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Wang Y, Wong J, Duncan JL, Roorda A, Tuten WS. Enhanced S-Cone Syndrome: Elevated Cone Counts Confer Supernormal Visual Acuity in the S-Cone Pathway. Invest Ophthalmol Vis Sci 2023; 64:17. [PMID: 37459066 PMCID: PMC10362924 DOI: 10.1167/iovs.64.10.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023] Open
Abstract
Purpose To measure photoreceptor packing density and S-cone spatial resolution as a function of retinal eccentricity in patients with enhanced S-cone syndrome (ESCS) and to discuss the possible mechanisms supporting their supernormal S-cone acuity. Methods We used an adaptive optics scanning laser ophthalmoscope (AOSLO) to characterize photoreceptor packing. A custom non-AO display channel was used to measure L/M- and S-cone-mediated visual acuity during AOSLO imaging. Acuity measurements were obtained using a four-alternative, forced-choice, tumbling E paradigm along the temporal meridian between the fovea and 4° eccentricity in five of six patients and in seven control subjects. L/M acuity was tested by presenting long-pass-filtered optotypes on a black background, excluding wavelengths to which S-cones are sensitive. S-cone isolation was achieved using a two-color, blue-on-yellow chromatic adaptation method that was validated on three control subjects. Results Inter-cone spacing measurements revealed a near-uniform cone density profile (ranging from 0.9-1.5 arcmin spacing) throughout the macula in ESCS. For comparison, normal cone density decreases by a factor of 14 from the fovea to 6°. Cone spacing of ESCS subjects was higher than normal in the fovea and subnormal beyond 2°. Compared to the control subjects (n = 7), S-cone-mediated acuities in patients with ESCS were normal near the fovea and became increasingly supernormal with retinal eccentricity. Beyond 2°, S-cone acuities were superior to L/M-cone-mediated acuity in the ESCS cohort, a reversal of the trend observed in normal retinas. Conclusions Higher than normal parafoveal cone densities (presumably dominated by S-cones) confer better than normal S-cone-mediated acuity in ESCS subjects.
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Affiliation(s)
- Yiyi Wang
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, California, United States
| | - Jessica Wong
- Department of Ophthalmology, University of California, San Francisco, California, United States
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, California, United States
| | - Austin Roorda
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, California, United States
| | - William S Tuten
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, California, United States
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2
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Fakhar AZ, Liu J, Pajerowska-Mukhtar KM, Mukhtar MS. The Lost and Found: Unraveling the Functions of Orphan Genes. J Dev Biol 2023; 11:27. [PMID: 37367481 PMCID: PMC10299390 DOI: 10.3390/jdb11020027] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 05/19/2023] [Accepted: 05/26/2023] [Indexed: 06/28/2023] Open
Abstract
Orphan Genes (OGs) are a mysterious class of genes that have recently gained significant attention. Despite lacking a clear evolutionary history, they are found in nearly all living organisms, from bacteria to humans, and they play important roles in diverse biological processes. The discovery of OGs was first made through comparative genomics followed by the identification of unique genes across different species. OGs tend to be more prevalent in species with larger genomes, such as plants and animals, and their evolutionary origins remain unclear but potentially arise from gene duplication, horizontal gene transfer (HGT), or de novo origination. Although their precise function is not well understood, OGs have been implicated in crucial biological processes such as development, metabolism, and stress responses. To better understand their significance, researchers are using a variety of approaches, including transcriptomics, functional genomics, and molecular biology. This review offers a comprehensive overview of the current knowledge of OGs in all domains of life, highlighting the possible role of dark transcriptomics in their evolution. More research is needed to fully comprehend the role of OGs in biology and their impact on various biological processes.
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Affiliation(s)
| | | | | | - M. Shahid Mukhtar
- Department of Biology, University of Alabama at Birmingham, 1300 University Blvd., Birmingham, AL 35294, USA
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3
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Angueyra JM, Kunze VP, Patak LK, Kim H, Kindt K, Li W. Transcription factors underlying photoreceptor diversity. eLife 2023; 12:e81579. [PMID: 36745553 PMCID: PMC9901936 DOI: 10.7554/elife.81579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 01/22/2023] [Indexed: 02/07/2023] Open
Abstract
During development, retinal progenitors navigate a complex landscape of fate decisions to generate the major cell classes necessary for proper vision. Transcriptional regulation is critical to generate diversity within these major cell classes. Here, we aim to provide the resources and techniques required to identify transcription factors necessary to generate and maintain diversity in photoreceptor subtypes, which are critical for vision. First, we generate a key resource: a high-quality and deep transcriptomic profile of each photoreceptor subtype in adult zebrafish. We make this resource openly accessible, easy to explore, and have integrated it with other currently available photoreceptor transcriptomic datasets. Second, using our transcriptomic profiles, we derive an in-depth map of expression of transcription factors in photoreceptors. Third, we use efficient CRISPR-Cas9 based mutagenesis to screen for null phenotypes in F0 larvae (F0 screening) as a fast, efficient, and versatile technique to assess the involvement of candidate transcription factors in the generation of photoreceptor subtypes. We first show that known phenotypes can be easily replicated using this method: loss of S cones in foxq2 mutants and loss of rods in nr2e3 mutants. We then identify novel functions for the transcription factor Tbx2, demonstrating that it plays distinct roles in controlling the generation of all photoreceptor subtypes within the retina. Our study provides a roadmap to discover additional factors involved in this process. Additionally, we explore four transcription factors of unknown function (Skor1a, Sall1a, Lrrfip1a, and Xbp1), and find no evidence for their involvement in the generation of photoreceptor subtypes. This dataset and screening method will be a valuable way to explore the genes involved in many other essential aspects of photoreceptor biology.
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Affiliation(s)
- Juan M Angueyra
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Vincent P Kunze
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Laura K Patak
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Hailey Kim
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Katie Kindt
- Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Wei Li
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
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4
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Navarro-Calvo J, Esquiva G, Gómez-Vicente V, Valor LM. MicroRNAs in the Mouse Developing Retina. Int J Mol Sci 2023; 24:ijms24032992. [PMID: 36769311 PMCID: PMC9918188 DOI: 10.3390/ijms24032992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/23/2023] [Accepted: 01/30/2023] [Indexed: 02/05/2023] Open
Abstract
The retina is among the highest organized tissues of the central nervous system. To achieve such organization, a finely tuned regulation of developmental processes is required to form the retinal layers that contain the specialized neurons and supporting glial cells to allow precise phototransduction. MicroRNAs are a class of small RNAs with undoubtful roles in fundamental biological processes, including neurodevelopment of the brain and the retina. This review provides a short overview of the most important findings regarding microRNAs in the regulation of retinal development, from the developmental-dependent rearrangement of the microRNA expression program to the key roles of particular microRNAs in the differentiation and maintenance of retinal cell subtypes.
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Affiliation(s)
- Jorge Navarro-Calvo
- Unidad de Investigación, Hospital General Universitario Dr. Balmis, ISABIAL, 03010 Alicante, Spain
| | - Gema Esquiva
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain
| | - Violeta Gómez-Vicente
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain
| | - Luis M. Valor
- Unidad de Investigación, Hospital General Universitario Dr. Balmis, ISABIAL, 03010 Alicante, Spain
- Correspondence: ; Tel.: +34-965-913-988
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5
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Wang Y, Wong J, Duncan JL, Roorda A, Tuten WS. Enhanced S-cone Syndrome, a Mini-review. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:189-194. [PMID: 37440033 DOI: 10.1007/978-3-031-27681-1_28] [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
Enhanced S-cone Syndrome (ESCS) is an autosomal recessive inherited retinal disease mostly associated with disease-causing variants in the NR2E3 gene. During retinal development in ESCS, rod photoreceptor precursors are misdirected to form photoreceptors similar to short-wavelength cones, or S-cones. Compared to a normal human retina, patients with ESCS have no rods and significantly increased numbers of S-cones. Night blindness is the main visual symptom, and visual acuity and color vision can be normal at early disease stages. Histology of donor eyes and adaptive optics imaging revealed increased S-cone density outside of the fovea compared to normal. Visual function testing reveals absent rod function and abnormally enhanced sensitivity to short-wavelength light. Unlike most retinal degenerative diseases, ESCS results in a gain in S-cone photoreceptor function. Research involving ESCS could improve understanding of this rare retinal condition and also shed light on the role of NR2E3 expression in photoreceptor survival.
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Affiliation(s)
- Yiyi Wang
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA.
| | - Jessica Wong
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Jacque L Duncan
- Department of Ophthalmology, University of California, San Francisco, CA, USA
| | - Austin Roorda
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA
| | - William S Tuten
- Herbert Wertheim School of Optometry and Vision Science, University of California, Berkeley, CA, USA
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6
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Sun C, Chen S. Disease-causing mutations in genes encoding transcription factors critical for photoreceptor development. Front Mol Neurosci 2023; 16:1134839. [PMID: 37181651 PMCID: PMC10172487 DOI: 10.3389/fnmol.2023.1134839] [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: 12/30/2022] [Accepted: 04/04/2023] [Indexed: 05/16/2023] Open
Abstract
Photoreceptor development of the vertebrate visual system is controlled by a complex transcription regulatory network. OTX2 is expressed in the mitotic retinal progenitor cells (RPCs) and controls photoreceptor genesis. CRX that is activated by OTX2 is expressed in photoreceptor precursors after cell cycle exit. NEUROD1 is also present in photoreceptor precursors that are ready to specify into rod and cone photoreceptor subtypes. NRL is required for the rod fate and regulates downstream rod-specific genes including the orphan nuclear receptor NR2E3 which further activates rod-specific genes and simultaneously represses cone-specific genes. Cone subtype specification is also regulated by the interplay of several transcription factors such as THRB and RXRG. Mutations in these key transcription factors are responsible for ocular defects at birth such as microphthalmia and inherited photoreceptor diseases such as Leber congenital amaurosis (LCA), retinitis pigmentosa (RP) and allied dystrophies. In particular, many mutations are inherited in an autosomal dominant fashion, including the majority of missense mutations in CRX and NRL. In this review, we describe the spectrum of photoreceptor defects that are associated with mutations in the above-mentioned transcription factors, and summarize the current knowledge of molecular mechanisms underlying the pathogenic mutations. At last, we deliberate the outstanding gaps in our understanding of the genotype-phenotype correlations and outline avenues for future research of the treatment strategies.
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Affiliation(s)
- Chi Sun
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, United States
- *Correspondence: Chi Sun,
| | - Shiming Chen
- Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, MO, United States
- Department of Developmental Biology, Washington University in St. Louis, St. Louis, MO, United States
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Bachu VS, Kandoi S, Park KU, Kaufman ML, Schwanke M, Lamba DA, Brzezinski JA. An enhancer located in a Pde6c intron drives transient expression in the cone photoreceptors of developing mouse and human retinas. Dev Biol 2022; 488:131-150. [PMID: 35644251 PMCID: PMC10676565 DOI: 10.1016/j.ydbio.2022.05.012] [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: 01/27/2022] [Revised: 04/29/2022] [Accepted: 05/19/2022] [Indexed: 02/04/2023]
Abstract
How cone photoreceptors are formed during retinal development is only partially known. This is in part because we do not fully understand the gene regulatory network responsible for cone genesis. We reasoned that cis-regulatory elements (enhancers) active in nascent cones would be regulated by the same upstream network that controls cone formation. To dissect this network, we searched for enhancers active in developing cones. By electroporating enhancer-driven fluorescent reporter plasmids, we observed that a sequence within an intron of the cone-specific Pde6c gene acted as an enhancer in developing mouse cones. Similar fluorescent reporter plasmids were used to generate stable transgenic human induced pluripotent stem cells that were then grown into three-dimensional human retinal organoids. These organoids contained fluorescently labeled cones, demonstrating that the Pde6c enhancer was also active in human cones. We observed that enhancer activity was transient and labeled a minor population of developing rod photoreceptors in both mouse and human systems. This cone-enriched pattern argues that the Pde6c enhancer is activated in cells poised between rod and cone fates. Additionally, it suggests that the Pde6c enhancer is activated by the same regulatory network that selects or stabilizes cone fate choice. To further understand this regulatory network, we identified essential enhancer sequence regions through a series of mutagenesis experiments. This suggested that the Pde6c enhancer was regulated by transcription factor binding at five or more locations. Binding site predictions implicated transcription factor families known to control photoreceptor formation and families not previously associated with cone development. These results provide a framework for deciphering the gene regulatory network that controls cone genesis in both human and mouse systems. Our new transgenic human stem cell lines provide a tool for determining which cone developmental mechanisms are shared and distinct between mice and humans.
