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Lusk S, LaPotin S, Presnell JS, Kwan KM. Increased Netrin downstream of overactive Hedgehog signaling disrupts optic fissure formation. Dev Dyn 2024. [PMID: 39166841 DOI: 10.1002/dvdy.733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2024] [Revised: 07/29/2024] [Accepted: 08/02/2024] [Indexed: 08/23/2024] Open
Abstract
BACKGROUND Uveal coloboma, a developmental eye defect, is caused by failed development of the optic fissure, a ventral structure in the optic stalk and cup where axons exit the eye and vasculature enters. The Hedgehog (Hh) signaling pathway regulates optic fissure development: loss-of-function mutations in the Hh receptor ptch2 produce overactive Hh signaling and can result in coloboma. We previously proposed a model where overactive Hh signaling disrupts optic fissure formation by upregulating transcriptional targets acting both cell- and non-cell-autonomously. Here, we examine the Netrin family of secreted ligands as candidate Hh target genes. RESULTS We find multiple Netrin ligands upregulated in the zebrafish ptch2 mutant during optic fissure development. Using a gain-of-function approach to overexpress Netrin in a spatiotemporally specific manner, we find that netrin1a or netrin1b overexpression is sufficient to cause coloboma and disrupt wild-type optic fissure formation. We used loss-of-function alleles, CRISPR/Cas9 mutagenesis, and morpholino knockdown to test if loss of Netrin can rescue coloboma in the ptch2 mutant: loss of netrin genes does not rescue the ptch2 mutant phenotype. CONCLUSION These results suggest that Netrin is sufficient but not required to disrupt optic fissure formation downstream of overactive Hh signaling in the ptch2 mutant.
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Affiliation(s)
- Sarah Lusk
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
| | - Sarah LaPotin
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
| | - Jason S Presnell
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
| | - Kristen M Kwan
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
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Chea S, Kreger J, Lopez-Burks ME, MacLean AL, Lander AD, Calof AL. Gastrulation-stage gene expression in Nipbl+/- mouse embryos foreshadows the development of syndromic birth defects. SCIENCE ADVANCES 2024; 10:eadl4239. [PMID: 38507484 PMCID: PMC10954218 DOI: 10.1126/sciadv.adl4239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 02/15/2024] [Indexed: 03/22/2024]
Abstract
In animal models, Nipbl deficiency phenocopies gene expression changes and birth defects seen in Cornelia de Lange syndrome, the most common cause of which is Nipbl haploinsufficiency. Previous studies in Nipbl+/- mice suggested that heart development is abnormal as soon as cardiogenic tissue is formed. To investigate this, we performed single-cell RNA sequencing on wild-type and Nipbl+/- mouse embryos at gastrulation and early cardiac crescent stages. Nipbl+/- embryos had fewer mesoderm cells than wild-type and altered proportions of mesodermal cell subpopulations. These findings were associated with underexpression of genes implicated in driving specific mesodermal lineages. In addition, Nanog was found to be overexpressed in all germ layers, and many gene expression changes observed in Nipbl+/- embryos could be attributed to Nanog overexpression. These findings establish a link between Nipbl deficiency, Nanog overexpression, and gene expression dysregulation/lineage misallocation, which ultimately manifest as birth defects in Nipbl+/- animals and Cornelia de Lange syndrome.
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Affiliation(s)
- Stephenson Chea
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California Irvine, Irvine, CA 92697, USA
- Center for Complex Biological Systems, University of California Irvine, Irvine, CA 92697, USA
| | - Jesse Kreger
- Department of Quantitative and Computational Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Martha E. Lopez-Burks
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California Irvine, Irvine, CA 92697, USA
- Center for Complex Biological Systems, University of California Irvine, Irvine, CA 92697, USA
| | - Adam L. MacLean
- Department of Quantitative and Computational Biology, Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Arthur D. Lander
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California Irvine, Irvine, CA 92697, USA
- Center for Complex Biological Systems, University of California Irvine, Irvine, CA 92697, USA
| | - Anne L. Calof
- Department of Developmental and Cell Biology, School of Biological Sciences, University of California Irvine, Irvine, CA 92697, USA
- Center for Complex Biological Systems, University of California Irvine, Irvine, CA 92697, USA
- Department of Anatomy and Neurobiology, School of Medicine, University of California Irvine, Irvine, CA 92697, USA
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Chea S, Kreger J, Lopez-Burks ME, MacLean AL, Lander AD, Calof AL. Gastrulation-stage gene expression in Nipbl +/- mouse embryos foreshadows the development of syndromic birth defects. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.16.558465. [PMID: 37905011 PMCID: PMC10614802 DOI: 10.1101/2023.10.16.558465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
In animal models, Nipbl-deficiency phenocopies gene expression changes and birth defects seen in Cornelia de Lange Syndrome (CdLS), the most common cause of which is Nipbl-haploinsufficiency. Previous studies in Nipbl+/- mice suggested that heart development is abnormal as soon as cardiogenic tissue is formed. To investigate this, we performed single-cell RNA-sequencing on wildtype (WT) and Nipbl+/- mouse embryos at gastrulation and early cardiac crescent stages. Nipbl+/- embryos had fewer mesoderm cells than WT and altered proportions of mesodermal cell subpopulations. These findings were associated with underexpression of genes implicated in driving specific mesodermal lineages. In addition, Nanog was found to be overexpressed in all germ layers, and many gene expression changes observed in Nipbl+/- embryos could be attributed to Nanog overexpression. These findings establish a link between Nipbl-deficiency, Nanog overexpression, and gene expression dysregulation/lineage misallocation, which ultimately manifest as birth defects in Nipbl+/- animals and CdLS. Teaser Gene expression changes during gastrulation of Nipbl-deficient mice shed light on early origins of structural birth defects.
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Selvarajah K, Tan JJ, Shaharuddin B. Corneal Epithelial Development and the Role of Induced Pluripotent Stem Cells for Regeneration. Curr Stem Cell Res Ther 2024; 19:292-306. [PMID: 36915985 DOI: 10.2174/1574888x18666230313094121] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 12/02/2022] [Accepted: 01/02/2023] [Indexed: 03/16/2023]
Abstract
Severe corneal disorders due to infective aetiologies, trauma, chemical injuries, and chronic cicatricial inflammations, are among vision-threatening pathologies leading to permanent corneal scarring. The whole cornea or lamellar corneal transplantation is often used as a last resort to restore vision. However, limited autologous tissue sources and potential adverse post-allotransplantation sequalae urge the need for more robust and strategic alternatives. Contemporary management using cultivated corneal epithelial transplantation has paved the way for utilizing stem cells as a regenerative potential. Humaninduced pluripotent stem cells (hiPSCs) can generate ectodermal progenitors and potentially be used for ocular surface regeneration. This review summarizes the process of corneal morphogenesis and the signaling pathways underlying the development of corneal epithelium, which is key to translating the maturation and differentiation process of hiPSCs in vitro. The current state of knowledge and methodology for driving efficient corneal epithelial cell differentiation from pluripotent stem cells are highlighted.
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Affiliation(s)
- Komathi Selvarajah
- Advanced Medical and Dental Institute, Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Penang, Malaysia
- Department of Microbiology, Faculty of Medicine, Asian Institute of Medical Sciences and Technology (AIMST) University, Kedah, Malaysia
| | - Jun Jie Tan
- Department of Microbiology, Faculty of Medicine, Asian Institute of Medical Sciences and Technology (AIMST) University, Kedah, Malaysia
| | - Bakiah Shaharuddin
- Department of Microbiology, Faculty of Medicine, Asian Institute of Medical Sciences and Technology (AIMST) University, Kedah, Malaysia
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Ponnimbaduge Perera P, Perez Guerra D, Riddle MR. The Mexican Tetra, Astyanax mexicanus, as a Model System in Cell and Developmental Biology. Annu Rev Cell Dev Biol 2023; 39:23-44. [PMID: 37437210 DOI: 10.1146/annurev-cellbio-012023-014003] [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: 07/14/2023]
Abstract
Our understanding of cell and developmental biology has been greatly aided by a focus on a small number of model organisms. However, we are now in an era where techniques to investigate gene function can be applied across phyla, allowing scientists to explore the diversity and flexibility of developmental mechanisms and gain a deeper understanding of life. Researchers comparing the eyeless cave-adapted Mexican tetra, Astyanax mexicanus, with its river-dwelling counterpart are revealing how the development of the eyes, pigment, brain, cranium, blood, and digestive system evolves as animals adapt to new environments. Breakthroughs in our understanding of the genetic and developmental basis of regressive and constructive trait evolution have come from A. mexicanus research. They include understanding the types of mutations that alter traits, which cellular and developmental processes they affect, and how they lead to pleiotropy. We review recent progress in the field and highlight areas for future investigations that include evolution of sex differentiation, neural crest development, and metabolic regulation of embryogenesis.
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Affiliation(s)
| | | | - Misty R Riddle
- Department of Biology, University of Nevada, Reno, Nevada, USA;
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Casey MA, Lusk S, Kwan KM. Eye Morphogenesis in Vertebrates. Annu Rev Vis Sci 2023; 9:221-243. [PMID: 37040791 DOI: 10.1146/annurev-vision-100720-111125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Proper eye structure is essential for visual function: Multiple essential eye tissues must take shape and assemble into a precise three-dimensional configuration. Accordingly, alterations to eye structure can lead to pathological conditions of visual impairment. Changes in eye shape can also be adaptive over evolutionary time. Eye structure is first established during development with the formation of the optic cup, which contains the neural retina, retinal pigment epithelium, and lens. This crucial yet deceptively simple hemispherical structure lays the foundation for all later elaborations of the eye. Building on descriptions of the embryonic eye that started with hand drawings and micrographs, the field is beginning to identify mechanisms driving dynamic changes in three-dimensional cell and tissue shape. A combination of molecular genetics, imaging, and pharmacological approaches is defining connections among transcription factors, signaling pathways, and the intracellular machinery governing the emergence of this crucial structure.
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Affiliation(s)
- Macaulie A Casey
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA; , ,
| | - Sarah Lusk
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA; , ,
| | - Kristen M Kwan
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA; , ,
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Jing J, Wu Z, Wang J, Luo G, Lin H, Fan Y, Zhou C. Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies. Signal Transduct Target Ther 2023; 8:315. [PMID: 37596267 PMCID: PMC10439210 DOI: 10.1038/s41392-023-01559-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 07/05/2023] [Indexed: 08/20/2023] Open
Abstract
The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.
