tsang SH. Mouse Models of Achromatopsia in Addressing Temporal "Point of No Return" in Gene-Therapy. Int J Mol Sci 2021; 22:8069. [PMID: 34360834 PMCID: PMC8347118 DOI: 10.3390/ijms22158069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 12/03/2022] Open
Abstract
Achromatopsia is characterized by amblyopia, photophobia, nystagmus, and color blindness. Previous animal models of achromatopsia have shown promising results using gene augmentation to restore cone function. However, the optimal therapeutic window to elicit recovery remains unknown. Here, we attempted two rounds of gene augmentation to generate recoverable mouse models of achromatopsia including a Cnga3 model with a knock-in stop cassette in intron 5 using Easi-CRISPR (Efficient additions with ssDNA inserts-CRISPR) and targeted embryonic stem (ES) cells. This model demonstrated that only 20% of CNGA3 levels in homozygotes derived from target ES cells remained, as compared to normal CNGA3 levels. Despite the low percentage of remaining protein, the knock-in mouse model continued to generate normal cone phototransduction. Our results showed that a small amount of normal CNGA3 protein is sufficient to form "functional" CNG channels and achieve physiological demand for proper cone phototransduction. Thus, it can be concluded that mutating the Cnga3 locus to disrupt the functional tetrameric CNG channels may ultimately require more potent STOP cassettes to generate a reversible achromatopsia mouse model. Our data also possess implications for future CNGA3-associated achromatopsia clinical trials, whereby restoration of only 20% functional CNGA3 protein may be sufficient to form functional CNG channels and thus rescue cone response.
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Affiliation(s)
- Nan-Kai Wang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
| | - Pei-Kang Liu
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80756, Taiwan
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Yang Kong
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
| | - Sarah R. Levi
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
| | - Wan-Chun Huang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
| | - Chun-Wei Hsu
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
| | - Hung-Hsi Wang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
| | - Nelson Chen
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
| | - Yun-Ju Tseng
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; (Y.-J.T.); (C.-S.L.)
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Peter M. J. Quinn
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
| | - Ming-Hong Tai
- Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
- Center for Neuroscience, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
- Graduate Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
| | - Chyuan-Sheng Lin
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA; (Y.-J.T.); (C.-S.L.)
- Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Stephen H. Tsang
- Department of Ophthalmology, Edward S. Harkness Eye Institute, Columbia University Irving Medical Center, New York, NY 10032, USA; (N.-K.W.); (P.-K.L.); (Y.K.); (S.R.L.); (W.-C.H.); (C.-W.H.); (H.-H.W.); (N.C.); (P.M.J.Q.)
- Jonas Children’s Vision Care, and Bernard and Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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26
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Kohl S, Baumann B, Dassie F, Mayer AK, Solaki M, Reuter P, Kühlewein L, Wissinger B, Maffei P. Paternal Uniparental Isodisomy of Chromosome 2 in a Patient with CNGA3-Associated Autosomal Recessive Achromatopsia. Int J Mol Sci 2021; 22:7842. [PMID: 34360608 PMCID: PMC8346044 DOI: 10.3390/ijms22157842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/13/2021] [Accepted: 07/21/2021] [Indexed: 01/18/2023] Open
Abstract
Achromatopsia (ACHM) is a rare autosomal recessively inherited retinal disease characterized by congenital photophobia, nystagmus, low visual acuity, and absence of color vision. ACHM is genetically heterogeneous and can be caused by biallelic mutations in the genes CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, or ATF6. We undertook molecular genetic analysis in a single female patient with a clinical diagnosis of ACHM and identified the homozygous variant c.778G>C;p.(D260H) in the CNGA3 gene. While segregation analysis in the father, as expected, identified the CNGA3 variant in a heterozygous state, it could not be displayed in the mother. Microsatellite marker analysis provided evidence that the homozygosity of the CNGA3 variant is due to partial or complete paternal uniparental isodisomy (UPD) of chromosome 2 in the patient. Apart from the ACHM phenotype, the patient was clinically unsuspicious and healthy. This is one of few examples proving UPD as the underlying mechanism for the clinical manifestation of a recessive mutation in a patient with inherited retinal disease. It also highlights the importance of segregation analysis in both parents of a given patient or especially in cases of homozygous recessive mutations, as UPD has significant implications for genetic counseling with a very low recurrence risk assessment in such families.
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Affiliation(s)
- Susanne Kohl
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Tübingen, 72076 Tübingen, Germany; (B.B.); (A.K.M.); (M.S.); (P.R.); (L.K.); (B.W.)
| | - Britta Baumann
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Tübingen, 72076 Tübingen, Germany; (B.B.); (A.K.M.); (M.S.); (P.R.); (L.K.); (B.W.)
| | - Francesca Dassie
- Department of Medicine (DIMED), University of Padua, 35121 Padua, Italy; (F.D.); (P.M.)
| | - Anja K. Mayer
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Tübingen, 72076 Tübingen, Germany; (B.B.); (A.K.M.); (M.S.); (P.R.); (L.K.); (B.W.)
| | - Maria Solaki
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Tübingen, 72076 Tübingen, Germany; (B.B.); (A.K.M.); (M.S.); (P.R.); (L.K.); (B.W.)
| | - Peggy Reuter
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Tübingen, 72076 Tübingen, Germany; (B.B.); (A.K.M.); (M.S.); (P.R.); (L.K.); (B.W.)
| | - Laura Kühlewein
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Tübingen, 72076 Tübingen, Germany; (B.B.); (A.K.M.); (M.S.); (P.R.); (L.K.); (B.W.)
- Centre for Ophthalmology, University Eye Hospital, University Tübingen, 72076 Tübingen, Germany
| | - Bernd Wissinger
- Centre for Ophthalmology, Institute for Ophthalmic Research, University Tübingen, 72076 Tübingen, Germany; (B.B.); (A.K.M.); (M.S.); (P.R.); (L.K.); (B.W.)
| | - Pietro Maffei
- Department of Medicine (DIMED), University of Padua, 35121 Padua, Italy; (F.D.); (P.M.)
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Täger J, Wissinger B, Kohl S, Reuter P. Identification of Chemical and Pharmacological Chaperones for Correction of Trafficking-Deficient Mutant Cyclic Nucleotide-Gated A3 Channels. Mol Pharmacol 2021; 99:460-468. [PMID: 33827965 DOI: 10.1124/molpharm.120.000180] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 03/30/2021] [Indexed: 12/19/2022] Open
Abstract
Trafficking deficiency caused by missense mutations is a well known phenomenon that occurs for mutant, misfolded proteins. Typically, the misfolded protein is retained by the protein quality-control system and degraded by the endoplasmic reticulum-associated protein degradation pathway and thus does not reach its destination, although residual function of the protein may be preserved. Chemical and pharmacological chaperones can improve the targeting of trafficking-deficient proteins and thus may be promising candidates for therapeutic applications. Here, we report the application of a cellular bioassay based on the bioluminescent calcium reporter aequorin to quantify surface expression of mutant CNGA3 channels associated with the autosomal recessively inherited retinal disease achromatopsia. A screening of 77 compounds enabled the identification of effective chemical and pharmacological chaperones that result in a 1.5- to 4.8-fold increase of surface expression of mutant CNGA3. Using selected compounds, we confirmed that the rescue of the defective trafficking is not limited to a single mutation in CNGA3. Active compounds and our structure-activity correlated data for the dihydropyridine compound class may provide valuable information for developing a treatment of the trafficking defect in achromatopsia. SIGNIFICANCE STATEMENT: This study describes a novel luminescence-based assay to detect the surface expression of mutant trafficking-deficient CNGA3 channels based on the calcium-sensitive photoprotein aequorin. Using this assay for a compound screening, this study identifies novel chemical and pharmacological chaperones that restore the surface localization of mutant trafficking-deficient CNGA3 channels. The results from this work may serve as starting point for the development of potent compounds that rescue trafficking deficiencies in the autosomal recessively inherited retinal disease achromatopsia.
