Gene expression profiling of Scgb1a1+, CD24low cells isolated from the lungs of Scgb1a1-CreER; Rosa26-mTmG mouse.
Ontology highlight
ABSTRACT: We established a new method to find out subpopulation of lung epithelial stem cells, named scMORN, and uncovered the existence of Club cell subpopulations contributing to alveolar regeneration. We isolated entire Club cells by sorting Scgb1a1+, CD24low cells from the lungs of Scgb1a1-CreER; Rosa26-mTmG mouse. The gene expression profiling revealed that two genetically distinct types of Club cells.
Project description:We uncovered an essential role of radiationtherapy (RT)-activated lung residential Scgb1a1+ club cells in synergizing efficacy of immuno-checkpoint inhibitors. We explored the mechanisms underlying RT by analyzing the differentially-regulated genes in tumor micro-environment.
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:Gene expression patterns of bronchiolar progenitors and club cells in mouse lung were examined by microarray experiments. Although it has not yet been fully characterized, a subset of epithelial cells lining bronchioles are best understood as bronchiolar progenitors that self-renew over the long term and that can differentiate into more differentiated club cells and ciliated cells. The bronchiolar progenitors are distinct from club cells and characteristically express the alveolar type 2 cell marker, prosurfactant protein C, with lower levels of club cell secretory protein/Scgb1a1. There are also functional differences between them; while club cells can be depleted by naphthalene because of the abundance of cytochrome P450 enzyme Cyp2f2, bronchiolar progenitors are resistant to naphthalene-induced depletion because of defects in the enzyme.
Project description:Alveolar macrophage (AM) is a mononuclear phagocyte key to the defense against respiratory infections. To understand AM’s role in airway disease development, we examined the influence of Secretoglobin family 1a member 1 (SCGB1A1), a pulmonary surfactant protein, on AM development and function. In a murine model, high-throughput RNA-sequencing and gene expression analyses were performed on purified AMs isolated from mice lacking in Scgb1a1 gene and were compared with that from mice expressing wild type Scgb1a1 at weaning (4wk), puberty (8wk), early adult (12wk) and middle age (40wk). AMs from early adult mice under Scgb1a1 sufficiency demonstrated a total of 37 upregulated biological pathways compared to that at weaning, from which 30 were directly involved with antigen presentation, anti-viral immunity and inflammation. Importantly, these pathways under Scgb1a1 deficiency were significantly downregulated compared to that in the age-matched Scgb1a1-sufficient counterparts. Furthermore, AMs from Scgb1a1-deficient mice showed an early activation of inflammatory pathways compared with that from Scgb1a1-sufficient mice. Our in vitro experiments with AM culture established that exogenous supplementation of SCGB1a1 protein significantly reduced AM responses to microbial stimuli where SCGB1a1 was effective in blunting the release of cytokines and chemokines (including IL-1b, IL-6, IL-8, MIP-1a, TNF-a and MCP-1). Taken together, these findings suggest an important role for Scgb1a1 in shaping AM-mediated inflammation and immune responses, and in mitigating cytokine surges in the lungs.
Project description:Basal cells (BC) are the resident stem/progenitor cells of the adult pseudostratified airway epithelium, whose differentiation program is orchestrated by the NOTCH signaling pathway. NOTCH3 receptor mediated signaling regulates BC to club cell differentiation; however, the downstream responses that regulate this process are largely unknown. In the present study we utilized an in vitro air-liquid interface model of the human pseudostratified airway epithelium to identify the NOTCH3-dependent downstream genes/pathways that regulate human BC to club cell differentiation. Activation of NOTCH3 signaling in BC via lentivirus-mediated over-expression of the active NOTCH3 intracellular domain (NICD3) promoted club cell differentiation. Bulk RNA-seq analysis of control vs NICD3 -transduced cells, identified 692 NICD3 responsive genes enriched for pathways linked to airway epithelial biology and differentiation including Wnt/β-catenin Signaling. Expression of the classical NOTCH target HEYL increased in response to NOTCH3 activation and positively correlated with the club cell marker SCGB1A1. Further, using single-cell RNA-seq, we report that HEYL+ cells primarily clustered with SCGB1A1+ and NOTCH3+ cells. Moreover, HEYL protein co-localized with SCGB1A1 in ALI cultures in vitro and in the human and mouse airway epithelium in vivo. siRNA-mediated knockdown of HEYL in BC led to changes in epithelial structure including altered morphology and significant reductions in transepithelial electrical resistance and expression of tight junction related genes. Finally, HEYL knockdown significantly reduced the number of SCGB1A1+ club cells, along with a corresponding increase in KRT8+ BC-intermediate cells. Overall, our data identifies NOTCH3-HEYL signaling as a key regulator of BC to club cell differentiation.
Project description:Basal cells (BC) are the resident stem/progenitor cells of the adult pseudostratified airway epithelium, whose differentiation program is orchestrated by the NOTCH signaling pathway. NOTCH3 receptor mediated signaling regulates BC to club cell differentiation; however, the downstream responses that regulate this process are largely unknown. In the present study we utilized an in vitro air-liquid interface model of the human pseudostratified airway epithelium to identify the NOTCH3-dependent downstream genes/pathways that regulate human BC to club cell differentiation. Activation of NOTCH3 signaling in BC via lentivirus-mediated over-expression of the active NOTCH3 intracellular domain (NICD3) promoted club cell differentiation. Bulk RNA-seq analysis of control vs NICD3 -transduced cells, identified 692 NICD3 responsive genes enriched for pathways linked to airway epithelial biology and differentiation including Wnt/β-catenin Signaling. Expression of the classical NOTCH target HEYL increased in response to NOTCH3 activation and positively correlated with the club cell marker SCGB1A1. Further, using single-cell RNA-seq, we report that HEYL+ cells primarily clustered with SCGB1A1+ and NOTCH3+ cells. Moreover, HEYL protein co-localized with SCGB1A1 in ALI cultures in vitro and in the human and mouse airway epithelium in vivo. siRNA-mediated knockdown of HEYL in BC led to changes in epithelial structure including altered morphology and significant reductions in transepithelial electrical resistance and expression of tight junction related genes. Finally, HEYL knockdown significantly reduced the number of SCGB1A1+ club cells, along with a corresponding increase in KRT8+ BC-intermediate cells. Overall, our data identifies NOTCH3-HEYL signaling as a key regulator of BC to club cell differentiation.
Project description:Club (“Clara”) cells, dome shaped cells with disease cytoplasmic granules and microvilli, are the major secretory cell of the human small (>6 generation) airways. Little is known regarding the biology of club cells in the human airway, nor of the ontogeny of this cell type. Taking advantage of the SCGB1A1 as the marker for club cells and our ability to sample the normal small airway epithelium by bronchoscopy and brushing healthy volunteers, we defined the transcriptome of the normal human airway club cell using single cell transcriptome sequencing. Analysis of the human small airway epithelial single cell transcriptome together with in vitro validation provides novel insights into the molecular phenotype and biological functions of the human club cell population and identifies the basal cell as the human progenitor cells for club cells.