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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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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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Zheng X, Li H, Hu Z, Su D, Yang J. Structural and functional characterization of an achromatopsia-associated mutation in a phototransduction channel. Commun Biol 2022; 5:190. [PMID: 35233102 PMCID: PMC8888761 DOI: 10.1038/s42003-022-03120-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 02/03/2022] [Indexed: 12/30/2022] Open
Abstract
Numerous missense mutations in cyclic nucleotide-gated (CNG) channels cause achromatopsia and retinitis pigmentosa, but the underlying pathogenic mechanisms are often unclear. We investigated the structural basis and molecular/cellular effects of R410W, an achromatopsia-associated, presumed loss-of-function mutation in human CNGA3. Cryo-EM structures of the Caenorhabditis elegans TAX-4 CNG channel carrying the analogous mutation, R421W, show that most apo channels are open. R421, located in the gating ring, interacts with the S4 segment in the closed state. R421W disrupts this interaction, destabilizes the closed state, and stabilizes the open state. CNGA3_R410W/CNGB3 and TAX4_R421W channels are spontaneously active without cGMP and induce cell death, suggesting cone degeneration triggered by spontaneous CNG channel activity as a possible cause of achromatopsia. Our study sheds new light on CNG channel allosteric gating, provides an impetus for a reevaluation of reported loss-of-function CNG channel missense disease mutations, and has implications for mutation-specific treatment of retinopathy.
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Affiliation(s)
- Xiangdong Zheng
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - Huan Li
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - Zhengshan Hu
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - Deyuan Su
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA
| | - Jian Yang
- Department of Biological Sciences, Columbia University, New York, NY, 10027, USA.
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Michalakis S, Gerhardt M, Rudolph G, Priglinger S, Priglinger C. Achromatopsia: Genetics and Gene Therapy. Mol Diagn Ther 2022; 26:51-59. [PMID: 34860352 PMCID: PMC8766373 DOI: 10.1007/s40291-021-00565-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2021] [Indexed: 01/02/2023]
Abstract
Achromatopsia (ACHM), also known as rod monochromatism or total color blindness, is an autosomal recessively inherited retinal disorder that affects the cones of the retina, the type of photoreceptors responsible for high-acuity daylight vision. ACHM is caused by pathogenic variants in one of six cone photoreceptor-expressed genes. These mutations result in a functional loss and a slow progressive degeneration of cone photoreceptors. The loss of cone photoreceptor function manifests at birth or early in childhood and results in decreased visual acuity, lack of color discrimination, abnormal intolerance to light (photophobia), and rapid involuntary eye movement (nystagmus). Up to 90% of patients with ACHM carry mutations in CNGA3 or CNGB3, which are the genes encoding the alpha and beta subunits of the cone cyclic nucleotide-gated (CNG) channel, respectively. No authorized therapy for ACHM exists, but research activities have intensified over the past decade and have led to several preclinical gene therapy studies that have shown functional and morphological improvements in animal models of ACHM. These encouraging preclinical data helped advance multiple gene therapy programs for CNGA3- and CNGB3-linked ACHM into the clinical phase. Here, we provide an overview of the genetic and molecular basis of ACHM, summarize the gene therapy-related research activities, and provide an outlook for their clinical application.
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Affiliation(s)
- Stylianos Michalakis
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany.
| | - Maximilian Gerhardt
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany
| | - Günther Rudolph
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany
| | - Siegfried Priglinger
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany
| | - Claudia Priglinger
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstr. 8, 80336, Munich, Germany
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Tekavčič Pompe M, Vrabič N, Volk M, Meglič A, Jarc-Vidmar M, Peterlin B, Hawlina M, Fakin A. Disease Progression in CNGA3 and CNGB3 Retinopathy; Characteristics of Slovenian Cohort and Proposed OCT Staging Based on Pooled Data from 126 Patients from 7 Studies. Curr Issues Mol Biol 2021; 43:941-957. [PMID: 34449556 PMCID: PMC8929018 DOI: 10.3390/cimb43020067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/02/2021] [Accepted: 08/05/2021] [Indexed: 11/20/2022] Open
Abstract
Achromatopsia has been proposed to be a morphologically predominately stable retinopathy with rare reports of progression of structural changes in the macula. A five-grade system of optical coherence tomography (OCT) features has been used for the classification of structural macular changes. However, their association with age remains questionable. We characterized the Slovenian cohort of 12 patients with pathogenic variants in CNGA3 or CNGB3 who had been followed up with OCT for up to 9 years. Based on observed structural changes in association with age, the following four-stage classification of retinal morphological changes was proposed: (I) preserved inner segment ellipsoid band (Ise), (II) disrupted ISe, (III) ISe loss and (IV) ISe and RPE loss. Data from six previously published studies reporting OCT morphology in CNGA3 and CNGB3 patients were additionally collected, forming the largest CNGA3/CNGB3 cohort to date, comprising 126 patients aged 1–71 years. Multiple regression analysis showed a significant correlation of OCT stage with age (p < 0.001) and no correlation with gene (p > 0.05). The median ages of patients with stages I–IV were 12 years, 23 years, 27 years and 48 years, respectively, and no patient older than 50 years had continuous ISe. Our findings suggest that achromatopsia presents with slowly but steadily progressive structural changes of the macular outer retinal layers. However, whether morphological changes in time follow the proposed four-stage linear pattern needs to be confirmed in a long-term study.
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Affiliation(s)
- Manca Tekavčič Pompe
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Nika Vrabič
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Marija Volk
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.V.); (B.P.)
| | - Andrej Meglič
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Martina Jarc-Vidmar
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Borut Peterlin
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.V.); (B.P.)
| | - Marko Hawlina
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
| | - Ana Fakin
- Eye Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia; (M.T.P.); (N.V.); (A.M.); (M.J.-V.); (M.H.)
- Correspondence:
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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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Spitschan M, Garbazza C, Kohl S, Cajochen C. Sleep and circadian phenotype in people without cone-mediated vision: a case series of five CNGB3 and two CNGA3 patients. Brain Commun 2021; 3:fcab159. [PMID: 34447932 PMCID: PMC8385249 DOI: 10.1093/braincomms/fcab159] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/14/2021] [Indexed: 01/28/2023] Open
Abstract
Light exposure entrains the circadian clock through the intrinsically photosensitive retinal ganglion cells, which sense light in addition to the cone and rod photoreceptors. In congenital achromatopsia (prevalence 1:30-50 000), the cone system is non-functional, resulting in severe light avoidance and photophobia at daytime light levels. How this condition affects circadian and neuroendocrine responses to light is not known. In this case series of genetically confirmed congenital achromatopsia patients (n = 7; age 30-72 years; 6 women, 1 male), we examined survey-assessed sleep/circadian phenotype, self-reported visual function, sensitivity to light and use of spectral filters that modify chronic light exposure. In all but one patient, we measured rest-activity cycles using actigraphy over 3 weeks and measured the melatonin phase angle of entrainment using the dim-light melatonin onset. Owing to their light sensitivity, congenital achromatopsia patients used filters to reduce retinal illumination. Thus, congenital achromatopsia patients experienced severely attenuated light exposure. In aggregate, we found a tendency to a late chronotype. We found regular rest-activity patterns in all patients and normal phase angles of entrainment in participants with a measurable dim-light melatonin onset. Our results reveal that a functional cone system and exposure to daytime light intensities are not necessary for regular behavioural and hormonal entrainment, even when survey-assessed sleep and circadian phenotype indicated a tendency for a late chronotype and sleep problems in our congenital achromatopsia cohort.
