In this tutorial review, we compare and contrast the chemical mechanisms of electrophile/oxidant sensing, and the molecular mechanisms of signal propagation. We critically analyze biological systems in which these different pathways are believed to be manifest and what the data really mean. Finally, we discuss applications of this knowledge to disease treatment and drug development.

Keap1 is associated with cytoprotective signaling. These roles of Keap1 typically focus on its role as a degrader of the antioxidant response (AR) transcription factor, Nrf2, and the inhibition of this process upon Keap1 labeling by electrophiles. However, work from several laboratories has reemphasized both the important role of Nrf2 binding in negatively regulating AR, and the fact that electrophile Keap1 modification dissociates Nrf2 from Keap1. This model appears to be applicable to other signaling modes regulated by Keap1. Here we use recent data we have derived using experiments in zebrafish and cultured cells to discuss different models of Keap1 regulation.

Immune-cell reprogramming driven by mitochondria-derived reactive electrophilic immunometabolites (mt-REMs—e.g., fumarate, itaconate) is an emerging phenomenon of major biomedical importance. Despite their localized production, mt-REMs elicit significantly-large local and global footprints within and across cells, through mechanisms involving electrophile signaling. Burgeoning efforts are being put into profiling mt-REMs’ potential protein-targets and phenotypic mapping of their multifaceted inflammatory behaviors. Yet, precision indexing of mt-REMs’ first-responders with spatiotemporal intelligence and locale-specific function assignments remains elusive. Highlighting the latest advances and overarching challenges, this perspective aims to stimulate thoughts and spur interdisciplinary innovations to address these unmet chemical-biotechnological needs at therapeutic immuno-signaling frontiers.