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Nipp GE, Sarici K, Lee T, Hadziahmetovic M. Risk Factors for Worsening Morphology and Visual Acuity in Eyes with Adult-Onset Foveomacular Vitelliform Dystrophy. Ophthalmol Retina 2024; 8:804-812. [PMID: 38461930 DOI: 10.1016/j.oret.2024.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 03/03/2024] [Accepted: 03/04/2024] [Indexed: 03/12/2024]
Abstract
PURPOSE To explore clinical risk factors and OCT features associated with worse visual acuity (VA), progression of disease, choroidal neovascularization (CNV), and atrophy in eyes with adult-onset foveomacular vitelliform dystrophy (AOFVD). DESIGN Single-center, retrospective, observational cohort study. PARTICIPANTS Patients seen at Duke Eye Center between January 2012 and May 2023 with a diagnosis of AOFVD confirmed via OCT and fundus autofluorescence. METHODS Baseline and final-visit images from eyes with AOFVD were examined. Disease stage was assigned, and presence of atrophy or CNV was determined. Clinical and OCT features associated with progression to atrophy and CNV were determined using t tests and chi-square analysis. Correlation with lower VA was determined using linear regression. MAIN OUTCOME MEASURES Association of clinical characteristics and OCT features with worse VA, progression of disease, CNV, and atrophy as determined by independent t tests, chi-square analysis, and linear regression (P < 0.05). RESULTS One hundred one eyes (63 patients) met inclusion criteria for this study, with mean follow-up duration of 48 months (standard deviation, 31 months). Fifty-one percent of eyes progressed beyond baseline staging during follow-up; among baseline stage 1 eyes, incidence of atrophy was 0.068/person-year; incidence of CNV was 0.022/person-year. Risk factors for worse final VA were baseline presence of vitreomacular traction ([VMT], P = 0.006), ellipsoid zone attenuation (P = 0.02), and increased lesion height and width (P < 0.001). Predictors of progression include diabetes mellitus (P = 0.01), statin use (P = 0.03), presence of hyperreflective foci (P = 0.01), and increased lesion width and volume (P = 0.03 and P = 0.04, respectively). Predictors of atrophy include the baseline presence of VMT (P = 0.02), decreased choroidal thickness (P = 0.03), and greater maximal height, width, and volume of the lesion (P = 0.03, P = 0.02, and P = 0.009, respectively). Lower baseline VA (P = 0.03) and increased lesion volume (P = 0.04) were associated with CNV. CONCLUSIONS Clinical and OCT imaging features at baseline may prove useful in stratifying patient risk for progression, atrophy, CNV, and worse VA. Features such as statin use, diabetes, baseline VA, and laterality should be accounted for. OCT features, such as lesion size, VMT, ellipsoid zone attenuation, choroidal thickness, and hyperreflective foci, may impart greater risk of poor outcomes. Future prospective analysis accounting for the time to development of atrophy and CNV is needed. FINANCIAL DISCLOSURES Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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Affiliation(s)
- Grace E Nipp
- Department of Ophthalmology, Duke University Medical Center, Durham North Carolina
| | - Kubra Sarici
- Department of Ophthalmology, Duke University Medical Center, Durham North Carolina
| | - Terry Lee
- Department of Ophthalmology, Duke University Medical Center, Durham North Carolina
| | - Majda Hadziahmetovic
- Department of Ophthalmology, Duke University Medical Center, Durham North Carolina.
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Georgiou M, Robson AG, Fujinami K, de Guimarães TAC, Fujinami-Yokokawa Y, Daich Varela M, Pontikos N, Kalitzeos A, Mahroo OA, Webster AR, Michaelides M. Phenotyping and genotyping inherited retinal diseases: Molecular genetics, clinical and imaging features, and therapeutics of macular dystrophies, cone and cone-rod dystrophies, rod-cone dystrophies, Leber congenital amaurosis, and cone dysfunction syndromes. Prog Retin Eye Res 2024; 100:101244. [PMID: 38278208 DOI: 10.1016/j.preteyeres.2024.101244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/28/2024]
Abstract
Inherited retinal diseases (IRD) are a leading cause of blindness in the working age population and in children. The scope of this review is to familiarise clinicians and scientists with the current landscape of molecular genetics, clinical phenotype, retinal imaging and therapeutic prospects/completed trials in IRD. Herein we present in a comprehensive and concise manner: (i) macular dystrophies (Stargardt disease (ABCA4), X-linked retinoschisis (RS1), Best disease (BEST1), PRPH2-associated pattern dystrophy, Sorsby fundus dystrophy (TIMP3), and autosomal dominant drusen (EFEMP1)), (ii) cone and cone-rod dystrophies (GUCA1A, PRPH2, ABCA4, KCNV2 and RPGR), (iii) predominant rod or rod-cone dystrophies (retinitis pigmentosa, enhanced S-Cone syndrome (NR2E3), Bietti crystalline corneoretinal dystrophy (CYP4V2)), (iv) Leber congenital amaurosis/early-onset severe retinal dystrophy (GUCY2D, CEP290, CRB1, RDH12, RPE65, TULP1, AIPL1 and NMNAT1), (v) cone dysfunction syndromes (achromatopsia (CNGA3, CNGB3, PDE6C, PDE6H, GNAT2, ATF6), X-linked cone dysfunction with myopia and dichromacy (Bornholm Eye disease; OPN1LW/OPN1MW array), oligocone trichromacy, and blue-cone monochromatism (OPN1LW/OPN1MW array)). Whilst we use the aforementioned classical phenotypic groupings, a key feature of IRD is that it is characterised by tremendous heterogeneity and variable expressivity, with several of the above genes associated with a range of phenotypes.
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Affiliation(s)
- Michalis Georgiou
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Anthony G Robson
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Kaoru Fujinami
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan.
| | - Thales A C de Guimarães
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Yu Fujinami-Yokokawa
- UCL Institute of Ophthalmology, University College London, London, United Kingdom; Laboratory of Visual Physiology, Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan; Department of Health Policy and Management, Keio University School of Medicine, Tokyo, Japan.
| | - Malena Daich Varela
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Nikolas Pontikos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Angelos Kalitzeos
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Omar A Mahroo
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom; Section of Ophthalmology, King s College London, St Thomas Hospital Campus, London, United Kingdom; Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, United Kingdom; Department of Translational Ophthalmology, Wills Eye Hospital, Philadelphia, PA, USA.
| | - Andrew R Webster
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Michel Michaelides
- Moorfields Eye Hospital, London, United Kingdom; UCL Institute of Ophthalmology, University College London, London, United Kingdom.
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Surl D, Won D, Lee ST, Lee CS, Lee J, Lim HT, Chung SA, Song WK, Kim M, Kim SS, Shin S, Choi JR, Sangermano R, Byeon SH, Bujakowska KM, Han J. Clinician-Driven Reanalysis of Exome Sequencing Data From Patients With Inherited Retinal Diseases. JAMA Netw Open 2024; 7:e2414198. [PMID: 38819824 PMCID: PMC11143468 DOI: 10.1001/jamanetworkopen.2024.14198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 03/18/2024] [Indexed: 06/01/2024] Open
Abstract
Importance Despite advances in next-generation sequencing (NGS), a significant proportion of patients with inherited retinal disease (IRD) remain undiagnosed after initial genetic testing. Exome sequencing (ES) reanalysis in the clinical setting has been suggested as one method for improving diagnosis of IRD. Objective To investigate the association of clinician-led reanalysis of ES data, which incorporates updated clinical information and comprehensive bioinformatic analysis, with the diagnostic yield in a cohort of patients with IRDs in Korea. Design, Setting, and Participants This was a multicenter prospective cohort study involving 264 unrelated patients with IRDs, conducted in Korea between March 2018 and February 2020. Comprehensive ophthalmologic examinations and ES analyses were performed, and ES data were reanalyzed by an IRD specialist for single nucleotide variants, copy number variants, mobile element insertions, and mitochondrial variants. Data were analyzed from March to July 2023. Main Outcomes and Measures Diagnostic rate of conventional bioinformatic analysis and clinician-driven ES reanalysis. Results A total of 264 participants (151 [57.2%] male; mean [SD] age at genetic testing, 33.6 [18.9] years) were enrolled, including 129 patients (48.9%) with retinitis pigmentosa and 26 patients (9.8%) with Stargardt disease or macular dystrophy. Initial bioinformatic analysis diagnosed 166 patients (62.9%). Clinician-driven reanalysis identified the molecular cause of diseases in an additional 22 patients, corresponding to an 8.3-percentage point increase in diagnostic rate. Key factors associated with new molecular diagnoses included clinical phenotype updates (4 patients) and detection of previously overlooked variation, such as structural variants (9 patients), mitochondrial variants (3 patients), filtered or not captured variants (4 patients), and noncanonical splicing variants (2 patients). Among the 22 patients, variants in 7 patients (31.8%) were observed in the initial analysis but not reported to patients, while those in the remaining 15 patients (68.2%) were newly detected by the ES reanalysis. Conclusions and Relevance In this cohort study, clinician-centered reanalysis of ES data was associated with improved molecular diagnostic yields in patients with IRD. This approach is important for uncovering missed genetic causes of retinal disease.
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Affiliation(s)
- Dongheon Surl
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Dongju Won
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Seung-Tae Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Christopher Seungkyu Lee
- Institute of Vision Research, Severance Hospital, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea
| | - Junwon Lee
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | | | - Seung Ah Chung
- Department of Ophthalmology, Ajou University School of Medicine, Suwon, South Korea
| | | | - Min Kim
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Sung Soo Kim
- Institute of Vision Research, Severance Hospital, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea
| | - Saeam Shin
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Jong Rak Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
| | - Riccardo Sangermano
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston
| | - Suk Ho Byeon
- Institute of Vision Research, Severance Hospital, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, South Korea
| | - Kinga M. Bujakowska
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston
| | - Jinu Han
- Institute of Vision Research, Department of Ophthalmology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston
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Williams BN, Draper A, Lang PF, Lewis TR, Smith AL, Mayerl SJ, Rougié M, Simon JM, Arshavsky VY, Greenwald SH, Gamm DM, Pinilla I, Philpot BD. Heterogeneity in the progression of retinal pathologies in mice harboring patient mimicking Impg2 mutations. Hum Mol Genet 2024; 33:448-464. [PMID: 37975905 PMCID: PMC10877459 DOI: 10.1093/hmg/ddad199] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 11/19/2023] Open
Abstract
Biallelic mutations in interphotoreceptor matrix proteoglycan 2 (IMPG2) in humans cause retinitis pigmentosa (RP) with early macular involvement, albeit the disease progression varies widely due to genetic heterogeneity and IMPG2 mutation type. There are currently no treatments for IMPG2-RP. To aid preclinical studies toward eventual treatments, there is a need to better understand the progression of disease pathology in appropriate animal models. Toward this goal, we developed mouse models with patient mimicking homozygous frameshift (T807Ter) or missense (Y250C) Impg2 mutations, as well as mice with a homozygous frameshift mutation (Q244Ter) designed to completely prevent IMPG2 protein expression, and characterized the trajectory of their retinal pathologies across postnatal development until late adulthood. We found that the Impg2T807Ter/T807Ter and Impg2Q244Ter/Q244Ter mice exhibited early onset gliosis, impaired photoreceptor outer segment maintenance, appearance of subretinal deposits near the optic disc, disruption of the outer retina, and neurosensorial detachment, whereas the Impg2Y250C/Y250C mice exhibited minimal retinal pathology. These results demonstrate the importance of mutation type in disease progression in IMPG2-RP and provide a toolkit and preclinical data for advancing therapeutic approaches.
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Affiliation(s)
- Brittany N Williams
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, United States
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, United States
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Adam Draper
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, United States
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Patrick F Lang
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, United States
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Tylor R Lewis
- Department of Ophthalmology, Duke University, Durham, NC 27705, United States
| | - Audrey L Smith
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, United States
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Steven J Mayerl
- Department of Ophthalmology and Visual Sciences, McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Marie Rougié
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, United States
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Jeremy M Simon
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, United States
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599, United States
| | - Vadim Y Arshavsky
- Department of Ophthalmology, Duke University, Durham, NC 27705, United States
| | | | - David M Gamm
- Department of Ophthalmology and Visual Sciences, McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Isabel Pinilla
- Department of Ophthalmology, Lozano Blesa University Hospital, Zaragoza 50009, Spain
- Aragón Health Research Institute (IIS Aragón), Zaragoza 50009, Spain
- Department of Surgery, University of Zaragoza, Zaragoza 50009, Spain
| | - Benjamin D Philpot
- Neuroscience Center, University of North Carolina, Chapel Hill, NC 27599, United States
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC 27599, United States
- Carolina Institute for Developmental Disabilities, University of North Carolina, Chapel Hill, NC 27599, United States
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5
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Nipp GE, Lee T, Sarici K, Malek G, Hadziahmetovic M. Adult-onset foveomacular vitelliform dystrophy: epidemiology, pathophysiology, imaging, and prognosis. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1237788. [PMID: 38983024 PMCID: PMC11182240 DOI: 10.3389/fopht.2023.1237788] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 07/25/2023] [Indexed: 07/11/2024]
Abstract
Adult-onset foveomacular dystrophy (AOFVD) is a retinal pattern dystrophy that may affect up to 1 in 7,400 individuals. There is much that is unknown regarding this disease's epidemiology, risk factors for development, and rate of progression through its four stages. Advancements in retinal imaging over the past 15 years have enabled improved characterization of the different stages of AOFVD. These imaging advancements also offer new ways of differentiating AOFVD from phenotypically similar retinal diseases like age-related macular degeneration and Best disease. This review synthesizes the most recent discoveries regarding imaging correlates within AOFVD as well as risk factors for the development of AOFVD, complications of AOFVD, and treatment options. Our aim is to provide ophthalmologists a succinct resource so that they may offer clarity, guidance, and appropriate monitoring and treatments for their patients with suspected AOFVD.
