The role of glutamate release on voltage-dependent anion channels (VDAC)-mediated apoptosis in an eleven vessel occlusion model in rats.

Abstract

Voltage-dependent anion channel (VDAC) is the main protein in mitochondria-mediated apoptosis, and the modulation of VDAC may be induced by the excessive release of extracellular glutamate. This study examined the role of glutamate release on VDAC-mediated apoptosis in an eleven vessel occlusion model in rats. Male Sprague-Dawley rats (250-350 g) were used for the 11 vessel occlusion ischemic model, which were induced for a 10-min transient occlusion. During the ischemic and initial reperfusion episode, the real-time monitoring of the extracellular glutamate concentration was measured using an amperometric microdialysis biosensor and the cerebral blood flow (CBF) was monitored by laser-Doppler flowmetry. To confirm neuronal apoptosis, the brains were removed 72 h after ischemia to detect the neuron-specific nuclear protein and pro-apoptotic proteins (cleaved caspase-3, VDAC, p53 and BAX). The changes in the mitochondrial morphology were measured by atomic force microscopy. A decrease in the % of CBF was observed, and an increase in glutamate release was detected after the onset of ischemia, which continued to increase during the ischemic period. A significantly higher level of glutamate release was observed in the ischemia group. The increased glutamate levels in the ischemia group resulted in the activation of VDAC and pro-apoptotic proteins in the hippocampus with morphological alterations to the mitochondria. This study suggests that an increase in glutamate release promotes VDAC-mediated apoptosis in an 11 vessel occlusion ischemic model.

• Authors: Eunkuk Park, Gi-Ja Lee, Samjin Choi, Seok-Keun Choi, Su-Jin Chae, Sung-Wook Kang, Youngmi Kim Pak, Hun-Kuk Park
• Journal: PloS one (PLoS One) Vol. 5 Issue 12 Pg. e15192 (Dec 21 2010) ISSN: 1932-6203 [Electronic] United States
• PMID: 21203570 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Tumor Suppressor Protein p53
• Voltage-Dependent Anion Channels
• bcl-2-Associated X Protein
• Glutamic Acid
• Caspase 3

Topics

• Animals
• Apoptosis
• Biosensing Techniques
• Caspase 3 (metabolism)
• Glutamic Acid (metabolism)
• Ischemia
• Laser-Doppler Flowmetry
• Male
• Microscopy, Atomic Force (methods)
• Mitochondria (metabolism)
• Neurons (metabolism)
• Rats
• Rats, Sprague-Dawley
• Tumor Suppressor Protein p53 (metabolism)
• Voltage-Dependent Anion Channels (metabolism)
• bcl-2-Associated X Protein (metabolism)