Abstract
Nitric oxide (NO) is an important mediator of inflammatory responses in the lung and a key regulator of bronchomotor tone. An airway NO synthase (NOS; EC 1.14.13.39) has been proposed as a source of endogenous NO in the lung but has not been clearly defined. Through molecular cloning, we conclusively demonstrate that NO synthesis in normal human airways is due to the continuous expression of the inducible NOS (iNOS) isoform in airway epithelial cells. Although iNOS mRNA expression is abundant in airway epithelial cells, expression is not detected in other pulmonary cell types, indicating that airway epithelial cells are unique in the continuous pattern of iNOS expression in the lung. In situ analysis reveals all airway epithelial cell types express iNOS. However, removal of epithelial cells from the in vivo airway environment leads to rapid loss of iNOS expression, which suggests expression is dependent upon conditions and/or factors present in the airway. Quantitation of NOS activity in epithelial cell lysates indicates nanomolar levels of NO synthesis occur in vivo. Remarkably, the high-level iNOS expression is constant in airway epithelium of normal individuals over time. However, expression is strikingly decreased by inhaled corticosteroids and beta-adrenergic agonists, medications commonly used in treatment of inflammatory airway diseases. Based upon these findings, we propose that respiratory epithelial cells are key inflammatory cells in the airway, functioning in host defense and potentially playing a role in airway inflammation.
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- Ahn K. Y., Mohaupt M. G., Madsen K. M., Kone B. C. In situ hybridization localization of mRNA encoding inducible nitric oxide synthase in rat kidney. Am J Physiol. 1994 Nov;267(5 Pt 2):F748–F757. doi: 10.1152/ajprenal.1994.267.5.F748. [DOI] [PubMed] [Google Scholar]
- Asano K., Chee C. B., Gaston B., Lilly C. M., Gerard C., Drazen J. M., Stamler J. S. Constitutive and inducible nitric oxide synthase gene expression, regulation, and activity in human lung epithelial cells. Proc Natl Acad Sci U S A. 1994 Oct 11;91(21):10089–10093. doi: 10.1073/pnas.91.21.10089. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Barnes P. J., Pedersen S. Efficacy and safety of inhaled corticosteroids in asthma. Report of a workshop held in Eze, France, October 1992. Am Rev Respir Dis. 1993 Oct;148(4 Pt 2):S1–26. doi: 10.1164/ajrccm/148.4_Pt_2.S1. [DOI] [PubMed] [Google Scholar]
- Charles I. G., Palmer R. M., Hickery M. S., Bayliss M. T., Chubb A. P., Hall V. S., Moss D. W., Moncada S. Cloning, characterization, and expression of a cDNA encoding an inducible nitric oxide synthase from the human chondrocyte. Proc Natl Acad Sci U S A. 1993 Dec 1;90(23):11419–11423. doi: 10.1073/pnas.90.23.11419. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Devalia J. L., Campbell A. M., Sapsford R. J., Rusznak C., Quint D., Godard P., Bousquet J., Davies R. J. Effect of nitrogen dioxide on synthesis of inflammatory cytokines expressed by human bronchial epithelial cells in vitro. Am J Respir Cell Mol Biol. 1993 Sep;9(3):271–278. doi: 10.1165/ajrcmb/9.3.271. [DOI] [PubMed] [Google Scholar]
