Aberrant Bmp signaling and notochord delamination in the pathogenesis of esophageal atresia.

  • Li Y, Litingtung Y, Ten Dijke P, Chiang C. Aberrant Bmp signaling and notochord delamination in the pathogenesis of esophageal atresia. Developmental dynamics : an official publication of the American Association of Anatomists. 2007 Mar;236(3). 746-54. PMID: 17260385 [PubMed].

Abstract 

Human foregut malformation known as esophageal atresia with tracheoesophageal fistula (EA/TEF) occurs in 1 in 4,000 live births with unknown etiology. We found that mice lacking Noggin (Nog(-/-)) displayed Type C EA/TEF, the most common form in humans, and notochordal defects strikingly similar to the adriamycin-induced rat EA/TEF model. In accord with esophageal atresia, Nog(-/-) embryos displayed reduction in the dorsal foregut endoderm, which was associated with reduced adhesion and disrupted basement membrane. However, significant apoptosis in the Nog(-/-) dorsal foregut was not observed. Instead, non-notochordal, likely endodermal, cells were found in Nog(-/-) notochord, suggesting that Noggin function is required in the notochordal plate for its proper delamination from the dorsal foregut. Notably, ablating Bmp7 function in Nog(-/-) embryos rescued EA/TEF and notochord branching defects, establishing a critical role of Noggin-mediated Bmp7 antagonism in EA/TEF pathogenesis.