Intercellular adhesion molecule-1 gene expression in human endothelial cells. Differential regulation by tumor necrosis factor-alpha and phorbol myristate acetate.
Intercellular adhesion molecule-1 (ICAM-1) is an inducible glycoprotein expressed on the surface of inflamed endothelium which mediates in part the extravasation of granulocytes into sites of infection or injury. ICAM-1 mRNA is not detected in unstimulated human umbilical vein endothelial cells (HUVECs), but accumulates transiently following tumor necrosis factor-alpha (TNF-alpha) or phorbol myristate acetate (PMA) treatment with maximal steady state levels occurring at 2 or 4 h, respectively. Pretreating HUVECs with PMA for 72 h down-regulates protein kinase C and inhibits the subsequent induction of ICAM-1 mRNA by PMA, but does not affect TNF-alpha-induced message accumulation. Nuclear run-on assays showed that the ICAM-1 gene is transcribed under basal conditions in HUVECs, and that TNF-alpha stimulates transcriptional activity 3- to 4-fold within 30 min of treatment. In contrast, PMA has little effect on ICAM-1 gene transcription up to 4 h following stimulation. Message stability studies established that ICAM-1 mRNA induced by PMA has a longer half-life than the TNF-alpha-induced message. These results suggest that PMA acts through protein kinase C to up-regulate ICAM-1 expression primarily at a post-transcriptional level by stabilizing ICAM-1 mRNA, whereas TNF-alpha transcriptionally regulates ICAM-1 gene expression through an undefined, protein kinase C-independent pathway.
Department of Biochemistry, Boehringer Ingelheim Pharmaceuticals Incorporated, Ridgefield, Connecticut 06877.
S J
SJ
Wertheimer
C L
CL
Myers
R W
RW
Wallace
T P
TP
Parks
D015703:Antigens, CD / Q000235:genetics*; D015815:Cell Adhesion Molecules / Q000235:genetics*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D018799:Intercellular Adhesion Molecule-1; D010957:Plasmids; D011493:Protein Kinase C / Q000378:metabolism; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000096:biosynthesis; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D018799:Intercellular Adhesion Molecule-1; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate