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Brinkmeier ML, Wang SQ, Pittman H, Cheung LY, Prasov L. Myelin regulatory factor ( Myrf ) is a critical early regulator of retinal pigment epithelial development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.591281. [PMID: 38746430 PMCID: PMC11092522 DOI: 10.1101/2024.04.26.591281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Myelin regulatory factor (Myrf) is a critical transcription factor in early retinal and retinal pigment epithelial development, and human variants in MYRF are a cause for nanophthalmos. Single cell RNA sequencing (scRNAseq) was performed on Myrf conditional knockout mice ( Rx>Cre Myrf fl/fl ) at 3 developmental timepoints. Myrf was expressed specifically in the RPE, and expression was abrogated in Rx>Cre Myrf fl/fl eyes. scRNAseq analysis revealed a loss of RPE cells at all timepoints resulting from cell death. GO-term analysis in the RPE revealed downregulation of melanogenesis and anatomic structure morphogenesis pathways, which were supported by electron microscopy and histologic analysis. Novel structural target genes including Ermn and Upk3b , along with macular degeneration and inherited retinal disease genes were identified as downregulated, and a strong upregulation of TGFß/BMP signaling and effectors was observed. Regulon analysis placed Myrf downstream of Pax6 and Mitf and upstream of Sox10 in RPE differentiation. Together, these results suggest a strong role for Myrf in the RPE maturation by regulating melanogenesis, cell survival, and cell structure, in part acting through suppression of TGFß signaling and activation of Sox10 . SUMMARY STATEMENT Myrf regulates RPE development, melanogenesis, and is important for cell structure and survival, in part through regulation of Ermn , Upk3b and Sox10, and BMP/TGFb signaling.
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Ovadia S, Cui G, Elkon R, Cohen-Gulkar M, Zuk-Bar N, Tuoc T, Jing N, Ashery-Padan R. SWI/SNF complexes are required for retinal pigmented epithelium differentiation and for the inhibition of cell proliferation and neural differentiation programs. Development 2023; 150:dev201488. [PMID: 37522516 PMCID: PMC10482007 DOI: 10.1242/dev.201488] [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: 11/27/2022] [Accepted: 07/14/2023] [Indexed: 08/01/2023]
Abstract
During embryonic development, tissue-specific transcription factors and chromatin remodelers function together to ensure gradual, coordinated differentiation of multiple lineages. Here, we define this regulatory interplay in the developing retinal pigmented epithelium (RPE), a neuroectodermal lineage essential for the development, function and maintenance of the adjacent retina. We present a high-resolution spatial transcriptomic atlas of the developing mouse RPE and the adjacent ocular mesenchyme obtained by geographical position sequencing (Geo-seq) of a single developmental stage of the eye that encompasses young and more mature ocular progenitors. These transcriptomic data, available online, reveal the key transcription factors and their gene regulatory networks during RPE and ocular mesenchyme differentiation. Moreover, conditional inactivation followed by Geo-seq revealed that this differentiation program is dependent on the activity of SWI/SNF complexes, shown here to control the expression and activity of RPE transcription factors and, at the same time, inhibit neural progenitor and cell proliferation genes. The findings reveal the roles of the SWI/SNF complexes in controlling the intersection between RPE and neural cell fates and the coupling of cell-cycle exit and differentiation.
