Retinal Pigment Epithelial (retinal + pigment_epithelial)

Distribution by Scientific Domains

Terms modified by Retinal Pigment Epithelial

  • retinal pigment epithelial cell
  • retinal pigment epithelial detachment

  • Selected Abstracts


    2135: Influence of Hsp90 and HDAC inhibition and tubulin acetylation on perinuclear protein aggregation in human retinal pigment epithelial cells

    ACTA OPHTHALMOLOGICA, Issue 2010
    K KAARNIRANTA
    Purpose Retinal pigment epithelial (RPE) cells are continually exposed to oxidative stress that contributes to protein misfolding, aggregation and functional abnormalities during aging. The protein aggregates formed at the cell periphery are delivered along the microtubulus network by dynein dependent retrograde trafficking to a juxtanuclear location. Methods Cellular organelles were analysed by transmission electron microscopy of ARPE-19 cells exposed 5 然 MG-132, 0.25 然 geldanamycin (GA), 1 然 trichostatin A (TSA), 1 然 taxol (TAX) or 5 然 nocodazole (NOC) for 24 hours. In addition, the cells were treated simultaneously with GA or TSA or TAX or NOC and MG-132 up to 24 hours. Ubiquitin, Hsp90, Hsp70, acetylated tubulin and Hsc70 protein levels were analyzed by western blotting. Results Hsp90 inhibition by geldanamycin can effectively suppress proteasome inhibitor, MG-132 ,induced protein aggregation in a way that is an independent of HDAC inhibition, or the tubulin acetylation levels in ARPE-19 cells. However, the tubulin acetylation and polymerization state affects the localization of the proteasome-inhibitor ,induced aggregation. Conclusion Hsp90 inhibition is effectively related to regulation of protein aggregation that is independent of HDAC inhibition or tubulin acetylation levels in the RPE cells. Our findings open new perspectives for understanding the pathogenesis of protein aggregation in retinal cells and can be useful for the development of therapeutic treatments to prevent retinal cell deterioration. [source]


    Actin-dependent motility of melanosomes from fish retinal pigment epithelial (RPE) cells investigated using in vitro motility assays

    CYTOSKELETON, Issue 2 2004
    E. L. McNeil
    Melanosomes (pigment granules) within retinal pigment epithelial (RPE) cells of fish and amphibians undergo massive migrations in response to light conditions to control light flux to the retina. Previous research has shown that melanosome motility within apical projections of dissociated fish RPE cells requires an intact actin cytoskeleton, but the mechanisms and motors involved in melanosome transport in RPE have not been identified. Two in vitro motility assays, the Nitella assay and the sliding filament assay, were used to characterize actin-dependent motor activity of RPE melanosomes. Melanosomes applied to dissected filets of the Characean alga, Nitella, moved along actin cables at a mean rate of 2 ,m/min, similar to the rate of melanosome motility in dissociated, cultured RPE cells. Path lengths of motile melanosomes ranged from 9 to 37 ,m. Melanosome motility in the sliding filament assay was much more variable, ranging from 0.4,33 ,m/min; 70% of velocities ranged from 1,15 ,m/min. Latex beads coated with skeletal muscle myosin II and added to Nitella filets moved in the same direction as RPE melanosomes, indicating that the motility is barbed-end directed. Immunoblotting using antibodies against myosin VIIa and rab27a revealed that both proteins are enriched on melanosome membranes, suggesting that they could play a role in melanosome transport within apical projections of fish RPE. Cell Motil. Cytoskeleton 58:71,82, 2004. 2004 Wiley-Liss, Inc. [source]


    Oxidative damage of retinal pigment epithelial cells and age-related macular degeneration

