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Tam BM, Burns P, Chiu CN, Moritz OL. Synchronized Photoactivation of T4K Rhodopsin Causes a Chromophore-Dependent Retinal Degeneration That Is Moderated by Interaction with Phototransduction Cascade Components. J Neurosci 2024; 44:e0453242024. [PMID: 39089885 PMCID: PMC11376340 DOI: 10.1523/jneurosci.0453-24.2024] [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: 03/06/2024] [Revised: 06/29/2024] [Accepted: 07/24/2024] [Indexed: 08/04/2024] Open
Abstract
Multiple mutations in the Rhodopsin gene cause sector retinitis pigmentosa in humans and a corresponding light-exacerbated retinal degeneration (RD) in animal models. Previously we have shown that T4K rhodopsin requires photoactivation to exert its toxic effect. Here we further investigated the mechanisms involved in rod cell death caused by T4K rhodopsin in mixed male and female Xenopus laevis In this model, RD was prevented by rearing animals in constant darkness but surprisingly also in constant light. RD was maximized by light cycles containing at least 1 h of darkness and 20 min of light exposure, light intensities >750 lux, and by a sudden light onset. Under conditions of frequent light cycling, RD occurred rapidly and synchronously, with massive shedding of ROS fragments into the RPE initiated within hours and subsequent death and phagocytosis of rod cell bodies. RD was minimized by reduced light levels, pretreatment with constant light, and gradual light onset. RD was prevented by genetic ablation of the retinal isomerohydrolase RPE65 and exacerbated by ablation of phototransduction components GNAT1, SAG, and GRK1. Our results indicate that photoactivated T4K rhodopsin is toxic, that cell death requires synchronized photoactivation of T4K rhodopsin, and that toxicity is mitigated by interaction with other rod outer segment proteins regardless of whether they participate in activation or shutoff of phototransduction. In contrast, RD caused by P23H rhodopsin does not require photoactivation of the mutant protein, as it was exacerbated by RPE65 ablation, suggesting that these phenotypically similar disorders may require different treatment strategies.
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Affiliation(s)
- Beatrice M Tam
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, British Columbia V5Z 3N9, Canada
| | - Paloma Burns
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, British Columbia V5Z 3N9, Canada
| | - Colette N Chiu
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, British Columbia V5Z 3N9, Canada
| | - Orson L Moritz
- Department of Ophthalmology & Visual Sciences, University of British Columbia, Vancouver, British Columbia V5Z 3N9, Canada
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2
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Ashtari M, Bennett J, Leopold DA. Central visual pathways affected by degenerative retinal disease before and after gene therapy. Brain 2024; 147:3234-3246. [PMID: 38538211 PMCID: PMC11370797 DOI: 10.1093/brain/awae096] [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: 08/23/2023] [Revised: 02/09/2024] [Accepted: 02/20/2024] [Indexed: 09/04/2024] Open
Abstract
Genetic diseases affecting the retina can result in partial or complete loss of visual function. Leber's congenital amaurosis (LCA) is a rare blinding disease, usually inherited in an autosomally recessive manner, with no cure. Retinal gene therapy has been shown to improve vision in LCA patients caused by mutations in the RPE65 gene (LCA2). However, little is known about how activity in central visual pathways is affected by the disease or by subsequent gene therapy. Functional MRI (fMRI) was used to assess retinal signal transmission in cortical and subcortical visual structures before and 1 year after retinal intervention. The fMRI paradigm consisted of 15-s blocks of flickering (8 Hz) black and white checkerboards interleaved with 15 s of blank (black) screen. Visual activation in the brain was assessed using the general linear model, with multiple comparisons corrected using the false discovery rate method. Response to visual stimulation through untreated eyes of LCA2 patients showed heightened fMRI responses in the superior colliculus and diminished activities in the lateral geniculate nucleus (LGN) compared to controls, indicating a shift in the patients' visual processing towards the retinotectal pathway. Following gene therapy, stimuli presented to the treated eye elicited significantly stronger fMRI responses in the LGN and primary visual cortex, indicating some re-engagement of the geniculostriate pathway (GS) pathway. Across patients, the post-treatment LGN fMRI responses correlated significantly with performance on a clinical test measuring light sensitivity. Our results demonstrate that the low vision observed in LCA2 patients involves a shift in visual processing toward the retinotectal pathway, and that gene therapy partially reinstates visual transmission through the GS pathway. This selective boosting of retinal output through the GS pathway and its correlation to improved visual performance, following several years of degenerative retinal disease, is striking. However, while retinal gene therapy and other ocular interventions have given hope to RPE65 patients, it may take years before development of therapies tailored to treat the diseases in other low vision patients are available. Our demonstration of a shift toward the retinotectal pathway in these patients may spur the development of new tools and rehabilitation strategies to help maximize the use of residual visual abilities and augment experience-dependent plasticity.
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Affiliation(s)
- Manzar Ashtari
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics (CAROT), University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David A Leopold
- Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
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Li S, Jin M. Ablation of Fatty Acid Transport Protein-4 Enhances Cone Survival, M-cone Vision, and Synthesis of Cone-Tropic 9- cis-Retinal in rd12 Mouse Model of Leber Congenital Amaurosis. J Neurosci 2024; 44:e1994232024. [PMID: 38811164 PMCID: PMC11223470 DOI: 10.1523/jneurosci.1994-23.2024] [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: 10/12/2023] [Revised: 12/03/2023] [Accepted: 05/22/2024] [Indexed: 05/31/2024] Open
Abstract
The canonical visual cycle employing RPE65 as the retinoid isomerase regenerates 11-cis-retinal to support both rod- and cone-mediated vision. Mutations of RPE65 are associated with Leber congenital amaurosis that results in rod and cone photoreceptor degeneration and vision loss of affected patients at an early age. Dark-reared Rpe65-/- mouse has been known to form isorhodopsin that employs 9-cis-retinal as the photosensitive chromophore. The mechanism regulating 9-cis-retinal synthesis and the role of the endogenous 9-cis-retinal in cone survival and function remain largely unknown. In this study, we found that ablation of fatty acid transport protein-4 (FATP4), a negative regulator of 11-cis-retinol synthesis catalyzed by RPE65, increased the formation of 9-cis-retinal, but not 11-cis-retinal, in a light-independent mechanism in both sexes of RPE65-null rd12 mice. Both rd12 and rd12;Fatp4-/- mice contained a massive amount of all-trans-retinyl esters in the eyes, exhibiting comparable scotopic vision and rod degeneration. However, expression levels of M- and S-opsins as well as numbers of M- and S-cones surviving in the superior retinas of rd12;Fatp4-/ - mice were at least twofold greater than those in age-matched rd12 mice. Moreover, FATP4 deficiency significantly shortened photopic b-wave implicit time, improved M-cone visual function, and substantially deaccelerated the progression of cone degeneration in rd12 mice, whereas FATP4 deficiency in mice with wild-type Rpe65 alleles neither induced 9-cis-retinal formation nor influenced cone survival and function. These results identify FATP4 as a new regulator of synthesis of 9-cis-retinal, which is a "cone-tropic" chromophore supporting cone survival and function in the retinas with defective RPE65.
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Affiliation(s)
- Songhua Li
- Neuroscience Center, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana 70112
| | - Minghao Jin
- Neuroscience Center, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana 70112
- Department of Ophthalmology, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana 70112
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Ku CA, Igelman AD, Huang SJ, Bailey ST, Lauer AK, Duncan JL, Weleber RG, Yang P, Pennesi ME. Perimacular Atrophy Following Voretigene Neparvovec-Rzyl Treatment in the Setting of Previous Contralateral Eye Treatment With a Different Viral Vector. Transl Vis Sci Technol 2024; 13:11. [PMID: 38888288 PMCID: PMC11186569 DOI: 10.1167/tvst.13.6.11] [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: 10/13/2023] [Accepted: 03/31/2024] [Indexed: 06/20/2024] Open
Abstract
Purpose To report on cases of unilateral perimacular atrophy after treatment with voretigene neparvovec-rzyl, in the setting of previous contralateral eye treatment with a different viral vector. Design Single-center, retrospective chart review. Methods In this case series, four patients between the ages of six and 11 years old with RPE65-related retinopathy were treated unilaterally with rAAV2-CB-hRPE65 as part of a gene augmentation clinical trial (NCT00749957). Six to 10 years later the contralateral eyes were treated with the Food and Drug Administration-approved drug, voretigene neparvovec-rzyl. Best-corrected visual acuity (BCVA), fundus photos, ocular coherence tomography, two-color dark-adapted perimetry, full field stimulus threshold testing (FST), and location of subretinal bleb and chorioretinal atrophy were evaluated. Results Three out of four patients showed unilateral perimacular atrophy after treatment with voretigene, ranging from five to 22 months after treatment. Areas of robust visual field improvement were followed by areas of chorioretinal atrophy. Despite perimacular changes, BCVA, FST, and subjective improvements in vision and nyctalopia were maintained. Perimacular atrophy was not observed in the first eye treated with the previous viral vector. Conclusions We observed areas of robust visual field improvement followed by perimacular atrophy in voretigene treated eyes, as compared to the initially treated contralateral eyes. Translational Relevance Caution is advised when using two different viral vectors between eyes in gene therapy. This may become an important issue in the future with increasing gene therapy clinical trials for inherited retinal dystrophies.
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Affiliation(s)
- Cristy A. Ku
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| | - Austin D. Igelman
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Samuel J. Huang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Steven T. Bailey
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Andreas K. Lauer
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Jacque L. Duncan
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA
| | - Richard G. Weleber
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Paul Yang
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
| | - Mark E. Pennesi
- Casey Eye Institute, Oregon Health & Science University, Portland, OR, USA
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Parameswarappa DC, Bagga DK, Upadhyaya A, Balasubramanian J, Pochaboina V, Muthineni V, Jalali S, Kannabiran C. RPE65 mutations in Leber congenital amaurosis, early-onset severe retinal dystrophy, and retinitis pigmentosa from a tertiary eye care center in India. Ophthalmic Genet 2024; 45:303-312. [PMID: 38323530 DOI: 10.1080/13816810.2024.2309559] [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: 06/22/2023] [Revised: 11/10/2023] [Accepted: 01/19/2024] [Indexed: 02/08/2024]
Abstract
INTRODUCTION Mutations in the retinal pigment epithelial 65 kilodalton protein (RPE65) gene are associated with various inherited retinal diseases (IRDs), including Leber congenital amaurosis (LCA), early-onset severe retinal dystrophy (EOSRD), and retinitis pigmentosa (RP). We screened for mutations in RPE65 in a series of Indian patients with these IRDs to determine the frequency/types of mutations and to describe the associated phenotypes. MATERIALS AND METHODS Diagnosis of LCA, EOSRD, and RP was made by standard and pre-defined criteria. Patients were evaluated by clinical, retinal imaging, and electrophysiological parameters. Genomic DNA from patients and available family members were used for identifying mutations by direct Sanger sequencing of the RPE65 gene or targeted NGS gene panel for IRDs covering 260+ genes. Variations detected were tested in healthy control populations and for co-segregation with the disease in available family members. RESULTS Mutations were found in eight patients, out of 220 total cases screened, all homozygous for the respective mutant alleles. Seven patients had mutations leading to premature termination codons and one patient had a missense change. The onset of visual loss ranged from birth to <2 years of life. At presentation, RPE mottling in the background retina was present in all cases with macular involvement in five cases with or without vascular attenuation and optic disc pallor. CONCLUSION RPE65 mutations in this series were found in 3.6% of cases associated with severe, early-onset disease, with consistent RPE mottling and variable manifestations with regard to the extent of disc pallor, arteriolar attenuation, and appearance of the macula.
