Regulation of Fibroblast Phenotype in Lung Fibrosis

描述（由申请人提供）：特发性肺纤维化（IPF）是一种发病率和死亡率不断上升的无法治愈的、致命的疾病。尽管有协调的尝试将体外和临床前模型的发现迅速转化为改善的护理，但几乎没有重大的治疗突破。导致IPF细胞表型改变的细胞间通讯的性质尚不清楚。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。我们发现，在应激反应中，成纤维细胞释放含有膜结合Thy-1的膜源性细胞外囊泡（EV）。在IPF患者的支气管灌洗液（BALF）中，EV相关的Thy-1水平与活检中纤维母细胞灶的数量相关，表明Thy-1+ EV可能是疾病活动性的有用生物标志物。在癌症和免疫学等其他领域，外泌体等外泌体越来越被认为是细胞间通讯的关键；它们通常含有非编码RNA和mRNA，被受体细胞吸收并改变其表型。此外，EV已被发现是许多疾病的优秀生物标志物。最近，含有EV的间充质干细胞（MSC）上清液已被证明可促进新生儿肺损伤的修复，这表明EV可传递与肺损伤和修复相关的有效信号。基于这些发现，我们假设活化成纤维细胞的细胞外囊泡（EV）维持和扩增，而间充质干细胞衍生的EV抑制肺纤维化的纤维化细胞表型。以下具体目标将验证这一假设：1：通过表征肺成纤维细胞和间充质干细胞在纤维化刺激下释放的EV，来定义在纤维化刺激下释放的EV的分子特征；2. 通过将成纤维细胞和间充质干细胞共培养于相关正常细胞和纤维化细胞类型的EV中，并测量其摄取和对细胞表型的影响，确定EV在肺细胞表型修饰中的作用；和3。通过表征来确定EV在纤维化中的作用

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.