Epithelial JNK-TGFb1 Signaling Axis in Airway Remodeling

气道重塑中的上皮 JNK-TGFb1 信号轴

• 批准号: 8459777
• 负责人: Yvonne M. W. Janssen-Heininger
• 金额: $ 39.27万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8459777
• 关键词: 3' Untranslated Regions; Ablation; Address; Alleles; Allergens; Antigens; Asthma; Binding; Bleomycin; Cells; Cicatrix; Collagen; Data; Deposition; Development; Disease; Enterobacteria phage P1 Cre recombinase; Epithelial; Epithelial Cells; Epithelium; Etiology; Event; Fibrosis; Future; Genes; Genetic; In Vitro; Lead; Left; Lung; MADH3 gene; MAPK8 gene; Mediating; Mediator of activation protein; Mesenchymal; Messenger RNA; MicroRNAs; Modeling; Mus; N-terminal; Outcome; Ovalbumin; Patients; Phosphorylation; Phosphotransferases; Play; Predisposition; Process; Publishing; Pyroglyphidae; Refractory; Repression; Resistance; Respiratory Mechanics; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Signaling Protein; Therapeutic; Time; Transgenic Mice; airway epithelium; airway remodeling; allergic airway disease; cell type; cytokine; epithelial to mesenchymal transition; fibrogenesis; human TGFB1 protein; in vivo; prevent; public health relevance; response; stress-activated protein kinase 1; tool; transcription factor

DESCRIPTION (provided by applicant): The development of subepithelial fibrosis represents an important feature of airway remodeling in asthma, and a critical role for epithelial cells herei is emerging. The pro-fibrotic cytokine, transforming growth factor beta-1 (TGF-¿1) plays a cardinal role in fibrogenesis. The outcome of TGF-¿1 signaling is highly dependent upon cooperation with other signaling pathways. We have recently identified a critical role for c-Jun-N-terminal- kinase 1 (JNK1) in augmenting the pro-fibrotic effects of TGF-¿1, in association with the causation of a mesenchymal transition of airway epithelial cells (EMT). Specifically, we have demonstrated that: 1) JNK is predominantly activated in airway epithelium from ovalbumin-sensitized and challenged mice; 2) mice lacking JNK1 (JNK1-/-) fail to induce mesenchymal genes or develop fibrosis in response to ovalbumin, TGF-¿1, or bleomycin; 3) TGF-¿1-induced EMT requires JNK1, through JNK1-dependent phosphorylation of SMAD3 in the linker domain. These data, suggest a critical role of airway epithelium-derived JNK1-dependent signals in orchestrating airways fibrosis. The hypothesis addressed herein is that activation of JNK1 in the airway epithelium is required for the development of subepithelial fibrosis in house dust mite- induced airways disease by promoting epithelial-mesenchymal transition (EMT). Specifically, we hypothesize that JNK1 enhances TGF-¿1 signaling via phosphorylation of SMAD3 in the linker domain, which enhances the competency of SMAD3 to decrease expression of let-7 microRNA (miRNA). Decreases in let-7 miRNA in turn enhances expression of the high mobility group A2 (HMGA2) gene, a proximal regulator of EMT, events that lead to subepithelial collagen deposition. In Specific Aim 1 we will determine the importance of JNK1-dependent phosphorylation of SMAD3 in the linker domain in repressing let-7 microRNA (miRNA) in lung epithelial cells, and subsequent enhancement of the high mobility group A2 (HMGA2) gene. We will also analyze expression of let-7 miRNA and HMGA2 in bronchial epithelial cells derived from asthmatics, compared to controls, and determine the susceptibility of asthmatic and normal epithelial cells to TGF-¿1-induced EMT, and elucidate the role of JNK and SMAD3 therein. In Specific Aim 2 we will elucidate whether activation of JNK1 within the airway epithelium is critical in the orchestration of house dust mite-induced epithelial to mesenchymal transition, airways fibrosis, and altered respiratory mechanics in vivo, and utilize mice that globally lack JNK1, or specifically within the bronchiolar epithelium, following and CRE-recombinase mediated ablation. In Specific Aim 3 we will determine the importance of SMAD3 linker domain phosphorylation and resultant decreases of let-7g miRNA in promoting epithelial to mesenchymal transition, airways fibrosis, and altered respiratory mechanics in vivo, via the creation of TetOP-FLAG-SMAD3-EPSM mice, which are refractory to phosphorylation by JNK in the linker domain, and TetOP-FLAG-SMAD3-wild type (WT) transgenic mice, as a control. We will assess the impact of delivery of let-7g pre-miRNA on HDM-induced remodeling.

