Laboratorio de Investigación (UGC Salud Mental), Instituto de Investigación Biomédica (IBIMA), Universidad de Málaga-Hospital Regional Universitario de Málaga Málaga, Spain ; CIBER OBN, Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación Madrid, Spain.
Laboratorio de Investigación (UGC Salud Mental), Instituto de Investigación Biomédica (IBIMA), Universidad de Málaga-Hospital Regional Universitario de Málaga Málaga, Spain.
Front Neuroanat. 2014 Mar 17;8:12. doi: 10.3389/fnana.2014.00012. eCollection 2014.
The N-acylethanolamines (NAEs), oleoylethanolamide (OEA) and palmithylethanolamide (PEA) are known to be endogenous ligands of PPARα receptors, and their presence requires the activation of a specific phospholipase D (NAPE-PLD) associated with intracellular Ca(2+) fluxes. Thus, the identification of a specific population of NAPE-PLD/PPARα-containing neurons that express selective Ca(2+)-binding proteins (CaBPs) may provide a neuroanatomical basis to better understand the PPARα system in the brain. For this purpose, we used double-label immunofluorescence and confocal laser scanning microscopy for the characterization of the co-existence of NAPE-PLD/PPARα and the CaBPs calbindin D28k, calretinin and parvalbumin in the rat hippocampus. PPARα expression was specifically localized in the cell nucleus and, occasionally, in the cytoplasm of the principal cells (dentate granular and CA pyramidal cells) and some non-principal cells of the hippocampus. PPARα was expressed in the calbindin-containing cells of the granular cell layer of the dentate gyrus (DG) and the SP of CA1. These principal PPARα(+)/calbindin(+) cells were closely surrounded by NAPE-PLD(+) fiber varicosities. No pyramidal PPARα(+)/calbindin(+) cells were detected in CA3. Most cells containing parvalbumin expressed both NAPE-PLD and PPARα in the principal layers of the DG and CA1/3. A small number of cells containing PPARα and calretinin was found along the hippocampus. Scattered NAPE-PLD(+)/calretinin(+) cells were specifically detected in CA3. NAPE-PLD(+) puncta surrounded the calretinin(+) cells localized in the principal cells of the DG and CA1. The identification of the hippocampal subpopulations of NAPE-PLD/PPARα-containing neurons that express selective CaBPs should be considered when analyzing the role of NAEs/PPARα-signaling system in the regulation of hippocampal functions.
N-酰基乙醇胺（NAEs），如油酰乙醇胺（OEA）和棕榈酰乙醇胺（PEA），是已知的 PPARα 受体的内源性配体，其存在需要与细胞内 Ca2+ 流相关的特定磷脂酶 D（NAPE-PLD）的激活。因此，鉴定表达选择性 Ca2+ 结合蛋白（CaBPs）的含有 NAPE-PLD/PPARα 的特定神经元群体，可能为更好地理解大脑中的 PPARα 系统提供神经解剖学基础。为此，我们使用双标记免疫荧光和共聚焦激光扫描显微镜来描述 NAPE-PLD/PPARα 与 CaBPs 钙结合蛋白 D28k、钙调蛋白和 parvalbumin 在大鼠海马中的共存。PPARα 表达特异性定位于细胞核，偶尔也定位于海马的主要细胞（齿状回颗粒细胞和 CA1 锥体细胞）和一些非主要细胞的细胞质中。PPARα 表达于颗粒细胞层的齿状回（DG）和 CA1 的 SP 中的 calbindin 阳性细胞中。这些主要的 PPARα(+)/calbindin(+) 细胞被 NAPE-PLD(+)纤维末梢紧密包围。在 CA3 中未检测到具有 pyramidal PPARα(+)/calbindin(+) 的细胞。含有 parvalbumin 的大多数细胞在 DG 和 CA1/3 的主要层中同时表达 NAPE-PLD 和 PPARα。在海马中发现了少量含有 PPARα 和 calretinin 的细胞。在 CA3 中特异性检测到分散的 NAPE-PLD(+)/calretinin(+) 细胞。NAPE-PLD(+) 斑点包围定位于 DG 和 CA1 主要细胞中的 calretinin(+) 细胞。当分析 NAE/PPARα 信号系统在调节海马功能中的作用时，应考虑鉴定含有 NAPE-PLD/PPARα 的神经元的海马亚群，这些神经元表达选择性的 CaBPs。
