N-arachidonoyl glycine, an abundant endogenous lipid, potently drives directed cellular migration through GPR18, the putative abnormal cannabidiol receptor.
N-arachidonoyl glycine, an abundant endogenous lipid, potently drives directed cellular migration through GPR18, the putative abnormal cannabidiol receptor.
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DOI：
10.1186/1471-2202-11-44
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发表时间：
2010-03-26
期刊：
影响因子：
2.4
通讯作者：
Bradshaw HB
中科院分区：
文献类型：
--
作者：
McHugh D;Hu SS;Rimmerman N;Juknat A;Vogel Z;Walker JM;Bradshaw HB
小胶质细胞提供CNS的连续免疫监视，并且在活化后迅速改变表型以表达在CNS损伤或感染期间响应于化学引诱物的受体。这些活化的小胶质细胞经历向受影响组织的定向迁移。重要的是，遇到的化学引诱物的分子种类决定了小胶质细胞是否以促炎或抗炎行为响应，但触发迁移的信号分子仍然知之甚少。内源性大麻素系统通过CB 2受体和一种尚未鉴定的称为“异常大麻二酚”（Abn-CBD）受体的GPCR调节小胶质细胞迁移。Abn-CBD是植物大麻素大麻二酚（CBD）的合成异构体，对CB 1或CB 2受体无活性，但在这种Gi/o偶联的GPCR中起选择性激动剂的作用。N-花生四烯酰甘氨酸（NAGly）是内源性大麻素anandamide的内源性代谢物，并作为GPR 18的有效激动剂。在这里，我们研究NAGly，Abn-CBD，未鉴定的'Abn-CBD'受体，GPR 18和BV-2小胶质细胞迁移之间的关系。使用Boyden室迁移实验、黄四唑（MTT）转化、细胞内蛋白质印迹、qPCR和免疫细胞化学，我们表明，亚纳摩尔浓度的NAGly和Abn-CBD在BV-2小胶质细胞和HEK 293-GPR 18转染的细胞中有效地驱动细胞迁移，但在HEK-GPR 55或未转染的HEK 293野生型细胞中均不诱导迁移。在这两个系统中，迁移作用被“Abn-CBD”受体拮抗剂O-1918和低功效激动剂N-花生四烯酸-丝氨酸和大麻二酚阻断或减弱。NAGly在低纳摩尔浓度下促进BV-2小胶质细胞和HEK 293-GPR 18细胞中MAP激酶的增殖和活化-与小胶质细胞迁移相关的细胞应答。此外，BV-2细胞显示GPR 18免疫细胞化学染色和丰富的GPR 18 mRNA。qPCR表明，原代小胶质细胞同样表达大量的GPR 18 mRNA。NAGly是目前报道的BV-2小胶质细胞的最有效的脂质募集剂，其作用类似于Abn-CBD的作用。这项研究产生的数据支持GPR 18是以前未鉴定的“Abn-CBD”受体的假设。NAGly作用于GPR 18以引发定向迁移、增殖和可能的其他MAPK依赖性现象的显著效力推进了我们对CNS所采用的基于脂质的信号传导机制的理解，所述基于脂质的信号传导机制将小胶质细胞主动募集到感兴趣的位点。它为开发治疗方法提供了一种新的研究途径，以引发神经再生小胶质细胞的自我更新群体，或者预防导致和加剧神经退行性疾病的误导性促炎性小胶质细胞的积累。
Microglia provide continuous immune surveillance of the CNS and upon activation rapidly change phenotype to express receptors that respond to chemoattractants during CNS damage or infection. These activated microglia undergo directed migration towards affected tissue. Importantly, the molecular species of chemoattractant encountered determines if microglia respond with pro- or anti-inflammatory behaviour, yet the signaling molecules that trigger migration remain poorly understood. The endogenous cannabinoid system regulates microglial migration via CB2 receptors and an as yet unidentified GPCR termed the 'abnormal cannabidiol' (Abn-CBD) receptor. Abn-CBD is a synthetic isomer of the phytocannabinoid cannabidiol (CBD) and is inactive at CB1 or CB2 receptors, but functions as a selective agonist at this Gi/o-coupled GPCR. N-arachidonoyl glycine (NAGly) is an endogenous metabolite of the endocannabinoid anandamide and acts as an efficacious agonist at GPR18. Here, we investigate the relationship between NAGly, Abn-CBD, the unidentified 'Abn-CBD' receptor, GPR18, and BV-2 microglial migration. Using Boyden chamber migration experiments, yellow tetrazolium (MTT) conversion, In-cell Western, qPCR and immunocytochemistry we show that NAGly, at sub-nanomolar concentrations, and Abn-CBD potently drive cellular migration in both BV-2 microglia and HEK293-GPR18 transfected cells, but neither induce migration in HEK-GPR55 or non-transfected HEK293 wildtype cells. Migration effects are blocked or attenuated in both systems by the 'Abn-CBD' receptor antagonist O-1918, and low efficacy agonists N-arachidonoyl-serine and cannabidiol. NAGly promotes proliferation and activation of MAP kinases in BV-2 microglia and HEK293-GPR18 cells at low nanomolar concentrations - cellular responses correlated with microglial migration. Additionally, BV-2 cells show GPR18 immunocytochemical staining and abundant GPR18 mRNA. qPCR demonstrates that primary microglia, likewise, express abundant amounts of GPR18 mRNA. NAGly is the most effective lipid recruiter of BV-2 microglia currently reported and its effects mimic those of Abn-CBD. The data generated from this study supports the hypothesis that GPR18 is the previously unidentified 'Abn-CBD' receptor. The marked potency of NAGly acting on GPR18 to elicit directed migration, proliferation and perhaps other MAPK-dependent phenomena advances our understanding of the lipid-based signaling mechanisms employed by the CNS to actively recruit microglia to sites of interest. It offers a novel research avenue for developing therapeutics to elicit a self-renewing population of neuroregenerative microglia, or alternatively, to prevent the accumulation of misdirected, pro-inflammatory microglia which contribute to and exacerbate neurodegenerative disease.
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影响因子：
3.6
作者：
Carrier, EJ;Kearn, CS;Hillard, CJ
通讯作者：
Hillard, CJ
影响因子：
6.7
作者：
Banati, RB
通讯作者：
Banati, RB
DOI：
10.1016/0165-3806(83)90201-8
发表时间：
1983-01-01
期刊：
DEVELOPMENTAL BRAIN RESEARCH
影响因子：
--
作者：
INNOCENTI, GM;CLARKE, S;KOPPEL, H
通讯作者：
KOPPEL, H
影响因子：
3.3
作者：
BLASI, E;BARLUZZI, R;BISTONI, F
通讯作者：
BISTONI, F
N-甲基肽通过与两种N-甲基肽受体（FPR）亚型的差异相互作用诱导小鼠中性粒细胞趋化性的两种不同浓度最佳。 FPR2的分子表征，第二小鼠中性粒细胞FPR。
影响因子：
15.3
作者：
Hartt, J K;Barish, G;Murphy, P M;Gao, J L
通讯作者：
Gao, J L