Monoterpenes affect composition and organization of neutral lipids and associated proteins in HepG2

MENDOZA-BERTELI, ANDREA; MONTERO VILLEGAS, SANDRA; LAYERENZA, JUAN P; VES-LOSADA, ANA; GARCÍA DE BRAVO, MARGARITA; POLO, MÓNICA

Congreso; Reunión Anual de la SAIB; 2012

SAIB

Lipid droplets (LDs) are dynamic organelles implicated in cellularlipids homeostasis. Stored lipids from LDs are used for synthesis ofhepatic VLDL, bile salts and membranes. Geraniol (G) is amonoterpene present in essential oils of aromatic plants. We havedemonstrated that treatment of Hep G2 cells with G 50 µMdecreased cholesterogenesis, and that concentrations above 300µM are required for inhibiting protein prenylation andphosphatidylcholine synthesis. These findings let us hypothesizethat geraniol could have an effect on the composition andorganization of cellular lipids. Cells were treated with G 200 and400 µM. LDs were analyzed by microscopy and separated into sixbands by sucrose gradient ultracentrifugation of sonicated cells.Total lipids (L) -from the major upper band (b-A) and whole cellwereextracted and cholesterol (Cho), cholesteryl esters (CE),triacylglycerides (TAG) and phospholipids (PL) were determined.Constitutive proteins of b-Awere separated and quantified by SDSPAGE/westernblot.We found that in treated cells: 1) TAG, Cho andCE content decreased while PL and L increased; 2) LDs numberincreased with preserved size; 3) b-A volume increased withconserved L/Protein ratio, decreased TAG, CE, Cho and PL andincreased perilipin, indicating that other lipids are stored in theseLDs. Geraniol produced alterations in cell lipid composition andLds organization.