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Lei Z, He‐Lin Z, Hai‐Yan W, Wei J, Ru W, Zhi‐Li C, Qian‐Feng W. Retinitis pigmentosa with iris coloboma due to miR-204 gene variant in a Chinese family. Mol Genet Genomic Med 2024; 12:e2481. [PMID: 38867642 PMCID: PMC11169764 DOI: 10.1002/mgg3.2481] [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: 03/07/2024] [Accepted: 05/28/2024] [Indexed: 06/14/2024] Open
Abstract
PURPOSE To characterize the phenotype and genotype of a Chinese family with autosomal-dominant retinitis pigmentosa (RP) accompanied by iris coloboma. METHODS The proband, a 34-year-old male, was examined with his family by using fundus photography, optical coherence tomography (OCT), autofluorescence, and full-field electroretinography (ffERG). Genetic analyses were conducted through whole-exome sequencing (WES) to screen for variations. RESULTS Three members of this Chinese family were shown to be bilateral iris coloboma. The male proband and his mother exhibited typical RP feature. The proband's late grandfather had been documented manifestation of iris coloboma. The mode of inheritance was confirmed to be autosomal dominance. Through linkage analysis and WES, a heterozygous variation in the miR-204 gene (n.37C>T), a noncoding RNA gene, was identified in these three members. CONCLUSIONS In this third independent and the first Asian family, the existence of a miR-204 variant associated with RP accompanied by iris coloboma was confirmed. Our findings reinforce the significance of miR-204 as an important factor influencing visual function in the retina. When phenotypes like RP accompanied by iris coloboma in an autosomal-dominant pattern, including in Chinese patients, miR-204 aberrations should be considered.
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Affiliation(s)
- Zhang Lei
- Xi'an Key Laboratory of Digital Medical Technology of Ophthalmologic ImagingShaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital)Xi'anShaanxiChina
| | - Zhu He‐Lin
- Xi'an Key Laboratory of Digital Medical Technology of Ophthalmologic ImagingShaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital)Xi'anShaanxiChina
| | - Wang Hai‐Yan
- Xi'an Key Laboratory of Digital Medical Technology of Ophthalmologic ImagingShaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital)Xi'anShaanxiChina
| | - Jia Wei
- Xi'an Key Laboratory of Digital Medical Technology of Ophthalmologic ImagingShaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital)Xi'anShaanxiChina
| | - Wang Ru
- Xi'an Key Laboratory of Digital Medical Technology of Ophthalmologic ImagingShaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital)Xi'anShaanxiChina
| | - Cui Zhi‐Li
- Xi'an Key Laboratory of Digital Medical Technology of Ophthalmologic ImagingShaanxi Eye Hospital, Xi'an People's Hospital (Xi'an Fourth Hospital)Xi'anShaanxiChina
| | - Wang Qian‐Feng
- Medical College of Optometry and OphthalmologyShandong University of Traditional Chinese MedicineJinanShandongChina
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2
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Li B, Xie T, Nawy S, Shen Y. The development and the genetic diseases of the ciliary body. CELL INSIGHT 2024; 3:100162. [PMID: 38595769 PMCID: PMC11002873 DOI: 10.1016/j.cellin.2024.100162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 03/03/2024] [Accepted: 03/04/2024] [Indexed: 04/11/2024]
Abstract
The ciliary body, located at the junction of the choroid and iris, is crucial in the development of the embryonic eye. Notch2 signalling, Wnt signalling, transforming growth factor β (TGF-β) signalling, and Pax6 signalling are critical for coordinating the ciliary body formation. These signalling pathways are coordinated with each other and participate in the ciliary body development, ensuring the precise formation and optimal functioning of the eye structure. Although rare, ciliary body hypoplasia, ciliary tumours, and genetic-related iritis indicate the intricate nature of ciliary body development. Given the ciliary body's important biological significance and potential medical relevance, we aim to provide a comprehensive overview of the developmental molecular mechanisms governing ciliary body formation and function. Here, we focus on the intricate signalling pathways governing ciliary body development and corresponding genetic ciliary diseases.
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Affiliation(s)
- Baige Li
- Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
| | - Ting Xie
- Division of Life Science, The Hong Kong University of Science and Technology, Kowloon, Hong Kong Special Administrative Region (SAR), China
| | - Scott Nawy
- University of California Berkeley, Department of Molecular and Cell Biology, Berkeley, CA, USA
| | - Yin Shen
- Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, Hubei, China
- Frontier Science Center for Immunology and Metabolism, Medical Research Institute, School of Medicine, Wuhan University, Wuhan, Hubei, China
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3
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Kim JM, Min KW, Kim YJ, Smits R, Basler K, Kim JW. Wnt/β-Catenin Signaling Pathway Is Necessary for the Specification but Not the Maintenance of the Mouse Retinal Pigment Epithelium. Mol Cells 2023; 46:441-450. [PMID: 37190767 PMCID: PMC10336276 DOI: 10.14348/molcells.2023.0029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/19/2023] [Indexed: 05/17/2023] Open
Abstract
β-Catenin (Ctnnb1) has been shown to play critical roles in the development and maintenance of epithelial cells, including the retinal pigment epithelium (RPE). Ctnnb1 is not only a component of intercellular junctions in the epithelium, it also functions as a transcriptional regulator in the Wnt signaling pathway. To identify which of its functional modalities is critically involved in mouse RPE development and maintenance, we varied Ctnnb1 gene content and activity in mouse RPE lineage cells and tested their impacts on mouse eye development. We found that a Ctnnb1 double mutant (Ctnnb1dm), which exhibits impaired transcriptional activity, could not replace Ctnnb1 in the RPE, whereas Ctnnb1Y654E, which has reduced affinity for the junctions, could do so. Expression of the constitutively active Ctnnb1∆ex3 mutant also suppressed the development of RPE, instead facilitating a ciliary cell fate. However, the post-mitotic or mature RPE was insensitive to the loss, inactivation, or constitutive activation of Ctnnb1. Collectively, our results suggest that Ctnnb1 should be maintained within an optimal range to specify RPE through transcriptional regulation of Wnt target genes in the optic neuroepithelium.
