An oligomer targeted against protein kinase C alpha prevents interleukin-1 alpha induction of cyclooxygenase expression in human endothelial cells

We have previously demonstrated that interleukin-1 alpha (IL-1), a potent polypeptide mediator of immune and inflammatory responses, induces the expression of cyclooxygenase (cox) in human endothelial cells. The mechanism by which binding of IL-1 to its receptor stimulates gene expression remains unclear. Since phorbol 12-myristate 13-acetate, which directly binds and activates protein kinase C (PKC), induced cox expression, we examined the role of PKC as an intracellular mediator of IL-1 activity in human endothelial cells. IL-1 induced the translocation of PKC from the cytosol to the membrane. H7, a selective inhibitor of PKC, as well as an antisense oligomer blocking PKC alpha translation suppressed IL-1 induction of cox mRNA. These findings establish that PKC plays a role in the signal transduction pathway leading to the induction of cox in human endothelial cells

Nuclear localization of endogenous basic fibroblast growth factor in cultured endothelial cells.

Indirect immunofluorescence using anti-human placental bFGF antibodies demonstrates the presence of bFGF-like reactivity in the cytoplasm and in the nucleus of adult bovine aortic endothelial cells and of normal and transformed fetal bovine aortic endothelial AG 7680 and GM 7372 cells. Biologically active immunoreactive Mr 18,000 bFGF can be isolated by heparin-Sepharose affinity chromatography from the extract of GM 7372 cell nuclei. Quantitation of bFGF content by biological and immunological methods indicates that 100,000 bFGF molecules per nucleus are present in GM 7372 cells, with nuclear bFGF corresponding to 25-30\% of total cellular bFGF. Immunoprecipitation experiments demonstrate that the nuclear localization of newly synthesized bFGF occurs when GM 7372 cells are biosynthetically labeled both in the absence and in the presence of suramin, a molecule that inhibits the binding of bFGF to its plasma membrane receptor. Thus the data indicate that endogenous bFGF undergoes an intracellular sorting to the nucleus of the endothelial cell