Integrative Chemical Proteomics and Metabolomics Identify AHCY as the Direct Target of Triptolide-induced Liver Injury.

BACKGROUND

Triptolide (TP), a bioactive compound derived from Tripterygium wilfordii, exhibits potent immunosuppressive activity but is limited in clinical application due to hepatotoxicity effects. The direct molecular targets mediating this toxicity remain unclear.

PURPOSE: This research was conducted to pinpoint the principal hepatic molecular target underlying TP-induced liver injury and to elucidate the associated toxicological mechanisms, providing insights for potential hepatoprotective interventions.

METHODS

Chemical proteomics and metabolomic profiling were integrated to identify direct TP targets. The interaction between TP and adenosylhomocysteinase (AHCY) was evaluated using molecular dynamics (MD) simulations and surface plasmon resonance (SPR) analysis. The protective potential of AHCY overexpression against TP-induced liver injury was investigated in experimental models.

RESULTS

Proteomics identified 29 candidate TP-binding proteins associated with liver injury. Metabolomics profiling indicated disturbances in amino acid metabolism, highlighting AHCY as a central mediator. TP exhibited high-affinity binding to AHCY (KD = 3.179 × 10-11 M), resulting in S-adenosylhomocysteine (SAH) accumulation, DNA hypomethylation, metabolic dysfunction, and oxidative stress. Notably, AHCY overexpression attenuated these TP-induced hepatotoxicity.

CONCLUSION

Inhibition of AHCY plays a pivotal role in TP-induced hepatotoxicity. Modulating AHCY activity may offer a promising strategy to enhance the hepatic safety profile of TP in therapeutic applications.