Functional analysis of nitric oxide and nitric oxide synthase expression in allergic rhinitis.

点击翻译按钮获取中文摘要

Expression of nitric oxide synthase (NOS) isoforms in patients with allergic rhintis :(1) We found the difference in NOS isoform expression in human nasal epithelial cells between normal subjects and patients with perennial allergic rhinitis (AR) by using immunocytochemistry and RT-PCR.AR patients showed significant increases in the levels of inducible NOS (iNOS) expression. However, the levels of endothelial NOS (eNOS) expression were identical between the groups. We also performed visualization and quantification of direct NO production in living cells by using a novel fluorescent indicator, DAF-2 DA.The results indicated that epithelial cells in AR patients produced larger amount of NO.Preincubation with NOS inhibitors (L-NAME or EIT) resulted in decrease in NO production to various degrees.(2) We examined whether in vitro stimulation with proinflammatory cytokines may influence the levels of different NOS isoform expression. The cytokine treatment (TNF-alpha, IFN-gamma, or IL-1beta … More ) significantly augmented iNOS expression in the nasal brushing cells, and dexamethazone significantly suppressed it. We presumed that the activation of transcription factor, nuclear factor-kappa B (NF-kB), might be intimately involved in the transcriptional regulatory mechanisms.(3) We examined the function of endogenously generated NO in the ciliary activity of the epithelial ciliated cells. Both TNE-alpha and IFN-gamma at a concentration of 10 ng/ml decreased ciliary beat frequency (CBF) in a time dependent manner with concomitant increase in iNOS immunoreactivity. We presume that NO modulates CBF in cultured ciliated cells differently under conditions when iNOS expression is strongly augmented inside the cells.Expression of proinflammalory and chemoattractive cytokines in allergic rhintis and chronic sinusitis :(1) We semiquantitatively analyzed the expression of mRNAs encoding GM-CSF, IL-1beta, IL-6, IL-8, RANTES, and eotaxin in nasal and paranasal sinus mucosa by RT-PCR.The analysis revealed that a significant increase in GM-CSF, IL-8, RANTES, and eotaxin expression in allergic patients. A significant increase in GM-CSF and IL-8 expression was observed in sinusitis patients.(2) We employed a primary explant-outgrowth culture model of human paranasal sinus mucosa in order to relate in vitro expression of the cytokines with the NF-kB activity. We found that the activation of NF-kB subunit p50 cultured cells was responsible for the expression of GM-CSF, IL-6, and IL-8 through the initiation of the transcriprional pathway.Further studies need to assesst therapeutic effects of various iNOS inhibitors on allergic responses in the nose as well as to examine other molecular approaches, such as the use of antisense oligonucleotides. Less