Lipid Droplets and the Pathophysiology of Liver Diseases

Abstract

Lipid droplets (LDs) are widespread intracellular organelles formed by a triglyceride, cholesteryl ester and retinyl ester core surrounded by a monolayer of phospholipids and free (unesterified) cholesterol. LDs number and size are maintained by an orchestrated action of different enzymes: from a reductionist point of view core lipids are formed by several enzymes present on the surface of the endoplasmic reticulum and hydrolyzed by different lipases to provide fatty acids, cholesterol and retinol for various cellular functions. In the last decades, LDs went from being mere lipid reservoirs to active and metabolically dynamic organelles. In fact, nowadays LDs are clearly involved in cellular physiology, but more importantly, LDs are embraced in the development of several cellular diseases. This review highlights the roles of different LD components on various liver diseases such as HCV infection, non-alcoholic fatty liver disease and non-alcoholic steatohepatitis. Future research will help us further understand the consequences of altering LD biology, and thus defining dietary or pharmaceutical possibilities to prevent or treat NAFLD and its complications, or HCV infection and propagation.