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Affiliation(s)
- Manuel Spitschan
- Department of Experimental Psychology, University of Oxford, Oxford, OX2 6GG, UK
- Centre for Chronobiology, Psychiatry Hospital of the University of Basel (UPK), CH-4002 Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, CH-4055 Basel, Switzerland
| | - Corrado Garbazza
- Centre for Chronobiology, Psychiatry Hospital of the University of Basel (UPK), CH-4002 Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, CH-4055 Basel, Switzerland
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, D-72076 Tübingen, Germany
| | - Christian Cajochen
- Centre for Chronobiology, Psychiatry Hospital of the University of Basel (UPK), CH-4002 Basel, Switzerland
- Transfaculty Research Platform Molecular and Cognitive Neurosciences (MCN), University of Basel, CH-4055 Basel, Switzerland
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8
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Brunet AA, Fuller-Carter PI, Miller AL, Voigt V, Vasiliou S, Rashwan R, Hunt DM, Carvalho LS. Validating Fluorescent Chrnb4.EGFP Mouse Models for the Study of Cone Photoreceptor Degeneration. Transl Vis Sci Technol 2020; 9:28. [PMID: 32879784 PMCID: PMC7442867 DOI: 10.1167/tvst.9.9.28] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/29/2020] [Indexed: 02/07/2023] Open
Abstract
Purpose To validate the application of a known transgenic mouse line with green fluorescent cones (Chrnb4.EGFP) to study cone photoreceptor biology and function in health and disease. Methods Chrnb4.EGFP retinas containing GFP+ cones were compared with retinas without the GFP transgene via immunohistochemistry, quantitative real-time polymerase chain reaction, electroretinograms, and flow cytometry. The Chrnb4.EGFP line was backcrossed to the mouse models of cone degeneration, Pde6ccpfl1 and Gnat2cpfl3 , generating the new lines Gnat2.GFP and Pde6c.GFP, which were also studied as described. Results GFP expression spanned the length of the cone cell in the Chrnb4.EGFP line, as well as in the novel Gnat2.GFP and Pde6c.GFP lines. The effect of GFP expression showed no significant changes to outer nuclear layer cell death, cone-specific gene expression, and immune response activation. A temporal decrease in GFP expression over time was observed, but GFP fluorescence was still detected through flow cytometry as late as 6 months. Furthermore, a functional analysis of photopic and scotopic electroretinogram responses of the Chrnb4 mouse showed no significant difference between GFP- and GFP+ mice, whereas electroretinogram recordings for the Pde6c.GFP and Gnat2.GFP lines matched previous reports from the original lines. Conclusions This study demonstrates that the Chrnb4.EGFP mouse can be a powerful tool to overcome the limitations of studying cone biology, including the use of this line to study different types of cone degeneration. Translational Relevance This work validates research tools that could potentially offer more reliable preclinical data in the development of treatments for cone-mediated vision loss conditions, shortening the gap to clinical translation.
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Affiliation(s)
- Alicia A. Brunet
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | | | - Annie L. Miller
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | | | | | - Rabab Rashwan
- Lions Eye Institute, Nedlands, Western Australia, Australia
- Department of Microbiology and Immunology, Faculty of Medicine, Minia University, Minia, Egypt
| | - David M. Hunt
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
| | - Livia S. Carvalho
- Centre for Ophthalmology and Visual Sciences, The University of Western Australia, Nedlands, Western Australia, Australia
- Lions Eye Institute, Nedlands, Western Australia, Australia
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Jacobson MA, Jones LJ, Colussi DJ, Tanaka JC. High-Throughput Ca 2+ Flux Assay To Monitor Cyclic Nucleotide-Gated Channel Activity and Characterize Achromatopsia Mutant Channel Function. ACS Chem Neurosci 2019; 10:3662-3670. [PMID: 31290651 DOI: 10.1021/acschemneuro.9b00231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Cone photoreceptor cyclic-nucleotide gated channels (CNG) are tetrameric proteins composed of subunits from CNGA3 and CNGB3. These channels transduce light information into electrical signals carried by both Na+ and Ca2+ ions. More than 100 mutations in the CNGA3 gene are associated with the inherited retinal disorder, achromatopsia 2 (ACHM2), which results in attenuation or loss of color vision, daylight blindness, and reduced visual acuity. Classical techniques to measure CNG channel function utilize patch clamp electrophysiology measuring Na currents in the absence of divalent cations, yet intracellular Ca2+ regulates both light and dark adaptation in photoreceptors. We developed a fluorescence-based, high-throughput Ca2+ flux assay using yellow fluorescent protein (YFP) tagged CNGA3 channels expressed in HEK293 cells which allow monitoring for folding defects in mutant channels. The cell permeant cGMP analog, 8-(4-chlorophenylthio)-cGMP (CPT-cGMP), was used to activate Ca2+ flux. The assay was validated using wild-type CNGA3 homomeric and heteromeric channels and ACHM2-associated homomeric mutant CNG channels, CNGA3-R427C, CNGA3-E590K, and CNGA3-L633P. Additionally, we examined two naturally occurring canine mutations causing day-blindness previously studied by patch clamp. We compared the CPT-cGMP K0.5 values of the channels with patch clamp values from previous studies. The assay provides a screen for modulation of gating and/or rescue of trafficking and/or misfolding defects in ACHM2-associated CNG channels. Importantly, the calcium flux assay is advantageous compared to patch clamp as it allows the ability to monitor CNG channel activity in the presence of calcium.
