Ferroptosis is a recently discovered pathway of programmed cell death, which involves iron and reactive oxygen species (ROS). Ferroptosis is distinct from apoptosis, autophagy and other forms of cell death. While it was first discovered in cancer, it has now been implicated in several neurologic diseases, including Alzheimer's disease (AD). Hallmarks of ferroptosis, e.g. lipid peroxidation and iron dysregulation, have long been observed in brain samples from AD patients. Genetic studies in mouse models of AD also support a substantial role for ferroptosis in neuronal death. Therefore, there is a clear need for better elucidating the regulatory pathways of ferroptosis that play a role in AD. We recently discovered a new regulatory program that modulates ferroptotic cell death in cancer cells. This pathway is especially intriguing as it involves an antisense RNA as the underlying mater regulator. We have names this antisense RNA NQO1-AS as it is transcribed from a promoter on the positive strand coinciding with the 3'UTR of gene NQO1. NQO1 is a redox protein and we have shown that the NQO1-AS modulates the redox state of the cell through binding and stabilization of the NQO1 mRNA. More importantly, this NQO1-AS/NQO1 regulatory axis plays a role in ferroptosis. We have shown that silencing NQO1-AS or NQO1 sensitizes cells to ferroptotic cell death following oxidative stress. Having discovered this new pathway, we asked whether evidence of its activity could be found in other biological systems. Interesting, we observed a significant reduction in NQO1 mRNA expression and stability in Alzheimer's disease datasets from the regions of the brain most affected by this pathology. This reduction persisted even in microdissected samples, which control for general neuronal loss. Given these findings, we see a strong case for the involvement of the NQO1-NQO1-AS in AD, and therefore we have taken steps to extend our studies in cancer cells to iPSC- derived neurons in models of Alzheimer's disease. The successful completion of this study will dissect the possible role of NQO1-mediated ferroptosis in AD and may provide new therapeutic pathways that restore NQO1 activity through synthetic oligos that mimic NQO1-AS and restore higher NQO1 activity.
