硫氧还蛋白硝基化在慢性阻塞性肺疾病发病中作用

Changes in thioredoxin nitration and the role in the pathogenesis of chronic obstructive pulmonary disease

目的探讨硫氧还蛋白（Trx）硝基化修饰在慢性阻塞性肺疾病（COPD）发病过程中作用。方法收集非吸烟者肺组织标本10例，吸烟者肺组织标本12例，COPD肺组织标本26例（根据GOLD指南将COPD患者肺功能进行了分级：GOLD2-3级（COPDⅡ—Ⅲ），GOLD4（COPDIV））。检测肺组织中Trx的活性及表达量，应用免疫组化及ELISA法检测硝基化酪氨酸含量，应用免疫共沉淀法检测硝基化Trx含量。结果非吸烟组、吸烟组、COPDⅡ—Ⅲ组、COPDIV组Trx相对蛋白表达量分别为[（0．13士0．03）、（0．29±0．06）、（0．45±0．1）、（0．68±0．21）]μmol·min^-1·mg^-1吸烟组及COPD组肺组织中Trx表达量较非吸烟组均上升（t=2．312、2．642、3．312，均P〈0．01）；非吸烟组、吸烟组、COPDⅡ-Ⅲ组、COPDIV组Trx活性分别为（（2．40±0．52）、（2．30±0．60）、（1．40±0．32）及（0．98±0．20）]μmol·min^-1·mg^-1蛋白，COPD组Trx活性较对照组下降（t=2．553、3．852、3．870，均P〈0．01）。非吸烟组、吸烟组、COPDⅡ-Ⅲ组、COPDIV组肺组织中硝基化Trx表达量分别[（1．9±0．2）、（2．8±0．3）、（7．9±1．7）及（9．1±2．7）]μmol·min^-1·mg^-1，COPD组硝基化Trx较非吸烟组上升（t=3．826、6．332、9．932，均P〈0．01）。结论Trx硝基化修饰后活性下降，在COPD发病过程可能扮演着重要角色，抑制Trx硝基化修饰可能成为COPD治疗的新靶点。

Objective Oxidant stimulation has been reported to be in the key place in the pathogenesis of chronic obstructive pulmonary disease（COPD）. In the research, we investigated the role of thioredoxin（Trx）nitration during the development of COPD. Methods The specimens of lung biopsy from nonsmokers （ n=10）, smokers （ n = 12 ）, and patients with chronic obstructive pulmonary disease（COPD,n=26, including GOLD stages 2 and 3 （GOLD Ⅱ-Ⅲ）and GOLD stages 4 （GOLD Ⅳ）on the basis of the lung function tests）were collected. The expression level of nitrated thioredoxin was examined by immunoprecipitation （IP）assay and immunoblotting （IB）assay. The expression and activity of thioredoxin in lung tissue were examined. Results The protein expression level of Trx were（0.13±0. 03 , 0. 29±0. 06 , 0. 45±0.10 and 0. 68±0. 21）μmol·min^-1·mg^-1 in nonsmokers, smokers, COPDⅡ-Ⅲ, COPD Ⅳ, respectively. The expression level of Trx was increased obviously in the smokers group and COPD group than in the nonsmokers（t=2. 312,2. 642,3. 312, P〈0.01）. The values of the activity of Trx in nonsmokers, smokers, COPDⅡ-Ⅲ patients, COPD Ⅳ patients were （2.40±0.52, 2.30±0.60, 1.40±0.32 and 0.98±0.20）μmol·min^-1·mg^-1 protein. The activity of Trx in patients with COPD was decreased compared with that of nonsmokers（t=2. 553,3.852,3. 870, 均 P〈0.01 ）. The values of nitrated Trx in nonsmokers, smokers, COPD Ⅱ-Ⅲ patients,COPD IV patients were （1.9±0.2,2.8±0.3,7.9±1.7 and 9.1±2.7）μmol·min^-1·mg^-1 respectively. The expression level of nitrated Trx was higher in COPD patients than in nonsmokers.（t=3. 826,6. 332,9. 932,均 P〈0.01）. Conclusions The decreased Trx activity after Trx nitration might be involved in the pathogenesis of COPD, which might be a new targeted point for creation of drug for COPD.