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Affiliation(s)
- Junjun Jing
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Zhuoxuan Wu
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Jiahe Wang
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Guowen Luo
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Hengyi Lin
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Yi Fan
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
- Department of Cariology and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
| | - Chenchen Zhou
- State Key Laboratory of Oral Diseases and National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
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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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George A, Lee J, Liu J, Kim S, Brooks BP. Zebrafish model of RERE syndrome recapitulates key ophthalmic defects that are rescued by small molecule inhibitor of shh signaling. Dev Dyn 2022; 252:495-509. [PMID: 36576487 DOI: 10.1002/dvdy.561] [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: 04/05/2022] [Revised: 12/02/2022] [Accepted: 12/12/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND RERE is a highly conserved transcriptional co-regulator that is associated with a human neurodevelopmental disorder with or without anomalies of the brain, eye, or heart (NEDBEH, OMIM: 616975). RESULTS We show that the zebrafish rerea mutant (babyface) robustly recapitulates optic fissure closure defects resulting from loss of RERE function, as observed in humans. These defects result from expansion of proximal retinal optic stalk (OS) and reduced expression of some of the ventral retinal fate genes due to deregulated protein signaling. Using zebrafish and cell-based assays, we determined that NEDBEH-associated human RERE variants function as hypomorphs in their ability to repress shh signaling and some exhibit abnormal nuclear localization. Inhibiting shh signaling by the protein inhibitor HPI-1 rescues coloboma, confirming our observation that coloboma in rerea mutants is indeed due to deregulation of shh signaling. CONCLUSIONS Zebrafish rerea mutants exhibit OS and optic fissure closure defects. The optic fissure closure defect was rescued by an shh signaling inhibitor, suggesting that this defect could arise due to deregulated shh signaling.
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Affiliation(s)
- Aman George
- Pediatric Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Jerry Lee
- Pediatric Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - James Liu
- Pediatric Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Suzie Kim
- Pediatric Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Brian P Brooks
- Pediatric Developmental & Genetic Ophthalmology Section, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
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Manuel M, Tan KB, Kozic Z, Molinek M, Marcos TS, Razak MFA, Dobolyi D, Dobie R, Henderson BEP, Henderson NC, Chan WK, Daw MI, Mason JO, Price DJ. Pax6 limits the competence of developing cerebral cortical cells to respond to inductive intercellular signals. PLoS Biol 2022; 20:e3001563. [PMID: 36067211 PMCID: PMC9481180 DOI: 10.1371/journal.pbio.3001563] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 09/16/2022] [Accepted: 07/08/2022] [Indexed: 12/13/2022] Open
Abstract
The development of stable specialized cell types in multicellular organisms relies on mechanisms controlling inductive intercellular signals and the competence of cells to respond to such signals. In developing cerebral cortex, progenitors generate only glutamatergic excitatory neurons despite being exposed to signals with the potential to initiate the production of other neuronal types, suggesting that their competence is limited. Here, we tested the hypothesis that this limitation is due to their expression of transcription factor Pax6. We used bulk and single-cell RNAseq to show that conditional cortex-specific Pax6 deletion from the onset of cortical neurogenesis allowed some progenitors to generate abnormal lineages resembling those normally found outside the cortex. Analysis of selected gene expression showed that the changes occurred in specific spatiotemporal patterns. We then compared the responses of control and Pax6-deleted cortical cells to in vivo and in vitro manipulations of extracellular signals. We found that Pax6 loss increased cortical progenitors' competence to generate inappropriate lineages in response to extracellular factors normally present in developing cortex, including the morphogens Shh and Bmp4. Regional variation in the levels of these factors could explain spatiotemporal patterns of fate change following Pax6 deletion in vivo. We propose that Pax6's main role in developing cortical cells is to minimize the risk of their development being derailed by the potential side effects of morphogens engaged contemporaneously in other essential functions.
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Affiliation(s)
- Martine Manuel
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Kai Boon Tan
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Zrinko Kozic
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael Molinek
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Tiago Sena Marcos
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Maizatul Fazilah Abd Razak
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Dániel Dobolyi
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Ross Dobie
- Centre for Inflammation Research, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Beth E. P. Henderson
- Centre for Inflammation Research, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Neil C. Henderson
- Centre for Inflammation Research, University of Edinburgh, Queen’s Medical Research Institute, Edinburgh, United Kingdom
| | - Wai Kit Chan
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - Michael I. Daw
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, Zhejiang, People’s Republic of China
| | - John O. Mason
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
| | - David J. Price
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, United Kingdom
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Ochi S, Manabe S, Kikkawa T, Osumi N. Thirty Years' History since the Discovery of Pax6: From Central Nervous System Development to Neurodevelopmental Disorders. Int J Mol Sci 2022; 23:6115. [PMID: 35682795 PMCID: PMC9181425 DOI: 10.3390/ijms23116115] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 05/19/2022] [Accepted: 05/27/2022] [Indexed: 12/23/2022] Open
Abstract
Pax6 is a sequence-specific DNA binding transcription factor that positively and negatively regulates transcription and is expressed in multiple cell types in the developing and adult central nervous system (CNS). As indicated by the morphological and functional abnormalities in spontaneous Pax6 mutant rodents, Pax6 plays pivotal roles in various biological processes in the CNS. At the initial stage of CNS development, Pax6 is responsible for brain patterning along the anteroposterior and dorsoventral axes of the telencephalon. Regarding the anteroposterior axis, Pax6 is expressed inversely to Emx2 and Coup-TF1, and Pax6 mutant mice exhibit a rostral shift, resulting in an alteration of the size of certain cortical areas. Pax6 and its downstream genes play important roles in balancing the proliferation and differentiation of neural stem cells. The Pax6 gene was originally identified in mice and humans 30 years ago via genetic analyses of the eye phenotypes. The human PAX6 gene was discovered in patients who suffer from WAGR syndrome (i.e., Wilms tumor, aniridia, genital ridge defects, mental retardation). Mutations of the human PAX6 gene have also been reported to be associated with autism spectrum disorder (ASD) and intellectual disability. Rodents that lack the Pax6 gene exhibit diverse neural phenotypes, which might lead to a better understanding of human pathology and neurodevelopmental disorders. This review describes the expression and function of Pax6 during brain development, and their implications for neuropathology.
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Affiliation(s)
| | | | | | - Noriko Osumi
- Department of Developmental Neuroscience, Tohoku University Graduate School of Medicine, Sendai 980-8575, Japan; (S.O.); (S.M.); (T.K.)
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Gaca PJ, Lewandowicz M, Lipczynska-Lewandowska M, Simon M, Matos PAW, Doulis A, Rokohl AC, Heindl LM. Embryonic Development of the Orbit. Klin Monbl Augenheilkd 2022; 239:19-26. [PMID: 35120374 DOI: 10.1055/a-1709-1310] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The embryonic and fetal development of the orbit comprises a series of sequential events, starting with the fertilization of the ovum and extending until birth. Most of the publications dealing with orbital morphogenesis describe the sequential development of each germinal layer, the ectoderm with its neuroectoderm derivative and the mesoderm. This approach provides a clear understanding of the mode of development of each layer but does not give the reader a general picture of the structure of the orbit within any specified time frame. In order to enhance our understanding of the developmental anatomy of the orbit, the authors have summarized the recent developments in orbital morphogenesis, a temporally precise and morphogenetically intricate process. Understanding this multidimensional process of development in prenatal life, identifying and linking signaling cascades, as well as the regulatory genes linked to existing diseases, may pave the way for advanced molecular diagnostic testing, developing minimally invasive interventions, and the use of progenitor/stem cell and even regenerative therapy.
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Affiliation(s)
- Piotr Jakub Gaca
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Michael Lewandowicz
- Department of Oncological Surgery, Multidisciplinary M. Copernicus Voivodeship Center for Oncology and Traumatology, Lodz, Poland
| | - Malgorzata Lipczynska-Lewandowska
- Clinic and Policlinic of Dental and Maxillofacial Surgery, Central Clinical Hospital of the Medical University of Lodz, Lodz, Poland
| | - Michael Simon
- Center for Integrated Oncology (CIO) Aachen - Bonn - Cologne, Duesseldorf, Cologne, Germany
| | - Philomena A Wawer Matos
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Alexandros Doulis
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Alexander C Rokohl
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Ludwig M Heindl
- Department of Ophthalmology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.,Center for Integrated Oncology (CIO) Aachen - Bonn - Cologne, Duesseldorf, Cologne, Germany
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13
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Wahlin KJ, Cheng J, Jurlina SL, Jones MK, Dash NR, Ogata A, Kibria N, Ray S, Eldred KC, Kim C, Heng JS, Phillips J, Johnston RJ, Gamm DM, Berlinicke C, Zack DJ. CRISPR Generated SIX6 and POU4F2 Reporters Allow Identification of Brain and Optic Transcriptional Differences in Human PSC-Derived Organoids. Front Cell Dev Biol 2021; 9:764725. [PMID: 34869356 PMCID: PMC8635054 DOI: 10.3389/fcell.2021.764725] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/11/2021] [Indexed: 01/29/2023] Open
Abstract
Human pluripotent stem cells (PSCs) represent a powerful tool to investigate human eye development and disease. When grown in 3D, they can self-assemble into laminar organized retinas; however, variation in the size, shape and composition of individual organoids exists. Neither the microenvironment nor the timing of critical growth factors driving retinogenesis are fully understood. To explore early retinal development, we developed a SIX6-GFP reporter that enabled the systematic optimization of conditions that promote optic vesicle formation. We demonstrated that early hypoxic growth conditions enhanced SIX6 expression and promoted eye formation. SIX6 expression was further enhanced by sequential inhibition of Wnt and activation of sonic hedgehog signaling. SIX6 + optic vesicles showed RNA expression profiles that were consistent with a retinal identity; however, ventral diencephalic markers were also present. To demonstrate that optic vesicles lead to bona fide "retina-like" structures we generated a SIX6-GFP/POU4F2-tdTomato dual reporter line that labeled the entire developing retina and retinal ganglion cells, respectively. Additional brain regions, including the hypothalamus and midbrain-hindbrain (MBHB) territories were identified by harvesting SIX6 + /POU4F2- and SIX6- organoids, respectively. Using RNAseq to study transcriptional profiles we demonstrated that SIX6-GFP and POU4F2-tdTomato reporters provided a reliable readout for developing human retina, hypothalamus, and midbrain/hindbrain organoids.
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Affiliation(s)
- Karl J. Wahlin
- Shiley Eye Institute, University of California, San Diego, San Diego, CA, United States,*Correspondence: Karl J. Wahlin,
| | - Jie Cheng
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Shawna L. Jurlina
- Shiley Eye Institute, University of California, San Diego, San Diego, CA, United States
| | - Melissa K. Jones
- Shiley Eye Institute, University of California, San Diego, San Diego, CA, United States
| | - Nicholas R. Dash
- Shiley Eye Institute, University of California, San Diego, San Diego, CA, United States
| | - Anna Ogata
- Shiley Eye Institute, University of California, San Diego, San Diego, CA, United States
| | - Nawal Kibria
- Shiley Eye Institute, University of California, San Diego, San Diego, CA, United States
| | - Sunayan Ray
- Shiley Eye Institute, University of California, San Diego, San Diego, CA, United States
| | - Kiara C. Eldred
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Catherine Kim
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Jacob S. Heng
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States,Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, United States,Department of Ophthalmology and Visual Science, Yale School of Medicine, New Haven, CT, United States
| | - Jenny Phillips
- Waisman Center, University of Wisconsin-Madison, Madison, WI, United States
| | - Robert J. Johnston
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - David M. Gamm
- Waisman Center, University of Wisconsin-Madison, Madison, WI, United States,Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, United States,McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Cynthia Berlinicke
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Donald J. Zack
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, United States,Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, United States,Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, United States,Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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14
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Lusk S, Kwan KM. Pax2a, but not pax2b, influences cell survival and periocular mesenchyme localization to facilitate zebrafish optic fissure closure. Dev Dyn 2021; 251:625-644. [PMID: 34535934 PMCID: PMC8930785 DOI: 10.1002/dvdy.422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/23/2021] [Accepted: 09/13/2021] [Indexed: 11/09/2022] Open
Abstract
Background Pax2 is required for optic fissure development in many organisms, including humans and zebrafish. Zebrafish loss‐of‐function mutations in pax2a display coloboma, yet the etiology of the morphogenetic defects is unclear. Further, pax2 is duplicated in zebrafish, and a role for pax2b in optic fissure development has not been examined. Results Using a combination of imaging and molecular genetics, we interrogated a potential role for pax2b and examined how loss of pax2 affects optic fissure development. Although optic fissure formation appears normal in pax2 mutants, an endothelial‐specific subset of periocular mesenchyme (POM) fails to initially localize within the optic fissure, yet both neural crest and endothelial‐derived POM ectopically accumulate at later stages in pax2a and pax2a; pax2b mutants. Apoptosis is not up‐regulated within the optic fissure in pax2 mutants, yet cell death is increased in tissues outside of the optic fissure, and when apoptosis is inhibited, coloboma is partially rescued. In contrast to pax2a, loss of pax2b does not appear to affect optic fissure morphogenesis. Conclusions Our results suggest that pax2a, but not pax2b, supports cell survival outside of the optic fissure and POM abundance within it to facilitate optic fissure closure. Zebrafish pax2a null mutants display a defect in optic fissure closure and coloboma Loss of pax2b does not affect optic fissure development An endothelial‐specific subset of periocular mesenchyme cells fails to initially localize to the optic fissure in pax2a mutants At a later stage of optic fissure development both neural crest and endothelial‐derived periocular mesenchyme ectopically accumulate within the optic fissure Pax2a mutants have increased apoptosis in surrounding tissues, but not within the optic fissure margin cells, and apoptosis in part underlies the coloboma phenotype
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Affiliation(s)
- Sarah Lusk
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
| | - Kristen M Kwan
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, USA
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15
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Ho EK, Stearns T. Hedgehog signaling and the primary cilium: implications for spatial and temporal constraints on signaling. Development 2021; 148:dev195552. [PMID: 33914866 PMCID: PMC8126410 DOI: 10.1242/dev.195552] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The mechanisms of vertebrate Hedgehog signaling are linked to the biology of the primary cilium, an antenna-like organelle that projects from the surface of most vertebrate cell types. Although the advantages of restricting signal transduction to cilia are often noted, the constraints imposed are less frequently considered, and yet they are central to how Hedgehog signaling operates in developing tissues. In this Review, we synthesize current understanding of Hedgehog signal transduction, ligand secretion and transport, and cilia dynamics to explore the temporal and spatial constraints imposed by the primary cilium on Hedgehog signaling in vivo.
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Affiliation(s)
- Emily K. Ho
- Department of Developmental Biology, Stanford School of Medicine, Stanford, CA 94305, USA
| | - Tim Stearns
- Department of Biology, Stanford University, Stanford, CA 94305, USA
- Department of Genetics, Stanford School of Medicine, Stanford, CA 94305, USA
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16
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Torres-Paz J, Rétaux S. Pescoids and Chimeras to Probe Early Evo-Devo in the Fish Astyanax mexicanus. Front Cell Dev Biol 2021; 9:667296. [PMID: 33928092 PMCID: PMC8078105 DOI: 10.3389/fcell.2021.667296] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 03/25/2021] [Indexed: 12/31/2022] Open
Abstract
The fish species Astyanax mexicanus with its sighted and blind eco-morphotypes has become an original model to challenge vertebrate developmental evolution. Recently, we demonstrated that phenotypic evolution can be impacted by early developmental events starting from the production of oocytes in the fish ovaries. A. mexicanus offers an amenable model to test the influence of maternal determinants on cell fate decisions during early development, yet the mechanisms by which the information contained in the eggs is translated into specific developmental programs remain obscure due to the lack of specific tools in this emergent model. Here we describe methods for the generation of pescoids from yolkless-blastoderm explants to test the influence of embryonic and extraembryonic tissues on cell fate decisions, as well as the production of chimeric embryos obtained by intermorph cell transplantations to probe cell autonomous or non-autonomous processes. We show that Astyanax pescoids have the potential to recapitulate the main ontogenetic events observed in intact embryos, including the internalization of mesodermal progenitors and eye development, as followed with zic:GFP reporter lines. In addition, intermorph cell grafts resulted in proper integration of exogenous cells into the embryonic tissues, with lineages becoming more restricted from mid-blastula to gastrula. The implementation of these approaches in A. mexicanus will bring new light on the cascades of events, from the maternal pre-patterning of the early embryo to the evolution of brain regionalization.
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Affiliation(s)
- Jorge Torres-Paz
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, Gif-sur-Yvette, France
| | - Sylvie Rétaux
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay, Gif-sur-Yvette, France
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17
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Dhakal S, Rotem-Bamberger S, Sejd JR, Sebbagh M, Ronin N, Frey RA, Beitsch M, Batty M, Taler K, Blackerby JF, Inbal A, Stenkamp DL. Selective Requirements for Vascular Endothelial Cells and Circulating Factors in the Regulation of Retinal Neurogenesis. Front Cell Dev Biol 2021; 9:628737. [PMID: 33898420 PMCID: PMC8060465 DOI: 10.3389/fcell.2021.628737] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/17/2021] [Indexed: 01/01/2023] Open
Abstract
Development of the vertebrate eye requires signaling interactions between neural and non-neural tissues. Interactions between components of the vascular system and the developing neural retina have been difficult to decipher, however, due to the challenges of untangling these interactions from the roles of the vasculature in gas exchange. Here we use the embryonic zebrafish, which is not yet reliant upon hemoglobin-mediated oxygen transport, together with genetic strategies for (1) temporally-selective depletion of vascular endothelial cells, (2) elimination of blood flow through the circulation, and (3) elimination of cells of the erythroid lineage, including erythrocytes. The retinal phenotypes in these genetic systems were not identical, with endothelial cell-depleted retinas displaying laminar disorganization, cell death, reduced proliferation, and reduced cell differentiation. In contrast, the lack of blood flow resulted in a milder retinal phenotype showing reduced proliferation and reduced cell differentiation, indicating that an endothelial cell-derived factor(s) is/are required for laminar organization and cell survival. The lack of erythrocytes did not result in an obvious retinal phenotype, confirming that defects in retinal development that result from vascular manipulations are not due to poor gas exchange. These findings underscore the importance of the cardiovascular system supporting and controlling retinal development in ways other than supplying oxygen. In addition, these findings identify a key developmental window for these interactions and point to distinct functions for vascular endothelial cells vs. circulating factors.
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Affiliation(s)
- Susov Dhakal
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Shahar Rotem-Bamberger
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Josilyn R Sejd
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Meyrav Sebbagh
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Nathan Ronin
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ruth A Frey
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Mya Beitsch
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Megan Batty
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States.,Department of Biology, Gonzaga University, Spokane, WA, United States
| | - Kineret Taler
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Jennifer F Blackerby
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States.,Department of Biology, Gonzaga University, Spokane, WA, United States
| | - Adi Inbal
- Department of Medical Neurobiology, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Deborah L Stenkamp
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
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18
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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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19
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Grocott T, Lozano-Velasco E, Mok GF, Münsterberg AE. The Pax6 master control gene initiates spontaneous retinal development via a self-organising Turing network. Development 2020; 147:dev185827. [PMID: 33214222 PMCID: PMC7774904 DOI: 10.1242/dev.185827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 11/05/2020] [Indexed: 12/14/2022]
Abstract
Understanding how complex organ systems are assembled from simple embryonic tissues is a major challenge. Across the animal kingdom a great diversity of visual organs are initiated by a 'master control gene' called Pax6, which is both necessary and sufficient for eye development. Yet precisely how Pax6 achieves this deeply homologous function is poorly understood. Using the chick as a model organism, we show that vertebrate Pax6 interacts with a pair of morphogen-coding genes, Tgfb2 and Fst, to form a putative Turing network, which we have computationally modelled. Computer simulations suggest that this gene network is sufficient to spontaneously polarise the developing retina, establishing the first organisational axis of the eye and prefiguring its further development. Our findings reveal how retinal self-organisation may be initiated independently of the highly ordered tissue interactions that help to assemble the eye in vivo These results help to explain how stem cell aggregates spontaneously self-organise into functional eye-cups in vitro We anticipate these findings will help to underpin retinal organoid technology, which holds much promise as a platform for disease modelling, drug development and regenerative therapies.
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Affiliation(s)
- Timothy Grocott
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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20
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Fiore L, Takata N, Acosta S, Ma W, Pandit T, Oxendine M, Oliver G. Optic vesicle morphogenesis requires primary cilia. Dev Biol 2020; 462:119-128. [PMID: 32169553 PMCID: PMC8167498 DOI: 10.1016/j.ydbio.2020.02.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 01/28/2020] [Accepted: 02/04/2020] [Indexed: 12/25/2022]
Abstract
Arl13b is a gene known to regulate ciliogenesis. Functional alterations in this gene's activity have been associated with Joubert syndrome. We found that in Arl13 null mouse embryos the orientation of the optic cup is inverted, such that the lens is abnormally surrounded by an inverted optic cup whose retina pigmented epithelium is oddly facing the surface ectoderm. Loss of Arl13b leads to the disruption of optic vesicle's patterning and expansion of ventral fates. We show that this phenotype is consequence of miss-regulation of Sonic hedgehog (Shh) signaling and demonstrate that the Arl13b-/- eye phenotype can be rescued by deletion of Gli2, a downstream effector of the Shh pathway. This work identified an unexpected role of primary cilia during the morphogenetic movements required for the formation of the eye.
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Affiliation(s)
- Luciano Fiore
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA
| | - Nozomu Takata
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA
| | - Sandra Acosta
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA; Institute of Evolutive Biology, Pompeu Fabra University, Barcelona, Spain
| | - Wanshu Ma
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA
| | - Tanushree Pandit
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Michael Oxendine
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA
| | - Guillermo Oliver
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA.
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21
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Emerson SE, Stergas HR, Bupp-Chickering SO, Ebert AM. Shootin-1 is required for nervous system development in zebrafish. Dev Dyn 2020; 249:1285-1295. [PMID: 32406957 DOI: 10.1002/dvdy.194] [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: 06/07/2019] [Revised: 04/09/2020] [Accepted: 05/05/2020] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Semaphorin6A (Sema6A) and its PlexinA2 (PlxnA2) receptor canonically function as repulsive axon guidance cues. To understand downstream signaling mechanisms, we performed a microarray screen and identified the "clutch molecule" shootin-1 (shtn-1) as a transcriptionally repressed target. Shtn-1 is a key proponent of cell migration and neuronal polarization and must be regulated during nervous system development. The mechanisms of Shtn-1 regulation and the phenotypic consequences of loss of repression are poorly understood. RESULTS We demonstrate shtn-1 overexpression results in impaired migration of the optic vesicles, lack of retinal pigmented epithelium, and pathfinding errors of retinotectal projections. We also observed patterning defects in the peripheral nervous system. Importantly, these phenotypes were rescued by overexpressing PlxnA2. CONCLUSIONS We demonstrate a functional role for repression of shtn-1 by PlxnA2 in development of the eyes and peripheral nervous system in zebrafish. These results demonstrate that careful regulation of shtn-1 is critical for development of the nervous system.
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Affiliation(s)
- Sarah E Emerson
- Department of Biology, University of Vermont, Burlington, Vermont, USA
| | - Helaina R Stergas
- Department of Biology, University of Vermont, Burlington, Vermont, USA
| | | | - Alicia M Ebert
- Department of Biology, University of Vermont, Burlington, Vermont, USA
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22
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Kansara K, Paruthi A, Misra SK, Karakoti AS, Kumar A. Montmorillonite clay and humic acid modulate the behavior of copper oxide nanoparticles in aqueous environment and induces developmental defects in zebrafish embryo. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113313. [PMID: 31600709 DOI: 10.1016/j.envpol.2019.113313] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 09/24/2019] [Accepted: 09/26/2019] [Indexed: 06/10/2023]
Abstract
Copper oxide nanoparticles (CuO NPs) is one of the most commonly used metal oxide nanoparticles for commercial and industrial products. An increase in the manufacturing and use of the CuO NPs based products has increased the likelihood of their release into the aquatic environment. This has attracted major attention among researchers to explore their impact in human as well as environmental systems. CuO NPs, once released into the environment interact with the biotic and abiotic constituents of the ecosystem. Hence the objective of the study was to provide a holistic understanding of the effect of abiotic factors on the stability and aggregation of CuO NPs and its correlation with their effect on the development of zebrafish embryo. It has been observed that the bioavailability of CuO NPs decrease in presence of humic acid (HA) and heteroagglomeration of CuO NPs occurs with clay minerals. CuO NPs, CuO NPs + HA and CuO NPs + Clay significantly altered the expression of genes involved in development of dorsoventral axis and neural network of zebrafish embryos. However, the presence of HA with clay showed protective effect on zebrafish embryo development. These findings provide new insights into the interaction of NPs with abiotic factors and combined effects of such complexes on developing zebrafish embryos genetic markers.
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Affiliation(s)
- Krupa Kansara
- Biological and Life Sciences, School of Arts and Science, Ahmedabad University, Navrangpura, Ahmedabad, Gujarat, India
| | - Archini Paruthi
- Materials Science and Engineering, Indian Institute of Technology, Gandhinagar, Gujarat, India
| | - Superb K Misra
- Materials Science and Engineering, Indian Institute of Technology, Gandhinagar, Gujarat, India
| | - Ajay S Karakoti
- Biological and Life Sciences, School of Arts and Science, Ahmedabad University, Navrangpura, Ahmedabad, Gujarat, India; School of Engineering, The University of Newcastle, Australia.
| | - Ashutosh Kumar
- Biological and Life Sciences, School of Arts and Science, Ahmedabad University, Navrangpura, Ahmedabad, Gujarat, India.
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23
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Cao M, Ouyang J, Liang H, Guo J, Lin S, Yang S, Xie T, Chen S. Regional Gene Expression Profile Comparison Reveals the Unique Transcriptome of the Optic Fissure. Invest Ophthalmol Vis Sci 2019; 59:5773-5784. [PMID: 30521666 DOI: 10.1167/iovs.18-23962] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The optic fissure (OF) is a transient opening in the ventral optic cup (OC) that acts as a passage for blood vessels and retinal ganglion cell axons during early eye development. Failure to close the OF is the developmental basis for uveal coloboma, a congenital blinding eye disease that significantly contributes to childhood blindness. Genes specifically expressed in the OF region may play important roles in OF development and function. The aim of this study was to characterize the transcriptome of OC cells in the OF region and investigate the function of OF-specific genes during OF closure. Methods Laser-assisted microdissection was used to collect different regions of OC tissues. Microarray analysis was used to obtain and compare gene expression profiles of different OC regions. RNA in situ hybridization (ISH) was used to further characterize OF-specific gene expression patterns. Morpholino knockdown in zebrafish was used to study the function of a newly discovered OF-specific gene during OF closure. Results Microarray comparison revealed that the OC at the OF region exhibited a unique gene expression profile. OC expression patterns of a number of newly discovered OF-specific genes were confirmed by ISH. Morpholino knockdown and downstream target expression and function analysis demonstrated that afap1l2, a newly discovered OF-specific gene, controls OF closure by regulating pax2a expression. Conclusions Our study characterized the unique transcriptome of the OF region of the OC and demonstrated the essential role of a newly discovered OF-specific gene in OF closure. This study provides a valuable foundation for future mechanism dissection in OF development and physiology, and for human coloboma etiology exploration.
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Affiliation(s)
- Mingzhe Cao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jiamin Ouyang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Huilin Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jingyi Guo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Siyuan Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shulan Yang
- Translational Medicine Centre, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ting Xie
- Stowers Institute for Medical Research, Kansas City, Missouri, United States
| | - Shuyi Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.,Guangdong Province Key Laboratory of Brain Function and Disease, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
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24
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An update on the genetics of ocular coloboma. Hum Genet 2019; 138:865-880. [PMID: 31073883 DOI: 10.1007/s00439-019-02019-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 04/19/2019] [Indexed: 01/04/2023]
Abstract
Ocular coloboma is an uncommon, but often severe, sight-threatening condition that can be identified from birth. This congenital anomaly is thought to be caused by maldevelopment of optic fissure closure during early eye morphogenesis. It has been causally linked to both inherited (genetic) and environmental influences. In particular, as a consequence of work to identify genetic causes of coloboma, new molecular pathways that control optic fissure closure have now been identified. Many more regulatory mechanisms still await better understanding to inform on the development of potential therapies for patients with this malformation. This review provides an update of known coloboma genes, the pathways they influence and how best to manage the condition. In the age of precision medicine, determining the underlying genetic cause in any given patient is of high importance.
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25
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Ohuchi H, Sato K, Habuta M, Fujita H, Bando T. Congenital eye anomalies: More mosaic than thought? Congenit Anom (Kyoto) 2019; 59:56-73. [PMID: 30039880 DOI: 10.1111/cga.12304] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 12/13/2022]
Abstract
The eye is a sensory organ that primarily captures light and provides the sense of sight, as well as delivering non-visual light information involving biological rhythms and neurophysiological activities to the brain. Since the early 1990s, rapid advances in molecular biology have enabled the identification of developmental genes, genes responsible for human congenital diseases, and relevant genes of mutant animals with various anomalies. In this review, we first look at the development of the eye, and we highlight seminal reports regarding archetypal gene defects underlying three developmental ocular disorders in humans: (1) holoprosencephaly (HPE), with cyclopia being exhibited in the most severe cases; (2) microphthalmia, anophthalmia, and coloboma (MAC) phenotypes; and (3) anterior segment dysgenesis (ASDG), known as Peters anomaly and its related disorders. The recently developed methods, such as next-generation sequencing and genome editing techniques, have aided the discovery of gene mutations in congenital eye diseases and gene functions in normal eye development. Finally, we discuss Pax6-genome edited mosaic eyes and propose that somatic mosaicism in developmental gene mutations should be considered a causal factor for variable phenotypes, sporadic cases, and de novo mutations in human developmental disorders.
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Affiliation(s)
- Hideyo Ohuchi
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Keita Sato
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Munenori Habuta
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Hirofumi Fujita
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Tetsuya Bando
- Department of Cytology and Histology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
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26
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Hong S, Hu P, Roessler E, Hu T, Muenke M. Loss-of-function mutations in FGF8 can be independent risk factors for holoprosencephaly. Hum Mol Genet 2019; 27:1989-1998. [PMID: 29584859 DOI: 10.1093/hmg/ddy106] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 03/19/2018] [Indexed: 12/27/2022] Open
Abstract
The utilization of next generation sequencing has been shown to accelerate gene discovery in human disease. However, our confidence in the correct disease-associations of rare variants continues to depend on functional analysis. Here, we employ a sensitive assay of human FGF8 variants in zebrafish to demonstrate that the spectrum of isoforms of FGF8 produced by alternative splicing can provide key insights into the genetic susceptibility to human malformations. In addition, we describe novel mutations in the FGF core structure that have both subtle and profound effects on ligand posttranslational processing and biological activity. Finally, we solve a case of apparent digenic inheritance of novel variants in SHH and FGF8, two genes known to functionally coregulate each other in the developing forebrain, as a simpler case of FGF8 diminished function.
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Affiliation(s)
- Sungkook Hong
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-3717, USA
| | - Ping Hu
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-3717, USA
| | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-3717, USA
| | - Tommy Hu
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-3717, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-3717, USA
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27
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Abstract
This chapter provides an overview of the early developmental origins of six ocular tissues: the cornea, lens, ciliary body, iris, neural retina, and retina pigment epithelium. Many of these tissue types are concurrently specified and undergo a complex set of morphogenetic movements that facilitate their structural interconnection. Within the context of vertebrate eye organogenesis, we also discuss the genetic hierarchies of transcription factors and signaling pathways that regulate growth, patterning, cell type specification and differentiation.
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Affiliation(s)
- Joel B Miesfeld
- Department of Cell Biology & Human Anatomy, University of California Davis School of Medicine, Davis, CA, United States
| | - Nadean L Brown
- Department of Cell Biology & Human Anatomy, University of California Davis School of Medicine, Davis, CA, United States.
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28
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Herrera E, Agudo-Barriuso M, Murcia-Belmonte V. Cranial Pair II: The Optic Nerves. Anat Rec (Hoboken) 2018; 302:428-445. [DOI: 10.1002/ar.23922] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/19/2017] [Accepted: 05/14/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Eloísa Herrera
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH); Av. Santiago Ramón y Cajal, s/n., 03550 Sant Joan d'Alacant Alicante Spain
| | - Marta Agudo-Barriuso
- Departamento de Oftalmología, Facultad de Medicina; Universidad de Murcia, Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca (IMIB-Arrixaca); Murcia Spain
| | - Verónica Murcia-Belmonte
- Instituto de Neurociencias de Alicante (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH); Av. Santiago Ramón y Cajal, s/n., 03550 Sant Joan d'Alacant Alicante Spain
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29
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Cavodeassi F, Creuzet S, Etchevers HC. The hedgehog pathway and ocular developmental anomalies. Hum Genet 2018; 138:917-936. [PMID: 30073412 PMCID: PMC6710239 DOI: 10.1007/s00439-018-1918-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 07/24/2018] [Indexed: 12/18/2022]
Abstract
Mutations in effectors of the hedgehog signaling pathway are responsible for a wide variety of ocular developmental anomalies. These range from massive malformations of the brain and ocular primordia, not always compatible with postnatal life, to subtle but damaging functional effects on specific eye components. This review will concentrate on the effects and effectors of the major vertebrate hedgehog ligand for eye and brain formation, Sonic hedgehog (SHH), in tissues that constitute the eye directly and also in those tissues that exert indirect influence on eye formation. After a brief overview of human eye development, the many roles of the SHH signaling pathway during both early and later morphogenetic processes in the brain and then eye and periocular primordia will be evoked. Some of the unique molecular biology of this pathway in vertebrates, particularly ciliary signal transduction, will also be broached within this developmental cellular context.
