Proteomic analysis of human cerebral endothelial cells activated by glutamate/MK-801: significance in ischemic stroke injury.

Glutamate is a major excitatory neurotransmitter in the central nervous system and plays a significant role in the pathophysiology of ischemic stroke. During acute ischemic cerebrovascular disease, glutamate efflux in the CNS produces excitotoxicity in neurons and may mediate forms of stress in other tissues expressing glutamate ionotropic (N-methyl-D-aspartate (NMDA)) receptors, e.g., cerebral endothelial cells. While endothelial cell stress in response to glutamate has been reported (oxidant stress, loss of barrier function), changes in protein expression produced by glutamate (an agonist of metabotropic and NMDA receptors) have not been documented. Here, we have examined how exposure of human cerebral endothelial cells to glutamate, in the presence and absence of the NMDA receptor antagonist MK-801, can alter the proteomic profile of cerebral endothelial cells. We found several important changes in the proteins expressed by cerebral endothelial cells in response to glutamate. Interestingly, MK-801 itself had some direct effects on cerebral endothelial cells. Taken together, our findings demonstrate that cerebral endothelial cells respond to glutamate by altering their protein expression profile. We assume that protein alterations found in the cerebral endothelial proteome, in response to glutamate and which were blocked by MK-801, may be important vascular targets in better understanding the pathogenesis of ischemic stroke.