Project description:The pulmonary alveolar epithelium which play key role in lung biological function is mainly composed of two types of epithelial cells: alveolar type I (AT1) and type II (AT2) cells. We know very little about developmental heterogeneity of the AT1 cell population. By using 10X genomics “Chromium Single Cell” technology, we performed single-cell RNA-seq (scRNA-seq) analyses of AT1 cells at postnatal day 3 (P3), P15, and P60, along with AT2 cells (P60) in mice. Our study identified a robust new genetic marker (Igfbp2) of postnatal AT1 cells. The study also provided the transcriptome information of AT1 cells during alveologensis.
Project description:Pulmonary alveolar microlithiasis is an autosomal recessive lung disease caused by a deficiency in the pulmonary epithelial Npt2b sodium-phosphate co-transporter that results in accumulation of phosphate and formation of hydroxyapatite microliths in the alveolar space. The single cell transcriptomic analysis of a pulmonary alveolar microlithiasis lung explant showing a robust osteoclast gene signature in alveolar monocytes and the finding that calcium phosphate microliths contain a rich protein and lipid matrix that includes bone resorbing osteoclast enzymes and other proteins suggested a role for osteoclast-like cells in the host response to microliths. While investigating the mechanisms of microlith clearance, we found that Npt2b modulates pulmonary phosphate homeostasis through effects on alternative phosphate transporter activity and alveolar osteoprotegerin, and that microliths induce osteoclast formation and activation in a receptor activator of nuclear factor kappa B (NF-kB) ligand and dietary phosphate dependent manner. This work reveals that Npt2b and pulmonary osteoclast like cells play key roles in pulmonary homeostasis and suggest potential new therapeutic targets for the treatment of lung disease.
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.
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.
Project description:Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and emphysema development, associated with enhanced tissue destruction and defective repair. Supporting cells in the alveolar niche play a crucial role in guiding the activation of alveolar epithelial progenitor cells during repair. Despite their close anatomical proximity, understanding of the supportive role of the pulmonary microvascular endothelium in adult alveolar epithelial repair remains limited. We hypothesized that angiocrine factors secreted by pulmonary endothelial cells support alveolar epithelial cell growth. Here, we report that human pulmonary microvasculature endothelial cells (HPMECs) support murine and human alveolar organoid formation through paracrine signaling via the secretion of extracellular vesicles and soluble factors. Transcriptomic and proteomic analysis pinpointed HPMEC-derived bone morphogenetic protein 6 (BMP6) as a critical factor for alveolar organoid formation. BMP6 deficiency was associated with reduced Wnt signaling and augmented oxidative stress signaling in murine lung tissue. Furthermore, BMP6 promoted alveolar epithelial cell growth, whereas function-blocking antibodies targeting BMP6 inhibited the beneficial effect of endothelial cells on murine alveolar organoid formation. Taken together, our findings highlight BMP6 as a key regulator of adult epithelial repair and suggest its potential as a therapeutic target for lung repair, particularly in individuals with COPD.
Project description:The pulmonary alveolar epithelium mainly composed of two types of epithelial cells: alveolar type I (AT1) and type II (AT2) cells. AT2 cells are the alveolar stem cells, and can differentiate into AT1 cells post-pneumonectomy (PNX). Here, we found that, compared with control mice (Sftpc-CreER; Cdc42flox/+; Rosa26-mTmG) at post-PNX day 21, Cdc42 AT2 null mice (Sftpc-CreER; Cdc42flox/-; Rosa26-mTmG) at post-PNX day 21 undergone fibrotic change. By using 10X genomics “Chromium Single Cell” technology, we performed single-cell RNA-seq analyses of AT2 cells of sham treated control mice (C0), AT2 cells of control mice at post PNX day 21 (C21) , AT2 cells of sham treated Cdc42 AT2 null mice (N0), and AT2 cells of Cdc42 AT2 null mice at post PNX day 21 (N21). The study identified a specific gene signature in AT2 cells of Cdc42 AT2 null mice at post PNX day 21 which is related to the fibrosis phenotype of Cdc42 AT2 null mice.
Project description:Pulmonary alveolar microlithiasis is an autosomal recessive lung disease caused by a deficiency in the pulmonary epithelial Npt2b sodium-phosphate co-transporter that results in accumulation of phosphate and formation of hydroxyapatite microliths in the alveolar space. The single cell transcriptomic analysis of a pulmonary alveolar microlithiasis lung explant showing a robust osteoclast gene signature in alveolar monocytes and the finding that calcium phosphate microliths contain a rich protein and lipid matrix that includes bone resorbing osteoclast enzymes and other proteins suggested a role for osteoclast-like cells in the host response to microliths. While investigating the mechanisms of microlith clearance, we found that Npt2b modulates pulmonary phosphate homeostasis through effects on alternative phosphate transporter activity and alveolar osteoprotegerin, and that microliths induce osteoclast formation and activation in a receptor activator of nuclear factor kappa B (NF-kB) ligand and dietary phosphate dependent manner. This work reveals that Npt2b and pulmonary osteoclast like cells play key roles in pulmonary homeostasis and suggest potential new therapeutic targets for the treatment of lung disease.
Project description:<p>Pulmonary fibrosis is a heterogenous syndrome in which fibrotic scar replaces normal lung tissue. We performed massively parallel single-cell RNA-Seq on lung tissue from eight lung transplant donors and eight patients with pulmonary fibrosis. Combined with in situ RNA hybridization, with amplification, these data provide a molecular atlas of disease pathobiology. We identified a distinct, novel population of profibrotic alveolar macrophages exclusively in patients with fibrosis. Within epithelial cells, the expression of genes involved in Wnt secretion and response was restricted to non-overlapping cells. We identified rare cell populations including airway stem cells and senescent cells emerging during pulmonary fibrosis. Analysis of a cryobiopsy specimen from a patient with early disease supports the clinical application of single-cell RNA-Seq to develop personalized approaches to therapy.</p>
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.