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Haller S, Marton RM, Marroquin KA, Shamir ER. Improved handling and embedding schemes for cultured murine neuroretinal explants. J Histotechnol 2022; 45:1-13. [PMID: 36222271 DOI: 10.1080/01478885.2022.2119639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Traumatic, inherited, and age-related degenerative diseases of the retina, such as retinal detachment, retinitis pigmentosa, and age-related macular degeneration, are characterized by the irreversible loss of retinal neurons. While current treatments aim to prevent neuronal degeneration, there are no available treatments to restore neurons after loss. Cultured murine neuroretinal tissue explants model retinal injury and offer a high throughput approach to identify experimental interventions capable of regenerating neurons. Formalin-fixed paraffin-embedded (FFPE) preparations of murine neuroretinal explants can be used to identify cells throughout the retinal layers to provide information on proliferation and activity following exposure to therapeutics. However, retinal explants are friable, particularly after ex vivo culture, sample handling and FFPE processing steps can result in tissue loss and damage. Friability also prohibits bisecting samples post-culture to display more than one region of interest for analysis. We developed a sample handling and embedding technique for cultured murine neuroretinal explants using HistogelTM in combination with a post-processing trimming step that eliminates tissue loss, increases cross-sectional retinal representation, and captures proximal and central retina on one slide to facilitate analysis of explants subjected to neurotrophic compounds.
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Affiliation(s)
- Susan Haller
- Department of Research Pathology, Genentech Inc, South San Francisco, CA, USA
| | - Rebecca M Marton
- Department of Immunology Discovery, Genentech Inc., South San Francisco, CA, USA
| | - Kevin A Marroquin
- Department of Research Pathology, Genentech Inc, South San Francisco, CA, USA
| | - Eliah R Shamir
- Department of Research Pathology, Genentech Inc, South San Francisco, CA, USA
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2
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Zhu Y, Cao B, Tolone A, Yan J, Christensen G, Arango-Gonzalez B, Ueffing M, Paquet-Durand F. In vitro Model Systems for Studies Into Retinal Neuroprotection. Front Neurosci 2022; 16:938089. [PMID: 35873807 PMCID: PMC9301112 DOI: 10.3389/fnins.2022.938089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 06/20/2022] [Indexed: 11/13/2022] Open
Abstract
Therapy development for neurodegenerative diseases of the retina constitutes a major unmet medical need, and this may be particularly relevant for inherited diseases of the retina, which are largely untreatable to this day. Therapy development necessitates appropriate models to improve the understanding of the underlying degenerative mechanisms, as well as for the testing and evaluation of novel treatment approaches. This review provides an overview of various in vitro model systems used to study retinal neuroprotection. The in vitro methods and technologies discussed range from primary retinal cell cultures and cell lines, to retinal organoids and organotypic retinal explants, to the cultivation of whole eyeballs. The advantages and disadvantages of these methods are compared and evaluated, also in view of the 3R principles (i.e., the refinement, reduction, and replacement of live animal testing), to identify suitable in vitro alternatives for in vivo experimentation. The article further expands on the use of in vitro models to test and evaluate neuroprotective treatments and to aid the development of retinal drug delivery systems. Among the pharmacological agents tested and characterized in vitro are such that interfere with aberrant cyclic guanosine monophosphate (cGMP) -signaling or such that inhibit the activities of poly (ADP-ribose) polymerase (PARP), histone deacetylases (HDAC), calpain-type proteases, as well as unfolded protein response-related stress. We then introduce nanoparticle-based drug delivery systems and discuss how different in vitro systems may be used to assess their efficacy in the treatment of retinal diseases. The summary provides a brief comparison of available in vitro models and relates their advantages and limitations to the various experimental requirements, for instance, for studies into disease mechanisms, novel treatments, or retinal toxicity. In many cases, combinations of different in vitro models may be required to obtain a comprehensive view of the efficacy of a given retinal neuroprotection approach.
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Affiliation(s)
- Yu Zhu
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Bowen Cao
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
- Molecular Biology of Retinal Degenerations, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Arianna Tolone
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Jie Yan
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Gustav Christensen
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- Graduate Training Centre of Neuroscience, University of Tübingen, Tübingen, Germany
| | - Blanca Arango-Gonzalez
- Molecular Biology of Retinal Degenerations, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Marius Ueffing
- Molecular Biology of Retinal Degenerations, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- *Correspondence: Marius Ueffing,
| | - François Paquet-Durand
- Cell Death Mechanisms Group, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
- François Paquet-Durand,
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3
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Grigoryan EN. Self-Organization of the Retina during Eye Development, Retinal Regeneration In Vivo, and in Retinal 3D Organoids In Vitro. Biomedicines 2022; 10:1458. [PMID: 35740479 PMCID: PMC9221005 DOI: 10.3390/biomedicines10061458] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/16/2022] [Accepted: 06/18/2022] [Indexed: 11/23/2022] Open
Abstract
Self-organization is a process that ensures histogenesis of the eye retina. This highly intricate phenomenon is not sufficiently studied due to its biological complexity and genetic heterogeneity. The review aims to summarize the existing central theories and ideas for a better understanding of retinal self-organization, as well as to address various practical problems of retinal biomedicine. The phenomenon of self-organization is discussed in the spatiotemporal context and illustrated by key findings during vertebrate retina development in vivo and retinal regeneration in amphibians in situ. Described also are histotypic 3D structures obtained from the disaggregated retinal progenitor cells of birds and retinal 3D organoids derived from the mouse and human pluripotent stem cells. The review highlights integral parts of retinal development in these conditions. On the cellular level, these include competence, differentiation, proliferation, apoptosis, cooperative movements, and migration. On the physical level, the focus is on the mechanical properties of cell- and cell layer-derived forces and on the molecular level on factors responsible for gene regulation, such as transcription factors, signaling molecules, and epigenetic changes. Finally, the self-organization phenomenon is discussed as a basis for the production of retinal organoids, a promising model for a wide range of basic scientific and medical applications.
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Affiliation(s)
- Eleonora N Grigoryan
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia
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Wagner N, Safaei A, Vogt PA, Gammel MR, Dick HB, Schnichels S, Joachim SC. Coculture of ARPE-19 Cells and Porcine Neural Retina as an Ex Vivo Retinal Model. Altern Lab Anim 2022; 50:27-44. [PMID: 35302924 DOI: 10.1177/02611929221082662] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Neural retinal organ cultures are used to investigate ocular pathomechanisms. However, these cultures lack the essential retinal pigment epithelium (RPE) cells, which are part of the actual in vivo retina. To simulate a more realistic ex vivo model, porcine neural retina explants were cocultured with ARPE-19 cells (ARPE-19 group), which are derived from human RPE. To identify whether the entire cells or just the cell factors are necessary, in a second experimental group, porcine neural retina explants were cultured with medium derived from ARPE-19 cells (medium group). Individually cultured neural retina explants served as controls (control group). After 8 days, all neural retinas were analysed to evaluate retinal thickness, photoreceptors, microglia, complement factors and synapses (n = 6-8 per group). The neural retina thickness in the ARPE-19 group was significantly better preserved than in the control group (p = 0.031). Also, the number of L-cones was higher in the ARPE-19 group, as compared to the control group (p < 0.001). Furthermore, the ARPE-19 group displayed an increased presynaptic glutamate uptake (determined via vGluT1 labelling) and enhanced post-synaptic density (determined via PSD-95 labelling). Combined Iba1 and iNOS detection revealed only minor effects of ARPE-19 cells on microglial activity, with a slight downregulation of total microglia activity apparent in the medium group. Likewise, only minor beneficial effects on photoreceptors and synaptic structure were found in the medium group. This novel system offers the opportunity to investigate interactions between the neural retina and RPE cells, and suggests that the inclusion of a RPE feeder layer has beneficial effects on the ex vivo maintenance of neural retina. By modifying the culture conditions, this coculture model allows a better understanding of photoreceptor death and photoreceptor-RPE cell interactions in retinal diseases.
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Affiliation(s)
- Natalie Wagner
- Experimental Eye Research Institute, University Eye Hospital, 9142Ruhr-University Bochum, Germany
| | - Armin Safaei
- Experimental Eye Research Institute, University Eye Hospital, 9142Ruhr-University Bochum, Germany
| | - Pia A Vogt
- Experimental Eye Research Institute, University Eye Hospital, 9142Ruhr-University Bochum, Germany
| | - Maurice R Gammel
- Experimental Eye Research Institute, University Eye Hospital, 9142Ruhr-University Bochum, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, 9142Ruhr-University Bochum, Germany
| | - Sven Schnichels
- Centre for Ophthalmology Tübingen, University Eye Hospital Tübingen, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, 9142Ruhr-University Bochum, Germany
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5
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Fernandez-Bueno I, Usategui-Martin R. Ex Vivo Model of Spontaneous Neuroretinal Degeneration for Evaluating Stem Cells' Paracrine Properties. Methods Mol Biol 2021; 2269:125-137. [PMID: 33687676 DOI: 10.1007/978-1-0716-1225-5_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ex vivo neuroretina cultures closely resemble in vivo conditions, retaining the complex neuroretina cells dynamics, connections, and functionality, under controlled conditions. Therefore, these models have allowed advancing in the knowledge of retinal physiology and pathobiology over the years. Furthermore, the ex vivo neuroretina models represent an adequate tool for evaluating stem cell therapies over neuroretinal degeneration processes.Here, we describe a physically separated co-culture of neuroretina explants with stem cells to evaluate the effect of stem cells paracrine properties on spontaneous neuroretinal degeneration.
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Affiliation(s)
- Ivan Fernandez-Bueno
- Instituto Universitario de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Campus Miguel Delibes, Paseo de Belén 17, Valladolid, Spain.
