Antidiabetic actions of a phosphatidylcholine ligand for nuclear receptor LRH-1

Abstract

Nuclear hormone receptors regulate diverse metabolic pathways and the orphan nuclear receptor LRH-1 (NR5A2) regulates bile acid biosynthesis ^{1, 2} . Structural studies have identified phospholipids as potential LRH-1 ligands ^{3– 5} , but their functional relevance is unclear. Here we show that an unusual phosphatidylcholine species with two saturated 12 carbon fatty acid acyl side chains (dilauroyl phosphatidylcholine, DLPC) is an LRH-1 agonist ligand in vitro. DLPC treatment induces bile acid biosynthetic enzymes in mouse liver, increases bile acid levels, and lowers hepatic triglycerides and serum glucose. DLPC treatment also decreases hepatic steatosis and improves glucose homeostasis in two mouse models of insulin resistance. Both the antidiabetic and lipotropic effects are lost in liver specific Lrh-1 knockouts. These findings identify an LRH-1 dependent phosphatidylcholine signaling pathway that regulates bile acid metabolism and glucose homeostasis.