Sphingosine-1-Phosphate Receptor 2 (S1PR2) Promotes Epithelial Mesenchymal Transition in Differentiated MDCK cells trough ERK1/2 Signaling Involving β-catenin and SNAI2

SANTACREU BJ; ROMERO DJ; FAVALE NO; MOSCA JM

Congreso; LVII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research (SAIB) XVI Annual Meeting of the Argentinean Society for General Microbiology (SAMIGE); 2021

SAIB?SAMIGE

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid, produced by sphingosine kinases (SKs), which is involved in different processes such as cell proliferation, growth, differentiation, and migration. S1P can act both intracellularly as a second messenger or extracellularly as a ligand of five different G protein-coupled receptors (S1PR1-5). The epithelial-mesenchymal transition (EMT) is a dynamic process by which differentiated epithelial cells can acquire a mesenchymal phenotype. It plays a pivotal role in embryonic development, tissue regeneration, organ fibrosis, and cancer progression. Previous results from our laboratory showed that fully differentiated Madin-Darby canine kidney (MDCK) cells at the wound edge can undergo EMT during wound healing to acquire their migratory profile. We also found that S1PR2 is critical in the modulation of this process. In the present work, we investigated the mechanisms by which S1PR2 activation induces EMT and whether its downstream signals are influenced by the differentiation stage of MDCK cells. We found that activation of S1PR2 in fully differentiated MDCK cells triggers changes in EMT markers, such as rearrangements of the actin cytoskeleton, vimentin expression, and nuclear translocation of β-catenin, as well as SNAI2. Inhibition of Rho-kinase did not suppress the S1PR2-induced nuclear translocation of β-cat and SNAI2, and also did not prevent vimentin expression on wound edge cells. On the contrary, treatment with an Erk inhibitor significantly decreased the percentage of both β-cat and SNAI2 positive nuclei and also vimentin expression. Moreover, immunofluorescence studies showed an increase of Erk phosphorylation following S1PR2 activation. Interestingly, no changes in EMT markers, as well as Erk phosphorylation were observed in not differentiated MDCK cells. These results suggest that in these cells S1PR2 might respond by triggering different intracellular signals that depend on the stage of differentiation. These findings highlight the great versatility of S1P on the control of the migration and other processes of renal cells with physiological relevance.