Mechanisms for recycling and biosynthesis of endogenous cannabinoids anandamide and 2-arachidonylglycerol.
Mechanisms for recycling and biosynthesis of endogenous cannabinoids anandamide and 2-arachidonylglycerol.
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内源性大麻素 anandamide 和 2-arachidonylglycerol 的回收和生物合成机制。
DOI：
10.1111/j.1471-4159.2008.05659.x
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发表时间：
2008
影响因子：
4.7
通讯作者：
Barker,EricL
中科院分区：
文献类型：
--
作者：
Placzek,EkaterinaA;Okamoto,Yasuo;Ueda,Natsuo;Barker,EricL
内源性大麻素生物合成的机制尚不完全清楚。我们假设双胺可以被细胞循环，形成新的内源性大麻素分子，并释放到细胞外空间。我们确定RBL-2H3细胞合成并释放了外源性花生胺或花生四烯酸衍生的新的内源性大麻素。用制霉菌素和孕酮处理RBL-2H3细胞，这两种破坏脂筏/小窝组织的药物，导致Anand酰胺和2-花生四烯基甘油的合成和/或释放对离子霉素的刺激反应减弱，这表明这些膜微区在内源性大麻素的生物合成中起作用。此外，由于在RBL-2H3细胞中未检测到N-酰基磷脂酰乙醇胺磷脂酶D的表达，因此该酶的合成可能不依赖于N-酰基磷脂酰乙醇胺。我们还证实，细胞外钙对于内源性大麻素的生物合成是必需的，因为单靠细胞内钙的释放并不能促进内源性大麻素的生物合成。接下来，我们研究了钙作为一个“开关”来激活花生胺的合成，同时减少摄取的作用。事实上，在钙存在的情况下，[~3H]山梨胺的摄取减少了。我们的发现暗示了钙调节激活花生胺合成和同时终止摄取的机制。
The mechanisms of endogenous cannabinoid biosynthesis are not completely understood. We hypothesized that anandamide could be recycled by the cell to form new endocannabinoid molecules and released into the extracellular space. We determined that new endocannabinoids derived from exogenous anandamide or arachidonic acid were synthesized and released from RBL‐2H3 cells in response to ionomycin. Treatment of RBL‐2H3 cells with nystatin and progesterone, agents that disrupt organization of lipid raft/caveolae, resulted in the attenuation of anandamide and 2‐arachidonyl glycerol synthesis and/or release in response to stimulation with ionomycin suggesting a role for these membrane microdomains in endocannabinoid biosynthesis. Furthermore, anandamide synthesis may be independent ofN‐acyl phosphatidylethanolamine phospholipase D as expression of the enzyme was not detected in RBL‐2H3 cells. We also established that extracellular calcium is necessary for endocannabinoid biosynthesis because release of intracellular calcium stores alone does not promote endocannabinoid biosynthesis. Next, we examined the role of calcium as a ‘switch’ to activate the synthesis of anandamide and simultaneously reduce uptake. Indeed, [3H] anandamide uptake was reduced in the presence of calcium. Our findings suggest a mechanism indicative of calcium‐modulated activation of anandamide synthesis and simultaneous termination of uptake.