特异性组蛋白去乙酰化酶6抑制剂通过调控HSP90乙酰化修饰治疗哮喘的机制研究

Asthma is a chronic inflammatory disease of the lung. Studies using OVA mice has shown that broad spectrum histone deacetylase inhibitor (HDACi) is able to inhibit airway inflammation, airway remodeling and airway hyper-responsiveness. However, whether HDAC inhibitors can be applied clinically is still under debate. Our previous studies already showed that selective HDAC6 inhibitor can reduce airway inflammation, airway remodeling and airway hyperresponsiveness in chronic allergic airway disease OVA mice. The initial results also confirmed that HDAC6i intervention could significantly reverse the HSP90 acetylation level during asthma attack and inhibit the activation of inflammatory relative-NF-κB and airway remodeling relative-TGF-β signaling pathway. This study will further investigate the molecular mechanism of HDAC6 inhibitor on asthma.We hypothesize that HDAC6 inhibitor may act through regulating the acetylation level of HSP90 to affect the NF-κB and TGF-β signaling pathway, and modulate airway remodeling and inflammatory reaction on asthma. This study will examine the molecular mechanism of HSP90 acetylation modulation of HDAC6 inhibitor treatment in asthma.

哮喘是一种常见的慢性呼吸道免疫性炎症。已有研究证实广谱组蛋白去乙酰化酶（Histone Deacetylases, HDACs）抑制剂能抑制气道炎症、气道重塑和气道高反应性，然而HDACs抑制剂是否能够在临床上用于哮喘治疗仍有争议。我们的前期实验利用哮喘小鼠模型证实HDAC6抑制剂可有效缓解慢性哮喘气道炎症、气道高反应和气道重塑，同时HDAC6抑制剂干预能显著逆转哮喘发作时HSP90乙酰化水平，抑制与哮喘炎症发生相关的NF-κB通路和与气道重塑相关的TGF-β1信号通路的激活。根据现有的研究进展及申请者的前期研究结果，申请者推测HDAC6特异性抑制剂于哮喘症状缓解的作用机制，很可能与HDAC6调控HSP90乙酰化水平，通过HSP90-IKK-NF-κB和HSP90-TGF-β1信号通路调控哮喘相关炎症与重塑性反应相关。本次课题将通过体内和体外实验对申请者的上述假设进行验证。

支气管哮喘是最常见的慢性呼吸系统疾病，组蛋白乙酰化修饰是当前哮喘病理生理研究的热点。我们通过构建OVA诱导的哮喘小鼠模型，通过同位素标记、乙酰化肽段IP富集等技术进行质谱分析，明确了哮喘致病时差异表达的组蛋白乙酰化修饰位点，并通过WesternBlot及免疫组织化学染色法对质谱数据进行验证。通过HDAC6特异性抑制剂干预哮喘小鼠模型，明确其对哮喘气道炎症、气道重塑及气道高反应性的作用，并明确其通过调控HAP90和H3K9乙酰化水平，进一步调控NF-kB和TGF-b信号通路从而缓解哮喘气道炎症和气道重塑。进而选择HDAC8特异性抑制剂PCI-34051，通过体内和体外实验证实了PCI-34051调控哮喘气道炎症时巨噬细胞极化的机制。同时外泌体miRNA已被广泛认为在表观遗传学中起重要作用，而在我们的研究中，我们通过PCI-34051诱导出外泌体miRNA入手，并选择当前研究较多的ADSCs来源的外泌体miRNA ，通过生信分析、细胞实验、动物实验、临床血清样本检测，从多角度探讨了两种miRNA在哮喘中的作用及可能机制，为哮喘诊断和治疗的新靶点，为哮喘的病理生理学研究提供新思路。