Overlapping role of c-Jun N-terminal kinase (JNK) 1 and 2 in imidazole ketone erastin-induced ferroptosis

Ferroptosis is an iron-dependent form of non-apoptotic cell death characterized by the generation of excess reactive oxygen species (ROS) and lipid peroxidation. However, it remains largely unknown whether signaling pathways, such as the ROS-activated mitogen-activated protein kinase (MAPK) pathways, affect ferroptosis. The c-Jun N-terminal kinase (JNK), a MAPK signaling molecule that plays an essential role in apoptosis, is activated in response to various stimuli, including oxidative stress. In this study, we examined the functional role of JNK in cell death induced by imidazole ketone erastin (IKE), a potent ferroptosis inducer, using gene knockout technology. We found that JNK1/2 double-knockout cells, but not JNK1 or JNK2 single-knockout cells, were much more tolerant to IKE-induced cell death compared to control cells. We further demonstrated that IKE-induced increase in CTH and HMOX1, key genes in ferroptosis, in control cells was substantially suppressed by the depletion of JNK1 and JNK2. These results suggested that JNK1 and JNK2 play an important, overlapping role in ferroptosis. Our findings advance our understanding of the JNK pathway, which could contribute to future pharmacological developments in ferroptosis-related diseases such as cancer and neurodegeneration.