Journal articles: 'Pigmented epithelium'

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Pittack, C., G. B. Grunwald, and T. A. Reh. "Fibroblast growth factors are necessary for neural retina but not pigmented epithelium differentiation in chick embryos." Development 124, no. 4 (February 15, 1997): 805–16. http://dx.doi.org/10.1242/dev.124.4.805.

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During eye development, optic vesicles evaginate laterally from the neural tube and develop into two bilayered eye cups that are composed of an outer pigment epithelium layer and an inner neural retina layer. Despite their similar embryonic origin, the pigment epithelium and neural retina differentiate into two very distinct tissues. Previous studies have demonstrated that the developmental potential of the pigmented epithelial cells is not completely restricted; until embryonic day 4.5 in chick embryos, the cells are able to switch their phenotype and differentiate into neural retina when treated with fibroblast growth factors (FGF) (Park, C. M., and Hollenberg, M. J. (1989). Dev. Biol. 134, 201–205; Pittack, C., Jones, M., and Reh, T. A. 1991). Development 113, 577–588; Guillemot, F. and Cepko, C. L. (1992). Development 114, 743–754). These studies motivated us to test whether FGF is necessary for neural retina differentiation during the initial stages of eye cup development. Optic vesicles from embryonic day 1.5 chick were cultured for 24 hours as explants in the presence of FGF or neutralizing antibodies to FGF2. The cultured optic vesicles formed eye cups that contained a lens vesicle, neural retina and pigmented epithelium, based on morphology and expression of neural and pigmented epithelium-specific antigens. Addition of FGF to the optic vesicles caused the presumptive pigmented epithelium to undergo neuronal differentiation and, as a consequence, a double retina was formed. By contrast, neutralizing antibodies to FGF2 blocked neural differentiation in the presumptive neural retina, without affecting pigmented epithelial cell differentiation. These data, along with evidence for expression of several FGF family members and their receptors in the developing eye, indicate that members of the FGF family may be required for establishing the distinction between the neural retina and pigmented epithelium in the optic vesicle.

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AbdullGaffar, Badr. "Pilar Cyst Pigmented Epithelial Remnants: A Potential Diagnostic Pitfall." International Journal of Surgical Pathology 27, no. 6 (April 30, 2019): 639–42. http://dx.doi.org/10.1177/1066896919846376.

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Pilar cysts are common cutaneous cysts of follicular origin. They are easy to diagnose clinically and pathologically. Histologic diagnostic difficulties might arise in certain situations, however. Acute inflammation with total destruction of the cyst wall due to rupture with replacement by an abscess formation, foreign body giant cell reaction, and fibrosis could obscure their recognition. Cysts with hybrid lining epithelium could be confused with other cutaneous cysts. Epithelial remnants of the basal layer with loss of the squamous epithelium and shelled out cyst contents might mimic other epithelial cysts and vascular lesions. Few studies focused on the phenomenon of epithelial remnants or epithelial separation of pilar cysts. We report a case of a scalp cyst composed of a single layer of pigmented cuboidal lining epithelium. The initial differential diagnosis was hidrocystoma, solid-cystic hidradenoma, arteriovenous malformation, and lymphangioma. The intraepithelial pigment was melanin. The lining epithelium was positive for cytokeratin cocktail, CK5/6, CK8, CK19, p63, and D2-40 with scattered S-100 protein and melan-A positive melanocytes. Being unaware of the phenomenon of epithelial split in pilar cysts, it was mislabeled as a melanin-pigmented eccrine hidrocystoma. Surgical pathologists should be aware of pilar cysts’ epithelial remnants to avoid potential diagnostic pitfalls. An attention to certain histologic hints and knowledge of the immunoprofile of the basal layer should help pathologists avoid this pitfall.

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Ly, Angelica, Lisa Nivison-Smith, Michael Hennessy, and Michael Kalloniatis. "Pigmented Lesions of the Retinal Pigment Epithelium." Optometry and Vision Science 92, no. 8 (August 2015): 844–57. http://dx.doi.org/10.1097/opx.0000000000000640.

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Jensen, A. M., C. Walker, and M. Westerfield. "mosaic eyes: a zebrafish gene required in pigmented epithelium for apical localization of retinal cell division and lamination." Development 128, no. 1 (January 1, 2001): 95–105. http://dx.doi.org/10.1242/dev.128.1.95.

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For proper function of the retina, the correct proportions of retinal cell types must be generated, they must be organized into cell-specific laminae, and appropriate synaptic connections must be made. To understand the genetic regulation of retinal development, we have analyzed mutations in the mosaic eyes gene that disrupt retinal lamination, the localization of retinal cell divisions to the retinal pigmented epithelial surface and retinal pigmented epithelial development. Although retinal organization is severely disrupted in mosaic eyes mutants, surprisingly, retinal cell differentiation occurs. The positions of dividing cells and neurons in the brain appear normal in mosaic eyes mutants, suggesting that wild-type mosaic eyes function is specifically required for normal retinal development. We demonstrate that mosaic eyes function is required within the retinal pigmented epithelium, rather than in dividing retinal cells. This analysis reveals an interaction between the retinal pigmented epithelium and the retina that is required for retinal patterning. We suggest that wild-type mosaic eyes function is required for the retinal pigmented epithelium to signal properly to the retina.

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Nguyen, M., and H. Arnheiter. "Signaling and transcriptional regulation in early mammalian eye development: a link between FGF and MITF." Development 127, no. 16 (August 15, 2000): 3581–91. http://dx.doi.org/10.1242/dev.127.16.3581.

