Derocq J M, Bouaboula M, Marchand J, Rinaldi-Carmona M, Ségui M, Casellas P
Sanofi Recherche, Montpellier, France.
FEBS Lett. 1998 Apr 3;425(3):419-25. doi: 10.1016/s0014-5793(98)00275-0.
The effect of anandamide, an endogenous ligand for central (CB1) and peripheral (CB2) cannabinoid receptors, was investigated on the growth of the murine IL-6-dependent lymphoid cell line B9 and the murine IL-3-dependent myeloblastic cell line FDC-P1. In conditions of low serum level, anandamide potentiated the growth of both cytokine-dependent cell lines. Comparison with other fatty acid cannabinoid ligands such as (R)-methanandamide, a ligand with improved selectivity for the CB1 receptor, or palmitylethanolamide, an endogenous ligand for the CB2 receptor, showed a very similar effect, suggesting that cell growth enhancement by anandamide or its analogs could be mediated through either receptor subtype. However, several lines of evidence indicated that this growth-promoting effect was cannabinoid receptor-independent. First, the potent synthetic cannabinoid agonist CP 55940, which displays high affinity for both receptors, was inactive in this model. Second, SR 141716A and SR 144528, which are potent and specific antagonists of CB1 and CB2 receptors respectively, were unable, alone or in combination, to block the anandamide-induced effect. Third, inactivation of both receptors by pretreatment of cells with pertussis toxin did not affect the potentiation of cell growth by anandamide. These data demonstrated that neither CB1 nor CB2 receptors were involved in the anandamide-induced effect. Moreover, using CB2-transfected Chinese hamster ovary cells, we demonstrated that after complete blockade of the receptors by the specific antagonist SR 144528, anandamide was still able to strongly stimulate a mitogen-activated protein (MAP) kinase activity, clearly indicating that the endogenous cannabinoid can transduce a mitogenic signal in the absence of available receptors. Finally, arachidonic acid, a structurally related compound and an important lipid messenger without known affinity for cannabinoid receptors, was shown to trigger MAP kinase activity and cell growth enhancement similar to those observed with anandamide. These findings provide clear evidence for a functional role of anandamide in activating a signal transduction pathway leading to cell activation and proliferation via a non-cannabinoid receptor-mediated process.
研究了内源性大麻素受体中枢（CB1）和外周（CB2）的配体花生四烯乙醇胺对小鼠白细胞介素-6依赖的淋巴细胞系B9和小鼠白细胞介素-3依赖的骨髓母细胞系FDC-P1生长的影响。在低血清水平条件下，花生四烯乙醇胺增强了两种细胞因子依赖细胞系的生长。与其他脂肪酸大麻素配体如对CB1受体具有更高选择性的配体（R）-甲基花生四烯酸乙醇胺或CB2受体的内源性配体棕榈酰乙醇胺进行比较，结果显示出非常相似的效应，这表明花生四烯乙醇胺或其类似物对细胞生长的增强作用可能是通过任一受体亚型介导的。然而，多条证据表明这种生长促进作用不依赖于大麻素受体。首先，对两种受体均具有高亲和力的强效合成大麻素激动剂CP 55940在该模型中无活性。其次，分别为CB1和CB2受体强效特异性拮抗剂的SR 141716A和SR 144528，单独或联合使用均无法阻断花生四烯乙醇胺诱导的效应。第三，用百日咳毒素预处理细胞使两种受体失活并不影响花生四烯乙醇胺对细胞生长的增强作用。这些数据表明，CB1和CB2受体均不参与花生四烯乙醇胺诱导的效应。此外，使用转染了CB2的中国仓鼠卵巢细胞，我们证明在特异性拮抗剂SR 144528完全阻断受体后，花生四烯乙醇胺仍能够强烈刺激丝裂原活化蛋白（MAP）激酶活性，这清楚地表明内源性大麻素在没有可用受体的情况下仍能转导促有丝分裂信号。最后，花生四烯酸，一种结构相关的化合物且是一种对大麻素受体无已知亲和力的重要脂质信使，被证明能引发与花生四烯乙醇胺所观察到的相似的MAP激酶活性和细胞生长增强。这些发现为花生四烯乙醇胺通过非大麻素受体介导的过程激活导致细胞活化和增殖的信号转导途径中的功能作用提供了明确证据。
