title: Directional protein secretion by the retinal pigment epithelium: roles in retinal health and the development of age-related macular degeneration.
abstract: The structural and functional integrity of the retinal pigment epithelium (RPE) is fundamental for maintaining the function of the neuroretina. These specialized cells form a polarized monolayer that acts as the retinal-blood barrier, separating two distinct environments with highly specialized functions: photoreceptors of the neuroretina at the apical side and Bruch's membrane/highly vascularized choriocapillaris at the basal side. The polarized nature of the RPE is essential for the health of these two regions, not only in nutrient and waste transport but also in the synthesis and directional secretion of proteins required in maintaining retinal homoeostasis and function. Although multiple malfunctions within the RPE cells have been associated with development of age-related macular degeneration (AMD), the leading cause of legal blindness, clear causative processes have not yet been conclusively characterized at the molecular and cellular level. This article focuses on the involvement of directionally secreted RPE proteins in normal functioning of the retina and on the potential association of incorrect RPE protein secretion with development of AMD. Understanding the importance of RPE polarity and the correct secretion of essential structural and regulatory components emerge as critical factors for the development of novel therapeutic strategies targeting AMD.
authors.affiliation: Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Kay
authors.forename: Yit C
authors.initials: YC
authors.lastname: Yang
authors.forename: Luminita
authors.initials: L
authors.lastname: Paraoan
mesh_terms: D000818:Animals; D016570:Bruch Membrane / Q000378:metabolism; D002829:Choroid / Q000502:physiology; D005136:Eye Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation; D006706:Homeostasis; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008268:Macular Degeneration / Q000378:metabolism*; D012160:Retina / Q000502:physiology*; D055213:Retinal Pigment Epithelium / Q000378:metabolism / Q000502:physiology*
chemical_list: D005136:Eye Proteins; D036341:Intercellular Signaling Peptides and Proteins
keywords: age-related macular degeneration; polarity; protein secretion; retina; retinal pigment epithelium