Induction of vascular cell adhesion molecule-1 expression by IL-4 in human aortic smooth muscle cells is not associated with increased nuclear NF-kappaB levels.
Vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) are upregulated in vascular endothelial and smooth muscle cells by cytokines produced at sites of inflammation. The cytokine profile for induction of VCAM-1, however, is different for the two cell types. Tumor necrosis factor-alpha (TNF-alpha) induced both VCAM-1 and ICAM-1 expression in human umbilical vein endothelial cells (HUVECs; ED50 approximately 300 and 30 U/ml, respectively). TNF-alpha and interleukin-1beta (IL-1beta) stimulated cell surface ICAM-1 expression, but not VCAM-1 expression, in human aortic smooth muscle cells (HASMCs). Conversely, IL-4 was a potent VCAM-1 inducer in HASMCs (ED50 approximately 100 pg/ml) but did not induce ICAM-1 expression. Nuclear extracts from IL-4-treated cells were compared with untreated cells for relative nuclear factor-kappa B (NF-kappaB) levels by using an electrophoretic mobility shift assay and surface plasmon resonance techniques. No significant increase in nuclear NF-kappaB DNA binding activity was detected in IL-4-treated HASMCs by either method of analysis. IL-1beta and TNF-alpha stimulated nuclear NF-kappaB levels by about fourfold and fivefold, respectively, in HASMCs. The antioxidant pyrrolidine dithiocarbamate (PDTC) similarly inhibited VCAM-1 upregulation in HASMCs incubated with IL-4 and in HUVECs incubated with TNF-alpha (IC50s of 25 and 40 microM, respectively). These data suggest that a significant increase in nuclear NF-kappaB levels is not necessary or sufficient for VCAM-1 upregulation in HASMCs and does not determine the relative sensitivity to inhibition of gene expression by PDTC.
Wright
P S
PS
Hoechst Marion Roussel, Inc., Bridgewater, New Jersey 08807-0800, USA. paul.wright@hmrag.com
Cooper
J R
JR
Kropp
K E
KE
Busch
S J
SJ
D001011:Aorta / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D014471:Umbilical Veins / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*
D007375:Interleukin-1; D016328:NF-kappa B; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D015847:Interleukin-4