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Affiliation(s)
- Marlene A Jacobson
- Department of Pharmaceutical Sciences, School of Pharmacy , Temple University , Philadelphia , Pennsylvania 19140 , United States
- Moulder Center for Drug Discovery Research, School of Pharmacy , Temple University , Philadelphia , Pennsylvania 19140 , United States
| | - Laura J Jones
- Department of Biology, College of Science and Technology , Temple University , Philadelphia , Pennsylvania 19122 , United States
| | - Dennis J Colussi
- Department of Pharmaceutical Sciences, School of Pharmacy , Temple University , Philadelphia , Pennsylvania 19140 , United States
- Moulder Center for Drug Discovery Research, School of Pharmacy , Temple University , Philadelphia , Pennsylvania 19140 , United States
| | - Jacqueline C Tanaka
- Department of Biology, College of Science and Technology , Temple University , Philadelphia , Pennsylvania 19122 , United States
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10
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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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11
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Moshiri A, Chen R, Kim S, Harris RA, Li Y, Raveendran M, Davis S, Liang Q, Pomerantz O, Wang J, Garzel L, Cameron A, Yiu G, Stout JT, Huang Y, Murphy CJ, Roberts J, Gopalakrishna KN, Boyd K, Artemyev NO, Rogers J, Thomasy SM. A nonhuman primate model of inherited retinal disease. J Clin Invest 2019; 129:863-874. [PMID: 30667376 PMCID: PMC6355306 DOI: 10.1172/jci123980] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 11/15/2018] [Indexed: 12/30/2022] Open
Abstract
Inherited retinal degenerations are a common cause of untreatable blindness worldwide, with retinitis pigmentosa and cone dystrophy affecting approximately 1 in 3500 and 1 in 10,000 individuals, respectively. A major limitation to the development of effective therapies is the lack of availability of animal models that fully replicate the human condition. Particularly for cone disorders, rodent, canine, and feline models with no true macula have substantive limitations. By contrast, the cone-rich macula of a nonhuman primate (NHP) closely mirrors that of the human retina. Consequently, well-defined NHP models of heritable retinal diseases, particularly cone disorders that are predictive of human conditions, are necessary to more efficiently advance new therapies for patients. We have identified 4 related NHPs at the California National Primate Research Center with visual impairment and findings from clinical ophthalmic examination, advanced retinal imaging, and electrophysiology consistent with achromatopsia. Genetic sequencing confirmed a homozygous R565Q missense mutation in the catalytic domain of PDE6C, a cone-specific phototransduction enzyme associated with achromatopsia in humans. Biochemical studies demonstrate that the mutant mRNA is translated into a stable protein that displays normal cellular localization but is unable to hydrolyze cyclic GMP (cGMP). This NHP model of a cone disorder will not only serve as a therapeutic testing ground for achromatopsia gene replacement, but also for optimization of gene editing in the macula and of cone cell replacement in general.
