Organotin-induced apoptosis occurs in small CD4+CD8+ thymocytes and is accompanied by an increase in RNA synthesis

The organotin compounds di-n-butyltin dichloride (DBTC) and tri-n-butyltin chloride (TBTC) induce thymus atrophy in rats. At low doses they inhibit immature thymocyte proliferation, whereas at higher doses in particular TBTC induces apoptotic cell death. In vitro, a similar concentration-effect relationship was observed, i.e. low concentrations...

Role of c-Jun and proximal phorbol 12-myristate-13-acetate-(PMA)-responsive elements in the regulation of basal and PMA-stimulated plasminogen-activator inhibitor-1 gene expression in HepG2

Experiments were designed to clarify the role of c-Jun/c-Fos and of putative phorbol 12-myristate-13-acetate-(PMA)-responsive elements (TREs) in the induction of plasminogen-activator inhibitor 1 (PAI-1) gene transcription in the human hepatoma cell line HepG2 by activators of protein kinase C (PKC). Treatment of HepG2 cells with the phorbol...

Stimulation of tissue-type plasminogen activator expression by retinoic acid in human endothelial cells requires retinoic acid receptor β2 induction

We previously showed the involvement of retinoic acid receptor α (RARα) in the induction of tissue-type plasminogen activator (t-PA) synthesis by RA in human umbilical vein endothelial cells (HUVECs). However, the rather slow onset of this induction of t-PA synthesis suggested an indirect role of RARα. Here, we show that the protein synthesis...

Pharmacological modulation of the endotoxin-induced increase in plasminogen activator inhibitor activity in rats

Pharmacological modulation of the in vivo induction of plasminogen activator inhibitor type-1 (PAI-1) synthesis was studied in rats using the induction of PAI-1 by endotoxin as a model system. Both the cyclooxygenase inhibitors acetylsalicylic acid and indomethacin enhanced PAI-1 induction. The combined cyclooxygenase-lipoxygenase inhibitor,...

Tumor necrosis factor and interleukin-1 induce expression of the verocytotoxin receptor globotriaosylceramide on human endothelial cells: Implications for the pathogenesis of the hemolytic uremic syndrome

The epidemic form of the hemolytic uremic syndrome (HUS), beginning with an acute gastroenteritis, has been associated with a verocytotoxin-producing Escherichia coli infection. The endothelial cell is believed to play an important role in the pathogenesis of HUS. Endothelial cell damage by verocytotoxin-1 (VT-1) in vitro is potentiated by the...

Different induction of two plasminogen activator inhibitor 1 mRNA species by phorbol ester in human hepatoma cells

In man, the plasminogen activator inhibitor 1 (PAI-1) gene codes for two mRNA species, one of 3.2 kilobases (kb) and the other of 2.4 kb. We report that the protein kinase C activating phorbol ester, phorbol 12-myristate-13-acetate (PMA), causes a different induction of the two PAI-1 mRNA species in the human hepatoma cell line, HepG2. Upon...

Protein synthesis inhibition by cycloheximide does not affect the acute release of tissue-type plasminogen activator

The acute release of tissue-type plasminogen activator (t-PA) was studied in perfused rat hindlegs. Pretreatment of rats with the protein synthesis inhibitor cycloheximide (2 mg/kg) at 1, 3 or 5 h prior to perfusion of rat hindlegs did not influence the amount of t-PA released by platelet-activating factor (20 nM) or bradykinin (1 μM). The...

Lipoprotein secretion by isolated rat hepatocytes: Characterization of the lipid-carrying particles and modulation of their release

Lipoprotein production by freshly isolated rat hepatocytes in suspension was studied during short (1-3 hr) incubation periods. The heaptocytes release very low density (91.10 g/ml). These particles with higher densities have not been positively identified; the latter group is dissimilar to the high density lipoprotein, which occurs in rat liver...