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Cvekl A, Vijg J. Aging of the eye: Lessons from cataracts and age-related macular degeneration. Ageing Res Rev 2024; 99:102407. [PMID: 38977082 DOI: 10.1016/j.arr.2024.102407] [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: 03/11/2024] [Revised: 06/18/2024] [Accepted: 07/01/2024] [Indexed: 07/10/2024]
Abstract
Aging is the greatest risk factor for chronic human diseases, including many eye diseases. Geroscience aims to understand the effects of the aging process on these diseases, including the genetic, molecular, and cellular mechanisms that underlie the increased risk of disease over the lifetime. Understanding of the aging eye increases general knowledge of the cellular physiology impacted by aging processes at various biological extremes. Two major diseases, age-related cataract and age-related macular degeneration (AMD) are caused by dysfunction of the lens and retina, respectively. Lens transparency and light refraction are mediated by lens fiber cells lacking nuclei and other organelles, which provides a unique opportunity to study a single aging hallmark, i.e., loss of proteostasis, within an environment of limited metabolism. In AMD, local dysfunction of the photoreceptors/retinal pigmented epithelium/Bruch's membrane/choriocapillaris complex in the macula leads to the loss of photoreceptors and eventually loss of central vision, and is driven by nearly all the hallmarks of aging and shares features with Alzheimer's disease, Parkinson's disease, cardiovascular disease, and diabetes. The aging eye can function as a model for studying basic mechanisms of aging and, vice versa, well-defined hallmarks of aging can be used as tools to understand age-related eye disease.
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Affiliation(s)
- Ales Cvekl
- Departments of Genetics and Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Jan Vijg
- Departments of Genetics and Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Arias-Montecino A, Sykes A, Álvarez-Hernán G, de Mera-Rodríguez JA, Calle-Guisado V, Martín-Partido G, Rodríguez-León J, Francisco-Morcillo J. Histological and scanning electron microscope observations on the developing retina of the cuttlefish (Sepia officinalis Linnaeus, 1758). Tissue Cell 2024; 88:102417. [PMID: 38820948 DOI: 10.1016/j.tice.2024.102417] [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: 01/29/2024] [Revised: 05/03/2024] [Accepted: 05/20/2024] [Indexed: 06/02/2024]
Abstract
In this work we present a detailed study of the major events during retinal histogenesis of the cuttlefish Sepia officinalis from early embryos to newly hatched animals and juveniles. For this purpose, we carried out morphometric and histological analyses using light and scanning electron microscopy. From St19, the first embryonic stage analysed, to St23/24 the embryonic retina is composed of a pseudostratified epithelium showing abundant mitotic figures in the more internal surface. At St24 the first photoreceptor nuclei appear in the presumptive inner segment layer, while an incipient layer of apical processes of the future rhabdomeric layer become visible at St25. From this stage onwards, both the rhabdomeric layer and the inner segment layer increase in size until postnatal ages. In contrast, the width of the supporting cell layer progressively decreases from St25/26 until postnatal ages. S. officinalis embryos hatched in a morphologically advanced state, showing a differentiated retina even in the last stages of the embryonic period. However, features of immaturity are still observable in the retinal tissue during the first postnatal weeks of life, such as the existence of mitotic figures in the apical region of the supporting cell layer and migrating nuclei of differentiating photoreceptors crossing the basal membrane to reach their final location in the inner segment layer. Therefore, postnatal retinal neurogenesis is present in juvenile specimens of S. officinalis.
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Affiliation(s)
- Alejandro Arias-Montecino
- Área de Biología Celular, Departamento de Anatomía, Biología Celular y Zoología, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06006, Spain
| | - Antonio Sykes
- Center of Marine Sciences, Universidade do Algarve Campus de Gambelas, Faro 8005-139, Portugal
| | - Guadalupe Álvarez-Hernán
- Área de Anatomía y Embriología Humana, Departamento de Anatomía, Biología Celular y Zoología, Facultad de Medicina, Universidad de Extremadura, Badajoz 06006, Spain.