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Affiliation(s)
- Ala Moshiri
- Department of Ophthalmology & Vision Science, School of Medicine, UC Davis, Sacramento, California, USA
| | - Rui Chen
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and.,Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Soohyun Kim
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
| | - R Alan Harris
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and
| | - Yumei Li
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and
| | | | - Sarah Davis
- California National Primate Research Center, Davis, California, USA
| | - Qingnan Liang
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Ori Pomerantz
- California National Primate Research Center, Davis, California, USA
| | - Jun Wang
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and
| | - Laura Garzel
- California National Primate Research Center, Davis, California, USA
| | - Ashley Cameron
- California National Primate Research Center, Davis, California, USA
| | - Glenn Yiu
- Department of Ophthalmology & Vision Science, School of Medicine, UC Davis, Sacramento, California, USA
| | - J Timothy Stout
- Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA
| | | | - Christopher J Murphy
- Department of Ophthalmology & Vision Science, School of Medicine, UC Davis, Sacramento, California, USA.,Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, USA.,EyeKor Inc., Madison, Wisconsin, USA
| | - Jeffrey Roberts
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, USA.,California National Primate Research Center, Davis, California, USA
| | | | - Kimberly Boyd
- Department of Molecular Physiology and Biophysics, and
| | - Nikolai O Artemyev
- Department of Molecular Physiology and Biophysics, and.,Department of Ophthalmology and Visual Sciences, The University of Iowa Carver College of Medicine, Iowa City, Iowa, USA
| | - Jeffrey Rogers
- Human Genome Sequencing Center and Department of Molecular and Human Genetics, and
| | - Sara M Thomasy
- Department of Ophthalmology & Vision Science, School of Medicine, UC Davis, Sacramento, California, USA.,Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, California, USA
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12
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Takahashi VKL, Takiuti JT, Jauregui R, Tsang SH. Gene therapy in inherited retinal degenerative diseases, a review. Ophthalmic Genet 2018; 39:560-568. [PMID: 30040511 DOI: 10.1080/13816810.2018.1495745] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Hereditary diseases of the retina represent a group of diseases with several heterogeneous mutations that have the common end result of progressive photoreceptor death leading to blindness. Retinal degenerations encompass multifactorial diseases such as age-related macular degeneration, Leber congenital amaurosis, Stargardt disease, and retinitis pigmentosa. Although there is currently no cure for degenerative retinal diseases, ophthalmology has been at the forefront of the development of gene therapy, which offers hope for the treatment of these conditions. This article will explore an overview of the clinical trials of gene supplementation therapy for retinal diseases that are underway or planned for the near future.
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Affiliation(s)
- Vitor K L Takahashi
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,c Department of Ophthalmology , Federal University of São Paulo , São Paulo , Brazil
| | - Júlia T Takiuti
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,d Division of Ophthalmology , University of São Paulo Medical School , São Paulo , Brazil
| | - Ruben Jauregui
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,e Weill Cornell Medical College , New York , NY , USA
| | - Stephen H Tsang
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,f Department of Pathology & Cell Biology, Stem Cell Initiative (CSCI), Institute of Human Nutrition, College of Physicians and Surgeons , Columbia University , New York , NY , USA
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13
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Abstract
The first step in vision is the absorption of photons by the photopigments in cone and rod photoreceptors. After initial amplification within the phototransduction cascade the signal is translated into an electrical signal by the action of cyclic nucleotide-gated (CNG) channels. CNG channels are ligand-gated ion channels that are activated by the binding of cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate (cAMP). Retinal CNG channels transduce changes in intracellular concentrations of cGMP into changes of the membrane potential and the Ca2+ concentration. Structurally, the CNG channels belong to the superfamily of pore-loop cation channels and share a common gross structure with hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and voltage-gated potassium channels (KCN). In this review, we provide an overview on the molecular properties of CNG channels and describe their physiological role in the phototransduction pathways. We also discuss insights into the pathophysiological role of CNG channel proteins that have emerged from the analysis of CNG channel-deficient animal models and human CNG channelopathies. Finally, we summarize recent gene therapy activities and provide an outlook for future clinical application.
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Affiliation(s)
- Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr, 5-13, 81377 Munich, Germany.
| | - Elvir Becirovic
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr, 5-13, 81377 Munich, Germany.
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr, 5-13, 81377 Munich, Germany.
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14
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Michalakis S, Schön C, Becirovic E, Biel M. Gene therapy for achromatopsia. J Gene Med 2018; 19. [PMID: 28095637 DOI: 10.1002/jgm.2944] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 01/13/2017] [Accepted: 01/13/2017] [Indexed: 02/02/2023] Open
Abstract
The present review summarizes the current status of achromatopsia (ACHM) gene therapy-related research activities and provides an outlook for their clinical application. ACHM is an inherited eye disease characterized by a congenital absence of cone photoreceptor function. As a consequence, ACHM is associated with strongly impaired daylight vision, photophobia, nystagmus and a lack of color discrimination. Currently, six genes have been linked to ACHM. Up to 80% of the patients carry mutations in the genes CNGA3 and CNGB3 encoding the two subunits of the cone cyclic nucleotide-gated channel. Various animal models of the disease have been established and their characterization has helped to increase our understanding of the pathophysiology associated with ACHM. With the advent of adeno-associated virus vectors as valuable gene delivery tools for retinal photoreceptors, a number of promising gene supplementation therapy programs have been initiated. In recent years, huge progress has been made towards bringing a curative treatment for ACHM into clinics. The first clinical trials are ongoing or will be launched soon and are expected to contribute important data on the safety and efficacy of ACHM gene supplementation therapy.
