Inhibition of Nuclear Factor-κB–Mediated Adhesion Molecule Expression in Human Endothelial Cells

Abstract

—The transcriptional regulatory protein nuclear factor-κB (NF-κB) participates in the control of gene expression of many modulators of the inflammatory and immune responses, including the adhesion molecules E-selectin and intercellular adhesion molecule-1 (ICAM-1). NF-κB is found in the cytoplasm complexed with its inhibitory protein IκB. On activation, IκB is phosphorylated and degraded, thereby freeing NF-κB for translocation to the nucleus. We have generated populations of endothelial cells expressing wild-type and a proteolysis-resistant mutation of IκB that is lacking the 36 N-terminal amino acids (IκBΔN) in order to examine the effects of expression of the mutated IκB on tumor necrosis factor-α (TNF-α)–induced E-selectin and ICAM-1 expression. Wild-type and IκBΔN were introduced into primary endothelial cells using retrovirus infection followed by selection with G418. The IκBΔN protein remained at untreated control levels in endothelial cells treated with TNF-α and also remained complexed with the NF-κB family member p65. Furthermore, TNF-α–induced NF-κB DNA binding activity was inhibited in the population of endothelial cells expressing IκBΔN. That population of cells was also refractory to upregulation of E-selectin and ICAM-1 after treatment with TNF-α. The use of a truncated IκBα protein to prevent NF-κB–mediated gene expression provides a novel and specific approach for investigating the role of NF-κB in processes associated with adhesion molecule expression during inflammation.

Delayed Treatment with MLN519 Reduces Infarction and Associated Neurologic Deficit Caused by Focal Ischemic Brain Injury in Rats via Antiinflammatory Mechanisms Involving Nuclear Factor-κB Activation, Gliosis, and Leukocyte Infiltration

“…For example, the induced upregulation of inflammatory cytokines can initiate an inflammatory response linked to increased necrotic demise of ischemic tissue. Evidence for this is supported by several studies describing effects of reduced NF-B activation mediating neuronal survival or antiinflammatory mechanisms (Clemens et al, 1998;Lockyer et al, 1998). Furthermore, our results, as well as other data Zhang et al, 2001), suggest that delayed postinjury treatment with the proteasome inhibitor MLN519 reduces brain infarction and increases neuronal viability after temporary focal ischemia in the rat.…”

Iodine and IFN-γ Synergistically Enhance Intercellular Adhesion Molecule 1 Expression on NOD.H2h4 Mouse Thyrocytes

“…The ICAM-1 promoter is complex, containing a large number of binding sites for inducible transcription factors (22). The major intracellular signal transduction pathways that regulate ICAM-1 expression include protein kinase C, JAK/STAT, MAPKs, and the NF-B (22,31,32). Reactive oxygen species (ROS) can also activate ICAM-1 transcription.…”

Tachykinin-1 receptor stimulates proinflammatory gene expression in lung epithelial cells through activation of NF-κB via a Gq-dependent pathway

“…To confirm that Tacr1 could induce the expression of an endogenous NF-B-responsive gene, IL-8 was measured in tissue culture supernatants. Treatment of Tacr1-transfected cells with SP resulted in a significant increase in IL-8 secretion, whereas cotransfection with a mutant "superrepressor" IB lacking Ser 32 and Ser 36 phosphorylation sites, which is known to prevent activation of NF-B (20), inhibited the SP-induced increase in IL-8 secretion (Fig. 3C).…”