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Affiliation(s)
- Florencia Cavodeassi
- Institute for Medical and Biomedical Education, St. George´s University of London, Cranmer Terrace, London, SW17 0RE, UK
| | - Sophie Creuzet
- Institut des Neurosciences Paris-Saclay (Neuro-PSI), UMR 9197, CNRS, Université Paris-Sud, 1 Avenue de la Terrasse, 91198, Gif-sur-Yvette Cedex, France
| | - Heather C Etchevers
- Aix-Marseille Univ, Marseille Medical Genetics (MMG), INSERM, Faculté de Médecine, 27 boulevard Jean Moulin, 13005, Marseille, France.
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30
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Ren X, Hamilton N, Müller F, Yamamoto Y. Cellular rearrangement of the prechordal plate contributes to eye degeneration in the cavefish. Dev Biol 2018; 441:221-234. [PMID: 30031755 DOI: 10.1016/j.ydbio.2018.07.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 07/16/2018] [Accepted: 07/18/2018] [Indexed: 12/23/2022]
Abstract
Astyanax mexicanus consists of two different populations: a sighted surface-dwelling form (surface fish) and a blind cave-dwelling form (cavefish). In the cavefish, embryonic expression of sonic hedgehog a (shha) in the prechordal plate is expanded towards the anterior midline, which has been shown to contribute to cavefish specific traits such as eye degeneration, enhanced feeding apparatus, and specialized brain anatomy. However, it is not clear how this expanded expression is achieved and which signaling pathways are involved. Nodal signaling has a crucial role for expression of shh and formation of the prechordal plate. In this study, we report increased expression of prechordal plate marker genes, nodal-related 2 (ndr2) and goosecoid (gsc) in cavefish embryos at the tailbud stage. To investigate whether Nodal signaling is responsible for the anterior expansion of the prechordal plate, we used an inhibitor of Nodal signaling and showed a decreased anterior expansion of the prechordal plate and increased pax6 expression in the anterior midline in treated cavefish embryos. Later in development, the lens and optic cup of treated embryos were significantly larger than untreated embryos. Conversely, increasing Nodal signaling in the surface fish embryo resulted in the expansion of anterior prechordal plate and reduction of pax6 expression in the anterior neural plate together with the formation of small lenses and optic cups later in development. These results confirmed that Nodal signaling has a crucial role for the anterior expansion of the prechordal plate and plays a significant role in cavefish eye development. We showed that the anterior expansion of the prechordal plate was not due to increased total cell number, suggesting the expansion is achieved by changes in cellular distribution in the prechordal plate. In addition, the distribution of presumptive prechordal plate cells in Spemann's organiser was also altered in the cavefish. These results suggested that changes in the cellular arrangement of Spemann's organiser in early gastrulae could have an essential role in the anterior expansion of the prechordal plate contributing to eye degeneration in the cavefish.
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Affiliation(s)
- Xiaoyun Ren
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Noémie Hamilton
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Ferenc Müller
- Institute of Cancer and Genomics Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Yoshiyuki Yamamoto
- Department of Cell and Developmental Biology, University College London, London, United Kingdom.
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31
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Abstract
As the embryonic ectoderm is induced to form the neural plate, cells inside this epithelium acquire restricted identities that will dictate their behavior and progressive differentiation. The first behavior adopted by most neural plate cells is called neurulation, a morphogenetic movement shaping the neuroepithelium into a tube. One cell population is not adopting this movement: the eye field. Giving eye identity to a defined population inside the neural plate is therefore a key neural fate decision. While all other neural population undergo neurulation similarly, converging toward the midline, the eye field moves outwards, away from the rest of the forming neural tube, to form vesicles. Thus, while delay in acquisition of most other fates would not have significant morphogenetic consequences, defect in the establishment of the eye field would dramatically impact the formation of the eye. Yet, very little is understood of the molecular and cellular mechanisms driving them. Here, we summarize what is known across vertebrate species and propose a model highlighting what is required to form the essential vesicles that initiate the vertebrate eyes.
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Affiliation(s)
- Florence A Giger
- Department of Developmental Neurobiology, Centre for Developmental Neurobiology and MRC Centre for Developmental Disorders, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London, London, United Kingdom
| | - Corinne Houart
- Department of Developmental Neurobiology, Centre for Developmental Neurobiology and MRC Centre for Developmental Disorders, Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London, London, United Kingdom
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32
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Genes and pathways in optic fissure closure. Semin Cell Dev Biol 2017; 91:55-65. [PMID: 29198497 DOI: 10.1016/j.semcdb.2017.10.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 08/29/2017] [Accepted: 10/10/2017] [Indexed: 12/22/2022]
Abstract
Embryonic development of the vertebrate eye begins with the formation of an optic vesicle which folds inwards to form a double-layered optic cup with a fissure on the ventral surface, known as the optic fissure. Closure of the optic fissure is essential for subsequent growth and development of the eye. A defect in this process can leave a gap in the iris, retina or optic nerve, known as a coloboma, which can lead to severe visual impairment. This review brings together current information about genes and pathways regulating fissure closure from human coloboma patients and animal models. It focuses especially on current understanding of the morphological changes and processes of epithelial remodelling occurring at the fissure margins.
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33
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Lupu FI, Burnett JB, Eggenschwiler JT. Cell cycle-related kinase regulates mammalian eye development through positive and negative regulation of the Hedgehog pathway. Dev Biol 2017; 434:24-35. [PMID: 29166577 DOI: 10.1016/j.ydbio.2017.10.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/30/2017] [Accepted: 10/30/2017] [Indexed: 01/20/2023]
Abstract
Cell cycle-related kinase (CCRK) is a conserved regulator of ciliogenesis whose loss in mice leads to a wide range of developmental defects, including exencephaly, preaxial polydactyly, skeletal abnormalities, and microphthalmia. Here, we investigate the role of CCRK in mouse eye development. Ccrk mutants show dramatic patterning defects, with an expansion of the optic stalk domain into the optic cup, as well as an expansion of the retinal pigment epithelium (RPE) into neural retina (NR) territory. In addition, Ccrk mutants display a shortened optic stalk. These defects are associated with bimodal changes in Hedgehog (Hh) pathway activity within the eye, including the loss of proximal, high level responses but a gain in distal, low level responses. We simultaneously removed the Hh activator GLI2 in Ccrk mutants (Ccrk-/-;Gli2-/-), which resulted in rescue of optic cup patterning and exacerbation of optic stalk length defects. Next, we disrupted the Hh pathway antagonist GLI3 in mutants lacking CCRK (Ccrk-/-;Gli3-/-), which lead to even greater expansion of the RPE markers into the NR domain and a complete loss of NR specification within the optic cup. These results indicate that CCRK functions in eye development by both positively and negatively regulating the Hh pathway, and they reveal distinct requirements for Hh signaling in patterning and morphogenesis of the eyes.
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Affiliation(s)
- Floria I Lupu
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
| | - Jacob B Burnett
- Department of Genetics, University of Georgia, Athens, GA 30602, USA
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34
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Grajales-Esquivel E, Luz-Madrigal A, Bierly J, Haynes T, Reis ES, Han Z, Gutierrez C, McKinney Z, Tzekou A, Lambris JD, Tsonis PA, Del Rio-Tsonis K. Complement component C3aR constitutes a novel regulator for chick eye morphogenesis. Dev Biol 2017; 428:88-100. [PMID: 28576690 PMCID: PMC5726978 DOI: 10.1016/j.ydbio.2017.05.019] [Citation(s) in RCA: 7] [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: 07/16/2015] [Revised: 08/05/2016] [Accepted: 05/17/2017] [Indexed: 12/22/2022]
Abstract
Complement components have been implicated in a wide variety of functions including neurogenesis, proliferation, cell migration, differentiation, cancer, and more recently early development and regeneration. Following our initial observations indicating that C3a/C3aR signaling induces chick retina regeneration, we analyzed its role in chick eye morphogenesis. During eye development, the optic vesicle (OV) invaginates to generate a bilayer optic cup (OC) that gives rise to the retinal pigmented epithelium (RPE) and neural retina. We show by immunofluorescence staining that C3 and the receptor for C3a (the cleaved and active form of C3), C3aR, are present in chick embryos during eye morphogenesis in the OV and OC. Interestingly, C3aR is mainly localized in the nuclear compartment at the OC stage. Loss of function studies at the OV stage using morpholinos or a blocking antibody targeting the C3aR (anti-C3aR Ab), causes eye defects such as microphthalmia and defects in the ventral portion of the eye that result in coloboma. Such defects were not observed when C3aR was disrupted at the OC stage. Histological analysis demonstrated that microphthalmic eyes were unable to generate a normal optic stalk or a closed OC. The dorsal/ventral patterning defects were accompanied by an expansion of the ventral markers Pax2, cVax and retinoic acid synthesizing enzyme raldh-3 (aldh1a3) domains, an absence of the dorsal expression of Tbx5 and raldh-1 (aldh1a1) and a re-specification of the ventral RPE to neuroepithelium. In addition, the eyes showed overall decreased expression of Gli1 and a change in distribution of nuclear β-catenin, suggesting that Shh and Wnt pathways have been affected. Finally, we observed prominent cell death along with a decrease in proliferating cells, indicating that both processes contribute to the microphthalmic phenotype. Together our results show that C3aR is necessary for the proper morphogenesis of the OC. This is the first report implicating C3aR in eye development, revealing an unsuspected hitherto regulator for proper chick eye morphogenesis.
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Affiliation(s)
- Erika Grajales-Esquivel
- Department of Biology, Miami University and Center for Visual Sciences at Miami University (CVSMU), Oxford, OH 45056, USA.
| | - Agustin Luz-Madrigal
- Department of Biology, Miami University and Center for Visual Sciences at Miami University (CVSMU), Oxford, OH 45056, USA; Department of Biology, University of Dayton and Center for Tissue Regeneration and Engineering at the University of Dayton (TREND), Dayton, OH 45469, USA.
| | - Jeffrey Bierly
- Department of Biology, Miami University and Center for Visual Sciences at Miami University (CVSMU), Oxford, OH 45056, USA.
| | - Tracy Haynes
- Department of Biology, Miami University and Center for Visual Sciences at Miami University (CVSMU), Oxford, OH 45056, USA.
| | - Edimara S Reis
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Zeyu Han
- Department of Biology, Miami University and Center for Visual Sciences at Miami University (CVSMU), Oxford, OH 45056, USA.
| | - Christian Gutierrez
- Department of Biology, Miami University and Center for Visual Sciences at Miami University (CVSMU), Oxford, OH 45056, USA.
| | - Zachary McKinney
- Department of Biology, Miami University and Center for Visual Sciences at Miami University (CVSMU), Oxford, OH 45056, USA.
| | - Apostolia Tzekou
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Panagiotis A Tsonis
- Department of Biology, University of Dayton and Center for Tissue Regeneration and Engineering at the University of Dayton (TREND), Dayton, OH 45469, USA.
| | - Katia Del Rio-Tsonis
- Department of Biology, Miami University and Center for Visual Sciences at Miami University (CVSMU), Oxford, OH 45056, USA.
