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Lamb WDB, Eastlake K, Luis J, Sharif NA, Khaw PT, Limb GA. MicroRNA profile of extracellular vesicles released by Müller glial cells. Front Cell Neurosci 2024; 17:1325114. [PMID: 38303973 PMCID: PMC10832456 DOI: 10.3389/fncel.2023.1325114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/15/2023] [Indexed: 02/03/2024] Open
Abstract
Introduction As with any other radial glia in the central nervous system, Müller glia derive from the same neuroepithelial precursors, perform similar functions, and exhibit neurogenic properties as radial glia in the brain. Müller glial cells retain progenitor-like characteristics in the adult human eye and can partially restore visual function upon intravitreal transplantation into animal models of glaucoma. Recently, it has been demonstrated that intracellular communication is possible via the secretion of nano-sized membrane-bound extracellular vesicles (EV), which contain bioactive molecules like microRNA (miRNA) and proteins that induce phenotypic changes when internalised by recipient cells. Methods We conducted high-throughput sequencing to profile the microRNA signature of EV populations secreted by Müller glia in culture and used bioinformatics tools to evaluate their potential role in the neuroprotective signalling attributed to these cells. Results Sequencing of miRNA within Müller EV suggested enrichment with species associated with stem cells such as miR-21 and miR-16, as well as with miRNA previously found to play a role in diverse Müller cell functions in the retina: miR-9, miR-125b, and the let-7 family. A total of 51 miRNAs were found to be differentially enriched in EV compared to the whole cells from which EV originated. Bioinformatics analyses also indicated that preferential enrichment of species was demonstrated to regulate genes involved in cell proliferation and survival, including PTEN, the master inhibitor of the PI3K/AKT pathway. Discussion The results suggest that the release by Müller cells of miRNA-enriched EV abundant in species that regulate anti-apoptotic signalling networks is likely to represent a significant proportion of the neuroprotective effect observed after the transplantation of these cells into animal models of retinal ganglion cell (RGC) depletion. Future studies will seek to evaluate the modulation of putative genes as well as the activation of these pathways in in vitro and in vivo models following the internalisation of Müller-EV by target retinal neurons.
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Affiliation(s)
- William D. B. Lamb
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
| | - Karen Eastlake
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
| | - Joshua Luis
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
| | - Najam A. Sharif
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
- Department of Global Alliances and Collaboration, Global Ophthalmology Research and Development, Santen Inc., Emeryville, CA, United States
| | - Peng T. Khaw
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
| | - G. Astrid Limb
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom
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Abstract
Glaucomatous optic neuropathy (GON) is the major cause of irreversible visual loss worldwide and can result from a range of disease etiologies. The defining features of GON are retinal ganglion cell (RGC) degeneration and characteristic cupping of the optic nerve head (ONH) due to tissue remodeling, while intraocular pressure remains the only modifiable GON risk factor currently targeted by approved clinical treatment strategies. Efforts to understand the mechanisms that allow species such as the zebrafish to regenerate their retinal cells have greatly increased our understanding of regenerative signaling pathways. However, proper integration within the retina and projection to the brain by the newly regenerated neuronal cells remain major hurdles. Meanwhile, a range of methods for in vitro differentiation have been developed to derive retinal cells from a variety of cell sources, including embryonic and induced pluripotent stem cells. More recently, there has been growing interest in the implantation of glial cells as well as cell-derived products, including neurotrophins, microRNA, and extracellular vesicles, to provide functional support to vulnerable structures such as RGC axons and the ONH. These approaches offer the advantage of not relying upon the replacement of degenerated cells and potentially targeting earlier stages of disease pathogenesis. In order to translate these techniques into clinical practice, appropriate cell sourcing, robust differentiation protocols, and accurate implantation methods are crucial to the success of cell-based therapy in glaucoma. Translational Relevance: Cell-based therapies for glaucoma currently under active development include the induction of endogenous regeneration, implantation of exogenously derived retinal cells, and utilization of cell-derived products to provide functional support.
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Affiliation(s)
- Joshua Luis
- NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology & Moorfields Eye Hospital, London, UK
| | - Karen Eastlake
- NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology & Moorfields Eye Hospital, London, UK
| | - William D. B. Lamb
- NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology & Moorfields Eye Hospital, London, UK
| | - G. Astrid Limb
- NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology & Moorfields Eye Hospital, London, UK
| | - Hari Jayaram
- NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology & Moorfields Eye Hospital, London, UK
| | - Peng T. Khaw
- NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology & Moorfields Eye Hospital, London, UK
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Eastlake K, Luis J, Wang W, Lamb W, Khaw PT, Limb GA. Transcriptomics of CD29 +/CD44 + cells isolated from hPSC retinal organoids reveals a single cell population with retinal progenitor and Müller glia characteristics. Sci Rep 2023; 13:5081. [PMID: 36977817 PMCID: PMC10050419 DOI: 10.1038/s41598-023-32058-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 03/21/2023] [Indexed: 03/30/2023] Open
Abstract
Müller glia play very important and diverse roles in retinal homeostasis and disease. Although much is known of the physiological and morphological properties of mammalian Müller glia, there is still the need to further understand the profile of these cells during human retinal development. Using human embryonic stem cell-derived retinal organoids, we investigated the transcriptomic profiles of CD29+/CD44+ cells isolated from early and late stages of organoid development. Data showed that these cells express classic markers of retinal progenitors and Müller glia, including NFIX, RAX, PAX6, VSX2, HES1, WNT2B, SOX, NR2F1/2, ASCL1 and VIM, as early as days 10-20 after initiation of retinal differentiation. Expression of genes upregulated in CD29+/CD44+ cells isolated at later stages of organoid development (days 50-90), including NEUROG1, VSX2 and ASCL1 were gradually increased as retinal organoid maturation progressed. Based on the current observations that CD24+/CD44+ cells share the characteristics of early and late-stage retinal progenitors as well as of mature Müller glia, we propose that these cells constitute a single cell population that upon exposure to developmental cues regulates its gene expression to adapt to functions exerted by Müller glia in the postnatal and mature retina.
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Affiliation(s)
- Karen Eastlake
- NIHR Biomedical Research Centre at Moorfields Eye Hospital, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
| | - Joshua Luis
- NIHR Biomedical Research Centre at Moorfields Eye Hospital, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Weixin Wang
- NIHR Biomedical Research Centre at Moorfields Eye Hospital, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
| | - William Lamb
- NIHR Biomedical Research Centre at Moorfields Eye Hospital, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
| | - Peng T Khaw
- NIHR Biomedical Research Centre at Moorfields Eye Hospital, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK
| | - G Astrid Limb
- NIHR Biomedical Research Centre at Moorfields Eye Hospital, UCL Institute of Ophthalmology, 11-43 Bath Street, London, EC1V 9EL, UK.
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Salimiaghdam N, Singh L, Schneider K, Chwa M, Atilano SR, Nalbandian A, Limb GA, Kenney MC. Effects of fluoroquinolones and tetracyclines on mitochondria of human retinal MIO-M1 cells. Exp Eye Res 2022; 214:108857. [PMID: 34856207 PMCID: PMC9949354 DOI: 10.1016/j.exer.2021.108857] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 10/25/2021] [Accepted: 11/17/2021] [Indexed: 01/26/2023]
Abstract
Our goal was to explore the detrimental impacts of ciprofloxacin (CPFX) and tetracycline (TETRA) on human retinal Müller (MIO-M1) cells in vitro. Cells were exposed to 30, 60 and 120 μg/ml of CPFX and TETRA. The cellular metabolism was measured with the MTT assay. The JC-1 and CM-H2DCFDA assays were used to evaluate the levels of mitochondrial membrane potential (MMP) and ROS (reactive oxygen species), respectively. Mitochondrial DNA (mtDNA) copy number, along with gene expression levels associated with apoptotic (BAX, BCL2-L13, BCL2, CASP-3 and CASP-9), inflammatory (IL-6, IL-1β, TGF-α, TGF-β1 and TGF-β2) and antioxidant pathways (SOD2, SOD3, GPX3 and NOX4) were analyzed via Quantitative Real-Time PCR (qRT-PCR). Bioenergetic profiles were measured using the Seahorse® XF Flux Analyzer. Cells exposed 24 h to 120 μg/ml TETRA demonstrated higher cellular metabolism compared to vehicle-treated cells. At each time points, (i) all TETRA concentrations reduced MMP levels and (ii) ROS levels were reduced by TETRA 120 μg/ml treatment. TETRA caused (i) higher expression of CASP-3, CASP-9, TGF-α, IL-1B, GPX3 and SOD3 but (ii) decreased levels of TGF-B2 and SOD2. ATP production and spare respiratory capacity declined with TETRA treatment. Cellular metabolism was reduced with CPFX 120 μg/ml in all cultures and 60 μg/ml after 72 h. The CPFX 120 μg/ml reduced MMP in all cultures and ROS levels (72 h). CPFX treatment (i) increased expression of CASP-3, CASP-9, and BCL2-L13, (ii) elevated the basal oxygen consumption rate, and (iii) lowered the mtDNA copy numbers and expression levels of TGF-B2, IL-6 and IL-1B compared to vehicle-control cells. We conclude that clinically relevant dosages of bactericidal and bacteriostatic antibiotics can have negative effects on the cellular metabolism and mitochondrial membrane potential of the retinal MIO-M1 cells in vitro. It is noteworthy to mention that apoptotic and inflammatory pathways in exposed cells were affected significantly This is the first study showing the negative impact of fluoroquinolones and tetracyclines on mitochondrial behavior of human retinal MIO-M1 cells.
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Affiliation(s)
- Nasim Salimiaghdam
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, 92697, USA
| | - Lata Singh
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, 92697, USA; Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, India
| | - Kevin Schneider
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, 92697, USA
| | - Marilyn Chwa
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, 92697, USA
| | - Shari R Atilano
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, 92697, USA
| | - Angele Nalbandian
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, 92697, USA
| | - G Astrid Limb
- Institute of Ophthalmology, University College, London, United Kingdom
| | - M Cristina Kenney
- Department of Ophthalmology, Gavin Herbert Eye Institute, University of California Irvine, Irvine, CA, 92697, USA; Department of Pathology and Laboratory Medicine, University of California Irvine, Irvine, CA, 92697, USA.
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Eastlake K, Jayaram H, Luis J, Hayes M, Khaw PT, Limb GA. Strain Specific Responses in a Microbead Rat Model of Experimental Glaucoma. Curr Eye Res 2021; 46:387-397. [PMID: 32842792 PMCID: PMC8025805 DOI: 10.1080/02713683.2020.1805472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/13/2020] [Accepted: 07/23/2020] [Indexed: 11/15/2022]
Abstract
PURPOSE A major challenge in glaucoma research is the lack of reproducible animal models of RGC and optic nerve damage, the characteristic features of this condition. We therefore examined the glaucomatous responses of two different rat strains, the Brown Norway (BN) and Lister Hooded (LH) rats, to high intraocular pressure (IOP) induced by injection of magnetic beads into the anterior chamber. METHODS Magnetic microsphere suspensions (20 µl of 5-20 mg/ml) were injected into the anterior chamber of BN (n = 9) or LH (N = 15) rats. Animals from each strain were divided into three groups, each receiving a different dose of microspheres. IOP was measured over 4 weeks using a rebound tonometer. Retinal ganglion cell (RGC) damage and function were assessed using scotopic electroretinograms (ERGs), retinal flatmounts and optic nerve histology. ANOVA and Student's t-tests were used to analyse the data. RESULTS A significant elevation in IOP was observed in BN rats receiving injections of 20 mg (37.18 ± 12.28 mmHg) or 10 mg microspheres/ml (36.95 ± 13.63 mmHg) when compared with controls (19.63 ± 4.29 mmHg) (p < .001) over 2 weeks. This correlated with a significant impairment of RGC function, as determined by scotopic ERG (p < .001), reduction in axon number (p < .05) and lower RGC density (P < .05) in animals receiving 20 mg or 10 mg microspheres/ml as compared with controls. LH rats receiving similar microsphere doses showed reduced scotopic ERG function (p < .001) after 2 weeks. No changes in IOP was seen in this strain, although a reduction in axon density was observed in optic nerve cross-sections (p < .05). Initial changes in IOP and ERG responses observed in BN rats remained unchanged for a duration of 7 weeks. In LH animals, ERG responses were decreased at 1-2 weeks and returned to control levels after 5 weeks. CONCLUSIONS Although this model was easily reproducible in BN rats, the phenotype of injury observed in LH rats was very different from that observed in BN animals. We suggest that differences in the glaucomatous response observed in these two strains may be ascribed to anatomical and physiological differences and merits further investigation.
