Department of Respiratory Medicine, Academic Medical Centre, Amsterdam, the Netherlands.
Allergy. 2012 Apr;67(4):552-9. doi: 10.1111/j.1398-9995.2011.02773.x. Epub 2012 Jan 9.
Altered deposition of extracellular matrix (ECM) in the airway smooth muscle (ASM) layer as observed in asthma may influence ASM mechanical properties. We hypothesized that ECM in ASM is associated with airway function in asthma. First, we investigated the difference in ECM expression in ASM between asthma and controls. Second, we examined whether ECM expression is associated with bronchoconstriction and bronchodilation in vivo.
Our cross-sectional study comprised 19 atopic mild asthma patients, 15 atopic and 12 nonatopic healthy subjects. Spirometry, methacholine responsiveness, deep-breath-induced bronchodilation (ΔR(rs) ) and bronchoscopy with endobronchial biopsies were performed. Positive staining of elastin, collagen I, III and IV, decorin, versican, fibronectin, laminin and tenascin in ASM was quantified as fractional area and mean density. Data were analysed using Pearson's or Spearman's correlation coefficient.
Extracellular matrix expression in ASM was not different between asthma and controls. In asthmatics, fractional area and mean density of collagen I and III were correlated with methacholine dose-response slope and ΔR(rs) , respectively (r = 0.71, P < 0.01; r = 0.60, P = 0.02). Furthermore, ASM collagen III and laminin in asthma were correlated with FEV(1) reversibility (r = -0.65, P = 0.01; r = -0.54, P = 0.04).
In asthma, ECM in ASM is related to the dynamics of airway function in the absence of differences in ECM expression between asthma and controls. This indicates that the ASM layer in its full composition is a major structural component in determining variable airways obstruction in asthma.
哮喘患者气道平滑肌（ASM）层中细胞外基质（ECM）的沉积改变可能会影响 ASM 的机械特性。我们假设 ASM 中的 ECM 与哮喘中的气道功能有关。首先，我们研究了哮喘和对照组之间 ASM 中 ECM 表达的差异。其次，我们检查了 ECM 表达是否与体内支气管收缩和支气管扩张有关。
我们的横断面研究包括 19 名特应性轻度哮喘患者、15 名特应性和 12 名非特应性健康受试者。进行了肺量测定、乙酰甲胆碱反应性、深呼吸诱导的支气管扩张（ΔR(rs) ）和支气管镜检查并进行支气管内膜活检。AS 中弹性蛋白、胶原 I、III 和 IV、饰胶蛋白、玻连蛋白、层粘连蛋白和腱蛋白的阳性染色作为分数面积和平均密度进行量化。使用 Pearson 或 Spearman 相关系数分析数据。
哮喘和对照组之间 ASM 中 ECM 表达没有差异。在哮喘患者中，胶原 I 和 III 的分数面积和平均密度分别与乙酰甲胆碱剂量反应斜率和 ΔR(rs) 相关（r = 0.71，P < 0.01；r = 0.60，P = 0.02）。此外，哮喘中 ASM 胶原 III 和层粘连蛋白与 FEV(1)可逆性相关（r = -0.65，P = 0.01；r = -0.54，P = 0.04）。
在哮喘中，AS 中的 ECM 与气道功能的动力学有关，而哮喘和对照组之间的 ECM 表达没有差异。这表明 ASM 层作为一个完整的组成部分，是决定哮喘中可变气道阻塞的主要结构成分。
