Functional G-protein-coupled receptor 35 is expressed by neurons in the CA1 field of the hippocampus
Functional G-protein-coupled receptor 35 is expressed by neurons in the CA1 field of the hippocampus
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DOI：
10.1016/j.bcp.2014.12.009
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发表时间：
2015-02-15
影响因子：
5.8
通讯作者：
Albuquerque, Edson X.
中科院分区：
文献类型：
--
作者：
Alkondon, Manickavasagom;Pereira, Edna F. R.;Albuquerque, Edson X.
g蛋白偶联受体35 （GPR35）在发现内源性色氨酸代谢物犬尿酸（KYNA）作为该受体的激动剂后被去孤化。大量证据支持GPR35主要存在于外周组织中。在这里，我们验证了GPR35存在于海马体中并影响神经元活动的假设。采用抗neun抗体（神经元标记物）、抗gfap抗体（胶质标记物）和抗GPR35抗体进行荧光免疫组化染色，结果显示海马CA1区定向层、锥体层和辐射层的神经元表达GPR35。为了确定功能性GPR35在神经回路中的存在，我们测试了各种GPR35激动剂对大鼠海马切片中辐射层中间神经元（SRIs）在细胞附着结构下以快速电流瞬变（CTs）记录的自发动作电位频率的影响。使用GPR35激动剂zaprinast （1-10 μ M）、dicumarol （50-100 μ M）、pamoic acid （500-1000 μ M）和amlexanox （3 μ M）可使ct频率呈浓度依赖性和时间依赖性降低。海马切片灌注GPR35拮抗剂ML145 （1 μ M）可增加ct的频率，降低zaprinast的抑制作用。磷酸二酯酶5抑制剂西地那非（1或5 μ M）浴液应用无效，而随后应用zaprinast可有效降低CT频率。本研究结果首次证实功能性GPR35s可通过CA1神经元表达，并提示这些受体可能是控制海马神经元活动的分子靶点。(C) 2015出版的爱思唯尔公司。
The G-protein-coupled receptor 35 (GPR35) was de-orphanized after the discovery that kynurenic acid (KYNA), an endogenous tryptophan metabolite, acts as an agonist of this receptor. Abundant evidence supports that GPR35 exists primarily in peripheral tissues. Here, we tested the hypothesis that GPR35 exists in the hippocampus and influences the neuronal activity. Fluorescence immunohistochemical staining using an antibody anti-NeuN (a neuronal marker), an antibody anti-GFAP (a glial marker), and an antibody anti-GPR35 revealed that neurons in the stratum oriens, stratum pyramidale, and stratum radiatum of the CA1 field of the hippocampus express GPR35. To determine the presence of functional GPR35 in the neurocircuitry, we tested the effects of various GPR35 agonists on the frequency of spontaneous action potentials recorded as fast current transients (CTs) from stratum radiatum interneurons (SRIs) under cell-attached configuration in rat hippocampal slices. Bath application of the GPR35 agonists zaprinast (1-10 mu M), dicumarol (50-100 mu M), pamoic acid (500-1000 mu M), and amlexanox (3 mu M) produced a concentration- and time-dependent reduction in the frequency of CTs. Superfusion of the hippocampal slices with the GPR35 antagonist ML145 (1 mu M) increased the frequency of CTs and reduced the inhibitory effect of zaprinast. Bath application of phosphodiesterase 5 inhibitor sildenafil (1 or 5 mu M) was ineffective, whereas a subsequent application of zaprinast was effective in reducing the CT frequency. The present results demonstrate for the first time that functional GPR35s are expressed by CA1 neurons and suggest that these receptors can be molecular targets for controlling neuronal activity in the hippocampus. (C) 2015 Published by Elsevier Inc.