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Saputra F, Kishida M, Hu SY. Oxidative stress induced by hydrogen peroxide disrupts zebrafish visual development by altering apoptosis, antioxidant and estrogen related genes. Sci Rep 2024; 14:14454. [PMID: 38914633 PMCID: PMC11196719 DOI: 10.1038/s41598-024-64933-5] [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: 03/07/2024] [Accepted: 06/14/2024] [Indexed: 06/26/2024] Open
Abstract
Hydrogen peroxide is considered deleterious molecule that cause cellular damage integrity and function. Its key redox signaling molecule in oxidative stress and exerts toxicity on a wide range of organisms. Thus, to understand whether oxidative stress alters visual development, zebrafish embryos were exposed to H2O2 at concentration of 0.02 to 62.5 mM for 7 days. Eye to body length ratio (EBR) and apoptosis in retina at 48 hpf, and optomotor response (OMR) at 7 dpf were all measured. To investigate whether hydrogen peroxide-induced effects were mediated by oxidative stress, embryos were co-incubated with the antioxidant, glutathione (GSH) at 50 μM. Results revealed that concentrations of H2O2 at or above 0.1 mM induced developmental toxicity, leading to increased mortality and hatching delay. Furthermore, exposure to 0.1 mM H2O2 decreased EBR at 48 hpf and impaired OMR visual behavior at 7 dpf. Additionally, exposure increased the area of apoptotic cells in the retina at 48 hpf. The addition of GSH reversed the effects of H2O2, suggesting the involvement of oxidative stress. H2O2 decreased the expression of eye development-related genes, pax6α and pax6β. The expression of apoptosis-related genes, tp53, casp3 and bax, significantly increased, while bcl2α expression decreased. Antioxidant-related genes sod1, cat and gpx1a showed decreased expression. Expression levels of estrogen receptors (ERs) (esr1, esr2α, and esr2β) and ovarian and brain aromatase genes (cyp19a1a and cyp19a1b, respectively) were also significantly reduced. Interestingly, co-incubation of GSH effectivity reversed the impact of H2O2 on most parameters. Overall, these results demonstrate that H2O2 induces adverse effects on visual development via oxidative stress, which leads to alter apoptosis, diminished antioxidant defenses and reduced estrogen production.
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Affiliation(s)
| | - Mitsuyo Kishida
- Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan.
| | - Shao-Yang Hu
- Department of Biological Science and Technology, National Pingtung University of Science and Technology, Pingtung, Taiwan.
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2
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Eintracht J, Owen N, Harding P, Moosajee M. Disruption of common ocular developmental pathways in patient-derived optic vesicle models of microphthalmia. Stem Cell Reports 2024; 19:839-858. [PMID: 38821055 DOI: 10.1016/j.stemcr.2024.05.001] [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: 09/13/2023] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 06/02/2024] Open
Abstract
Genetic perturbations influencing early eye development can result in microphthalmia, anophthalmia, and coloboma (MAC). Over 100 genes are associated with MAC, but little is known about common disease mechanisms. In this study, we generated induced pluripotent stem cell (iPSC)-derived optic vesicles (OVs) from two unrelated microphthalmia patients and healthy controls. At day 20, 35, and 50, microphthalmia patient OV diameters were significantly smaller, recapitulating the "small eye" phenotype. RNA sequencing (RNA-seq) analysis revealed upregulation of apoptosis-initiating and extracellular matrix (ECM) genes at day 20 and 35. Western blot and immunohistochemistry revealed increased expression of lumican, nidogen, and collagen type IV, suggesting ECM overproduction. Increased apoptosis was observed in microphthalmia OVs with reduced phospho-histone 3 (pH3+) cells confirming decreased cell proliferation at day 35. Pharmacological inhibition of caspase-8 activity with Z-IETD-FMK decreased apoptosis in one patient model, highlighting a potential therapeutic approach. These data reveal shared pathophysiological mechanisms contributing to a microphthalmia phenotype.
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Affiliation(s)
| | | | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London EC1V 9EL, UK; Moorfields Eye Hospital NHS Foundation Trust, London EC1V 9EL, UK; Francis Crick Institute, London NW1 1AT, UK.
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3
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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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4
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Dong Z, He W, Lin G, Chen X, Cao S, Guan T, Sun Y, Zhang Y, Qi M, Guo B, Zhou Z, Zhuo R, Wu R, Liu M, Liu Y. Histone acetyltransferase KAT2A modulates neural stem cell differentiation and proliferation by inducing degradation of the transcription factor PAX6. J Biol Chem 2023; 299:103020. [PMID: 36791914 PMCID: PMC10011063 DOI: 10.1016/j.jbc.2023.103020] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/15/2023] Open
Abstract
Neural stem cells (NSCs) proliferation and differentiation rely on proper expression and post-translational modification of transcription factors involved in the determination of cell fate. Further characterization is needed to connect modifying enzymes with their transcription factor substrates in the regulation of these processes. Here, we demonstrated that the inhibition of KAT2A, a histone acetyltransferase, leads to a phenotype of small eyes in the developing embryo of zebrafish, which is associated with enhanced proliferation and apoptosis of NSCs in zebrafish eyes. We confirmed that this phenotype is mediated by the evaluated level of PAX6 protein. We further verified that KAT2A negatively regulates PAX6 at the protein level in cultured neural stem cells of rat cerebral cortex. We revealed that PAX6 is a novel acetylation substrate of KAT2A, and the acetylation of PAX6 promotes its ubiquitination mediated by the E3 ligase RNF8 that facilitated PAX6 degradation. Our study proposes that KAT2A inhibition results in accelerated proliferation, delayed differentiation, or apoptosis, depending on the context of PAX6 dosage. Thus, the KAT2A/PAX6 axis plays an essential role to keep a balance between the self-renewal and differentiation of NSCs.
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Affiliation(s)
- Zhangji Dong
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Wei He
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Ge Lin
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Xu Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Sixian Cao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Tuchen Guan
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Ying Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Yufang Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Mengwei Qi
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Beibei Guo
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Zhihao Zhou
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Run Zhuo
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Ronghua Wu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China
| | - Mei Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China.
| | - Yan Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Nantong University, China.
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Grisé KN, Coles BLK, Bautista NX, van der Kooy D. Activation of adult mammalian retinal stem cells in vivo via antagonism of BMP and sFRP2. Stem Cell Res Ther 2021; 12:560. [PMID: 34717744 PMCID: PMC8557620 DOI: 10.1186/s13287-021-02630-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/17/2021] [Indexed: 11/15/2022] Open
Abstract
Background The adult mammalian retina does not have the capacity to regenerate cells lost due to damage or disease. Therefore, retinal injuries and blinding diseases result in irreversible vision loss. However, retinal stem cells (RSCs), which participate in retinogenesis during development, persist in a quiescent state in the ciliary epithelium (CE) of the adult mammalian eye. Moreover, RSCs retain the ability to generate all retinal cell types when cultured in vitro, including photoreceptors. Therefore, it may be possible to activate endogenous RSCs to induce retinal neurogenesis in vivo and restore vision in the adult mammalian eye. Methods To investigate if endogenous RSCs can be activated, we performed combinatorial intravitreal injections of antagonists to BMP and sFRP2 proteins (two proposed mediators of RSC quiescence in vivo), with or without growth factors FGF and Insulin. We also investigated the effects of chemically-induced N-methyl-N-Nitrosourea (MNU) retinal degeneration on RSC activation, both alone and in combination withthe injected factors. Further, we employed inducible Msx1-CreERT2 genetic lineage labeling of the CE followed by stimulation paradigms to determine if activated endogenous RSCs could migrate into the retina and differentiate into retinal neurons. Results We found that in vivo antagonism of BMP and sFRP2 proteins induced CE cells in the RSC niche to proliferate and expanded the RSC population. BMP and sFRP2 antagonism also enhanced CE cell proliferation in response to exogenous growth factor stimulation and MNU-induced retinal degeneration. Furthermore, Msx1-CreERT2 genetic lineage tracing revealed that CE cells migrated into the retina following stimulation and/or injury, where they expressed markers of mature photoreceptors and retinal ganglion cells. Conclusions Together, these results indicate that endogenous adult mammalian RSCs may have latent regenerative potential that can be activated by modulating the RSC niche and hold promise as a means for endogenous retinal cell therapy to repair the retina and improve vision. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-021-02630-0.
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Affiliation(s)
- Kenneth N Grisé
- Department of Molecular Genetics, University of Toronto, Donnelly Centre Rm 1110, 160 College Street, Toronto, ON, M5S 3E1, Canada.
| | - Brenda L K Coles
- Department of Molecular Genetics, University of Toronto, Donnelly Centre Rm 1110, 160 College Street, Toronto, ON, M5S 3E1, Canada
| | - Nelson X Bautista
- Department of Molecular Genetics, University of Toronto, Donnelly Centre Rm 1110, 160 College Street, Toronto, ON, M5S 3E1, Canada
| | - Derek van der Kooy
- Department of Molecular Genetics, University of Toronto, Donnelly Centre Rm 1110, 160 College Street, Toronto, ON, M5S 3E1, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
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6
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Grisé KN, Bautista NX, Jacques K, Coles BLK, van der Kooy D. Glucocorticoid agonists enhance retinal stem cell self-renewal and proliferation. Stem Cell Res Ther 2021; 12:83. [PMID: 33494791 PMCID: PMC7831262 DOI: 10.1186/s13287-021-02136-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/01/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Adult mammalian retinal stem cells (RSCs) readily proliferate, self-renew, and generate progeny that differentiate into all retinal cell types in vitro. RSC-derived progeny can be induced to differentiate into photoreceptors, making them a potential source for retinal cell transplant therapies. Despite their proliferative propensity in vitro, RSCs in the adult mammalian eye do not proliferate and do not have a regenerative response to injury. Thus, identifying and modulating the mechanisms that regulate RSC proliferation may enhance the capacity to produce RSC-derived progeny in vitro and enable RSC activation in vivo. METHODS Here, we used medium-throughput screening to identify small molecules that can expand the number of RSCs and their progeny in culture. In vitro differentiation assays were used to assess the effects of synthetic glucocorticoid agonist dexamethasone on RSC-derived progenitor cell fate. Intravitreal injections of dexamethasone into adult mouse eyes were used to investigate the effects on endogenous RSCs. RESULTS We discovered that high-affinity synthetic glucocorticoid agonists increase RSC self-renewal and increase retinal progenitor proliferation up to 6-fold without influencing their differentiation in vitro. Intravitreal injection of synthetic glucocorticoid agonist dexamethasone induced in vivo proliferation in the ciliary epithelium-the niche in which adult RSCs reside. CONCLUSIONS Together, our results identify glucocorticoids as novel regulators of retinal stem and progenitor cell proliferation in culture and provide evidence that GCs may activate endogenous RSCs.
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Affiliation(s)
- Kenneth N Grisé
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada.
| | - Nelson X Bautista
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Krystal Jacques
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Brenda L K Coles
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
| | - Derek van der Kooy
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, M5S 3E1, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
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Markitantova Y, Simirskii V. Inherited Eye Diseases with Retinal Manifestations through the Eyes of Homeobox Genes. Int J Mol Sci 2020; 21:E1602. [PMID: 32111086 PMCID: PMC7084737 DOI: 10.3390/ijms21051602] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 02/21/2020] [Accepted: 02/24/2020] [Indexed: 12/14/2022] Open
Abstract
Retinal development is under the coordinated control of overlapping networks of signaling pathways and transcription factors. The paper was conceived as a review of the data and ideas that have been formed to date on homeobox genes mutations that lead to the disruption of eye organogenesis and result in inherited eye/retinal diseases. Many of these diseases are part of the same clinical spectrum and have high genetic heterogeneity with already identified associated genes. We summarize the known key regulators of eye development, with a focus on the homeobox genes associated with monogenic eye diseases showing retinal manifestations. Recent advances in the field of genetics and high-throughput next-generation sequencing technologies, including single-cell transcriptome analysis have allowed for deepening of knowledge of the genetic basis of inherited retinal diseases (IRDs), as well as improve their diagnostics. We highlight some promising avenues of research involving molecular-genetic and cell-technology approaches that can be effective for IRDs therapy. The most promising neuroprotective strategies are aimed at mobilizing the endogenous cellular reserve of the retina.
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Induction of Rod and Cone Photoreceptor-Specific Progenitors from Stem Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019. [PMID: 31884669 DOI: 10.1007/978-3-030-27378-1_90] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
Retinal degeneration includes a variety of diseases for which there is no regenerative therapy. Cellular transplantation is one potential approach for future therapy for retinal degeneration, and stem cells have emerged as a promising source for future cell therapeutics. One major barrier to therapy is the ability to specify individual photoreceptor lineages from a variety of stem cell sources. In this review, we focus on photoreceptor genesis from progenitor populations in the developing embryo and how this understanding has given us the tools to manipulate cultures to specific unique rod and cone lineages from adult stem cell populations. We discuss experiments and evidence uncovering the lineage mechanisms at play in the establishment of fate-specific rod and cone photoreceptor progenitors. This may lead to an improved understanding of retinal development in vivo, as well as new cell sources for transplantation.
