iNOS gene upregulation is associated with the early proliferative response of human lung fibroblasts to cytokine stimulation.
Increased release of oxidants has been implicated in the pathogenesis of pulmonary fibrosis. Previous work in the rat showed that formation of the early fibrotic lesion is associated with increased expression of inducible nitric oxide synthase (iNOS) in pulmonary fibroblasts. The aim of this study was to test the hypothesis that NO is involved in the activation of pulmonary fibroblasts. The effects of endogenous and exogenous NO on proliferation of human pulmonary fibroblasts were investigated by administration of cytomix or SNAP, respectively. At low concentrations, both treatments increased cell numbers, an effect attenuated by iNOS inhibitor or NO scavenger. Induction of iNOS was confirmed by measurement of nitrate/nitrite production and by immunodetection. Quantitative RT-PCR showed an increase in iNOS mRNA as early as 3 h after stimulation. These results support the hypothesis and show that upregulation of the iNOS gene is an early event in the proliferative response of human lung fibroblasts to inflammatory stimuli.
Department of Histochemistry, Imperial College School of Medicine, Hammersmith Hospital, London.
Hanna M
HM
Romanska
Julia M
JM
Polak
Robert A
RA
Coleman
Rowena S
RS
James
Daniel W
DW
Harmer
Jennifer C
JC
Allen
Anne E
AE
Bishop
D015153:Blotting, Western / Q000379:methods; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D003497:Cyclic N-Oxides / Q000494:pharmacology; D016207:Cytokines / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology; D016166:Free Radical Scavengers / Q000494:pharmacology; D005786:Gene Expression Regulation; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D008168:Lung / Q000201:enzymology*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000235:genetics*; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D010396:Penicillamine / Q000031:analogs & derivatives* / Q000494:pharmacology; D011658:Pulmonary Fibrosis / Q000201:enzymology*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013268:Stimulation, Chemical; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology
D003497:Cyclic N-Oxides; D016207:Cytokines; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D007093:Imidazoles; D007375:Interleukin-1; D020030:Nitric Oxide Donors; D012333:RNA, Messenger; C110881:S-nitro-N-acetylpenicillamine; D014409:Tumor Necrosis Factor-alpha; C079391:2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; D019323:omega-N-Methylarginine; D007371:Interferon-gamma; C496319:NOS2 protein, human; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D010396:Penicillamine