Autotaxin Lysophophatidic acid pathway in bronchiolitis obliterans post-lung tran

肺移植后闭塞性细支气管炎中自分泌运动因子溶血磷脂酸途径

• 批准号: 8694759
• 负责人: Vibha N Lama
• 金额: $ 51.88万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8694759
• 关键词: AXIN2 protein; Acids; Affect; Allografting; Animals; Binding; Biological Assay; Biological Markers; Bronchiolitis Obliterans; Bronchoalveolar Lavage; Bronchoalveolar Lavage Fluid; Cell Differentiation process; Cell Nucleus; Cells; Cessation of life; Chronic; Cicatrix; Clinical Trials; Collagen; Cyclin D1; Data; Deltastab; Dependency; Development; Disease; Drug Targeting; Embryo; Family; Felis catus; Fibrosis; Future; Gene Targeting; Generations; Genetic Transcription; Glycogen Synthase Kinase 3; Histology; Human; Human Activities; Hydroxyproline; Immunosuppression; Investigation; Label; Lead; Ligation; Link; Lipids; Lung; Lung Transplantation; Lymphoid; Lysophosphatidylcholines; Lysophospholipase; Lysophospholipids; Mediating; Membrane Lipids; Mesenchymal; Mesenchyme; Modeling; Mus; Organ Transplantation; Outcome; Pathogenesis; Pathway interactions; Patients; Phenotype; Phospholipase C; Phosphorylation; Play; Population; Protein Kinase C; Publishing; Receiver Operator Characteristics; Reporter; Respiratory physiology; Role; Route; Sampling; Scheme; Secondary to; Signal Pathway; Signal Transduction; Signaling Molecule; Small Interfering RNA; Solid; Syndrome; TCF Transcription Factor; Testing; Therapeutic; Time; Tissues; Tomatoes; Transcriptional Activation; Transgenic Mice; Transplant Recipients; Transplantation; Up-Regulation; Work; activating transcription factor; autocrine; cohort; enhancer binding protein; extracellular; fibrogenesis; graft failure; human data; in vivo; lung allograft; lysophosphatidic acid; migration; mortality; novel; novel therapeutic intervention; nuclear factors of activated T-cells; preclinical study; prevent; prognostic; protein expression; public health relevance; research study; therapeutic target; transcription factor; vzg-1 Receptor

DESCRIPTION (provided by applicant): Impaired lung function secondary to fibrotic scarring and obliteration of small airways, termed bronchiolitis obliterans syndrome (BOS), is the major cause of chronic graft failure and mortality following lung transplantation. Understanding mechanistic pathways involved in lung allograft fibrogenesis is the key to novel therapeutic approaches in this arena. Studies of mesenchymal cells (MCs) from human lung allografts have led us to target a novel signaling pathway of MC mobilization and activation. An increase in number of donor-derived MCs is seen in the bronchoalveolar lavage (BAL) of patients with BOS. MCs from BOS lungs also demonstrated a stable activated phenotype marked by an increased collagen and ¿-catenin protein expression as well as an increased autotaxin (ATX) secretory activity. ATX is a secreted lysophopholipase D which generates lysophosphatidic acid (LPA), a bioactive lipid with a role in tissue fibrosis, from membrane lipids. Our published work has revealed a unique signaling cascade where through LPA1 ligation and subsequent phosphokinase-C mediated glycogen synthase kinase-3¿ activation, LPA leads to ¿-catenin stabilization and transcriptional activation. New preliminary data demonstrates that autocrine ATX secretion and LPA1 ligation contributes to stable ¿-catenin and collagen upregulation noted in MCs isolated from human fibrotic lung grafts. Furthermore, LPA levels were noted to be higher in BAL samples from patients with BOS. This human data has led us to propose experiments investigating the in vivo role of ATX-LPA-¿-catenin pathway in pathogenesis of BO and to investigate if LPA1 antagonism can be a potential therapeutic option in this disease. To achieve these aims we have established a whole lung mouse orthotopic lung transplant model where a moderate MHC mismatch leads to development of airway fibrosis by day 28. In Aim 1, we propose to investigate the time course of ATX and LPA upregulation in the resident MCs and other cellular components of the allograft in vivo using this murine model. We will utilize mice with BAC florescent labeling of Foxf1, a transcription factor seen in embryonic lung mesenchyme and shown to be highly expressed in lung MCs, to specifically identify and study graft-resident MCs. These studies will also inform us of the role of graft-resident MCs in fibrogenesis. Aim 2 will focus on understanding the role of ¿-catenin in MC differentiation and dissecting the mechanisms by which it affects the cells fibrotic functions. The mechanistic pathways will be studied in human cells. However, we will utilize a reporter mouse (Axin2LacZ) to follow ¿-catenin transcriptional activity during allograft fibrogenesis and test the in vivo rol of LPA1 ligation in MC ¿-catenin activation. In Aim 3 we will determine if LPA levels in BAL samples can predict subsequent development of BOS. Importantly, we will test if LPA1 antagonist can prevent onset or progression of allograft fibrosis in the murine orthotopic single lung transplant model. The proposed work will be the first investigation of ATX/LPA/LPA1/ ¿-catenin signaling in BOS and will provide important rationale for future clinical trials targeting this pathway in lung transplantation.

