Sphingomyelin synthesis is involves in de-differentiation process in MDCK cells

FAVALE, NICOLÁS; SANTACREU BRUNO; UDOVIN LUCAS; MARQUEZ MG

Mar del Plata

Congreso; LI REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIONES EN BIOQUÍMICA Y BIOLOGÍA MOLECULAR (SAIB); 2015

SOCIEDAD ARGENTINA DE INVESTIGACIONES EN BIOQUÍMICA Y BIOLOGÍA MOLECULAR (SAIB)

We have demonstrated that sphingomyelin (SM) biosynthesis is essential for hypertonicity-induced MDCK cell differentiation. Under inhibition of SM synthesis, MDCK cells instead to differentiate switch to mesenchymal phenotype thus performing an epithelial to mesenchymal transition (EMT). To study the sphingolipid metabolic pathway involved in such process, confluent MDCK cells were subjected to hypertonicity and concomitantly SMS was inhibited by pharmacological and knockdown strategies. Both strategies showed alteration of polarized phenotype with acquisition of mesenchymal phenotype. The phenotype alteration was accompanied with alteration in plasma membrane SM distribution, suggesting an alteration in cell polarization. To evaluate the EMT, different markers were performed. Results showed an increase in mesenchymal marker, citoskeleton reorganization and loss of the epithelial marker. Moreover, SM inhibition induced an increase in lectin BSL-1 expression (mesenchymal marker) and a decrease in lectin DBA (collecting duct cell marker). It has been reported that these cell could suffer a trans-differentiation to myofibroblast, however, no increase in alpha-smooth muscle actin was observed in our model. These results suggest that the inhibition of SM synthesis induces the de-differentiation of MDCK, thus suggesting the implication of SM in EMT