Differential regulation of vascular cell adhesion molecule 1 gene expression by specific NF-kappa B subunits in endothelial and epithelial cells.

Abstract

Vascular cell adhesion molecule 1 (VCAM-1) is expressed in both endothelial and epithelial cell types, where it contributes to lymphocyte migration to sites of inflammation. Its expression is regulated by cytokines, in part through two KB-like regulatory elements. Because NF-KB can be composed of multiple alternative subunits with differential effects on gene expression, the role of different specific NF-KB family members subunits in VCAM-1 regulation is unknown. In this report, we define the contribution of different NF-KB family members to VCAM-1 gene regulation. We show that both KB sites in the VCAM-1 enhancer are required to optimally stimulate gene expression, but the enhancer is differentially regulated by specific combinations of NF-cB subunits. At low concentrations, RelA(p65) acted in concert with the -50-kDa product of p105 NF-KB, NF-KBI(p5O), to stimulate transcription, and at high concentrations, RelA(p65) alone stimulated the VCAM-1 promoter. In contrast, NF-KB2 inhibited functional activation of the VCAM reporter by p65. Consistent with this finding, an additional binding complex was detected by using recombinant NF-KB2(p49)/RelA(p65) with radiolabeled VCAM KB site probes. Interestingly, the human immunodeficiency virus enhancer responded differently to stimulation by NF-KB subunits, with optimal response to p49(100)/p65. Analysis of NF-KB mRNA in human umbilical vein endothelial cells revealed that nflcbl, nflcb2, and reL4 NF-KB but not c-rel were induced by tumor necrosis factor alpha and lipopolysaccharide, which also induce VCAM-1. These data suggest that specific subunits of NF-KB regulate VCAM-1 and differentially activate other genes in these cells.

An interaction between the DNA-binding domains of RelA(p65) and Sp1 mediates human immunodeficiency virus gene activation.

“…The pET NF-KB1(p50) plasmid has been described previously (18). The pET ReIA (41,53,66). CAT assays were performed essentially as previously described (41).…”

“…The release of the active NF-KB-binding protein is thought to be controlled by the phosphorylation of different IKB gene products (3,7,21,26,32,48,65,78). Other potential regulatory steps include the processing of the high-molecular-weight precursor of the -50-kDa DNA-binding subunit (19,43,56), the differential regulation of NF-KB mRNAs (1), or the formation of specific heteromeric complexes by different family members (25,36,54,62,66).…”

Andrographolide inhibits NF-κB activation and attenuates neointimal hyperplasia in arterial restenosis

“…The de novo synthesis of E-selectin and VCAM-1 in vascular endothelial cells is well known to be exclusively regulated by NF-κB transcription factors [9,[14][15][16][17][18][19][20]. We thus examined whether the expression of E-selectin and VCAM-1 is regulated by p50-mediated NF-κB activation in our murine models of experimental arterial restenosis.…”

Effects of tacrolimus on ischemia-reperfusion injury

“…This ubiquitous transcription factor mediates early gene expression of cytokines, chemokines, growth factors, immunoreceptors, and cell adhesion molecules during I-R injury. 65,[74][75][76][77][78][79][80][81][82][83][84] Selective blockade of NF-B with proline dithiocarbamate during the early phase of reperfusion resulted in remarkable tissue protection after severe ischemic stress. 85 In parallel, tacrolimus has been documented to block early activation of NF-B.…”