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Affiliation(s)
- Deepika C Parameswarappa
- Srimati Kanuri Santhamma Center for Vitreoretinal Diseases, Anant Bajaj Retina Institute, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, India
| | - Deepak Kumar Bagga
- Meera and L B Deshpande Centre for Sight Enhancement, Institute for Vision Rehabilitation, L V Prasad Eye Institute, Hyderabad, India
| | - Abhishek Upadhyaya
- Srimati Kanuri Santhamma Center for Vitreoretinal Diseases, Anant Bajaj Retina Institute, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, India
| | | | - Venkatesh Pochaboina
- Department of Clinical Genetics and Genetic Counseling, L V Prasad Eye Institute, Hyderabad, India
| | - Vani Muthineni
- Kallam Anji Reddy Molecular Genetics Laboratory, L V Prasad Eye Institute, Hyderabad, India
| | - Subhadra Jalali
- Srimati Kanuri Santhamma Center for Vitreoretinal Diseases, Anant Bajaj Retina Institute, Kallam Anji Reddy Campus, L V Prasad Eye Institute, Hyderabad, India
| | - Chitra Kannabiran
- Kallam Anji Reddy Molecular Genetics Laboratory, L V Prasad Eye Institute, Hyderabad, India
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Chen Y, Zizmare L, Calbiague V, Wang L, Yu S, Herberg FW, Schmachtenberg O, Paquet-Durand F, Trautwein C. Retinal metabolism displays evidence for uncoupling of glycolysis and oxidative phosphorylation via Cori-, Cahill-, and mini-Krebs-cycle. eLife 2024; 12:RP91141. [PMID: 38739438 PMCID: PMC11090511 DOI: 10.7554/elife.91141] [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: 05/14/2024] Open
Abstract
The retina consumes massive amounts of energy, yet its metabolism and substrate exploitation remain poorly understood. Here, we used a murine explant model to manipulate retinal energy metabolism under entirely controlled conditions and utilised 1H-NMR spectroscopy-based metabolomics, in situ enzyme detection, and cell viability readouts to uncover the pathways of retinal energy production. Our experimental manipulations resulted in varying degrees of photoreceptor degeneration, while the inner retina and retinal pigment epithelium were essentially unaffected. This selective vulnerability of photoreceptors suggested very specific adaptations in their energy metabolism. Rod photoreceptors were found to rely strongly on oxidative phosphorylation, but only mildly on glycolysis. Conversely, cone photoreceptors were dependent on glycolysis but insensitive to electron transport chain decoupling. Importantly, photoreceptors appeared to uncouple glycolytic and Krebs-cycle metabolism via three different pathways: (1) the mini-Krebs-cycle, fuelled by glutamine and branched chain amino acids, generating N-acetylaspartate; (2) the alanine-generating Cahill-cycle; (3) the lactate-releasing Cori-cycle. Moreover, the metabolomics data indicated a shuttling of taurine and hypotaurine between the retinal pigment epithelium and photoreceptors, likely resulting in an additional net transfer of reducing power to photoreceptors. These findings expand our understanding of retinal physiology and pathology and shed new light on neuronal energy homeostasis and the pathogenesis of neurodegenerative diseases.
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Affiliation(s)
- Yiyi Chen
- Institute for Ophthalmic Research, University of TübingenTuebingenGermany
| | - Laimdota Zizmare
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, University of TübingenTuebingenGermany
- Core Facility Metabolomics, Faculty of Medicine, University of TübingenTuebingenGermany
| | - Victor Calbiague
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de ValparaísoValparaísoChile
| | - Lan Wang
- Institute for Ophthalmic Research, University of TübingenTuebingenGermany
| | - Shirley Yu
- Institute for Ophthalmic Research, University of TübingenTuebingenGermany
| | - Fritz W Herberg
- Biochemistry Department, University of KasselTuebingenGermany
| | - Oliver Schmachtenberg
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de ValparaísoValparaísoChile
| | | | - Christoph Trautwein
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, University of TübingenTuebingenGermany
- Core Facility Metabolomics, Faculty of Medicine, University of TübingenTuebingenGermany
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7
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Zeng Y, Gao S, Li Y, Marangoni D, De Silva T, Wong WT, Chew EY, Sun X, Li T, Sieving PA, Qian H. OCT Intensity of the Region between Outer Retina Band 2 and Band 3 as a Biomarker for Retinal Degeneration and Therapy. Bioengineering (Basel) 2024; 11:449. [PMID: 38790316 PMCID: PMC11118669 DOI: 10.3390/bioengineering11050449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/23/2024] [Accepted: 04/26/2024] [Indexed: 05/26/2024] Open
Abstract
Optical coherence tomography (OCT) is widely used to probe retinal structure and function. This study investigated the outer retina band (ORB) pattern and reflective intensity for the region between bands 2 and 3 (Dip) in three mouse models of inherited retinal degeneration (Rs1KO, TTLL5KO, RPE65KO) and in human AMD patients from the A2A database. OCT images were manually graded, and reflectivity signals were used to calculate the Dip ratio. Qualitative analyses demonstrated the progressive merging band 2 and band 3 in all three mouse models, leading to a reduction in the Dip ratio compared to wildtype (WT) controls. Gene replacement therapy in Rs1KO mice reverted the ORB pattern to one resembling WT and increased the Dip ratio. The degree of anatomical rescue in these mice was highly correlated with level of transgenic RS1 expression and with the restoration of ERG b-wave amplitudes. While the inner retinal cavity was significantly enlarged in dark-adapted Rs1KO mice, the Dip ratio was not altered. A reduction of the Dip ratio was also detected in AMD patients compared with healthy controls and was also positively correlated with AMD severity on the AMD score. We propose that the ORB and Dip ratio can be used as non-invasive early biomarkers for retina health, which can be used to probe therapeutic gene expression and to evaluate the effectiveness of therapy.
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Affiliation(s)
- Yong Zeng
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (Y.Z.); (S.G.); (Y.L.)
| | - Shasha Gao
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (Y.Z.); (S.G.); (Y.L.)
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Yichao Li
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (Y.Z.); (S.G.); (Y.L.)
| | - Dario Marangoni
- Section for Translational Research in Retinal and Macular Degeneration, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Tharindu De Silva
- Unit on Clinical Investigation of Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wai T. Wong
- Section on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Emily Y. Chew
- Clinical Trials Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xun Sun
- Neurobiology Neurodegeneration & Repair Laboratory (N-NRL), National Eye Institute, Bethesda, MD 20892, USA (T.L.)
| | - Tiansen Li
- Neurobiology Neurodegeneration & Repair Laboratory (N-NRL), National Eye Institute, Bethesda, MD 20892, USA (T.L.)
| | | | - Haohua Qian
- Visual Function Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (Y.Z.); (S.G.); (Y.L.)
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8
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Cheng YW, Huang YC, Chang KF, Huang XF, Sheu GT, Tsai NM. Protective Effect of Curcumin on the Tight Junction Integrity and Cellular Senescence in Human Retinal Pigment Epithelium of Early Diabetic Retinopathy. JOURNAL OF PHYSIOLOGICAL INVESTIGATION 2024; 67:107-117. [PMID: 38857204 DOI: 10.4103/ejpi.ejpi-d-23-00035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 05/05/2024] [Indexed: 06/12/2024]
Abstract
Diabetic retinopathy (DR) is a secondary complication of diabetes that can lead to visual impairment and blindness. The retinal pigment epithelium (RPE) is a monolayer of pigment cells that forms the blood-retinal barrier (BRB) via tight junction (TJ) proteins and plays a crucial role in the physiological function of the retina. Hyperglycemia induces RPE death and BRB breakdown, which accelerates the process of DR. Curcumin, an active extract of Curcuma longa , has anti-inflammatory, antioxidant, antiapoptotic, and neuroprotective properties. However, the effect of Curcumin on the BRB under high glucose conditions remains unknown. This study aimed to investigate the protective effects of Curcumin on RPE physiology in vitro and in vivo . Curcumin significantly alleviated cell viability inhibition under high glucose conditions. Moreover, high glucose reduced extracellular signal-regulated kinase and Akt pathways activation to diminish RPE cell growth but reversed by Curcumin treatment. Curcumin protected not only TJ integrity but also retinoid regeneration through TJ proteins and isomerase modulation in diabetic retina. Furthermore, Curcumin decreased the expression of angiogenic factor to inhibit retinal neovascularization. Finally, Curcumin treatment markedly reduced apoptosis during hyperglycemia. In conclusion, Curcumin can alleviate the progression of DR by promoting RPE survival, TJ integrity, retinoid isomerase activity, RPE senescence inhibition, and neovascularization. Therefore, Curcumin exhibits high potential for use as a therapeutic agent for early DR.
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Affiliation(s)
- Yu-Wen Cheng
- Department of Internal Medicine, Lee's General Hospital, Miaoli, Taiwan
| | - Ya-Chih Huang
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Kai-Fu Chang
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Xiao-Fan Huang
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
| | - Gwo-Tarng Sheu
- Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Nu-Man Tsai
- Department of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
- Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan
- Department of Life-and-Death Studies, Nanhua University, Chiayi, Taiwan
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9
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Xu F, Zheng C, Xu W, Zhang S, Liu S, Chen X, Yao K. Breaking genetic shackles: The advance of base editing in genetic disorder treatment. Front Pharmacol 2024; 15:1364135. [PMID: 38510648 PMCID: PMC10953296 DOI: 10.3389/fphar.2024.1364135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2024] [Accepted: 02/26/2024] [Indexed: 03/22/2024] Open
Abstract
The rapid evolution of gene editing technology has markedly improved the outlook for treating genetic diseases. Base editing, recognized as an exceptionally precise genetic modification tool, is emerging as a focus in the realm of genetic disease therapy. We provide a comprehensive overview of the fundamental principles and delivery methods of cytosine base editors (CBE), adenine base editors (ABE), and RNA base editors, with a particular focus on their applications and recent research advances in the treatment of genetic diseases. We have also explored the potential challenges faced by base editing technology in treatment, including aspects such as targeting specificity, safety, and efficacy, and have enumerated a series of possible solutions to propel the clinical translation of base editing technology. In conclusion, this article not only underscores the present state of base editing technology but also envisions its tremendous potential in the future, providing a novel perspective on the treatment of genetic diseases. It underscores the vast potential of base editing technology in the realm of genetic medicine, providing support for the progression of gene medicine and the development of innovative approaches to genetic disease therapy.
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Affiliation(s)
- Fang Xu
- 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
| | - Caiyan Zheng
- 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
| | - Weihui Xu
- 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
| | - Shiyao 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
| | - Shanshan Liu
- 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
| | - Xiaopeng Chen
- 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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10
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Jung R, Kempf M, Holocher S, Kortüm FC, Stingl K, Stingl K. Multi-luminance mobility testing after gene therapy in the context of retinal functional diagnostics. Graefes Arch Clin Exp Ophthalmol 2024; 262:601-607. [PMID: 37768368 PMCID: PMC10844143 DOI: 10.1007/s00417-023-06237-4] [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: 05/04/2023] [Revised: 08/25/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND Voretigene neparvovec (Luxturna®) is the first approved gene therapy for RPE65-linked Leber congenital amaurosis (LCA). Though individual effects are highly variable, most recipients report improved vision in everyday life. To describe such effects, visual navigation tests are now frequently used in clinical trials. However, it is still unclear how their results should be interpreted compared to conventional parameters of visual function. METHODS Seven LCA patients underwent a multi-luminance visual navigation test (Ora-VNCTM) before and 3 months after receiving Luxturna gene therapy. Their performance was rated based on the luminance level at which they passed the course. Differences between the first and second test were correlated to changes in visual acuity, full-field stimulus thresholds, chromatic pupil campimetry, and dark-adapted perimetry. RESULTS A few patients displayed notable improvements in conventional measures of visual function whereas patients with advanced retinal degeneration showed no relevant changes. Independent of these results, almost all participants improved in the visual navigation task by one or more levels. The improvement in the mobility test was best correlated to the change in full-field stimulus thresholds. Other measures of visual functions showed no clear correlation with visual navigation. DISCUSSION In patients who passed the test's more difficult levels, improved visual navigation can be attributed to the reactivation of rods. However, the performance of patients with low vision seemed to depend much more on confounding factors in the easier levels. In sum, such tests might only be meaningful for patients with better preserved visual functions.
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Affiliation(s)
- Ronja Jung
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Elfriede-Aulhorn-Str.7, Tübingen, Germany.
| | - Melanie Kempf
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Elfriede-Aulhorn-Str.7, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany
| | - Saskia Holocher
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Elfriede-Aulhorn-Str.7, Tübingen, Germany
| | - Friederike C Kortüm
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Elfriede-Aulhorn-Str.7, Tübingen, Germany
| | - Krunoslav Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Elfriede-Aulhorn-Str.7, Tübingen, Germany
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany
| | - Katarina Stingl
- University Eye Hospital, Center for Ophthalmology, University of Tuebingen, Elfriede-Aulhorn-Str.7, Tübingen, Germany.
- Center for Rare Eye Diseases, University of Tübingen, Tübingen, Germany.