    DRUG DEVELOPMENT RESEARCH, Issue 5 2007
    Suofu Qin
    Abstract Damage to the retinal pigment epithelial (RPE) cells is an early and crucial event in the molecular pathways leading to clinically relevant age-related macular degeneration (AMD) changes. Oxidative stress, the major environmental risk factor for atrophic AMD, causes RPE injury that results in a chronic inflammatory response, drusen formation, and RPE atrophy. RPE degeneration ultimately leads to a progressive irreversible degeneration of photoreceptors. In vitro studies show that oxidant-treated RPE cells undergo apoptosis, a possible mechanism by which RPE cells are lost during the early phase of atrophic AMD. The main target of oxidative injury appears to be mitochondria, an organelle known to accumulate genomic damage during aging. Addition of GSH, the most abundant intracellular thiol antioxidant, protects RPE cells from oxidant-induced apoptosis. Similar protection occurs with dietary enzyme inducers that increase GSH synthesis. In addition, enhancing survival signaling preserves RPE cells under oxidative stress. These results indicate that therapeutic or nutritional intervention to enhance the antioxidant capacity and survival signaling of RPE may provide an effective way to prevent or treat AMD. This review describes major molecular and cellular events leading to RPE death, and presents currently used and new experimental, forthcoming therapeutic strategies. Drug Dev Res 68:213,225, 2007. 2007 Wiley-Liss, Inc. [source]


    Expression of GITR ligand abrogates immunosuppressive function of ocular tissue and differentially modulates inflammatory cytokines and chemokines

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2006
    Sankaranarayana
    Abstract The glucocorticoid-induced TNF-related receptor ligand (GITRL) was previously shown to be constitutively expressed at low levels in human eye, including retinal pigment epithelial (RPE) cells. By expressing enhanced yellow fluorescent protein-tagged human GITRL in human RPE cells, we investigated the significance of expression of GITRL on human ocular tissue. Confocal immunofluorescence microscopy and flow cytometry confirmed the surface expression of GITRL on RPE cells. However, a soluble form of GITRL was also detected. Remarkably, expression of GITRL on the RPE cells abrogated RPE-mediated immunosuppression of CD3+ T cells, implicated as a possible mechanism for ocular immune privilege. This abrogation of immunosuppression by GITRL-RPE was dependent on GITR-GITRL interaction and could not be mimicked by anti-CD28 antibody. Analysis of cytokine profiles revealed high level of TGF-beta during the immunosuppression by RPE cells while expression of GITRL abrogated the RPE cell-induced TGF-beta secretion. Expression of GITRL also stimulates secretion of an array of proinflammatory cytokines/chemokines from T cells. GITR-GITRL interaction provides a unique proinflammatory costimulation that may signal through a different pathway than that of CD28-B7 costimulation. This study implicated that GITRL could be a potential candidate for regulation of the ocular immune privilege and the balance between immune privilege and inflammation. [source]


    Crosstalk between Hsp70 molecular chaperone, lysosomes and proteasomes in autophagy-mediated proteolysis in human retinal pigment epithelial cells

    JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 9b 2009
    Tuomas Ryh鄚en
    Abstract The pathogenesis of age-related macular degeneration involves chronic oxidative stress, impaired degradation of membranous discs shed from photoreceptor outer segments and accumulation of lysosomal lipofuscin in retinal pigment epithelial (RPE) cells. It has been estimated that a major part of cellular proteolysis occurs in proteasomes, but the importance of proteasomes and the other proteolytic pathways including autophagy in RPE cells is poorly understood. Prior to proteolysis, heat shock proteins (Hsps), agents that function as molecular chaperones, attempt to refold misfolded proteins and thus prevent the accumulation of cytoplasmic protein aggregates. In the present study, the roles of the Hsp70 molecular chaperone and proteasomal and lysosomal proteolytic pathways were evaluated in human RPE cells (ARPE-19). The Hsp70 and ubiquitin protein levels and localization were analysed by Western blotting and immunofluorescense. Confocal and transmission electron microscopy were used to detect cellular organelles and to evaluate the morphological changes. Hsp70 levels were modulated using RNA interference and overexpression techniques. Cell viability was measured by colorimetric assay. The proteasome inhibitor MG-132 evoked the accumulation of perinuclear aggregates positive for Hsp70, ubiquitin-protein conjugates and the lysosomal membrane protein LAMP-2. Interestingly, the hsp70 mRNA depletion significantly increased cell death in conjunction with proteasome inhibition. We found that the accumulation of lysosomes was reversible: a cessation of proteasome inhibition led to clearance of the deposits via a mechanism believed to include autophagy. The molecular chaperone Hsp70, proteasomes and autophagy have an important regulatory role in the protein turnover of human RPE cells and may thus open new avenues for understanding degenerative processes in retinal cells. [source]