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Affiliation(s)
- Joachim Täger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research (J.T., B.W., S.K., P.R.), and Graduate School of Cellular and Molecular Neuroscience (J.T.), University of Tübingen, Tübingen, Germany
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research (J.T., B.W., S.K., P.R.), and Graduate School of Cellular and Molecular Neuroscience (J.T.), University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research (J.T., B.W., S.K., P.R.), and Graduate School of Cellular and Molecular Neuroscience (J.T.), University of Tübingen, Tübingen, Germany
| | - Peggy Reuter
- Molecular Genetics Laboratory, Institute for Ophthalmic Research (J.T., B.W., S.K., P.R.), and Graduate School of Cellular and Molecular Neuroscience (J.T.), University of Tübingen, Tübingen, Germany
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28
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Georgiou M, Singh N, Kane T, Zaman S, Hirji N, Aboshiha J, Kumaran N, Kalitzeos A, Carroll J, Weleber RG, Michaelides M. Long-Term Investigation of Retinal Function in Patients with Achromatopsia. Invest Ophthalmol Vis Sci 2021; 61:38. [PMID: 32960951 PMCID: PMC7509756 DOI: 10.1167/iovs.61.11.38] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the long-term natural history of retinal function of achromatopsia (ACHM). Methods Subjects with molecularly confirmed ACHM were recruited in a prospective cohort study of mesopic microperimetry. Coefficient of repeatability and intraclass correlation coefficient (ICC) of mean sensitivity (MS) were calculated. Best-corrected visual acuity (BCVA), bivariate contour ellipse area (BCEA), contrast sensitivity (CS), MS, total volume (VTOT), and central field volume (V5°) from volumetric and topographic analyses were acquired. Correlation of functional parameters with structural findings from optical coherence tomography (OCT) was performed. Results Eighteen subjects were recruited. Mean follow-up was 7.2 years. The MS test–retest repeatability coefficient was 1.65 decibels (dB), and the ICC was 0.973 (95% confidence interval, 0.837–0.98). Mean MS was similar for right and left eyes (16.97dB and 17.14dB, respectively). A negative significant correlation between logMAR BCVA and the retinal sensitivity indices (MS, VTOT, V5°) was found. A significant negative correlation between logCS and MS, VTOT, and V5° was also observed. BCVA and BCEA improved during follow-up. Mean CS, MS, VTOT, and V5° at final follow-up were similar to baseline. MS was similar between CNGA3- and CNGB3-ACHM. Patients with and without the presence of a foveal ellipsoid zone on OCT had similar MS (16.64 dB and 17.17 dB, respectively). Conclusions We demonstrate a highly reproducible assessment of MS. Retinal function including MS, volumetric indices, and CS are stable in ACHM. Improvement of fixation stability and small changes of BCVA over time may be part of the natural history of the disease.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Navjit Singh
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Thomas Kane
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Serena Zaman
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Nashila Hirji
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Jonathan Aboshiha
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Neruban Kumaran
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Wauwatosa, Wisconsin, United States
| | - Richard G Weleber
- Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom
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29
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Georgiou M, Fujinami K, Michaelides M. Inherited retinal diseases: Therapeutics, clinical trials and end points-A review. Clin Exp Ophthalmol 2021; 49:270-288. [PMID: 33686777 DOI: 10.1111/ceo.13917] [Citation(s) in RCA: 69] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/22/2021] [Accepted: 03/01/2021] [Indexed: 12/18/2022]
Abstract
Inherited retinal diseases (IRDs) are a clinically and genetically heterogeneous group of disorders characterised by photoreceptor degeneration or dysfunction. These disorders typically present with severe vision loss that can be progressive, with disease onset ranging from congenital to late adulthood. The advances in genetics, retinal imaging and molecular biology, have conspired to create the ideal environment for establishing treatments for IRDs, with the first approved gene therapy and the commencement of multiple clinical trials. The scope of this review is to familiarise clinicians and scientists with the current management and the prospects for novel therapies for: (1) macular dystrophies, (2) cone and cone-rod dystrophies, (3) cone dysfunction syndromes, (4) Leber congenital amaurosis, (5) rod-cone dystrophies, (6) rod dysfunction syndromes and (7) chorioretinal dystrophies. We also briefly summarise the investigated end points for the ongoing trials.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Kaoru Fujinami
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.,Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
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30
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Zang J, Neuhauss SCF. Biochemistry and physiology of zebrafish photoreceptors. Pflugers Arch 2021; 473:1569-1585. [PMID: 33598728 PMCID: PMC8370914 DOI: 10.1007/s00424-021-02528-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/25/2021] [Accepted: 01/28/2021] [Indexed: 02/06/2023]
Abstract
All vertebrates share a canonical retina with light-sensitive photoreceptors in the outer retina. These photoreceptors are of two kinds: rods and cones, adapted to low and bright light conditions, respectively. They both show a peculiar morphology, with long outer segments, comprised of ordered stacks of disc-shaped membranes. These discs host numerous proteins, many of which contribute to the visual transduction cascade. This pathway converts the light stimulus into a biological signal, ultimately modulating synaptic transmission. Recently, the zebrafish (Danio rerio) has gained popularity for studying the function of vertebrate photoreceptors. In this review, we introduce this model system and its contribution to our understanding of photoreception with a focus on the cone visual transduction cascade.
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Affiliation(s)
- Jingjing Zang
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrase 190, CH - 8057, Zürich, Switzerland
| | - Stephan C F Neuhauss
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrase 190, CH - 8057, Zürich, Switzerland.
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31
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Brunetti-Pierri R, Karali M, Melillo P, Di Iorio V, De Benedictis A, Iaccarino G, Testa F, Banfi S, Simonelli F. Clinical and Molecular Characterization of Achromatopsia Patients: A Longitudinal Study. Int J Mol Sci 2021; 22:1681. [PMID: 33562422 PMCID: PMC7914547 DOI: 10.3390/ijms22041681] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/28/2021] [Accepted: 02/03/2021] [Indexed: 02/08/2023] Open
Abstract
Achromatopsia (ACHM) is a rare genetic disorder of infantile onset affecting cone photoreceptors. To determine the extent of progressive retinal changes in achromatopsia, we performed a detailed longitudinal phenotyping and genetic characterization of an Italian cohort comprising 21 ACHM patients (17 unrelated families). Molecular genetic testing identified biallelic pathogenic mutations in known ACHM genes, including four novel variants. At baseline, the patients presented a reduced best corrected visual acuity (BCVA), reduced macular sensitivity (MS), normal dark-adapted electroretinogram (ERG) responses and undetectable or severely reduced light-adapted ERG. The longitudinal analysis of 16 patients (mean follow-up: 5.4 ± 1.0 years) showed a significant decline of BCVA (0.012 logMAR/year) and MS (-0.16 dB/year). Light-adapted and flicker ERG responses decreased below noise level in three and two patients, respectively. Only two patients (12.5%) progressed to a worst OCT grading during the follow-up. Our findings corroborate the notion that ACHM is a progressive disease in terms of BCVA, MS and ERG responses, and affects slowly the structural integrity of the retina. These observations can serve towards the development of guidelines for patient selection and intervention timing in forthcoming gene replacement therapies.
