Division of Psychiatry I, Department of Psychiatry, Psychotherapy and Psychosomatics, Medical University Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria.
Stiftung Maria Ebene, Maria Ebene 17, 6820, Frastanz, Austria.
Brain Struct Funct. 2018 Jul;223(6):2663-2671. doi: 10.1007/s00429-018-1653-x. Epub 2018 Mar 21.
In this study, we investigated the tissue expression levels, alpha subunit composition and distribution of Shaker-related voltage-dependent potassium Kv1 channels in human hippocampus by combining western blotting experiments, toxin autoradiography, in vivo radioligand binding studies, immunoprecipitation and immunohistochemistry. Tissue expression of Kv1.1 and Kv1.2 α-subunits in human post-mortem brain tissue was confirmed in immunoblot analysis using a panel of specific monoclonal and polyclonal antibodies. Immunoprecipitation experiments using toxin-prelabeled Kv1 channels revealed that all toxin-sensitive Kv1 channels in human hippocampus contained either a Kv1.1 or Kv1.2 α-subunit with the majority being composed of Kv1.1/Kv1.2 heterotetramers. Receptor autoradiography suggested Kv1.1/Kv1.2 channel expression in the molecular layer of dentate gyrus. In accordance, immunohistochemical experiments also observed Kv1.1 and Kv1.2 α-subunits in the molecular layer of the dentate gyrus, in addition to the CA3 stratum lucidum and the CA1 stratum oriens. These findings indicate expression in axons and terminals of hippocampal pathways, namely the perforant path, the mossy fiber pathway and the Schaffer collaterals. Herein we present the first direct demonstration that Kv1.1 and Kv1.2 channel proteins are targeted to distinct compartments of the human hippocampal formation and that this expression pattern largely reflects their distribution profile in murine brain.
在这项研究中，我们通过结合 Western blot 实验、毒素放射性自显影、体内放射性配体结合研究、免疫沉淀和免疫组织化学方法，研究了 Shaker 相关电压依赖性钾 Kv1 通道在人海马体中的组织表达水平、α 亚基组成和分布。使用一系列特异性单克隆和多克隆抗体，在免疫印迹分析中证实了 Kv1.1 和 Kv1.2α亚基在人死后脑组织中的组织表达。使用毒素预标记的 Kv1 通道进行免疫沉淀实验表明，人海马体中所有毒素敏感的 Kv1 通道均含有 Kv1.1 或 Kv1.2α亚基，其中大多数由 Kv1.1/Kv1.2 异四聚体组成。受体放射性自显影表明 Kv1.1/Kv1.2 通道在齿状回分子层中表达。相应地，免疫组织化学实验还观察到 Kv1.1 和 Kv1.2α亚基在齿状回的分子层中，以及 CA3 层的 lucidum 和 CA1 层的 oriens。这些发现表明 Kv1.1 和 Kv1.2 通道蛋白在海马通路的轴突和末梢中表达，即穿通通路、苔藓纤维通路和 Schaffer 侧支。本文首次直接证明 Kv1.1 和 Kv1.2 通道蛋白靶向人海马体的不同隔室，并且这种表达模式在很大程度上反映了它们在鼠脑中的分布模式。
