Okamoto Tatsuya, Gohil Kishorchandra, Finkelstein Erik I, Bove Peter, Akaike Takaaki, van der Vliet Albert
Department of Internal Medicine, University of California, Davis, 95616, USA.
Am J Physiol Lung Cell Mol Physiol. 2004 Jan;286(1):L198-209. doi: 10.1152/ajplung.00136.2003. Epub 2003 Sep 12.
Acute lung inflammation and injury were induced by intranasal instillation of lipopolysaccharide (LPS) in normal and type 2 nitric oxide synthase (NOS2)-deficient (NOS2-/-) C57BL/6 mice. LPS-induced increases in extravasated airway neutrophils and in lung lavage fluid of TNF-alpha and macrophage inflammatory protein-2 were markedly lower in NOS2-/- than in wild-type mice, indicating that NOS2-derived nitric oxide (NO.) participates in inflammatory cytokine production and neutrophil recruitment. Instillation of LPS also increased total lung lavage protein and induced matrix metalloproteinase-9 and mucin 5AC, as indexes of lung epithelial injury and/or mucus hyperplasia, and increased tyrosine nitration of lung lavage proteins, a marker of oxidative injury. All these responses were less pronounced in NOS2-/- than in wild-type mice. Inhibition of NOS activity also suppressed production of TNF-alpha and macrophage inflammatory protein-2 by LPS-stimulated mouse alveolar MH-S macrophages, and this was restored by NO. donors, illustrating involvement of NO. in macrophage cytokine signaling. Oligonucleotide microarray (GeneChip) analysis of global lung gene expression revealed that LPS inhalation induced a range of transcripts encoding proinflammatory cytokines and chemokines, stress-inducible factors, and other extracellular factors and suppressed mRNAs encoding certain cytoskeletal proteins and signaling proteins, responses that were generally attenuated in NOS2-/- mice. Comparison of both mouse strains revealed altered expression of several cytoskeletal proteins, cell surface proteins, and signaling proteins in NOS2-/- mice, changes that may partly explain the reduced responsiveness to LPS. Collectively, our results suggest that NOS2 participates in the acute inflammatory response to LPS by multiple mechanisms: involvement in proinflammatory cytokine signaling and alteration of the expression of various genes that affect inflammatory-immune responses to LPS.
通过向正常和2型一氧化氮合酶（NOS2）缺陷（NOS2-/-）的C57BL/6小鼠鼻内滴注脂多糖（LPS）来诱导急性肺部炎症和损伤。与野生型小鼠相比，LPS诱导的NOS2-/-小鼠气道中性粒细胞渗出以及肿瘤坏死因子-α（TNF-α）和巨噬细胞炎性蛋白-2在肺灌洗液中的增加明显更低，这表明NOS2衍生的一氧化氮（NO·）参与炎性细胞因子的产生和中性粒细胞募集。滴注LPS还增加了肺灌洗总蛋白，并诱导了基质金属蛋白酶-9和黏蛋白5AC，作为肺上皮损伤和/或黏液增生的指标，同时增加了肺灌洗蛋白的酪氨酸硝化，这是氧化损伤的标志物。所有这些反应在NOS2-/-小鼠中比在野生型小鼠中都不那么明显。抑制NOS活性也抑制了LPS刺激的小鼠肺泡MH-S巨噬细胞产生TNF-α和巨噬细胞炎性蛋白-2，而这可被NO·供体恢复，说明NO·参与巨噬细胞细胞因子信号传导。对全肺基因表达进行的寡核苷酸微阵列（基因芯片）分析显示，吸入LPS诱导了一系列编码促炎细胞因子和趋化因子、应激诱导因子及其他细胞外因子的转录本，并抑制了编码某些细胞骨架蛋白和信号蛋白的mRNA，这些反应在NOS2-/-小鼠中通常减弱。对两种小鼠品系的比较显示，NOS2-/-小鼠中几种细胞骨架蛋白、细胞表面蛋白和信号蛋白的表达发生了改变，这些变化可能部分解释了对LPS反应性降低的原因。总体而言，我们的结果表明，NOS2通过多种机制参与对LPS的急性炎症反应：参与促炎细胞因子信号传导以及改变影响对LPS炎症免疫反应的各种基因的表达。
