Regulation of the Alveolar Epithelial Transitional State in Murine and Human Pulmonary Fibrosis
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE223302 | GEO | 2023/10/18
REPOSITORIES: GEO
Similar Datasets
Project description:Many lung diseases result from a failure of efficient regeneration of damaged alveolar epithelial cells (AECs) after lung injury. During regeneration, AEC2s proliferate to replace lost cells, after which proliferation halts and some AEC2s transdifferentiate into AEC1s to restore normal alveolar structure and function. Although the mechanisms underlying AEC2 proliferation have been studied, the mechanisms responsible for halting proliferation and inducing transdifferentiation are poorly understood. To identify candidate signaling pathways responsible for halting proliferation and inducing transdifferentiation, we performed single cell RNA sequencing on AEC2s during regeneration in a murine model of lung injury induced by intratracheal LPS. Unsupervised clustering revealed distinct subpopulations of regenerating AEC2s: proliferating, cell cycle arrest, and transdifferentiating. Gene expression analysis of these transitional subpopulations revealed that TGFβ signaling was highly upregulated in the cell cycle arrest subpopulation and relatively downregulated in transdifferentiating cells. In cultured AEC2s, TGFβ was necessary for cell cycle arrest but impeded transdifferentiation. We conclude that during regeneration after LPS-induced lung injury, TGFβ is a critical signal halting AEC2 proliferation but must be inactivated to allow transdifferentiation. This study provides insight into the molecular mechanisms regulating alveolar regeneration and the pathogenesis of diseases resulting from a failure of regeneration.
2019-03-27 | GSE113049 | GEO
Project description:Interstitial lung diseases (ILDs) such as idiopathic pulmonary fibrosis (IPF) is diffuse parenchymal lung disorders characterized by varying degrees of inflammation and fibrosis of the lung interstitium. The failure of lung alveolar regeneration in IPF is critical for this incurable disease. Here we report that chronic lung injury causes a profibrotic phenotype of alveolar macrophages that release extracellular vehicles (EVs) to promote PF development through repressing the stemness traits of type 2 alveolar epithelial cells (AEC2s). We found that an increased expression of acetylases KAT5 interacts with and acetylates protein kinase MLKL, which directly promotes release of EVs from AMs following chronic lung injury. AEC2s takes up the EVs and releases miR-148a-3p to repress expression of endogenous b-catennin agonist Wnt10b and alveolar regeneration. Pharmacologic inhibition of the miR-148a-3p expression or interruption of the KAT5-MLKL interaction restores regenerative capacity of AEC2s and exhibits potent therapeutic efficacy against PF. Our study confers a potential strategy for the treatment of IPF and other interstitial lung diseases.
2023-09-01 | GSE184147 | GEO
Project description:Idiopathic Pulmonary Fibrosis (IPF) is a progressive and often fatal chronic respiratory disease thought to result from repetitive injury and failed repair of the lung alveoli, and recent studies have identified a number of disease-emergent intermediate/transitional cell states in the IPF lung supporting this concept. In this study, we found that persistent activation of hypoxia-inducible factor (HIF)-signaling in airway-derived, repair-associated cell types/states is a hallmark of dysfunctional epithelial repair in the IPF lung epithelium and experimental models of recurrent lung epithelial injury. Disrupting Hif-signaling attenuated experimental lung fibrosis, reduced mucous-secretory cell polarization, and promoted functional alveolar regeneration following repetitive injury. Mouse and human organoid studies demonstrated that small-molecule-based HIF2 inhibition promoted alveolar epithelial cell proliferation and maturation while preventing the emergence of maladaptive intermediate/transitional states analogous to those in IPF. Together, these studies indicate that targeted HIF2-inhibition represents a novel and effective therapeutic strategy to promote functional lung regeneration, and could be readily translated into human studies of IPF and other chronic interstitial lung diseases with disease modifying effect.