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Affiliation(s)
- Vismaya S Bachu
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sangeetha Kandoi
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, USA
| | - Ko Uoon Park
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Michael L Kaufman
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Michael Schwanke
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Deepak A Lamba
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA; Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, CA, USA
| | - Joseph A Brzezinski
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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8
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Hussey KA, Hadyniak SE, Johnston RJ. Patterning and Development of Photoreceptors in the Human Retina. Front Cell Dev Biol 2022; 10:878350. [PMID: 35493094 PMCID: PMC9049932 DOI: 10.3389/fcell.2022.878350] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/25/2022] [Indexed: 01/04/2023] Open
Abstract
Humans rely on visual cues to navigate the world around them. Vision begins with the detection of light by photoreceptor cells in the retina, a light-sensitive tissue located at the back of the eye. Photoreceptor types are defined by morphology, gene expression, light sensitivity, and function. Rod photoreceptors function in low-light vision and motion detection, and cone photoreceptors are responsible for high-acuity daytime and trichromatic color vision. In this review, we discuss the generation, development, and patterning of photoreceptors in the human retina. We describe our current understanding of how photoreceptors are patterned in concentric regions. We conclude with insights into mechanisms of photoreceptor differentiation drawn from studies of model organisms and human retinal organoids.
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Ortega JT, Jastrzebska B. Rhodopsin as a Molecular Target to Mitigate Retinitis Pigmentosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1371:61-77. [PMID: 34962636 DOI: 10.1007/5584_2021_682] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Retinitis pigmentosa (RP) is a group of hereditary degenerative diseases affecting 1 of 4000 people worldwide and being the most prevalent cause of visual handicap among working populations in developed countries. These disorders are mainly related to the abnormalities in the rod G protein-coupled receptor (GPCR), rhodopsin reflected in the dysregulated membrane trafficking, stability and phototransduction processes that lead to progressive loss of retina function and eventually blindness. Currently, there is no cure for RP, and the therapeutic options are limited. Targeting rhodopsin with small molecule chaperones to improve the folding and stability of the mutant receptor is one of the most promising pharmacological approaches to alleviate the pathology of RP. This review provides an update on the current knowledge regarding small molecule compounds that have been evaluated as rhodopsin modulators to be considered as leads for the development of novel therapies for RP.
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Affiliation(s)
- Joseph T Ortega
- Department of Pharmacology, School of Medicine, Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, OH, USA
| | - Beata Jastrzebska
- Department of Pharmacology, School of Medicine, Cleveland Center for Membrane and Structural Biology, Case Western Reserve University, Cleveland, OH, USA.
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10
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de Carvalho ER, Robson AG, Arno G, Boon CJF, Webster AA, Michaelides M. Enhanced S-Cone Syndrome: Spectrum of Clinical, Imaging, Electrophysiologic, and Genetic Findings in a Retrospective Case Series of 56 Patients. Ophthalmol Retina 2021; 5:195-214. [PMID: 32679203 PMCID: PMC7861019 DOI: 10.1016/j.oret.2020.07.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 07/06/2020] [Accepted: 07/09/2020] [Indexed: 11/19/2022]
Abstract
PURPOSE To describe the detailed phenotype, long-term clinical course, clinical variability, and genotype of patients with enhanced S-cone syndrome (ESCS). DESIGN Retrospective case series. PARTICIPANTS Fifty-six patients with ESCS. METHODS Clinical history, examination, imaging, and electrophysiologic findings of 56 patients (age range, 1-75 years) diagnosed with ESCS were reviewed. Diagnosis was established by molecular confirmation of disease-causing variants in the NR2E3 gene (n = 38) or by diagnostic full-field electroretinography findings (n = 18). MAIN OUTCOME MEASURES Age at onset of visual symptoms, best-corrected visual acuity (BCVA), quantitative age-related electrophysiologic decline, and imaging findings. RESULTS Mean age at onset of visual symptoms was 4.0 years, and median age at presentation was 20.5 years, with mean follow-up interval being 6.1 years. Six patients were assessed once. Disease-causing variants in NR2E3 were identified in 38 patients. Mean BCVA of the better-seeing eye was 0.32 logarithm of the minimum angle of resolution (logMAR) at baseline and 0.39 logMAR at follow-up. In most eyes (76% [76/100]), BCVA remained stable, with a mean BCVA change of 0.07 logMAR during follow-up. Nyctalopia was the most common initial symptom, reported in 92.9% of patients (52/56). Clinical findings were highly variable and included foveomacular schisis (41.1% [26/56]), yellow-white dots (57.1% [32/56]), nummular pigmentation (85.7% [48/56]), torpedo-like lesions (10.7% [6/56]), and circumferential subretinal fibrosis (7.1% [4/56]). Macular and peripheral patterns of autofluorescence were classified as (1) minimal change, (2) hypoautofluorescent (mild diffuse, moderate speckled, moderate diffuse, or advanced), or (3) hyperautofluorescent flecks. One patient showed undetectable electroretinography findings; quantification of main electroretinography components in all other patients revealed amplitude and peak time variability but with pathognomonic electroretinography features. The main electroretinography components showed evidence of age-related worsening over 6.7 decades, at a rate indistinguishable from that seen in unaffected control participants. Eighteen sequence variants in NR2E3 were identified, including 4 novel missense changes. CONCLUSIONS Enhanced S-cone syndrome has a highly variable phenotype with relative clinical and imaging stability over time. Most electroretinography findings have pathognomonic features, but quantitative assessment reveals variability and a normal mean rate of age-related decline, consistent with largely nonprogressive peripheral retinal dysfunction.
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Affiliation(s)
- Emanuel R de Carvalho
- Moorfields Eye Hospital, London, United Kingdom; Department of Ophthalmology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; Department of Ophthalmology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Gavin Arno
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Camiel J F Boon
- Department of Ophthalmology, Amsterdam University Medical Centers, Amsterdam, The Netherlands; Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Andrew A Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Iannaccone A, Brabbit E, Lopez-Miro C, Love Z, Griffiths V, Kedrov M, Haider NB. Interspecies Correlations between Human and Mouse NR2E3-Associated Recessive Disease. J Clin Med 2021; 10:jcm10030475. [PMID: 33513943 PMCID: PMC7865474 DOI: 10.3390/jcm10030475] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/13/2021] [Accepted: 01/18/2021] [Indexed: 11/16/2022] Open
Abstract
NR2E3-associated recessive disease in humans is historically defined by congenital night blinding retinopathy, characterized by an initial increase in short-wavelength (S)-cone sensitivity and progressive loss of rod and cone function. The retinal degeneration 7 (rd7) murine model, harboring a recessive mutation in the mouse ortholog of NR2E3, has been a well-studied disease model and recently evaluated as a therapeutic model for NR2E3-associated retinal degenerations. This study aims to draw parallels between human and mouse NR2E3-related disease through examination of spectral domain optical coherence tomography (SD-OCT) imaging between different stage of human disease and its murine counterpart. We propose that SD-OCT is a useful non-invasive diagnostic tool to compare human clinical dystrophy presentation with that of the rd7 mouse and make inference that may be of therapeutically relevance. Additionally, a longitudinal assessment of rd7 disease progression, utilizing available clinical data from our patients as well as extensive retrospective analysis of visual acuity data from published cases of human NR2E3-related disease, was curated to identify further valuable correlates between human and mouse Nr2e3 disease. Results of this study validate the slow progression of NR2E3-associated disease in humans and the rd7 mice and identify SD-OCT characteristics in patients at or near the vascular arcades that correlate well with the whorls and rosettes that are seen also in the rd7 mouse and point to imaging features that appear to be associated with better preserved S-cone mediated retinal function. The correlation of histological findings between rd7 mice and human imaging provides a solid foundation for diagnostic use of pathophysiological and prognostic information to further define characteristics and a relevant timeline for therapeutic intervention in the field of NR2E3-associated retinopathies.
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Affiliation(s)
- Alessandro Iannaccone
- Center for Retinal Degenerations and Ophthalmic Genetic Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, NC 27710, USA; (C.L.-M.); (V.G.); (M.K.)
- Correspondence: (A.I.); (N.B.H.)
| | - Emily Brabbit
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; (E.B.); (Z.L.)
| | - Christiaan Lopez-Miro
- Center for Retinal Degenerations and Ophthalmic Genetic Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, NC 27710, USA; (C.L.-M.); (V.G.); (M.K.)
| | - Zoe Love
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; (E.B.); (Z.L.)
| | - Victoria Griffiths
- Center for Retinal Degenerations and Ophthalmic Genetic Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, NC 27710, USA; (C.L.-M.); (V.G.); (M.K.)
| | - Marina Kedrov
- Center for Retinal Degenerations and Ophthalmic Genetic Diseases, Department of Ophthalmology, Duke Eye Center, Duke University School of Medicine, Durham, NC 27710, USA; (C.L.-M.); (V.G.); (M.K.)
| | - Neena B. Haider
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; (E.B.); (Z.L.)
- Correspondence: (A.I.); (N.B.H.)
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Nr2e3 functional domain ablation by CRISPR-Cas9D10A identifies a new isoform and generates retinitis pigmentosa and enhanced S-cone syndrome models. Neurobiol Dis 2020; 146:105122. [PMID: 33007388 DOI: 10.1016/j.nbd.2020.105122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 12/18/2022] Open
Abstract
Mutations in NR2E3 cause retinitis pigmentosa (RP) and enhanced S-cone syndrome (ESCS) in humans. This gene produces a large isoform encoded in 8 exons and a previously unreported shorter isoform of 7 exons, whose function is unknown. We generated two mouse models by targeting exon 8 of Nr2e3 using CRISPR/Cas9-D10A nickase. Allele Δ27 is an in-frame deletion of 27 bp that ablates the dimerization domain H10, whereas allele ΔE8 (full deletion of exon 8) produces only the short isoform, which lacks the C-terminal part of the ligand binding domain (LBD) that encodes both H10 and the AF2 domain involved in the Nr2e3 repressor activity. The Δ27 mutant shows developmental alterations and a non-progressive electrophysiological dysfunction that resembles the ESCS phenotype. The ΔE8 mutant exhibits progressive retinal degeneration, as occurs in human RP patients. Our mutants suggest a role for Nr2e3 as a cone-patterning regulator and provide valuable models for studying mechanisms of NR2E3-associated retinal dystrophies and evaluating potential therapies.