| | - José Antonio de Mera-Rodríguez
- Área de Biología Celular, Departamento de Anatomía, Biología Celular y Zoología, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06006, Spain
| | - Violeta Calle-Guisado
- Área de Anatomía y Embriología Humana, Departamento de Anatomía, Biología Celular y Zoología, Facultad de Medicina, Universidad de Extremadura, Badajoz 06006, Spain
| | - Gervasio Martín-Partido
- Área de Biología Celular, Departamento de Anatomía, Biología Celular y Zoología, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06006, Spain
| | - Joaquín Rodríguez-León
- Área de Anatomía y Embriología Humana, Departamento de Anatomía, Biología Celular y Zoología, Facultad de Medicina, Universidad de Extremadura, Badajoz 06006, Spain
| | - Javier Francisco-Morcillo
- Área de Biología Celular, Departamento de Anatomía, Biología Celular y Zoología, Facultad de Ciencias, Universidad de Extremadura, Badajoz 06006, Spain
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Zhang T, Zhu L, Sun Y, Yang L, Yi S, Zhong W. Novel Insights on 6:6 Perfluoroalkyl Phosphonic Acid-Induced Melanin Synthesis Disorders Leading to Pigmentation in Tadpoles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:11032-11042. [PMID: 37467139 DOI: 10.1021/acs.est.3c02920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
As alternatives to traditional per- and polyfluoroalkyl substances, perfluoroalkyl phosphonic acids (PFPiAs) are widely present in aquatic environments and can potentially harm aquatic organisms. Pigmentation affects the probability of aquatic organisms being preyed on and serves as an important toxic endpoint of development, but little is known about the impacts of PFPiAs on the development of aquatic organisms. In this study, Xenopus laevis embryos were exposed to 6:6 PFPiA (1, 10, and 100 nM) for 14 days. The developed tadpoles exhibited evident pigmentation with increased melanin particle size and density on the skin. Pathological and behavioral experiments revealed that the retinal layers became thinner, reducing the photosensitivity and disturbing the circadian rhythm of the tadpoles. Compared to the control group, the exposed tadpoles showed higher levels but less changes of melanin throughout the light/dark cycle, as well as distinct oxidative damage. Consequently, the expression level of microphthalmia-associated transcription factor (MITF), a key factor inducing melanin synthesis, increased significantly. Molecular docking analysis suggested that 6:6 PFPiA forms strong interactions in the binding pocket of MITF, implying that it could activate MITF directly. The activation of MITF ultimately promotes melanin synthesis, resulting in pigmentation on tadpoles.
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Affiliation(s)
- Tianxu Zhang
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| | - Lingyan Zhu
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| | - Yumeng Sun
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| | - Liping Yang
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| | - Shujun Yi
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
| | - Wenjue Zhong
- Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering of Nankai University, Tianjin 300350, China
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4
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Cardozo MJ, Sánchez-Bustamante E, Bovolenta P. Optic cup morphogenesis across species and related inborn human eye defects. Development 2023; 150:286775. [PMID: 36714981 PMCID: PMC10110496 DOI: 10.1242/dev.200399] [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] [Indexed: 01/31/2023]
Abstract
The vertebrate eye is shaped as a cup, a conformation that optimizes vision and is acquired early in development through a process known as optic cup morphogenesis. Imaging living, transparent teleost embryos and mammalian stem cell-derived organoids has provided insights into the rearrangements that eye progenitors undergo to adopt such a shape. Molecular and pharmacological interference with these rearrangements has further identified the underlying molecular machineries and the physical forces involved in this morphogenetic process. In this Review, we summarize the resulting scenarios and proposed models that include common and species-specific events. We further discuss how these studies and those in environmentally adapted blind species may shed light on human inborn eye malformations that result from failures in optic cup morphogenesis, including microphthalmia, anophthalmia and coloboma.
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Affiliation(s)
- Marcos J Cardozo
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolás Cabrera 1, Cantoblanco, Madrid 28049, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolás Cabrera 1, Cantoblanco, Madrid 28049, Spain
| | - Elena Sánchez-Bustamante
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolás Cabrera 1, Cantoblanco, Madrid 28049, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolás Cabrera 1, Cantoblanco, Madrid 28049, Spain
| | - Paola Bovolenta
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolás Cabrera 1, Cantoblanco, Madrid 28049, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolás Cabrera 1, Cantoblanco, Madrid 28049, Spain
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Owen N, Toms M, Young RM, Eintracht J, Sarkar H, Brooks BP, Moosajee M. Identification of 4 novel human ocular coloboma genes ANK3, BMPR1B, PDGFRA, and CDH4 through evolutionary conserved vertebrate gene analysis. Genet Med 2022; 24:1073-1084. [PMID: 35034853 DOI: 10.1016/j.gim.2021.12.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 12/17/2021] [Indexed: 11/15/2022] Open
Abstract
PURPOSE Ocular coloboma arises from genetic or environmental perturbations that inhibit optic fissure (OF) fusion during early eye development. Despite high genetic heterogeneity, 70% to 85% of patients remain molecularly undiagnosed. In this study, we have identified new potential causative genes using cross-species comparative meta-analysis. METHODS Evolutionarily conserved differentially expressed genes were identified through in silico analysis, with in situ hybridization, gene knockdown, and rescue performed to confirm spatiotemporal gene expression and phenotype. Interrogation of the 100,000 Genomes Project for putative pathogenic variants was performed. RESULTS Nine conserved differentially expressed genes between zebrafish and mouse were identified. Expression of zebrafish ank3a, bmpr1ba/b, cdh4, and pdgfaa was localized to the OF, periocular mesenchyme cells, or ciliary marginal zone, regions traversed by the OF. Knockdown of ank3, bmpr1b, and pdgfaa revealed a coloboma and/or microphthalmia phenotype. Novel pathogenic variants in ANK3, BMPR1B, PDGFRA, and CDH4 were identified in 8 unrelated coloboma families. We showed BMPR1B rescued the knockdown phenotype but variant messenger RNAs failed, providing evidence of pathogenicity. CONCLUSION We show the utility of cross-species meta-analysis to identify several novel coloboma disease-causing genes. There is a potential to increase the diagnostic yield for new and unsolved patients while adding to our understanding of the genetic basis of OF morphogenesis.