2023-09-18 | GSE243252 | GEO
Project description:Gas exchange in the mammalian lung occurs in the alveolar sacs lined by epithelial cells that form a barrier allowing effective oxygen diffusion. Telomere syndromes have their most common manifestation in degenerative disease of the alveoli, both pulmonary fibrosis and emphysema. We tested the role of telomere dysfunction by inducing deletion of the telomere binding protein Trf2 in type 2 alveolar epithelial cells (AEC2s) that both express the gene encoding surfactant protein C and constitute the regenerative compartment of the alveolar epithelium. Acquired telomere dysfunction in these cells preferentially induced cellular senescence, and mouse lungs were marked by an inflammatory response even though the telomere dysfunction was restricted to the epithelium. Senescent AECs had altered gene expression that differentially fell in inflammatory cell signaling pathways. Bleomycin challenge was uniformly fatal, and Trf2-depleted cells failed to generate clonal alveolar colonies in vitro. The telomere dysfunction response in AEC2s was in part p53-dependent, and we found evidence of a p53-mediated paracrine survival signal to the mesenchyme. These data indicate that telomere dysfunction in the alveolar epithelium limits its regenerative capacity and is sufficient to induce inflammation. It may thus be a primary driving event in telomere-mediated lung disease. Efforts to restore epithelial regenerative capacity may be an effective approach in a subset of fibrosis and emphysema patients. We studied the gene expression changes in adult type II pneumocytes 7 days after deleting Trf2. Mice carried floxed allele of Trf2 and mTmG reporter allele. Type II pneumocytes were collected by FACs sorting GFP+ cells from lungs 7 days after administering tamoxifen. 6 total samples were analysed. Three were from control samples that were heterozygous for Trf2 and three samples had Trf2 deleted.
2015-04-20 | E-GEOD-56892 | biostudies-arrayexpress
Project description:The successful repair of alveolar epithelial injury is required to restore the integrity of gas exchanging regions of the lung and preserve organ function. Severe pulmonary fibrosis is the result of repeated episodes of epithelial injury, activation of fibroblasts, and matrix accumulation. Thus, impaired alveolar epithelial progenitor cell renewal could contribute to the progression of fibrosis. We provide evidence that expression of TLR4 and hyaluronan (HA) on Type 2 alveolar epithelial cells (AEC2s) is necessary for self-renewal. Either deletion of TLR4 or HA synthase 2 leads to impaired regeneration of AEC2s, severe fibrosis and mortality, in part due to blunted production of IL-6. AEC2s from patients with pulmonary fibrosis have reduced cell surface HA, and impaired renewal capacity, suggesting that interactions between HA and TLR4 are key regulators of lung stem cell renewal, repair of lung injury and that severe pulmonary fibrosis is the result of epithelial stem cell failure. We used microarrays to detail the gene expression of AEC2 cells from WT and TLR4-/- mice.
2016-10-03 | GSE68704 | GEO
Project description:Idiopathic pulmonary fibrosis (IPF) is a lethal interstitial lung disease causing alveolar remodeling, inflammation, and fibrosis. We utilized single cell RNA-sequencing (scRNA-Seq) to identify epithelial cell types and associated biological processes involved in the pathogenesis of IPF. Transcriptomic analysis of epithelial cells from normal human lung defined gene expression patterns associated with highly differentiated alveolar type 2 (AT2) cells, indicated by enrichment of RNAs critical for surfactant homeostasis. In contrast, scRNA-seq of IPF cells identified three distinct subsets of epithelial cell types with characteristics of conducting airway basal and goblet cells and, an additional atypical "transitional" cell that contribute to pathological processes in IPF. Individual IPF cells frequently co-expressed alveolar AT1, AT2, and conducting airway selective markers, demonstrating "indeterminate" states of differentiation not seen in normal lung development. Pathway analysis predicted aberrant activation of canonical signaling via TGF-ß, HIPPO/YAP, P53, and AKT-PI3 Kinase. Immunofluorescence confocal microscopy identified the disruption of alveolar structure and loss of the normal proximal-peripheral differentiation of pulmonary epithelial cells. Single cell transcriptomic analyses of respiratory epithelial cells identified loss of normal epithelial cell identities and unique contributions of epithelial cells to the pathogenesis of IPF. Present scRNA-seq transcriptomic analysis of normal and IPF respiratory epithelial cells provides a rich data source to further explore lung health and disease.