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Affiliation(s)
- Raffaella Brunetti-Pierri
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Marianthi Karali
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
- Telethon Institute of Genetics and Medicine, via Campi Flegrei 34, 80078 Pozzuoli, Italy;
| | - Paolo Melillo
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Valentina Di Iorio
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Antonella De Benedictis
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Gennarfrancesco Iaccarino
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Francesco Testa
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, via Campi Flegrei 34, 80078 Pozzuoli, Italy;
- Medical Genetics, Department of Precision Medicine, Università degli Studi della Campania “Luigi Vanvitelli”, via Luigi De Crecchio 7, 80138 Naples, Italy
| | - Francesca Simonelli
- Eye Clinic, Multidisciplinary Department of Medical, Surgical and Dental Sciences, Università degli Studi della Campania “Luigi Vanvitelli”, via Pansini 5, 80131 Naples, Italy; (R.B.-P.); (M.K.); (P.M.); (V.D.I.); (A.D.B.); (G.I.); (F.T.)
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Andersen MKG, Kessel L. Ametropia and Emmetropization in CNGB3 Achromatopsia. Invest Ophthalmol Vis Sci 2021; 62:10. [PMID: 33560291 PMCID: PMC7873492 DOI: 10.1167/iovs.62.2.10] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 01/18/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose Emmetropization is the process of adjusting ocular growth to the focal plane in order to achieve a clear image. Chromatic light may be involved as a cue to guide this process. Achromats are color blind and lack normal cone function; they are often described as being hyperopic, indicating a failure to emmetropize. We aim to describe the refraction and refractive development in a population of genetically characterized achromats. Methods Refractive error data were collected retrospectively from 28 medical records of CNGB3 c.1148delC homozygous achromats. The distribution of spherical equivalent refractive error (SER) and spherical error was analyzed in adults. The refractive development in children was analyzed by documenting astigmatic refractive error and calculating median SER in 1-year age groups and by analyzing the individual development when possible. Results The distribution of SER and spherical error resembled a Gaussian distribution, indicating that emmetropization was disturbed in achromats, but we found indication of some decrease in SER during the first years of childhood. The prevalence of refractive errors was high and broadly distributed. Astigmatic refractive errors were frequent but did not seem to increase with age. Conclusions Refractive development in achromats is more complicated than a complete failure to emmetropize. The spread of refractive errors is larger than previously documented. Results presented here support the theory that chromatic cues and cone photoreceptors may play a role in emmetropization in humans but that it is not essential.
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Affiliation(s)
| | - Line Kessel
- Department of Ophthalmology, Copenhagen University Hospital, Rigshospitalet-Glostrup, Glostrup, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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33
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Noel NCL, MacDonald IM, Allison WT. Zebrafish Models of Photoreceptor Dysfunction and Degeneration. Biomolecules 2021; 11:78. [PMID: 33435268 PMCID: PMC7828047 DOI: 10.3390/biom11010078] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 12/15/2022] Open
Abstract
Zebrafish are an instrumental system for the generation of photoreceptor degeneration models, which can be utilized to determine underlying causes of photoreceptor dysfunction and death, and for the analysis of potential therapeutic compounds, as well as the characterization of regenerative responses. We review the wealth of information from existing zebrafish models of photoreceptor disease, specifically as they relate to currently accepted taxonomic classes of human rod and cone disease. We also highlight that rich, detailed information can be derived from studying photoreceptor development, structure, and function, including behavioural assessments and in vivo imaging of zebrafish. Zebrafish models are available for a diversity of photoreceptor diseases, including cone dystrophies, which are challenging to recapitulate in nocturnal mammalian systems. Newly discovered models of photoreceptor disease and drusenoid deposit formation may not only provide important insights into pathogenesis of disease, but also potential therapeutic approaches. Zebrafish have already shown their use in providing pre-clinical data prior to testing genetic therapies in clinical trials, such as antisense oligonucleotide therapy for Usher syndrome.
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Affiliation(s)
- Nicole C. L. Noel
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
| | - Ian M. MacDonald
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, AB T6G 2R7, Canada
| | - W. Ted Allison
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada; (I.M.M.); (W.T.A.)
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada
- Centre for Prions and Protein Folding Diseases, University of Alberta, Edmonton, AB T6G 2M8, Canada
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34
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Self JE, Lee H. Novel therapeutics in nystagmus: what has the genetics taught us so far? THERAPEUTIC ADVANCES IN RARE DISEASE 2021; 2:2633004021998714. [PMID: 37181109 PMCID: PMC10032456 DOI: 10.1177/2633004021998714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 02/08/2021] [Indexed: 05/16/2023]
Abstract
Nystagmus is a disorder characterised by uncontrolled, repetitive, to-and-fro movement of the eyes. It can occur as a seemingly isolated disorder but is most commonly the first, or most obvious, feature in a host of ophthalmic and systemic disorders. The number of underlying causes is vast, and recent improvements in the provision of genetic testing have shown that many conditions can include nystagmus as a feature, but that phenotypes overlap significantly. Therefore, an increase in the understanding of the genetic causes of nystagmus has shown that successful novel therapeutics for 'nystagmus' can target either specific underlying disorders and mechanisms (aiming to treat the underlying condition as a whole), or a final common pathway (aiming to treat the nystagmus directly). Plain language summary Novel treatments for a disorder of eye movement (nystagmus): what has the genetics taught us so far? Nystagmus is a disorder of eye movement characterised by uncontrolled, to-and-fro movements. It can occur as an isolated disorder, in conditions affecting other parts of the eye, in conditions affecting multiple other parts of the body or secondary to neurological diseases (brain diseases). In recent years, advances in genetic testing methods and increase in genetic testing in healthcare systems have provided a greater understanding of the underlying causes of nystagmus. They have highlighted the bewildering number of genetic causes that can result in what looks like a very similar eye movement disorder.In recent years, new classes of drugs have been developed for some of the causes of nystagmus, and some new drugs have been developed for other conditions which have the potential to work in certain types of nystagmus. For these reasons, genetics has taught us that identifying new possible treatments for nystagmus can either be dependent on identifying the underlying genetic cause and aiming to treat that, or aiming to treat the nystagmus per se by targeting a final common pathway. A toolkit based on specific treatments for specific conditions is more to have meaningful impact on 'nystagmus' than pursuing a panacea based on a 'one size fits all' approach.
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Affiliation(s)
- Jay E Self
- Clinical and Experimental Sciences, Faculty of
Medicine, University of Southampton, Tremona Road, Southampton SO16 6YD,
UK
- University Hospital Southampton, Southampton,
UK
| | - Helena Lee
- Clinical and Experimental Sciences, Faculty of
Medicine, University of Southampton, Southampton, UK
- University Hospital Southampton, Southampton,
UK
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35
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Litts KM, Georgiou M, Langlo CS, Patterson EJ, Mastey RR, Kalitzeos A, Linderman RE, Lam BL, Fishman GA, Pennesi ME, Kay CN, Hauswirth WW, Michaelides M, Carroll J. Interocular Symmetry of Foveal Cone Topography in Congenital Achromatopsia. Curr Eye Res 2020; 45:1257-1264. [PMID: 32108519 PMCID: PMC7487033 DOI: 10.1080/02713683.2020.1737138] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 02/25/2020] [Indexed: 01/26/2023]
Abstract
Purpose: To determine the interocular symmetry of foveal cone topography in achromatopsia (ACHM) using non-confocal split-detection adaptive optics scanning light ophthalmoscopy (AOSLO). Methods: Split-detector AOSLO images of the foveal cone mosaic were acquired from both eyes of 26 subjects (mean age 24.3 years; range 8-44 years, 14 females) with genetically confirmed CNGA3- or CNGB3-associated ACHM. Cones were identified within a manually delineated rod-free zone. Peak cone density (PCD) was determined using an 80 × 80 μm sampling window within the rod-free zone. The mean and standard deviation (SD) of inter-cell distance (ICD) were calculated to derive the coefficient of variation (CV). Cone density difference maps were generated to compare cone topography between eyes. Results: PCD (mean ± SD) was 17,530 ± 9,614 cones/mm2 and 17,638 ± 9,753 cones/mm2 for right and left eyes, respectively (p = .677, Wilcoxon test). The mean (± SD) for ICD was 9.05 ± 2.55 µm and 9.24 ± 2.55 µm for right and left eyes, respectively (p = .410, paired t-test). The mean (± SD) for CV of ICD was 0.16 ± 0.03 µm and 0.16 ± 0.04 µm for right and left eyes, respectively (p = .562, paired t-test). Cone density maps demonstrated that cone topography of the ACHM fovea is non-uniform with local variations in cone density between eyes. Conclusions: These results demonstrate the interocular symmetry of the foveal cone mosaic (both density and packing) in ACHM. As cone topography can differ between eyes of a subject, PCD does not completely describe the foveal cone mosaic in ACHM. Nonetheless, these findings are of value in longitudinal monitoring of patients during treatment trials and further suggest that both eyes of a given subject may have similar therapeutic potential and non-study eye can be used as a control.
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Affiliation(s)
- Katie M. Litts
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Christopher S. Langlo
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Emily J. Patterson
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Rebecca R. Mastey
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Angelos Kalitzeos
- Moorfields Eye Hospital, London, United Kingdom
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Rachel E. Linderman
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Byron L. Lam
- Bascom Palmer Eye Institute, University of Miami, Miami, Florida, United States of America
| | - Gerald A. Fishman
- Pangere Center for Inherited Retinal Diseases, The Chicago Lighthouse, Chicago, Illinois, United States
| | - Mark E. Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239
| | | | | | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Joseph Carroll
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
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Abstract
Inherited retinal diseases (IRD) are a leading cause of blindness in the working age population. The advances in ocular genetics, retinal imaging and molecular biology, have conspired to create the ideal environment for establishing treatments for IRD, with the first approved gene therapy and the commencement of multiple therapy trials. The scope of this review is to familiarize clinicians and scientists with the current landscape of retinal imaging in IRD. Herein we present in a comprehensive and concise manner the imaging findings of: (I) macular dystrophies (MD) [Stargardt disease (ABCA4), X-linked retinoschisis (RS1), Best disease (BEST1), pattern dystrophy (PRPH2), Sorsby fundus dystrophy (TIMP3), and autosomal dominant drusen (EFEMP1)], (II) cone and cone-rod dystrophies (GUCA1A, PRPH2, ABCA4 and RPGR), (III) cone dysfunction syndromes [achromatopsia (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2, ATF6], blue-cone monochromatism (OPN1LW/OPN1MW array), oligocone trichromacy, bradyopsia (RGS9/R9AP) and Bornholm eye disease (OPN1LW/OPN1MW), (IV) Leber congenital amaurosis (GUCY2D, CEP290, CRB1, RDH12, RPE65, TULP1, AIPL1 and NMNAT1), (V) rod-cone dystrophies [retinitis pigmentosa, enhanced S-Cone syndrome (NR2E3), Bietti crystalline corneoretinal dystrophy (CYP4V2)], (VI) rod dysfunction syndromes (congenital stationary night blindness, fundus albipunctatus (RDH5), Oguchi disease (SAG, GRK1), and (VII) chorioretinal dystrophies [choroideremia (CHM), gyrate atrophy (OAT)].
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Kaoru Fujinami
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Jinda W, Tuekprakhon A, Thongnoppakhun W, Limwongse C, Trinavarat A, Atchaneeyasakul LO. Molecular and clinical characterization of Thai patients with achromatopsia: identification of three novel disease-associated variants in the CNGA3 and CNGB3 genes. Int Ophthalmol 2020; 41:121-134. [PMID: 32869108 DOI: 10.1007/s10792-020-01559-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 08/17/2020] [Indexed: 11/24/2022]
Abstract
PURPOSE Achromatopsia (ACHM) is an autosomal recessive cone disorder characterized by pendular nystagmus, photophobia, reduced visual acuity, and partial or total absence of color vision. Mutations in six genes (CNGA3, CNGB3, GNAT2, PDE6C, PDE6H, and ATF6) have been reported in ACHM. There is no information on these disease-associated genes in Thai population. This study aimed to investigate the molecular and clinical characteristics in Thai patients with ACHM. METHODS Seven unrelated Thai patients with ACHM were recruited. Detailed ophthalmologic examination was performed. Polymerase chain reaction (PCR)-coupled single-strand conformation polymorphism (SSCP) screening followed by Sanger sequencing was used to identify sequence variants in all exons and splice junctions of three genes (CNGA3, CNGB3, and GNAT2). The pathogenicity of the detected variants was interpreted. Segregation analysis was performed to determine variant sharing in available family members. RESULTS Four patients displayed different SSCP migration patterns. Sequence analysis revealed a reported pathogenic and a novel disease-associated variant in the CNGA3 gene. For the CNGB3 gene, we found two novel disease-associated variants and a reported variant of uncertain significance (VUS). Segregation analysis confirmed that the variants identified in each patient were present in the heterozygous state in their corresponding family members, which was consistent with an autosomal recessive mode of inheritance. CONCLUSIONS This study demonstrated the first molecular and clinical characterization of ACHM in Thai patients. The identification of disease-associated genes in a specific population leads to a personalized gene therapy benefiting those affected patients.