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Affiliation(s)
- Shai Ovadia
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Guizhong Cui
- Guangzhou National Laboratory, Department of Basic Research, Guangzhou 510005, China
| | - Ran Elkon
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Mazal Cohen-Gulkar
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nitay Zuk-Bar
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
| | - Tran Tuoc
- Department of Human Genetics, Ruhr University of Bochum, 44791 Bochum, Germany
| | - Naihe Jing
- Guangzhou National Laboratory, Department of Basic Research, Guangzhou 510005, China
| | - Ruth Ashery-Padan
- Department of Human Molecular Genetics and Biochemistry, Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 69978, Israel
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Kim JM, Min KW, Kim YJ, Smits R, Basler K, Kim JW. Wnt/β-Catenin Signaling Pathway Is Necessary for the Specification but Not the Maintenance of the Mouse Retinal Pigment Epithelium. Mol Cells 2023; 46:441-450. [PMID: 37190767 PMCID: PMC10336276 DOI: 10.14348/molcells.2023.0029] [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: 02/06/2023] [Accepted: 03/19/2023] [Indexed: 05/17/2023] Open
Abstract
β-Catenin (Ctnnb1) has been shown to play critical roles in the development and maintenance of epithelial cells, including the retinal pigment epithelium (RPE). Ctnnb1 is not only a component of intercellular junctions in the epithelium, it also functions as a transcriptional regulator in the Wnt signaling pathway. To identify which of its functional modalities is critically involved in mouse RPE development and maintenance, we varied Ctnnb1 gene content and activity in mouse RPE lineage cells and tested their impacts on mouse eye development. We found that a Ctnnb1 double mutant (Ctnnb1dm), which exhibits impaired transcriptional activity, could not replace Ctnnb1 in the RPE, whereas Ctnnb1Y654E, which has reduced affinity for the junctions, could do so. Expression of the constitutively active Ctnnb1∆ex3 mutant also suppressed the development of RPE, instead facilitating a ciliary cell fate. However, the post-mitotic or mature RPE was insensitive to the loss, inactivation, or constitutive activation of Ctnnb1. Collectively, our results suggest that Ctnnb1 should be maintained within an optimal range to specify RPE through transcriptional regulation of Wnt target genes in the optic neuroepithelium.
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Affiliation(s)
- Jong-Myeong Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Kwang Wook Min
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - You-Joung Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Ron Smits
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, 3015 GD Rotterdam, The Netherlands
| | - Konrad Basler
- Department of Molecular Life Sciences, University of Zurich, CH-8057 Zurich, Switzerland
| | - Jin Woo Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
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Paşcalău R, Badea TC. Signaling - transcription interactions in mouse retinal ganglion cells early axon pathfinding -a literature review. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1180142. [PMID: 38983012 PMCID: PMC11182120 DOI: 10.3389/fopht.2023.1180142] [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: 03/05/2023] [Accepted: 04/21/2023] [Indexed: 07/11/2024]
Abstract
Sending an axon out of the eye and into the target brain nuclei is the defining feature of retinal ganglion cells (RGCs). The literature on RGC axon pathfinding is vast, but it focuses mostly on decision making events such as midline crossing at the optic chiasm or retinotopic mapping at the target nuclei. In comparison, the exit of RGC axons out of the eye is much less explored. The first checkpoint on the RGC axons' path is the optic cup - optic stalk junction (OC-OS). OC-OS development and the exit of the RGC pioneer axons out of the eye are coordinated spatially and temporally. By the time the optic nerve head domain is specified, the optic fissure margins are in contact and the fusion process is ongoing, the first RGCs are born in its proximity and send pioneer axons in the optic stalk. RGC differentiation continues in centrifugal waves. Later born RGC axons fasciculate with the more mature axons. Growth cones at the end of the axons respond to guidance cues to adopt a centripetal direction, maintain nerve fiber layer restriction and to leave the optic cup. Although there is extensive information on OC-OS development, we still have important unanswered questions regarding its contribution to the exit of the RGC axons out of the eye. We are still to distinguish the morphogens of the OC-OS from the axon guidance molecules which are expressed in the same place at the same time. The early RGC transcription programs responsible for axon emergence and pathfinding are also unknown. This review summarizes the molecular mechanisms for early RGC axon guidance by contextualizing mouse knock-out studies on OC-OS development with the recent transcriptomic studies on developing RGCs in an attempt to contribute to the understanding of human optic nerve developmental anomalies. The published data summarized here suggests that the developing optic nerve head provides a physical channel (the closing optic fissure) as well as molecular guidance cues for the pioneer RGC axons to exit the eye.
