基于线粒体通路在EMT中的动态改变探讨咖啡酸苯乙酯干预肺纤维化的机理研究

Pulmonary fibrosis(PF) is a serious result of various lung diseases. Its incidence and fatality were increasing by years. However, the pathogenesy of pulmonary fibrosis remains unclear, so there is lack of efficient therapeutic methods. It has become a large medical problem needed to be solved urgently. The abnormal repairing of alveolar epithelial cells after injury is an important characteristic of pulmonary fibrosis, and epithelial-mesenchymal transition (EMT) is the key step of matrix deposition. Our initial research shows that, along with the process of pulmonary fibrosis, the amounts or functions of mitochondria in alveolar epithelial cells are changing , which will regulate cell growth and status. The results imply the fibrogenesis factors may influence the alveolar epithelial cell via mitochondria path, and cause EMT and extracellular matrix abnormal deposition, which leads to pulmonary fibrosis. Some studies show that a phytochemical, caffeic acid phenethyl ester(CAPE) plays an important role in alleviating acute lung injury, and it is also shown to inhibit the occurrence of EMT. Through establishing animal model and cell model, then applying RNA interference, immunofluorescence and flow cytometry technology, this project is to explore the effects and mechanisms of changes in mitochondrial pathway to pulmonary fibrosis on a whole and cellular levels. Then we will futher testify the effect of CAPE on EMT and collagen metabolism by regulating mitochondrial pathways, and develope new strategies for prevention and control measures of PF.

肺纤维化是呼吸系统疾病临床死亡的主要原因之一，发病率与病死率逐年上升，由于机制不清尚缺乏有效的治疗方法，成为亟待解决的医学难题。肺泡上皮细胞损伤与异常修复是肺纤维化的重要特征，上皮间质细胞转化（EMT）是影响基质沉积的关键环节。我们前期研究表明，在肺纤维化过程中伴随肺泡上皮细胞内线粒体的异常变化，而线粒体的变化可以控制细胞的生长状态，据此推测致纤维化因素可能通过影响肺泡上皮细胞的线粒体通路而引起EMT与细胞外基质异常沉积，从而导致肺纤维化。研究显示，植物化学物咖啡酸苯乙酯(CAPE)在减轻急性肺损伤中发挥显著作用，同时也可阻遏EMT的发生，本课题通过建立动物模型和细胞模型，应用RNA干涉、免疫荧光、流式细胞术等技术，从整体和细胞水平探讨线粒体通路的改变在肺纤维化中的作用机制，研究CAPE通过线粒体途径对EMT及胶原代谢的调控作用，探索肺纤维化新的预防策略。

肺纤维化是呼吸系统疾病临床死亡的主要原因之一，发病率与病死率逐年上升，由于机制不清尚缺乏有效的治疗方法，成为亟待解决的医学难题。肺泡上皮细胞损伤与异常修复是肺纤维化的重要特征，上皮间质细胞转化（EMT）是影响基质沉积的关键环节。我们前期研究表明，在肺纤维化过程中伴随肺泡上皮细胞内线粒体的异常变化，而线粒体的变化可以控制细胞的生长状态，据此推测致纤维化因素可能通过影响肺泡上皮细胞的线粒体通路而引起EMT与细胞外基质异常沉积，从而导致肺纤维化。研究显示，植物化学物咖啡酸苯乙酯(CAPE)在减轻急性肺损伤中发挥显著作用，同时也可阻遏EMT的发生，本课题旨在通过体内、体外模型，明确致纤维化因素会诱发肺泡上皮细胞线粒体功能与相关信号的改变；明确线粒体数量减少、功能障碍会导致肺泡上皮细胞上皮-间质转化（EMT）发生，调节线粒体功能可阻止或逆转EMT；证明咖啡酸苯乙酯（CAPE）可以通过调节线粒体途径，阻止或逆转EMT，并改善肺纤维化。结果发现，TGF-β1诱导细胞发生上皮-间质转化（EMT）的过程中，存在线粒体合成与功能异常；线粒体功能障碍促进上皮间质转化进程；通过SIRT1/PGC-1α途径可保护线粒体功能抑制上皮间质转化以及如肿瘤转移等相关疾病；CAPE可以调控线粒体数量或功能，并对细胞EMT模型与动物肺纤维化模型均有改善作用。以上结果从营养学角度为防治肺纤维化提供新的策略，具有良好的应用前景与潜在的社会价值。