Benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) Induces Ferroptosis in Rat Cortical Neurons via...

Benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), the ultimate metabolite of benzo(a)pyrene, has been implicated in the induction of neuronal cell death. Our previous research established that BPDE initiates ferroptosis in neuroblastoma SH-SY5Y cells; however, the underlying mechanisms remain elusive. This study examines BPDE-induced ferroptosis in rat primary cortical neurons, revealing a significant increase in intracellular reactive oxygen species (ROS) and Fe²⁺ concentrations. Following exposure to 0.5 μM BPDE, distinctive morphological changes in mitochondria, indicative of ferroptosis, were observed. An upregulation of malondialdehyde (MDA) expression was observed, alongside a downregulation of glutathione (GSH) levels, glutathione peroxidase (GSH-PX) activity, and superoxide dismutase (SOD) activity postexposure. Additionally, there was an increase in the expression of ferroptosis-associated proteins ACSL4 and COX2, whereas the levels of SLC7A11 and GPX4 were reduced. Notably, the application of lipid peroxidation inhibitors and iron chelators, such as deferoxamine (DFO) and ferrostatin-1 (Fer-1), partially mitigated these effects. These findings suggest that BPDE is capable of inducing ferroptosis in primary rat neurons. Mechanistically, exposure to BPDE resulted in the upregulation of p53 expression, a reduction in SLC7A11 levels, and the promotion of ALOX12, SAT1, and ALOX15. In contrast, treatment with the p53-specific inhibitor Pifithrin-μ led to an increase in SLC7A11 levels and a significant decrease in ALOX12, SAT1, and ALOX15 levels, thereby mitigating BPDE-induced ferroptosis. In summary, these findings indicate that BPDE induces ferroptosis in primary rat cortical neurons via the p53-SLC7A11-ALOX12 and p53-SAT1-ALOX15 pathways.