Covalent peroxisome proliferator-activated receptor gamma adduction by nitro-fatty acids: selective ligand activity and anti-diabetic signaling actions

SCHOPFER FJ, COLE MP, GROEGER AL, CHEN CS, KHOO NK, WOODCOCK SR, GOLIN-BISELLO F, MOTANYA UN, LI Y, ZHANG J, GARCIA-BARRIO MT, RUDOLPH TK, RUDOLPH V, BONACCI G, BAKER PR, XU HE, BATTHYANY CI, CHEN YE, HALLIS TM, FREEMAN BA.

JOURNAL OF BIOLOGICAL CHEMISTRY

AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC

Año: 2010 vol. 285 p. 12321 - 12333

0021-9258

The peroxisome proliferator-activated receptor-gamma (PPARgamma) binds diverse ligands to transcriptionally regulate metabolism and inflammation. Activators of PPARgamma include lipids and anti-hyperglycemic drugs such as thiazolidinediones (TZDs). Recently, TZDs have raised concern after being linked with increased risk of peripheral edema, weight gain, and adverse cardiovascular events. Most reported endogenous PPARgamma ligands are intermediates of lipid metabolism and oxidation that bind PPARgamma with very low affinity. In contrast, nitro derivatives of unsaturated fatty acids (NO2-FA) are endogenous products of nitric oxide (*NO) and nitrite (NO2-)-mediated redox reactions that activate PPARgamma at nanomolar concentrations. We report that NO2-FA act as partial agonists of PPARgamma and covalently bind PPARgamma at Cys-285 via Michael addition. NO2-FA show selective PPARgamma modulator characteristics by inducing coregulator protein interactions, PPARgamma-dependent expression of key target genes, and lipid accumulation is distinctively different from responses induced by the TZD rosiglitazone. Administration of this class of signaling mediators to ob/ob mice revealed that NO2-FA lower insulin and glucose levels without inducing adverse side effects such as the increased weight gain induced by TZDs.