- Centro en Red de Medicina Regenerativa y Terapia Celular de Castilla y León, Valladolid, Spain.
- Red Temática de Investigación Cooperativa en Salud (RETICS), Oftared, Instituto de Salud Carlos III, Valladolid, Spain.
| | - Ricardo Usategui-Martin
- Instituto Universitario de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Campus Miguel Delibes, Paseo de Belén 17, Valladolid, Spain
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Ghareeb AE, Lako M, Steel DH. Coculture techniques for modeling retinal development and disease, and enabling regenerative medicine. Stem Cells Transl Med 2020; 9:1531-1548. [PMID: 32767661 PMCID: PMC7695644 DOI: 10.1002/sctm.20-0201] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/22/2020] [Accepted: 07/05/2020] [Indexed: 12/14/2022] Open
Abstract
Stem cell-derived retinal organoids offer the opportunity to cure retinal degeneration of wide-ranging etiology either through the study of in vitro models or the generation of tissue for transplantation. However, despite much work in animals and several human pilot studies, satisfactory therapies have not been developed. Two major challenges for retinal regenerative medicine are (a) physical cell-cell interactions, which are critical to graft function, are not formed and (b) the host environment does not provide suitable queues for development. Several strategies offer to improve the delivery, integration, maturation, and functionality of cell transplantation. These include minimally invasive delivery, biocompatible material vehicles, retinal cell sheets, and optogenetics. Optimizing several variables in animal models is practically difficult, limited by anatomical and disease pathology which is often different to humans, and faces regulatory and ethical challenges. High-throughput methods are needed to experimentally optimize these variables. Retinal organoids will be important to the success of these models. In their current state, they do not incorporate a representative retinal pigment epithelium (RPE)-photoreceptor interface nor vascular elements, which influence the neural retina phenotype directly and are known to be dysfunctional in common retinal diseases such as age-related macular degeneration. Advanced coculture techniques, which emulate the RPE-photoreceptor and RPE-Bruch's-choriocapillaris interactions, can incorporate disease-specific, human retinal organoids and overcome these drawbacks. Herein, we review retinal coculture models of the neural retina, RPE, and choriocapillaris. We delineate the scientific need for such systems in the study of retinal organogenesis, disease modeling, and the optimization of regenerative cell therapies for retinal degeneration.
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Affiliation(s)
- Ali E. Ghareeb
- Sunderland Eye Infirmary, South Tyneside and Sunderland NHS Foundation TrustSunderlandUK
- Biosciences Institute, Newcastle UniversityNewcastle‐upon‐TyneUK
| | - Majlinda Lako
- Biosciences Institute, Newcastle UniversityNewcastle‐upon‐TyneUK
| | - David H. Steel
- Sunderland Eye Infirmary, South Tyneside and Sunderland NHS Foundation TrustSunderlandUK
- Biosciences Institute, Newcastle UniversityNewcastle‐upon‐TyneUK
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7
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Hydrogel-mediated co-transplantation of retinal pigmented epithelium and photoreceptors restores vision in an animal model of advanced retinal degeneration. Biomaterials 2020; 257:120233. [DOI: 10.1016/j.biomaterials.2020.120233] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/07/2020] [Accepted: 07/10/2020] [Indexed: 01/01/2023]
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Schnichels S, Paquet-Durand F, Löscher M, Tsai T, Hurst J, Joachim SC, Klettner A. Retina in a dish: Cell cultures, retinal explants and animal models for common diseases of the retina. Prog Retin Eye Res 2020; 81:100880. [PMID: 32721458 DOI: 10.1016/j.preteyeres.2020.100880] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 06/23/2020] [Accepted: 06/26/2020] [Indexed: 12/11/2022]
Abstract
For many retinal diseases, including age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy (DR), the exact pathogenesis is still unclear. Moreover, the currently available therapeutic options are often unsatisfactory. Research designed to remedy this situation heavily relies on experimental animals. However, animal models often do not faithfully reproduce human disease and, currently, there is strong pressure from society to reduce animal research. Overall, this creates a need for improved disease models to understand pathologies and develop treatment options that, at the same time, require fewer or no experimental animals. Here, we review recent advances in the field of in vitro and ex vivo models for AMD, glaucoma, and DR. We highlight the difficulties associated with studies on complex diseases, in which both the initial trigger and the ensuing pathomechanisms are unclear, and then delineate which model systems are optimal for disease modelling. To this end, we present a variety of model systems, ranging from primary cell cultures, over organotypic cultures and whole eye cultures, to animal models. Specific advantages and disadvantages of such models are discussed, with a special focus on their relevance to putative in vivo disease mechanisms. In many cases, a replacement of in vivo research will mean that several different in vitro models are used in conjunction, for instance to analyze and validate causative molecular pathways. Finally, we argue that the analytical decomposition into appropriate cell and tissue model systems will allow making significant progress in our understanding of complex retinal diseases and may furthermore advance the treatment testing.
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Affiliation(s)
- Sven Schnichels
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Germany.
| | - François Paquet-Durand
- Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Germany
| | - Marina Löscher
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Germany
| | - Teresa Tsai
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Germany
| | - José Hurst
- University Eye Hospital, Centre for Ophthalmology, University of Tübingen, Germany
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, Germany
| | - Alexa Klettner
- Department of Ophthalmology, University Medical Center, University of Kiel, Kiel, Germany
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9
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Rettinger CL, Wang HC. Current Advancements in the Development and Characterization of Full-Thickness Adult Neuroretina Organotypic Culture Systems. Cells Tissues Organs 2019; 206:119-132. [PMID: 30879015 DOI: 10.1159/000497296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 01/25/2019] [Indexed: 11/19/2022] Open
Abstract
Retinal degenerative diseases such as macular degeneration, glaucoma, and diabetic retinopathy constitute the leading cause of blindness in the industrialized world. There is a continuous demand in investigative ophthalmic research for the development of new treatment modalities for retinal therapy. Unfortunately, efforts to identify novel neuroprotective and neuroregenerative agents have often been hindered by an experimental model gap that exists between high-throughput methods via dissociated cells and preclinical animal models. Even though dissociated cell culture is rapid and high-throughput, it is limited in its ability to reproduce the in vivo conditions. In contrast, preclinical animal models may offer greater fidelity, albeit they lack efficiency and experimental control. Retina explant cultures provide an ideal bridge to close this gap and have been used to study an array of biological processes such as retinal development and neurodegeneration. However, it is often difficult to interpret findings from these studies due to the wide variety of experimental species and culture methods used. This review provides a comprehensive overview of current ex vivo neuroretina culture methods and assessments, with a focus on their suitability, advantages, and disadvantages, along with novel insights and perspectives on the organotypic culture model as a high-throughput platform for screening promising molecules for retinal regeneration.
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Affiliation(s)
- Christina L Rettinger
- Ocular and Sensory Trauma Task Area, U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas, USA,
| | - Heuy-Ching Wang
- Ocular and Sensory Trauma Task Area, U.S. Army Institute of Surgical Research, Fort Sam Houston, Texas, USA
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Abstract
Retinal explant culture systems have the potential to mimic the functional dynamics of the organ beyond those of the dissociated cells, thus making this technique a very powerful intermediate model system between in vitro cell cultures and in vivo animal models. The different retinal layers made of highly specialized cell types remain intact, while glia cell reactions and/or intercellular interactions can be evaluated under well-defined conditions in the lab.In retinal disorders neurodegeneration of mature retinal cells takes place. Therefore, we investigated the adult murine neuroretina in organ culture to test its suitability for use in preclinical therapeutic applications. Here we describe a method for the organ culture of adult murine retina (>12 weeks) used to establish survival, cellular changes and early degeneration patterns of neuronal and glial cells. After enucleation of the eyeball and careful dissection of the retina from the sclera and retinal pigment epithelium, the detached retina is cultured with photoreceptor facing down on a supporting track-etched polycarbonate membrane in a 6-well culture plate maintained in a humidified atmosphere of 5% CO2 and 95% air at 37 °C. After 1, 2, 3, 4, 6, 8, or 10 days retinal explants can be harvested and immediately processed for RNA isolation or fixed in paraformaldehyde for histological analysis.
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Rettinger CL, Wang HC. Quantitative Assessment of Retina Explant Viability in a Porcine Ex Vivo Neuroretina Model. J Ocul Pharmacol Ther 2018; 34:521-530. [PMID: 29924674 DOI: 10.1089/jop.2018.0021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE Given that porcine and human retinas have similar structures and characteristics, ex vivo culture of porcine neuroretina provides an attractive model for studying mechanisms of human retinal injury and degenerative disease. Here, we describe the method that was used to establish and characterize an adult porcine retina culture system as a rapid screening tool for retinal survival in real time. METHODS Neuroretina explants 8 mm in diameter were harvested from adult swine and cultured on porous cell culture inserts with adjustable heights. Retina explant viability was evaluated at 1, 4, 7, 11, and 14 days of culture using a resazurin-based metabolic assay. The explants were analyzed morphologically through immunohistochemistry for glial activation and apoptosis. Morphometric analysis was also performed on hematoxylin and eosin-stained retina sections from each time point. RESULTS The viability of retina explants gradually decreased over time in culture. The laminar structure of the neuroretina was well preserved during the first 7 days. However, by day 14, most explants showed significant loss of cells in each laminar layer and obvious thinning. Overall, the progressive loss of retinal lamination and thickness, and increase in apoptotic nuclei with activated hypertrophic Müller cells were well correlated with the metabolic activity of the ex vivo neuroretina explants. CONCLUSIONS This study was the first report to describe the use of a high-throughput and quantitative method for monitoring retina explant viability in real time. Ex vivo neuroretina cultures closely mimic the functional dynamics of the organ, and can be used efficiently to screen novel therapeutics for retinal neurodegenerative disease.