- Erzurum S. C., Danel C., Gillissen A., Chu C. S., Trapnell B. C., Crystal R. G. In vivo antioxidant gene expression in human airway epithelium of normal individuals exposed to 100% O2. J Appl Physiol (1985) 1993 Sep;75(3):1256–1262. doi: 10.1152/jappl.1993.75.3.1256. [DOI] [PubMed] [Google Scholar]
- Felley-Bosco E., Ambs S., Lowenstein C. J., Keefer L. K., Harris C. C. Constitutive expression of inducible nitric oxide synthase in human bronchial epithelial cells induces c-fos and stimulates the cGMP pathway. Am J Respir Cell Mol Biol. 1994 Aug;11(2):159–164. doi: 10.1165/ajrcmb.11.2.7519434. [DOI] [PubMed] [Google Scholar]
- Geller D. A., Lowenstein C. J., Shapiro R. A., Nussler A. K., Di Silvio M., Wang S. C., Nakayama D. K., Simmons R. L., Snyder S. H., Billiar T. R. Molecular cloning and expression of inducible nitric oxide synthase from human hepatocytes. Proc Natl Acad Sci U S A. 1993 Apr 15;90(8):3491–3495. doi: 10.1073/pnas.90.8.3491. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gunning P., Ponte P., Okayama H., Engel J., Blau H., Kedes L. Isolation and characterization of full-length cDNA clones for human alpha-, beta-, and gamma-actin mRNAs: skeletal but not cytoplasmic actins have an amino-terminal cysteine that is subsequently removed. Mol Cell Biol. 1983 May;3(5):787–795. doi: 10.1128/mcb.3.5.787. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hamid Q., Springall D. R., Riveros-Moreno V., Chanez P., Howarth P., Redington A., Bousquet J., Godard P., Holgate S., Polak J. M. Induction of nitric oxide synthase in asthma. Lancet. 1993 Dec 18;342(8886-8887):1510–1513. doi: 10.1016/s0140-6736(05)80083-2. [DOI] [PubMed] [Google Scholar]
- Holtzman M. J., Hansbrough J. R., Rosen G. D., Turk J. Uptake, release and novel species-dependent oxygenation of arachidonic acid in human and animal airway epithelial cells. Biochim Biophys Acta. 1988 Dec 16;963(3):401–413. doi: 10.1016/0005-2760(88)90308-6. [DOI] [PubMed] [Google Scholar]
- Jain B., Rubinstein I., Robbins R. A., Leise K. L., Sisson J. H. Modulation of airway epithelial cell ciliary beat frequency by nitric oxide. Biochem Biophys Res Commun. 1993 Feb 26;191(1):83–88. doi: 10.1006/bbrc.1993.1187. [DOI] [PubMed] [Google Scholar]
- Janssens S. P., Shimouchi A., Quertermous T., Bloch D. B., Bloch K. D. Cloning and expression of a cDNA encoding human endothelium-derived relaxing factor/nitric oxide synthase. J Biol Chem. 1992 Jul 25;267(21):14519–14522. [PubMed] [Google Scholar]
- Kamijo R., Harada H., Matsuyama T., Bosland M., Gerecitano J., Shapiro D., Le J., Koh S. I., Kimura T., Green S. J. Requirement for transcription factor IRF-1 in NO synthase induction in macrophages. Science. 1994 Mar 18;263(5153):1612–1615. doi: 10.1126/science.7510419. [DOI] [PubMed] [Google Scholar]
- Kharitonov S. A., Yates D., Robbins R. A., Logan-Sinclair R., Shinebourne E. A., Barnes P. J. Increased nitric oxide in exhaled air of asthmatic patients. Lancet. 1994 Jan 15;343(8890):133–135. doi: 10.1016/s0140-6736(94)90931-8. [DOI] [PubMed] [Google Scholar]
- Kobzik L., Bredt D. S., Lowenstein C. J., Drazen J., Gaston B., Sugarbaker D., Stamler J. S. Nitric oxide synthase in human and rat lung: immunocytochemical and histochemical localization. Am J Respir Cell Mol Biol. 1993 Oct;9(4):371–377. doi: 10.1165/ajrcmb/9.4.371. [DOI] [PubMed] [Google Scholar]
