Regulation of type 1 plasminogen activator inhibitor gene expression in cultured bovine aortic endothelial cells. Induction by transforming growth factor-beta, lipopolysaccharide, and tumor necrosis factor-alpha.

摘要: Abstract Cultured bovine aortic endothelial cells (BAEs) synthesize and secrete type 1 plasminogen activator inhibitor (PAI-1), an Mr 50,000 glycoprotein which inhibits both urokinase tissue-type activators. The synthesis of PAI-1 in BAEs is positively regulated by a variety agents. To elucidate the mechanisms govern expression gene, total cytoplasmic RNA was prepared from analyzed Northern blotting using 1.3-kilobase (kb) human cDNA probe. Hybridization under conditions high stringency revealed two species, 3.0 1.6 kb length. ratio species approximately 4:1. 3.0-kb mRNA bound oligo(dT)-cellulose, whereas 1.6-kb form not, suggesting that latter lacked poly(A) terminus. Treatment with transforming growth factor beta (TGF-beta), bacterial lipopolysaccharide (LPS), or tumor necrosis alpha (TNF-alpha) markedly enhanced steady-state levels species. In each case, increases were detectable within h, maximal effects (i.e. greater than 30-fold increase) observed between 6 18 h treatment, followed decline to near-basal 48 h. response these agents dose-dependent, induction at concentrations 10 ng/ml TGF-beta, LPS, 25 TNF-alpha. Induction not blocked protein cycloheximide, de novo required. fact, treatment cycloheximide (2 micrograms/ml) alone also increased levels. combination TNF-alpha further accumulation mRNA. Nuclear transcription run-on experiments indicated elevated rate gene 20-30-fold template activity temporally correlated These data are consistent conclusion result primary on transcription.