Abstract
The ligand specificity of transforming growth factor beta (TGFβ) in vivo in mouse cardiac cushion epithelial-to-mesenchymal transition (EMT) is poorly understood. To elucidate the function of TGFβ in cushion EMT, we analyzed Tgfb1-/-, Tgfb2-/-, and Tgfb3-/- mice between embryonic day (E) 9.5 and E14.5 using both in vitro and in vivo approaches. Atrioventricular (AV) canal collagen gel assays at E9.5 indicated normal EMT in both Tgfb1-/- and Tgfb3-/- mice. However, analysis of Tgfb2-/- AV explants at E9.5 and E10.5 indicated that EMT, but not cushion cell proliferation, was initially delayed but later remained persistent. This was concordant with the observation that Tgfb2 -/- embryos, and not Tgfb1-/- or Tgfb3-/- embryos, develop enlarged cushions at E14.5 with elevated levels of well-validated indicators of EMT. Collectively, these data indicate that TGFβ2, and not TGFβ1 or TGFβ3, mediates cardiac cushion EMT by promoting both the initiation and cessation of EMT.
Original language | English (US) |
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Pages (from-to) | 431-442 |
Number of pages | 12 |
Journal | Developmental Dynamics |
Volume | 238 |
Issue number | 2 |
DOIs | |
State | Published - Feb 2009 |
Externally published | Yes |
Keywords
- Epithelial mesenchymal transformation
- Heart development
- Transforming growth factor beta
- Valvulogenesis
ASJC Scopus subject areas
- Developmental Biology