RAGE介导自噬诱导气道上皮细胞病理性增生及功能异常：哮喘早期气道重塑的新机制

The pathological features of asthma include eosinophilia inflammation and airway remodeling. It was often considered that only eosinophilia inflammation occurs in the early stage of asthma and airway remodeling develops late in the disease process as a consequence of persistent inflammation. But recently researches have demonstrated that airway remodeling exerts in the initial stage of asthma and are parallel to inflammation. Airway remodeling progresses continually in the patients without any clinical symptom. Given the equal importance of inflammation and remodeling in asthma pathogenesis, the majority focus on the role of inflammation. Although novel therapeutics such as those targeted against Th2 mediators have arisen, it is apparent that targeting inflammation alone has not allowed disease modification. There is no available therapy proven to prevent or reverse airway remodeling. Therefore, unless airway remodeling is addressed for future therapeutic strategies, it is unlikely that we will progress towards a cure for asthma. . Proliferation of epithelial cells occurs after allergen challenge in animals. A recent study has shown increases in collagen deposition in the sub-epithelial layer, mucus secreting goblet cells and cell proliferation in both sub-epithelial layer and sub-mucosal layer after bronchoconstriction. New evidence now suggests that epithelial cells derived from donors without asthma versus donors with asthma, even in the absence of inflammatory cells or mediators, express modes of collective migration that innately differ not only in the amount of migration but also in the kind of migration, thus suggesting an immature or dysmature epithelial phenotype in asthma. . We also observed aberrant metaplasia of airway epithelial cells in TDI-induced asthma mice. Double membrane autophago- somes were detected in epithelial cells from moderately severe asthma patients, though fewer or no autophagosome was detected in healthy ones. Inhalation of OVA in mice increases levels of autophagic markers in mouse airway tissues. The modulation of autophagy may have the potential to treat asthma. Regretfully, we found no significant publications using HDM antigen or other antigens in the study of autophagy. The mechanism of asthma resulting from airway epithelial autophagy is still unknown. Activated RAGE induces cell proliferation through MAPK enzymes or JAK/STAT signaling pathway. But it is not reported whether activated RAGE can induce autophagy and then causes epithelial cells metaplasia, especially in asthma pathogenic. Recently, we identified the important role of RAGE in TDI-induced asthma mice. . According the observation mentioned above, we hypotheses that RAGE-induced Autophagy causes Epithelial Cells Metaplasia and Dysfunction, which maybe a novel Mechanism for Airway Remodeling in the initial Stage of Asthma.

哮喘的病理特征是嗜酸性炎症和气道重塑，过去认为持续炎症导致重塑，最近发现哮喘早期即存在气道重塑，重塑与炎症是平行发展的，哮喘无症状时气道重塑仍持续进展，单独抗炎没能缓解疾病的进展，目前无药物能阻止或逆转气道重塑，故哮喘必须在早期就干预气道重塑。过敏原刺激上皮细胞增生和功能异常，气道痉挛可引起上皮增殖，哮喘与健康者的上皮集体迁移力度和种类有差异，存在未成熟或成熟障碍上皮细胞表型哮喘。TDI哮喘小鼠早期气道上皮细胞病理性增殖明显。哮喘患者和OVA小鼠气道上皮自噬过度，但鲜见自噬在哮喘上皮细胞的基础研究。RAGE促进肿瘤存活与自噬过度有关，它激活MAPK酶或JAK/STAT信号通路促进细胞增殖，但RAGE是否诱导上皮自噬并促进细胞增殖仍不明确。我们已证明RAGE在TDI哮喘小鼠的重要作用，因此推测，RAGE介导自噬促进上皮细胞病理性增殖、功能异常可能是TDI哮喘气道重塑的启动机制之一。

项目背景：.哮喘的病理特征是嗜酸性炎症和气道重塑，过去认为持续炎症导致重塑，最近发现哮喘早期即存在气道重塑，重塑与炎症是平行发展的，哮喘无症状时气道重塑仍持续进展，单独抗炎没能缓解疾病的进展，目前无药物能阻止或逆转气道重塑，故哮喘必须干预气道重塑。TDI哮喘小鼠早期气道上皮细胞病理性增殖明显。哮喘患者和OVA小鼠气道上皮自噬过度，但鲜见自噬在哮喘上皮细胞的基础研究。RAGE促进肿瘤存活与自噬过度有关，它激活MAPK酶或JAK/STAT信号通路促进细胞增殖，但RAGE是否诱导上皮自噬并促进细胞增殖仍不明确。我们已证明RAGE在TDI哮喘小鼠的重要作用，因此推测，RAGE介导自噬促进上皮细胞病理性增殖、功能异常可能是TDI哮喘气道重塑的启动机制之一。..研究内容：.体内实验（动物实验）：建立 TDI 小鼠哮喘模型，通过抑制 RAGE 观察上皮细胞自噬、上皮细胞形态/功能的变化情况。测量 小鼠病理情况、RAGE、Beclin-1、LC3B、E-cadherin、Vimentin表达情况，电镜下静态观察上皮细胞自噬体形成数目。.体外研究（细胞实验）：TDI-HSA 激活 RAGE 后对气道上皮细胞的增殖、 .自噬体形成以及上皮细胞形态功能（气道重塑）变化的影响。用免疫荧光、WB等方法检测Rage、Beclin-1、LC3B、E-cadherin、Vimentin等标记物。..重要结果及关键数据：（具体请看正文）.1.哮喘患者相较于健康人，自噬体数目明显增多，表明在哮喘患者气道上皮组织中，自噬被激活。.2.FPS-ZM1与3-MA可减轻TDI诱导小鼠哮喘模型气道上皮增生及气管旁炎症。.3.TDI刺激可激活Rage与Autophagy的表达，同时发生了气道重塑。抑制Rage及抑制自噬均可改善TDI诱导的小鼠哮喘模型的气道重构。而且，Rage抑制剂治疗后，自噬Marker表达也相应下降，我们推测自噬可能被Rage所调控。.4.电镜下，相对于AOO组，TDI组小鼠气道上皮自噬体明显增多，而使用FPS-ZM1与3-MA治疗后，自噬体明显减少。.5.细胞实验与动物实验结果一致。