Nogo-B receptor is essential for angiogenesis in zebrafish via Akt pathway

B Zhao, C Chun, Z Liu, MA Horswill… - Blood, The Journal …, 2010 - ashpublications.org
B Zhao, C Chun, Z Liu, MA Horswill, K Pramanik, GA Wilkinson, R Ramchandran, RQ Miao
Blood, The Journal of the American Society of Hematology, 2010ashpublications.org
Our previous work has shown that axon guidance gene family Nogo-B and its receptor
(NgBR) are essential for chemotaxis and morphogenesis of endothelial cells in vitro. To
investigate NogoB-NgBR function in vivo, we cloned the zebrafish ortholog of both genes
and studied loss of function in vivo using morpholino antisense technology. Zebrafish
ortholog of Nogo-B is expressed in somite while expression of zebrafish NgBR is localized
in intersomitic vessel (ISV) and axial dorsal aorta during embryonic development. NgBR or …
Abstract
Our previous work has shown that axon guidance gene family Nogo-B and its receptor (NgBR) are essential for chemotaxis and morphogenesis of endothelial cells in vitro. To investigate NogoB-NgBR function in vivo, we cloned the zebrafish ortholog of both genes and studied loss of function in vivo using morpholino antisense technology. Zebrafish ortholog of Nogo-B is expressed in somite while expression of zebrafish NgBR is localized in intersomitic vessel (ISV) and axial dorsal aorta during embryonic development. NgBR or Nogo-B knockdown embryos show defects in ISV sprouting in the zebrafish trunk. Mechanistically, we found that NgBR knockdown not only abolished its ligand Nogo-B–stimulated endothelial cell migration but also reduced the vascular endothelial growth factor (VEGF)–stimulated phosphorylation of Akt and vascular endothelial growth factor–induced chemotaxis and morphogenesis of human umbilical vein endothelial cells. Further, constitutively activated Akt (myristoylated [myr]Akt) or human NgBR can rescue the NgBR knockdown umbilical vein endothelial cell migration defects in vitro or NgBR morpholino-caused ISV defects in vivo. These data place Akt at the downstream of NgBR in both Nogo-B– and VEGF-coordinated sprouting of ISVs. In summary, this study identifies the in vivo functional role for Nogo-B and its receptor (NgBR) in angiogenesis in zebrafish.
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