Dataset Information

A genome-wide expression comparison of productive and unproductive airway epithelial repair

ABSTRACT: Defective epithelial repair in the setting of chronic lung disease has been suggested to contribute to uncontrolled extracellular matrix (ECM) deposition and development of fibrosis. We sought to directly test this hypothesis through gene expression profiling of total lung RNA isolated from mouse models of selective epithelial cell injury that are associated with either productive or abortive repair. Analysis of gene expression in repairing lungs of naphthalene-exposed mice revealed prominent clusters of up-regulated genes with putative roles in regulation of the extracellular matrix and cellular proliferation. Further analysis of tenascin C (Tnc), a representative matrix protein, in total lung RNA revealed a transient 4.5-fold increase in mRNA abundance 1 day after injury and a return to steady-state levels by Recovery Day 3. Tnc was deposited by the peribronchiolar mesenchyme immediately after injury and was remodeled to basement membrane subtending the bronchiolar epithelium during epithelial repair. Epithelial restitution was accompanied by a decrease in Tnc mRNA and protein expression to steady-state levels. In contrast, abortive repair using a transgenic model allowing ablation of all reparative cells led to a progressive increase in Tnc mRNA within lung tissue and accumulation of its gene product within the subepithelial mesenchyme of both conducting airways and alveoli. These data demonstrate that the ECM is dynamically remodeled in response to selective epithelial cell injury and that this process is activated without resolution in the setting of defective airway epithelial repair. Bronchiolar Clara cells undergo phenotypic changes during development and in disease. These changes are poorly described due to a paucity of molecular markers. We used chemical and transgenic approaches to ablate Clara cells, allowing identification of their unique gene expression profile. Flavin monooxygenase 3 (Fmo3), paraoxonase 1 (Pon1), aldehyde oxidase 3 (Aox3), and claudin 10 (Cldn10) were identified as novel Clara cell markers. New and existing Clara cell marker genes were categorized into three classes based on their unique developmental expression pattern. Cldn10 was uniformly expressed in the epithelium at Embryonic Day (E)14.5 and became restricted to secretory cells at E18.5. This transition was defined by induction of Clara Cell Secretory Protein (CCSP). Maturation of secretory cells was associated with progressive increases in the expression of Fmo3, Pon1, Aox3, and Cyp2f2 between late embryonic and postnatal periods. Messenger RNA abundance of all categories of genes was dramatically decreased after naphthalene-induced airway injury, and displayed a sequence of temporal induction during repair that suggested sequential secretory cell maturation. We have defined a broader repertoire of Clara cell-specific genes that allows staging of epithelial maturation during development and repair.