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Affiliation(s)
- Christina L Rettinger
- Ocular and Sensory Trauma Task Area, United States Army Institute of Surgical Research , Fort Sam Houston, Texas
| | - Heuy-Ching Wang
- Ocular and Sensory Trauma Task Area, United States Army Institute of Surgical Research , Fort Sam Houston, Texas
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12
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Abstract
In this study we wanted to examine how an adult neuroretina from an animal with an eye similar to the human one survives in vitro. We also wanted to investigate how the culture process affects the adult retina when used in a transplantation paradigm. Full-thickness neuroretinal sheets from adult porcine eyes were dissected into pieces measuring 3 mm in diameter. These were kept in culture for 1–3 days. After this time, the explants were fixed or transplanted subretinally to adult pigs, which were killed after 72–74 days. Transplanted eyes, as well as tissue kept in culture only, were processed for hematoxylin and eosin staining and immunohistochemistry. Explants kept 1 day in vitro (DIV) displayed the normal morphology. In these specimens, single pyknotic cells were evident in the outer nuclear layer (ONL) and ganglion cell layer, but were more frequent in the inner nuclear layer (INL). After longer times in vitro, severe degenerative changes appeared. Transplanted explants kept 1 DIV prior to transplantation exhibited normal retinal lamination in two out of four specimens. Transducin and recoverin labeling revealed photoreceptors with inner segments in these grafts. Rod bipolar cells displayed a normal morphology. Vertically arranged Mùller cells were also seen in the laminated grafts. Two of the three transplants kept 2 DIV displayed minimal lamination. Eyes with transplants kept 3 DIV prior to transplantation displayed degenerated grafts in all eyes. This study shows that adult porcine neuroretinal explants kept in culture for 1 day display a normal morphology in their major part. Additionally, 1-day explants can survive transplantation with retained morphology even after several months. This indicates the possibility of storing adult donor tissue between harvest and transplantation. The culture system may also be used in the future as a tool for manipulating retinal donor tissue prior to transplantation.
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Affiliation(s)
- Karl Engelsberg
- Department of Ophthalmology, Lund University Hospital, Lund, Sweden.
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Photoreceptor Outer Segment-like Structures in Long-Term 3D Retinas from Human Pluripotent Stem Cells. Sci Rep 2017; 7:766. [PMID: 28396597 PMCID: PMC5429674 DOI: 10.1038/s41598-017-00774-9] [Citation(s) in RCA: 179] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 03/14/2017] [Indexed: 12/22/2022] Open
Abstract
The retinal degenerative diseases, which together constitute a leading cause of hereditary blindness worldwide, are largely untreatable. Development of reliable methods to culture complex retinal tissues from human pluripotent stem cells (hPSCs) could offer a means to study human retinal development, provide a platform to investigate the mechanisms of retinal degeneration and screen for neuroprotective compounds, and provide the basis for cell-based therapeutic strategies. In this study, we describe an in vitro method by which hPSCs can be differentiated into 3D retinas with at least some important features reminiscent of a mature retina, including exuberant outgrowth of outer segment-like structures and synaptic ribbons, photoreceptor neurotransmitter expression, and membrane conductances and synaptic vesicle release properties consistent with possible photoreceptor synaptic function. The advanced outer segment-like structures reported here support the notion that 3D retina cups could serve as a model for studying mature photoreceptor development and allow for more robust modeling of retinal degenerative disease in vitro.
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14
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Bell K, Wilding C, Funke S, Perumal N, Beck S, Wolters D, Holz-Müller J, Pfeiffer N, Grus FH. Neuroprotective effects of antibodies on retinal ganglion cells in an adolescent retina organ culture. J Neurochem 2016; 139:256-269. [PMID: 27507598 DOI: 10.1111/jnc.13765] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 07/04/2016] [Accepted: 07/29/2016] [Indexed: 11/28/2022]
Abstract
Glaucoma, a neurodegenerative disease, is characterized by a progressive loss of retinal ganglion cells (rgc). Up- and down-regulated autoantibody immunoreactivities in glaucoma patients have been demonstrated. Previous studies showed protective effects of down-regulated antibodies [gamma (γ)-synuclein and glial fibrillary acidic protein [GFAP]) on neuroretinal cells. The aim of this study was to test these protective antibody effects on rgc in an organ culture model and to get a better understanding of cell-cell interactions of the retina in the context of the protective effect. We used an adolescent retinal organ culture (pig) with an incubation time of up to 4 days. Retinal explants were incubated with different antibodies for 24 h (anti-GFAP, anti-γ-synuclein and anti-myoglobin antibody as a control). Brn3a and TUNEL staining were performed. We also conducted glutamine synthetase staining and quantification of the retinal explants. Mass spectrometry analyses were performed as well as protein analyses via microarray. We detected a continuous decrease of rgc/mm in the retinal explants throughout the 4 days of incubation with increased TUNEL rgc staining. Immunohistochemical analyses showed a protective effect of anti-γ-synuclein (increased rgc/mm of 41%) and anti-GFAP antibodies (increased rgc/mm of 37%). Mass spectrometric, microarray and immunohistochemical analyses demonstrated Müller cell involvement and decreased endoplasmic reticulum stress response in the antibody-treated retinae. We could detect that the tested antibodies have a protective effect on rgc which seems to be the result of reduced stress levels in the retina as well as a shift of glutamine synthetase localization in the endfeet of the Müller cells towards the inner retinal layer. Loss of retinal ganglion cells (rgc) in glaucoma leads to blindness. Several antibodies are down-regulated in glaucoma patients. Our aim was to test if these antibodies have a protective effect of rgc in a retinal organ culture. This could be shown with an increase of rgc numbers. This effect results through reduced stress levels and the shift of glutamine synthetase localization.
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Affiliation(s)
- Katharina Bell
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Corina Wilding
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sebastian Funke
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Natarajan Perumal
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sabine Beck
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Dominik Wolters
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jana Holz-Müller
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Norbert Pfeiffer
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Franz H Grus
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
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Complimentary action: C1q increases ganglion cell survival in an in vitro model of retinal degeneration. J Neuroimmunol 2016; 298:117-29. [PMID: 27609284 DOI: 10.1016/j.jneuroim.2016.07.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/27/2016] [Accepted: 07/15/2016] [Indexed: 12/31/2022]
Abstract
Using a previously described retinal explant culture system as an acute injury model, we here explore the role of C1q, the initiator of the classical complement pathway, in neuronal cell survival and retinal homeostasis. Full-thickness adult rat retinal explants were divided into four groups, receiving the following supplementation: C1q (50nM), C1-inhibitor (C1-inh; Berinert; 500mg/l), C1q+C1-inh, and no supplementation (culture controls). Explants were kept for 12h or 2days after which they were examined morphologically and with a panel of immunohistochemical markers. C1q supplementation protects ganglion cells from degeneration within the explant in vitro system. This effect is correlated to an attenuated endogenous production of C1q, and a quiesced gliotic response.
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Taylor L, Arnér K, Kolewe M, Pritchard C, Hendy G, Langer R, Ghosh F. Seeing through the interface: poly(ε-Caprolactone) surface modification of poly(glycerol-co-sebacic acid) membranes in adult porcine retinal explants. J Tissue Eng Regen Med 2016; 11:2349-2358. [PMID: 27098673 DOI: 10.1002/term.2135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 12/10/2015] [Accepted: 12/10/2015] [Indexed: 02/03/2023]
Affiliation(s)
- Linnéa Taylor
- Department of Ophthalmology, Lund University Hospital, Lund, Sweden
| | - Karin Arnér
- Department of Ophthalmology, Lund University Hospital, Lund, Sweden
| | - Martin Kolewe
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Christopher Pritchard
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Gillian Hendy
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Robert Langer
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Fredrik Ghosh
- Department of Ophthalmology, Lund University Hospital, Lund, Sweden
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Primary retinal cultures as a tool for modeling diabetic retinopathy: an overview. BIOMED RESEARCH INTERNATIONAL 2015; 2015:364924. [PMID: 25688355 PMCID: PMC4320900 DOI: 10.1155/2015/364924] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/04/2014] [Accepted: 12/23/2014] [Indexed: 12/21/2022]
Abstract
Experimental models of diabetic retinopathy (DR) have had a crucial role in the comprehension of the pathophysiology of the disease and the identification of new therapeutic strategies. Most of these studies have been conducted in vivo, in animal models. However, a significant contribution has also been provided by studies on retinal cultures, especially regarding the effects of the potentially toxic components of the diabetic milieu on retinal cell homeostasis, the characterization of the mechanisms on the basis of retinal damage, and the identification of potentially protective molecules. In this review, we highlight the contribution given by primary retinal cultures to the study of DR, focusing on early neuroglial impairment. We also speculate on possible themes into which studies based on retinal cell cultures could provide deeper insight.