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Affiliation(s)
- Karen Eastlake
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - Hari Jayaram
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - Joshua Luis
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - Matthew Hayes
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - Peng T. Khaw
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
| | - G. Astrid Limb
- NIHR Biomedical Research Centre at Moorfields, Eye Hospitaland UCL Institute of Ophthalmology, London, UK
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Luis J, Eastlake K, Khaw PT, Limb GA. Galectins and their involvement in ocular disease and development. Exp Eye Res 2020; 197:108120. [PMID: 32565112 DOI: 10.1016/j.exer.2020.108120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 05/25/2020] [Accepted: 06/15/2020] [Indexed: 12/27/2022]
Abstract
Galectins are carbohydrate binding proteins with high affinity to ß-galactoside containing glycoconjugates. Understanding of the functions of galectins has grown steadily over the past decade, as a result of substantial advancements in the field of glycobiology. Galectins have been shown to be versatile molecules that participate in a range of important biological systems, including inflammation, neovascularisation and fibrosis. These processes are of particular importance in ocular tissues, where a major theme of recent research has been to divert diseases away from pathways which result in loss of function into pathways of repair and regeneration. This review summarises our current understanding of galectins in the context important ocular diseases, followed by an update on current clinical studies and future directions.
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Affiliation(s)
- Joshua Luis
- National Institute for Health Research (NIHR), Biomedical Research Centre at Moorfields Eye Hospital, NHS Foundation Trust, UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom.
| | - Karen Eastlake
- National Institute for Health Research (NIHR), Biomedical Research Centre at Moorfields Eye Hospital, NHS Foundation Trust, UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom
| | - Peng T Khaw
- National Institute for Health Research (NIHR), Biomedical Research Centre at Moorfields Eye Hospital, NHS Foundation Trust, UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom
| | - G Astrid Limb
- National Institute for Health Research (NIHR), Biomedical Research Centre at Moorfields Eye Hospital, NHS Foundation Trust, UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom
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Nweze M, Baker T, Limb GA, Shipley RJ. Insights into the design of spray systems for cell therapies for retinal disease using computational modelling. Math Biosci Eng 2020; 17:2741-2759. [PMID: 32233564 DOI: 10.3934/mbe.2020150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Chronic eye diseases are the main cause of vision loss among adults. Among these, retinal degenerative diseases affect millions of people globally, causing permanent loss of cells and organ dysfunction. Despite recent progress in developing stem cell therapies for retinal diseases, methods for delivery remain an area of intense research. Aerosol technology is a promising technique with the potential to spray cells evenly and directly across the retinal surface, promoting cell attachment and survival. Here we implement mathematical modelling of the spraying process to develop organ-specific spraying parameters in this therapeutic scenario. Firstly, we characterise the rheological parameters for a typical hydrogel used for spraying cells. These parameters are then integrated into a 3D computational model of an adult human eye under realistic surgical conditions. Simulation results provide quantitative relationships between the volume flow rate of the cell-laden hydrogel, external pressure needed for aerosolization, angle of the spraying, and properties of the cell delivery. An experimental assessment is also carried out to explore the impact of spraying under the regimes identified by the computational model on cell viability. This is the first stage towards using computational models to inform the design of spray systems to deliver cell therapies onto the human retina.
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Affiliation(s)
- Miriam Nweze
- Department of Mechanical Engineering, University College London, UK
- Institute of Healthcare Engineering, University College London, UK
| | - Tim Baker
- Department of Mechanical Engineering, University College London, UK
| | - G Astrid Limb
- Institute of Ophthalmology, University College London, UK
| | - Rebecca J Shipley
- Department of Mechanical Engineering, University College London, UK
- Institute of Healthcare Engineering, University College London, UK
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Abstract
Müller glia constitute the main glial cells of the retina. They are spatially distributed along this tissue, facilitating their close membrane interactions with all retinal neurons. Müller glia are characterized by their active metabolic functions, which are neuroprotective in nature. Although they can become reactive under pathological conditions, leading to their production of inflammatory and neurotoxic factors, their main metabolic functions confer neuroprotection to the retina, resulting in the promotion of neural cell repair and survival. In addition to their protective metabolic features, Müller glia release several neurotrophic factors and antioxidants into the retinal microenvironment, which are taken up by retinal neurons for their survival. This review summarizes the Müller glial neuroprotective mechanisms and describes advances made on the clinical application of these factors for the treatment of retinal degenerative diseases. It also discusses prospects for the use of these cells as a vehicle to deliver neuroprotective factors into the retina.
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Affiliation(s)
- Karen Eastlake
- UCL Institute of Ophthalmology and NIHR Biomedical Research Centre at Moorfields Eye Hospital, London, UK
| | - Joshua Luis
- UCL Institute of Ophthalmology and NIHR Biomedical Research Centre at Moorfields Eye Hospital, London, UK
| | - G Astrid Limb
- UCL Institute of Ophthalmology and NIHR Biomedical Research Centre at Moorfields Eye Hospital, London, UK
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Cáceres-Del-Carpio J, Moustafa MT, Toledo-Corral J, Hamid MA, Atilano SR, Schneider K, Fukuhara PS, Costa RD, Norman JL, Malik D, Chwa M, Boyer DS, Limb GA, Kenney MC, Kuppermann BD. In vitro response and gene expression of human retinal Müller cells treated with different anti-VEGF drugs. Exp Eye Res 2020; 191:107903. [PMID: 31904361 PMCID: PMC7058176 DOI: 10.1016/j.exer.2019.107903] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 11/18/2019] [Accepted: 12/23/2019] [Indexed: 12/14/2022]
Affiliation(s)
| | - M Tarek Moustafa
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA
| | | | - Mohamed A Hamid
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA
| | - Shari R Atilano
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA
| | - Kevin Schneider
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA
| | - Paula S Fukuhara
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA
| | | | - J Lucas Norman
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA
| | - Deepika Malik
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA
| | - David S Boyer
- Retina-Vitreous Associates Medical Group, Los Angeles, CA, USA
| | - G Astrid Limb
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, UK
| | - M Cristina Kenney
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA; Department of Pathology and Laboratory Medicine, University of California, Irvine, CA, USA.
| | - Baruch D Kuppermann
- Gavin Herbert Eye Institute, University of California, Irvine, CA, USA; Department of Biomedical Engineering, University of California, Irvine, USA
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Eastlake K, Wang W, Jayaram H, Murray‐Dunning C, Carr AJF, Ramsden CM, Vugler A, Gore K, Clemo N, Stewart M, Coffey P, Khaw PT, Limb GA. Phenotypic and Functional Characterization of Müller Glia Isolated from Induced Pluripotent Stem Cell-Derived Retinal Organoids: Improvement of Retinal Ganglion Cell Function upon Transplantation. Stem Cells Transl Med 2019; 8:775-784. [PMID: 31037833 PMCID: PMC6646702 DOI: 10.1002/sctm.18-0263] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 03/22/2019] [Indexed: 12/25/2022] Open
Abstract
Glaucoma is one of the leading causes of blindness, and there is an ongoing need for new therapies. Recent studies indicate that cell transplantation using Müller glia may be beneficial, but there is a need for novel sources of cells to provide therapeutic benefit. In this study, we have isolated Müller glia from retinal organoids formed by human induced pluripotent stem cells (hiPSCs) in vitro and have shown their ability to partially restore visual function in rats depleted of retinal ganglion cells by NMDA. Based on the present results, we suggest that Müller glia derived from retinal organoids formed by hiPSC may provide an attractive source of cells for human retinal therapies, to prevent and treat vision loss caused by retinal degenerative conditions. Stem Cells Translational Medicine 2019;8:775&784.
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Affiliation(s)
- Karen Eastlake
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | - Weixin Wang
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | - Hari Jayaram
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | - Celia Murray‐Dunning
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | - Amanda J. F. Carr
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | - Conor M. Ramsden
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | - Anthony Vugler
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | | | | | - Mark Stewart
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | - Pete Coffey
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | - Peng T. Khaw
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
| | - G. Astrid Limb
- NIHR Biomedical Research CentreUCL Institute of Ophthalmology and Moorfields Eye HospitalLondonUnited Kingdom
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Eastlake K, Heywood WE, Banerjee P, Bliss E, Mills K, Khaw PT, Charteris D, Limb GA. Comparative proteomic analysis of normal and gliotic PVR retina and contribution of Müller glia to this profile. Exp Eye Res 2018; 177:197-207. [PMID: 30176221 PMCID: PMC6280037 DOI: 10.1016/j.exer.2018.08.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/07/2018] [Accepted: 08/20/2018] [Indexed: 12/21/2022]
Abstract
Müller glia are responsible for the neural retina regeneration observed in fish and amphibians throughout life. Despite the presence of these cells in the adult human retina, there is no evidence of regeneration occurring in humans following disease or injury. It may be possible that factors present in the degenerated retina could prevent human Müller glia from proliferating and neurally differentiating within the diseased retina. On this basis, investigations into the proteomic profile of these cells and the abundance of key proteins associated to Müller glia in the gliotic PVR retina, may assist in the identification of factors with the potential to control Müller proliferation and neural differentiation in vivo. Label free mass spectrometry identified 1527 proteins in Müller glial cell preparations, 1631 proteins in normal retina and 1074 in gliotic PVR retina. Compared to normal retina, 28 proteins were upregulated and 196 proteins downregulated by 2-fold or more in the gliotic PVR retina. As determined by comparative proteomic analyses, of the proteins highly upregulated in the gliotic PVR retina, the most highly abundant proteins in Müller cell lysates included vimentin, GFAP, polyubiquitin and HSP90a. The observations that proteins highly upregulated in the gliotic retina constitute major proteins expressed by Müller glia provide the basis for further studies into mechanisms that regulate their production. In addition investigations aimed at controlling the expression of these proteins may aid in the identification of factors that could potentially promote endogenous regeneration of the adult human retina after disease or injury. Proteomic analyses showed evidence for Müller glia contribution to retinal gliosis. Polyubiquitin-C and HSP90a produced by Müller glia, are upregulated in gliotic retina. Müller glia are a source of prelamin, elongation factor and serpin found in retina.
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Affiliation(s)
- Karen Eastlake
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| | - Wendy E Heywood
- Centre for Translational Omics, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Phillip Banerjee
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| | - Emily Bliss
- Centre for Translational Omics, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Kevin Mills
- Centre for Translational Omics, UCL Great Ormond Street Institute of Child Health, London, UK
| | - Peng T Khaw
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| | - David Charteris
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
| | - G Astrid Limb
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK.
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12
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Petrou P, Banerjee PJ, Wilkins MR, Singh M, Eastlake K, Limb GA, Charteris DG. Characteristics and vitreoretinal management of retinal detachment in eyes with Boston keratoprosthesis. Br J Ophthalmol 2017; 101:629-633. [PMID: 27565989 DOI: 10.1136/bjophthalmol-2016-308854] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 07/28/2016] [Accepted: 07/30/2016] [Indexed: 11/03/2022]
Abstract
PURPOSE To review the incidence and features of vitreoretinal complications of a permanent Boston keratoprosthesis and to report the use and outcomes of 23-gauge vitrectomy to manage vitreoretinal pathology. DESIGN Retrospective non-comparative, interventional case series. SUBJECT, PARTICIPANTS 27 eyes of 27 patients managed with a Boston keratoprosthesis at Moorfields Eye Hospital over a 3-year period. METHODS All eyes that underwent pars plana vitrectomy (PPV) and had at least 6 months follow-up were analysed with a specific focus on the anatomical and histological characteristics of retinal detachment and outcomes of surgery. MAIN OUTCOME MEASURES Anatomical success and characteristics of retinal detachment over the follow-up period. RESULTS 27 patients underwent Boston keratoprosthesis implantation over the study period. Of these, six (22%) required PPV for retinal detachment which demonstrated a specific pattern of serous elevation with subsequent severe anterior proliferative vitreoretinopathy (PVR). The mean follow-up period was 9 months (range 6-14 months). At final follow-up, visual acuity ranged from perception of light to 6/18, and five of six cases had attached retinae under the silicone oil. Histological analysis of a subretinal membrane demonstrated a predominantly glial/retinal pigment epithelium fibrocellular tissue, consistent with PVR. CONCLUSIONS The study showed that retinal detachment complicated by PVR, as demonstrated by the clinical and histological characteristics of this condition, is common in patients undergoing Boston keratoprosthesis. We also showed that 23-gauge vitrectomy can be effectively performed in patients with a permanent prosthesis. Visual acuity often remains poor, despite successful anatomical results.
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Affiliation(s)
| | - Philip J Banerjee
- Moorfields eye Hospital, London, UK.,UCL Institute of Ophthalmology, London, UK
| | - Mark R Wilkins
- Moorfields eye Hospital, London, UK.,NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology and Moorfields Eye Hospital, London, UK
| | - Mandeep Singh
- Moorfields eye Hospital, London, UK.,Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, USA
| | | | - G Astrid Limb
- NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology and Moorfields Eye Hospital, London, UK
| | - David G Charteris
- Moorfields eye Hospital, London, UK.,NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology and Moorfields Eye Hospital, London, UK
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13
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Eastlake K, Heywood WE, Tracey-White D, Aquino E, Bliss E, Vasta GR, Mills K, Khaw PT, Moosajee M, Limb GA. Comparison of proteomic profiles in the zebrafish retina during experimental degeneration and regeneration. Sci Rep 2017; 7:44601. [PMID: 28300160 PMCID: PMC5353638 DOI: 10.1038/srep44601] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/09/2017] [Indexed: 12/15/2022] Open
Abstract
Zebrafish spontaneously regenerate the retina after injury. Although the gene expression profile has been extensively studied in this species during regeneration, this does not reflect protein function. To further understand the regenerative process in the zebrafish, we compared the proteomic profile of the retina during injury and upon regeneration. Using two-dimensional difference gel electrophoresis (2D-DIGE) and label-free quantitative proteomics (quadrupole time of flight LC-MS/MS), we analysed the retina of adult longfin wildtype zebrafish at 0, 3 and 18 days after Ouabain injection. Gene ontology analysis indicates reduced metabolic processing, and increase in fibrin clot formation, with significant upregulation of fibrinogen gamma polypeptide, apolipoproteins A-Ib and A-II, galectin-1, and vitellogenin-6 during degeneration when compared to normal retina. In addition, cytoskeleton and membrane transport proteins were considerably altered during regeneration, with the highest fold upregulation observed for tubulin beta 2 A, histone H2B and brain type fatty acid binding protein. Key proteins identified in this study may play an important role in the regeneration of the zebrafish retina and investigations on the potential regulation of these proteins may lead to the design of protocols to promote endogenous regeneration of the mammalian retina following retinal degenerative disease.
