RhoA signaling controls mesenchymal stem cell lineage commitment via Lef-1 in asthma

RhoA 信号通过 Lef-1 控制哮喘中的间充质干细胞谱系定型

• 批准号: 9892555
• 负责人: Peisong Gao
• 金额: $ 45万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-05 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9892555
• 关键词: Affect; Allergens; Allergic inflammation; Asthma; Biological; Bone Marrow; Cell Lineage; Cells; Cellular Structures; Chronic Disease; Clinical; Computer Simulation; Data; Development; Dominant-Negative Mutation; Endogenous Factors; Epithelial; Epithelial Cells; Etiology; Exposure to; Extrinsic asthma; Fibroblasts; Genes; Goals; Immune response; Immunoprecipitation; In Vitro; Inflammation Mediators; Knock-in; Lead; Link; MADH2 gene; Mediating; Mesenchymal Differentiation; Mesenchymal Stem Cells; Modeling; Molecular; Multipotent Stem Cells; Mus; Myofibroblast; Pathway interactions; Plasmids; Prevention; Public Health; RHOA gene; RNA; Research; Role; Signal Pathway; Signal Transduction; Site; Structure; Structure of parenchyma of lung; Tamoxifen; Testing; Therapeutic; Tissues; United States; WNT Signaling Pathway; airway inflammation; airway remodeling; asthma model; asthmatic airway; asthmatic patient; base; cockroach allergen; environmental allergen; experimental study; injured; knock-down; lung injury; lymphoid enhancer-binding factor 1; mouse model; nestin protein; new therapeutic target; prophylactic; recruit; repaired; stem; stem cell differentiation; time use; transcriptome sequencing

ABSTRACT Asthma is a serious chronic illness, and a growing clinical and public health concern. A major obstacle to the prevention and treatment of asthma has been its diverse etiologies and our inadequate understanding of the biological mechanisms. Our long-term goals are to elucidate the fundamental underlying mechanisms and identify novel therapeutic targets for asthma. Recent studies suggest that allergen caused epithelial damage allows environmental allergens access to the airway tissue and may lead to the development of airway remodeling. Numerous studies have suggested that mesenchymal stem cells (MSCs), multipotent stem cells, can migrate to injured sites and differentiate into epithelial cells or fibroblasts/myofibroblasts that may contribute to airway repair/remodeling. However, these studies were performed either in cultured MSCs or transferred exogenous MSCs in mouse model of lung injury, and the primary endogenous factors that control MSC differentiation remain unclear. In this proposal, we aim to directly track the lineage commitment/differentiation of MSCs in mouse model of asthma over time using MSC lineage tracing mouse model and elucidate the underlying mechanisms. During the pilot stage, our group has made significant contributions to uncovering an important link between MSCs and asthma. We observed increased MSCs in the airways of asthma mouse model and demonstrated that active TGFβ1 is essential for the recruitment of MSCs to the damaged airways. However, a major breakthrough came with our recent finding that TGFβ1-activated RhoA functions as a molecular switch for the fate of MSCs during arterial repair/remodeling. This finding raises the possibility that RhoA signaling may also be critical in determining the lineage fate of MSCs for airway repair/remodeling. Indeed, we have utilized MSC lineage tracing model to track the RhoA-mediated MSC differentiation and found that inhibition of RhoA signaling suppressed MSC differentiation into myofibroblasts, but promoted MSC differentiation into epithelial cells in our mouse model. Furthermore, we identified the Wnt signaling lymphoid enhancer-binding factor 1 (Lef1) as the most up-regulated gene of RhoA-activation in MSCs. Intriguingly, knockdown of Lef1 induced MSC differentiation away from fibroblasts/myofibroblasts but towards airway epithelial cells. These exciting new data led us to test the hypothesis that RhoA signaling controls MSC lineage commitment/differentiation during airway repair/remodeling in asthma through Lef1. Three independent yet related specific aims are proposed. Aim 1 proposes experiments to define the role of RhoA signaling pathway in the lineage commitment/differentiation of MSCs in asthma mouse model over time using an established tamoxifen inducible MSC lineage tracing mouse model. Aim 2 will elucidate the molecular mechanisms underlying the RhoA signaling regulated lineage commitment/differentiation of MSCs. Aim 3 proposes studies to determine the role of RhoA-activated Lef1 in the lineage commitment/differentiation of MSCs. Collectively, these studies are significant in understanding of how environmental allergen-induced asthma occurs and in the development of new therapeutic targets for asthma.

抽象的 哮喘是一种严重的慢性疾病，也是日益增长的临床和公共卫生问题。一个主要障碍 预防和治疗哮喘一直是其潜水员的病因，我们对 生物学机制。我们的长期目标是阐明基本的潜在机制和 确定哮喘的新型治疗靶标。最近的研究表明，过敏原造成上皮损伤 允许环境过敏原进入气道组织，并可能导致气道发展 重塑。大量研究表明，间充质干细胞（MSC），多能干细胞， 可以迁移到受伤的部位并分化为上皮细胞或成纤维细胞/成纤维细胞可能有助于 进行气道维修/改建。但是，这些研究是在培养的MSC中进行的或转移的 肺损伤小鼠模型中的外源MSC和控制MSC的主要内源性因素 差异化尚不清楚。在此提案中，我们旨在直接跟踪谱系的承诺/差异化 使用MSC谱系跟踪小鼠模型的哮喘小鼠模型中的MSC并阐明了基础 机制。在飞行员阶段，我们的小组为揭示重要链接做出了重大贡献 在MSC和哮喘之间。我们观察到在哮喘小鼠模型的气道中增加了MSC和 证明主动TGFβ1对于将MSC募集到受损的气道中至关重要。但是， 我们最近的发现是，TGFβ1激活的RhoA充当分子开关 动脉修复/重塑期间MSC的命运。这一发现增加了Rhoa信号的可能性 对于确定MSC的血统命运至关重要，以进行气道修复/重塑。确实，我们已经使用了 MSC谱系跟踪模型跟踪RhoA介导的MSC分化，并发现RhoA的抑制作用 信号传导抑制MSC分化为肌纤维细胞，但促进了MSC分化为上皮 我们的小鼠模型中的细胞。此外，我们确定了Wnt信号传导淋巴增强剂结合因子1（LEF1） 作为MSC中RhoA激活的最上调基因。有趣的是，LEF1诱导的MSC敲低 与成纤维细胞/成肌纤维细胞不同，但向气道上皮细胞区分开。这些令人兴奋的新数据 导致我们检验了RhoA信号控制MSC谱系承诺/差异化的假设 通过LEF1修复/重塑哮喘。提出了三个独立但相关的特定目标。目标1 提案实验来定义RhoA信号通路在谱系承诺/分化中的作用 哮喘小鼠模型的MSC随着时间的流逝，使用已建立的他莫昔芬诱导MSC谱系追踪小鼠 模型。 AIM 2将阐明RHOA信号传导谱系的分子机制 MSC的承诺/差异化。 AIM 3提案研究以确定RhoA激活的LEF1在 MSC的血统承诺/差异化。总的来说，这些研究在理解如何 环境过敏原引起的哮喘发生并在开发哮喘的新治疗靶点。