Abstract
Angiogenesis involves sprouting, migration, and proliferation of endothelial cells. The angiomotin-like2 gene (amotl2) has been found in blood vessels in zebrafish embryos, but its function in angiogenesis and underlying mechanisms remain unknown. In this study, we demonstrate that knockdown of amotl2 in zebrafish Tg(fli1:EGFP)(y1) and Tg(fli1:nEGFP)(y7) transgenic embryos impairs the intersegmental vessel growth and suppresses proliferation of endothelial cells. Transplantation experiments indicate that function of amotl2 in intersegmental vessel growth is cell-autonomous. AMOTL2 knockdown in cultured human umbilical vein endothelial cells also inhibits cell proliferation and migration and disrupts cell polarity, ultimately interrupting the formation of vascular tube-like structures. Amotl2 promotes MAPK/ERK activation via c-Src, which is dependent on phosphorylation of tyrosine residue at position 103 but independent of the C-terminal PDZ-binding domain. Taking together, our data indicate that Amotl2 plays a pivotal role in polarity, migration and proliferation of angiogenic endothelial cells.
Highlights
Amotl2 is expressed in blood vessels, but its function in vasculature formation is unknown
We demonstrate that zebrafish amotl2 is required for intersegmental vessels (ISVs) growth, and proangiogenic activity of Amotl2 is conserved in cultured human umbilical vein endothelial cells (HUVECs)
We found that 40% (n ϭ 80) of Tg(fli1:EGFP)y1 embryos injected with amotl2-⌬PDZ mRNA exhibited slow migrating of some intersegmental vessels at 36 and 48 hpf (Fig. 6, E and H) in a way similar to those observed in amotl2 morphants (Fig. 1, D and E), whereas almost all embryos injected with amotl2 mRNA had normal intersegmental vessels (Fig. 6, D and G)
Summary
Amotl is expressed in blood vessels, but its function in vasculature formation is unknown. Results: Amotl knockdown impairs intersegmental vessel growth in zebrafish embryos and in vitro tube formation of human endothelial cells. Conclusion: Amotl is required for angiogenesis by regulating cell polarity, migration, and proliferation in a way related to MAPK activation. We demonstrate that knockdown of amotl in zebrafish Tg(fli1:EGFP)y1 and Tg(fli1:nEGFP)y7 transgenic embryos impairs the intersegmental vessel growth and suppresses proliferation of endothelial cells. The extracellular signal-regulated kinases (ERKs) are activated by growth factors and other extracellular cues and play important roles in cell proliferation, cell migration, organogenesis, and tumorigenesis [17]. We demonstrate that zebrafish amotl is required for ISV growth, and proangiogenic activity of Amotl is conserved in cultured human umbilical vein endothelial cells (HUVECs).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
