Glutamate causes a loss in human cerebral endothelial barrier integrity through activation of NMDA receptor.
Glutamate causes a loss in human cerebral endothelial barrier integrity through activation of NMDA receptor.
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DOI：
10.1152/ajpheart.00520.2003
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发表时间：
2003-12
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影响因子：
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通讯作者：
C. D. Sharp;Ian N Hines;J. Houghton;A. Warren;T. H. Jackson;A. Jawahar;Anil Nanda;J. Elrod;A. Long;A. Chi;A. Minagar;J. Alexander
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作者：
C. D. Sharp;Ian N Hines;J. Houghton;A. Warren;T. H. Jackson;A. Jawahar;Anil Nanda;J. Elrod;A. Long;A. Chi;A. Minagar;J. Alexander
L-谷氨酸是一种主要的兴奋性神经递质，与离子型和代谢型谷氨酸受体结合。许多物种的脑内皮细胞都表达多种形式的谷氨酸受体；然而，人脑内皮细胞还没有表达N-甲基-D-天冬氨酸(NMDA)受体的信息或蛋白。这项研究为人脑内皮细胞表达NMDA受体的信息和蛋白提供了证据。检测了谷氨酸受体激动剂、拮抗剂和第二信息阻滞剂对人脑内皮细胞单层电阻的影响。RT-PCR和Western印迹分析证实NMDA受体的存在。谷氨酸和N-甲基-D-天冬氨酸(1 MM)暴露后2小时，与假手术组比较，其电阻显著降低；N-甲基-D-天冬氨酸拮抗剂MK-80 1、细胞内钙离子拮抗剂N-(N，N-diethylamino)-n-octyl-3，4，5-trimethyoxybenzoate)和抗氧化剂N-乙酰-L-半胱氨酸均能显著阻断这一效应。代谢性受体激动剂Trans(+/-)-1-amino-1，3-cyclopentanedicarboxylic酸(1 MM)不能显著降低细胞的电阻。我们的结果与谷氨酸在兴奋毒性水平下可能通过激活NMDA受体导致血脑屏障崩溃的模型是一致的。
l-Glutamate is a major excitatory neurotransmitter that binds ionotropic and metabotropic glutamate receptors. Cerebral endothelial cells from many species have been shown to express several forms of glutamate receptors; however, human cerebral endothelial cells have not been shown to express either the N-methyl-D-aspartate (NMDA) receptor message or protein. This study provides evidence that human cerebral endothelial cells express the message and protein for NMDA receptors. Human cerebral endothelial cell monolayer electrical resistance changes in response to glutamate receptor agonists, antagonists, and second message blockers were tested. RT-PCR and Western blot analysis were used to demonstrate the presence of the NMDA receptor. Glutamate and NMDA (1 mM) caused a significant decrease in electrical resistance compared with sham control at 2 h postexposure; this response could be blocked significantly by MK-801 (an NMDA antagonist), 8-(N,N-diethylamino)-n-octyl-3,4,5-trimethyoxybenzoate (an intracellular Ca2+ antagonist), and N-acetyl-L-cystein (an antioxidant). Trans(+/-)-1-amino-1,3-cyclopentanedicarboxylic acid, a metabotropic receptor agonist (1 mM), did not significantly decrease electrical resistance. Our results are consistent with a model where glutamate, at excitotoxic levels, may lead to a breakdown in the blood brain barrier via activation of NMDA receptors.