Regulation of Fibroblast Phenotype in Lung Fibrosis

描述(由申请人提供)：特发性肺纤维化(IPF)是一种无法治愈的致命疾病，发病率和死亡率都在增加。尽管协调努力迅速将体外和临床前模型的发现转化为改善的护理，但在治疗方面几乎没有重大突破。导致IPF细胞表型改变的细胞间通讯的性质尚未得到很好的描述。我们已经证明，细胞表面糖蛋白Thy-1是一种纤维化抑制因子，它调节肺成纤维细胞纤维化表型的关键方面。我们已经发现，作为对压力的响应，成纤维细胞释放含有膜结合Thy-1的膜源细胞外小泡(EV)。在IPF患者的支气管灌洗液(BALF)中，EV相关的Thy-1水平与活检组织中成纤维细胞的数目相关，提示Thy-1+EV可能是反映疾病活动性的有用生物标志物。在其他领域，如癌症和免疫学，肠病毒，如外切体，越来越被认为是细胞间交流的关键；它们通常含有非编码的RNA和mRNA，由受体细胞摄取并改变其表型。此外，EV在许多疾病中也被发现是很好的生物标志物。最近，含有EV的间充质干细胞(MSC)的培养上清被证明能够促进新生儿肺损伤的修复，提示EV传递了与肺损伤和修复相关的强大信号。基于这些发现，我们假设在肺纤维化中，激活的成纤维细胞产生的细胞外小泡(EV)持续并放大，而MSC来源的EV抑制促纤维化的细胞表型。以下特定目的将检验这一假说：1：通过表征肺成纤维细胞和间充质干细胞对纤维化刺激的反应，确定EV释放的分子特征；2.通过将来自相关正常和纤维化细胞类型的EV与成纤维细胞和MSC共同培养，并测量它们的摄取和对细胞表型的影响，确定EV在肺细胞表型改变中的作用；以及3.通过表征EV在纤维化中的作用 EV在肺纤维化和IPF动物模型中产生，并通过在纤维化动物模型中传递成纤维细胞或MSC来源的EV来确定其纤维化和治疗效果。定义与肺纤维化相关的“水泡体”对于理解和改变这种恶性疾病的细胞间通讯至关重要。

DESCRIPTION (provided by applicant): Idiopathic pulmonary fibrosis (IPF) is an incurable, fatal disease with increasing incidence and mortality. Despite coordinated attempts to rapidly translate findings from in vitro and preclinical models into improved care, there have been few major therapeutic breakthroughs. The nature of the intercellular communications leading to altered cellular phenotypes in IPF is poorly characterized. We have demonstrated that the cell surface glycoprotein Thy-1 is a fibrosis suppressor which modulates critical aspects of the fibrogenic phenotype in lung fibroblasts. We have found that in response to stress, fibroblasts release membrane-originating extracellular vesicles (EV) containing membrane-bound Thy-1. In bronchial lavage fluid (BALF) from IPF patients, the level of EV-associated Thy-1 correlates with numbers of fibroblastic foci on biopsy, suggesting that Thy-1+ EV may be useful biomarkers of disease activity. In other fields such as cancer and immunology, EV such as exosomes are increasingly appreciated as critical in cell-cell communication; they usually contain non-coding RNA and mRNA that are taken up by recipient cells and alter their phenotypes. Also, EV have been found to be excellent biomarkers in many diseases. Recently, supernatants from mesenchymal stem cells (MSC), which contain EV, have been shown to promote repair of neonatal lung injury, suggesting that EV transmit potent signals relevant to lung injury and repair. Based on these findings, we hypothesize that extracellular vesicles (EV) from activated fibroblasts sustain and amplifiy, whereas MSC- derived EV inhibit, profibrotic cellular phenotypes in pulmonary fibrosis. The following specific aims will test the hypothesis: 1: To define the molecular characteristics of EV released in response to profibrotic stimuli, by characterizing EV released from lung fibroblasts and MSCs in response to fibrogenic stimuli; 2. To define the role of EV in the phenotypic modification of lung cells, by co-culturing fibroblasts and MSC in EV derived from relevant normal and profibrotic cell types, and measuring their uptake and effect on cell phenotype; and 3. To define the role of EV in fibrosis, by characterizing the EV produced in animal models of lung fibrosis and IPF, and by delivering fibroblast- or MSC-derived EV in animal models of fibrosis to determine their fibrogenic and therapeutic effects. Defining the "vesiculome" relevant to lung fibrosis is critical to understanding and modifying intercellular communication in this pernicious disorder.