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Affiliation(s)
- Worapoj Jinda
- Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Aekkachai Tuekprakhon
- Clinical Molecular Pathology Laboratory, Department of Clinical Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Wanna Thongnoppakhun
- Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Chanin Limwongse
- Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.,Division of Medical Genetics, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Adisak Trinavarat
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - La-Ongsri Atchaneeyasakul
- Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
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Sun W, Li S, Xiao X, Wang P, Zhang Q. Genotypes and phenotypes of genes associated with achromatopsia: A reference for clinical genetic testing. Mol Vis 2020; 26:588-602. [PMID: 32913385 PMCID: PMC7479066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 08/20/2020] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Achromatopsia is a congenital autosomal recessive cone disorder, and it has been found to be associated with six genes. However, pathogenic variants in these six genes have been identified in patients with various retinal dystrophies with the exception of achromatopsia. Thus, this study aims to investigate the contribution of these genes in hereditary retinal diseases and the potential genotype-phenotype correlations. METHODS Biallelic variants in six achromatopsia-related genes, namely, CNGA3, CNGB3, GNAT2, ATF6, PDE6C, and PDE6H, were analyzed based on data obtained from 7,195 probands with different eye conditions. A systematic genotype-phenotype analysis of these genes was performed based on these data, along with the data reported in the literature. RESULTS Biallelic potential pathogenic variants (PPVs) in five of the six genes were identified in 119 probands with genetic eye diseases. The variants in CNGA3 were the most common and accounted for 81.5% (97/119). Of the 119 probands, 62.2% (74/119) have cone-rod dystrophy, whereas only 25.2% (30/119) have achromatopsia. No biallelic pathogenic variants in these genes were identified in patients with rod-dominant degeneration. A systematic review of genotypes and phenotypes revealed certain characteristics of each of the six genes, providing clues for the pathogenicity evaluation of the variants of the genes. CONCLUSIONS PPVs in the six genes were identified in various inherited retinal degeneration diseases, most of which are cone-dominant diseases but no rod-dominant diseases based on the data from a cohort of 7,195 probands with different eye conditions. The systematic genotype-phenotype analysis of these genes will be useful in drafting guidelines for the clinical genetic diagnostic application for the investigated genes.
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Georgiou M, Singh N, Kane T, Robson AG, Kalitzeos A, Hirji N, Webster AR, Dubra A, Carroll J, Michaelides M. Photoreceptor Structure in GNAT2-Associated Achromatopsia. Invest Ophthalmol Vis Sci 2020; 61:40. [PMID: 32203983 PMCID: PMC7401776 DOI: 10.1167/iovs.61.3.40] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to report GNAT2-associated achromatopsia (GNAT2-ACHM) natural history, characterize photoreceptor mosaic, and determine a therapeutic window for potential intervention. Methods Patients with GNAT2-ACHM were recruited from a single tertiary referral eye center (Moorfields Eye Hospital, London, UK). We performed longitudinal clinical evaluation and ophthalmic examination, and multimodal retinal imaging, including adaptive optics scanning light ophthalmoscopy, quantitative analysis of the cone mosaic, and outer nuclear layer (ONL) thickness, including cone densities evaluation in selected regions of interest and comparison with reported healthy controls. Results All nine subjects (3 women) presented with nystagmus, decreased visual acuity (VA), light sensitivity, and highly variable color vision loss. One patient had normal color vision and better VA. Mean VA was 1.01 (±0.10) logarithms of the minimal angle of resolution (LogMAR) at baseline, and 1.04 (±0.10) LogMAR after a mean follow-up (range) of 7.6 years (1.7−12.8 years). Optical coherence tomography showed preservation of the foveal ellipsoid zone (EZ; n = 8; 88.9%), and EZ disruption (n = 1; 11.1%). Mean ONL thickness (range, ± SD) was 84.72 µm (28.57−113.33, ± 25.46 µm) and 86.47 µm (28.57−113.33, ± 24.65 µm) for right and left eyes, respectively. Mean cone densities (±SD) at 190 µm, 350 µm, and 500 µm from the foveal center, were 48.4 (±24.6), 37.8 (±14.7), and 30.7 (±9.9), ×103 cones/mm2, respectively. Mean cone densities were lower than these of unaffected individuals, but with an overlap. Conclusions The cone mosaic in GNAT2-ACHM is relatively well preserved, potentially allowing for a wide therapeutic window for cone-directed interventions.
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40
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Georgiou M, Litts KM, Singh N, Kane T, Patterson EJ, Hirji N, Kalitzeos A, Dubra A, Michaelides M, Carroll J. Intraobserver Repeatability and Interobserver Reproducibility of Foveal Cone Density Measurements in CNGA3- and CNGB3-Associated Achromatopsia. Transl Vis Sci Technol 2020; 9:37. [PMID: 32832242 PMCID: PMC7414701 DOI: 10.1167/tvst.9.7.37] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 04/13/2020] [Indexed: 01/06/2023] Open
Abstract
Purpose To examine repeatability and reproducibility of foveal cone density measurements in patients with CNGA3 - and CNGB3-associated achromatopsia (ACHM) using split-detection adaptive optics scanning light ophthalmoscopy (AOSLO). Methods Thirty foveae from molecularly confirmed subjects with ACHM, half of whom harbored disease-causing variants in CNGA3 and half in CNGB3, underwent nonconfocal split-detection AOSLO imaging. Cone photoreceptors within the manually delineated rod-free zone were manually identified twice by two independent observers. The coordinates of the marked cones were used for quantifying foveal cone density. Cone density and difference maps were generated to compare cone topography between trials. Results We observed excellent intraobserver repeatability in foveal cone density estimates, with intraclass correlation coefficients (ICCs) ranging from 0.963 to 0.991 for CNGA3 and CNGB3 subjects. Interobserver reproducibility was also excellent for both CNGA3 (ICC = 0.952; 95% confidence interval [CI], 0.903-1.0) and CNGB3 (ICC = 0.968; 95% CI, 0.935-1.0). However, Bland-Altman analysis revealed bias between observers. Conclusions Foveal cone density can be measured using the described method with good repeatability and reproducibility both for CNGA3- and CNGB3-associated ACHM. Any degree of bias observed among the observers is of uncertain clinical significance but should be evaluated on a study-specific basis. Translational Relevance This approach could be used to explore disease natural history, as well as to facilitate stratification of patients and monitor efficacy of interventions for ongoing and upcoming ACHM gene therapy trials.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Katie M Litts
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Navjit Singh
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Thomas Kane
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Emily J Patterson
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Nashila Hirji
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, CA, USA
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
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Lee EJ, Chiang WCJ, Kroeger H, Bi CX, Chao DL, Skowronska-Krawczyk D, Mastey RR, Tsang SH, Chea L, Kim K, Lambert SR, Grandjean JM, Baumann B, Audo I, Kohl S, Moore AT, Wiseman RL, Carroll J, Lin JH. Multiexon deletion alleles of ATF6 linked to achromatopsia. JCI Insight 2020; 5:136041. [PMID: 32271167 PMCID: PMC7205249 DOI: 10.1172/jci.insight.136041] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/04/2020] [Indexed: 12/20/2022] Open
Abstract
Achromatopsia (ACHM) is an autosomal recessive disease that results in severe visual loss. Symptoms of ACHM include impaired visual acuity, nystagmus, and photoaversion starting from infancy; furthermore, ACHM is associated with bilateral foveal hypoplasia and absent or severely reduced cone photoreceptor function on electroretinography. Here, we performed genetic sequencing in 3 patients from 2 families with ACHM, identifying and functionally characterizing 2 mutations in the activating transcription factor 6 (ATF6) gene. We identified a homozygous deletion covering exons 8-14 of the ATF6 gene from 2 siblings from the same family. In another patient from a different family, we identified a heterozygous deletion covering exons 2 and 3 of the ATF6 gene found in trans with a previously identified ATF6 c.970C>T (p.Arg324Cys) ACHM disease allele. Recombinant ATF6 proteins bearing these exon deletions showed markedly impaired transcriptional activity by qPCR and RNA-Seq analysis compared with WT-ATF6. Finally, RNAscope revealed that ATF6 and the related ATF6B transcripts were expressed in cones as well as in all retinal layers in normal human retina. Overall, our data identify loss-of-function ATF6 disease alleles that cause human foveal disease.
