title: Proper development of the outer longitudinal smooth muscle of the mouse pylorus requires Nkx2-5 and Gata3.
abstract: OBJECTIVE
  Infantile hypertrophic pyloric stenosis is a common birth anomaly characterized by obstruction of the pyloric lumen. A genome-wide association study implicated NKX2-5, which encodes a transcription factor that is expressed in embryonic heart and pylorus, in the pathogenesis of infantile hypertrophic pyloric stenosis. However, the function of the NKX2-5 in pyloric smooth muscle development has not been examined directly. We investigated the pattern of Nkx2-5 during the course of murine pyloric sphincter development and examined coexpression of Nkx2-5 with Gata3 and Sox9-other transcription factors with pyloric-specific mesenchymal expression. We also assessed pyloric sphincter development in mice with disruption of Nkx2-5 or Gata3.
  
  
  METHODS
  We used immunofluorescence analysis to compare levels of NKX2-5, GATA3, and SOX9 in different regions of smooth muscle cells. Pyloric development was assessed in mice with conditional or germline deletion of Nkx2-5 or Gata3, respectively.
  
  
  RESULTS
  Gata3, Nkx2-5, and Sox9 are coexpressed in differentiating smooth muscle cells of a distinct fascicle of the pyloric outer longitudinal muscle. Expansion of this fascicle coincides with development of the pyloric sphincter. Disruption of Nkx2-5 or Gata3 causes severe hypoplasia of this fascicle and alters pyloric muscle shape. Although expression of Sox9 requires Nkx2-5 and Gata3, there is no apparent hierarchical relationship between Nkx2-5 and Gata3 during pyloric outer longitudinal muscle development.
  
  
  CONCLUSIONS
  Nkx2-5 and Gata3 are independently required for the development of a pyloric outer longitudinal muscle fascicle, which is required for pyloric sphincter morphogenesis in mice. These data indicate that regulatory changes that alter Nkx2-5 or Gata3 expression could contribute to pathogenesis of infantile hypertrophic pyloric stenosis.
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Udager
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109.
authors.forename: Ajay
authors.initials: A
authors.lastname: Prakash
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109.
authors.forename: David A
authors.initials: DA
authors.lastname: Saenz
authors.affiliation: Department of Medicine, Cardiovascular Division, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215.
authors.forename: Martina
authors.initials: M
authors.lastname: Schinke
authors.affiliation: Department of Medical Biochemistry, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Moriguchi
authors.affiliation: Departments of Pediatrics and Genetics, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110.
authors.forename: Patrick Y
authors.initials: PY
authors.lastname: Jay
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109.
authors.forename: Kim-Chew
authors.initials: KC
authors.lastname: Lim
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109.
authors.forename: James Douglas
authors.initials: JD
authors.lastname: Engel
authors.affiliation: Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI 48109.
authors.forename: Deborah L
authors.initials: DL
authors.lastname: Gumucio
mesh_terms: D000818:Animals; D005455:Fluorescent Antibody Technique; D050990:GATA3 Transcription Factor / Q000378:metabolism*; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000378:metabolism*; D051379:Mice; D024510:Muscle Development / Q000502:physiology*; D009130:Muscle, Smooth / Q000196:embryology* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D011708:Pylorus / Q000196:embryology* / Q000378:metabolism; D055758:SOX9 Transcription Factor / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D050990:GATA3 Transcription Factor; C494748:Gata3 protein, mouse; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C484469:Nkx2-5 protein, mouse; D055758:SOX9 Transcription Factor; C527933:Sox9 protein, mouse; D014157:Transcription Factors
keywords: BMP; E; ICM; IHPS; Infantile Hypertrophic Pyloric Stenosis; OLM; Primary Duodenogastric Reflux; SRF; Smooth Muscle Development; Sox9; WT; bone morphogenetic protein; embryonic day; infantile hypertrophic pyloric stenosis; inner circular muscle; outer longitudinal muscle; serum response factor; wild type; α-smooth muscle actin; αSMA