ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of glutamate on the expression of vascular endothelial growth factor (VEGF) mRNA and protein in cultured rat astrocytes under hypoxia.</p><p><b>METHODS</b>Cultured rat astrocytes were randomly divided control group, glutamate group, hypoxia group and hypoxia+glutamate group. The cells in the control and glutamate groups were cultured under nomoxic condition (95% air and 5% CO(2)), and those in the other two groups under hypoxic condition (94% N(2), 5% CO(2) and 1% O(2)). The total RNA was extracted from the cells at different time points of hypoxic exposure for real-time FQ-PCR and ELISA to detect the expression of VEGF mRNA and protein in cultured astrocytes, respectively.</p><p><b>RESULTS</b>The expressions of VEGF mRNA and protein underwent no significant changes in the control glutamate groups, but increased obviously in both hypoxia and hypoxia+glutamate groups at 2, 4, 6, 8 and 12 h of hypoxic exposure. At these time points, VEGF expressions at both the mRNA and protein levels were significantly higher in hypoxia+glutamate group than in hypoxia group.</p><p><b>CONCLUSION</b>Glutamate at 1 micromol/L can further increase the expression of VEGF mRNA and protein in astrocytes exposed to hypoxia, which may result from the adaptive changes of glutamate receptors in hypoxic astrocytes.</p>
Subject(s)
Animals , Female , Male , Rats , Animals, Newborn , Astrocytes , Cell Biology , Metabolism , Cell Hypoxia , Cells, Cultured , Glutamic Acid , Pharmacology , RNA, Messenger , Genetics , Metabolism , Rats, Sprague-Dawley , Vascular Endothelial Growth Factor A , Genetics , MetabolismABSTRACT
Objective: To study the effect of glutamate on the expression of vascular endothelial growth factor (VEGF) mRNA and protein in cultured rat astrocytes. Methods: Cultured rat astrocytes were randomly divided into 6 groups: control group (C), glutamate group (G), QA group (Q), DCG-IV group (D), L-AP4 group (L) and glutamate+MCPG group (G+M). Cells were cultured under nomoxic condition (95% air, 5% CO2). RT-PCR and ELISA methods were used to detect the expression of VEGF mRNA and protein in cultured astrocytes, respectively. G+M group was preincubated with 1mM MCPG for 30 min prior to the stimulation with glutamate. There were 7 time points at 0, 4, 8, 12, 16, 24 and 48 h in each group except G+M group. Results: The expression of VEGF mRNA and protein did not differ significantly among D group, L group and C group. Different from that in C group, the expression of VEGF mRNA and protein could be enhanced both in a dose-dependent and time-dependent manner in G group and Q group. Meanwhile, the enhanced expression of VEGF mRNA and protein in G group was completely suppressed by MCPG after 24 h. Conclusion: Glutamate can increase the expression of VEGF mRNA and protein in cultured astrocytes, which may be due to the activation of group I metabotropic glutamate receptors in astrocytes.