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During vertebrate eye development, the optic vesicle is partitioned into a domain at its distal tip that will give rise to the neuroretina, and another at its proximal base that will give rise to the pigmented epithelium. Both domains are initially bipotential, each capable of giving rise to either neuroretina or pigmented epithelium. The partitioning depends on extrinsic signals, notably fibroblast growth factors, which emanate from the overlying surface ectoderm and induce the adjacent neuroepithelium to assume the neuroretinal fate. Using explant cultures of mouse optic vesicles, we demonstrate that bipotentiality of the optic neuroepithelium is associated with the initial coexpression of the basic-helix-loop-helix-zipper transcription factor MITF, which is later needed solely in the pigmented epithelium, and a set of distinct transcription factors that become restricted to the neuroretina. Implantation of fibroblast growth factor-coated beads close to the base of the optic vesicle leads to a rapid downregulation of MITF and the development of an epithelium that, by morphology, gene expression, and lack of pigmentation, resembles the future neuroretina. Conversely, the removal of the surface ectoderm results in the maintenance of MITF in the distal optic epithelium, lack of expression of the neuroretinal-specific CHX10 transcription factor, and conversion of this epithelium into a pigmented monolayer. This phenomenon can be prevented by the application of fibroblast growth factor alone. In Mitf mutant embryos, parts of the future pigment epithelium become thickened, lose expression of a number of pigment epithelium transcription factors, gain expression of neuroretinal transcription factors, and eventually transdifferentiate into a laminated second retina. The results support the view that the bipotential optic neuroepithelium is characterized by overlapping gene expression patterns and that selective gene repression, brought about by local extrinsic signals, leads to the separation into discrete expression domains and, hence, to domain specification.

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Moszczynska, Anna, and Michal Opas. "Regulation of adhesion-related protein tyrosine kinases during in vitro differentiation of retinal pigment epithelial cells: translocation of pp60c-src to the nucleus is accompanied by downregulation of pp125FAK." Biochemistry and Cell Biology 72, no. 1-2 (January 1, 1994): 43–48. http://dx.doi.org/10.1139/o94-007.

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In the present report we show that induction of expression of a differentiated phenotype in cultured retinal pigmented epithelium of chick embryo is accompanied by coordinate regulation of expression and distribution of two adhesion-related nonreceptor protein tyrosine kinases, pp60c-src and pp125FAK∙pp60c-src translocates from the cell surface in flat undifferentiated cells to the nucleus in the packed differentiated cells. In contrast, pp125FAK, abundant in focal adhesions of flat undifferentiated cells, is downregulated in cells that have differentiated and packed into an epithelial sheet.Key words: retinal pigment epithelium, retina, tyrosine kinases, adhesion, differentiation.

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Kharitonov, A. E., A. V. Surdina, O. S. Lebedeva, A. N. Bogomazova, and M. A. Lagarkova. "Possibilities for Using Pluripotent Stem Cells for Restoring Damaged Eye Retinal Pigment Epithelium." Acta Naturae 10, no. 3 (September 15, 2018): 30–39. http://dx.doi.org/10.32607/20758251-2018-10-3-30-39.

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The retinal pigment epithelium is a monolayer of pigmented, hexagonal cells connected by tight junctions. These cells compose part of the outer blood-retina barrier, protect the eye from excessive light, have important secretory functions, and support the function of photoreceptors, ensuring the coordination of a variety of regulatory mechanisms. It is the degeneration of the pigment epithelium that is the root cause of many retinal degenerative diseases. The search for reliable cell sources for the transplantation of retinal pigment epithelium is of extreme urgency. Pluripotent stem cells (embryonic stem or induced pluripotent) can be differentiated with high efficiency into the pigment epithelium of the retina, which opens up possibilities for cellular therapy in macular degeneration and can slow down the development of pathology and, perhaps, restore a patient's vision. Pioneering clinical trials on transplantation of retinal pigment epithelial cells differentiated from pluripotent stem cells in the United States and Japan confirmed the need for developing and optimizing such approaches to cell therapy. For effective use, pigment epithelial cells differentiated from pluripotent stem cells should have a set of functional properties characteristic of such cells in vivo. This review summarizes the current state of preclinical and clinical studies in the field of retinal pigment epithelial transplantation therapy. We also discuss different differentiation protocols based on data in the literature and our own data, and the problems holding back the widespread therapeutic application of retinal pigment epithelium differentiated from pluripotent stem cells.

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Hyer, J., T. Mima, and T. Mikawa. "FGF1 patterns the optic vesicle by directing the placement of the neural retina domain." Development 125, no. 5 (March 1, 1998): 869–77. http://dx.doi.org/10.1242/dev.125.5.869.

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Patterning of the bipotential retinal primordia (the optic vesicles) into neural retina and retinal pigmented epithelium depends on its interaction with overlaying surface ectoderm. The surface ectoderm expresses FGFs and the optic vesicles express FGF receptors. Previous FGF-expression data and in vitro analyses support the hypothesis that FGF signaling plays a significant role in patterning the optic vesicle. To test this hypothesis in vivo we removed surface ectoderm, a rich source of FGFs. This ablation generated retinas in which neural and pigmented cell phenotypes were co-mingled. Two in vivo protocols were used to replace FGF secretion by surface ectoderm: (1) implantation of FGF-secreting fibroblasts, and (2) injection of replication-incompetent FGF retroviral expression vectors. The retinas in such embryos exhibited segregated neural and pigmented epithelial domains. The neural retina domains were always close to a source of FGF secretion. These results indicate that, in the absense of surface ectoderm, cells of the optic vesicles display both neural and pigmented retinal phenotypes, and that positional cues provided by FGF organize the bipotential optic vesicle into specific neural retina and pigmented epithelium domains. We conclude that FGF can mimic one of the earliest functions of surface ectoderm during eye development, namely the demarcation of neural retina from pigmented epithelium.

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Cherney, Edward. "Congenital hypertrophy of the retinal pigment epithelium." Ophthalmology journal 6, no. 4 (December 15, 2013): 55–59. http://dx.doi.org/10.17816/ov2013455-59.

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Congenital hypertrophy of the retinal pigment epithelium is a benign pigmented lesion of the posterior pole with a unique clinical appearance. It is flat, round, and has sharp edges. While it is usually black, it may have internal lacunae without pigment. The lesion may also be all hypopigmented. Over many years, the lesions may grow slightly and change their pigmentation. Even though malignant transformation is extremely rare, annual examinations should be performed.

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Soares, Andresa Borges, Vera Cavalcanti de Araújo, Fabricio Passador-Santos, Luiz Alexandre Thomaz, Andre Luis Santana de Freitas, Mario Claudio Mautoni, Rafael Fantelli Stelini, and Maria Leticia Cintra. "Uncommon Pigmented Carcinoma In Situ: Case Report and Brief Review." Clinical Pathology 14 (January 2021): 2632010X2110098. http://dx.doi.org/10.1177/2632010x211009819.

