中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2023, Vol. 18 ›› Issue (3): 594-602.doi: 10.4103/1673-5374.350206

• 原著:脑损伤修复保护与再生 • 上一篇    下一篇

活化代谢型谷氨酸受体1调节癫痫持续状态下海马CA1区的兴奋性

  

  • 出版日期:2023-03-15 发布日期:2022-08-27
  • 基金资助:
    中国国家自然科学基金项目（81760242）

Activation of metabotropic glutamate receptor 1 regulates hippocampal CA1 region excitability in rats with status epilepticus by suppressing the HCN1 channel

Xiao-Dan Luo1, Tao Xiang1, 2, Si-Jun Li1, Mei-Gang Ma1, Mei-Ling Chen1, 3, Yuan Wu1, *   

  1. 1Department of Neurology, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, China; 2Department of Neurology, First Affiliated Hospital of University of South China, Hengyang, Hunan Province, China; 3Department of Neurology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi Zhuang Autonomous Region, China
  • Online:2023-03-15 Published:2022-08-27
  • Contact: Yuan Wu, MD, PhD, nwuyuan90@163.com.
  • Supported by:
    This work was supported by the National Natural Science Foundation of China, No. 81760242 (to MGM).

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摘要：

超极化激活的环核苷酸门控阳离子通道表达失调可导致神经元兴奋性发生变化，但其在癫痫持续状态中的作用尚不完全清楚。（1）实验构建了戊四唑诱导的癫痫持续状态大鼠模型。（2）蛋白印迹和免疫荧光染色结果发现，海马CA1区中超极化激活的环核苷酸门控阳离子1明显减少，尤其是超极化激活的环核苷酸门控阳离子1表面蛋白，而超极化激活的环核苷酸门控阳离子2的表达没有变化，且代谢谷氨酸受体1表达增加。（3）在大鼠右侧脑室注射1组代谢型谷氨酸受体激动剂(RS)-3,5-二羟基苯甘氨酸（DHPG）提高了戊四唑诱导癫痫持续状态的敏感性和严重性，而代谢型谷氨酸受体1选择性拮抗剂LY367385则减轻戊四唑诱导癫痫持续状态的严重程度。（4）免疫荧光双标记结果显示代谢型谷氨酸受体1 和超极化激活的环核苷酸门控阳离子1在海马CA1区存在共定位。（5）腹腔注射蛋白激酶A 抑制剂H89成功逆转了超极化激活的环核苷酸门控阳离子1 通道的作用，从而抑制戊四唑诱导癫痫持续状态的严重性并延长了潜伏期。（6）H89还能降低海马CA1区代谢型谷氨酸受体1水平，下调 环磷酸腺苷-蛋白激酶A表达，逆转调节超极化激活的环核苷酸门控阳离子1表面蛋白Rab8b相互作用的TRIP8b (1a-4)及TRIP8b (1b-2)水平。（7）活化代谢型谷氨酸受体1调节癫痫持续状态下海马CA1区兴奋性的研究还需深入揭示是否为调节此状态时的核心靶点，才有可能具有应用开发的潜力。

https://orcid.org/0000-0002-3282-1298 (Yuan Wu)

关键词:

超极化激活的环核苷酸门控阳离子通道, 超极化激活的环核苷酸门控阳离子1, 激活代谢型谷氨酸受体, 戊四唑, 癫痫持续状态, 海马CA1区, 兴奋性, (RS)-3,5-二羟基苯甘氨酸（DHPG）, LY367385, H89

Abstract: Dysregulation of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels alters neuronal excitability. However, the role of HCN channels in status epilepticus is not fully understood. In this study, we established rat models of pentylenetetrazole-induced status epilepticus. We performed western blot assays and immunofluorescence staining. Our results showed that HCN1 channel protein expression, particularly HCN1 surface protein, was significantly decreased in the hippocampal CA1 region, whereas the expression of HCN2 channel protein was unchanged. Moreover, metabolic glutamate receptor 1 (mGluR1) protein expression was increased after status epilepticus. The mGluR1 agonist (RS)-3,5-dihydroxyphenylglycine injected intracerebroventricularly increased the sensitivity and severity of pentylenetetrazole-induced status epilepticus, whereas application of the mGluR1 antagonist (+)-2-methyl-4-carboxyphenylglycine (LY367385) alleviated the severity of pentylenetetrazole-induced status epilepticus. The results from double immunofluorescence labeling revealed that mGluR1 and HCN1 were co-localized in the CA1 region. Subsequently, a protein kinase A inhibitor (H89) administered intraperitoneally successfully reversed HCN1 channel inhibition, thereby suppressing the severity and prolonging the latency of pentylenetetrazole-induced status epilepticus. Furthermore, H89 reduced the level of mGluR1, downregulated cyclic adenosine monophosphate (cAMP)/protein kinase A expression, significantly increased tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b) (1a-4) expression, and restored TRIP8b (1b-2) levels. TRIP8b (1a-4) and TRIP8b (1b-2) are subunits of Rab8b interacting protein that regulate HCN1 surface protein. 

Key words: (RS)-3,5-dihydroxyphenylglycine, CA1 region, excitability, H89, HCN1 channel, LY367385, mGluR1, pentylenetetrazole, status epilepticus