ABSTRACT: Epithelial basal cells (BCs) are an important stem cell population of the airways. We purified BCs from a KRT5-GFP transgenic mouse line and used Affymetrix arrays to compare there gene expression to that of non-BC epithelium.
Project description:Epithelial basal cells (BCs) are an important stem cell population of the airways. We purified BCs from a KRT5-GFP transgenic mouse line and used Affymetrix arrays to compare there gene expression to that of non-BC epithelium. Experiment Overall Design: Three populations of cells were obtained by FACS: 1. KRT5-GFP-, lectin- columnar epithelium. 2. KRT5-GFP-, lectin+ BCs. 3. KRT5-GFP+, lectin+ BCs. Three biological replicates of each sample were hybridized to Affymetrix microarray.
Project description:Airway remodelling in chronic obstructive pulmonary disease (COPD) originates, in part, from smoking-induced changes in airway basal stem/progenitor cells (BCs). Based on the knowledge that bone morphogenetic protein 4 (BMP4) influences epithelial progenitor function in the developing and adult mouse lung, we hypothesised that BMP4 signalling may regulate the biology of adult human airway BCs relevant to COPD. BMP4 signalling components in human airway epithelium were analysed at the mRNA and protein levels, and the differentiation of BCs was assessed using the BC expansion and air-liquid interface models in the absence/presence of BMP4, BMP receptor inhibitor and/or small interfering RNAs against BMP receptors and downstream signalling.
Project description:Airway remodelling in chronic obstructive pulmonary disease (COPD) originates, in part, from smoking-induced changes in airway basal stem/progenitor cells (BCs). Based on the knowledge that bone morphogenetic protein 4 (BMP4) influences epithelial progenitor function in the developing and adult mouse lung, we hypothesised that BMP4 signalling may regulate the biology of adult human airway BCs relevant to COPD. BMP4 signalling components in human airway epithelium were analysed at the mRNA and protein levels, and the differentiation of BCs was assessed using the BC expansion and air-liquid interface models in the absence/presence of BMP4, BMP receptor inhibitor and/or small interfering RNAs against BMP receptors and downstream signalling.
Project description:The conducting airway epithelium of the rodent and human lung is made up of about equal proportions of ciliated and secretory cells. In addition, in regions where the epithelium is pseudostratfied, ~30% of the epithelium consists of undifferentiated basal cells (BCs). Evidence suggests that these BCs are multipotent stem cells that can self renew over the long term and give rise to both ciliated and secretory lineages. The goal of this project is to identify cellular and molecular mechanisms by which the basal cells normally maintain the epithelium and repair it after injury. We used Affymetrix microarray analysis to compare transcripts in tracheal epithelium before and after SO2 injury.
Project description:The conducting airway epithelium of the rodent and human lung is made up of about equal proportions of ciliated and secretory cells. In addition, in regions where the epithelium is pseudostratfied, ~30% of the epithelium consists of undifferentiated basal cells (BCs). Evidence suggests that these BCs are multipotent stem cells that can self renew over the long term and give rise to both ciliated and secretory lineages. The goal of this project is to identify cellular and molecular mechanisms by which the basal cells normally maintain the epithelium and repair it after injury. We used Affymetrix microarray analysis to compare transcripts in tracheal epithelium before and after SO2 injury. Mice tracheal epithelium and mesenchyme were separate for RNA extraction before and 48hrs after SO2 injury. Cells from tracheas of 4 male C57Bl/6 mice were pooled for each biological experiment. The experiments were repeated three times for triplicate samples.
Project description:KRT5+P63+ progenitor cells located in the basal layer of the airway epithelium have been identified as a promising candidate for lung epithelium repair. Such cells are originated from primitive progenitors in distal airways and could expand/migrate to inflamed damaged lung parenchymal region to form ‘saccule’. To further investigate the characteristics and potential function of the saccule structure, we performed the high-resolution spatial transcriptomic analysis on the 35 dpt lung section.
