Molecular docking- and reporter-based screening identify dicoumarol against ER stress-induced liver injury in mice through inhibiting IRE1α activity

Drug-induced liver injury is among the most challenging liver disorders. Endoplasmic reticulum (ER) is responsible for the correct protein folding and secretion, which are highly active in hepatocytes. Failure in maintaining the proper protein folding under pathological condition or external stimuli leads to the unfolded protein response (UPR) to restore ER homeostasis or induce cell death. IRE1α pathway is the most conserved UPR branch with diverse physiological and pathological functions. This study aimed to screen for natural compounds to alleviate hepatic ER stress and liver injury by modulating IRE1α activity.

ATP-competitive molecules from chemical libraries were recognized by virtual screening for targeting the IRE1α kinase domain. IRE1α activity-based XBP1s-reporter cell lines with flow cytometric analysis were employed to validate candidates from chemical libraries. Then the functions of the top candidate compound on IRE1α signaling were analyzed followed by the treatment with ER stress agonists in vitro. Finally, the candidate compound was used to treat ER stress-induced acute liver injury to evaluate its protective effect in vivo.

Dicoumarol (DIC) was discovered as a potential inhibitor of IRE1α activation in HEK293T cells, HepG2 cells and primary hepatocytes. Particularly, DIC ameliorates tunicamycin (Tm)- and carbon tetrachloride (CCl₄)-induced acute hepatic ER stress to protect against liver injury.

This study established a drug screening strategy against IRE1α activation and identified potential new therapeutic effects of DIC in treating liver injury-related diseases.