title: T-box gene products are required for mesenchymal induction of epithelial branching in the embryonic mouse lung.
abstract: The regulation of signaling pathways is a prerequisite for coordinating the induction between mesenchymal and epithelial tissues during morphogenesis. Mesenchymal FGF10 is known to be an important paracrine factor regulating the branching morphogenesis of the bronchial epithelium. By using antisense oligonucleotides (AS ODNs) and in vitro culture of embryonic lungs, we demonstrate that the transcription factors Tbx4 and Tbx5 are critical for the expression of mesenchymal FGF10. Treatment of embryonic lung cultures with AS ODNs to Tbx4 and Tbx5 reduces the level of these transcripts, suppresses Fgf10 expression in the mesenchyme, and completely eliminates the formation of new lung branches. If FGF10 is locally replaced in these AS ODN-treated lungs, epithelial branching is restored. These studies provide evidence that the production of branching signals by the lung mesenchyme is mediated by T-box genes.
authors.affiliation: Department of Biology, Franklin and Marshall College, Lancaster, Pennsylvania, USA. jacebra@hotmail.com
authors.forename: Judith A
authors.initials: JA
authors.lastname: Cebra-Thomas
authors.forename: Jason
authors.initials: J
authors.lastname: Bromer
authors.forename: Rose
authors.initials: R
authors.lastname: Gardner
authors.forename: Gordon K
authors.initials: GK
authors.lastname: Lam
authors.forename: Hillary
authors.initials: H
authors.lastname: Sheipe
authors.forename: Scott F
authors.initials: SF
authors.lastname: Gilbert
mesh_terms: D000818:Animals; D004848:Epithelium / Q000196:embryology*; D051526:Fibroblast Growth Factor 10; D005346:Fibroblast Growth Factors / Q000096:biosynthesis / Q000378:metabolism; D053823:Hedgehog Proteins; D017403:In Situ Hybridization; D008168:Lung / Q000196:embryology*; D008648:Mesoderm / Q000378:metabolism*; D051379:Mice; D009024:Morphogenesis; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D020825:T-Box Domain Proteins / Q000096:biosynthesis / Q000502:physiology*; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism
chemical_list: C496464:Fgf10 protein, mouse; D051526:Fibroblast Growth Factor 10; D053823:Hedgehog Proteins; D016376:Oligonucleotides, Antisense; C465570:Shh protein, mouse; C097348:T-Box Domain Protein 2; D020825:T-Box Domain Proteins; C103172:T-box transcription factor 5; C103177:Tbx4 protein, mouse; D015534:Trans-Activators; D005346:Fibroblast Growth Factors