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Affiliation(s)
- Karen Eastlake
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom
| | - Wendy E. Heywood
- Centre for Translational Omics, UCL Great Ormond Street Institute of Child Health, 30 Guilford St, London WC1N 1EH, United Kingdom
| | - Dhani Tracey-White
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom
| | - Erika Aquino
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom
| | - Emily Bliss
- Centre for Translational Omics, UCL Great Ormond Street Institute of Child Health, 30 Guilford St, London WC1N 1EH, United Kingdom
| | - Gerardo R. Vasta
- Department of Microbiology and Immunology, University of Maryland School of Medicine and IMET, Columbus Center, 701 E, Pratt Street, 3061/3062, Baltimore, USA
| | - Kevin Mills
- Centre for Translational Omics, UCL Great Ormond Street Institute of Child Health, 30 Guilford St, London WC1N 1EH, United Kingdom
| | - Peng T. Khaw
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom
| | - Mariya Moosajee
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom
| | - G. Astrid Limb
- National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, EC1V 9EL, United Kingdom
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14
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Eastlake K, Banerjee PJ, Angbohang A, Charteris DG, Khaw PT, Limb GA. Müller glia as an important source of cytokines and inflammatory factors present in the gliotic retina during proliferative vitreoretinopathy. Glia 2016; 64:495-506. [PMID: 26556395 PMCID: PMC4981913 DOI: 10.1002/glia.22942] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 10/23/2015] [Indexed: 12/12/2022]
Abstract
Retinal gliosis is characterized by biochemical and physiological changes that often lead to Müller glia proliferation and hypertrophy and is a feature of many neuro-degenerative and inflammatory diseases such as proliferative vitreoretinopathy (PVR). Although Müller glia are known to release inflammatory factors and cytokines, it is not clear whether cytokine production by these cells mirrors the pattern of factors present in the gliotic retina. Lysates from normal cadaveric retina and gliotic retinal specimens from patients undergoing retinectomy for treatment of PVR, the Müller cell line MIO-M1 and four human Müller glial cell preparations isolated from normal retina were examined for their expression of cytokines and inflammatory factors using semi-quantitative dot blot antibody arrays and quantitative arrays. Comparative analysis of the expression of inflammatory factors showed that in comparison with normal retina, gliotic retina exhibited greater than twofold increase in 24/102 factors examined by semiquantitative arrays, and a significant increase in 19 out of 27 factors assessed by quantitative methods (P < 0.05 to P < 0.001). It was observed that with the exception of some chemotactic factors, the majority of cytokines and inflammatory factors were produced by Müller glia in vitro and included G-CSF, MCP-1, PDGF-bb, RANTES, VEGF, and TGFβ2. These results showed that a large number of inflammatory factors expressed by Müller glia in vitro are upregulated in the gliotic retina, suggesting that targeting the production of inflammatory factors by Müller glia may constitute a valid approach to prevent neural damage during retinal gliosis and this merits further investigations.
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Affiliation(s)
- K Eastlake
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - P J Banerjee
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - A Angbohang
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - D G Charteris
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
| | - P T Khaw
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
| | - G A Limb
- NIHR Biomedical Research Centre at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
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15
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Abstract
PURPOSE Although the rabbit eye is of a similar size to the human eye, our limited understanding of the differences in retinal physiology to other species hinders its use in retinal research. The role of voltage-gated sodium channels (Nav) in the propagation of excitatory potentials along bipolar cells remains unclear, as conflicting data have been reported in the rabbit. The present study assesses the relative contributions of Nav to the scotopic and photopic flash ERGs as well as the wavelength-dependence of Nav blockade on the rabbit flicker ERG. MATERIALS AND METHODS Tetrodotoxin (TTX, 1 μM) was injected into the vitreous cavity of Chinchilla bastard rabbits. Scotopic ERGs were evoked by white flashes ranging from 10(-5) to 10 cds m(-2), photopic ERGs on a background of 25 cdm(-2) using flash intensities of 0.032-25 cds m(-2). Flicker ERGs (3-50 Hz) were elicited by blue, green and yellow stimuli at 2.34 cds m(-2) on a white background of 30 cdm(-2). RESULTS The a- and b-waves of the scotopic ERG were unaffected by intravitreal injection of the Nav blocker TTX. In contrast, the b-wave, but not the a-wave, of the photopic ERG was selectively blocked by TTX. The reduction by TTX of the flicker ERG was greater for blue than for green and yellow stimuli. DISCUSSION The data suggest that Nav selectively contribute to the generation of the photopic b-wave in the rabbit, indicating that they play an important role in the propagation of excitatory signals on bipolar cells in the cone, but not rod pathways. Importantly, the present study resolves conflicting previous reports into the role of Nav in the retinal function of the rabbit.
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Affiliation(s)
- Silke Becker
- a Division of Ocular Biology and Therapeutics , UCL Institute of Ophthalmology , London , UK and
| | - Hari Jayaram
- b NIHR Biomedical Research Centre for at Moorfields Eye Hospital and UCL Institute of Ophthalmology , London , UK
| | - Graham E Holder
- b NIHR Biomedical Research Centre for at Moorfields Eye Hospital and UCL Institute of Ophthalmology , London , UK
| | - G Astrid Limb
- b NIHR Biomedical Research Centre for at Moorfields Eye Hospital and UCL Institute of Ophthalmology , London , UK
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16
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Becker S, Eastlake K, Jayaram H, Jones MF, Brown RA, McLellan GJ, Charteris DG, Khaw PT, Limb GA. Allogeneic Transplantation of Müller-Derived Retinal Ganglion Cells Improves Retinal Function in a Feline Model of Ganglion Cell Depletion. Stem Cells Transl Med 2016; 5:192-205. [PMID: 26718648 PMCID: PMC4729554 DOI: 10.5966/sctm.2015-0125] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 11/11/2015] [Indexed: 11/16/2022] Open
Abstract
Human Müller glia with stem cell characteristics (hMGSCs) have been shown to improve retinal function upon transplantation into rat models of retinal ganglion cell (RGC) depletion. However, their translational potential may depend upon successful engraftment and improvement of retinal function in experimental models with anatomical and functional features resembling those of the human eye. We investigated the effect of allogeneic transplantation of feline Müller glia with the ability to differentiate into cells expressing RGC markers, following ablation of RGCs by N-methyl-d-aspartate (NMDA). Unlike previous observations in the rat, transplantation of hMGSC-derived RGCs into the feline vitreous formed aggregates and elicited a severe inflammatory response without improving visual function. In contrast, allogeneic transplantation of feline MGSC (fMGSC)-derived RGCs into the vitrectomized eye improved the scotopic threshold response (STR) of the electroretinogram (ERG). Despite causing functional improvement, the cells did not attach onto the retina and formed aggregates on peripheral vitreous remnants, suggesting that vitreous may constitute a barrier for cell attachment onto the retina. This was confirmed by observations that cellular scaffolds of compressed collagen and enriched preparations of fMGSC-derived RGCs facilitated cell attachment. Although cells did not migrate into the RGC layer or the optic nerve, they significantly improved the STR and the photopic negative response of the ERG, indicative of increased RGC function. These results suggest that MGSCs have a neuroprotective ability that promotes partial recovery of impaired RGC function and indicate that cell attachment onto the retina may be necessary for transplanted cells to confer neuroprotection to the retina. Significance: Müller glia with stem cell characteristics are present in the adult human retina, but they do not have regenerative ability. These cells, however, have potential for development of cell therapies to treat retinal disease. Using a feline model of retinal ganglion cell (RGC) depletion, cell grafting methods to improve RGC function have been developed. Using cellular scaffolds, allogeneic transplantation of Müller glia-derived RGC promoted cell attachment onto the retina and enhanced retinal function, as judged by improvement of the photopic negative and scotopic threshold responses of the electroretinogram. The results suggest that the improvement of RGC function observed may be ascribed to the neuroprotective ability of these cells and indicate that attachment of the transplanted cells onto the retina is required to promote effective neuroprotection.
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Affiliation(s)
- Silke Becker
- Institute of Ophthalmology, University College London, London, United Kingdom
| | - Karen Eastlake
- Institute of Ophthalmology, University College London, London, United Kingdom
| | - Hari Jayaram
- National Institute for Health Research Biomedical Research Centre for Ophthalmology, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Megan F Jones
- Institute of Ophthalmology, University College London, London, United Kingdom
| | - Robert A Brown
- Institute of Orthopaedics and Musculoskeletal Science, University College London, London, United Kingdom
| | - Gillian J McLellan
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | - David G Charteris
- National Institute for Health Research Biomedical Research Centre for Ophthalmology, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Peng T Khaw
- National Institute for Health Research Biomedical Research Centre for Ophthalmology, Institute of Ophthalmology, University College London, London, United Kingdom
| | - G Astrid Limb
- National Institute for Health Research Biomedical Research Centre for Ophthalmology, Institute of Ophthalmology, University College London, London, United Kingdom
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17
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Wakx A, Dutot M, Massicot F, Mascarelli F, Limb GA, Rat P. Amyloid β Peptide Induces Apoptosis Through P2X7 Cell Death Receptor in Retinal Cells: Modulation by Marine Omega-3 Fatty Acid DHA and EPA. Appl Biochem Biotechnol 2016; 178:368-81. [PMID: 26467741 PMCID: PMC4718936 DOI: 10.1007/s12010-015-1878-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 09/28/2015] [Indexed: 11/25/2022]
Abstract
Retinal Müller glial cells have already been implicated in age-related macular degeneration (AMD). AMD is characterized by accumulation of toxic amyloid-β peptide (Aβ); the question we raise is as follows: is P2X7 receptor, known to play an important role in several degenerative diseases, involved in Aβ toxicity on Müller cells? Retinal Müller glial cells were incubated with Aβ for 48 h. Cell viability was assessed using the alamarBlue assay and cytotoxicity using the lactate dehydrogenase (LDH) release assay. P2X7 receptor expression was highlighted by immunolabeling observed on confocal microscopy and its activation was evaluated by YO-PRO-1 assay. Hoechst 33342 was used to evaluate chromatin condensation, and caspases 8 and 3 activation was assessed using AMC assays. Lipid formulation rich in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) used in Age-Related Eye Disease Study 2 was incubated on cells for 15 min prior to Aβ incubation. For the first time, we showed that Aβ induced caspase-independent apoptosis through P2X7 receptor activation on our retinal model. DHA and EPA are polyunsaturated fatty acids recommended in food supplement to prevent AMD. We therefore modulated Aβ cytotoxicity using a lipid formulation rich in DHA and EPA to have a better understanding of the results observed in clinical studies. We showed that fish oil rich in EPA and DHA, in combination with a potent P2X7 receptor antagonist, represents an efficient modulator of Aβ toxicity and that P2X7 could be an interesting therapeutic target to prevent AMD.
