Department of Neuroscience, Biomedicum, Karolinska Institutet, Stockholm, Sweden.
Department of Molecular Neurosciences, Center for Brain Research, Medical University of Vienna, Vienna, Austria.
Cannabis Cannabinoid Res. 2021 Apr 15;6(2):119-136. doi: 10.1089/can.2020.0010. eCollection 2021 Apr.
In mammals, sn-1-diacylglycerol lipases (DAGL) generate 2-arachidonoylglycerol (2-AG) that, as the major endocannabinoid, modulates synaptic neurotransmission by acting on CB1 cannabinoid receptors (CBR). Even though the insect genome codes for , which is a DAGL ortholog (dDAGL), its products and their functions remain unknown particularly because insects lack chordate-type cannabinoid receptors. Gain-of-function and loss-of-function genetic manipulations were carried out in , including the generation of both dDAGL-deficient and mammalian CBR-overexpressing flies. Neuroanatomy, dietary manipulations coupled with targeted mass spectrometry determination of arachidonic acid and 2-linoleoyl glycerol (2-LG) production, behavioral assays, and signal transduction profiling for Akt and Erk kinases were employed. Findings from were validated by a CBR-binding assay for 2-LG in mammalian cortical homogenates with functionality confirmed in neurons using high-throughput real-time imaging . In this study, we show that dDAGL is primarily expressed in the brain and nerve cord of during larval development and in adult with 2-LG being its chief product as defined by dietary precursor availability. Overexpression of the human CBR in the ventral nerve cord compromised the mobility of adult . The causality of 2-LG signaling to CBR-induced behavioral impairments was shown by inactivation normalizing defunct motor coordination. The 2-LG-induced activation of transgenic CBRs affected both Akt and Erk kinase cascades by paradoxical signaling. Data from models were substantiated by showing 2-LG-mediated displacement of [H]CP 55,940 in mouse cortical homogenates and reduced neurite extension and growth cone collapsing responses in cultured mouse neurons. Overall, these results suggest that 2-LG is an endocannabinoid-like signal lipid produced by dDAGL in .
在哺乳动物中， sn-1-二酰基甘油脂肪酶（DAGL）产生 2-花生四烯酸甘油（2-AG），作为主要的内源性大麻素，通过作用于 CB1 大麻素受体（CBR）来调节突触神经传递。尽管昆虫基因组编码 ，这是 DAGL 的同源物（dDAGL），但其产物及其功能仍然未知，特别是因为昆虫缺乏脊索动物型大麻素受体。 在 中进行了功能获得和功能丧失的遗传操作，包括生成 dDAGL 缺陷和哺乳动物 CBR 过表达的果蝇。神经解剖学、饮食操作以及靶向质 谱法测定花生四烯酸和 2-亚油酸甘油（2-LG）的产生、行为测定以及 Akt 和 Erk 激酶的信号转导分析都被采用。 在哺乳动物皮质匀浆中使用 CBR-2-LG 结合测定法和在神经元中使用高通量实时成像功能验证了 ，在神经元中证实了功能。 在这项研究中，我们表明 dDAGL 在幼虫发育期间主要在 和成虫的大脑和神经索中表达，并且 2-LG 是其主要产物，如饮食前体可用性所定义的。 在腹神经索中过表达人类 CBR 会损害 的移动性。 通过 失活使功能失调的运动协调正常化，显示了 2-LG 信号对 CBR 诱导的行为损伤的因果关系。 2-LG 诱导的转基因 CBR 激活通过矛盾信号影响 Akt 和 Erk 激酶级联。 通过显示 2-LG 介导的 [H]CP 55,940 在小鼠皮质匀浆中的置换以及在培养的小鼠神经元中减少神经突延伸和生长锥塌陷反应，证实了 模型的数据。 总体而言，这些结果表明 2-LG 是由 在 中产生的内源性大麻素样信号脂质。