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Affiliation(s)
- Jong-Myeong Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Kwang Wook Min
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - You-Joung Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Ron Smits
- Department of Gastroenterology and Hepatology, Erasmus MC-University Medical Center, 3015 GD Rotterdam, The Netherlands
| | - Konrad Basler
- Department of Molecular Life Sciences, University of Zurich, CH-8057 Zurich, Switzerland
| | - Jin Woo Kim
- Department of Biological Sciences and KAIST Stem Cell Center, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
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4
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Cardo LF, de la Fuente DC, Li M. Impaired neurogenesis and neural progenitor fate choice in a human stem cell model of SETBP1 disorder. Mol Autism 2023; 14:8. [PMID: 36805818 PMCID: PMC9940404 DOI: 10.1186/s13229-023-00540-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 02/07/2023] [Indexed: 02/22/2023] Open
Abstract
BACKGROUND Disruptions of SETBP1 (SET binding protein 1) on 18q12.3 by heterozygous gene deletion or loss-of-function variants cause SETBP1 disorder. Clinical features are frequently associated with moderate to severe intellectual disability, autistic traits and speech and motor delays. Despite the association of SETBP1 with neurodevelopmental disorders, little is known about its role in brain development. METHODS Using CRISPR/Cas9 genome editing technology, we generated a SETBP1 deletion model in human embryonic stem cells (hESCs) and examined the effects of SETBP1-deficiency in neural progenitors (NPCs) and neurons derived from these stem cells using a battery of cellular assays, genome-wide transcriptomic profiling and drug-based phenotypic rescue. RESULTS Neural induction occurred efficiently in all SETBP1 deletion models as indicated by uniform transition into neural rosettes. However, SETBP1-deficient NPCs exhibited an extended proliferative window and a decrease in neurogenesis coupled with a deficiency in their ability to acquire ventral forebrain fate. Genome-wide transcriptome profiling and protein biochemical analysis revealed enhanced activation of Wnt/β-catenin signaling in SETBP1 deleted cells. Crucially, treatment of the SETBP1-deficient NPCs with a small molecule Wnt inhibitor XAV939 restored hyper canonical β-catenin activity and restored both cortical and MGE neuronal differentiation. LIMITATIONS The current study is based on analysis of isogenic hESC lines with genome-edited SETBP1 deletion and further studies would benefit from the use of patient-derived iPSC lines that may harbor additional genetic risk that aggravate brain pathology of SETBP1 disorder. CONCLUSIONS We identified an important role for SETBP1 in controlling forebrain progenitor expansion and neurogenic differentiation. Our study establishes a novel regulatory link between SETBP1 and Wnt/β-catenin signaling during human cortical neurogenesis and provides mechanistic insights into structural abnormalities and potential therapeutic avenues for SETBP1 disorder.
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Affiliation(s)
- Lucia F Cardo
- Neuroscience and Mental Health Innovation Institute, School of Medicine and School of Bioscience, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK.
| | - Daniel C de la Fuente
- Neuroscience and Mental Health Innovation Institute, School of Medicine and School of Bioscience, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Meng Li
- Neuroscience and Mental Health Innovation Institute, School of Medicine and School of Bioscience, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK.
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5
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Angueyra JM, Kunze VP, Patak LK, Kim H, Kindt K, Li W. Transcription factors underlying photoreceptor diversity. eLife 2023; 12:e81579. [PMID: 36745553 PMCID: PMC9901936 DOI: 10.7554/elife.81579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 01/22/2023] [Indexed: 02/07/2023] Open
Abstract
During development, retinal progenitors navigate a complex landscape of fate decisions to generate the major cell classes necessary for proper vision. Transcriptional regulation is critical to generate diversity within these major cell classes. Here, we aim to provide the resources and techniques required to identify transcription factors necessary to generate and maintain diversity in photoreceptor subtypes, which are critical for vision. First, we generate a key resource: a high-quality and deep transcriptomic profile of each photoreceptor subtype in adult zebrafish. We make this resource openly accessible, easy to explore, and have integrated it with other currently available photoreceptor transcriptomic datasets. Second, using our transcriptomic profiles, we derive an in-depth map of expression of transcription factors in photoreceptors. Third, we use efficient CRISPR-Cas9 based mutagenesis to screen for null phenotypes in F0 larvae (F0 screening) as a fast, efficient, and versatile technique to assess the involvement of candidate transcription factors in the generation of photoreceptor subtypes. We first show that known phenotypes can be easily replicated using this method: loss of S cones in foxq2 mutants and loss of rods in nr2e3 mutants. We then identify novel functions for the transcription factor Tbx2, demonstrating that it plays distinct roles in controlling the generation of all photoreceptor subtypes within the retina. Our study provides a roadmap to discover additional factors involved in this process. Additionally, we explore four transcription factors of unknown function (Skor1a, Sall1a, Lrrfip1a, and Xbp1), and find no evidence for their involvement in the generation of photoreceptor subtypes. This dataset and screening method will be a valuable way to explore the genes involved in many other essential aspects of photoreceptor biology.
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Affiliation(s)
- Juan M Angueyra
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Vincent P Kunze
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Laura K Patak
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Hailey Kim
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
| | - Katie Kindt
- Section on Sensory Cell Development and Function, National Institute on Deafness and Other Communication Disorders, National Institutes of HealthBethesdaUnited States
| | - Wei Li
- Unit of Retinal Neurophysiology, National Eye Institute, National Institutes of HealthBethesdaUnited States
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6
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Fishman ES, Louie M, Miltner AM, Cheema SK, Wong J, Schlaeger NM, Moshiri A, Simó S, Tarantal AF, La Torre A. MicroRNA Signatures of the Developing Primate Fovea. Front Cell Dev Biol 2021; 9:654385. [PMID: 33898453 PMCID: PMC8060505 DOI: 10.3389/fcell.2021.654385] [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: 01/16/2021] [Accepted: 03/16/2021] [Indexed: 11/22/2022] Open
Abstract
Rod and cone photoreceptors differ in their shape, photopigment expression, synaptic connection patterns, light sensitivity, and distribution across the retina. Although rods greatly outnumber cones, human vision is mostly dependent on cone photoreceptors since cones are essential for our sharp visual acuity and color discrimination. In humans and other primates, the fovea centralis (fovea), a specialized region of the central retina, contains the highest density of cones. Despite the vast importance of the fovea for human vision, the molecular mechanisms guiding the development of this region are largely unknown. MicroRNAs (miRNAs) are small post-transcriptional regulators known to orchestrate developmental transitions and cell fate specification in the retina. Here, we have characterized the transcriptional landscape of the developing rhesus monkey retina. Our data indicates that non-human primate fovea development is significantly accelerated compared to the equivalent retinal region at the other side of the optic nerve head, as described previously. Notably, we also identify several miRNAs differentially expressed in the presumptive fovea, including miR-15b-5p, miR-342-5p, miR-30b-5p, miR-103-3p, miR-93-5p as well as the miRNA cluster miR-183/-96/-182. Interestingly, miR-342-5p is enriched in the nasal primate retina and in the peripheral developing mouse retina, while miR-15b is enriched in the temporal primate retina and increases over time in the mouse retina in a central-to-periphery gradient. Together our data constitutes the first characterization of the developing rhesus monkey retinal miRNome and provides novel datasets to attain a more comprehensive understanding of foveal development.