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Affiliation(s)
- Anaïs Wakx
- />UMR CNRS 8638—Chimie-Toxicologie Analytique et Cellulaire, Sorbonne Paris Cité, Faculté de Pharmacie, Université Paris Descartes, 4 avenue de l’Observatoire, 75006 Paris, France
- />Inserm U598, Physiopathologie des maladies oculaires, Innovations thérapeutiques, Centre de Recherches Biomédicales des Cordeliers, 75270 Paris Cedex 06, France
| | - Mélody Dutot
- />UMR CNRS 8638—Chimie-Toxicologie Analytique et Cellulaire, Sorbonne Paris Cité, Faculté de Pharmacie, Université Paris Descartes, 4 avenue de l’Observatoire, 75006 Paris, France
- />Laboratoire Yslab, 2 rue Félix Le Dantec, 29000 Quimper, France
- />Inserm U598, Physiopathologie des maladies oculaires, Innovations thérapeutiques, Centre de Recherches Biomédicales des Cordeliers, 75270 Paris Cedex 06, France
| | - France Massicot
- />UMR CNRS 8638—Chimie-Toxicologie Analytique et Cellulaire, Sorbonne Paris Cité, Faculté de Pharmacie, Université Paris Descartes, 4 avenue de l’Observatoire, 75006 Paris, France
- />Inserm U598, Physiopathologie des maladies oculaires, Innovations thérapeutiques, Centre de Recherches Biomédicales des Cordeliers, 75270 Paris Cedex 06, France
| | - Frédéric Mascarelli
- />INSERM U 872—Physiopathologie des maladies oculaires: Innovations thérapeutiques, Centre de Recherches des Cordeliers, 15 Rue de l’Ecole de Médecine, 75006 Paris, France
- />Inserm U598, Physiopathologie des maladies oculaires, Innovations thérapeutiques, Centre de Recherches Biomédicales des Cordeliers, 75270 Paris Cedex 06, France
| | - G. Astrid Limb
- />Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology and Moorfields Eye Hospital, 11 Bath Street, London, EC1V 9EL UK
| | - Patrice Rat
- />UMR CNRS 8638—Chimie-Toxicologie Analytique et Cellulaire, Sorbonne Paris Cité, Faculté de Pharmacie, Université Paris Descartes, 4 avenue de l’Observatoire, 75006 Paris, France
- />Inserm U598, Physiopathologie des maladies oculaires, Innovations thérapeutiques, Centre de Recherches Biomédicales des Cordeliers, 75270 Paris Cedex 06, France
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18
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Angbohang A, Wu N, Charalambous T, Eastlake K, Lei Y, Kim YS, Sun XH, Limb GA. Downregulation of the Canonical WNT Signaling Pathway by TGFβ1 Inhibits Photoreceptor Differentiation of Adult Human Müller Glia with Stem Cell Characteristics. Stem Cells Dev 2016; 25:1-12. [PMID: 26456050 PMCID: PMC4692127 DOI: 10.1089/scd.2015.0262] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 10/09/2015] [Indexed: 12/29/2022] Open
Abstract
Müller glia are responsible for the retina regeneration observed in zebrafish. Although the human retina harbors Müller glia with stem cell characteristics, there is no evidence that they regenerate the retina after disease or injury. Transforming growth factor-β (TGFβ) and Wnt signaling regulate retinal neurogenesis and inflammation, but their roles in the neural differentiation of human Müller stem cells (hMSC) are not known. We examined hMSC lines in vitro for the expression of various Wnt signaling components and for their modulation by TGFβ1, as well as the effect of this cytokine on the photoreceptor differentiation of these cells. Culture of hMSC with a combination of factors that induce photoreceptor differentiation of hMSC (FGF2, taurine, retinoic acid, and insulin-like growth factor type1; FTRI), markedly upregulated the expression of components of the canonical Wnt signaling pathway, including WNT2B, DKK1, and active β-CATENIN. Although FTRI did not modify mRNA expression of WNT5B, a component of the noncanonical/planar cell polarity Wnt pathway, it upregulated its secretion. Furthermore, TGFβ1 not only decreased WNT2B expression, but also inhibited FTRI-induced photoreceptor differentiation of hMSC, as determined by expression of the photoreceptor markers NR2E3, RHODOPSIN, and RECOVERIN. Inhibition of TGFβ1 signaling by an ALK5 inhibitor prevented TGFβ1-induced changes in the expression of the two Wnt ligands examined. More importantly, inhibition of the canonical WNT signaling by XAV-939 prevented FTRI-induced photoreceptor differentiation. These observations suggest that TGFβ may play a key role in preventing neural differentiation of hMSC and may constitute a potential target for induction of endogenous regeneration of the human retina.
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Affiliation(s)
- Angshumonik Angbohang
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Na Wu
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Thalis Charalambous
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Karen Eastlake
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Yuan Lei
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Yung Su Kim
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, London, United Kingdom
| | - Xinghuai H. Sun
- Department of Ophthalmology and Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - G. Astrid Limb
- NIHR Biomedical Research Centre for Ophthalmology at Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, United Kingdom
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19
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Ramírez C, Cáceres-del-Carpio J, Chu J, Chu J, Moustafa MT, Chwa M, Limb GA, Kuppermann BD, Kenney MC. Brimonidine Can Prevent In Vitro Hydroquinone Damage on Retinal Pigment Epithelium Cells and Retinal Müller Cells. J Ocul Pharmacol Ther 2015; 32:102-8. [PMID: 26624556 DOI: 10.1089/jop.2015.0083] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
PURPOSE Brimonidine is a selective alpha-2 adrenergic agonist used to reduce intraocular pressure and it has been shown to have some neuroprotective effects. Hydroquinone (HQ) is a toxicant present in cigarette smoke, and other sources. In this study, we investigated the cyto-protective effects in vitro of Brimonidine on human retinal pigment epithelium cells (ARPE-19) and human retinal Müller cells (MIO-M1) that had been treated with HQ. METHODS Cells were pretreated for 6 h with different doses of Brimonidine tartrate 0.1% (1/2×, 1×, 5×, 10×), followed by a 24-h exposure to 100 μM of HQ, while the Brimonidine was still present. Assays were used to measure cell viability, mitochondrial membrane potential (ΔΨm), reactive oxygen species (ROS) production, and lactate dehydrogenase (LDH) release. RESULTS Brimonidine increased the cell viability at all concentrations studied in both cell lines studied. ΔΨm also improved at all Brimonidine doses in ARPE-19 cells and in the 5× and 10× dosages MIO-M1 cells. The ROS levels decreased at 1×, 5×, and 10× doses of Brimonidine in ARPE-19 but only at 10× on MIO-M1 cells. The 10×-Brimonidine ARPE-19 cells had decreased LDH release, but no LDH changes were observed on MIO-M1 cells. CONCLUSION HQ-induced toxicity is mediated through mitochondrial damaging, oxidative stress-related and necrosis-related pathways; Brimonidine significantly prevented the mitochondrial damaging and oxidative stress-related effects but had little effect on blocking the necrosis component of HQ-toxicity. Brimonidine protective effects differ between the different retinal cell types and high concentrations of Brimonidine (10×) have minimal damaging effects on human retinal cells.
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Affiliation(s)
- Claudio Ramírez
- 1 Gavin Herbert Eye Institute, University of California , Irvine, Irvine, California
| | | | - Justin Chu
- 1 Gavin Herbert Eye Institute, University of California , Irvine, Irvine, California
| | - Joshua Chu
- 1 Gavin Herbert Eye Institute, University of California , Irvine, Irvine, California
| | - M Tarek Moustafa
- 1 Gavin Herbert Eye Institute, University of California , Irvine, Irvine, California.,2 Ophthalmology Department, Minia University , Minia, Egypt
| | - Marilyn Chwa
- 1 Gavin Herbert Eye Institute, University of California , Irvine, Irvine, California
| | - G Astrid Limb
- 3 Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology , London, United Kingdom
| | - Baruch D Kuppermann
- 1 Gavin Herbert Eye Institute, University of California , Irvine, Irvine, California
| | - M Cristina Kenney
- 1 Gavin Herbert Eye Institute, University of California , Irvine, Irvine, California.,4 Department of Pathology and Laboratory Medicine, University of California Irvine , Irvine, California
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20
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Mansoor S, Sharma A, Cáceres-del-Carpio J, Zacharias LC, Patil AJ, Gupta N, Limb GA, Kenney MC, Kuppermann BD. Effects of light on retinal pigment epithelial cells, neurosensory retinal cells and Müller cells treated with Brilliant Blue G. Clin Exp Ophthalmol 2015; 43:820-9. [DOI: 10.1111/ceo.12568] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 04/22/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Saffar Mansoor
- Gavin Herbert Eye Institute; School of Medicine; University of California; Irvine California USA
| | - Ashish Sharma
- Gavin Herbert Eye Institute; School of Medicine; University of California; Irvine California USA
- Department of Ophthalmology; Lotus Eye Care Hospital; Coimbatore TN India
| | | | - Leandro C Zacharias
- Gavin Herbert Eye Institute; School of Medicine; University of California; Irvine California USA
- Serviço de Oftalmologia; Faculdade de Medicina da Universidade de São Paulo; São Paulo Brazil
| | - A Jayaprakash Patil
- Department of Ophthalmology; University Hospitals of Morecambe Bay NHS Foundation Trust; Kendal LA9 5JE UK
| | - Navin Gupta
- Gavin Herbert Eye Institute; School of Medicine; University of California; Irvine California USA
| | - G Astrid Limb
- Department of Paediatric Ophthalmology; University Hospitals of Morecambe Bay NHS Foundation Trust; Kendal LA9 5JE UK
| | - M Cristina Kenney
- Gavin Herbert Eye Institute; School of Medicine; University of California; Irvine California USA
- Department of Paediatric Ophthalmology; University Hospitals of Morecambe Bay NHS Foundation Trust; Kendal LA9 5JE UK
| | - Baruch D Kuppermann
- Gavin Herbert Eye Institute; School of Medicine; University of California; Irvine California USA
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21
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Liu X, Ye F, Xiong H, Hu DN, Limb GA, Xie T, Peng L, Zhang P, Wei Y, Zhang W, Wang J, Wu H, Lee P, Song E, Zhang DY. IL-1β induces IL-6 production in retinal Müller cells predominantly through the activation of p38 MAPK/NF-κB signaling pathway. Exp Cell Res 2015; 331:223-231. [PMID: 25239226 DOI: 10.1016/j.yexcr.2014.08.040] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 08/28/2014] [Accepted: 08/28/2014] [Indexed: 12/16/2022]
Abstract
IL-6 plays an important role in various inflammatory ocular diseases, including diabetic retinopathy. Müller cells are the major source of inflammatory mediators, including IL-6, in the retina. However, the mechanism of regulating IL-6 production in these cells remains unclear. Examination of signaling pathways in human retinal Müller cells (MIO-M1 cell line) cultured with IL-1β, TNF-α, IL-6, IL-8, VEGF, IFN-γ, glucose or mannitol showed that IL-1β was the most potent stimulator of IL-6 production. In addition, IL-1 β also increased NF-κB p50 protein level and phosphorylation of p38 MAPK, ERK1/2 and c-Jun. Induction of IL-6 production by IL-1β was significantly reduced by addition of p38 MAPK (SB203580), MEK1/2 (U0126) or NF-κB (BAY11-7082) inhibitors, with the highest effect being observed with SB203580. To explore the specific elements in IL-6 promoter responsible for IL-1β-induction of IL-6 expression, a series of plasmids bearing various IL-6 promoter mutations were transiently expressed in MIO-MI cells cultured in the presence or absence of IL-1β (10ng/ml) and/or SB203580 (10µM). Results showed that IL-6 promoter activity of the parent pIL-6-Luc651 was significantly enhanced by IL-1β, but the level was significantly attenuated by SB203580. Furthermore, the IL-6 promoter activity was also reduced upon deletion of NF-κB, AP-1 or C/EBP binding sites, with NF-κB deletion being the greatest. These results are the first demonstration that IL-1β induces IL-6 production in Müller cells by activation of IL-6 promoter activity predominantly through the p38 MAPK/NF-κB pathway.
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Affiliation(s)
- Xiufen Liu
- Department of Ophthalmology, The First Hospital, Jilin University, Xinmin Street 71, Changchun, Jilin 130021, China
| | - Fei Ye
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Huabao Xiong
- Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Dan-Ning Hu
- Tissue Culture Center, New York Eye and Ear Infirmary of Mount Sinai, New York, NY 10003, USA
| | - G Astrid Limb
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, Bath Street, London EC1V 9EL, UK
| | - Tian Xie
- Department of neurosurgery, The People׳s Hospital of Jilin Province, Changchun, Jilin 130021
| | - Liang Peng
- Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Pili Zhang
- Department of Medicine, Endocrinology, Diabetes and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Yi Wei
- Department of Ophthalmology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Wiley Zhang
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Juan Wang
- Department of Medicine, Immunology Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Hongwei Wu
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Peng Lee
- Departments of Pathology, Urology, NYU Cancer Institute, New York Harbor Healthcare System, New York University, School of Medicine, New York, NY 10010, USA
| | - E Song
- Department of Ophthalmology, The First Hospital, Jilin University, Xinmin Street 71, Changchun, Jilin 130021, China; The Ophthalmology Hospital Affiliated Suzhou University, Jiangsu, Suzhou 215021, China.
| | - David Y Zhang
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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Liu X, Ye F, Xiong H, Hu D, Limb GA, Xie T, Peng L, Yang W, Sun Y, Zhou M, Song E, Zhang DY. IL-1β Upregulates IL-8 Production in Human Müller Cells Through Activation of the p38 MAPK and ERK1/2 Signaling Pathways. Inflammation 2014; 37:1486-95. [PMID: 24706000 DOI: 10.1007/s10753-014-9874-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Diabetic retinopathy shares some similarity with chronic inflammation and Müller cells dysfunction may play an important role in its initiation and progression since these cells are thought to be a major source of inflammatory factors. The goal of this study was to examine the effect of cytokines on human retinal Müller cells and to understand the underlying signal transduction pathways regulating interleukin-8 (IL-8) expression. In this study, human MIO-M1 cells were treated with interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), IL-8, vascular endothelial growth factor (VEGF), interferon-gamma (IFN-γ), glucose, or mannitol, followed by examination of their IL-8 protein and mRNA levels by Western blotting and PCR, respectively. After treatment with IL-1β, the levels of phosphorylated p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), c-Jun N-terminal kinase (JNK), Janus kinase 2 (JAK2), and signal transducer and activator of transcription 3 (STAT3) were measured. IL-8 was also measured by Western blotting and ELISA following Müller cell culture with IL-1β and specific inhibitors of the p38 MAPK, ERK1/2, JNK, or JAK2 pathways. The results showed that IL-1β was a potent inducer of IL-8 expression in MIO-M1 cells, although a relatively small increase was induced by TNF-α. IL-6, IL-8, VEGF, and IFN-γ did not modify IL-8 expression. Increase of IL-8 expression was accompanied by a significant increased phosphorylation of p38 MAPK, ERK, and JNK, but not of JAK2 and STAT3. Furthermore, inhibitors of p38 MAPK and MEK1/2, but not for JNK and JAK2, significantly inhibited IL-8 expression. In conclusion, IL-1β potently stimulates IL-8 expression in Müller cells mainly through the p38 MAPK and ERK1/2 pathways.