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Taylor L, Arnér K, Ghosh F. First Responders: Dynamics of Pre-Gliotic Müller Cell Responses in The Isolated Adult Rat Retina. Curr Eye Res 2014; 40:1245-60. [DOI: 10.3109/02713683.2014.988360] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Generation of three-dimensional retinal tissue with functional photoreceptors from human iPSCs. Nat Commun 2014; 5:4047. [PMID: 24915161 PMCID: PMC4370190 DOI: 10.1038/ncomms5047] [Citation(s) in RCA: 654] [Impact Index Per Article: 65.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 05/05/2014] [Indexed: 12/17/2022] Open
Abstract
Many forms of blindness result from the dysfunction or loss of retinal photoreceptors. Induced pluripotent stem cells (iPSCs) hold great potential for the modelling of these diseases or as potential therapeutic agents. However, to fulfill this promise, a remaining challenge is to induce human iPSC to recreate in vitro key structural and functional features of the native retina, in particular the presence of photoreceptors with outer-segment discs and light sensitivity. Here we report that hiPSC can, in a highly autonomous manner, recapitulate spatiotemporally each of the main steps of retinal development observed in vivo and form three-dimensional retinal cups that contain all major retinal cell types arranged in their proper layers. Moreover, the photoreceptors in our hiPSC-derived retinal tissue achieve advanced maturation, showing the beginning of outer-segment disc formation and photosensitivity. This success brings us one step closer to the anticipated use of hiPSC for disease modelling and open possibilities for future therapies.
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Taylor L, Arnér K, Taylor IH, Ghosh F. Feet on the ground: Physical support of the inner retina is a strong determinant for cell survival and structural preservation in vitro. Invest Ophthalmol Vis Sci 2014; 55:2200-13. [PMID: 24595389 DOI: 10.1167/iovs.13-13535] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The purpose of this study was to explore the importance of local physical tissue support for homeostasis in the isolated retina. METHODS Full-thickness retinal sheets were isolated from adult porcine eyes. Retinas were cultured for 5 or 10 days using the previously established explant protocol with photoreceptors positioned against the culture membrane (porous polycarbonate) or the Müller cell endfeet and inner limiting membrane (ILM) apposed against the membrane. The explants were analyzed morphologically using hematoxylin and eosin staining, immunohistochemistry, TUNEL labeling, and transmission electron microscopy (TEM). RESULTS Standard cultures displayed a progressive loss of retinal lamination and extensive cell death, with activated, hypertrophic Müller cells. In contrast, explants cultured with the ILM facing the membrane displayed a maintenance of the retinal laminar architecture, and a statistically significant attenuation of photoreceptor and ganglion cell death. Transmission electron microscopy revealed intact synapses as well as preservation of normal cellular membrane structures. Immunohistochemistry showed no signs of Müller cell activation (glial fibrillary acidic protein [GFAP]), with maintained expression of important metabolic markers (glutamine synthetae [GS], bFGF). CONCLUSIONS Providing physical support to the inner but not the outer retina appears to prevent the tissue collapse resulting from perturbation of the normal biomechanical milieu in the isolated retinal sheet. Using this novel paradigm, gliotic reactions are attenuated and metabolic processes vital for tissue health are preserved, which significantly increases neuronal cell survival. This finding opens up new avenues of adult retinal tissue culture research and increases our understanding of pathological reactions in biomechanically related conditions in vivo.
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Affiliation(s)
- Linnéa Taylor
- Department of Ophthalmology, Lund University Hospital, Lund, Sweden
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21
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Time course modifications in organotypic culture of human neuroretina. Exp Eye Res 2012; 104:26-38. [PMID: 23022403 DOI: 10.1016/j.exer.2012.08.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 08/29/2012] [Accepted: 08/31/2012] [Indexed: 02/01/2023]
Abstract
The purpose of this study was to characterize organ culture of human neuroretina and to establish survival and early degeneration patterns of neural and glial cells. Sixteen neuroretina explants were prepared from 2 postmortem eyes of 2 individuals. Four explants were used as fresh retina controls, and 12 were evaluated at 3, 6, and 9 days of culture. Neuroretina explants (5 × 5 mm) were cultured in Transwell(®) dishes with the photoreceptor layer facing the supporting membrane. Culture medium (Neurobasal A-based) was maintained in contact with the membrane beneath the explant. Cryostat and ultrathin sections were prepared for immunohistochemistry and electron microscopy. Neuroretinal modifications were evaluated after toluidine blue staining and after immunostaining for neuronal and glial cell markers. Ultrastructural changes were analyzed by electron microscopy. From 0 to 9 days in culture, there was progressive retinal degeneration, including early pyknosis of photoreceptor nuclei, cellular vacuolization in the ganglion cell layer, decrease of both plexiform layer thicknesses, disruption and truncation of photoreceptor outer segments (OS), and marked reduction in the number of nuclei at both nuclear layers where the cells were less densely packed. At 3 days there was swelling of cone OS with impairment of pedicles, loss of axons and dendrites of horizontal and rod bipolar cells that stained for calbindin (CB) and protein kinase C (PKC-α), respectively. After 9 days, horizontal cells were pyknotic and without terminal tips. There were similar degenerative processes in the outer plexiform layer for rod bipolar cells and loss of axon terminal lateral varicosities in the inner plexiform layer. Glial fibrillary acidic protein (GFAP) staining did not reveal a dramatic increase of gliosis in Müller cells. However, some Müller cells were CB immunoreactive at 6 days of culture. Over 9 days of culture, human neuroretina explants underwent morphological changes in photoreceptors, particularly the OS and axon terminals, and in postsynaptic horizontal and bipolar cells. These early changes, not previously described in cultured human samples, reproduce some celullar modifications after retinal damage. Thus, this model may be suitable to evaluate therapeutic agents during retinal degeneration processes.
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Ghosh F, Taylor L, Arnér K. Exogenous Glutamate Modulates Porcine Retinal Development in vitro. Dev Neurosci 2012; 34:428-39. [DOI: 10.1159/000343721] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 09/27/2012] [Indexed: 12/27/2022] Open
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McUsic AC, Lamba DA, Reh TA. Guiding the morphogenesis of dissociated newborn mouse retinal cells and hES cell-derived retinal cells by soft lithography-patterned microchannel PLGA scaffolds. Biomaterials 2011; 33:1396-405. [PMID: 22115999 DOI: 10.1016/j.biomaterials.2011.10.083] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Accepted: 10/30/2011] [Indexed: 11/26/2022]
Abstract
Embryonic stem (ES) cell-derived photoreceptors are a promising cell source for enhanced in vitro models of retinal degenerative diseases, but the more differentiated characteristics of retinal cells do not typically develop in dissociated cell cultures. Therefore, we have reconstructed organized retinal tissue by seeding dissociated cells into an array of aligned units that more faithfully mimics the retina. We solvent-processed poly(lactic-co-glycolic acid) (PLGA) into a microchannel scaffold format to achieve this geometric constraint. We compared the effect of PLGA concentration on channel morphology and, along with other culture conditions, on the infiltration of dissociated newborn mouse retinal cells into the channels. Culturing scaffolds at the gas-liquid interface with low serum media increased infiltrated rod photoreceptor viability 18-fold over submerged, high serum cultures when evaluated after seven days. Rod photoreceptors and Müller glia aligned processes parallel to the microchannel walls. Otx2+ and Pax6+ subpopulations recapitulated lamination behavior. Further, we constructed scaffold/retinal pigment epithelium (RPE) co-cultures and observed rods extending rhodopsin-positive processes toward RPE cells, mimicking normal rod polarization and morphology. Finally, human embryonic stem cell-derived photoreceptors exhibited infiltration and morphological characteristics similar to mouse retinal cells inside the scaffolds. These findings constitute an important advance in generating tissue-level retinal models from dissociated cells for use as drug screening platforms and in regenerative medicine.
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Affiliation(s)
- Andrew C McUsic
- Department of Bioengineering, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98109, USA
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24
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Thangaraj G, Greif A, Layer PG. Simple explant culture of the embryonic chicken retina with long-term preservation of photoreceptors. Exp Eye Res 2011; 93:556-64. [DOI: 10.1016/j.exer.2011.07.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Revised: 07/18/2011] [Accepted: 07/20/2011] [Indexed: 11/29/2022]
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25
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Cell death and proliferation in acute slices and organotypic cultures of mammalian CNS. Prog Neurobiol 2009; 88:221-45. [DOI: 10.1016/j.pneurobio.2009.01.002] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Revised: 12/09/2008] [Accepted: 01/07/2009] [Indexed: 11/24/2022]
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Engelsberg K, Ehinger B, Ghosh F. Early Development of Retinal Subtypes in Long-Term Cultures of Human Embryonic Retina. Curr Eye Res 2009; 33:185-91. [DOI: 10.1080/02713680701843784] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Groeger G, Mackey AM, Pettigrew CA, Bhatt L, Cotter TG. Stress-induced activation of Nox contributes to cell survival signalling via production of hydrogen peroxide. J Neurochem 2009; 109:1544-54. [DOI: 10.1111/j.1471-4159.2009.06081.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Wallace DM, Cotter TG. Histone deacetylase activity in conjunction with E2F-1 and p53 regulates Apaf-1 expression in 661W cells and the retina. J Neurosci Res 2009; 87:887-905. [PMID: 18951482 DOI: 10.1002/jnr.21910] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Apaf-1 and the cysteine proteases known as caspases are genes central to the intrinsic apoptotic pathway in the retina. Previously, we have shown that histone deacetylase (HDAC) activity regulates Apaf-1 expression in the retina. In this study, we unravel the detailed molecular mechanism of HDAC-mediated regulation of Apaf-1 initially by use of a cell line (661W), which expresses some cone-specific genes and then by means of an ex vivo retinal explant system. Inhibition of HDAC activity by trichostatin A (TSA) up-regulates Apaf-1 expression, which precedes the induction of apoptosis. Furthermore, by a bioinformatics approach, we identify E2F-1 and p53 binding sites on the mouse Apaf-1 promoter and show by chromatin immunoprecipitation assays that these sites are occupied in vitro and that treatment with TSA results in increased binding of E2F-1 and p53 to the Apaf-1 promoter. By performing siRNA to these transcription factors, we illustrate that they govern Apaf-1 expression levels in vitro. Finally, in a retinal explant system, we show that similar to our 661W results, E2F-1 and p53 are up-regulated after inhibition of HDAC activity in the retina. This correlates with our previous observation in the explant system that Apaf-1 expression increases significantly and leads to an induction of apoptosis after inhibition of HDAC activity. Overall, we propose a role for HDAC activity, E2F-1, and p53 in the regulation of Apaf-1 expression in 661W cells; initial data also indicate a regulatory role in the retina.
