Objective: To explore the role of extracellular histones in the pathogenesis of coal worker's pneumoconiosis (CWP) , the relationship of extracellular histones in plasma with pulmonary fibrosis caused by coal mine dust was analyzed, and the stimulating effect of extracellular histones on fibroblast proliferation was studied. Methods: In May 2019, a total of 220 coal mine dust exposure workers (including coal miners and CWP patients) who visited the occupational disease outpatient department of Peking University Third Hospital from 2012 to 2015 were enrolled in the study. According to the classification of small opacity profusion (SOP) in chest radiograph for pneumoconiosis diagnosis (category 0, 1, 2, 3) , 61 coal miners were in category 0 SOP, 65 coal miners were in category 1 SOP, 56 coal miners were in category 2 SOP and 38 coal miners were in category 3 SOP. The plasma levels of extracellular histone H4 and platelet-derived growth factor (PDGF) were measured by enzyme-linked immunosorbent assay (ELISA) kit. The stimulating effects of CWP patients' plasma and calf thymus histones (CTHs) on fibroblast and the antagonizing effect of anti-H4 antibody were investigated by fibroblast proliferation experiment in vitro. Results: Among the study subjects, there were 195 males (88.6%, 195/220) and 25 females (11.4%, 25/220) , age (55.1±7.2) years, coal mine dust exposure time (16.3±4.4) years. The plasma concentrations of histone H4 in the coal miners with category 0, 1, 2 and 3 SOP were (3.92±1.75) 、(9.84±4.17) 、(14.35±5.52) and (17.83±7.69) μg/ml, respectively. There were significant differences among the four groups (P<0.01) . The plasma level of histone H4 was positively correlated with the plasma level of PDGF in the coal miners (r=0.769, P<0.01) . Compared with healthy control plasma group, the cell proliferation percentages of patients' plasma group (272%±87%) and CTH group (283%±84%) were significantly increased (P<0.05) . Compared with patients' plasma group, the cell proliferation percentage of patients' plasma+anti-H4 antibody group (185%±66%) was significantly decreased (P<0.05) . Compared with CTH group, the cell proliferation percentage of CTH+anti-H4 antibody group (167%±59%) was significantly decreased (P<0.05) . Conclusion: Extracellular histones in plasma are associated with pulmonary fibrosis in patients with CWP. Studies in vitro have shown that extracellular histones can promote proliferation of pulmonary fibroblasts. It is suggested that extracellular histones can be important biomarkers for pulmonary fibrosis caused by coal mine dust.
目的： 通过研究血浆中细胞外组蛋白与煤矿粉尘所致肺纤维化的关系及其对肺成纤维细胞的促增殖作用，探索细胞外组蛋白在煤工尘肺发生中的作用。 方法： 在2019年5月，选取2012至2015年在北京大学第三医院职业病科门诊就诊的220例煤矿粉尘接触者（包括煤矿接尘工人和煤工尘肺患者）为研究对象，包括小阴影密集度0、1、2、3级者分别61、65、56、38例。应用酶联免疫吸附试验（ELISA）测量血浆中细胞外组蛋白H4和血小板源性生长因子（PDGF）的浓度。通过体外细胞试验研究煤工尘肺患者血浆和小牛胸腺组蛋白（CTHs）对肺成纤维细胞的促增殖效果以及抗组蛋白抗体的拮抗作用。 结果： 研究对象中，男性195例（88.6%，195/220），女性25例（11.4%，25/220），年龄（55.1±7.2）岁，接尘工龄（16.3±4.4）年。小阴影密集度分别为0、1、2、3级的煤矿粉尘接触者的血浆细胞外组蛋白H4浓度分别为（3.92±1.75）、（9.84±4.17）、（14.35±5.52）和（17.83±7.69）μg/ml，各组间差异均有统计学意义（P<0.01）。煤矿粉尘接触者血浆中细胞外组蛋白H4浓度与PDGF浓度呈正相关性（r=0.769，P<0.01）。与正常血浆对照组相比，患者血浆组（272%±87%）、外源CTH组（283%±84%）的细胞增殖百分比明显升高，差异均有统计学意义（P<0.05）；与患者血浆组相比，患者血浆+抗H4抗体组细胞增殖百分比明显下降（185%±66%），差异有统计学意义（P<0.05）；与外源CTH组相比，外源CTH+抗H4抗体组细胞增殖百分比明显下降（167%±59%），差异有统计学意义（P<0.05）。 结论： 血浆中的细胞外组蛋白浓度与煤矿粉尘接触者的肺纤维化程度相关，细胞外组蛋白对肺成纤维细胞具有促增殖作用，提示细胞外组蛋白可作为煤矿粉尘所致肺纤维化的重要生物标志物。.
Keywords: Coal worker's pneumoconiosis; Extracellular histones; Inflammation; Platelet-derived growth factor; Pneumoconiosis; Pulmonary fibrosis.