Exosome-mediated Cooperative Mechanisms of Macrophage/Fibroblast Activation in Systemic Sclerosis

摘要 系统性硬化症是一种病因不明的慢性自身免疫性疾病，其特点是 血管病变、纤维化和炎症。SSc没有治愈方法，FDA批准的疾病也很少- 修改治疗方法。虽然成纤维细胞在疾病发展中的贡献得到了广泛的认可，但最近 研究表明，巨噬细胞(M？S)也在SSc的发病机制中发挥作用。在最近出版的著作中， 我们建立了干细胞M？S的免疫表型图谱，并证明了M？S与干细胞共培养 真皮成纤维细胞导致这些细胞类型的相互激活。然而，影响SSC M？的因素 激活是未知的。在这一点上，我们新的初步研究涉及SSc真皮成纤维细胞来源 外切体在SSC中作为M？激活的介导物。我们发现干细胞来源的真皮成纤维细胞的摄取 外切酶体能诱导纤维蛋白原的M？活化。此外，干细胞成纤维细胞激活的M？S刺激干细胞成纤维细胞 产生炎症细胞因子和细胞外基质(ECM)成分。因此，我们假设 外切体刺激的M？S与SSc成纤维细胞相互激活。这项研究的目的是 目的是确定分泌型成纤维细胞来源的外切体和S促进纤维化的机制 SSC的炎性激活。我们将定义分子机制、途径和关键分子 介导成纤维细胞外切体与M？S之间的串扰，并将检验其治疗效果 使用最近开发的3D人类SSC皮肤模型来靶向这些调节器。这项工作的成果将提供 为开发新的有效的治疗SSc方法提供了合理的依据。将在以下方面测试的目标 此应用程序包括： 1.定义成纤维细胞胞外液，并确定调节SSC中M？激活的成分。 基因组和分子生物学方法将被用来鉴定引起 SSC M？激活，并确定支持这种激活的信号通路。 2.确定胞外体介导的M？活化改变如何促进SSC的炎症和纤维化。 共培养研究表明，SSc MäS诱导SSc成纤维细胞激活，暗示其在 在诱导和维持纤维化中的M？衍生因子。这一目标将决定SSC M？ 激活会影响成纤维细胞的激活。

ABSTRACT Systemic sclerosis (SSc) is a chronic autoimmune disease of unknown etiology that is characterized by vasculopathy, fibrosis, and inflammation. There is no cure for SSc and there are very few FDA-approved disease- modifying treatments. While the contribution of fibroblasts to disease development is widely appreciated, recent studies suggest macrophages (MØs) also play a role in the pathogenesis of SSc. In recently published work, we developed an immunophenotypic profile for SSc MØs, and demonstrated that co-culture of MØs with SSc dermal fibroblasts resulted in mutual activation of these cell types. However, the factors responsible for SSc MØ activation are unknown. In this regard, our new preliminary studies implicate SSc dermal fibroblast-derived exosomes as mediators of MØ activation in SSc. We show that uptake of SSc dermal fibroblast-derived exosomes induces profibrotic MØ activation. In addition, SSc fibroblast-activated MØs stimulate SSc fibroblast production of inflammatory cytokines and extracellular matrix (ECM) components. Therefore, we hypothesize that exosome-stimulated MØs and SSc fibroblasts engage in reciprocal activation. The goal of this study is to determine the mechanisms through which secreted fibroblast-derived exosomes and MØs promote fibrotic and inflammatory activation in SSc. We will define the molecular mechanisms, pathways, and key molecules that mediate cross-talk between fibroblast exosomes and MØs in SSc, and will test the therapeutic efficacy of targeting these regulators using a recently developed 3D human SSc skin model. Results of this work will provide the rational basis for the development of novel and effective treatments for SSc. The aims that will be tested in this application are: 1. Define fibroblast exosomal cargo and identify the components that regulate MØ activation in SSc. Genomic and molecular biology approaches will be used to identify the exosome mediators that induce SSc MØ activation and to identify the signaling pathways that underlie this activation. 2. Determine how exosomal-mediated changes in MØ activation promote inflammation and fibrosis in SSc. Co-culture studies demonstrate that SSc MØs induce activation of SSc fibroblasts, implicating a role for MØ-derived factors in the induction and maintenance of fibrosis. This aim will determine how SSc MØ activation impacts fibroblast activation.