2017-02-06 | GSE94555 | GEO
Project description:Idiopathic pulmonary fibrosis (IPF) is a lethal interstitial lung disease causing alveolar remodeling, inflammation, and fibrosis. We utilized single cell RNA-sequencing (scRNA-Seq) to identify epithelial cell types and associated biological processes involved in the pathogenesis of IPF. Transcriptomic analysis of epithelial cells from normal human lung defined gene expression patterns associated with highly differentiated alveolar type 2 (AT2) cells, indicated by enrichment of RNAs critical for surfactant homeostasis. In contrast, scRNA-seq of IPF cells identified three distinct subsets of epithelial cell types with characteristics of conducting airway basal and goblet cells and, an additional atypical "transitional" cell that contribute to pathological processes in IPF. Individual IPF cells frequently co-expressed alveolar AT1, AT2, and conducting airway selective markers, demonstrating "indeterminate" states of differentiation not seen in normal lung development. Pathway analysis predicted aberrant activation of canonical signaling via TGF-ß, HIPPO/YAP, P53, and AKT-PI3 Kinase. Immunofluorescence confocal microscopy identified the disruption of alveolar structure and loss of the normal proximal-peripheral differentiation of pulmonary epithelial cells. Single cell transcriptomic analyses of respiratory epithelial cells identified loss of normal epithelial cell identities and unique contributions of epithelial cells to the pathogenesis of IPF. Present scRNA-seq transcriptomic analysis of normal and IPF respiratory epithelial cells provides a rich data source to further explore lung health and disease.
2016-12-08 | GSE86618 | GEO
Project description:Chronic lung disease is increasing in prevalence and there is urgent need to advance our understanding of human lung biology in order to improve diagnosis and current treatments. The Th2 inflammatory cytokine Interleukin 13 (IL13) has been associated with both obstructive and fibrotic lung diseases, but its specific effect on the epithelial stem cells in the gas exchange compartment of the lung (alveolar space) has not been explored. Here, we use in vivo lung models of homeostasis and repair, ex vivo organoid platforms, and novel quantitative proteomic techniques to show that IL13 can directly disrupt the self-renewal and differentiation of both murine and human type 2 alveolar epithelial cells (AEC2s). We also show that IL13 promotes ectopic expression of markers typically associated with bronchiolar airway cells and commonly seen in the alveolar region of lung tissue from patients with idiopathic pulmonary fibrosis (IPF). Furthermore, we identify a number of proteins that are differentially secreted by AEC2s in response to IL13, suggesting that protein-based biomarkers may identify subsets of patients with pulmonary disease that is driven by “Th2-high” biology. This would allow us to understand some of the biological heterogeneity that exists in patients with chronic lung disease and to identify subsets of patients who may be more likely to respond to targeted anti-IL13 treatments.
2020-06-05 | PXD013006 | Pride
Project description:We applied next-generation sequencing to investigate the gene expression profiles in mouse alveolar epithelial cells (AECs). We identified a number of differentially regulated genes in the AECs of mice with bleomycin induced pulmonary fibrosis and LPS induced acute lung injury.
2018-02-01 | GSE109913 | GEO
Project description:Gas exchange in the mammalian lung occurs in the alveolar sacs lined by epithelial cells that form a barrier allowing effective oxygen diffusion. Telomere syndromes have their most common manifestation in degenerative disease of the alveoli, both pulmonary fibrosis and emphysema. We tested the role of telomere dysfunction by inducing deletion of the telomere binding protein Trf2 in type 2 alveolar epithelial cells (AEC2s) that both express the gene encoding surfactant protein C and constitute the regenerative compartment of the alveolar epithelium. Acquired telomere dysfunction in these cells preferentially induced cellular senescence, and mouse lungs were marked by an inflammatory response even though the telomere dysfunction was restricted to the epithelium. Senescent AECs had altered gene expression that differentially fell in inflammatory cell signaling pathways. Bleomycin challenge was uniformly fatal, and Trf2-depleted cells failed to generate clonal alveolar colonies in vitro. The telomere dysfunction response in AEC2s was in part p53-dependent, and we found evidence of a p53-mediated paracrine survival signal to the mesenchyme. These data indicate that telomere dysfunction in the alveolar epithelium limits its regenerative capacity and is sufficient to induce inflammation. It may thus be a primary driving event in telomere-mediated lung disease. Efforts to restore epithelial regenerative capacity may be an effective approach in a subset of fibrosis and emphysema patients. We studied the gene expression changes in adult type II pneumocytes 7 days after deleting Trf2. Mice carried floxed allele of Trf2 and mTmG reporter allele. Type II pneumocytes were collected by FACs sorting GFP+ cells from lungs 7 days after administering tamoxifen.
2015-04-20 | GSE56892 | GEO