Migration of retinal pigment epithelium cells is regulated by sphingosine-1- phosphate.

SIMON M.V.; VERA M; PRADO SPALM F.H.; ROTSTEIN N.P.

Buenos Aires

Congreso; II Reunión Conjunta de Sociedades de Biociencias; 2017

SAIC-SAIB-SAA-SAFE-SAB-SAFIS-SAH-SAI-SAP

MIGRATION OF RETINAL PIGMENT EPITHELIUM CELLS IS REGULATED BY SPHINGOSINE-1- PHOSPHATESIMON, MV; VERA, MS; PRADO SPALM, FH and ROTSTEIN, NP Retina proliferative diseases, such as diabetic retinopathy, are common causes of blindness. These pathologies are characterized by increased migration of two cell types that normally support retinal function: retinal pigment epithelium (RPE) and Müller glial cells (MGC). We previously found that sphingosine-1- phosphate (S1P), a bioactive lipid, increases MGC migration (Simon, et al; 2015). Now we analyzed if S1P also regulates RPE cell migration. Cultures of ARPE19 cells, a human retinal pigment epithelial cell line, were supplemented with 5 µM S1P and migration was evaluated by scratch-wound assays. To investigate whether ARPE19 cells synthesized S1P to promote migration, cultures were treated with 30 µM sphingosine kinase 1 inhibitor 2 (SphKI 2), a SphK1 inhibitor. To analyze the role of PI3K and ERK/MAPK signaling pathways in cell migration, cultures were pre-incubated with 10 µM LY294002 and 10 µM U0126 -a PI3K and ERK/ MAPK inhibitor, respectively- before S1P supplementation.S1P addition significantly enhanced RPE cell migration; after a 24 hour treatment, migration in S1P- supplemented cells doubled compared to migration in control conditions. Pre-treatment with SphKI 2 reduced 30% the migration observed in control cultures, implying RPE cells synthesized S1P to promote migration. Addition of exogenous S1P to SphKI2- treated cultures significantly restored RPE cell migration. Finally, S1P activated both PI3K and ERK/ MAPK signaling pathways to induce ARPE migration. Cultures pre-treated with LY294002 or U0126 and then with S1P barely showed 3% and 0.1%, respectively, of the migration observed in S1P-supplemented cultures. Hence, our results suggest that RPE cells synthesize S1P, which activates PI3K and ERK/MAPK pathways to induce migration and the increase in S1P levels exacerbates this migration. Since deregulation of this process is involved in several retinal pathologies, S1P signaling emerges as a potential tool for treating these diseases.