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35
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Burnett JB, Lupu FI, Eggenschwiler JT. Proper ciliary assembly is critical for restricting Hedgehog signaling during early eye development in mice. Dev Biol 2017; 430:32-40. [PMID: 28778798 DOI: 10.1016/j.ydbio.2017.07.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/20/2017] [Accepted: 07/20/2017] [Indexed: 11/25/2022]
Abstract
Patterning of the vertebrate eye into optic stalk, retinal pigment epithelium (RPE) and neural retina (NR) territories relies on a number of signaling pathways, but how these signals are interpreted by optic progenitors is not well understood. The primary cilium is a microtubule-based organelle that is essential for Hedgehog (Hh) signaling, but it has also been implicated in the regulation of other signaling pathways. Here, we show that the optic primordium is ciliated during early eye development and that ciliogenesis is essential for proper patterning and morphogenesis of the mouse eye. Ift172 mutants fail to generate primary cilia and exhibit patterning defects that resemble those of Gli3 mutants, suggesting that cilia are required to restrict Hh activity during eye formation. Ift122 mutants, which produce cilia with abnormal morphology, generate optic vesicles that fail to invaginate to produce the optic cup. These mutants also lack formation of the lens, RPE and NR. Such phenotypic features are accompanied by strong, ectopic Hh pathway activity, evidenced by altered gene expression patterns. Removal of GLI2 from Ift122 mutants rescued several aspects of optic cup and lens morphogenesis as well as RPE and NR specification. Collectively, our data suggest that proper assembly of primary cilia is critical for restricting the Hedgehog pathway during eye formation in the mouse.
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Affiliation(s)
- Jacob B Burnett
- Department of Genetics, University of Georgia, Athens, GA 30602, United States
| | - Floria I Lupu
- Department of Genetics, University of Georgia, Athens, GA 30602, United States
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36
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hmmr mediates anterior neural tube closure and morphogenesis in the frog Xenopus. Dev Biol 2017; 430:188-201. [PMID: 28778799 DOI: 10.1016/j.ydbio.2017.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 07/19/2017] [Accepted: 07/26/2017] [Indexed: 12/20/2022]
Abstract
Development of the central nervous system requires orchestration of morphogenetic processes which drive elevation and apposition of the neural folds and their fusion into a neural tube. The newly formed tube gives rise to the brain in anterior regions and continues to develop into the spinal cord posteriorly. Conspicuous differences between the anterior and posterior neural tube become visible already during neural tube closure (NTC). Planar cell polarity (PCP)-mediated convergent extension (CE) movements are restricted to the posterior neural plate, i.e. hindbrain and spinal cord, where they propagate neural fold apposition. The lack of CE in the anterior neural plate correlates with a much slower mode of neural fold apposition anteriorly. The morphogenetic processes driving anterior NTC have not been addressed in detail. Here, we report a novel role for the breast cancer susceptibility gene and microtubule (MT) binding protein Hmmr (Hyaluronan-mediated motility receptor, RHAMM) in anterior neurulation and forebrain development in Xenopus laevis. Loss of hmmr function resulted in a lack of telencephalic hemisphere separation, arising from defective roof plate formation, which in turn was caused by impaired neural tissue narrowing. hmmr regulated polarization of neural cells, a function which was dependent on the MT binding domains. hmmr cooperated with the core PCP component vangl2 in regulating cell polarity and neural morphogenesis. Disrupted cell polarization and elongation in hmmr and vangl2 morphants prevented radial intercalation (RI), a cell behavior essential for neural morphogenesis. Our results pinpoint a novel role of hmmr in anterior neural development and support the notion that RI is a major driving force for anterior neurulation and forebrain morphogenesis.
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37
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Lateral thinking - Interocular symmetry and asymmetry in neurovascular patterning, in health and disease. Prog Retin Eye Res 2017; 59:131-157. [PMID: 28457789 DOI: 10.1016/j.preteyeres.2017.04.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 03/24/2017] [Accepted: 04/24/2017] [Indexed: 02/07/2023]
Abstract
No biological system or structure is likely to be perfectly symmetrical, or have identical right and left forms. This review explores the evidence for eye and visual pathway asymmetry, in health and in disease, and attempts to provide guidance for those studying the structure and function of the visual system, where recognition of symmetry or asymmetry may be essential. The principal question with regards to asymmetry is not 'are the eyes the same?', for some degree of asymmetry is pervasive, but 'when are they importantly different?'. Knowing if right and left eyes are 'importantly different' could have significant consequences for deciding whether right or left eyes are included in an analysis or for examining the association between a phenotype and ocular parameter. The presence of significant asymmetry would also have important implications for the design of normative databases of retinal and optic nerve metrics. In this review, we highlight not only the universal presence of asymmetry, but provide evidence that some elements of the visual system are inherently more asymmetric than others, pointing to the need for improved normative data to explain sources of asymmetry and their impact on determining associations with genetic, environmental or health-related factors and ultimately in clinical practice.
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38
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Brorin is required for neurogenesis, gliogenesis, and commissural axon guidance in the zebrafish forebrain. PLoS One 2017; 12:e0176036. [PMID: 28448525 PMCID: PMC5407822 DOI: 10.1371/journal.pone.0176036] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Accepted: 04/04/2017] [Indexed: 12/28/2022] Open
Abstract
Bmps regulate numerous neural functions with their regulators. We previously identified Brorin, a neural-specific secreted antagonist of Bmp signaling, in humans, mice, and zebrafish. Mouse Brorin has two cysteine-rich domains containing 10 cysteine residues in its core region, and these are located in similar positions to those in the cysteine-rich domains of Chordin family members, which are secreted Bmp antagonists. Zebrafish Brorin had two cysteine-rich domains with high similarity to those of mouse Brorin. We herein examined zebrafish brorin in order to elucidate its in vivo actions. Zebrafish brorin was predominantly expressed in developing neural tissues. The overexpression of brorin led to the inactivation of Bmp signaling. On the other hand, the knockdown of brorin resulted in the activation of Bmp signaling and brorin morphants exhibited defective development of the ventral domain in the forebrain. Furthermore, the knockdown of brorin inhibited the generation of γ–aminobutyric acid (GABA)ergic interneurons and oligodendrocytes and promoted the generation of astrocytes in the forebrain. In addition, brorin was required for axon guidance in the forebrain. The present results suggest that Brorin is a secreted Bmp antagonist predominantly expressed in developing neural tissues and that it plays multiple roles in the development of the zebrafish forebrain.
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39
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Seigfried FA, Cizelsky W, Pfister AS, Dietmann P, Walther P, Kühl M, Kühl SJ. Frizzled 3 acts upstream of Alcam during embryonic eye development. Dev Biol 2017; 426:69-83. [PMID: 28427856 DOI: 10.1016/j.ydbio.2017.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/09/2017] [Accepted: 04/14/2017] [Indexed: 12/18/2022]
Abstract
Formation of a functional eye during vertebrate embryogenesis requires different processes such as cell differentiation, cell migration, cell-cell interactions as well as intracellular signalling processes. It was previously shown that the non-canonical Wnt receptor Frizzled 3 (Fzd3) is required for proper eye formation, however, the underlying mechanism is poorly understood. Here we demonstrate that loss of Fzd3 induces severe malformations of the developing eye and that this defect is phenocopied by loss of the activated leukocyte cell adhesion molecule (Alcam). Promoter analysis revealed the presence of a Fzd3 responsive element within the alcam promoter, which is responsible for alcam expression during anterior neural development. In-depth analysis identified the jun N-terminal protein kinase 1 (JNK1) and the transcription factor paired box 2 (Pax2) to be important for the activation of alcam expression. Altogether our study reveals that alcam is activated through non-canonical Wnt signalling during embryonic eye development in Xenopus laevis and shows that this pathway plays a similar role in different tissues.
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Affiliation(s)
- Franziska A Seigfried
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany; International Graduate School in Molecular Medicine Ulm, 89081 Ulm, Germany; Tissue Homeostasis Joint-PhD-Programme in Cooperation with the University of Oulu, Finland
| | - Wiebke Cizelsky
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany; International Graduate School in Molecular Medicine Ulm, 89081 Ulm, Germany
| | - Astrid S Pfister
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Petra Dietmann
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Paul Walther
- Central Facility for Electron Microscopy, Ulm University, Albert-Einstein-Allee 11, D-89081 Ulm, Germany
| | - Michael Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Susanne J Kühl
- Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
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40
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Krishnan J, Rohner N. Cavefish and the basis for eye loss. Philos Trans R Soc Lond B Biol Sci 2017; 372:20150487. [PMID: 27994128 PMCID: PMC5182419 DOI: 10.1098/rstb.2015.0487] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2016] [Indexed: 11/12/2022] Open
Abstract
Animals have colonized the entire world from rather moderate to the harshest environments, some of these so extreme that only few animals are able to survive. Cave environments present such a challenge and obligate cave animals have adapted to perpetual darkness by evolving a multitude of traits. The most common and most studied cave characteristics are the regression of eyes and the overall reduction in pigmentation. Studying these traits can provide important insights into how evolutionary forces drive convergent and regressive adaptation. The blind Mexican cavefish (Astyanax mexicanus) has emerged as a useful model to study cave evolution owing to the availability of genetic and genomic resources, and the amenability of embryonic development as the different populations remain fertile with each other. In this review, we give an overview of our current knowledge underlying the process of regressive and convergent evolution using eye degeneration in cavefish as an example.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'.
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Affiliation(s)
- Jaya Krishnan
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
| | - Nicolas Rohner
- Stowers Institute for Medical Research, 1000 East 50th Street, Kansas City, MO 64110, USA
- Department of Molecular and Integrative Physiology, The University of Kansas Medical Center, Kansas City, KS 66160, USA
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41
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Bloomquist RF, Fowler TE, Sylvester JB, Miro RJ, Streelman JT. A compendium of developmental gene expression in Lake Malawi cichlid fishes. BMC DEVELOPMENTAL BIOLOGY 2017; 17:3. [PMID: 28158974 PMCID: PMC5291978 DOI: 10.1186/s12861-017-0146-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 01/26/2017] [Indexed: 12/24/2022]
Abstract
BACKGROUND Lake Malawi cichlids represent one of a growing number of vertebrate models used to uncover the genetic and developmental basis of trait diversity. Rapid evolutionary radiation has resulted in species that share similar genomes but differ markedly in phenotypes including brains and behavior, nuptial coloration and the craniofacial skeleton. Research has begun to identify the genes, as well as the molecular and developmental pathways that underlie trait divergence. RESULTS We assemble a compendium of gene expression for Lake Malawi cichlids, across pharyngula (the phylotypic stage) and larval stages of development, encompassing hundreds of gene transcripts. We chart patterns of expression in Bone morphogenetic protein (BMP), Fibroblast growth factor (FGF), Hedgehog (Hh), Notch and Wingless (Wnt) signaling pathways, as well as genes involved in neurogenesis, calcium and endocrine signaling, stem cell biology, and numerous homeobox (Hox) factors-in three planes using whole-mount in situ hybridization. Because of low sequence divergence across the Malawi cichlid assemblage, the probes we employ are broadly applicable in hundreds of species. We tabulate gene expression across general tissue domains, and highlight examples of unexpected expression patterns. CONCLUSIONS On the heels of recently published genomes, this compendium of developmental gene expression in Lake Malawi cichlids provides a valuable resource for those interested in the relationship between evolution and development.
