Emerging roles of phospholipases D in retinal pigment epithelium cells exposed to high glucose

SALVADOR, G.A.; GIUSTO, N.M.; TENCONI, P.E.; MATEOS, M.V.

Córdoba

Congreso; LII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2016

SAIB

Diabetic retinopathy (DR) is a serious complication of diabetes that can lead to blindness. The aim of this work was to study the role of classical phospholipases D (PLD1 and PLD2) in retinal pigment epithelium (RPE) cells exposed to an in vitro DR model. ARPE-19 cells were exposed to high glucose (16.5 and 33 mM, HG) or to normal glucose (5.5 mM, NG) concentrations for 4 and 72 h. After sustained HG (72h) treatment, RPE cell viability was reduced by 30% with respect to NG and reactive oxygen species (ROS) generation was increased 5 times with respect to NG, in accordance with a decreased peroxiredoxin (PRX) expression. Western blot and immunocytochemistry assays showed activation of the extracellular signal-regulated kinase (ERK) and nuclear factor-κB (NF-κB) translocation to the nucleus after 4 h HG exposure. After 4 h of incubation, PLD activity was increased by 80% in cells exposed to HG. The pre-incubation with selective inhibitors showed that ERK and NF-κB activation was dependent on PLD1 and PLD2 activities. Moreover, PLD1, PLD2, ERK and cyclooxygenase-2 (COX-2) inhibition partially restored the reduced cell viability induced by HG. Our results show that subsequent activation of PLDs, ERK and COX-2 mediates RPE cell damage during HG condition and point to the use of classical PLDs as new therapeutic targets for DR treatment.