Monoterpenes affect composition and organization of neutral lipids and associated proteins in Hep G2

MENDOZA-BERTELLI, SANDRA; LAYERENZA, JUAN PABLO; MOTERO VILLEGAS SANDRA; VES LOSADA, ANA; GARCÍA DE BRAVO, MARGARITA M.; POLO, MÓNICA

Mendoza

Congreso; XLVIII Reunión Anual de SAIB; 2012

SAIB

Lipid droplets (LDs) are dynamic organelles implicated in cellular lipids homeostasis. Stored lipids from LDs are used for synthesis of VLDL, bile salts and membranes. Geraniol (G) is a monoterpene present in essential oils of aromatic plants. We have demonstrated that treatment of Hep G2 cells with G 50 uM decreased cholesterogenesis, and that concentrations above 300 uM are required for inhibiting proteins prenylation and phosphatidylcholine synthesis. These findings let us hypothesize that geraniol could have an effect on the composition and organization of cellular lipids. Cells were treated with G 200 and 400 uM. LDs were analyzed by microscopy and separated into six bands by sucrose gradient ultracentrifugation of sonicated cells. Total lipids (L) -from the major upper band (b-A) and whole cell- were extracted and cholesterol (Cho), cholesteryl esters (CE), triacylglycerides (TAG) and phospholipids (PL) were determined. Constitutive proteins of b-A were separated and quantified by SDS-PAGE/western blot. We found that in Geraniol treated cells: TAG, Cho and CE content decreased while PL and L increased; LDs number increased with preserved size; b-A volume increased with conserved L/Protein ratio, decreased TAG, CE, Cho and PL and increased perilipin, indicating that other lipids are stored in these LDs. Geraniol produced alterations in cell lipid composition and LDs organization.