胰蛋白酶与糖皮质激素影响肺成纤维细胞增殖与骨架蛋白的表达

背景：肺成纤维细胞不但是肺组织的结构支持细胞，还能够通过增殖、收缩、趋化及分泌细胞外基质等多种功能在肺组织的炎症损伤-修复过程中发挥关键作用。目的：观察原代培养的人肺成纤维细胞在胰蛋白酶或糖皮质激素作用下增殖特性与骨架蛋白表达的变化。方法：采用人肺成纤维细胞体外培养，胰酶处理24 h，终浓度分别为0，0.5，1.0，5，10 mg/L胰酶；地塞米松处理72 h，在有血清培养条件下进行，浓度范围10^-9-10^-6 mol/L。MTT法测定成纤维细胞增殖情况；免疫印迹方法测定细胞波形蛋白和肌动蛋白的表达。结果与结论：胰蛋白酶在低浓度(0.1-0.5 mg/L)时刺激肺成纤维细胞增殖；而较高浓度(1-10 mg/L)明显抑制细胞生长。地塞米松对肺成纤维细胞增殖作用的影响不明显。胰蛋白酶显著上调肺成纤维细胞α平滑肌肌动蛋白的表达，但对波形蛋白的表达无明显影响；地塞米松(10^-9-10^-6 mol/L)显著抑制波形蛋白的表达。结果表明在慢性阻塞性肺病等支气管肺慢炎症性疾病的发病过程中，胰蛋白酶和糖皮质激素可以通过参与成纤维细胞增殖和骨架蛋白的表达发挥作用。

Trypsin and dexamethasone affect proliferation and cytoskeleton protein expression of human lung fibroblasts

BACKGROUND:In addition to the supporting function, lung fibroblasts play a pivotal role in the process of lung tissue injury and repair through proliferation, contraction, chemotaxis and secretion of the extracellular matrix.OBJECTIVE:To investigate the effects of trypsin and dexamethasone on the proliferation and cytoskeleton protein expression of lung fibroblasts.METHODS:Human lung fibroblasts were isolated and cultured in vitro followed by trypsin (0, 0.5, 1.0, 5, 10 mg/L) treatment for 24 hours or dexamethasone (10^-9-10^-6 mol/L) treatment for 72 hours. The expression of vimentin and α-smooth muscle actin was detected by immunoblotting. 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay was utilized for measuring fibroblasts proliferation.RESULTS AND CONCLUSION:Trypsin at lower concentrations (0.1-0.5 mg/L) significantly stimulated lung fibroblasts proliferation, while higher concentrations (1-10 mg/L) of trypsin inhibited lung fibroblasts proliferation. No effect on fibroblasts proliferation was observed with dexamethasone. Trypsin significantly increased the expression of α-smooth muscle actin in a dose-dependent manner, but had no influence on vimentin expression. Dexamethasone (10^-9-10^-6 mol/L) significantly inhibited vimentin expression in a concentration-dependent manner. The data reveal that trypsin and glucocorticosteroids may participate in the tissue remodeling process of chronic inflammatory airway diseases through affecting lung fibroblasts proliferation and the expression of cytoskeleton protein.