Biochemical and Biophysical Research Communications, Vol.465, No.3, 542-547, 2015
Fenofibrate activates Nrf2 through p62-dependent Keap1 degradation
Peroxisome proliferator-activated receptor alpha (PPAR alpha) activates the beta-oxidation of fatty acids in the liver. Fenofibrate is a potent agonist of PPAR alpha and is used in the treatment of hyperlipidemia. Fenofibrate treatment often induces the production of intracellular reactive oxygen species (ROS), leading to cell death. The nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway is an essential component of the defense mechanism against oxidative stress. However, the molecular mechanism underlying the regulation of the Nrf2-Keap1 pathway in fenofibrate-induced cell death is not known. In this study, we demonstrated that fenofibrate induces Keapl degradation and Nrf2 activation. This fenofibrate-mediated Keap1 degradation is partly dependent on autophagy. Furthermore, fenofibrate-induced Keap1 degradation followed by Nrf2 activation is mainly mediated by p62, which functions as an adaptor protein in the autophagic pathway. Consistent with these findings, ablation of p62 increased fenofibrate-mediated apoptotic cell death associated with ROS accumulation. These results strongly suggest that p62 plays a crucial role in preventing fenofibrate-induced cell death. (C) 2015 Elsevier Inc. All rights reserved.