Selective activation of endothelial cells by the antioxidant pyrrolidine dithiocarbamate: involvement of C-jun N-terminal kinase and AP-1 activation.
The antioxidant agent pyrrolidine dithiocarbamate (PDTC) has been shown to protect endothelial cells (EC) from pro-inflammatory-induced and pro-oxidant-induced NF-kappaB activation. It also perturbs EC by altering activator protein-1 (AP-1) status and inducing ICAM-1. Experiments were performed to investigate the upstream mechanism by which PDTC produces these effects. We have demonstrated that PDTC not only induced AP-1 binding and ICAM-1 expression by itself, but it also augmented AP-1 activation and ICAM-1 induction in low-dose IL-1alpha treated cells. To dissect the mechanism of these effects, we measured c-Jun and c-Fos expression, and the activity of c-Jun NH2-terminal kinase (JNK) and extracellular signal regulated kinase (ERK) in human umbilical vein endothelial cells (HUVEC). We detected an increase in JNK activity in PDTC-treated HUVEC. Following cotransfection with JNK[K-M], a kinase-deficient JNK1, the PDTC-increased AP-1-driven-luciferase activity was attenuated. Utilizing a specific trans-reporting system we confirmed c-Jun activation by upstream signaling mechanisms. The results show that c-Jun activity was increased 9-fold after PDTC treatment. In addition, PDTC promoted more transient activation in ERK-c-fos. In contrast, PDTC produced sustained JNK-c-Jun activation, which translated into long-lasting ICAM-1 production. These results suggest that an antioxidant may contribute to chronic vascular endothelial activation.
Liao
H L
HL
Division of Biomedical Sciences, University of California, Riverside 92521, USA.
Zhu
Y
Y
Wang
N
N
Verna
L
L
Stemerman
M B
MB
D000975:Antioxidants / Q000494:pharmacology*; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000187:drug effects / Q000378:metabolism; D007375:Interleukin-1 / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000187:drug effects / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000187:drug effects / Q000378:metabolism; D011759:Pyrrolidines / Q000494:pharmacology*; D013859:Thiocarbamates / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000187:drug effects / Q000378:metabolism*; D014162:Transfection; D014471:Umbilical Veins / Q000187:drug effects / Q000201:enzymology
D000975:Antioxidants; D007375:Interleukin-1; D016328:NF-kappa B; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D011759:Pyrrolidines; D013859:Thiocarbamates; D018808:Transcription Factor AP-1; D018799:Intercellular Adhesion Molecule-1; C020972:pyrrolidine dithiocarbamic acid; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases