Project description:Background: Basal cells within the human airway epithelium constitute the stem/progenitor cells for other epithelial cell types. Basal cells respond to mucosal injury and damage to the airway mucosa in an ordered sequence of spreading, migration, proliferation and phenotype shifting (differentiation) to other needed cell types. However, dynamic gene transcription in the early events of injury and repair has not been examined in these cells. Methodology and findings: Airway epithelial cells were obtained from donated lungs and grown in submersion culture on pliable membranes to obtain a pure population of basal cells. Microarrays were used to assess the transcriptome of basal cells 8 and 24 hr after mechanical injury (MI), or to cyclic stretch (CS) in a Flexcell system (0.5 Hz, 20% distension), or both treatments. We identified 121 signature genes with > 2-fold higher differential expression (DE) 8 hr after MI; expression of nearly all of these genes returned to baseline at 24 hr after injury. In cells subjected to CS, little change in DE was noted at 8 hr, whereas at 24 hr a CS signature of 1430 DE genes were identified. The MI signature was characterized by genes encoding growth factor receptors related to the EGF pathway, IL-6, IL-8 and IL-33, extracellular matrix components, and NF-kB and p38-MAPK signaling pathways, whereas the CS signature was characterized by a broad range of genes that did not identify specific signaling pathways. Combined MI and CS at 8 hr elicited DE of down-regulated genes not seen with either stimulus alone, and at 24 hr elicited DE that was similar to that seen with CS alone. Conclusion and significance: The human airway basal epithelial cell transcription signature in the first hours after MI, after CS, and after both stimuli identifies unique differentially expressed genes and pathways that may be important in the early molecular response and biology to airway injury. Total RNA obtained from primary (AEC) and differentiated (dAEC) human airway epithelial cells subjected to 8 or 24 hours in vitro mechanical or cyclic stretch or both injuries compared to sham control as well as to type of injury. Cells were collected from four donated lungs and cultured separated in submission or air liquid interface condition prior to injury for various durations.

Project description:Background. The human airway epithelium consists of 4 major cell types: ciliated, secretory, columnar and basal cells. During natural turnover and in response to injury, the airway basal cells function as stem / progenitor cells for the other airway cell types. The objective of this study is to better understand basal cell biology by defining the subset of expressed genes that characterize the signature of human airway epithelial basal cells. Methodology / Principal Findings. Microarrays were used to assess the transcriptome of basal cells purified from the airway epithelium of healthy nonsmokers obtained by bronchial brushings in comparison to the transcriptome of the complete differentiated airway epithelium. This analysis identified the “human airway basal cell signature” as 1,161 unique genes with >5-fold higher expression level in basal cells compared to the differentiated epithelium. The basal cell signature was suppressed when the basal cells differentiated into a ciliated airway epithelium in vitro. The human airway basal cell signature displayed extensive overlap with genes expressed in basal cells from other human tissues and murine airway basal cells. Consistent with self-modulation as well as signaling to other airway cell types, the airway basal cell signature was characterized by genes encoding extracellular matrix components, and growth factors and growth factor receptors, including genes related to EGFR and VEGFR signaling. However, while human airway basal cells share similarity with basal-like cells of other organs, the human airway basal cell signature has features not previously associated with this cell type, including a unique pattern of genes encoding extracellular matrix components, integrins, G protein-coupled receptors, neuroactive ligands and receptors, and ion channels. Conclusion / Significance. The human airway epithelial basal cells signature identified in the present study provides novel insights into the ontogeny, molecular phenotype and biology of the stem / progenitor cells of the human airway epithelium. This study was designed to distinguish the transcriptome of the airway epithelium basal cell from that of differentiated airway epithelium. A basal cell signature was derived and analyzed for functional significance. The signature was also evaluated as basal cells differentiated into ciliated epithelium in vitro.

Project description:Background. The human airway epithelium consists of 4 major cell types: ciliated, secretory, columnar and basal cells. During natural turnover and in response to injury, the airway basal cells function as stem / progenitor cells for the other airway cell types. The objective of this study is to better understand basal cell biology by defining the subset of expressed genes that characterize the signature of human airway epithelial basal cells. Methodology / Principal Findings. Microarrays were used to assess the transcriptome of basal cells purified from the airway epithelium of healthy nonsmokers obtained by bronchial brushings in comparison to the transcriptome of the complete differentiated airway epithelium. This analysis identified the “human airway basal cell signature” as 1,161 unique genes with >5-fold higher expression level in basal cells compared to the differentiated epithelium. The basal cell signature was suppressed when the basal cells differentiated into a ciliated airway epithelium in vitro. The human airway basal cell signature displayed extensive overlap with genes expressed in basal cells from other human tissues and murine airway basal cells. Consistent with self-modulation as well as signaling to other airway cell types, the airway basal cell signature was characterized by genes encoding extracellular matrix components, and growth factors and growth factor receptors, including genes related to EGFR and VEGFR signaling. However, while human airway basal cells share similarity with basal-like cells of other organs, the human airway basal cell signature has features not previously associated with this cell type, including a unique pattern of genes encoding extracellular matrix components, integrins, G protein-coupled receptors, neuroactive ligands and receptors, and ion channels. Conclusion / Significance. The human airway epithelial basal cells signature identified in the present study provides novel insights into the ontogeny, molecular phenotype and biology of the stem / progenitor cells of the human airway epithelium.

