Molecular pharmacology
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Molecular pharmacology · Apr 1998
Activation of protein kinase C alpha and/or epsilon enhances transcription of the human endothelial nitric oxide synthase gene.
In primary human umbilical vein endothelial cells (HUVECs), incubation with phorbol-12-myristate-13-acetate (PMA) enhanced basal and bradykinin-stimulated nitric oxide production. In the HUVEC-derived cell line EA.hy 926, PMA and phorbol-12,13-dibutyrate stimulated endothelial nitric oxide synthase (NOS III) mRNA expression in a concentration- and time-dependent manner. Maximal mRNA expression (3.3-fold increase) was observed after 18 hr. ⋯ When human endothelial cells (ECV 304 or EA.hy 926) were transiently or stably transfected with a 3.5-kb fragment of the human NOS III promoter driving a luciferase reporter gene, PMA stimulated promoter activity up to 2.5-fold. On the other hand, PMA did not change the stability of the NOS III mRNA. These data indicate that stimulation of PKC alpha, PKC epsilon, or both by active phorbol esters represents an efficacious pathway activating the human NOS III promoter in human endothelium.