- Maier R., Bilbe G., Rediske J., Lotz M. Inducible nitric oxide synthase from human articular chondrocytes: cDNA cloning and analysis of mRNA expression. Biochim Biophys Acta. 1994 Sep 21;1208(1):145–150. doi: 10.1016/0167-4838(94)90171-6. [DOI] [PubMed] [Google Scholar]
- Nathan C., Xie Q. W. Regulation of biosynthesis of nitric oxide. J Biol Chem. 1994 May 13;269(19):13725–13728. [PubMed] [Google Scholar]
- Nunokawa Y., Ishida N., Tanaka S. Cloning of inducible nitric oxide synthase in rat vascular smooth muscle cells. Biochem Biophys Res Commun. 1993 Feb 26;191(1):89–94. doi: 10.1006/bbrc.1993.1188. [DOI] [PubMed] [Google Scholar]
- Pendino K. J., Laskin J. D., Shuler R. L., Punjabi C. J., Laskin D. L. Enhanced production of nitric oxide by rat alveolar macrophages after inhalation of a pulmonary irritant is associated with increased expression of nitric oxide synthase. J Immunol. 1993 Dec 15;151(12):7196–7205. [PubMed] [Google Scholar]
- Persson M. G., Zetterström O., Agrenius V., Ihre E., Gustafsson L. E. Single-breath nitric oxide measurements in asthmatic patients and smokers. Lancet. 1994 Jan 15;343(8890):146–147. doi: 10.1016/s0140-6736(94)90935-0. [DOI] [PubMed] [Google Scholar]
- Peunova N., Enikolopov G. Nitric oxide triggers a switch to growth arrest during differentiation of neuronal cells. Nature. 1995 May 4;375(6526):68–73. doi: 10.1038/375068a0. [DOI] [PubMed] [Google Scholar]
- Robbins R. A., Barnes P. J., Springall D. R., Warren J. B., Kwon O. J., Buttery L. D., Wilson A. J., Geller D. A., Polak J. M. Expression of inducible nitric oxide in human lung epithelial cells. Biochem Biophys Res Commun. 1994 Aug 30;203(1):209–218. doi: 10.1006/bbrc.1994.2169. [DOI] [PubMed] [Google Scholar]
- Robbins R. A., Springall D. R., Warren J. B., Kwon O. J., Buttery L. D., Wilson A. J., Adcock I. M., Riveros-Moreno V., Moncada S., Polak J. Inducible nitric oxide synthase is increased in murine lung epithelial cells by cytokine stimulation. Biochem Biophys Res Commun. 1994 Feb 15;198(3):835–843. doi: 10.1006/bbrc.1994.1119. [DOI] [PubMed] [Google Scholar]
- Rosenfeld M. A., Siegfried W., Yoshimura K., Yoneyama K., Fukayama M., Stier L. E., Päkkö P. K., Gilardi P., Stratford-Perricaudet L. D., Perricaudet M. Adenovirus-mediated transfer of a recombinant alpha 1-antitrypsin gene to the lung epithelium in vivo. Science. 1991 Apr 19;252(5004):431–434. doi: 10.1126/science.2017680. [DOI] [PubMed] [Google Scholar]
- Schmidt H. H., Walter U. NO at work. Cell. 1994 Sep 23;78(6):919–925. doi: 10.1016/0092-8674(94)90267-4. [DOI] [PubMed] [Google Scholar]
- Sherman P. A., Laubach V. E., Reep B. R., Wood E. R. Purification and cDNA sequence of an inducible nitric oxide synthase from a human tumor cell line. Biochemistry. 1993 Nov 2;32(43):11600–11605. doi: 10.1021/bi00094a017. [DOI] [PubMed] [Google Scholar]
- Stuehr D. J., Griffith O. W. Mammalian nitric oxide synthases. Adv Enzymol Relat Areas Mol Biol. 1992;65:287–346. doi: 10.1002/9780470123119.ch8. [DOI] [PubMed] [Google Scholar]
- Toogood J. H. Complications of topical steroid therapy for asthma. Am Rev Respir Dis. 1990 Feb;141(2 Pt 2):S89–S96. [PubMed] [Google Scholar]
- Tracey W. R., Xue C., Klinghofer V., Barlow J., Pollock J. S., Förstermann U., Johns R. A. Immunochemical detection of inducible NO synthase in human lung. Am J Physiol. 1994 Jun;266(6 Pt 1):L722–L727. doi: 10.1152/ajplung.1994.266.6.L722. [DOI] [PubMed] [Google Scholar]