DAMP分子－HMGB1在气道上皮对哮喘气道炎症关键介质TSLP的作用及机制研究

Thymic stromal lymphopoietin (TSLP) derived from airway epithelial cells is a key pro-allergic cytokine that has recently been linked to chronic inflammation of asthma. Emerging evidence in the pathogenesis of asthma has attracted TSLP as a promising therapeutic target. However, the definite regulation mechanism of TSLP expression in airway epithelial cells of asthma remains to be resolved..In our previous study,we have indentified that sputum and plasma concentrations of damage-associated molecular patterns(DAMPs)-HMGB1 in patients with asthma were significantly higher than concentrations in control subjects and were significantly negatively correlated with forced expiratory volume in 1 s (FEV1)and FEV1(% predicted).Then,the levels of HMGB1 in the airway mucosa were significantly higher in OVA and RSV induced asthma groups than in the control group.Furthermore,we also found that asthma stimulus such as house dust mites (HDMs) and H202 can significantly induce HMGB1 expression in airway epithelial cells,and recombinant human HMGB1 can increase TSLP expression in airway epithelial cells in vitro. Therefore we propose a new mechainism that DAMP molecule-HMGB1 can influence the expression and release of key inflammation factor-TSLP in airway epithelial of asthma..This study will further explore in airway epithelial cells and asthma models by way of lentivirus infection, gene overexpression and RNA interference,and et al, focusing on whether and how HMGB1 collabration with IL-1β regulate the expression of TSLP in airway epithelial and proving the feasibility of targetting of HMGB1 in inprove airway inflammation of asthma model. Our study may further clarify the pathogenesis of asthma and provide new therapeutic targets for asthma.

气道上皮细胞来源的TSLP是促发和维持哮喘慢性炎症的关键分子。我们已经证明哮喘病人诱导痰中损伤相关分子模式(DAMPs)分子-HMGB1水平越高，疾病越严重。那么HMGB1促进哮喘发病的分子机制是什么？进一步研究显示：呼吸道合孢病毒及卵蛋白诱导的哮喘小鼠气道粘膜HMGB1表达增强，体外多种哮喘致敏物可促进气道上皮细胞HMGB1表达及释放，且HMGB1可显著增加气道上皮细胞 TSLP的释放。由此，我们提出了HMGB1对哮喘气道上皮细胞 TSLP调控的新机制。本项目拟采用慢病毒载体感染技术，通过基因过表达及干扰等方法，分别在气道上皮细胞和哮喘小鼠模型进一步观察HMGB1协同IL-1β对气道上皮细胞调控炎症关键分子TSLP的影响及可能机制，探讨阻断HMGB1途径改善哮喘炎症的可行性。本项目为确立阻断HMGB1途径作为哮喘防治的新靶标提供科学依据。

气道上皮细胞来源的TSLP是促发和维持哮喘气道炎症的关键分子。损伤相关模式分子-HMGB1与哮喘关系密切。然而HMGB1促进哮喘发病的分子机制尚不确切。本项目重点探讨HMGB1在哮喘气道炎症调控作用及其通过影响气道上皮细胞关键炎症介质TSLP表达和释放的作用及可能分子机制。重要结果及关键数据：.1、 首次发现血浆sRAGE水平在不同哮喘炎症表型存在差异，经抗哮喘治疗可恢复sRAGE水平；诱导痰中性粒细胞百分比是血浆sRAGE独立影响因素；2、首次报道重组HMGB1（rhHMGB1）单独及协同IL-1β对可以增加气道上皮细胞IL-8的释放；3、首次发现TDI-HSA和rhHMGB1可以增加气道上皮细胞long TSLP表达，对short TSLP无明显促进作用，其机制可能与STAT5和P38途径有关；4、rhHMGB1可时间依赖增加屏障的破坏，HMGB1联合IL-1β具有协同作用。RAGE中和抗体及ERK抑制剂显著抑制HMGB1上述作用；5、首次发现rhHMGB1可以引起支气管上皮NLRP3炎症小体活化，促进IL-1β的快速表达和释放，且这依赖于RAGE途径。6、首次建立基于雾化吸入的激发方式建立TDI哮喘模型，降低了实验过程中小鼠死亡率；7、首次报道了HMGB1非特异性抑制剂丙酮酸乙酯（EP）能够抑制TDI哮喘模型气道中性粒细胞炎症；8、首次报道了EP可以减少TDI诱导的哮喘小鼠气道上皮细胞粘附连接分子E-cadherin的破坏；9、首次报道IgY anti-HMGB1抗体能够加重 TDI所诱导的过敏性气道炎症，原因可能是IgY而不是抗HMGB1抗体在其中扮演重要角色；10、首次报道了PI3K介导TDI哮喘小鼠肺组织caspase-1激活和HMGB1产生；11、首次报道RAGE通过稳定β-catenin信号参与调控TDI哮喘气道炎症；12、首次发现short TSLP通过影响HMGB1/RAGE轴减轻TDI诱导的哮喘小鼠气道炎症。本项目共发表SCI论文11篇，国内核心期刊论著8篇，综述1篇。会议论文12篇。培养博士研究生6名，硕士研究生5名。为确立阻断或调节HMGB1/RAGE途径作为哮喘防治新靶标提供科学依据。