老年大鼠肺成纤维细胞表型改变和转化生长因子-β1水平变化

Changes of fibroblast phenotype and TGF-βl level in aged rat lung

目的对比观察老年大鼠和成年大鼠肺脏成纤维细胞表型的改变和转化生长因子（TGF）-β1水平的变化，寻找肺间质纤维化发病率随年龄增长而增高的可能机制。方法免疫组化法测定大鼠肺组织内”平滑肌肌动弹白（α-SMA）含量，观察成纤维细胞表型的改变。ELISA法测定TGF-β1蛋白水平。荧光定量PCR（reahimePCR）技术测定TGF-β1 mRNA表达量的变化。结果老年大鼠肺脏较成年大鼠肺脏肌成纤维细胞比例增加（P〈0，01），TGF-β1蛋白水平升高[分别为（999．54±246．11）pg／g和（755，7±160．38）pg／g]（P〈0．05），TGF-β1 mRNA（P〈0．01）表达水平降低。结论老年大鼠肺脏肌成纤维细胞比例增加和TGF-β1蛋白水平升高可以构成肺间质纤维化随年龄增长发病率增高的基础，老化肺脏内TGF-β1水平升高是受到mRNA转录后调控机制的影响。

Objective To investigate the possible mechanism of age related elevation in pulmonary fibrosis incidence, and compare the difference in lung fibroblast phenotype and TGF-β1 concentration between aged and adult rats. Methods Rat lung fibroblast phenotype, α-SMA, TGF-β1 protein and TGF-β1 mRNA concentrations in lung tissue were evaluated using immunohistochemistry, enzyme linked immunosorbent assay and real-time PCR. Results The proportion of lung fibroblast and concentration of TGF-β1 protein were significantly elevated in aged versus adult rats[（999.54 ± 246, 11 ） pg/g vs. （755.7 ± 160. 38 ） pg/g] （P 〈 0.05 ）, but the TGF-β1 mRNA expression was lower in the aged group. Conclusions Elevation of fibroblast proportion and TGF-β1 protein concentration may be the possible underlying mechanism of the increased incidence of idiopathic pulmonary fibrosis in aged lungs.