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11
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Zhao J, Kim HJ, Montenegro D, Dunaief JL, Sparrow JR. Iron overload and chelation modulates bisretinoid levels in the retina. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1305864. [PMID: 38983013 PMCID: PMC11182296 DOI: 10.3389/fopht.2023.1305864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 12/07/2023] [Indexed: 07/11/2024]
Abstract
Aim Iron dysregulation in conjunction with other disease processes may exacerbate retinal degeneration. We employed models of iron overload and iron chelation to explore the interactions between iron-catalyzed oxidation and photoreactive bisretinoid lipofuscin. Methods The mice were injected intravitreally with ferric ammonium citrate (FAC) or were treated using the iron chelator deferiprone (DFP) from birth to 2 months of age. Short-wavelength fundus autofluorescence (SW-AF) and spectral-domain optical coherence tomography (SD-OCT) scans were acquired. The bisretinoid levels were quantified using ultra performance liquid chromatography (UPLC) and in vivo through quantitative fundus autofluorescence (qAF). In histologic sections, the photoreceptor cell viability was assessed by measuring the thickness of the outer nuclear layer (ONL). Results The levels of bisretinoids, all-trans-retinal dimers, and A2PE were significantly increased in the FAC-injected eyes of C57BL/6J mice. Seven days after FAC injection, hyperautofluorescent foci were visible in fundus autofluorescence (488 nm) images, and in SD-OCT scans, aberrant hyperreflectivity was present in the outer retina and ONL thinning was observed. In FAC-injected Abca4-/- mice with pronounced RPE bisretinoid lipofuscin accumulation, the hyperautofluorescent puncta were more abundant than in the wild-type mice, and the extent of ONL thinning was greater. Conversely, the intravitreal injection of FAC in Mertk-/- mice led to a more modest increase in A2PE after 2 days. In contrast to the effect of iron accumulation, chelation with DFP resulted in significantly increased levels of A2E and A2-GPE and qAF due to the reduced iron-catalyzed oxidation of bisretinoids. In Mertk-/- mice, the A2E level was significantly lower and the ONL area was smaller than in DFP-treated mice. DFP chelation did not impair the visual cycle in BALB/cJ mice. Conclusion Iron accumulation was associated with progressive impairment in photoreceptor cells that was associated with the increased formation of a bisretinoid species known to form in photoreceptor outer segments as a precursor to A2E. Additionally, disease features such as the development of hyperautofluorescence puncta in fundus AF images, hyperreflectivity in the outer retina of SD-OCT scans, and ONL thinning were more pronounced when iron was delivered to Abca4-/- mice with a greater propensity for bisretinoid formation. Higher bisretinoid levels and enhanced qAF are indicative of lesser bisretinoid loss due to oxidation.
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Affiliation(s)
- Jin Zhao
- Departments of Ophthalmology, Columbia University Medical Center, New York, NY, United States
| | - Hye Jin Kim
- Departments of Ophthalmology, Columbia University Medical Center, New York, NY, United States
| | - Diego Montenegro
- Departments of Ophthalmology, Columbia University Medical Center, New York, NY, United States
| | - Josh L Dunaief
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, United States
| | - Janet R Sparrow
- Departments of Ophthalmology, Columbia University Medical Center, New York, NY, United States
- Pathology and Cell Biology, Columbia University Medical Center, New York, NY, United States
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12
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Braslavsky SE. Outstanding women scientists who have broadened the knowledge on biological photoreceptors. Photochem Photobiol Sci 2023; 22:2799-2815. [PMID: 37864671 DOI: 10.1007/s43630-023-00487-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/22/2023] [Indexed: 10/23/2023]
Abstract
Short biographical sketches are given of women born before 1955 who have contributed to our knowledge on the function, structure, and molecular basis of biological photoreceptors, both energy converters and photosensors.
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Affiliation(s)
- Silvia E Braslavsky
- Max Planck Institute for Chemical Energy Conversion, 45410, Mülheim an der Ruhr, Germany.
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13
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Cao M, Xu T, Song Y, Wang H, Wei S, Yin D. 2,2',4,4'-tetrabromodiphenyl ether causes depigmentation in zebrafish larvae via a light-mediated pathway. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 897:165382. [PMID: 37422226 DOI: 10.1016/j.scitotenv.2023.165382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 07/04/2023] [Accepted: 07/05/2023] [Indexed: 07/10/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs) are organic pollutants widely detected in various environmental media due to their high persistence and bioaccumulation. PBDE-induced visual impairment and neurotoxicity were previously demonstrated using zebrafish (Danio rerio) models, and recent research reported the phenotypic depigmentation effect of PBDEs at high concentrations on zebrafish, but whether those effects are still present at environment-relevant levels is still unclear. Herein, we performed both phenotypic examination and mechanism investigation in zebrafish embryos (48 hpf) and larvae (5 dpf) about their pigmentation status when exposing to PBDE congener BDE-47 (2,2',4,4'-tetrabrominated diphenyl ether) at levels from 0.25 to 25 μg/L. Results showed that low-level BDE-47 can restrain the relative melanin abundance of zebrafish larvae to 70.47% (p < 0.05) and 61.54% (p < 0.01) respectively under 2.5 and 25 μg/L BDE-47 compared with control, and the thickness of retinal pigment epithelium (RPE) remarkably reduced from 571.4 nm to 350.3 nm (p < 0.001) under 25 μg/L BDE-47 exposure. We also observed disrupted expressions of melanin synthesis genes and disorganized mitfa differentiation patterns based on Tg(mifta:EGFP), as well as visual impairment resulting from thinner RPE. Considering both processes of visual development and melanin synthesis are highly sensitive to ambient light conditions, we prolonged the light regime of maintaining zebrafish larvae from 14 hours light versus 10 hours dark (14L:10D) to 18 hours light versus 6 hours dark (18L:6D). Lengthening photoperiod successfully rescued the fluorescent level of mitfa in zebrafish epidermis and most gene expressions associated with melanin synthesis under 25 μg/L BDE-47 exposure to the normal level. In conclusion, our work reported the effects of low-level PBDEs on melanin production using zebrafish embryos and larvae, and identified the potential role of a light-mediated pathway in the neurotoxic mechanism of PBDEs.
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Affiliation(s)
- Miao Cao
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Ting Xu
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Yiqun Song
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Huan Wang
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Sheng Wei
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Daqiang Yin
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
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14
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Kohn DB, Chen YY, Spencer MJ. Successes and challenges in clinical gene therapy. Gene Ther 2023; 30:738-746. [PMID: 37935854 PMCID: PMC10678346 DOI: 10.1038/s41434-023-00390-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/20/2023] [Accepted: 02/07/2023] [Indexed: 11/09/2023]
Abstract
Despite the ups and downs in the field over three decades, the science of gene therapy has continued to advance and provide enduring treatments for increasing number of diseases. There are active clinical trials approaching a variety of inherited and acquired disorders of different organ systems. Approaches include ex vivo modification of hematologic stem cells (HSC), T lymphocytes and other immune cells, as well as in vivo delivery of genes or gene editing reagents to the relevant target cells by either local or systemic administration. In this article, we highlight success and ongoing challenges in three areas of high activity in gene therapy: inherited blood cell diseases by targeting hematopoietic stem cells, malignant disorders using immune effector cells genetically modified with chimeric antigen receptors, and ophthalmologic, neurologic, and coagulation disorders using in vivo administration of adeno-associated virus (AAV) vectors. In recent years, there have been true cures for many of these diseases, with sustained clinical benefit that exceed those from other medical approaches. Each of these treatments faces ongoing challenges, namely their high one-time costs and the complexity of manufacturing the therapeutic agents, which are biological viruses and cell products, at pharmacologic standards of quality and consistency. New models of reimbursement are needed to make these innovative treatments widely available to patients in need.
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Affiliation(s)
- Donald B Kohn
- Department of Microbiology, Immunology & Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
- The Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Yvonne Y Chen
- Department of Microbiology, Immunology & Molecular Genetics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Chemical and Biomolecular Engineering, Henry Samueli School of Engineering, University of California, Los Angeles, Los Angeles, CA, USA
- Parker Institute for Cancer Immunotherapy Center at UCLA, University of California, Los Angeles, Los Angeles, CA, USA
| | - Melissa J Spencer
- The Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA, USA
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
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15
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Swinkels D, Kocherlakota S, Das Y, Dane AD, Wever EJM, Vaz FM, Bazan NG, Van Veldhoven PP, Baes M. DHA Shortage Causes the Early Degeneration of Photoreceptors and RPE in Mice With Peroxisomal β-Oxidation Deficiency. Invest Ophthalmol Vis Sci 2023; 64:10. [PMID: 37934161 PMCID: PMC10631513 DOI: 10.1167/iovs.64.14.10] [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: 05/23/2023] [Accepted: 09/06/2023] [Indexed: 11/08/2023] Open
Abstract
Purpose Patients deficient in peroxisomal β-oxidation, which is essential for the synthesis of docosahexaenoic acid (DHA, C22:6n-3) and breakdown of very-long-chain polyunsaturated fatty acids (VLC-PUFAs), both important components of photoreceptor outer segments, develop retinopathy present with retinopathy. The representative mouse model lacking the central enzyme of this pathway, multifunctional protein 2 (Mfp2-/-), also show early-onset retinal decay and cell-autonomous retinal pigment epithelium (RPE) degeneration, accompanied by reduced plasma and retinal DHA levels. In this study, we investigated whether DHA supplementation can rescue the retinal degeneration of Mfp2-/- mice. Methods Mfp2+/- breeding pairs and their offspring were fed a 0.12% DHA or control diet during gestation and lactation and until sacrifice. Offspring were analyzed for retinal function via electroretinograms and for lipid composition of neural retina and plasma with lipidome analysis and gas chromatography, respectively, and histologically using retinal sections and RPE flatmounts at the ages of 4, 8, and 16 weeks. Results DHA supplementation to Mfp2-/- mice restored retinal DHA levels and prevented photoreceptor shortening, death, and impaired functioning until 8 weeks. In addition, rescue of retinal DHA levels temporarily improved the ability of the RPE to phagocytose outer segments and delayed the RPE dedifferentiation. However, despite the initial rescue of retinal integrity, DHA supplementation could not prevent retinal degeneration at 16 weeks. Conclusions We reveal that the shortage of a systemic supply of DHA is pivotal for the early retinal degeneration in Mfp2-/- mice. Furthermore, we report that adequate retinal DHA levels are essential not only for photoreceptors but also for RPE homeostasis.
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Affiliation(s)
- Daniëlle Swinkels
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Sai Kocherlakota
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Yannick Das
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Adriaan D. Dane
- Department of Epidemiology and Data Science, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Core Facility Metabolomics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Eric J. M. Wever
- Department of Epidemiology and Data Science, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Core Facility Metabolomics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Frédéric M. Vaz
- Core Facility Metabolomics, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Department of Clinical Chemistry and Pediatrics, Laboratory Genetic Metabolic Diseases, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Inborn Errors of Metabolism, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam, The Netherlands
| | - Nicolas G. Bazan
- Neuroscience Center of Excellence, Louisiana State University School of Medicine, Louisiana State University, New Orleans, Louisiana, United States
| | - Paul P. Van Veldhoven
- Laboratory of Peroxisome Biology and Intracellular Communication, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
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16
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Kerschensteiner D. Losing, preserving, and restoring vision from neurodegeneration in the eye. Curr Biol 2023; 33:R1019-R1036. [PMID: 37816323 PMCID: PMC10575673 DOI: 10.1016/j.cub.2023.08.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/12/2023]
Abstract
The retina is a part of the brain that sits at the back of the eye, looking out onto the world. The first neurons of the retina are the rod and cone photoreceptors, which convert changes in photon flux into electrical signals that are the basis of vision. Rods and cones are frequent targets of heritable neurodegenerative diseases that cause visual impairment, including blindness, in millions of people worldwide. This review summarizes the diverse genetic causes of inherited retinal degenerations (IRDs) and their convergence onto common pathogenic mechanisms of vision loss. Currently, there are few effective treatments for IRDs, but recent advances in disparate areas of biology and technology (e.g., genome editing, viral engineering, 3D organoids, optogenetics, semiconductor arrays) discussed here enable promising efforts to preserve and restore vision in IRD patients with implications for neurodegeneration in less approachable brain areas.
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Affiliation(s)
- Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neuroscience, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University School of Medicine, St. Louis, MO 63110, USA.
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17
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Senapati S, Park PSH. Understanding the Rhodopsin Worldview Through Atomic Force Microscopy (AFM): Structure, Stability, and Activity Studies. CHEM REC 2023; 23:e202300113. [PMID: 37265335 PMCID: PMC10908267 DOI: 10.1002/tcr.202300113] [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: 03/28/2023] [Revised: 05/12/2023] [Indexed: 06/03/2023]
Abstract
Rhodopsin is a G protein-coupled receptor (GPCR) present in the rod outer segment (ROS) of photoreceptor cells that initiates the phototransduction cascade required for scotopic vision. Due to the remarkable advancements in technological tools, the chemistry of rhodopsin has begun to unravel especially over the past few decades, but mostly at the ensemble scale. Atomic force microscopy (AFM) is a tool capable of providing critical information from a single-molecule point of view. In this regard, to bolster our understanding of rhodopsin at the nanoscale level, AFM-based imaging, force spectroscopy, and nano-indentation techniques were employed on ROS disc membranes containing rhodopsin, isolated from vertebrate species both in normal and diseased states. These AFM studies on samples from native retinal tissue have provided fundamental insights into the structure and function of rhodopsin under normal and dysfunctional states. We review here the findings from these AFM studies that provide important insights on the supramolecular organization of rhodopsin within the membrane and factors that contribute to this organization, the molecular interactions stabilizing the structure of the receptor and factors that can modify those interactions, and the mechanism underlying constitutive activity in the receptor that can cause disease.
