GENE EXPRESSION AND PROTEIN DISTRIBUTION OF OREXINS AND OREXIN RECEPTORS IN RAT RETINA
GENE EXPRESSION AND PROTEIN DISTRIBUTION OF OREXINS AND OREXIN RECEPTORS IN RAT RETINA
复制标题
大鼠视网膜中食欲素和食欲素受体的基因表达和蛋白质分布
DOI：
10.1016/j.neuroscience.2011.04.011
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发表时间：
2011-08-25
期刊：
影响因子：
3.3
通讯作者：
Zhong, Y. M.
中科院分区：
文献类型：
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作者：
Liu, F.;Xu, G. Z.;Zhong, Y. M.
食欲素由食欲素A和食欲素B组成，被鉴定为两种孤儿G蛋白偶联受体：食欲素1和食欲素2受体（Ox 1 R和Ox 2 R）的内源性配体。Orexins参与调节觉醒/睡眠状态、摄食行为等。本研究采用逆转录-聚合酶链反应（RT-PCR）和免疫荧光双标记技术，研究了Orexin A、Orexin B、OX1 R和OX2 R在大鼠视网膜中的分布。RT-PCR分析显示大鼠视网膜中存在前食欲素原、OX1R和OX2R的mRNA。在内核层和神经节细胞层的许多细胞中观察到食欲素A和食欲素B的免疫染色。在外视网膜，水平细胞，标记的钙结合蛋白，双极细胞，标记的同源框蛋白Chx10，食欲素A和食欲素B阳性。在视网膜内层，分别用酪氨酸羟化酶和胆碱乙酰转移酶染色，在GABA能无长突细胞（AC）中发现两种食欲素，包括多巴胺能和胆碱能AC。甘氨酸能AC，包括所有AC，也表达食欲素。增食欲素A和增食欲素B的弱至中度标记弥漫分布于内丛状层。此外，orexins表达在几乎所有的神经节细胞（GC）逆行标记的霍乱毒素B亚基。具体地，双标记实验表明，黑视素阳性GC（固有光敏视网膜GC，ipRGC）被两种食欲素标记。此外，OX1R免疫反应在大多数GC和所有多巴胺能AC中观察到，以及在外和内丛状层。相反，在大鼠视网膜中没有明显的OX2R免疫染色。这些结果表明，食欲素可以调节神经元的功能，特别是在视网膜内层。我们进一步假设，食欲素信号通过ipRGCs可能参与设置视交叉上核（SCN）昼夜节律钟。(C)2011年IBRO。由爱思唯尔有限公司出版。保留所有权利。
Orexins, composed of orexin A and orexin B, are identified as endogenous ligands of two orphan G-protein-coupled receptors: orexin 1 and orexin 2 receptors (OX1R and OX2R). Orexins are implicated in regulating wake/sleep states, feeding behaviors, etc. Using reverse transcription-polymerase chain reactive (RT-PCR) analysis and immunofluorescence double labeling, we investigated the distributions of orexin A, orexin B, OX1R and OX2R in rat retina. RT-PCR analysis revealed the presence of mRNAs of preproorexin, OX1R and OX2R in rat retina. Immunostaining for orexin A and orexin B was observed in many cells in the inner nuclear layer and the ganglion cell layer. In the outer retina, horizontal cells, labeled by calbindin, and bipolar cells, labeled by homeobox protein Chx10, were orexin A- and orexin B-positive. In the inner retina, two orexins were both found in GABAergic amacrine cells (ACs), including dopaminergic and cholinergic ones, stained by tyrosine hydroxylase and choline acetyltransferase respectively. Glycinergic ACs, including All ACs, also expressed orexins. Weak to moderate labeling for orexin A and orexin B was diffusely distributed in the inner plexiform layer. Additionally, orexins were expressed in almost all ganglion cells (GCs) retrogradely labeled by cholera toxin B subunit. Specifically, double-labeling experiments demonstrated that melanopsin-positive GCs (intrinsically photosensitive retinal GCs, ipRGCs) were labeled by two orexins. Morever, OX1R immunoreactivity was observed in most of GCs and all dopaminergic ACs, as well as in both outer and inner plexiform layers. In contrast, no obvious OX2R immunostaining was detectable in the rat retina. These results suggest that orexins may modulate the function of neurons, especially in the inner retina. We further hypothesize that the orexin signaling via ipRGCs may be involved in setting the suprachiasmatic nucleus (SCN) circadian clock. (C) 2011 IBRO. Published by Elsevier Ltd. All rights reserved.