ROS-mediated JNK pathway critically contributes to PFOS-triggered apoptosis in SH-SY5Y cells

Recent studies have indicated that perfluorooctane sulfonate (PFOS) and its derivatives can lead to neurotoxicity. In the present study, we showed that PFOS may trigger neuronal apoptosis through a c-Jun N-terminal kinase (JNK)-related mechanism. We revealed that c-Jun N-terminal kinase (JNK) was robustly activated in PFOS-exposed neuronal cells. The doses of PFOS that initiates JNK activation coincides with that inducing neuronal apoptosis, as confirmed by western blot and Annexin V-PE/7-AAD analyses. In addition, we found that reactive oxidative species (ROS) accumulation plays a casual role in PFOS-initiated JNK activation, as treatment with ROS scavenger N-acetyl-l-cysteine (NAC) abrogated PFOS-induced mitochondrial and nuclear translocation of phosphorylated JNK (p-JNK). In keeping with this notion, the expression of JNK downstream pro-apoptotic target Bim was increased following PFOS exposure in JNK- and ROS-dependent manners. Finally, Annexin V-PE/7-AAD analysis uncovered that treatment with NAC or SP600125 could significantly impair PFOS-induced neuronal apoptosis. These findings implicate that JNK signaling is critically involved in PFOS-induced neuronal death by virtue of mitochondrial translocation and the transcription of pro-apoptotic genes.