ABSTRACT: Proper lung development and function maintenance depend on the cross-talk between resident immune cell populations and lung epithelial cells. However, understanding the underlying cellular and molecular mechanisms are difficult to study in human. Here, we present a method to develop macrophage-containing alveolar organoids from human pluripotent stem cells to investigate reciprocal interactions between alveolar macrophages and epithelial cells in lung development.
Project description:Proper lung development and function maintenance depend on the cross-talk between resident immune cell populations and lung epithelial cells. However, understanding the underlying cellular and molecular mechanisms are difficult to study in human. Here, we present a method to develop macrophage-containing alveolar organoids from human pluripotent stem cells to investigate reciprocal interactions between alveolar macrophages and epithelial cells in lung development.
Project description:In fibrotic lung, upregulation of p53 signaling in alveolar epithelium is observed. Then, we performed p53 ChIP-seq using alveolar organoids to investigate genes directly targeted by p53 protein in bleomycin-treated p53-upregulated alveolar epithelial cells.
Project description:We developed an in vitro model of pulmonary fibrosis using alveolar organoids, consisting of human induced pluripotent stem cell-derived alveolar epithelial cells and human lung fibroblasts. In this model, fibroblasts were activated by bleomysin (BLM) treatment in an epithelial cell-dependent manner simillar to the pathogenic mechanism of pulmonary fibrosis.
Project description:Disseminated cancer cells reside in the lung alveolar niche where they are exposed to interactions with alveolar macrophages. Here we report bulk RNA-sequencing data from co-cultured MMTV-HER2 mammary early lesion cells or mammary primary tumor cells cultured with lung alveolar macrophages. We discovered reciprocal regulation between mammary cells and alveolar macrophages, where early lesion cells instruct alveolar macrophages to maintain an anti-tumor phenotype and alveolar macrophages activate an epithelial to mesenchymal program in early lesion cells. Coveresely, primary tumor cells activate inflammatory prorgams in alveolar macrophages, while alveolar macrophages are not able to activate growth restriction programs in primary tumor cells. Receptor-ligand analysis highlighted two known pathways invovled in quiencesce, namely the TGF-beta pathway and the OSM pathway.
Project description:Idiopathic pulmonary fibrosis (IPF) is the prototypic progressive fibrotic lung disease with a median survival of 2-4 years. Injury to and/or dysfunction of alveolar epithelium are strongly implicated in IPF disease initiation, but what factors determine why fibrosis progresses rather than normal tissue repair occurs remain poorly understood. We previously demonstrated that ZEB1-mediated epithelial-mesenchymal transition (EMT) in human alveolar epithelial type II (ATII) cells augments TGF-β-induced profibrogenic responses in underlying lung fibroblasts by paracrine signalling. Here we investigated bi-directional epithelial-mesenchymal crosstalk and its potential to drive fibrosis progression. RNA sequencing (RNA-seq) of lung fibroblasts exposed to conditioned media from ATII cells undergoing RAS-induced EMT identified many differentially expressed genes including those involved in cell migration and extracellular matrix (ECM) regulation. We confirmed that paracrine signalling between AS-activated ATII cells and fibroblasts augmented fibroblast recruitment and demonstrated that this involved a ZEB1-tissue plasminogen activator (tPA) axis. In a reciprocal fashion, paracrine signalling from TGF-β-activated lung fibroblasts or IPF fibroblasts induced RAS activation in ATII cells, at least partially via the secreted protein, SPARC. Together these data identify that aberrant bi-directional epithelial-mesenchymal crosstalk in IPF drives a chronic feedback loop that maintains a wound-healing phenotype and provides self-sustaining pro-fibrotic signals.
Project description:We developed an in vitro model of pulmonary fibrosis using alveolar organoids, consisting of human induced pluripotent stem cell-derived alveolar epithelial cells and human lung fibroblasts. In this model, fibroblasts were activated by bleomysin (BLM) treatment in an epithelial cell-dependent manner simillar to the pathogenic mechanism observed in pulmonary fibrosis.