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13
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Targeting of the NRL Pathway as a Therapeutic Strategy to Treat Retinitis Pigmentosa. J Clin Med 2020; 9:jcm9072224. [PMID: 32668775 PMCID: PMC7408925 DOI: 10.3390/jcm9072224] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/28/2020] [Accepted: 07/07/2020] [Indexed: 12/26/2022] Open
Abstract
Retinitis pigmentosa (RP) is an inherited retinal dystrophy (IRD) with a prevalence of 1:4000, characterized by initial rod photoreceptor loss and subsequent cone photoreceptor loss with accompanying nyctalopia, visual field deficits, and visual acuity loss. A diversity of causative mutations have been described with autosomal dominant, autosomal recessive, and X-linked inheritance and sporadic mutations. The diversity of mutations makes gene therapy challenging, highlighting the need for mutation-agnostic treatments. Neural leucine zipper (NRL) and NR2E3 are factors important for rod photoreceptor cell differentiation and homeostasis. Germline mutations in NRL or NR2E3 leads to a loss of rods and an increased number of cones with short wavelength opsin in both rodents and humans. Multiple groups have demonstrated that inhibition of NRL or NR2E3 activity in the mature retina could endow rods with certain properties of cones, which prevents cell death in multiple rodent RP models with diverse mutations. In this review, we summarize the literature on NRL and NR2E3, therapeutic strategies of NRL/NR2E3 modulation in preclinical RP models, as well as future directions of research. In summary, inhibition of the NRL/NR2E3 pathway represents an intriguing mutation agnostic and disease-modifying target for the treatment of RP.
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14
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Li S, Datta S, Brabbit E, Love Z, Woytowicz V, Flattery K, Capri J, Yao K, Wu S, Imboden M, Upadhyay A, Arumugham R, Thoreson WB, DeAngelis MM, Haider NB. Nr2e3 is a genetic modifier that rescues retinal degeneration and promotes homeostasis in multiple models of retinitis pigmentosa. Gene Ther 2020; 28:223-241. [PMID: 32123325 PMCID: PMC7483267 DOI: 10.1038/s41434-020-0134-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 02/05/2020] [Accepted: 02/18/2020] [Indexed: 12/21/2022]
Abstract
Recent advances in viral vector engineering, as well as an increased understanding of the cellular and molecular mechanism of retinal diseases, have led to the development of novel gene therapy approaches. Furthermore, ease of accessibility and ocular immune privilege makes the retina an ideal target for gene therapies. In this study, the nuclear hormone receptor gene Nr2e3 was evaluated for efficacy as broad-spectrum therapy to attenuate early to intermediate stages of retinal degeneration in five unique mouse models of retinitis pigmentosa (RP). RP is a group of heterogenic inherited retinal diseases associated with over 150 gene mutations, affecting over 1.5 million individuals worldwide. RP varies in age of onset, severity, and rate of progression. In addition, ~40% of RP patients cannot be genetically diagnosed, confounding the ability to develop personalized RP therapies. Remarkably, Nr2e3 administered therapy resulted in reduced retinal degeneration as observed by increase in photoreceptor cells, improved electroretinogram, and a dramatic molecular reset of key transcription factors and associated gene networks. These therapeutic effects improved retinal homeostasis in diseased tissue. Results of this study provide evidence that Nr2e3 can serve as a broad-spectrum therapy to treat multiple forms of RP.
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Affiliation(s)
- Sujun Li
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Shyamtanu Datta
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Emily Brabbit
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Zoe Love
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Victoria Woytowicz
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Kyle Flattery
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Jessica Capri
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Katie Yao
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Siqi Wu
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | | | | | | | - Wallace B Thoreson
- Department of Ophthalmology and Visual Sciences, Truhlsen Eye Institute, University of Nebraska Medical Center, Omaha, NE, USA
| | | | - Neena B Haider
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA.
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15
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Buenaventura DF, Corseri A, Emerson MM. Identification of Genes With Enriched Expression in Early Developing Mouse Cone Photoreceptors. Invest Ophthalmol Vis Sci 2019; 60:2787-2799. [PMID: 31260032 PMCID: PMC6607928 DOI: 10.1167/iovs.19-26951] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Purpose The early transcriptional events that occur in newly generated cone photoreceptors are not well described. Knowledge of these events is critical to provide benchmarks for in vitro-derived cone photoreceptors and to understand the process of cone and rod photoreceptor diversification. We sought to identify genes with differential gene expression in embryonic mouse cone photoreceptors. Methods The specificity of expression of the LHX4 transcription factor in developing cone photoreceptors was examined using immunofluorescence visualization in both mouse and chicken retinas. A LHX4 transgenic reporter line with high specificity for developing mouse cone photoreceptors was identified and used to purify early-stage cone photoreceptors for profiling by single-cell RNA sequencing. Comparisons were made to previous datasets targeting photoreceptors. Results The LHX4 transcription factor and a transgenic reporter were determined to be highly specific to early developing cone photoreceptors in the mouse. Single-cell transcriptional profiling identified new genes with enriched expression in cone photoreceptors relative to concurrent cell populations. Comparison to previous profiling datasets allowed for further characterization of these genes across developmental time, species, photoreceptor type, and gene regulatory network. Conclusions The LHX4 gene is highly enriched in developing cone photoreceptors as are several new genes identified through transcriptional profiling, some of which are expressed in subclusters of cones. Many of these cone-enriched genes do not show obvious de-repression in profiling of retinas mutant for the rod-specific transcription factor NRL, highlighting differences between endogenous cones and those induced in NRL mutants.
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Affiliation(s)
- Diego F Buenaventura
- Department of Biology, The City College of New York, City University of New York, New York, New York, United States.,Biology PhD Program, Graduate Center, City University of New York, New York, New York, United States
| | - Adrianne Corseri
- Department of Biology, The City College of New York, City University of New York, New York, New York, United States
| | - Mark M Emerson
- Department of Biology, The City College of New York, City University of New York, New York, New York, United States.,Biology PhD Program, Graduate Center, City University of New York, New York, New York, United States.,Biochemistry PhD Program, Graduate Center, City University of New York, New York, New York, United States
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16
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Correction of NR2E3 Associated Enhanced S-cone Syndrome Patient-specific iPSCs using CRISPR-Cas9. Genes (Basel) 2019; 10:genes10040278. [PMID: 30959774 PMCID: PMC6523438 DOI: 10.3390/genes10040278] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/02/2019] [Accepted: 04/03/2019] [Indexed: 12/24/2022] Open
Abstract
Enhanced S-cone syndrome (ESCS) is caused by recessive mutations in the photoreceptor cell transcription factor NR2E3. Loss of NR2E3 is characterized by repression of rod photoreceptor cell gene expression, over-expansion of the S-cone photoreceptor cell population, and varying degrees of M- and L-cone photoreceptor cell development. In this study, we developed a CRISPR-based homology-directed repair strategy and corrected two different disease-causing NR2E3 mutations in patient-derived induced pluripotent stem cells (iPSCs) generated from two affected individuals. In addition, one patient’s iPSCs were differentiated into retinal cells and NR2E3 transcription was evaluated in CRISPR corrected and uncorrected clones. The patient’s c.119-2A>C mutation caused the inclusion of a portion of intron 1, the creation of a frame shift, and generation of a premature stop codon. In summary, we used a single set of CRISPR reagents to correct different mutations in iPSCs generated from two individuals with ESCS. In doing so we demonstrate the advantage of using retinal cells derived from affected patients over artificial in vitro model systems when attempting to demonstrate pathophysiologic mechanisms of specific mutations.
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17
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Garafalo AV, Calzetti G, Cideciyan AV, Roman AJ, Saxena S, Sumaroka A, Choi W, Wright AF, Jacobson SG. Cone Vision Changes in the Enhanced S-Cone Syndrome Caused by NR2E3 Gene Mutations. Invest Ophthalmol Vis Sci 2019; 59:3209-3219. [PMID: 29971438 DOI: 10.1167/iovs.18-24518] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To determine the progression of cone vision loss in patients with recessive disease from NR2E3 gene mutations. Methods Patients with NR2E3 mutations (n = 37) were studied as a retrospective observational case series clinically and with chromatic static perimetry. Patients were investigated cross-sectionally, and a subset was followed longitudinally. Results Patients showed a range of visual acuities; there was no clear relationship to age. With kinetic perimetry (V4e target), a full field could be retained over many years. Other patients showed progression from a full field, with or without pericentral scotomas, to a small central island. Three patterns of S-cone function were defined, based on percentage of hypersensitive S-cone loci in the field. From occupying most of the visual field, hyperfunctioning S-cone loci could diminish in percent, remaining largely in the periphery. Normal S-cone functioning then dominates, followed by the appearance of an annular region of abnormal S-cone loci approximately 10° to 40° from the fovea. Overall, S-cone sensitivity declined 2.6 times faster than L/M-cone sensitivity. Conclusions Murine proof-of-concept studies suggest that clinical trials of patients with NR2E3 mutations may be forthcoming. Patterns of S-cone hyperfunction across the field would serve as a means to categorize patients as entry criteria or cohort selection in clinical trials. S-cone perimetry can be measured in the clinic and would be the logical efficacy monitor for therapeutic strategies. Given further understanding of the natural history of the disease, targeting the annular region of S-cone dysfunction for a focal therapy or for monitoring in a retina-wide intervention warrants consideration.
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Affiliation(s)
- Alexandra V Garafalo
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Giacomo Calzetti
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alejandro J Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Supna Saxena
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Windy Choi
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Alan F Wright
- Medical Research Council Human Genetics Unit, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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18
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Xie S, Han S, Qu Z, Liu F, Li J, Yu S, Reilly J, Tu J, Liu X, Lu Z, Hu X, Yimer TA, Qin Y, Huang Y, Lv Y, Jiang T, Shu X, Tang Z, Jia H, Wong F, Liu M. Knockout of Nr2e3 prevents rod photoreceptor differentiation and leads to selective L-/M-cone photoreceptor degeneration in zebrafish. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1273-1283. [PMID: 30684641 DOI: 10.1016/j.bbadis.2019.01.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 01/20/2019] [Accepted: 01/21/2019] [Indexed: 01/28/2023]
Abstract
Mutations in the photoreceptor cell-specific nuclear receptor gene Nr2e3 increased the number of S-cone photoreceptors in human and murine retinas and led to retinal degeneration that involved photoreceptor and non-photoreceptor cells. The mechanisms underlying these complex phenotypes remain unclear. In the hope of understanding the precise role of Nr2e3 in photoreceptor cell fate determination and differentiation, we generated a line of Nr2e3 knockout zebrafish using CRISPR technology. In these Nr2e3-null animals, rod precursors undergo terminal mitoses but fail to differentiate as rods. Rod-specific genes are not expressed and the outer segment (OS) fails to form. Formation and differentiation of cone photoreceptors is normal. Specifically, there is no increase in the number of UV-cone or S-cone photoreceptors. Laminated retinal structure is maintained. After normal development, L-/M-cones selectively degenerate, with progressive shortening of OS that starts at age 1 month. The amount of cone phototransduction proteins is concomitantly reduced, whereas UV- and S-cones have normal OS lengths even at age 10 months. In vitro studies show Nr2e3 synergizes with Crx and Nrl to enhance rhodopsin gene expression. Nr2e3 does not affect cone opsin expression. Our results extend the knowledge of Nr2e3's roles and have specific implications for the interpretation of the phenotypes observed in human and murine retinas. Furthermore, our model may offer new opportunities in finding treatments for enhanced S-cone syndrome (ESCS) and other retinal degenerative diseases.
