自噬调节上皮间质转化在百草枯中毒肺纤维化形成中的分子调控机制研究

Paraquat (PQ) poisoning is one of the high mortality lethal diseases in emergency. Most of the patients died from pulmonary fibrosis. Epithelial-mesenchymal transition (EMT) involved in the fibrosis of many organs. Autophagy has been reported to play the key role in the process of cell damage and repair. Our preliminary data showed that autophagy was inhibited, and EMT was activated in PQ-treated lung epithelial cells. PQ mediated pulmonary fibrosis was inhibited in rapamycin treated mice. However, the exact mechanism is unclear. In the present study, the dynamic changes of EMT, autophagy and pulmonary fibrosis were identified in the PQ treated alveolar epithelial cells model. And the mechanisms of AMPK, mTOR, Smad, Snail, Twist signaling were also dissected in PQ treated alveolar epithelial cells. Moreover, the pulmonary fibrosis and its mechanism were explored by adding the inhibitor or inducer of autophagy in PQ poisoning animal models. Our study dissected the novel mechanisms and provided a new treatment strategy in PQ mediated pulmonary fibrosis.

百草枯（PQ）中毒是急诊常见的疾病之一，死亡率高，肺间质纤维化是导致死亡的主要原因。上皮间质转化（EMT）参与多种重要脏器的纤维化过程，自噬报道在多种细胞损伤和修复中发挥重要作用。我们的前期研究发现，PQ诱导肺纤维化模型中，自噬受到抑制，上皮细胞发生EMT，应用雷帕霉素激活自噬，可以减轻肺纤维化，但其确切调控机制不清。本项目通过建立体内外PQ中毒模型，观察肺泡上皮细胞EMT、自噬及肺纤维化的动态变化，分析其相关性，探索AMPK、mTOR、Smad、Snail、Twist等自噬和EMT关键信号通路对肺纤维化的影响，阐明在PQ中毒中自噬调控EMT的分子机制。在PQ中毒动物模型中，通过气管内滴注或腹腔注射药物改变自噬活性，证实自噬对肺纤维化进程的影响及调控机制。本项目从自噬和EMT角度阐述了PQ中毒引起肺纤维化新分子机制，对研究PQ中毒的分子机理，探索新的治疗方法提供理论依据。

百草枯（PQ）中毒是急诊常见的疾病之一，死亡率高，肺间质纤维化是导致死亡的主要原因。上皮间质转化（EMT）参与多种重要脏器的纤维化过程，自噬报道在多种细胞损伤和修复中发挥重要作用。我们研究发现，PQ诱导肺纤维化模型中，自噬受到抑制，上皮细胞发生EMT，应用雷帕霉素激活自噬，可以减轻肺纤维化，证实PQ可以诱导体外肺上皮细胞发生发生凋亡，PQ可以诱导体外肺上皮细胞发生EMT样变化，促细胞迁移能力，上调EMT相关标志物表达。在体外培养的肺上皮细胞中，PQ可以抑制自噬过程，诱导EMT，应用雷帕霉素激活自噬，可以逆转PQ诱导EMT发生，证实PQ可以抑制自噬过程，主要是依赖于AMPK信号途径来完成，进一步研究证实百草枯抑制肺泡上皮细胞可激活AKT，GSK3b和m-Tor的信号通路，这种活化依赖于AMPK的表达。最后，成功建立PQ中毒小鼠肺纤维化模型，激活自噬，可以抑制肺纤维化。本项目从自噬和EMT角度阐述了PQ中毒引起肺纤维化新分子机制，对研究PQ中毒的分子机理，探索新的治疗方法提供理论依据。