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Affiliation(s)
- Raluca Paşcalău
- Research and Development Institute, Transilvania University of Braşov, Braşov, Romania
- Ophthalmology Clinic, Cluj County Emergency Hospital, Cluj-Napoca, Romania
| | - Tudor Constantin Badea
- Research and Development Institute, Transilvania University of Braşov, Braşov, Romania
- National Center for Brain Research, Institutul de Cercetări pentru Inteligență Artificială, Romanian Academy, Bucharest, Romania
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5
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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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Bradshaw SN, Allison WT. Hagfish to Illuminate the Developmental and Evolutionary Origins of the Vertebrate Retina. Front Cell Dev Biol 2022; 10:822358. [PMID: 35155434 PMCID: PMC8826474 DOI: 10.3389/fcell.2022.822358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 01/07/2022] [Indexed: 11/13/2022] Open
Abstract
The vertebrate eye is a vital sensory organ that has long fascinated scientists, but the details of how this organ evolved are still unclear. The vertebrate eye is distinct from the simple photoreceptive organs of other non-vertebrate chordates and there are no clear transitional forms of the eye in the fossil record. To investigate the evolution of the eye we can examine the eyes of the most ancient extant vertebrates, the hagfish and lamprey. These jawless vertebrates are in an ideal phylogenetic position to study the origin of the vertebrate eye but data on eye/retina development in these organisms is limited. New genomic and gene expression data from hagfish and lamprey suggest they have many of the same genes for eye development and retinal neurogenesis as jawed vertebrates, but functional work to determine if these genes operate in retinogenesis similarly to other vertebrates is missing. In addition, hagfish express a marker of proliferative retinal cells (Pax6) near the margin of the retina, and adult retinal growth is apparent in some species. This finding of eye growth late into hagfish ontogeny is unexpected given the degenerate eye phenotype. Further studies dissecting retinal neurogenesis in jawless vertebrates would allow for comparison of the mechanisms of retinal development between cyclostome and gnathostome eyes and provide insight into the evolutionary origins of the vertebrate eye.
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Co-activation of Sonic hedgehog and Wnt signaling in murine retinal precursor cells drives ocular lesions with features of intraocular medulloepithelioma. Oncogenesis 2021; 10:78. [PMID: 34785636 PMCID: PMC8595639 DOI: 10.1038/s41389-021-00369-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/19/2021] [Accepted: 10/28/2021] [Indexed: 11/12/2022] Open
Abstract
Intraocular medulloepithelioma (IO-MEPL) is a rare embryonal ocular neoplasm, prevalently occurring in children. IO-MEPLs share histomorphological features with CNS embryonal tumors with multilayered rosettes (ETMRs), referred to as intracranial medulloepitheliomas. While Sonic hedgehog (SHH) and WNT signaling pathways are crucial for ETMR pathogenesis, the impact of these pathways on human IO-MEPL development is unclear. Gene expression analyses of human embryonal tumor samples revealed similar gene expression patterns and significant overrepresentation of SHH and WNT target genes in both IO-MEPL and ETMR. In order to unravel the function of Shh and Wnt signaling for IO-MEPL pathogenesis in vivo, both pathways were activated in retinal precursor cells in a time point specific manner. Shh and Wnt co-activation in early Sox2- or Rax-expressing precursor cells resulted in infiltrative ocular lesions that displayed extraretinal expansion. Histomorphological, immunohistochemical, and molecular features showed a strong concordance with human IO-MEPL. We demonstrate a relevant role of WNT and SHH signaling in IO-MEPL and report the first mouse model to generate tumor-like lesions with features of IO-MEPL. The presented data may be fundamental for comprehending IO-MEPL initiation and developing targeted therapeutic approaches.
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8
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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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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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10
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Chen HY, Lehmann OJ, Swaroop A. Genetics and therapy for pediatric eye diseases. EBioMedicine 2021; 67:103360. [PMID: 33975254 PMCID: PMC8122153 DOI: 10.1016/j.ebiom.2021.103360] [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: 12/17/2020] [Revised: 03/29/2021] [Accepted: 04/12/2021] [Indexed: 12/26/2022] Open
Abstract
Ocular morphogenesis in vertebrates is a highly organized process, orchestrated largely by intrinsic genetic programs that exhibit stringent spatiotemporal control. Alternations in these genetic instructions can lead to hereditary or nonhereditary congenital disorders, a major cause of childhood visual impairment, and contribute to common late-onset blinding diseases. Currently, limited treatment options exist for clinical phenotypes involving eye development. This review summarizes recent advances in our understanding of early-onset ocular disorders and highlights genetic complexities in development and diseases, specifically focusing on coloboma, congenital glaucoma and Leber congenital amaurosis. We also discuss innovative paradigms for potential therapeutic modalities.
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Affiliation(s)
- Holly Y Chen
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892 USA.
| | - Ordan J Lehmann
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Canada; Department of Medical Genetics, University of Alberta, Edmonton, Canada.
| | - Anand Swaroop
- Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892 USA.