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Affiliation(s)
- Deborah M Wallace
- Cell Development and Disease Laboratory, Department of Biochemistry, Biosciences Institute, University College, Cork, Ireland
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Wang X, Nookala S, Narayanan C, Giorgianni F, Beranova-Giorgianni S, McCollum G, Gerling I, Penn JS, Jablonski MM. Proteomic analysis of the retina: removal of RPE alters outer segment assembly and retinal protein expression. Glia 2009; 57:380-92. [PMID: 18803304 PMCID: PMC2653273 DOI: 10.1002/glia.20765] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The mechanisms that regulate the complex physiological task of photoreceptor outer segment assembly remain an enigma. One limiting factor in revealing the mechanism(s) by which this process is modulated is that not all of the role players who participate in this process are known. The purpose of this study was to determine some of the retinal proteins that likely play a critical role in regulating photoreceptor outer segment assembly. To do so, we analyzed and compared the proteome map of tadpole Xenopus laevis retinal pigment epithelium (RPE)-supported retinas containing organized outer segments with that of RPE-deprived retinas containing disorganized outer segments. Solubilized proteins were labeled with CyDye fluors followed by multiplexed two-dimensional separation. The intensity of protein spots and comparison of proteome maps was performed using DeCyder software. Identification of differentially regulated proteins was determined using nanoLC-ESI-MS/MS analysis. We found a total of 27 protein spots, 21 of which were unique proteins, which were differentially expressed in retinas with disorganized outer segments. We predict that in the absence of the RPE, oxidative stress initiates an unfolded protein response. Subsequently, downregulation of several candidate Müller glial cell proteins may explain the inability of photoreceptors to properly fold their outer segment membranes. In this study, we have used identification and bioinformatics assessment of proteins that are differentially expressed in retinas with disorganized outer segments as a first step in determining probable key molecules involved in regulating photoreceptor outer segment assembly.
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Affiliation(s)
- XiaoFei Wang
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN
| | - Suba Nookala
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN
| | | | - Francesco Giorgianni
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN
| | | | - Gary McCollum
- Department of Ophthalmology, Vanderbilt University, Nashville, TN
| | - Ivan Gerling
- Department of Medicine, University of Tennessee Health Science Center, Memphis, TN
| | - John S. Penn
- Department of Ophthalmology, Vanderbilt University, Nashville, TN
| | - Monica M. Jablonski
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN
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30
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Fan W, Cooper NGF. Glutamate-induced NFkappaB activation in the retina. Invest Ophthalmol Vis Sci 2008; 50:917-25. [PMID: 18836176 DOI: 10.1167/iovs.08-2555] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PURPOSE To determine the distribution and glutamate-mediated activation of nuclear factor (NF) kappaB members in the retina and pan-purified retinal ganglion cells (RGCs) and to characterize steps in the signal transduction events that lead to NFkappaB activation. METHODS Retinal expression patterns and RGCs were evaluated for five NFkappaB proteins with the aid of immunohistochemistry. Retinal explants or RGCs were treated with glutamate with or without the presence of the NDMA receptor antagonist memantine, the calcium chelator EGTA, or a specific inhibitor for calcium/calmodulin-dependent protein kinase-II (CaMKII). Characterizations of NFkappaB activation were performed with the aid of electrophoretic mobility shift assays and supershift assays. RESULTS All five NFkappaB proteins were present in the retina and in the pan-purified RGCs. In response to a glutamate stimulus, all NFkappaB proteins except c-Rel were activated. P65 was unique in that it was not constitutively active but showed a glutamate-inducible activation in the retina and in the cultured RGCs. Memantine, EGTA, or autocamtide-2-related inhibitory peptide (AIP) inhibited NFkappaB activation in the retina. Furthermore, AIP significantly reduced the level of glutamate-induced degradation of IkappaBs. CONCLUSIONS These data indicate that glutamate activates distinct NFkappaB proteins in the retina. P65 activation may be especially important with regard to RGC responses to glutamate given that its activity is induced by conditions known to lead to the death of these cells. The NMDA receptor-Ca(2+)-CaMKII signaling pathway is involved in glutamate-induced NFkappaB activation. Because AIP blocks the degradation of IkappaB, its regulation is clearly downstream of CaMKII.
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Affiliation(s)
- Wei Fan
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA
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Kaempf S, Walter P, Salz AK, Thumann G. Novel organotypic culture model of adult mammalian neurosensory retina in co-culture with retinal pigment epithelium. J Neurosci Methods 2008; 173:47-58. [DOI: 10.1016/j.jneumeth.2008.05.018] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2007] [Revised: 05/13/2008] [Accepted: 05/16/2008] [Indexed: 12/19/2022]
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Ma L, Cantrup R, Varrault A, Colak D, Klenin N, Götz M, McFarlane S, Journot L, Schuurmans C. Zac1 functions through TGFbetaII to negatively regulate cell number in the developing retina. Neural Dev 2007; 2:11. [PMID: 17559664 PMCID: PMC1913510 DOI: 10.1186/1749-8104-2-11] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Accepted: 06/08/2007] [Indexed: 12/25/2022] Open
Abstract
Background Organs are programmed to acquire a particular size during development, but the regulatory mechanisms that dictate when dividing progenitor cells should permanently exit the cell cycle and stop producing additional daughter cells are poorly understood. In differentiated tissues, tumor suppressor genes maintain a constant cell number and intact tissue architecture by controlling proliferation, apoptosis and cell dispersal. Here we report a similar role for two tumor suppressor genes, the Zac1 zinc finger transcription factor and that encoding the cytokine TGFβII, in the developing retina. Results Using loss and gain-of-function approaches, we show that Zac1 is an essential negative regulator of retinal size. Zac1 mutants develop hypercellular retinae due to increased progenitor cell proliferation and reduced apoptosis at late developmental stages. Consequently, supernumerary rod photoreceptors and amacrine cells are generated, the latter of which form an ectopic cellular layer, while other retinal cells are present in their normal number and location. Strikingly, Zac1 functions as a direct negative regulator of a rod fate, while acting cell non-autonomously to modulate amacrine cell number. We implicate TGFβII, another tumor suppressor and cytokine, as a Zac1-dependent amacrine cell negative feedback signal. TGFβII and phospho-Smad2/3, its downstream effector, are expressed at reduced levels in Zac1 mutant retinae, and exogenous TGFβII relieves the mutant amacrine cell phenotype. Moreover, treatment of wild-type retinae with a soluble TGFβ inhibitor and TGFβ receptor II (TGFβRII) conditional mutants generate excess amacrine cells, phenocopying the Zac1 mutant phenotype. Conclusion We show here that Zac1 has an essential role in cell number control during retinal development, akin to its role in tumor surveillance in mature tissues. Furthermore, we demonstrate that Zac1 employs a novel cell non-autonomous strategy to regulate amacrine cell number, acting in cooperation with a second tumor suppressor gene, TGFβII, through a negative feedback pathway. This raises the intriguing possibility that tumorigenicity may also be associated with the loss of feedback inhibition in mature tissues.
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Affiliation(s)
- Lin Ma
- IMCH, HBI, University of Calgary, T2N 4N1, Canada
| | | | - Annie Varrault
- Institut de Génomique Fonctionnelle, Montpellier, France
| | - Dilek Colak
- Institute of Stem Cell Research, GSF, München, Germany
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Azadi S, Johnson LE, Paquet-Durand F, Perez MTR, Zhang Y, Ekström PAR, van Veen T. CNTF+BDNF treatment and neuroprotective pathways in the rd1 mouse retina. Brain Res 2007; 1129:116-29. [PMID: 17156753 DOI: 10.1016/j.brainres.2006.10.031] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 10/05/2006] [Accepted: 10/06/2006] [Indexed: 11/22/2022]
Abstract
The rd1 mouse is a relevant model for studying the mechanisms of photoreceptor degeneration in retinitis pigmentosa. Treatment with ciliary neurotrophic factor (CNTF) in combination with brain derived neurotrophic factor (BDNF) is known to rescue photoreceptors in cultured rd1 retinal explants. To shed light on the underlying mechanisms, we studied the effects of 9 days (starting at postnatal day 2) in vitro CNTF+BDNF treatment on the endogenous production of CNTF, BDNF, fibroblast growth factor 2 (FGF2), or the activation of extracellular signal-regulated kinase (ERK), Akt and cAMP-response-element-binding protein (CREB) in retinal explants. In rd1 explants, CNTF+BDNF decreased the number of TUNEL-positive photoreceptors. The treatment also increased endogenous rd1 levels of CNTF and BDNF, but lowered the level of FGF2 expression in rd1 explants. When wild-type explants were treated, endogenous CNTF was similarly increased, while BDNF and FGF2 levels remained unaffected. In addition, treatment of rd1 retinas strongly increased the phosphorylation of ERK, Akt and CREB. In treated wild-type explants, the same parameters were either unchanged (ERK) or decreased (Akt and CREB). The results suggest a role for Akt, ERK and CREB in conveying the neuroprotective effect of CNTF+BDNF treatment in rd1 retinal explants.