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9
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Grigoryan EN. Endogenous Cell Sources for Eye Retina Regeneration in Vertebrate Animals and Humans. Russ J Dev Biol 2019. [DOI: 10.1134/s106236041901003x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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10
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Liu Y, Li Y, Wang C, Zhang Y, Su G. Morphologic and histopathologic change of sodium iodate-induced retinal degeneration in adult rats. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2019; 12:443-454. [PMID: 31933849 PMCID: PMC6945090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 12/18/2018] [Indexed: 06/10/2023]
Abstract
Adult teleost fish are capable of regenerating their retinas following injury. In contrast, the adult mammalian retina has little capacity for regeneration. Here, we describe the morphologic and histopathologic course of sodium iodate (NaIO3) injection on rat retinas. A single dose of NaIO3 (50 mg/kg) was administered intravenously to adult Sprague-Dawley male rats. Control animals received sodium chloride. Morphologic and molecular changes following NaIO3 injection were monitored by histological and gene expression analysis. We observed retinal pigment epithelium (RPE) cell death began at 6 h PI. After 3 and 7 days, we found local tissue repair by RPE cell regeneration. This was further confirmed by a significant decrease in photoreceptor cell apoptosis in the outer nuclear layer. Protein-level analysis demonstrated the attenuated regulation of cellular markers specially related to active gliosis in retinal Müller cells, including cellular retinaldehyde-binding protein (CRALBP) and glutamine synthetase (GS), after NaIO3 treatment for 3rd and 7th days. The Müller cells exhibited signs of dedifferentiation, as paired box 6 (PAX6) and SRY box 2 (SOX2) were expressed by NaIO3 stimulated Müller glia proliferation and overexpression of proliferating cell nuclear antigen (PCNA). We concluded that NaIO3 injection can result in significant and progressive damage to RPE and photoreceptor cells. Our observations suggest that Müller cell transient differentiation and RPE recovery is induced in the mammalian retina by relatively high doses of NaIO3. Transient change in Müller cell differentiation and RPE cell recovery may result in photoreceptor apoptosis decrease.
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Affiliation(s)
- Yang Liu
- Eye Center, The Second Hospital of Jilin University Changchun, Jilin, China
| | - Ying Li
- Eye Center, The Second Hospital of Jilin University Changchun, Jilin, China
| | - Chenguang Wang
- Eye Center, The Second Hospital of Jilin University Changchun, Jilin, China
| | - Yinan Zhang
- Eye Center, The Second Hospital of Jilin University Changchun, Jilin, China
| | - Guanfang Su
- Eye Center, The Second Hospital of Jilin University Changchun, Jilin, China
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Uslupehlivan M, Şener E, Deveci R. In silico analysis of Pax6 protein glycosylation in vertebrates. Comput Biol Chem 2018; 77:116-122. [PMID: 30286322 DOI: 10.1016/j.compbiolchem.2018.09.016] [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: 04/16/2018] [Revised: 08/15/2018] [Accepted: 09/24/2018] [Indexed: 11/16/2022]
Abstract
Pax6 is a transcription factor that involves in the formation of the eye, brain, and central nervous system in vertebrates. Due to various roles in the eye morphogenesis, Pax6 interacts with DNA and various transcription factors via post-translational modifications. Post-translational modifications of Pax6 have been studied extensively but there is a paucity of information about the glycosylation. Here, we focused on predicting the glycosylation positions of Pax6 protein in vertebrates. Also, 3D protein and glycoprotein models were generated using I-TASSER and GLYCAM servers in order to understand the effect of glycosylation on the Pax6 protein structure. We predicted N-glycosylation, mucin-type O-glycosylation, O-α-GlcNAcylation, and O-β-GlcNAcylation positions on Pax6 protein besides O-GlcNAc modification. Moreover, we found ying-yang positions suggesting the presence of O-GlcNAcylation/phosphorylation competition in Pax6. As to 3D glycoprotein models of Pax6, Ser24, Ser65, and Ser74 residues at the PD domain of Pax6 protein was evaluated as a strong candidate for the DNA binding site. We suggest that determination of the glycosylation positions on 3D glycoprotein model will facilitate the understanding of glycosylation role on Pax6 protein interactions in transcription and intracellular activities.
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Affiliation(s)
- Muhammet Uslupehlivan
- Ege University, Faculty of Science, Department of Biology, Molecular Biology Section, Izmir, Turkey.
| | - Ecem Şener
- Ege University, Faculty of Science, Department of Biology, Molecular Biology Section, Izmir, Turkey.
| | - Remziye Deveci
- Ege University, Faculty of Science, Department of Biology, Molecular Biology Section, Izmir, Turkey.
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12
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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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Tokuda K, Kuramitsu Y, Byron B, Kitagawa T, Tokuda N, Kobayashi D, Nagayama M, Araki N, Sonoda KH, Nakamura K. Up-regulation of DRP-3 long isoform during the induction of neural progenitor cells by glutamate treatment in the ex vivo rat retina. Biochem Biophys Res Commun 2015; 463:593-9. [DOI: 10.1016/j.bbrc.2015.05.102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 05/29/2015] [Indexed: 10/23/2022]
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Jayakody SA, Gonzalez-Cordero A, Ali RR, Pearson RA. Cellular strategies for retinal repair by photoreceptor replacement. Prog Retin Eye Res 2015; 46:31-66. [PMID: 25660226 DOI: 10.1016/j.preteyeres.2015.01.003] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 01/13/2015] [Accepted: 01/19/2015] [Indexed: 02/08/2023]
Abstract
Loss of photoreceptors due to retinal degeneration is a major cause of blindness in the developed world. While no effective treatment is currently available, cell replacement therapy, using pluripotent stem cell-derived photoreceptor precursor cells, may be a feasible future treatment. Recent reports have demonstrated rescue of visual function following the transplantation of immature photoreceptors and we have seen major advances in our ability to generate transplantation-competent donor cells from stem cell sources. Moreover, we are beginning to realise the possibilities of using endogenous populations of cells from within the retina itself to mediate retinal repair. Here, we present a review of our current understanding of endogenous repair mechanisms together with recent progress in the use of both ocular and pluripotent stem cells for the treatment of photoreceptor loss. We consider how our understanding of retinal development has underpinned many of the recent major advances in translation and moved us closer to the goal of restoring vision by cellular means.
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Affiliation(s)
- Sujatha A Jayakody
- Gene and Cell Therapy Group, Department of Genetics, UCL Institute of Ophthalmology, 11-43 Bath St, London EC1V 9EL, UK
| | - Anai Gonzalez-Cordero
- Gene and Cell Therapy Group, Department of Genetics, UCL Institute of Ophthalmology, 11-43 Bath St, London EC1V 9EL, UK
| | - Robin R Ali
- Gene and Cell Therapy Group, Department of Genetics, UCL Institute of Ophthalmology, 11-43 Bath St, London EC1V 9EL, UK; NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, City Road, London EC1V 2PD, UK
| | - Rachael A Pearson
- Gene and Cell Therapy Group, Department of Genetics, UCL Institute of Ophthalmology, 11-43 Bath St, London EC1V 9EL, UK.
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15
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Sahel JA, Marazova K. Toward postnatal reversal of ocular congenital malformations. J Clin Invest 2013; 124:81-4. [PMID: 24355915 DOI: 10.1172/jci73560] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aniridia is a panocular disorder that severely affects vision in early life. Most cases are caused by dominantly inherited mutations or deletions of the PAX6 gene, which encodes a transcription factor that is essential for the development of the eye and the central nervous system. In this issue of the JCI, Gregory-Evans and colleagues demonstrate that early postnatal topical administration of an ataluren-based formulation reverses congenital malformations in the postnatal mouse eye, providing evidence that manipulation of PAX6 after birth may lead to corrective tissue remodeling. These findings offer hope that ataluren administration could be a therapeutic paradigm applicable to some major congenital eye defects.
