Hydroxysafflor yellow A(HSYA)was reported to be neuroprotective both in middle cerebral artery occlusion(MCAO)animal model and in cultured cortical ***,the underlying mechanism remains *** has been known that mass...
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Hydroxysafflor yellow A(HSYA)was reported to be neuroprotective both in middle cerebral artery occlusion(MCAO)animal model and in cultured cortical ***,the underlying mechanism remains *** has been known that mass glutamate release and over stimulation of N-methyl-d-aspartate(NMDA)type glutamate receptors are the main cause of neuronaldeath inbrain *** patch-clamp recordings of mouse hippocampal slices,primary hippocampal cultures,Ca2+imaging,and Western blot approaches,we found that HSYA effectively inhibited NMDA rreceptor-mediated excitatory postsynaptic currents(NMDAR EPSCs)which had a half maximum inhibition of0μ*** was also suppressed presynaptic glutamate transmitter ***,HSYA suppressed NMDAR-mediated oxygen-glucose-deprivation(OGD)evoked long-term potentiation(LTP)which resemble the reperfusion damage in brain *** cell viability assay,HSYA attenuated NMDA induced apoptotic and necrotic cell death *** attenuation effect was HSYA concentration ***2+imaging experiments also exihibited that NMDA-evoked inctracellular Ca2+concentration([Ca2+]i)increase was distinctly reduced or even abolished by containing different concentration of HSYA in extracellular *** western blot assay,we found that the intracellular apoptotic signaling molecule,cleaved-caspase3,expression was also suppressed by ***,HSYA protected CA1pyramidal cells of hippocampus against NMDA receptor-mediated membrane depolarization currents in OGD *** together,our data for the first time give the direct evidences that HSYA inhibits NMDAR-mediated synaptic transmission in hippocampal slices and intracellular Ca2+increase evoked by NMDA in hippocampal cultures,exerting the neuronal protection effect in the condition of high concentration of extracellular NMDA or glutamate,such as in brain *** data indicate that HSYA has a strong neuronal protection effect on NMDAR-mediated excitotoxic death and migh
NMDARs and ASIC1a both exist in central synapses and mediate important physiological and pathological conditions,but the functional relationship between them is *** we report several novel findings that may shed light...
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NMDARs and ASIC1a both exist in central synapses and mediate important physiological and pathological conditions,but the functional relationship between them is *** we report several novel findings that may shed light on the functional relationship between these two important receptor ***,NMDAR activation by either NMDA or OGD led to increased[Ca2+]i and greater apoptotic and necrotic cell deaths in cultured hippocampal neurons;these cell deaths were prevented by application of NMDAR ***,ASIC1a activation with p H6.0 ECS induced similar increases in apoptotic and necrotic cell deaths;these cell deaths were prevented by ASIC1a antagonists,and also by NMDAR *** increased[Ca2+]i leads to increased cell deaths and since NMDAR exhibits much greater calcium permeability than ASIC1a,these data suggest that ASIC1a-induced neuronal death is mediated through activation of ***,treatment of hippocampal cultures with both NMDA and acidic ECS induced greater cell deaths than either NMDA or acidic ECS treatment *** results suggest that ASIC1a activation up-regulates NMDAR *** data supporting the functional relationship between ASIC1a and NMDAR are found in our electrophysiology experiments in hippocampal slices,where stimulation of ASIC1a induced a marked increase in NMDAR EPSC amplitude,and inhibition of ASIC1a resulted in a decrease in NMDAR EPSC *** summary,we present evidence that ASIC1a activity modulates NMDAR function and exacerbates NMDAR-mediated neuronal death in brain *** findings are invaluable to the search for novel therapeutic targets in the treatment of brain ischemia.
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