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Zeng Y, Li M, Zou T, Chen X, Li Q, Li Y, Ge L, Chen S, Xu H. The Impact of Particulate Matter (PM2.5) on Human Retinal Development in hESC-Derived Retinal Organoids. Front Cell Dev Biol 2021; 9:607341. [PMID: 33644046 PMCID: PMC7907455 DOI: 10.3389/fcell.2021.607341] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 01/04/2021] [Indexed: 12/21/2022] Open
Abstract
Increasing evidence demonstrated that PM2.5 could cross the placenta and fetal blood-brain barrier, causing neurotoxicity of embryonic development. The retina, an embryologic extension of the central nervous system, is extremely sensitive and vulnerable to environmental insults. The adverse effects of PM2.5 exposure on the retina during embryonic neurodevelopment are still largely unknown. Our goal was to investigate the effect of PM2.5 on human retinal development, which was recapitulated by human embryonic stem cell (hESC)-derived retinal organoids (hEROs). In the present study, using the hEROs as the model, the influences and the mechanisms of PM2.5 on the developing retina were analyzed. It demonstrated that the formation rate of the hERO-derived neural retina (NR) was affected by PM2.5 in a concentration dosage-dependent manner. The areas of hEROs and the thickness of hERO-NRs were significantly reduced after PM2.5 exposure at the concentration of 25, 50, and 100 μg/ml, which was due to the decrease of proliferation and the increase of apoptosis. Although we did not spot significant effects on retinal differentiation, PM2.5 exposure did lead to hERO-NR cell disarranging and structural disorder, especially retinal ganglion cell dislocation. Transcriptome analysis showed that PM2.5 treatment was significantly associated with the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/AKT pathways and reduced the level of the fibroblast growth factors (FGFs), particularly FGF8 and FGF10. These results provided evidence that PM2.5 exposure potentially inhibited proliferation and increased apoptosis at the early development stage of the human NR, probably through the MAPK and PI3K/Akt pathway. Our study suggested that exposure to PM2.5 suppressed cell proliferation and promoted cell apoptosis, thereby contributing to abnormal human retinal development.
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Affiliation(s)
- Yuxiao Zeng
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Minghui Li
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Ting Zou
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Xi Chen
- Department of Ophthalmology, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Qiyou Li
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Yijian Li
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Lingling Ge
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Siyu Chen
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
| | - Haiwei Xu
- Southwest Hospital/Southwest Eye Hospital, Third Military Medical University (Army Medical University), Chongqing, China
- Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, Chongqing, China
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Multiple roles for Pax2 in the embryonic mouse eye. Dev Biol 2021; 472:18-29. [PMID: 33428890 DOI: 10.1016/j.ydbio.2020.12.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/23/2020] [Accepted: 12/24/2020] [Indexed: 02/07/2023]
Abstract
The vertebrate eye anlage grows out of the brain and folds into bilayered optic cups. The eye is patterned along multiple axes, precisely controlled by genetic programs, to delineate neural retina, pigment epithelium, and optic stalk tissues. Pax genes encode developmental regulators of key morphogenetic events, with Pax2 being essential for interpreting inductive signals, including in the eye. PAX2 mutations cause ocular coloboma, when the ventral optic fissure fails to close. Previous studies established that Pax2 is necessary for fissure closure and to maintain the neural retina -- glial optic stalk boundary. Using a Pax2GFP/+ knock-in allele we discovered that the mutant optic nerve head (ONH) lacks molecular boundaries with the retina and RPE, rendering the ONH larger than normal. This was preceded by ventronasal cup mispatterning, a burst of overproliferation and followed by optic cup apoptosis. Our findings support the hypothesis that ONH cells are tripotential, requiring Pax2 to remain committed to glial fates. This work extends current models of ocular development, contributes to broader understanding of tissue boundary formation and informs the underlying mechanisms of human coloboma.