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Affiliation(s)
- Grace E Nipp
- School of Medicine, Duke University, Durham, NC, United States
| | - Terry Lee
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, United States
| | - Kubra Sarici
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, United States
| | - Goldis Malek
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, United States
- Department of Pathology, Duke University Medical Center, Durham, NC, United States
| | - Majda Hadziahmetovic
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, United States
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Jahrig C, Ku CA, Marra M, Pennesi ME, Yang P. Vitelliform maculopathy in MELAS syndrome. Am J Ophthalmol Case Rep 2023; 30:101842. [PMID: 37096132 PMCID: PMC10121376 DOI: 10.1016/j.ajoc.2023.101842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 03/01/2023] [Accepted: 04/02/2023] [Indexed: 04/26/2023] Open
Abstract
Purpose We present a unique case of foveomacular vitelliform lesions in a patient with metabolic encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS). Observations After performing large panel next generation sequencing genetic testing, there was no likely alternative genetic etiology for vitelliform maculopathy in this patient. Conclusions and Importance We present a rare case of a visually asymptomatic pediatric patient with MELAS and vitelliform maculopathy, which may be part of the spectrum of retinal manifestations in MELAS. Pediatric-onset vitelliform maculopathy in MELAS may be under-diagnosed due to its asymptomatic nature. Given the known risk of choroidal neovascularization in vitelliform maculopathy, it is important to identify these patients for proper surveillance.
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Affiliation(s)
- Cody Jahrig
- Department of Medicine, Nassau University Medical Center, East Meadow, NY, United States
| | - Cristy A. Ku
- Department of Ophthalmology, University of California Davis, Sacramento, CA, United States
| | - Molly Marra
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University (OHSU), Portland, OR, United States
| | - Mark E. Pennesi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University (OHSU), Portland, OR, United States
| | - Paul Yang
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University (OHSU), Portland, OR, United States
- Corresponding author. Casey Eye Institute, 545 SW Campus Drive, Portland, OR, 97239, United States.
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Sharkova M, Chow E, Erickson T, Hocking JC. The morphological and functional diversity of apical microvilli. J Anat 2023; 242:327-353. [PMID: 36281951 PMCID: PMC9919547 DOI: 10.1111/joa.13781] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/03/2022] [Accepted: 10/05/2022] [Indexed: 11/30/2022] Open
Abstract
Sensory neurons use specialized apical processes to perceive external stimuli and monitor internal body conditions. The apical apparatus can include cilia, microvilli, or both, and is adapted for the functions of the particular cell type. Photoreceptors detect light through a large, modified cilium (outer segment), that is supported by a surrounding ring of microvilli-like calyceal processes (CPs). Although first reported 150 years ago, CPs remain poorly understood. As a basis for future study, we therefore conducted a review of existing literature about sensory cell microvilli, which can act either as the primary sensory detector or as support for a cilia-based detector. While all microvilli are finger-like cellular protrusions with an actin core, the processes vary across cell types in size, number, arrangement, dynamics, and function. We summarize the current state of knowledge about CPs and the characteristics of the microvilli found on inner ear hair cells (stereocilia) and cerebral spinal fluid-contacting neurons, with comparisons to the brush border of the intestinal and renal epithelia. The structure, stability, and dynamics of the actin core are regulated by a complement of actin-binding proteins, which includes both common components and unique features when compared across cell types. Further, microvilli are often supported by lateral links, a glycocalyx, and a defined extracellular matrix, each adapted to the function and environment of the cell. Our comparison of microvillar features will inform further research into how CPs support photoreceptor function, and also provide a general basis for investigations into the structure and functions of apical microvilli found on sensory neurons.
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Affiliation(s)
- Maria Sharkova
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Erica Chow
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Timothy Erickson
- Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Jennifer C Hocking
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Division of Anatomy, Department of Surgery, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.,Women and Children's Health Research Institute, University of Alberta, Edmonton, Alberta, Canada
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Serjanov D, Hyde DR. Extracellular Matrix: The Unexplored Aspects of Retinal Pathologies and Regeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:309-317. [PMID: 37440050 DOI: 10.1007/978-3-031-27681-1_45] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Nearly a billion people worldwide are affected by vision-impairing conditions, with retinal degenerative diseases being a major cause of blindness. Unfortunately, such diseases are often permanent and progressive, resulting in further degeneration and loss of sight, due to the human retina possessing little, if any, regenerative capacity. Despite numerous efforts and great progress being made to understand the molecular mechanisms of these diseases and possible therapies, the majority of investigations focused on cell-intrinsic factors. However, the microenvironment surrounding retinal cells throughout these processes also plays an important role, though our current understanding of its involvement remains limited. Here we present a brief overview of the current state of the field of extracellular matrix studies within the retina and its potential roles in retinal diseases and potential therapeutic approaches.
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Affiliation(s)
- Dmitri Serjanov
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - David R Hyde
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA.
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Mitchell B, Coulter C, Geldenhuys WJ, Rhodes S, Salido EM. Interphotoreceptor matrix proteoglycans IMPG1 and IMPG2 proteolyze in the SEA domain and reveal localization mutual dependency. Sci Rep 2022; 12:15535. [PMID: 36109576 PMCID: PMC9478142 DOI: 10.1038/s41598-022-19910-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 09/06/2022] [Indexed: 11/08/2022] Open
Abstract
The interphotoreceptor matrix (IPM) is a specialized extracellular mesh of molecules surrounding the inner and outer segments of photoreceptor neurons. Interphotoreceptor matrix proteoglycan 1 and 2 (IMPG1 and IMPG2) are major components of the IPM. Both proteoglycans possess SEA (sperm protein, enterokinase and agrin) domains, which may support proteolysis. Interestingly, mutations in the SEA domains of IMPG1 and IMPG2 are associated with vision disease in humans. However, if SEA domains in IMPG molecules undergo proteolysis, and how this contributes to vision pathology is unknown. Therefore, we investigated SEA-mediated proteolysis of IMPG1 and IMPG2 and its significance to IPM physiology. Immunoblot analysis confirmed proteolysis of IMPG1 and IMPG2 in the retinas of wildtype mice. Point mutations mimicking human mutations in the SEA domain of IMPG1 that are associated with vision disease inhibited proteolysis. These findings demonstrate that proteolysis is part of the maturation of IMPG1 and IMPG2, in which deficits are associated with vision diseases. Further, immunohistochemical assays showed that proteolysis of IMPG2 generated two subunits, a membrane-attached peptide and an extracellular peptide. Notably, the extracellular portion of IMPG2 trafficked from the IPM around the inner segment toward the outer segment IPM by an IMPG1-dependent mechanism. This result provides the first evidence of a trafficking system that shuttles IMPG1 and IMPG2 from the inner to outer IPM in a co-dependent manner. In addition, these results suggest an interaction between IMPG1-IMPG2 and propose that mutations affecting one IMPG could affect the localization of the normal IMPG partner, contributing to the disease mechanism of vision diseases associated with defective IMPG molecules.
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Affiliation(s)
- Benjamin Mitchell
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV, USA
| | - Chloe Coulter
- Undergraduate Program in Biochemistry, West Virginia University, Morgantown, WV, USA
| | - Werner J Geldenhuys
- Department of Neuroscience, School of Medicine, West Virginia University, Morgantown, WV, USA
- Department of Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV, USA
| | - Scott Rhodes
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV, USA
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV, USA
| | - Ezequiel M Salido
- Department of Ophthalmology and Visual Sciences, West Virginia University, Morgantown, WV, USA.
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV, USA.
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Lee W, Su PY, Zernant J, Nagasaki T, Tsang SH, Allikmets R. Longitudinal Analysis of a Resolving Foveomacular Vitelliform Lesion in ABCA4 Disease. Ophthalmol Retina 2022; 6:847-860. [PMID: 35413457 PMCID: PMC9464664 DOI: 10.1016/j.oret.2022.04.005] [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: 02/01/2022] [Revised: 03/27/2022] [Accepted: 04/05/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE To describe the longitudinal progression and phenotypic association of bilateral foveomacular vitelliform lesions in the setting of ABCA4 disease. DESIGN Case report and cross-sectional cohort study. PARTICIPANTS Nineteen patients with confirmed ABCA4 disease exhibiting an optical gap phenotype. METHODS Multimodal retinal imaging across multiple visits included autofluorescence imaging, spectral-domain OCT (SD-OCT), and OCT angiography. Electro-oculogram (EOG) and full-field electroretinogram testing results were analyzed. Exome sequencing was performed for diagnostic confirmation and the verification of other variations. MAIN OUTCOME MEASURES Light-peak-to-dark-trough ratio (Arden ratio) on EOG; thickness and en face maps of various retinal layers on SD-OCT; area measurements on 488- and 787-nm autofluorescence images; and the presence of variation in vitelliform-associated genes identified using exome sequencing. RESULTS A 25-year-old White man presented with bilateral central vision loss due to foveal lesions consisting of vitelliform fluid. The result of EOG testing was inconsistent with bestrophinopathy (Arden ratio = 1.62), and no generalized rod or cone dysfunction was detected on full-field electroretinogram. Exome sequencing identified the pathogenic variants c.5882G>A (p.(Gly1961Glu)) and c.4139C>T (p.(Pro1380Leu)) in ABCA4 and no other vitelliform-associated genes. Significant thinning and abnormal reflectivity of photoreceptor-attributable layers as well as near-infrared autofluorescence abnormalities were found in lesion-adjacent areas. Complete resorption of the vitelliform fluid occurred after 30 months, after which the optical gap lesions exhibited an enlarged and "cavitated" appearance. Phenotypic screening for additional cases from a large ABCA4 disease database (n = 602) identified 18 additional patients at various stages of optical gap lesion formation, most of whom harbored the c.5882G>A (p.(Gly1961Glu)) variant (P < 0.001), although none had apparent vitelliform fluid. At least 5 of the 18 (31.6%) patients exhibited optical gap lesions with the distinct "cavitated" appearance, whereas the lesions remained unperturbed in the other patients over the course of examination. CONCLUSIONS Foveomacular vitelliform deposition is a mechanistically congruent but rare manifestation of ABCA4 disease. Specifically, this disease phenotype may be clinically associated with the c.5882G>A (p.(Gly1961Glu)) allele and optical gap lesions.
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Affiliation(s)
- Winston Lee
- Department of Genetics & Development, Columbia University, New York, New York; Department of Ophthalmology, Columbia University, New York, New York
| | - Pei-Yin Su
- Department of Ophthalmology, Columbia University, New York, New York
| | - Jana Zernant
- Department of Ophthalmology, Columbia University, New York, New York
| | - Takayuki Nagasaki
- Department of Ophthalmology, Columbia University, New York, New York
| | - Stephen H Tsang
- Department of Genetics & Development, Columbia University, New York, New York; Department of Pathology & Cell Biology, Columbia University, New York, New York
| | - Rando Allikmets
- Department of Genetics & Development, Columbia University, New York, New York; Department of Pathology & Cell Biology, Columbia University, New York, New York.
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11
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Wang Z, Huang X, Lv X, Chen C, Qu S, Ma X, Zhang L, Bi Y. Bioinformatic analysis identifies potential key genes in the pathogenesis of age-related macular degeneration. Indian J Ophthalmol 2022; 70:3347-3355. [PMID: 36018119 PMCID: PMC9675553 DOI: 10.4103/ijo.ijo_3211_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 04/05/2022] [Accepted: 05/19/2022] [Indexed: 11/05/2022] Open
Abstract
Purpose Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in older individuals. More studies focused on screening the genes, which may be correlated with the development of AMD. With advances in various technologies like multiple microarray datasets, researchers could identify differentially expressed genes (DEGs) more accurately. Exploring abnormal gene expression in disease status can help to understand pathophysiological changes in complex diseases. This study aims to identify the key genes and upstream regulators in AMD and reveal factors, especially genetic association, and the prognosis of the development of this disease. Methods Data from expression profile GSE125564 and profile GSE29801 were obtained from the Gene Expression Omnibus (GEO) database. We analyzed DEGs using R software (version 3.6.3). Functional enrichment and PPI network analysis were performed using the R package and online database STRING (version 11.0). Results We compared AMD with normal and found 68 up-regulated genes (URGs) and 25 down-regulated genes (DRGs). We also compared wet AMD with dry AMD and found 41 DRGs in dry AMD. Further work including PPI network analysis, GO classification, and KEGG analysis was done to find connections with AMD. The URGs were mainly enriched in the biological process such as DNA replication, nucleoplasm, extracellular exosome, and cadherin binding. Besides, DRGs were mainly enriched in these functions such as an integral component of membrane and formation of the blood-aqueous barrier (BAB). Conclusion This study implied that core genes might involve in the process of AMD. Our findings may contribute to revealing the pathogenesis, developing new biomarkers, and raising strategies of treatment for AMD.