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Affiliation(s)
- Elizabeth S Fishman
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States
| | - Mikaela Louie
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States
| | - Adam M Miltner
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States
| | - Simranjeet K Cheema
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States
| | - Joanna Wong
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States
| | - Nicholas M Schlaeger
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States
| | - Ala Moshiri
- Department of Ophthalmology, University of California, Davis, Davis, CA, United States
| | - Sergi Simó
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States
| | - Alice F Tarantal
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States.,Department of Pediatrics, University of California, Davis, Davis, CA, United States.,California National Primate Research Center, University of California, Davis, Davis, CA, United States
| | - Anna La Torre
- Department of Cell Biology and Human Anatomy, University of California, Davis, Davis, CA, United States
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7
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Surendran H, Nandakumar S, Reddy K VB, Stoddard J, Mohan K V, Upadhyay PK, McGill TJ, Pal R. Transplantation of retinal pigment epithelium and photoreceptors generated concomitantly via small molecule-mediated differentiation rescues visual function in rodent models of retinal degeneration. Stem Cell Res Ther 2021; 12:70. [PMID: 33468244 PMCID: PMC7814459 DOI: 10.1186/s13287-021-02134-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/01/2021] [Indexed: 01/01/2023] Open
Abstract
Background Age-related macular degeneration (AMD) is a result of degeneration/damage of the retinal pigment epithelium (RPE) while retinitis pigmentosa (RP), an inherited early-onset disease, results from premature loss of photoreceptors. A promising therapeutic approach for both is the replacement of lost/damaged cells with human induced pluripotent stem cell (hiPSC)-derived retinal cells. Methods The aim of this study was to investigate the in vivo functionality of RPE and photoreceptor progenitor (PRP) cells derived from a clinical-grade hiPSC line through a unified protocol. De novo-generated RPE and PRP were characterized extensively to validate their identity, purity, and potency. Results RPE expressed tight junction proteins, showed pigmentation and ciliation, and secreted polarization-related factors vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF). PRP expressed neural retina proteins and cone and rod markers, and responded to KCl-induced polarization. Transcriptomic analysis demonstrated an increase in the expression of mature retinal tissue-specific genes coupled with concomitant downregulation of genes from undesired lineages. RPE transplantation rescued visual function in RCS rats shown via optokinetic tracking and photoreceptor rescue. PRP transplantation improved light perception in NOD.SCID-rd1 mice, and positive electroretinography signals indicated functional photoreceptor activity in the host’s outer nuclear layer. Graft survival and integration were confirmed using immunohistochemistry, and no animals showed teratoma formation or any kind of ectopic growth in the eye. Conclusions To our knowledge, this is the first demonstration of a unified, scalable, and GMP-adaptable protocol indicating strong animal efficacy and safety data with hiPSC-derived RPE and PRP cells. These findings provide robust proof-of-principle results for IND-enabling studies to test these potential regenerative cell therapies in patients. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02134-x.
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Affiliation(s)
- Harshini Surendran
- Eyestem Research, Centre for Cellular and Molecular Platforms (C-CAMP), National Centre for Biological Sciences-Tata Institute of Fundamental Research (NCBS-TIFR) Campus, GKVK Post, Bellary Road, Bangalore, 560065, Karnataka, India
| | - Swapna Nandakumar
- Eyestem Research, Centre for Cellular and Molecular Platforms (C-CAMP), National Centre for Biological Sciences-Tata Institute of Fundamental Research (NCBS-TIFR) Campus, GKVK Post, Bellary Road, Bangalore, 560065, Karnataka, India
| | - Vijay Bhaskar Reddy K
- Eyestem Research, Centre for Cellular and Molecular Platforms (C-CAMP), National Centre for Biological Sciences-Tata Institute of Fundamental Research (NCBS-TIFR) Campus, GKVK Post, Bellary Road, Bangalore, 560065, Karnataka, India
| | - Jonathan Stoddard
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, USA
| | | | | | - Trevor J McGill
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, USA
| | - Rajarshi Pal
- Eyestem Research, Centre for Cellular and Molecular Platforms (C-CAMP), National Centre for Biological Sciences-Tata Institute of Fundamental Research (NCBS-TIFR) Campus, GKVK Post, Bellary Road, Bangalore, 560065, Karnataka, India.
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8
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Zhang Y, Zhang S, Zhang Z, Dong Y, Ma X, Qiang R, Chen Y, Gao X, Zhao C, Chen F, He S, Chai R. Knockdown of Foxg1 in Sox9+ supporting cells increases the trans-differentiation of supporting cells into hair cells in the neonatal mouse utricle. Aging (Albany NY) 2020; 12:19834-19851. [PMID: 33099273 PMCID: PMC7655167 DOI: 10.18632/aging.104009] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 08/15/2020] [Indexed: 05/30/2023]
Abstract
Foxg1 plays important roles in regeneration of hair cell (HC) in the cochlea of neonatal mouse. Here, we used Sox9-CreER to knock down Foxg1 in supporting cells (SCs) in the utricle in order to investigate the role of Foxg1 in HC regeneration in the utricle. We found Sox9 an ideal marker of utricle SCs and bred Sox9CreER/+Foxg1loxp/loxp mice to conditionally knock down Foxg1 in utricular SCs. Conditional knockdown (cKD) of Foxg1 in SCs at postnatal day one (P01) led to increased number of HCs at P08. These regenerated HCs had normal characteristics, and could survive to at least P30. Lineage tracing showed that a significant portion of newly regenerated HCs originated from SCs in Foxg1 cKD mice compared to the mice subjected to the same treatment, which suggested SCs trans-differentiate into HCs in the Foxg1 cKD mouse utricle. After neomycin treatment in vitro, more HCs were observed in Foxg1 cKD mice utricle compared to the control group. Together, these results suggest that Foxg1 cKD in utricular SCs may promote HC regeneration by inducing trans-differentiation of SCs. This research therefore provides theoretical basis for the effects of Foxg1 in trans-differentiation of SCs and regeneration of HCs in the mouse utricle.
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Affiliation(s)
- Yuan Zhang
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Shasha Zhang
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Zhonghong Zhang
- Department of Ophthalmology, Zhongda Hospital, Southeast University, Nanjing, China
| | - Ying Dong
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Xiangyu Ma
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Ruiying Qiang
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Yin Chen
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, China
| | - Xia Gao
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, China
| | - Chunjie Zhao
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Shuangba He
- Department of Otolaryngology Head and Neck, Nanjing Tongren Hospital, School of Medicine, Southeast University, China
| | - Renjie Chai
- MOE Key Laboratory for Developmental Genes and Human Disease, School of Life Sciences and Technology, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, China
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, China
- Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, China
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9
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Medina-Martinez O, Haller M, Rosenfeld JA, O'Neill MA, Lamb DJ, Jamrich M. The transcription factor Maz is essential for normal eye development. Dis Model Mech 2020; 13:dmm044412. [PMID: 32571845 PMCID: PMC7449797 DOI: 10.1242/dmm.044412] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 06/10/2020] [Indexed: 12/19/2022] Open
Abstract
Wnt/β-catenin signaling has an essential role in eye development. Faulty regulation of this pathway results in ocular malformations, owing to defects in cell-fate determination and differentiation. Herein, we show that disruption of Maz, the gene encoding Myc-associated zinc-finger transcription factor, produces developmental eye defects in mice and humans. Expression of key genes involved in the Wnt cascade, Sfrp2, Wnt2b and Fzd4, was significantly increased in mice with targeted inactivation of Maz, resulting in abnormal peripheral eye formation with reduced proliferation of the progenitor cells in the region. Paradoxically, the Wnt reporter TCF-Lef1 displayed a significant downregulation in Maz-deficient eyes. Molecular analysis indicates that Maz is necessary for the activation of the Wnt/β-catenin pathway and participates in the network controlling ciliary margin patterning. Copy-number variations and single-nucleotide variants of MAZ were identified in humans that result in abnormal ocular development. The data support MAZ as a key contributor to the eye comorbidities associated with chromosome 16p11.2 copy-number variants and as a transcriptional regulator of ocular development.