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Affiliation(s)
- Shanglun Xie
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Shanshan Han
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Zhen Qu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Fei Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Jingzhen Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Shanshan Yu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - James Reilly
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland, United Kingdom of Great Britain and Northern Ireland
| | - Jiayi Tu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xiliang Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Zhaojing Lu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xuebin Hu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Tinsae Assefa Yimer
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yayun Qin
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuwen Huang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Yuexia Lv
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Tao Jiang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Xinhua Shu
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4 0BA, Scotland, United Kingdom of Great Britain and Northern Ireland
| | - Zhaohui Tang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China
| | - Haibo Jia
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China.
| | - Fulton Wong
- Department of Ophthalmology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, PR China.
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19
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A Novel FLVCR1 Variant Implicated in Retinitis Pigmentosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1185:203-207. [PMID: 31884612 DOI: 10.1007/978-3-030-27378-1_33] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Here we describe the identification and evaluation of a rare novel autosomal recessive mutation in FLVCR1 which is implicated solely in RP, with no evidence of posterior column ataxia in a number of affected patients. The mutation was detected as part of an ongoing target capture NGS study (Target 5000), aimed at identifying candidate variants in pedigrees with inherited retinal degenerations (IRDs) in Ireland. The mutation, FLVCR1 p.Tyr341Cys, was observed homozygously in seven affected patients across four pedigrees. FLVCR1 p.Tyr341Cys is a very rare mutation, with no previous reports of pathogenicity and no homozygous cases reported in online allele frequency databases. Our sequencing study identified seven homozygotes across multiple pedigrees, all with similar clinical presentations of RP without ataxia, a scenario extremely unlikely to occur by chance for a benign allele, particularly given the low population frequency of p.Tyr341Cys.
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20
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Jean-Charles N, Buenaventura DF, Emerson MM. Identification and characterization of early photoreceptor cis-regulatory elements and their relation to Onecut1. Neural Dev 2018; 13:26. [PMID: 30466480 PMCID: PMC6251108 DOI: 10.1186/s13064-018-0121-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/31/2018] [Indexed: 12/19/2022] Open
Abstract
Background Cone and rod photoreceptors are two of the primary cell types affected in human retinal disease. Potential strategies to combat these diseases are the use of gene therapy to rescue compromised photoreceptors or to generate new functional photoreceptors to replace those lost in the diseased retina. Cis-regulatory elements specific to cones, rods, or both types of photoreceptors are critical components of successful implementation of these two strategies. The purpose of this study was to identify and characterize the cell type specificity and activity of cis-regulatory elements active in developing photoreceptors. Methods Cis-regulatory elements were introduced into the developing chicken and mouse retina by electroporation. Characterization of reporter activity in relation with cell type markers was determined using confocal microscopy. In addition, two high-throughput flow cytometry assay were developed to assess whether these elements were downstream of Onecut1 in the photoreceptor specification network. Results The majority of cis-regulatory elements were active in both cone and rod photoreceptors and were largely uninfluenced by a Onecut1 dominant-negative construct. Elements associated with the Thrb, Nr2e3, and Rhodopsin genes showed highly enriched activity in cones or rods, and were affected by interference in Onecut1 signaling. Rhodopsin promoter activity was the most highly influenced by Onecut1 activity and its induction could be modulated by the Maf family transcription factor L-Maf. Nr2e3 elements were observed to have activity in cone photoreceptors and Nr2e3 protein was expressed in developing cone photoreceptors, suggesting a role for this predominant rod gene in cone photoreceptor development. Conclusions The analysis presented here provides an experimental framework to determine the specificity and strength of photoreceptor elements within specific genetic networks during development. The Onecut1 transcription factor is one such factor that influences the gene regulatory networks specific to cones and rods, but not those that are common to both. Electronic supplementary material The online version of this article (10.1186/s13064-018-0121-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nathalie Jean-Charles
- Department of Biology, The City College of New York, City University of New York, New York, NY, 10031, USA.,Current Address: The Public Health Laboratory, NYC Department of Health and Mental Hygeine, New York, NY, 10016, USA
| | - Diego F Buenaventura
- Department of Biology, The City College of New York, City University of New York, New York, NY, 10031, USA.,Biology Ph.D. Program, Graduate Center, City University of New York, New York, NY, 10031, USA
| | - Mark M Emerson
- Department of Biology, The City College of New York, City University of New York, New York, NY, 10031, USA. .,Biology Ph.D. Program, Graduate Center, City University of New York, New York, NY, 10031, USA.
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21
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Novel clinical findings in autosomal recessive NR2E3-related retinal dystrophy. Graefes Arch Clin Exp Ophthalmol 2018; 257:9-22. [PMID: 30324420 DOI: 10.1007/s00417-018-4161-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/01/2018] [Accepted: 10/03/2018] [Indexed: 02/07/2023] Open
Abstract
PURPOSE To evaluate the clinical phenotype of autosomal recessive NR2E3-related retinal dystrophy. METHODS We retrospectively studied 11 patients carrying out at least 2 NR2E3 mutations; they had undergone comprehensive ophthalmological examination, fundus photography, optical coherence tomography, electrophysiological testing, and visual field at the Regional Reference Center for Hereditary Retinal Degenerations of the Eye Clinic in Florence. RESULTS Five females and six males with a diagnosis of NR2E3-related retinal dystrophy were included in the study. All patients complained of nyctalopia. Visual acuity ranged from 0.00 logMAR to hand motion. Two patients presented bull's eye maculopathy, and one of these was characterized by a triple hyper-autofluorescent ring at the fundus autofluorescence examination. Three patients showed small yellowish dots and spots at the mid-periphery. One patient was characterized by widespread subretinal drusenoid deposits (SDD) at the posterior pole. Four patients showed vitreous abnormalities. Optical coherence tomography (OCT) examinations detected variable degrees of abnormal retinal lamination and schitic changes. Seven patients were compound heterozygous and four were homozygous for mutations in NR2E3. CONCLUSIONS Our study confirmed high variable phenotype in autosomal recessive NR2E3-related retinal dystrophy. Bull's eye maculopathy, subretinal drusenoid deposits, and foveal hypoplasia represent novel clinical findings in NR2E3-related retinal dystrophy. Macular involvement was detectable in all the patients, and the abnormal foveal avascular zone (FAZ) supports the role of NR2E3 in retinal development.
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22
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Özateş S, Tekin K, Teke MY. Goldmann-Favre Syndrome: Case Series. Turk J Ophthalmol 2018; 48:47-51. [PMID: 29576899 PMCID: PMC5854860 DOI: 10.4274/tjo.76158] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 09/20/2017] [Indexed: 12/12/2022] Open
Abstract
Goldmann-Favre syndrome, which is caused by mutation of the NR2E3 gene, is a retinal degenerative disease with a wide spectrum of phenotypic properties. Variations in clinical presentation result in difficulties in differential diagnosis. In this article, Goldmann-Favre syndrome cases with different clinical findings are presented. Clinical characteristics of our cases were reviewed and discussed in light of the literature.
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Affiliation(s)
- Serdar Özateş
- University of Health Sciences, Dr. Sami Ulus Maternity and Children Training and Research Hospital, Ophthalmology Clinic, Ankara, Turkey
| | - Kemal Tekin
- Kars Harakani State Hospital, Ophthalmology Clinic, Kars, Turkey
| | - Mehmet Yasin Teke
- University of Health Sciences, Ulucanlar Eye Training and Research Hospital, Ophthalmology Clinic, Ankara, Turkey
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23
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Mechanisms of Photoreceptor Patterning in Vertebrates and Invertebrates. Trends Genet 2017; 32:638-659. [PMID: 27615122 DOI: 10.1016/j.tig.2016.07.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 07/25/2016] [Accepted: 07/28/2016] [Indexed: 11/22/2022]
Abstract
Across the animal kingdom, visual systems have evolved to be uniquely suited to the environments and behavioral patterns of different species. Visual acuity and color perception depend on the distribution of photoreceptor (PR) subtypes within the retina. Retinal mosaics can be organized into three broad categories: stochastic/regionalized, regionalized, and ordered. We describe here the retinal mosaics of flies, zebrafish, chickens, mice, and humans, and the gene regulatory networks controlling proper PR specification in each. By drawing parallels in eye development between these divergent species, we identify a set of conserved organizing principles and transcriptional networks that govern PR subtype differentiation.
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24
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Nakamura PA, Shimchuk AA, Tang S, Wang Z, DeGolier K, Ding S, Reh TA. Small molecule Photoregulin3 prevents retinal degeneration in the RhoP23H mouse model of retinitis pigmentosa. eLife 2017; 6. [PMID: 29148976 PMCID: PMC5693111 DOI: 10.7554/elife.30577] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 10/24/2017] [Indexed: 12/25/2022] Open
Abstract
Regulation of rod gene expression has emerged as a potential therapeutic strategy to treat retinal degenerative diseases like retinitis pigmentosa (RP). We previously reported on a small molecule modulator of the rod transcription factor Nr2e3, Photoregulin1 (PR1), that regulates the expression of photoreceptor-specific genes. Although PR1 slows the progression of retinal degeneration in models of RP in vitro, in vivo analyses were not possible with PR1. We now report a structurally unrelated compound, Photoregulin3 (PR3) that also inhibits rod photoreceptor gene expression, potentially though Nr2e3 modulation. To determine the effectiveness of PR3 as a potential therapy for RP, we treated RhoP23H mice with PR3 and assessed retinal structure and function. PR3-treated RhoP23H mice showed significant structural and functional photoreceptor rescue compared with vehicle-treated littermate control mice. These results provide further support that pharmacological modulation of rod gene expression provides a potential strategy for the treatment of RP. There are several diseases that cause people to lose their eyesight and become blind. One of these diseases, called retinitis pigmentosa, kills cells at the back of the eye known as rod cells. At first, it affects vision in low light and peripheral vision, but later it affects vision during the daytime as well. There are no effective treatments for patients with retinitis pigmentosa. Yet previous genetic studies have shown that disrupting the activity of genes in rod cells can slow the progression of the disease and preserve vision in mice. As for all genes, proteins called transcription factors regulate the activity of rod cell genes. Nakamura et al. now report the discovery of a small drug-like molecule, that they name Photoregulin3, which alters the activity of a transcription factor that regulates rod genes. In follow-up experiments, mice with a mutation that replicates many of the features of retinitis pigmentosa were given Photoregulin3 to see if it could slow the progression of the disease. Indeed, Photoregulin3 could stop many of the rod cells from degenerating in the treated mice. At the end of the experiment, the mice treated with this small molecule had about twice as many rods as the control mice. The treated mice also responded better to flashes of light. Nakamura et al. hope that the findings will one day benefit patients with retinitis pigmentosa. But first more research needs to be done before testing Photoregulin3 in humans. For example, the drug-like molecule needs to be made more potent, and if possible adapted to work when given orally, meaning patients could take it as a pill.
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Affiliation(s)
- Paul A Nakamura
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, United States
| | - Andy A Shimchuk
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, United States
| | - Shibing Tang
- Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, University of California, San Francisco, San Francisco, United States
| | - Zhizhi Wang
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, United States
| | - Kole DeGolier
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, United States
| | - Sheng Ding
- Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, University of California, San Francisco, San Francisco, United States
| | - Thomas A Reh
- Department of Biological Structure, University of Washington, School of Medicine, Seattle, United States
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Samd7 is a cell type-specific PRC1 component essential for establishing retinal rod photoreceptor identity. Proc Natl Acad Sci U S A 2017; 114:E8264-E8273. [PMID: 28900001 DOI: 10.1073/pnas.1707021114] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Precise transcriptional regulation controlled by a transcription factor network is known to be crucial for establishing correct neuronal cell identities and functions in the CNS. In the retina, the expression of various cone and rod photoreceptor cell genes is regulated by multiple transcription factors; however, the role of epigenetic regulation in photoreceptor cell gene expression has been poorly understood. Here, we found that Samd7, a rod-enriched sterile alpha domain (SAM) domain protein, is essential for silencing nonrod gene expression through H3K27me3 regulation in rod photoreceptor cells. Samd7-null mutant mice showed ectopic expression of nonrod genes including S-opsin in rod photoreceptor cells and rod photoreceptor cell dysfunction. Samd7 physically interacts with Polyhomeotic homologs (Phc proteins), components of the Polycomb repressive complex 1 (PRC1), and colocalizes with Phc2 and Ring1B in Polycomb bodies. ChIP assays showed a significant decrease of H3K27me3 in the genes up-regulated in the Samd7-deficient retina, showing that Samd7 deficiency causes the derepression of nonrod gene expression in rod photoreceptor cells. The current study suggests that Samd7 is a cell type-specific PRC1 component epigenetically defining rod photoreceptor cell identity.
