Endogenous molecules stimulating N-acylethanolamine-hydrolyzing acid amidase(NAAA)
Endogenous molecules stimulating N-acylethanolamine-hydrolyzing acid amidase(NAAA)
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刺激N-酰基乙醇胺水解酸性酰胺酶（NAAA）的内源分子
DOI：
10.1021/cn300007s
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Ueda N
中科院分区：
文献类型：
--
作者：
Tai T;Tsuboi K;Uyama T;Ma Cravatt BF;Houchi H;Ueda N
脂肪酸酰胺水解酶（FAAH）在脑和外周组织中生物活性N-酰基乙醇胺如内源性大麻素花生四烯酰乙醇酰胺（anandamide）的降解中起核心作用。被称为N-酰基乙醇胺水解酸性酰胺酶（NAAA）的溶酶体酶催化相同的反应，优选棕榈酰乙醇酰胺（内源性镇痛和神经保护物质），因此预期作为治疗药物的潜在靶标。在迄今为止进行的体外试验中，在非离子去污剂（Triton X-100或Nonidet P-40）和SH试剂二硫苏糖醇存在下，NAAA达到最大活性。然而，可能取代这些合成化合物的内源性分子仍然知之甚少。在这里，我们研究了内源性磷脂和巯基化合物对重组NAAA的刺激作用。在测试的不同磷脂中，含胆碱或乙醇胺的磷脂显示出有效的作用，1 mM磷脂酰胆碱使NAAA活性增加6.6倍。关于内源性硫醇化合物，0.1-1 mM的二氢硫辛酸是最活跃的，引起8.5-9.0倍的刺激。这些结果表明，内源性磷脂和二氢硫辛酸可能有助于保持NAAA在溶酶体中的活性。然而，即使在磷脂酰胆碱和二氢硫辛酸的存在下，棕榈酰乙醇酰胺的优先水解是不变的。我们还研究了FAAH缺陷小鼠脑和其他组织中NAAA mRNA的可能代偿诱导。然而，NAAA的表达水平在所有组织检查没有显着改变，从野生型小鼠。
Fatty acid amide hydrolase (FAAH) plays the central role in the degradation of bioactive N-acylethanolamines such as the endocannabinoid arachidonoylethanolamide (anandamide) in brain and peripheral tissues. A lysosomal enzyme referred to as N-acylethanolamine-hydrolyzing acid amidase (NAAA) catalyzes the same reaction with preference to palmitoylethanolamide, an endogenous analgesic and neuroprotective substance, and is therefore expected as a potential target of therapeutic drugs. In the in vitro assays thus far performed, the maximal activity of NAAA was achieved in the presence of both nonionic detergent (Triton X-100 or Nonidet P-40) and the SH reagent dithiothreitol. However, endogenous molecules that might substitute for these synthetic compounds remain poorly understood. Here, we examined stimulatory effects of endogenous phospholipids and thiol compounds on recombinant NAAA. Among different phospholipids tested, choline-or ethanolamine-containing phospholipids showed potent effects, and 1 mM phosphatidylcholine increased NAAA activity by 6.6-fold. Concerning endogenous thiol compounds, dihydrolipoic acid at 0.1–1 mM was the most active, causing 8.5–9.0-fold stimulation. These results suggest that endogenous phospholipids and dihydrolipoic acid may contribute in keeping NAAA active in lysosomes. Even in the presence of phosphatidylcholine and dihydrolipoic acid, however, the preferential hydrolysis of palmitoylethanolamide was unaltered. We also investigated a possible compensatory induction of NAAA mRNA in brain and other tissues of FAAH-deficient mice. However, NAAA expression levels in all the tissues examined were not significantly altered from those in wild-type mice.