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Affiliation(s)
- Stylianos Michalakis
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Schön
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Elvir Becirovic
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
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15
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Hirji N, Aboshiha J, Georgiou M, Bainbridge J, Michaelides M. Achromatopsia: clinical features, molecular genetics, animal models and therapeutic options. Ophthalmic Genet 2018; 39:149-157. [PMID: 29303385 DOI: 10.1080/13816810.2017.1418389] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Achromatopsia is an autosomal recessive condition, characterised by reduced visual acuity, impaired colour vision, photophobia and nystagmus. The symptoms can be profoundly disabling, and there is no cure currently available. However, the recent development of gene-based interventions may lead to improved outcomes in the future. This article aims to provide a comprehensive review of the clinical features of the condition, its genetic basis and the underlying pathogenesis. We also explore the insights derived from animal models, including the implications for gene supplementation approaches. Finally, we discuss current human gene therapy trials.
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Affiliation(s)
- Nashila Hirji
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
| | - Jonathan Aboshiha
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
| | - Michalis Georgiou
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
| | - James Bainbridge
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
| | - Michel Michaelides
- a UCL Institute of Ophthalmology, University College London , London , UK.,b Moorfields Eye Hospital , London , UK
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16
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Abeshi A, Zulian A, Beccari T, Dundar M, Falsini B, Bertelli M. Genetic testing for achromatopsia. EUROBIOTECH JOURNAL 2017. [DOI: 10.24190/issn2564-615x/2017/s1.03] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
We studied the scientific literature and disease guidelines in order to summarize the clinical utility of genetic testing for achromatopsia. The disease has autosomal recessive inheritance, a prevalence of 1/30000-1/50000, and is caused by mutations in the CNGB3, CNGA3, GNAT2, PDE6C, ATF6 and PDE6H genes. Clinical diagnosis is by ophthalmological examination, color vision testing and electrophysiological testing. Genetic testing is useful for confirming diagnosis and for differential diagnosis, couple risk assessment and access to clinical trials.
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Affiliation(s)
- Andi Abeshi
- MAGI Balkans, Tirana , Albania
- MAGI’S Lab, Rovereto , Italy
| | | | - Tommaso Beccari
- Department of Pharmaceutical Sciences, University of Perugia, Perugia , Italy
| | - Munis Dundar
- Department of Medical Genetics, Erciyes University Medical School, Kayseri , Turkey
| | - Benedetto Falsini
- Department of Ophthalmology, Catholic University of Rome, Rome , Italy
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17
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Moore NA, Morral N, Ciulla TA, Bracha P. Gene therapy for inherited retinal and optic nerve degenerations. Expert Opin Biol Ther 2017; 18:37-49. [DOI: 10.1080/14712598.2018.1389886] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Nicholas A. Moore
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Nuria Morral
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Thomas A. Ciulla
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA
- Retina Service, Midwest Eye Institute, Indianapolis, IN, USA
| | - Peter Bracha
- Department of Ophthalmology, Indiana University School of Medicine, Indianapolis, IN, USA
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18
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Sengillo JD, Justus S, Tsai YT, Cabral T, Tsang SH. Gene and cell-based therapies for inherited retinal disorders: An update. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2016; 172:349-366. [PMID: 27862925 DOI: 10.1002/ajmg.c.31534] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinal degenerations present a unique challenge as disease progression is irreversible and the retina has little regenerative potential. No current treatments for inherited retinal disease have the ability to reverse blindness, and current dietary supplement recommendations only delay disease progression with varied results. However, the retina is anatomically accessible and capable of being monitored at high resolution in vivo. This, in addition to the immune-privileged status of the eye, has put ocular disease at the forefront of advances in gene- and cell-based therapies. This review provides an update on gene therapies and randomized control trials for inherited retinal disease, including Leber congenital amaurosis, choroideremia, retinitis pigmentosa, Usher syndrome, X-linked retinoschisis, Leber hereditary optic neuropathy, and achromatopsia. New gene-modifying and cell-based strategies are also discussed. © 2016 Wiley Periodicals, Inc.