    Mitogen-activated protein kinase pathway mediates N -(4-hydroxyphenyl)retinamide-induced neuronal differentiation in the ARPE-19 human retinal pigment epithelial cell line

    JOURNAL OF NEUROCHEMISTRY, Issue 2 2008
    William Samuel
    Abstract We have shown previously that N -(4-hydroxyphenyl)retinamide (4HPR, fenretinide), a retinoic acid derivative, induces neuronal differentiation in cultured human retinal pigment epithelial (RPE) cells [Chen et al., J. Neurochem., 84 (2003), 972]. We asked the question whether the mitogen-activated protein kinase (MAPK) pathway is involved in the regulation of the 4HPR-induced neuronal differentiation of RPE (ARPE-19) cells. When we treated ARPE-19 cells with 4HPR, c-Raf and MEK1/2 kinase were activated resulting in activation of the downstream effector ERK1/2 and of SAPK/JNK. By blocking the upstream kinase MEK1/2 with specific inhibitor U0126 we abrogated the 4HPR-induced phosphorylation of ERK1/2 and SAPK/JNK, indicating that the neuronal differentiation occurs through a positive cross-talk between the ERK and the SAPK/JNK pathways. Both U0126 and the suppression of ERK1/2 expression with small interfering RNA effectively blocked the 4HPR-induced neuronal differentiation of RPE cells and the expression of calretinin. The activated ERK1/2 then induced a sequential activation of p90RSK, and increase in phosphorylation of transcription factors c- fos and c- jun leading to transcriptional activation of AP-1. Taken together, our results clearly demonstrate that c-Raf/MEK1/2 signaling cascade involving ERK1/2 plays a central role in mediating the 4HPR-induced neuronal differentiation and calretinin expression in the human ARPE-19 retinal pigment epithelial cell line. [source]


    Effects of Light Exposure and Use of Intraocular Lens on Retinal Pigment Epithelial Cells In Vitro

    PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2009
    Sheng Hui
    To investigate the effect of a blue light-filtering intraocular lens (IOL) and a UV-absorbing IOL on light-induced damage to retinal pigment epithelial (RPE) cells laden with the lipofuscin fluorophore N -retinylidene- N -retinylethanolamine (A2E), A2E-laden RPE cells were exposed to white light which was filtered by either a blue light-filtering IOL or a UV-absorbing IOL. After 30 min of illumination the cell viability and the level of reactive oxygen species (ROS), free glutathione (GSH), vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) were determined. In the absence of an IOL, the white light exposure decreased cell viability to 37.2% of the nonirradiated control. The UV-absorbing IOL tended to reduce light-induced cell death; however, the decrease was not significant. The blue light-filtering IOL significantly attenuated light-induced cell damage, increasing cell viability to 79.5% of the nonirradiated control. The presence of the blue light-filtering IOL significantly increased GSH and PEDF levels, and decreased ROS and VEGF levels. This study suggests that a blue light-filtering IOL may be more protective against A2E-induced light damage and inhibit more light-induced ROS and VEGF production than a conventional UV-absorbing IOL. [source]


    OT-674 Suppresses Photooxidative Processes Initiated by an RPE Lipofuscin Fluorophore

    PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2008
    Jilin Zhou
    The pathological processes involved in age-related macular degeneration (AMD) include retinal pigment epithelial (RPE) cell degeneration; oxidative mechanisms likely contribute to the demise of these cells. Indeed, RPE cells may be particularly susceptible to photooxidative mechanisms since they accumulate retinoid-derived photoreactive compounds that constitute the lipofuscin of the cell. Thus we undertook to test the capacity of OT-674, the reduction product (Tempol-H) of the nitroxide Tempol, to suppress photooxidative processes initiated by the RPE lipofuscin fluorophore A2E. Accordingly, when ARPE-19 cells that had accumulated A2E were irradiated at 430 nm, pretreatment with OT-674 (0.01,10 mm) was found to confer a resistance to cell death. Monitoring by quantitative HPLC also showed that OT-674 reduced A2E photooxidation in a cell-free system. Moreover, when presented with a singlet oxygen generator, OT-674 served as a quencher of singlet oxygen that was more effective than Trolox and ,-tocopherol. We conclude that OT-674 is a potent antioxidant that suppresses photooxidative processes generated in cultured RPE cells by the lipofuscin fluorophore A2E. As oxidative damage to RPE cells is considered to be a risk factor for AMD, antioxidant therapy with OT-674 may serve a protective role. [source]


    Photochemistry and Photocytotoxicity of Alkaloids from Goldenseal (Hydrastis canadensis L.) 3: Effect on Human Lens and Retinal Pigment Epithelial Cells

    PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2007
    Colin F. Chignell
    ABSTRACT The dried root or rhizome of Goldenseal (Hydrastis canadensis L.) contains several alkaloids including berberine, hydrastine, palmatine and lesser amounts of canadine and hydrastinine. Preparations derived from Goldenseal have been used to treat skin and eye ailments. Berberine, the major alkaloid in Goldenseal root powder, has been used in eye drops to treat trachoma, a disease characterized by keratoconjunctivitis. Berberine and palmatine are also present in extracts from Berberis amurensis Ruprecht (Berberidaceae) which are used to treat ocular disorders. We have previously shown that Goldenseal alkaloids are phototoxic to keratinocytes (Chem Res Toxicol. 14, 1529, 2001; ibid 19, 739, 2006) and now report their effect on human lens and retinal pigment epithelial cells. Human lens epithelial cells (HLE-B3) were severely damaged when incubated with berberine (25 ,M) and exposed to UVA (5 J cm,2). Under the same conditions, palmatine was less phototoxic and hydrastine, canadine and hydrastinine were inactive. Moderate protection against berberine phototoxicity was afforded by the antioxidants ascorbate (2 mM) and N -acetylcysteine (5 mM). When exposed to UVA (5 J cm,2) both berberine (10 ,M) and palmatine (10 ,M) caused mild DNA damage as determined by the alkaline comet assay which measures single strand breaks. Berberine and palmatine are the only Goldenseal alkaloids with appreciable absorption above 400 nm. Because light at wavelengths below 400 nm is cut off by the anterior portion of the adult human eye only berberine and palmatine were tested for phototoxicity to human retinal pigment epithelial (hRPE) cells. Although berberine did damage hRPE cells when irradiated with visible light (, > 400 nm) approximately 10 times higher concentrations were required to produce the same amount of damage as seen in lens cells. Palmatine was not phototoxic to hRPE cells. Neither berberine nor palmatine photodamaged DNA in hRPE. Infusions of Goldenseal are estimated to contain ,1 mM berberine, while in tinctures the alkaloid concentration may be more than 10 times higher. Our findings show that eyewashes and lotions derived from Goldenseal or containing berberine must be used with caution when the eyes are exposed to bright sunlight but that oral preparations are not likely to cause ocular phototoxicity. [source]


    Phototoxicity in Human Retinal Pigment Epithelial Cells Promoted by Hypericin, a Component of St. John's Wort,

    PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2007
    Albert R. Wielgus
    ABSTRACT St. John's wort (SJW), an over-the-counter antidepressant, contains hypericin, which absorbs light in the UV and visible ranges. In vivo studies have determined that hypericin is phototoxic to skin and our previous in vitro studies with lens tissues have determined that it is potentially phototoxic to the human lens. To determine if hypericin might also be phototoxic to the human retina, we exposed human retinal pigment epithelial (hRPE) cells to 10,7 to 10,5 M hypericin. Fluorescence emission detected from the cells (,ex = 488 nm; ,em = 505 nm) confirmed hypericin uptake by human RPE. Neither hypericin exposure alone nor visible light exposure alone reduced cell viability. However when irradiated with 0.7 J cm,2 of visible light (, > 400 nm) there was loss of cell viability as measured by MTS and lactate dehydrogenase assays. The presence of hypericin in irradiated hRPE cells significantly changed the redox equilibrium of glutathione and a decrease in the activity of glutathione reductase. Increased lipid peroxidation as measured by the thiobarbituric acid reactive substances assay correlated to hypericin concentration in hRPE cells and visible light radiation. Thus, ingested SJW is potentially phototoxic to the retina and could contribute to retinal or early macular degeneration. [source]


    2231: Age-related modifications in RPE cells

    ACTA OPHTHALMOLOGICA, Issue 2010
    E MANNERMAA
    Age-related macular degeneration (AMD) is a multi-factorial polygenetic aging disease. It has been shown that RPE dysfunction predisposes neural retinal dysfunction and the development of choroidal neovascularization. The pathogenesis of age-related macular degeneration (AMD) essentially involves chronic oxidative stress, increased accumulation of lipofuscin in retinal pigment epithelial (RPE) cells and extracellular drusen formation, as well as the presence of chronic inflammation. The capacity to prevent the accumulation of cellular cytotoxic protein aggregates is decreased in senescent cells which may evoke lipofuscin accumulation into lysosomes in postmitotic RPE cells. This presence of lipofuscin decreases lysosomal enzyme activity and impairs autophagic clearance of damaged proteins which should be removed from cells. Proteasomes are another crucial proteolytic machine which degrades especially cellular proteins damaged by oxidative stress. The cross-talk between lysosomes, autophagy and proteasomes in RPE cell protein aggregation, their role as a possible therapeutic target and their involvement in the pathogenesis of AMD is discussed. In addition, age related changes in Bruch's membrane and choroidal blood flow may take part in the pathogenesis of AMD. This will be also discussed. [source]


    2232: Why are retinal pigment epithelial cells so resistant to oxidative stress?

    ACTA OPHTHALMOLOGICA, Issue 2010
    U BRUNK
    Purpose The functional integrity of postmitotic retinal pigment epithelial (RPE) cells is crucial for photoreceptor survival, and RPE malfunction is considered an important factor behind age-related macular degeneration (AMD). Although RPE cells daily phagocytose large amounts of fatty acid-rich distal photoreceptor material, their lysosomal accumulation of lipofuscin (LF) is nevertheless slow. Only late in life do humans have LF-loaded RPE cells, which then not only have a reduced capacity to endocytose photoreceptor material but also are less capable of keeping up with normal autophagy. The latter activity is important for normal turnover of the cell's own components. Methods ARPE-19 cells in culture were evaluated with respect to lysosomal stability at oxidative stress. Redox-active iron, autophagic activity (evaluation of LC3-I and LC3-II protein), and anti-oxidative proteins were assayed using cytochemistry (Sulphide-Silver Method), electron spin resonance (ESR) and western blotting for a variety of stress proteins. Results The lysosomal compartment of the ARPE-19 cells was found remarkably resistant to oxidative stress. The SSM and ESR methods suggested low lysosomal amounts of redox-active iron and no enhanced autophagy following oxidative stress. The normal autophagy rate was higher than in other professional scavengers. Conclusion The found low amount of lysosomal redox-active iron explains the slow formation of lipofuscin over time and the remarkable stability that ARPE-19 cells and their lysosomes show even under severe oxidative stress. The molecular mechanisms behind this phenomenon may be an unusual capacity to quickly export low mass iron from lysosomes to the cytosol and/or a high normal degree of autophagy of iron-binding stress proteins. [source]