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Affiliation(s)
- Zhiyue Wang
- Department of Ophthalmology, Tongji Hospital Affiliated with Tongji University School of Medicine, Shanghai, China
| | - Xinyu Huang
- Department of Ophthalmology, Tongji Hospital Affiliated with Tongji University School of Medicine, Shanghai, China
| | - Xiao Lv
- Department of Ophthalmology, Tongji Hospital Affiliated with Tongji University School of Medicine, Shanghai, China
| | - Chao Chen
- Department of Ophthalmology, Tongji Hospital Affiliated with Tongji University School of Medicine, Shanghai, China
| | - Shen Qu
- Department of Ophthalmology, Tongji Hospital Affiliated with Tongji University School of Medicine, Shanghai, China
| | - Xiaoyu Ma
- Department of Ophthalmology, Tongji Hospital Affiliated with Tongji University School of Medicine, Shanghai, China
| | - Li Zhang
- Department of Ophthalmology, Tongji Hospital Affiliated with Tongji University School of Medicine, Shanghai, China
| | - Yanlong Bi
- Department of Ophthalmology, Tongji Hospital Affiliated with Tongji University School of Medicine, Shanghai, China
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12
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SPACR Encoded by IMPG1 Is Essential for Photoreceptor Survival by Interplaying between the Interphotoreceptor Matrix and the Retinal Pigment Epithelium. Genes (Basel) 2022; 13:genes13091508. [PMID: 36140676 PMCID: PMC9498744 DOI: 10.3390/genes13091508] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/18/2022] [Accepted: 08/21/2022] [Indexed: 11/20/2022] Open
Abstract
Several pathogenic variants have been reported in the IMPG1 gene associated with the inherited retinal disorders vitelliform macular dystrophy (VMD) and retinitis pigmentosa (RP). IMPG1 and its paralog IMPG2 encode for two proteoglycans, SPACR and SPACRCAN, respectively, which are the main components of the interphotoreceptor matrix (IPM), the extracellular matrix surrounding the photoreceptor cells. To determine the role of SPACR in the pathological mechanisms leading to RP and VMD, we generated a knockout mouse model lacking Impg1, the mouse ortholog. Impg1-deficient mice show abnormal accumulation of autofluorescent deposits visible by fundus imaging and spectral-domain optical coherence tomography (SD-OCT) and attenuated electroretinogram responses from 9 months of age. Furthermore, SD-OCT of Impg1−/− mice shows a degeneration of the photoreceptor layer, and transmission electron microscopy shows a disruption of the IPM and the retinal pigment epithelial cells. The decrease in the concentration of the chromophore 11-cis-retinal supports this loss of photoreceptors. In conclusion, our results demonstrate the essential role of SPACR in maintaining photoreceptors. Impg1−/− mice provide a novel model for mechanistic investigations and the development of therapies for VMD and RP caused by IMPG1 pathogenic variants.
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Vázquez-Domínguez I, Li CHZ, Fadaie Z, Haer-Wigman L, Cremers FPM, Garanto A, Hoyng CB, Roosing S. Identification of a Complex Allele in IMPG2 as a Cause of Adult-Onset Vitelliform Macular Dystrophy. Invest Ophthalmol Vis Sci 2022; 63:27. [PMID: 35608844 PMCID: PMC9150824 DOI: 10.1167/iovs.63.5.27] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 04/21/2022] [Indexed: 12/25/2022] Open
Abstract
Purpose Inherited retinal diseases are a group of clinically and genetically heterogeneous disorders with approximately 270 genes involved. IMPG2 is associated with adult-onset vitelliform macular dystrophy. Here, we investigated two unrelated patients with vitelliform macular dystrophy to identify the underlying genetic cause. Methods Whole-exome sequencing identified a putative causal complex allele consisting of c.3023-15T>A and c.3023G>A (p.(Gly1008Asp)) in IMPG2 in both individuals. To assess its effect, in vitro splice assays in HEK293T and further characterization in patient-derived photoreceptor precursor cells (PPCs) were conducted. Results The results of the midigene splice assays in HEK293T showed that the complex allele causes a variety of splicing defects ranging from a small deletion to (multiple-)exon skipping. This finding was further validated using patient-derived PPCs that showed a significant increase of out-of-frame transcripts lacking one or multiple exons compared to control-derived PPCs. Overall, control PPCs consistently showed low levels of aberrantly spliced IMPG2 transcripts that were highly elevated in patient-derived PPCs. These differences were even more obvious upon inhibition of nonsense-mediated decay with cycloheximide. Conclusions We report a heterozygous complex allele in IMPG2 causative for adult-onset vitelliform macular dystrophy in two unrelated individuals with mild visual loss and bilateral vitelliform lesions. The predicted causal missense mutation c.3023G>A, located in the consensus splice acceptor site, enhances the splicing effect of the upstream variant c.3023-15T>A, leading to the generation of aberrant transcripts that decrease the full-length IMPG2 levels. These results suggest a haploinsufficiency mechanism of action and highlight the complementarity of using different models to functionally assesses splicing defects.
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Affiliation(s)
- Irene Vázquez-Domínguez
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Catherina H. Z. Li
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Zeinab Fadaie
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Lonneke Haer-Wigman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Frans P. M. Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Alejandro Garanto
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Pediatrics, Amalia Children's Hospital and Radboud Institute of Molecular Life Sciences (RIMLS), Radboud University Medical Center, Nijmegen, the Netherlands
| | - Carel B. Hoyng
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Susanne Roosing
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
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14
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Chatterjee S, Gupta S, Chaudhry VN, Chaudhry P, Mukherjee A, Mutsuddi M. Whole exome sequencing identifies a novel splice-site mutation in IMPG2 gene causing Stargardt-like juvenile macular dystrophy in a north Indian family. Gene 2022; 816:146158. [PMID: 34990796 DOI: 10.1016/j.gene.2021.146158] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 12/10/2021] [Indexed: 12/01/2022]
Abstract
We report on the genetic analysis of a north Indian family affected with Stargardt-like juvenile macular dystrophy. Considering an autosomal recessive inheritance of macular dystrophy in the recruited family, whole exome sequencing was employed in two affected siblings and their mother. We have identified a novel splice-site variant NC_000003.11(NM_016247.3):c.1239 + 1G > T, co-segregating in the affected siblings, in the Interphotoreceptor Matrix Proteoglycan 2 (IMPG2) gene. The identified variant is present immediately after exon 11, and is predicted to disrupt the wild-type donor splice-site of IMPG2 transcripts. We confirmed the splice-site changes in the IMPG2 transcripts using minigene functional assay. Although a number of studies on IMPG2 have demonstrated its involvement in retinitis pigmentosa and vitelliform macular dystrophy, this is the first report of a splice-site variant in IMPG2 that is responsible for Stargardt-like juvenile macular dystrophy.
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Affiliation(s)
- Souradip Chatterjee
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Shashank Gupta
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | | | | | - Ashim Mukherjee
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi 221005, India
| | - Mousumi Mutsuddi
- Department of Molecular and Human Genetics, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
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15
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Lofaro FD, Mucciolo DP, Murro V, Pavese L, Quaglino D, Boraldi F. A Case Report of Pseudoxanthoma Elasticum with Rare Sequence Variants in Genes Related to Inherited Retinal Diseases. Diagnostics (Basel) 2021; 11:diagnostics11101800. [PMID: 34679498 PMCID: PMC8534466 DOI: 10.3390/diagnostics11101800] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/17/2021] [Accepted: 09/27/2021] [Indexed: 01/11/2023] Open
Abstract
A case of a patient with an early and severe visual impairment is described. Due to the occurrence of skin papules a suspect of pseudoxanthoma elasticum (PXE) was posed. PXE is a rare autosomal recessive disease clinically characterized by skin, cardiovascular and ocular manifestations, these last being those that most severely affect patients’ quality of life. A whole exome sequencing approach focusing on 340 genes related to the calcification process and/or to inherited retinal diseases (IRDs) was performed. Rare monoallelic sequence variants in ABCA4, ABCC6, IMPG1, POC1B and RAX2 were found. The presence of calcified elastic fibers was assessed by ultrastructural analysis on a skin biopsy. Diagnosis of PXE was based on clinical, biomolecular and morphological results, although the additional involvement of several IRD genes is important to explain the unexpectedly severe ophthalmological phenotype of the patient also in prognostic and therapeutic perspectives. Data indicate that genetic screening using a wide-spectrum analysis approach is essential to assist ophthalmologists in improving patient counseling.
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Affiliation(s)
- Francesco Demetrio Lofaro
- Department of Life Science, University of Modena and Reggio Emilia, 41125 Modena, Italy; (F.D.L.); (D.Q.)
| | - Dario Pasquale Mucciolo
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Eye Clinic, 50139 Florence, Italy; (D.P.M.); (V.M.); (L.P.)
| | - Vittoria Murro
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Eye Clinic, 50139 Florence, Italy; (D.P.M.); (V.M.); (L.P.)
| | - Laura Pavese
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Eye Clinic, 50139 Florence, Italy; (D.P.M.); (V.M.); (L.P.)
| | - Daniela Quaglino
- Department of Life Science, University of Modena and Reggio Emilia, 41125 Modena, Italy; (F.D.L.); (D.Q.)
| | - Federica Boraldi
- Department of Life Science, University of Modena and Reggio Emilia, 41125 Modena, Italy; (F.D.L.); (D.Q.)
- Correspondence:
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16
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Gupta MP, Brodie SE, Freund KB. UNUSUAL EARLY-ONSET VITELLIFORM DYSTROPHY POSSIBLY LINKED TO THE INTERPHOTORECEPTOR MATRIX PROTEOGLYCAN-1 P.LEU154PRO MUTATION. Retin Cases Brief Rep 2021; 15:527-531. [PMID: 30688845 DOI: 10.1097/icb.0000000000000843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
PURPOSE To describe a case of symptomatic outer retinal disruption in a patient heterozygous for the p.Leu154Pro interphotoreceptor matrix proteoglycan-1 (IMPG1) mutation implicated in adult-onset foveomacular vitelliform dystrophy. METHODS Observational case report. RESULTS We describe a case of a 25-year-old female patient with symptomatic scotoma and vision decrease who exhibited bilateral small foveal yellow spots. Optical coherence tomography revealed disorganization and decreased reflectance of the foveal ellipsoid and interdigitation zones in the left eye more than in the right eye. Fundus autofluorescence imaging showed minimal findings, and dye angiography was unrevealing. Multifocal electroretinogram revealed slightly decreased retinal sensitivity in the central retina of the left eye. Genetic testing identified a heterozygous p.Leu154Pro mutation in the IMPG1 gene. CONCLUSION The p.Leu154Pro IMPG1 mutation may cause symptomatic outer retinal disturbance in the heterozygous state. Further studies are necessary.
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Affiliation(s)
- Mrinali P Gupta
- Department of Ophthalmology, Weill Cornell Medical College, New York, New York
| | - Scott E Brodie
- Department of Ophthalmology, NYU School of Medicine, New York, New York
| | - K Bailey Freund
- Vitreous Retina Macual Consultants of New York, New York, New York; and
- LuEster T. Mertz Retinal Research Center, Manhattan Eye, Ear, and Throat Hospital, New York, New York
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17
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Durán A, Rebolledo-Jaramillo B, Olguin V, Rojas-Herrera M, Las Heras M, Calderón JF, Zanlungo S, Priestman DA, Platt FM, Klein AD. Identification of genetic modifiers of murine hepatic β-glucocerebrosidase activity. Biochem Biophys Rep 2021; 28:101105. [PMID: 34458595 PMCID: PMC8379285 DOI: 10.1016/j.bbrep.2021.101105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 12/18/2022] Open
Abstract
The acid β-glucocerebrosidase (GCase) enzyme cleaves glucosylceramide into glucose and ceramide. Loss of function variants in the gene encoding for GCase can lead to Gaucher disease and Parkinson's disease. Therapeutic strategies aimed at increasing GCase activity by targeting a modulating factor are attractive and poorly explored. To identify genetic modifiers, we measured hepatic GCase activity in 27 inbred mouse strains. A genome-wide association study (GWAS) using GCase activity as a trait identified several candidate modifier genes, including Dmrtc2 and Arhgef1 (p=2.1x10−7), and Grik5 (p=2.1x10−7). Bayesian integration of the gene mapping with transcriptomics was used to build integrative networks. The analysis uncovered additional candidate GCase regulators, highlighting modules of the acute phase response (p=1.01x10−8), acute inflammatory response (p=1.01x10−8), fatty acid beta-oxidation (p=7.43x10−5), among others. Our study revealed previously unknown candidate modulators of GCase activity, which may facilitate the design of therapies for diseases with GCase dysfunction. Hepatic GCase activity significantly differs among mouse strains. Genome-wide association study revealed putative modifier genes of GCase activity. Bayesian integration of multi-omics identified a regulatory network of GCase activity. This study may facilitate the design of therapies for diseases with GCase dysfunction.
