PTD-FNK Alleviated LPS-Induced Oxidative Stress of Boar Testicular Sertoli Cells via Keap1-Nrf2 Pathway

PTD-FNK, a synthetic anti-apoptotic protein, has been shown to potently alleviate cellular injuries. However, the effects of PTD-FNK on oxidative defense in boar testicular Sertoli cells (SCs) against oxidative injury has not been explored. In this study, we show that exposure of SCs to 100 mg/L lipopolysaccharide (LPS) for 12 h leads to decreased survival rate, superoxide dismutase (SOD) activity, and increased malondialdehyde (MDA). Treatment with 0.01 nmol/L PTD-FNK for 4 h significantly enhanced the activity of SOD, catalase (CAT), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) in SCs. Concurrently, PTD-FNK treatment effectively reduced the production of reactive oxygen species (ROS) and the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in SCs. Moreover, using His pull-down and LC-MS techniques, we identified PTD-FNK-interacting proteins and confirmed that this protective effect may be mediated by the regulation of the <i>Keap1</i>-<i>Nrf2</i> signaling pathway by PTD-FNK. Therefore, PTD-FNK alleviates LPS-induced oxidative stress via the <i>Keap1</i>/<i>Nrf2</i> pathway, providing novel insights for the development of therapeutic agents targeting testicular oxidative damage.