CTNNAL1分子调控支气管上皮细胞应激保护机制

We found that adhesion molecule catenin alpha-like 1(CTNNAL1) was down-regulated in asthma patients and confirmed that CTNNAL1 expression was induced by the airway stress in our previous NSFC project. Based on those findings, we put forward a hypothesis that during the stress signal transduction in bronchial epithelial cells (BECs), CTNNAL1 may produce protective responses such as influencing epithelial cell proliferation and repair and activating inflammation and immune response signals by regulating particular signal molecule complex assembly. This project plans to observe the effect of different CTNNAL1 expression levels on BEC function in a ozone stress model. We will study the basic biology behavior of BEC, activation of lymphocytes and the level spectrum of lymphocyte cytokines, as well as antigen uptake and expression spectrum of co-stimulate molecules after BECs are stressed by ozone treatment. Taking the CTNNAL1 interaction proteins as signal node molecules, we will try to identify the components of signal supermolecules assembly and their cellular localization in response to stress in different expression level of CTNNAL1 in BECs. Potential inhibiting molecules aimed at the signal supermolecules assembly will be screened and their effects on cells stress function will be studied as well. This study will expand our understanding of CTNNAL1 biological significance and its role in the network in airway inflammation, gain new insight into airway homeostasis protection and provide novel targets for treating airway inflammation.

申请者在上个结题的基金项目中发现哮喘患者存在支气管上皮细胞（BEC）CTNNAL1表达缺陷且与气道反应性增高相关，CTNNAL1参与气道应激反应。本项目假设，在气道上皮细胞应激信号传递产生气道高反应的机制中，CTNNAL1通过参与特定的信号分子组装，影响上皮细胞的增殖和修复、炎症信号传递及激活免疫反应，产生保护性应答反应。本项目拟以臭氧为应激刺激，观察不同表达水平 CTNNAL1对BEC基本生物学行为；与炎症细胞的选择性粘附、激活和炎症因子分泌谱变化及对上皮细胞协同刺激分子谱表达、抗原提呈等免疫功能的影响。并以申请者筛选出来的CTNNAL1相互作用蛋白作为信号节点分子，鉴定CTNNAL1应激信号传递链的信号超分子组装成分及细胞内定位和迁移，设计阻抑手段进行功能验证。该研究将拓展对CTNNAL1生物学意义及其在气道炎症网络中的作用的认识，对寻找气道上皮稳态保护机制和新的治疗位点具有重要意义。

在上个结题的基金项目中发现哮喘患者存在支气管上皮细胞（BEC）CTNNAL1 表达缺陷且与气道反应性增高相关，CTNNAL1 参与气道应激反应。本项目构建CTNNAL1正常表达、过表达和沉默BEC细胞系以及臭氧、OVA及HDM应激的细胞和动物模型，探讨上皮细胞粘附分子 CTNNAL1 在气道应激保护中的作用，并寻找保护位点及保护机制。研究结果如下：①CTNNAL1可促进HBEC的增殖能力和基质性粘附能力，同时增加结构性粘附分子的表达水平，可缓解臭氧引起的气道上皮的结构完整性的损伤；②CTNNAL1抑制上皮细胞与白细胞的粘附，减少BEC在受到应激刺激时炎性细胞因子IL-1、IL-8和趋化因子CCL20和TSLP的分泌量，降低炎症性粘附分子表达，对于白细胞的趋化以及激活传递炎症或应激信号具有一定减弱作用；③CTNNAL1促进CD4+T淋巴细胞向Th1方向分化，抑制Th2和Th17型炎症发生； ④CTNNAL1可减少内源性TGF-β1分泌并抑制臭氧应激诱发的人支气管上皮细胞EMT作用，有助于受损细胞维持上皮表型，可能参与调控肺脏损伤后上皮修复与间质修复的平衡；⑤在哮喘及肺纤维化动物模型上检测到FAK、RhoA及HSP90的表达与CTNNAL1存在相关性，并对CTNNAL1相关的磷酸化信号节点分子进行了初步分析。这些研究结果提示在气道上皮细胞应激信号传递产生气道高反应的机制中，CTNNAL1 通过参与特定的信号分子组装，影响上皮细胞的增殖和修复、炎症信号传递及激活免疫反应，产生保护性应答反应。该研究将拓展对CTNNAL1 生物学意义及其在气道炎症网络中的作用的认识，对寻找气道上皮稳态保护机制和新的治疗位点具有重要意义。