Co-expression of the voltage-gated potassium channel Kv1.4 with transient receptor potential channels (TRPV1 and TRPV2) and the cannabinoid receptor CB1 in rat dorsal root ganglion neurons
Co-expression of the voltage-gated potassium channel Kv1.4 with transient receptor potential channels (TRPV1 and TRPV2) and the cannabinoid receptor CB1 in rat dorsal root ganglion neurons
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DOI：
10.1016/j.neuroscience.2006.06.020
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发表时间：
2006-10-13
期刊：
影响因子：
3.3
通讯作者：
Treede, R. -D.
中科院分区：
文献类型：
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作者：
Binzen, U.;Greffrath, W.;Treede, R. -D.
钾通道有助于基本的神经元兴奋性和调节。在这里，我们通过免疫荧光双标记在大鼠背根神经节 (DRG) 切片中检查了电压门控钾通道 Kv1.4、伤害性转导通道 TRPV1 和 TRPV2 以及假定的抗伤害性大麻素受体 CB1 的表达模式。Kv1.4、TRPV1 和 CB1 分别在 约三分之一的神经元（分别为35.7+/-0.5%、29.4+/-1.1%和36.4+/-0.5%，平均直径19.1+/-0.3μm）。 TRPV2 存在于 4.4 +/- 0.4% 的所有神经元中，其直径明显较大（27.4 +/- 0.7 μm；P < 0.001）。抗体双标记显示大多数 Kv1.4 阳性神经元共表达 TRPV1 (73.9 +/- 1.5%)，而没有一个表达 TRPV2。 CB1 的重叠最大 (93.1 +/- 0.1%)。 CB1 表达与 Kv1.4 相似，因为大多数表达 CB1 蛋白的神经元也表达 TRPV1 (69.4 +/- 6.5%)，但不表达 TRPV2 (0.6 +/- 0.3%)。当使用原位杂交检测 CB1-mRNA 时，标记了额外的较大神经元子集，包括 82.4 +/- 17.7% 的 TRPV2 表达神经元。然而，Kv1.4 与 CB1-mRNA（92%，平均直径：18.5 μ m）的共定位与 CB1-蛋白的共定位基本相同。 CB1 和 Kv1.4 在伤害性 DRG 神经元中几乎完全重叠，表明 Kv1.4 和 CB1 之间存在功能协同作用。钾通道在伤害感受中可能有两个重要作用。作为 A 型电流的分子基础，它可能参与外周末端重复放电的控制，并作为 CB1 的下游信号转导位点控制中枢末端突触前递质的释放。 (c) 2006 年国际广播组织。由爱思唯尔有限公司出版。保留所有权利。
Potassium channels contribute to basic neuronal excitability and modulation. Here, we examined expression patterns of the voltage-gated potassium channel Kv1.4, the nociceptive transduction channels TRPV1 and TRPV2 as well as the putative anti-nociceptive cannabinoid receptor CB1 by immunofluorescence double-labelings in sections of rat dorsal root ganglia (DRGs).Kv1.4, TRPV1 and CB1 were each detected in about one third of neurons (35.7 +/- 0.5%, 29.4 +/- 1.1% and 36.4 +/- 0.5%, respectively, mean diameter 19.1 +/- 0.3 mu m). TRPV2 was present in 4.4 +/- 0.4% of all neurons that were significantly larger in diameter (27.4 +/- 0.7 mu m; P < 0.001). Antibody double-labeling revealed that the majority of Kv1.4-positive neurons co-expressed TRPV1 (73.9 +/- 1.5%) whereas none expressed TRPV2. The largest overlap was found with CB1 (93.1 +/- 0.1%). CB1 expression resembled that seen for Kv1.4 since the majority of neurons expressing CB1-protein also expressed TRPV1 (69.4 +/- 6.5%) but not TRPV2 (0.6 +/- 0.3%). When CB1-mRNA was detected using in situ hybridizations an additional subset of larger neurons was labeled including 82.4 +/- 17.7% of the TRPV2 expressing neurons. However, co-localization of Kv1.4 with CB1-mRNA (92%, mean diameter: 18.5 mu m) was essentially the same as with CB1-protein.The almost complete overlap of CB1 and Kv1.4 in nociceptive DRG neurons suggests a functional synergistic action between Kv1.4 and CB1. The potassium channel may have two important roles in nociception. As the molecular basis of A-type current it could be involved in the control of repetitive discharges at peripheral terminals and as a downstream signal transduction site of CB1 in the control of presynaptic transmitter release at central terminals. (c) 2006 IBRO. Published by Elsevier Ltd. All rights reserved.