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Affiliation(s)
- Subhadip Senapati
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
- Prayoga Institute of Education Research, Bengaluru, KA 560116, India
| | - Paul S-H Park
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA
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18
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Wang L, Shah SM, Mangwani-Mordani S, Gregori NZ. Updates on Emerging Interventions for Autosomal Recessive ABCA4-Associated Stargardt Disease. J Clin Med 2023; 12:6229. [PMID: 37834872 PMCID: PMC10573680 DOI: 10.3390/jcm12196229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 09/25/2023] [Accepted: 09/25/2023] [Indexed: 10/15/2023] Open
Abstract
Autosomal recessive Stargardt disease (STGD1) is an inherited retinal degenerative disease associated with a mutated ATP-binding cassette, subfamily A, member 4 (ABCA4) gene. STGD1 is the most common form of juvenile macular degeneration with onset in late childhood to early or middle adulthood and causes progressive, irreversible visual impairment and blindness. No effective treatment is currently available. In the present article, we review the most recent updates in clinical trials targeting the management of STGD1, including gene therapy, small molecule therapy, and stem cell therapy. In gene therapy, dual adeno-associated virus and non-viral vectors have been successful in delivering the human ABCA4 gene in preclinical studies. For pharmaceutical therapies ALK-001, deuterated vitamin A shows promise with preliminary data for phase 2 trial, demonstrating a decreased atrophy growth rate after two years. Stem cell therapy using human pluripotent stem cell-derived retinal pigment epithelium cells demonstrated long-term safety three years after implantation and visual acuity improvements in the first two years after initiation of therapy. Many other treatment options have ongoing investigations and clinical trials. While multiple potential interventions have shown promise in attenuating disease progression, further exploration is necessary to demonstrate treatment safety and efficacy.
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Affiliation(s)
- Liang Wang
- University of Miami Miller School of Medicine, Miami, FL 33136, USA; (L.W.); (S.M.S.)
| | - Serena M. Shah
- University of Miami Miller School of Medicine, Miami, FL 33136, USA; (L.W.); (S.M.S.)
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Simran Mangwani-Mordani
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
| | - Ninel Z. Gregori
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA;
- Miami Veterans Administration Medical Center, Miami, FL 33125, USA
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19
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Bourdin A, Ortoli M, Karadayi R, Przegralek L, Sennlaub F, Bodaghi B, Guillonneau X, Carpentier A, Touhami S. Efficacy and Safety of Low-Intensity Pulsed Ultrasound-Induced Blood-Retinal Barrier Opening in Mice. Pharmaceutics 2023; 15:1896. [PMID: 37514082 PMCID: PMC10384184 DOI: 10.3390/pharmaceutics15071896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/22/2023] [Accepted: 07/04/2023] [Indexed: 07/30/2023] Open
Abstract
Systemic drugs can treat various retinal pathologies such as retinal cancers; however, their ocular diffusion may be limited by the blood-retina barrier (BRB). Sonication corresponds to the use of ultrasound (US) to increase the permeability of cell barriers including in the BRB. The objective was to study the efficacy and safety of sonication using microbubble-assisted low-intensity pulsed US in inducing a transient opening of the BRB. The eyes of C57/BL6J mice were sonicated at different acoustic pressures (0.10 to 0.50 MPa). Efficacy analyses consisted of fluorescein angiography (FA) performed at different timepoints and the size of the leaked molecules was assessed using FITC-marked dextrans. Tolerance was assessed by fundus photographs, optical coherence tomography, immunohistochemistry, RT-qPCR, and electroretinograms. Sonication at 0.15 MPa was the most suitable pressure for transient BRB permeabilization without altering the morphology or function of the retina. It did not increase the expression of inflammation or apoptosis markers in the retina, retinal pigment epithelium, or choroid. The dextran assay suggested that drugs up to 150 kDa in size can cross the BRB. Microbubble-assisted sonication at an optimized acoustic pressure of 0.15 MPa provides a non-invasive method to transiently open the BRB, increasing the retinal diffusion of systemic drugs without inducing any noticeable side-effect.
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Affiliation(s)
- Alexandre Bourdin
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, 75012 Paris, France
| | - Manon Ortoli
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, 75012 Paris, France
| | - Remi Karadayi
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, 75012 Paris, France
| | - Lauriane Przegralek
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, 75012 Paris, France
| | - Florian Sennlaub
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, 75012 Paris, France
| | - Bahram Bodaghi
- Ophthalmology Department, Pitié Salpêtrière University Hospital, AP-HP, Sorbonne Université, 75013 Paris, France
| | - Xavier Guillonneau
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, 75012 Paris, France
| | - Alexandre Carpentier
- Department of Neurosurgery, Pitié Salpêtrière University Hospital, AP-HP, Sorbonne Université, 75013 Paris, France
- NeurOn Brain Machine Interface Clinical Research Group, Pitié Salpêtrière University Hospital, AP-HP, Sorbonne Université, 75013 Paris, France
- ASTRL Advanced Surgical Technologies Research Laboratory, Sorbonne Université, 75013 Paris, France
| | - Sara Touhami
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, 75012 Paris, France
- Ophthalmology Department, Pitié Salpêtrière University Hospital, AP-HP, Sorbonne Université, 75013 Paris, France
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20
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Feathers KL, Jia L, Khan NW, Smith AJ, Ma JX, Ali RR, Thompson DA. Gene Supplementation in Mice Heterozygous for the D477G RPE65 Variant Implicated in Autosomal Dominant Retinitis Pigmentosa. Hum Gene Ther 2023; 34:639-648. [PMID: 37014074 PMCID: PMC10354729 DOI: 10.1089/hum.2022.240] [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: 12/22/2022] [Accepted: 03/20/2023] [Indexed: 04/05/2023] Open
Abstract
The use of AAV-RPE65 vectors for gene supplementation has achieved spectacular success as a treatment for individuals with autosomal recessive retinal disease caused by biallelic mutations in the visual cycle gene RPE65. However, the efficacy of this approach in treating autosomal dominant retinitis pigmentosa (adRP) associated with a monoallelic mutation encoding a rare D477G RPE65 variant has not been studied. Although lacking a severe phenotype, we now find that knock-in mice heterozygous for D477G RPE65 (D477G KI mice) can be used to evaluate outcomes of AAV-RPE65 gene supplementation. Total RPE65 protein levels, which are decreased in heterozygous D477G KI mice, were doubled following subretinal delivery of rAAV2/5.hRPE65p.hRPE65. In addition, rates of recovery of the chromophore 11-cis retinal after bleaching were significantly increased in eyes that received AAV-RPE65, consistent with increased RPE65 isomerase activity. While dark-adapted chromophore levels and a-wave amplitudes were not affected, b-wave recovery rates were modestly improved. The present findings establish that gene supplementation enhances 11-cis retinal synthesis in heterozygous D477G KI mice and complement previous studies showing that chromophore therapy results in improved vision in individuals with adRP associated with D477G RPE65.
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Affiliation(s)
- Kecia L. Feathers
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Lin Jia
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Naheed W. Khan
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Alexander J. Smith
- Centre for Stem Cells & Regenerative Medicine, King's College London, London, United Kingdom
| | - Jian-Xing Ma
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Robin R. Ali
- Centre for Stem Cells & Regenerative Medicine, King's College London, London, United Kingdom
| | - Debra A. Thompson
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan, USA
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21
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Bassetto M, Zaluski J, Li B, Zhang J, Badiee M, Kiser PD, Tochtrop GP. Tuning the Metabolic Stability of Visual Cycle Modulators through Modification of an RPE65 Recognition Motif. J Med Chem 2023; 66:8140-8158. [PMID: 37279401 PMCID: PMC10824489 DOI: 10.1021/acs.jmedchem.3c00461] [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] [Indexed: 06/08/2023]
Abstract
In the eye, the isomerization of all-trans-retinal to 11-cis-retinal is accomplished by a metabolic pathway termed the visual cycle that is critical for vision. RPE65 is the essential trans-cis isomerase of this pathway. Emixustat, a retinoid-mimetic RPE65 inhibitor, was developed as a therapeutic visual cycle modulator and used for the treatment of retinopathies. However, pharmacokinetic liabilities limit its further development including: (1) metabolic deamination of the γ-amino-α-aryl alcohol, which mediates targeted RPE65 inhibition, and (2) unwanted long-lasting RPE65 inhibition. We sought to address these issues by more broadly defining the structure-activity relationships of the RPE65 recognition motif via the synthesis of a family of novel derivatives, which were tested in vitro and in vivo for RPE65 inhibition. We identified a potent secondary amine derivative with resistance to deamination and preserved RPE65 inhibitory activity. Our data provide insights into activity-preserving modifications of the emixustat molecule that can be employed to tune its pharmacological properties.
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Affiliation(s)
- Marco Bassetto
- Department of Physiology and Biophysics, School of Medicine, University of California - Irvine, Irvine, California 92697, United States
- Department of Ophthalmology, Gavin Herbert Eye Institute, Center for Translational Vision Research, School of Medicine, University of California - Irvine, Irvine, California 92697, United States
- Research Service, VA Long Beach Healthcare System, Long Beach, California 90822, United States
| | - Jordan Zaluski
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Bowen Li
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Jianye Zhang
- Department of Ophthalmology, Gavin Herbert Eye Institute, Center for Translational Vision Research, School of Medicine, University of California - Irvine, Irvine, California 92697, United States
| | - Mohsen Badiee
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Philip D Kiser
- Department of Physiology and Biophysics, School of Medicine, University of California - Irvine, Irvine, California 92697, United States
- Department of Ophthalmology, Gavin Herbert Eye Institute, Center for Translational Vision Research, School of Medicine, University of California - Irvine, Irvine, California 92697, United States
- Department of Clinical Pharmacy Practice, School of Pharmacy and Pharmaceutical Sciences, University of California - Irvine, Irvine, California 92697, United States
- Research Service, VA Long Beach Healthcare System, Long Beach, California 90822, United States
| | - Gregory P Tochtrop
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States
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22
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Moon J, Zhou G, Jankowsky E, von Lintig J. Vitamin A deficiency compromises the barrier function of the retinal pigment epithelium. PNAS NEXUS 2023; 2:pgad167. [PMID: 37275262 PMCID: PMC10235913 DOI: 10.1093/pnasnexus/pgad167] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/01/2023] [Indexed: 06/07/2023]
Abstract
A major cause for childhood blindness worldwide is attributed to nutritional vitamin A deficiency. Surprisingly, the molecular basis of the ensuing retinal degeneration has not been well defined. Abundant expression of the retinoid transporter STRA6 in the retinal pigment epithelium (RPE) and homeostatic blood levels of retinol-binding protein delay vitamin A deprivation of the mouse eyes. Hence, genetic dissection of STRA6 makes mice susceptible to nutritional manipulation of ocular retinoid status. We performed RNA-seq analyses and complemented the data with tests of visual physiology, ocular morphology, and retinoid biochemistry to compare eyes with different vitamin A status. Mild ocular vitamin A deficiency decreased transcripts of photoreceptor transduction pathway-related genes and increased transcripts of oxidative stress pathways. The response was associated with impaired visual sensitivity and an accumulation of fluorescent debris in the retina. Severe vitamin A deficiency did not only impair visual perception but also decreased transcripts of genes encoding cell adhesion and cellular junction proteins. This response altered cell morphology, resulted in significant changes in transport pathways of small molecules, and compromised the barrier function of the RPE. Together, our analyses characterize the molecular events underlying nutritional blindness in a novel mouse model and indicate that breakdown of the outer blood-retinal barrier contributes to retinal degeneration and photoreceptor cell death in severe vitamin A deficiency.
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Affiliation(s)
- Jean Moon
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Gao Zhou
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Johannes von Lintig
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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23
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Qin H, Zhang W, Zhang S, Feng Y, Xu W, Qi J, Zhang Q, Xu C, Liu S, Zhang J, Lei Y, Liu W, Feng S, Wang J, Fu X, Xu Z, Li P, Yao K. Vision rescue via unconstrained in vivo prime editing in degenerating neural retinas. J Exp Med 2023; 220:e20220776. [PMID: 36930174 PMCID: PMC10037108 DOI: 10.1084/jem.20220776] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 12/23/2022] [Accepted: 02/08/2023] [Indexed: 03/18/2023] Open
Abstract
Retinitis pigmentosa (RP) is an inherited retinal dystrophy causing progressive and irreversible loss of retinal photoreceptors. Here, we developed a genome-editing tool characterized by the versatility of prime editors (PEs) and unconstrained PAM requirement of a SpCas9 variant (SpRY), referred to as PESpRY. The diseased retinas of Pde6b-associated RP mouse model were transduced via a dual AAV system packaging PESpRY for the in vivo genome editing through a non-NGG PAM (GTG). The progressing cell loss was reversed once the mutation was corrected, leading to substantial rescue of photoreceptors and production of functional PDE6β. The treated mice exhibited significant responses in electroretinogram and displayed good performance in both passive and active avoidance tests. Moreover, they presented an apparent improvement in visual stimuli-driven optomotor responses and efficiently completed visually guided water-maze tasks. Together, our study provides convincing evidence for the prevention of vision loss caused by RP-associated gene mutations via unconstrained in vivo prime editing in the degenerating retinas.
