Earthworm fibrinolytic enzyme A and fibrin-derived peptide Bβ15-42 attenuate atherosclerosis via the VE-Cadherin signaling pathway.

AIM: Earthworm fibrinolytic enzymes A (EFEa) is the main active component of earthworm fibrinolytic enzymes which possesses anticoagulant, fibrinolytic, and potential anti-atherosclerotic effects. However, the biological function and mechanism of action of EFEa remains unclear. This study aims to investigate the role of EFEa and the fibrin-derived peptide Bβ15-42 (Bβ15-42) in attenuating atherosclerosis by modulating endothelial adhesion and inflammation via the vascular endothelial (VE)-cadherin signaling pathway. METHODS: In this study, we established both a rabbit model of atherosclerosis and an in vitro endothelial cell model. Bβ15-42, EFEa, and rosuvastatin (ROS) were administered to evaluate their effects on atherosclerotic plaque formation and inflammatory responses. Plaque size and intimal thickening were evaluated using Oil Red O and hematoxylin-eosin (HE) staining. Fibrinogen deposition and VE-cadherin expression were analyzed via western blotting and immunohistochemistry. Furthermore, macrophage migration assays and CDH5-positive (CDH5(+)) human umbilical vein endothelial cell (HUVEC) models were utilized to investigate the effects of these compounds on inflammatory cell migration and VE-cadherin-mediated endothelial barrier function. RESULTS: Treatment with Bβ15-42, EFEa, and ROS significantly reduced atherosclerotic plaque formation and intimal thickening in the rabbit model of atherosclerosis (P < 0.05). Both Bβ15-42 and EFEa significantly reduced fibrinogen deposition and inflammatory cell infiltration in the aortic tissue of atherosclerotic rabbits (P < 0.05). Western blot and immunohistochemical analyses confirmed that Bβ15-42 and EFEa effectively up-regulated VE-cadherin expression (P < 0.05). In vitro, Bβ15-42 and EFEa significantly inhibited fibrin-induced macrophage transmigration across endothelial cell monolayers, reducing migration by 83.3 % and 56.1 %, respectively (P < 0.05, respectively). CONCLUSION: EFEa and Bβ15-42 exert protective effects against atherosclerosis via the VE-cadherin pathway. Our findings lay the groundwork for further research into the anti-atherosclerotic mechanisms of EFEa, as well as its potential for future development and application.