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16
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Del Debbio CB, Peng X, Xiong H, Ahmad I. Adult ciliary epithelial stem cells generate functional neurons and differentiate into both early and late born retinal neurons under non-cell autonomous influences. BMC Neurosci 2013; 14:130. [PMID: 24148749 PMCID: PMC3856605 DOI: 10.1186/1471-2202-14-130] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 10/14/2013] [Indexed: 12/31/2022] Open
Abstract
Background The neural stem cells discovered in the adult ciliary epithelium (CE) in higher vertebrates have emerged as an accessible source of retinal progenitors; these cells can self-renew and possess retinal potential. However, recent studies have cast doubt as to whether these cells could generate functional neurons and differentiate along the retinal lineage. Here, we have systematically examined the pan neural and retinal potential of CE stem cells. Results Molecular and cellular analysis was carried out to examine the plasticity of CE stem cells, obtained from mice expressing green fluorescent protein (GFP) under the influence of the promoter of the rod photoreceptor-specific gene, Nrl, using the neurospheres assay. Differentiation was induced by specific culture conditions and evaluated by both transcripts and protein levels of lineage-specific regulators and markers. Temporal pattern of their levels were examined to determine the expression of genes and proteins underlying the regulatory hierarchy of cells specific differentiation in vitro. Functional attributes of differentiation were examined by the presence of current profiles and pharmacological mobilization of intracellular calcium using whole cell recordings and Fura-based calcium imaging, respectively. We demonstrate that stem cells in adult CE not only have the capacity to generate functional neurons, acquiring the expression of sodium and potassium channels, but also respond to specific cues in culture and preferentially differentiate along the lineages of retinal ganglion cells (RGCs) and rod photoreceptors, the early and late born retinal neurons, respectively. The retinal differentiation of CE stem cells was characterized by the temporal acquisition of the expression of the regulators of RGCs and rod photoreceptors, followed by the display of cell type-specific mature markers and mobilization of intracellular calcium. Conclusions Our study demonstrates the bonafide retinal potential of adult CE stem cells and suggests that their plasticity could be harnessed for clinical purposes once barriers associated with any lineage conversion, i.e., low efficiency and fidelity is overcome through the identification of conducive culture conditions.
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Affiliation(s)
| | | | | | - Iqbal Ahmad
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Durham Research Center 1, Room 4044, 985840 Nebraska Medical Center, Omaha, NE 68198-5840, USA.
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17
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Inactivation of the microRNA-183/96/182 cluster results in syndromic retinal degeneration. Proc Natl Acad Sci U S A 2013; 110:E507-16. [PMID: 23341629 DOI: 10.1073/pnas.1212655110] [Citation(s) in RCA: 148] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The microRNA-183/96/182 cluster is highly expressed in the retina and other sensory organs. To uncover its in vivo functions in the retina, we generated a knockout mouse model, designated "miR-183C(GT/GT)," using a gene-trap embryonic stem cell clone. We provide evidence that inactivation of the cluster results in early-onset and progressive synaptic defects of the photoreceptors, leading to abnormalities of scotopic and photopic electroretinograms with decreased b-wave amplitude as the primary defect and progressive retinal degeneration. In addition, inactivation of the miR-183/96/182 cluster resulted in global changes in retinal gene expression, with enrichment of genes important for synaptogenesis, synaptic transmission, photoreceptor morphogenesis, and phototransduction, suggesting that the miR-183/96/182 cluster plays important roles in postnatal functional differentiation and synaptic connectivity of photoreceptors.
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18
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Clarke L, Ballios BG, van der Kooy D. Generation and clonal isolation of retinal stem cells from human embryonic stem cells. Eur J Neurosci 2012; 36:1951-9. [PMID: 22591375 DOI: 10.1111/j.1460-9568.2012.08123.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Retinal stem cells (RSCs) are present within the pigmented ciliary epithelium (CE) of the adult human eye and produce progeny that differentiate in vitro into all neural retinal subtypes and retinal pigmented epithelium (RPE). We hypothesized that a RSC population, similar to the adult CE-derived RSC, is contained within pigmented colonies that arise in long-term cultures of human embryonic stem cells (hESCs) suggested to recapitulate retinal development in vitro. Single pigmented hESC-derived cells were isolated and plated in serum-free media containing growth factors and, after 2 weeks, clonal sphere colonies containing both pigmented and non-pigmented cells were observed. These colonies expressed the early retinal transcription factors Rx, Chx10 and Pax6, and could be dissociated and replated as single cells to form secondary clonal colonies. When allowed to differentiate, expression of markers for both RPE and neurons was observed. Rhodopsin expression was detected after explant co-culture and transplantation into the developing mouse eye as well as following treatment with soluble factors in vitro. We show that RSCs emerge in an in vitro model of retinal development and are a potential source of human photoreceptors for use in transplantation.
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Affiliation(s)
- Laura Clarke
- Institute of Medical Science, University of Toronto, 1 King's College Circle, Toronto, ON, Canada.
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19
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Shaham O, Menuchin Y, Farhy C, Ashery-Padan R. Pax6: a multi-level regulator of ocular development. Prog Retin Eye Res 2012; 31:351-76. [PMID: 22561546 DOI: 10.1016/j.preteyeres.2012.04.002] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 04/19/2012] [Accepted: 04/24/2012] [Indexed: 02/08/2023]
Abstract
Eye development has been a paradigm for the study of organogenesis, from the demonstration of lens induction through epithelial tissue morphogenesis, to neuronal specification and differentiation. The transcription factor Pax6 has been shown to play a key role in each of these processes. Pax6 is required for initiation of developmental pathways, patterning of epithelial tissues, activation of tissue-specific genes and interaction with other regulatory pathways. Herein we examine the data accumulated over the last few decades from extensive analyses of biochemical modules and genetic manipulation of the Pax6 gene. Specifically, we describe the regulation of Pax6's expression pattern, the protein's DNA-binding properties, and its specific roles and mechanisms of action at all stages of lens and retinal development. Pax6 functions at multiple levels to integrate extracellular information and execute cell-intrinsic differentiation programs that culminate in the specification and differentiation of a distinct ocular lineage.
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Affiliation(s)
- Ohad Shaham
- Sackler Faculty of Medicine, Department of Human Molecular Genetics and Biochemistry, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
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20
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Ballios BG, Clarke L, Coles BLK, Shoichet MS, Van Der Kooy D. The adult retinal stem cell is a rare cell in the ciliary epithelium whose progeny can differentiate into photoreceptors. Biol Open 2012; 1:237-46. [PMID: 23213414 PMCID: PMC3507281 DOI: 10.1242/bio.2012027] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Self-renewing, multipotential retinal stem cells (RSCs) reside in the pigmented ciliary epithelium of the peripheral retina in adult mammals. RSCs can give rise to rhodopsin positive-cells, which can integrate into early postnatal retina, and represent a potentially useful option for cellular therapy. The ability to purify a stem cell population and direct the differentiation toward a particular cell lineage is a challenge facing the application of stem cells in regenerative medicine. Here we use cell sorting to prospectively enrich mouse RSCs based on size, granularity and low expression of P-cadherin and demonstrate that only rare cells with defined properties proliferate to form colonies. We show that clonally-derived mouse and human RSC progeny are multipotent and can differentiate into mature rhodopsin-positive cells with high efficiency using combinations of exogenous culture additives known to influence neural retinal development, including taurine and retinoic acid. This directed RSC differentiation follows the temporal sequence of photoreceptor differentiation in vivo, and the cells exhibit morphology, protein and gene expression consistent with primary cultures of rods in vitro. These results demonstrate that the RSC, an adult stem cell, can be enriched and directed to produce photoreceptors as a first step toward a targeted cell replacement strategy to treat retinal degenerative disease.