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Affiliation(s)
- Eun-Jin Lee
- Department of Ophthalmology, Shiley Eye Institute, and
- Department of Pathology, UCSD, San Diego, California, USA
- Department of Ophthalmology, Stanford University, Stanford, California, USA
| | - Wei-Chieh Jerry Chiang
- Department of Pathology, UCSD, San Diego, California, USA
- Developmental Neurobiology Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Heike Kroeger
- Department of Pathology, UCSD, San Diego, California, USA
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA
| | | | | | | | - Rebecca R. Mastey
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Stephen H. Tsang
- Departments of Ophthalmology and Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Leon Chea
- Department of Pathology, Stanford University, Stanford, California, USA
| | - Kyle Kim
- Department of Pathology, UCSD, San Diego, California, USA
| | - Scott R. Lambert
- Department of Ophthalmology, Stanford University, Stanford, California, USA
| | - Julia M.D. Grandjean
- Department of Molecular Medicine, The Scripps Research Institute, San Diego, California, USA
| | - Britta Baumann
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
- CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DGOS CIC1423, Paris, France
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Anthony T. Moore
- Department of Ophthalmology, UCSF, San Francisco, California, USA
| | - R. Luke Wiseman
- Department of Molecular Medicine, The Scripps Research Institute, San Diego, California, USA
| | - Joseph Carroll
- Department of Ophthalmology and Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Jonathan H. Lin
- Department of Ophthalmology, Stanford University, Stanford, California, USA
- Department of Pathology, Stanford University, Stanford, California, USA
- VA Palo Alto Healthcare System, Palo Alto, California, USA
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Magnuson JT, Bautista NM, Lucero J, Lund AK, Xu EG, Schlenk D, Burggren WW, Roberts AP. Exposure to Crude Oil Induces Retinal Apoptosis and Impairs Visual Function in Fish. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2843-2850. [PMID: 32036658 DOI: 10.1021/acs.est.9b07658] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Polycyclic aromatic hydrocarbons (PAHs) present in crude oil are known to impair visual development in fish. However, the underlying mechanism of PAH-induced toxicity to the visual system of fish is not understood. Embryonic zebrafish (Danio rerio) at 4 h post fertilization were exposed to weathered crude oil and assessed for visual function using an optokinetic response, with subsequent samples taken for immunohistochemistry and gene expression analysis. Cardiotoxicity was also assessed by measuring the heart rate, stroke volume, and cardiac output, as cardiac performance has been proposed to be a contributing factor to eye-associated malformations following oil exposure. Larvae exposed to the highest concentrations of crude oil (89.8 μg/L) exhibited an increased occurrence of bradycardia, though no changes in stroke volume or cardiac output were observed. However, genes important in eye development and phototransduction were downregulated in oil-exposed larvae, with an increased occurrence of cellular apoptosis, reduced neuronal connection, and reduced optokinetic behavioral response in zebrafish larvae.
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Affiliation(s)
- Jason T Magnuson
- Department of Biological Sciences and Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76203, United States
| | - Naim M Bautista
- Department of Biological Sciences and Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76203, United States
| | - JoAnn Lucero
- Department of Biological Sciences and Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76203, United States
| | - Amie K Lund
- Department of Biological Sciences and Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76203, United States
| | - Elvis Genbo Xu
- Department of Chemical Engineering, McGill University, Montreal, Quebec H3A0C5, Canada
| | - Daniel Schlenk
- Department of Environmental Sciences, University of California, Riverside, Riverside, California 92521, United States
| | - Warren W Burggren
- Department of Biological Sciences and Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76203, United States
| | - Aaron P Roberts
- Department of Biological Sciences and Advanced Environmental Research Institute, University of North Texas, Denton, Texas 76203, United States
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RD Genes Associated with High Photoreceptor cGMP-Levels (Mini-Review). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1185:245-249. [PMID: 31884619 DOI: 10.1007/978-3-030-27378-1_40] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Many RD-causing mutations lead to a dysregulation of cyclic guanosine monophosphate (cGMP), making cGMP signalling a prime target for the development of new treatment approaches. We showed previously that an analogue of cGMP, which inhibited cGMP signalling targets, increased photoreceptor viability in three rodent RD models carrying different genetic defects, in different RD genes. This raises the question of the possible generality of this approach as a treatment for RD. Here, we review RD genes that can be associated with high cGMP and discuss which RD genes might be amenable to a treatment aimed at inhibiting excessive cGMP signalling.
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Zhang Y, Wang S, Xu M, Pang J, Yuan Z, Zhao C. AAV-mediated human CNGB3 restores cone function in an all-cone mouse model of CNGB3 achromatopsia. J Biomed Res 2020; 34:114-121. [PMID: 32305965 DOI: 10.7555/jbr.33.20190056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Complete congenital achromatopsia is a devastating hereditary visual disorder. Mutations in the CNGB3 gene account for more than 50% of all known cases of achromatopsia. This work investigated the efficiency of subretinal (SR) delivered AAV8 (Y447, 733F) vector containing a human PR2.1 promoter and a human CNGB3 cDNA in Cngb3 -/-/ Nrl -/- mice. The Cngb3 -/-/ Nrl -/- mouse was a cone-dominant model with Cngb3 channel deficiency, which partially mimicked the all-cone foveal structure of human achromatopsia with CNGB3 mutations. Following SR delivery of the vector, AAV-mediated CNGB3 expression restored cone function which was assessed by the restoration of the cone-mediated electroretinogram (ERG) and immunohistochemistry. This therapeutic rescue resulted in long-term improvement of retinal function with the restoration of cone ERG amplitude. This study demonstrated an AAV-mediated gene therapy in a cone-dominant mouse model using a human gene construct and provided the potential to be utilized in clinical trials.
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Affiliation(s)
- Yuxin Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Shanshan Wang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Miao Xu
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Jijing Pang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China;Department of Ophthalmology, University of Florida, Gainesville, FL 32610, USA
| | - Zhilan Yuan
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Chen Zhao
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China
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Mastey RR, Georgiou M, Langlo CS, Kalitzeos A, Patterson EJ, Kane T, Singh N, Vincent A, Moore AT, Tsang SH, Lin JH, Young MP, Hartnett ME, Héon E, Kohl S, Michaelides M, Carroll J. Characterization of Retinal Structure in ATF6-Associated Achromatopsia. Invest Ophthalmol Vis Sci 2019; 60:2631-2640. [PMID: 31237654 PMCID: PMC6594318 DOI: 10.1167/iovs.19-27047] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Purpose Mutations in six genes have been associated with achromatopsia (ACHM): CNGA3, CNGB3, PDE6H, PDE6C, GNAT2, and ATF6. ATF6 is the most recent gene to be identified, though thorough phenotyping of this genetic subtype is lacking. Here, we sought to test the hypothesis that ATF6-associated ACHM is a structurally distinct form of congenital ACHM. Methods Seven genetically confirmed subjects from five nonconsanguineous families were recruited. Foveal hypoplasia and the integrity of the ellipsoid zone (EZ) band (a.k.a., IS/OS) were graded from optical coherence tomography (OCT) images. Images of the photoreceptor mosaic were acquired using confocal and nonconfocal split-detection adaptive optics scanning light ophthalmoscopy (AOSLO). Parafoveal cone and rod density values were calculated and compared to published normative data as well as data from two subjects harboring CNGA3 or CNGB3 mutations who were recruited for comparative purposes. Additionally, nonconfocal dark-field AOSLO images of the retinal pigment epithelium were obtained, with quantitative analysis performed in one subject with ATF6-ACHM. Results Foveal hypoplasia was observed in all subjects with ATF6 mutations. Absence of the EZ band within the foveal region (grade 3) or appearance of a hyporeflective zone (grade 4) was seen in all subjects with ATF6 using OCT. There was no evidence of remnant foveal cone structure using confocal AOSLO, although sporadic cone-like structures were seen in nonconfocal split-detection AOSLO. There was a lack of cone structure in the parafovea, in direct contrast to previous reports. Conclusions Our data demonstrate a near absence of cone structure in subjects harboring ATF6 mutations. This implicates ATF6 as having a major role in cone development and suggests that at least a subset of subjects with ATF6-ACHM have markedly fewer cellular targets for cone-directed gene therapies than do subjects with CNGA3- or CNGB3-ACHM.
