Oxidative stress-mediated down-regulation of bcl-2 promoter in hippocampal neurons
Article first published online: 18 FEB 2003
Journal of Neurochemistry
Volume 84, Issue 5, pages 982–996, March 2003
How to Cite
Pugazhenthi, S., Nesterova, A., Jambal, P., Audesirk, G., Kern, M., Cabell, L., Eves, E., Rosner, M. R., Boxer, L. M. and Reusch, J. E.-B. (2003), Oxidative stress-mediated down-regulation of bcl-2 promoter in hippocampal neurons. Journal of Neurochemistry, 84: 982–996. doi: 10.1046/j.1471-4159.2003.01606.x
- Issue published online: 18 FEB 2003
- Article first published online: 18 FEB 2003
- Received September 11, 2002; revised manuscript received November 1, 2002; accepted November 1, 2002.
- bcl-2 promoter;
- cyclic AMP response element binding protein;
- hippocampal neuron;
- neuronal survival;
- oxidative stress
Generation of oxidative stress/reactive oxygen species (ROS) is one of the causes of neuronal apoptosis. We have examined the effects of ROS at the transcriptional level in an immortalized hippocampal neuronal cell line (H19-7) and in rat primary hippocampal neurons. Treatment of H19-7 cells with hydrogen peroxide (150 µm) resulted in a 40% decrease in Bcl-2 protein and a parallel decrease in bcl-2 mRNA levels. H19-7 cells overexpressing bcl-2 were found to be resistant to ROS-induced apoptosis. We had previously shown that bcl-2 promoter activity is positively regulated by the transcription factor cyclic AMP response element binding protein (CREB) in neurons. In the present study, we demonstrate that ROS decreases the activity of luciferase reporter gene driven by a cyclic AMP response element site containing bcl-2 promoter. Exposure of neurons to ROS for 6 h resulted in basal and fibroblast growth factor-2-stimulated phosphorylation/activation of CREB. Chronic 24 h treatment with ROS led to a significant (p < 0.01) decrease in CREB protein and CREB mRNA levels. Adenoviral overexpression of wild type CREB in H19-7 cells resulted in significant (p < 0.01) protection against ROS-induced apoptosis through up-regulation of Bcl-2 expression whereas dominant negative CREB exaggerated the injury. These findings demonstrate that loss of CREB function contributes to oxidative stress-induced neuronal dysfunction.