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Affiliation(s)
- Brian G Ballios
- Institute of Medical Science, University of Toronto, 1 King's College Circle , Toronto, Ontario M5S 1A8 , Canada
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21
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Frøen RC, Johnsen EO, Petrovski G, Berényi E, Facskó A, Berta A, Nicolaissen B, Moe MC. Pigment epithelial cells isolated from human peripheral iridectomies have limited properties of retinal stem cells. Acta Ophthalmol 2011; 89:e635-44. [PMID: 21801333 DOI: 10.1111/j.1755-3768.2011.02198.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE The identification of cells with properties of retinal progenitor cells (RPCs) in the adult human ciliary margin (CM) prompted a number of studies of their proliferative and differentiation potential. One of the remaining challenges is to find a feasible method of isolating RPCs from the patient's eye. In the human CM, only the iris pigment epithelium (IPE) is easily obtained by a minimally invasive procedure. In the light of recent studies questioning the existence of RPCs in the adult mammalian CM, we wanted to assess the potential of the adult human IPE as source of RPCs. METHODS The IPE were isolated from peripheral iridectomies during glaucoma surgery, and IPE and ciliary body (CB) epithelium were also isolated from post-mortem tissue. Cells were cultivated in sphere-promoting conditions or as monolayers. Whole-tissue samples, undifferentiated and differentiated cells were studied by immunocytochemistry, RT-PCR and transmission electron microscopy. RESULTS The adult human IPE, like the CB, expressed markers of RPCs such as Pax6, Sox2 and Nestin in vivo. Both sphere-promoting and monolayer cultures preserved this phenotype. However, both IPE/CB cultures expressed markers of differentiated epithelial cells such as Claudin, microphtalmia-associated transcription factor (MITF) and Cytokeratin-19. Ultrastructurally, IPE spheres displayed epithelial-like junctions and contained mature melanosomes. After induced differentiation, IPE-derived cells showed only partial neuronal differentiation expressing β-III-tubulin, Map-2 and Rhodopsin, whereas no mature glial markers were found. CONCLUSION Proliferative cells with some properties of RPCs can be isolated from the adult human IPE by peripheral iridectomies. Yet, many cells retain properties of differentiated epithelial cells and lack central properties of somatic stem cells.
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Affiliation(s)
- Rebecca C Frøen
- Department of Ophthalmology, Oslo University Hospital, Center for Eye Research, University of Oslo, Oslo, Norway
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22
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Bhatia B, Jayaram H, Singhal S, Jones MF, Limb GA. Differences between the neurogenic and proliferative abilities of Müller glia with stem cell characteristics and the ciliary epithelium from the adult human eye. Exp Eye Res 2011; 93:852-61. [PMID: 21989110 PMCID: PMC3268355 DOI: 10.1016/j.exer.2011.09.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 09/19/2011] [Accepted: 09/27/2011] [Indexed: 11/19/2022]
Abstract
Much controversy has arisen on the nature and sources of stem cells in the adult human retina. Whilst ciliary epithelium has been thought to constitute a source of neural stem cells, a population of Müller glia in the neural retina has also been shown to exhibit neurogenic characteristics. This study aimed to compare the neurogenic and proliferative abilities between these two major cell populations. It also examined whether differences exist between the pigmented and non-pigmented ciliary epithelium (CE) from the adult human eye. On this basis, Müller glia with stem cell characteristics and pigmented and non-pigmented CE were isolated from human neural retina and ciliary epithelium respectively. Expression of glial, epithelial and neural progenitor markers was examined in these cells following culture under adherent and non-adherent conditions and treatments to induce neural differentiation. Unlike pigmented CE which did not proliferate, non-pigmented CE cells exhibited limited proliferation in vitro, unless epidermal growth factor (EGF) was present in the culture medium to prolong their survival. In contrast, Müller glial stem cells (MSC) cultured as adherent monolayers reached confluence within a few weeks and continued to proliferative indefinitely in the absence of EGF. Both MSC and non-pigmented CE expressed markers of neural progenitors, including SOX2, PAX6, CHX10 and NOTCH. Nestin, a neural stem cell marker, was only expressed by MSC. Non-pigmented CE displayed epithelial morphology, limited photoreceptor gene expression and stained strongly for pigmented epithelial markers upon culture with neural differentiation factors. In contrast, MSC adopted neural morphology and expressed markers of retinal ganglion cells and photoreceptors when cultured under similar conditions. This study provides the first demonstration that pigmented CE possess different proliferative abilities from non-pigmented CE. It also showed that although non-pigmented CE express genes of retinal progenitors, they do not differentiate into neurons in vitro, as that seen with Müller glia that proliferate indefinitely in vitro and that acquire markers of retinal neurons in culture under neural differentiation protocols. From these observations it is possible to suggest that Müller glia that express markers of neural progenitors and become spontaneously immortalized in vitro constitute a potential source of retinal neurons for transplantation studies and fulfil the characteristics of true stem cells due to their proliferative and neurogenic ability.
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Affiliation(s)
| | | | | | | | - G. Astrid Limb
- Corresponding author. Tel.: +44 (0) 20 7608 6974; fax: +44 (0) 20 7608 4034.
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23
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Suppressor of fused is required to maintain the multipotency of neural progenitor cells in the retina. J Neurosci 2011; 31:5169-80. [PMID: 21451052 DOI: 10.1523/jneurosci.5495-10.2011] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The morphogen sonic hedgehog (Shh) plays a crucial role in development of the CNS, including the neural retina. Suppressor of fused (Sufu) has been recently identified as a critical regulator of Hh signaling in mammals. However, the precise roles that Sufu plays in the regulation of proliferation and cell-fate decisions in neural progenitors is unknown. Here, we have addressed these questions by conditionally deleting Sufu in mouse multipotent retinal progenitor cells (RPCs). Sufu deletion in RPCs results in transient increases in Hh activity and proliferation followed by developmentally premature cell-cycle exit. Importantly, we demonstrate a novel role for Sufu in the maintenance of multipotency in RPCs. Sufu-null RPCs downregulate transcription factors required to specify or maintain RPC identity (Rax, Vsx2) and multipotency (Pax6) but continue to express the neural progenitor marker Sox2. These cells fail to express retinal lineage-specific transcription factors, such as Math5, and adopt an amacrine or horizontal cell fate at the expense of all other classes of retinal neurons. Genetic elimination of Gli2 in Sufu-null RPCs attenuates Hh pathway activity and restores multipotency in neural progenitors. These data provide novel evidence that Sufu-mediated antagonism of Hh/Gli2 signaling is required to maintain RPC multipotency and identity.
