MSC Exosome Treatment for BPD: Impact on Immunity and Lung Development

摘要 支气管肺发育不良（BPD）是早产儿的一种多因素慢性肺部疾病。没有单一 预防或治疗BPD的有效疗法，需要新的工具来治疗和降低风险 与极端早产相关的进一步并发症是紧迫的。事实上，间充质基质/干细胞 干细胞（MSC）疗法在BPD的临床前模型中显示出前景，然而最近的研究 确定MSC的主要治疗载体包含在其分泌组中，并由 外来体外来体是亚微米的脂质双层封闭的细胞外囊泡（EV），由大多数细胞表达。 细胞它们不同的起源、生物起源和分子组成使它们在多种和有效的生理学上成为可能。 作用，其中最有趣的是一种有效的细胞间通讯方法。MSC exosome 据报道，该组合物包括小的非编码RNA、游离脂肪酸、表面受体和 蛋白质，作为MSC治疗效果的载体。因此，除了它们的不同作用外， 健康和疾病，外泌体代表了用于治疗应用的新试剂。我们分离了外泌体 从人MSC条件培养基，称为MEx，并表明他们抑制BPD在新生儿高氧 小鼠模型具体地，一个剂量的Mex抑制肺部炎症、肺泡损伤、肺部炎症、肺损伤和肺损伤。 高血压，纤维化，并使长期肺功能正常化。我们已经证明了MEx被吸收 通过巨噬细胞（Mφs），并因此将Mφ表型转变为炎症消退，抗纤维化和抗纤维化。 重塑我们假设Mφ是MEx治疗作用的关键载体， 肺内分泌系统是肺内分泌系统的一个组成部分，其可以传递信号以促进正常的肺泡形成并恢复肺内稳态。我们将测试这个 SA#1：分离和全面表征MEx 亚群，并研究其作用机制和体外和体内生物学效价; SA#2： 测试单核细胞/Mφ作为MEx信号介导剂对肺细胞的作用; SA#3：研究生物学作用 MEx修饰的单核细胞/Mφ对体内高氧诱导的BPD的作用。

ABSTRACT Bronchopulmonary dysplasia (BPD) is a multifactorial chronic lung disease of preterm infants. With no single effective therapy for either the prevention or treatment of BPD, the need for new tools to treat and reduce risk of further complications associated with extreme preterm birth is urgent. Indeed, mesenchymal stromal/stem cell (MSC) therapy had shown promise in preclinical models of BPD, however more recent studies have established that the main therapeutic vectors of MSCs is comprised in their secretome and represented by exosomes. Exosomes are submicron, lipid bilayer-enclosed extracellular vesicles (EVs) expressed by most cells. Their varied origin, biogenesis and molecular composition enroll them in diverse and potent physiological roles, the most intriguing of which is an effective method of cell-to-cell communication. The MSC exosome composition has been reported to include small noncoding RNAs, free fatty acids, surface receptors and proteins, serving as vectors of MSC therapeutic effects. Consequently, in addition to their diverse roles in health and disease, exosomes represent novel reagents for therapeutic applications. We isolated exosomes from human MSC conditioned media, termed MEx, and showed that they inhibit BPD in the neonatal hyperoxia mouse model. Specifically, one dose of Mex inhibits lung inflammation, alveolar injury, pulmonary hypertension, fibrosis, and normalizes long-term lung function. We have demonstrated that MEx are taken up by macrophages (Mφs) and, as result, shift the Mφ phenotype to inflammation resolving, antifibrotic, and anti- remodeling. We hypothesize that Mφs are key vectors of MEx therapeutic action, orchestrating cell-to-cell communication signals to promote normal alveogenesis and to restore lung homeostasis. We will test this hypothesis in the following specific aims: SA#1: To isolate and comprehensively characterize MEx subpopulations and investigate mechanisms of their action and biological potency in vitro and in vivo; SA#2: To test the role of monocytes/Mφs as mediators of MEx signals to lung cells; SA#3: To investigate the biologic function of monocytes/Mφs, modified by MEx, on hyperoxia-induced BPD in vivo.