    2233: Endoplasmic reticulum stress and inflammation signaling in RPE cells

    ACTA OPHTHALMOLOGICA, Issue 2010
    A SALMINEN
    Pathogenesis of AMD is linked to augmentation of cellular stress, e.g. oxidative and proteotoxic stress, hypoxia and inflammation. All these conditions trigger stress in endoplasmic reticulum (ER) and in that way can disturb the protein quality control in retinal pigment epithelial (RPE) cells. ER stress stimulates the unfolded protein response (UPR) via the activation of IRE1, PERK and ATF6 transducers. The UPR signaling can restore cellular homeostasis but chronic and overwhelming stress can induce inflammatory response via different UPR signaling pathways and lead to apoptotic cell death. Moreover, ER stress is a well-known inducer of vascular endothelial growth factor (VEGF) expression and in AMD, ER stress could provoke neovascularization and the conversion of dry form to wet counterpart. ER stress has a fundamental role in the pathogenesis of several diseases, e.g. in diabetes and neurodegenerative diseases. This lecture will review the recent advance in understanding the inducers of ER stress, present in RPE cells during AMD, and the possible role of ER stress in evoking inflammation and neovascularization during the pathogenesis of AMD. [source]


    2133: p62/sequestosome 1 as a regulator of proteasome inhibitor-induced autophagy in human retinal pigment epithelial cells

    ACTA OPHTHALMOLOGICA, Issue 2010
    K KAARNIRANTA
    Purpose The pathogenesis of age-related macular degeneration involves impaired protein degradation in retinal pigment epithelial (RPE) cells. The ubiquitin-proteasome pathway and the lysosomal pathway including autophagy are the major proteolytic systems in eukaryotic cells. Prior to proteolysis, heat shock proteins (HSPs) attempt to refold stress ,induced misfolded proteins and thus prevent the accumulation of cytoplasmic protein aggregates. The functional roles of p62 and HSP70 were evaluated in conjunction with protesome inhibitor -induced autophagy in human RPE cells (ARPE-19). Methods The p62, HSP70 and ubiquitin protein levels and localization were analyzed by Western blotting and immunofluorescense. Confocal and transmission electron microscopy were used to detect cellular organelles and to evaluate the morphological changes. The p62 and HSP70 levels were modulated using RNA interference and overexpression techniques. Cell viability was measured by colorimetric assay. Results Proteasome inhibition evoked the accumulation of p62 and HSP70 that strongly co-localized with each other in perinuclear aggregates. The p62 accumulation was time and concentration dependent after MG-132 proteasome inhibitor loading. Interestingly, autophagy induction was p62 and Hsp70 independent. In addition, the p62 silencing decreased the ubiquitination level of the perinuclear aggregates. Recently we showed that hsp70 mRNA depletion increased cell death in ARPE-19 cells. Here we now demonstrate that p62 mRNA silencing has similar effects on cellular viability. Conclusion The p62 and HSP70 are central molecules in the regulation of protein turnover in human retinal pigment epithelial cells in proteasome inhibitor- induced autophagy. [source]


    Functional analysis of mutants of the optineurin gene, associated with some forms of glaucoma