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Affiliation(s)
- Xiufen Liu
- Department of Ophthalmology, The First Hospital, Jilin University, Changchun, Jilin, 130021, China
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Jayaram H, Becker S, Eastlake K, Jones MF, Charteris DG, Limb GA. Optimized feline vitrectomy technique for therapeutic stem cell delivery to the inner retina. Vet Ophthalmol 2014; 17:300-4. [PMID: 24661435 PMCID: PMC4258072 DOI: 10.1111/vop.12160] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Objective To describe an optimized surgical technique for feline vitrectomy which reduces bleeding and aids posterior gel clearance in order to facilitate stem cell delivery to the inner retina using cellular scaffolds. Procedures Three-port pars plana vitrectomies were performed in six-specific pathogen-free domestic cats using an optimized surgical technique to improve access and minimize severe intraoperative bleeding. Results The surgical procedure was successfully completed in all six animals. Lens sparing vitrectomy resulted in peripheral lens touch in one of three animals but without cataract formation. Transient bleeding from sclerotomies, which was readily controlled, was seen in two of the six animals. No cases of vitreous hemorrhage, severe postoperative inflammation, retinal detachment, or endophthalmitis were observed during postoperative follow-up. Conclusions Three-port pars plana vitrectomy can be performed successfully in the cat in a safe and controlled manner when the appropriate precautions are taken to minimize the risk of developing intraoperative hemorrhage. This technique may facilitate the use of feline models of inner retinal degeneration for the development of stem cell transplantation techniques using cellular scaffolds.
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Affiliation(s)
- Hari Jayaram
- Ocular Biology & Therapeutics, UCL Institute of Ophthalmology, London, UK
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Jayaram H, Jones MF, Eastlake K, Cottrill PB, Becker S, Wiseman J, Khaw PT, Limb GA. Transplantation of photoreceptors derived from human Muller glia restore rod function in the P23H rat. Stem Cells Transl Med 2014; 3:323-33. [PMID: 24477073 PMCID: PMC3952927 DOI: 10.5966/sctm.2013-0112] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 11/04/2013] [Indexed: 02/07/2023] Open
Abstract
Müller glia possess stem cell characteristics that have been recognized to be responsible for the regeneration of injured retina in fish and amphibians. Although these cells are present in the adult human eye, they are not known to regenerate human retina in vivo. Human Müller glia with stem cell characteristics (hMSCs) can acquire phenotypic and genotypic characteristics of rod photoreceptors in vitro, suggesting that they may have potential for use in transplantation strategies to treat human photoreceptor degenerations. Much work has been undertaken in rodents using various sources of allogeneic stem cells to restore photoreceptor function, but the effect of human Müller glia-derived photoreceptors in the restoration of rod photoreceptor function has not been investigated. This study aimed to differentiate hMSCs into photoreceptor cells by stimulation with growth and differentiation factors in vitro to upregulate gene and protein expression of CRX, NR2E3, and rhodopsin and various phototransduction markers associated with rod photoreceptor development and function and to examine the effect of subretinal transplantation of these cells into the P23H rat, a model of primary photoreceptor degeneration. Following transplantation, hMSC-derived photoreceptor cells migrated and integrated into the outer nuclear layer of the degenerated retinas and led to significant improvement in rod photoreceptor function as shown by an increase in a-wave amplitude and slope using scotopic flash electroretinography. These observations suggest that hMSCs can be regarded as a cell source for development of cell-replacement therapies to treat human photoreceptor degenerations and may also offer potential for the development of autologous transplantation.
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Becker S, Singhal S, Jones MF, Eastlake K, Cottrill PB, Jayaram H, Limb GA. Acquisition of RGC phenotype in human Müller glia with stem cell characteristics is accompanied by upregulation of functional nicotinic acetylcholine receptors. Mol Vis 2013; 19:1925-36. [PMID: 24049438 PMCID: PMC3774575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 09/10/2013] [Indexed: 11/05/2022] Open
Abstract
PURPOSE Human Müller glia with stem cell characteristics (hMGSCs) can be induced to express genes and proteins of retinal ganglion cells (RGCs) upon in vitro inhibition of Notch-1 activity. However, it is not known whether expression of these markers is accompanied by acquisition of RGC function. This study investigated whether hMGSCs that express RGC markers also display neural functionality, as measured by their intracellular calcium concentration ([Ca(2+)]i) responsiveness following neurotransmitter stimulation in vitro. METHODS Changes in mRNA expression of RGC markers and neurotransmitter receptors were assessed either by conventional or quantitative reverse transcription PCR (RT-PCR), while changes in protein levels were confirmed by immunocytochemistry. The [Ca(2+)]i levels were estimated by fluorescence microscopy. RESULTS We showed that while undifferentiated hMGSCs displayed a profound elevation of [Ca(2+)]i after stimulation with N-methyl-D-aspartate (NMDA), this was lost following Notch-1 inhibition. Conversely, untreated hMGSCs did not respond to muscarinic receptor stimulation, whereas [Ca(2+)]i was increased in differentiated hMGSCs that expressed RGC precursor markers. Differentiated hMGSC-derived RGCs, but not undifferentiated hMGSCs, responded to stimulation by nicotine with a substantial rise in [Ca(2+)]i, which was inhibited by the α4β2 and α6β2 nicotinic receptor antagonist methyllycaconitine. Notch-1 attenuation not only caused a decrease in the gene expression of the Notch effector HES1 and increased expression of RGC markers, but also an increase in the gene and protein expression of α4 and α6 nicotinic receptor subunits. CONCLUSIONS These observations suggest that in response to Notch-1 inhibition, hMGSCs differentiate into a population of RGCs that exhibit some of the functionality observed in differentiated RGCs.
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Affiliation(s)
- Silke Becker
- Division of Ocular Biology & Therapeutics, Institute of Ophthalmology, University College London, London, UK
| | - Shweta Singhal
- Division of Ocular Biology & Therapeutics, Institute of Ophthalmology, University College London, London, UK
| | - Megan F. Jones
- Division of Ocular Biology & Therapeutics, Institute of Ophthalmology, University College London, London, UK
| | - Karen Eastlake
- Division of Ocular Biology & Therapeutics, Institute of Ophthalmology, University College London, London, UK
| | - Phillippa B. Cottrill
- Division of Ocular Biology & Therapeutics, Institute of Ophthalmology, University College London, London, UK
| | - Hari Jayaram
- Division of Ocular Biology & Therapeutics, Institute of Ophthalmology, University College London, London, UK
- NIHR Biomedical Research Centre for Ophthalmology, UCL Institute of Ophthalmology and Moorfields Eye Hospital, London, UK
| | - G. Astrid Limb
- Division of Ocular Biology & Therapeutics, Institute of Ophthalmology, University College London, London, UK
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Chandra A, Jones M, Cottrill P, Eastlake K, Limb GA, Charteris DG. Gene expression and protein distribution of ADAMTSL-4 in human iris, choroid and retina. Br J Ophthalmol 2013; 97:1208-12. [DOI: 10.1136/bjophthalmol-2013-303353] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Mansoor S, Gupta N, Luczy-Bachman G, Limb GA, Kuppermann BD, Kenney MC. Protective effects of lipoic acid on chrysene-induced toxicity on Müller cells in vitro. Mol Vis 2013; 19:25-38. [PMID: 23335848 PMCID: PMC3541045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 01/03/2013] [Indexed: 11/13/2022] Open
Abstract
PURPOSE This study evaluates the toxic effects of chrysene (a component from cigarette smoke) on Müller cells (MIO-M1) in vitro and investigates whether the inhibitor lipoic acid can reverse the chrysene-induced toxic effects. METHODS MIO-M1 cells were exposed to varying concentrations of chrysene with or without lipoic acid. Cell viability was measured by a trypan blue dye exclusion assay. Caspase-3/7 activity was measured by a fluorochrome assay. Lactate dehydrogenase (LDH) release was quantified by an LDH assay. The production of reactive oxygen/nitrogen species (ROS/RNS) was measured with a 2',7'-dichlorodihydrofluorescein diacetate dye assay. Mitochondrial membrane potential (ΔΨm) was measured using the JC-1 assay. Intracellular ATP content was determined by the ATPLite kit. RESULTS MIO-M1 cells showed significantly decreased cell viability, increased caspase-3/7 activity, LDH release at the highest chrysene concentration, elevated ROS/RNS levels, decreased ΔΨm value, and decreased intracellular ATP content after exposure to 300, 500, and 1,000 µM chrysene compared with the control. Pretreatment with 80 µM lipoic acid reversed loss of cell viability in 500-µM-chrysene-treated cultures (24.7%, p<0.001). Similarly, pretreatment with 80 µM lipoic acid before chrysene resulted in decreased caspase-3/7 activities (75.7%, p<0.001), decreased ROS/RNS levels (80.02%, p<0.001), increased ΔΨm values (86%, p<0.001), and increased ATP levels (40.5%, p<0.001) compared to 500-µM-chrysene-treated cultures. CONCLUSIONS Chrysene, a component of cigarette smoke, can diminish cell viability in MIO-M1 cells in vitro by apoptosis at the lower concentrations of Chrysene (300 and 500 µM) and necrosis at the highest concentration. Moreover, mitochondrial function was particularly altered. However, lipoic acid can partially reverse the cytotoxic effect of chrysene. Lipoic acid administration may reduce or prevent Müller cell degeneration in retinal degenerative disorders.
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Affiliation(s)
- Saffar Mansoor
- From the Gavin Herbert Eye Institute, School of Medicine, University of California, Irvine, CA
| | - Navin Gupta
- From the Gavin Herbert Eye Institute, School of Medicine, University of California, Irvine, CA
| | - Georgia Luczy-Bachman
- Department of Pediatrics, Clinical Translational Science Center, University of California, Irvine, CA
| | - G. Astrid Limb
- Department of Ocular Biology and Therapeutics, UCL, Institute of Ophthalmology, London, United Kingdom
| | - Baruch D. Kuppermann
- From the Gavin Herbert Eye Institute, School of Medicine, University of California, Irvine, CA
| | - M. Cristina Kenney
- From the Gavin Herbert Eye Institute, School of Medicine, University of California, Irvine, CA
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Becker S, Jayaram H, Limb GA. Recent Advances towards the Clinical Application of Stem Cells for Retinal Regeneration. Cells 2012; 1:851-73. [PMID: 24710533 PMCID: PMC3901131 DOI: 10.3390/cells1040851] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 09/29/2012] [Accepted: 10/10/2012] [Indexed: 01/10/2023] Open
Abstract
Retinal degenerative diseases constitute a major cause of irreversible blindness in the world. Stem cell-based therapies offer hope for these patients at risk of or suffering from blindness due to the deterioration of the neural retina. Various sources of stem cells are currently being investigated, ranging from human embryonic stem cells to adult-derived induced pluripotent stem cells as well as human Müller stem cells, with the first clinical trials to investigate the safety and tolerability of human embryonic stem cell-derived retinal pigment epithelium cells having recently commenced. This review aims to summarize the latest advances in the development of stem cell strategies for the replacement of retinal neurons and their supportive cells, the retinal pigment epithelium (RPE) affected by retinal degenerative conditions. Particular emphasis will be given to the advances in stem cell transplantation and the challenges associated with their translation into clinical practice.
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Affiliation(s)
- Silke Becker
- Ocular Biology and Therapeutics, Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK.
| | - Hari Jayaram
- Ocular Biology and Therapeutics, Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK.
| | - G Astrid Limb
- Ocular Biology and Therapeutics, Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK.
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Singhal S, Bhatia B, Jayaram H, Becker S, Jones MF, Cottrill PB, Khaw PT, Salt TE, Limb GA. Human Müller glia with stem cell characteristics differentiate into retinal ganglion cell (RGC) precursors in vitro and partially restore RGC function in vivo following transplantation. Stem Cells Transl Med 2012; 1:188-99. [PMID: 23197778 PMCID: PMC3659849 DOI: 10.5966/sctm.2011-0005] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 01/30/2012] [Indexed: 01/29/2023] Open
Abstract
Müller glia with stem cell characteristics have been identified in the adult human eye, and although there is no evidence that they regenerate retina in vivo, they can be induced to grow and differentiate into retinal neurons in vitro. We differentiated human Müller stem cells into retinal ganglion cell (RGC) precursors by stimulation with fibroblast growth factor 2 together with NOTCH inhibition using the γ-secretase inhibitor N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT). Differentiation into RGC precursors was confirmed by gene and protein expression analysis, changes in cytosolic [Ca(2+)] in response to neurotransmitters, and green fluorescent protein (GFP) expression by cells transduced with a transcriptional BRN3b-GFP reporter vector. RGC precursors transplanted onto the inner retinal surface of Lister hooded rats depleted of RGCs by N-methyl-d-aspartate aligned onto the host RGC layer at the site of transplantation but did not extend long processes toward the optic nerve. Cells were observed extending processes into the RGC layer and expressing RGC markers in vivo. This migration was observed only when adjuvant anti-inflammatory and matrix degradation therapy was used for transplantation. RGC precursors induced a significant recovery of RGC function in the transplanted eyes as determined by improvement of the negative scotopic threshold response of the electroretinogram (indicative of RGC function). The results suggest that transplanted RGC precursors may be capable of establishing local interneuron synapses and possibly release neurotrophic factors that facilitate recovery of RGC function. These cells constitute a promising source of cells for cell-based therapies to treat retinal degenerative disease caused by RGC dysfunction.