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Affiliation(s)
- R F Bloomquist
- Georgia Institute of Technology, School of Biological Sciences and Institute for Bioengineering and Bioscience, Atlanta, GA, USA.,Medical College of Georgia, School of Dentistry, Augusta, GA, USA
| | - T E Fowler
- Georgia Institute of Technology, School of Biological Sciences and Institute for Bioengineering and Bioscience, Atlanta, GA, USA
| | - J B Sylvester
- Georgia Institute of Technology, School of Biological Sciences and Institute for Bioengineering and Bioscience, Atlanta, GA, USA
| | - R J Miro
- Georgia Institute of Technology, School of Biological Sciences and Institute for Bioengineering and Bioscience, Atlanta, GA, USA
| | - J T Streelman
- Georgia Institute of Technology, School of Biological Sciences and Institute for Bioengineering and Bioscience, Atlanta, GA, USA.
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42
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Frisca F, Colquhoun D, Goldshmit Y, Änkö ML, Pébay A, Kaslin J. Role of ectonucleotide pyrophosphatase/phosphodiesterase 2 in the midline axis formation of zebrafish. Sci Rep 2016; 6:37678. [PMID: 27883058 PMCID: PMC5121889 DOI: 10.1038/srep37678] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 11/01/2016] [Indexed: 11/12/2022] Open
Abstract
Lysophosphatidic acid (LPA) is a unique bioactive lysophospholipid that induces pleiotropic effects in various cell types and organisms by acting on its specific receptors. LPA is mainly synthetised extracellularly by the ectonucleotide pyrophosphatase/phosphodiesterase 2/autotaxin (enpp2). Altered LPA signalling is associated with embryonic abnormalities, suggesting critical roles for LPA during development. However, the role of LPA signalling during early embryogenesis is not well established. We demonstrate that enpp2/LPA signalling in the early zebrafish embryo results in altered axis and midline formation, defects in left right (L-R) patterning, ciliogenesis of the Kupffer’s vesicle (KV), through the modulation of cell migration during gastrulation in a lpar1–3 Rho/ROCK-dependant manner. Overall, this study demonstrates an essential role of enpp2/LPA signalling during early embryogenesis.
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Affiliation(s)
- Frisca Frisca
- Australian Regenerative Medicine Institute, Building 75, Monash University, Australia.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital &Ophthalmology, the University of Melbourne, Department of Surgery, Australia
| | - Daniel Colquhoun
- Australian Regenerative Medicine Institute, Building 75, Monash University, Australia
| | - Yona Goldshmit
- Australian Regenerative Medicine Institute, Building 75, Monash University, Australia.,Department of Neurobiology, Tel-Aviv University, Israel
| | - Minna-Liisa Änkö
- Monash Biomedicine Discovery Institute Department of Anatomy and Developmental Biology, Biomedicine Discovery Institute, Monash University, Australia
| | - Alice Pébay
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital &Ophthalmology, the University of Melbourne, Department of Surgery, Australia
| | - Jan Kaslin
- Australian Regenerative Medicine Institute, Building 75, Monash University, Australia
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43
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Hedgehog-dependent E3-ligase Midline1 regulates ubiquitin-mediated proteasomal degradation of Pax6 during visual system development. Proc Natl Acad Sci U S A 2016; 113:10103-8. [PMID: 27555585 DOI: 10.1073/pnas.1600770113] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Pax6 is a key transcription factor involved in eye, brain, and pancreas development. Although pax6 is expressed in the whole prospective retinal field, subsequently its expression becomes restricted to the optic cup by reciprocal transcriptional repression of pax6 and pax2 However, it remains unclear how Pax6 protein is removed from the eyestalk territory on time. Here, we report that Mid1, a member of the RBCC/TRIM E3 ligase family, which was first identified in patients with the X-chromosome-linked Opitz BBB/G (OS) syndrome, interacts with Pax6. We found that the forming eyestalk is a major domain of mid1 expression, controlled by the morphogen Sonic hedgehog (Shh). Here, Mid1 regulates the ubiquitination and proteasomal degradation of Pax6 protein. Accordantly, when Mid1 levels are knocked down, Pax6 expression is expanded and eyes are enlarged. Our findings indicate that remaining or misaddressed Pax6 protein is cleared from the eyestalk region to properly set the border between the eyestalk territory and the retina via Mid1. Thus, we identified a posttranslational mechanism, regulated by Sonic hedgehog, which is important to suppress Pax6 activity and thus breaks pax6 autoregulation at defined steps during the formation of the visual system.
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44
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Noh H, Lee H, Park E, Park S. Proper closure of the optic fissure requires ephrin A5-EphB2-JNK signaling. Development 2016; 143:461-72. [PMID: 26839344 DOI: 10.1242/dev.129478] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The development of complex organs such as the eye requires a delicate and coordinated balance of cell division and cell death. Although apoptosis is prevalent in the proximoventral optic cup, the precise role it plays in eye development needs to be investigated further. In this study, we show that reduced apoptosis in the proximoventral optic cup prevents closure of the optic fissure. We also show that expression of ephrin A5 (Efna5) partially overlaps with Eph receptor B2 (Ephb2) expression in the proximoventral optic cup and that binding of EphB2 to ephrin A5 induces a sustained activation of JNK. This prolonged JNK signal promotes apoptosis and prevents cell proliferation. Thus, we propose that the unique cross-subclass interaction of EphB2 with ephrin A5 has evolved to function upstream of JNK signaling for the purpose of maintaining an adequate pool of progenitor cells to ensure proper closure of the optic fissure.
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Affiliation(s)
- Hyuna Noh
- Department of Biological Science, Sookmyung Women's University, Chungpa-ro 47gil 100, Yongsan-gu, Seoul 140-742, Korea
| | - Haeryung Lee
- Department of Biological Science, Sookmyung Women's University, Chungpa-ro 47gil 100, Yongsan-gu, Seoul 140-742, Korea
| | - Eunjeong Park
- Department of Biological Science, Sookmyung Women's University, Chungpa-ro 47gil 100, Yongsan-gu, Seoul 140-742, Korea
| | - Soochul Park
- Department of Biological Science, Sookmyung Women's University, Chungpa-ro 47gil 100, Yongsan-gu, Seoul 140-742, Korea
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45
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Stem Cell Therapy for Treatment of Ocular Disorders. Stem Cells Int 2016; 2016:8304879. [PMID: 27293447 PMCID: PMC4884591 DOI: 10.1155/2016/8304879] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 04/10/2016] [Indexed: 12/30/2022] Open
Abstract
Sustenance of visual function is the ultimate focus of ophthalmologists. Failure of complete recovery of visual function and complications that follow conventional treatments have shifted search to a new form of therapy using stem cells. Stem cell progenitors play a major role in replenishing degenerated cells despite being present in low quantity and quiescence in our body. Unlike other tissues and cells, regeneration of new optic cells responsible for visual function is rarely observed. Understanding the transcription factors and genes responsible for optic cells development will assist scientists in formulating a strategy to activate and direct stem cells renewal and differentiation. We review the processes of human eye development and address the strategies that have been exploited in an effort to regain visual function in the preclinical and clinical state. The update of clinical findings of patients receiving stem cell treatment is also presented.
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46
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Chassaing N, Davis EE, McKnight KL, Niederriter AR, Causse A, David V, Desmaison A, Lamarre S, Vincent-Delorme C, Pasquier L, Coubes C, Lacombe D, Rossi M, Dufier JL, Dollfus H, Kaplan J, Katsanis N, Etchevers HC, Faguer S, Calvas P. Targeted resequencing identifies PTCH1 as a major contributor to ocular developmental anomalies and extends the SOX2 regulatory network. Genome Res 2016; 26:474-85. [PMID: 26893459 PMCID: PMC4817771 DOI: 10.1101/gr.196048.115] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 02/04/2016] [Indexed: 12/17/2022]
Abstract
Ocular developmental anomalies (ODA) such as anophthalmia/microphthalmia (AM) or anterior segment dysgenesis (ASD) have an estimated combined prevalence of 3.7 in 10,000 births. Mutations in SOX2 are the most frequent contributors to severe ODA, yet account for a minority of the genetic drivers. To identify novel ODA loci, we conducted targeted high-throughput sequencing of 407 candidate genes in an initial cohort of 22 sporadic ODA patients. Patched 1 (PTCH1), an inhibitor of sonic hedgehog (SHH) signaling, harbored an enrichment of rare heterozygous variants in comparison to either controls, or to the other candidate genes (four missense and one frameshift); targeted resequencing of PTCH1 in a second cohort of 48 ODA patients identified two additional rare nonsynonymous changes. Using multiple transient models and a CRISPR/Cas9-generated mutant, we show physiologically relevant phenotypes altering SHH signaling and eye development upon abrogation of ptch1 in zebrafish for which in vivo complementation assays using these models showed that all six patient missense mutations affect SHH signaling. Finally, through transcriptomic and ChIP analyses, we show that SOX2 binds to an intronic domain of the PTCH1 locus to regulate PTCH1 expression, findings that were validated both in vitro and in vivo. Together, these results demonstrate that PTCH1 mutations contribute to as much as 10% of ODA, identify the SHH signaling pathway as a novel effector of SOX2 activity during human ocular development, and indicate that ODA is likely the result of overactive SHH signaling in humans harboring mutations in either PTCH1 or SOX2.