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Pigmented lesions of the oral mucosa encompass several benign and malignant conditions that may be a matter of concern under both clinical and histopathological views. We reported a case of a 62-year-old woman, presenting with an asymptomatic, deeply pigmented lesion on the soft palate. On examination, it appeared asymmetrical, with irregular borders and an area of ulceration. A biopsy, taken to rule out melanoma, revealed a pigmented carcinoma in situ. Throughout the tumor thickness, numerous interspersed melanocytes were found that did not extend to neighboring epithelium. These were large, richly dendritic, and presented abundance of melanin granules and small nuclei. Mild melanin incontinence was found. Scanty transfer of pigment to dysplastic epithelial cells was found through Fontana Masson staining. On immunohistochemical analyses, there were pancytokeratin-stained tumor epithelial cells; increased cell proliferation throughout the entire thickness of the tumor was emphasized by Ki-67 immunomarking. P16 was negative. The dendritic cells were selectively stained for S-100, HMB45 and Melan A. Wide spectrum in situ hybridization for human papillomavirus (HPV) was negative. Unfortunately, following diagnosis, the patient refused any treatment option. Pigmented squamous cell carcinoma with melanocyte colonization must be taken into account in the differential diagnosis of pigmented lesions of the oral cavity.

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Armstrong, M. T., and P. B. Armstrong. "Mechanisms of epibolic tissue spreading analyzed in a model morphogenetic system. Roles for cell migration and tissue contractility." Journal of Cell Science 102, no. 2 (June 1, 1992): 373–85. http://dx.doi.org/10.1242/jcs.102.2.373.

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The processes responsible for epithelial spreading during wound healing and embryonic morphogenesis were investigated in an organ culture model in which an epithelial tissue (chick embryo pigmented retinal epithelium) spread over the surface of an aggregate of mesenchyme cells (chick embryo cardiac mesenchyme). The heart mesenchyme aggregate is differentiated into a core of stellate cells associated with a fibronectin-poor matrix surrounded by a cortical zone, 2–5 cells in thickness, of flattened cells embedded in a fibronectin-rich extracellular matrix. Envelopment of the mesenchyme aggregate is accompanied by a movement of the cells and the fibronectin-rich extracellular matrix of the cortex over the core tissue in advance of the spreading pigmented retina tissue. Three distinct processes were identified as contributing to epithelial spreading in this system: (1) active migration of the pigmented retinal epithelium; (2) active contraction of the cortical cells of the mesenchyme aggregate to tow the attached epithelial tissue over the mesenchyme aggregate; and (3) ingression of surface-located cells of the mesenchyme aggregate to decrease the exposed surface area by decreasing the number of cells at the surface.

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Schafer, D. A., M. S. Mooseker, and J. A. Cooper. "Localization of capping protein in chicken epithelial cells by immunofluorescence and biochemical fractionation." Journal of Cell Biology 118, no. 2 (July 15, 1992): 335–46. http://dx.doi.org/10.1083/jcb.118.2.335.

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We have localized capping protein in epithelial cells of several chicken tissues using affinity-purified polyclonal antibodies and immunofluorescence. Capping protein has a distribution in each tissue coincident with proteins of the cell-cell junctional complex, which includes the zonula adherens, zonula occludens, and desmosome. "En face" views of the epithelial cells showed capping protein distributed in a polygonal pattern coincident with cell boundaries in intestinal epithelium, sensory epithelium of the cochlea, and the pigmented epithelium of the retina and at regions of cell-cell contact between chick embryo kidney cells in culture. "Edge-on" views obtained by confocal microscopy of intact single intestinal epithelial cells and of retinal pigmented epithelium showed that capping protein is located in the apical region of the epithelial cells coincident with the junctional complexes. These images do not resolve the individual types of junctions of the junctional complex. Immunolabeling of microvilli or stereocilia was faint or not detectable. Capping protein was also detected in the cytoplasm of intact intestinal epithelial cells and in nuclei of cells in the pigmented retina and in the kidney cell cultures, but not in nuclei of cells of the intestinal epithelium or sensory epithelium. Biochemical fractionation of isolated intestinal epithelial cells shows capping protein in the brush border fraction, which contains the junctional complexes, and in the soluble fraction. These results are consistent with the results of the immunolabeling experiments. Highly purified microvilli of the brush borders also contained capping protein; this result was unexpected based on the low intensity of immunofluorescence staining of microvilli and stereocilia. The microvilli were not contaminated with junctional complexes, as defined by the absence of several markers for cell junctions. The cause and significance of this discrepancy is not certain at this time. Since capping protein binds the barbed end of actin filaments in vitro, we hypothesize that capping protein is bound to the barbed ends of actin filaments associated with one or more of the junctions of the junctional complex.

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Hamann, Steffen, Thomas Zeuthen, Morten La Cour, Erlend A. Nagelhus, Ole Petter Ottersen, Peter Agre, and Søren Nielsen. "Aquaporins in complex tissues: distribution of aquaporins 1–5 in human and rat eye." American Journal of Physiology-Cell Physiology 274, no. 5 (May 1, 1998): C1332—C1345. http://dx.doi.org/10.1152/ajpcell.1998.274.5.c1332.

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Multiple physiological fluid movements are involved in vision. Here we define the cellular and subcellular sites of aquaporin (AQP) water transport proteins in human and rat eyes by immunoblotting, high-resolution immunocytochemistry, and immunoelectron microscopy. AQP3 is abundant in bulbar conjunctival epithelium and glands but is only weakly present in corneal epithelium. In contrast, AQP5 is prominent in corneal epithelium and apical membranes of lacrimal acini. AQP1 is heavily expressed in scleral fibroblasts, corneal endothelium and keratocytes, and endothelium covering the trabecular meshwork and Schlemm’s canal. Although AQP1 is plentiful in ciliary nonpigmented epithelium, it is not present in ciliary pigmented epithelium. Posterior and anterior epithelium of the iris and anterior lens epithelium also contain significant amounts of AQP1, but AQP0 (major intrinsic protein of the lens) is expressed in lens fiber cells. Retinal Müller cells and astrocytes exhibit notable concentrations of AQP4, whereas neurons and retinal pigment epithelium do not display aquaporin immunolabeling. These studies demonstrate selective expression of AQP1, AQP3, AQP4, and AQP5 in distinct ocular epithelia, predicting specific roles for each in the complex network through which water movements occur in the eye.