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Affiliation(s)
- Anyelo Durán
- Centro de Genética y Genómica, Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Boris Rebolledo-Jaramillo
- Centro de Genética y Genómica, Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Valeria Olguin
- Centro de Genética y Genómica, Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Marcelo Rojas-Herrera
- Centro de Genética y Genómica, Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Macarena Las Heras
- Centro de Genética y Genómica, Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Juan F Calderón
- Centro de Genética y Genómica, Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Silvana Zanlungo
- Department of Gastroenterology, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - David A Priestman
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - Andrés D Klein
- Centro de Genética y Genómica, Facultad de Medicina, Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
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18
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Olivier G, Corton M, Intartaglia D, Verbakel SK, Sergouniotis PI, Le Meur G, Dhaenens CM, Naacke H, Avila-Fernández A, Hoyng CB, Klevering J, Bocquet B, Roubertie A, Sénéchal A, Banfi S, Muller A, Hamel CL, Black GC, Conte I, Roosing S, Zanlonghi X, Ayuso C, Meunier I, Manes G. Pathogenic variants in IMPG1 cause autosomal dominant and autosomal recessive retinitis pigmentosa. J Med Genet 2021; 58:570-578. [PMID: 32817297 DOI: 10.1136/jmedgenet-2020-107150] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 06/09/2020] [Accepted: 06/24/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND Inherited retinal disorders are a clinically and genetically heterogeneous group of conditions and a major cause of visual impairment. Common disease subtypes include vitelliform macular dystrophy (VMD) and retinitis pigmentosa (RP). Despite the identification of over 90 genes associated with RP, conventional genetic testing fails to detect a molecular diagnosis in about one third of patients with RP. METHODS Exome sequencing was carried out for identifying the disease-causing gene in a family with autosomal dominant RP. Gene panel testing and exome sequencing were performed in 596 RP and VMD families to identified additional IMPG1 variants. In vivo analysis in the medaka fish system by knockdown assays was performed to screen IMPG1 possible pathogenic role. RESULTS Exome sequencing of a family with RP revealed a splice variant in IMPG1. Subsequently, the same variant was identified in individuals from two families with either RP or VMD. A retrospective study of patients with RP or VMD revealed eight additional families with different missense or nonsense variants in IMPG1. In addition, the clinical diagnosis of the IMPG1 retinopathy-associated variant, originally described as benign concentric annular macular dystrophy, was also revised to RP with early macular involvement. Using morpholino-mediated ablation of Impg1 and its paralog Impg2 in medaka fish, we confirmed a phenotype consistent with that observed in the families, including a decreased length of rod and cone photoreceptor outer segments. CONCLUSION This study discusses a previously unreported association between monoallelic or biallelic IMPG1 variants and RP. Notably, similar observations have been reported for IMPG2.
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Affiliation(s)
- Guillaume Olivier
- Institute for Neurosciences of Montpellier, University of Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier, France
| | - Marta Corton
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM)-Center for Biomedical Network Research on Rare Diseases-(CIBERER), Madrid, Spain
| | - Daniela Intartaglia
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Telethon Institute of Genetics and Medicine, Pozzuoli (NA), and Medical Genetics, Naples, Italy
| | - Sanne K Verbakel
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Panagiotis I Sergouniotis
- Manchester Royal Eye Hospital, Manchester Academic Health Science Centre, Central Manchester NHS Foundation Trust, Manchester Royal Eye Hospital, Manchester, M13 9WL, UK
| | - Guylène Le Meur
- Service Ophtalmologie, CHU Nantes, Nantes Université, Nantes, France
| | - Claire-Marie Dhaenens
- University Lille-Nord de France, INSERM U837, Lille, France
- Lille Neuroscience & Cognition, LilNCog, Lille, France
| | - Hélène Naacke
- Service d'ophtalmologie, Clinique Saint Joseph, Angouleme, Nouvelle Aquitaine, France
| | - Almudena Avila-Fernández
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM)-Center for Biomedical Network Research on Rare Diseases-(CIBERER), Madrid, Spain
| | - Carel B Hoyng
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jeroen Klevering
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Béatrice Bocquet
- Institute for Neurosciences of Montpellier, University of Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier, France
| | - Agathe Roubertie
- Département de Neuropédiatrie, CHU Montpellier, Hôpital Gui de Chauliac, Montpellier, Hérault, France
- Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier, Hérault, France
| | - Audrey Sénéchal
- Institute for Neurosciences of Montpellier, University of Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier, France
| | - Sandro Banfi
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Telethon Institute of Genetics and Medicine, Naples, Italy
| | - Agnès Muller
- Institute for Neurosciences of Montpellier, University of Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier, France
| | - Christian L Hamel
- Service d'ophtalmologie, Hôpital Gui de Chauliac, CHU Montpellier, Montpellier, France
| | - Graeme C Black
- Department of Genetic Medicine, University of Manchester, Manchester, UK
| | - Ivan Conte
- Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Telethon Institute of Genetics and Medicine, Pozzuoli (NA), and Medical Genetics, Naples, Italy
- Department of Biology, University of Naples Federico II, Napoli, Campania, Italy
| | - Susanne Roosing
- Department of Ophthalmology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Xavier Zanlonghi
- Institut Ophtalmologique de l'Ouest, Eye Clinic Jules Verne, Nantes, France
| | - Carmen Ayuso
- Department of Genetics & Genomics, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM)-Center for Biomedical Network Research on Rare Diseases-(CIBERER), Madrid, Spain
- Department of Genetics & Genomics, Centro de Investigacion Biomedica en Red (CIBER) de Enfermedades Raras, ISCIII, Madrid, Spain
| | - Isabelle Meunier
- Institute for Neurosciences of Montpellier, University of Montpellier, Montpellier, France
- National Centre in Rare Diseases, Genetics of Sensory Diseases, CHU Montpellier, Montpellier, Languedoc-Roussillon, France
| | - Gaël Manes
- Institute for Neurosciences of Montpellier, University of Montpellier, Montpellier, France
- Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier, France
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19
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Sodi A, Mucciolo DP, Giorgio D, Passerini I, Pacini B, Bruschi M, Verdina T, Virgili G, Giansanti F, Murro V. Clinical and molecular findings in patients with pattern dystrophy. Ophthalmic Genet 2021; 42:577-587. [PMID: 34240658 DOI: 10.1080/13816810.2021.1938140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Purposes: To study the clinical and genetic background of a series of Italian patients affected by pattern dystrophy (PD).Methods: We reviewed patients with a clinical diagnosis of PD examined at the Eye Clinic in Florence from 2012 to 2019. We took into consideration patients with a standard ophthalmological examination, personal and familial ophthalmological history, fundus imaging, and molecular genetic analysis of genes PRPH2 and BEST1. We labelled patients with BEST1 and PRPH2 mutations as m-PD group (mutated) whereas patients with no mutations in these 2 genes as nm-PD group (non-mutated).Results: Seventy-seven PD patients were assessed (average age 59.7 ± 14.2, range 31-88 years). Fifty patients were placed in the nm-PD group and 27 in the m-PD. Pathogenic BEST1 and PRPH2 mutations were detected in 7% and 22% of PD patients, respectively. In total, we reported 1 BEST1 and 8 PRPH2 novel mutations. Ten patients were characterized by drusen in the nm-PD group whereas in no patients in the m-PD group drusen were detected at the fundus.Conclusions: An important proportion of patients affected by PD showed BEST1 or PRPH2 mutations. Patients affected by drusen represent a different sub-phenotype. Genetic examination is recommended for a correct clinical management.
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Affiliation(s)
- Andrea Sodi
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Dario Pasquale Mucciolo
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy.,Ophthalmology Unit, San Jacopo Hospital, Pistoia, Italy
| | - Dario Giorgio
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Ilaria Passerini
- Department of Genetic Diagnosis, Careggi Teaching Hospital, Florence, Italy
| | - Bianca Pacini
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Mario Bruschi
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Tommaso Verdina
- Institute of Ophthalmology, University of Modena and Reggio Emilia, Modena, Italy
| | - Gianni Virgili
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy.,IRCCS Fondazione G. B. Bietti, Roma, Italy
| | - Fabrizio Giansanti
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
| | - Vittoria Murro
- Department of Neuroscience, Psychology, Drug Research and Child Health, University of Florence, Florence, Italy
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20
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Tonade D, Kern TS. Photoreceptor cells and RPE contribute to the development of diabetic retinopathy. Prog Retin Eye Res 2021; 83:100919. [PMID: 33188897 PMCID: PMC8113320 DOI: 10.1016/j.preteyeres.2020.100919] [Citation(s) in RCA: 88] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 10/27/2020] [Accepted: 10/31/2020] [Indexed: 12/26/2022]
Abstract
Diabetic retinopathy (DR) is a leading cause of blindness. It has long been regarded as vascular disease, but work in the past years has shown abnormalities also in the neural retina. Unfortunately, research on the vascular and neural abnormalities have remained largely separate, instead of being integrated into a comprehensive view of DR that includes both the neural and vascular components. Recent evidence suggests that the most predominant neural cell in the retina (photoreceptors) and the adjacent retinal pigment epithelium (RPE) play an important role in the development of vascular lesions characteristic of DR. This review summarizes evidence that the outer retina is altered in diabetes, and that photoreceptors and RPE contribute to retinal vascular alterations in the early stages of the retinopathy. The possible molecular mechanisms by which cells of the outer retina might contribute to retinal vascular damage in diabetes also are discussed. Diabetes-induced alterations in the outer retina represent a novel therapeutic target to inhibit DR.
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Affiliation(s)
- Deoye Tonade
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA
| | - Timothy S Kern
- Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA; Veterans Administration Medical Center Research Service, Cleveland, OH, USA; Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, USA; Veterans Administration Medical Center Research Service, Long Beach, CA, USA.
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21
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A bird eye view on cystic fibrosis: An underestimated multifaceted chronic disorder. Life Sci 2020; 268:118959. [PMID: 33383045 DOI: 10.1016/j.lfs.2020.118959] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 01/19/2023]
Abstract
Cystic fibrosis (CF) is an autosomal recessive disease which involves the mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CF involves in the inflammatory processes and is considered as a multisystem disorder that is not confined to lungs, but it also affects other vital organs that leads to numerous co-morbidities. The respiratory disorder in the CF results in mortality and morbidity which is characterized by series of serious events involving mucus hypersecretion, microbial infections, airways obstruction, inflammation, destruction of epithelium, tissue remodeling and terminal lung diseases. Mucins are the high molecular weight glycoproteins important for the viscoelastic properties of the mucus, play a significant role in the disease mechanisms. Determining the functional association between the CFTR and mucins might help to identify the putative target for specific therapeutic approach. In fact, furin enzyme which helps in the entry of novel COVID-19 virus into the cell, is upregulated in CF and this can also serve as a potential target for CF treatment. Moreover, the use of nano-formulations for CF treatment is an area of research being widely studied as they have also demonstrated promising outcomes. The in-depth knowledge of non-coding RNAs like miRNAs and lncRNAs and their functional association with CFTR gene expression and mutation can provide a different range of opportunity to identify the promising therapeutic approaches for CF.
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22
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Xuan Y, Zhang Y, Zong Y, Wang M, Li L, Ye X, Liu W, Chen J, Sun X, Zhang Y, Chen Y. The Clinical Features and Genetic Spectrum of a Large Cohort of Chinese Patients With Vitelliform Macular Dystrophies. Am J Ophthalmol 2020; 216:69-79. [PMID: 32278767 DOI: 10.1016/j.ajo.2020.03.047] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/18/2020] [Accepted: 03/31/2020] [Indexed: 11/18/2022]
Abstract
PURPOSE To provide the clinical and genetic characteristics of a large cohort of Chinese patients with vitelliform macular dystrophies. DESIGN Cross-sectional study. METHODS One hundred and thirty-four unrelated Chinese patients diagnosed with Best vitelliform macular dystrophy (BVMD), autosomal recessive bestrophinopathy (ARB), or adult vitelliform macular dystrophy (AVMD) were enrolled. Detailed ophthalmic examinations and genetic testing on vitelliform macular dystrophy-related genes were performed. Genotype and phenotype association were analyzed among different diagnostic groups. RESULTS In total, 87 BVMD, 30 AVMD, and 17 ARB patients were enrolled in this study. Genetic analysis identified 37 BEST1 mutations in 53 patients with BVMD and ARB. Of these, 5 variants (c.254A>C, c.291C>G, c.722C>G, c.848_850del, c.1740-2A>C) were novel. The variant c.898G>A was a hotspot mutation, which was identified in 13 patients with BVMD and 1 patient with ARB. There were significant differences of ocular biometric parameters among patients with homozygous or compound heterozygous mutations, heterozygous mutations, and those without mutations of BEST1. Homozygous or compound heterozygous patients had shortest axial length (AL), shallowest anterior chamber depth (ACD), and highest intraocular pressure (IOP); patients without mutations had longest AL, deepest ACD, and lowest IOP; and heterozygous patients were in between. Moreover, 7 patients harboring heterozygous mutations in BEST1 and 3 patients without BEST1 mutations showed similar clinical appearance to ARB in our cohort. CONCLUSIONS This is the largest sample size study of Chinese vitelliform macular dystrophy patients. Our results indicated that assessment of angle-closure risk is a necessary consideration for all types of BEST1-related vitelliform macular dystrophies. The study expanded both the clinical and genetic findings of 3 common types of vitelliform macular dystrophies in a Chinese population.