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Affiliation(s)
- Nicholas Owen
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Maria Toms
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Rodrigo M Young
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Jonathan Eintracht
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Hajrah Sarkar
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD
| | - Mariya Moosajee
- Development, Ageing and Disease, UCL Institute of Ophthalmology, London, United Kingdom; Department of Genetics, Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; Department of Ophthalmology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom; Ocular Genomics and Therapeutics, The Francis Crick Institute, London, United Kingdom.
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Chen XF, Chen ZF, Lin ZC, Liao XL, Zou T, Qi Z, Cai Z. Toxic effects of triclocarban on larval zebrafish: A focus on visual dysfunction. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 241:106013. [PMID: 34731642 DOI: 10.1016/j.aquatox.2021.106013] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/07/2021] [Accepted: 10/24/2021] [Indexed: 06/13/2023]
Abstract
Triclocarban (TCC) is considered an endocrine disruptor and shows antagonist activity on thyroid receptors. In view of the report that thyroid hormone signaling mediates retinal cone photoreceptor specification, we hypothesize that TCC could impair visual function, which is vital to wildlife. In order to verify our hypothesis, we assessed alteration in the retinal structure (retinal layer thickness and cell density), visually-mediated behavior, cone and rod opsin gene expression, and photoreceptor immunostaining in zebrafish larvae exposed to TCC at environmentally realistic concentrations (0.16 ± 0.005 µg/L, L-group) and one-fifth of the median lethal concentrations (25.4 ± 1.02 µg/L, H-group). Significant decrease in eye size, ganglion cell density, optokinetic response, and phototactic response can be observed in the L-group, while the thickness of outer nuclear layer, where the cell bodies of cone and rod cells are located, was significantly reduced with the down-regulation of critical opsin gene (opn1sw2, opn1mw1, opn1mw3, opn1lw1, opn1lw2, and rho) expression and rhodopsin immunofluorescence in the H-group. It should be noted that TCC could affect the sensitivity of zebrafish larvae to red and green light according to the results of behavioral and opsin gene expression analysis. These findings provide the first evidence to support our hypothesis that the visual system, a novel toxicological target, is affected by TCC. Consequently, we urgently call for a more in-depth exploration of TCC-induced ocular toxicity to aquatic organisms and even to humans.
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Affiliation(s)
- Xiao-Fan Chen
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Zhi-Feng Chen
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China; Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety, South China Normal University, Guangzhou 510006, China.
| | - Zhi-Cheng Lin
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Xiao-Liang Liao
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Ting Zou
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Zenghua Qi
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Zongwei Cai
- Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China; State Key Laboratory of Environmental and Biological Analysis, Department of Chemistry, Hong Kong Baptist University, Hong Kong 999077, China
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Rasys AM, Pau SH, Irwin KE, Luo S, Kim HQ, Wahle MA, Trainor PA, Menke DB, Lauderdale JD. Ocular elongation and retraction in foveated reptiles. Dev Dyn 2021; 250:1584-1599. [PMID: 33866663 PMCID: PMC10731578 DOI: 10.1002/dvdy.348] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/09/2021] [Accepted: 04/11/2021] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Pronounced asymmetric changes in ocular globe size during eye development have been observed in a number of species ranging from humans to lizards. In contrast, largely symmetric changes in globe size have been described for other species like rodents. We propose that asymmetric changes in the three-dimensional structure of the developing eye correlate with the types of retinal remodeling needed to produce areas of high photoreceptor density. To test this idea, we systematically examined three-dimensional aspects of globe size as a function of eye development in the bifoveated brown anole, Anolis sagrei. RESULTS During embryonic development, the anole eye undergoes dynamic changes in ocular shape. Initially spherical, the eye elongates in the presumptive foveal regions of the retina and then proceeds through a period of retraction that returns the eye to its spherical shape. During this period of retraction, pit formation and photoreceptor cell packing are observed. We found a similar pattern of elongation and retraction associated with the single fovea of the veiled chameleon, Chamaeleo calyptratus. CONCLUSIONS These results, together with those reported for other foveated species, support the idea that areas of high photoreceptor packing occur in regions where the ocular globe asymmetrically elongates and retracts during development.