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Affiliation(s)
- Olga Medina-Martinez
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Meade Haller
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jill A Rosenfeld
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
- Baylor Genetics Laboratories, Houston, TX 77021, USA
| | - Marisol A O'Neill
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX 77030, USA
| | - Dolores J Lamb
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX 77030, USA
- James Buchanan Brady Foundation Department of Urology, Weill Cornell Medical College, New York City, NY 10065, USA
- Englander Institute for Precision Medicine, Weill Cornell Medical College, New York City, NY 10065, USA
- Center for Reproductive Genomics, Weill Cornell Medical College, New York City, NY 10065, USA
| | - Milan Jamrich
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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10
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Zhao Y, Huang Z, Huang J, Zhang C, Meng F. Phylogenetic analysis and expression differences of eye-related genes in cavefish genus Sinocyclocheilus. Integr Zool 2020; 16:354-367. [PMID: 32652757 DOI: 10.1111/1749-4877.12466] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The adaptive evolution of visual systems has been observed in many cavefish. However, little is known about the molecular mechanisms underlying these adaptations, which include regressive changes such as eye degeneration. Here, we analyzed phylogenetic and expression patterns of 6 eye-related genes (crx, foxg1b, opn1sw2, otx2, rho and sox2) in 12 Sinocyclocheilus species from China, including 8 stygobionts and 4 stygophiles, and examined photoreceptor cell morphology of these species. Those eye-degenerated species of Sinocyclocheilus were polyphyletic and showed different degrees of photoreceptor defects in responses to cave environments. The eye loss and degeneration are the result of convergent evolution. Although S. anophthalmus grouped with the eye-normal species, it displayed not only a high degree of eye degeneration but also significant expression differences in eye-related genes compared with the eye-normal species. The gene foxg1b, which was determined to be under positive selection, might play an important role in the process of eye degeneration in S. anophthalmus based on differential expression. Eye-related gene expression and selection may have contributed to the polyphyly of the cave species. We examined gene expression and duplication in 6 eye-related genes and revealed that these genes displayed considerable diversity in relative expression in Sinocyclocheilus fishes. Otx2 and sox2 were significantly up-regulated in individual cave species, while the other 4 genes (crx, foxg1b, opn1sw2 and rho) were significantly down-regulated. These findings provide a valuable resource for elucidating molecular mechanisms associated with visual system evolution in cavefish.
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Affiliation(s)
- Yahui Zhao
- State Key Laboratory of Membrane Biology, State Key Laboratory of Integrated Pest Management, Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zushi Huang
- State Key Laboratory of Membrane Biology, State Key Laboratory of Integrated Pest Management, Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Jinqing Huang
- State Key Laboratory of Membrane Biology, State Key Laboratory of Integrated Pest Management, Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Faculty of Basic Medical Sciences, Guilin Medical University, Guilin, China
| | - Chunguang Zhang
- State Key Laboratory of Membrane Biology, State Key Laboratory of Integrated Pest Management, Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Fanwei Meng
- State Key Laboratory of Membrane Biology, State Key Laboratory of Integrated Pest Management, Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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11
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Abstract
Binocular vision depends on retinal ganglion cell (RGC) axon projection either to the same side or to the opposite side of the brain. In this article, we review the molecular mechanisms for decussation of RGC axons, with a focus on axon guidance signaling at the optic chiasm and ipsi- and contralateral axon organization in the optic tract prior to and during targeting. The spatial and temporal features of RGC neurogenesis that give rise to ipsilateral and contralateral identity are described. The albino visual system is highlighted as an apt comparative model for understanding RGC decussation, as albinos have a reduced ipsilateral projection and altered RGC neurogenesis associated with perturbed melanogenesis in the retinal pigment epithelium. Understanding the steps for RGC specification into ipsi- and contralateral subtypes will facilitate differentiation of stem cells into RGCs with proper navigational abilities for effective axon regeneration and correct targeting of higher-order visual centers.
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Affiliation(s)
- Carol Mason
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10027, USA; .,Department of Neuroscience, Columbia University, New York, NY 10027, USA.,Department of Ophthalmology, Columbia University, New York, NY 10027, USA.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA;
| | - Nefeli Slavi
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA;
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12
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Zhang S, Zhang Y, Dong Y, Guo L, Zhang Z, Shao B, Qi J, Zhou H, Zhu W, Yan X, Hong G, Zhang L, Zhang X, Tang M, Zhao C, Gao X, Chai R. Knockdown of Foxg1 in supporting cells increases the trans-differentiation of supporting cells into hair cells in the neonatal mouse cochlea. Cell Mol Life Sci 2020; 77:1401-1419. [PMID: 31485717 PMCID: PMC7113235 DOI: 10.1007/s00018-019-03291-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 08/08/2019] [Accepted: 08/28/2019] [Indexed: 12/17/2022]
Abstract
Foxg1 is one of the forkhead box genes that are involved in morphogenesis, cell fate determination, and proliferation, and Foxg1 was previously reported to be required for morphogenesis of the mammalian inner ear. However, Foxg1 knock-out mice die at birth, and thus the role of Foxg1 in regulating hair cell (HC) regeneration after birth remains unclear. Here we used Sox2CreER/+ Foxg1loxp/loxp mice and Lgr5-EGFPCreER/+ Foxg1loxp/loxp mice to conditionally knock down Foxg1 specifically in Sox2+ SCs and Lgr5+ progenitors, respectively, in neonatal mice. We found that Foxg1 conditional knockdown (cKD) in Sox2+ SCs and Lgr5+ progenitors at postnatal day (P)1 both led to large numbers of extra HCs, especially extra inner HCs (IHCs) at P7, and these extra IHCs with normal hair bundles and synapses could survive at least to P30. The EdU assay failed to detect any EdU+ SCs, while the SC number was significantly decreased in Foxg1 cKD mice, and lineage tracing data showed that much more tdTomato+ HCs originated from Sox2+ SCs in Foxg1 cKD mice compared to the control mice. Moreover, the sphere-forming assay showed that Foxg1 cKD in Lgr5+ progenitors did not significantly change their sphere-forming ability. All these results suggest that Foxg1 cKD promotes HC regeneration and leads to large numbers of extra HCs probably by inducing direct trans-differentiation of SCs and progenitors to HCs. Real-time qPCR showed that cell cycle and Notch signaling pathways were significantly down-regulated in Foxg1 cKD mice cochlear SCs. Together, this study provides new evidence for the role of Foxg1 in regulating HC regeneration from SCs and progenitors in the neonatal mouse cochlea.
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Affiliation(s)
- Shasha Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Yuan Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Ying Dong
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Lingna Guo
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Zhong Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Buwei Shao
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Jieyu Qi
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Han Zhou
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - Weijie Zhu
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Xiaoqian Yan
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Guodong Hong
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Liyan Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Xiaoli Zhang
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - Mingliang Tang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Chunjie Zhao
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China
| | - Xia Gao
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, China
| | - Renjie Chai
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China.
- Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, China.
- Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 211189, China.
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, 210008, China.
- Key Laboratory of Hearing Medicine of NHFPC, ENT Institute and Otorhinolaryngology Department of Affiliated Eye and ENT Hospital, Shanghai Engineering Research Centre of Cochlear Implant, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200031, China.
