RNA interference suggests a primary role for monoacylglycerol lipase in the degradation of the endocannabinoid 2-arachidonoylglycerol
RNA interference suggests a primary role for monoacylglycerol lipase in the degradation of the endocannabinoid 2-arachidonoylglycerol
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DOI：
10.1124/mol.104.002071
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发表时间：
2004-11-01
影响因子：
3.6
通讯作者：
Piomelli, D
中科院分区：
文献类型：
--
作者：
Dinh, TP;Kathuria, S;Piomelli, D
内源性大麻素2-花生四烯醇甘油（2-AG）是由神经元和其他细胞以刺激依赖的方式产生的，并通过转运到细胞和催化水解经历快速的生物失活。负责2-AG降解的酶途径仅部分了解。我们之前已经证明，单酰基甘油脂肪酶（MGL）是一种细胞质丝氨酸水解酶，可将1-和2-单酰基甘油裂解为脂肪酸和甘油，过表达可减少刺激依赖性2-AG在大鼠脑神经原代培养中的积累。我们在这里报道，RNA干扰介导的MGL表达沉默极大地增强了2-AG在HeLa细胞中的积累。在用钙离子载体离子霉素刺激后，mgl沉默细胞中的2-AG水平与使用2-AG水解的非选择性抑制剂花生四烯基氟膦酸甲酯阻断2-AG降解的细胞中的2-AG水平相当。结果表明，MGL在完整HeLa细胞内源性2-AG的降解中起重要作用。此外，免疫消耗实验表明，MGL至少占大鼠脑可溶性部分2-AG水解总活性的50%，这表明该酶也有助于中枢神经系统2-AG失活。
The endogenous cannabinoid 2-arachidonoylglycerol (2-AG) is produced by neurons and other cells in a stimulus-dependent manner and undergoes rapid biological inactivation through transport into cells and catalytic hydrolysis. The enzymatic pathways responsible for 2-AG degradation are only partially understood. We have shown previously that overexpression of monoacylglycerol lipase (MGL), a cytosolic serine hydrolase that cleaves 1- and 2-monoacylglycerols to fatty acid and glycerol, reduces stimulus-dependent 2-AG accumulation in primary cultures of rat brain neurons. We report here that RNA interference-mediated silencing of MGL expression greatly enhances 2-AG accumulation in HeLa cells. After stimulation with the calcium ionophore ionomycin, 2-AG levels in MGL-silenced cells were comparable with those found in cells in which 2-AG degradation had been blocked using methyl arachidonyl fluorophosphonate, a nonselective inhibitor of 2-AG hydrolysis. The results indicate that MGL plays an important role in the degradation of endogenous 2-AG in intact HeLa cells. Furthermore, immunodepletion experiments show that MGL accounts for at least 50% of the total 2-AG-hydrolyzing activity in soluble fractions of rat brain, suggesting that this enzyme also contributes to 2-AG deactivation in the central nervous system.