<p><b>OBJECTIVE</b>To study the effect of nuclear
transcription factor AP-1 on
tumor necrosis factor alpha (
TNF-alpha) or minimal modified
low density lipoprotein (mmLDL)-induced expression of
plasminogen activator inhibitor-1 (
PAI-1) in
human vascular endothelial cells.</p><p><b>
METHODS</b>Using
gene recombination techniques, four
luciferase reporter gene plasmids containing different length of
human PAI-1 gene promoter were constructed. Through the
transient transfection analysis, the
roles of
AP-1 element (from -823 bp to -553 bp) in
PAI-1 promoter have been determined. In order to further verify the
role of
AP-1 element, the three site-directed mutants were recovered using
PCR and sequencing assay.</p><p><b>RESULTS</b>The induction by
TNF-alpha or mmLDL were decreased markedly when the three
AP-1 elements in
PAI-1 promoter had been mutated respectively.</p><p><b>CONCLUSIONS</b>These results indicate that the
AP-1 element in
PAI-1 promoter may have important
role in
PAI-1 gene transcriptions in
endothelial cells induced by
TNF-alpha or mmLDL.</p>