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Affiliation(s)
- Ashley M. Rasys
- Department of Cellular Biology, The University of Georgia, Athens, Georgia
| | - Shana H. Pau
- Department of Genetics, The University of Georgia, Athens, Georgia
| | - Katherine E. Irwin
- Department of Cellular Biology, The University of Georgia, Athens, Georgia
| | - Sherry Luo
- Department of Genetics, The University of Georgia, Athens, Georgia
| | - Hannah Q. Kim
- Department of Cellular Biology, The University of Georgia, Athens, Georgia
| | | | - Paul A. Trainor
- Stowers Institute for Medical Research, Kansas City, Missouri
- Department of Anatomy & Cell Biology, The University of Kansas School of Medicine, Kansas City, Kansas
| | - Douglas B. Menke
- Department of Genetics, The University of Georgia, Athens, Georgia
| | - James D. Lauderdale
- Department of Cellular Biology, The University of Georgia, Athens, Georgia
- Neuroscience Division of the Biomedical and Translational Sciences Institute, The University of Georgia, Athens, Georgia
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Devos L, Agnès F, Edouard J, Simon V, Legendre L, El Khallouki N, Barbachou S, Sohm F, Rétaux S. Eye morphogenesis in the blind Mexican cavefish. Biol Open 2021; 10:bio059031. [PMID: 34590124 PMCID: PMC8565469 DOI: 10.1242/bio.059031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 01/13/2023] Open
Abstract
The morphogenesis of the vertebrate eye consists of a complex choreography of cell movements, tightly coupled to axial regionalization and cell type specification processes. Disturbances in these events can lead to developmental defects and blindness. Here, we have deciphered the sequence of defective events leading to coloboma in the embryonic eye of the blind cavefish of the species Astyanax mexicanus. Using comparative live imaging on targeted enhancer-trap Zic1:hsp70:GFP reporter lines of both the normal, river-dwelling morph and the cave morph of the species, we identified defects in migratory cell behaviours during evagination that participate in the reduced optic vesicle size in cavefish, without proliferation defect. Further, impaired optic cup invagination shifts the relative position of the lens and contributes to coloboma in cavefish. Based on these results, we propose a developmental scenario to explain the cavefish phenotype and discuss developmental constraints to morphological evolution. The cavefish eye appears as an outstanding natural mutant model to study molecular and cellular processes involved in optic region morphogenesis.
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Affiliation(s)
- Lucie Devos
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris-Saclay, 91198 Gif sur Yvette, France
| | - François Agnès
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris-Saclay, 91198 Gif sur Yvette, France
| | - Joanne Edouard
- AMAGEN, CNRS, INRA, Université Paris-Saclay, 91198, Gif sur Yvette, France
| | - Victor Simon
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris-Saclay, 91198 Gif sur Yvette, France
- AMAGEN, CNRS, INRA, Université Paris-Saclay, 91198, Gif sur Yvette, France
| | - Laurent Legendre
- AMAGEN, CNRS, INRA, Université Paris-Saclay, 91198, Gif sur Yvette, France
| | - Naima El Khallouki
- AMAGEN, CNRS, INRA, Université Paris-Saclay, 91198, Gif sur Yvette, France
| | - Sosthène Barbachou
- AMAGEN, CNRS, INRA, Université Paris-Saclay, 91198, Gif sur Yvette, France
| | - Frédéric Sohm
- AMAGEN, CNRS, INRA, Université Paris-Saclay, 91198, Gif sur Yvette, France
| | - Sylvie Rétaux
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris-Saclay, 91198 Gif sur Yvette, France
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Moreno-Mármol T, Ledesma-Terrón M, Tabanera N, Martin-Bermejo MJ, Cardozo MJ, Cavodeassi F, Bovolenta P. Stretching of the retinal pigment epithelium contributes to zebrafish optic cup morphogenesis. eLife 2021; 10:63396. [PMID: 34545806 PMCID: PMC8530511 DOI: 10.7554/elife.63396] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 09/20/2021] [Indexed: 12/15/2022] Open
Abstract
The vertebrate eye primordium consists of a pseudostratified neuroepithelium, the optic vesicle (OV), in which cells acquire neural retina or retinal pigment epithelium (RPE) fates. As these fates arise, the OV assumes a cup shape, influenced by mechanical forces generated within the neural retina. Whether the RPE passively adapts to retinal changes or actively contributes to OV morphogenesis remains unexplored. We generated a zebrafish Tg(E1-bhlhe40:GFP) line to track RPE morphogenesis and interrogate its participation in OV folding. We show that, in virtual absence of proliferation, RPE cells stretch and flatten, thereby matching the retinal curvature and promoting OV folding. Localized interference with the RPE cytoskeleton disrupts tissue stretching and OV folding. Thus, extreme RPE flattening and accelerated differentiation are efficient solutions adopted by fast-developing species to enable timely optic cup formation. This mechanism differs in amniotes, in which proliferation drives RPE expansion with a