HDAC1通过RAGE/β-catenin轴对TDI哮喘气道炎症的调控及机制研究

We firstly found that the RAGE/β-catenin axis in airway epithelial plays an important role in airway inflammation in toluene diisocyanate (TDI) induced asthma, but its mechanism is not yet clear. Histone deacetylase (HDAC) - mediated epigenetic regulation is involved in the pathogenesis of asthma and glucocorticoid resistance, and is also a hot topic in recent years. The regulation of non histone proteins by HDAC has been paid more and more attention. RAGE is involved in a variety of inflammatory processes through epigenetic mechanisms, but whether it affects airway inflammation is unclear. Studies have shown that the expression of HDAC1 was up-regulated in asthmatic mucosa, and mediated the barrier destruction. In our pre-experiment, in vitro TDI stimulation of airway epithelial cells can increase the expression of HDAC1, and knockdown of RAGE can significantly inhibit the expression of HDAC1, we further found that inhibition of HDACs by Quisinostat(or JNJ-26481585) can reduce of β-catenin L45 acetylation and its mediated protein expression such as HMGB1 and VEGF. Therefore, we hypothesized that RAGE mediated β-catenin activation by HDAC signaling could promote airway inflammation in TDI-induced asthma. In order to verify the hypothesis,we will use airway epithelium as the main object of study, and use the mature model which have been setted up in our lab, to investigate the effect of HDAC1 in RAGE/β-Catenin on airway inflammation in vivo and in vitro study. This study will provide a new way to expand the regulation mechanism of RAGE/ beta-catenin TDI-induced airway inflammation.

我们发现气道上皮RAGE/β-catenin轴在甲苯二异氰酸酯(TDI)哮喘气道炎症扮演重要角色，然而其机制尚不清楚。组蛋白去乙酰化酶（HDACs）介导表观遗传调节参与了哮喘发病及糖皮质激素抵抗，也是近年来关注热点，HDACs对非组蛋白调节也越来越受到重视。RAGE通过表观遗传机制参与多种疾病过程，然而，其如何影响气道炎症尚不明确。研究显示HDAC1在哮喘粘膜上调表达，且介导了屏障破坏。预实验发现，体外TDI刺激气道上皮细胞可增加HDAC1表达，而敲除RAGE可以显著抑制HDAC1表达，进一步发现抑制HDACs可以减少β-catenin乙酰化及其介导的基因表达。由此我们推测：HDAC1通过RAGE/β-Catenin轴促进TDI哮喘气道炎症。我们以气道上皮为主要研究对象，拟采用既有成熟模型，从体内，外层面验证上述假说。本研究为拓展RAGE/β-catenin在气道炎症的调控机制提供新思路。

气道上皮RAGE/β-catenin轴在甲苯二异氰酸酯(TDI)哮喘气道炎症扮演重要角色，然而其机制尚不清楚。组蛋白去乙酰化酶（HDACs）介导的表观遗传调节参与了哮喘发病，也是近年来关注热点。有报道称RAGE可通过表观遗传机制参与多种疾病过程，然而，其如何影响气道炎症尚不明确。本项目重点探讨RAGE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蛋白β-catenin表达和重分布的作用及可能分子机制。本研究为拓展RAGE/β-catenin在气道炎症的调控机制提供新思路。重要结果及关键数据：（1）首次发现在TDI诱导的小鼠哮喘模型中，RAGE通过PI3K/AKT通路调节HDAC1的表达，抑制HDAC可改善TDI诱导的气道炎症。（2）首次发现抑制HDAC可改善TDI哮喘小鼠的气道上皮屏障，表现为气道上皮E-cadherin和β-catenin的重分布。（3）首次证实RAGE通过激活Src/p- cav1轴介导TDI哮喘小鼠β-连环蛋白的重分布。抑制RAGE和Cav-1的磷酸化减弱了β-catenin从细胞膜到细胞质的易位。（4）首次发现哮喘患者血清RAGE和p- JNK的表达增高，且与支气管哮喘的严重程度相关。（5）首次发现抑制JNK可降低TDI驱动RAGE表达和β-catenin易位，而JNK激动剂Anisomycin则相反。此外，RAGE的基因敲低并不影响JNK的磷酸化，说明JNK在RAGE的上游起作用。（6）首次发现RAGE/ERK轴参与调节Lrp6磷酸化，且与气道上皮细胞中的β-catenin易位相关，表明Lrp6在RAGE/β-catenin轴与经典Wnt/β-catenin交互作用中起重要作用。本项目共发表SCI论文6篇，中文核心2期，述评2篇。培养硕士研究生7名。为确立阻断或调节RAGE/β-catenin途径作为哮喘防治新靶标提供科学依据。