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Affiliation(s)
| | | | - Hari Jayaram
- Divisions of Ocular Biology and Therapeutics and
| | - Silke Becker
- Divisions of Ocular Biology and Therapeutics and
| | | | | | - Peng T. Khaw
- Divisions of Ocular Biology and Therapeutics and
| | - Thomas E. Salt
- Visual Neurosciences, NIHR BRC University College London Institute of Ophthalmology and Moorfields Eye Hospital, London, United Kingdom
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Bhatia B, Jayaram H, Singhal S, Jones MF, Limb GA. Differences between the neurogenic and proliferative abilities of Müller glia with stem cell characteristics and the ciliary epithelium from the adult human eye. Exp Eye Res 2011; 93:852-61. [PMID: 21989110 PMCID: PMC3268355 DOI: 10.1016/j.exer.2011.09.015] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 09/19/2011] [Accepted: 09/27/2011] [Indexed: 11/19/2022]
Abstract
Much controversy has arisen on the nature and sources of stem cells in the adult human retina. Whilst ciliary epithelium has been thought to constitute a source of neural stem cells, a population of Müller glia in the neural retina has also been shown to exhibit neurogenic characteristics. This study aimed to compare the neurogenic and proliferative abilities between these two major cell populations. It also examined whether differences exist between the pigmented and non-pigmented ciliary epithelium (CE) from the adult human eye. On this basis, Müller glia with stem cell characteristics and pigmented and non-pigmented CE were isolated from human neural retina and ciliary epithelium respectively. Expression of glial, epithelial and neural progenitor markers was examined in these cells following culture under adherent and non-adherent conditions and treatments to induce neural differentiation. Unlike pigmented CE which did not proliferate, non-pigmented CE cells exhibited limited proliferation in vitro, unless epidermal growth factor (EGF) was present in the culture medium to prolong their survival. In contrast, Müller glial stem cells (MSC) cultured as adherent monolayers reached confluence within a few weeks and continued to proliferative indefinitely in the absence of EGF. Both MSC and non-pigmented CE expressed markers of neural progenitors, including SOX2, PAX6, CHX10 and NOTCH. Nestin, a neural stem cell marker, was only expressed by MSC. Non-pigmented CE displayed epithelial morphology, limited photoreceptor gene expression and stained strongly for pigmented epithelial markers upon culture with neural differentiation factors. In contrast, MSC adopted neural morphology and expressed markers of retinal ganglion cells and photoreceptors when cultured under similar conditions. This study provides the first demonstration that pigmented CE possess different proliferative abilities from non-pigmented CE. It also showed that although non-pigmented CE express genes of retinal progenitors, they do not differentiate into neurons in vitro, as that seen with Müller glia that proliferate indefinitely in vitro and that acquire markers of retinal neurons in culture under neural differentiation protocols. From these observations it is possible to suggest that Müller glia that express markers of neural progenitors and become spontaneously immortalized in vitro constitute a potential source of retinal neurons for transplantation studies and fulfil the characteristics of true stem cells due to their proliferative and neurogenic ability.
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Affiliation(s)
| | | | | | | | - G. Astrid Limb
- Corresponding author. Tel.: +44 (0) 20 7608 6974; fax: +44 (0) 20 7608 4034.
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Limb GA, Martin KR. Current Prospects in Optic Nerve Protection and Regeneration: Sixth ARVO/Pfizer Ophthalmics Research Institute Conference. ACTA ACUST UNITED AC 2011; 52:5941-54. [DOI: 10.1167/iovs.10-6894] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- G. Astrid Limb
- From the Institute of Ophthalmology, University College, London, and Moorfields Eye Hospital, United Kingdom; and
| | - Keith R. Martin
- the Department of Ophthalmology, Centre for Brain Repair and NIHR Biomedical Research Centre, University of Cambridge, Cambridge, United Kingdom
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Bhatia B, Singhal S, Tadman DN, Khaw PT, Limb GA. SOX2 is required for adult human muller stem cell survival and maintenance of progenicity in vitro. Invest Ophthalmol Vis Sci 2011; 52:136-45. [PMID: 20739473 DOI: 10.1167/iovs.10-5208] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE SOX2, a high-mobility group transcription factor, is expressed by retinal progenitors during development. It has been associated with the ability of progenitor cells to differentiate into retinal neurons and is highly expressed by human Müller stem cells (hMSCs) in culture. The authors investigated the role of this factor in the maintenance of progenicity and neural differentiation of hMSCs in vitro. METHODS SOX2 silencing was induced by transfection of hMSCs in culture with two pGSU6-GFP SOX2 silencing constructs and a scrambled control vector. Silencing was confirmed by examination of gene and protein expression coding for SOX2. Effects of SOX2 downregulation were investigated by expression of proliferation (Ki67) and apoptotic (TUNEL, caspase) cell markers and by the expression of markers of retinal neurons (HuD, βIII tubulin, rhodopsin, BRN3B, ISL1), glia (vimentin), and the progenitor marker PAX6. RESULTS SOX2 silencing caused hMSCs to rapidly adopt a neural-like morphology and was accompanied by the upregulation of specific markers of retinal neurons, including βIII tubulin, rhodopsin, BRN3B, and ISL1, and by the downregulation of the neural progenitor marker PAX6 and the glial cell marker vimentin. Interestingly, SOX2 silencing induced apoptosis, suggesting a crucial role of this factor on hMSC survival in vitro. CONCLUSIONS These in vitro results parallel that seen when Sox2 is silenced in neural stem cells of lower species during development, and they suggest that Sox2 may have an important role in adult hMSC differentiation into retinal neurons in vitro.
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Yong PH, Zong H, Medina RJ, Limb GA, Uchida K, Stitt AW, Curtis TM. Evidence supporting a role for N-(3-formyl-3,4-dehydropiperidino)lysine accumulation in Müller glia dysfunction and death in diabetic retinopathy. Mol Vis 2010; 16:2524-38. [PMID: 21151599 PMCID: PMC3000235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Accepted: 11/27/2010] [Indexed: 11/03/2022] Open
Abstract
PURPOSE Recent evidence suggests that neuroglial dysfunction and degeneration contributes to the etiology and progression of diabetic retinopathy. Advanced lipoxidation end products (ALEs) have been implicated in the pathology of various diseases, including diabetes and several neurodegenerative disorders. The purpose of the present study was to investigate the possible link between the accumulation of ALEs and neuroretinal changes in diabetic retinopathy. METHODS Retinal sections obtained from diabetic rats and age-matched controls were processed for immunohistochemistry using antibodies against several well defined ALEs. In vitro experiments were also performed using a human Müller (Moorfields/Institute of Ophthalmology-Müller 1 [MIO-M1]) glia cell line. Western blot analysis was used to measure the accumulation of the acrolein-derived ALE adduct Nε-(3-formyl-3,4-dehydropiperidino)lysine (FDP-lysine) in Müller cells preincubated with FDP-lysine-modified human serum albumin (FDP-lysine-HSA). Responses of Müller cells to FDP-lysine accumulation were investigated by analyzing changes in the protein expression of heme oxygenase-1 (HO-1), glial fibrillary acidic protein (GFAP), and the inwardly rectifying potassium channel Kir4.1. In addition, mRNA expression levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), and tumor necrosis factor-α (TNFα) were determined by reverse transcriptase PCR (RT-PCR). Apoptotic cell death was evaluated by fluorescence-activated cell sorting (FACS) analysis after staining with fluorescein isothiocyanate (FITC)-labeled annexin V and propidium iodide. RESULTS No significant differences in the levels of malondialdehyde-, 4-hydroxy-2-nonenal-, and 4-hydroxyhexenal-derived ALEs were evident between control and diabetic retinas after 4 months of diabetes. By contrast, FDP-lysine immunoreactivity was markedly increased in the Müller glia of diabetic rats. Time-course studies revealed that FDP-lysine initially accumulated within Müller glial end feet after only a few months of diabetes and thereafter spread distally throughout their inner radial processes. Exposure of human Müller glia to FDP-lysine-HSA led to a concentration-dependent accumulation of FDP-lysine-modified proteins across a broad molecular mass range. FDP-lysine accumulation was associated with the induction of HO-1, no change in GFAP, a decrease in protein levels of the potassium channel subunit Kir4.1, and upregulation of transcripts for VEGF, IL-6, and TNF-α. Incubation of Müller glia with FDP-lysine-HSA also caused apoptosis at high concentrations. CONCLUSIONS Collectively, these data strongly suggest that FDP-lysine accumulation could be a major factor contributing to the Müller glial abnormalities occurring in the early stages of diabetic retinopathy.
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Affiliation(s)
- Phaik Har Yong
- Centre for Vision and Vascular Science, The Queen's University of Belfast, Institute of Clinical Sciences, The Royal Victoria Hospital, Grosvenor Road, Belfast, Northern Ireland
| | - Hongliang Zong
- Centre for Vision and Vascular Science, The Queen's University of Belfast, Institute of Clinical Sciences, The Royal Victoria Hospital, Grosvenor Road, Belfast, Northern Ireland
| | - Reinhold J. Medina
- Centre for Vision and Vascular Science, The Queen's University of Belfast, Institute of Clinical Sciences, The Royal Victoria Hospital, Grosvenor Road, Belfast, Northern Ireland
| | - G. Astrid Limb
- Institute of Ophthalmology, University College London, UK
| | - Koji Uchida
- Department of Food and Biodynamics, Nagoya University, Japan
| | - Alan W. Stitt
- Centre for Vision and Vascular Science, The Queen's University of Belfast, Institute of Clinical Sciences, The Royal Victoria Hospital, Grosvenor Road, Belfast, Northern Ireland
| | - Tim M. Curtis
- Centre for Vision and Vascular Science, The Queen's University of Belfast, Institute of Clinical Sciences, The Royal Victoria Hospital, Grosvenor Road, Belfast, Northern Ireland
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Zong H, Ward M, Madden A, Yong PH, Limb GA, Curtis TM, Stitt AW. Hyperglycaemia-induced pro-inflammatory responses by retinal Müller glia are regulated by the receptor for advanced glycation end-products (RAGE). Diabetologia 2010; 53:2656-66. [PMID: 20835858 DOI: 10.1007/s00125-010-1900-z] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 08/09/2010] [Indexed: 01/07/2023]
Abstract
AIMS/HYPOTHESIS Up-regulation of the receptor for AGEs (RAGE) and its ligands in diabetes has been observed in various tissues. Here, we sought to determine levels of RAGE and one of its most important ligands, S100B, in diabetic retina, and to investigate the regulatory role of S100B and RAGE in Müller glia. METHODS Streptozotocin-diabetes was induced in Sprague-Dawley rats. RAGE, S100B and glial fibrillary acidic protein (GFAP) were detected in retinal cryosections. In parallel, the human retinal Müller cell line, MIO-M1, was maintained in normal glucose (5.5 mmol/l) or high glucose (25 mmol/l). RAGE knockdown was achieved using small interfering RNA (siRNA), while soluble RAGE was used as a competitive inhibitor of RAGE ligand binding. RAGE, S100B and cytokines were detected using quantitative RT-PCR, western blotting, cytokine protein arrays or ELISA. Activation of mitogen-activated protein kinase (MAPK) by RAGE was determined by western blotting. RESULTS Compared with non-diabetic controls, RAGE and S100B were significantly elevated in the diabetic retina with apparent localisation in the Müller glia, occurring concomitantly with upregulation of GFAP. Exposure of MIO-M1 cells to high glucose induced increased production of RAGE and S100B. RAGE signalling via MAPK pathway was linked to cytokine production. Blockade of RAGE prevented cytokine responses induced by high glucose and S100B in Müller glia. CONCLUSIONS/INTERPRETATION Hyperglycaemia in vivo and in vitro exposure to high glucose induce upregulation of RAGE and its ligands, leading to RAGE signalling, which links to pro-inflammatory responses by retinal Müller glia. These data shed light on the potential clinical application of RAGE blockade to inhibit the progression of diabetic retinopathy.
