Takeno S, Osada R, Furukido K, Chen J H, Yajin K
Department of Otolaryngology, Hiroshima University School of Medicine, Hiroshima, Japan.
Clin Exp Allergy. 2001 Jun;31(6):881-8. doi: 10.1046/j.1365-2222.2001.01093.x.
Nitric oxide (NO) is believed to participate in the regulation of airway clearance and non-specific cellular immunity. Recent studies have suggested that airway epithelial cells of allergic and non-allergic individuals may differ in their ability to produce this molecule.
The aim of this study was to detect the difference in NO production in human nasal epithelial cells between normal subjects and patients with perennial allergic rhinitis (AR), and to assess the relationship between the expression of nitric oxide synthase (NOS) isoforms and the severity of the disease.
Nasal epithelial cells were obtained from the inferior turbinate. The expression of mRNAs encoding constitutive endothelial NOS (eNOS) and inducible NOS (iNOS) was studied by reverse transcription-polymerase chain reaction (RT-PCR). Direct NO production in living cells was visualized and quantified by a fluorescent indicator, DAF-2 DA.
RT-PCR analysis demonstrated that AR patients with a RAST score of 5 or 6 showed significant increases in the levels of iNOS mRNA and slight reductions in those of eNOS mRNA. Patients with a RAST score of 2-4 also revealed the same tendency however, the difference was not significant. DAF-2 DA imaging demonstrated that epithelial cells, especially the ciliated cells, produced a larger amount of NO than non-epithelial inflammatory cells. Preincubation with L-NAME resulted in an approximate 40% decrease in both groups.
These results directly indicate that nasal epithelial cells of AR patients overall produce higher levels of NO through the concomitant expression of different NOS isoforms. Continuous NO production by the epithelial cells in normal subjects further support the hypothesis that NO derived from epithelium may play dual roles in the regulation of nasal airway clearance and in the host defense. In addition, the use of DAF-2 DA provides a reliable method to visualize and quantify the direct NO production of living cells.
一氧化氮（NO）被认为参与气道清除和非特异性细胞免疫的调节。最近的研究表明，过敏和非过敏个体的气道上皮细胞产生这种分子的能力可能存在差异。
本研究旨在检测正常受试者和常年性变应性鼻炎（AR）患者鼻上皮细胞中NO产生的差异，并评估一氧化氮合酶（NOS）亚型的表达与疾病严重程度之间的关系。
从下鼻甲获取鼻上皮细胞。通过逆转录聚合酶链反应（RT-PCR）研究编码组成型内皮型NOS（eNOS）和诱导型NOS（iNOS）的mRNA的表达。使用荧光指示剂DAF-2 DA对活细胞中的直接NO产生进行可视化和定量。
RT-PCR分析表明，RAST评分为5或6的AR患者iNOS mRNA水平显著升高，eNOS mRNA水平略有降低。RAST评分为2-4的患者也显示出相同的趋势，然而差异不显著。DAF-2 DA成像显示，上皮细胞，尤其是纤毛细胞，比非上皮炎性细胞产生更多的NO。两组用L-NAME预孵育后，NO产生量均下降约40%。
这些结果直接表明，AR患者的鼻上皮细胞总体上通过不同NOS亚型的共同表达产生更高水平的NO。正常受试者上皮细胞持续产生NO进一步支持了这样的假设，即源自上皮的NO可能在鼻气道清除调节和宿主防御中发挥双重作用。此外，使用DAF-2 DA提供了一种可靠的方法来可视化和定量活细胞的直接NO产生。
