Chitinase1 Regulation of Pulmonary Fibrosis and Therapeutic Targeting

项目总结 几丁三糖苷酶(Chitinase1；Chit1)是人体内主要的真几丁质酶。它可以在流通领域找到 在以炎症、组织为特征的各种疾病中进一步增加 重塑和/或纤维化，包括细菌或真菌感染，溶酶体储存病(Gaucher‘s)， 结节病、慢性阻塞性肺疾病(COPD)和间质性肺疾病。然而，具体的作用是 Chit1在这些疾病中的发病机制尚未阐明。最近我们报道了Chit1增强 转化生长因子-β1(转化生长因子-β1)是组织纤维化的关键介质，在健康和疾病中的作用 与硬皮病相关的间质性肺疾病(SSC-ILD)的发病机制有关。然而， Chit1用于调节纤维化组织反应的机制以及这些机制在 特发性肺纤维化的定义尚不清楚。在初步研究中，我们证明了Chit1 促进促纤维化巨噬细胞活化，转化生长因子-β-1刺激的成纤维细胞增殖，肌成纤维细胞 分化、细胞外基质基因表达和蛋白质积累。重要的是，这些影响是 通过Chit1抑制转化生长因子-β1对其反馈抑制物Smad7的诱导而发挥作用。Chit1与 转化生长因子-β受体相关蛋白1(TgfbRap1)和Forkhead Box 03(FOXO_3) Chit1在促进转化生长因子-β-1信号和效应反应中的作用及FOXO_3在转化生长因子-1中的关键作用 β-1诱导Samd7。通过广泛的药物文库筛选，我们鉴定了卡苏格霉素(KSM)是一种小分子 强烈抑制几丁质酶活性的分子及其对博莱霉素诱导的治疗作用 肺纤维化。在这项评估中，KSM显示出令人印象深刻的预防和抗纤维化效果 治疗条件。这些发现使我们得出了一个假设，即Chit1和它的互动伙伴是潜在的 肺纤维化干预治疗靶点和KSM可作为一类新的治疗靶点 肺纤维化患者的治疗药物。为了检验这一假设，我们将 目的1.明确TgfbRap1在Chit1介导的肺纤维化中的具体作用和机制。 目的：研究转化生长因子-β诱导的肺纤维化过程中FoxO_3和Smad7对Chit1的调节作用。 目的3.研究KsM作为Chit1抑制剂在肺纤维化中的治疗作用。

PROJECT SUMMARY Chitotriosidase (chitinase 1; Chit1) is the major true chitinase in humans. It can be found 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, chronic obstructive lung diseases (COPD) and interstitial lung diseases. However, specific role of Chit1 in the pathogenesis of these diseases have not been elucidated. Recently we reported that Chit1 augments the effects of transforming growth factor-β1 (TGF-β1), a critical mediator of tissue fibrosis in health and disease, contributes to the pathogenesis of interstitial lung disease associated with Scleroderma (SSc-ILD). However, the mechanisms that Chit1 uses to regulate fibrotic tissue responses and the importance of these mechanisms in idiopathic pulmonary fibrosis have not been clearly defined. In preliminary studies, we demonstrate that Chit1 enhances profibrotic macrophage activation, TGF-β1-stimulated fibroblast proliferation, myofibroblast differentiation, extracellular matrix gene expression and protein accumulation. Importantly, these effects are mediated by the ability of Chit1 to inhibit TGF-β1 induction of its feedback inhibitor, Smad7. Chit1 interacts with TGF-β receptor associated protein 1 (Tgfbrap1) and Forkhead Box O3 (FoxO3) with Tgfbrap1 playing a critical role in Chit1 enhancement of TGF-β1 signaling and effector responses and FoxO3 playing a critical role in TGF- β1 induction of Samd7. Through extensive drug library screening, we identified Kasugamycin (KSM) as a small molecule that strongly inhibits Chit1 enzyme activity and tested its therapeutic effect in bleomycin induced pulmonary fibrosis. In this evaluation, KSM showed an impressive anti-fibrotic effect in both preventive and therapeutic conditions. These findings led us to a hypothesis that Chit1 and its interacting partners are potential therapeutic targets for the intervention of pulmonary fibrosis and KSM can be developed as a new class of therapeutic drug for the patients with pulmonary fibrosis. To test this hypothesis, we will Aim 1. Define the specific role and mechanism of Tgfbrap1 in Chit1 mediated pulmonary fibrosis. Aim 2. Characterize Chit1 regulation of FoxO3 and Smad7 in TGF-β stimulated pulmonary fibrosis. Aim 3. Characterize the therapeutic use of Kasugamycin (KSM) as a Chit1 inhibitor in pulmonary fibrosis.