E-selectin gene expression in vascular smooth muscle cells. Evidence for a tissue-specific repressor protein.
E-Selectin is an inducible, endothelium-specific, cell surface adhesion molecule that mediates inflammatory responses in the vasculature. Nonendothelial cell types such as cultured human aortic smooth muscle cells (HASMCs) lack the ability to express E-selectin. We tested the hypothesis that HASMCs express a negative regulatory factor that inhibits E-selectin gene expression. E-Selectin mRNA and gene transcription were not detected in HASMCs after treatment with tumor necrosis factor-alpha (TNF-alpha) by Northern and nuclear runoff analyses, respectively. However, both E-selectin mRNA and gene transcription were dramatically induced by TNF-alpha in the same cells pretreated with the protein synthesis inhibitor cycloheximide. Lipopolysaccharide demonstrated similar effects. Furthermore, E-selectin was detected on the cell surface of HASMCs after washing out of cycloheximide. Cycloheximide pretreatment enabled immortalized human dermal microvascular endothelial cells that have lost the ability to express E-selectin to induce both E-selectin mRNA and gene transcription in response to TNF-alpha. Induction of E-selectin mRNA by lipopolysaccharide or TNF-alpha in cycloheximide-treated HASMCs was inhibited by the antioxidant pyrrolidinedithiocarbamate and the serine protease inhibitor N alpha-L-tosyl-L-phenylalanine chloromethyl ketone, suggesting that a nuclear factor-kappa B-like mechanism may play an important role in E-selectin gene expression in HASMCs. These data strongly suggest that a labile repressor protein(s) plays an important role in inhibiting E-selectin gene expression in HASMCs likely at the level of gene transcription. Except for this repressor, HASMCs and endothelial cells may share similar regulatory mechanisms for controlling E-selectin expression.
Chen
X L
XL
Department of Medicine, Emory University School of Medicine, Atlanta, Ga. 30322, USA.
Tummala
P E
PE
Olliff
L
L
Medford
R M
RM
D000975:Antioxidants / Q000494:pharmacology; D001011:Aorta; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D019040:E-Selectin / Q000235:genetics* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism*; D016328:NF-kappa B / Q000502:physiology; D009928:Organ Specificity; D011392:Proline / Q000031:analogs & derivatives / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D012097:Repressor Proteins / Q000187:drug effects / Q000502:physiology*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013859:Thiocarbamates / Q000494:pharmacology; D013997:Time Factors; D014108:Tosylphenylalanyl Chloromethyl Ketone / Q000494:pharmacology; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
D000975:Antioxidants; D019040:E-Selectin; D008070:Lipopolysaccharides; D016328:NF-kappa B; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D012097:Repressor Proteins; D015842:Serine Proteinase Inhibitors; D013859:Thiocarbamates; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; C066229:prolinedithiocarbamate; D014108:Tosylphenylalanyl Chloromethyl Ketone; D003513:Cycloheximide; D011392:Proline