Chitinase1 as a Biomarker and Therapeutic Target in Scleroderma Lung Disease

几丁质酶1作为硬皮病肺病的生物标志物和治疗靶点

• 批准号: 8632560
• 负责人: CHUN GEUN LEE
• 金额: $ 38.39万
• 依托单位: BROWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-21 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8632560
• 关键词: Apoptosis; Bacterial Artificial Chromosomes; Bacterial Infections; Binding; Biological; Biological Markers; Biology; Bleomycin; Blood; Blood Circulation; Bronchoalveolar Lavage; Chitin; Chitin Synthase; Chitinase; Chronic Obstructive Airway Disease; Cleaved cell; Clinical; Co-Immunoprecipitations; Disease; Epithelial; Epithelial Cells; Evaluation; Fibroblasts; Fibrosis; Gene Family; Human; Hydrolase; In Vitro; Individual; Inflammation; Interleukin-13; Interstitial Lung Diseases; Knowledge; Life; Lung; Lung diseases; Lysosomal Storage Diseases; Macrophage Activation; Mammals; Mediating; Membrane Potentials; Mesenchymal; Messenger RNA; Mission; Mus; Mutant Strains Mice; Mycoses; Myofibroblast; Nature; Nutrient; Pathogenesis; Patients; Play; Polysaccharides; Production; Prokaryotic Cells; Protein Binding; Proteins; Pulmonary Fibrosis; Research; Role; Sarcoidosis; Scleroderma; Serum; Severities; Signal Transduction; Site; Testing; Time; Tissues; Transgenic Mice; Transgenic Organisms; Two-Hybrid System Techniques; Wild Type Mouse; Yeasts; alveolar type II cell; cohort; disability; enzyme activity; in vivo; injury and repair; macrophage; man; member; overexpression; public health relevance; receptor; receptor expression; response; therapeutic target; translational approach

PROJECT SUMMARY Chitotriosidase (chitinase 1; Chit1), a member of the glycosyl hydrolase 18 (GH18) gene family, is the major true chitinase in humans. It can be found in detectable quantities in the circulation of normal individuals and is further increased in a variety of diseases characterized by inflammation, tissue remodeling and/or fibrosis including bacterial or fungal infections, lysosomal storage diseases (Gaucher's), sarcoidosis, and interstitial lung diseases. However, the effector functions of Chit1 have not been defined, and its roles in the pathogenesis of these diseases have not been elucidated. To begin to define the in vivo roles of Chit1 in pulmonary injury and repair, we characterized the levels of circulating Chit1 activity in patients with Scleroderma (SSc) and have begun to investigate the bleomycin-induced responses in newly generated Chit1 null mutant mice (Chit1-/-), lung-targeted Chit1 overexpressing transgenic mice (Chit1 Tg), and humanized Chit1 bacterial artificial chromosome (BAC) mice (HBAC-Chit) that contain human Chit1 and its regulatory sequences on a murine Chit1-/- background. Using yeast two hybrid assays, we have also identified potential partners/receptors that Chit1 binds to. These studies demonstrate that (a) the levels of circulating Chit1 activity are increased in patients with SSc where they correlate with the presence and severity of interstitial lung disease (SSc-ILD); (b) Chit1 is induced in macrophages and alveolar type II cells after bleomycin challenge; and (c) bleomycin-induced fibrosis is significantly ameliorated in Chit1-/- mice, but enhanced in Chit1 Tg mice compared to wild type (WT) controls. They also demonstrate that Chit1 augments TGF-b1-induced fibroblast proliferation, receptor expression and canonical and non-canonical signaling while binding to TGF-b receptor associated protein-1 (Tgfbrap1). These findings led us to hypothesize that Chit1 is a biomarker of and also a therapeutic target in SSc-ILD patients. These studies also suggest that Chit1 mediates its fibrotic effects, at least in part, via its ability to augment TGF-b1 responses by interacting with Tgfbrap1. To test the hypotheses, the studies in this project will use in vivo and in vitro and translational approaches to: 1. Define the levels of circulating Chit1 and Chit1 bioactivity and their roles as biomarkers in SSc. 2. Define the roles of Chit1 in the pathogenesis of bleomycin- and IL-13-induced fibrosis. 3. Define the mechanisms that Chit1 uses to augment tissue fibrosis. 4. Define the interaction of Chit1 with Tgfbrap1 and the role(s) of this interaction in the pathogenesis of the biologic effects of Chit1.

项目摘要 壳三糖苷酶（Chitotriosidase，chitinase 1; Chit 1）是糖基水解酶18（glycosylhydrolase 18，GH 18）基因家族的成员，是糖基水解酶18基因家族的主要功能酶。 真正的几丁质酶它可以在正常个体的循环中以可检测的量发现， 在以炎症、组织重塑和/或纤维化为特征的多种疾病中进一步增加 包括细菌或真菌感染、溶酶体贮积病（戈谢氏病）、结节病和间质性 肺部疾病然而，Chit 1的效应器功能尚未被定义，其在细胞凋亡中的作用也未被阐明。 这些疾病的发病机制尚未阐明。为了开始确定Chit 1在体内的作用， 肺损伤和修复，我们的特点是循环Chit 1活性水平的患者， 硬皮病（SSc），并已开始研究博来霉素诱导的新产生的Chit 1 空突变小鼠（Chit 1-/-）、肺靶向Chit 1过表达转基因小鼠（Chit 1 Tg）和人源化小鼠（Chit 1-/-）。 Chit 1细菌人工染色体（BAC）小鼠（HBAC-Chit），其含有人Chit 1及其调控基因， 在鼠Chit 1-/-背景上的序列。使用酵母双杂交试验，我们还确定了潜在的 Chit 1结合的伴侣/受体。这些研究表明：（a）循环Chit 1活性水平 在与间质性肺损伤的存在和严重程度相关的SSc患者中， （B）博来霉素攻击后，Chit 1在巨噬细胞和肺泡II型细胞中被诱导; 博来霉素诱导的纤维化在Chit 1-/-小鼠中显著改善，但在Chit 1 Tg小鼠中增强 与野生型（WT）对照相比。他们还证明Chit 1增强TGF-β 1诱导的成纤维细胞 与TGF-b受体结合时的增殖、受体表达以及经典和非经典信号传导 相关蛋白1（Tgfbrap 1）。这些发现使我们假设Chit 1是的生物标志物，也是 SSc-ILD患者的治疗目标。这些研究还表明Chit 1介导其纤维化作用， 至少部分是通过其与Tgfbrap 1相互作用增强TGF-b1应答的能力。为了验证这些假设， 本项目的研究将采用体内、体外和转化方法： 1.确定循环Chit 1和Chit 1生物活性的水平及其作为SSc生物标志物的作用。 2.确定Chit 1在博来霉素和IL-13诱导的纤维化发病机制中的作用。 3.定义Chit 1用于增加组织纤维化的机制。 4.定义Chit 1与Tgfbrap 1的相互作用以及这种相互作用在肿瘤发病机制中的作用。 Chit 1的生物效应。