描述（由申请人提供）：上皮下纤维化的发展代表了哮喘气道重塑的一个重要特征，并且上皮细胞在此的关键作用正在显现。促纤维化细胞因子转化生长因子β-1 (TGF-¿1) 在纤维形成中发挥着重要作用。 TGF-¿1 信号传导的结果高度依赖于与其他信号传导途径的合作。我们最近发现 c-Jun-N-末端激酶 1 (JNK1) 在增强 TGF-¿1 的促纤维化作用中发挥着关键作用，与气道上皮细胞 (EMT) 的间质转化有关。具体来说，我们已经证明：1) JNK 主要在卵清蛋白致敏和攻击小鼠的气道上皮中被激活； 2）缺乏JNK1（JNK1-/-）的小鼠无法诱导间充质基因或对卵清蛋白、TGF-¿1或博来霉素产生纤维化； 3) TGF-¿1诱导的EMT需要JNK1，通过接头结构域中SMAD3的JNK1依赖性磷酸化。这些数据表明气道上皮来源的 JNK1 依赖性信号在协调气道纤维化中发挥着关键作用。本文提出的假设是，在屋尘螨诱发的气道疾病中，气道上皮中 JNK1 的激活是上皮下纤维化发展所必需的，通过促进上皮间质转化 (EMT)。具体来说，我们假设 JNK1 通过接头结构域中 SMAD3 的磷酸化来增强 TGF-¿1 信号传导，从而增强 SMAD3 降低 let-7 microRNA (miRNA) 表达的能力。 let-7 miRNA 的减少反过来会增强高迁移率组 A2 (HMGA2) 基因的表达，该基因是 EMT 的近端调节因子，导致上皮下胶原蛋白沉积。在具体目标 1 中，我们将确定接头结构域中 SMAD3 的 JNK1 依赖性磷酸化在抑制肺上皮细胞中的 let-7 microRNA (miRNA) 以及随后增强高迁移率 A2 (HMGA2) 基因方面的重要性。我们还将分析哮喘患者支气管上皮细胞中let-7 miRNA和HMGA2的表达，并与对照组进行比较，确定哮喘和正常上皮细胞对TGF-¿1诱导的EMT的敏感性，并阐明JNK和SMAD3在其中的作用。在具体目标 2 中，我们将阐明气道上皮内 JNK1 的激活对于屋尘螨诱导的上皮间质转化、气道纤维化和体内呼吸力学改变的协调是否至关重要，并利用在 CRE 重组酶介导的消融后全局缺乏 JNK1 或具体在细支气管上皮内缺乏 JNK1 的小鼠。在具体目标 3 中，我们将通过创建 TetOP-FLAG-SMAD3-EPSM 小鼠（该小鼠对接头结构域中的 JNK 磷酸化具有抵抗力）来确定 SMAD3 接头结构域磷酸化以及由此产生的 let-7g miRNA 减少在促进上皮间质转化、气道纤维化和体内呼吸力学改变方面的重要性，以及 TetOP-FLAG-SMAD3-野生型（WT）转基因小鼠，作为对照。我们将评估 let-7g pre-miRNA 的递送对 HDM 诱导的重塑的影响。