The role of CCL2, CCL7, ICAM-1, and VCAM-1 in interaction of endothelial cells and natural killer cells.

Natural killer (NK) cell-based therapy has been studied for the treatment of patients with cancers, but the inadequate infiltration of NK cells into solid tumors remains a big challenge to its clinical application. In this study, we examined the interaction between NK cells and endothelial cells, which might play a major role in NK cell homing to solid tumors. We found that endothelial cells were activated by TNF-α and IL-1ß, which were produced by tumor-associated CD11b+ cells, which included F4/80+ macrophages. TNF-α-treated endothelial cells increased NK cell migration by producing CCL2 and CCL7, which was proved by transwell and imaging assays. TNF-α-treated endothelial cells adhered well to NK cells, which was due to a TNF-α-induced increase in ICAM-1 and VCAM-1 expression on endothelial cells. Imaging data confirmed that TNF-α-treated endothelial cells transfected with ICAM-1 or VCAM-1 siRNAs did not establish stable contacts with NK cells. Taken together, our data suggest that CCL2, CCL7, ICAM-1, and VCAM-1 expressed by endothelial cells will be potential targets to guide adequate interaction with NK cells, which is a crucial step for NK cell homing to the tumor microenvironment.

Antiatherogenic Effect of Resveratrol Attributed to Decreased Expression of ICAM-1 (Intercellular Adhesion Molecule-1).

Objective- Increasing evidence shows that resveratrol has antiatherogenic effects, but its underlying mechanisms are unknown. Thus, we evaluated the molecular mechanisms underlying the antiatherogenic effect of resveratrol. Approach and Results- Using the previously established mouse atherosclerosis model of partial ligation of the left carotid artery, we evaluated the role of resveratrol in antiatherosclerosis. We attempted to determine the mechanisms associated with focal adhesions using vascular endothelial cells. The results showed that resveratrol stimulated focal adhesion kinase cleavage via resveratrol-increased expression of lactoferrin in endothelial cells. Furthermore, we found that an N-terminal focal adhesion kinase fragment cleaved by resveratrol contained the FERM (band 4.1, ezrin, radixin, and moesin)-kinase domain. Furthermore, resveratrol inhibited lipopolysaccharide-stimulated adhesion of THP-1 human monocytes by decreased expression of ICAM-1 (intercellular adhesion molecule-1). A decreased ICAM-1 level was also observed in the left carotid artery of mice treated with resveratrol. To understand the relationship between resveratrol-induced antiinflammation and focal adhesion disruption, endothelial cells were transfected with FERM-kinase. Ectopically expressed FERM-kinase, the resveratrol-cleaved focal adhesion kinase fragment, was found in the nuclear fraction and inhibited the transcription level of icam-1 via the Nrf2 (nuclear factor erythroid 2-related factor 2)-antioxidant response element complex. Finally, ectopically expressed FERM-kinase blocked tumor necrosis factor-α- or IL- (interleukin) stimulated monocytic binding to endothelial cells. Conclusions- Our results show that resveratrol inhibits the expression of ICAM-1 via transcriptional regulation of the FERM-kinase and Nrf2 interaction, thereby blocking monocyte adhesion. These suppressive effects on the inflammatory mechanism suggest that resveratrol delayed the onset of atherosclerosis.