Calcitonin receptor-like and receptor activity modifying protein 1 in the rat dorsal horn localization in glutamatergic presynaptic terminal containing opioids and adrenergic α2c receptor
Calcitonin receptor-like and receptor activity modifying protein 1 in the rat dorsal horn localization in glutamatergic presynaptic terminal containing opioids and adrenergic α2c receptor
复制标题
DOI：
10.1016/j.neuroscience.2007.05.036
复制
发表时间：
2007-08-10
期刊：
影响因子：
3.3
通讯作者：
Todd, A. J.
中科院分区：
文献类型：
--
作者：
Marvizon, J. C. G.;Perez, O. A.;Todd, A. J.
降钙素基因相关肽（CGRP）在初级传入纤维的中枢终末含量丰富。然而，CGRP受体在脊髓中的功能仍不清楚。CGRP受体是降钙素受体样受体（CRLR）和受体活性修饰蛋白1（RAMP 1）的异源二聚体。我们研究了CRLR和RAMP 1在大鼠背角的定位，使用针对它们的表征良好的抗体，其标记了板层I-II中的许多斑点。此外，RAMP 1在细胞体中被发现，在细胞表面形成斑块。CRLR-和RAMP 1-免疫反应性斑点的进一步特点是使用双重和三重标记。使用Imaris软件在共聚焦堆栈中定量共定位。CRLR没有与初级传入标记共定位，表明这些斑点不是初级传入终末。CRLR和RAMP 1免疫反应点含有突触素和囊泡谷氨酸转运体2（VGLUT 2），表明它们是突触前神经元能的终末。电镜免疫组化证实，CRLR免疫反应存在于轴突终扣，而不是在突触肾小球。使用酪胺信号放大与CRLR和RAMP 1抗体的双标记，我们发现了一些明确的CRLR与RAMP 1共定位在斑点的情况下，但他们的整体共定位是低的。特别地，CRLR在含有RAMP 1的细胞中不存在。CRLR和RAMP 1染色的许多斑点被抗阿片和抗脑啡肽抗体标记。CRLR和RAMP 1在较小程度上也与肾上腺素能α（2c）受体共定位。三重标记研究证明了CRLR-VGLUT 2-突触素、CRLR-VGLUT 2-阿片样物质和CRLR-阿片样物质-α（2c）受体的三向共定位。总之，CRLR位于含有α（2c）肾上腺素能受体和阿片类药物的背角中的多巴胺能突触前末梢。这些末端中的一些含有RAMP 1，其可以与CRLR形成CGRP受体，但在其他CRLR中可能通过与RAMP 2或RAMP 3二聚化形成其他受体。这些结果表明，CGRP或肾上腺髓质素受体调节阿片类药物的释放在背角。(c)2007年IBRO。由爱思唯尔有限公司出版。保留所有权利。
Calcitonin gene-related peptide (CGRP) is abundant in the central terminals of primary afferents. However, the function of CGRP receptors in the spinal cord remains unclear. CGRP receptors are heterodimers of calcitonin receptor-like receptor (CRLR) and receptor activity modifying protein 1 (RAMP1). We studied the localization of CRLR and RAMP1 in the rat dorsal horn using well-characterized antibodies against them, which labeled numerous puncta in laminae I-II. In addition, RAMP1 was found in cell bodies, forming patches at the cell surface. The CRLR- and RAMP1-immunoreactive puncta were further characterized using double and triple labeling. Colocalization was quantified in confocal stacks using Imaris software. CRLR did not colocalize with primary afferent markers, indicating that these puncta were not primary afferent terminals. CRLR- and RAMP1-immunoreactive puncta contained synaptophysin and vesicular glutamate transporter-2 (VGLUT2), showing that they were glutamatergic presynaptic terminals. Electron microscopic immunohistochemistry confirmed that CRLR immunoreactivity was present in axonal boutons that were not in synaptic glomeruli. Using tyramide signal amplification for double labeling with the CRLR and RAMP1 antibodies, we found some clear instances of colocalization of CRLR with RAMP1 in puncta, but their overall colocalization was low. In particular, CRLR was absent from RAMP1-containing cells. Many of the puncta stained for CRLR and RAMP1 were labeled by antiopioid and anti-enkephalin antibodies. CRLR and, to a lesser extent, RAMP1 also colocalized with adrenergic alpha(2c) receptors. Triple label studies demonstrated three-way colocalization of CRLR-VGLUT2-synaptophysin, CRLR-VGLUT2-opioids, and CRLR-opioids-alpha(2c) receptors. In conclusion, CRLR is located in glutamatergic presynaptic terminals in the dorsal horn that contain alpha(2c) adrenergic receptors and opioids. Some of these terminals contain RAMP1, which may form CGRP receptors with CRLR, but in others CRLR may form other receptors, possibly by dimerizing with RAMP2 or RAMP3. These findings suggest that CGRP or adrenomedullin receptors modulate opioid release in the dorsal horn. (c) 2007 IBRO. Published by Elsevier Ltd. All rights reserved.