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Affiliation(s)
- H Zong
- Centre for Vision and Vascular Science, Queen's University Belfast, Royal Victoria Hospital, Belfast BT12 6BA, Northern Ireland, UK
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Abstract
Recent advances in retinal stem cell research have raised the possibility that these cells have the potential to be used to repair or regenerate diseased retina. Various cell sources for replacement of retinal neurons have been identified, including embryonic stem cells, the adult ciliary epithelium, adult Müller stem cells and induced pluripotent stem cells (iPS). However, the true stem cell nature of the ciliary epithelium and its possible application in cell therapies has now been questioned, leaving other cell sources to be carefully examined as potential candidates for such therapies. The need for identification of the ontogenetic state of grafted stem cells in order to achieve their successful integration into the murine retina has been recognized. However, it is not known whether the same requirements may apply to achieve transplant cell integration into the adult human eye. In addition, the existence of natural barriers for stem cell transplantation, including microglial accumulation and abnormal extracellular matrix deposition have been demonstrated, suggesting that several obstacles need to be overcome before such therapies may be implemented. This review addresses recent scientific developments in the field and discusses various strategies that may be potentially used to design cell based therapies to treat human retinal disease.
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Affiliation(s)
- Bhairavi Bhatia
- Division of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology and Moorfields Eye Hospital, London, UK
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Mansoor S, Gupta N, Luczy-Bachman G, Limb GA, Kuppermann BD, Kenney MC. Protective effects of memantine and epicatechin on catechol-induced toxicity on Müller cells in vitro. Toxicology 2010; 271:107-14. [DOI: 10.1016/j.tox.2010.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 03/06/2010] [Accepted: 03/20/2010] [Indexed: 11/29/2022]
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Dahlmann-Noor AH, Vijay S, Limb GA, Khaw PT. Strategies for optic nerve rescue and regeneration in glaucoma and other optic neuropathies. Drug Discov Today 2010; 15:287-99. [PMID: 20197108 DOI: 10.1016/j.drudis.2010.02.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 02/16/2010] [Accepted: 02/19/2010] [Indexed: 12/01/2022]
Abstract
Glaucoma is the most common age-related optic nerve disease and also the most common neuropathy, affecting approximately 60 million people worldwide in its most common forms. This figure is expected to rise to 80 million by 2020. Glaucoma is a neurodegenerative disease in which various triggers induce cascades of secondary events, which ultimately lead to apoptotic retinal ganglion cell (RGC) death. The main risk factor for glaucomatous nerve damage is raised pressure in the eye. Understanding the cascades mediating optic nerve damage enables the development of new, neuroprotective treatment strategies that might not only target the initial insult but also prevent or delay secondary neurodegeneration. Furthermore, neuroregeneration and repopulation of the visual pathway by stem or neural precursor cells is becoming possible. Increasing understanding of the pathways involved in directed axon growth and manipulation of stem and progenitor cells towards an RGC fate have facilitated first successes in animal models of glaucoma.
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Affiliation(s)
- A H Dahlmann-Noor
- NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital and UCL Institute of Ophthalmology, London, UK
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Limb GA, Daniels JT, Cambrey AD, Secker GA, Shortt AJ, Lawrence JM, Khaw PT. Current Prospects for Adult Stem Cell–Based Therapies in Ocular Repair and Regeneration. Curr Eye Res 2009; 31:381-90. [PMID: 16714229 DOI: 10.1080/02713680600681210] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Recent advances in stem cell biology have led to the exploration of stem cell-based therapies to treat a wide range of human diseases. In the ophthalmic field, much hope has been placed on the potential use of these cells to restore sight, particularly in those conditions in which other established treatments have failed and in which visual function has been irreversibly damaged by disease or injury. At present, there are many limitations for the immediate use of embryonic stem cells to treat ocular disease, and as more evidence emerges that adult stem cells are present in the adult human eye, it is clear that these cells may have advantages to develop into feasible therapeutic treatments without the problems associated with embryonic research and immune rejection. Here we discuss the current prospects for the application of various adult ocular stem cells to human therapies for restoration of vision.
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Affiliation(s)
- G A Limb
- Ocular Repair and Regeneration Biology Unit, Departments of Cell Biology and Pathology, Institute of Ophthalmology, UCL and Moorfields Eye Hospital, 11 Bath Street, London, UK.
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Burmeister SL, Hartwig D, Limb GA, Kremling C, Hoerauf H, Müller M, Geerling G. Effect of various platelet preparations on retinal muller cells. Invest Ophthalmol Vis Sci 2009; 50:4881-6. [PMID: 19443715 DOI: 10.1167/iovs.08-3057] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Peeling of the internal limiting membrane is the treatment of choice for macular holes. Fresh platelet suspension (PS) is used to support wound healing in persistent macular holes. The concentration of growth factors in fresh, frozen, and thrombin-activated PSs were compared, to optimize their trophic potential and examine their capacity to support proliferation, migration, and contraction of human retinal Müller cells. METHODS The concentration of various growth factors in frozen PS, thrombin-activated PS, and plasma were evaluated by ELISA. The effect of these preparations on proliferation, migration, and contraction of human Müller cells were evaluated with an ATP-assay, a colony-dispersion assay, and a detached collagen gel contraction assay respectively. Plasma was tested as a control. RESULTS Frozen and thrombin-activated PSs contained significantly more EGF, TGF-beta1, and PDGF than did plasma. The highest concentrations of EGF and FGF were found in frozen PS. All platelet preparations and plasma supported cell growth significantly better than the control, which was serum-free culture medium. Müller cells migrated better when incubated with thrombin-activated PS than with any other test solution. Contraction was extremely strong after incubation with fresh PS compared with plasma or thrombin-activated or frozen PSs. CONCLUSIONS Frozen and thrombin-activated PSs may be suitable alternatives to fresh PS for persisting macular holes, due to their superior effect on Müller cell migration.
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Sancho-Pelluz J, Wunderlich KA, Rauch U, Romero FJ, van Veen T, Limb GA, Crocker PR, Perez MT. Sialoadhesin Expression in Intact Degenerating Retinas and Following Transplantation. ACTA ACUST UNITED AC 2008; 49:5602-10. [DOI: 10.1167/iovs.08-2117] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Javier Sancho-Pelluz
- From the Department of Ophthalmology and2Fundacio´n Oftalmolo´gica del Mediterra´neo (FOM) and Universidad Cardenal Herrera-CEU, Valencia, Spain;3Experimental Ophthalmology, University Eye Hospital, Tu¨bingen, Germany; the Divisions of
| | | | - Uwe Rauch
- Vessel Wall Biology Group, Lund University, Lund, Sweden; the
| | - F. Javier Romero
- Fundacio´n Oftalmolo´gica del Mediterra´neo (FOM) and Universidad Cardenal Herrera-CEU, Valencia, Spain
| | - Theo van Veen
- From the Department of Ophthalmology and3Experimental Ophthalmology, University Eye Hospital, Tu¨bingen, Germany; the Divisions of
| | - G. Astrid Limb
- Pathology and6Cell Biology, UCL Institute of Ophthalmology, London, United Kingdom; the
| | - Paul R. Crocker
- Wellcome Trust Biocentre, University of Dundee, Dundee, United Kingdom; and the
| | - Maria-Thereza Perez
- From the Department of Ophthalmology and8Department of Ophthalmology, University of Copenhagen, Glostrup Hospital, Glostrup, Denmark
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Bull ND, Limb GA, Martin KR. Human Müller stem cell (MIO-M1) transplantation in a rat model of glaucoma: survival, differentiation, and integration. Invest Ophthalmol Vis Sci 2008; 49:3449-56. [PMID: 18408183 DOI: 10.1167/iovs.08-1770] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Stem cell transplantation is a potential treatment strategy for neurodegenerative diseases such as glaucoma. The Müller stem cell line MIO-M1 can be differentiated to produce retinal neurons and glia. The survival, migration, differentiation, and integration of MIO-M1 cells were investigated in a rat model of glaucoma. The effect of modulating the retinal environment with either chondroitinase ABC or erythropoietin was also studied. METHODS Intraocular pressure was chronically increased unilaterally by using a laser glaucoma model in adult rats. EGFP-transduced MIO-M1 cells were transplanted into the vitreous or subretinal space of glaucomatous or untreated eyes. Oral immune suppressants were administered to reduce xenograft rejection. Survival, migration, differentiation, and integration of grafted cells were assessed by immunohistochemistry. RESULTS Transplanted cells survived for 2 to 3 weeks in vivo, although microglia/macrophage infiltration and a reduction in graft survival were seen by 4 weeks. Grafted cells displayed a migratory phenotype with an elongated bipolar shape often oriented toward the retina. Transplanted cells expressed markers such as PSA-NCAM, GFAP, and beta-III-tubulin. The host retina was resistant to MIO-M1 migration, but modification of the local environment with erythropoietin or chondroitinase ABC facilitated retinal infiltration by MIO-M1 cells. CONCLUSIONS The results demonstrate that differentiating MIO-M1 cells within the glaucomatous eye produced cells that expressed neuronal and glial cell markers. The retina was relatively resistant to transplant integration, and long-term xenograft survival was limited. However, local modulation of the retinal environment enhanced the integration of MIO-M1 cells into the glaucomatous retina.
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Affiliation(s)
- Natalie D Bull
- Cambridge Centre for Brain Repair, University of Cambridge, Cambridge, United Kingdom
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Ghazi-Nouri SMS, Ellis JS, Moss S, Limb GA, Charteris DG. Expression and localisation of BDNF, NT4 and TrkB in proliferative vitreoretinopathy. Exp Eye Res 2008; 86:819-27. [PMID: 18405896 DOI: 10.1016/j.exer.2008.02.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Revised: 01/12/2008] [Accepted: 02/26/2008] [Indexed: 01/14/2023]
Abstract
Exogenous brain derived neurotrophic factor (BDNF) is known to rescue ganglion cell death after optic nerve injury. Its mechanism of action is believed to be indirect via glial cells in the retina. In this study we investigated the changes in expression and localisation of BDNF, neurotrophin-4 (NT4) and their common receptor (TrkB) in retinectomy sections of patients with proliferative vitreoretinopathy (PVR). Nine full-thickness retinectomy specimens obtained at retinal reattachment surgery for PVR were fixed in 4% paraformaldehyde immediately after excision and compared to similarly processed normal donor retinas (4 eyes). Agarose-embedded sections (100 microm thick) were double labelled for immunohistochemistry by confocal microscopy, with antibodies against BDNF, NT4, TrkB, rod opsin, glial fibrillary acidic protein (GFAP), cellular retinaldehyde binding protein (CRALBP) and Brn3. This study demonstrates expression of NT4 by ganglion cells and shows expression of BDNF and NT4 in the outer photoreceptor segments is downregulated during PVR, whilst NT4 is markedly upregulated throughout the retina during this condition. The findings here suggest that NT4 may play a neural protective role during the development of PVR. It also shows that upregulation of NT4 in PVR is localised to Müller glial cells, indicating either over-expression of this factor by Müller cells or that Müller cells internalise NT4 for trafficking across the retina. TrkB expression was not observed in PVR retina. The observations that Müller glia demonstrate upregulation of NT4 suggests that retinal injury may lead to activation of this neurotrophin by Müller cells as part of their neuroprotective functions.
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Singhal S, Lawrence JM, Bhatia B, Ellis JS, Kwan AS, Macneil A, Luthert PJ, Fawcett JW, Perez MT, Khaw PT, Limb GA. Chondroitin sulfate proteoglycans and microglia prevent migration and integration of grafted Müller stem cells into degenerating retina. Stem Cells 2008; 26:1074-82. [PMID: 18218817 DOI: 10.1634/stemcells.2007-0898] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
At present, there are severe limitations to the successful migration and integration of stem cells transplanted into the degenerated retina to restore visual function. This study investigated the potential role of chondroitin sulfate proteoglycans (CSPGs) and microglia in the migration of human Müller glia with neural stem cell characteristics following subretinal injection into the Lister hooded (LH) and Royal College of Surgeons (RCS) rat retinae. Neonate LH rat retina showed minimal baseline microglial accumulation (CD68-positive cells) that increased significantly 2 weeks after transplantation (p < .001), particularly in the ganglion cell layer (GCL) and inner plexiform layer. In contrast, nontransplanted 5-week-old RCS rat retina showed considerable baseline microglial accumulation in the outer nuclear layer (ONL) and photoreceptor outer segment debris zone (DZ) that further increased (p < .05) throughout the retina 2 weeks after transplantation. Marked deposition of the N-terminal fragment of CSPGs, as well as neurocan and versican, was observed in the DZ of 5-week-old RCS rat retinae, which contrasted with the limited expression of these proteins in the GCL of the adult and neonate LH rat retinae. Staining for CSPGs and CD68 revealed colocalization of these two molecules in cells infiltrating the ONL and DZ of the degenerating RCS rat retina. Enhanced immune suppression with oral prednisolone and intraperitoneal injections of indomethacin caused a reduction in the number of microglia but did not facilitate Müller stem cell migration. However, injection of cells with chondroitinase ABC combined with enhanced immune suppression caused a dramatic increase in the migration of Müller stem cells into all the retinal cell layers. These observations suggest that both microglia and CSPGs constitute a barrier for stem cell migration following transplantation into experimental models of retinal degeneration and that control of matrix deposition and the innate microglial response to neural retina degeneration may need to be addressed when translating cell-based therapies to treat human retinal disease.