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The nuclear hormone receptor gene Nr2c1 (Tr2) is a critical regulator of early retina cell patterning. Dev Biol 2017; 429:343-355. [DOI: 10.1016/j.ydbio.2017.05.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 05/17/2017] [Accepted: 05/19/2017] [Indexed: 02/08/2023]
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Olivares AM, Jelcick AS, Reinecke J, Leehy B, Haider A, Morrison MA, Cheng L, Chen DF, DeAngelis MM, Haider NB. Multimodal Regulation Orchestrates Normal and Complex Disease States in the Retina. Sci Rep 2017; 7:690. [PMID: 28386079 PMCID: PMC5429617 DOI: 10.1038/s41598-017-00788-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 03/13/2017] [Indexed: 12/20/2022] Open
Abstract
Regulation of biological processes occurs through complex, synergistic mechanisms. In this study, we discovered the synergistic orchestration of multiple mechanisms regulating the normal and diseased state (age related macular degeneration, AMD) in the retina. We uncovered gene networks with overlapping feedback loops that are modulated by nuclear hormone receptors (NHR), miRNAs, and epigenetic factors. We utilized a comprehensive filtering and pathway analysis strategy comparing miRNA and microarray data between three mouse models and human donor eyes (normal and AMD). The mouse models lack key NHRS (Nr2e3, RORA) or epigenetic (Ezh2) factors. Fifty-four total miRNAs were differentially expressed, potentially targeting over 150 genes in 18 major representative networks including angiogenesis, metabolism, and immunity. We identified sixty-eight genes and 5 miRNAS directly regulated by NR2E3 and/or RORA. After a comprehensive analysis, we discovered multimodal regulation by miRNA, NHRs, and epigenetic factors of three miRNAs (miR-466, miR1187, and miR-710) and two genes (Ell2 and Entpd1) that are also associated with AMD. These studies provide insight into the complex, dynamic modulation of gene networks as well as their impact on human disease, and provide novel data for the development of innovative and more effective therapeutics.
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Affiliation(s)
- A M Olivares
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States of America
| | - A S Jelcick
- Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - J Reinecke
- Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - B Leehy
- Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - A Haider
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States of America
| | - M A Morrison
- Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - L Cheng
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States of America
| | - D F Chen
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States of America
| | - M M DeAngelis
- Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - N B Haider
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA, United States of America.
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Bodofsky S, Koitz F, Wightman B. CONSERVED AND EXAPTED FUNCTIONS OF NUCLEAR RECEPTORS IN ANIMAL DEVELOPMENT. NUCLEAR RECEPTOR RESEARCH 2017; 4:101305. [PMID: 29333434 PMCID: PMC5761748 DOI: 10.11131/2017/101305] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The nuclear receptor gene family includes 18 members that are broadly conserved among multiple disparate animal phyla, indicating that they trace their evolutionary origins to the time at which animal life arose. Typical nuclear receptors contain two major domains: a DNA-binding domain and a C-terminal domain that may bind a lipophilic hormone. Many of these nuclear receptors play varied roles in animal development, including coordination of life cycle events and cellular differentiation. The well-studied genetic model systems of Drosophila, C. elegans, and mouse permit an evaluation of the extent to which nuclear receptor function in development is conserved or exapted (repurposed) over animal evolution. While there are some specific examples of conserved functions and pathways, there are many clear examples of exaptation. Overall, the evolutionary theme of exaptation appears to be favored over strict functional conservation. Despite strong conservation of DNA-binding domain sequences and activity, the nuclear receptors prove to be highly-flexible regulators of animal development.
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Affiliation(s)
- Shari Bodofsky
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
| | - Francine Koitz
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
| | - Bruce Wightman
- Biology Department, Muhlenberg College, 2400 Chew St., Allentown, PA 18104
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Kuniyoshi K, Hayashi T, Sakuramoto H, Mishima H, Tsuneoka H, Tsunoda K, Iwata T, Shimomura Y. New truncation mutation of the NR2E3 gene in a Japanese patient with enhanced S-cone syndrome. Jpn J Ophthalmol 2016; 60:476-485. [PMID: 27522502 DOI: 10.1007/s10384-016-0470-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Accepted: 06/29/2016] [Indexed: 11/30/2022]
Abstract
PURPOSE The enhanced S-cone syndrome (ESCS) is a rare hereditary retinal degeneration that has enhanced short wavelength-sensitive cone (S-cone) functions. The longitudinal clinical course of this disease has been rarely reported, and the genetic aspects of ESCS have not been well investigated in the Japanese population. In this report, we present our clinical and genetic findings for 2 patients with ESCS. PATIENTS AND METHODS The patients were 2 unrelated Japanese men. Standard ophthalmic examinations and mutation screening for the NR2E3 gene were performed. RESULTS Patient 1 was a 36-year-old man, and his clinical findings were typical of ESCS. His decimal best-corrected visual acuity (BCVA) was 1.0 OD and 0.5 OS after removal of cataracts. Genetic investigations revealed a homozygous truncation frameshift, the p.I307LfsX33 mutation. Patient 2 was an 11-year-old boy when he was first examined by us. His clinical findings were typical of ESCS except for uveitis in the left eye. His decimal BCVA at the age of 39 years was maintained at 1.5 in each eye, although the retinal degeneration and visual field impairments had progressed during the follow-up period. The genetic investigations revealed homozygous mutations of p.R104Q in the NR2E3 gene. CONCLUSIONS The frameshift mutation, p.I307LfsX33, in the NR2E3 gene is a new causative mutation for ESCS. The clinical observations for patient 2 are the longest ever reported. The retinal degeneration caused by this mutation is slowly progressive, and these patients maintained good vision with maintenance of the foveal structure until their late thirties.
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Affiliation(s)
- Kazuki Kuniyoshi
- Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan.
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Hiroyuki Sakuramoto
- Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan
| | - Hiroshi Mishima
- Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan
| | - Hiroshi Tsuneoka
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Kazushige Tsunoda
- Laboratory of Visual Physiology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Yoshikazu Shimomura
- Department of Ophthalmology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka, 589-8511, Japan
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30
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Olivares AM, Moreno-Ramos OA, Haider NB. Role of Nuclear Receptors in Central Nervous System Development and Associated Diseases. J Exp Neurosci 2016; 9:93-121. [PMID: 27168725 PMCID: PMC4859451 DOI: 10.4137/jen.s25480] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/06/2016] [Accepted: 01/07/2016] [Indexed: 11/13/2022] Open
Abstract
The nuclear hormone receptor (NHR) superfamily is composed of a wide range of receptors involved in a myriad of important biological processes, including development, growth, metabolism, and maintenance. Regulation of such wide variety of functions requires a complex system of gene regulation that includes interaction with transcription factors, chromatin-modifying complex, and the proper recognition of ligands. NHRs are able to coordinate the expression of genes in numerous pathways simultaneously. This review focuses on the role of nuclear receptors in the central nervous system and, in particular, their role in regulating the proper development and function of the brain and the eye. In addition, the review highlights the impact of mutations in NHRs on a spectrum of human diseases from autism to retinal degeneration.
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Affiliation(s)
- Ana Maria Olivares
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Oscar Andrés Moreno-Ramos
- Departamento de Ciencias Biológicas, Facultad de Ciencias, Universidad de los Andes, Bogotá, Colombia
| | - Neena B Haider
- Department of Ophthalmology, Schepens Eye Research Institute, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
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Grishchuk Y, Stember KG, Matsunaga A, Olivares AM, Cruz NM, King VE, Humphrey DM, Wang SL, Muzikansky A, Betensky RA, Thoreson WB, Haider N, Slaugenhaupt SA. Retinal Dystrophy and Optic Nerve Pathology in the Mouse Model of Mucolipidosis IV. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 186:199-209. [PMID: 26608452 DOI: 10.1016/j.ajpath.2015.09.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 08/31/2015] [Accepted: 09/10/2015] [Indexed: 11/19/2022]
Abstract
Mucolipidosis IV is a debilitating developmental lysosomal storage disorder characterized by severe neuromotor retardation and progressive loss of vision, leading to blindness by the second decade of life. Mucolipidosis IV is caused by loss-of-function mutations in the MCOLN1 gene, which encodes the transient receptor potential channel protein mucolipin-1. Ophthalmic pathology in patients includes corneal haze and progressive retinal and optic nerve atrophy. Herein, we report ocular pathology in Mcoln1(-/-) mouse, a good phenotypic model of the disease. Early, but non-progressive, thinning of the photoreceptor layer, reduced levels of rhodopsin, disrupted rod outer segments, and widespread accumulation of the typical storage inclusion bodies were the major histological findings in the Mcoln1(-/-) retina. Electroretinograms showed significantly decreased functional response (scotopic a- and b-wave amplitudes) in the Mcoln1(-/-) mice. At the ultrastructural level, we observed formation of axonal spheroids and decreased density of axons in the optic nerve of the aged (6-month-old) Mcoln1(-/-) mice, which indicates progressive axonal degeneration. Our data suggest that mucolipin-1 plays a role in postnatal development of photoreceptors and provides a set of outcome measures that can be used for ocular therapy development for mucolipidosis IV.
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Affiliation(s)
- Yulia Grishchuk
- Department of Neurology, Center for Human Genetic Research, Harvard Medical School, Boston, Massachusetts.
| | - Katherine G Stember
- Department of Neurology, Center for Human Genetic Research, Harvard Medical School, Boston, Massachusetts
| | - Aya Matsunaga
- Department of Neurology, Center for Human Genetic Research, Harvard Medical School, Boston, Massachusetts
| | - Ana M Olivares
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
| | - Nelly M Cruz
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
| | - Victoria E King
- Department of Neurology, Center for Human Genetic Research, Harvard Medical School, Boston, Massachusetts
| | - Daniel M Humphrey
- Department of Neurology, Center for Human Genetic Research, Harvard Medical School, Boston, Massachusetts
| | - Shirley L Wang
- Department of Neurology, Center for Human Genetic Research, Harvard Medical School, Boston, Massachusetts
| | - Alona Muzikansky
- Massachusetts General Hospital Biostatistics Center, Massachusetts General Hospital, Boston, Massachusetts
| | - Rebecca A Betensky
- Department of Biostatistics, Harvard School of Public Health, Boston, Massachusetts
| | - Wallace B Thoreson
- Department of Ophthalmology & Visual Sciences, University of Nebraska Medical Center, Omaha, Nebraska
| | - Neena Haider
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
| | - Susan A Slaugenhaupt
- Department of Neurology, Center for Human Genetic Research, Harvard Medical School, Boston, Massachusetts
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von Alpen D, Tran HV, Guex N, Venturini G, Munier FL, Schorderet DF, Haider NB, Escher P. Differential dimerization of variants linked to enhanced S-cone sensitivity syndrome (ESCS) located in the NR2E3 ligand-binding domain. Hum Mutat 2015; 36:599-610. [PMID: 25703721 DOI: 10.1002/humu.22775] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Accepted: 02/10/2015] [Indexed: 11/11/2022]
Abstract
NR2E3 encodes the photoreceptor-specific nuclear hormone receptor that acts as a repressor of cone-specific gene expression in rod photoreceptors, and as an activator of several rod-specific genes. Recessive variants located in the ligand-binding domain (LBD) of NR2E3 cause enhanced short wavelength sensitive- (S-) cone syndrome (ESCS), a retinal degeneration characterized by an excess of S-cones and non-functional rods. We analyzed the dimerization properties of NR2E3 and the effect of disease-causing LBD missense variants by bioluminescence resonance energy transfer (BRET(2) ) protein interaction assays. Homodimerization was not affected in presence of p.A256V, p.R039G, p.R311Q, and p.R334G variants, but abolished in presence of p.L263P, p.L336P, p.L353V, p.R385P, and p.M407K variants. Homology modeling predicted structural changes induced by NR2E3 LBD variants. NR2E3 LBD variants did not affect interaction with CRX, but with NRL and rev-erbα/NR1D1. CRX and NRL heterodimerized more efficiently together, than did either with NR2E3. NR2E3 did not heterodimerize with TLX/NR2E1 and RXRα/NR2C1. The identification of a new compound heterozygous patient with detectable rod function, who expressed solely the p.A256V variant protein, suggests a correlation between LBD variants able to form functional NR2E3 dimers and atypical mild forms of ESCS with residual rod function.
