Norepinephrine-induced downregulation of GLT-1 mRNA in rat astrocytes
Norepinephrine-induced downregulation of GLT-1 mRNA in rat astrocytes
复制标题
去甲肾上腺素诱导大鼠星形胶质细胞中 GLT-1 mRNA 的下调
DOI：
10.1016/j.bbrc.2018.08.137
复制
发表时间：
2018
影响因子：
3.1
通讯作者：
Morimatsu Hiroshi
中科院分区：
文献类型：
--
作者：
Kurita Masako;Matsuoka Yoshikazu;Nakatsuka Kosuke;Ono Daisuke;Muto Noriko;Kaku Ryuji;Morimatsu Hiroshi
研究目的谷氨酸转运蛋白-1(GLT-1，又称兴奋性氨基酸转运蛋白2)在维持突触间隙谷氨酸稳态中起重要作用。已有报道在慢性疼痛模型中脊髓中GLT-1表达下调，这表明GLT-1参与了慢性疼痛的发生。然而，GLT-1在脊髓中下调的机制仍不清楚。我们推测去甲肾上腺素参与了GLT-1的调节。本研究旨在探讨去甲肾上腺素对体外培养的星形胶质细胞GLT-1表达的影响。我们首次用实时定量RT-PCR验证了备用神经损伤(SNI)大鼠脊髓中GLT-1mRNA表达的变化。接下来，用去甲肾上腺素刺激原代培养的大鼠脊髓星形胶质细胞，并对GLT-1mRNA进行定量。用去甲肾上腺素和其他α受体激动剂刺激星形胶质细胞株RNB细胞。体外研究表明，去甲肾上腺素和苯肾上腺素呈剂量依赖性地下调原代星形胶质细胞和RNB细胞中GLT-1的表达。结论去甲肾上腺素通过α受体拮抗剂下调星形胶质细胞α-1mRNA的表达。我们的结果为慢性疼痛模型中GLT-1下调的机制提供了新的见解。
Aim of the researchGlutamate transporter-1 (GLT-1; also known as excitatory amino acid transporter 2) plays an important role in the maintenance of glutamate homeostasis in the synaptic cleft. Downregulation of GLT-1 in the spinal cord has been reported in chronic pain models, which suggests that GLT-1 is involved in the development of chronic pain. However, the mechanism by which GLT-1 is downregulated in the spinal cord is still unknown. We hypothesized that norepinephrine is involved in the regulation of GLT-1. The aim of this study was to investigate the effect of norepinephrine onGLT-1expression in cultured astrocytes.MethodsThis study involved bothin vivoandin vitroexperiments. We first validated changes inGLT-1mRNA expression in the spinal cord of rats with spared nerve injury (SNI) using real-time RT-PCR. Next, cultured primary astrocytes from the rat spinal cord were stimulated with norepinephrine, andGLT-1mRNA was subsequently quantitated. RNB cells, an astrocytic cell line, were also stimulated with norepinephrine and other α-adrenoceptor agonists.ResultsSNI resulted in bilateral downregulation ofGLT-1in rat spinal cord. Thein vitrostudy showed that norepinephrine and phenylephrine dose-dependently downregulatedGLT-1in primary astrocytes and RNB cells. Furthermore, the effect of norepinephrine was reversed by an α-adrenoceptor antagonist.ConclusionNorepinephrine downregulatesGLT-1mRNA expression in astrocytes via the α1-adrenoceptor. Our results provide new insight into the mechanisms involved in downregulation of GLT-1 in the chronic pain models.