Investigating the role of the ROS/CncC-xenobiotics signaling pathway in the response to Fenpropathrin in Cyprinus carpio lymphocytes: Involving lipid peroxidation and Fe2+ metabolism imbalance

Fenpropathrin (FPT) is a synthetic pyrethroid insecticide, the persistence and accumulation in water of which could cause harmful effects on vulnerable groups like aquatic creatures, particularly posing significant risks to fish immune systems. This study aimed to investigate how environmentally relevant FPT concentrations (10–1000 μ/M) affect lipid peroxidation and Fe²⁺ metabolism in Cyprinus carpio head kidney lymphocytes, and its relationship with oxidative stress and immunotoxicity. Firstly, CCK-8 results demonstrated that FPT caused a significant increase in lymphocyte death. Secondly, lymphocytes exposed to FPT could lead ferroptosis in lymphocytes, accompanied by evidence of the Fe²⁺ transporter imbalance, lipid peroxidation, Fe²⁺ accumulation and ferroptosis related protein increment. Thirdly, we found that FPT esposure leads to a decrease in ATP, mitochondrial DNA and NADPH/NADP⁺ levels, and the mRNA associated with mitochondrial function-related genes (Fis1, Drp1, and OPA1) in lymphocytes. Additionally, FPT induced the increased the levels of inflammatory genes (TNF-α, IFN-γ, and IL-6) in head kidney lymphocytes. Importantly, exposure to FPT induced oxidative stress to produce intracellular ROS, disrupting the function of the CncC signaling pathway and expression disorder of xenobiotics detoxification (CYP 450 family) genes. Notably, Treatment with NAC (a ROS inhibitor, 5 μM) demonstrated that inhibiting ROS alleviated FPT-induced lymphocyte ferroptosis and inflammatory response via the ROS/CncC-xenobiotics signaling pathway. These findings not only introduces a novel approach to investigating the immunotoxicity of FPT but also offers critical insights into mitigating the adverse effects of FPT on aquatic animal health.