Inflammation and Oxidative Stress in Retinal Diseases: The Role of Intracellular Signaling in the Retinal Pigment Epithelium

MATEOS,M.V.; PAULA ESTEFANIA TENCONI; GIUSTO,N.M.; SALVADOR,G.A.

International Journal of Ophthalmology and Clinical Research

ClinMed International Library

Año: 2015 vol. 2 p. 1 - 7

2378-346X

The retinal pigment epithelium (RPE) is essential for the integrityand function of the retina. RPE cells exert key functions to maintainphotoreceptors´ (PRs) viability and functionality, such as lightabsorption and protection against photo-oxidation, phagocytosisof photoreceptor outer segments (POS), transport of nutrients andwater, secretion of several growth factors and reisomerization ofall-trans-retinal. The RPE is also part of the outer blood-retinalbarrier (BRB) and can secrete immunomodulatory molecules.This review summarizes signaling events elicited in RPE cellsunder stress conditions, such as bacterial endophthalmitis,hyperglycemia and oxidative stress (OS). Inflammation and OSparticipate in the pathogenesis of several retinal diseases thateventually end in vision loss and blindness, such as age-relatedmacular degeneration (AMD), diabetic retinopathy (DR), retinitispigmentosa and uveitis. Elucidating the molecular events involvedin the inflammatory process in the RPE could thus lead to thediscovery of new therapeutic targets for the treatment of retinaldegenerative diseases.RPE response to inflammatory situations can mediate retinaldamage or survival depending on the inflammatory contextand stress duration. Independently of the nature of the stressinductor, intracellular events involved in RPE cell damage couldbe postulated as therapeutic targets for the treatment of ocularinflammatory diseases, among them: extracellular signal-regulatedkinase (ERK) as well as the nuclear transcription factor-κB (NF-κB)activation and increased inducible nitric oxide synthase (iNOS) andcyclooxygenase-2 (COX-2) expression.