Hypoxia inducible factors in pulmonary endothelial cells regulate allergic inflammatory airways disease

每12个美国人中就有一个患有哮喘。超过50%的哮喘患者(1200万)每人都有哮喘发作 年。哮喘是一种慢性炎症性疾病，严重影响患者的生活质量。不受控制和 未经治疗的哮喘会导致旷工和缺课，以及高昂的医疗费用。有很多不同的 各种类型的哮喘，其中一些是目前导致疾病控制的治疗方法很好的靶点。然而， 有一些哮喘的内型，如Th2-低中性粒细胞哮喘，没有靶向治疗。 可用。这些内型是由对类固醇不起反应的炎症途径驱动的，因此它们 常见于类固醇抵抗型哮喘。我们提议的工作的前提是有额外的 哮喘中可识别和靶向的细胞类型和途径。 低氧诱导因子(HIF)被发现在表达时是炎症的主要调节因子 在免疫细胞中。缺氧诱导因子-1α在所有细胞中有结构性表达，并在代谢调节中起重要作用。 细胞增殖和细胞迁移，以及调节炎症途径。HIF-2α有更多的限制 但像缺氧诱导因子-1α一样，它在肺内皮细胞中表达，并调节代谢和 发炎。我们研究了HIF-α两个亚基在哮喘发病过程中的作用，发现每一个亚基都调节 以促炎的方式通过髓系细胞致炎。当任何一个被系统地抑制时 给予小分子抑制剂，对变态反应性炎症有更深刻的影响， 提示非髓系细胞也通过HIF-α亚单位促进炎症。 肺内皮细胞是通过循环进入肺部的门户。我们假设HIF- 1α和HIF-2α在肺部炎症过程中参与了肺内皮细胞的激活，导致 血管表面黏附分子的表达与循环炎症细胞移行 进入肺部。我们建议使用肺内皮细胞特异性HIF-1α和HIF-2α基因敲除小鼠 评价HIF在哮喘样变过程中嗜酸性粒细胞等炎性细胞募集中的作用 发炎。由于哮喘的异质性，以及缺乏对非TH2非-TH2的治疗选择 哮喘的过敏性表型，我们将使用三种免疫不同的哮喘小鼠模型来评估 这些HIF分子在哮喘发病机制中的作用。 小鼠模型的强大之处在于它们可以评估生理变化，以及器官和系统水平 效果。此外，小鼠的基因敲除是了解单个蛋白质作用的有力工具。 关于疾病的诱发和发展。然而，在免疫功能和炎症方面存在差异。 小鼠和人类细胞之间的反应，因此小鼠的数据并不总是反映人类的反应。 因此，我们将利用体外培养的人内皮细胞和人免疫细胞来研究其抑制作用 通过小分子抑制剂抑制哮喘相关细胞类型的内皮迁移：嗜酸性粒细胞， 尤其是中性粒细胞、巨噬细胞和淋巴细胞。我们希望所提出的研究将阐明小说 哮喘药物开发的靶点。

Asthma affects 1 in 12 Americans. More than 50% of asthmatics (12 million) have asthma attacks each year. Asthma is a chronic inflammatory disease which has great impact on quality of life. Uncontrolled and untreated asthma leads to missed work and school, as well as high healthcare costs. There are many different types of asthma, some of which are well targeted by current therapeutics leading to disease control. However, there are some endotypes of asthma, such as TH2-low neutrophilic asthma, that do not have targeted therapies available. These endotypes are driven by inflammatory pathways that do not respond to steroids, and thus they are commonly found in steroid-resistant asthma. The premise of our proposed work is that there are additional cell types and pathways that can be identified and targeted in asthma. Hypoxia inducible factors (HIF) have been found to be master regulators of inflammation when expressed in immune cells. HIF-1α is constitutively expressed in all cells, and is important in the regulation of metabolism, cell proliferation and cell migration, in addition to regulating inflammatory pathways. HIF-2α has more limited expression, but like HIF-1α it is expressed in pulmonary endothelial cells and regulates both metabolism and inflammation. We have studied both HIF-α subunits in the setting of asthma, and have found that each regulates inflammation through myeloid cells in a pro-inflammatory manner. When either was suppressed through systemic administration of small molecule inhibitors, a more profound effect on allergic inflammation was seen, which suggests that non-myeloid cells also promote inflammation via HIF-α subunits. Pulmonary endothelial cells are the gateway to the lungs from the circulation. We hypothesize that HIF- 1α and HIF-2α play a role in activation of pulmonary endothelial cells during pulmonary inflammation, leading to expression of adhesion molecules on the vascular surface and transmigration of circulating inflammatory cells into the lungs. We propose to use pulmonary endothelial cell specific HIF-1α and HIF-2α knock-out mice to evaluate the role of HIFs in the recruitment of inflammatory cells such as eosinophils during asthma-like inflammation. Because of the heterogeneity of asthma, and the lack of therapeutic options for non-TH2 non- allergic phenotypes of asthma, we will use three immunologically disparate mouse models of asthma to evaluate the role of these HIF molecules in asthma pathogenesis. Mouse models are powerful in that they can assess for physiologic changes, and organ and system-level effects. In addition, gene knockouts in mice are a powerful tool for understanding the roles of individual proteins on disease induction and progression. However, there are differences in immune function and inflammatory responses between murine and human cells, such that murine data does not always reflect human responses. Thus, we will use human endothelial cells and human immune cells ex vivo to study the effects of suppression of HIF via small molecule inhibitors on transendothelial migration of cell types relevant to asthma: eosinophils, neutrophils, macrophages and lymphocytes in particular. We hope that the studies proposed will elucidate novel targets for drug development in asthma.