Cellular crosstalk and molecular mechanisms in the initiation and progression of pulmonary fibrosis

肺纤维化发生和进展的细胞串扰和分子机制

基本信息

批准号：
10517432
负责人：
Purushothama Rao Tata
金额：
$ 52.92万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-06-15 至 2026-05-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10517432
关键词：
Ablation Accounting Address Alveolar Alveolar Cell Biological Assay Cell Fate Control Cells Cessation of life Clinical Coculture Techniques Communication Coupled Data Disease Ectopic Expression Epithelial Cells Equilibrium Experimental Models Extracellular Matrix Fibroblasts Fibrosis Future Gases Genetic Genetic Transcription Goals Histologic Homeostasis Human Impairment In Vitro Injury Interstitial Lung Diseases Lead Ligands Lung Lung Transplantation Mediating Mesenchymal Modeling Molecular Mus Myofibroblast Natural regeneration Outcome PDGFA gene PDGFRA gene Pathogenesis Pathologic Pharmacology Population Pulmonary Fibrosis Quality of life RUNX1 gene Recurrence Regenerative Medicine Serum Signal Transduction Signaling Molecule Slice Specimen Testing Therapeutic Tissues Transcriptional Regulation Transforming Growth Factor beta United States Work alveolar epithelium alveolar homeostasis base clinically relevant design effective therapy epithelial injury fibrogenesis fibrotic lung genome wide association study improved in vivo injury and repair loss of function lung regeneration mouse model novel novel therapeutics prevent programs pulmonary function receptor response single-cell RNA sequencing therapeutic development transcription factor transcriptome

项目摘要

SUMMARY Recurrent alveolar injury and dysregulated signaling in alveolar cell niche have been implicated in the pathogenesis of pulmonary fibrosis. While genome-wide association studies further supported this model, the precise cellular triggers and the molecular mechanisms that drive alveolar fibroblasts replication and their conversion into excessive extracellular matrix producing myofibroblasts remain elusive. Currently we lack a comprehensive understanding of the cell intrinsic and extrinsic homeostatic mechanisms that normally control fibroblasts replication and prevent their conversion into pathological myofibroblasts. Our recent finding that either conditional ablation of alveolar epithelial type-1 (AT1) cells, or loss of Pdgfra specifically in PDGFRA-expressing fibroblasts (alveolar fibroblasts) in vivo, results in spontaneous conversion of alveolar fibroblasts into myofibroblasts and fibrosis. Single cell transcriptome guided ligand-receptor pair predictions coupled with alveolar fibroblast cultures in serum-free conditions suggest that AT1 cell-derived PDGFA is required in proper amounts to both maintain alveolar fibroblasts identity (i.e., prevent their conversion to myofibroblasts) and control replication. Exploring downstream mechanisms, we have uncovered an increase in the expression of the transcription factor RUNX1 in both replicating alveolar fibroblasts as well as TGFβ- induced myofibrogenesis both in vivo and ex vivo. Significantly, our preliminary data also indicate that genetic loss of Runx1 abrogates PDGFA or TGFβ-induced alveolar fibroblasts proliferation or conversion into myofibroblasts, respectively. These preliminary data lead us to hypothesize that AT1 cells maintain alveolar fibroblasts identity via PDGFA – PDGFRA signaling axis and that a fine balance in the amount of PDGFA is essential for fibroblast quiescence and replication at homeostasis and injury repair. We also hypothesize that RUNX1 is an essential regulator of both PDGFRA and TGFβ signaling to regulate replication and myofibrogenic programs in alveolar fibroblasts during regeneration and fibrosis. The major objectives of this proposal are to define the communication between AT1 cells and alveolar fibroblasts and to study transcriptional control of myofibrogenesis. In Aim1, we will test the hypothesis that PDGFA-PDGFRA signaling between AT1 cells and alveolar fibroblasts is essential for alveolar homeostasis. In Aim2, we will determine context specific functions of RUNX1 in alveolar fibroblasts replication and myofibrogenesis. We will use novel in vivo genetic mouse models and pharmacological loss-of-function models, human lung fibroblasts and precision cut lung slice cultures, and molecular assays to study these specific aims. Our prior expertise in lung regeneration and transcriptional control of cell fates will aid us in studying the proposed aims. The outcomes from the proposed studies will have broader impact on lung regenerative medicine and will form the basis for development of therapeutics to prevent and reverse human lung fibrosis.

概括反复的肺泡损伤和肺泡细胞生态位中的信号失调与虽然全基因组关联研究进一步支持了这一模型，但精确的细胞触发因素和驱动肺泡成纤维细胞复制的分子机制及其转化为产生过多细胞外基质的肌成纤维细胞仍然难以捉摸。全面了解通常控制的细胞内在和外在稳态机制成纤维细胞复制并防止其转化为病理性肌成纤维细胞。我们最近发现，要么有条件地消融 1 型肺泡上皮 (AT1) 细胞，要么损失 Pdgfra 特别是在体内表达 PDGFRA 的成纤维细胞（肺泡成纤维细胞）中，导致自发转化肺泡成纤维细胞转化为肌成纤维细胞和纤维化。与无血清条件下的肺泡成纤维细胞培养相结合的预测表明，AT1 细胞衍生的需要适量的 PDGFA 来维持肺泡成纤维细胞的特性（即防止其转化）肌成纤维细胞）和控制复制，我们发现了增加。复制型肺泡成纤维细胞和 TGFβ- 中转录因子 RUNX1 的表达值得注意的是，我们的初步数据也表明遗传。 Runx1 的缺失会消除 PDGFA 或 TGFβ 诱导的肺泡成纤维细胞增殖或转化为这些初步数据使我们发现 AT1 细胞维持肺泡的功能。通过 PDGFA – PDGFRA 信号轴识别成纤维细胞，并实现 PDGFA 数量的良好平衡对于成纤维细胞的稳态和复制以及损伤修复至关重要。 RUNX1 是 PDGFRA 和 TGFβ 信号传导的重要调节因子再生和纤维化过程中肺泡成纤维细胞的复制和肌纤维形成程序。该提案的主要目标是定义 AT1 细胞和肺泡之间的通信成纤维细胞并研究肌纤维形成的转录控制。在 Aim1 中，我们将检验以下假设： AT1 细胞和肺泡成纤维细胞之间的 PDGFA-PDGFRA 信号传导对于肺泡稳态至关重要。目标2，我们将确定 RUNX1 在肺泡成纤维细胞复制和我们将使用新型体内遗传小鼠模型和药理学功能丧失模型，人类肺成纤维细胞和精确切割的肺切片培养物以及分子研究这些特定的目的。我们之前在肺再生和细胞命运转录控制方面的专业知识将帮助我们研究拟议的拟议研究的结果将对肺再生医学产生更广泛的影响。构成开发预防和逆转人类肺纤维化疗法的基础。