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Affiliation(s)
- Yi Xuan
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Youjia Zhang
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Yuan Zong
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China; NHC Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China
| | - Min Wang
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Lei Li
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Xiaofeng Ye
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Wei Liu
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Junyi Chen
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China; NHC Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China
| | - Xinghuai Sun
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China; State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China; NHC Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China
| | - Yongjin Zhang
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Yuhong Chen
- Department of Ophthalmology & Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China; NHC Key Laboratory of Myopia, Fudan University, Chinese Academy of Medical Sciences, Shanghai, China.
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23
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Proteoglycan IMPG2 Shapes the Interphotoreceptor Matrix and Modulates Vision. J Neurosci 2020; 40:4059-4072. [PMID: 32265257 DOI: 10.1523/jneurosci.2994-19.2020] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/29/2020] [Accepted: 03/19/2020] [Indexed: 12/13/2022] Open
Abstract
Photoreceptor neurons are surrounded by an extracellular matrix, called the interphotoreceptor matrix (IPM). Activities crucial to vision occur within the IPM, including trafficking of nutrients and metabolites, retinal attachment, and interactions needed for normal outer segment phagocytosis. The IPM includes the following two unique proteoglycans: IPM proteoglycan 1 (IMPG1) and IMPG2. Patients with mutations in IMPG1/IMPG2 develop visual deficits with subretinal material accumulation, highlighting the critical role of the IPM in vision. To determine the role of these proteoglycans in retinal physiology and the pathologic mechanisms that lead to vision loss, we generated mouse models lacking IMPG1/IMPG2. In normal retina, IMPG1 and IMPG2 occupy distinct IPM compartments, represent the main source of chondroitin sulfate and are fundamental for the constitution of the cone-specific glycocalyx stained by the PNA (peanut agglutinin) lectin marker. No evident morphologic or functional deficits were found in mice lacking IMPG1. In the absence of IMPG2, IMPG1 abnormally accumulated at the subretinal space need, likely leading to the formation of subretinal lesions and reduced visual function. Interestingly, mice lacking both IMPG1 and IMPG2, regardless of sex, showed normal retinal structure and function, demonstrating that the aberrant IMPG1 distribution is the main cause of the visual alterations observed in the absence of IMPG2. In conclusion, our results show the dependence of secreted proteoglycans such as IMPG1 on the extracellular environment to properly integrate into the matrix, demonstrate the role of IMPG2 in shaping the IPM, and shed light on the potential mechanisms leading to the development of subretinal lesions and vision loss.SIGNIFICANCE STATEMENT The photoreceptors are specialized neurons that drive phototransduction in the mammalian retina. These cells are organized and surrounded by an extracellular matrix, the interphotoreceptor matrix (IPM). Mutations in IPM proteoglycans are associated with blindness in humans. Our studies show that two specific proteoglycans of the IPM, IPM proteoglycan 1 (IMPG1) and IMPG2, form a dynamic structure with distinct localization and dependency. When IMPG2 is absent, IMPG1 cannot integrate into the IPM, leading to abnormal proteoglycan accumulation and visual deficits. This work adds a new layer of understanding to IPM physiology and describes the pathologic events following deficits in proteoglycans, providing novel possibilities for visual restoration in patients with IMPG-related pathologies.
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Noguera ME, Jakoncic J, Ermácora MR. High-resolution structure of intramolecularly proteolyzed human mucin-1 SEA domain. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140361. [PMID: 31923589 DOI: 10.1016/j.bbapap.2020.140361] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 01/04/2020] [Accepted: 01/06/2020] [Indexed: 01/26/2023]
Abstract
SEA domains are ubiquitous in large proteins associated with highly glycosylated environments. Certain SEA domains undergo intramolecular proteolysis involving a nucleophilic attack of a serine hydroxyl group on the preceding glycine carbonyl. The mucin-1 (MUC1) SEA domain has been extensively investigated as a model of intramolecular proteolysis. Since neither a general base, a general acid, nor an oxyanion hole could be identified in MUC1 SEA, it has been suggested that proteolysis is accelerated by a non-planarity of the scissile peptide bond imposed by protein folding. A reactant distorted peptide bond has been also invoked to explain the autoproteolysis of several unrelated proteins. However, the only evidence of peptide distortion in MUC1 SEA stems from molecular dynamic simulations of the reactant modeled upon a single NMR structure of the cleaved product. We report the first high-resolution X-ray structure of cleaved MUC1 SEA. Structural comparison with uncleaved SEA domains suggests that the number of residues evolutionarily inserted in the cleaved loop of MUC1 SEA precludes the formation of a properly hydrogen-bonded beta turn. By sequence analysis, we show that this conformational frustration is shared by all known cleaved SEA domains. In addition, alternative conformations of the uncleaved precursor could be modeled in which the scissile peptide bond is planar. The implications of these structures for autoproteolysis are discussed in the light of the previous research on autoproteolysis.
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Affiliation(s)
- Martín E Noguera
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Argentina; Instituto de Química y Físico-Química Biológicas, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jean Jakoncic
- Photon Science Directorate, Brookhaven National Laboratory, Upton, New York, United States
| | - Mario R Ermácora
- Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Argentina; Grupo de Biología Estructural y Biotecnología, IMBICE, CONICET, Universidad Nacional de Quilmes,Argentina.
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25
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Sun L, Wang X, Hou S, Liang M, Yang J. Identification of MYO6 copy number variation associated with cochlear aplasia by targeted sequencing. Int J Pediatr Otorhinolaryngol 2020; 128:109689. [PMID: 31785455 DOI: 10.1016/j.ijporl.2019.109689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 08/12/2019] [Accepted: 09/18/2019] [Indexed: 11/24/2022]
Abstract
Copy number variation is an extensively studied cause of hereditary diseases. However, its role in hereditary sensorineural deafness has been rarely reported. Using targeted sequencing, SNP array and qPCR, we found a novel 622.2 kb duplication of 6q14.1 in a patient with congenital sensorineural hearing loss and cochlear aplasia. The duplication included MYO6 and IMPG1 genes. FISH study confirmed that this duplication was inherited from the patient's mosaic mother.
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Affiliation(s)
- Lianhua Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute Shanghai Jiaotong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Xiaowen Wang
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute Shanghai Jiaotong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Shule Hou
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute Shanghai Jiaotong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Min Liang
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute Shanghai Jiaotong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China
| | - Jun Yang
- Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China; Ear Institute Shanghai Jiaotong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, China.
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26
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Novel eye genes systematically discovered through an integrated analysis of mouse transcriptomes and phenome. Comput Struct Biotechnol J 2019; 18:73-82. [PMID: 31934309 PMCID: PMC6951830 DOI: 10.1016/j.csbj.2019.12.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 12/04/2019] [Accepted: 12/14/2019] [Indexed: 01/23/2023] Open
Abstract
In the last few decades, reverse genetic and high throughput approaches have been frequently applied to the mouse (Mus musculus) to understand how genes function in tissues/organs and during development in a mammalian system. Despite these efforts, the associated phenotypes for the majority of mouse genes remained to be fully characterized. Here, we performed an integrated transcriptome-phenome analysis by identifying coexpressed gene modules based on tissue transcriptomes profiled with each of various platforms and functionally interpreting these modules using the mouse phenotypic data. Consequently, >15,000 mouse genes were linked with at least one of the 47 tissue functions that were examined. Specifically, our approach predicted >50 genes previously unknown to be involved in mice (Mus musculus) visual functions. Fifteen genes were selected for further analysis based on their potential biomedical relevance and compatibility with further experimental validation. Gene-specific morpholinos were introduced into zebrafish (Danio rerio) to target their corresponding orthologs. Quantitative assessments of phenotypes of developing eyes confirmed predicted eye-related functions of 13 out of the 15 genes examined. These novel eye genes include: Adal, Ankrd33, Car14, Ccdc126, Dhx32, Dkk3, Fam169a, Grifin, Kcnj14, Lrit2, Ppef2, Ppm1n, and Wdr17. The results highlighted the potential for this phenome-based approach to assist the experimental design of mutating and phenotyping mouse genes that aims to fully reveal the functional landscape of mammalian genomes.
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27
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Rahman N, Georgiou M, Khan KN, Michaelides M. Macular dystrophies: clinical and imaging features, molecular genetics and therapeutic options. Br J Ophthalmol 2019; 104:451-460. [PMID: 31704701 PMCID: PMC7147237 DOI: 10.1136/bjophthalmol-2019-315086] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 09/24/2019] [Accepted: 10/21/2019] [Indexed: 11/03/2022]
Abstract
Macular dystrophies (MDs) consist of a heterogeneous group of disorders that are characterised by bilateral symmetrical central visual loss. Advances in genetic testing over the last decade have led to improved knowledge of the underlying molecular basis. The developments in high-resolution multimodal retinal imaging have also transformed our ability to make accurate and more timely diagnoses and more sensitive quantitative assessment of disease progression, and allowed the design of optimised clinical trial endpoints for novel therapeutic interventions. The aim of this review was to provide an update on MDs, including Stargardt disease, Best disease, X-linked r etinoschisis, pattern dystrophy, Sorsby fundus dystrophy and autosomal dominant drusen. It highlights the range of innovations in retinal imaging, genotype-phenotype and structure-function associations, animal models of disease and the multiple treatment strategies that are currently in clinical trial or planned in the near future, which are anticipated to lead to significant changes in the management of patients with MDs.
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Affiliation(s)
| | - Michalis Georgiou
- Moorfields Eye Hospital, London, UK.,Institute of Ophthalmology, UCL, London, UK
| | - Kamron N Khan
- Ophthalmology Department, St James's University Hospital, Leeds, UK
| | - Michel Michaelides
- Moorfields Eye Hospital, London, UK .,Institute of Ophthalmology, UCL, London, UK
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28
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Blond F, Léveillard T. Functional Genomics of the Retina to Elucidate its Construction and Deconstruction. Int J Mol Sci 2019; 20:E4922. [PMID: 31590277 PMCID: PMC6801968 DOI: 10.3390/ijms20194922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/01/2019] [Indexed: 12/20/2022] Open
Abstract
The retina is the light sensitive part of the eye and nervous tissue that have been used extensively to characterize the function of the central nervous system. The retina has a central position both in fundamental biology and in the physiopathology of neurodegenerative diseases. We address the contribution of functional genomics to the understanding of retinal biology by reviewing key events in their historical perspective as an introduction to major findings that were obtained through the study of the retina using genomics, transcriptomics and proteomics. We illustrate our purpose by showing that most of the genes of interest for retinal development and those involved in inherited retinal degenerations have a restricted expression to the retina and most particularly to photoreceptors cells. We show that the exponential growth of data generated by functional genomics is a future challenge not only in terms of storage but also in terms of accessibility to the scientific community of retinal biologists in the future. Finally, we emphasize on novel perspectives that emerge from the development of redox-proteomics, the new frontier in retinal biology.
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Affiliation(s)
- Frédéric Blond
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
| | - Thierry Léveillard
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
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29
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Abstract
The pattern dystrophies of the retinal pigment epithelium (RPE) include a group of disorders: Butterfly-type pattern dystrophy (Figs. 17.1, 17.2, 17.3, 17.4 and 17.5) Adult-onset foveomacular vitelliform dystrophy Sjögren's reticular-type pattern dystrophy Fundus pulverulentus.
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Affiliation(s)
- Stephen H Tsang
- Jonas Children's Vision Care, Bernard & Shirlee Brown Glaucoma Laboratory, Columbia Stem Cell Initiative-Departments of Ophthalmology, Biomedical Engineering, Pathology & Cell Biology, Institute of Human Nutrition, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA.,Department of Ophthalmology, Columbia University, Edward S. Harkness Eye Institute, NewYork-Presbyterian Hospital, New York, NY, USA
| | - Tarun Sharma
- Department of Ophthalmology, Columbia University, Edward S. Harkness Eye Institute, NewYork-Presbyterian Hospital, New York, NY, USA.
