Cell specific role of proteolytic shedding by the metalloproteinases ADAM10 and ADAM17 in chronic lung infammation

急性和慢性炎症由表面表达的效应分子的活性和促炎介质的释放驱动。金属蛋白酶ADAM 10和ADAM 17介导几种表面分子（细胞因子、受体、趋化因子、生长因子和粘附分子）的裂解和释放，调节血管通透性和白细胞的募集。使用细胞特异性敲除小鼠，我们已经证明了ADAM 10和ADAM 17对鼻内应用LPS或酸诱导的急性肺部炎症的重要贡献。虽然内皮细胞ADAM 17活性与粘附分子的裂解和渗透性调节有关，但平滑肌细胞ADAM 17功能与生长因子的脱落和随后的细胞反式激活有关。在白细胞中，ADAM 10而不是ADAM 17通过促进白细胞的迁移、粘附和信号传导而参与急性肺部炎症，除了在急性肺部炎症中的促炎作用外，ADAM 10和ADAM 17在慢性炎症的后期阶段如肺纤维化和过敏性哮喘中的作用尚不清楚。在这里，我们的目的是研究ADAM 10和ADAM 17在慢性肺部炎症过程中的可能作用，以及它们作为决定进展和消退/修复之间的开关分子的功能。我们的第一个实验表明，内皮细胞ADAM 10在早期急性炎症中起促炎作用，但在炎症后期起保护作用。因此，我们的假设是，这两种蛋白酶通过以细胞特异性方式脱落表面分子来差异调节炎症的早期和晚期。因此，我们将研究ADAM在肺内滴注博莱霉素诱导的小鼠肺部炎症和纤维化发展的不同阶段中的调节和活性，并研究细胞特异性敲除ADAM 10和ADAM 17对T细胞募集、细胞因子释放、胶原蛋白产生和组织重塑的作用。蛋白酶的活性将与粘附分子、生长因子、Notch等的脱落有关。将使用来自细胞特异性敲除小鼠或在药理学或转录抑制ADAM 10或ADAM 17后的原代人和鼠肺细胞和白细胞，对细胞迁移、渗透性、介质分泌、增殖、存活、再生和反式激活进行机制分析。将使用相同的程序来研究ADAM 10和ADAM 17是否也控制响应于OVA免疫和通过一般或疾病特异性途径激发的哮喘性肺部炎症的早期和晚期。本研究旨在探讨从急性肺炎症到慢性肺炎症过程中ADAM蛋白酶的时间依赖性和细胞依赖性功能转换。这对ADAM抑制剂抗炎治疗策略的发展具有重要意义。

Acute and chronic inflammation is driven by the activity of surface expressed effector molecules and the release of pro-inflammatory mediators. The metalloproteinases ADAM10 and ADAM17 mediate the cleavage and release of several surface molecules (cytokines, receptors, chemokines, growth factors and adhesion molecules) regulating vascular permeability and recruitment of leukocytes. Using cell-specific knockout mice we have demonstrated a crucial contribution of ADAM10 and ADAM17 towards acute lung inflammation induced by intranasal application of LPS or acid. While endothelial ADAM17 activity was related to the cleavage of adhesion molecules and permeability regulation, smooth muscle ADAM17 function was linked to the shedding of growth factors and subsequent transactivation of the cells. In leukocytes ADAM10 but not ADAM17 contributes to acute lung inflammation by promoting leukocyte migration, adhesion and signalling.Besides their proinflammatory function in actute lung inflammation, the contribution of ADAM10 and ADAM17 towards later stages of chronic inflammation such as lung fibrosis and allergic asthma remains completely unclear. Here we aim to investigate the possible role of ADAM10 and ADAM17 during the course of chronic lung inflammation and their function as switch molecules deciding between progression and resolution/repair. Our first experiments indicate that endothelial ADAM10 acts proinflammatory in early acute inflammation but holds a protective role at later stages of inflammation. Our hypothesis therefore is that both proteases differentially regulate early and late phases of inflammation by shedding of surface molecules in a cell-specific manner. We will therefore study the regulation and activity of ADAMs in different phases of lung inflammation and fibrosis development induced in mice by intratracheal instillation of bleomycin and investigate the role of cell-specific knockout of ADAM10 and ADAM17 for T cell recruitment, cytokine release, collagen production and tissue remodelling. The activity of the proteases will be linked to the shedding of adhesion molecules, growth factors, Notch and others. Mechanistic analysis on cell migration, permeability, mediator secretion, proliferation, survival, regeneration, and transactivation will be performed with primary human and murine lung cells and leukocytes either from cell-specific knockout mice or after pharmacological or transcriptional suppression of ADAM10 or ADAM17. The same procedure will be used to investigate whether ADAM10 and ADAM17 also control early and late phases of asthmatic lung inflammation in response to OVA immunization and challenge by general or disease specific pathways. This study shall investigate the time- and cell-dependent functional switch of ADAM proteases in the course from actute to chronic lung inflammation. This should have important implications for the development of antinfammatory treatment strategies with ADAM inhibitors.