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13
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Morazzani EM, Compton JR, Leary DH, Berry AV, Hu X, Marugan JJ, Glass PJ, Legler PM. Proteolytic cleavage of host proteins by the Group IV viral proteases of Venezuelan equine encephalitis virus and Zika virus. Antiviral Res 2019; 164:106-122. [PMID: 30742841 DOI: 10.1016/j.antiviral.2019.02.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 01/13/2019] [Accepted: 02/01/2019] [Indexed: 12/12/2022]
Abstract
The alphaviral nonstructural protein 2 (nsP2) cysteine proteases (EC 3.4.22.-) are essential for the proteolytic processing of the nonstructural (ns) polyprotein and are validated drug targets. A common secondary role of these proteases is to antagonize the effects of interferon (IFN). After delineating the cleavage site motif of the Venezuelan equine encephalitis virus (VEEV) nsP2 cysteine protease, we searched the human genome to identify host protein substrates. Here we identify a new host substrate of the VEEV nsP2 protease, human TRIM14, a component of the mitochondrial antiviral-signaling protein (MAVS) signalosome. Short stretches of homologous host-pathogen protein sequences (SSHHPS) are present in the nonstructural polyprotein and TRIM14. A 25-residue cyan-yellow fluorescent protein TRIM14 substrate was cleaved in vitro by the VEEV nsP2 protease and the cleavage site was confirmed by tandem mass spectrometry. A TRIM14 cleavage product also was found in VEEV-infected cell lysates. At least ten other Group IV (+)ssRNA viral proteases have been shown to cleave host proteins involved in generating the innate immune responses against viruses, suggesting that the integration of these short host protein sequences into the viral protease cleavage sites may represent an embedded mechanism of IFN antagonism. This interference mechanism shows several parallels with those of CRISPR/Cas9 and RNAi/RISC, but with a protease recognizing a protein sequence common to both the host and pathogen. The short host sequences embedded within the viral genome appear to be analogous to the short phage sequences found in a host's CRISPR spacer sequences. To test this algorithm, we applied it to another Group IV virus, Zika virus (ZIKV), and identified cleavage sites within human SFRP1 (secreted frizzled related protein 1), a retinal Gs alpha subunit, NT5M, and Forkhead box protein G1 (FOXG1) in vitro. Proteolytic cleavage of these proteins suggests a possible link between the protease and the virus-induced phenotype of ZIKV. The algorithm may have value for selecting cell lines and animal models that recapitulate virus-induced phenotypes, predicting host-range and susceptibility, selecting oncolytic viruses, identifying biomarkers, and de-risking live virus vaccines. Inhibitors of the proteases that utilize this mechanism may both inhibit viral replication and alleviate suppression of the innate immune responses.
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Affiliation(s)
- Elaine M Morazzani
- United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - Jaimee R Compton
- Center for Bio/molecular Science and Engineering, U.S. Naval Research Laboratory, Washington, DC 20375, USA
| | - Dagmar H Leary
- Center for Bio/molecular Science and Engineering, U.S. Naval Research Laboratory, Washington, DC 20375, USA
| | | | - Xin Hu
- NIH Chemical Genomics Center, National Center for Advancing Translational Sciences, Rockville, MD 20850, USA
| | - Juan J Marugan
- NIH Chemical Genomics Center, National Center for Advancing Translational Sciences, Rockville, MD 20850, USA
| | - Pamela J Glass
- United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, USA
| | - Patricia M Legler
- Center for Bio/molecular Science and Engineering, U.S. Naval Research Laboratory, Washington, DC 20375, USA.
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14
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Diacou R, Zhao Y, Zheng D, Cvekl A, Liu W. Six3 and Six6 Are Jointly Required for the Maintenance of Multipotent Retinal Progenitors through Both Positive and Negative Regulation. Cell Rep 2018; 25:2510-2523.e4. [PMID: 30485816 PMCID: PMC6317371 DOI: 10.1016/j.celrep.2018.10.106] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 09/19/2018] [Accepted: 10/29/2018] [Indexed: 11/16/2022] Open
Abstract
Gene regulation of multipotent neuroretinal progenitors is partially understood. Through characterizing Six3 and Six6 double knockout retinas (DKOs), we demonstrate Six3 and Six6 are jointly required for the maintenance of multipotent neuroretinal progenitors. Phenotypes in DKOs were not found in either Six3 nulls or Six6 nulls. At the far periphery, ciliary margin (CM) markers Otx1 and Cdon together with Wnt3a and Fzd1 were ectopically upregulated, whereas neuroretinal progenitor markers Sox2, Notch1, and Otx2 were absent or reduced. At the mid periphery, multi-lineage differentiation was defective. The gene set jointly regulated by Six3 and Six6 significantly overlapped with the gene networks regulated by WNT3A, CTNNB1, POU4F2, or SOX2. Stimulation of Wnt/β-catenin signaling by either Wnt-3a or a GS3Kβ inhibitor promoted CM progenitors at the cost of neuroretinal identity at the periphery of eyecups. Therefore, Six3 and Six6 together directly or indirectly suppress Wnt/β-catenin signaling but promote retinogenic factors for the maintenance of multipotent neuroretinal progenitors.
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Affiliation(s)
- Raven Diacou
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Yilin Zhao
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Deyou Zheng
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Ales Cvekl
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Wei Liu
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, New York, NY 10461, USA.
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15
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He Z, Fang Q, Li H, Shao B, Zhang Y, Zhang Y, Han X, Guo R, Cheng C, Guo L, Shi L, Li A, Yu C, Kong W, Zhao C, Gao X, Chai R. The role of FOXG1 in the postnatal development and survival of mouse cochlear hair cells. Neuropharmacology 2018; 144:43-57. [PMID: 30336149 DOI: 10.1016/j.neuropharm.2018.10.021] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 09/30/2018] [Accepted: 10/14/2018] [Indexed: 12/17/2022]
Abstract
The development of therapeutic interventions for hearing loss requires a detailed understanding of the genes and proteins involved in hearing. The FOXG1 protein plays an important role in early neural development and in a variety of neurodevelopmental disorders. Previous studies have shown that there are severe deformities in the inner ear in Foxg1 knockout mice, but due to the postnatal lethality of Foxg1 knockout mice, the role of FOXG1 in hair cell (HC) development and survival during the postnatal period has not been investigated. In this study, we took advantage of transgenic mice that have a specific knockout of Foxg1 in HCs, thus allowing us to explore the role of FOXG1 in postnatal HC development and survival. In the Foxg1 conditional knockout (CKO) HCs, an extra row of HCs appeared in the apical turn of the cochlea and some parts of the middle turn at postnatal day (P)1 and P7; however, these HCs gradually underwent apoptosis, and the HC number was significantly decreased by P21. Auditory brainstem response tests showed that the Foxg1 CKO mice had lost their hearing by P30. The RNA-Seq results and the qPCR verification both showed that the Wnt, Notch, IGF, EGF, and Hippo signaling pathways were down-regulated in the HCs of Foxg1 CKO mice. The significant down-regulation of the Notch signaling pathway might be the reason for the increased numbers of HCs in the cochleae of Foxg1 CKO mice at P1 and P7, while the down-regulation of the Wnt, IGF, and EGF signaling pathways might lead to subsequent HC apoptosis. Together, these results indicate that knockout of Foxg1 induces an extra row of HCs via Notch signaling inhibition and induces subsequent apoptosis of these HCs by inhibiting the Wnt, IGF, and EGF signaling pathways. This study thus provides new evidence for the function and mechanism of FOXG1 in HC development and survival in mice.
