Differential regulation of vascular cell adhesion molecule 1 gene expression by specific NF-kappa B subunits in endothelial and epithelial cells.
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 kappa B-like regulatory elements. Because NF-kappa B can be composed of multiple alternative subunits with differential effects on gene expression, the role of different specific NF-kappa B family members subunits in VCAM-1 regulation is unknown. In this report, we define the contribution of different NF-kappa B family members to VCAM-1 gene regulation. We show that both kappa B sites in the VCAM-1 enhancer are required to optimally stimulate gene expression, but the enhancer is differentially regulated by specific combinations of NF-kappa B subunits. At low concentrations, RelA(p65) acted in concert with the approximately 50-kDa product of p105 NF-kappa B, NF-kappa B1(p50), to stimulate transcription, and at high concentrations, RelA(p65) alone stimulated the VCAM-1 promoter. In contrast, NF-kappa B2 inhibited functional activation of the VCAM reporter by p65. Consistent with this finding, an additional binding complex was detected by using recombinant NF-kappa B2(p49)/RelA(p65) with radiolabeled VCAM kappa B site probes. Interestingly, the human immunodeficiency virus enhancer responded differently to stimulation by NF-kappa B subunits, with optimal response to p49(100)/p65. Analysis of NF-kappa B mRNA in human umbilical vein endothelial cells revealed that nfkb1, nfkb2, and relA NF-kappa B 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-kappa B regulate VCAM-1 and differentially activate other genes in these cells.
Shu
H B
HB
Department of Internal Medicine, Howard Hughes Medical Institute, University of Michigan Medical Center, Ann Arbor 48109-0650.
Agranoff
A B
AB
Nabel
E G
EG
Leung
K
K
Duckett
C S
CS
Neish
A S
AS
Collins
T
T
Nabel
G J
GJ
D000818:Animals; D000081242:B-Cell Lymphoma 3 Protein; D001483:Base Sequence; D001665:Binding Sites; D015815:Cell Adhesion Molecules / Q000235:genetics*; D002460:Cell Line; D004247:DNA; D004268:DNA-Binding Proteins / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006678:HIV / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D020672:I-kappa B Proteins; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000494:pharmacology; D013552:Swine; D014157:Transcription Factors; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1
D000081242:B-Cell Lymphoma 3 Protein; C000631344:BCL3 protein, human; D015815:Cell Adhesion Molecules; D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D000072000:NF-KappaB Inhibitor alpha; D004247:DNA