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Muntz, W. R. A., and S. L. Wentworth. "Structure of the Adhesive Surface of the Digital Tentacles ofNautilus Pompilius." Journal of the Marine Biological Association of the United Kingdom 75, no. 3 (August 1995): 747–50. http://dx.doi.org/10.1017/s0025315400039163.

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The cirri of the digital tentacles ofNautilus pompiliusare covered by annular ridges, more pronounced on the oral (adhesive) than the aboral side. On the oral side the epithelium is thicker on the proximal and outer surfaces of the ridges than on their distal surfaces. Prominent electron-dense granules occur in the cells of the thick epithelium, but are absent from the thin epithelium and the epithelium of the aboral surface. These granules contain mucopolysaccharide and may be responsible for adhesion.The digital tentacles ofNautilusare used for attachment to, for example, prey, the substratum, or the partner's shell during mating. Their general structure and histology have been described by Owen (1832), Willey (1898), Barber & Wright (1969), Fukuda (1987) and Kier (1987). The mechanism of adhesion is still uncertain. Barber & Wright (1969) report epithelial cells of two types: pigmented cells containing pigment granules 0–5–1 µm in diameter, interspersed with a small number of mucus-producing cells which may help with the adhesive process.

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Rennie, I. G., M. K. Faulkner, and M. A. Parsons. "Adenoma of the pigmented ciliary epithelium." British Journal of Ophthalmology 78, no. 6 (June 1, 1994): 484–85. http://dx.doi.org/10.1136/bjo.78.6.484.

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Sukeda, A., T. Mori, S. Suzuki, and A. Ochiai. "Adenocarcinoma of the pigmented ciliary epithelium." Case Reports 2014, jul11 1 (July 11, 2014): bcr2014204534. http://dx.doi.org/10.1136/bcr-2014-204534.

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DAMATO, B. "Irido-ciliary tumours of the pigmented and non-pigmented ciliary epithelium." Acta Ophthalmologica 91 (August 2013): 0. http://dx.doi.org/10.1111/j.1755-3768.2013.3244.x.

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Teke, Mehmet Yasin, Pinar Ç. Özdal, Figen Batioglu, Ufuk Elgin, and Faruk Öztürk. "Congenital Simple Hamartoma of Retinal Pigment Epithelium: Clinical and Imaging Findings." Case Reports in Ophthalmological Medicine 2012 (2012): 1–3. http://dx.doi.org/10.1155/2012/654502.

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Congenital simple hamartoma of retinal pigment epithelium (CSHRPE) is a rare, asymptomatic, and incidentally detected benign lesion. However, it is very important to do the differential diagnosis from other pigmented retinal lesions. Its clinical presentation and imaging findings are very helpful in doing this differentiation. This paper presents clinical and imaging findings of a 56-year-old woman with incidentally detected CSHRPE. The lesion was small, heavily pigmented, well circumscribed, and slightly elevated. Optical coherence tomography (OCT) scanning was diagnostic and showed an elevated retina at the site of the lesion, increased optical reflectivity on its inner surface, optical shadowing of deeper structures, and clearly cut tumor margins. Ocular ultrasonography, fluorescein angiography, and fundus autofluorescence imaging which is firstly described in this report did not show any characteristic finding.

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Polkinghorne, P. J., S. Ritchie, K. Neale, G. Schoeppner, J. P. S. Thomson, and B. S. Jay. "Pigmented lesions of the retinal pigment epithelium and familial adenomatous polyposis." Eye 4, no. 1 (January 1990): 216–21. http://dx.doi.org/10.1038/eye.1990.29.

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Scupola, Andrea, Gabriela Grimaldi, Maria G. Sammarco, Paola Sasso, Michele Marullo, and Maria A. Blasi. "Multimodal imaging evaluation of combined hamartoma of the retina and retinal pigment epithelium." European Journal of Ophthalmology 30, no. 3 (February 14, 2019): 595–99. http://dx.doi.org/10.1177/1120672119831223.

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Purpose: Combined hamartoma of the retina and retinal pigment epithelium is a rare benign tumor characterized by a variable combination of glial, vascular, and pigmented components. The purpose of our study was to analyze the features of combined hamartoma of the retina and retinal pigment epithelium on optical coherence tomography angiography. Methods: Small case series of two cases of combined hamartoma of the retina and retinal pigment epithelium with macular and optic nerve involvement, evaluated with multimodal imaging including optical coherence tomography, fluorescein angiography, and optical coherence tomography angiography. Results: On optical coherence tomography, combined hamartoma of the retina and retinal pigment epithelium is characterized by disruption of the inner neurosensory retina and a variable degree of involvement of the external retina. Optical coherence tomography angiography showed diffuse alterations of the retinal vessels of the superficial and deeper layers, extended to the peripapillary area. Vessel abnormalities included increased tortuosity and caliber of vessels, vascular traction, and vessel stretching within the lesion. Conclusion: Optical coherence tomography angiography allows in-depth multilayer analysis of tumor vascular network, highlighting the fine abnormalities of retinal vasculature characteristic of combined hamartoma of the retina and retinal pigment epithelium.

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Altynbaev, U. R., and O. I. Lebedeva. "Morphological features of choroidal neovascular membranes in age-related macular degeneration complicated by high pigment epithelial detachment." Kazan medical journal 96, no. 3 (June 15, 2015): 364–68. http://dx.doi.org/10.17750/kmj2015-364.

