Open AccessFstl1 Antagonizes BMP Signaling and Regulates Ureter Development
Author(s) -
Jingyue Xu,
Xin Qi,
Jianfeng Gong,
Mingyan Yu,
Fang-Xiong Zhang,
Haibo Sha,
Xiang Gao
Publication year - 2012
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0032554
Subject(s) - follistatin , bone morphogenetic protein , microbiology and biotechnology , ureter , sonic hedgehog , signal transduction , biology , cell signaling , hedgehog signaling pathway , bone morphogenetic protein 4 , urothelial cell , mesenchymal stem cell , medicine , urinary system , endocrinology , urothelium , gene , genetics , urology
Bone morphogenetic protein (BMP) signaling pathway plays important roles in urinary tract development although the detailed regulation of its activity in this process remains unclear. Here we report that follistatin-like 1 ( Fstl1 ), encoding a secreted extracellular glycoprotein, is expressed in developing ureter and antagonizes BMP signaling activity. Mouse embryos carrying disrupted Fstl1 gene displayed prominent hydroureter arising from proximal segment and ureterovesical junction defects. These defects were associated with significant reduction in ureteric epithelial cell proliferation at E15.5 and E16.5 as well as absence of subepithelial ureteral mesenchymal cells in the urinary tract at E16.5 and E18.5. At the molecular level, increased BMP signaling was found in Fstl1 deficient ureters, indicated by elevated pSmad1/5/8 activity. In vitro study also indicated that Fstl1 can directly bind to ALK6 which is specifically expressed in ureteric epithelial cells in developing ureter. Furthermore, Sonic hedgehog (SHH) signaling, which is crucial for differentiation of ureteral subepithelial cell proliferation, was also impaired in Fstl1 -/- ureter. Altogether, our data suggest that Fstl1 is essential in maintaining normal ureter development by antagonizing BMP signaling.