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Kuniyoshi K, Muraki-Oda S, Ueyama H, Toyoda F, Sakuramoto H, Ogita H, Irifune M, Yamamoto S, Nakao A, Tsunoda K, Iwata T, Ohji M, Shimomura Y. Novel mutations in the gene for α-subunit of retinal cone cyclic nucleotide-gated channels in a Japanese patient with congenital achromatopsia. Jpn J Ophthalmol 2016; 60:187-97. [PMID: 27040408 DOI: 10.1007/s10384-016-0424-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 12/22/2015] [Indexed: 10/22/2022]
Abstract
PURPOSE To present the characteristics and pathology of a patient with congenital achromatopsia. PATIENT AND METHODS The patient was a 22-year-old Japanese woman who was 8 years old when she first visited our clinic. Comprehensive ophthalmic examinations including visual acuity measurements, perimetry, optical coherence tomography (OCT), fundus autofluorescence (FAF) imaging, electroretinography (ERG), and color vision tests were performed. Her genomic DNA was used as the template for the amplification of exons of five candidate genes for achromatopsia; CNGA3, CNGB3, GNAT2, PDE6C, and PDE6H, and the amplified products were sequenced. A missense mutation, found in the CNGA3, was studied both electrophysiologically and biochemically. RESULTS Her phenotype was typical of congenital complete achromatopsia. She was followed for 14 years, and her vision and fundus findings were stable. However, the scotopic ERG b-waves at age 22 were smaller than those at age 8, and her FAF images showed increased autofluorescence in both maculae. Genetic examinations revealed combined heterozygous mutations of c.997_998delGA and p.M424V in the CNGA3 gene. The homomeric channel consisting of the CNGA3 subunit with the p.M424V mutation had a weak cGMP-activated current in patch-clamp recordings. In heterologous expression analyses, the expression at the cell surface of the mutant CNGA3 subunit was about 28 % of the wild type. CONCLUSIONS The two novel mutations found in the CNGA3 gene, c.997_998delGA and p.M424V, can cause complete achromatopsia. The vision of the patient was stationary until the third decade of life although the FAF was altered at the age of 22 years.
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Affiliation(s)
- Kazuki Kuniyoshi
- Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka, 589-8911, Japan.
| | - Sanae Muraki-Oda
- Department of Ophthalmology, Shiga University of Medical Science, Otsu, Japan
| | - Hisao Ueyama
- Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Otsu, Japan
| | - Futoshi Toyoda
- Department of Physiology, Shiga University of Medical Science, Otsu, Japan
| | - Hiroyuki Sakuramoto
- Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka, 589-8911, Japan
| | - Hisakazu Ogita
- Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Otsu, Japan
| | - Motohiro Irifune
- Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka, 589-8911, Japan
- Irifune Eye Clinic, Izumi, Japan
| | - Shuji Yamamoto
- Jin Eye Clinic, Nishinomiya, Japan
- Department of Ophthalmology, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Akira Nakao
- Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka, 589-8911, Japan
| | - Kazushige Tsunoda
- Laboratory of Visual Physiology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Masahito Ohji
- Department of Ophthalmology, Shiga University of Medical Science, Otsu, Japan
| | - Yoshikazu Shimomura
- Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-Sayama, Osaka, 589-8911, Japan
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20
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Zobor D, Zobor G, Kohl S. Achromatopsia: on the doorstep of a possible therapy. Ophthalmic Res 2015; 54:103-8. [PMID: 26304472 DOI: 10.1159/000435957] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 06/15/2015] [Indexed: 11/19/2022]
Abstract
Achromatopsia (ACHM) is a rare autosomal recessive inherited retinal disorder with an incidence of approximately 1 in 30,000. It presents at birth or early infancy and is typically characterized by reduced visual acuity, nystagmus, photophobia, and very poor or absent color vision. The symptoms arise from isolated cone dysfunction, which can be caused by mutations in the crucial components of the cone phototransduction cascade. Although ACHM is considered a functionally nonprogressive disease affecting only the cone system, recent studies have described progressive age-dependent changes in retinal architecture. Currently, no specific therapy is available for ACHM; however, gene replacement therapy performed on animal models for three ACHM genes has shown promising results. Accurate genetic and clinical diagnosis of patients may therefore enhance and enable therapeutic intervention in the near future. This short review summarizes the genetic background, pathophysiology, clinical findings, diagnostics, and therapeutic perspectives in ACHM.