Project description:Cigarette smoke (CS)-induced airway inflammation is an important pathologic feature of chronic obstructive pulmonary disease (COPD). Recent studies suggest a potential role of JunD in the regulation of inflammation, but its role in CS-induced airway inflammation has not been reported. This study aimed to determine its role in CS-induced airway inflammation through bioinformatics analysis and in vitro and in vivo experiments. Data from the Gene Expression Omnibus (GEO) database (GSE37147) were analyzed using weighted gene co-expression network analysis (WGCNA) and key driver analysis (KDA), and these analyses were validated using the GSE47460 dataset. The effect of CS on JunD expression was examined in lung tissues of COPD patients and CS-exposed mice and in CS extract (CSE)-exposed BEAS-2B cells. The effects of CSE on airway epithelial inflammatory injury after JunD knockdown or overexpression were also investigated. mRNA-seq and chromatin immunoprecipitation (ChIP)-seq were used to explore the mechanism of JunD-mediated CS-induced airway inflammation. Mice were injected with adeno-associated virus serotype 9 (AAV9)-JunD vector or control vector and then exposed to CS for 4 weeks, and lung tissue morphology and airway inflammation were evaluated. KDA of the lung function-related gene modules in GSE37147 revealed a potential role of JunD in COPD, which was validated in GSE47460. JunD was downregulated in lung tissues of COPD patients and CS-exposed mice and in BEAS-2B cells. JunD knockdown aggravated CSE-induced tumor necrosis factor (TNF)-α and interleukin (IL)-1β release by BEAS-2B cells, while JunD overexpression attenuated these effects. mRNA-seq and ChIP-seq identified several JunD-regulated genes, which are involved in the immune response and TNF signaling pathway and are commonly dysregulated in cell models of airway inflammation. In vivo, JunD overexpression attenuated the CS-induced inflammatory cell infiltration and inflammatory cytokine release in mouse lungs. Thus, JunD is involved in CS-induced airway inflammation and JunD-based therapy may be useful in CS-induced airway disorders.

Project description:Background: Ozone (O3) is the predominant oxidant air pollutant associated with respiratory inflammation, lung dysfunction, and worsening preexisting airway diseases. We determined that TNFR signlaing pathway plays a key role in lung injury and inflammation caused by O3 in mice. However, downstream molecular mechanisms underlying TNFR pathway have not been investigated. Methods: To investigate the role of TNFR pathway in gene expression changes, Tnfr1/2-deficient (Tnfr-/-) and wild-type (Tnfr+/+, C57BL/6J) mice were exposed to air or 0.3-ppm O3. Total RNAs were isolated from lung homogenates and cDNA microarray analyses were performed to elucidate TNFR-directed transcriptomics in basal lungs (air-exposed) as well as in the lung exposed to time course of O3 (24, 48, and 72 hr). Results: O3 caused time-dependent changes in lung gene expressions with the greatest transcriptome changes at 48-72 hr of exposure in Tnfr+/+ mice. At early time of exposure (24 hr), acute phase and inflammatory responses gene as well as redox and lipid metabolism genes were increased by O3 while cell cycle and DNA damage repair genes were markedly increased by O3 at later time points (48-72 hr). Compared to Tnfr+/+ mice, Tnfr-/- mice had lowered expression of inflammatory response and vascular disorder-related genes at baseline (air). After O3 exposure, Tnfr-/- had enhanced expression of immune and inflammatory genes at 24 hr, indicating compensatory or adpative poentiation of immunity in Tnfr-/- mice. At 48 hr of O3 exposure, Tnfr-/- mice showed suppressed expression of genes involved in epithelial proliferation, inflammatory cell influxes and epithelial injury, compared to Tnfr+/+ mice. At 72 hr of O3 exposure, neurodegeneration and neurotransmitter transport genes were suppressed in Tnfr-/- than in Tnfr+/+. Conclusion: Overall, deficiency of TNFR-mediated signaling in mouse lungs altered transcriptomes to protect lungs from O3-induced inflammation, cell proliferation, oxidative stress, and neuronal disorders.

Dataset Information

The human airway epithelial basal cell transcriptome in the early response to injury

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets