ROCKⅠ及TGF-β_1在慢性血栓栓塞性肺动脉高压大鼠肺小动脉的表达

Expression of ROCK Ⅰ and TGF-β_1 in pulmonary arterioles of rat with chronic thromboembolism pulmonary hypertension

目的:观察Rho激酶(ROCKⅠ)及转化生长因子β1(TGF-β1)在慢性血栓栓塞性肺动脉高压大鼠肺小动脉表达的动态变化。方法:雄性Wistar大鼠64只,随机分为8组,每组8只:初始对照组、栓塞3 d组、1周组、2周组、4周组、8周组、12周组、终末对照组。采血制备血栓,颈静脉注入,2周后第2次栓塞,全程腹腔注射氨甲环酸。达实验设定日期后,测各组大鼠平均肺动脉压(mPAP)、肺动脉相对中膜厚度(PAMT)、管壁面积/管总面积(WA/TA)、右室肥厚指数(RVHI),原位杂交检测ROCKⅠmRNA表达,免疫组化检测TGF-β1蛋白表达。结果:栓塞4周组至12周组大鼠随时间延长mPAP明显增高(均P<0.01);PAMT、WA/TA在4周后随时间延长显著增高(4周组P<0.05,8周、12周组P<0.01);8周后RVHI较对照组明显增高(8周组P<0.05,12周组P<0.01);栓塞后ROCKⅠmRNA原位杂交染色强度随时间延长出现增高趋势(3 d组至2周组P<0.05,4周组至12周组P<0.01),TGF-β1蛋白免疫组化染色强度随时间延长出现增高趋势(1周组、2周组P<0.05,4周组至12周组P<0.01)。相关分析表明,ROCKⅠmRNA及TGF-β1蛋白与mPAP、RVHI及血管重构指标均呈正相关(均P<0.01);ROCKⅠmRNA与TGF-β1蛋白表达呈正相关(r=0.612,P<0.01)。结论:ROCKⅠ和TGF-β1均可能参与慢性血栓栓塞性肺动脉高压、肺血管重构的病理生理过程,此过程中Rho/Rho激酶信号通路可能是TGF-β1发挥生物学效应的重要途径之一。

AIM ： To investigate the dynamic expression of Rho kinase （ ROCK I） and transforming growth factor β1 （TGF -β1 ） in pulmonary arterioles of rat with chronic thromboembolic pulmonary hypertension. METHODS： Sixty - four male Wister rats were randomly divided into eight groups ： beginning control group, embolism for 3 d, 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks groups and end control group. The pulmonary thromboembolism （PTE） model was established by injecting thrombin into jugular vein two times in two weeks and each rat underwent peritoneal injection with tranexamic acid one time a day during experiment to prevent thrombolysis. The mean pulmonary artery pressure （mPAP）, right ventricular hypertrophy index （ RVHI）, relative medial thickness of small pulmonary arteries （PAMT） and vessel wall area/total area （WA/TA） were measured. The levels of ROCK I mRNA and TGF -β1 protein in rat pulmonary artery were determined by in situ hybridization, immunohistochemistry and image analysis, respectively. RESULTS： mPAP, PAMT and WA/TA were higher respectively in embolism from 4 weeks group to 12 weeks group than those in beginning control group （mPAP： all P 〈0.01, PAMT and WA/TA： 4 weeks group P 〈0.05, 8 weeks group and 12 weeks group P 〈 0. 01 ）. RVHI was elevated in 8 weeks group P 〈0.05, in 12 weeks group P 〈0. 01. ROCK I mRNA and TGF -β1 protein in pulmonary arterioles got the enhanced positive signals of in situ hybridization or immunohistochemistry staining with prolonging the time of rats with pulmonary thromboembolism. ROCK I mRNA： embolism from 3 d group to 2 weeks group P 〈0.05,4 weeks group to 12 weeks group P 〈 0. 01, TGF -β1, protein： 1 week group and 2 weeks group P 〈 0. 05, 4 weeks group to 12 weeks group P 〈 0.01. Linear correlation analysis showed that ROCK I mRNA and TGF -β1 protein were positively correlated with mPAP, RVHI and vessel remodeling index （ all P 〈0. 01 ）, ROCK I mRNA were positively correlated with TGF-β1 protein （P 〈0.01 ）. CONCLUSION： ROCK I and TGF- β1 play a role in the pathogenesis of chronic thromboembolic pulmonary hypertension and pulmonary vessel remodeling. TGF -β1 produces biological effect by active ROCK signal pathway.