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Affiliation(s)
- Huan Qin
- Institute of Visual Neuroscience and Stem Cell Engineering, 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
| | - Shiyao Zhang
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Yuan Feng
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Weihui Xu
- Institute of Visual Neuroscience and Stem Cell Engineering, 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
| | - Qian Zhang
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Chunxiu Xu
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Shanshan Liu
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Jia Zhang
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Yushuang Lei
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Wanqin Liu
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Shuyu Feng
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Jingjing Wang
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Xuefei Fu
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Zifen Xu
- Institute of Visual Neuroscience and Stem Cell Engineering, Wuhan University of Science and Technology, Wuhan, China
| | - Ping Li
- Institute of Visual Neuroscience and Stem Cell Engineering, 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
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24
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Ren W, Duan S, Dai C, Xie C, Jiang L, Shi Y. Nanotechnology Lighting the Way for Gene Therapy in Ophthalmopathy: From Opportunities toward Applications. Molecules 2023; 28:molecules28083500. [PMID: 37110734 PMCID: PMC10141718 DOI: 10.3390/molecules28083500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/04/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Hereditary ophthalmopathy is a well-described threat to human visual health affecting millions of people. Gene therapy for ophthalmopathy has received widespread attention with the increasing understanding of pathogenic genes. Effective and safe delivery of accurate nucleic acid drugs (NADs) is the core of gene therapy. Efficient nanodelivery and nanomodification technologies, appropriate targeted genes, and the choice of drug injection methods are the guiding lights of gene therapy. Compared with traditional drugs, NADs can specifically change the expression of specific genes or restore the normal function of mutant genes. Nanodelivery carriers can improve targeting and nanomodification can improve the stability of NADs. Therefore, NADs, which can fundamentally solve pathogeny, hold great promise in the treatment of ophthalmopathy. This paper reviews the limitations of ocular disease treatment, discusses the classification of NADs in ophthalmology, reveals the delivery strategies of NADs to improve bioavailability, targeting, and stability, and summarizes the mechanisms of NADs in ophthalmopathy.
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Affiliation(s)
- Weiming Ren
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
| | - Suyang Duan
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
| | - Chao Dai
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
| | - Chunbao Xie
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
| | - Lingxi Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
| | - Yi Shi
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
- Department of Laboratory Medicine, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu 610072, China
- Department of Ophthalmology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu 610072, China
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25
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Dörschmann P, Seeba C, Thalenhorst T, Roider J, Klettner A. Anti-inflammatory properties of antiangiogenic fucoidan in retinal pigment epithelium cells. Heliyon 2023; 9:e15202. [PMID: 37123974 PMCID: PMC10130777 DOI: 10.1016/j.heliyon.2023.e15202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 05/02/2023] Open
Abstract
Age-related macular degeneration (AMD) is a multifactorial disease in which angiogenesis, oxidative stress and inflammation are important contributing factors. In this study, we investigated the anti-inflammatory effects of a fucoidan from the brown algae Fucus vesiculosus (FV) in primary porcine RPE cells. Inflammation was induced by lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (Poly I:C), Pam2CSK4 (Pam), or tumor necrosis factor alpha (TNF-α). Cell viability was tested with thiazolyl blue tetrazolium bromide (MTT) test, barrier function by measuring transepithelial electric resistance (TEER), interleukin 6 (IL-6) and interleukin 8 (IL-8) secretion in ELISA, retinal pigment epithelium-specific 65 kDa protein (RPE65) and protectin (CD59) expression in Western blot, gene expression with quantitative polymerase chain reaction (qPCR) (IL6, IL8, MERTK, PIK3CA), and phagocytotic activity in a microscopic assay. FV fucoidan did not influence RPE cell viability. FV fucoidan reduced the Poly I:C proinflammatory cytokine secretion of IL-6 and IL-8. In addition, it decreased the expression of IL-6 and IL-8 in RT-PCR. LPS and TNF-α reduced the expression of CD59 in Western blot, this reduction was lost under FV fucoidan treatment. Also, LPS and TNF-α reduced the expression of visual cycle protein RPE65, this reduction was again lost under FV fucoidan treatment. Furthermore, the significant reduction of barrier function after Poly I:C stimulation is ameliorated by FV fucoidan. Concerning phagocytosis, however, the inflammation-induced reduction was not improved by FV fucoidan. FV and proinflammatory milieu did not relevantly influence phagocytosis relevant gene expression either. In conclusion, we show that fucoidan from FV can reduce proinflammatory stimulation in RPE induced by toll-like receptor 3 (TLR-3) activation and is of high interest as a potential compound for early AMD treatment.
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26
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Palczewska G, Wojtkowski M, Palczewski K. From mouse to human: Accessing the biochemistry of vision in vivo by two-photon excitation. Prog Retin Eye Res 2023; 93:101170. [PMID: 36787681 PMCID: PMC10463242 DOI: 10.1016/j.preteyeres.2023.101170] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 02/13/2023]
Abstract
The eye is an ideal organ for imaging by a multi-photon excitation approach, because ocular tissues such as the sclera, cornea, lens and neurosensory retina, are highly transparent to infrared (IR) light. The interface between the retina and the retinal pigment epithelium (RPE) is especially informative, because it reflects the health of the visual (retinoid) cycle and its changes in response to external stress, genetic manipulations, and drug treatments. Vitamin A-derived retinoids, like retinyl esters, are natural fluorophores that respond to multi-photon excitation with near IR light, bypassing the filter-like properties of the cornea, lens, and macular pigments. Also, during natural aging some retinoids form bisretinoids, like diretinoid-pyridiniumethanolamine (A2E), that are highly fluorescent. These bisretinoids appear to be elevated concurrently with aging. Vitamin A-derived retinoids and bisretinoidss are detected by two-photon ophthalmoscopy (2PO), using a new class of light sources with adjustable spatial, temporal, and spectral properties. Furthermore, the two-photon (2P) absorption of IR light by the visual pigments in rod and cone photoreceptors can initiate visual transduction by cis-trans isomerization of retinal, enabling parallel functional studies. Recently we overcame concerns about safety, data interpretation and complexity of the 2P-based instrumentation, the major roadblocks toward advancing this modality to the clinic. These imaging and retina-function assessment advancements have enabled us to conduct the first 2P studies with humans.
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Affiliation(s)
- Grazyna Palczewska
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA; International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland; Polgenix, Inc., Department of Medical Devices, Cleveland, OH, USA; Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland.
| | - Maciej Wojtkowski
- International Center for Translational Eye Research, Polish Academy of Sciences, Warsaw, Poland; Department of Physical Chemistry of Biological Systems, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland; Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Torun, Poland.
| | - Krzysztof Palczewski
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California, Irvine, CA, USA; Department of Physiology & Biophysics, School of Medicine, And Chemistry, Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
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27
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Liu Z, Mo F, Dong X, Chen G, Gao J, Zhang J. Progressive degeneration of the retina in Loxl3 mutant mouse model of Stickler syndrome. Dev Biol 2023; 495:54-62. [PMID: 36610533 DOI: 10.1016/j.ydbio.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 01/02/2023] [Accepted: 01/03/2023] [Indexed: 01/06/2023]
Abstract
Stickler syndrome is a multisystem collagenopathy with affected individuals exhibiting a high rate of ocular complications. Lysyl oxidase-like 3 (LOXL3) is a human disease gene candidate with a critical role in catalyzing collagen crosslinking. A homozygous missense variant of LOXL3 was reported in Stickler syndrome with severe myopia. However, the underlying mechanisms of the LOXL3 missense mutation that causes Stickler syndrome are unknown. In this study, a mouse model of Stickler syndrome induced by LOXL3 mutation (c.2027G > A, p.Cys676Try) was obtained using CRISPR/Cas9 gene editing techniques. The Loxl3 mutant mice exhibited perinatal death, spinal deformity, and cleft palate, and Loxl3 mutation also induced skeletal dysplasia and progressive visual degeneration. Furthermore, we observed the damage of the bruch's membrane (BrM) and an increase in the levels of glial fibrillary acidic protein (GFAP) and Rpe65 in the Loxl3 mutant mice. Thus, we provided the critical in vivo evidence that Loxl3 possibly has a pivotal role in maintaining the eye function.
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Affiliation(s)
- Ziyi Liu
- Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, China
| | - Fan Mo
- School of Life Science, Shandong University, Qingdao, China
| | - Xinyu Dong
- School of Life Science, Shandong University, Qingdao, China
| | - Ge Chen
- School of Life Science, Shandong University, Qingdao, China
| | - Jiangang Gao
- School of Life Science, Shandong University, Qingdao, China.
| | - Jian Zhang
- School of Life Science, Shandong University, Qingdao, China.
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28
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Hofmann KP, Lamb TD. Rhodopsin, light-sensor of vision. Prog Retin Eye Res 2023; 93:101116. [PMID: 36273969 DOI: 10.1016/j.preteyeres.2022.101116] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/06/2022]
Abstract
The light sensor of vertebrate scotopic (low-light) vision, rhodopsin, is a G-protein-coupled receptor comprising a polypeptide chain with bound chromophore, 11-cis-retinal, that exhibits remarkable physicochemical properties. This photopigment is extremely stable in the dark, yet its chromophore isomerises upon photon absorption with 70% efficiency, enabling the activation of its G-protein, transducin, with high efficiency. Rhodopsin's photochemical and biochemical activities occur over very different time-scales: the energy of retinaldehyde's excited state is stored in <1 ps in retinal-protein interactions, but it takes milliseconds for the catalytically active state to form, and many tens of minutes for the resting state to be restored. In this review, we describe the properties of rhodopsin and its role in rod phototransduction. We first introduce rhodopsin's gross structural features, its evolution, and the basic mechanisms of its activation. We then discuss light absorption and spectral sensitivity, photoreceptor electrical responses that result from the activity of individual rhodopsin molecules, and recovery of rhodopsin and the visual system from intense bleaching exposures. We then provide a detailed examination of rhodopsin's molecular structure and function, first in its dark state, and then in the active Meta states that govern its interactions with transducin, rhodopsin kinase and arrestin. While it is clear that rhodopsin's molecular properties are exquisitely honed for phototransduction, from starlight to dawn/dusk intensity levels, our understanding of how its molecular interactions determine the properties of scotopic vision remains incomplete. We describe potential future directions of research, and outline several major problems that remain to be solved.
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Affiliation(s)
- Klaus Peter Hofmann
- Institut für Medizinische Physik und Biophysik (CC2), Charité, and, Zentrum für Biophysik und Bioinformatik, Humboldt-Unversität zu Berlin, Berlin, 10117, Germany.
| | - Trevor D Lamb
- Eccles Institute of Neuroscience, John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2600, Australia.
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29
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Hara M, Wu W, Malechka VV, Takahashi Y, Ma JX, Moiseyev G. PNPLA2 mobilizes retinyl esters from retinosomes and promotes the generation of 11-cis-retinal in the visual cycle. Cell Rep 2023; 42:112091. [PMID: 36763501 PMCID: PMC10406976 DOI: 10.1016/j.celrep.2023.112091] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/22/2022] [Accepted: 01/25/2023] [Indexed: 02/10/2023] Open
Abstract
Retinosomes are intracellular lipid bodies found in the retinal pigment epithelium (RPE). They contain retinyl esters (REs) and are thought to be involved in visual chromophore regeneration during dark adaptation and in case of chromophore depletion. However, key enzymes in chromophore regeneration, retinoid isomerase (RPE65), and lecithin:retinol acyltransferase (LRAT) are located in the endoplasmic reticulum (ER). The mechanism and the enzyme responsible for mobilizing REs from retinosomes remained unknown. Our study demonstrates that patatin-like phospholipase domain containing 2 (PNPLA2) mobilizes all-trans-REs from retinosomes. The absence of PNPLA2 in mouse eyes leads to a significant accumulation of lipid droplets in RPE cells, declined electroretinography (ERG) response, and delayed dark adaptation compared with those of WT control mouse. Our work suggests a function of PNPLA2 as an RE hydrolase in the RPE, mobilizing REs from lipid bodies and functioning as an essential component of the visual cycle.
