放射性肺损伤小鼠肺组织TGFβ1与α-SMA、Col1a1、FN mRNA表达的关系

The Relationship between TGFβ 1 and α- SMA,Col1a1,FN mRNA Expression in Radiation Induced Lung Injury in Mice

目的观察转化生长因子β1(TGFβ1)在小鼠放射性肺损伤中的表达与纤维化标志物α-平滑肌肌动蛋白(α-SMA)、胶原蛋白Ⅰ(Col1a1)、纤维连接蛋白(FN)的关系。方法选用雌性C57BL/6小鼠40只,分为A、B两组,每组20只,每组又随机分为对照组和照射组,即对照A组和照射A组与对照B组和照射B组,每组10只。采用瓦里安直线加速器6MV X射线对照射A、B组小鼠右侧胸腔进行单次单前野照射,A组照射剂量为12.5 Gy,B组照射剂量为22.5Gy,两组对照组只麻醉不照射。A组照射3周后取右肺上叶部分组织行HE染色,B组照射12周后取右肺上叶部分组织行Masson染色,剩余右肺组织均采用实时荧光定量PCR方法定量测定肺组织TGFβ1和纤维化标志物α-SMA、Col1a1、FN mRNA的表达。结果照射A组行HE染色显示肺组织结构紊乱,肺泡壁增厚,肺间质内及细支气管周围大量炎症细胞浸润,呈明显的肺泡炎症改变;照射B组行Masson染色显示肺泡周围及肺间质大量蓝染的胶原纤维,呈典型的肺纤维化病变;照射A组和照射B组小鼠受损伤右肺组织细胞因子TGFβ1和纤维化标志物α-SMA、Col1a1和FN的mRNA表达水平均高于相应对照组(P均<0.05)。结论 TGFβ1可能在放射性肺纤维化的起始和形成过程中发挥重要作用。

Objective To investigate the relationship between TGF- β1 expression and fibrosis markers ofα- SMA,Col1a1、FN in radiation induced lung injury. Methods 40 female C57 BL / 6 mice were divided into A,B groups( n = 20 in each group). These two groups were randomly divided into control group and irradiation group( n = 10 in each group). Mice were irradiated with a single dose of 12. 5 Gy 6MV X- ray for group A,and 22. 5 Gy 6MV X- ray for group B over their right hemithorax using a varian linear accelerator. Mice in control group were only anesthetized and not irradiated. After 3 weeks of irradiation,right upper lobe lung from mice in group A were processed for HE staining. After 12 weeks of irradiation,right upper lobe lung from mice in group B were processed for Masson staining. Remaining lung lobes were used for real time- PCR analysis to investigate TGFβ1,α- SMA,Col1a1,FN mRNA expression levels. that lung tissue structure was disorder and inflammatory cell infiltration into lung interstitial or around bronchioles,showing serious alveolar inflammation changes. Pathology of lung tissues in irradiation group of group B through Masson staining presented massive blue staining collagen fiber deposited in lung interstitial and around the alveolar,showing typical pulmonary fibrosis lesions. TGFβ1,α- SMA,Col1a1,FN mRNA expression in both A and B irradiation groups were significantly higher than those in two corresponding control groups( P < 0. 05). Conclusion TGFβ1 plays an important role in the beginning and formation process of radiation induced lung fibrosis.