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Aim. To study the morphological features of choroidal neovascular membranes in patients with wet age-related macular degeneration, complicated by high pigment epithelial detachment. Methods. The study enrolled 10 patients with wet age-related macular degeneration, who underwent vitrectomy with choroidal neovascular membranes removal, including 4 patients with occult choroidal neovascularization and 6 patients with classic choroidal neovascular membrane. Results. Histologic pattern consisting of pigmented epithelium cells layer with Bruch’s membrane, fibrovascular membrane, photoreceptors segments layer and, in some of the cases, choroid fragments, was discovered in tissue specimens of patients with classic choroidal neovascular membrane. Histologic pattern of choroidal neovascular membrane in patients with occult choroidal neovascularization also consisted of pigment epithelium cells layer with Bruch’s membrane, fibrotic neovascular membrane itself and photoreceptors segments layer. Pigment epithelium cell layer, in contrast to the control group, had apparent signs of hyperplasia. Average thickness of pigment layer of the retina was 16.08±4.64 μm in patients with high pigment epithelial detachment, by 30% higher compared to the control group (11.22±3.38 μm, р <0.05). Mean Bruch’s membrane thickness was 6.7±0.19 μm in the main group, which also exceeded the similar values in the control group (5.7±3.8 μm, р <0.05). Histochemical studies revealed qualitative differences between the study groups in the levels of collagen types I and III. Glycosaminoglycans, in contrast, were detected only in the group with classic choroidal neovascular membrane. Conclusion. In patients with occult choroidal neovascular membrane complicated by high pigment epithelial detachment, Bruch’s membrane thickening was found due to collagen type 1 deposits on the outer surface, which caused a local hydrodynamics alterations and influences the bioavailability of medications.

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Mansoor, S. "Ciliary body adenoma of non-pigmented epithelium." Journal of Clinical Pathology 57, no. 9 (September 1, 2004): 997–98. http://dx.doi.org/10.1136/jcp.2004.017871.

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Lara-Medina, J., C. Ispa Callén, F. González del Valle, and A. Mate Valdezate. "Macroadenoma of the non-pigmented ciliary epithelium." Archivos de la Sociedad Española de Oftalmología (English Edition) 89, no. 6 (June 2014): 232–34. http://dx.doi.org/10.1016/j.oftale.2014.07.011.

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Lieb, Wolfgang E., Jerry A. Shields, Ralph C. Eagle, Daniel Kwa, and Carol L. Shields. "Cystic Adenoma of the Pigmented Ciliary Epithelium." Ophthalmology 97, no. 11 (November 1990): 1489–93. http://dx.doi.org/10.1016/s0161-6420(90)32375-8.

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Ishikawa, Eri, Maria Suzanne Sabundayo, Yasuhiro Takahashi, and Hirohiko Kakizaki. "Lacrimal Caruncle Nevus with Papilloma." Case Reports in Ophthalmology 8, no. 3 (December 5, 2017): 535–38. http://dx.doi.org/10.1159/000480725.

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Purpose: The aim of this article is to report a case of lacrimal caruncle nevus with papilloma. Methods: This is a case report of a 39-year-old female with a progressively enlarging pigmented lesion on the left lacrimal caruncle. She had been aware of a raised whitish wart on the top of this pigmented lesion for several months before her initial visit. Slit lamp examination revealed a papillomatous lesion over a well-circumscribed, pigmented lesion on the left lacrimal caruncle. Results: The histopathological examination of the excised tumor disclosed 2 characteristic findings, which include nests of nevus cells within the dermis and papillomatous structures which had fibrovascular cores overlying squamous cell epithelia with variable levels of acanthosis. The findings were consistent with an intradermal nevus and a papilloma arising from the conjunctival epithelium of the nevus. Conclusion: This is the first case report of a lacrimal caruncle nevus with papilloma. The clinical history and pathological findings of this case underscore the fact that an intradermal nevus primarily occurred on the lacrimal caruncle, after which a papilloma arose from the epithelium of the nevus as a consequence of human papillomavirus autoinoculation.

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White, Mary P., Akira Negi, and Peggy A. Hock. "Effects of hemicholinium-3 on the pigmented rabbit retina and pigment epithelium." Current Eye Research 9, no. 7 (January 1990): 669–76. http://dx.doi.org/10.3109/02713689008999582.

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Guillemot, F., and C. L. Cepko. "Retinal fate and ganglion cell differentiation are potentiated by acidic FGF in an in vitro assay of early retinal development." Development 114, no. 3 (March 1, 1992): 743–54. http://dx.doi.org/10.1242/dev.114.3.743.

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One of the earliest events in vertebrate eye development is the establishment of the pigmented epithelium and neural retina. These fundamentally different tissues derive from the invaginated optic vesicle, or optic cup. Even after achieving a fairly advanced state of differentiation, the pigmented epithelium exhibits the same potential as the optic cup in that it can “transdifferentiate” into neural retina. C. M. Park and M. J. Hollenberg (Dev. Biol. 134, 201–205, 1989) discovered that administration of basic fibroblast growth factor, coupled with retinal removal, could trigger this transformation in vivo. We have developed a quantitative in vitro assay to study the role(s) of the fibroblast growth factor (FGF) family in this phenomenon and more generally in early retinal development. We found that several aspects of the process, including inhibition of pigmented epithelium differentiation, proliferation, and conversion to a retinal fate, were not strictly correlated. Both acidic and basic FGFs were found to potentiate all aspects of the process, with acidic FGF being 4 to 20 times more potent than basic FGF for inhibition of pigmentation and induction of retinal antigens. Depending upon its concentration, acidic FGF induced from 40% to 80% of the cells in the explants to produce antigens normally expressed by retinal ganglion cells, the first cell type to be generated in retinal development. Expression of such a ganglion cell marker could be directly stimulated in non-dividing cells as well as in dividing cells, indicating that conversion from the pigmented epithelial to retinal fate did not require cell division. These data suggest that acidic FGF, or a related molecule, may function in establishment of retinal fate from the optic cup. This effect may be directly or indirectly mediated by induction of retinal ganglion cell fate among multipotent progenitor cells.

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Yan, C. Y. Irene, Eliane Rossi, and Fernanda Siwiec. "Wnt5A, a marker for dorsal retinal pigmented epithelium." Developmental Biology 295, no. 1 (July 2006): 397–98. http://dx.doi.org/10.1016/j.ydbio.2006.04.219.

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Kasahara, M., T. Matsuzawa, M. Kokubo, Y. Gushiken, K. Tashiro, T. Koide, H. Watanabe, and N. Katunuma. "Immunohistochemical localization of ornithine aminotransferase in normal rat tissues by Fab'-horseradish peroxidase conjugates." Journal of Histochemistry & Cytochemistry 34, no. 11 (November 1986): 1385–88. http://dx.doi.org/10.1177/34.11.3534076.

