Studies on change in airway hyperresponsiveness at bronchial asthma using the technique of RhoA gene manipulation

（1）作者首次发现反复抗原激发气道高反应（AHR）大鼠支气管平滑肌rhoA mRNA表达和RhoA蛋白上调。我们认为RhoA蛋白激活引起的Ca^2+敏感性增强可能诱发AHR。（2）应用蛋白质/DNA芯片技术研究RhoA蛋白表达的转录因子。观察到AHR状态下Stat 5、CDP、HSE、SBE、SIE和CBF被激活。（3）哮喘患者支气管肺泡液中TNF-α可增强ACh对支气管的收缩作用，并伴有rhoA mRNA和蛋白表达的增加。（4）支气管细胞经ACh刺激后，RhoA蛋白从胞浆转位到质膜，提示ACh对RhoA有激活作用。（5）在AHR支气管平滑肌中，与RhoA一样参与Ca^2+敏化的另一种蛋白CPI-17也增加。因此，RhoA/Rho激酶/CPI-17交叉通路可能参与了AHR大鼠支气管平滑肌的Ca^2+增敏。

(1)The authors have found for the first time that expression of rhoA mRNA and upregulation of RhoA protein in bronchial smooth muscle of airway hyperresponsive (AHR) rats which received repeated antigen-challenge. We propose that enhanced Ca^<2+> sensitization induced by such RhoA protein activation may evoke the AHR. (2)Transcriptional factors involved in RhoA protein expression were investigated by protein/DNA array. Stat5,CDP,HSE,SBE,SIE and CBF were observed to be activated at AHR state. (3)TNF-a detected in broncho-alveolar fluid of asthmatics enhanced the bronchosonstriction by ACh, which accompanied with increases in rhoA mRNA and protein. (4)Translocation of RhoA protein from cytosol to plasma membrane was observed after ACh stimulation of bronchial cells, suggesting an activation of RhoA by ACh. (5)Another protein CPI-17 involved in Ca^<2+> sensitization as well as RhoA was also increased in the AHR bronchial smooth muscle. Therefore, RhoA/Rho-kinase/CPI-17 cross-pathway might work at Ca^<2+> sensitization of bronchial smooth muscle of AHR rats.