    ACTA OPHTHALMOLOGICA, Issue 2008
    D BALASUBRAMANIAN
    Purpose Mutations in the gene OPTN are associated with normal tension and open angle glaucomas. We have studied the effects of some of these mutations on the cellular biology of retinal ganglion cells, and tried to infer the role of the protein optineurin. Methods We transfected plasmids expressing normal or wild-type (WT) and E50K, R545Q, H26D, and H486R mutant optineurin into a variety of cells such as HeLa, COS-1, retinal pigment epithelial (RPE), and the rat retinal ganglion cell (RGC) line RGC-5, and followed their effects on cell survival by morphologic observation of cells. Expression of optineurin and its mutants was monitored by immunofluorescence staining of cells and by Western blotting. Results The E50K mutant of optineurin, which is associated with the severest phenotype, was seen to selectively induce the death of retinal ganglion cells but not of the other cell lines tested. Neither the wild type cDNA nor the other mutants have any such effect. This cell death induced by E50K OPTN was inhibited by the antioxidants N-acetylcysteine and Trolox. E50K was seen to generate reactive oxygen species (ROS), which were reduced by antioxidants. Coexpression of manganese superoxide dismutase with the E50K mutant abolished ROS production and inhibited cell death. Conclusion E50K optineurin is a gain of function mutant, which has acquired the ability to induce cell death selectively in retinal ganglion cells. This cell death was mediated by oxidative stress. The present findings suggest the possibility of antioxidant use for delaying or controlling some forms of glaucoma. [source]


    Cyclosporine treatment of RPE allografts in the rabbit subretinal space

    ACTA OPHTHALMOLOGICA, Issue 2 2000
    Sven Crafoord
    ABSTRACT. Purpose: To determine the effects of systemic cyclosporine A (CsA) on the survival of retinal pigment epithelial (RPE) allografts in the subretinal space in an animal model using atraumatic transplantation surgery. Methods: Following pars plana vitrectomy, an RPE cell suspension from brown rabbits was injected with a glass micropipette into the subretinal space of 39 albino rabbits. For immunosuppression, 22 rabbits were given an injection of CsA, 20 mg daily intramuscularly, 17 rabbits with RPE grafts were controls. The grafts were monitored by biomicroscopy, color fundus photography, and fluorescein angiography. Rabbits were sacrificed at 1, 3 and 6 months, respectively, and the eyes processed for light and electron microscopy including immunohistochemistry. Results: After three months, the transplanted RPE cells, in both the CsA group and the controls, formed a monolayer in the subretinal space. Although a few macrophages were encountered, there was no massive cellular infiltration and the photoreceptor layer was well preserved. After six months, however, there was a disruption of grafted RPE cells in both groups, characterized by dispersion of melanin pigment in the subretinal space, and invasion of macrophages with focal photoreceptor damage but no infiltration of lymphocytes in the retina or choroid. No significant differences between the CsA treated and the control eyes were discernible. Conclusion: Although the subretinal space has been considered an immunologically privileged site, we found that the survival of RPE allografts was limited. CsA did not prevent RPE allograft destruction in the subretinal space. The transplant seems to be disrupted either by immunological mechanisms that are not inhibited by CsA, or by nonimmunologic events. [source]


    Bilateral macular sub-retinal fluid and retinal pigment epithelial detachment associated with type 2 membrano-proliferative glomerulonephritis

    CLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 5 2008
    Muhammad Amer Awan
    Choroidal neovascularisation (CNV) and idiopathic central serous chorioretinopathy (ICSC) are recognised ocular complications related to type 2 membrano-proliferative glomerulonephritis. We report a 38-year-old white male who presented with a 10-day history of blurring of vision, micropsia and metamorphopsia. He had been diagnosed recently to have type 2 membrano-proliferative glomerulonephritis. On examination, there was bilateral retinal pigment epithelial (RPE) detachment with overlying sub-retinal fluid without any drusen. Fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) confirmed the diagnosis of atypical ICSC. Three months later, sub-retinal fluid and RPE detachment resolved and VA had recovered to 6/6. The case highlights the importance of ophthalmological assessment in these patients to recognise sight-threatening complications. [source]