Reprogramming of type 2 alveolar epithelial cells in idiopathic pulmonary fibrosis and regulation by TGFb1.

特发性肺纤维化中 2 型肺泡上皮细胞的重编程及 TGFb1 的调节。

• 批准号: 10821591
• 负责人: Max Louis Cohen
• 金额: $ 4.04万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10821591
• 关键词: Abnormal Cell; Abnormal Epithelial Cell; Adult; Affect; Alveolar; Antibodies; Attenuated; Automobile Driving; Basal Cell; Biochemical Markers; Biopsy; Biopsy Specimen; Cell Differentiation process; Cell Line; Cell Reprogramming; Cells; Cessation of life; Clinical Trials; Coculture Techniques; Critical Care; Cyst; Data; Dependence; Development; Diagnosis; Diagnostic; Disease; Ectopic Expression; Embryo; Epigallocatechin Gallate; Epithelial Cells; Epithelium; Extracellular Matrix; Fellowship; Fibroblasts; Fibrosis; Gene Expression; Gene Expression Profiling; Genes; Human; Immunohistochemistry; In Vitro; Institution; Knowledge; Lung; MUC5B gene; Medicine; Mesenchymal; Mesenchyme; Messenger RNA; Modeling; Monitor; Nature; Operative Surgical Procedures; Organoids; Overlapping Genes; Pathogenesis; Pathway Analysis; Pathway interactions; Patients; Phase; Population; RNA; Regulation; Research; Resources; Role; Sampling; Schedule; Secretory Cell; Signal Pathway; Signal Transduction; Slice; Source; Structure of parenchyma of lung; Surface; System; Testing; Time; Tissues; Transforming Growth Factor beta; Transforming Growth Factors; Transitional Cell; Type II Epithelial Receptor Cell; Undifferentiated; WNT Signaling Pathway; airway epithelium; alveolar epithelium; career; cell type; clinical diagnosis; diagnostic signature; fibrotic interstitial lung disease; fibrotic lung; idiopathic pulmonary fibrosis; in vitro Model; in vivo; inhibitor; insight; lung development; migration; notch protein; programs; repaired; response; self-renewal; single-cell RNA sequencing; surfactant; targeted treatment; tissue culture; transcriptome sequencing; transcriptomics; transdifferentiation

Idiopathic Pulmonary Fibrosis (IPF) is the most common fibrotic interstitial lung disease among adults. The cause of IPF is not fully understood, and it is frequently progressive, often leading to death within several years of diagnosis. In IPF, there is loss of alveolar epithelial cells, including type 1 cells (AEC1s), which line the alveolar airspace surface, and type 2 (AEC2s), which secrete surfactant, self-renew, and give rise to AEC1s and development of honeycomb cysts. These cysts are lined by "bronchiolized" epithelium, so-called because of expression of airway and secretory cell markers such as p63, KRT5, KRT17, and MUC5B. The origin of the cells lining these cysts is not understood, but have generally been thought to be the result of migration of airway epithelial cells (basal and/or club), in a failed attempt at alveolar repair. Recent single-cell RNA (sc-RNA) sequencing studies have uncovered widespread AEC2 and other epithelial cell abnormalities in end-stage IPF tissue, such as intermediate/transitional cell states and ectopic expression of genes associated with airway cells (such as KRT5+ AEC2s). Our lab has recently shown that AEC2s are capable of reprogramming into KRT5+ basal-cell like cells in in vitro organoid cultures. These suggest a new hypothesis that the bronchiolized epithelium lining honeycomb cysts may actually be derived from reprogrammed AEC2s. This study seeks to characterize whether the epithelial abnormalities present in end-stage IPF tissue are also present earlier in the IPF disease course and to determine the role of TGFβ1 in regulating the aforementioned reprogramming. Samples from patients undergoing surgical biopsy for the purpose of clinical diagnosis will be analyzed by sc-RNA sequencing, to characterize the AEC2 and other epithelial cell populations and reconstruct estimated lineages, especially surrounding the induction of the basal-cell differentiation master- regulator Sox2 within AEC2s. These samples will be compared to normal and end-stage IPF tissue, in order to test the hypothesis that AEC2 reprogramming is an early feature of IPF. In addition, diagnostic biopsy samples will be obtained from patients who took epigallocatechin gallate (EGCG) for two weeks prior to biopsy. EGCG is a mesenchyme-specific inhibitor of TGFβ signaling under study in humans and will therefore allow us to examine the hypothesis that AEC2 reprogramming abnormalities seen in diagnostic biopsies can be reversed by TGFβ blockade. Finally, organoid co-cultures and precision-cut lung slices cultures will be used to examine the contribution of important signaling pathways, such as TGFβ, Wnt, and Notch, in driving AEC2 reprograming towards a SPC-/KRT5+ basal-cell like state. Knowledge of the mechanisms driving AEC2 reprograming in IPF may provide fundamental insight into the cause of this disorder and contribute to the development of targeted therapies for this incurable and frequently fatal disease. This proposed project will be performed as part of the research phase of Pulmonary & Critical Care Medicine Fellowship at UCSF and utilizes comprehensive institutional support and resources, in order to prepare the applicant for an independent research career.

特发性肺纤维化（Idiopathic Pulmonary Fibrosis， IPF）是最常见的肺间质性纤维化疾病