THE INFLAMMATORY RESPONSE OF RETINAL PIGMENT EPITHELIUM CELLS EXPOSED TO HIGH GLUCOSE CONCENTRATIONS: THE ROLE OF CLASSICAL PHOSPHOLIPASES D

TENCONI, S; BERMUDEZ V; ORESTI, M.; SALVADOR, G; GIUSTO, N; MATEOS, M.

Buenos Aires

Congreso; . LIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)- Reunión Conjunta de Sociedades de Biociencias; 2017

Sociedades de Biociencias Argentina

(1039) THE INFLAMMATORY RESPONSE OF RETINALPIGMENT EPITHELIUM CELLS EXPOSED TO HIGH GLUCOSECONCENTRATIONS: THE ROLE OF CLASSICALPHOSPHOLIPASES DPaula Estefania Tenconi (1, 2), Vicente Bermúdez (1), GerardoMartín Oresti (1, 2), Gabriela Alejandra Salvador (1, 2),Norma María Giusto (1, 2), Melina Valeria Mateos (1, 2)(1) Instituto de Investigaciones Bioquímicas de Bahía Blanca(INIBIBB)-CONICET, (2) Depto. de Biología, Bioquímica yFarmacia (DBByF)-Universidad Nacional del Sur (UNS)Diabetic retinopathy (DR) is one of the main causes of visualdysfunction and blindness in working-age adults. Chronic hyperglycemia,oxidative stress and inflammation are key players in thepathogenesis of DR. The aim of the present work is to study the roleof classical phospholipases D (PLD1 and PLD2) in retinal pigmentepithelium (RPE) cells exposed to an in vitro DR model induced byhigh glucose (HG) concentrations.ARPE-19 and D407 human RPE cells were exposed to normalglucose concentration (Control condition or NG, 5.5 mM) or to HGconcentrations (16.5 or 33 mM) for 4, 24 or 72 h. To study the role ofclassical PLDs and the ERK pathway cells were pre-incubated for 1h with EVJ (VU0359595, 0.15 μM) to inhibit PLD1 activity, with APV(VU0285655-1, 0.5 μM) to inhibit PLD2 or U0126 (10 µM) to inhibitthe MEK/ERK pathway, prior to cell exposure to HG. Statistical analysiswas performed using ANOVA followed by Bonferroni´s test andp-values ≤ 0.05 were considered statistically significant.Our results demonstrate that 72 h exposure to HG reduced cell viabilityand increased caspase-3 cleavage. In addition, HG exposurefor 4 h induced early and concatenated events, as PLD, ERK andnuclear factor kappa B (NFκB) activation. NFκB activation inducedby HG correlated with the increment in pro-inflammatory interleukins(IL-6 and IL-8) and cyclooxygenase-2 (COX-2) mRNA levels (p ≤0.0001). The effect of pharmacological inhibitors demonstrated thatERK and NFκB activation were dependent on both PLD isoforms.Furthermore, the increment in IL-6 and COX-2 mRNA levels inducedby HG was reduced to control levels in cells pre-incubated with bothPLD inhibitors. However, the rise in IL-8 mRNA levels was only reducedin cells incubated with the PLD1 inhibitor, EVJ.In conclusion, our findings demonstrate that PLD1 and PLD2 mediatethe inflammatory response of RPE cells exposed to HG, pointingto the potential use of classical PLDs as a therapeutic target forDR treatment.Keywords: diabetic retinopathy, retinal pigment epithelium, phospholipaseD, inflammation