Role for ETS domain transcription factors Pea3/Erm in mouse lung development.
During the development of the mouse lung, the expression of a number of genes, including those encoding growth factors and components of their downstream signaling pathways, is enriched in the epithelium and/or mesenchyme of the distal buds. In this location, they regulate processes such as cell proliferation, branching morphogenesis, and the differentiation of specialized cell types. Here, we report that the expression of Pea3 and Erm (or Etv5, Ets variant gene 5), which encode Pea3 subfamily ETS domain transcription factors, is initially restricted to the distal buds of the developing mouse lung. Erm is transcribed exclusively in the epithelium, while Pea3 is expressed in both epithelium and mesenchyme. Erm/Pea3 are downstream of FGF signaling from the mesenchyme, but their responses toward different FGFs are not the same. The functions of the two proteins were investigated by transgenic expression of a repressor form of Erm specifically in the embryonic lung epithelium. When examined at E18.5, the distal epithelium of transgenic lungs is composed predominantly of immature type II cells, while no mature type I cells are observed. In contrast, the differentiation of proximal epithelial cells, including ciliated cells and Clara cells, appears to be unaffected. A model is proposed for the role of Pea3/Erm during the dynamic process of lung bud outgrowth and proximal-distal differentiation, in response to FGF signaling. Our results provide the first functional evidence that Pea3 subfamily members play a role in epithelial-mesenchymal interactions during lung organogenesis.
Liu
Yuru
Y
Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA.
Jiang
Haiyan
H
Crawford
Howard C
HC
Hogan
Brigid L M
BL
D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D002455:Cell Division; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins; D004848:Epithelium / Q000196:embryology; D051526:Fibroblast Growth Factor 10; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D017930:Genes, Reporter; D018398:Homeodomain Proteins / Q000235:genetics; D006801:Humans; D017403:In Situ Hybridization; D008156:Luciferases / Q000235:genetics; D008168:Lung / Q000166:cytology / Q000196:embryology* / Q000502:physiology; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D008822:Mice, Transgenic; D008954:Models, Biological; D009924:Organ Culture Techniques; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000502:physiology*
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C086680:ETV5 protein, human; C063459:En protein, Drosophila; C513242:Etv5 protein, mouse; C496453:FGF7 protein, human; C496454:Fgf7 protein, mouse; D051526:Fibroblast Growth Factor 10; D018398:Homeodomain Proteins; D014157:Transcription Factors; C065788:transcription factor PEA3; D051523:Fibroblast Growth Factor 7; D005346:Fibroblast Growth Factors; D008156:Luciferases