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30
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Hanif AM, Yan J, Jain N. Pattern Dystrophy: An Imprecise Diagnosis in the Age of Precision Medicine. Int Ophthalmol Clin 2019; 59:173-194. [PMID: 30585925 DOI: 10.1097/iio.0000000000000262] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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Extracellular matrix component expression in human pluripotent stem cell-derived retinal organoids recapitulates retinogenesis in vivo and reveals an important role for IMPG1 and CD44 in the development of photoreceptors and interphotoreceptor matrix. Acta Biomater 2018; 74:207-221. [PMID: 29777959 DOI: 10.1016/j.actbio.2018.05.023] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 05/07/2018] [Accepted: 05/15/2018] [Indexed: 02/08/2023]
Abstract
The extracellular matrix (ECM) plays an important role in numerous processes including cellular proliferation, differentiation, migration, maturation, adhesion guidance and axonal growth. To date, there has been no detailed analysis of the ECM distribution during retinal ontogenesis in humans and the functional importance of many ECM components is poorly understood. In this study, the expression of key ECM components in adult mouse and monkey retina, developing and adult human retina and retinal organoids derived from human pluripotent stem cells was studied. Our data indicate that basement membrane ECMs (Fibronectin and Collagen IV) were expressed in Bruch's membrane and the inner limiting membrane of the developing human retina, whilst the hyalectins (Versican and Brevican), cluster of differentiation 44 (CD44), photoreceptor-specific ECMs Interphotoreceptor Matrix Proteoglycan 1 (IMPG1) and Interphotoreceptor Matrix Proteoglycan 2 (IMPG2) were detected in the developing interphotoreceptor matrix (IPM). The expression of IMPG1, Versican and Brevican in the developing IPM was conserved between human developing retina and human pluripotent stem cell-derived retinal organoids. Blocking the action of CD44 and IMPG1 in pluripotent stem cell derived retinal organoids affected the development of photoreceptors, their inner/outer segments and connecting cilia and disrupted IPM formation, with IMPG1 having an earlier and more significant impact. Together, our data suggest an important role for IMPG1 and CD44 in the development of photoreceptors and IPM formation during human retinogenesis. STATEMENT OF SIGNIFICANCE The expression and the role of many extracellular matrix (ECM) components during human retinal development is not fully understood. In this study, expression of key ECM components (Collagen IV, Fibronectin, Brevican, Versican, IMPG1 and IMPG2) was investigated during human retinal ontogenesis. Collagen IV and Fibronectin were expressed in Bruch's membrane; whereas Brevican, Versican, IMPG1 & IMPG2 in the developing interphotoreceptor matrix (IPM). Retinal organoids were successfully generated from pluripotent stem cells. The expression of ECM components was examined in the retinal organoids and found to recapitulate human retinal development in vivo. Using functional blocking experiments, we were able to highlight an important role for IMPG1 and CD44 in the development of photoreceptors and IPM formation.
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Carnevali A, Al-Dolat W, Sacconi R, Corbelli E, Querques L, Bandello F, Querques G. Diagnosis, management and future treatment options for adult-onset foveomacular vitelliform dystrophy. EXPERT REVIEW OF OPHTHALMOLOGY 2018. [DOI: 10.1080/17469899.2018.1483722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Adriano Carnevali
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
- Department of Ophthalmology, University of ‘Magna Graecia’, Catanzaro, Italy
| | - Wedad Al-Dolat
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Riccardo Sacconi
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
- Department of Ophthalmology, University of Verona, University hospital of Verona, Verona, Italy
| | - Eleonora Corbelli
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Lea Querques
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Giuseppe Querques
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, Milan, Italy
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Abeshi A, Coppola P, Beccari T, Dundar M, Di Nicola M, Viola F, Colombo L, Bertelli M. Genetic testing for pattern dystrophies. EUROBIOTECH JOURNAL 2017. [DOI: 10.24190/issn2564-615x/2017/s1.27] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
We studied the scientific literature and disease guidelines in order to summarize the clinical utility of the genetic test for pattern dystrophies. Pattern dystrophies are mostly inherited in an autosomal dominant manner (autosomal recessive transmission is rare). The overall prevalence is currently unknown. Pattern dystrophies are caused by variations in the BEST1, IMPG1, IMPG2, OTX2, PRPH2 and CTNNA1 genes. Clinical diagnosis is based on clinical findings, ophthalmological examination, optical coherence tomography, electrooculography and electroretinography. The genetic test is useful for confirming diagnosis and for differential diagnosis, couple risk assessment and access to clinical trials.
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Affiliation(s)
- Andi Abeshi
- MAGI Balkans, Tirana , Albania
- MAGI’S Lab, Rovereto , Italy
| | | | - Tommaso Beccari
- Department of Pharmaceutical Sciences, University of Perugia, Perugia , Italy
| | - Munis Dundar
- Department of Medical Genetics, Erciyes University Medical School, Kayseri , Turkey
| | - Maura Di Nicola
- Department of Clinical Sciences and Community Health, University of Milan, Ophthalmological Unit, IRCCS-Cà Granda Foundation-Ospedale Maggiore Policlinico, Milan , Italy
| | - Francesco Viola
- Department of Clinical Sciences and Community Health, University of Milan, Ophthalmological Unit, IRCCS-Cà Granda Foundation-Ospedale Maggiore Policlinico, Milan , Italy
| | - Leonardo Colombo
- Department of Ophthalmology, ASST Santi Paolo e Carlo, University of Milan, Milan , Italy
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Adult-Onset Vitelliform Macular Dystrophy caused by BEST1 p.Ile38Ser Mutation is a Mild Form of Best Vitelliform Macular Dystrophy. Sci Rep 2017; 7:9146. [PMID: 28831140 PMCID: PMC5567297 DOI: 10.1038/s41598-017-09629-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/20/2017] [Indexed: 01/08/2023] Open
Abstract
Adult-onset vitelliform macular dystrophy (AVMD) is a common and benign macular degeneration which can be caused by BEST1 mutation. Here, we investigated the clinical characteristics associated with a newly identified BEST1 mutation, p.Ile38Ser and confirmed the associated physiological functional defects. The 51-year-old patient presented bilateral small subretinal yellow deposits. Consistent with AVMD, the corresponding lesions showed hyperautofluorescence, late staining in fluorescein angiography, and subretinal hyper-reflective materials in spectral-domain optical coherence tomography. Genetic analysis demonstrated that the patient presented with a heterozygous p.Ile38Ser BEST1 mutation. Surface biotinylation and patch clamp experiments were performed in transfected HEK293T cells. Although, the identified BEST1 mutant maintains normal membrane expression, p.Ile38Ser mutant showed significantly smaller currents than wild type (WT). However, it showed larger currents than other BEST1 mutants, p.Trp93Cys, causing autosomal dominant best vitelliform macular dystrophy (BVMD), and p.Ala195Val, causing autosomal recessive bestrophinopathy (ARB). The cells expressing both WT and each BEST1 mutant showed that the functional defect of p.Ile38ser was milder than that of p.Trp93Cys, whereas combination of p.Ala195Val with WT showed good current. We identified and described the phenotype and in vitro functions of a novel BEST1 mutation causing AVMD. AVMD induced by p.Ile38Ser BEST1 mutation is a mild form of BVMD.
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Brandl C, Schulz HL, Charbel Issa P, Birtel J, Bergholz R, Lange C, Dahlke C, Zobor D, Weber BHF, Stöhr H. Mutations in the Genes for Interphotoreceptor Matrix Proteoglycans, IMPG1 and IMPG2, in Patients with Vitelliform Macular Lesions. Genes (Basel) 2017. [PMID: 28644393 PMCID: PMC5541303 DOI: 10.3390/genes8070170] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A significant portion of patients diagnosed with vitelliform macular dystrophy (VMD) do not carry causative mutations in the classic VMD genes BEST1 or PRPH2. We therefore performed a mutational screen in a cohort of 106 BEST1/PRPH2-negative VMD patients in two genes encoding secreted interphotoreceptor matrix proteoglycans-1 and -2 (IMPG1 and IMPG2). We identified two novel mutations in IMPG1 in two simplex VMD cases with disease onset in their early childhood, a heterozygous p.(Leu238Pro) missense mutation and a homozygous c.807 + 5G > A splice site mutation. The latter induced partial skipping of exon 7 of IMPG1 in an in vitro splicing assay. Furthermore, we found heterozygous mutations including three stop [p.(Glu226*), p.(Ser522*), p.(Gln856*)] and five missense mutations [p.(Ala243Pro), p.(Gly1008Asp), p.(Phe1016Ser), p.(Tyr1042Cys), p.(Cys1077Phe)] in the IMPG2 gene, one of them, p.(Cys1077Phe), previously associated with VMD. Asymptomatic carriers of the p.(Ala243Pro) and p.(Cys1077Phe) mutations show subtle foveal irregularities that could characterize a subclinical stage of disease. Taken together, our results provide further evidence for an involvement of dominant and recessive mutations in IMPG1 and IMPG2 in VMD pathology. There is a remarkable similarity in the clinical appearance of mutation carriers, presenting with bilateral, central, dome-shaped foveal accumulation of yellowish material with preserved integrity of the retinal pigment epithelium (RPE). Clinical symptoms tend to be more severe for IMPG1 mutations.
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Affiliation(s)
- Caroline Brandl
- Klinik und Poliklinik für Augenheilkunde, Universitätsklinikum Regensburg, 93053 Regensburg, Germany;
- Institut für Humangenetik, Universität Regensburg, 93053 Regensburg, Germany; (H.L.S.); (B.H.F.W.)
- Lehrstuhl für Genetische Epidemiologie, Universität Regensburg, 93053 Regensburg, Germany
| | - Heidi L. Schulz
- Institut für Humangenetik, Universität Regensburg, 93053 Regensburg, Germany; (H.L.S.); (B.H.F.W.)
| | - Peter Charbel Issa
- Department of Ophthalmology, University of Bonn, 53113 Bonn, Germany;
- Oxford Eye Hospital, OUH NHS Foundation Trust and the Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford OX1 3BD, UK
| | - Johannes Birtel
- Department of Ophthalmology, University of Bonn, 53113 Bonn, Germany;
| | - Richard Bergholz
- Klinik für Augenheilkunde, Charité—Universitätsmedizin Berlin, 10117 Berlin, Germany;
| | - Clemens Lange
- Klinik für Augenheilkunde, Universitätsklinikum Freiburg, Medizinische Fakultät, Albert Ludwigs Universität Freiburg, 79085 Freiburg, Germany;
| | - Claudia Dahlke
- Klinik für Augenheilkunde, Universitätsklinikum Köln, 50937 Köln, Germany;
| | - Ditta Zobor
- Forschungsinstitut für Augenheilkunde, Universitätsklinikum Tübingen, 72076 Tübingen, Germany;
| | - Bernhard H. F. Weber
- Institut für Humangenetik, Universität Regensburg, 93053 Regensburg, Germany; (H.L.S.); (B.H.F.W.)
| | - Heidi Stöhr
- Institut für Humangenetik, Universität Regensburg, 93053 Regensburg, Germany; (H.L.S.); (B.H.F.W.)
- Correspondence: ; Tel.: +49-941-944-5424
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Guziewicz KE, Sinha D, Gómez NM, Zorych K, Dutrow EV, Dhingra A, Mullins RF, Stone EM, Gamm DM, Boesze-Battaglia K, Aguirre GD. Bestrophinopathy: An RPE-photoreceptor interface disease. Prog Retin Eye Res 2017; 58:70-88. [PMID: 28111324 PMCID: PMC5441932 DOI: 10.1016/j.preteyeres.2017.01.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 01/16/2017] [Accepted: 01/18/2017] [Indexed: 11/17/2022]
Abstract
Bestrophinopathies, one of the most common forms of inherited macular degenerations, are caused by mutations in the BEST1 gene expressed in the retinal pigment epithelium (RPE). Both human and canine BEST1-linked maculopathies are characterized by abnormal accumulation of autofluorescent material within RPE cells and bilateral macular or multifocal lesions; however, the specific mechanism leading to the formation of these lesions remains unclear. We now provide an overview of the current state of knowledge on the molecular pathology of bestrophinopathies, and explore factors promoting formation of RPE-neuroretinal separations, using the first spontaneous animal model of BEST1-associated retinopathies, canine Best (cBest). Here, we characterize the nature of the autofluorescent RPE cell inclusions and report matching spectral signatures of RPE-associated fluorophores between human and canine retinae, indicating an analogous composition of endogenous RPE deposits in Best Vitelliform Macular Dystrophy (BVMD) patients and its canine disease model. This study also exposes a range of biochemical and structural abnormalities at the RPE-photoreceptor interface related to the impaired cone-associated microvillar ensheathment and compromised insoluble interphotoreceptor matrix (IPM), the major pathological culprits responsible for weakening of the RPE-neuroretina interactions, and consequently, formation of vitelliform lesions. These salient alterations detected at the RPE apical domain in cBest as well as in BVMD- and ARB-hiPSC-RPE model systems provide novel insights into the pathological mechanism of BEST1-linked disorders that will allow for development of critical outcome measures guiding therapeutic strategies for bestrophinopathies.