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Affiliation(s)
- Ditta Zobor
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
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21
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Katagiri S, Hayashi T, Yoshitake K, Sergeev Y, Akahori M, Furuno M, Nishino J, Ikeo K, Tsunoda K, Tsuneoka H, Iwata T. Congenital Achromatopsia and Macular Atrophy Caused by a Novel Recessive PDE6C Mutation (p.E591K). Ophthalmic Genet 2015; 36:137-44. [PMID: 25605338 DOI: 10.3109/13816810.2014.991932] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE We have previously reported clinical features of two siblings, a sister with complete achromatopsia (ACHM) and a brother with incomplete ACHM, in a consanguineous Japanese family. With the current study, we intended to identify a disease-causing mutation in the siblings and to investigate why the phenotypes of the siblings differed. METHODS We performed a comprehensive ophthalmic examination for each sibling and parent. Whole-exome and Sanger sequencing were performed on genomic DNA. Molecular modeling was analyzed in an in silico study. RESULTS The ophthalmic examination revealed severe macular atrophy in the older female sibling at 30 years of age and mild macular atrophy in the brother at 26 years of age. The genetic analysis identified a novel homozygous PDE6C mutation (p.E591K) as the disease-causing allele in the siblings. Each parent was heterozygous for the mutation. Molecular modeling showed that the mutation could cause a conformational change in the PDE6C protein and result in reduced phosphodiesterase activity. We also identified an OPN1SW mutation (p.G79R), which is associated with congenital tritan deficiencies, in the sister and the father but not in the brother. CONCLUSIONS A novel homozygous PDE6C mutation was identified as the cause of ACHM. In addition, we identified an OPN1SW mutation in the sibling with complete ACHM, which might explain the difference in phenotype (complete versus incomplete ACHM) between the siblings.
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Affiliation(s)
- Satoshi Katagiri
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center , Tokyo , Japan
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Sahel JA, Marazova K, Audo I. Clinical characteristics and current therapies for inherited retinal degenerations. Cold Spring Harb Perspect Med 2014; 5:a017111. [PMID: 25324231 DOI: 10.1101/cshperspect.a017111] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Inherited retinal degenerations (IRDs) encompass a large group of clinically and genetically heterogeneous diseases that affect approximately 1 in 3000 people (>2 million people worldwide) (Bessant DA, Ali RR, Bhattacharya SS. 2001. Molecular genetics and prospects for therapy of the inherited retinal dystrophies. Curr Opin Genet Dev 11: 307-316.). IRDs may be inherited as Mendelian traits or through mitochondrial DNA, and may affect the entire retina (e.g., rod-cone dystrophy, also known as retinitis pigmentosa, cone dystrophy, cone-rod dystrophy, choroideremia, Usher syndrome, and Bardet-Bidel syndrome) or be restricted to the macula (e.g., Stargardt disease, Best disease, and Sorsby fundus dystrophy), ultimately leading to blindness. IRDs are a major cause of severe vision loss, with profound impact on patients and society. Although IRDs remain untreatable today, significant progress toward therapeutic strategies for IRDs has marked the past two decades. This progress has been based on better understanding of the pathophysiological pathways of these diseases and on technological advances.
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Affiliation(s)
- José-Alain Sahel
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Paris, F-75012, France INSERM, U968, Paris, F-75012, France CNRS, UMR 7210, Paris, F-75012, France Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France Fondation Ophtalmologique Adolphe de Rothschild, Paris, F-75019, France Académie des Sciences-Institut de France, Paris, F-75006, France Institute of Ophthalmology-University College London, London EC1V 9EL, United Kingdom
| | - Katia Marazova
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Paris, F-75012, France INSERM, U968, Paris, F-75012, France CNRS, UMR 7210, Paris, F-75012, France
| | - Isabelle Audo
- Institut de la Vision, Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Paris, F-75012, France INSERM, U968, Paris, F-75012, France CNRS, UMR 7210, Paris, F-75012, France Centre Hospitalier National d'Ophtalmologie des Quinze-Vingts, DHU ViewMaintain, INSERM-DHOS CIC 1423, Paris, F-75012, France Institute of Ophthalmology-University College London, London EC1V 9EL, United Kingdom
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