Disease relevance of Pigment Epithelium of Eye

• We isolated a novel transcript from the OA1 critical region in Xp22.3-22.2 which is expressed at high levels in RNA samples from retina, including the retinal pigment epithelium, and from melanoma [1].
• Since AR2 overexpression in the retinal pigment epithelium has been associated with diabetic retinopathy, the regulation of AR2 gene expression and associated changes in sorbitol and myo-inositol were studied in human retinal pigment epithelial cells in culture [2].
• Congenital hypertrophy of retinal pigment epithelium and risk estimation in adenomatous polyposis coli [3].
• Mutations in the retinal pigment epithelium gene encoding RPE65 are a cause of the incurable early-onset recessive human retinal degenerations known as Leber congenital amaurosis [4].
• Vitelliform macular dystrophy (Best's disease) is an autosomal dominant, early-onset form of macular degeneration in which the primary defect is thought to occur at the level of the retinal pigment epithelium [5].

Psychiatry related information on Pigment Epithelium of Eye

• We present the cases of three siblings (two boys and one girl) with true autosomal recessive microcephaly without mental retardation and without associated systemic anomalies who showed hypertrophy of the retinal pigment epithelium similar to that described in Gardner's syndrome [6].

High impact information on Pigment Epithelium of Eye

• Rpe65 is the retinoid isomerase in bovine retinal pigment epithelium [7].
• Mutations in the gene encoding RPE65, a protein vital for regeneration of the visual pigment rhodopsin in the retinal pigment epithelium, account for 10-15% of LCA cases [8].
• 1. This region contains CDH3, encoding P-cadherin, which is expressed in the retinal pigment epithelium and hair follicles [9].
• To regenerate rhodopsin and maintain normal visual sensitivity, the all-trans isomer must be metabolized and reisomerized to produce the chromophore 11-cis-retinal in biochemical steps that constitute the visual cycle and involve the retinal pigment epithelium (RPE; refs. 3-8) [10].
• The all-trans retinal that is generated after cone and rod photopigments absorb photons of light is recycled back to 11-cis retinal by the retinal pigment epithelium and Müller cells of the retina [11].

Chemical compound and disease context of Pigment Epithelium of Eye

• Characterization of a dehydrogenase activity responsible for oxidation of 11-cis-retinol in the retinal pigment epithelium of mice with a disrupted RDH5 gene. A model for the human hereditary disease fundus albipunctatus [12].
• Fluorescein angiography and electrophysiological tests suggested toxicity at the level of retinal pigment epithelium and photoreceptors [13].
• This case supports the primacy of isolated vitamin A deficiency in the etiology of corneal xerosis and "fundus xerophthalmicus"; demonstrates that stromal edema is an important early component of corneal involvement; and localizes the funduscopic abnormalities to the retinal pigment epithelium [14].
• Phagocytic activity of cultured retinal pigment epithelium. Uptake of polystyrene spheres and Staphylococcus aureus [15].
• Effect of phytanic acid on cultured retinal pigment epithelium: an in vitro model for Refsum's disease [16].

Biological context of Pigment Epithelium of Eye

• Identification of a membrane protein binding the retinol in retinal pigment epithelium [17].
• We propose that retinal pigment epithelium (which normally expresses tyrosinase) secretes a modulatory factor, possibly L-DOPA, which regulates light adaptation in the retinal circuitry [18].
• Daily alphavbeta5 integrin-dependent phagocytosis of spent photoreceptor outer segment fragments by the retinal pigment epithelium (RPE) is critical for retinal function [19].
• Except for Ca(2+), which plays a negative feedback role in adaptation, and 11-cis-retinal, supplied by the retinal pigment epithelium, all of the biochemical machinery of phototransduction is thought to be contained within rod outer segments without involvement of extrinsic regulatory molecules [20].
• Using a proximal murine rod opsin promoter (+86 to -385) to drive expression, reporter gene product was found exclusively in photoreceptors, not in any other retinal cell type or in the adjacent retinal pigment epithelium [21].