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Affiliation(s)
- Karina E Guziewicz
- Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, PA 19104, USA.
| | - Divya Sinha
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA; McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Néstor M Gómez
- Department of Anatomy & Cell Biology, School of Dental Medicine, University of Pennsylvania, PA 19104, USA
| | - Kathryn Zorych
- Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, PA 19104, USA
| | - Emily V Dutrow
- Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, PA 19104, USA
| | - Anuradha Dhingra
- Department of Biochemistry, School of Dental Medicine, University of Pennsylvania, PA 19104, USA
| | - Robert F Mullins
- Department of Ophthalmology & Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Edwin M Stone
- Department of Ophthalmology & Visual Sciences, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - David M Gamm
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA; McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53705, USA; Department of Ophthalmology & Visual Sciences, University of Wisconsin-Madison, Madison, WI 53705, USA
| | | | - Gustavo D Aguirre
- Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, PA 19104, USA
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Sullivan LS, Bowne SJ, Koboldt DC, Cadena EL, Heckenlively JR, Branham KE, Wheaton DH, Jones KD, Ruiz RS, Pennesi ME, Yang P, Davis-Boozer D, Northrup H, Gurevich VV, Chen R, Xu M, Li Y, Birch DG, Daiger SP. A Novel Dominant Mutation in SAG, the Arrestin-1 Gene, Is a Common Cause of Retinitis Pigmentosa in Hispanic Families in the Southwestern United States. Invest Ophthalmol Vis Sci 2017; 58:2774-2784. [PMID: 28549094 PMCID: PMC5455168 DOI: 10.1167/iovs.16-21341] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 04/23/2017] [Indexed: 01/22/2023] Open
Abstract
Purpose To identify the causes of autosomal dominant retinitis pigmentosa (adRP) in a cohort of families without mutations in known adRP genes and consequently to characterize a novel dominant-acting missense mutation in SAG. Methods Patients underwent ophthalmologic testing and were screened for mutations using targeted-capture and whole-exome next-generation sequencing. Confirmation and additional screening were done by Sanger sequencing. Haplotypes segregating with the mutation were determined using short tandem repeat and single nucleotide variant polymorphisms. Genealogies were established by interviews of family members. Results Eight families in a cohort of 300 adRP families, and four additional families, were found to have a novel heterozygous mutation in the SAG gene, c.440G>T; p.Cys147Phe. Patients exhibited symptoms of retinitis pigmentosa and none showed symptoms characteristic of Oguchi disease. All families are of Hispanic descent and most were ascertained in Texas or California. A single haplotype including the SAG mutation was identified in all families. The mutation dramatically alters a conserved amino acid, is extremely rare in global databases, and was not found in 4000+ exomes from Hispanic controls. Molecular modeling based on the crystal structure of bovine arrestin-1 predicts protein misfolding/instability. Conclusions This is the first dominant-acting mutation identified in SAG, a founder mutation possibly originating in Mexico several centuries ago. The phenotype is clearly adRP and is distinct from the previously reported phenotypes of recessive null mutations, that is, Oguchi disease and recessive RP. The mutation accounts for 3% of the 300 families in the adRP Cohort and 36% of Hispanic families in this cohort.
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Affiliation(s)
- Lori S. Sullivan
- Human Genetics Center, School of Public Health, The University of Texas Health Science Center, Houston, Texas, United States
| | - Sara J. Bowne
- Human Genetics Center, School of Public Health, The University of Texas Health Science Center, Houston, Texas, United States
| | | | - Elizabeth L. Cadena
- Human Genetics Center, School of Public Health, The University of Texas Health Science Center, Houston, Texas, United States
| | | | - Kari E. Branham
- Kellogg Eye Center, University of Michigan, Ann Arbor, Michigan, United States
| | | | - Kaylie D. Jones
- Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Richard S. Ruiz
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center, Houston, Texas, United States
| | - Mark E. Pennesi
- Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Paul Yang
- Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - David Davis-Boozer
- Casey Eye Institute, Oregon Health and Science University, Portland, Oregon, United States
| | - Hope Northrup
- Department of Pediatrics, McGovern Medical School, The University of Texas Health Science Center, Houston, Texas, United States
| | | | - Rui Chen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States
| | - Mingchu Xu
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States
| | - Yumei Li
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, United States
| | - David G. Birch
- Retina Foundation of the Southwest, Dallas, Texas, United States
| | - Stephen P. Daiger
- Human Genetics Center, School of Public Health, The University of Texas Health Science Center, Houston, Texas, United States
- Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center, Houston, Texas, United States
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Pei J, Grishin NV. Expansion of divergent SEA domains in cell surface proteins and nucleoporin 54. Protein Sci 2017; 26:617-630. [PMID: 27977898 DOI: 10.1002/pro.3096] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Revised: 11/28/2016] [Accepted: 11/29/2016] [Indexed: 12/13/2022]
Abstract
SEA (sea urchin sperm protein, enterokinase, agrin) domains, many of which possess autoproteolysis activity, have been found in a number of cell surface and secreted proteins. Despite high sequence divergence, SEA domains were also proposed to be present in dystroglycan based on a conserved autoproteolysis motif and receptor-type protein phosphatase IA-2 based on structural similarity. The presence of a SEA domain adjacent to the transmembrane segment appears to be a recurring theme in quite a number of type I transmembrane proteins on the cell surface, such as MUC1, dystroglycan, IA-2, and Notch receptors. By comparative sequence and structural analyses, we identified dystroglycan-like proteins with SEA domains in Capsaspora owczarzaki of the Filasterea group, one of the closest single-cell relatives of metazoans. We also detected novel and divergent SEA domains in a variety of cell surface proteins such as EpCAM, α/ε-sarcoglycan, PTPRR, collectrin/Tmem27, amnionless, CD34, KIAA0319, fibrocystin-like protein, and a number of cadherins. While these proteins are mostly from metazoans or their single cell relatives such as choanoflagellates and Filasterea, fibrocystin-like proteins with SEA domains were found in several other eukaryotic lineages including green algae, Alveolata, Euglenozoa, and Haptophyta, suggesting an ancient evolutionary origin. In addition, the intracellular protein Nucleoporin 54 (Nup54) acquired a divergent SEA domain in choanoflagellates and metazoans.
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Affiliation(s)
| | - Nick V Grishin
- Howard Hughes Medical Institute.,Department of Biophysics and Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, 75390, USA
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Hunt NC, Hallam D, Karimi A, Mellough CB, Chen J, Steel DHW, Lako M. 3D culture of human pluripotent stem cells in RGD-alginate hydrogel improves retinal tissue development. Acta Biomater 2017; 49:329-343. [PMID: 27826002 DOI: 10.1016/j.actbio.2016.11.016] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 11/01/2016] [Accepted: 11/03/2016] [Indexed: 12/22/2022]
Abstract
No treatments exist to effectively treat many retinal diseases. Retinal pigmented epithelium (RPE) and neural retina can be generated from human embryonic stem cells/induced pluripotent stem cells (hESCs/hiPSCs). The efficacy of current protocols is, however, limited. It was hypothesised that generation of laminated neural retina and/or RPE from hiPSCs/hESCs could be enhanced by three dimensional (3D) culture in hydrogels. hiPSC- and hESC-derived embryoid bodies (EBs) were encapsulated in 0.5% RGD-alginate; 1% RGD-alginate; hyaluronic acid (HA) or HA/gelatin hydrogels and maintained until day 45. Compared with controls (no gel), 0.5% RGD-alginate increased: the percentage of EBs with pigmented RPE foci; the percentage EBs with optic vesicles (OVs) and pigmented RPE simultaneously; the area covered by RPE; frequency of RPE cells (CRALBP+); expression of RPE markers (TYR and RPE65) and the retinal ganglion cell marker, MATH5. Furthermore, 0.5% RGD-alginate hydrogel encapsulation did not adversely affect the expression of other neural retina markers (PROX1, CRX, RCVRN, AP2α or VSX2) as determined by qRT-PCR, or the percentage of VSX2 positive cells as determined by flow cytometry. 1% RGD-alginate increased the percentage of EBs with OVs and/or RPE, but did not significantly influence any other measures of retinal differentiation. HA-based hydrogels had no significant effect on retinal tissue development. The results indicated that derivation of retinal tissue from hESCs/hiPSCs can be enhanced by culture in 0.5% RGD-alginate hydrogel. This RGD-alginate scaffold may be useful for derivation, transport and transplantation of neural retina and RPE, and may also enhance formation of other pigmented, neural or epithelial tissue. STATEMENT OF SIGNIFICANCE The burden of retinal disease is ever growing with the increasing age of the world-wide population. Transplantation of retinal tissue derived from human pluripotent stem cells (PSCs) is considered a promising treatment. However, derivation of retinal tissue from PSCs using defined media is a lengthy process and often variable between different cell lines. This study indicated that alginate hydrogels enhanced retinal tissue development from PSCs, whereas hyaluronic acid-based hydrogels did not. This is the first study to show that 3D culture with a biomaterial scaffold can improve retinal tissue derivation from PSCs. These findings indicate potential for the clinical application of alginate hydrogels for the derivation and subsequent transplantation retinal tissue. This work may also have implications for the derivation of other pigmented, neural or epithelial tissue.
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Affiliation(s)
- Nicola C Hunt
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK.
| | - Dean Hallam
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK.
| | - Ayesha Karimi
- Cumberland Infirmary, North Cumbria University Hospitals NHS Trust, Carlisle CA2 7HY, UK
| | - Carla B Mellough
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK.
| | - Jinju Chen
- School of Mechanical & Systems Engineering, Stephenson Building, Newcastle University, Newcastle upon Tyne, UK.
| | - David H W Steel
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK; Sunderland Eye Infirmary, Queen Alexandra Road, Sunderland SR2 9HP, UK.
| | - Majlinda Lako
- Institute of Genetic Medicine, Newcastle University, International Centre for Life, Central Parkway, Newcastle NE1 3BZ, UK.
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Johnson AA, Guziewicz KE, Lee CJ, Kalathur RC, Pulido JS, Marmorstein LY, Marmorstein AD. Bestrophin 1 and retinal disease. Prog Retin Eye Res 2017; 58:45-69. [PMID: 28153808 DOI: 10.1016/j.preteyeres.2017.01.006] [Citation(s) in RCA: 141] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 01/23/2017] [Accepted: 01/25/2017] [Indexed: 12/18/2022]
Abstract
Mutations in the gene BEST1 are causally associated with as many as five clinically distinct retinal degenerative diseases, which are collectively referred to as the "bestrophinopathies". These five associated diseases are: Best vitelliform macular dystrophy, autosomal recessive bestrophinopathy, adult-onset vitelliform macular dystrophy, autosomal dominant vitreoretinochoroidopathy, and retinitis pigmentosa. The most common of these is Best vitelliform macular dystrophy. Bestrophin 1 (Best1), the protein encoded by the gene BEST1, has been the subject of a great deal of research since it was first identified nearly two decades ago. Today we know that Best1 functions as both a pentameric anion channel and a regulator of intracellular Ca2+ signaling. Best1 is an integral membrane protein which, within the eye, is uniquely expressed in the retinal pigment epithelium where it predominantly localizes to the basolateral plasma membrane. Within the brain, Best1 expression has been documented in both glial cells and astrocytes where it functions in both tonic GABA release and glutamate transport. The crystal structure of Best1 has revealed critical information about how Best1 functions as an ion channel and how Ca2+ regulates that function. Studies using animal models have led to critical insights into the physiological roles of Best1 and advances in stem cell technology have allowed for the development of patient-derived, "disease in a dish" models. In this article we review our knowledge of Best1 and discuss prospects for near-term clinical trials to test therapies for the bestrophinopathies, a currently incurable and untreatable set of diseases.
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Affiliation(s)
- Adiv A Johnson
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA; Nikon Instruments, Melville, NY, USA
| | - Karina E Guziewicz
- Department of Clinical Studies-Philadelphia, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - C Justin Lee
- Center for Neuroscience and Functional Connectomics, Brain Science Institute, Korea Institute of Science and Technology, Seoul, South Korea
| | - Ravi C Kalathur
- New York Structural Biology Center, New York Consortium on Membrane Protein Structure, New York, NY, USA
| | - Jose S Pulido
- Department of Ophthalmology, Mayo Clinic, Rochester, MN, USA
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Khan KN, Mahroo OA, Khan RS, Mohamed MD, McKibbin M, Bird A, Michaelides M, Tufail A, Moore AT. Differentiating drusen: Drusen and drusen-like appearances associated with ageing, age-related macular degeneration, inherited eye disease and other pathological processes. Prog Retin Eye Res 2016; 53:70-106. [DOI: 10.1016/j.preteyeres.2016.04.008] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Revised: 04/24/2016] [Accepted: 04/27/2016] [Indexed: 12/11/2022]
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Hull S, Mukherjee R, Holder GE, Moore AT, Webster AR. The clinical features of retinal disease due to a dominant mutation in RPE65. Mol Vis 2016; 22:626-35. [PMID: 27307694 PMCID: PMC4901053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 06/08/2016] [Indexed: 10/24/2022] Open
Abstract
PURPOSE To present a detailed phenotypic and molecular study of two families with autosomal dominant RPE65-related retinal dystrophy. METHODS Five patients from two families were ascertained from the retinal clinics of a tertiary referral center. Phenotyping included retinal imaging and electrophysiological testing. Bidirectional Sanger sequencing of exon 13 of RPE65 and its intron-exon boundaries was performed on all reported patients and segregation confirmed in available relatives. The main outcome measures were the results of an ophthalmic examination and investigation and molecular genetic analysis. RESULTS Four affected patients from two families presented with nyctalopia and central visual disturbance in adulthood progressing to severe visual loss by the fifth to eighth decades. The patients had extensive chorioretinal atrophy with a relatively preserved anterior retina. In the second family, one patient had bilateral, vitelliform-like foveal lesions consistent with adult onset vitelliform macular dystrophy and no peripheral retinal changes. These unrelated families were both heterozygous for c.1430A>G (p.Asp477Gly). One unaffected family member also tested positive for this mutation but had good vision at age 80 years. CONCLUSIONS Autosomal dominant retinal dystrophy resembling choroideremia can arise from a heterozygous mutation in RPE65. It may manifest with mild disease or be non-penetrant. Awareness of these unusual presentations can facilitate targeted molecular investigation.
