The Isoquinoline PRL-295 Increases the Thermostability of Keap1 and Disrupts Its Interaction with Nrf2

Transcription factor Nrf2 and its negative regulator Keap1 orchestrate a comprehensive cytoprotective response against oxidative, electrophilic, metabolic, inflammatory stress. is drug target, with several small molecules currently in development. Here, we show that the isoquinoline PRL-295 increased thermostability lysates from cells stably expressing fluorescently-tagged Keap1. The of endogenous also intact murine liver following treatment. Fluorescence Lifetime Imaging - Forster Resonance Energy Transfer (FLIM-FRET) experiments co-expressing sfGFP-Nrf2 Keap1-mCherry further showed prolonged fluorescence lifetime donor, indicating disruption Keap1-Nrf2 protein complex. Orally-administered to mice activated Nrf2-transcriptional target NAD(P)H:oxidoreductase 1 decreased plasma alanine aminotransferase upon acetaminophen-induced hepatic injury. Thus, engages vivo, disrupting interaction Nrf2, leading activation Nrf2-dependent transcription, hepatocellular protection.