much-reduced need of cell flattening. Rounded eyeballs help to optimize vision – but how do they acquire their distinctive shape? In animals with backbones, including humans, the eye begins to form early in development. A single layer of embryonic tissue called the optic vesicle reorganizes itself into a two-layered structure: a thin outer layer of cells, known as the retinal pigmented epithelium (RPE for short), and a thicker inner layer called the neural retina. If this process fails, the animal may be born blind or visually impaired. How this flat two-layered structure becomes round is still being investigated. In fish, studies have shown that the inner cell layer – the neural retina – generates mechanical forces that cause the developing tissue to curve inwards to form a cup-like shape. But it was unclear whether the outer layer of cells (the RPE) also contributed to this process. Moreno-Marmol et al. were able to investigate this question by genetically modifying zebrafish to make all new RPE cells fluoresce. Following the early development of the zebrafish eye under a microscope revealed that RPE cells flattened themselves into long thin structures that stretched to cover the entire neural retina. This change was made possible by the cell’s internal skeleton reorganizing. In fact, preventing this reorganization stopped the RPE cells from flattening, and precluded the optic cup from acquiring its curved shape. The results thus confirmed a direct role for the RPE in generating curvature. The entire process did not require the RPE to produce new cells, allowing the curved shape to emerge in just a few hours. This is a major advantage for fast-developing species such as zebrafish. In species whose embryos develop more slowly, such as mice and humans, the RPE instead grows by producing additional cells – a process that takes many days. The development of the eye thus shows how various species use different evolutionary approaches to achieve a common goal.
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Affiliation(s)
- Tania Moreno-Mármol
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/ Nicolás Cabrera, 1, Campus de la Universidad Autónoma de Madrid, Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Mario Ledesma-Terrón
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/ Nicolás Cabrera, 1, Campus de la Universidad Autónoma de Madrid, Madrid, Spain
| | - Noemi Tabanera
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/ Nicolás Cabrera, 1, Campus de la Universidad Autónoma de Madrid, Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Maria Jesús Martin-Bermejo
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/ Nicolás Cabrera, 1, Campus de la Universidad Autónoma de Madrid, Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Marcos J Cardozo
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/ Nicolás Cabrera, 1, Campus de la Universidad Autónoma de Madrid, Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Florencia Cavodeassi
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/ Nicolás Cabrera, 1, Campus de la Universidad Autónoma de Madrid, Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Paola Bovolenta
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, c/ Nicolás Cabrera, 1, Campus de la Universidad Autónoma de Madrid, Madrid, Spain.,CIBER de Enfermedades Raras (CIBERER), Madrid, Spain
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10
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Buono L, Corbacho J, Naranjo S, Almuedo-Castillo M, Moreno-Marmol T, de la Cerda B, Sanabria-Reinoso E, Polvillo R, Díaz-Corrales FJ, Bogdanovic O, Bovolenta P, Martínez-Morales JR. Analysis of gene network bifurcation during optic cup morphogenesis in zebrafish. Nat Commun 2021; 12:3866. [PMID: 34162866 PMCID: PMC8222258 DOI: 10.1038/s41467-021-24169-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 06/03/2021] [Indexed: 01/04/2023] Open
Abstract
Sight depends on the tight cooperation between photoreceptors and pigmented cells, which derive from common progenitors through the bifurcation of a single gene regulatory network into the neural retina (NR) and retinal-pigmented epithelium (RPE) programs. Although genetic studies have identified upstream nodes controlling these networks, their regulatory logic remains poorly investigated. Here, we characterize transcriptome dynamics and chromatin accessibility in segregating NR/RPE populations in zebrafish. We analyze cis-regulatory modules and enriched transcription factor motives to show extensive network redundancy and context-dependent activity. We identify downstream targets, highlighting an early recruitment of desmosomal genes in the flattening RPE and revealing Tead factors as upstream regulators. We investigate the RPE specification network dynamics to uncover an unexpected sequence of transcription factors recruitment, which is conserved in humans. This systematic interrogation of the NR/RPE bifurcation should improve both genetic counseling for eye disorders and hiPSCs-to-RPE differentiation protocols for cell-replacement therapies in degenerative diseases.
