INVESTIGADORES
FAVALE Nicolas Octavio
artículos
Título:
Glycosphingolipid synthesis is essential for MDCK cell differentiation
Autor/es:
PESCIO, LG; FAVALE, NO; MARQUEZ, MG; STERIN-SPEZIALE, NB
Revista:
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2012 vol. 1821 p. 884 - 894
ISSN:
1388-1981
Resumen:
Glycosphingolipids (GSLs), which are highly concentrated at the apical
membrane of polarized epithelial cells, are key components of cell
membranes and are involved in a large number of processes. Here, we
investigated the ability of hypertonicity (high salt medium) to induce
MadinDarby Canine Kidney (MDCK) cell differentiation and found an
increase in GSL synthesis under hypertonic conditions. Then, we
investigated the role of GSLs in MDCK cell differentiation induced by
hypertonicity by using two approaches. First, cultured cells were
depleted of GSLs by exposure to D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol
(D-PDMP). Second, cells were transfected with an siRNA specific to
glucosylceramide synthase, the key enzyme in GSL synthesis. Exposure of
cells to both treatments resulted in the impairment of the development
of the apical membrane domain and the formation of the primary cilium.
Enzymatic inhibitions of the de novo and the salvage pathway of
GSL synthesis were used to determine the source of ceramide responsible
of the GSL increase involved in the development of the apical membrane
domain induced by hypertonicity. The results from this study show that
extracellular hypertonicity induces the development of a differentiated
apical membrane in MDCK cells by performing a sphingolipid metabolic
program that includes the formation of a specific pool of GSLs. The
results suggest as precursor a specific pool of ceramides formed by
activation of a Fumonisin B1-resistant ceramide synthase as a component
of the salvage pathway.