Vascular endothelial growth factor promotes neurite maturation in primary CNS neuronal cultures

• Published in: Brain research. Developmental brain research Vol. 148; no. 1; pp. 59 - 68
• Main Authors: Khaibullina, Alfia A., Rosenstein, Jeffrey M., Krum, Janette M.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 31.01.2004
• Subjects: Androstadienes - pharmacology; Animals; Animals, Newborn; Cells, Cultured; Central Nervous System - cytology; Central Nervous System - metabolism; Dendrite; Dose-Response Relationship, Drug; Drug Interactions; Enzyme Inhibitors - pharmacology; Flavonoids - pharmacology; Gene Expression - drug effects; Immunohistochemistry - methods; Map-2; Microtubule-Associated Proteins - metabolism; Neurites - drug effects; Neurites - physiology; Neurons - drug effects; Neurons - physiology; Neurotrophic factor; Oligonucleotides, Antisense - pharmacology; Phosphopyruvate Hydratase - metabolism; Rats; Rats, Wistar; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA, Messenger - biosynthesis; Tubulin - metabolism; Vascular Endothelial Growth Factor A - pharmacology; Vascular Endothelial Growth Factor Receptor-1 - metabolism; Vascular Endothelial Growth Factor Receptor-2 - genetics; Vascular Endothelial Growth Factor Receptor-2 - metabolism; VEGFR1; VEGFR2; Wortmannin; VEGFR2; Neurotrophic factor; VEGFR1; Map-2; Development and regeneration; Dendrite
• ISSN: 0165-3806
• DOI: 10.1016/j.devbrainres.2003.09.022

Recent studies have demonstrated that vascular endothelial growth factor (VEGF) and its receptor VEGFR2 (flk-1) are expressed by neurons during development and following hypoxic–ischemic events. Moreover, fetal CNS tissue explants exposed to exogenous VEGF exhibit increased neuronal Map-2 expression, suggesting that VEGF could have an effect on neuronal maturation. To determine whether this effect is of a direct nature, we examined the expression of Map-2 in the presence of VEGF in primary CNS neuronal cultures. After 3 days in culture, a statistically significant dose-dependent increase in the length of Map-2(+) processes was observed, with the peak occurring at 10 ng/ml of VEGF. Immunohistochemical analysis of the cultures demonstrated the presence of VEGFR2 after VEGF treatment, as well as the expression of the VEGF receptor VEGFR1 (flt-1). Treatment of the cultures with antisense oligonucleotides against VEGFR2, but not against VEGFR1, abolished the effect of VEGF on the length of Map-2(+) processes. RT-PCR analyses of Map-2 and VEGFR1 indicated that mRNAs of these two genes are upregulated in the presence of VEGF. The addition of wortmannin, an inhibitor of PI3K/Akt signal-transduction pathway, to the media did not affect the VEGF-dependent increase in Map-2(+) length. In contrast PD98059, which inhibits the MAPK pathway, partially abolished this effect of VEGF. These experiments suggest that VEGF has a direct effect on neuronal growth and maturation under normoxic conditions during CNS development, which is mediated by the VEGFR2 receptor via the MAPK pathway.