Involvement of N-acylethanolamine-hydrolyzing acid amidase in the degradation of anandamide and other N-acylethanolamines in macrophages.
Involvement of N-acylethanolamine-hydrolyzing acid amidase in the degradation of anandamide and other N-acylethanolamines in macrophages.
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DOI：
10.1016/j.bbalip.2005.08.010
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发表时间：
2005-10
期刊：
影响因子：
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通讯作者：
Yong-xin Sun;K. Tsuboi;Li-ying Zhao;Y. Okamoto;D. Lambert;N. Ueda
中科院分区：
文献类型：
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作者：
Yong-xin Sun;K. Tsuboi;Li-ying Zhao;Y. Okamoto;D. Lambert;N. Ueda
已知包括内源性大麻素anandamide的生物活性N-酰基乙醇胺通过脂肪酸酰胺水解酶（FAAH）水解为脂肪酸和乙醇胺。此外，我们最近克隆了一种称为“N-酰基乙醇胺水解酸性酰胺酶（NAAA）"的同工酶，其仅在酸性pH下有活性[Tsuboi，Sun，Okamoto，Araki，Tonai，上田，J.Biol.Chem.285（2005）11082-11092]。然而，NAAA的生理作用仍不清楚。在这里，我们研究了可能的贡献NAAA的各种N-酰基乙醇胺在巨噬细胞中的降解。NAAA mRNA和FAAH mRNA在几种巨噬细胞样细胞中检测到，包括RAW 264.7和小鼠腹腔巨噬细胞。RAW264.7细胞的匀浆显示出NAAA和FAAH活性，这在它们各自的特异性抑制剂N-环己烷羰基十五胺（CCP）和URB 597的帮助下得到证实。如用完整细胞分析的，RAW264.7细胞和腹膜巨噬细胞降解花生四烯酸、N-棕榈酰乙醇胺、N-油酰乙醇胺和N-硬脂酰乙醇胺。用CCP或URB 597预处理细胞部分抑制降解，并且两种化合物的组合引起更深刻的抑制。相反，尽管NAAA在脑中表达，但小鼠脑中的花生四烯酸水解似乎主要归因于FAAH。这些结果表明，NAAA和FAAH在巨噬细胞中协同降解多种N-酰基乙醇胺。
Bioactive N-acylethanolamines including the endocannabinoid anandamide are known to be hydrolyzed to fatty acids and ethanolamine by fatty acid amide hydrolase (FAAH). In addition, we recently cloned an isozyme termed “N-acylethanolamine-hydrolyzing acid amidase (NAAA)”, which is active only at acidic pH [Tsuboi, Sun, Okamoto, Araki, Tonai, Ueda, J. Biol. Chem. 285 (2005) 11082–11092]. However, physiological roles of NAAA remained unclear. Here, we examined a possible contribution of NAAA to the degradation of various N-acylethanolamines in macrophage cells. NAAA mRNA as well as FAAH mRNA was detected in several macrophage-like cells, including RAW264.7, and mouse peritoneal macrophages. The homogenates of RAW264.7 cells showed both the NAAA and FAAH activities which were confirmed with the aid of their respective specific inhibitors, N-cyclohexanecarbonylpentadecylamine (CCP) and URB597. As analyzed with intact cells, RAW264.7 cells and peritoneal macrophages degraded anandamide, N-palmitoylethanolamine, N-oleoylethanolamine, and N-stearoylethanolamine. Pretreatment of the cells with CCP or URB597 partially inhibited the degradation, and a combination of the two compounds caused more profound inhibition. In contrast, the anandamide hydrolysis in mouse brain appeared to be principally attributable to FAAH despite the expression of NAAA in the brain. These results suggested that NAAA and FAAH cooperatively degraded various N-acylethanolamines in macrophages.