INVESTIGADORES
PESCIO Lucila Gisele
congresos y reuniones científicas
Título:
The role of sphingolipids in MDCK cells polarization submitted to hypertonic stress
Autor/es:
PESCIO L; LEOCATA NIETO F; FERNÁNDEZ TOME M; STERIN SPEZIALE N
Lugar:
Rosario , Santa Fe, Argentina
Reunión:
Congreso; XLII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research; 2006
Institución organizadora:
SAIB
Resumen:
Renal papilla plays a key role in water and electrolytic
homeostasis since regulates urinary pH and ionic concentration.
These functions are carried out by papillary collecting ducts
constituted by highly polarized epithelial cells which present two
membrane domains, apical and basolateral. Both domains show
different lipid composition: high concentration of
glycosphingolipids (GSL) in apical domain while basolateral is
enriched in sphingomyelin (SM). It has been reported that during
renal development hypertonicity induces differentiation of tubular
structures which implies cellular polarization, but the mechanism
involved is not well understood. In order to explore the role of
sphingolipids (SL) in renal epithelial differentiation, we studied SL
metabolism and gp135 expression, as polarization parameter, in
MDCK cells submitted to hypertonicity. Cultures were grown in
high NaCl media (250 mM) for 24 and 48 hs in presence of 14CPalmitic
acid or 14C-Galactose to monitor de novo SL and GSL
synthesis, respectively. Total 14C-Palmitic acid incorporation to
SLs was significantly higher in cells under hypertonicity, even
more at 48 hs. SM labeling registered the mayor increase.
Similarly, GSL synthesis was also increased in hypertonic
conditions. Increased SLs metabolism preceded gp135 protein in
apical membranes suggesting early sphingolipid participation in
cell polarization.