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Journal Francais D'ophtalmologie Mar 2022
Topics: Fluorescein Angiography; Fundus Oculi; Humans; Retinal Detachment; Retinal Perforations; Retinal Pigments; Tomography, Optical Coherence
PubMed: 35078647
DOI: 10.1016/j.jfo.2021.05.016 -
Retinal Cases & Brief Reports Sep 2023The purpose of this study was to describe the occurrence of acute retinal pigment epitheliitis in association with serologic evidence of acute Coxsackie A virus...
PURPOSE
The purpose of this study was to describe the occurrence of acute retinal pigment epitheliitis in association with serologic evidence of acute Coxsackie A virus infection.
METHODS
This study is a case report.
RESULTS
A 37-year-old man noted an acute onset of paracentral scotomas in his right eye correlating with stippled retinal pigment epithelial pigment alterations with whitish halos surrounding the fovea. Spectral domain optical coherence tomography revealed scattered distinct retinal pigment epithelial elevations in the paracentral macular region arranged in an annular fashion, with associated alterations in the interdigitation and ellipsoid zone layers anterior to the retinal pigment epithelial, characteristic of acute retinal pigment E. Suspicion of acute Coxsackie A virus in the patient because of the presence of simultaneous viral exanthematous illness in the patient's 1-year-old son prompted serologic testing for Coxsackie virus. Titers showed strongly positive IgM ("early") antibody for several Coxsackievirus A serotypes, including A16 (most commonly associated with hand-foot-mouth disease). Spontaneous regression of the anatomical and clinical findings occurred over the next month, with complete resolution noted 16 months later.
CONCLUSION
This is the first documented case of acute retinal pigment epitheliitis associated with evidence of acute Coxsackie A virus infection. Corroboration with serology in future cases would add to evidence that acute retinal pigment epitheliitis is part of the apparently expanding spectrum of recognized "Coxsackie retinopathies."
Topics: Male; Humans; Adult; Infant; Retinitis; Virus Diseases; Retinal Diseases; Retina; Pigmentation Disorders; Retinal Pigments
PubMed: 37643032
DOI: 10.1097/ICB.0000000000001234 -
Journal of Visualized Experiments : JoVE Sep 2022The retinal pigment epithelium (RPE) is a monolayer of polarized pigmented epithelial cells, located between the choroid and neuroretina in the retina. Multiple...
The retinal pigment epithelium (RPE) is a monolayer of polarized pigmented epithelial cells, located between the choroid and neuroretina in the retina. Multiple functions, including phagocytosis, nutrient/metabolite transportation, vitamin A metabolism, etc., are conducted by the RPE on a daily basis. RPE cells are terminally differentiated epithelial cells with little or no regenerative capacity. Loss of RPE cells results in multiple eye diseases leading to visual impairment, such as age-related macular degeneration. Therefore, the establishment of an in vitro culture model of primary RPE cells, which more closely resembles the RPE in vivo than cell lines, is critical for the characteristic and mechanistic studies of RPE cells. Considering the fact that the source of human eyeballs is limited, we create a protocol to culture primary porcine RPE cells. By using this protocol, RPE cells can be easily dissociated from adult porcine eyeballs. Subsequently, these dissociated cells attach to culture dishes/inserts, proliferate to form a confluent monolayer, and quickly re-establish key features of epithelial tissue in vivo within 2 wks. By qRT-PCR, it is demonstrated that primary porcine RPE cells express multiple signature genes at comparable levels with native RPE tissue, while the expressions of most of these genes are lost/highly reduced in human RPE-like cells, ARPE-19. Moreover, the immunofluorescence staining shows the distribution of tight junction, tissue polarity, and cytoskeleton proteins, as well as the presence of RPE65, an isomerase critical for vitamin A metabolism, in cultured primary cells. Altogether, we have developed an easy-to-follow approach to culture primary porcine RPE cells with high purity and native RPE features, which could serve as a good model to understand RPE physiology, study cell toxicities, and facilitate drug screenings.
Topics: Adult; Animals; Swine; Humans; Vitamin A; Retinal Pigment Epithelium; Retina; Cells, Cultured; Epithelial Cells; Retinal Pigments
PubMed: 36282683
DOI: 10.3791/64244 -
Investigative Ophthalmology & Visual... Aug 2023To model the in vivo effects of chloroquine on the retinal pigment epithelium in experimentally tractable cell culture systems and determine the effects of mild...
PURPOSE
To model the in vivo effects of chloroquine on the retinal pigment epithelium in experimentally tractable cell culture systems and determine the effects of mild chloroquine treatment on lysosome function and turnover.
METHODS
Effects of low-dose chloroquine treatment on lysosomal function and accessibility to newly endocytosed cargo were investigated in primary and embryonic stem cell-derived RPE cells and ARPE19 cells using fluorescence and electron microscopy of fluorescent and gold-labeled probes. Lysosomal protein expression and accumulation were measured by quantitative PCR and Western blotting.
RESULTS
Initial chloroquine-induced lysosome neutralization was followed by partial recovery, lysosomal expansion, and accumulation of undegraded endocytic, phagocytic, and autophagic cargo and inhibition of cathepsin D processing. Accumulation of enlarged lysosomes was accompanied by a gradual loss of accessibility of these structures to the endocytic pathway, implying impaired lysosome reformation. Chloroquine-induced accumulation of pro-cathepsin D, as well as the lysosomal membrane protein, LAMP1, was reproduced by treatment with protease inhibitors and preceded changes in lysosomal gene expression.
CONCLUSIONS
Low-dose chloroquine treatment inhibits lysosome reformation, causing a gradual depletion of lysosomes able to interact with cargo-carrying vacuoles and degrade their content. The resulting accumulation of newly synthesized pro-cathepsin D and LAMP1 reflects inhibition of normal turnover of lysosomal constituents and possibly lysosomes themselves. A better understanding of the mechanisms underlying lysosome reformation may reveal new targets for the treatment of chloroquine-induced retinopathy.
Topics: Humans; Chloroquine; Lysosomes; Phagocytosis; Autophagy; Retinal Diseases; Epithelial Cells; Retinal Pigments
PubMed: 37548963
DOI: 10.1167/iovs.64.11.10 -
Methods in Molecular Biology (Clifton,... 2022Several model systems have been developed to investigate mechanisms and regulation of intracellular organelle motility. The fish retinal pigment epithelial (RPE) cell...
Several model systems have been developed to investigate mechanisms and regulation of intracellular organelle motility. The fish retinal pigment epithelial (RPE) cell represents an unusual but simple system for the study of actin-dependent organelle motility. Primary cultures of RPE dissociated from the eye are amenable to motility studies using a simple perfusion chamber and conventional phase contrast microscopy. In vivo, melanin-containing pigment granules (melanosomes) within fish RPE migrate distances up to 100 μm in response to light flux. When sheets of RPE are removed from the eye and dissociated, they attach to the substrate with apical projections extending radially from the central cell body. Melanosomes can be chemically triggered to aggregate or disperse throughout the projections. Melanosome migration in RPE apical projections is dependent on actin filaments and thus renders this model system useful for investigations of actin-dependent organelle motility.
Topics: Actins; Animals; Melanosomes; Perciformes; Pigment Epithelium of Eye; Retinal Pigments
PubMed: 34542860
DOI: 10.1007/978-1-0716-1661-1_15 -
Journal of Visualized Experiments : JoVE May 2023This protocol describes the isolation of cells of the retinal pigment epithelium (RPE) from the eyes of young pigmented guinea pigs for potential application in...
This protocol describes the isolation of cells of the retinal pigment epithelium (RPE) from the eyes of young pigmented guinea pigs for potential application in molecular biology studies, including gene expression analyses. In the context of eye growth regulation and myopia, the RPE likely plays a role as a cellular relay for growth modulatory signals, as it is located between the retina and the two walls of the eye, such as the choroid and sclera. While protocols for isolating the RPE have been developed for both chicks and mice, these protocols have proven not to be directly translatable to the guinea pig, which has become an important and widely used mammalian myopia model. In this study, molecular biology tools were used to examine the expression of specific genes to confirm that the samples were free of contamination from the adjacent tissues. The value of this protocol has already been demonstrated in an RNA-Seq study of RPE from young pigmented guinea pigs exposed to myopia-inducing optical defocus. Beyond eye growth regulation, this protocol has other potential applications in studies of retinal diseases, including myopic maculopathy, one of the leading causes of blindness in myopes, in which the RPE has been implicated. The main advantage of this technique is that it is relatively simple and once perfected, yields high-quality RPE samples suitable for molecular biology studies, including RNA analysis.
Topics: Animals; Guinea Pigs; Epithelial Cells; Mammals; Myopia; Retina; Retinal Pigment Epithelium; Retinal Pigments
PubMed: 37246877
DOI: 10.3791/64837 -
Indian Journal of Ophthalmology May 2020
Topics: Fluorescein Angiography; Humans; Retinal Pigment Epithelium; Retinal Pigments; Retinitis; Tomography, Optical Coherence
PubMed: 32317484
DOI: 10.4103/ijo.IJO_1350_19 -
Eye (London, England) Feb 2024
Topics: Humans; Retinitis; Retinal Diseases; Retinal Pigments; Fluorescein Angiography; Acute Disease
PubMed: 37532834
DOI: 10.1038/s41433-023-02683-w -
The American Journal of Pathology Nov 2023
Topics: Humans; Macular Degeneration; Epithelial Cells; Retinal Pigments
PubMed: 37160188
DOI: 10.1016/j.ajpath.2023.04.005 -
Indian Journal of Ophthalmology Mar 2022
Topics: Central Serous Chorioretinopathy; Choroid; Choroid Diseases; Fluorescein Angiography; Humans; Retinal Pigments
PubMed: 35225538
DOI: 10.4103/ijo.IJO_2753_21