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24
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Ballios BG, van der Kooy D. Biology and therapeutic potential of adult retinal stem cells. Can J Ophthalmol 2010; 45:342-51. [PMID: 20648091 DOI: 10.3129/i10-070] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Retinal degeneration encompasses a constellation of common pathologies for which there is no regenerative treatment. Vision loss has a devastating impact on quality of life and activities of daily living. Pharmacologic treatments serve to stave off disease progression but do not represent a restorative approach. Cellular transplantation is considered to be a promising approach for future therapy for retinal degeneration. There are, however, significant barriers that must be overcome if cell transplantation is to become a clinical reality. In this review, we focus on the need for a cellular replacement therapy for retinal disease and the promise of stem cells as candidate cellular therapeutics. In particular, we discuss the origins of stem cells in the retina, the discovery and characterization of retinal stem cells isolated from adult humans, and their transplantation potential and clinical implications.
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Affiliation(s)
- Brian G Ballios
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ont
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25
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Abstract
The adult mouse retinal stem cell (RSC) is a rare quiescent cell found within the ciliary epithelium (CE) of the mammalian eye1,2,3. The CE is made up of non-pigmented inner and pigmented outer cell layers, and the clonal RSC colonies that arise from a single pigmented cell from the CE are made up of both pigmented and non-pigmented cells which can be differentiated to form all the cell types of the neural retina and the RPE. There is some controversy about whether all the cells within the spheres all contain at least some pigment4; however the cells are still capable of forming the different cell types found within the neural retina1-3. In some species, such as amphibians and fish, their eyes are capable of regeneration after injury5, however; the mammalian eye shows no such regenerative properties. We seek to identify the stem cell in vivo and to understand the mechanisms that keep the mammalian retinal stem cells quiescent6-8, even after injury as well as using them as a potential source of cells to help repair physical or genetic models of eye injury through transplantation9-12. Here we describe how to isolate the ciliary epithelial cells from the mouse eye and grow them in culture in order to form the clonal retinal stem cell spheres. Since there are no known markers of the stem cell in vivo, these spheres are the only known way to prospectively identify the stem cell population within the ciliary epithelium of the eye.
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26
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Inoue T, Coles BLK, Dorval K, Bremner R, Bessho Y, Kageyama R, Hino S, Matsuoka M, Craft CM, McInnes RR, Tremblay F, Prusky GT, van der Kooy D. Maximizing functional photoreceptor differentiation from adult human retinal stem cells. Stem Cells 2010; 28:489-500. [PMID: 20014120 DOI: 10.1002/stem.279] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Retinal stem cells (RSCs) are present in the ciliary margin of the adult human eye and can give rise to all retinal cell types. Here we show that modulation of retinal transcription factor gene expression in human RSCs greatly enriches photoreceptor progeny, and that strong enrichment was obtained with the combined transduction of OTX2 and CRX together with the modulation of CHX10. When these genetically modified human RSC progeny are transplanted into mouse eyes, their retinal integration and differentiation is superior to unmodified RSC progeny. Moreover, electrophysiologic and behavioral tests show that these transplanted cells promote functional recovery in transducin mutant mice. This study suggests that gene modulation in human RSCs may provide a source of photoreceptor cells for the treatment of photoreceptor disease.
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Affiliation(s)
- Tomoyuki Inoue
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
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27
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Kashiwagi Y, Kato N, Sassa T, Nishitsuka K, Yamamoto T, Takamura H, Yamashita H. Cotylenin A inhibits cell proliferation and induces apoptosis and PAX6 mRNA transcripts in retinoblastoma cell lines. Mol Vis 2010; 16:970-82. [PMID: 20577596 PMCID: PMC2890574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Accepted: 06/01/2010] [Indexed: 11/12/2022] Open
Abstract
PURPOSE Retinoblastoma, a childhood cancer of the retina, is caused by inactivation of the tumor suppressor gene retinoblastoma (RB). Cotylenin A (CN-A), a novel fusicoccane-diterpene glycoside, accelerates the differentiation of several types of myeloid cell lines and is a candidate for a new type of anticancer therapeutic agent with this effect. However, whether CN-A has the same effect on retinoblastoma cells is unknown. We studied the response of two retinoblastoma cell lines, Y-79 and WERI-Rb-1, to CN-A. METHODS We studied the response of two retinoblastoma cell lines to CN-A with respect to cell growth, apoptosis, morphology, mRNA, protein expression analysis of specific genes (N-myc, cyclin-dependent kinase inhibitor 1A [P21], paired box gene 6 [PAX6], and rhodopsin [RHO]), and activity of three PAX6 promoters (P0, P1, and Palpha). RESULTS CN-A inhibited cell proliferation and induced apoptosis via caspase activity in the two retinoblastoma cell lines. In addition, CN-A induced mRNA expression of P21, PAX6, and RHO and protein expression of P21. In Y-79 cells, PAX6 P1 promoter was activated by CN-A. In WERI-Rb-1 cells, PAX6 P0, P1, and Palpha promoter were activated by CN-A. CN-A decreased mRNA and protein expression of N-myc in two retinoblastoma cell lines. CONCLUSIONS The responses of retinoblastoma cells to CN-A include inhibition of cell growth, induction of apoptosis, and the potential to change neuroblastoma characteristics of retinoblastoma cells.
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Affiliation(s)
- Yoshiko Kashiwagi
- Department of Ocular Cellular Engineering, Faculty of Medicine, Yamagata University, Yamagata City, Yamagata, Japan
| | - Nobuo Kato
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki City, Osaka, Japan
| | - Takeshi Sassa
- Department of Bioresource Engineering, Faculty of Agriculture, Yamagata University, Tsuruoka City, Yamagata, Japan
| | - Koichi Nishitsuka
- Department of Ophthalmology and Visual Sciences, Faculty of Medicine, Yamagata University, Yamagata City, Yamagata, Japan
| | - Teiko Yamamoto
- Department of Ocular Cellular Engineering, Faculty of Medicine, Yamagata University, Yamagata City, Yamagata, Japan
| | - Hiroshi Takamura
- Department of Ophthalmology and Visual Sciences, Faculty of Medicine, Yamagata University, Yamagata City, Yamagata, Japan
| | - Hidetoshi Yamashita
- Department of Ophthalmology and Visual Sciences, Faculty of Medicine, Yamagata University, Yamagata City, Yamagata, Japan
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Avdonin PP, Grigoryan EN, Markitantova YV. Transcriptional factor Pitx2: Localization during triton retina regeneration. BIOL BULL+ 2010. [DOI: 10.1134/s1062359010030039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Thummel R, Enright JM, Kassen SC, Montgomery JE, Bailey TJ, Hyde DR. Pax6a and Pax6b are required at different points in neuronal progenitor cell proliferation during zebrafish photoreceptor regeneration. Exp Eye Res 2010; 90:572-82. [PMID: 20152834 DOI: 10.1016/j.exer.2010.02.001] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 01/29/2010] [Accepted: 02/03/2010] [Indexed: 01/09/2023]
Abstract
The light-damaged zebrafish retina results in the death of photoreceptor cells and the subsequent regeneration of the missing rod and cone cells. Photoreceptor regeneration initiates with asymmetric Müller glial cell division to produce neuronal progenitor cells, which amplify, migrate to the outer nuclear layer (ONL), and differentiate into both classes of photoreceptor cells. In this study, we examined the role of the Pax6 protein in regeneration. In zebrafish, there are two Pax6 proteins, one encoded by the pax6a gene and the other encoded by the pax6b gene. We intravitreally injected and electroporated morpholinos that were complementary to either the pax6a or pax6b mRNA to knockdown the translation of the corresponding protein. Loss of Pax6b expression did not affect Müller glial cell division, but blocked the subsequent first cell division of the neuronal progenitors. In contrast, the paralogous Pax6a protein was required for later neuronal progenitor cell divisions, which maximized the number of neuronal progenitors. Without neuronal progenitor cell amplification, proliferation of resident ONL rod precursor cells, which can only regenerate rods, increased inversely proportional to the number of INL neuronal progenitor cells. This confirmed that Müller glial-derived neuronal progenitor cells are necessary to regenerate cones and that distinct mechanisms selectively regenerate rod and cone photoreceptors. This work also defines distinct roles for Pax6a and Pax6b in regulating neuronal progenitor cell proliferation in the adult zebrafish retina and increases our understanding of the molecular pathways required for photoreceptor cell regeneration.