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Affiliation(s)
- Zuhong He
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Qiaojun Fang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - He Li
- Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Buwei Shao
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Yuan Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Yuhua Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Xiao Han
- Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Rongrong Guo
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Cheng Cheng
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Lingna Guo
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Lusen Shi
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, 210008, China
| | - Ao Li
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, 210008, China
| | - Chenjie Yu
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, 210008, China
| | - Weijia Kong
- Department of Otorhinolaryngology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Chunjie Zhao
- Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, 210009, China; Center of Depression, Beijing Institute for Brain Disorders, China.
| | - Xia Gao
- Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical School, Jiangsu Provincial Key Medical Discipline (Laboratory), Nanjing, 210008, China.
| | - Renjie Chai
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast University, Nanjing, 210096, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China; Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, Southeast University, Nanjing, 211189, China; Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, China.
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16
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The peripheral eye: A neurogenic area with potential to treat retinal pathologies? Prog Retin Eye Res 2018; 68:110-123. [PMID: 30201383 DOI: 10.1016/j.preteyeres.2018.09.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 08/31/2018] [Accepted: 09/03/2018] [Indexed: 12/14/2022]
Abstract
Numerous degenerative diseases affecting visual function, including glaucoma and retinitis pigmentosa, are produced by the loss of different types of retinal cells. Cell replacement therapy has emerged as a promising strategy for treating these and other retinal diseases. The retinal margin or ciliary body (CB) of mammals has been proposed as a potential source of cells to be used in degenerative conditions affecting the retina because it has been reported it might hold neurogenic potential beyond embryonic development. However, many aspects of the origin and biology of the CB are unknown and more recent experiments have challenged the capacity of CB cells to generate different types of retinal neurons. Here we review the most recent findings about the development of the marginal zone of the retina in different vertebrates and some of the mechanisms underlying the proliferative and neurogenic capacity of this fascinating region of the vertebrates eye. In addition, we performed experiments to isolate CB cells from the mouse retina, generated neurospheres and observed that they can be expanded with a proliferative ratio similar to neural stem cells. When induced to differentiate, cells derived from the CB neurospheres start to express early neural markers but, unlike embryonic stem cells, they are not able to fully differentiate in vitro or generate retinal organoids. Together with previous reports on the neurogenic capacity of CB cells, also reviewed here, our results contribute to the current knowledge about the potentiality of this peripheral region of the eye as a therapeutic source of functional retinal neurons in degenerative diseases.
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Smith R, Huang YT, Tian T, Vojtasova D, Mesalles-Naranjo O, Pollard SM, Pratt T, Price DJ, Fotaki V. The Transcription Factor Foxg1 Promotes Optic Fissure Closure in the Mouse by Suppressing Wnt8b in the Nasal Optic Stalk. J Neurosci 2017; 37:7975-7993. [PMID: 28729440 PMCID: PMC5559767 DOI: 10.1523/jneurosci.0286-17.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 06/25/2017] [Accepted: 07/02/2017] [Indexed: 11/21/2022] Open
Abstract
During vertebrate eye morphogenesis, a transient fissure forms at its inferior part, known as the optic fissure. This will gradually close, giving rise to a healthy, spherical optic cup. Failure of the optic fissure to close gives rise to an ocular disorder known as coloboma. During this developmental process, Foxg1 is expressed in the optic neuroepithelium, with highest levels of expression in the nasal optic stalk. Foxg1-/- mutant mice have microphthalmic eyes with a large ventral coloboma. We found Wnt8b expression upregulated in the Foxg1-/- optic stalk and hypothesized that, similar to what is observed in telencephalic development, Foxg1 directs development of the optic neuroepithelium through transcriptional suppression of Wnt8b To test this, we generated Foxg1-/-;Wnt8b-/- double mutants of either sex and found that the morphology of the optic cup and stalk and the closure of the optic fissure were substantially rescued in these embryos. This rescue correlates with restored Pax2 expression in the anterior tip of the optic fissure. In addition, although we do not find evidence implicating altered proliferation in the rescue, we observe a significant increase in apoptotic cell density in Foxg1-/-;Wnt8b-/- double mutants compared with the Foxg1-/- single mutant. Upregulation of Wnt/β-catenin target molecules in the optic cup and stalk may underlie the molecular and morphological defects in the Foxg1-/- mutant. Our results show that proper optic fissure closure relies on Wnt8b suppression by Foxg1 in the nasal optic stalk to maintain balanced apoptosis and Pax2 expression in the nasal and temporal edges of the fissure.SIGNIFICANCE STATEMENT Coloboma is an ocular disorder that may result in a loss of visual acuity and accounts for ∼10% of childhood blindness. It results from errors in the sealing of the optic fissure (OF), a transient structure at the bottom of the eye. Here, we investigate the colobomatous phenotype of the Foxg1-/- mutant mouse. We identify upregulated expression of Wnt8b in the optic stalk of Foxg1-/- mutants before OF closure initiates. Foxg1-/-;Wnt8b-/- double mutants show a substantial rescue of the Foxg1-/- coloboma phenotype, which correlates with a rescue in molecular and cellular defects of Foxg1-/- mutants. Our results unravel a new role of Foxg1 in promoting OF closure providing additional knowledge about the molecules and cellular mechanisms underlying coloboma formation.
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Affiliation(s)
- Rowena Smith
- Edinburgh Medical School, Biomedical Sciences, Centre for Integrative Physiology, Edinburgh, EH8 9XD, United Kingdom
| | - Yu-Ting Huang
- Edinburgh Medical School, Biomedical Sciences, Centre for Integrative Physiology, Edinburgh, EH8 9XD, United Kingdom
| | - Tian Tian
- Edinburgh Medical School, Biomedical Sciences, Centre for Integrative Physiology, Edinburgh, EH8 9XD, United Kingdom
| | - Dominika Vojtasova
- Edinburgh Medical School, Biomedical Sciences, Centre for Integrative Physiology, Edinburgh, EH8 9XD, United Kingdom
| | - Oscar Mesalles-Naranjo
- Information Service Division, NHS National Services Scotland, Edinburgh, EH12 9EB, United Kingdom
| | - Steven M Pollard
- Medical Research Council Centre for Regenerative Medicine, Edinburgh, EH16 4UU, United Kingdom, and
- Edinburgh Cancer Research UK Cancer Centre, Edinburgh, EH16 4UU, United Kingdom
| | - Thomas Pratt
- Edinburgh Medical School, Biomedical Sciences, Centre for Integrative Physiology, Edinburgh, EH8 9XD, United Kingdom
| | - David J Price
- Edinburgh Medical School, Biomedical Sciences, Centre for Integrative Physiology, Edinburgh, EH8 9XD, United Kingdom
| | - Vassiliki Fotaki
- Edinburgh Medical School, Biomedical Sciences, Centre for Integrative Physiology, Edinburgh, EH8 9XD, United Kingdom,
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18
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Alldredge A, Fuhrmann S. Loss of Axin2 Causes Ocular Defects During Mouse Eye Development. Invest Ophthalmol Vis Sci 2017; 57:5253-5262. [PMID: 27701636 PMCID: PMC5054732 DOI: 10.1167/iovs.15-18599] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The scaffold protein Axin2 is an antagonist and universal target of the Wnt/β-catenin pathway. Disruption of Axin2 may lead to developmental eye defects; however, this has not been examined. The purpose of this study was to investigate the role of Axin2 during ocular and extraocular development in mouse. Methods Animals heterozygous and homozygous for a Axin2lacZ knock-in allele were analyzed at different developmental stages for reporter expression, morphology as well as for the presence of ocular and extraocular markers using histologic and immunohistochemical techniques. Results During early eye development, the Axin2lacZ reporter was expressed in the periocular mesenchyme, RPE, and optic stalk. In the developing retina, Axin2lacZ reporter expression was initiated in ganglion cells at late embryonic stages and robustly expressed in subpopulations of amacrine and horizontal cells postnatally. Activation of the Axin2lacZ reporter overlapped with labeling of POU4F1, PAX6, and Calbindin. Germline deletion of Axin2 led to variable ocular phenotypes ranging from normal to severely defective eyes exhibiting microphthalmia, coloboma, lens defects, and expanded ciliary margin. These defects were correlated with abnormal tissue patterning in individual affected tissues, such as the optic fissure margins in the ventral optic cup and in the expanded ciliary margin. Conclusions Our results reveal a critical role for Axin2 during ocular development, likely by restricting the activity of the Wnt/β-catenin pathway.
