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: 9291503
• 负责人: CHUN GEUN LEE
• 金额: $ 35.59万
• 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 2019-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9291503
• 关键词: Apoptosis; Bacterial Artificial Chromosomes; Bacterial Infections; Binding; Binding Proteins; Biological; Biological Markers; Biology; Bleomycin; Blood; Blood Circulation; Bronchoalveolar Lavage; Chitin; Chitin Synthase; Chitinase; Chronic Obstructive Airway Disease; Cleaved cell; 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; Proteins; Pulmonary Fibrosis; Research; Role; Sarcoidosis; Scleroderma; Serum; Severities; Signal Transduction; Site; Testing; Time; Tissues; Transforming Growth Factor beta Receptors; Transgenic Mice; Transgenic Organisms; Two-Hybrid System Techniques; United States National Institutes of Health; Wild Type Mouse; Yeasts; alveolar type II cell; clinical predictors; cohort; disability; enzyme activity; in vivo; injury and repair; macrophage; man; member; overexpression; potential biomarker; public health relevance; receptor; receptor expression; response; therapeutic target; translational approach

DESCRIPTION (provided by applicant): 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 Chit 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-�1-induced fibroblast proliferation, receptor expression and canonical and non-canonical signaling while binding to TGF-� 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-�1 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.

描述(申请人提供)：几丁质酶(Chitinase 1；Chit1)是糖基水解酶18(GH18)基因家族的成员，是人类主要的真正几丁质酶。在正常人的循环中可以检测到它的含量，在以炎症、组织重塑和/或纤维化为特征的各种疾病中进一步增加，包括细菌或真菌感染、溶酶体储存病(Gaucher‘s)、结节病和间质性肺部疾病。然而，Chit1的效应器功能尚未定义，其 在这些疾病的发病机制中的作用尚未阐明。为了确定Chit1在肺损伤和修复中的体内作用，我们表征了硬皮病患者循环Chit活性的水平，并开始在新产生的Chit1缺失突变小鼠(Chit1-/-)、肺靶向Chit1过表达转基因小鼠(Chit1 TG)和人源化Chit1细菌人工染色体(BAC)小鼠(HBAC-Chit)中观察博莱霉素诱导的反应，这些小鼠含有人Chit1及其调控序列。利用酵母双杂交试验，我们还确定了Chit1结合的潜在合作伙伴/受体。这些研究表明：(A)与间质性肺疾病(SSC-ILD)的存在和严重程度相关的SSc患者循环Chit1活性水平增加；(B)博莱霉素刺激后巨噬细胞和肺泡II型细胞中Chit1被诱导；(C)博莱霉素诱导的纤维化在Chit1-/-小鼠中显著缓解，但在Chit1TG小鼠中与野生型(WT)对照鼠相比明显增强。它们还表明，Chit1在与转化生长因子-�受体相关蛋白-1(TgfbRap1)结合的同时，增强了转化生长因子-�1诱导的成纤维细胞的增殖、受体表达以及规范和非规范信号。这些发现使我们假设Chit1是SSc-ILD患者的生物标记物和治疗靶点。这些研究还表明，Chit1至少部分地通过与TgfbRap1相互作用来增强转化生长因子-�1的反应，从而介导其纤维化效应。为了验证假设，该项目的研究将使用体内和体外以及翻译方法来：1.定义循环Chit1的水平 和Chit1的生物活性及其作为SSC生物标志物的作用。2.明确Chit1在博莱霉素和IL-13诱导的肝纤维化发病机制中的作用。3.确定Chit1用来增强组织纤维化的机制。4.明确Chit1与TgfbRap1的相互作用以及这种相互作用在Chit1生物学效应发生机制中的作用(S)。