ABSTRACT
AIM:To investigate the effect of dopamine ( DA) on the glutamate ( Glu)-uptake ability of astro-cytes, and the role of mammalian target of rapamycin (mTOR)-excitatory amino acid transporter 2(EAAT2) pathway in this process .METHODS:Extracellular Glu levels in DA-treated primary cortical astrocytes ( PCAs) were measured by a fluorimetric method .The relative expression of EAAT 2 and mTOR at mRNA and protein levels was measured by RT-qPCR and Western blot .PCAs stimulated with or without DA in the presence or absence of mTOR antagonist rapamycin or mTOR agonist MHY1485 were used to determine the expression of mTOR and EAAT 2, and Glu content in the culture supernatant was also measured.RESULTS: The expression of mTOR in DA-treated PCAs was decreased, the expression of EAAT2 was also decreased .Extracellular Glu levels of DA-treated PCAs were elevated significantly .When the PCAs were stimula-ted with DA in the presence of rapamycin , the expression of EAAT2 was decreased , and the levels of extracellular Glu was significantly increased.In the presence of MHY1485, the expression of EAAT2 was elevated, and significant decrease in the levels of extracellular Glu was also observed .CONCLUSION:DA interacts with mTOR-EAAT2 pathway to reduce the Glu-uptake ability of the astrocytes , and causes extracellular Glu accumulation , ultimately destroys the function of astro-cytes.
ABSTRACT
AIM:To investigate the effect of dopamine ( DA) on the glutamate ( Glu)-uptake ability of astro-cytes, and the role of mammalian target of rapamycin (mTOR)-excitatory amino acid transporter 2(EAAT2) pathway in this process .METHODS:Extracellular Glu levels in DA-treated primary cortical astrocytes ( PCAs) were measured by a fluorimetric method .The relative expression of EAAT 2 and mTOR at mRNA and protein levels was measured by RT-qPCR and Western blot .PCAs stimulated with or without DA in the presence or absence of mTOR antagonist rapamycin or mTOR agonist MHY1485 were used to determine the expression of mTOR and EAAT 2, and Glu content in the culture supernatant was also measured.RESULTS: The expression of mTOR in DA-treated PCAs was decreased, the expression of EAAT2 was also decreased .Extracellular Glu levels of DA-treated PCAs were elevated significantly .When the PCAs were stimula-ted with DA in the presence of rapamycin , the expression of EAAT2 was decreased , and the levels of extracellular Glu was significantly increased.In the presence of MHY1485, the expression of EAAT2 was elevated, and significant decrease in the levels of extracellular Glu was also observed .CONCLUSION:DA interacts with mTOR-EAAT2 pathway to reduce the Glu-uptake ability of the astrocytes , and causes extracellular Glu accumulation , ultimately destroys the function of astro-cytes.