Gustavsson L, Boyano-Adánez M C, Larsson C, Aradottir S, Lundqvist C
Department of Medical Neurochemistry, Lund University Hospital, Sweden.
J Lipid Mediat Cell Signal. 1996 Sep;14(1-3):229-35. doi: 10.1016/0929-7855(96)00530-5.
The regulation of phospholipase D was studied in human neuroblastoma cells using phosphatidylethanol as a marker of the enzyme activity. Carbachol induced phospholipase D activity in SH-SY5Y cells. Muscarinic antagonists inhibited the response with potencies suggesting that muscarinic M1 receptors are responsible for the activation. In permeabilized SH-SY5Y cells, both the carbachol- and GTP gamma S-induced Peth formation was inhibited by GDP beta S, indicating that both responses are mediated via a G-protein. The protein kinase C inhibitors, bisindolylmaleimide and staurosporine significantly inhibited the carbachol-induced Peth formation whereas H7 had no effect. Thus, the cholinergic activation of phospholipase D in SH-SY5Y cells is probably mediated via a direct receptor-G-protein coupling but an involvement of protein kinase C cannot be excluded. Calmidazolium, a calmodulin antagonist, induced an increase in phosphatidylethanol formation in both SH-SY5Y and IMR-32 cells. This effect was inhibited by genistein and tyrphostin, indicating a tyrosine kinase dependent pathway for phospholipase D activation in neuroblastoma cells.
利用磷脂酰乙醇作为磷脂酶D活性的标志物，对人神经母细胞瘤细胞中磷脂酶D的调节进行了研究。卡巴胆碱可诱导SH-SY5Y细胞中的磷脂酶D活性。毒蕈碱拮抗剂抑制该反应的效力表明毒蕈碱M1受体负责激活。在透化的SH-SY5Y细胞中，GDP-β-S抑制了卡巴胆碱和GTP-γ-S诱导的磷脂酰乙醇（Peth）形成，表明这两种反应均通过G蛋白介导。蛋白激酶C抑制剂双吲哚马来酰胺和星形孢菌素显著抑制卡巴胆碱诱导的Peth形成，而H7则无作用。因此，SH-SY5Y细胞中磷脂酶D的胆碱能激活可能通过直接的受体-G蛋白偶联介导，但不能排除蛋白激酶C的参与。钙调蛋白拮抗剂氯咪达唑可诱导SH-SY5Y和IMR-32细胞中磷脂酰乙醇形成增加。该效应被金雀异黄素和 tyrphostin抑制，表明神经母细胞瘤细胞中磷脂酶D激活存在酪氨酸激酶依赖性途径。