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Affiliation(s)
- Lorena Buono
- Centro Andaluz de Biología del Desarrollo-CABD (CSIC/UPO/JA), Seville, Spain
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Seville, Spain
| | - Jorge Corbacho
- Centro Andaluz de Biología del Desarrollo-CABD (CSIC/UPO/JA), Seville, Spain
| | - Silvia Naranjo
- Centro Andaluz de Biología del Desarrollo-CABD (CSIC/UPO/JA), Seville, Spain
| | | | | | - Berta de la Cerda
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER (CSIC/US/UPO/JA), Seville, Spain
| | | | - Rocío Polvillo
- Centro Andaluz de Biología del Desarrollo-CABD (CSIC/UPO/JA), Seville, Spain
| | | | - Ozren Bogdanovic
- Genomics and Epigenetics Division, Garvan Institute of Medical Research, Sydney, NSW, Australia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Paola Bovolenta
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Seville, Spain.
- CIBERER, ISCIII, Madrid, Spain.
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11
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Retinal Pigment Epithelium and Neural Retinal Progenitors Interact via Semaphorin 6D to Facilitate Optic Cup Morphogenesis. eNeuro 2021; 8:ENEURO.0053-21.2021. [PMID: 33811086 PMCID: PMC8116109 DOI: 10.1523/eneuro.0053-21.2021] [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: 02/09/2021] [Revised: 03/25/2021] [Accepted: 03/29/2021] [Indexed: 11/21/2022] Open
Abstract
Cell movement propels embryonic tissues to acquire shapes required for mature function. The movements are driven both by acto-myosin signaling and by cells interacting with the extracellular matrix (ECM). Unknown is whether cell-cell interactions within a tissue are also required, and the molecular mechanisms by which such communication might occur. Here, we use the developing visual system of zebrafish as a model to understand the role cell-cell communication plays in tissue morphogenesis in the embryonic nervous system. We identify that cell-cell-mediated contact between two distinct cell populations, progenitors of the neural retina and retinal pigment epithelium (RPE), facilitates epithelial flow to produce the mature cupped retina. We identify for the first time the need in eye morphogenesis for distinct populations of progenitors to interact, and suggest a novel role for a member of a key developmental signaling family, the transmembrane Semaphorin6d, as mediating communication between distinct cell types to control tissue morphogenesis.
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12
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George SM, Lu F, Rao M, Leach LL, Gross JM. The retinal pigment epithelium: Development, injury responses, and regenerative potential in mammalian and non-mammalian systems. Prog Retin Eye Res 2021; 85:100969. [PMID: 33901682 DOI: 10.1016/j.preteyeres.2021.100969] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 03/23/2021] [Accepted: 04/07/2021] [Indexed: 12/13/2022]
Abstract
Diseases that result in retinal pigment epithelium (RPE) degeneration, such as age-related macular degeneration (AMD), are among the leading causes of blindness worldwide. Atrophic (dry) AMD is the most prevalent form of AMD and there are currently no effective therapies to prevent RPE cell death or restore RPE cells lost from AMD. An intriguing approach to treat AMD and other RPE degenerative diseases is to develop therapies focused on stimulating endogenous RPE regeneration. For this to become feasible, a deeper understanding of the mechanisms underlying RPE development, injury responses and regenerative potential is needed. In mammals, RPE regeneration is extremely limited; small lesions can be repaired by the expansion of adjacent RPE cells, but large lesions cannot be repaired as remaining RPE cells are unable to functionally replace lost RPE tissue. In some injury paradigms, RPE cells proliferate but do not regenerate a morphologically normal monolayer, while in others, proliferation is pathogenic and results in further disruption to the retina. This is in contrast to non-mammalian vertebrates, which possess tremendous RPE regenerative potential. Here, we discuss what is known about RPE formation during development in mammalian and non-mammalian vertebrates, we detail the processes by which RPE cells respond to injury, and we describe examples of RPE-to-retina and RPE-to-RPE regeneration in non-mammalian vertebrates. Finally, we outline barriers to RPE-dependent regeneration in mammals that could potentially be overcome to stimulate a regenerative response from the RPE.
