Xenopus Dab2 is required for embryonic angiogenesis.

ABSTRACT: BACKGROUND: The molecular mechanisms governing the formation of the embryonic vascular system remain poorly understood. Here, we show that Disabled-2 (Dab2), a cytosolic adaptor protein, has a pivotal role in the blood vessel formation in Xenopus early embryogenesis. RESULTS: Xenopus Disabled-2 (XDab2) is spatially localized to the blood vessels including the intersomitic veins (ISV) in early embryos. Both antisense morpholino oligonucleotide (MO)-mediated knockdown and overexpression of XDab2 inhibit the formation of ISV, which arise from angiogenesis. In addition, we found that activin-like signaling is essential for this angiogenic event. Functional assays in Xenopus animal caps reveal that activin-like signals induce VEGF expression and this induction can be inhibited by XDab2 depletion. However, XDab2 MO has no effects on the induction of other target genes by activin-like signals. Furthermore, we show that the disruption of the sprouting ISV in XDab2-depleted embryos can be rescued by coexpression of VEGF. CONCLUSION: Taking together, we suggest that XDab2 regulates the embryonic angiogenesis by mediating the VEGF induction by activin-like signaling in Xenopus early development.

SUBMITTER: Cheong SM 

PROVIDER: S-EPMC1766927 | biostudies-literature | 2006

REPOSITORIES: biostudies-literature