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Affiliation(s)
- Nicolas Chassaing
- CHU Toulouse, Service de Génétique Médicale, Hôpital Purpan, 31059 Toulouse, France; Université Paul-Sabatier Toulouse III, EA-4555, 31000 Toulouse, France; Inserm U1056, 31000 Toulouse, France
| | - Erica E Davis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina 27701, USA; Department of Pediatrics and Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27701, USA
| | - Kelly L McKnight
- Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina 27701, USA
| | - Adrienne R Niederriter
- Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina 27701, USA
| | - Alexandre Causse
- Université Paul-Sabatier Toulouse III, EA-4555, 31000 Toulouse, France; CHU Toulouse, Service d'Ophtalmologie, Hôpital Purpan, 31059 Toulouse, France
| | - Véronique David
- Institut de Génétique et Développement, CNRS UMR6290, Université de Rennes 1, IFR140 GFAS, Faculté de Médecine, 35043 Rennes, France; Laboratoire de Génétique Moléculaire, CHU Pontchaillou, 35043 Rennes Cedex, France
| | - Annaïck Desmaison
- Université Paul-Sabatier Toulouse III, EA-4555, 31000 Toulouse, France
| | - Sophie Lamarre
- Université de Toulouse; INSA, UPS, INP, LISBP, F-31077 Toulouse, France; INRA, UMR792, Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; CNRS, UMR5504, F-31400 Toulouse, France; Plateforme Biopuces de la Génopole de Toulouse Midi Pyrénées, INSA/DGBA 135, 31077 Toulouse, France
| | | | - Laurent Pasquier
- Service de Génétique Clinique, Hôpital Sud, 35200 Rennes, France
| | - Christine Coubes
- Service de Génétique Médicale, Hôpital Arnaud de Villeneuve, 34295 Montpellier, France
| | - Didier Lacombe
- Service de Génétique Médicale, Hôpital Pellegrin, 33076 Bordeaux Cedex, France; Université Bordeaux Segalen, Laboratoire MRGM, 33076 Bordeaux, France
| | - Massimiliano Rossi
- Service de Génétique, Hospices Civils de Lyon, Groupement Hospitalier Est, 69677 Bron, France; INSERM U1028 UMR CNRS 5292, UCBL, CRNL TIGER Team, 69677 Bron Cedex, France
| | - Jean-Louis Dufier
- Service d'Ophtalmologie, Hôpital Necker Enfants Malades, 75015 Paris, France
| | - Helene Dollfus
- Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, 67091 Strasbourg, France
| | - Josseline Kaplan
- INSERM U781 & Department of Genetics, Paris Descartes University, 75015 Paris, France
| | - Nicholas Katsanis
- Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina 27701, USA; Department of Pediatrics and Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27701, USA
| | - Heather C Etchevers
- Université Paul-Sabatier Toulouse III, EA-4555, 31000 Toulouse, France; INSERM, UMR_S910, Aix-Marseille University, Faculté de Médecine, 13385 Marseille, France
| | | | - Patrick Calvas
- CHU Toulouse, Service de Génétique Médicale, Hôpital Purpan, 31059 Toulouse, France; Université Paul-Sabatier Toulouse III, EA-4555, 31000 Toulouse, France; Inserm U1056, 31000 Toulouse, France
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47
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Samuel A, Rubinstein AM, Azar TT, Ben-Moshe Livne Z, Kim SH, Inbal A. Six3 regulates optic nerve development via multiple mechanisms. Sci Rep 2016; 6:20267. [PMID: 26822689 PMCID: PMC4731751 DOI: 10.1038/srep20267] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 12/30/2015] [Indexed: 12/05/2022] Open
Abstract
Malformations of the optic nerve lead to reduced vision or even blindness. During optic nerve development, retinal ganglion cell (RGC) axons navigate across the retina, exit the eye to the optic stalk (OS), and cross the diencephalon midline at the optic chiasm en route to their brain targets. Many signalling molecules have been implicated in guiding various steps of optic nerve pathfinding, however much less is known about transcription factors regulating this process. Here we show that in zebrafish, reduced function of transcription factor Six3 results in optic nerve hypoplasia and a wide repertoire of RGC axon pathfinding errors. These abnormalities are caused by multiple mechanisms, including abnormal eye and OS patterning and morphogenesis, abnormal expression of signalling molecules both in RGCs and in their environment and anatomical deficiency in the diencephalic preoptic area, where the optic chiasm normally forms. Our findings reveal new roles for Six3 in eye development and are consistent with known phenotypes of reduced SIX3 function in humans. Hence, the new zebrafish model for Six3 loss of function furthers our understanding of the mechanisms governing optic nerve development and Six3-mediated eye and forebrain malformations.
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Affiliation(s)
- Anat Samuel
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Ariel M. Rubinstein
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Tehila T. Azar
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Zohar Ben-Moshe Livne
- Department of Neurobiology, The George S. Wise Faculty of Life Sciences and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Seok-Hyung Kim
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee, USA
| | - Adi Inbal
- Department of Medical Neurobiology, Institute for Medical Research - Israel-Canada, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
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48
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Kumar P, Kasiviswanathan D, Sundaresan L, Kathirvel P, Veeriah V, Dutta P, Sankaranarayanan K, Gupta R, Chatterjee S. Harvesting clues from genome wide transcriptome analysis for exploring thalidomide mediated anomalies in eye development of chick embryo: Nitric oxide rectifies the thalidomide mediated anomalies by swinging back the system to normal transcriptome pattern. Biochimie 2015; 121:253-67. [PMID: 26717904 DOI: 10.1016/j.biochi.2015.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/18/2015] [Indexed: 11/29/2022]
Abstract
Thalidomide, the notorious teratogen is known to cause various developmental abnormalities, among which a range of eye deformations are very common. From the clinical point of view, it is necessary to pinpoint the mechanisms of teratogens that tune the gene expression. However, to our knowledge, the molecular basis of eye deformities under thalidomide treatmenthas not been reported so far. Present study focuses on the possible mechanism by which thalidomide affects eye development and the role of Nitric Oxide in recovering thalidomide-mediated anomalies of eye development using chick embryo and zebrafish models with transcriptome analysis. Transcriptome analysis showed that 403 genes were up-regulated and 223 genes were down-regulated significantly in thalidomide pre-treated embryos. 8% of the significantly modulated genes have been implicated in eye development including Pax6, OTX2, Dkk1 and Shh. A wide range of biological process and molecular function was affected by thalidomide exposure. Biological Processes including structural constituent of eye lens and Molecular functions such as visual perception and retinal metabolic process formed strong annotation clustersindicating the adverse effects of thalidomide on eye development and function. Here, we have discussed the whole embryo transcriptome with the expression of PAX6, SOX2, and CRYAAgenes from developing eyes. Our experimental data showing structural and functional aspects includingeye size, lens transparency and optic nerve activity and bioinformatics analyses of transcriptome suggest that NO could partially protect thalidomide treated embryos from its devastating effects on eye development and function.
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Affiliation(s)
- Pavitra Kumar
- Vascular Biology Lab, AU-KBC Research Centre, Chennai, Tamil Nadu, India
| | - Dharanibalan Kasiviswanathan
- Vascular Biology Lab, AU-KBC Research Centre, Chennai, Tamil Nadu, India; Department of Biotechnology, Anna University, Chennai, Tamil Nadu, India
| | - Lakshmikirupa Sundaresan
- Vascular Biology Lab, AU-KBC Research Centre, Chennai, Tamil Nadu, India; Department of Biotechnology, Anna University, Chennai, Tamil Nadu, India
| | | | - Vimal Veeriah
- Vascular Biology Lab, AU-KBC Research Centre, Chennai, Tamil Nadu, India
| | - Priya Dutta
- Department of Biotechnology, Anna University, Chennai, Tamil Nadu, India
| | | | | | - Suvro Chatterjee
- Vascular Biology Lab, AU-KBC Research Centre, Chennai, Tamil Nadu, India; Department of Biotechnology, Anna University, Chennai, Tamil Nadu, India.
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49
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Jin K, Xiao D, Andersen B, Xiang M. Lmo4 and Other LIM domain only factors are necessary and sufficient for multiple retinal cell type development. Dev Neurobiol 2015; 76:900-15. [PMID: 26579872 DOI: 10.1002/dneu.22365] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 10/01/2015] [Accepted: 11/12/2015] [Indexed: 12/13/2022]
Abstract
Understanding the molecular basis by which distinct cell types are specified is a central issue in retinogenesis and retinal disease development. Here we examined the role of LIM domain only 4 (Lmo4) in retinal development using both gain-of-function and loss-of-function approaches. By immunostaining, Lmo4 was found to be expressed in mouse retina from E10.5 to mature stages. Retroviral delivery of Lmo4 into retinal progenitor cells could promote the amacrine, bipolar and Müller cell fates at the expense of photoreceptors. It also inhibited the fate of early-born retinal ganglion cells. Using a dominant-negative form of Lmo4 which suppresses transcriptional activities of all LIM domain only factors, we demonstrated that LIM domain only factors are both necessary and sufficient for promoting amacrine and bipolar cell development, but not for the differentiation of ganglion, horizontal, Müller, or photoreceptor cells. Taken together, our study uncovers multiple roles of Lmo4 during retinal development and demonstrates the importance of LIM domain only factors in ensuring proper retinal cell specification and differentiation. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 900-915, 2016.
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Affiliation(s)
- Kangxin Jin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, China.,Center for Advanced Biotechnology and Medicine and Department of Pediatrics, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854
| | - Dongchang Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, China
| | - Bogi Andersen
- Department of Medicine, Division of Endocrinology and Metabolism, University of California, Irvine, California, 92697-4030.,Department of Biological Chemistry, Division of Endocrinology and Metabolism, University of California, Irvine, California, 92697-4030
| | - Mengqing Xiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, China.,Center for Advanced Biotechnology and Medicine and Department of Pediatrics, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey, 08854
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50
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Hernández-Bejarano M, Gestri G, Spawls L, Nieto-López F, Picker A, Tada M, Brand M, Bovolenta P, Wilson SW, Cavodeassi F. Opposing Shh and Fgf signals initiate nasotemporal patterning of the zebrafish retina. Development 2015; 142:3933-42. [PMID: 26428010 PMCID: PMC4712879 DOI: 10.1242/dev.125120] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 09/21/2015] [Indexed: 01/12/2023]
Abstract
The earliest known determinants of retinal nasotemporal identity are the transcriptional regulators Foxg1, which is expressed in the prospective nasal optic vesicle, and Foxd1, which is expressed in the prospective temporal optic vesicle. Previous work has shown that, in zebrafish, Fgf signals from the dorsal forebrain and olfactory primordia are required to specify nasal identity in the dorsal, prospective nasal, optic vesicle. Here, we show that Hh signalling from the ventral forebrain is required for specification of temporal identity in the ventral optic vesicle and is sufficient to induce temporal character when activated in the prospective nasal retina. Consequently, the evaginating optic vesicles become partitioned into prospective nasal and temporal domains by the opposing actions of Fgfs and Shh emanating from dorsal and ventral domains of the forebrain primordium. In absence of Fgf activity, foxd1 expression is established irrespective of levels of Hh signalling, indicating that the role of Shh in promoting foxd1 expression is only required in the presence of Fgf activity. Once the spatially complementary expression of foxd1 and foxg1 is established, the boundary between expression domains is maintained by mutual repression between Foxd1 and Foxg1. Summary: In the fish eye, Hh signalling from the ventral forebrain regulates spatial identity in the retina by promoting foxd1 expression. This role is required only in the presence of Fgf activity.
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Affiliation(s)
| | - Gaia Gestri
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1 6BT, UK
| | - Lana Spawls
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1 6BT, UK
| | - Francisco Nieto-López
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), C/Nicolás Cabrera 1, 28049, Madrid, Spain
| | - Alexander Picker
- Center of Regenerative Therapies Dresden (CRTD), Biotechnology Center, Dresden University of Technology, 01062 Dresden, Germany
| | - Masazumi Tada
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1 6BT, UK
| | - Michael Brand
- Center of Regenerative Therapies Dresden (CRTD), Biotechnology Center, Dresden University of Technology, 01062 Dresden, Germany
| | - Paola Bovolenta
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), C/Nicolás Cabrera 1, 28049, Madrid, Spain CIBER de Enfermedades Raras (CIBERER), C/Nicolás Cabrera 1, 28049, Madrid, Spain
| | - Stephen W Wilson
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1 6BT, UK
| | - Florencia Cavodeassi
- Centro de Biología Molecular Severo Ochoa (CSIC-UAM), C/Nicolás Cabrera 1, 28049, Madrid, Spain CIBER de Enfermedades Raras (CIBERER), C/Nicolás Cabrera 1, 28049, Madrid, Spain
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