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Affiliation(s)
- Seifollah Azadi
- Department of Ophthalmology, University of Lund, BMC-B13, SE-221 84 LUND, Sweden
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Reidel B, Orisme W, Goldmann T, Smith WC, Wolfrum U. Photoreceptor vitality in organotypic cultures of mature vertebrate retinas validated by light-dependent molecular movements. Vision Res 2006; 46:4464-71. [PMID: 16979692 DOI: 10.1016/j.visres.2006.07.019] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 07/24/2006] [Accepted: 07/26/2006] [Indexed: 12/01/2022]
Abstract
Vertebrate photoreceptor cells are polarized neurons highly specialized for light absorption and visual signal transduction. Photoreceptor cells consist of the light sensitive outer segment and the biosynthetic active inner segment linked by a slender connecting cilium. The function of mature photoreceptor cells is strictly dependent on this compartmentalization which is maintained in the specialized retinal environment. To keep this fragile morphologic and functional composition for further cell biological studies and treatments we established organotypic retina cultures of mature mice and Xenopus laevis. The organotypic retina cultures of both model organisms are created as co-cultures of the retina and the pigment epithelium, still attached to outer segments of the photoreceptor cells. To demonstrate the suitability of the culture system for physiological analyses we performed apoptotic cell death analyses and verified photoreceptor viability. Furthermore, light-dependent bidirectional movements of arrestin and transducin in photoreceptors in vivo and in the retinal cultures were indistinguishable indicating normal photoreceptor cell-biologic function in organotypic cultures. Our established culture systems allow the analysis of mature photoreceptor cells and their accessibility to treatments, characteristic for common cell culture. Furthermore, this culturing technique also provides an appropriate system for gene delivery to retinal cells and will serve to simulate gene therapeutic approaches prior to difficult and time-consuming in vivo experiments.
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Affiliation(s)
- Boris Reidel
- Institute of Zoology, Department of Cell and Matrix Biology, University of Mainz, Germany
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Rzeczinski S, Victorov IV, Lyjin AA, Aleksandrova OP, Harms C, Kronenberg G, Freyer D, Scheibe F, Priller J, Endres M, Dirnagl U. Roller Culture of Free-Floating Retinal Slices: A New System of Organotypic Cultures of Adult Rat Retina. Ophthalmic Res 2006; 38:263-9. [PMID: 16974126 DOI: 10.1159/000095768] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Accepted: 02/01/2006] [Indexed: 11/19/2022]
Abstract
No experimental system exists to date for the in vitro study of retinal ganglion cell populations in a three-dimensional organotypic tissue environment. Here, we describe such a novel method for roller cultivation of adult retinas. Retinas of adult (1-3 months old) rats were cut into rectangular slices of approximately 1 mm(2). Free-floating slices were cultured on a horizontal rotating roller drum (50-60 rpm) in a dry incubator at 36.5 degrees C. During the first days of cultivation, primary flat retinal slices changed their configuration and transformed into ball-shaped tissue spheres (retinal bodies). Histological and immunocytochemical studies showed that the outer wall of the retinal bodies was formed by cell and fibre layers typical of mature retina with photoreceptors located on the outside. Initially, retinal bodies contained an inner cavity which later was completely obliterated and filled with glial cells, sprouting nerve fibres, and vascular structures. This culture system was further developed into a robust model of glutamate-induced neurotoxicity. Using a novel culture method of adult rat retina, preservation of the three-dimensional organotypic retinal cytoarchitecture was achieved, including survival of neurons in the ganglion cell layer and sprouting of nerve fibres of the axotomized retinal ganglion cells. This novel culture model promises to facilitate studies of retinal physiology and pathology.
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Affiliation(s)
- Stefan Rzeczinski
- Laboratory of Experimental Neurocytology, Brain Research Institute, Moscow, Russia
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36
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Lamba DA, Karl MO, Ware CB, Reh TA. Efficient generation of retinal progenitor cells from human embryonic stem cells. Proc Natl Acad Sci U S A 2006; 103:12769-74. [PMID: 16908856 PMCID: PMC1568922 DOI: 10.1073/pnas.0601990103] [Citation(s) in RCA: 495] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The retina is subject to degenerative conditions, leading to blindness. Although retinal regeneration is robust in lower vertebrates, regeneration does not occur in the adult mammalian retina. Thus, we have developed efficient methods for deriving retinal neurons from human embryonic stem (hES) cells. Under appropriate culture conditions, up to 80% of the H1 line can be directed to the retinal progenitor fate, and express a gene expression profile similar to progenitors derived from human fetal retina. The hES cell-derived progenitors differentiate primarily into inner retinal neurons (ganglion and amacrine cells), with functional glutamate receptors. Upon coculture with retinas derived from a mouse model of retinal degeneration, the hES cell derived retinal progenitors integrate with the degenerated mouse retina and increase in their expression of photoreceptor-specific markers. These results demonstrate that human ES cells can be selectively directed to a neural retinal cell fate and thus may be useful in the treatment of retinal degenerations.
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Affiliation(s)
- Deepak A. Lamba
- Departments of *Biological Structure and
- Neurobiology and Behavior Program, University of Washington, Seattle, WA 98195
| | | | | | - Thomas A. Reh
- Departments of *Biological Structure and
- Neurobiology and Behavior Program, University of Washington, Seattle, WA 98195
- To whom correspondence should be addressed. E-mail:
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van Rossum AGSH, Aartsen WM, Meuleman J, Klooster J, Malysheva A, Versteeg I, Arsanto JP, Le Bivic A, Wijnholds J. Pals1/Mpp5 is required for correct localization of Crb1 at the subapical region in polarized Muller glia cells. Hum Mol Genet 2006; 15:2659-72. [PMID: 16885194 DOI: 10.1093/hmg/ddl194] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Mutations in the human Crumbs homologue-1 (CRB1) gene cause retinal diseases including Leber's congenital amaurosis (LCA) and retinitis pigmentosa type 12. The CRB1 transmembrane protein localizes at a subapical region (SAR) above intercellular adherens junctions between photoreceptor and Müller glia (MG) cells. We demonstrate that the Crb1-/- phenotype, as shown in Crb1-/- mice, is accelerated and intensified in primary retina cultures. Immuno-electron microscopy showed strong Crb1 immunoreactivity at the SAR in MG cells but barely in photoreceptor cells, whereas Crb2, Crb3, Patj, Pals1 and Mupp1 were present in both cell types. Human CRB1, introduced in MG cells in Crb1-/- primary retinas, was targeted to the SAR. RNA interference-induced silencing of the Crb1-interacting-protein Pals1 (protein associated with Lin7; Mpp5) in MG cells resulted in loss of Crb1, Crb2, Mupp1 and Veli3 protein localization and partial loss of Crb3. We conclude that Pals1 is required for correct localization of Crb family members and its interactors at the SAR of polarized MG cells.
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Affiliation(s)
- Agnes G S H van Rossum
- Department of Neuromedical Genetics, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
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Roberts MR, Srinivas M, Forrest D, Morreale de Escobar G, Reh TA. Making the gradient: thyroid hormone regulates cone opsin expression in the developing mouse retina. Proc Natl Acad Sci U S A 2006; 103:6218-23. [PMID: 16606843 PMCID: PMC1458858 DOI: 10.1073/pnas.0509981103] [Citation(s) in RCA: 201] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Most mammals have two types of cone photoreceptors, which contain either medium wavelength (M) or short wavelength (S) opsin. The number and spatial organization of cone types varies dramatically among species, presumably to fine-tune the retina for different visual environments. In the mouse, S- and M-opsin are expressed in an opposing dorsal-ventral gradient. We previously reported that cone opsin patterning requires thyroid hormone beta2, a nuclear hormone receptor that regulates transcription in conjunction with its ligand, thyroid hormone (TH). Here we show that exogenous TH inhibits S-opsin expression, but activates M-opsin expression. Binding of endogenous TH to TRbeta2 is required to inhibit S-opsin and to activate M-opsin. TH is symmetrically distributed in the retina at birth as S-opsin expression begins, but becomes elevated in the dorsal retina at the time of M-opsin onset (postnatal day 10). Our results show that TH is a critical regulator of both S-opsin and M-opsin, and suggest that a TH gradient may play a role in establishing the gradient of M-opsin. These results also suggest that the ratio and patterning of cone types may be determined by TH availability during retinal development.
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Affiliation(s)
- Melanie R. Roberts
- *Graduate Program in Neurobiology and Behavior and Department of Biological Structure, University of Washington, Box 357420, Seattle, WA 98195-7420
| | - Maya Srinivas
- Department of Human Genetics, Mount Sinai School of Medicine, 1425 Madison Avenue, New York, NY 10029
| | - Douglas Forrest
- National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD 20892; and
| | - Gabriella Morreale de Escobar
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Cientificas and Universidad Autonóma de Madrid, Arturo Duperier 4, 28029 Madrid, Spain
| | - Thomas A. Reh
- *Graduate Program in Neurobiology and Behavior and Department of Biological Structure, University of Washington, Box 357420, Seattle, WA 98195-7420
- To whom correspondence should be addressed. E-mail:
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Donovan M, Doonan F, Cotter TG. Decreased expression of pro-apoptotic Bcl-2 family members during retinal development and differential sensitivity to cell death. Dev Biol 2006; 291:154-69. [PMID: 16427039 DOI: 10.1016/j.ydbio.2005.12.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2005] [Revised: 11/22/2005] [Accepted: 12/09/2005] [Indexed: 11/21/2022]
Abstract
Apoptosis plays a crucial role in the sculpture of the mammalian retina during development. However, once the retina is fully differentiated, the emphasis must shift towards survival and mechanisms have to be put in place to prevent inappropriate cell death. In this study, we identify a potential control point at the level of mitochondrial permeability. We show that pro-apoptotic Bcl-2 family members known to be involved in the regulation of permeability transition and physiological cell death in the retina are down regulated during postnatal retinal development. In addition, we demonstrate an age-dependent susceptibility to retinal cell death induced by various stimuli known to target mitochondrion. These results potentially explain why retinal cells employ different death pathways depending on their stage of development. In contrast to developmental apoptosis, pathological retinal cell death in several animal models has been reported to occur independently of caspase activation. Here, we show that not only is cytochrome c release precluded from degenerating retinas but other pro-death molecules such as Omi/HtrA2 and AIF also remain in the mitochondrion. Our results indicate that transcriptional regulation of 'death genes' such as pro-apoptotic Bcl-2 family members during retinal development affords protection in adult post-mitotic neurons by preventing execution of the archetypal mitochondrial death pathway.
