THE IMPLICATION OF SPHINGOSINE-1-PHOSPHATE RECEPTOR 2 (S1PR2) IN EPITHELIAL CELL MIGRATION AND DIFFERENTIATION

TARALLO, E; FAVALE, NO; ROMERO, DJ; HERRERA, P; SANTACREU, BJ; OTERO, D

Salta

Congreso; 55th Annual Meeting Argentine Society for Biochemistry and Molceular Biology; 2019

Sociedad Argentina de Investigación Bioquímica y Biología Molecular

Epithelial cell differentiation is a process that involves the mesenchymal to epithelium transition (MET) and includes cell cycle arrest, cell-cell junction maturation in addition to changes in cell migration capacity. The epithelial-mesenchymal transition (EMT) is a dynamic process by whichfully differentiated epithelial cells can acquire a mesenchymal phenotype. During EMT, cell adhesion and apical-basal polarity are lost, and the cytoskeleton is reorganized. Previous results from our laboratory shown that in Madin-Darby canine kidney cells (MDCK) under different culture conditions can achieve different stages of differentiation resembling MET. Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid, produced by the phosphorylation of sphingosine by sphingosine kinases (SPHK), which is involved in different processes such as proliferation, cell growth, differentiation and migration. S1P can act both intracellularly as a second messenger and extracellularly as a ligand of 5 different G protein coupled receptors (S1PR1-5). In the present work we evaluated the importance of S1P acting on S1PR2 in the modulation of cell migration and its association with cell differentiation of MDCK cells. We found that there are differences in the migratory profile of MDCK cells that depends both on the differentiation stage and S1PR2 activity. In addition, we found that in differentiated cells, migration depends on EMT. Inhibition of S1PR2 triggers changes in EMT markers, such as rearrangements of the actin cytoskeleton, expression of vimentin and nuclear translocation of betacatenin, as well as slug. The expression levels of S1PR2 in the different stages of differentiation of MDCK cells did not show significant differences. Instead, immunofluorescence studies showed that during cell differentiation, S1PR2 was progressively enriched at the plasma membrane. These results suggest that the location of S1PR2 depends on the stage of cell differentiation and this determines its role. S1PR2 can either reduce migration and this would be necessary for a successful MET and, on the other hand, this receptor can promote migration, through the stimulation of EMT.