Effects of Cornu Bubali (CB) on the Adhesion of Leukocyte and Endothelial Cells

Abstract

Background: The interaction between leukocytes and vascular endothelial cells is ubiquitous in the occurrence and development of many diseases, especially in the body's defense response. The purpose of the present study was to investigate the effect of cornu bubali (CB) on the adhesion of leukocytes to endothelial cells. Materials and methods: Human leukemic cell line (HL-60) and human umbilical vein endothelial cells (HUVECs) were used to simulate the adhesion effect between cells. After HUVECs were treated with TNF- α(15 ng/mL) combined with different dose of CB (15, 30 and 60 μmol/L) and dexamethasone (DEX, 2 μg/ml) for 24 h, HL-60 cells were added into the coculture system for another 1 h. CCK8 assay was performed to investigate cell viability of HUVECs. HL-60 cells adhesion to HUVECs was quantified using Hoechst 33342 staining. Subsequently, the levels of adhesion molecules were detected by the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis and ELISA, respectively. RT-qPCR and western blot were performed to assess the levels of inflammatory cytokines, chemokines and the expression of Notch signaling pathway. Results: Treatment with CB could reduce the adherence of HL-60 to HUVECs induced by TNF- in a dose-dependent manner. CB inhibited the expression of ICAM-1, VCAM-1, CD44, IL-1β, COX-2 and CCL4 in HUVECs. Western blot and RT-qPCR analysis confirmed that CB prevented TNF-α -induced over-expression of Notch receptors (Notch1 and Notch2), Notch ligands (DLL1 and Jagged1), signaling effectors (Hes1) and adhesion related proteins (NF-κB/p65, p-I B and IκBκ) in HUVECs. Conclusion: CB induces interactions between leukocytes and endothelial cells through the activation of Notch signaling pathway. These data contribute to further explain the protective effect of CB against development of inflammatory process of hemorrhage in acute leukemia.