VEGF release by retinal glia depends on both oxygen and glucose supply.
Isolated retinae or isolated Müller cells were cultured in vitro, and vascular endothelial growth factor (VEGF) was assayed as protein (by ELISA) and as mRNA (by semi-quantitative RT-PCR). In both types of cultures, hypoxia (5% O2) resulted in an upregulated VEGF release. While the unstimulated VEGF secretion was virtually independent of glucose (0.125 - 25 mM), elevated glucose concentrations (10 - 25 mM) blocked most of the stimulatory effect of hypoxia on VEGF mRNA synthesis (determined in Müller cell cultures) as well as on VEGF release (in both retina and Müller cell cultures). It is concluded that in retinal glial (Müller) cells, being responsible for retinal VEGF synthesis (and, thus, for undesirable neovascularization), the metabolic effects of hypoxia can be compensated by a surplus of glucose.
Eichler
W
W
Department of Ophthalmology, University of Leipzig, Germany.
Kuhrt
H
H
Hoffmann
S
S
Wiedemann
P
P
Reichenbach
A
A
D000818:Animals; D015687:Cell Hypoxia / Q000502:physiology*; D002478:Cells, Cultured; D016228:Endothelial Growth Factors / Q000235:genetics* / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005947:Glucose / Q000494:pharmacology*; D007700:Kinetics; D008222:Lymphokines / Q000235:genetics* / Q000378:metabolism*; D009457:Neuroglia / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D010100:Oxygen / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D011817:Rabbits; D012160:Retina / Q000166:cytology* / Q000502:physiology; D014158:Transcription, Genetic / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D016228:Endothelial Growth Factors; D008222:Lymphokines; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D005947:Glucose; D010100:Oxygen