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Affiliation(s)
- Miwa Hara
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; Department of Biochemistry, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Wenjing Wu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; Department of Biochemistry, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Volha V Malechka
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Yusuke Takahashi
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; Department of Biochemistry, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; Department of Biochemistry, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
| | - Gennadiy Moiseyev
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA; Department of Biochemistry, Wake Forest School of Medicine, Winston Salem, NC 27157, USA.
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30
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Loewinger AS, Pfau M, Herrmann P, Holz FG, Pfau K. Choriocapillaris Flow Signal Impairment in Patients With Pseudoxanthoma Elasticum. Invest Ophthalmol Vis Sci 2023; 64:21. [PMID: 36809302 PMCID: PMC9946047 DOI: 10.1167/iovs.64.2.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Purpose To quantify choriocapillaris flow alterations in patients with pseudoxanthoma elasticum (PXE) in pre-atrophic stages and its association with structural changes of the choroid and outer retina. Methods Thirty-two eyes of 21 patients with PXE and 35 healthy eyes of 35 controls were included. The density of choriocapillaris flow signal deficits (FDs) was quantified on 6 × 6-mm optical coherence tomography angiography (OCTA) images. Spectral-domain optical coherence tomography (SD-OCT) images were analyzed for thicknesses of the choroid and outer retinal microstructure and correlated with choriocapillaris FDs in the respective Early Treatment Diabetic Retinopathy Study subfield. Results The multivariable mixed model analysis for choriocapillaris FDs revealed significantly higher FDs associated with the group (PXE patients vs. controls +13.6; 95% confidence interval [CI] 9.87-17.3; P < 0.001), with increasing age (+0.22% per year; 95% CI 0.12-0.33; P < 0.001), and with retinal location (significantly higher FDs in nasal compared to temporal subfields). Choroidal thickness (CT) did not differ significantly between both groups (P = 0.078). The CT and choriocapillaris FDs were inversely correlated (-1.92 µm per %FDs; interquartile range -2.81 to -1.03; P < 0.001). Larger values of the choriocapillaris FDs were associated with significant thinning of the overlying photoreceptor layers (outer segments: -0.21 µm per %FDs, P < 0.001; inner segments: -0.12 µm per %FDs, P = 0.001; outer nuclear layer: -0.72 µm per %FDs; P < 0.001). Conclusions Patients with PXE display significant alterations of the choriocapillaris on OCTA even in pre-atrophic stages and in the absence of significant choroidal thinning. The analysis favors choriocapillaris FDs over choroidal thickness as a potential early outcome measure for future interventional trials in PXE. Further, increased FDs in nasal compared to temporal locations mirror the centrifugal spread of Bruch's membrane calcification in PXE.
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Affiliation(s)
| | - Maximilian Pfau
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany,Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, Maryland, United States
| | - Philipp Herrmann
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Frank G. Holz
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany
| | - Kristina Pfau
- Department of Ophthalmology, University Hospital Bonn, Bonn, Germany,Division of Epidemiology and Clinical Applications, National Eye Institute, Bethesda, Maryland, United States
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31
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Cellular and Molecular Mechanisms of Pathogenesis Underlying Inherited Retinal Dystrophies. Biomolecules 2023; 13:biom13020271. [PMID: 36830640 PMCID: PMC9953031 DOI: 10.3390/biom13020271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/23/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) are congenital retinal degenerative diseases that have various inheritance patterns, including dominant, recessive, X-linked, and mitochondrial. These diseases are most often the result of defects in rod and/or cone photoreceptor and retinal pigment epithelium function, development, or both. The genes associated with these diseases, when mutated, produce altered protein products that have downstream effects in pathways critical to vision, including phototransduction, the visual cycle, photoreceptor development, cellular respiration, and retinal homeostasis. The aim of this manuscript is to provide a comprehensive review of the underlying molecular mechanisms of pathogenesis of IRDs by delving into many of the genes associated with IRD development, their protein products, and the pathways interrupted by genetic mutation.
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Hollingsworth TJ, Wang X, Simpson RN, White WA, Williams RW, Jablonski MM. Current Advancements in Mouse Models of Retinal Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:371-376. [PMID: 37440059 DOI: 10.1007/978-3-031-27681-1_54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
The field of retinal degenerative (RDs) disease study has been in a state of exponential growth from discovering the underlying genetic components of such diseases as age-related macular degeneration (AMD) and retinitis pigmentosa (RP) to the first gene therapy developed and approved for human Leber congenital amaurosis. However, a source for high-fidelity animal models of these complex, multifactorial, and/or polygenic diseases is a need that has yet to be fulfilled. While models for AMD and RP do exist, they often require aging the animals for a year or more, feeding special diets, or introduction of external modulators such as exposure to cigarette smoke. Currently, work is being done to uncover high-fidelity naturally occurring models of these retinal diseases with the hope and intent of providing the vision community the tools it needs to better understand, treat, and, one day, cure the patients suffering from these devastating afflictions.
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Affiliation(s)
- T J Hollingsworth
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Memphis, TN, USA.
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, TN, USA.
- Hamilton Eye Institute, University of Tennessee Health Sciences Center, Memphis, TN, USA.
| | - Xiangdi Wang
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Hamilton Eye Institute, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Raven N Simpson
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Hamilton Eye Institute, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - William A White
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Hamilton Eye Institute, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Robert W Williams
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Hamilton Eye Institute, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Department of Genetics, Genomics, and Informatics, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Monica M Jablonski
- Department of Ophthalmology, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Department of Medicine, University of Tennessee Health Sciences Center, Memphis, TN, USA
- Hamilton Eye Institute, University of Tennessee Health Sciences Center, Memphis, TN, USA
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Uppal S, Poliakov E, Gentleman S, Redmond TM. The Amphipathic Helix in Visual Cycle Proteins: A Review. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:533-537. [PMID: 37440083 PMCID: PMC11299856 DOI: 10.1007/978-3-031-27681-1_78] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
The visual cycle is a complex biological process that involves the sequential action of proteins in the retinal pigment epithelial (RPE) cells and photoreceptors to modify and shuttle visual retinoids. A majority of the visual cycle proteins are membrane proteins, either integral or peripheral membrane proteins. Despite significant progress in understanding their physiological function, very limited structural information is available for the visual cycle proteins. Moreover, the mechanism of membrane interaction is not yet clear in all cases. Here, we demonstrate the presence of an amphipathic helix in selected RPE visual cycle proteins, using in silico tools, and highlight their role in membrane association and function.
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Affiliation(s)
- Sheetal Uppal
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Eugenia Poliakov
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Susan Gentleman
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA.
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Wu W, Takahashi Y, Ma X, Moiseyev G, Ma JX. Environmental Light Has an Essential Effect on the Disease Expression in a Dominant RPE65 Mutation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:415-419. [PMID: 37440066 DOI: 10.1007/978-3-031-27681-1_61] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
The retina pigmented epithelium 65 kDa protein (RPE65) is an essential enzyme in the visual cycle that regenerates the 11-cis-retinal chromophore obligatory for vision. Mutations in RPE65 are associated with blinding diseases. D477G (C.1430G > A) is the only known RPE65 variant to cause autosomal dominant retinitis pigmentosa (adRP). Previously, we reported that the heterozygous D477G knock-in (WT/KI) mice exposed to dim light intensity demonstrated delayed chromophore regeneration rates and slowed recovery of photoreceptor sensitivity following photobleaching. However, visual function and retinal architecture were indistinguishable from the wild-type (WT) mice. In this study, when maintained under the physiological day-light intensity (2 K lux), the WT/KI heterozygous mice displayed retina degeneration and reduced electroretinography (ERG) amplitude, recapitulating that observed in human patients. Our findings indicated the importance of the light environment in the mechanism of RPE65 D477G pathogenicity.
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Affiliation(s)
- Wenjing Wu
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Yusuke Takahashi
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Xiang Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Gennadiy Moiseyev
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Jian-Xing Ma
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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Stingl K, Kempf M, Jung R, Kortüm F, Righetti G, Reith M, Dimopoulos S, Ott S, Kohl S, Stingl K. Therapy with voretigene neparvovec. How to measure success? Prog Retin Eye Res 2023; 92:101115. [PMID: 36096933 DOI: 10.1016/j.preteyeres.2022.101115] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/17/2022] [Accepted: 08/19/2022] [Indexed: 02/01/2023]
Abstract
Retinal gene supplementation therapy such as the first approved one, voretigene neparvovec, delivers a functioning copy of the missing gene enabling the protein transcription in retinal cells and restore visual functions. After gene supplementation for the genetic defect, a complex network of functional regeneration is the consequence, whereas the extent is very individualized. Diagnostic and functional testings that have been used routinely by ophthalmologists so far to define the correct diagnosis, cannot be applied in the new context of defining small, sometimes subtle changes in visual functions. New view on retinal diagnostics is needed to understand this processes that define safety and efficacy of the treatment. Not only does vision have many aspects that must be addressed by specific evaluations and imaging techniques, but objective readouts of local retinal function for rods and cones separately have been an unmet need until recently. A reliable test-retest variability is necessary in rare diseases such as inherited retinal dystrophies, because statistics are often not applicable due to a low number of participants. Methods for a reliable individual evaluation of the therapy success are needed. In this manuscript we present an elaboration on retinal diagnostics combining psychophysics (eg. full-field stimulus threshold or dark adapted perimetry) as well as objective measures for local retinal function (eg. photopic and scotopic chromatic pupil campimetry) and retinal imaging for a meaningful workflow to apply in evaluation of the individual success in patients receiving gene therapy for photoreceptor diseases.
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Affiliation(s)
- Krunoslav Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany; Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany.
| | - Melanie Kempf
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany; Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany.
| | - Ronja Jung
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Friederike Kortüm
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Giulia Righetti
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Milda Reith
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Spyridon Dimopoulos
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Saskia Ott
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany.
| | - Susanne Kohl
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tuebingen, Tuebingen, Germany.
| | - Katarina Stingl
- Center for Ophthalmology, University Eye Hospital, University of Tuebingen, Tuebingen, Germany; Center for Rare Eye Diseases, University of Tuebingen, Tuebingen, Germany.
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Preclinical Models of Retinitis Pigmentosa. Methods Mol Biol 2022; 2560:181-215. [PMID: 36481897 DOI: 10.1007/978-1-0716-2651-1_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinitis pigmentosa (RP) is the name for a group of phenotypically-related heritable retinal degenerative disorders. Many genes have been implicated as causing variants of RP, and while the clinical phenotypes are remarkably similar, they may differ in age of onset, progression, and severity. Common inheritance patterns for specific genes connected with the development of the disorder include autosomal dominant, autosomal recessive, and X-linked. Modeling the disease in animals and other preclinical systems offers a cost-conscious, ethical, and time-efficient method for studying the disease subtypes. The history of RP models is briefly examined, and both naturally occurring and transgenic preclinical models of RP in many different organisms are discussed. Syndromic forms of RP and models thereof are reviewed as well.
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Karamali F, Behtaj S, Babaei-Abraki S, Hadady H, Atefi A, Savoj S, Soroushzadeh S, Najafian S, Nasr Esfahani MH, Klassen H. Potential therapeutic strategies for photoreceptor degeneration: the path to restore vision. J Transl Med 2022; 20:572. [PMID: 36476500 PMCID: PMC9727916 DOI: 10.1186/s12967-022-03738-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 10/29/2022] [Indexed: 12/12/2022] Open
Abstract
Photoreceptors (PRs), as the most abundant and light-sensing cells of the neuroretina, are responsible for converting light into electrical signals that can be interpreted by the brain. PR degeneration, including morphological and functional impairment of these cells, causes significant diminution of the retina's ability to detect light, with consequent loss of vision. Recent findings in ocular regenerative medicine have opened promising avenues to apply neuroprotective therapy, gene therapy, cell replacement therapy, and visual prostheses to the challenge of restoring vision. However, successful visual restoration in the clinical setting requires application of these therapeutic approaches at the appropriate stage of the retinal degeneration. In this review, firstly, we discuss the mechanisms of PR degeneration by focusing on the molecular mechanisms underlying cell death. Subsequently, innovations, recent developments, and promising treatments based on the stage of disorder progression are further explored. Then, the challenges to be addressed before implementation of these therapies in clinical practice are considered. Finally, potential solutions to overcome the current limitations of this growing research area are suggested. Overall, the majority of current treatment modalities are still at an early stage of development and require extensive additional studies, both pre-clinical and clinical, before full restoration of visual function in PR degeneration diseases can be realized.