描述(申请人提供)：继发于纤维化瘢痕形成和小气道闭塞的肺功能受损，称为闭塞性细支气管炎综合征(BOS)，是肺移植后慢性移植物失败和死亡的主要原因。了解参与同种异体肺移植纤维化形成的机制是这一领域新的治疗方法的关键。对人同种异体肺间充质细胞(MC)的研究使我们找到了一条新的MC动员和激活的信号通路。在BOS患者的支气管肺泡灌洗液(BAL)中可以看到供体来源的MC数量增加。BOS肺来源的MCs也表现出稳定的激活表型，其显著特征是胶原蛋白和β-连环素蛋白表达增加，以及自体趋化蛋白(ATX)分泌活性增加。ATX是一种分泌的溶血磷脂酶D，它从膜脂中产生溶血磷脂酸(LPA)，这是一种在组织纤维化中起作用的生物活性脂质。我们已发表的工作揭示了一个独特的信号级联反应，其中通过LPA1连接和随后的磷酸激酶C介导的糖原合成酶激酶3的激活，LPA导致连环蛋白稳定和转录激活。新的初步数据表明，自分泌ATX和LPA1结扎有助于从人纤维肺移植物分离的MC中稳定地上调连环蛋白和胶原。此外，BOS患者的BAL样本中LPA水平也较高。这一人类数据使我们建议进行实验，研究ATX-LPA-β-catenin途径在BO发病机制中的体内作用，并研究LPA1拮抗是否可以作为该疾病的潜在治疗选择。为了实现这些目标，我们建立了一种全肺小鼠原位肺移植模型，在该模型中，中度MHC不匹配会导致第28天前发生呼吸道纤维化。在目标1中，我们建议使用这个小鼠模型来研究ATX和LPA在体内移植物的常驻MC和其他细胞成分中上调的时间进程。我们将利用BAC荧光标记Foxf1的小鼠来特异性地鉴定和研究移植物驻留的MCs。Foxf1是一种在胚胎肺间充质中看到的转录因子，被证明在肺MC中高表达。这些研究还将告诉我们移植物驻留的MC在纤维化形成中的作用。目的2重点了解连环蛋白在MC分化中的作用，并剖析其影响细胞纤维化功能的机制。这些机械途径将在人类细胞中进行研究。然而，我们将利用一只报告小鼠(Axin2LacZ)跟踪同种异体移植肝纤维化过程中-连环蛋白的转录活性，并测试体内LPA1结扎在MC-连环蛋白激活中的作用。在目标3中，我们将确定BAL样本中的LPA水平是否可以预测BOS的后续发展。重要的是，我们将测试LPA1拮抗剂是否可以在小鼠原位单肺移植模型中预防同种异体移植纤维化的发生或进展。这项拟议的工作将是首次研究ATX/LPA/LPA1/？-catenin信号在BOS中的作用，并将为未来肺移植中针对这一途径的临床试验提供重要的理论依据。