Targeting PTPalpha to Prevent Lung Fibrosis

描述(由申请人提供)：肺纤维化可能发生在职业接触二氧化硅和石棉后，或没有可识别的原因，如特发性肺纤维化(IPF)。不幸的是，这些疾病没有有效的治疗方法。据认为，肺损伤不缓解会导致纤维化生长因子的过度产生，如转化生长因子-β，从而推动进行性纤维化。来自我的实验室的令人兴奋的初步研究表明，PTP的遗传缺陷在不改变急性炎症反应的发生或消退的情况下，可以在小鼠模型中预防肺纤维化。这种特异性表明，PTP？是一种具有靶向胞外结构域的跨膜PTP，可能成为治疗纤维化的有前途的药物靶点，并强调了确定PTP如何促进肺纤维化的重要性。我们还发现，在肺纤维化信号通路中，PTP可增强转化生长因子的反应性。使用相互的骨髓嵌合体，我们确定PTP？//-肺驻留细胞而不是骨髓来源的细胞赋予保护性表型。然而，目前可用的全球基因缺陷小鼠施加的限制使我们无法确定哪些肺驻留细胞对这种表型负责。这一信息对于描述PTP选择性驱动肺纤维化的分子机制至关重要。我们假设PTP通过增强肺成纤维细胞中促纤维化的转化生长因子-β信号而促进肺纤维化。目的1是建立PTP在成纤维细胞或肺泡II型上皮细胞中选择性缺失的小鼠。我们已经从EUCOMM购买了具有靶向Ptp？等位基因的B6/N ES细胞系，并使用这些细胞来产生嵌合小鼠，这些嵌合小鼠将被配对产生具有Ptp？等位基因(Ptp？f/f)的小鼠。为了产生成纤维细胞特异性的PTP？缺失，我们将PTP？f/f小鼠与col1？2-Cre小鼠杂交。为了产生ATII特异性的Ptp？缺失，我们将Ptp？f/f小鼠与Sftpc-Cre小鼠杂交。我们将确定PTP是否在培养的成纤维细胞和从这些小鼠分离的ATII细胞中促进转化生长因子-β诱导的促纤维化信号。目的2是利用细胞类型特异性基因靶向小鼠，确定肺成纤维细胞或ATII细胞中PTP在促进肺纤维化中的重要性。我们将比较三种模型的肺纤维化的严重程度：气管内滴注(I)博莱霉素，(II)二氧化硅，或(III)表达活性转化生长因子的腺病毒，在成纤维细胞(COL1-Cre/Ptp？f/f)或ATII细胞(Sftpc-Cre/Ptp？f/f)中存在PTP遗传缺陷的小鼠。这种高影响力的方法将使我们能够确定PTP是否控制成纤维细胞或ATII细胞中依赖转化生长因子的促纤维化信号，并将提供一种 为社会提供宝贵的资源。从这些研究中获得的知识最终将被用于开发药理学或生物学方法来治疗无意中暴露在含硅粉尘等致纤维化物质中的个人(建筑工人、急救人员)，以防止进行性肺纤维化。

DESCRIPTION (provided by applicant): Pulmonary fibrosis may occur after occupational exposure to silica and asbestos or without an identifiable cause, as in Idiopathic Pulmonary Fibrosis (IPF). Unfortunately, there is no effective therapy for these disorders. It is thought tha nonresolving lung injury results in excessive production of fibrogenic growth factors, such as TGF-¿, which drive progressive fibrosis. Exciting preliminary studies from my laboratory have revealed that genetic deficiency of PTP¿ prevents pulmonary fibrosis in a murine model without altering the genesis or resolution of the acute inflammatory response. This specificity suggests that PTP¿, a transmembrane PTP with a targetable extracellular domain, could be a promising drug target for fibrosis and highlights the importance of determining how PTP¿ promotes lung fibrosis. We have also discovered that PTP¿ enhances TGF-¿ responsiveness in fibrogenic signaling pathways in the lung. Using reciprocal bone marrow chimeras, we determined that PTP¿-/- lung resident cells and not bone marrow-derived cells, confer the protective phenotype. However, the limitations imposed by the currently available globally gene-deficient mice prevent us from determining which lung resident cells are responsible for this phenotype. This information is critical to delineate the molecular mechanisms by which PTP¿ selectively drives fibrosis in the lung. We hypothesize that PTP¿ promotes pulmonary fibrosis by augmenting profibrotic TGF-¿ signals in lung fibroblasts. Aim 1 is to generate mice in which PTP¿ is selectively deleted in either fibroblasts or alveolar type (AT)II epithelial cells. We have purchased B6/N ES cell lines with a targeted PTP¿ allele from EUCOMM and used these to generate chimeric mice that will be mated to generate mice with a floxed PTP¿ allele (PTP¿f/f). To generate a fibroblast-specific deletion of PTP¿, we will cross PTP¿f/f mice with Col1¿2-Cre mice. To generate ATII-specific deletion of PTP¿, we will cross PTP¿f/f mice with Sftpc-Cre mice. We will determine whether PTP¿ promotes TGF-¿-induced profibrotic signaling in cultured fibroblasts and ATII cells isolated from these mice. Aim 2 is to determine the importance of PTP¿ in lung fibroblasts or ATII cells in promoting pulmonary fibrosis using cell type-specific gene-targeted mice. We will compare the severity of pulmonary fibrosis in three models: intratracheal instillation of (i) bleomycin, (ii) silica, or (iii) adenovirus expressing active TGF¿ in mice that are genetically deficient in PTP¿ in either fibroblasts (Col1¿2-Cre/PTP¿f/f) or ATII cells (Sftpc-Cre/PTP¿f/f). This high impact approach will enable us to determine whether PTP¿ controls TGF-¿ dependent profibrotic signaling in fibroblasts or ATII cells and will also provide a valuable resource for the community. Knowledge gained from these studies will ultimately be used to develop pharmacological or biological approaches to treat individuals (construction workers, first responders) who are inadvertently exposed to fibrogenic agents such as silica-containing dust to prevent progressive pulmonary fibrosis.