title: Formation and differentiation of multiple mesenchymal lineages during lung development is regulated by beta-catenin signaling.
abstract: BACKGROUND
  The role of ss-catenin signaling in mesodermal lineage formation and differentiation has been elusive.
  
  
  METHODS
  To define the role of ss-catenin signaling in these processes, we used a Dermo1(Twist2)(Cre/+) line to target a floxed beta-catenin allele, throughout the embryonic mesenchyme. Strikingly, the Dermo1(Cre/+); beta-catenin(f/-) conditional Knock Out embryos largely phenocopy Pitx1(-/-)/Pitx2(-/-) double knockout embryos, suggesting that ss-catenin signaling in the mesenchyme depends mostly on the PITX family of transcription factors. We have dissected this relationship further in the developing lungs and find that mesenchymal deletion of beta-catenin differentially affects two major mesenchymal lineages. The amplification but not differentiation of Fgf10-expressing parabronchial smooth muscle progenitor cells is drastically reduced. In the angioblast-endothelial lineage, however, only differentiation into mature endothelial cells is impaired.
  
  
  CONCLUSIONS
  Taken together these findings reveal a hierarchy of gene activity involving ss-catenin and PITX, as important regulators of mesenchymal cell proliferation and differentiation.
authors.affiliation: Developmental Biology Program, Department of Surgery, Saban Research Institute of Childrens Hospital Los Angeles, Los Angeles, California, USA.
authors.forename: Stijn P
authors.initials: SP
authors.lastname: De Langhe
authors.forename: Gianni
authors.initials: G
authors.lastname: Carraro
authors.forename: Denise
authors.initials: D
authors.lastname: Tefft
authors.forename: Changgong
authors.initials: C
authors.lastname: Li
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Yang
authors.initials: Y
authors.lastname: Chai
authors.forename: Parviz
authors.initials: P
authors.lastname: Minoo
authors.forename: Mohammad K
authors.initials: MK
authors.lastname: Hajihosseini
authors.forename: Jacques
authors.initials: J
authors.lastname: Drouin
authors.forename: Vesa
authors.initials: V
authors.lastname: Kaartinen
authors.forename: Savério
authors.initials: S
authors.lastname: Bellusci
mesh_terms: D000818:Animals; D015153:Blotting, Western; D019070:Cell Lineage; D049109:Cell Proliferation; D005346:Fibroblast Growth Factors / Q000378:metabolism; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D017403:In Situ Hybridization; D008168:Lung / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism; D034741:RNA, Small Interfering; D015398:Signal Transduction; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: D016271:Proto-Oncogene Proteins c-myc; D034741:RNA, Small Interfering; D051176:beta Catenin; D005346:Fibroblast Growth Factors