Transcriptional analysis of injured airway epithelial cells in Mmp7-null and wildtype mice
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ABSTRACT: Matrix metalloproteinase 7 (MMP7) is expressed at low levels in intact, normal airways by non-mucous-producing cells, including ciliated cells. In response to injury and infection, MMP7 expression is quickly and markedly upregulated and functions to regulate wound repair and various mucosal immune processes. We evaluated the global transcriptional response of airway epithelial cells from wild type and Mmp7-null mice cultured at an air-liquid interface. A common injury response was seen in both genotypes with up-regulation of genes associated with proliferation and migration. Analysis of differentially expressed genes between genotypes after injury revealed enrichment of functional categories associated with inflammation, cilia and differentiation. Because these analyses suggested MMP7 regulated ciliogenesis, we evaluated the recovery of the airway epithelium in wild type and Mmp7-null mice in vivo after naphthalene injury. These studies identified a new role for MMP7 in attenuating ciliogenesis during wound repair. A total of 16 air-liquid interface cultures of mouse airway epithelial cells were studied under four conditions: 1. Mmp7-null, no injury (n = 4); 2. Mmp7-null, scratch injury (n = 4); 3. Wildtype, no injury (n =4); 4. Wiltype, scratch injury (n = 4).
Project description:Matrix metalloproteinase 7 (MMP7) is expressed at low levels in intact, normal airways by non-mucous-producing cells, including ciliated cells. In response to injury and infection, MMP7 expression is quickly and markedly upregulated and functions to regulate wound repair and various mucosal immune processes. We evaluated the global transcriptional response of airway epithelial cells from wild type and Mmp7-null mice cultured at an air-liquid interface. A common injury response was seen in both genotypes with up-regulation of genes associated with proliferation and migration. Analysis of differentially expressed genes between genotypes after injury revealed enrichment of functional categories associated with inflammation, cilia and differentiation. Because these analyses suggested MMP7 regulated ciliogenesis, we evaluated the recovery of the airway epithelium in wild type and Mmp7-null mice in vivo after naphthalene injury. These studies identified a new role for MMP7 in attenuating ciliogenesis during wound repair.
Project description:Wound healing requires orchestration of cellular migration, adhesion molecule synthesis, and cell cycle regulation. However, the cellular receptors necessary for the repair of damaged tissue remain poorly understood. This study investigated whether extracellular transmembrane receptors in the leucine rich repeat and nogo interacting protein family (LINGO) were required for the recovery of airway epithelial cells from from scratch wound injury. CRISPR/Cas9-mediated deletion mutants for either LINGO1, LINGO2, or LINGO3 or their putative co-receptors, Tumor Necrosis Factor Receptor Superfamily, Member 19 (TROY) and Reticulon 4 Receptor (RTN4R) in the mouse airway epithelial cell line MLE-12 were used for mRNA sequencing. Cells for all lines were grown to a monolayer and subjected to a scratch with a pipette tip. Cells from each mutant line and the parental line were collected for sequencing after 24 hours post-scratch. In addition the parental line was sequenced under baseline un-scratch conditions.
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:Nf-kB activity is associated with the key pathological features of chronic respiratory diseases including epithelial remodelling, excess mucous production, and submucosal gland hyperplasia. However, the role of Nf-kB activity in airway epithelial differentiation remains controversial. In the present study we demonstrate that Nf-kB adaptor protein Myd88 deficiency promotes increased airway submucosal gland abundance and abnormal epithelial differentiation in proximal adult airways. Abnormal airway differentiation was not developmentally determined, became exacerbated following acute lung injury, and did not involve altered epithelial proliferation or apoptosis. Instead, we demonstrate that tracheal Myd88 deficiency promotes upregulation of a unique gene expression profile that includes activation of alternate, Myd88-independent Nf-kB signalling. Finally, we show that these effects are not intrinsically maintained in vitro using an air-liquid interface epithelial culture. This finding indicates that Myd88 deficiency promotes adult airway remodelling by regulating non-epithelial, non-cell autonomous Nf-kB activity. 20 microarray samples of whole trachea RNA in total: 5 samples wildtype control tissue 5 samples Myd88 KO control tissue 5 samples wildtype 3 day polidocanol injury tissue 5 samples Myd88 KO 3 day polidocanol injury tissue
Project description:Mouse tracheal epithelial cells were cultured at air-liquid interface (ALI), RNA was harvested at days 0, 2, and 7 post-ALI, and hybridized to two-channel MEEBO arrays. The experiment was designed to allow investigators to identify genes differentially expressed during airway epithelial cell differentiation and development, including ciliogenesis.
