The PPARδ agonist GW0742X reduces atherosclerosis in LDLR ^-/- mice

Several lines of evidence suggest a biological role for peroxisome proliferator-activated receptor (PPARδ) in the pathogenesis of atherosclerosis. Administration of synthetic PPARδ agonists to obese rhesus monkeys elevates serum high-density lipoprotein (HDL) cholesterol as a result of increased reverse cholesterol transport whilst in vitro studies have suggested a role for PPARδ in lipid uptake into macrophages. Recent studies have found that PPARδ depletion from macrophages in LDL receptor (LDLR^-/-) mice decreases lesion area via modulation of the inflammatory status of the macrophage, an effect also seen on pharmacological activation of PPARδ in vitro. We demonstrate here that the PPARδ agonist, GW0742X has potent anti-atherogenic activity in the LDLR^-/- mouse, decreasing lesion area by up to 50%. Administration of GW0742X had no effect on total cholesterol, HDL or LDL cholesterol and modest effects on very low-density lipoprotein (VLDL). Treatment with GW0742X resulted in decreased expression of monocyte chemoattractant protein 1 (MCP-1) and intracellular adhesion moleculae 1 (ICAM-1) in the aortae of treated mice. In addition, GW0742X decreased tumour necrosis factor-alpha (TNFα) expression in peritoneal macrophages, aortae and adipose tissue in comparison with control animals. Changes in gene expression were reflected in decreased plasma levels of MCP-1. These observations support an atheroprotective effect of PPARδ agonists in vivo.