Sphingomyelin synthase1 activity is essential for the renal cell differentiation

FAVALE NICOLAS; SANTACREU BRUNO; LUCILA GISELA PESCIO; MARÍA GABRIELA MÁRQUEZ; STERIN SPEZIALE NORMA

Banff Alberta

Congreso; Frontiers in Lipid Biology; 2012

American Society for Biochemistry and Molecular Biology joint meeting with the International Conference on the Bioscience of Lipids and the Canadian Lipoprotein Conference

We have previously demonstrated that sphingomyelin biosynthesis is essential for hypertonicity-induced MDCK differentiation. Under inhibition of SM synthesis, MDCK cells instead to differentiate switch to mesenchymal phenotype thus performing an ephitelial to mesenchymal transition. We aim to study the sphingolipid metabolic pathway as well as the sphingomyelin synthase isoform involved in such a process. Confluent MDCK cells were submitted to hypertonicity and concomitantly treated or not (control) with 15 micromolar D609 or siRNA-SMS 1. Sphingolipid metabolism was determined by using [14C]Palmitic acid precursor in the presence or absence of cicloserine (CS) or fumonisin B1(FB1). Cell viability was determined by tripan blue, cell phenotype visualized by confocal immunofluorescence of the cytoskeleton using phalloidin and adherens junction determined by visualization of E-cadherin distribution.. By using D609 as well as siRNA SMS 1 the characteristic polarized phenotype of the cells were lost and it was not retrieved by a concomitant treatment with CS or FB1; which denote no involvement of intermediate metabolite accummulation. Acquirement of messenchymal phenotype was accompanied by the loss of the epithelial marker (cad16) and the rise of the mesnchymal marker ( vimentin). These results demonstrate implication of SM synthesis in the ephithelial-mesenchymal transition EMT). Is important to note that EMT has been implicated in the development of cancer and renal fibrosis, consequently SMS activity emerge as possible target molecule for the study of such important human pathologies.