Metabolic link between lipid synthesis and lipid droplets morphology induced by oleic acid

LAGRUTTA, LUCÍA C.; LAYERENZA, JUAN P.; MOTERO VILLEGAS SANDRA; SISTI MARTÍN S.; GARCÍA DE BRAVO, MARGARITA M.; VES LOSADA, ANA

Rosario, Santa Fe

Congreso; L Reunión Anual de SAIB; 2014

SAIB

Nuclear lipid droplets (nLD) are a new nuclear (N) domain where neutral lipids are stored and organized. These droplets would be built up around a hydrophobic core of TAG and CE enriched in oleic acid and surrounded by a monolayer of polar lipids along with C (cholesterol) and associated proteins. nLD could be involved in nuclear-lipid homeostasis and provide or incorporate lipids and proteins involved in signaling pathways and transcription factors. The aim of the present work was to determine if nLD reversibly respond to external stimuli. The addition of oleic acid (OA) to HepG2 cells or primary culture of rat hepatocytes determined cellular shape modification, thus increasing TAG and CE content and cLD and nLD (number + size); LD increments would be reverted if OA was excluded. cLD and nLD induction by OA was prevented by ACS (acyl-Co-A synthetase) inhibitor (TriacsinC) involved in lipid biosynthesis. nLD and cLD were stained with BODIPY and N with DAPI. In conclusion, 1) nLD are a dynamic nuclear domain, 2) nLD number, size and lipid content are reversibly induced by OA, 3) nLD and cLD have a coordinated metabolism with a cellular regulation, 4) nLD and cLD are induced by OA by a reversible mechanism that involves ACS activity and TAG and CE biosynthesis.