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Affiliation(s)
- Rebecca R Mastey
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Christopher S Langlo
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Emily J Patterson
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Thomas Kane
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Navjit Singh
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Ajoy Vincent
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, The University of Toronto, Toronto, Canada
| | - Anthony T Moore
- Department of Ophthalmology, University of California-San Francisco Medical School, San Francisco, California, United States
| | - Stephen H Tsang
- Jonas Children's Vision Care, Departments of Ophthalmology, Pathology and Cell Biology, Columbia Stem Cell Initiative, New York, New York, United States
| | - Jonathan H Lin
- Department of Ophthalmology, University of California-San Diego, La Jolla, California, United States.,Department of Pathology, University of California-San Diego, La Jolla, California, United States
| | - Marielle P Young
- Moran Eye Center, University of Utah, Salt Lake City, Utah, United States
| | | | - Elise Héon
- Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, The University of Toronto, Toronto, Canada
| | - Susanne Kohl
- Centre for Ophthalmology Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom.,Moorfields Eye Hospital, London, United Kingdom
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States.,Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
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Georgiou M, Robson AG, Singh N, Pontikos N, Kane T, Hirji N, Ripamonti C, Rotsos T, Dubra A, Kalitzeos A, Webster AR, Carroll J, Michaelides M. Deep Phenotyping of PDE6C-Associated Achromatopsia. Invest Ophthalmol Vis Sci 2019; 60:5112-5123. [PMID: 31826238 PMCID: PMC6905659 DOI: 10.1167/iovs.19-27761] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 10/23/2019] [Indexed: 11/29/2022] Open
Abstract
Purpose To perform deep phenotyping of subjects with PDE6C achromatopsia and examine disease natural history. Methods Eight subjects with disease-causing variants in PDE6C were assessed in detail, including clinical phenotype, best-corrected visual acuity, fundus autofluorescence, and optical coherence tomography. Six subjects also had confocal and nonconfocal adaptive optics scanning light ophthalmoscopy, axial length, international standard pattern and full-field electroretinography (ERG), short-wavelength flash (S-cone) ERGs, and color vision testing. Results All subjects presented with early-onset nystagmus, decreased best-corrected visual acuity, light sensitivity, and severe color vision loss, and five of them had high myopia. We identified three novel disease-causing variants and provide phenotype data associated with nine variants for the first time. No subjects had foveal hypoplasia or residual ellipsoid zone (EZ) at the foveal center; one had an absent EZ, three had a hyporeflective zone, and four had outer retinal atrophy. The mean width of the central EZ lesion on optical coherence tomography at baseline was 1923 μm. The mean annual increase in EZ lesion size was 48.3 μm. Fundus autofluorescence revealed a central hypoautofluorescence with a surrounding ring of increased signal (n = 5). The mean hypoautofluorescent area at baseline was 3.33 mm2 and increased in size by a mean of 0.13 mm2/year. Nonconfocal adaptive optics scanning light ophthalmoscopy revealed residual foveal cones in only one of two cases. Full-field ERGs were consistent with severe generalized cone system dysfunction but with relative preservation of S-cone sensitivity. Conclusions PDE6C retinopathy is a severe cone dysfunction syndrome often presenting as typical achromatopsia but without foveal hypoplasia. Myopia and slowly progressive maculopathy are common features. There are few (if any) residual foveal cones for intervention in older adults.
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Affiliation(s)
- Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Anthony G. Robson
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Navjit Singh
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Nikolas Pontikos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Thomas Kane
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Nashila Hirji
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | | | - Tryfon Rotsos
- First Division of Ophthalmology, National and Kapodistrian University of Athens, General Hospital of Athens, Athens, Greece
| | - Alfredo Dubra
- Department of Ophthalmology, Stanford University, Palo Alto, California, United States
| | - Angelos Kalitzeos
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Andrew R. Webster
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
| | - Joseph Carroll
- Department of Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, United Kingdom
- Moorfields Eye Hospital NHS Foundation Trust, City Road, London, United Kingdom
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Mastey RR, Gaffney M, Litts KM, Langlo CS, Patterson EJ, Strampe MR, Kalitzeos A, Michaelides M, Carroll J. Assessing the Interocular Symmetry of Foveal Outer Nuclear Layer Thickness in Achromatopsia. Transl Vis Sci Technol 2019; 8:21. [PMID: 31602346 PMCID: PMC6779097 DOI: 10.1167/tvst.8.5.21] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 08/12/2019] [Indexed: 02/02/2023] Open
Abstract
Purpose We examine the interocular symmetry of foveal outer nuclear layer (ONL) thickness measurements in subjects with achromatopsia (ACHM). Methods Images from 76 subjects with CNGA3- or CNGB3-associated ACHM and 42 control subjects were included in the study. Line or volume scans through the fovea of each eye were acquired using optical coherence tomography (OCT). Image quality was assessed for each image included in the analysis using a previously-described maximum tissue contrast index (mTCI) metric. Three foveal ONL thickness measurements were made by a single observer and interocular symmetry was assessed using the average of the three measurements for each eye. Results Mean (± standard deviation) foveal ONL thickness for subjects with ACHM was 79.7 ± 18.3 μm (right eye) and 79.2 ± 18.7 μm (left eye) compared to 112.9 ± 15.2 (right eye) and 112.1 ± 13.9 μm (left eye) for controls. Foveal ONL thickness did not differ between eyes for ACHM (P = 0.636) or control subjects (P = 0.434). No significant relationship between mTCI and observer repeatability was observed for either control (P = 0.140) or ACHM (P = 0.351) images. Conclusions While foveal ONL thickness is reduced in ACHM compared to controls, the high interocular symmetry indicates that contralateral ONL measurements could be used as a negative control in early-phase monocular treatment trials. Translational Relevance Foveal ONL thickness can be measured using OCT images over a wide range of image quality. The interocular symmetry of foveal ONL thickness in ACHM and control populations supports the use of the non-study eye as a control for clinical trial purposes.
