Benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) Induces Ferroptosis in Rat Cortical Neurons via p53-SLC7A11-ALOX12/p53-SAT1-ALOX15 Pathways.

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 Fe 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.