Anatomical context of Pigment Epithelium of Eye

• CRALBP is not expressed in photoreceptors but is abundant in the retinal pigment epithelium (RPE) and Müller cells of the neuroretina, where it carries 11-cis-retinol and 11-cis-retinaldehyde [22].
• Bestrophin, the product of the Best vitelliform macular dystrophy gene (VMD2), localizes to the basolateral plasma membrane of the retinal pigment epithelium [23].
• Carbonic anhydrase XIV is enriched in specific membrane domains of retinal pigment epithelium, Muller cells, and astrocytes [24].
• In situ hybridization with multiple probes on both primate and mouse eye sections demonstrates that RNR is expressed in the retinal pigment epithelium and in Müller glial cells [25].
• In normal mice, Cp and Heph localize to Müller glia and retinal pigment epithelium, a blood-brain barrier [26].

Associations of Pigment Epithelium of Eye with chemical compounds

• This microsomal enzyme is abundant in the retinal pigment epithelium, where it has been proposed to catalyse the conversion of 11-cis retinol to 11-cis retinal [11].
• Mutation of RPE65 can cause severe blindness from birth or early childhood, and RPE65 protein is associated with retinal pigment epithelium (RPE) vitamin A metabolism [27].
• The receptor mediating light damage, however, has not yet been conclusively identified; candidate molecules include prostaglandin synthase, cytochrome oxidase, rhodopsin, and opsins of the cones and the retinal pigment epithelium (PE) [28].
• Biochemical abnormalities in the retinal pigment epithelium of experimentally diabetic animals include increased sorbitol and decreased myo-inositol [29].
• A unique distribution of lactate transporters is found in the retinal pigment epithelium (RPE), which regulates lactate levels of the outer retina [30].

Gene context of Pigment Epithelium of Eye

• RPE65 is an abundant protein in the retinal pigment epithelium [31].
• Rpe65 Leu450Met variant is associated with reduced levels of the retinal pigment epithelium lipofuscin fluorophores A2E and iso-A2E [32].
• Mice deficient in both Cp and Heph, but not each individually, had a striking, age-dependent increase in retinal pigment epithelium and retinal iron [26].
• Mutations in the crumbs homologue 1 (CRB1) gene cause a specific form of retinitis pigmentosa (RP) that is designated "RP12" and is characterized by a preserved para-arteriolar retinal pigment epithelium (PPRPE) and by severe loss of vision at age <20 years [33].
• Retina-specific nuclear receptor: A potential regulator of cellular retinaldehyde-binding protein expressed in retinal pigment epithelium and Müller glial cells [25].

Analytical, diagnostic and therapeutic context of Pigment Epithelium of Eye

• In this report, an animal model for this disease, 11-cis-rdh-/- mice, was used to investigate the flow of retinoids after a bleach, and microsomal membranes from the retinal pigment epithelium of these mice were employed to characterize remaining enzymatic activities oxidizing 11-cis-retinol [12].
• The endogenous retinoids associated with three cellular retinoid-binding proteins from bovine retina and retinal pigment epithelium have been identified by their spectral characteristics and their co-migration with authentic retinoids on high performance liquid chromatography [34].
• In addition, we used laser capture microdissection to examine chemokine mRNA production by both retinal pigment epithelium cells and infiltrating leukocytes in inflamed eyes [35].
• Using sodium dodecyl sulphate/polyacrylamide gels to analyse detergent-insoluble residues, and indirect immunofluorescence, we have found that the major protein of intermediate filaments in cultures and freshly explanted fragments of chick embryonic retinal pigment epithelium (RPE) is vimentin [36].
• Intracellular microelectrode techniques were used to characterize the electrical responses of the bovine retinal pigment epithelium (RPE)-choroid to epinephrine (EP) and several other catecholamines that are putative paracrine signals between the neural retina and the RPE [37].

References