INHIBITION OF NUCLEAR FACTOR KAPPA-B NUCLEAR-LOCALIZATION REDUCES HUMAN E-SELECTIN EXPRESSION AND THE SYSTEMIC INFLAMMATORY RESPONSE

Background-One proinflammatory property observed during endothelial ce ll activation is the expression of the neutrophil adhesion molecule E- selectin on the surface of endothelial cells. An important regulatory element in endothelial cell E-selectin expression is the nuclear local ization of the transcription factor nuclear factor (NK)-kappa B, which binds to and affects the function of several genes encoding proteins mediating inflammation. Methods and Results-In this study, we investig ated the ability of pyrrolidine dithiocarbamate (PDTC), an agent that inhibits the nuclear localization of NF-kappa B, to (1) block endothel ial cell E-selectin expression in vitro in response to tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, and lipopolysaccharide (LPS) a nd (2) reduce neutrophil infiltration in a rabbit model of systemic in flammation. As measured with the use of an enzyme-linked itnmunosorben t assay, TNF-alpha, IL-1, and LPS each induced a significant increase in surface expression of E-selectin in cultured human umbilical vein e ndothelial cells (HUVECs) compared with HUVECs treated with medium alo ne. In contrast, E-selectin surface expression was blocked in HUVECs p retreated with PDTC before TNF-alpha, IL-1, or LPS stimulation. NF-kap pa B was present in HUVEC nuclei treated with TNF-alpha, whereas trans location of NF-kappa B to the nucleus was absent in TNF-alpha-treated HUVECs pretreated with PDTC. In vivo, rabbits pretreated with PDTC bef ore LPS infusion showed significantly less neutrophil infiltration in the lungs, liver, and heart compared with animals infused with LPS alo ne. This correlated with a reduction in E-selectin expression in vivo. Conclusions-Our data suggest that NF-kappa B regulation of gene expre ssion in the vascular endothelium may be an important cellular mechani sm in endothelial cell activation.