ORGANISM(S): Mus musculus

PROVIDER: GSE17693 | GEO | 2009/08/18

SECONDARY ACCESSION(S): PRJNA118479

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Defective epithelial repair in the setting of chronic lung disease has been suggested to contribute to uncontrolled extracellular matrix (ECM) deposition and development of fibrosis. We sought to directly test this hypothesis through gene expression profiling of total lung RNA isolated from mouse models of selective epithelial cell injury that are associated with either productive or abortive repair. Analysis of gene expression in repairing lungs of naphthalene-exposed mice revealed prominent clusters of up-regulated genes with putative roles in regulation of the extracellular matrix and cellular proliferation. Further analysis of tenascin C (Tnc), a representative matrix protein, in total lung RNA revealed a transient 4.5-fold increase in mRNA abundance 1 day after injury and a return to steady-state levels by Recovery Day 3. Tnc was deposited by the peribronchiolar mesenchyme immediately after injury and was remodeled to basement membrane subtending the bronchiolar epithelium during epithelial repair. Epithelial restitution was accompanied by a decrease in Tnc mRNA and protein expression to steady-state levels. In contrast, abortive repair using a transgenic model allowing ablation of all reparative cells led to a progressive increase in Tnc mRNA within lung tissue and accumulation of its gene product within the subepithelial mesenchyme of both conducting airways and alveoli. These data demonstrate that the ECM is dynamically remodeled in response to selective epithelial cell injury and that this process is activated without resolution in the setting of defective airway epithelial repair. Bronchiolar Clara cells undergo phenotypic changes during development and in disease. These changes are poorly described due to a paucity of molecular markers. We used chemical and transgenic approaches to ablate Clara cells, allowing identification of their unique gene expression profile. Flavin monooxygenase 3 (Fmo3), paraoxonase 1 (Pon1), aldehyde oxidase 3 (Aox3), and claudin 10 (Cldn10) were identified as novel Clara cell markers. New and existing Clara cell marker genes were categorized into three classes based on their unique developmental expression pattern. Cldn10 was uniformly expressed in the epithelium at Embryonic Day (E)14.5 and became restricted to secretory cells at E18.5. This transition was defined by induction of Clara Cell Secretory Protein (CCSP). Maturation of secretory cells was associated with progressive increases in the expression of Fmo3, Pon1, Aox3, and Cyp2f2 between late embryonic and postnatal periods. Messenger RNA abundance of all categories of genes was dramatically decreased after naphthalene-induced airway injury, and displayed a sequence of temporal induction during repair that suggested sequential secretory cell maturation. We have defined a broader repertoire of Clara cell-specific genes that allows staging of epithelial maturation during development and repair. 32 samples were isolated and used to screen UniSet Mouse 20K I Bioarrays (total lung RNA Mus musculus). Control RNA was isolated from uninjured mice (N = 4 mice), and RNA was also isolated from mice exposed to naphthalene and recovered for 1, 2, 3, and 6 days (N = 4 mice per timepoint). Additionally, transgenic mice expressing HSV-tk under control of the mouse CCSP promoter were exposed to Ganciclovir (GCV) and recovered for 3, 6, and 9 days (N = 4 mice per timepoint).

Project description:Transcriptional profiling of Control and RbpjkCNULL lungs from E18.5. For microarray profiling, total RNA from E18.5 lungs was submitted for labeling and hybridization (Mouse Gene 1.0 ST Whole Genome Array, Affymetrix) to the Boston University Microarray Core facility. Clara cells (CCs) are a morphologically and operationally heterogeneous population of secretoglobin Scgb1a1-expressing secretory cells crucial for airway homeostasis and post-injury repair. Insights into the extent and origin of CC diversity have been hindered by the limited knowledge of markers of these cells and their precursors. To identify novel putative markers of CCs we characterized global changes in gene expression in embryonic lungs in which CCs were suppressed by conditional disruption of Notch signaling (Rbpjkcnull). Microarray profiling and Real Time PCR (qRT-PCR) identified eleven genes differentially downregulated in the E18.5 airways of Rbpjkcnull compared to controls, nearly half not previously known to mark CCs. Remarkably, in situ hybridization (ISH) revealed overlapping but also distinct domains of expression of these genes in E18.5 controls. Notably, Reg3g, Chad, Gabrp and Lrrc26 were selectively expressed in CCs of proximal airways and Upk3a expression was highly enriched in a CC subpopulation surrounding Neuroepithelial Bodies (NEBs). All genes expressed in the adult airways were found to be expressed in adult CCs and downregulated by selective CC ablation in a Naphthalene model of injury. Flow cytometry-based isolation of CCs from different airway regions of adult B1-EGFP reporter mice and qRT-PCR corroborated the spatial enrichment in gene expression observed by ISH. Remarkably, although, Scgb3a2, Upk3a, Cyp2f2, Cbr2, Krt15 could be detected unambiguously in airway progenitors as early as E14.5, only Scgb3a2 and Upk3a had their expression suppressed by disruption of Notch signaling, implicating both genes as the earliest markers for CC differentiation. Our study supports the idea that the diversification of the CC phenotype already arises during embryonic development and identifies candidate markers that can be used to investigate this process. Control (n=3) versus RbpjkCNULL(n=3)

Dataset Information

A genome-wide expression comparison of productive and unproductive airway epithelial repair

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets