Distal airways in mice exposed to cigarette smoke - Nrf2-regulated genes are increased in Clara cells
Distal airways in mice exposed to cigarette smoke - Nrf2-regulated genes are increased in Clara cells
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DOI：
10.1165/rcmb.2007-0295oc
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发表时间：
2008-10-01
影响因子：
6.4
通讯作者：
Betsuyaku, Tomoko
中科院分区：
文献类型：
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作者：
Adair-Kirk, Tracy L.;Atkinson, Jeffrey J.;Betsuyaku, Tomoko
香烟烟雾（CS）是慢性阻塞性肺病（COPD）的主要危险因素。终末细支气管是 COPD 病理生理学的关键区域，但人们对 CS 响应中终末细支气管内壁细胞发生的细胞和分子变化知之甚少。我们对 C.57BL/6 小鼠进行 CS（每周 6 天，最长 6 个月），寻找终末细支气管内衬的形态变化，并使用激光捕获显微切割选择性分离终末细支气管中的细胞以研究基因表达。形态学和免疫组织化学分析表明，尽管接触 CS 6 个月，Clara 细胞优势仍然存在。由于 Clara 细胞具有防止氧化应激的作用，因此我们利用微阵列分析重点关注抗氧化/解毒基因的表达。在 6 个月的 CS 暴露后，35 个抗氧化/解毒基因的表达增加了至少 2.5 倍，其中 21 个是 NF-E2 相关因子 2 (Nrf2) 调节的基因。其中包括细胞色素 P450 1b1、谷胱甘肽还原酶、硫氧还蛋白还原酶、谷胱甘肽 S-转移酶家族的成员以及 Nrf2 本身。使用永生化小鼠 Clara 细胞 (C22) 的体外研究表明，CS 诱导 Nrf2 的稳定和核转位，这与抗氧化和解毒基因的诱导相关。此外，通过siRNA减少Nrf2表达导致CS诱导的C22细胞中几种抗氧化和解毒基因的表达相应减少。这些数据表明 Clara 细胞对 CS 暴露的保护反应主要受转录因子 Nrf2 调节。
Cigarette smoke (CS) is the main risk factor for chronic obstructive pulmonary disease (COPD). Terminal bronchioles are critical zones in the pathophysiology of COPD, but little is known about the cellular and molecular changes that occur in cells lining terminal bronchioles in response to CS. We subjected C.57BL/6 mice to CS (6 d/wk, up to 6 mo), looked for morphologic changes lining the terminal bronchioles, and used laser capture microdissection to selectively isolate cells in terminal bronchioles to study gene expression. Morphologic and immunohistochemical analyses showed that Clara cell predominance remained despite 6 months of CS exposure. Since Clara cells have a role in protection against oxidative stress, we focused on the expression of antioxidant/detoxification genes using microarray analysis. Of the 35 antioxidant/detoxification genes with at least 2.5-fold increased expression in response to 6 months of CS exposure, 21 were NF-E2-related factor 2 (Nrf2)-regulated genes. Among these were cytochrome P450 1b1, glutathione reductase, thioredoxin reductase, and members of the glutathione S-transferase family, as well as Nrf2 itself. In vitro studies using immortalized murine Clara cells (C22) showed that CS induced the stabilization and nuclear translocation of Nrf2, which correlated with the induction of antioxidant and detoxification genes. Furthermore, decreasing Nrf2 expression by siRNA resulted in a corresponding decrease in CS-induced expression of several antioxidant and detoxification genes by C22 cells. These data suggest that the protective response by Clara cells to CS exposure is predominantly regulated by the transcription factor Nrf2.