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Affiliation(s)
- Ryan Thummel
- Department of Biological Sciences and the Center for Zebrafish Research, University of Notre Dame, Notre Dame, IN 46556, USA.
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30
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Arora A, Guduric-Fuchs J, Harwood L, Dellett M, Cogliati T, Simpson DA. Prediction of microRNAs affecting mRNA expression during retinal development. BMC DEVELOPMENTAL BIOLOGY 2010; 10:1. [PMID: 20053268 PMCID: PMC2821300 DOI: 10.1186/1471-213x-10-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2009] [Accepted: 01/06/2010] [Indexed: 02/06/2023]
Abstract
BACKGROUND MicroRNAs (miRNAs) are small RNA molecules (~22 nucleotides) which have been shown to play an important role both in development and in maintenance of adult tissue. Conditional inactivation of miRNAs in the eye causes loss of visual function and progressive retinal degeneration. In addition to inhibiting translation, miRNAs can mediate degradation of targeted mRNAs. We have previously shown that candidate miRNAs affecting transcript levels in a tissue can be deduced from mRNA microarray expression profiles. The purpose of this study was to predict miRNAs which affect mRNA levels in developing and adult retinal tissue and to confirm their expression. RESULTS Microarray expression data from ciliary epithelial retinal stem cells (CE-RSCs), developing and adult mouse retina were generated or downloaded from public repositories. Analysis of gene expression profiles detected the effects of multiple miRNAs in CE-RSCs and retina. The expression of 20 selected miRNAs was confirmed by RT-PCR and the cellular distribution of representative candidates analyzed by in situ hybridization. The expression levels of miRNAs correlated with the significance of their predicted effects upon mRNA expression. Highly expressed miRNAs included miR-124, miR-125a, miR-125b, miR-204 and miR-9. Over-expression of three miRNAs with significant predicted effects upon global mRNA levels resulted in a decrease in mRNA expression of five out of six individual predicted target genes assayed. CONCLUSIONS This study has detected the effect of miRNAs upon mRNA expression in immature and adult retinal tissue and cells. The validity of these observations is supported by the experimental confirmation of candidate miRNA expression and the regulation of predicted target genes following miRNA over-expression. Identified miRNAs are likely to be important in retinal development and function. Misregulation of these miRNAs might contribute to retinal degeneration and disease. Conversely, manipulation of their expression could potentially be used as a therapeutic tool in the future.
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Affiliation(s)
- Amit Arora
- Centre for Vision and Vascular Science, Queen's University Belfast, Ophthalmic Research Centre, Institute of Clinical Science, Royal Victoria Hospital, Belfast BT12 6BA, UK
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31
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Davis N, Yoffe C, Raviv S, Antes R, Berger J, Holzmann S, Stoykova A, Overbeek PA, Tamm ER, Ashery-Padan R. Pax6 dosage requirements in iris and ciliary body differentiation. Dev Biol 2009; 333:132-42. [DOI: 10.1016/j.ydbio.2009.06.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 06/18/2009] [Accepted: 06/22/2009] [Indexed: 11/15/2022]
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32
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Lamba D, Karl M, Reh T. Neural regeneration and cell replacement: a view from the eye. Cell Stem Cell 2009; 2:538-49. [PMID: 18522847 DOI: 10.1016/j.stem.2008.05.002] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Neuronal degenerations in the retina are leading causes of blindness. Like most other areas of the CNS, the neurons of the mammalian retina are not replaced following degeneration. However, in nonmammalian vertebrates, endogenous repair processes restore neurons very efficiently, even after complete loss of the retina. We describe the phenomenon of retinal regeneration in nonmammalian vertebrates and attempts made in recent years to stimulate similar regenerative processes in the mammalian retina. In addition, we review the various strategies employed to replace lost neurons in the retina and the recent use of stem cell technologies to address problems of retinal repair.
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Affiliation(s)
- Deepak Lamba
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
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33
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Larsen KB, Lutterodt M, Rath MF, Møller M. Expression of the homeobox genes
PAX6
,
OTX2
, and
OTX1
in the early human fetal retina. Int J Dev Neurosci 2009; 27:485-92. [DOI: 10.1016/j.ijdevneu.2009.04.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2009] [Revised: 04/07/2009] [Accepted: 04/27/2009] [Indexed: 11/30/2022] Open
Affiliation(s)
- Karen B. Larsen
- Department of Neuroscience and Pharmacology, Faculty of Health SciencesUniversity of CopenhagenDenmark
| | - Melissa Lutterodt
- Laboratory of Biology and ReproductionRigshospitaletDenmark
- Department of Gynecology and ObstetricsFrederiksberg HospitalCopenhagenDenmark
| | - Martin F. Rath
- Department of Neuroscience and Pharmacology, Faculty of Health SciencesUniversity of CopenhagenDenmark
| | - Morten Møller
- Department of Neuroscience and Pharmacology, Faculty of Health SciencesUniversity of CopenhagenDenmark
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Carter DA, Dick AD, Mayer EJ. CD133+ adult human retinal cells remain undifferentiated in Leukaemia Inhibitory Factor (LIF). BMC Ophthalmol 2009; 9:1. [PMID: 19236693 PMCID: PMC2649894 DOI: 10.1186/1471-2415-9-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 02/23/2009] [Indexed: 12/17/2022] Open
Abstract
Background CD133 is a cell surface marker of haematopoietic stem and progenitor cells. Leukaemia inhibitory factor (LIF), sustains proliferation and not differentiation of embryonic stem cells. We used CD133 to purify adult human retinal cells and aimed to determine what effect LIF had on these cultures and whether they still had the ability to generate neurospheres. Methods Retinal cell suspensions were derived from adult human post-mortem tissue with ethical approval. With magnetic automated cell sorting (MACS) CD133+ retinal cells were enriched from post mortem adult human retina. CD133+ retinal cell phenotype was analysed by flow cytometry and cultured cells were observed for proliferative capacity, neuropshere generation and differentiation with or without LIF supplementation. Results We demonstrated purification (to 95%) of CD133+ cells from adult human postmortem retina. Proliferating cells were identified through BrdU incorporation and expression of the proliferation markers Ki67 and Cyclin D1. CD133+ retinal cells differentiated whilst forming neurospheres containing appropriate lineage markers including glia, neurons and photoreceptors. LIF maintained CD133+ retinal cells in a proliferative and relatively undifferentiated state (Ki67, Cyclin D1 expression) without significant neurosphere generation. Differentiation whilst forming neurospheres was re-established on LIF withdrawal. Conclusion These data support the evidence that CD133 expression characterises a population of cells within the resident adult human retina which have progenitor cell properties and that their turnover and differentiation is influenced by LIF. This may explain differences in retinal responses observed following disease or injury.
