VEGF-functionalized dextran has longer intracellular bioactivity than VEGF in endothelial cells.
Herein, we report that VEGF-functionalized dextran (dexOx-VEGF) is comparatively superior to free VEGF in prolonging the phosphorylation of VEGF receptor 2 (VEGFR-2). Both dexOx-VEGF and free VEGF activate VEGFR-2, and the complexes are internalized into early endosomes (EEA1(+) vesicles) and then transported to lysosomes (Rab7(+) vesicles). However, after cell activation, dexOx-VEGF is preferentially colocalized in early endosomes where VEGF signaling is still active while free VEGF is preferentially transported to late endosomes or lysosomes. We further show that dexOx-VEGF after phosphorylation of VEGF receptor 2 induces an increase of intracellular Ca(2+) and activates VEGF downstream effectors such as Akt and extracellular signal-regulated kinase (ERK1/2) proteins. Under specific conditions, the activation level is different from the one observed for free VEGF, thus suggesting mechanistic differences, which is illustrated by cell migration and cord-like formation studies. DexOx-VEGF can be cross-linked with adipic acid dihydrazide to form a degradable gel, which in turn can be incorporated in a fibrin gel containing endothelial cells (ECs) to modulate their activity. We envision that these constructs might be beneficial to extend the pro-angiogenic activity of VEGF in ischemic tissues and to modulate the biological activity of vascular cells.
Chemical Engineering Department, Faculty of Science and Technology, University of Coimbra, Coimbra, Portugal.
João
J
Maia
Helena
H
Vazão
Dora C S
DC
Pedroso
Catarina S H
CS
Jesus
Rui M M
RM
Brito
Mário
M
Grãos
Maria H
MH
Gil
Lino
L
Ferreira
D002118:Calcium / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D003911:Dextrans / Q000737:chemistry*; D004705:Endocytosis / Q000187:drug effects; D011992:Endosomes / Q000187:drug effects* / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D020100:Hydrogels; D008247:Lysosomes / Q000187:drug effects* / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000737:chemistry / Q000378:metabolism
D003911:Dextrans; D020100:Hydrogels; D020033:Protein Isoforms; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2; D051057:Proto-Oncogene Proteins c-akt; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D002118:Calcium