Oxidative stress-mediated signaling pathways: A review

Once the cells are challenged by intraand extracellular environmental stimuli such as nitric oxide, calcium and pathogenic organisms, the oxidative balance between reactive oxygen species (ROS) (such as O 2 , H 2 O 2 , OH·) production and antioxidant defense systems (such as glutathione reductase and catalase) is broken, resulting in accumulation of ROS within cells. ROS is linked with various cellular signaling pathways, including the nuclear factor erythroid 2-related factor 2/Keap1(Nrf2/Keap1), mitogen-activated protein kinases (MAPKs), the nuclear factor kappa B (NF-κB), protein kinase C (PKC), signal transducers and activators of transcription 3 (STAT3), and peroxisome proliferator-activated receptor-γ (PPARγ), which engaged in regulating pro-oxidant genes and antioxidant genes expression, and mediate cells oxidative injury and antioxidant defense system. This article therefore mainly focuses on: 1) the production of ROS; 2) Nrf2/Keap1, MAPKs, NF-κB, PKC, STAT3, and PPARγ activation mechanism by ROS.