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Affiliation(s)
- Stephanie M George
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Fangfang Lu
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Mishal Rao
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Lyndsay L Leach
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Jeffrey M Gross
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA; Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
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13
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Harding P, Cunha DL, Moosajee M. Animal and cellular models of microphthalmia. THERAPEUTIC ADVANCES IN RARE DISEASE 2021; 2:2633004021997447. [PMID: 37181112 PMCID: PMC10032472 DOI: 10.1177/2633004021997447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/02/2021] [Indexed: 05/16/2023]
Abstract
Microphthalmia is a rare developmental eye disorder affecting 1 in 7000 births. It is defined as a small (axial length ⩾2 standard deviations below the age-adjusted mean) underdeveloped eye, caused by disruption of ocular development through genetic or environmental factors in the first trimester of pregnancy. Clinical phenotypic heterogeneity exists amongst patients with varying levels of severity, and associated ocular and systemic features. Up to 11% of blind children are reported to have microphthalmia, yet currently no treatments are available. By identifying the aetiology of microphthalmia and understanding how the mechanisms of eye development are disrupted, we can gain a better understanding of the pathogenesis. Animal models, mainly mouse, zebrafish and Xenopus, have provided extensive information on the genetic regulation of oculogenesis, and how perturbation of these pathways leads to microphthalmia. However, differences exist between species, hence cellular models, such as patient-derived induced pluripotent stem cell (iPSC) optic vesicles, are now being used to provide greater insights into the human disease process. Progress in 3D cellular modelling techniques has enhanced the ability of researchers to study interactions of different cell types during eye development. Through improved molecular knowledge of microphthalmia, preventative or postnatal therapies may be developed, together with establishing genotype-phenotype correlations in order to provide patients with the appropriate prognosis, multidisciplinary care and informed genetic counselling. This review summarises some key discoveries from animal and cellular models of microphthalmia and discusses how innovative new models can be used to further our understanding in the future. Plain language summary Animal and Cellular Models of the Eye Disorder, Microphthalmia (Small Eye) Microphthalmia, meaning a small, underdeveloped eye, is a rare disorder that children are born with. Genetic changes or variations in the environment during the first 3 months of pregnancy can disrupt early development of the eye, resulting in microphthalmia. Up to 11% of blind children have microphthalmia, yet currently no treatments are available. By understanding the genes necessary for eye development, we can determine how disruption by genetic changes or environmental factors can cause this condition. This helps us understand why microphthalmia occurs, and ensure patients are provided with the appropriate clinical care and genetic counselling advice. Additionally, by understanding the causes of microphthalmia, researchers can develop treatments to prevent or reduce the severity of this condition. Animal models, particularly mice, zebrafish and frogs, which can also develop small eyes due to the same genetic/environmental changes, have helped us understand the genes which are important for eye development and can cause birth eye defects when disrupted. Studying a patient's own cells grown in the laboratory can further help researchers understand how changes in genes affect their function. Both animal and cellular models can be used to develop and test new drugs, which could provide treatment options for patients living with microphthalmia. This review summarises the key discoveries from animal and cellular models of microphthalmia and discusses how innovative new models can be used to further our understanding in the future.
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Affiliation(s)
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, 11-43 Bath
Street, London, EC1V 9EL, UK
- Moorfields Eye Hospital NHS Foundation Trust,
London, UK
- Great Ormond Street Hospital for Children NHS
Foundation Trust, London, UK
- The Francis Crick Institute, London, UK
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14
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Sun WR, Ramirez S, Spiller KE, Zhao Y, Fuhrmann S. Nf2 fine-tunes proliferation and tissue alignment during closure of the optic fissure in the embryonic mouse eye. Hum Mol Genet 2020; 29:3373-3387. [PMID: 33075808 DOI: 10.1093/hmg/ddaa228] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 09/29/2020] [Accepted: 10/12/2020] [Indexed: 11/14/2022] Open
Abstract
Uveal coloboma represents one of the most common congenital ocular malformations accounting for up to 10% of childhood blindness (~1 in 5000 live birth). Coloboma originates from defective fusion of the optic fissure (OF), a transient gap that forms during eye morphogenesis by asymmetric, ventral invagination. Genetic heterogeneity combined with the activity of developmentally regulated genes suggests multiple mechanisms regulating OF closure. The tumor suppressor and FERM domain protein Neurofibromin 2 (NF2) controls diverse processes in cancer, development and regeneration, via Hippo pathway and cytoskeleton regulation. In humans, NF2 mutations can cause ocular abnormalities, including coloboma, however, its actual role in OF closure is unknown. Using conditional inactivation in the embryonic mouse eye, our data indicate that loss of Nf2 function results in a novel underlying cause for coloboma. In particular, mutant eyes show substantially increased retinal pigmented epithelium (RPE) proliferation in the fissure region with concomitant acquisition of RPE cell fate. Cells lining the OF margin can maintain RPE fate ectopically and fail to transition from neuroepithelial to cuboidal shape. In the dorsal RPE of the optic cup, Nf2 inactivation leads to a robust increase in cell number, with local disorganization of the cytoskeleton components F-actin and pMLC2. We propose that RPE hyperproliferation is the primary cause for the observed defects causing insufficient alignment of the OF margins in Nf2 mutants and failure to fuse properly, resulting in persistent coloboma. Our findings indicate that limiting proliferation particularly in the RPE layer is a critical mechanism during OF closure.