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Affiliation(s)
- Sarah Hull
- UCL Institute of Ophthalmology, London, UK,Moorfields Eye Hospital, London, UK
| | - Rajarshi Mukherjee
- UCL Institute of Ophthalmology, London, UK,Moorfields Eye Hospital, London, UK
| | - Graham E. Holder
- UCL Institute of Ophthalmology, London, UK,Moorfields Eye Hospital, London, UK
| | - Anthony T. Moore
- UCL Institute of Ophthalmology, London, UK,Moorfields Eye Hospital, London, UK,Ophthalmology Department, University of California, San Francisco, CA
| | - Andrew R. Webster
- UCL Institute of Ophthalmology, London, UK,Moorfields Eye Hospital, London, UK
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Grunin M, Tiosano L, Jaouni T, Averbukh E, Sharon D, Chowers I. Evaluation of the association of single nucleotide polymorphisms in the PRPH2 gene with adult-onset foveomacular vitelliform dystrophy. Ophthalmic Genet 2016; 37:285-9. [PMID: 26849151 DOI: 10.3109/13816810.2015.1059456] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE A minority of patients with adult-onset foveomacular vitelliform dystrophy (AFVD) carry mutations in the PRPH2 gene. This gene is highly polymorphic and it was suggested that single-nucleotide polymorphisms (SNPs) in PRPH2 may also be associated with AFVD. We aimed to evaluate for such an association. METHODS A single center cohort from a tertiary referral center including 52 consecutive patients with a clinical diagnosis of AFVD and 91 unaffected individuals was assessed. Sanger sequencing was performed for the PRPH2, BEST1, and IMPG1/2 genes. Investigation as to the frequency of minor alleles for SNPs in PRPH2 was performed and compared to HapMap and Exome Variant Server (EVS) data. RESULTS None of the patients carry a mutation in PRPH2, BEST1, or IMPG1/2. Five of 14 known SNPs (rs835, rs361524, rs434102, rs425876, rs390659) in exon 3 of PRPH2 were identified in AFVD patients. A high frequency and percentage of minor alleles of these five SNPs was found in the Israeli AFVD patients and controls compared with European, Chinese, Japanese and African populations identified via HapMap and EVS (p < 0.05). Power calculation suggested that the sample size was sufficient (80%) to rule out an association with an odds ratio above 2.5. CONCLUSIONS These results suggest that genetic variants in PRPH2 do not compose a major genetic risk factor for AFVD. The Israeli population shows a higher percentage of minor allele frequencies in SNPs in the PRPH2 gene, as compared with other populations. This emphasizes the need for appropriate genetic background when performing SNP association testing.
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Affiliation(s)
- Michelle Grunin
- a Department of Ophthalmology , Hadassah-Hebrew University Medical Center , Jerusalem , Israel
| | - Liran Tiosano
- a Department of Ophthalmology , Hadassah-Hebrew University Medical Center , Jerusalem , Israel
| | - Tareq Jaouni
- a Department of Ophthalmology , Hadassah-Hebrew University Medical Center , Jerusalem , Israel
| | - Edward Averbukh
- a Department of Ophthalmology , Hadassah-Hebrew University Medical Center , Jerusalem , Israel
| | - Dror Sharon
- a Department of Ophthalmology , Hadassah-Hebrew University Medical Center , Jerusalem , Israel
| | - Itay Chowers
- a Department of Ophthalmology , Hadassah-Hebrew University Medical Center , Jerusalem , Israel
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Katagiri S, Hayashi T, Ohkuma Y, Sekiryu T, Takeuchi T, Gekka T, Kondo M, Iwata T, Tsuneoka H. Mutation analysis of BEST1 in Japanese patients with Best's vitelliform macular dystrophy. Br J Ophthalmol 2015. [PMID: 26201355 DOI: 10.1136/bjophthalmol-2015-306830] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To describe the clinical and genetic features of Japanese patients with Best's vitelliform macular dystrophy (BVMD). PATIENTS AND METHODS This study examined 22 patients, including 16 probands from 16 families with BVMD. Comprehensive ophthalmic examinations were performed, including dilated funduscopy, full-field electroretinography (ERG) and electro-oculography (EOG). BEST1 mutation analysis was performed by Sanger sequencing. RESULTS All 16 probands exhibited characteristic BVMD fundus appearances, abnormal EOG, and normal ERG responses with the exception of one diabetic retinopathy proband. Genetic analysis identified 12 BEST1 variants in 13 probands (81%). Of these, 10 variants (p.T2A, p.R25W, p.F80L, p.V81M, p.A195V, p.R218H, p.G222E, p.V242M, p.D304del and p.E306D) have been previously reported in BVMD, while two variants (p.S7N and p.P346H) were novel, putative disease-causing variants. Single BEST1 variants were found in 12 probands. The one proband with compound heterozygous variants (p.S7N and p.R218H) exhibited typical BVMD phenotypes (pseudohypopyon stage and vitelliruptive stage in the right and left eyes, respectively). CONCLUSIONS Twelve different variants, two of which (p.S7N and p.P346H) were novel, were identified in the 13 Japanese families with BVMD. Compound heterozygous variants were found in one proband exhibiting a typical BVMD phenotype. Our results suggest that BEST1 variants do play a large role in Japanese patients with BVMD.
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Affiliation(s)
- Satoshi Katagiri
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Takaaki Hayashi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Yasuhiro Ohkuma
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Tetsuju Sekiryu
- Department of Ophthalmology, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Tomokazu Takeuchi
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Tamaki Gekka
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
| | - Mineo Kondo
- Department of Ophthalmology, Mie University School of Medicine, Mie, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization Tokyo Medical Center, Tokyo, Japan
| | - Hiroshi Tsuneoka
- Department of Ophthalmology, The Jikei University School of Medicine, Tokyo, Japan
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Adult-onset foveomacular vitelliform dystrophy: A fresh perspective. Prog Retin Eye Res 2015; 47:64-85. [DOI: 10.1016/j.preteyeres.2015.02.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Revised: 02/01/2015] [Accepted: 02/04/2015] [Indexed: 01/06/2023]
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Marfany G, Gonzàlez-Duarte R. Clinical applications of high-throughput genetic diagnosis in inherited retinal dystrophies: Present challenges and future directions. World J Med Genet 2015; 5:14-22. [DOI: 10.5496/wjmg.v5.i2.14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 12/30/2014] [Accepted: 02/09/2015] [Indexed: 02/06/2023] Open
Abstract
The advent of next generation sequencing (NGS) techniques has greatly simplified the molecular diagnosis and gene identification in very rare and highly heterogeneous Mendelian disorders. Over the last two years, these approaches, especially whole exome sequencing (WES), alone or combined with homozygosity mapping and linkage analysis, have proved to be successful in the identification of more than 25 new causative retinal dystrophy genes. NGS-approaches have also identified a wealth of new mutations in previously reported genes and have provided more comprehensive information concerning the landscape of genotype-phenotype correlations and the genetic complexity/diversity of human control populations. Although whole genome sequencing is far more informative than WES, the functional meaning of the genetic variants identified by the latter can be more easily interpreted, and final diagnosis of inherited retinal dystrophies is extremely successful, reaching 80%, particularly for recessive cases. Even considering the present limitations of WES, the reductions in costs and time, the continual technical improvements, the implementation of refined bioinformatic tools and the unbiased comprehensive genetic information it provides, make WES a very promising diagnostic tool for routine clinical and genetic diagnosis in the future.
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Schatz P, Sharon D, Al-Hamdani S, Andréasson S, Larsen M. Retinal structure in young patients aged 10 years or less with Best vitelliform macular dystrophy. Graefes Arch Clin Exp Ophthalmol 2015; 254:215-21. [DOI: 10.1007/s00417-015-3025-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 04/08/2015] [Accepted: 04/20/2015] [Indexed: 11/30/2022] Open
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Ishikawa M, Sawada Y, Yoshitomi T. Structure and function of the interphotoreceptor matrix surrounding retinal photoreceptor cells. Exp Eye Res 2015; 133:3-18. [DOI: 10.1016/j.exer.2015.02.017] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 02/20/2015] [Accepted: 02/20/2015] [Indexed: 12/21/2022]
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Multifocal retinopathy in Dachshunds with CLN2 neuronal ceroid lipofuscinosis. Exp Eye Res 2015; 134:123-32. [PMID: 25697710 DOI: 10.1016/j.exer.2015.02.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 02/10/2015] [Accepted: 02/12/2015] [Indexed: 11/24/2022]
Abstract
The CLN2 form of neuronal ceroid lipofuscinosis is an autosomal recessively inherited lysosomal storage disease that is characterized by progressive vision loss culminating in blindness, cognitive and motor decline, neurodegeneration, and premature death. CLN2 disease results from mutations in the gene that encodes the soluble lysosomal enzyme tripeptidyl peptidase-1. A null mutation in the TPP1 gene encoding this enzyme causes a CLN2-like disease in Dachshunds. Dachshunds that are homozygous for this mutation serve as a model for human CLN2 disease, exhibiting clinical signs and neuropathology similar to those of children with this disorder. Affected dogs reach end-stage terminal disease status at 10-11 months of age. In addition to retinal changes typical of CLN2 disease, a retinopathy consisting of multifocal, bullous retinal detachment lesions was identified in 65% of (TPP1-/-) dogs in an established research colony. These lesions did not occur in littermates that were heterozygous or homozygous for the normal TPP1 allele. Retinal changes and the functional effects of this multifocal retinopathy were examined objectively over time using ophthalmic examinations, fundus photography, electroretinography (ERG), quantitative pupillary light response (PLR) recording, fluorescein angiography, optical coherence tomography (OCT) and histopathology. The retinopathy consisted of progressive multifocal serous retinal detachments. The severity of the disease-related retinal thinning was no more serious in most detached areas than in adjacent areas of the retina that remained in close apposition to the retinal pigment epithelium. The retinopathy observed in these dogs was somewhat similar to canine multifocal retinopathy (CMR), a disease caused by a mutation of the bestrophin gene BEST1. ERG a-wave amplitudes were relatively preserved in the Dachshunds with CLN2 disease, whether or not they developed the multifocal retinopathy. The retinopathy also had minimal effects on the PLR. Histological evaluation indicated that the CLN2 disease-related retinal degeneration was not exacerbated in areas where the retina was detached except where the detached areas were very large. DNA sequence analysis ruled out a mutation in the BEST1 exons or splice junctions as a cause for the retinopathy. Perfect concordance between the TPP1 mutation and the retinopathy in the large number of dogs examined indicates that the retinopathy most likely occurs as a direct result of the TPP1 mutation. Therefore, inhibition of the development and progression of these lesions can be used as an indicator of the efficacy of therapeutic interventions currently under investigation for the treatment of CLN2 disease in the Dachshund model. In addition, these findings suggest that TPP1 mutations may underlie multifocal retinopathies of unknown cause in animals and humans.
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Abstract
Statistical inference on conditional dependence is essential in many fields including genetic association studies and graphical models. The classic measures focus on linear conditional correlations, and are incapable of characterizing non-linear conditional relationship including non-monotonic relationship. To overcome this limitation, we introduces a nonparametric measure of conditional dependence for multivariate random variables with arbitrary dimensions. Our measure possesses the necessary and intuitive properties as a correlation index. Briefly, it is zero almost surely if and only if two multivariate random variables are conditionally independent given a third random variable. More importantly, the sample version of this measure can be expressed elegantly as the root of a V or U-process with random kernels and has desirable theoretical properties. Based on the sample version, we propose a test for conditional independence, which is proven to be more powerful than some recently developed tests through our numerical simulations. The advantage of our test is even greater when the relationship between the multivariate random variables given the third random variable cannot be expressed in a linear or monotonic function of one random variable versus the other. We also show that the sample measure is consistent and weakly convergent, and the test statistic is asymptotically normal. By applying our test in a real data analysis, we are able to identify two conditionally associated gene expressions, which otherwise cannot be revealed. Thus, our measure of conditional dependence is not only an ideal concept, but also has important practical utility.
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Affiliation(s)
- Xueqin Wang
- Sun Yat-Sen University, North Carolina State University, Yale University
| | - Wenliang Pan
- Sun Yat-Sen University, North Carolina State University, Yale University
| | - Wenhao Hu
- Sun Yat-Sen University, North Carolina State University, Yale University
| | - Yuan Tian
- Sun Yat-Sen University, North Carolina State University, Yale University
| | - Heping Zhang
- Sun Yat-Sen University, North Carolina State University, Yale University
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