Decreased Fibronectin Production Significantly Contributes to Dysregulated Repair of Asthmatic Epithelium
Decreased Fibronectin Production Significantly Contributes to Dysregulated Repair of Asthmatic Epithelium
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DOI：
10.1164/rccm.200907-1071oc
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发表时间：
2010-05-01
影响因子：
24.7
通讯作者：
Knight, Darryl A.
中科院分区：
文献类型：
--
作者：
Kicic, Anthony;Hallstrand, Teal S.;Knight, Darryl A.
原理：气道上皮损伤后，细胞外基质（ECM）沉积和相邻上皮细胞迁移。我们已经证明，哮喘儿童的上皮细胞在体外不能愈合伤口。目的：确定上皮细胞ECM的产生失调是否在哮喘的异常修复中起作用。方法：来自哮喘儿童（n = 36）、健康特应性对照受试者（n = 23）、通过微阵列、基因表达和沉默、转录调控分析以及闭合机械创伤的能力来研究健康的非特应性对照受试者（n = 53）。健康儿童和特应性儿童的AEC在体外修复机械伤口的时间无显著差异，且均快于哮喘儿童的AEC。微阵列分析揭示了与哮喘AEC修复和重塑相关的多个基因组的差异表达。纤维连接蛋白（FN）是唯一的ECM成分，其表达显着降低哮喘AEC。定量聚合酶链反应和ELISA证实了表达差异，并且在哮喘细胞中FN表达持续降低。非哮喘AEC中FN表达的沉默抑制了创伤修复，而哮喘AEC中加入FN则恢复了修复能力。哮喘AEC不能合成FN响应创伤或细胞因子/生长因子刺激。暴露于5 '，2'脱氧氮杂胞苷没有影响FN的表达和随后的FN启动子的分析没有显示DNA methylation.Conclusions证据：这些数据表明，哮喘上皮细胞分泌FN的能力降低是一个重要的贡献者在这些细胞中观察到的AEC修复失调。
Rationale: Damage to airway epithelium is followed by deposition of extracellular matrix (ECM) and migration of adjacent epithelial cells. We have shown that epithelial cells from children with asthma fail to heal a wound in vitro.Objectives: To determine whether dysregulated ECM production by the epithelium plays a role in aberrant repair in asthma.Methods: Airway epithelial cells (AEC) from children with asthma (n = 36), healthy atopic control subjects (n = 23), and healthy nonatopic control subjects (n = 53) were investigated by microarray, gene expression and silencing, transcript regulation analysis, and ability to close mechanical wounds.Measurements and Main Results: Time to repair a mechanical wound in vitro by AEC from healthy and atopic children was not significantly different and both were faster than AEC from children with asthma. Microarray analysis revealed differential expression of multiple gene sets associated with repair and remodeling in asthmatic AEC. Fibronectin (FN) was the only ECM component whose expression was significantly lower in asthmatic AEC. Expression differences were verified by quantitative polymerase chain reaction and ELISA, and reduced FN expression persisted in asthmatic cells over passage. Silencing of FN expression in nonasthmatic AEC inhibited wound repair, whereas addition of FN to asthmatic AEC restored reparative capacity. Asthmatic AEC failed to synthesize FN in response to wounding or cytokine/growth factor stimulation. Exposure to 5', 2'deoxyazacytidine had no effect on FN expression and subsequent analysis of the FN promoter did not show evidence of DNA methylation.Conclusions: These data show that the reduced capacity of asthmatic epithelial cells to secrete FN is an important contributor to the dysregulated AEC repair observed in these cells.