Project description:The regeneration of the airway mucociliary epithelium involves several sequential events including migration, proliferation, polarization and final differentiation (i.e ciliogenesis). We used microarrays to detail the global programme of gene expression that occurs during regeneration and ciliogenesis of the human airway mucociliary epithelium. The four time points of regeneration of the airway epithelium (ALI-D0 which corresponds to the end of proliferation step; ALI-D7 which corresponds to the polarization step; ALI-D14 which corresponds to the onset of ciliogenesis and ALI-D21 corresponding to the terminal differentiation step) for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Leucine-rich repeat and IgG-like domain containing NOGO-receptor interacting protein 1 (LINGO1) has an inhibitory role in neuronal growth and regeneration following injury; yet LINGO1 involvement in the injury response of other tissues has not been thoroughly explored. Previous studies have demonstrated that the reparative cytokines of the Trefoil factor family interact with members of the LINGO receptor family in maintenance of gastrointestinal barrier integrity, suggesting a role for LINGO receptors in epithelial repair processes. In this study, we investigated whether LINGO1 had a role in alveolar epithelial repair. A mouse alveolar epithelial cell line, MLE-12, was utilized in an in vitro scratch assay as a model of epithelial injury and repair. CRISPR/Cas9-mediated deletion of Lingo1 resulted in significantly reduced wound closure at both 24 and 48 h post-scratch in comparison to parental (WT) cells. We preformed RNA sequencing of 24h post-scratch cells or un-scratched cells, and revealed a set of 147 differentially expressed genes between WT and Lingo1KO cells following scratch.
Project description:Airway epithelium is the initial point of host-pathogen interaction in Pseudomonas aeruginosa infection, an important pathogen in cystic fibrosis and nosocomial pneumonia. We used global gene expression analysis to determine airway epithelial transcriptional responses dependent on matrilysin (MMP-7) and stromelysin-2 (MMP-10), two matrix metalloproteinases induced by acute P. aeruginosa pulmonary infection. Extraction of Differential Gene Expression (EDGE) analysis of gene expression changes in P. aeruginosa infected organotypic tracheal epithelial cell cultures from wildtype, Mmp7-/-, and Mmp10-/- mice identified 2,089 matrilysin-dependent and 1,628 stromelysin-2-dependent genes that were differentially expressed. Key node network analysis showed that these MMPs controlled distinct gene expression programs involved in proliferation, cell death, immune responses, and signal transduction, among other host defense processes. Our results demonstrate discrete roles for these MMPs in regulating epithelial responses to pseudomonas infection and show that a global genomics strategy can be used to assess MMP function. Experiment Overall Design: C57Bl6, Mmp7-/- and Mmp10-/- mouse epithelium at an organotypic air liquid interface culture was exposed to Pseudomonas aeruginosa for 1 and 24 h. RNA was collected from these samples as well as uninfected 0 h and assessed for expression changes using Affymetrix Mouse 430 2.0 Arrays. Triplicate samples were processed for each genotype at each time point.
Project description:The regeneration of the airway mucociliary epithelium involves several sequential events including migration, proliferation, polarization and final differentiation (i.e ciliogenesis). We used microarrays to detail the global programme of gene expression that occurs during regeneration and ciliogenesis of the human airway mucociliary epithelium.