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Affiliation(s)
- Désirée von Alpen
- IRO-Institute for Research in Ophthalmology, Sion, Switzerland.,EPFL-Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Hoai Viet Tran
- Jules-Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland
| | - Nicolas Guex
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | | | - Francis L Munier
- Jules-Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland
| | - Daniel F Schorderet
- IRO-Institute for Research in Ophthalmology, Sion, Switzerland.,EPFL-Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.,Jules-Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland
| | - Neena B Haider
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute, Boston, Massachusetts
| | - Pascal Escher
- IRO-Institute for Research in Ophthalmology, Sion, Switzerland.,Jules-Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland
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Owen LA, Morrison MA, Ahn J, Woo SJ, Sato H, Robinson R, Morgan DJ, Zacharaki F, Simeonova M, Uehara H, Chakravarthy U, Hogg RE, Ambati BK, Kotoula M, Baehr W, Haider NB, Silvestri G, Miller JW, Tsironi EE, Farrer LA, Kim IK, Park KH, DeAngelis MM. FLT1 genetic variation predisposes to neovascular AMD in ethnically diverse populations and alters systemic FLT1 expression. Invest Ophthalmol Vis Sci 2014; 55:3543-54. [PMID: 24812550 DOI: 10.1167/iovs.14-14047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Current understanding of the genetic risk factors for age-related macular degeneration (AMD) is not sufficiently predictive of the clinical course. The VEGF pathway is a key therapeutic target for treatment of neovascular AMD; however, risk attributable to genetic variation within pathway genes is unclear. We sought to identify single nucleotide polymorphisms (SNPs) associated with AMD within the VEGF pathway. METHODS Using a tagSNP, direct sequencing and meta-analysis approach within four ethnically diverse cohorts, we identified genetic risk present in FLT1, though not within other VEGF pathway genes KDR, VEGFA, or VASH1. We used ChIP and ELISA in functional analysis. RESULTS The FLT1 SNPs rs9943922, rs9508034, rs2281827, rs7324510, and rs9513115 were significantly associated with increased risk of neovascular AMD. Each association was more significant after meta-analysis than in any one of the four cohorts. All associations were novel, within noncoding regions of FLT1 that do not tag for coding variants in linkage disequilibrium. Analysis of soluble FLT1 demonstrated higher expression in unaffected individuals homozygous for the FLT1 risk alleles rs9943922 (P = 0.0086) and rs7324510 (P = 0.0057). In silico analysis suggests that these variants change predicted splice sites and RNA secondary structure, and have been identified in other neovascular pathologies. These data were supported further by murine chromatin immunoprecipitation demonstrating that FLT1 is a target of Nr2e3, a nuclear receptor gene implicated in regulating an AMD pathway. CONCLUSIONS Although exact variant functions are not known, these data demonstrate relevancy across ethnically diverse genetic backgrounds within our study and, therefore, hold potential for global efficacy.
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Affiliation(s)
- Leah A Owen
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States
| | - Margaux A Morrison
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States
| | - Jeeyun Ahn
- Department of Ophthalmology, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Republic of Korea
| | - Se Joon Woo
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seoungnam, Republic of Korea
| | - Hajime Sato
- Department of Ophthalmology, Tohoku University Graduate School of Medicine, Aoba-ku, Sendai, Japan
| | - Rosann Robinson
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States
| | - Denise J Morgan
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States
| | - Fani Zacharaki
- Department of Ophthalmology, University of Thessaly, School of Medicine, Larissa, Greece
| | - Marina Simeonova
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Hironori Uehara
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States
| | - Usha Chakravarthy
- Centre for Experimental Medicine, Queen's University, Belfast, United Kingdom
| | - Ruth E Hogg
- Centre for Experimental Medicine, Queen's University, Belfast, United Kingdom
| | - Balamurali K Ambati
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States
| | - Maria Kotoula
- Department of Ophthalmology, University of Thessaly, School of Medicine, Larissa, Greece
| | - Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States
| | - Neena B Haider
- Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts, United States
| | - Giuliana Silvestri
- Centre for Experimental Medicine, Queen's University, Belfast, United Kingdom
| | - Joan W Miller
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Evangelia E Tsironi
- Department of Ophthalmology, University of Thessaly, School of Medicine, Larissa, Greece
| | - Lindsay A Farrer
- Departments of Medicine (Biomedical Genetics), Ophthalmology, Neurology, Epidemiology, and Biostatistics, Boston University Schools of Medicine and Public Health, Boston, Massachusetts, United States
| | - Ivana K Kim
- Retina Service, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Kyu Hyung Park
- Department of Ophthalmology, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul, Republic of Korea
| | - Margaret M DeAngelis
- Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, United States
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Modifier genes as therapeutics: the nuclear hormone receptor Rev Erb alpha (Nr1d1) rescues Nr2e3 associated retinal disease. PLoS One 2014; 9:e87942. [PMID: 24498227 PMCID: PMC3909326 DOI: 10.1371/journal.pone.0087942] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 12/30/2013] [Indexed: 11/19/2022] Open
Abstract
Nuclear hormone receptors play a major role in many important biological processes. Most nuclear hormone receptors are ubiquitously expressed and regulate processes such as metabolism, circadian function, and development. They function in these processes to maintain homeostasis through modulation of transcriptional gene networks. In this study we evaluate the effectiveness of a nuclear hormone receptor gene to modulate retinal degeneration and restore the integrity of the retina. Currently, there are no effective treatment options for retinal degenerative diseases leading to progressive and irreversible blindness. In this study we demonstrate that the nuclear hormone receptor gene Nr1d1 (Rev-Erbα) rescues Nr2e3-associated retinal degeneration in the rd7 mouse, which lacks a functional Nr2e3 gene. Mutations in human NR2E3 are associated with several retinal degenerations including enhanced S cone syndrome and retinitis pigmentosa. The rd7 mouse, lacking Nr2e3, exhibits an increase in S cones and slow, progressive retinal degeneration. A traditional genetic mapping approach previously identified candidate modifier loci. Here, we demonstrate that in vivo delivery of the candidate modifier gene, Nr1d1 rescues Nr2e3 associated retinal degeneration. We observed clinical, histological, functional, and molecular restoration of the rd7 retina. Furthermore, we demonstrate that the mechanism of rescue at the molecular and functional level is through the re-regulation of key genes within the Nr2e3-directed transcriptional network. Together, these findings reveal the potency of nuclear receptors as modulators of disease and specifically of NR1D1 as a novel therapeutic for retinal degenerations.
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35
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Tan MHE, Zhou XE, Soon FF, Li X, Li J, Yong EL, Melcher K, Xu HE. The crystal structure of the orphan nuclear receptor NR2E3/PNR ligand binding domain reveals a dimeric auto-repressed conformation. PLoS One 2013; 8:e74359. [PMID: 24069298 PMCID: PMC3771917 DOI: 10.1371/journal.pone.0074359] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 07/31/2013] [Indexed: 01/20/2023] Open
Abstract
Photoreceptor-specific nuclear receptor (PNR, NR2E3) is a key transcriptional regulator of human photoreceptor differentiation and maintenance. Mutations in the NR2E3-encoding gene cause various retinal degenerations, including Enhanced S-cone syndrome, retinitis pigmentosa, and Goldman-Favre disease. Although physiological ligands have not been identified, it is believed that binding of small molecule agonists, receptor desumoylation, and receptor heterodimerization may switch NR2E3 from a transcriptional repressor to an activator. While these features make NR2E3 a potential therapeutic target for the treatment of retinal diseases, there has been a clear lack of structural information for the receptor. Here, we report the crystal structure of the apo NR2E3 ligand binding domain (LBD) at 2.8 Å resolution. Apo NR2E3 functions as transcriptional repressor in cells and the structure of its LBD is in a dimeric auto-repressed conformation. In this conformation, the putative ligand binding pocket is filled with bulky hydrophobic residues and the activation-function-2 (AF2) helix occupies the canonical cofactor binding site. Mutations designed to disrupt either the AF2/cofactor-binding site interface or the dimer interface compromised the transcriptional repressor activity of this receptor. Together, these results reveal several conserved structural features shared by related orphan nuclear receptors, suggest that most disease-causing mutations affect the receptor's structural integrity, and allowed us to model a putative active conformation that can accommodate small ligands in its pocket.
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Affiliation(s)
- M. H. Eileen Tan
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
- Department of Obstetrics & Gynecology, National University Hospital, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - X. Edward Zhou
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
| | - Fen-Fen Soon
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
- Department of Obstetrics & Gynecology, National University Hospital, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Xiaodan Li
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
- Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, China
| | - Jun Li
- Department of Obstetrics & Gynecology, National University Hospital, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Eu-Leong Yong
- Department of Obstetrics & Gynecology, National University Hospital, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Karsten Melcher
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
| | - H. Eric Xu
- Laboratory of Structural Sciences, Van Andel Research Institute, Grand Rapids, Michigan, United States of America
- Van Andel Research Institute/Shanghai Institute of Materia Medica Center, Chinese Academy of Sciences-Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
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Abstract
AbstractS cones expressing the short wavelength-sensitive type 1 (SWS1) class of visual pigment generally form only a minority type of cone photoreceptor within the vertebrate duplex retina. Hence, their primary role is in color vision, not in high acuity vision. In mammals, S cones may be present as a constant fraction of the cones across the retina, may be restricted to certain regions of the retina or may form a gradient across the retina, and in some species, there is coexpression of SWS1 and the long wavelength-sensitive (LWS) class of pigment in many cones. During retinal development, SWS1 opsin expression generally precedes that of LWS opsin, and evidence from genetic studies indicates that the S cone pathway may be the default pathway for cone development. With the notable exception of the cartilaginous fishes, where S cones appear to be absent, they are present in representative species from all other vertebrate classes. S cone loss is not, however, uncommon; they are absent from most aquatic mammals and from some but not all nocturnal terrestrial species. The peak spectral sensitivity of S cones depends on the spectral characteristics of the pigment present. Evidence from the study of agnathans and teleost fishes indicates that the ancestral vertebrate SWS1 pigment was ultraviolet (UV) sensitive with a peak around 360 nm, but this has shifted into the violet region of the spectrum (>380 nm) on many separate occasions during vertebrate evolution. In all cases, the shift was generated by just one or a few replacements in tuning-relevant residues. Only in the avian lineage has tuning moved in the opposite direction, with the reinvention of UV-sensitive pigments.
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Gregory-Evans CY, Wallace VA, Gregory-Evans K. Gene networks: dissecting pathways in retinal development and disease. Prog Retin Eye Res 2012; 33:40-66. [PMID: 23128416 DOI: 10.1016/j.preteyeres.2012.10.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 10/18/2012] [Accepted: 10/19/2012] [Indexed: 01/21/2023]
Abstract
During retinal neurogenesis, diverse cellular subtypes originate from multipotent neural progenitors in a spatiotemporal order leading to a highly specialized laminar structure combined with a distinct mosaic architecture. This is driven by the combinatorial action of transcription factors and signaling molecules which specify cell fate and differentiation. The emerging approach of gene network analysis has allowed a better understanding of the functional relationships between genes expressed in the developing retina. For instance, these gene networks have identified transcriptional hubs that have revealed potential targets and pathways for the development of therapeutic options for retinal diseases. Much of the current knowledge has been informed by targeted gene deletion experiments and gain-of-functional analysis. In this review we will provide an update on retinal development gene networks and address the wider implications for future disease therapeutics.
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Affiliation(s)
- Cheryl Y Gregory-Evans
- Department of Ophthalmology, University of British Columbia, Vancouver, BC V5Z 3N9, Canada.
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Forrest D, Swaroop A. Minireview: the role of nuclear receptors in photoreceptor differentiation and disease. Mol Endocrinol 2012; 26:905-15. [PMID: 22556342 DOI: 10.1210/me.2012-1010] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Rod and cone photoreceptors are specialized sensory cells that mediate vision. Transcriptional controls are critical for the development and long-term survival of photoreceptors; when these controls become ineffective, retinal dysfunction or degenerative disease may result. This review discusses the role of nuclear receptors, a class of ligand-regulated transcription factors, at key stages of photoreceptor life in the mammalian retina. Nuclear receptors with known ligands, such as retinoids or thyroid hormone, together with several orphan receptors without identified physiological ligands, complement other classes of transcription factors in directing the differentiation and functional maintenance of photoreceptors. The potential of nuclear receptors to respond to ligands introduces versatility into the control of photoreceptor development and function and may suggest new opportunities for treatments of photoreceptor disease.
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Affiliation(s)
- Douglas Forrest
- Laboratory of Endocrinology and Receptor Biology, National Institutes of Health, Bethesda, MD 20892, USA.
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Cheng H, Khan NW, Roger JE, Swaroop A. Excess cones in the retinal degeneration rd7 mouse, caused by the loss of function of orphan nuclear receptor Nr2e3, originate from early-born photoreceptor precursors. Hum Mol Genet 2011; 20:4102-15. [PMID: 21813656 DOI: 10.1093/hmg/ddr334] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The orphan nuclear receptor NR2E3 is a direct transcriptional target of NRL, the key basic motif leucine zipper transcription factor that dictates rod versus cone photoreceptor cell fate in the mammalian retina. The lack of NR2E3 function in humans and in retinal degeneration rd7 mutant mouse leads to increased S-cones accompanied by rod degeneration, whereas ectopic expression of Nr2e3 in the cone-only Nrl(-/-) retina generates rod-like cells that do not exhibit any visual function. Using GFP to tag the newborn rods and by 5-bromo-2'-deoxyuridine birthdating, we demonstrate that early-born post-mitotic photoreceptor precursors in the rd7 retina express cone-specific genes. Transgenic mouse studies in the rd7 background show that Nr2e3 when expressed under the control of Crx promoter can restore rod photoreceptor function and suppress cone gene expression. Furthermore, Nr2e3 expression in photoreceptor precursors committed to be rods (driven by the Nrl promoter) could completely rescue the retinal phenotype of the rd7 mice. We conclude that excess of S-cones in the rd7 retina originate from photoreceptor precursors with a 'default' fate and not from proliferation of cones and that Nr2e3 is required to suppress the expression of S-cone genes during normal rod differentiation. These studies further support the 'transcriptional dominance' model of photoreceptor cell fate determination and provide insights into the pathogenesis of retinal disease phenotypes caused by NR2E3 mutations.
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Affiliation(s)
- Hong Cheng
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, USA
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40
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Jelcick AS, Yuan Y, Leehy BD, Cox LC, Silveira AC, Qiu F, Schenk S, Sachs AJ, Morrison MA, Nystuen AM, DeAngelis MM, Haider NB. Genetic variations strongly influence phenotypic outcome in the mouse retina. PLoS One 2011; 6:e21858. [PMID: 21779340 PMCID: PMC3136482 DOI: 10.1371/journal.pone.0021858] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 06/07/2011] [Indexed: 01/22/2023] Open
Abstract
Variation in genetic background can significantly influence the phenotypic outcome of both disease and non-disease associated traits. Additionally, differences in temporal and strain specific gene expression can also contribute to phenotypes in the mammalian retina. This is the first report of microarray based cross-strain analysis of gene expression in the retina investigating genetic background effects. Microarray analyses were performed on retinas from the following mouse strains: C57BL6/J, AKR/J, CAST/EiJ, and NOD.NON-H2-nb1 at embryonic day 18.5 (E18.5) and postnatal day 30.5 (P30.5). Over 3000 differentially expressed genes were identified between strains and developmental stages. Differential gene expression was confirmed by qRT-PCR, Western blot, and immunohistochemistry. Three major gene networks were identified that function to regulate retinal or photoreceptor development, visual perception, cellular transport, and signal transduction. Many of the genes in these networks are implicated in retinal diseases such as bradyopsia, night-blindness, and cone-rod dystrophy. Our analysis revealed strain specific variations in cone photoreceptor cell patterning and retinal function. This study highlights the substantial impact of genetic background on both development and function of the retina and the level of gene expression differences tolerated for normal retinal function. These strain specific genetic variations may also be present in other tissues. In addition, this study will provide valuable insight for the development of more accurate models for human retinal diseases.
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Affiliation(s)
- Austin S. Jelcick
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Yang Yuan
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Barrett D. Leehy
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Lakeisha C. Cox
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Alexandra C. Silveira
- Ocular Molecular Genetics Institute, Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, United States of America
| | - Fang Qiu
- Division of Biostatistics, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Sarah Schenk
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Andrew J. Sachs
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Margaux A. Morrison
- Ocular Molecular Genetics Institute, Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, United States of America
| | - Arne M. Nystuen
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Margaret M. DeAngelis
- Moran Eye Center, University of Utah, Salt Lake City, Utah, United States of America
| | - Neena B. Haider
- Department of Ophthalmology, Harvard Medical School, Schepens Eye Research Institute, Boston, Massachusetts, United States of America
- * E-mail:
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41
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Abstract
Mammalian retinas display an astonishing diversity in the spatial arrangement of their spectral cone photoreceptors, probably in adaptation to different visual environments. Opsin expression patterns like the dorsoventral gradients of short-wave-sensitive (S) and middle- to long-wave-sensitive (M) cone opsin found in many species are established early in development and thought to be stable thereafter throughout life. In mouse early development, thyroid hormone (TH), through its receptor TRβ2, is an important regulator of cone spectral identity. However, the role of TH in the maintenance of the mature cone photoreceptor pattern is unclear. We here show that TH also controls adult cone opsin expression. Methimazole-induced suppression of serum TH in adult mice and rats yielded no changes in cone numbers but reversibly altered cone patterns by activating the expression of S-cone opsin and repressing the expression of M-cone opsin. Furthermore, treatment of athyroid Pax8(-/-) mice with TH restored a wild-type pattern of cone opsin expression that reverted back to the mutant S-opsin-dominated pattern after termination of treatment. No evidence for cone death or the generation of new cones from retinal progenitors was found in retinas that shifted opsin expression patterns. Together, this suggests that opsin expression in terminally differentiated mammalian cones remains subject to control by TH, a finding that is in contradiction to previous work and challenges the current view that opsin identity in mature mammalian cones is fixed by permanent gene silencing.
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42
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Nuclear receptor Rev-erb alpha (Nr1d1) functions in concert with Nr2e3 to regulate transcriptional networks in the retina. PLoS One 2011; 6:e17494. [PMID: 21408158 PMCID: PMC3050883 DOI: 10.1371/journal.pone.0017494] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 02/07/2011] [Indexed: 12/23/2022] Open
Abstract
The majority of diseases in the retina are caused by genetic mutations affecting the development and function of photoreceptor cells. The transcriptional networks directing these processes are regulated by genes such as nuclear hormone receptors. The nuclear hormone receptor gene Rev-erb alpha/Nr1d1 has been widely studied for its role in the circadian cycle and cell metabolism, however its role in the retina is unknown. In order to understand the role of Rev-erb alpha/Nr1d1 in the retina, we evaluated the effects of loss of Nr1d1 to the developing retina and its co-regulation with the photoreceptor-specific nuclear receptor gene Nr2e3 in the developing and mature retina. Knock-down of Nr1d1 expression in the developing retina results in pan-retinal spotting and reduced retinal function by electroretinogram. Our studies show that NR1D1 protein is co-expressed with NR2E3 in the outer neuroblastic layer of the developing mouse retina. In the adult retina, NR1D1 is expressed in the ganglion cell layer and is co-expressed with NR2E3 in the outer nuclear layer, within rods and cones. Several genes co-targeted by NR2E3 and NR1D1 were identified that include: Nr2c1, Recoverin, Rgr, Rarres2, Pde8a, and Nupr1. We examined the cyclic expression of Nr1d1 and Nr2e3 over a twenty-four hour period and observed that both nuclear receptors cycle in a similar manner. Taken together, these studies reveal a novel role for Nr1d1, in conjunction with its cofactor Nr2e3, in regulating transcriptional networks critical for photoreceptor development and function.
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43
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A novel mutation (Cys83Tyr) in the second zinc finger of NR2E3 in enhanced S-cone syndrome. Graefes Arch Clin Exp Ophthalmol 2010; 249:201-8. [PMID: 20725840 DOI: 10.1007/s00417-010-1482-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 07/25/2010] [Accepted: 07/26/2010] [Indexed: 10/19/2022] Open
Abstract
BACKGROUND Enhanced S-cone syndrome (ESCS) is an autosomal recessive retinal disorder characterized by an increased number of S-cones over L/M cones and rods. Mutations in the NR2E3 gene, encoding a photoreceptor-specific nuclear receptor, are identified in patients with ESCS. The purpose of this study is to report the ophthalmic features of a 25-year-old Portuguese male with a typical ESCS phenotype and a novel homozygous NR2E3 mutation. METHODS The patient underwent a detailed ophthalmic examination including fundus photography, fluorescein angiography (FAF), fundus autofluorescence imaging (FAI), and spectral domain optical coherence tomography (SD-OCT). Full-field electroretinography (ERG), S-cone ERG, and multifocal ERG were performed. Mutation screening of the NR2E3 gene was performed with polymerase chain reaction amplification and direct sequencing. RESULTS The patient had poor visual acuity but good color vision. Funduscopy showed degenerative changes from the vascular arcades to the midperipheral retina. The SD-OCT revealed macular schisis and cystoid changes that had no fluorescein leakage. The posterior pole showed diffusely increased autofluorescence compared with eccentric areas in both eyes. International-standard full-field ERG showed the typical pathognomonic changes associated with ESCS and the short-wavelength flash ERG was simplified, delayed, and similar to the standard photopic flash ERG. Multifocal ERG showed widespread delay and reduction. Genetic analysis revealed a novel homozygous mutation (p.C83Y), which resides in the second zinc finger of the DNA-binding domain. CONCLUSIONS This homozygous mutation is likely to affect binding to target DNA sites, resulting in a non-functional behavior of NR2E3 protein. It is associated with a typical form of ESCS with a nondetectable rod response and reduced/delayed mfERG responses at all eccentricities.