Project description:The Vomeronasal organ (VNO) is a part of the accessory olfactory system, which is responsible for detecting pheromones, chemical factors that trigger a spectrum of sexual and social behaviors. The vomeronasal epithelium (VNE) shares several features with the epithelium of the main olfactory epithelium (MOE). However, it is a distinct neuroepithelium populated by chemosensory neurons that differ from the olfactory sensory neurons (OSNs) in cellular structure, receptor expression, and connectivity. The vomeronasal organ of rodents comprises a sensory epithelium and a thin nonsensory epithelium that morphologically resembles the respiratory epithelium. Sox2-positive cells have been previously identified as the stem cell population that gives rise to neuronal progenitors in MOE and VNE. In addition to these, the MOE also comprises p63 positive horizontal basal cells (HBCs), a second pool of quiescent stem cells that become active in response to injury. Immunolabeling against the transcription factor p63, Keratin-5 (Krt5), Krt14 and Krt5Cre tracing experiments highlighted the existence of horizontal basal cells distributed along the basal lamina of the VNO forming from progenitors along the basal lamina oft the marginal zones. Moreover, these experiments revealed that the NSE of rodents is, like the respiratory epithelium, a stratified epithelium where the p63/Krt5+ basal cells self-replicate and give rise to the apical columnar cells facing the lumen of the VNO.
Project description:Rationale: Genome-wide association studies (GWAS) and candidate gene studies have identified a number of loci linked to susceptibility of chronic obstructive pulmonary disease (COPD), a smoking-related disorder that originates in the airway epithelium. Objectives: Since airway basal cell (BC) stem/progenitor cells exhibit the earliest abnormalities associated with smoking (hyperplasia, squamous metaplasia), we hypothesized that smoker BC have a dysregulated transcriptome linked, in part, to known GWAS/candidate gene loci. Methods: Massive parallel RNA sequencing was used to compare the transcriptome of BC purified from the airway epithelium of healthy nonsmokers (n=10) and smokers (n=7). The chromosomal location of the differentially expressed genes was compared to loci identified by GWAS and candidate gene studies to confer risk for COPD. Measurements and Main Results: Smoker BC have 676 known genes differentially expressed compared to nonsmoker BC, dominated by smoking up-regulation. Strikingly, 166 (25%) of these genes are located on chromosome 19, with 13 localized to 19q13.2 (p<10-4 compared to chance), including TGFB1, LTBP4, EGLN2 and NFKBIB, genes associated with risk for COPD. Conclusions: These observations provide the first direct link of known genetic risks for smoking-related lung disease with the specific population of lung cells that undergoes the earliest changes associated with smoking. The human airway basal cell transcriptome of 7 smokers versus 10 nonsmokers was compared using massive parallel RNA sequencing (Illumina HiSeq 2000).
Project description:Airway basal cells (BC) function as progenitor cells capable of differentiating into ciliated and secretory cells to replenish the airway epithelium during physiological turnover and repair. The objective of this study was to define the role of Notch signaling in regulating human airway BC differentiation into a pseudostratified mucociliated epithelium. Notch inhibition with γ-secretase inhibitors demonstrated Notch activation is essential for BC differentiation into secre-tory cells and ciliated cells, but more so for the secretory lineage. Sustained Notch activation via lentivirus expression of the intracellular domain of each Notch receptor (NICD1-4) demonstrated that the Notch 2 and 4 pathways have little effect on BC differentiation, while activation of the Notch1 or 3 pathways has a major influence, with persistent expression of NICD1 or 3 resulting in a skewing toward secretory cell differentiation with a parallel decrease in ciliated cell differentiation. These observations provide insights into the control of the balance of BC differentiation into the secretory vs ciliated cell lineage, a balance that is critical for maintaining the normal function of the airway epithelium in barrier defense against the inhaled environment. Array-based expression profiling of the Notch signaling pathway genes specifically in human airway basal cells.
Project description:The pathology of chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis and the majority of lung cancers involve the small airway epithelium (SAE), the single continuous layer of cells lining the airways ?6th generations. The basal cells (BC) are the stem/progenitor cells of the SAE, responsible for the differentiation into intermediate cells and ciliated, club and mucous differentiated cells. To facilitate the study of the biology of the human SAE in health and disease, we immortalized and characterized a normal human SAE basal cell line. The immortalized hSABC-NS1.1 cell line has diverse differentiation capacities and retains SAE features, which will be useful for understanding the biology of SAE, the pathogenesis of SAE-related diseases, and testing new pharmacologic agents.