Sphingomyelin synthesis is involved in differentiation and de-differentiation process in MDCK cells

FAVALE NICOLAS; SANTACREU BRUNO; UDOVIN LUCAS; MARQUEZ MG; STERIN-SPEZIALE N

Puerto Iguazú-Misiones

Congreso; 56th INTERNATIONAL CONFERENCE ON THE BIOSCIENCE OF LIPIDS (ICBL); 2015

CONFERENCE ON THE BIOSCIENCE OF LIPIDS (ICBL)

Sphingolipids (SLs) are relevant lipid componentsof eukaryotic cells. Besides regulating various cellularprocesses, SLs provide the structural framework for plasmamembrane organization. Particularly, SM is associatedwith detergent-resistant microdomains. We have previouslyshown that the adherens junction (AJ) complex, the relevantcell-cell adhesion structure involved in cell differentiationand tissue organization, is located in an SM-rich membranelipid domain. We have also demonstrated that under hypertonicconditions, Madin-Darby canine kidney (MDCK) cellsacquire a differentiated phenotype with changes in SL metabolism.For these reasons, we decided to evaluate whetherSM metabolism is involved in the acquisition of the differentiatedphenotype of MDCK cells. We found that SM synthesismediated by SM synthase 1 is involved in hypertonicityinducedformation of mature AJs, necessary for correctepithelial cell differentiation. Inhibition of SM synthesisimpaired the acquisition of mature AJs, evoking a disintegration-like process refl ected by the dissipation of E-cadherinand - and -catenins from the AJ complex. As a consequence,MDCK cells did not develop the hypertonicityinduceddifferentiated epithelial cell phenotype.