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A 350 bp region of the proximal promoter of Rds drives cell-type specific gene expression. Exp Eye Res 2010; 91:186-94. [PMID: 20447394 DOI: 10.1016/j.exer.2010.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 04/23/2010] [Accepted: 04/26/2010] [Indexed: 11/23/2022]
Abstract
RDS (retinal degeneration slow) is a photoreceptor-specific tetraspanin protein required for the biogenesis and maintenance of rod and cone outer segments. Mutations in the Rds gene are associated with multiple forms of rod- and cone-dominant retinal degeneration. To gain more insight into the mechanisms underlying the regulation of this gene, the identification of regulatory sequences within the promoter of Rds was undertaken. A 3.5 kb fragment of the 5' flanking region of the mouse Rds gene was isolated and binding sites for Crx, Otx2, Nr2e3, RXR family members, Mef2C, Esrrb, NF1, AP1, and SP1 in addition to several E-boxes, GC-boxes and GAGA-boxes were identified. Crx binding sequences were conserved in all mammalian species examined. Truncation expression analysis of the Rds promoter region in Y-79 retinoblastoma cells showed maximal activity in the 350 bp proximal promoter region. We also show that inclusion of more distal fragments reduced promoter activity to the basal level, and that the promoter activities are cell-type and direction specific. Co-transfection with Nrl increased promoter activity, suggesting that this gene positively regulates Rds expression. Based on these findings, a relatively small fragment of the Rds promoter may be useful in future gene transfer studies to drive gene expression in photoreceptors.
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45
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Schorderet DF, Escher P. NR2E3 mutations in enhanced S-cone sensitivity syndrome (ESCS), Goldmann-Favre syndrome (GFS), clumped pigmentary retinal degeneration (CPRD), and retinitis pigmentosa (RP). Hum Mutat 2010; 30:1475-85. [PMID: 19718767 DOI: 10.1002/humu.21096] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
NR2E3, also called photoreceptor-specific nuclear receptor (PNR), is a transcription factor of the nuclear hormone receptor superfamily whose expression is uniquely restricted to photoreceptors. There, its physiological activity is essential for proper rod and cone photoreceptor development and maintenance. Thirty-two different mutations in NR2E3 have been identified in either homozygous or compound heterozygous state in the recessively inherited enhanced S-cone sensitivity syndrome (ESCS), Goldmann-Favre syndrome (GFS), and clumped pigmentary retinal degeneration (CPRD). The clinical phenotype common to all these patients is night blindness, rudimental or absent rod function, and hyperfunction of the "blue" S-cones. A single p.G56R mutation is inherited in a dominant manner and causes retinitis pigmentosa (RP). We have established a new locus-specific database for NR2E3 (www.LOVD.nl/eye), containing all reported mutations, polymorphisms, and unclassified sequence variants, including novel ones. A high proportion of mutations are located in the evolutionarily-conserved DNA-binding domains (DBDs) and ligand-binding domains (LBDs) of NR2E3. Based on homology modeling of these NR2E3 domains, we propose a structural localization of mutated residues. The high variability of clinical phenotypes observed in patients affected by NR2E3-linked retinal degenerations may be caused by different disease mechanisms, including absence of DNA-binding, altered interactions with transcriptional coregulators, and differential activity of modifier genes.
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46
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Roduit R, Escher P, Schorderet DF. Mutations in the DNA-binding domain of NR2E3 affect in vivo dimerization and interaction with CRX. PLoS One 2009; 4:e7379. [PMID: 19823680 PMCID: PMC2757917 DOI: 10.1371/journal.pone.0007379] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Accepted: 09/16/2009] [Indexed: 02/04/2023] Open
Abstract
Background NR2E3 (PNR) is an orphan nuclear receptor essential for proper photoreceptor determination and differentiation. In humans, mutations in NR2E3 have been associated with the recessively inherited enhanced short wavelength sensitive (S-) cone syndrome (ESCS) and, more recently, with autosomal dominant retinitis pigmentosa (adRP). NR2E3 acts as a suppressor of the cone generation program in late mitotic retinal progenitor cells. In adult rod photoreceptors, NR2E3 represses cone-specific gene expression and acts in concert with the transcription factors CRX and NRL to activate rod-specific genes. NR2E3 and CRX have been shown to physically interact in vitro through their respective DNA-binding domains (DBD). The DBD also contributes to homo- and heterodimerization of nuclear receptors. Methodology/Principal Findings We analyzed NR2E3 homodimerization and NR2E3/CRX complex formation in an in vivo situation by Bioluminescence Resonance Energy Transfer (BRET2). NR2E3 wild-type protein formed homodimers in transiently transfected HEK293T cells. NR2E3 homodimerization was impaired in presence of disease-causing mutations in the DBD, except for the p.R76Q and p.R104W mutant proteins. Strikingly, the adRP-linked p.G56R mutant protein interacted with CRX with a similar efficiency to that of NR2E3 wild-type and p.R311Q proteins. In contrast, all other NR2E3 DBD-mutant proteins did not interact with CRX. The p.G56R mutant protein was also more effective in abolishing the potentiation of rhodospin gene transactivation by the NR2E3 wild-type protein. In addition, the p.G56R mutant enhanced the transrepression of the M- and S-opsin promoter, while all other NR2E3 DBD-mutants did not. Conclusions/Significance These results suggest different disease mechanisms in adRP- and ESCS-patients carrying NR2E3 mutations. Titration of CRX by the p.G56R mutant protein acting as a repressor in trans may account for the severe clinical phenotype in adRP patients.
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Affiliation(s)
- Raphael Roduit
- IRO, Institute for Research in Ophthalmology, Sion, Switzerland.
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47
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Retinoid-related orphan nuclear receptor RORbeta is an early-acting factor in rod photoreceptor development. Proc Natl Acad Sci U S A 2009; 106:17534-9. [PMID: 19805139 DOI: 10.1073/pnas.0902425106] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Rods and cones are morphologically and developmentally distinct photoreceptor types with different functions in vision. Cones mediate daylight and color vision and in most mammals express M and S opsin photopigments for sensitivity to medium-long and short light wavelengths, respectively. Rods mediate dim light vision and express rhodopsin photopigment. The transcription factor networks that direct differentiation of each photoreceptor type are incompletely defined. Here, we report that Rorb(-/-) mice lacking retinoid-related orphan nuclear receptor beta lose rods but overproduce primitive S cones that lack outer segments. The phenotype reflects pronounced plasticity between rod and cone lineages and resembles that described for Nrl(-/-) mice lacking neural retina leucine zipper factor. Rorb(-/-) mice lack Nrl expression and reexpression of Nrl in Rorb(-/-) mice converts cones to rod-like cells. Thus, Rorb directs rod development and does so at least in part by inducing the Nrl-mediated pathway of rod differentiation.
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48
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Wang NK, Fine HF, Chang S, Chou CL, Cella W, Tosi J, Lin CS, Nagasaki T, Tsang SH. Cellular origin of fundus autofluorescence in patients and mice with a defective NR2E3 gene. Br J Ophthalmol 2009; 93:1234-40. [PMID: 19429590 PMCID: PMC2742679 DOI: 10.1136/bjo.2008.153577] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIM To characterise new clinical features in a family with enhanced S-cone syndrome (ESCS) and investigate the pathogenesis of these clinical features in the homozygous Nr2e3(rd7) (rd7) mutant mice. METHODS Four patients from an affected family were included for genotypic and phenotypic study. Eye tissues from rd7 mice were used to detect a possible relationship between macrophages and autofluorescent material by immunohistochemistry (IHC) staining. RESULTS Homozygous mutation in R311Q in NR2E3 was detected in this family. Colour photographs revealed that white dots do not correlate to hyperautofluorescent spots seen in autofluorescence imaging of the macula. OCT showed rosette-like lesions similar to those found in rd7 mice histology sections. From IHC analysis, we observed that F4/80 (a pan macrophage marker) and autofluorescence were colocalised to the same cells within the retina rosettes. CONCLUSIONS The retinal structure of a young ESCS patient with homozygous R311Q mutation in the NR2E3 gene is similar to that seen in the rd7 mice. The macrophages were found to contain autofluorescent materials in the retinal rosettes of rd7 mice. These data are consistent with macrophage infiltration contributing to the hyperautofluorescent spots found in our patients.
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Affiliation(s)
- N-K Wang
- Bernard & Shirlee Brown Glaucoma Laboratory, Edward S Harkness Eye Institute, New York 10032, USA
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49
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Abstract
Although outnumbered more than 20:1 by rod photoreceptors, cone cells in the human retina mediate daylight vision and are critical for visual acuity and color discrimination. A variety of human diseases are characterized by a progressive loss of cone photoreceptors but the low abundance of cones and the absence of a macula in non-primate mammalian retinas have made it difficult to investigate cones directly. Conventional rodents (laboratory mice and rats) are nocturnal rod-dominated species with few cones in the retina, and studying other animals with cone-rich retinas presents various logistic and technical difficulties. Originating in the early 1900s, past research has begun to provide insights into cone ultrastructure but has yet to afford an overall perspective of cone cell organization. This review summarizes our past progress and focuses on the recent introduction of special mammalian models (transgenic mice and diurnal rats rich in cones) that together with new investigative techniques such as atomic force microscopy and cryo-electron tomography promise to reveal a more unified concept of cone photoreceptor organization and its role in retinal diseases.
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50
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Escher P, Gouras P, Roduit R, Tiab L, Bolay S, Delarive T, Chen S, Tsai CC, Hayashi M, Zernant J, Merriam JE, Mermod N, Allikmets R, Munier FL, Schorderet DF. Mutations in NR2E3 can cause dominant or recessive retinal degenerations in the same family. Hum Mutat 2009; 30:342-51. [PMID: 19006237 DOI: 10.1002/humu.20858] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
NR2E3, a photoreceptor-specific nuclear receptor (PNR), represses cone-specific genes and activates several rod-specific genes. In humans, mutations in NR2E3 have been associated with the recessively-inherited enhanced short-wavelength sensitive S-cone syndrome (ESCS) and, recently, with autosomal dominant (ad) retinitis pigmentosa (RP) (adRP). In the present work, we describe two additional families affected by adRP that carry a heterozygous c.166G>A (p.G56R) mutation in the NR2E3 gene. Functional analysis determined the dominant negative activity of the p.G56R mutant protein as the molecular mechanism of adRP. Interestingly, in one pedigree, the most common causal variant for ESCS (p.R311Q) cosegregated with the adRP-linked p.G56R mutation, and the compound heterozygotes exhibited an ESCS-like phenotype, which in 1 of the 2 cases was strikingly "milder" than the patients carrying the p.G56R mutation alone. Impaired repression of cone-specific genes by the corepressors atrophin-1 (dentatorubral-pallidoluysian atrophy [DRPLA] gene product) and atrophin-2 (arginine-glutamic acid dipeptide repeat [RERE] protein) appeared to be a molecular mechanism mediating the beneficial effect of the p.R311Q mutation. Finally, the functional dominance of the p.R311Q variant to the p.G56R mutation is discussed.
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Affiliation(s)
- Pascal Escher
- Institut de Recherche en Ophtalmologie, Sion, Switzerland
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