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Affiliation(s)
- Wesley R Sun
- Department of Ophthalmology and Visual Sciences, VEI, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sara Ramirez
- Department of Ophthalmology and Visual Sciences, VEI, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
| | - Kelly E Spiller
- Department of Ophthalmology and Visual Sciences, VEI, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Yan Zhao
- Department of Ophthalmology and Visual Sciences, VEI, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Sabine Fuhrmann
- Department of Ophthalmology and Visual Sciences, VEI, Vanderbilt University Medical Center, Nashville, TN 37232, USA.,Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37240, USA
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15
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Cassar S, Dunn C, Ramos MF. Zebrafish as an Animal Model for Ocular Toxicity Testing: A Review of Ocular Anatomy and Functional Assays. Toxicol Pathol 2020; 49:438-454. [PMID: 33063651 DOI: 10.1177/0192623320964748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Xenobiotics make their way into organisms from diverse sources including diet, medication, and pollution. Our understanding of ocular toxicities from xenobiotics in humans, livestock, and wildlife is growing thanks to laboratory animal models. Anatomy and physiology are conserved among vertebrate eyes, and studies with common mammalian preclinical species (rodent, dog) can predict human ocular toxicity. However, since the eye is susceptible to toxicities that may not involve a histological correlate, and these species rely heavily on smell and hearing to navigate their world, discovering visual deficits can be challenging with traditional animal models. Alternative models capable of identifying functional impacts on vision and requiring minimal amounts of chemical are valuable assets to toxicology. Human and zebrafish eyes are anatomically and functionally similar, and it has been reported that several common human ocular toxicants cause comparable toxicity in zebrafish. Vision develops rapidly in zebrafish; the tiny larvae rely on visual cues as early as 4 days, and behavioral responses to those cues can be monitored in high-throughput fashion. This article describes the comparative anatomy of the zebrafish eye, the notable differences from the mammalian eye, and presents practical applications of this underutilized model for assessment of ocular toxicity.
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Affiliation(s)
- Steven Cassar
- Preclinical Safety, 419726AbbVie, Inc, North Chicago, IL, USA
| | - Christina Dunn
- Preclinical Safety, 419726AbbVie, Inc, North Chicago, IL, USA
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16
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Cardozo MJ, Almuedo-Castillo M, Bovolenta P. Patterning the Vertebrate Retina with Morphogenetic Signaling Pathways. Neuroscientist 2019; 26:185-196. [PMID: 31509088 DOI: 10.1177/1073858419874016] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The primordium of the vertebrate eye is composed of a pseudostratified and apparently homogeneous neuroepithelium, which folds inward to generate a bilayered optic cup. During these early morphogenetic events, the optic vesicle is patterned along three different axes-proximo-distal, dorso-ventral, and naso-temporal-and three major domains: the neural retina, the retinal pigment epithelium (RPE), and the optic stalk. These fundamental steps that enable the subsequent development of a functional eye, entail the precise coordination among genetic programs. These programs are driven by the interplay of signaling pathways and transcription factors, which progressively dictate how each tissue should evolve. Here, we discuss the contribution of the Hh, Wnt, FGF, and BMP signaling pathways to the early patterning of the retina. Comparative studies in different vertebrate species have shown that their morphogenetic activity is repetitively used to orchestrate the progressive specification of the eye with evolutionary conserved mechanisms that have been adapted to match the specific need of a given species.
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Affiliation(s)
- Marcos J Cardozo
- Centro de Biología Molecular "Severo Ochoa," (CSIC/UAM), Madrid, Spain.,CIBERER, ISCIII, Madrid, Spain
| | | | - Paola Bovolenta
- Centro de Biología Molecular "Severo Ochoa," (CSIC/UAM), Madrid, Spain.,CIBERER, ISCIII, Madrid, Spain
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17
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Cavodeassi F, Wilson SW. Looking to the future of zebrafish as a model to understand the genetic basis of eye disease. Hum Genet 2019; 138:993-1000. [PMID: 31422478 PMCID: PMC6710215 DOI: 10.1007/s00439-019-02055-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 07/31/2019] [Indexed: 02/07/2023]
Abstract
In this brief commentary, we provide some of our thoughts and opinions on the current and future use of zebrafish to model human eye disease, dissect pathological progression and advance in our understanding of the genetic bases of microphthalmia, andophthalmia and coloboma (MAC) in humans. We provide some background on eye formation in fish and conservation and divergence across vertebrates in this process, discuss different approaches for manipulating gene function and speculate on future research areas where we think research using fish may prove to be particularly effective.
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Affiliation(s)
- Florencia Cavodeassi
- Institute of Medical and Biomedical Education, St. George's, University of London, Cranmer Terrace, London, SW17 0RE, UK.
| | - Stephen W Wilson
- Department of Cell and Developmental Biology, Biosciences, UCL, Gower St, London, WC1E 6BT, UK
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