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Affiliation(s)
- Fereshteh Karamali
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sanaz Behtaj
- grid.1022.10000 0004 0437 5432Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Queensland, Australia ,grid.1022.10000 0004 0437 5432Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222 Australia
| | - Shahnaz Babaei-Abraki
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Hanieh Hadady
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Atefeh Atefi
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Soraya Savoj
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Sareh Soroushzadeh
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Samaneh Najafian
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Mohammad Hossein Nasr Esfahani
- grid.417689.5Department of Animal Biotechnology, Cell Science Research Center, Royan Institute for Biotechnology, ACECR, Isfahan, Iran
| | - Henry Klassen
- grid.266093.80000 0001 0668 7243Gavin Herbert Eye Institute, Irvine, CA USA
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Visual function restoration in a mouse model of Leber congenital amaurosis via therapeutic base editing. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 31:16-27. [PMID: 36589710 PMCID: PMC9792702 DOI: 10.1016/j.omtn.2022.11.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
Leber congenital amaurosis (LCA), an inherited retinal degeneration, causes severe visual dysfunction in children and adolescents. In patients with LCA, pathogenic variants, such as RPE65, are evident in specific genes, related to the functions of retinal pigment epithelium and photoreceptors. In contrast to the original Cas9, base editing tools can correct pathogenic substitutions without generation of DNA double-stranded breaks (DSBs). In this study, dual adeno-associated virus (AAV) vectors containing split adenine base editors (ABEs) with trans-splicing intein were prepared for in vivo base editing in retinal degeneration of 12 (rd12) mice, an animal model of LCA, possessing a nonsense mutation of C to T transition in the Rpe65 gene (p.R44X). Subretinal injection of AAV-ABE in retinal pigment epithelial cells of rd12 mice resulted in an A to G transition. The on-target editing was sufficient for recovery of wild-type mRNA, RPE65 protein, and light-induced electrical responses from the retina. Compared with our previous therapeutic editing strategies using Cas9 and prime editing, or with the gene transfer strategy shown in the current study, our results suggest that, considering the editing efficacy and functional recovery, ABEs could be a strong, reliable method for correction of pathogenic variants in the treatment of LCA.
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Cho EH, Park JE, Lee T, Ha K, Ki CS. Carrier frequency and incidence estimation of RPE65-associated inherited retinal diseases in East Asian population by population database-based analysis. Orphanet J Rare Dis 2022; 17:409. [PMID: 36352427 PMCID: PMC9644481 DOI: 10.1186/s13023-022-02566-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/07/2022] [Accepted: 10/30/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Inherited retinal diseases (IRDs) are clinically and genetically heterogenous disorders leading to visual impairment and blindness. Because gene therapy for RPE65-associated IRDs was recently approved, it is necessary to predict the carrier frequency and prevalence for RPE65-associated IRDs. This study aimed to analyze the carrier frequency and expected incidence of RPE65-associated IRDs in East Asians and Koreans using exome data from the Genome Aggregation Database (gnomAD) and the Korean Reference Genome Database (KRGDB). METHODS We analyzed 9,197 exomes for East Asian populations from gnomAD comprising 1,909 Korean and 1,722 Korean genomes from KRGDB. All identified RPE65 variants were classified according to the 2015 American College of Medical Genetics and Genomics and the Association for Molecular Pathology guidelines. RESULTS The total carrier frequencies of East Asians and Koreans from both gnomAD and KRGDB were 0.10% (11/10,919) and 0.06% (2/3,631), respectively. The estimated incidence of RPE65-associated IRDs was 1/3,941,308 in East Asians and 1/13,184,161 in Koreans. CONCLUSION This study identified carrier frequencies of RPE65-associated IRDs in East Asians and Koreans using gnomAD and KRGDB. We confirmed that the carrier frequency of RPE65-associated IRDs patients was low in Koreans among all East Asian populations, and the incidence was also predicted to be lower than in other East Asian populations. The variant spectrum of RPE65 gene in East Asian and Korean populations differed greatly from those of other ethnic groups.
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Affiliation(s)
- Eun Hye Cho
- Department of Laboratory Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Jong Eun Park
- Department of Laboratory Medicine, Hanyang University Guri Hospital, Hanyang University College of Medicine, Hanyang University Guri Hospital, 153, Gyeongchun-ro, 11923, Guri-si, Gyeonggi-do, Republic of Korea.
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Uppal S, Liu T, Galvan E, Gomez F, Tittley T, Poliakov E, Gentleman S, Redmond TM. An inducible amphipathic α-helix mediates subcellular targeting and membrane binding of RPE65. Life Sci Alliance 2022; 6:6/1/e202201546. [PMID: 36265895 PMCID: PMC9585964 DOI: 10.26508/lsa.202201546] [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: 06/02/2022] [Revised: 09/27/2022] [Accepted: 09/28/2022] [Indexed: 11/24/2022] Open
Abstract
RPE65 retinol isomerase is an indispensable player in the visual cycle between the vertebrate retina and RPE. Although membrane association is critical for RPE65 function, its mechanism is not clear. Residues 107-125 are believed to interact with membranes but are unresolved in all RPE65 crystal structures, whereas palmitoylation at C112 also plays a role. We report the mechanism of membrane recognition and binding by RPE65. Binding of aa107-125 synthetic peptide with membrane-mimicking micellar surfaces induces transition from unstructured loop to amphipathic α-helical (AH) structure but this transition is automatic in the C112-palmitoylated peptide. We demonstrate that the AH significantly affects palmitoylation level, membrane association, and isomerization activity of RPE65. Furthermore, aa107-125 functions as a membrane sensor and the AH as a membrane-targeting motif. Molecular dynamic simulations clearly show AH-membrane insertion, supporting our experimental findings. Collectively, these studies allow us to propose a working model for RPE65-membrane binding, and to provide a novel role for cysteine palmitoylation.
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Affiliation(s)
| | | | | | | | | | | | | | - T Michael Redmond
- Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
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The novel visual cycle inhibitor (±)-RPE65-61 protects retinal photoreceptors from light-induced degeneration. PLoS One 2022; 17:e0269437. [PMID: 36227868 PMCID: PMC9560169 DOI: 10.1371/journal.pone.0269437] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/23/2022] [Indexed: 11/25/2022] Open
Abstract
The visual cycle refers to a series of biochemical reactions of retinoids in ocular tissues and supports the vision in vertebrates. The visual cycle regenerates visual pigments chromophore, 11-cis-retinal, and eliminates its toxic byproducts from the retina, supporting visual function and retinal neuron survival. Unfortunately, during the visual cycle, when 11-cis-retinal is being regenerated in the retina, toxic byproducts, such as all-trans-retinal and bis-retinoid is N-retinylidene-N-retinylethanolamine (A2E), are produced, which are proposed to contribute to the pathogenesis of the dry form of age-related macular degeneration (AMD). The primary biochemical defect in Stargardt disease (STGD1) is the accelerated synthesis of cytotoxic lipofuscin bisretinoids, such as A2E, in the retinal pigment epithelium (RPE) due to mutations in the ABCA4 gene. To prevent all-trans-retinal-and bisretinoid-mediated retinal degeneration, slowing down the retinoid flow by modulating the visual cycle with a small molecule has been proposed as a therapeutic strategy. The present study describes RPE65-61, a novel, non-retinoid compound, as an inhibitor of RPE65 (a key enzyme in the visual cycle), intended to modulate the excessive activity of the visual cycle to protect the retina from harm degenerative diseases. Our data demonstrated that (±)-RPE65-61 selectively inhibited retinoid isomerase activity of RPE65, with an IC50 of 80 nM. Furthermore, (±)-RPE65-61 inhibited RPE65 via an uncompetitive mechanism. Systemic administration of (±)-RPE65-61 in mice resulted in slower chromophore regeneration after light bleach, confirming in vivo target engagement and visual cycle modulation. Concomitant protection of the mouse retina from high-intensity light damage was also observed. Furthermore, RPE65-61 down-regulated the cyclic GMP-AMP synthase stimulator of interferon genes (cGAS-STING) pathway, decreased the inflammatory factor, and attenuated retinal apoptosis caused by light-induced retinal damage (LIRD), which led to the preservation of the retinal function. Taken together, (±)-RPE65-61 is a potent visual cycle modulator that may provide a neuroprotective therapeutic benefit for patients with STGD and AMD.
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Staurenghi F, McClements ME, Salman A, MacLaren RE. Minicircle Delivery to the Neural Retina as a Gene Therapy Approach. Int J Mol Sci 2022; 23:11673. [PMID: 36232975 PMCID: PMC9569440 DOI: 10.3390/ijms231911673] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 09/26/2022] [Accepted: 09/28/2022] [Indexed: 11/07/2022] Open
Abstract
Non-viral gene therapy has the potential to overcome several shortcomings in viral vector-based therapeutics. Methods of in vivo plasmid delivery have developed over recent years to increase the efficiency of non-viral gene transfer, yet further improvements still need to be made to improve their translational capacity. Gene therapy advances for inherited retinal disease have been particularly prominent over the recent decade but overcoming physical and physiological barriers present in the eye remains a key obstacle in the field of non-viral ocular drug delivery. Minicircles are circular double-stranded DNA vectors that contain expression cassettes devoid of bacterial DNA, thereby limiting the risks of innate immune responses induced by such elements. To date, they have not been extensively used in pre-clinical studies yet remain a viable vector option for the treatment of inherited retinal disease. Here, we explore the potential of minicircle DNA delivery to the neural retina as a gene therapy approach. We consider the advantages of minicircles as gene therapy vectors as well as review the challenges involved in optimising their delivery to the neural retina.
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Affiliation(s)
- Federica Staurenghi
- Nuffield Laboratory of Ophthalmology, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Michelle E. McClements
- Nuffield Laboratory of Ophthalmology, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Ahmed Salman
- Nuffield Laboratory of Ophthalmology, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Robert E. MacLaren
- Nuffield Laboratory of Ophthalmology, Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
- Oxford University Hospital, Oxford OX3 9DU, UK
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Polikarpova AV, Egorova TV, Bardina MV. Genetically modified animal models of hereditary diseases for testing of gene-directed therapy. RESEARCH RESULTS IN PHARMACOLOGY 2022. [DOI: 10.3897/rrpharmacology.8.82618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Disease-causing genes have been identified for many severe muscular and neurological genetic disorders. Advances in the gene therapy field offer promising solutions for drug development to treat these life-threatening conditions. Depending on how the mutation affects the function of the gene product, different gene therapy approaches may be beneficial. Gene replacement therapy is appropriate for diseases caused by mutations that result in the deficiency of the functional protein. Gene suppression strategy is suggested for disorders caused by the toxic product of the mutant gene. Splicing modulators, genome editing, and base editing techniques can be applied to disorders with different types of underlying mutations. Testing potential drugs in animal models of human diseases is an indispensable step of development. Given the specific gene therapy approach, appropriate animal models can be generated using a variety of technologies ranging from transgenesis to precise genome editing. In this review, we discuss technologies used to generate small and large animal models of the most common muscular and neurological genetic disorders. We specifically focus on animal models that were used to test gene therapies based on adeno-associated vectors and antisense nucleotides.
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Widjaja-Adhi MAK, Kolesnikov AV, Vasudevan S, Park PSH, Kefalov VJ, Golczak M. Acyl-CoA:wax alcohol acyltransferase 2 modulates the cone visual cycle in mouse retina. FASEB J 2022; 36:e22390. [PMID: 35665537 DOI: 10.1096/fj.202101855rrr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/12/2022] [Accepted: 05/23/2022] [Indexed: 11/11/2022]
Abstract
The daylight and color vision of diurnal vertebrates depends on cone photoreceptors. The capability of cones to operate and respond to changes in light brightness even under high illumination is attributed to their fast rate of recovery to the ground photosensitive state. This process requires the rapid replenishing of photoisomerized visual chromophore (11-cis-retinal) to regenerate cone visual pigments. Recently, several gene candidates have been proposed to contribute to the cone-specific retinoid metabolism, including acyl-CoA wax alcohol acyltransferase 2 (AWAT2, aka MFAT). Here, we evaluated the role of AWAT2 in the regeneration of visual chromophore by the phenotypic characterization of Awat2-/- mice. The global absence of AWAT2 enzymatic activity did not affect gross retinal morphology or the rate of visual chromophore regeneration by the canonical RPE65-dependent visual cycle. Analysis of Awat2 expression indicated the presence of the enzyme throughout the murine retina, including the retinal pigment epithelium (RPE) and Müller cells. Electrophysiological recordings revealed reduced maximal rod and cone dark-adapted responses in AWAT2-deficient mice compared to control mice. While rod dark adaptation was not affected by the lack of AWAT2, M-cone dark adaptation both in isolated retina and in vivo was significantly suppressed. Altogether, these results indicate that while AWAT2 is not required for the normal operation of the canonical visual cycle, it is a functional component of the cone-specific visual chromophore regenerative pathway.
