Lipid droplet formation in response to oleic acid in Huh-7 cells is a fatty acid receptor mediated event

Abstract

It is unclear how changes in lipid droplet size and number are regulated, whether this involves a signalling pathway, or is directed by cellular lipid uptake. Here we show that oleic acid stimulates lipid droplet formation through activating the long chain fatty acid receptor FFAR4 coupled through a pertussis toxin sensitive G-protein signalling pathway involving phosphoinositide-3-kinase, AKT/Protein-kinase B and phospholipase D activities. This initial lipid droplet formation is not dependent upon exogenous lipid whilst the subsequent, more sustained increase in lipid droplets is dependent upon lipid uptake. These two mechanisms of lipid droplet formation point to distinct potential intervention points.