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Immunohistochemical localization of ornithine aminotransferase (L-ornithine: 2-oxo-acid aminotransferase, EC 2.6.1.13), a mitochondrial enzyme whose hereditary absence induces gyrate atrophy of the choroid and retina, was elucidated by a direct immunoperoxidase method using Fab'-horseradish peroxidase conjugates. In immunodiffusion studies, the antibodies raised with the re-crystallized enzyme were highly specific to ornithine aminotransferase. To show localization of ornithine aminotransferase in normal rat tissues, clear immunohistochemical staining of this enzyme through the inner mitochondrial membrane in paraffin sections was achieved with Fab'-horseradish peroxidase conjugates. Strong immunoreactivity was present in cerebral neurons, hepatocytes, and epithelial cells of renal tubuli, gut mucous membranes, and ocular tissues. Specific distribution of ornithine aminotransferase was found in ependymal cell groups: namely, epithelial cells of the choroid plexus, pigmented and nonpigmented epithelial cells of the ciliary body. and Müller cells and pigment epithelium of the retina.

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Bata, Bashar M., Sachin M. Salvi, and Hardeep Singh Mudhar. "Primary acquired melanosis (PAM) without atypia/WHO low-grade conjunctival melanocytic intraepithelial lesion over areas of oculodermal melanocytosis." BMJ Case Reports 13, no. 10 (October 2020): e236741. http://dx.doi.org/10.1136/bcr-2020-236741.

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An elderly white man with a history of left oculodermal melanocytosis presented with new onset brown pigmentation of the left bulbar and inferior tarsal conjunctiva. The bulbar conjunctival pigmentation was at the level of the conjunctival epithelium and was overlying areas of typical slate-grey scleral pigmentation characteristic of oculodermal melanocytosis. Both areas of new pigmentation were biopsied. The bulbar conjunctiva revealed primary acquired melanosis (PAM) without atypia with increased melanin production and the tarsal conjunctival biopsy showed PAM without atypia sine pigmentio overlying areas of substantia propria spindle-shaped heavily pigmented melanocytes of oculodermal melanocytosis. The case report examines the relationship between the epithelial and substantia propria melanocytes and correlates the findings with what is known about this association from the dermatopathology literature.

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De los Monteros, A. Espinosa, J. Martín de las Mulas, A. Fernández, J. Orós, and F. Rodríguez. "Immunohistopathologic Characterization of a Dermal Melanocytoma-Acanthoma in a German Shepherd Dog." Veterinary Pathology 37, no. 3 (May 2000): 268–71. http://dx.doi.org/10.1354/vp.37-3-268.

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A cutaneous melanocytoma-acanthoma in a 2-year-old female German Shepherd Dog was characterized by the presence of two populations of neoplastic cells: epithelial and melanocytic. The epithelial component consisted of nests of well-differentiated stratified squamous epithelium closely associated with neoplastic melanocytes. The epithelial cells immunoreacted with both monoclonal and polyclonal anti-cytokeratin antibodies, and immunoreaction to S-100 protein and vimentin was observed in the melanocytic cells. This rare pigmented skin neoplasm of the dog apparently has a benign behavior.

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Pita-Ortiz, I. Y., E. Padilla-García, A. Ramirez-Estudillo, and G. Graue-Moreno. "Not every pigmented tumour is melanoma: Adenoma of the ciliary body pigment epithelium." Archivos de la Sociedad Española de Oftalmología (English Edition) 95, no. 9 (September 2020): 463–66. http://dx.doi.org/10.1016/j.oftale.2020.03.010.

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33

Clare, Everton, and S. G. Hoskins. "A novel antigen is shared by retinal pigment epithelium and pigmented neural crest." Development Genes and Evolution 206, no. 3 (November 4, 1996): 195–206. http://dx.doi.org/10.1007/s004270050045.

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Philp, N. J., and V. T. Nachmias. "Components of the cytoskeleton in the retinal pigmented epithelium of the chick." Journal of Cell Biology 101, no. 2 (August 1, 1985): 358–62. http://dx.doi.org/10.1083/jcb.101.2.358.

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The retinal pigmented epithelium (RPE) is a simple cuboidal epithelium with apical processes which, unlike many epithelia, do not extend freely into a lumen but rather interdigitate closely with the outer segments of the neural retina. To determine whether this close association was reflected in the cytoskeletal organization of the RPE, we studied the components of the cytoskeleton of the RPE and their localization in the body of the cell and in the apical processes. By relative mobility on SDS gels and by immunoblotting, we identified actin, vimentin, myosin, spectrin (240/235), and alpha-actinin as major components, and vinculin as a minor component. In addition, the RPE cytoskeleton contains polypeptides of Mr 280,000 and 250,000; the latter co-electrophoreses with actin-binding protein. By immunofluorescence, the terminal web region appeared similar to the comparable region of the intestinal epithelium that consists of broad belts of microfilaments containing myosin, actin, spectrin, and alpha-actinin. However, the components of the apical processes were very different from those of intestinal microvilli. We observed staining along the process for myosin, actin, spectrin, alpha-actinin, and vinculin. The presence in the apical processes of contractile proteins and also of proteins typically found at sites of cell attachments suggests that the RPE may actively adhere to, and exert tension on, the neural retina.

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Bravo Portela, I., V. S. Martinez-Zorzano, I. Molist- Perez, and P. Molist García. "Ultrastructure and Glycoconjugate Pattern of the Foot Epithelium of the AbaloneHaliotis tuberculata(Linnaeus, 1758) (Gastropoda, Haliotidae)." Scientific World Journal 2012 (2012): 1–12. http://dx.doi.org/10.1100/2012/960159.