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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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Eintracht J, Toms M, Moosajee M. The Use of Induced Pluripotent Stem Cells as a Model for Developmental Eye Disorders. Front Cell Neurosci 2020; 14:265. [PMID: 32973457 PMCID: PMC7468397 DOI: 10.3389/fncel.2020.00265] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/28/2020] [Indexed: 12/15/2022] Open
Abstract
Approximately one-third of childhood blindness is attributed to developmental eye disorders, of which 80% have a genetic cause. Eye morphogenesis is tightly regulated by a highly conserved network of transcription factors when disrupted by genetic mutations can result in severe ocular malformation. Human-induced pluripotent stem cells (hiPSCs) are an attractive tool to study early eye development as they are more physiologically relevant than animal models, can be patient-specific and their use does not elicit the ethical concerns associated with human embryonic stem cells. The generation of self-organizing hiPSC-derived optic cups is a major advancement to understanding mechanisms of ocular development and disease. Their development in vitro has been found to mirror that of the human eye and these early organoids have been used to effectively model microphthalmia caused by a VSX2 variant. hiPSC-derived optic cups, retina, and cornea organoids are powerful tools for future modeling of disease phenotypes and will enable a greater understanding of the pathophysiology of many other developmental eye disorders. These models will also provide an effective platform for identifying molecular therapeutic targets and for future clinical applications.
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Affiliation(s)
| | - Maria Toms
- UCL Institute of Ophthalmology, London, United Kingdom.,The Francis Crick Institute, London, United Kingdom
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, United Kingdom.,The Francis Crick Institute, London, United Kingdom.,Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom.,Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom
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Vickers E, Osypenko D, Clark C, Okur Z, Scheiffele P, Schneggenburger R. LTP of inhibition at PV interneuron output synapses requires developmental BMP signaling. Sci Rep 2020; 10:10047. [PMID: 32572071 PMCID: PMC7308402 DOI: 10.1038/s41598-020-66862-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 05/27/2020] [Indexed: 11/09/2022] Open
Abstract
Parvalbumin (PV)-expressing interneurons (PV-INs) mediate well-timed inhibition of cortical principal neurons, and plasticity of these interneurons is involved in map remodeling of primary sensory cortices during critical periods of development. To assess whether bone morphogenetic protein (BMP) signaling contributes to the developmental acquisition of the synapse- and plasticity properties of PV-INs, we investigated conditional/conventional double KO mice of BMP-receptor 1a (BMPR1a; targeted to PV-INs) and 1b (BMPR1a/1b (c)DKO mice). We report that spike-timing dependent LTP at the synapse between PV-INs and principal neurons of layer 4 in the auditory cortex was absent, concomitant with a decreased paired-pulse ratio (PPR). On the other hand, baseline synaptic transmission at this connection, and action potential (AP) firing rates of PV-INs were unchanged. To explore possible gene expression targets of BMP signaling, we measured the mRNA levels of the BDNF receptor TrkB and of P/Q-type Ca2+ channel α-subunits, but did not detect expression changes of the corresponding genes in PV-INs of BMPR1a/1b (c)DKO mice. Our study suggests that BMP-signaling in PV-INs during and shortly after the critical period is necessary for the expression of LTP at PV-IN output synapses, involving gene expression programs that need to be addressed in future work.
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Affiliation(s)
- Evan Vickers
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.,Institute of Neuroscience, University of Oregon, Eugene, OR, 97403, USA
| | - Denys Osypenko
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Christopher Clark
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.,Institute for Regenerative Medicine, University of Zürich, 8952, Schlieren, Switzerland
| | - Zeynep Okur
- Biozentrum, University of Basel, 4056, Basel, Switzerland
| | | | - Ralf Schneggenburger
- Laboratory of Synaptic Mechanisms, Brain Mind Institute, School of Life Science, École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
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Neuronal Reprogramming for Tissue Repair and Neuroregeneration. Int J Mol Sci 2020; 21:ijms21124273. [PMID: 32560072 PMCID: PMC7352898 DOI: 10.3390/ijms21124273] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/08/2020] [Accepted: 06/08/2020] [Indexed: 02/07/2023] Open
Abstract
Stem cell and cell reprogramming technology represent a rapidly growing field in regenerative medicine. A number of novel neural reprogramming methods have been established, using pluripotent stem cells (PSCs) or direct reprogramming, to efficiently derive specific neuronal cell types for therapeutic applications. Both in vitro and in vivo cellular reprogramming provide diverse therapeutic pathways for modeling neurological diseases and injury repair. In particular, the retina has emerged as a promising target for clinical application of regenerative medicine. Herein, we review the potential of neuronal reprogramming to develop regenerative strategy, with a particular focus on treating retinal degenerative diseases and discuss future directions and challenges in the field.
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