Effects of Carbamazepine, Lacosamide and Zonisamide on Gliotransmitter Release Associated with Activated Astroglial Hemichannels
Effects of Carbamazepine, Lacosamide and Zonisamide on Gliotransmitter Release Associated with Activated Astroglial Hemichannels
复制标题
DOI：
10.3390/ph13060117
复制
发表时间：
2020-06-01
期刊：
影响因子：
4.6
通讯作者：
Okada, Motohiro
中科院分区：
文献类型：
--
作者：
Fukuyama, Kouji;Ueda, Yuto;Okada, Motohiro
近期利用遗传性部分癫痫模型进行的研究表明，星形胶质细胞半通道功能亢进有助于癫痫发作的病理机制。因此，为了探索新的抗惊厥机制，本研究确定了电压依赖性钠通道（VDSC）抑制性抗惊厥药卡马西平（CBZ）、拉考沙胺（LCM）和唑尼沙胺（ZNS）对星形胶质细胞释放L - 谷氨酸和三磷酸腺苷（ATP）的影响。采用微透析法测定了治疗相关剂量的三种抗惊厥药亚慢性给药对眶额皮质（OFC）中L - 谷氨酸和ATP释放的影响。利用原代培养的星形胶质细胞测定了抗惊厥药急性和亚慢性给药对星形胶质细胞神经胶质递质释放的浓度依赖性影响。采用Simple Western系统测定了抗惊厥药亚慢性给药对原代培养的星形胶质细胞质膜上连接蛋白43（Cx43）表达的浓度依赖性影响。细胞外K⁺水平升高导致星形胶质细胞释放L - 谷氨酸和ATP呈浓度依赖性增加。单独降低细胞外Ca²⁺水平并不影响星形胶质细胞神经胶质递质释放，但通过激活星形胶质细胞半通道加速了K⁺诱发的神经胶质递质释放。非选择性半通道抑制剂甘草次酸（CBX）和选择性Cx43抑制剂GAP19均能阻止通过激活的星形胶质细胞半通道释放神经胶质递质以及由细胞外K⁺水平升高和细胞外Ca²⁺水平降低所诱导的半通道激活过程。ZNS亚慢性降低Cx43表达，并急性/亚慢性抑制Cx43半通道活性。LCM急性抑制半通道活性，但亚慢性不影响Cx43表达。治疗相关浓度的CBZ不影响半通道活性或Cx43表达，但超治疗浓度的CBZ降低Cx43表达和半通道活性。因此，本研究证明了CBZ、LCM和ZNS通过调节星形胶质细胞半通道功能对神经胶质递质释放具有不同的影响。三种VDSC抑制性抗惊厥药对与半通道相关的星形胶质细胞传递的影响具有不同特征，这至少部分可能有助于形成这三种抗惊厥药的特性，包括抗癫痫谱以及与情绪和认知障碍有关的不良反应。
Recent studies using the genetic partial epilepsy model have demonstrated that hyperfunction of astroglial hemichannels contributes to pathomechanism of epileptic seizure. Therefore, to explore the novel anticonvulsive mechanisms, the present study determined the effects of voltage-dependent Na+ channel (VDSC)-inhibiting anticonvulsants, carbamazepine (CBZ), lacosamide (LCM), and zonisamide (ZNS) on the astroglial release ofl-glutamate and adenosine triphosphate (ATP). The effects of subchronic administration of therapeutic-relevant dose of three anticonvulsants on the release ofl-glutamate and ATP in the orbitofrontal cortex (OFC) were determined using microdialysis. The concentration-dependent effects of acute and subchronic administrations of anticonvulsants on astroglial gliotransmitter release were determined using primary cultured astrocytes. The concentration-dependent effects of subchronic administrations of anticonvulsants on connexin43 (Cx43) expression in the plasma membrane of primary cultured astrocytes were determined using the Simple Western system. An increase in the levels of extracellular K+ resulted in a concentration-dependent increase in the astroglial release ofl-glutamate and ATP. The depleted levels of extracellular Ca2+ alone did not affect astroglial gliotransmitter release but did accelerate K+-evoked gliotransmitter release via activation of astroglial hemichannels. Both non-selective hemichannel inhibitor carbenoxolone (CBX) and selective Cx43 inhibitor GAP19 prevented both gliotransmitter release through activated astroglial hemichannels and the hemichannel-activating process induced by elevation of the levels of extracellular K+ with depletion of the levels of extracellular Ca2+. ZNS subchronically decreased Cx43 expression and acutely/subchronically inhibited Cx43 hemichannel activity. LCM acutely inhibited hemichannel activity but did not subchronically affect Cx43 expression. Therapeutic-relevant concentration of CBZ did not affect hemichannel activity or Cx43 expression, but supratherapeutic concentration of CBZ decreased Cx43 expression and hemichannel activity. Therefore, the present study demonstrated the distinct effects of CBZ, LCM, and ZNS on gliotransmitter release via modulation of astroglial hemichannel function. The different features of the effects of three VDSC-inhibiting anticonvulsants on astroglial transmission associated with hemichannels, at least partially, possibly contributing to the formation of the properties of these three anticonvulsants, including the antiepileptic spectrum and adverse effects regarding mood and cognitive disturbance.