Lipins, not just metabolic enzymes. Immune implications

Abstract

The lipins have been described as metabolic enzymes that regulate lipid biosynthesis and also signaling processes by controlling the cellular concentration of bioactive lipids, phosphatidic acid, and diacylgycerol. Most cellular studies on lipins have been conducted in metabolically active tissues such as the adipose tissue and the liver. However, little is known on the possible roles of lipins in the immune system and inflammation. I will present recent data of our laboratory concerning the implication of lipin-1 and -2 in immune processes. Collectively, our data have shown that lipin-1 associates with lipid droplets and regulates the activation of cytosolic group IVA phospholipase A2 in macrophages. Lipin-2, however, has a protective role during proinflammatory signaling mediated by saturated fatty acids that occurs concomitantly with an enhanced cellular capacity for triacylglycerol synthesis.