CRISPR screen identifies MAP2K3 as a key target for oleuropein to alleviate deoxynivalenol-induced hepatic injury.

INTRODUCTION

Deoxynivalenol (DON), a widely prevalent mycotoxin in temperate climates, causes significant hepatic injury upon the consumption of contaminated cereals. However, the key targets and mechanisms underlying DON-induced inflammatory hepatic injury remain unclear, thus hindering the development of targeted therapeutics.

OBJECTIVES

This study aimed to identify the key host targets mediating DON-induced inflammatory hepatic injury and its underlying molecular mechanism, as well as to discover potential therapeutic agents for alleviating this damage.

METHODS

We established a J774A.1-CRISPR-Cas9 whole-genome knockout library to screen for host genes essential for DON-induced apoptosis. Structure-based virtual screening was employed to identify MAP2K3 inhibitors, and the mechanism of oleuropein (Ole) action was explored using both in vivo and in vitro models.

RESULTS

CRISPR screening revealed that MAP2K3 is crucial for DON-induced apoptosis. Mechanistically, MAP2K3 mediates inflammatory hepatic injury by activating the p38/p53/caspase-8/caspase-9/caspase-3 pathway. Virtual screening identified Ole as a direct MAP2K3 inhibitor, which binds to key amino acid residues (Lys149, Ser194, Tyr230). Ole effectively inhibited DON-induced hepatic damage in vitro. In the DON-induced murine hepatitis model, Ole demonstrated robust therapeutic effects against DON-induced hepatitis, and its efficacy was superior to that of N-acetylcysteine (NAC).

CONCLUSION

This study demonstrates that MAP2K3 is a key target mediating DON-induced inflammatory hepatic injury and confirms oleuropein (Ole) as a potential therapeutic agent. Together, these findings advance our understanding of the underlying mechanisms and propose a new treatment strategy.