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Affiliation(s)
| | - Alexander V Kolesnikov
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, California, USA
| | - Sreelakshmi Vasudevan
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Paul S-H Park
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, USA
| | - Vladimir J Kefalov
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California, Irvine, California, USA.,Department of Physiology and Biophysics, University of California, Irvine, California, USA
| | - Marcin Golczak
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio, USA.,Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
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45
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Samimi K, Pattnaik BR, Capowski EE, Saha K, Gamm DM, Skala MC. In situ autofluorescence lifetime assay of a photoreceptor stimulus response in mouse retina and human retinal organoids. BIOMEDICAL OPTICS EXPRESS 2022; 13:3476-3492. [PMID: 35781966 PMCID: PMC9208582 DOI: 10.1364/boe.455783] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/25/2022] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
Photoreceptors are the key functional cell types responsible for the initiation of vision in the retina. Phototransduction involves isomerization and conversion of vitamin A compounds, known as retinoids, and their recycling through the visual cycle. We demonstrate a functional readout of the visual cycle in photoreceptors within stem cell-derived retinal organoids and mouse retinal explants based on spectral and lifetime changes in autofluorescence of the visual cycle retinoids after exposure to light or chemical stimuli. We also apply a simultaneous two- and three-photon excitation method that provides specific signals and increases contrast between these retinoids, allowing for reliable detection of their presence and conversion within photoreceptors. This multiphoton imaging technique resolves the slow dynamics of visual cycle reactions and can enable high-throughput functional screening of retinal tissues and organoid cultures with single-cell resolution.
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Affiliation(s)
- Kayvan Samimi
- Morgridge Institute for Research, Madison, WI 53715, USA
| | - Bikash R. Pattnaik
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | | - Krishanu Saha
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - David M. Gamm
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Melissa C. Skala
- Morgridge Institute for Research, Madison, WI 53715, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA
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46
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Daich Varela M, Michaelides M. RDH12 retinopathy: clinical features, biology, genetics and future directions. Ophthalmic Genet 2022; 43:1-6. [PMID: 35491887 PMCID: PMC10479312 DOI: 10.1080/13816810.2022.2062392] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/14/2022] [Accepted: 03/22/2022] [Indexed: 10/18/2022]
Abstract
Retinol dehydrogenase 12 (RDH12) is a small gene located on chromosome 14, encoding an enzyme capable of metabolizing retinoids. It is primarily located in photoreceptor inner segments and thereby is believed to have an important role in clearing excessive retinal and other toxic aldehydes produced by light exposure. Clinical features: RDH12-associated retinopathy has wide phenotypic variability; including early-onset severe retinal dystrophy/Leber Congenital Amaurosis (EOSRD/LCA; most frequent presentation), retinitis pigmentosa, cone-rod dystrophy, and macular dystrophy. It can be inherited in an autosomal recessive and dominant fashion. RDH12-EOSRD/LCA's key features are early visual impairment, petal-shaped, coloboma-like macular atrophy with variegated watercolour-like pattern, peripapillary sparing, and often dense bone spicule pigmentation. Future directions: There is currently no treatment available for RDH12-retinopathy. However, extensive preclinical investigations and an ongoing prospective natural history study are preparing the necessary foundation to design and establish forthcoming clinical trials. Herein, we will concisely review pathophysiology, molecular genetics, clinical features, and discuss therapeutic approaches.
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Affiliation(s)
- Malena Daich Varela
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital, London, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital, London, UK
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47
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Wang J, Tao Z, Deng H, Cui Y, Xu Z, Lyu Q, Zhao J. Therapeutic implications of nanodrug and tissue engineering for retinal pigment epithelium-related diseases. NANOSCALE 2022; 14:5657-5677. [PMID: 35352082 DOI: 10.1039/d1nr08337f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The retinal pigment epithelium (RPE), as a single layer of cells that performs multiple functions posteriorly in the eye, is a promising target site for the prevention and treatment of several clinical diseases, including proliferative diabetic retinopathy, age-related macular degeneration, chorionic neovascularization, and retinitis pigmentosa. In recent decades, several nanodrug delivery platforms and tissue-engineered RPE have been widely developed to treat RPE-related diseases. This work summarizes the recent advances in nanoplatforms and tissue engineering scaffolds developed in these fields. The diseases associated with pathological RPE and their common therapy strategies are first introduced. Then, the recent progress made with a variety of drug delivery systems is presented, with an emphasis on the modification strategies of nanomaterials for targeted delivery. Tissue engineering-mediated RPE transplantation for treating these diseases is subsequently described. Finally, the clinical translation challenges in these fields are discussed in depth. This article will offer readers a better understanding of emerging nanotechnology and tissue engineering related to the treatment of RPE-related diseases and could facilitate their widespread use in experiments in vivo and in clinical applications.
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Affiliation(s)
- Jiao Wang
- Shenzhen Eye Hospital, Shenzhen Eye Institute, Shenzhen Eye Hospital affiliated to Jinan University, School of Optometry, Shenzhen University, Shenzhen 518000, China.
| | - Zhengyang Tao
- Shenzhen Eye Hospital, Shenzhen Eye Institute, Shenzhen Eye Hospital affiliated to Jinan University, School of Optometry, Shenzhen University, Shenzhen 518000, China.
| | - Hongwei Deng
- Shenzhen Eye Hospital, Shenzhen Eye Institute, Shenzhen Eye Hospital affiliated to Jinan University, School of Optometry, Shenzhen University, Shenzhen 518000, China.
| | - Yubo Cui
- Department of Ophthalmology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen 518020, China.
| | - Zhirong Xu
- Jinzhou Medical University, Jinzhou, Liaoning 121000, P.R. China
| | - Qinghua Lyu
- Shenzhen Eye Hospital, Shenzhen Eye Institute, Shenzhen Eye Hospital affiliated to Jinan University, School of Optometry, Shenzhen University, Shenzhen 518000, China.
- Institute of Microscale Optoelectronics, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Jun Zhao
- Department of Ophthalmology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen 518020, China.
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48
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Influence of carrier materials and coatings on retinal pigment epithelium cultivation and functions. Exp Eye Res 2022; 219:109063. [DOI: 10.1016/j.exer.2022.109063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 03/29/2022] [Accepted: 03/30/2022] [Indexed: 11/22/2022]
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49
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Daich Varela M, Cabral de Guimaraes TA, Georgiou M, Michaelides M. Leber congenital amaurosis/early-onset severe retinal dystrophy: current management and clinical trials. Br J Ophthalmol 2022; 106:445-451. [PMID: 33712480 PMCID: PMC8961750 DOI: 10.1136/bjophthalmol-2020-318483] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 01/18/2021] [Accepted: 02/23/2021] [Indexed: 12/26/2022]
Abstract
Leber congenital amaurosis (LCA) is a severe congenital/early-onset retinal dystrophy. Given its monogenic nature and the immunological and anatomical privileges of the eye, LCA has been particularly targeted by cutting-edge research. In this review, we describe the current management of LCA, and highlight the clinical trials that are on-going and planned. RPE65-related LCA pivotal trials, which culminated in the first Food and Drug Administration-approved and European Medicines Agency-approved ocular gene therapy, have paved the way for a new era of genetic treatments in ophthalmology. At present, multiple clinical trials are available worldwide applying different techniques, aiming to achieve better outcomes and include more genes and variants. Genetic therapy is not only implementing gene supplementation by the use of adeno-associated viral vectors, but also clustered regularly interspaced short palindromic repeats (CRISPR)-mediated gene editing and post-transcriptional regulation through antisense oligonucleotides. Pharmacological approaches intending to decrease photoreceptor degeneration by supplementing 11-cis-retinal and cell therapy's aim to replace the retinal pigment epithelium, providing a trophic and metabolic retinal structure, are also under investigation. Furthermore, optoelectric devices and optogenetics are also an option for patients with residual visual pathway. After more than 10 years since the first patient with LCA received gene therapy, we also discuss future challenges, such as the overlap between different techniques and the long-term durability of efficacy. The next 5 years are likely to be key to whether genetic therapies will achieve their full promise, and whether stem cell/cellular therapies will break through into clinical trial evaluation.
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Affiliation(s)
- Malena Daich Varela
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, London, UK
| | | | - Michalis Georgiou
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, London, UK
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London, London, UK
- Moorfields Eye Hospital NHS Foundation Trust, London, London, UK
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50
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Idelfonso-García OG, Alarcón-Sánchez BR, Vásquez-Garzón VR, Baltiérrez-Hoyos R, Villa-Treviño S, Muriel P, Serrano H, Pérez-Carreón JI, Arellanes-Robledo J. Is Nucleoredoxin a Master Regulator of Cellular Redox Homeostasis? Its Implication in Different Pathologies. Antioxidants (Basel) 2022; 11:antiox11040670. [PMID: 35453355 PMCID: PMC9030443 DOI: 10.3390/antiox11040670] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/26/2022] [Accepted: 03/28/2022] [Indexed: 01/27/2023] Open
Abstract
Nucleoredoxin (NXN), an oxidoreductase enzyme, contributes to cellular redox homeostasis by regulating different signaling pathways in a redox-dependent manner. By interacting with seven proteins so far, namely disheveled (DVL), protein phosphatase 2A (PP2A), phosphofructokinase-1 (PFK1), translocation protein SEC63 homolog (SEC63), myeloid differentiation primary response gene-88 (MYD88), flightless-I (FLII), and calcium/calmodulin-dependent protein kinase II type alpha (CAMK2A), NXN is involved in the regulation of several key cellular processes, including proliferation, organogenesis, cell cycle progression, glycolysis, innate immunity and inflammation, motility, contraction, protein transport into the endoplasmic reticulum, neuronal plasticity, among others; as a result, NXN has been implicated in different pathologies, such as cancer, alcoholic and polycystic liver disease, liver fibrogenesis, obesity, Robinow syndrome, diabetes mellitus, Alzheimer’s disease, and retinitis pigmentosa. Together, this evidence places NXN as a strong candidate to be a master redox regulator of cell physiology and as the hub of different redox-sensitive signaling pathways and associated pathologies. This review summarizes and discusses the current insights on NXN-dependent redox regulation and its implication in different pathologies.
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Affiliation(s)
- Osiris Germán Idelfonso-García
- Laboratory of Liver Diseases, National Institute of Genomic Medicine–INMEGEN, Mexico City 14610, Mexico; (O.G.I.-G.); (B.R.A.-S.); (J.I.P.-C.)
- Department of Health Sciences, Metropolitan Autonomous University-Iztapalapa Campus, Mexico City 09340, Mexico;
| | - Brisa Rodope Alarcón-Sánchez
- Laboratory of Liver Diseases, National Institute of Genomic Medicine–INMEGEN, Mexico City 14610, Mexico; (O.G.I.-G.); (B.R.A.-S.); (J.I.P.-C.)
- Department of Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute–CINVESTAV-IPN, Mexico City 07360, Mexico;
| | - Verónica Rocío Vásquez-Garzón
- Laboratory of Fibrosis and Cancer, Faculty of Medicine and Surgery, ‘Benito Juárez’ Autonomous University of Oaxaca–UABJO, Oaxaca 68020, Mexico; (V.R.V.-G.); (R.B.-H.)
- Directorate of Cátedras, National Council of Science and Technology–CONACYT, Mexico City 03940, Mexico
| | - Rafael Baltiérrez-Hoyos
- Laboratory of Fibrosis and Cancer, Faculty of Medicine and Surgery, ‘Benito Juárez’ Autonomous University of Oaxaca–UABJO, Oaxaca 68020, Mexico; (V.R.V.-G.); (R.B.-H.)
- Directorate of Cátedras, National Council of Science and Technology–CONACYT, Mexico City 03940, Mexico
| | - Saúl Villa-Treviño
- Department of Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute–CINVESTAV-IPN, Mexico City 07360, Mexico;
| | - Pablo Muriel
- Laboratory of Experimental Hepatology, Department of Pharmacology, Center for Research and Advanced Studies of the National Polytechnic Institute–CINVESTAV-IPN, Mexico City 07360, Mexico;
| | - Héctor Serrano
- Department of Health Sciences, Metropolitan Autonomous University-Iztapalapa Campus, Mexico City 09340, Mexico;
| | - Julio Isael Pérez-Carreón
- Laboratory of Liver Diseases, National Institute of Genomic Medicine–INMEGEN, Mexico City 14610, Mexico; (O.G.I.-G.); (B.R.A.-S.); (J.I.P.-C.)
| | - Jaime Arellanes-Robledo
- Laboratory of Liver Diseases, National Institute of Genomic Medicine–INMEGEN, Mexico City 14610, Mexico; (O.G.I.-G.); (B.R.A.-S.); (J.I.P.-C.)
- Directorate of Cátedras, National Council of Science and Technology–CONACYT, Mexico City 03940, Mexico
- Correspondence: ; Tel.: +52-55-5350-1900 (ext. 1218)
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