Integrated transcriptomics and proteomics reveal ferroptosis induced by B[a]P and BPDE in mouse hippocampal neurons

The environmental pollutant Benzo[a]pyrene (B[a]P) and its ultimate metabolite B[a]P-7,8-diol-9,10-epoxide (BPDE) exhibit neurotoxic effects, yet the underlying molecular mechanisms remain enigmatic. Recently, ferroptosis has emerged as a potential player in B[a]P/BPDE-induced cellular damage. However, whether ferroptosis contributes to B[a]P/BPDE-induced neuron injury remains uncertain. We established a mouse model of learning and memory dysfunction through sub-chronic intragastric administration of B[a]P, with confirmation provided by behavioral alterations and pathological changes in the hippocampus. Furthermore, ferroptosis hallmarks, such as mitochondrial shrinkage, iron and glutamate metabolism disorders, and increased MDA level, were evident. Meanwhile, treatment with 1 mg/kg Ferrostatin-1 (Fer-1), a ferroptosis inhibitor, could effectively reduce hippocampal neuronal ferroptosis and improve learning and memory ability. HT22 cells were treated with 0, 0.5, and 0.75 µM BPDE, and ferroptosis was observed. Subsequent proteomic and transcriptomic analyses elucidated the underlying mechanisms of ferroptosis. Using integrated bi-omics and machine-learning algorithms, we delineated a network involving autophagy, ATP concentration, and molecule transport. Mechanistically, BPDE inhibited the transport of iron, amino acids and carbohydrates, decreased ATP content, increased ROS levels, and promoted autophagy, potentially leading to metabolic disorders and imbalance of oxidation and antioxidant systems, culminating in ferroptosis. These findings expand our understanding of B[a]P/BPDE neurotoxicity and pave the way for future investigations.