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Affiliation(s)
- Maryanne Donovan
- Cell Development and Disease Laboratory, Dept. of Biochemistry, Biosciences Institute, University College Cork, Ireland
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Curatola AM, Moscatelli D, Norris A, Hendricks-Munoz K. Retinal blood vessels develop in response to local VEGF-A signals in the absence of blood flow. Exp Eye Res 2005; 81:147-58. [PMID: 16011835 DOI: 10.1016/j.exer.2005.06.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The role of hemodynamic forces and other signals from circulating blood in guiding the development of the retinal vasculature was examined by following the growth of these vessels in organ cultures. Retinal vascular development in organ cultures was monitored by immunofluorescent staining of retinal whole-mounts using antibodies against ICAM-2, a specific marker for endothelial cells and by vascular adenosine disphosphatase activity. Under culture conditions, the retinal vasculature from mice at postnatal day 3 (P3) grew from the optic nerve area to the edge of the retina in a manner similar to that observed in vivo. Both inner and outer vascular plexuses formed in retinal explants. Within the first few days of organ culture, the initial uniform meshwork of blood vessels was reorganized into arterioles, venules, and capillaries. As in animals, the initial retinal vascular plexus contained abundant vessels, and afterward some vessels regressed leading to the formation of a mature vascular bed. Changes in vascular density due to blood vessel growth and remodeling were confirmed by RT-PCR and Western blot analyses of ICAM-2 mRNA and protein levels, respectively. In addition, during in vitro retinal vascularization, arterioles acquired mural cell coverage, as shown by positive staining for alpha-smooth muscle actin. Thus, blood flow and blood-derived signals were not required for the development and maturation of retinal vessels. In contrast, stability of blood vessels in retinal explants was tightly regulated by endogenous levels of vascular endothelial growth factor-A (VEGF-A). VEGF-A was expressed in the explants throughout the culture period, and addition of neutralizing antibodies against VEGF-A to the organ culture caused a severe regression of blood vessels from the vascular front toward the optic nerve. In contrast, addition of anti-FGF-2 antibodies had no effect on the developing vasculature. Thus, retinal vascular development is dependent on local VEGF-A signals rather than systemic signals.
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Affiliation(s)
- Anna Maria Curatola
- Department of Pediatrics, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA.
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41
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Engelsberg K, Johansson K, Ghosh F. Development of the embryonic porcine neuroretina in vitro. Ophthalmic Res 2005; 37:104-11. [PMID: 15746566 DOI: 10.1159/000084252] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2004] [Accepted: 09/13/2004] [Indexed: 11/19/2022]
Abstract
PURPOSE The objective of this study was to investigate the survival and morphology of embryonic porcine full-thickness neuroretina in culture. METHODS Porcine fetuses were taken out by cesarian section, and the eyes were enucleated. Neuroretinas were explanted on culture plate inserts and were kept for 0-42 days in vitro under standard culture conditions. Green nucleic acid (Sytox) was used for measuring the extent of cell death, and 4,6-diaminidine-2-phenylindoldihydrochloride was used as a marker for the cellular layers. The explants were examined as whole-mount preparations and vertical sections. Sectioned tissue was stained with hematoxylin-eosin and labeled for immunohistochemistry with photoreceptor-specific antibodies raised against transducin and recoverin. RESULTS In explants kept for 0-5 days in vitro, the developing retina consisted of multiple rows of neuroblastic cells and a more defined, but multilayered ganglion cell layer (GCL). Older explants revealed a more differentiated appearance with ultimately all normal retinal layers present, even after 42 days in vitro. Transducin- and recoverin-labeled photoreceptors were seen in these specimens, but no outer segments were found. The whole-mount preparation revealed extensively Sytox-labeled cells in the GCL at 2 days in vitro, but very few cells were labeled in older explants. CONCLUSION This study shows that cultured fetal porcine full-thickness neuroretina can survive and develop according to its intrinsic timetable for at least 6 weeks in vitro. The in vitro system for culturing of the full-thickness retina may be useful in experiments involving retinal transplantation.
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Affiliation(s)
- Karl Engelsberg
- Department of Ophthalmology, University Hospital, SE-22185 Lund, Sweden.
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42
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Ahuja P, Caffé AR, Ahuja S, Ekström P, van Veen T. Decreased glutathione transferase levels in rd1/rd1 mouse retina: Replenishment protects photoreceptors in retinal explants. Neuroscience 2005; 131:935-43. [PMID: 15749346 DOI: 10.1016/j.neuroscience.2004.11.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2004] [Indexed: 11/18/2022]
Abstract
Currently much attention is focused on glutathione S transferase (GST)-induced suppression of apoptosis. The objective of our studies was therefore to see if GST isoenzymes rescue photoreceptors in retinal explants from rd1/rd1 mice, in which photoreceptors degenerate rapidly. Eyes from C3H rd1/rd1 and +/+ mice were collected at various time points between postnatal day (PN) 2 and PN28. Localization and content of alpha-GST and mu-GST was investigated by immunofluorescence and semi-quantitative Western blot analysis, respectively. In addition, PN2 and PN7 retinal explants were cultured till PN28, during which they were treated with 10 ng/ml alpha-GST or mu-GST. The spatiotemporal expression of both GST isoforms was closely similar: early presence in ganglion cell layer after which staining became restricted to Muller cells (particularly in the endfeet) and horizontal cell fibers in both rd1/rd1 and +/+. Doublets of alpha-GST and mu-GST were detected by Western blot analysis. Densitometry of these bands indicated steady reduction of alpha-GST content in rd1/rd1 retina starting from the second postnatal week. When alpha-GST and mu-GST were added exogenously to rd1/rd1 explants, photoreceptor rescue was produced that was more prominent in PN2 than in PN7 explants and more effective by alpha-GST than mu-GST. We propose that alpha-GST neuroprotection is mediated by reduction of tissue oxidative stress.
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Affiliation(s)
- P Ahuja
- Wallenberg Retina Centre, Department of Ophthalmology, Lund University, BMC-B13, Klinikgatan 26, Lund 221 84, Sweden
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43
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de Melo J, Du G, Fonseca M, Gillespie LA, Turk WJ, Rubenstein JLR, Eisenstat DD. Dlx1 and Dlx2 function is necessary for terminal differentiation and survival of late-born retinal ganglion cells in the developing mouse retina. Development 2004; 132:311-22. [PMID: 15604100 DOI: 10.1242/dev.01560] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Dlx homeobox genes, the vertebrate homologs of Distal-less, play important roles in the development of the vertebrate forebrain, craniofacial structures and limbs. Members of the Dlx gene family are also expressed in retinal ganglion cells (RGC), amacrine and horizontal cells of the developing and postnatal retina. Expression begins at embryonic day 12.5 and is maintained until late embryogenesis for Dlx1, while Dlx2 expression extends to adulthood. We have assessed the retinal phenotype of the Dlx1/Dlx2 double knockout mouse, which dies at birth. The Dlx1/2 null retina displays a reduced ganglion cell layer (GCL), with loss of differentiated RGCs due to increased apoptosis, and corresponding thinning of the optic nerve. Ectopic expression of Crx, the cone and rod photoreceptor homeobox gene, in the GCL and neuroblastic layers of the mutants may signify altered cell fate of uncommitted RGC progenitors. However, amacrine and horizontal cell differentiation is relatively unaffected in the Dlx1/2 null retina. Herein, we propose a model whereby early-born RGCs are Dlx1 and Dlx2 independent, but Dlx function is necessary for terminal differentiation of late-born RGC progenitors.
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Affiliation(s)
- Jimmy de Melo
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, R3E 3J7, Canada
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44
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Coles BLK, Angénieux B, Inoue T, Del Rio-Tsonis K, Spence JR, McInnes RR, Arsenijevic Y, van der Kooy D. Facile isolation and the characterization of human retinal stem cells. Proc Natl Acad Sci U S A 2004; 101:15772-7. [PMID: 15505221 PMCID: PMC524825 DOI: 10.1073/pnas.0401596101] [Citation(s) in RCA: 284] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
This study identifies and characterizes retinal stem cells (RSCs) in early postnatal to seventh-decade human eyes. Different subregions of human eyes were dissociated and cultured by using a clonal sphere-forming assay. The stem cells were derived only from the pars plicata and pars plana of the retinal ciliary margin, at a frequency of approximately 1:500. To test for long-term self-renewal, both the sphere assay and monolayer passaging were used. By using the single sphere passaging assay, primary spheres were dissociated and replated, and individual spheres demonstrated 100% self-renewal, with single spheres giving rise to one or more new spheres in each subsequent passage. The clonal retinal spheres were plated under differentiation conditions to assay the differentiation potential of their progeny. The spheres were produced all of the different retinal cell types, demonstrating multipotentiality. Therefore, the human eye contains a small population of cells (approximately equal to 10,000 cells per eye) that have retinal stem-cell characteristics (proliferation, self-renewal, and multipotentiality). To test the in vivo potential of the stem cells and their progeny, we transplanted dissociated human retinal sphere cells, containing both stem cells and progenitors, into the eyes of postnatal day 1 NOD/SCID mice and embryonic chick eyes. The progeny of the RSCs were able to survive, migrate, integrate, and differentiate into the neural retina, especially as photoreceptors. Their facile isolation, integration, and differentiation suggest that human RSCs eventually may be valuable in treating human retinal diseases.