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Affiliation(s)
- Ashley Alldredge
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Sabine Fuhrmann
- Department of Ophthalmology and Visual Sciences, Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee, United States
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19
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Ipsilateral and Contralateral Retinal Ganglion Cells Express Distinct Genes during Decussation at the Optic Chiasm. eNeuro 2016; 3:eN-NWR-0169-16. [PMID: 27957530 PMCID: PMC5136615 DOI: 10.1523/eneuro.0169-16.2016] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Revised: 10/18/2016] [Accepted: 11/08/2016] [Indexed: 12/20/2022] Open
Abstract
The increasing availability of transcriptomic technologies within the last decade has facilitated high-throughput identification of gene expression differences that define distinct cell types as well as the molecular pathways that drive their specification. The retinal projection neurons, retinal ganglion cells (RGCs), can be categorized into distinct morphological and functional subtypes and by the laterality of their projections. Here, we present a method for purifying the sparse population of ipsilaterally projecting RGCs in mouse retina from their contralaterally projecting counterparts during embryonic development through rapid retrograde labeling followed by fluorescence-activated cell sorting. Through microarray analysis, we uncovered the distinct molecular signatures that define and distinguish ipsilateral and contralateral RGCs during the critical period of axonal outgrowth and decussation, with more than 300 genes differentially expressed within these two cell populations. Among the differentially expressed genes confirmed through in vivo expression validation, several genes that mark “immaturity” are expressed within postmitotic ipsilateral RGCs. Moreover, at least one complementary pair, Igf1 and Igfbp5, is upregulated in contralateral or ipsilateral RGCs, respectively, and may represent signaling pathways that determine ipsilateral versus contralateral RGC identity. Importantly, the cell cycle regulator cyclin D2 is highly expressed in peripheral ventral retina with a dynamic expression pattern that peaks during the period of ipsilateral RGC production. Thus, the molecular signatures of ipsilateral and contralateral RGCs and the mechanisms that regulate their differentiation are more diverse than previously expected.
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Fujimura N. WNT/β-Catenin Signaling in Vertebrate Eye Development. Front Cell Dev Biol 2016; 4:138. [PMID: 27965955 PMCID: PMC5127792 DOI: 10.3389/fcell.2016.00138] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/09/2016] [Indexed: 01/04/2023] Open
Abstract
The vertebrate eye is a highly specialized sensory organ, which is derived from the anterior neural plate, head surface ectoderm, and neural crest-derived mesenchyme. The single central eye field, generated from the anterior neural plate, divides to give rise to the optic vesicle, which evaginates toward the head surface ectoderm. Subsequently, the surface ectoderm, in conjunction with the optic vesicle invaginates to form the lens vesicle and double-layered optic cup, respectively. This complex process is controlled by transcription factors and several intracellular and extracellular signaling pathways including WNT/β-catenin signaling. This signaling pathway plays an essential role in multiple developmental processes and has a profound effect on cell proliferation and cell fate determination. During eye development, the activity of WNT/β-catenin signaling is tightly controlled. Faulty regulation of WNT/β-catenin signaling results in multiple ocular malformations due to defects in the process of cell fate determination and differentiation. This mini-review summarizes recent findings on the role of WNT/β-catenin signaling in eye development. Whilst this mini-review focuses on loss-of-function and gain-of-function mutants of WNT/β-catenin signaling components, it also highlights some important aspects of β-catenin-independent WNT signaling in the eye development at later stages.
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Affiliation(s)
- Naoko Fujimura
- Laboratory of Eye Biology, BIOCEV Division, Institute of Molecular Genetics Prague, Czechia
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Adutwum-Ofosu KK, Magnani D, Theil T, Price DJ, Fotaki V. The molecular and cellular signatures of the mouse eminentia thalami support its role as a signalling centre in the developing forebrain. Brain Struct Funct 2015; 221:3709-27. [PMID: 26459142 PMCID: PMC5009181 DOI: 10.1007/s00429-015-1127-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 09/30/2015] [Indexed: 12/20/2022]
Abstract
The mammalian eminentia thalami (EmT) (or thalamic eminence) is an embryonic forebrain structure of unknown function. Here, we examined the molecular and cellular properties of the mouse EmT. We first studied mRNA expression of signalling molecules and found that the EmT is a structure, rich in expression of secreted factors, with Wnts being the most abundantly detected. We then examined whether EmT tissue could induce cell fate changes when grafted ectopically. For this, we transplanted EmT tissue from a tau-GFP mouse to the ventral telencephalon of a wild type host, a telencephalic region where Wnt signalling is not normally active but which we showed in culture experiments is competent to respond to Wnts. We observed that the EmT was able to induce in adjacent ventral telencephalic cells ectopic expression of Lef1, a transcriptional activator and a target gene of the Wnt/β-catenin pathway. These Lef1-positive;GFP-negative cells expressed the telencephalic marker Foxg1 but not Ascl1, which is normally expressed by ventral telencephalic cells. These results suggest that the EmT has the capacity to activate Wnt/β-catenin signalling in the ventral telencephalon and to suppress ventral telencephalic gene expression. Altogether, our data support a role of the EmT as a signalling centre in the developing mouse forebrain.
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Affiliation(s)
- Kevin Kofi Adutwum-Ofosu
- The University of Edinburgh, Centre for Integrative Physiology, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.,Department of Anatomy, College of Health Sciences, University of Ghana, Accra, Ghana
| | - Dario Magnani
- The University of Edinburgh, Centre for Integrative Physiology, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.,MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, EH16 4SB, UK
| | - Thomas Theil
- The University of Edinburgh, Centre for Integrative Physiology, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - David J Price
- The University of Edinburgh, Centre for Integrative Physiology, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK
| | - Vassiliki Fotaki
- The University of Edinburgh, Centre for Integrative Physiology, Hugh Robson Building, George Square, Edinburgh, EH8 9XD, UK.
