肺泡巨噬细胞弹性蛋白酶在COPD患者气道炎症和重塑中的作用

The Role of Elastase Derived from Alveolar Macrophages in the Process of Airway Inflammation and Remodeling in Patients with Chronic Obstructive Pulmonary Disease

目的探讨肺泡巨噬细胞(AM)弹性蛋白酶(MMP-12)在慢性阻塞肺疾病(COPD)发生发展过程中的作用。方法以24例COPD患者和25名健康者为研究对象,收集其支气管肺泡灌洗液(BALF)和支气管黏膜,对BALF细胞成分进行瑞氏染色、分类计数,用考马斯亮蓝法测定BALF中蛋白的含量,用双抗体夹心ELISA法测定BALF中MMP-12的浓度,用免疫组织化学方法计算气道黏膜中MMP-12阳性AM数和气道黏膜厚度。结果COPD组BALF中细胞总数、AM数及中性粒细胞(PMN)数均高于正常对照组(均P<0.05);COPD组BALF和AM培养上清液中MMP-12浓度、气道黏膜中MMP-12阳性AM数及气道黏膜厚度均高正常对照组(均P<0.01);BALF中MMP-12浓度与AM培养上清液中MMP-12浓度呈正相关(r=0.678,P<0.01);COPD组BALF中MMP-12的浓度及黏膜内MMP-12阳性AM数均与黏膜厚度均呈正相关(r=0.613,P<0.01;r=0.479,P<0.05);COPD组BALF中的AM数、MMP-12浓度、黏膜内MMP-12阳性AM数及黏膜厚度均与FEV1%Pre呈负相关(r=-0.488,P<0.05;r=-0.619,P<0.01;r=-0.561,P<0.01;r=-0.642,P<0.01)。结论COPD稳定期患者气道内存在以AM和PMN增高为主的慢性非特异性炎症,MMP-12可能参与了其气道炎症和气道重塑的发生发展过程。

[Objective]To investigate the＇role of elastase（MMP-12） derived from alveolar macrophages （AMs） in the development of chronic obstructive pulmonary disease （COPD）, [Methods]Bronchoalveolar lavage fluid（BALF） and bronchial mucosa biopsies were performed as usual on 24 cases of COPD. Total cells in the BALF were counted using hemacytometer. Differential cells counts were made with Wright＇s stained cell smear. The concentrations of protein in BALF were measured by Coomasie brilliant blue way. The levels of MMP-12 in BALF and in supernatants of cultured AMs were measured by ELISA. The positive number of macrophages expressing MMP-12 in mucosa and the thickness of mucosa were measured with immunohisto- chemistry technique. The results were compared with those of 25 healthy non-smokers. [Results]The number of all cells, AMs and polymorphonuclear neutrophils （PMN） in BALF in patients with COPD was significantly higher than that in the healthy subjects （ P 〈0.01, respectively）. The concentrations of MMP-12 in BALF and the culture supernatants , the thickness of mucosa were significantly higher in COPD group than those in the control group（ P 〈0.01, respectively）. The MMP-12 activities in BALF of COPD group were positively correlated with those in the culture supernatants of their AMs（r= 0. 678, P 〈0.01 ）. Both the concentration of MMP-12 in BALF and the positive number of cells expressing MMP-12 were positively correlated with the thickness of mucosa（ r= 0. 613 , P 〈0.01; r=0. 479 , P 〈0.05, respectively）. Both the concentration of MMP-12 in BALF and the positive number of cells expressing MMP-12 were inversely correlated with forced expiratory volume in one second as percentage of predicted volume （FEV1%Pre） （ r = - 0.619, P 〈0.01 ; r = -0. 561, P 〈0.01 ,respectively）. [Conclusion]During the remission period of the stable stage of COPD, there exists chronic nonspecific airway inflammation characterized by increased number of AMs and PMNs . MMP 12 may be involved in the occurrence and process of airway inflammation and remodeling.