Vascular endothelial growth factor enhances migration of astroglial cells in subventricular zone neurosphere cultures.
Vascular endothelial growth factor (VEGF) is an endothelial and neuronal survival factor and a mitogen for endothelial cells and astrocytes in both explant and in vivo injury models. In the CNS, interplay between the vasculature and neural stem progenitor (NSP) cells is required for the maintenance of angiogenic/neurogenic coordination in the germinal niche in the subventricular zone (SVZ) of the lateral ventricle. Using an in vitro SVZ neurosphere (NS) model, this study aimed to understand the direct effects of VEGF and its receptor signaling on neonatal NSP cell growth and migration. Our data indicate that VEGF administration, compared with untreated or brain-derived neurotrophic factor-treated NS, significantly increased growth and migratory capacity of glial fibrillary acidic protein (GFAP)(+) and nestin(+) NSP cells and in secondary cultures induced a stellate astrocyte morphology. Blockade of both VEGF, which is normally expressed in some NS cells, and its flt-1 receptor signaling by neutralizing antibodies caused morphological changes specifically in GFAP(+) cells and disrupted sphere formation and outward migration. These cells did not appear as conventional polygonal astrocytes; their process growth was severely restricted, and overall migration was reduced by up to 76% of control cultures. Blockade of VEGF's flk-1 receptor reduced VEGF expression and caused a lesser, though significant, decrease (29%) in NSP (GFAP(+)) cell migration. The results show that both VEGF and, in particular, flt-1 receptor signaling are critical to the proper configuration of the NS and its subsequent development. VEGF is also an important growth and migratory factor particularly for GFAP(+) cells developing in SVZ-derived NS in culture.
Mani
Nina
N
Department of Anatomy and Regenerative Biology, The George Washington University Medical Center, Washington, DC 20037, USA. ananxm@gwumc.edu
Khaibullina
Alfia
A
Krum
Janette M
JM
Rosenstein
Jeffrey M
JM
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000502:physiology*; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D049108:Cell Enlargement; D002465:Cell Movement / Q000502:physiology*; D002478:Cells, Cultured; D002552:Cerebral Ventricles; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007381:Intermediate Filament Proteins / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction; D055153:Stem Cell Niche / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism
D019208:Brain-Derived Neurotrophic Factor; D005904:Glial Fibrillary Acidic Protein; D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577486:Nes protein, rat; D064231:Nestin; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; C501164:Flt1 protein, rat; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2