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MiR-204 is responsible for inherited retinal dystrophy associated with ocular coloboma. Proc Natl Acad Sci U S A 2015; 112:E3236-45. [PMID: 26056285 DOI: 10.1073/pnas.1401464112] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Ocular developmental disorders, including the group classified as microphthalmia, anophthalmia, and coloboma (MAC) and inherited retinal dystrophies, collectively represent leading causes of hereditary blindness. Characterized by extreme genetic and clinical heterogeneity, the separate groups share many common genetic causes, in particular relating to pathways controlling retinal and retinal pigment epithelial maintenance. To understand these shared pathways and delineate the overlap between these groups, we investigated the genetic cause of an autosomal dominantly inherited condition of retinal dystrophy and bilateral coloboma, present in varying degrees in a large, five-generation family. By linkage analysis and exome sequencing, we identified a previously undescribed heterozygous mutation, n.37 C > T, in the seed region of microRNA-204 (miR-204), which segregates with the disease in all affected individuals. We demonstrated that this mutation determines significant alterations of miR-204 targeting capabilities via in vitro assays, including transcriptome analysis. In vivo injection, in medaka fish (Oryzias latipes), of the mutated miR-204 caused a phenotype consistent with that observed in the family, including photoreceptor alterations with reduced numbers of both cones and rods as a result of increased apoptosis, thereby confirming the pathogenic effect of the n.37 C > T mutation. Finally, knockdown assays in medaka fish demonstrated that miR-204 is necessary for normal photoreceptor function. Overall, these data highlight the importance of miR-204 in the regulation of ocular development and maintenance and provide the first evidence, to our knowledge, of its contribution to eye disease, likely through a gain-of-function mechanism.
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Heavner WE, Andoniadou CL, Pevny LH. Establishment of the neurogenic boundary of the mouse retina requires cooperation of SOX2 and WNT signaling. Neural Dev 2014; 9:27. [PMID: 25488119 PMCID: PMC4295269 DOI: 10.1186/1749-8104-9-27] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/14/2014] [Indexed: 12/03/2022] Open
Abstract
Background Eye development in vertebrates relies on the critical regulation of SOX2 expression. Humans with mutations in SOX2 often suffer from eye defects including anophthalmia (no eye) and microphthalmia (small eye). In mice, deletion of Sox2 in optic cup progenitor cells results in loss of neural competence and cell fate conversion of the neural retina to a non-neurogenic fate, specifically the acquisition of fate associated with progenitors of the ciliary epithelium. This fate is also promoted with constitutive expression of stabilized β-Catenin in the optic cup, where the WNT pathway is up-regulated. We addressed whether SOX2 co-ordinates the neurogenic boundary of the retina through modulating the WNT/β-Catenin pathway by using a genetic approach in the mouse. Results Upon deletion of Sox2 in the optic cup, response to WNT signaling was expanded, correlating with loss of neural competence, cell fate conversion of the neural retina to ciliary epithelium primordium and, in addition, increased cell cycle time of optic cup progenitors. Removal of Ctnnb1 rescued the cell fate conversion; however, the loss of neural competence and the proliferation defect resulting from lack of SOX2 were not overcome. Lastly, central Sox2-deficient optic cup progenitor cells exhibited WNT-independent up-regulation of D-type Cyclins. Conclusion We propose two distinct roles for SOX2 in the developing retina. Our findings suggest that SOX2 antagonizes the WNT pathway to maintain a neurogenic fate and, in contrast, regulates cycling of optic cup progenitors in a WNT-independent manner. Given that WNT signaling acting upstream of SOX2 has been implicated in the tumorigenicity of embryonic stem cell-derived retinal progenitor cells, our results distinguish the endogenous role of WNT signaling in early optic cup patterning and support a WNT-independent role for SOX2 in maintaining retinal progenitor cell proliferation. Electronic supplementary material The online version of this article (doi:10.1186/1749-8104-9-27) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Whitney E Heavner
- UNC Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA.
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Bankhead EJ, Colasanto MP, Dyorich KM, Jamrich M, Murtaugh LC, Fuhrmann S. Multiple requirements of the focal dermal hypoplasia gene porcupine during ocular morphogenesis. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 185:197-213. [PMID: 25451153 DOI: 10.1016/j.ajpath.2014.09.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 08/25/2014] [Accepted: 09/02/2014] [Indexed: 12/13/2022]
Abstract
Wnt glycoproteins control key processes during development and disease by activating various downstream pathways. Wnt secretion requires post-translational modification mediated by the O-acyltransferase encoded by the Drosophila porcupine homolog gene (PORCN). In humans, PORCN mutations cause focal dermal hypoplasia (FDH, or Goltz syndrome), an X-linked dominant multisystem birth defect that is frequently accompanied by ocular abnormalities such as coloboma, microphthalmia, or even anophthalmia. Although genetic ablation of Porcn in mouse has provided insight into the etiology of defects caused by ectomesodermal dysplasia in FDH, the requirement for Porcn and the actual Wnt ligands during eye development have been unknown. In this study, Porcn hemizygosity occasionally caused ocular defects reminiscent of FDH. Conditional inactivation of Porcn in periocular mesenchyme led to defects in mid- and hindbrain and in craniofacial development, but was insufficient to cause ocular abnormalities. However, a combination of conditional Porcn depletion in optic vesicle neuroectoderm, lens, and neural crest-derived periocular mesenchyme induced severe eye abnormalities with high penetrance. In particular, we observed coloboma, transdifferentiation of the dorsal and ventral retinal pigment epithelium, defective optic cup periphery, and closure defects of the eyelid, as well as defective corneal morphogenesis. Thus, Porcn is required in both extraocular and neuroectodermal tissues to regulate distinct Wnt-dependent processes during morphogenesis of the posterior and anterior segments of the eye.
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Affiliation(s)
- Elizabeth J Bankhead
- Departments of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Mary P Colasanto
- Departments of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Kayla M Dyorich
- Departments of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah
| | - Milan Jamrich
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | | | - Sabine Fuhrmann
- Departments of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
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Heparan sulfotransferases Hs6st1 and Hs2st keep Erk in check for mouse corpus callosum development. J Neurosci 2014; 34:2389-401. [PMID: 24501377 DOI: 10.1523/jneurosci.3157-13.2014] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The corpus callosum (CC) connects the left and right cerebral hemispheres in mammals and its development requires intercellular communication at the telencephalic midline mediated by signaling proteins. Heparan sulfate (HS) is a sulfated polysaccharide that decorates cell surface and extracellular matrix proteins and regulates the biological activity of numerous signaling proteins via sugar-protein interactions. HS is subject to regulated enzymatic sulfation and desulfation and an attractive, although not proven, hypothesis is that the biological activity of HS is regulated by a sugar sulfate code. Mutant mouse embryos lacking the heparan sulfotransferases Hs2st or Hs6st1 have severe CC phenotypes and form Probst bundles of noncrossing axons flanking large tangles of midline glial processes. Here, we identify a precocious accumulation of Sox9-expressing glial cells in the indusium griseum region and a corresponding depletion at the glial wedge associated with the formation of Probst bundles along the rostrocaudal axis in both mutants. Molecularly, we found a surprising hyperactivation of Erk signaling in Hs2st(-/-) (2-fold) and Hs6st1(-/-) (6-fold) embryonic telencephalon that was most striking at the midline, where Erk signaling is lowest in wild-types, and a 2-fold increase in Fgf8 protein levels in Hs6st1(-/-) embryos that could underpin Erk hyperactivation and excessive glial movement to the indusium griseum. The tightly linked Hs6st1(-/-) CC glial and axonal phenotypes can be rescued by genetic or pharmacological suppression of Fgf8/Erk axis components. Overall, our data fit a model in which Hs2st and Hs6st1 normally generate conditions conducive to CC development by generating an HS-containing environment that keeps Erk signaling in check.
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