Rho激酶-1在肺纤维化小鼠肺组织中的表达变化与上皮-间充质转化

目的 观察Rho激酶-1(Rock-1) 在博莱霉素（BLM）致小鼠肺纤维化中的表达变化, 探讨其在肺纤维化中与上皮间充质细胞转化(EMT) 的关系。 方法 将60只小鼠随机分成正常对照组（Cont组）, BLM致肺纤维化模型组, 地塞米松（DXM）治疗组。BLM组给予0.04ml BLM (5mg/kg)一次性气管内灌注,治疗组在BLM一次性气管内灌注后每天给予DXM 5mg/kg腹腔注射。各组分别于第3、7、14和28天各处死5只小鼠, 取肺组织, 做病理切片，HE染色观察小鼠肺炎症和纤维化的程度, 以样本碱水解法检测肺组织中羟脯氨酸(HYP)含量, 免疫组织化学检测不同实验组小鼠间充质细胞标记物α-平滑肌肌动蛋白(α-SMA) 和上皮细胞标记物上皮钙黏素( E-Cad) 的表达,应用Western blotting法测定不同实验组小鼠Rock-1的表达水平。 结果 BLM组肺组织病理切片按时间顺序呈现由肺泡炎至纤维化的动态改变，肺组织胶原含量在第7天明显增加, 第28天达高峰, HYP含量测定动态增高。与Cont组比较、BLM组、DXM组E-Cad的蛋白表达降低,α-SMA蛋白表达增高。Western blotting结果显示，BLM组Rock-1的表达与正常对照组比较显著增高( P<0.05),第14天时达到高峰。DXM组Rock-1的表达逐步下降。 结论 Rock-1在小鼠肺纤维化中表达增高, 表明其可能是肺纤维化形成的促进因子, 且随着Rock-1的增高，α-SMA逐步增高 E-Cad逐步降低, 推测Rock-1在肺纤维化形成中的机制可能与促进EMT有关。

Change of Rho associated kinase-1 and epithelial-mesenchymal transition in mouse pulmonary fibrosis

Objective To investigate the developing expression of Rho associated kinase-1(Rock-1) and its relation to epithelial-mesenchymal transition in bleomycin-induced pulmonary fibrosis in mice. Methods Sixty mice were randomly divided into three groups, control group(EM>n/EM>=20)(normal saline),experimental group (EM>n/EM>=20)( blemycin-injected 5mg/kg,intratracheal injection) and treated group (EM>n/EM>=20)(dexamethason-injected 5mg/kg every day, intraperitoneal injection). On day 3,7,14 and 28 after treatment, lung tissue was stained with HE method.Lung hydroxyproline (HYP) content was evaluated. Immunohistochemistry was used to detect the expression of alpha-smooth muscle actin (α-SMA) and E-cadherin(E-cad). Western blotting was used to detect the expression of Rock-1. Results In experimental group, dynamic changes from alveolitis to pulmonary fibrosis could be observed in the slices by pathological method. Collagen deposition increased evidently on day 3, and peaked on day 28. Lung hydroxyproline (HYP) content increased gradually. Compared to those in the control group, the protein level of α-SMA increased significantly in the model group and treated group, while the protein level of E-cadherin decreased significantly. The expressions of Rock-1 protein in lung tissues in experimental group were higher than those in the control group(EM>P/EM>< 0.05),which increased from the third day, and peaked on the 14th day, then decreased on the 28th day. While the protein level of Rock-1 in treated group decreased significantly. Conclusion The expression of Rock-1 is positively correlated with not only the degree of pulmonary fibrosis but also the level of α-SMA and E-Cad, which probably suggests that Rock-1 is a promoter to pulmonary fibrosis via the induction of epithelial-mesenchymal