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Affiliation(s)
- Debra A Carter
- Academic Unit of Ophthalmology, Department of Clinical Sciences South Bristol, University of Bristol, Bristol Eye Hospital, Lower Maudlin Street, Bristol BS12LX, UK.
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Rath MF, Bailey MJ, Kim JS, Coon SL, Klein DC, Møller M. Developmental and daily expression of the Pax4 and Pax6 homeobox genes in the rat retina: localization of Pax4 in photoreceptor cells. J Neurochem 2008; 108:285-94. [PMID: 19012751 DOI: 10.1111/j.1471-4159.2008.05765.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pax4 is a homeobox gene encoding Pax4, a transcription factor that is essential for embryonic development of the endocrine pancreas. In the pancreas, Pax4 counters the effects of the related transcription factor, Pax6, which is known to be essential for eye morphogenesis. In this study, we have discovered that Pax4 is strongly expressed in retinal photoreceptors of the rat. Pax4 expression is not detectable in the foetal eye; however, postnatal Pax4 transcript levels rapidly increase. In contrast, Pax6 exhibits an inverse developmental pattern of expression being more strongly expressed in the foetal eye. Histological analysis revealed that Pax4 mRNA is exclusively expressed in the retinal photoreceptors, whereas Pax6 mRNA and protein are present in the inner nuclear layer and in the ganglion cell layer of the mature retina. In the adult retina, Pax4 transcripts exhibit a diurnal rhythm with maximal levels occurring during the light period, whereas retinal Pax6 transcript levels do not change throughout the day. The daily changes in Pax4 expression may contribute to daily changes in function in the differentiated retinal photoreceptor.
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Affiliation(s)
- Martin F Rath
- Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark.
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36
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Firsova NV, Zinovieva RD. Molecular genetic aspects of human eye development. BIOL BULL+ 2008. [DOI: 10.1134/s106235900804002x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Osumi N, Shinohara H, Numayama-Tsuruta K, Maekawa M. Concise review: Pax6 transcription factor contributes to both embryonic and adult neurogenesis as a multifunctional regulator. Stem Cells 2008; 26:1663-72. [PMID: 18467663 DOI: 10.1634/stemcells.2007-0884] [Citation(s) in RCA: 273] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pax6 is a highly conserved transcription factor among vertebrates and is important in various developmental processes in the central nervous system (CNS), including patterning of the neural tube, migration of neurons, and formation of neural circuits. In this review, we focus on the role of Pax6 in embryonic and postnatal neurogenesis, namely, production of new neurons from neural stem/progenitor cells, because Pax6 is intensely expressed in these cells from the initial stage of CNS development and in neurogenic niches (the subgranular zone of the hippocampal dentate gyrus and the subventricular zone of the lateral ventricle) throughout life. Pax6 is a multifunctional player regulating proliferation and differentiation through the control of expression of different downstream molecules in a highly context-dependent manner.
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Affiliation(s)
- Noriko Osumi
- Division of Developmental Neuroscience, Center for Translational and Advanced Animal Research, Tohoku University School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
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Djojosubroto MW, Arsenijevic Y. Retinal stem cells: promising candidates for retina transplantation. Cell Tissue Res 2007; 331:347-57. [PMID: 17912553 DOI: 10.1007/s00441-007-0501-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Accepted: 08/29/2007] [Indexed: 12/12/2022]
Abstract
Stem cell transplantation is widely considered as a promising therapeutic approach for photoreceptor degeneration, one of the major causes of blindness. In this review, we focus on the biology of retinal stem cells (RSCs) and progenitor cells (RPCs) isolated from fetal, postnatal, and adult animals, with emphasis on those from rodents and humans. We discuss the origin of RSCs/RPCs, the markers expressed by these cells and the conditions for the isolation, culture, and differentiation of these cells in vitro or in vivo by induction with exogenous stimulation.
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Affiliation(s)
- Meta W Djojosubroto
- Unit of Gene Therapy & Stem Cell Biology, Jules-Gonin Eye Hospital, Ophthalmology Department, University of Lausanne, 15 Avenue de France, 1004, Lausanne, Switzerland
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Hewitt AW. Genetic diseases of the optic nerve head: from embryogenesis to pathogenesis. EXPERT REVIEW OF OPHTHALMOLOGY 2007. [DOI: 10.1586/17469899.2.5.769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Liu H, Xu S, Wang Y, Mazerolle C, Thurig S, Coles BLK, Ren JC, Taketo MM, van der Kooy D, Wallace VA. Ciliary margin transdifferentiation from neural retina is controlled by canonical Wnt signaling. Dev Biol 2007; 308:54-67. [PMID: 17574231 DOI: 10.1016/j.ydbio.2007.04.052] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Revised: 04/09/2007] [Accepted: 04/30/2007] [Indexed: 11/30/2022]
Abstract
The epithelial layers of the ciliary body (CB) and iris are non-neural structures that differentiate from the anterior region of the eyecup, the ciliary margin (CM). We show here that activation of the canonical Wnt signaling pathway is sufficient and necessary for the normal development of anterior eye structures. Pharmacological activation of beta-catenin signaling with lithium (Li(+)) treatment in retinal explants in vitro induced the ectopic expression of the CM markers Otx1 and Msx1. Cre-mediated stabilization of beta-catenin expression in the peripheral retina in vivo induced a cell autonomous upregulation of CM markers at the expense of neural retina (NR) markers and inhibited neurogenesis. Consistent with a cell autonomous conversion to peripheral eye fates, the proliferation index in the region of the retina that expressed stabilized beta-catenin was identical to the wild-type CM and there was an expansion of CB-like structures at later stages. Conversely, Cre-mediated inactivation of beta-catenin reduced CM marker expression as well as the size of the CM and CB/iris. Aberrant CB development in both mouse models was also associated with a reduction in the number of retinal stem cells in vitro. In summary, activation of canonical Wnt signaling is sufficient to promote the development of peripheral eyecup fates at the expense of the NR and is also required for the normal development of anterior eyecup structures.
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Affiliation(s)
- Hong Liu
- Molecular Medicine Program, Ottawa Health Research Institute, 501 Smyth Road, Ottawa, Ontario, Canada K1H 8L6
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