A novel EndMT inhibitor, xanthotoxin, attenuates non-alcoholic fatty liver disease by acting as TGFβR2 antagonist

Background

Endothelial-to-mesenchymal transition (EndMT) has emerged as a key process contributing to the pathology of non-alcoholic fatty liver disease (NAFLD). Thus, identifying EndMT inhibitors may help impede NAFLD progression.

Purpose

Our research aims to identify potent natural EndMT inhibitors and explore their therapeutic potential and mechanisms of action in NAFLD.

Methods

A natural compound library was employed to screen potential EndMT inhibitors. High-fat diet (HFD)-induced ApoE^-/- mice and free fatty acid (FFA)-treated human hepatic sinusoidal endothelial cells (HHSECs) were employed as animal and cellular models of NAFLD. EndMT was evaluated by western blotting, qRT-PCR, immunofluorescence staining, tube formation, wound healing, and transwell assays. LC-MS/MS was applied to screen for altered secreted proteins during EndMT. Molecular docking, CETSA, and SPR assays were employed to validate the combination of xanthotoxin with TGFβR2.

Results

Xanthotoxin was identified as a novel EndMT inhibitor. Further investigation revealed that xanthotoxin ameliorates NAFLD in ApoE^-/- mice. By inhibiting EndMT, xanthotoxin improves endothelial dysfunction, reduces the pro-NAFLD factor ANGPTL2 secretion, and increases the anti-NAFLD factor SOD2 secretion, thus reducing hepatocyte steatosis, inflammation, and hepatic stellate cell fibrosis. Additional studies demonstrated that xanthotoxin binds to TGFβR2 and acts as its antagonist to block EndMT. In mice, EC-specific overexpression of TGFβR2 negated xanthotoxin’s therapeutic impact on NAFLD.

Conclusion

This study reveals for the first time that xanthotoxin attenuates NAFLD by acting as a TGFβR2 antagonist to inhibit EndMT. These findings highlight the significant therapeutic potential of xanthotoxin in NAFLD treatment.