PUBLICATION

ALK5- and TGFBR2-independent role of ALK1 in the pathogenesis of hereditary hemorrhagic telangiectasia type 2

Authors
Park, S.O., Lee, Y.J., Seki, T., Hong, K.H., Fliess, N., Jiang, Z., Park, A., Wu, X., Kaartinen, V., Roman, B.L., and Oh, S.P.
ID
ZDB-PUB-110712-1
Date
2008
Source
Blood   111(2): 633-642 (Journal)
Registered Authors
Roman, Beth
Keywords
none
MeSH Terms
  • Activin Receptors, Type I/genetics
  • Activin Receptors, Type I/metabolism*
  • Animals
  • Cell Line
  • Endothelium, Vascular/metabolism
  • Endothelium, Vascular/pathology
  • Ligands
  • Mice
  • Mice, Knockout
  • Neovascularization, Pathologic/genetics
  • Neovascularization, Pathologic/metabolism*
  • Neovascularization, Pathologic/pathology
  • Protein Serine-Threonine Kinases/genetics
  • Protein Serine-Threonine Kinases/metabolism*
  • Receptors, Transforming Growth Factor beta/genetics
  • Receptors, Transforming Growth Factor beta/metabolism*
  • Signal Transduction*/genetics
  • Telangiectasia, Hereditary Hemorrhagic/genetics
  • Telangiectasia, Hereditary Hemorrhagic/metabolism*
  • Telangiectasia, Hereditary Hemorrhagic/pathology
  • Transforming Growth Factor beta1/genetics
  • Transforming Growth Factor beta1/metabolism
  • Zebrafish/genetics
  • Zebrafish/metabolism
  • Zebrafish Proteins
PubMed
17911384 Full text @ Blood
Abstract
ALK1 belongs to the type I receptor family for transforming growth factor-β family ligands. Heterozygous ALK1 mutations cause hereditary hemorrhagic telangiectasia type 2 (HHT2), a multisystemic vascular disorder. Based largely on in vitro studies, TGF-β1 has been considered as the most likely ALK1 ligand related to HHT, yet the identity of the physiologic ALK1 ligand remains controversial. In cultured endothelial cells, ALK1 and another TGF-β type I receptor, ALK5, regulate angiogenesis by controlling TGF-β signal transduction, and ALK5 is required for ALK1 signaling. However, the extent to which such interactions between these 2 receptors play a role in pathogenesis of HHT is unknown. We directly addressed these issues in vivo by comparing the phenotypes of mice in which the Alk1, Alk5, or Tgfbr2 gene was conditionally deleted in restricted vascular endothelia using a novel endothelial Cre transgenic line. Alk1-conditional deletion resulted in severe vascular malformations mimicking all pathologic features of HHT. Yet Alk5- or Tgfbr2-conditional deletion in mice, or Alk5 inhibition in zebrafish, did not affect vessel morphogenesis. These data indicate that neither ALK5 nor TGFBR2 is required for ALK1 signaling pertinent to the pathogenesis of HHT and suggest that HHT might not be a TGF-β subfamily disease.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping