Phospholipase A2 regulation of lipid droplet formation

• Abnormal regulation of lipid droplet production leads to various metabolic diseases.
• PLA2s critically regulate the biogenesis of lipid droplets by different mechanisms.
• PLA2s generate metabolites that control biogenesis of the organelle.
• cPLA2α activation by phosphorylation is necessary for lipid droplet formation.
• sPLA2s promote atherosclerosis progression by affecting lipid droplet formation.

The classical regard of lipid droplets as mere static energy-storage organelles has evolved dramatically. Nowadays these organelles are known to participate in key processes of cell homeostasis, and their abnormal regulation is linked to several disorders including metabolic diseases (diabetes, obesity, atherosclerosis or hepatic steatosis), inflammatory responses in leukocytes, cancer development and neurodegenerative diseases. Hence, the importance of unraveling the cell mechanisms controlling lipid droplet biosynthesis, homeostasis and degradation seems evident. Phospholipase A2s, a family of enzymes whose common feature is to hydrolyze the fatty acid present at the sn-2 position of phospholipids, play pivotal roles in cell signaling and inflammation. These enzymes have recently emerged as key regulators of lipid droplet homeostasis, regulating their formation at different levels. This review summarizes recent results on the roles that various phospholipase A2 forms play in the regulation of lipid droplet biogenesis under different conditions. These roles expand the already wide range of functions that these enzymes play in cell physiology and pathophysiology.