The Effects Of CTNNAL1on Balancing Regulation Between Epithelial And Mesenchymal Repair In Pulmonary Stress Injury

As the first interaction between inner and outer world, lung and airway often suffered from the stress or damage of the external environment, which basically act as the trigger of many lung diseases or systemic diseases. While the airway epithelium is the primary defense against lung stress, and the impaired epithelium could immediately activated the repair process, including the reversible repair of epithelial system and the irreversible repair of mesenchymal pathway.Epithelial-mesenchymal transition (EMT), a reversible process in which epithelial cells transdifferentiate into cells with mesenchymal characteristics, has been suggested as possible mechanisms for myfibroblast generation. In addition, EMT is also widely considered to be a crucial biological-event in these two repair processes. However, a specific repair pathway may depend on the adhesion molecule spectroscopy which could detect its own condition and surroundings. In the preliminary research, our group has found the down-regulation of the catenin alpha-like1(belong to the catenin family) in the asthma patients. In vitro experiments showed that CTNNAL1was participated in the stress response and the repair/proliferation process of human bronchial epithelial cells (HBECs). The results revealed that CTNNAL1was not just as a kind of adhesion molecule, but as an active factor in the response of stress and the protection of airway epithelial cells.Based on these facts, we assumed that in the lung stress injury and repairing process, CTNNAL1may play a active role in epithelial cells, and balancing the epithelial and mesenchymal repair after the lung injury.Objective:The aim of the present study is to investigate the effects of CTNNAL1on the EMT of HBECs (stressed with ozone), preliminarily explore the significance of CTNNAL1in the stress response of the airway.Method:(1) HBECs were designed to be pretreated with ozone stress, the expression of epithelial and mesenchymal markers were observed by real time quantitative PCR, Western blot and Immunostaining.(2) Real time quantitative PCR and Western blot detect the expression of epithelial and mesenchymal markers of stably transfected HBECs lines, and observe the effects of CTNNAL1on EMT.(3) ELISA was used to detect the secretory volume of TGF-β1in different HBECs lines.Result:(1) We successfully constructed the EMT model of HBECs, HBECs stressed with ozone (30min/d) for4days could down-regulates the epithelial markers (E-cad, CK19), meanwhile, up-regulates the mesenchymal markers (Vim, FN and α-SMA)(2) The over-expression of CTNNAL1could promote the expression of epithelial markers and inhibit the expression of mesenchymal markers, while the opposite effects have been shown when CTNNAL1were silenced in HBECs.(3) The secretion of TGF-β1was increased after ozone (30min/d) for4days and CTNNAL1lessened the level of TGF-β1.Conclusion: We successfully constructed the EMT model after HBECs stessed with ozone(30min/d)for4days, and this stress increased the secretion of TGF-β1, while CTNNAL1could inhibit EMT, and reduce the level of TGF-β.