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The foot epithelium of the gastropodHaliotis tuberculatais studied by light and electron microscopy in order to contribute to the understanding of the anatomy and functional morphology of the mollusks integument. Study of the external surface by scanning electron microscopy reveals that the side foot epithelium is characterized by a microvillus border with a very scant presence of small ciliary tufts, but the sole foot epithelium bears a dense field of long cilia. Ultrastructural examination by transmission electron microscopy of the side epithelial cells shows deeply pigmented cells with high electron-dense granular content which are not observed in the epithelial sole cells. Along the pedal epithelium, seven types of secretory cells are present; furthermore, two types of subepithelial glands are located just in the sole foot. The presence and composition of glycoconjugates in the secretory cells and subepithelial glands are analyzed by conventional and lectin histochemistry. Subepithelial glands contain mainly N-glycoproteins rich in fucose and mannose whereas secretory cells present mostly acidic sulphated glycoconjugates such as glycosaminoglycans and mucins, which are rich in galactose, N-acetyl-galactosamine, and N-acetyl-glucosamine. No sialic acid is present in the foot epithelium.

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Letelier, Joaquín, Paola Bovolenta, and Juan R. Martínez-Morales. "The pigmented epithelium, a bright partner against photoreceptor degeneration." Journal of Neurogenetics 31, no. 4 (October 2, 2017): 203–15. http://dx.doi.org/10.1080/01677063.2017.1395876.

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Opas, Michal. "Cell adhesion and cytoskeleton in the retinal pigmented epithelium." Proceedings, annual meeting, Electron Microscopy Society of America 50, no. 1 (August 1992): 484–85. http://dx.doi.org/10.1017/s0424820100122824.

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The development and differentiation of tissues depend on the ability of cells to move and control their shape. In cell movement, a force generated by the contractile cytoplasmic machinery which includes the cytoskeletal microfilaments (MF) is, through cell-substratum adhesion, translated into traction. The chick embryonic retinal pigmented epithelium (RPE) differentiates in vitro, it can also be persuaded to transdifferentiate, and it displays differentiation dependent organization of the cytoskeleton, adhesiveness and ECM production.

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Campochiaro, Peter A., Sean F. Hackett, and Stanley A. Vinores. "Growth factors in the retina and retinal pigmented epithelium." Progress in Retinal and Eye Research 15, no. 2 (January 1996): 547–67. http://dx.doi.org/10.1016/1350-9462(96)00012-2.

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Sinha, Debasish, Mallika Valapala, Peng Shang, Stacey Hose, Rhonda Grebe, Gerard A. Lutty, J. Samuel Zigler, Kai Kaarniranta, and James T. Handa. "Lysosomes: Regulators of autophagy in the retinal pigmented epithelium." Experimental Eye Research 144 (March 2016): 46–53. http://dx.doi.org/10.1016/j.exer.2015.08.018.

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Helbig, Horst, Christoph Korbmacher, Dagmar Kühner, Susanne Berweck, and Michael Wiederholt. "Characterization of exchange in cultured bovine pigmented ciliary epithelium." Experimental Eye Research 47, no. 4 (October 1988): 515–23. http://dx.doi.org/10.1016/0014-4835(88)90091-7.

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Smyth, Robert J., Shinichi Kitada, and David A. Lee. "Growth of rabbit pigmented and nonpigmented ciliary body epithelium." Vision Research 34, no. 2 (January 1994): 137–41. http://dx.doi.org/10.1016/0042-6989(94)90326-3.

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Wang, Xiaobing, Kai Xiong, Lei Lu, Dandan Gu, Songtao Wang, Jing Chen, Honglei Xiao, and Guomin Zhou. "Developmental Origin of the Posterior Pigmented Epithelium of Iris." Cell Biochemistry and Biophysics 71, no. 2 (October 26, 2014): 1067–76. http://dx.doi.org/10.1007/s12013-014-0310-0.

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Knight, Jennifer K., and Pamela A. Raymond. "Retinal pigmented epithelium does not transdifferentiate in adult goldfish." Journal of Neurobiology 27, no. 4 (August 1995): 447–56. http://dx.doi.org/10.1002/neu.480270402.

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Ramón Martínez-Morales, Juan, Isabel Rodrigo, and Paola Bovolenta. "Eye development: a view from the retina pigmented epithelium." BioEssays 26, no. 7 (June 21, 2004): 766–77. http://dx.doi.org/10.1002/bies.20064.

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Julien, Sylvie, Antje Biesemeier, Despina Kokkinou, Oliver Eibl, and Ulrich Schraermeyer. "Zinc Deficiency Leads to Lipofuscin Accumulation in the Retinal Pigment Epithelium of Pigmented Rats." PLoS ONE 6, no. 12 (December 22, 2011): e29245. http://dx.doi.org/10.1371/journal.pone.0029245.

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46

Williams Jr., Basil K., Maura Di Nicola, J. Antonio Lucio-Alvarez, David R. Lally, and Carol L. Shields. "Choroidal Melanoma Simulating Adenoma of the Retinal Pigment Epithelium Arising at the Site of Congenital Hypertrophy of the Retinal Pigment Epithelium." Ocular Oncology and Pathology 6, no. 1 (July 30, 2019): 39–43. http://dx.doi.org/10.1159/000501084.

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Neoplasms of the retinal pigment epithelium (RPE) are rare tumors that can simulate choroidal melanoma, but clinical and imaging characteristics often differentiate these lesions. We report a 70-year-old male with an abruptly elevated pigmented lesion that arose at the site of congenital hypertrophy of the RPE and demonstrated associated exudation, as well as feeding and draining vessels, suggestive of RPE adenoma. Optical coherence tomography showed retinal elevation with serous retinal detachment adjacent to the mass, and ultrasonography revealed an abruptly elevated, moderately echodense mass of 6.4-mm thickness. Fluorescein angiography showed early tumor hypofluorescence, late tumor hyperfluorescence with staining and leakage, and retinal vessels buried under the mass, suggestive of a retinal tumor. The patient was monitored with the presumed diagnosis of RPE adenoma, but 3 months later, the growth was documented and fine-needle aspiration biopsy revealed choroidal melanoma. Management with I-125 plaque radiotherapy was performed leading to tumor regression and a thickness of 4.6 mm.

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Ito, Yuka, and Masahito Ohji. "Long-Term Follow-Up of Congenital Simple Hamartoma of the Retinal Pigment Epithelium: A Case Report." Case Reports in Ophthalmology 9, no. 1 (March 22, 2018): 215–20. http://dx.doi.org/10.1159/000487631.