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Affiliation(s)
- Shweta Singhal
- Institute of Ophthalmology and Moorfields Eye Hospital, London, United Kingdom
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Abstract
BACKGROUND Advances in the stem cell field provide much hope for the use of these cells in the regeneration of ocular tissue damaged by diseases for which no treatments are yet available. Here, we discuss the current status and limitations on the application of stem cells to ocular therapies, and consider the future prospects for their use in the restoration of vision. SOURCE OF DATA The review summarizes the achievements to date and the present areas of stem cell investigations in the ophthalmic field, based on a literature search and knowledge gained by the authors' work in the subject. AREAS OF AGREEMENT Owing to its accessibility, the cornea constitutes an easy anatomical target for stem cell regeneration. On this basis, limbal epithelial stem transplantation is the only ocular cell-based therapy already in use in the clinical setting. AREAS OF CONTROVERSY Regeneration of the retina, a less accessible and complex neural tissue, currently constitutes a major challenge. Investigations into the potential use of stem cells for retina regeneration have generated variable data and no therapies have yet been designed for human treatments. GROWING POINTS Despite the present limitations, it has been progressively accepted that various stem cells may have potential use for the development of cell-based therapies to restore retinal function. AREAS FOR RESEARCH DEVELOPMENT: There is need to understand the cell requirements and environmental conditions that may promote functional integration and long-term survival of stem cells within the diseased retina. At present, this constitutes a major area of research.
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Affiliation(s)
- G Astrid Limb
- UCL Institute of Ophthalmology, 11 Bath Street, London EC1V 9EL, UK.
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Shortt AJ, Secker GA, Notara MD, Limb GA, Khaw PT, Tuft SJ, Daniels JT. Transplantation of ex vivo cultured limbal epithelial stem cells: a review of techniques and clinical results. Surv Ophthalmol 2007; 52:483-502. [PMID: 17719371 DOI: 10.1016/j.survophthal.2007.06.013] [Citation(s) in RCA: 220] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ex vivo cultured limbal epithelial stem cells have been used successfully to treat corneal limbal stem cell deficiency. We identified 17 reports of the application of this novel cell-based therapy in humans. In addition we identified four reports of the use of culture oral mucosal epithelial cells to treat limbal stem cell deficiency. We examined these reports to discern the success rate, complication rate, visual outcome, whether there is an optimal technique and which patients are the most likely to benefit. We also discuss the different culture methods employed and the regulations governing cell banks that are providing this service. We found that the techniques used to cultivate and transplant cells varied, but that no individual method was clearly superior. The reported success rate is similar across all studies for both allografts and autografts. The clinical indications for this treatment are not clearly defined as indicated by the variety of disorders treated. Follow-up is limited and the long-term success rate is yet to be established. Nonetheless, we conclude that there is sufficient evidence to support the continued use and refinement of this procedure as a treatment for corneal stem cell deficiency.
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Affiliation(s)
- Alex J Shortt
- Ocular Repair and Regeneration Biology Unit, Institute of Ophthalmology, London
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Limb GA, Matter K, Murphy G, Cambrey AD, Bishop PN, Morris GE, Khaw PT. Matrix metalloproteinase-1 associates with intracellular organelles and confers resistance to lamin A/C degradation during apoptosis. Am J Pathol 2005; 166:1555-63. [PMID: 15855654 PMCID: PMC1606407 DOI: 10.1016/s0002-9440(10)62371-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Since the first description of matrix metalloproteinase (MMP)-1 as an interstitial collagenase, great importance has been ascribed to this enzyme in extracellular matrix remodeling during tumoral, inflammatory, and angiogenic processes. As more evidence for the role of MMPs in targeting nonmatrix substrates emerges, casual observations that intracellular MMP-1 is found in vitro and in vivo prompt investigation of the role that MMP-1 may play on basic cell functions such as cell division and apoptosis. Here we show for the first time that MMP-1 not only has extracellular functions but that it is strongly associated with mitochondria and nuclei and accumulates within the cells during the mitotic phase of the cell cycle. On induction of apoptosis, MMP-1 co-localized with aggregated mitochondria and accumulated around fragmented nuclei. Inhibition of this enzyme by RNA interference or treatment with a broad MMP inhibitor caused faster degradation of lamin A, activation of caspases, and fragmentation of DNA when compared with untreated cells. These observations strongly suggest that intracellular association of MMP-1 to mitochondria and nuclei confers resistance to apoptosis and may explain the well-known association of this enzyme with tumor cell survival and spreading.
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Affiliation(s)
- G Astrid Limb
- Department of Pathology, Institute of Ophthalmology, University College London and Moorfields Eye Hospital, 11 Bath St., London EC1V 9EL.
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Hollborn M, Tenckhoff S, Jahn K, Iandiev I, Biedermann B, Schnurrbusch UEK, Limb GA, Reichenbach A, Wolf S, Wiedemann P, Kohen L, Bringmann A. Changes in retinal gene expression in proliferative vitreoretinopathy: glial cell expression of HB-EGF. Mol Vis 2005; 11:397-413. [PMID: 15988409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
PURPOSE To compare the gene expression pattern of control postmortem retinas with retinas from patients with proliferative vitreoretinopathy (PVR), to determine the expression of the heparin binding epidermal growth factor-like growth factor (HB-EGF) by glial cells in fibroproliferative membranes, and to examine whether cells of the human Müller cell line, MIO-M1, respond to HB-EGF with proliferation, migration, and secretion of the vascular endothelial growth factor (VEGF). METHODS To identify genes that were differently expressed in PVR and control retinas, the RNA from the neural retinas of seven postmortem donors and of two patients with PVR were analyzed for differential gene expression, by hybridization of labeled cRNA probes to an Affymetrix human genome microarray set. The results were validated by real time PCR experiments investigating RNA from 6 postmortem retinas and 4 PVR retinas. Epiretinal PVR membranes were immunohistochemically stained for colocalization of HB-EGF and the glial cell marker, glial fibrillary acidic protein (GFAP). The HB-EGF evoked proliferation of cultured Müller cells was investigated by a bromodeoxyuridine immunoassay, chemotaxis was assessed with a migration assay, and the release of VEGF was evaluated by ELISA. RESULTS Out of the 12,600 genes and expressed sequence tags investigated, the levels of 80 showed an increased expression, and 21 were expressed at decreased levels, in the retinas of PVR patients compared to the control retinas. The upregulated signals include genes for nuclear and cell cycle related proteins, extracellular secretory proteins, cytosolic signaling proteins, and proteins of the membrane and the extracellular matrix. The genes of the hepatocyte growth factor and of HB-EGF were found to be expressed in PVR retinas but not in control retinas. In epiretinal membranes of patients with PVR, HB-EGF immunoreactivity partially colocalized with GFAP. In cultured Müller cells, HB-EGF stimulated both proliferation and chemotaxis, and the secretion of VEGF, via activation of the extracellular signal regulated kinases 1 and 2 and of the phosphatidylinositol-3 kinase. CONCLUSIONS The development of PVR is accompanied by complex changes of the gene expression in the neural retina, with an upregulation of genes that support cell proliferation, cell signaling, cell motility, and extracellular matrix remodeling. HB-EGF is one of the factors that are significantly upregulated in PVR retinas. HB-EGF expression in fibroproliferative tissue and its stimulatory effect on glial cell proliferation, chemotaxis, and VEGF secretion suggest that HB-EGF may be a factor mediating glial cell responses during PVR.
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Affiliation(s)
- Margrit Hollborn
- Department of Ophthalmology, University Eye Hospital, University of Leipzig, Leipzig, Germany.
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Asaria RHY, Kon CH, Bunce C, Sethi CS, Limb GA, Khaw PT, Aylward GW, Charteris DG. Silicone oil concentrates fibrogenic growth factors in the retro-oil fluid. Br J Ophthalmol 2004; 88:1439-42. [PMID: 15489490 PMCID: PMC1772397 DOI: 10.1136/bjo.2003.040402] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIM To determine whether silicone oil concentrates protein and growth factors in the retro-oil fluid. METHODS A laboratory analysis of intraocular fluid and vitreous specimens obtained from patients undergoing removal of silicone oil, revision vitrectomy, or primary vitrectomy for macular hole, proliferative vitreoretinopathy (PVR), or retinal detachment. Patients were prospectively recruited from routine vitreoretinal operating lists. Vitreous cavity fluid and vitreous samples were analysed for the presence of transforming growth factor beta (TGF-beta2), basic fibroblast growth factor (bFGF), interleukin 6 (IL-6), and total protein using either commercially available enzyme linked immunosorbent assays (ELISA) or protein assay kits. RESULTS The median levels of bFGF, IL-6, and protein in the retro-oil fluid were raised (p<0.05) compared to all the other vitreous and vitreous cavity fluid samples. bFGF, IL-6, and protein levels were raised in PVR vitreous compared to non-PVR vitreous. TGF-beta2 levels were not significantly raised in retro-oil fluid or in PVR vitreous. CONCLUSIONS The concentration of fibrogenic (bFGF) and inflammatory (IL-6) growth factors and protein is raised in retro-silicone oil fluid. This may contribute to the process of retro-oil perisilicone proliferation and subsequent fibrocellular membrane formation.
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Hollborn M, Krausse C, Iandiev I, Yafai Y, Tenckhoff S, Bigl M, Schnurrbusch UEK, Limb GA, Reichenbach A, Kohen L, Wolf S, Wiedemann P, Bringmann A. Glial cell expression of hepatocyte growth factor in vitreoretinal proliferative disease. J Transl Med 2004; 84:963-72. [PMID: 15156160 DOI: 10.1038/labinvest.3700121] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The hepatocyte growth factor (HGF) has been crucially implicated in the development of proliferative retinal diseases; however, it is unclear whether retinal glial cells express or respond to HGF. Therefore, we examined the expression of HGF and of the receptor for HGF, c-Met, by immunohistochemical costaining with glial fibrillary acidic protein (GFAP) in epiretinal membranes of patients with proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR), respectively. Furthermore, it was determined whether cells of the human retinal glial cell line, MIO-M1, secrete HGF protein, and whether HGF stimulates proliferation and chemotaxis, and secretion of the vascular endothelial growth factor (VEGF). Neuroretinas of patients with PVR express elevated mRNA level for HGF in comparison to control retinas. In epiretinal membranes of patients with PVR or PDR, immunoreactivity for HGF and for c-Met, respectively, partially colocalized with immunoreactivity for GFAP. Fetal bovine serum and basic fibroblast growth factor, but not heparin-binding epidermal or platelet-derived growth factors, evoked HGF secretion by cultured retinal glial cells. HGF displayed only a marginal effect on cell proliferation while it stimulated chemotaxis. HGF promoted the secretion of VEGF, via activation of the phosphatidylinositol-3 kinase. It is concluded that glial cells in epiretinal membranes express both HGF protein and c-Met receptors. The results suggest an autocrine/paracrine role of HGF in glial cell responses during proliferative vitreoretinal disorders as well as in retinal neovascularization, by stimulating of VEGF release.
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Affiliation(s)
- Margrit Hollborn
- Department of Ophthalmology, University Eye Clinic, Leipzig, Germany
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Hollborn M, Jahn K, Limb GA, Kohen L, Wiedemann P, Bringmann A. Characterization of the basic fibroblast growth factor-evoked proliferation of the human Müller cell line, MIO-M1. Graefes Arch Clin Exp Ophthalmol 2004; 242:414-22. [PMID: 14963717 DOI: 10.1007/s00417-004-0879-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2003] [Revised: 01/07/2004] [Accepted: 01/19/2004] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND Basic fibroblast growth factor (bFGF) has been suggested to mediate activation of Müller glial cells in the ischemic-hypoxic retina. However, the intracellular pathways activated by bFGF in human Müller cells have been little explored. We characterized the signaling transduction pathways which are involved in the control and growth factor-evoked proliferation of a recently described human Müller cell line, MIO-M1. In addition, we investigated whether bFGF evoked the release of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) from the cells. METHODS The growth factor-evoked proliferation of cultured MIO-M1 cells was estimated by means of a bromodeoxyuridine immunoassay, in the absence and presence of blockers of mitogen-activated protein kinases (MAPKs) and of the phosphatidylinositol-3 kinase (PI3K). The activation state of the p44/p42 MAPK was determined by Western blotting, and the bFGF-evoked release of VEGF and HGF was evaluated by ELISA. RESULTS bFGF evoked a concentration-dependent increase of the cell proliferation, with an EC50 of approximately 1 ng/ml, via activation of both the p44/p42 MAPK and the p38 MAPK. In contrast, the mitogenic effects of the platelet-derived and the heparin-binding epidermal growth factors were dependent on p44/p42 MAPK activation and independent of activation of p38 MAPK. The transforming growth factors beta1 and beta2 also evoked cell proliferation which was independent of activation of the MAPKs investigated. bFGF evoked a release of VEGF and of HGF by the cells; these effects were independent of MAPK activation and were possibly mediated by activation of the PI3K signaling pathway. CONCLUSION bFGF evokes multiple intracellular signaling pathways in human Müller cells which underlie the gliotic cell responses upon ischemic-hypoxic insults in the retina. Beside the stimulation of cell proliferation, which is dependent on activation of p44/p42 and p38 MAPKs, bFGF induces the secretion of VEGF and HGF by Müller cells.
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Affiliation(s)
- Margrit Hollborn
- Department of Ophthalmology and Eye Clinic, University of Leipzig, Liebigstrasse 10-14, 04103, Leipzig, Germany.
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