Brivaracetam prevents astroglial L-glutamate release associated with hemichannel through modulation of synaptic vesicle protein
Brivaracetam prevents astroglial L-glutamate release associated with hemichannel through modulation of synaptic vesicle protein
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DOI：
10.1016/j.biopha.2021.111462
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发表时间：
2021-03-08
影响因子：
7.5
通讯作者：
Ueda, Yuto
中科院分区：
文献类型：
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作者：
Okada, Motohiro;Fukuyama, Kouji;Ueda, Yuto
布里伐西坦的抗癫痫/抗惊厥作用被认为是通过调节突触囊泡蛋白2A(SV2A)来实现的；然而，其药理作用机制尚未完全阐明。为探讨布伐西坦的抗癫痫/抗惊厥机制，本研究检测了布伐西坦对星形胶质细胞L谷氨酸释放与连接蛋白43(Cx43)、肿瘤坏死因子？(肿瘤坏死因子？)和？-amino-3-hydroxy-5-methyl-4-isoxazolepropionic酸(AMPA)/谷氨酸受体。用毛细管免疫印迹法检测肿瘤坏死因子？、细胞外K+升高和布列伐西坦对SV2A和Cx43表达的影响。肿瘤坏死因子？细胞外K+浓度升高主要促进星形胶质细胞的L-谷氨酸释放，这与相应的AMPA/谷氨酸受体和半通道有关。肿瘤坏死因子的协同作用可增强上述作用。细胞外K+升高。亚慢性给药可抑制星形胶质细胞L-谷氨酸释放及质膜Sv2a和Cx43的表达，但急性给药对其无明显影响。这些结果提示，SV2a通过高兴奋性迁移到星形胶质细胞质膜，激活星形胶质细胞谷氨酸能传递，可能是通过半通道激活。亚慢性给药可通过抑制异位SV2a抑制肿瘤坏死因子？诱导的AMPA/谷氨酸受体和半通道的激活。这些发现提示，囊泡和异位SV2a功能的联合抑制参与了布伐西坦的抗癫痫/抗惊厥机制。
The antiepileptic/anticonvulsive action of brivaracetam is considered to occur via modulation of synaptic vesicle protein 2A (SV2A); however, the pharmacological mechanisms of action have not been fully characterised. To explore the antiepileptic/anticonvulsive mechanism of brivaracetam associated with SV2A modulation, this study determined concentration-dependent effects of brivaracetam on astroglial L-glutamate release associated with connexin43 (Cx43), tumour-necrosis factor-? (TNF?) and ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/glutamate receptor of rat primary cultured astrocytes using ultra-highperformance liquid chromatography. Furthermore, interaction among TNF?, elevated extracellular K+ and brivaracetam on expression of SV2A and Cx43 was determined using capillary immunoblotting. TNF? and elevated extracellular K+ predominantly enhanced astroglial L-glutamate release associated with respective AMPA/ glutamate receptor and hemichannel. These effects were enhanced by a synergistic effect of TNF? and elevated extracellular K+ in combination. The activation of astroglial L-glutamate release, and expression of SV2A and Cx43 in the plasma membrane was suppressed by subchronic brivaracetam administration but were unaffected by acute administration. These results suggest that migration of SV2A to the astroglial plasma membrane by hyperexcitability activates astroglial glutamatergic transmission, perhaps via hemichannel activation. Subchronic brivaracetam administration suppressed TNF?-induced activation of AMPA/glutamate receptor and hemichannel via inhibition of ectopic SV2A. These findings suggest that combined inhibition of vesicular and ectopic SV2A functions contribute to the antiepileptic/anticonvulsive mechanism of brivaracetam action.