Focal Adhesion Modulation of IL-1 Signaling: Importance in Pulmonary Fibrosis

描述（由申请方提供）：特发性肺纤维化（IPF）是一种进行性且经常致命的疾病，目前尚无有效的治疗策略。目前的建议集中在白细胞介素-1（IL-1），一种有效的促炎细胞因子，诱导成纤维细胞中的多个信号级联。这些信号在宿主防御中起作用，但矛盾的是，可能导致炎性组织损伤和肺及其他器官的纤维化。IL-1刺激Ca 2+释放和多种细胞因子和炎性因子的表达，所述细胞因子和炎性因子例如基质金属蛋白酶（MMP），所述基质金属蛋白酶（MMP）通过丝裂原活化蛋白（MAP）激酶途径驱动细胞外基质降解。目前，IL-1诱导的信号被缓和或终止的机制还不完全清楚。我们迄今为止的研究已经确定，在成纤维细胞中，IL-1诱导的信号传导需要局灶性粘连（FA），并且IL-1信号被我们开发的FA分散肽耗散。我们最近的研究表明，两种蛋白酪氨酸磷酸酶（PTP），SHP- 2和PTP-2，在调节IL-1诱导的FA成熟和IL-1诱导的信号中的重要性。我们发现，SHP-2介导粘着斑和内质网之间的功能性相互作用，这对ER Ca 2+释放至关重要;这些相互作用与粘着斑一起是IL-1信号传导的中心决定因素。我们的假设是FA中的PTP介导了FA对IL- 1的响应的成熟和重塑。在这些多分子信号传导平台中，PTP（与SHP-2相互作用并使其去磷酸化，导致募集和激活额外的信号传导和支架分子，这些分子对于Ca 2+从内质网释放、向ERK的信号传导以及MMP-1和3分泌是必需的。在具体目标1中，我们将确定PTP如何调节FA依赖性IL-1信号传导，导致ERK激活和MMP-1和3分泌。我们将使用来自正常和IPF肺的培养的人肺成纤维细胞和来自SHP-2或PTP（-null）胚胎的鼠成纤维细胞，用野生型或突变蛋白重建，作为体外模型来研究FA限制的信号传导。ERK激活和MMP 1和3释放将被用作IL-1信号传导的结果，以评估SHP-2和PTP的影响。在具体目标2中，我们将确定PTP的作用（通过粘着斑和ER调节IL-1信号传导）。我们将研究PTP和SHP-2相互作用的分子决定因素，以及它们如何调节IP 3受体和其他导致MMP表达的FA依赖性信号。在具体目标3中，我们将评估PTP和MMP 3在博来霉素诱导的肺纤维化小鼠模型中的体内作用。我们还将检查肺纤维化患者库存肺组织样本中PTP和SHP-2表达和/或活化的潜在变化。这些样本将用于确定这些患者肺中SHP 2和PTP（mRNA和蛋白质）的表达是否存在与肺纤维化严重程度相关的变化。由于IL-1是肺纤维化等慢性炎症性疾病的关键介质，因此阐明IL-1信号通路对于识别有效抗炎药的特定靶点至关重要。这通过特异性PTP的小分子抑制剂和被设计为选择性干扰促纤维化途径的肽作为潜在治疗剂来举例说明。项目叙述：肺纤维化（肺瘢痕形成）是一种进行性的，通常是致命的疾病，目前还没有有效的治疗方法。目前认为，瘢痕形成过程是由肺的衬里细胞（上皮）受损开始的，可能是病毒感染或环境污染物的结果。我们已经发现，白细胞介素-1，一种由肺内衬细胞分泌的小分子，强烈促进导致肺瘢痕形成的途径。我们建议对这些途径进行表征，目的是确定治疗的特定靶点，以减少这一破坏性过程。

DESCRIPTION (provided by applicant): Idiopathic pulmonary fibrosis (IPF) is a progressive and frequently fatal disorder for which there are currently no effective treatment strategies. The current proposal focuses on Interleukin-1 (IL-1), a potent, pro-inflammatory cytokine that induces multiple signaling cascades in fibroblasts. These signals serve in host defense but, paradoxically, may contribute to inflammatory tissue injury and to fibrosis of the lung and other organs. IL-1 stimulates Ca2+ release and expression of multiple cytokines and inflammatory factors such as matrix metalloproteinases (MMPs) that drive extracellular matrix degradation via mitogen activated protein (MAP) kinase pathways. Currently, the mechanisms by which IL-1-induced signals are moderated or terminated are incompletely understood. Our studies to date have determined that in fibroblasts, IL-1-induced signaling requires focal adhesions (FA) and that IL-1 signals are dissipated by FA dispersing peptides that we have developed. Our recent studies indicate the importance of two protein tyrosine phosphatases (PTP), SHP- 2 and PTP(, in the regulation of IL-1-induced FA maturation and IL-1 induced signals. We discovered that SHP-2 mediates functional interactions between focal adhesions and the endoplasmic reticulum that are crucial for ER Ca2+ release; these interactions, together with focal adhesions, are central determinants of IL-1 signaling. Our hypothesis is that the PTP( in FA mediates maturation and remodeling of FA in response to IL- 1. In these multi-molecular signaling platforms, PTP( interacts with and dephosphorylates SHP-2, leading to recruitment and activation of additional signaling and scaffold molecules that are essential for Ca2+ release from the endoplasmic reticulum, signaling to ERK, and MMP-1 and 3 secretion. In Specific Aim 1 we will determine how PTP( regulates FA-dependent IL-1 signaling leading to ERK activation and MMP-1 and 3 secretion. We will use cultured human lung fibroblasts from normals and IPF lungs and murine fibroblasts from SHP-2 or PTP(-null embryos, reconstituted with wild type or mutant proteins, as in vitro models to study FA-restricted signaling. ERK activation and MMP1 and 3 release will be used as outcomes of IL-1 signaling to assess the impact of SHP-2 and PTP(. In Specific Aim 2, we will determine the role of PTP( in regulating IL-1 signaling through focal adhesions and the ER. We will examine the molecular determinants of PTP( and SHP-2 interactions and how they regulate the IP3 receptor and other FA-dependent signals leading to MMP expression. In Specific Aim 3, we will assess the roles of PTP( and MMP3 in vivo in a murine model of bleomycin-induced pulmonary fibrosis. We will also examine potential alterations in PTP( and SHP-2 expression and/or activation in samples of banked lung tissue from patients with pulmonary fibrosis. These samples will be used to determine if there are alterations in the expression of SHP2 and PTP( mRNA and protein in the lungs of these patients that are associated with severity of pulmonary fibrosis. As IL-1 is a critical mediator of chronic inflammatory conditions such as pulmonary fibrosis, elucidation of IL-1 signaling pathways is fundamental in the identification of specific targets for effective anti-inflammatory agents. This is exemplified by small molecule inhibitors of specific PTP and peptides designed to selectively interfere with pro-fibrotic pathways as potential therapeutics. PROJECT NARRATIVE: Pulmonary fibrosis (scarring of the lung) is a progressive and usually fatal disorder for which there is currently no effective therapy. It is currently believed that the scarring process is started by damage to the lining cells of the lung (epithelium), perhaps as the result of a viral infection or from environmental pollutants. We have discovered that Interleukin-1, a small molecule secreted by the cells lining the lung, strongly promotes pathways leading to scarring in the lung. We propose to characterize these pathways with the aim of identifying specific targets for therapies to curtail this devastating process.