Monitoring Nrf2/ARE Pathway Activity with a New Zebrafish Reporter System

Among multiple cytoprotective mechanisms, eukaryotic cells exhibit a complex transcriptional program relying on the Nrf2 transcription factor, which is generally recruited upon biological stressors including oxidative-stress-based cellular insults. The relevance of this master regulator has remarkably emerged in recent years in several research fields such as cancer, inflammatory disorders and age-related neurological diseases. Here, we document the generation and characterization of a novel Nrf2/ARE pathway biosensor fish which exhibits a dynamic spatiotemporal expression profile during the early developmental stages. The transgenic line is responsive to known Nrf2 pathway modulators but also to Edaravone, which direct activity on the Nrf2 pathway has never been documented in a live transgenic fish model. We also show that the reporter is faithfully activated during fin regeneration, and its degree of expression is slightly affected in a glucocerebrosidase (Gba1) morphant zebrafish model. Therefore, this novel transgenic fish may represent a valuable tool to be exploited for the characterization of zebrafish models of human diseases, as well as for primary high-throughput drug screening.

Automated summary

Among cytoprotective mechanisms, eukaryotic cells rely on the Nrf2 transcription factor to initiate a complex transcriptional program during biological stressors, including oxidative stress. Nrf2 has recently been found to play a crucial role in various research fields, such as cancer, inflammatory disorders, and age-related neurological diseases. In this study, a novel Nrf2/ARE pathway biosensor fish was generated and characterized, demonstrating spatiotemporal expression during early development. This transgenic fish shows responsiveness to Nrf2 pathway modulators and Edaravone, which has not been seen in any live transgenic fish models before. The activated reporter in this fish is also shown to be faithful during fin regeneration and slightly affected in a glucocerebrosidase morphant zebrafish model. Therefore, this innovative transgenic fish can serve as a valuable tool for studying zebrafish models of human diseases and primary high-throughput drug screening.