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Background: Congenital simple hamartoma of the retinal pigment epithelium (CSHRPE) is a rare benign tumor of the retinal pigment epithelium characterized by a focal, darkly pigmented nodule in the macular lesion in healthy persons. We report a case of CSHRPE with long-term follow-up. Case: A 41-year-old Japanese woman was incidentally discovered to have a dark lesion on the fundus of the left eye. We evaluated the patient by measuring her best-corrected visual acuity (BCVA) and by slit-lamp biomicroscopy, fundus color photography, and optical coherence tomography (OCT) over a 10-year period. The BCVA gradually declined during the early follow-up period, having decreased from 1.2 to 0.8 in the left eye 3 years after the initial examination, and then has been maintained for the following 7 years. The lesion did not show a change in OCT 10 years after the first examination. Conclusion: It is important to follow a CSHRPE carefully over the long term because visual acuity might decrease.

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Storm, Tina, Thomas Burgoyne, and Clare E. Futter. "Membrane trafficking in the retinal pigment epithelium at a glance." Journal of Cell Science 133, no. 16 (August 15, 2020): jcs238279. http://dx.doi.org/10.1242/jcs.238279.

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ABSTRACTThe retinal pigment epithelium (RPE) is a highly specialised pigmented monolayer sandwiched between the choroid and the photoreceptors in the retina. Key functions of the RPE include transport of nutrients to the neural retina, removal of waste products and water from the retina to the blood, recycling of retinal chromophores, absorption of scattered light and phagocytosis of the tips of the photoreceptor outer segments. These functions place a considerable membrane trafficking burden on the RPE. In this Cell Science at a Glance article and the accompanying poster, we focus on RPE-specific adaptations of trafficking pathways. We outline mechanisms underlying the polarised expression of membrane proteins, melanosome biogenesis and movement, and endocytic trafficking, as well as photoreceptor outer segment phagocytosis and degradation. We also briefly discuss theories of how dysfunction in trafficking pathways contributes to retinal disease.

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Kumar, Vinod, Devesh Kumawat, Ruchir Tewari, and Pradeep Venkatesh. "Ultra-wide field imaging of pigmented para-venous retino-choroidal atrophy." European Journal of Ophthalmology 29, no. 4 (September 3, 2018): 444–52. http://dx.doi.org/10.1177/1120672118795056.

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Objective: To describe the ultra-wide field imaging features of pigmented para-venous retino-choroidal atrophy. Design: Retrospective review at a tertiary care centre. Participants: Eight eyes of five patients with pigmented para-venous retino-choroidal atrophy who presented to our retina clinic over last 2 years. Methods: Retrospective review of ultra-wide field pseudo-colour and short wave autofluorescence imaging was performed. In vivo histology of the macula and areas of retino-choroidal atrophy was studied with swept source optical coherence tomography (SS-OCT). Results: The median age was 40 years (range: 22–67 years). Best corrected visual acuity ranged from perception of light to 20/20. The para-venous retino-choroidal atrophy and pigment clumping not only involved the major arcade vessels but also extended into the peripapillary area and retinal periphery. The affected areas demonstrated hypoautofluorescence with sharp hyperautofluorescent borders. Macular atrophy, epiretinal membrane and optic disc pallor were noted in two eyes each. In all cases, the affected pigmentary area had disorganization of inner retinal layers, disruption of outer retinal layers and retinal pigment epithelium and markedly thinned out choroid on swept source optical coherence tomography. Concurrent involvement with retinitis pigmentosa in the fellow eye was noted in two patients. Conclusion: Ultra-wide field imaging of pigmented para-venous retino-choroidal atrophy sheds light onto the widespread retino-choroidal abnormalities. Concurrent disc and macular involvement may jeopardize the visual function. Pigmented para-venous retino-choroidal atrophy may be considered as a self-limited form of retinitis pigmentosa.

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Rohrer, Bärbel, Manas R. Biswal, Elisabeth Obert, Yujing Dang, Yanhui Su, Xiaofeng Zuo, Ben Fogelgren, Altaf A. Kondkar, Glenn P. Lobo, and Joshua H. Lipschutz. "Conditional Loss of the Exocyst Component Exoc5 in Retinal Pigment Epithelium (RPE) Results in RPE Dysfunction, Photoreceptor Cell Degeneration, and Decreased Visual Function." International Journal of Molecular Sciences 22, no. 10 (May 11, 2021): 5083. http://dx.doi.org/10.3390/ijms22105083.

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To characterize the mechanisms by which the highly conserved exocyst trafficking complex regulates eye physiology in zebrafish and mice, we focused on Exoc5 (also known as sec10), a central exocyst component. We analyzed both exoc5 zebrafish mutants and retinal pigmented epithelium (RPE)-specific Exoc5 knockout mice. Exoc5 is present in both the non-pigmented epithelium of the ciliary body and in the RPE. In this study, we set out to establish an animal model to study the mechanisms underlying the ocular phenotype and to establish if loss of visual function is induced by postnatal RPE Exoc5-deficiency. Exoc5−/− zebrafish had smaller eyes, with decreased number of melanocytes in the RPE and shorter photoreceptor outer segments. At 3.5 days post-fertilization, loss of rod and cone opsins were observed in zebrafish exoc5 mutants. Mice with postnatal RPE-specific loss of Exoc5 showed retinal thinning associated with compromised visual function and loss of visual photoreceptor pigments. Abnormal levels of RPE65 together with a reduced c-wave amplitude indicate a dysfunctional RPE. The retinal phenotype in Exoc5−/− mice was present at 20 weeks, but was more pronounced at 27 weeks, indicating progressive disease phenotype. We previously showed that the exocyst is necessary for photoreceptor ciliogenesis and retinal development. Here, we report that exoc5 mutant zebrafish and mice with RPE-specific genetic ablation of Exoc5 develop abnormal RPE pigmentation, resulting in retinal cell dystrophy and loss of visual pigments associated with compromised vision. Together, these data suggest that exocyst-mediated signaling in the RPE is required for RPE structure and function, indirectly leading to photoreceptor degeneration.

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Journal articles on the topic 'Pigmented epithelium'

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