title: Gas6 stimulates angiogenesis of human retinal endothelial cells and of zebrafish embryos via ERK1/2 signaling.
abstract: OBJECTIVE
  To determine if growth arrest-specific 6 (Gas6) plays an important role in the regulation of angiogenesis in human retinal microvascular endothelial cells (HRMECs) and in vessel development of zebrafish.
  
  
  METHODS
  Proliferation, wound-healing cell migration, and tube formation were measured in HRMECs treated with recombinant human Gas6 (rhGas6). Sprague-Dawley rat aortas in Matrigels were treated with rhGas6, and microvessel sprouting emanating from arterial rings was analyzed. Transgenic zebrafish embryos (flk:GFP) were microinjected with rhGas6 at 50 hours post-fertilization (hpf), and ectopic sprouting of subintestinal vessels (SIVs) was observed under a confocal microscope. Morpholino oligonucleotides (MOs) were microinjected to knockdown gas6 in zebrafish embryos, and intersegmental vessel impairment was observed. The effect of the extracellular signal-regulated kinase (ERK1/2) inhibitor on the migration of HRMECs and on vessel development in zebrafish embryos was tested.
  
  
  RESULTS
  rhGas6 stimulated proliferation, migration, and tube formation in HRMECs in a dose-dependent manner. In rat aortas, rhGas6 induced vessel outgrowth, and the sprouting length was longer than that of controls. The rhGas6-microinjected zebrafish embryos had significantly increased vessel outgrowth in the SIVs. Recombinant human vascular endothelial growth factor (rhVEGF) served as a positive control. Knockdown of gas6 inhibited angiogenesis in the developing vessels of zebrafish. The ERK1/2 inhibitor inhibited HRMEC migration and intersegmental vessel formation in zebrafish embryos.
  
  
  CONCLUSIONS
  These data suggest that Gas6 plays a pivotal role in proliferation, migration, and sprouting of angiogenic endothelial cells in the retina and in zebrafish embryos. Furthermore, Gas6 induced angiogenic processes are induced via phosphorylation of ERK1/2.
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea.
authors.forename: Young Sook
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea.
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Jung
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea.
authors.forename: Dong Ho
authors.initials: DH
authors.lastname: Jung
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea.
authors.forename: So-Jin
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea.
authors.forename: Yu-Ri
authors.initials: YR
authors.lastname: Lee
authors.affiliation: Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon, Republic of Korea.
authors.forename: Jin Sook
authors.initials: JS
authors.lastname: Kim
mesh_terms: D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D049109:Cell Proliferation / Q000187:drug effects; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D023061:Gene Order; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000235:genetics*; D010641:Phenotype; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D012160:Retina / Q000378:metabolism*; D015027:Zebrafish; D000099255:Growth Arrest-Specific Protein 6
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D047428:Protein Kinase Inhibitors; D000099255:Growth Arrest-Specific Protein 6