The novel anthraquinone compound Kanglexin prevents endothelial-to-mesenchymal transition in atherosclerosis by activating FGFR1 and suppressing integrin β1/TGFβ signaling.

Endothelial-mesenchymal transition (EndMT) disrupts vascular endothelial integrity and induces atherosclerosis. Active integrin β1 plays a pivotal role in promoting EndMT by facilitating TGFβ/Smad signaling in endothelial cells. Here, we report a novel anthraquinone compound, Kanglexin (KLX), which prevented EndMT and atherosclerosis by activating MAP4K4 and suppressing integrin β1/TGFβ signaling. First, KLX effectively counteracted the EndMT phenotype and mitigated the dysregulation of endothelial and mesenchymal markers induced by TGFβ1. Second, KLX suppressed TGFβ/Smad signaling by inactivating integrin β1 and inhibiting the polymerization of TGFβR1/2. The underlying mechanism involved the activation of FGFR1 by KLX, resulting in the phosphorylation of MAP4K4 and Moesin, which led to integrin β1 inactivation by displacing Talin from its β-tail. Oral administration of KLX effectively stimulated endothelial FGFR1 and inhibited integrin β1, thereby preventing vascular EndMT and attenuating plaque formation and progression in the aorta of atherosclerotic Apoe^-/- mice. Notably, KLX (20 mg/kg) exhibited superior efficacy compared with atorvastatin, a clinically approved lipid-regulating drug. In conclusion, KLX exhibited potential in ameliorating EndMT and retarding the formation and progression of atherosclerosis through direct activation of FGFR1. Therefore, KLX is a promising candidate for the treatment of atherosclerosis to mitigate vascular endothelial injury.