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Affiliation(s)
- Brenda L K Coles
- Departments of Medical Genetics and Microbiology, University of Toronto, 1 Kings College Circle, Toronto, Ontario, Canada M5S 1A8
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Pang J, Cheng M, Stevenson D, Trousdale MD, Dorey CK, Blanks JC. Adenoviral-mediated gene transfer to retinal explants during development and degeneration. Exp Eye Res 2004; 79:189-201. [PMID: 15325566 DOI: 10.1016/j.exer.2004.03.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2003] [Accepted: 03/18/2004] [Indexed: 10/26/2022]
Abstract
Naturally occurring mutations of the beta subunit of the cyclic guanosine monophosphate (cGMP) phosphodiesterase (beta-PDE) gene in rod photoreceptors of mice and dogs are similar to one of the inherited retinal degenerations termed retinitis pigmentosa in humans. Defects in the rod beta-PDE gene leading to photoreceptor cell degeneration in retinal degenerative (rd) mice can be corrected by transfer of a wild type beta-PDE gene. However, the rapid photoreceptor degeneration in this mutant makes the study of gene therapy difficult. Since the retinal degeneration is slowed in vitro, we have employed retinal explants from rd mice to study factors influencing viral transduction. Retinal explants provide a rapid, efficient method to compare the transduction efficiency of adenoviral vector-mediated reporter gene delivery at different ages in normal and rd mice. Retinal explants from postnatal day (P)2 to P28 control (C57BL/6J) and P2-P42 rd mice were exposed for 20 hr to 2.5 x 10(8) plaque forming units (pfu) ml(-1) of adenoviral vector with a beta-galactosidase (Lac Z) reporter gene (Ad-CMV-Lac Z). After incubation in vector-free media for an additional 3 days, the explants were fixed and histochemically stained for beta-galactosidase to reveal Lac Z gene expression. The explants were also embedded and sectioned for light microscopic observation. Transduction efficiency was higher in rd mice than in controls on all postnatal days examined. In normal retinal explants, expression of the Lac Z gene increased from P2 to a peak around P7-P8, then decreased at subsequent ages; little transduction could be found after P17. In rd mice transduction efficiency of Ad-CMV-Lac Z increased from P2 to P7, decreased by P10 and increased again after P10. The most dramatic increase in the transduction efficiency occurred in the rd retina between P10 and P15 when Lac Z was intensely expressed throughout the retina. Microscopic examination of retinal sections revealed the types and distribution of Lac Z-positive cells responsible for the deep blue staining in the retinal whole mount. In normal and rd mice, Lac Z-positive cells were located throughout the retina. However, larger numbers of Lac Z-positive cells were present at all ages examined in retinal explants from rd mice compared to normal mice. These data indicate a difference in transduction efficiency between normal and rd mice, especially after P12, and suggest efficient adenovirus-mediated gene transfer is more attainable in developing or degenerating retina. Thus, transduction efficiency in rd mice depends on the relationship between development, maturation and the degenerative state of the photoreceptor cells.
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Affiliation(s)
- Jijing Pang
- Eye Research Institute, Oakland University, 422 Dodge Hall, Rochester, MI 48309-4480, USA
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46
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Jablonski MM. The intact Xenopus laevis eye rudiment: a quasi-in vivo system for the study of retinal development and degenerations. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 533:189-96. [PMID: 15180264 DOI: 10.1007/978-1-4615-0067-4_24] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Affiliation(s)
- Monica M Jablonski
- Department of Ophthalmology, University of Tennessee Health Science Center, 956 Court Avenue, Suite D228, Memphis, TN 38163, USA.
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Saito K, Kawaguchi A, Kashiwagi S, Yasugi S, Ogawa M, Miyata T. Morphological asymmetry in dividing retinal progenitor cells. Dev Growth Differ 2003; 45:219-29. [PMID: 12828683 DOI: 10.1046/j.1524-4725.2003.690.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
For the understanding of histogenetic events in the 3-D retinal neuroepithelium, direct observation of the progenitor cells and their morphological changes is required. A slice culture method has been developed by which the behavior of single progenitor cells can be monitored. Although it has been believed that each retinal progenitor cell loses its basal process while it is in M phase, it is reported here that the process is retained throughout M phase and is inherited by one daughter cell, which can be a neuron or a progenitor cell. Daughter neurons used an inherited process for neuronal translocation and positioning. In divisions that produced two mitotic daughters, both of which subsequently divided to form four granddaughter cells, only one daughter cell inherited the original basal process while the other extended a new process. Interestingly, behavioral differences were often noted between such mitotic sisters in the trajectory of interkinetic nuclear movement, cell cycle length, and the composition of the granddaughter pair. Therefore, "symmetric" (progenitor --> progenitor + progenitor) divisions are in fact morphologically asymmetric, and the behavior of the mitotic daughters can often be asymmetric, indicating the necessity for studying possible associations between the process inheritance and the cell fate choice.
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Affiliation(s)
- Kanako Saito
- Laboratory for Cell Culture Development, Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan
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48
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Abstract
Neural retina can be isolated from mouse embryos and maintained in culture for 2-3 weeks. In such retinal explant cultures, precursor cells differentiate into neurons and glial cells and form three cellular layers, mimicking well the normal development. This explant culture system is suitable for genetic manipulation, such as retrovirus-mediated gene transfer. Retroviral vectors can efficiently transfer genes into retinal precursors, and the copy of the viral genome is precisely transmitted to the progeny of infected cells. Thus, this is an excellent method to change stably the phenotypes of dividing cells. It has been shown that retroviruses carrying transcription factor genes efficiently change the fates of infected cells. Bicistronic expression by retroviral vectors is useful to test the effects of various combinations of many transcription factors. With this method, the transcriptional codes for retinal cell type specification are now being elucidated. Thus, retrovirus-mediated gene transfer to the retinal explant culture system offers a powerful and unique tool to analyze the molecular mechanism of neural development.
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Akita J, Takahashi M, Hojo M, Nishida A, Haruta M, Honda Y. Neuronal differentiation of adult rat hippocampus-derived neural stem cells transplanted into embryonic rat explanted retinas with retinoic acid pretreatment. Brain Res 2002; 954:286-93. [PMID: 12414111 DOI: 10.1016/s0006-8993(02)03356-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The purpose of this study was to evaluate the effects of the retinal environment and retinoic acid (RA) pretreatment on the differentiation of transplanted adult rat hippocampus-derived neural stem cells (AHSCs). AHSCs were transplanted into embryonic (E18) or neonatal (P6) rat retinal explants and the mixture was cultured for 2 weeks. Other AHSCs were stimulated by 0.5 microM all-trans RA for 6 days before transplantation. Immunofluorescent double staining showed that a larger number of AHSCs became beta-tubulin III-positive neurons in the E18 than in P6 retinas. In addition, many AHSCs became MAP2ab-positive and MAP5-positive neurons following RA pretreatment and transplantation. Only a few AHSCs became HPC-1-, calbindin-, PKC- or rhodopsin-positive cells under these conditions. We conclude that the microenvironment supplied by embryonic retinas is conductive to neuronal differentiation in general. RA stimulation before transplantation was also effective in stimulating differentiation.
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Affiliation(s)
- Joe Akita
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan
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50
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Winkler J, Hagelstein S, Rohde M, Laqua H. Cellular and cytoskeletal dynamics within organ cultures of porcine neuroretina. Exp Eye Res 2002; 74:777-88. [PMID: 12126951 DOI: 10.1006/exer.2002.1188] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to establish a retinal organ culture and to follow the cellular and cytoskeletal changes. For this purpose the authors detached porcine neuroretinas from the underlying pigment epithelium, and incubated them for 2 weeks under standardized conditions. After 3, 6, 10, and 13 days in culture the retinal tissues were fixed, embedded in LR-White resin or paraffin wax and processed for electron-, light-, immunofluorescence- and confocal laser scanning microscopy. Antibodies directed against alpha-tubulin, actin, glial fibrillary acidic protein (GFAP), vimentin, neurofilament(200) and beta-catenin were used to investigate the cytoskeletal changes over a certain period of time. After experimental detachment Müller cells quickly started to hypertrophy showing increased levels of intermediate filaments (i.e. vimentin and GFAP). The actin labelling of photoreceptor cells decreased concomitantly with a rapid degeneration of the outer segments. After 1 week of detachment the Müller cell cytoplasm revealed increasing amounts of actin and tubulin staining. Actin filaments appeared frequently organized in thick bundles across the full width of the retina, whereas increasing levels of tubulin shifted into the outer nuclear region especially concentrated near the outer limiting membrane. A prolonged time of explant culturing resulted in a discontinuous staining of beta-catenin along the adherent junctions of the outer limiting membrane, followed by an outgrowth of Müller cell extensions into the subretinal space. Double staining of tubulin and cones showed that this outgrowth predominantly occurred between cone inner segments. The outer limiting membrane was penetrated by stalk-like structures, highly enriched with tubulin and associated with swollen tips, reaching into the subretina. Electron microscopy demonstrated in detail the focal disruption of the outer limiting membrane by Müller cell extensions and subsequent subretinal gliosis. The cytoskeletal reactions described here were compared with degenerative changes observed after induced retinal detachments.
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Affiliation(s)
- Jörg Winkler
- Department of Experimental Ophthalmology, Medical University of Lübeck, D-23538, Lübeck, Germany.
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