矽肺大鼠血清和支气管灌洗液CC16及SP-D的变化

Changes of CC16 and SP-D in serum and Br oncho-alveoear lavage fluid of silicosis rats

目的探讨不同剂量的矽尘和不同染尘时间对大鼠血清和支气管肺泡灌洗液(BALF)中克拉拉细胞蛋白(Clara cell protein,CC16)和肺泡表面活性蛋白D(surfactant protein D,SP-D)表达水平的影响,探讨矽肺的早期诊断新指标。方法制作矽尘致大鼠肺纤维化模型,矽尘剂量和染尘时间各组不同,测定大鼠BALF中羟脯氨酸(HYP)含量、BALF和血清中CC16及SP-D含量以及肺组织中CC16表达的免疫组化染色分析。结果 BALF中CC16的含量在染尘后第3天(49.65 ng/mg)、第7天(47.10 ng/mg)、第14天(46.15 ng/mg)、第21天(41.63 ng/mg)、第28天(38.02 ng/mg),均较对照组(分别为61.27 ng/mg,60.67 ng/mg,61.20 ng/mg,60.61 ng/mg,56.76 ng/mg)显著降低(P<0.05),并出现下降趋势;血清中CC16的含量在第7天(9.8 ng/ml)、第14天(9.36 ng/ml)、第21天(9.0 ng/ml)、第28天(8.78 ng/ml)也较对照组(11.04 ng/ml,10.84 ng/ml,10.88 ng/ml,10.96 ng/ml)显著降低(P<0.05)。大鼠血清中SP-D的含量较对照组显著下降(P<0.05),BALF中SP-D含量随染尘时间变化出现抛物线趋势。肺组织CC16免疫组化显示Clara细胞损伤严重,CC16表达降低。只有50 mg/ml染尘组BALF的HYP高于对照组(P<0.05)。结论在矽尘引起肺组织病变过程中CC16和SP-D具有肺组织特异性,可能作为矽肺的一个早期标志物。

Objective The aim of this study was to observe the changes of CC16 and SPD levels in serum and BALF of silicosis rats, thereby to explore the possibility of using them as early markers of silicosis in clinical practice. Methods To make the pulmo nary fibrosis rats model, using different silica exposure dose. Collecting the BALF and serum of the rats at different time after expo sure, then examining the levels of CC16 and SPD with ELASA techniques. Meanwhile, the hydroxyproline （HYP） level in BALF and CC16 level in lung tissues were also detected by immanohistochemistry. Results The results showed that the level of CC16 de creased with the silica exposure compared with the contrels （P 〈0.05）, which were 49.65 rig/rag, 47.10 ng/mg, 46.15 ng/mg, 41.63 ng/mg and 38. 02 ng/mg, respectively at the 3rd day, 7th day, 14th day, 21st day and 28th day after silica exposure, the controls accordingly were 61.27 ng/mg, 60. 67 ng/mg, 61.20 ng/mg, 60. 61 ng/mg and 56. 76 ng/rng. The serum CC16 also showed the same change： the levels at 7th day, 14th day, 21st day, 28th doy were 9. 8 ng/ml, 9. 36 ng/ml 9. 0 ng/ml, and 8. 78 ng/ml re spectively, while the controls groups accordingly were 11.04 ng/ml, 10. 84 ng/ml, 10. 88 ng/ml, 10. 96 ng/ml. The levels of SPD in serum of silica exposed groups not only decreased compared with the controls, and BALF SPD also presemed palaboralike change with silica exposure. Lung tissue immunohistochemical examination showed the Clara cells were severe damaged and the CC16 expres sion was also obviously decreased. But only the 50 mg/ml silica exposed group the HYP level in BALF was higher than that of control group. Conclusion The results suggest that CC16 and SPD has pulmonary tissuespecificity, which may be used as the potential early biomarkers in silica induced pulmonary fibrosis.