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Affiliation(s)
- Rebecca R Mastey
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Mina Gaffney
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Katie M Litts
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Christopher S Langlo
- Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Emily J Patterson
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Margaret R Strampe
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.,University of Minnesota Medical School, Minneapolis, MN, USA
| | - Angelos Kalitzeos
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK.,Moorfields Eye Hospital, London, EC1V 2PD, UK
| | - Michel Michaelides
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK.,Moorfields Eye Hospital, London, EC1V 2PD, UK
| | - Joseph Carroll
- Ophthalmology & Visual Sciences, Medical College of Wisconsin, Milwaukee, WI, USA.,Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA
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48
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Leinonen H, Choi EH, Gardella A, Kefalov VJ, Palczewski K. A Mixture of U.S. Food and Drug Administration-Approved Monoaminergic Drugs Protects the Retina From Light Damage in Diverse Models of Night Blindness. Invest Ophthalmol Vis Sci 2019; 60:1442-1453. [PMID: 30947334 PMCID: PMC6736410 DOI: 10.1167/iovs.19-26560] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Purpose The purpose of this study was to test the extent of light damage in different models of night blindness and apply these paradigms in testing the therapeutic efficacy of combination therapy by drugs acting on the Gi, Gs, and Gq protein-coupled receptors. Methods Acute bright light exposure was used to test susceptibility to light damage in mice lacking the following crucial phototransduction proteins: rod transducin (GNAT1), cone transducin (GNAT2), visual arrestin 1 (ARR1), and rhodopsin kinase 1 (GRK1). Mice were intraperitoneally injected with either vehicle or drug combination consisting of metoprolol (β1-receptor antagonist), bromocriptine (dopamine family-2 receptor agonist) and tamsulosin (α1-receptor antagonist) before bright light exposure. Light damage was primarily assessed with optical coherence tomography and inspection of cone population in retinal whole mounts. Retinal inflammation was assessed in a subset of experiments using autofluorescence imaging by scanning laser ophthalmoscopy and by postmortem inspection of microglia and astrocyte activity. Results The Gnat1−/− mice showed slightly increased susceptibility to rod light damage, whereas the Gnat2−/− mice were very resistant. The Arr1−/− and Grk1−/− mice were sensitive for both rod and cone light damage and showed robust retinal inflammation 7 days after bright light exposure. Pretreatment with metoprolol + bromocriptine + tamsulosin rescued the retina in all genetic backgrounds, starting at doses of 0.2 mg/kg metoprolol, 0.02 mg/kg bromocriptine, and 0.01 mg/kg tamsulosin in the Gnat1−/− mice. The therapeutic drug doses increased in parallel with light-damage severity. Conclusions Our results suggest that congenital stationary night blindness and Oguchi disease patients can be at an elevated risk of the toxic effects of bright light. Furthermore, systems pharmacology drug regimens that stimulate Gi signaling and attenuate Gs and Gq signaling present a promising disease-modifying therapy for photoreceptor degenerative diseases.
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Affiliation(s)
- Henri Leinonen
- Gavin Herbert Eye Institute and the Department of Ophthalmology, University of California-Irvine, Irvine, California, United States.,Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Elliot H Choi
- Gavin Herbert Eye Institute and the Department of Ophthalmology, University of California-Irvine, Irvine, California, United States.,Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
| | - Anthony Gardella
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, United States
| | - Vladimir J Kefalov
- Department of Ophthalmology and Visual Sciences, Washington University, St. Louis, Missouri, United States
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute and the Department of Ophthalmology, University of California-Irvine, Irvine, California, United States.,Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, United States
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49
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Power M, Das S, Schütze K, Marigo V, Ekström P, Paquet-Durand F. Cellular mechanisms of hereditary photoreceptor degeneration - Focus on cGMP. Prog Retin Eye Res 2019; 74:100772. [PMID: 31374251 DOI: 10.1016/j.preteyeres.2019.07.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Revised: 07/25/2019] [Accepted: 07/29/2019] [Indexed: 12/21/2022]
Abstract
The cellular mechanisms underlying hereditary photoreceptor degeneration are still poorly understood, a problem that is exacerbated by the enormous genetic heterogeneity of this disease group. However, the last decade has yielded a wealth of new knowledge on degenerative pathways and their diversity. Notably, a central role of cGMP-signalling has surfaced for photoreceptor cell death triggered by a subset of disease-causing mutations. In this review, we examine key aspects relevant for photoreceptor degeneration of hereditary origin. The topics covered include energy metabolism, epigenetics, protein quality control, as well as cGMP- and Ca2+-signalling, and how the related molecular and metabolic processes may trigger photoreceptor demise. We compare and integrate evidence on different cell death mechanisms that have been associated with photoreceptor degeneration, including apoptosis, necrosis, necroptosis, and PARthanatos. A special focus is then put on the mechanisms of cGMP-dependent cell death and how exceedingly high photoreceptor cGMP levels may cause activation of Ca2+-dependent calpain-type proteases, histone deacetylases and poly-ADP-ribose polymerase. An evaluation of the available literature reveals that a large group of patients suffering from hereditary photoreceptor degeneration carry mutations that are likely to trigger cGMP-dependent cell death, making this pathway a prime target for future therapy development. Finally, an outlook is given into technological and methodological developments that will with time likely contribute to a comprehensive overview over the entire metabolic complexity of photoreceptor cell death. Building on such developments, new imaging technology and novel biomarkers may be used to develop clinical test strategies, that fully consider the genetic heterogeneity of hereditary retinal degenerations, in order to facilitate clinical testing of novel treatment approaches.
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Affiliation(s)
- Michael Power
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany; Centre for Integrative Neurosciences (CIN), University of Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Germany
| | - Soumyaparna Das
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany; Graduate Training Centre of Neuroscience (GTC), University of Tübingen, Germany
| | | | - Valeria Marigo
- Department of Life Sciences, University of Modena and Reggio Emilia, Italy
| | - Per Ekström
- Ophthalmology, Department of Clinical Sciences Lund, Faculty of Medicine, Lund University, Sweden
| | - François Paquet-Durand
- Cell Death Mechanism Group, Institute for Ophthalmic Research, University of Tübingen, Germany.
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50
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Langer BE, Roscito JG, Hiller M. REforge Associates Transcription Factor Binding Site Divergence in Regulatory Elements with Phenotypic Differences between Species. Mol Biol Evol 2019; 35:3027-3040. [PMID: 30256993 PMCID: PMC6278867 DOI: 10.1093/molbev/msy187] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Elucidating the genomic determinants of morphological differences between species is key to understanding how morphological diversity evolved. While differences in cis-regulatory elements are an important genetic source for morphological evolution, it remains challenging to identify regulatory elements involved in phenotypic differences. Here, we present Regulatory Element forward genomics (REforge), a computational approach that detects associations between transcription factor binding site divergence in putative regulatory elements and phenotypic differences between species. By simulating regulatory element evolution in silico, we show that this approach has substantial power to detect such associations. To validate REforge on real data, we used known binding motifs for eye-related transcription factors and identified significant binding site divergence in vision-impaired subterranean mammals in 1% of all conserved noncoding elements. We show that these genomic regions are significantly enriched in regulatory elements that are specifically active in mouse eye tissues, and that several of them are located near genes, which are required for eye development and photoreceptor function and are implicated in human eye disorders. Thus, our genome-wide screen detects widespread divergence of eye-regulatory elements and highlights regulatory regions that likely contributed to eye degeneration in subterranean mammals. REforge has broad applicability to detect regulatory elements that could be involved in many other phenotypes, which will help to reveal the genomic basis of morphological diversity.
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Affiliation(s)
- Björn E Langer
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology, Dresden, Germany
| | - Juliana G Roscito
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology, Dresden, Germany
| | - Michael Hiller
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Systems Biology, Dresden, Germany
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