p11 expression in human bronchial epithelial cells is increased by nitric oxide in a cGMP-dependent pathway involving protein kinase G activation

The effect of nitric oxide on p11 expression was studied in an immortalized human bronchial epithelial cell line (BEAS-2B cells). Three nitric oxide d onors were used: spermine NONOate (SP), (+/-)-S-nitroso-N-acetylpenicillami ne (SNAP), and S-nitrosoglutathione (SNOG). All three nitric oxide donors h ad similar effects resulting in dose-dependent and time-dependent accumulat ion of pll protein and an increase of steady-state p11 mRNA. Studies using a reporter gene containing the region from -1499 to +89 of the pll promoter demonstrated an increase in transcriptional activity after stimulation wit h NO donors for 4 h. These effects were abolished at the promoter and prote in level using protein kinase G inhibitors (KT5823 and R-p-8-pCPT-cGMPS). I ncubation of transfected cells with a cell permeable cGMP analogue (8-Br-cG MP) resulted in a dose-related increase of promoter activity. An electropho retic mobility shift assay of nuclear proteins extracted from BEAS-2B cells identified an AP-1 site located at -82 to -77 of the p11 promoter region a s an NO- and cGMP- dependent response element. These data were confirmed us ing a c-jun dominant negative mutant vector and a e-jun expression plasmid. Therefore, we conclude that nitric oxide-induced p11 expression in human b ronchial epithelial cells is mediated at least in part through increased bi nding of activator protein one to the p11 promoter.