Signal transduction pathways coupled to a P2U receptor in neuroblastoma x glioma (NG108-15) cells.
Signal transduction pathways coupled to a P2U receptor in neuroblastoma x glioma (NG108-15) cells.
复制标题
神经母细胞瘤 x 神经胶质瘤 (NG108-15) 细胞中与 P2U 受体偶联的信号转导通路。
DOI：
10.1111/j.1471-4159.1993.tb03262.x
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发表时间：
1993
影响因子：
4.7
通讯作者：
Sun,GY
中科院分区：
文献类型：
--
作者：
Lin,TA;Lustig,KD;Sportiello,MG;Weisman,GA;Sun,GY
细胞外ATP在CNS和PNS中具有神经递质样性质，由细胞表面P2嘌呤能受体介导。在本研究中，我们广泛地表征了与培养的神经母细胞瘤×胶质瘤杂交细胞系（NG 108 - 15细胞）中P2 U受体活化相关的信号转导途径。向NG 108 - 15细胞中加入≥1 μM ATP可引起[Ca 2 +] i一过性升高，当EGTA螯合细胞外钙时，[Ca 2 +] i可抑制40%。ATP浓度≥500 μ M时，[Ca ~（2+）] i持续升高，EGTA螯合细胞外Ca ~（2+）后，[Ca ~（2+）] i明显降低。ATP引起的[Ca 2 +]增加伴随着[32 P]-磷脂酰肌醇4，5-二磷酸的水解和肌醇1，4，5-三磷酸水平的增加。ATP还导致锂处理细胞中[3 H]肌醇单磷酸水平的时间和剂量依赖性增加。通过离子色谱法分离肌醇单磷酸异构体，发现肌醇4-单磷酸水平有特定增加。ATP引起的[Ca 2 +]增加幅度与培养基中完全电离形式ATP（ATP 4-）的浓度相关，而与镁-ATP（MgATP 2-）的浓度无关。与ATP类似，UTP也诱导多磷酸肌醇分解、磷酸肌醇形成和[Ca 2 +]i增加。ADP、ITP、TTP、GTP、ATP-γS、2-甲硫基ATP、β，γ-亚氨基ATP或3′-O-（4-苯甲酰基）苯甲酰基ATP也引起[Ca 2 +]i增加，但CTP、AMP、β，γ-亚甲基ATP或腺苷不引起[Ca 2 +]i增加。在用[32 P]Pior [14 C]-花生四烯酸标记的细胞中，ATP引起标记磷脂酸水平的短暂增加，但对花生四烯酸水平没有影响。ATP引起的磷脂酸水平增加显然不是由于磷脂酶D的激活，因为ATP不会诱导在乙醇存在下孵育的[14 C]肉豆蔻酸标记细胞中磷脂酰乙醇的形成。这些发现支持以下假设：NG 108 - 15细胞中的P2核苷酸受体与涉及磷脂酶C和质膜钙通道激活的信号转导途径偶联，但不与磷脂酶A2和D激活的信号转导途径偶联。
Extracellular ATP has neurotransmitter‐like properties in the CNS and PNS that are mediated by a cell‐surface P2purinergic receptor. In the present study, we have extensively characterized the signal transduction pathways that are associated with activation of a P2U receptor in a cultured neuroblastoma × glioma hybrid cell line (NG108‐15 cells). The addition of ≥1 μM ATP to NG108‐15 cells caused a transient increase in [Ca2+]ithat was inhibited by 40% when extracellular calcium was chelated by EGTA. ATP concentrations ≥500 μMalso elicited a sustained increase in [Ca2+]ithat was inhibited when extracellular calcium was chelated by EGTA. The increase in [Ca2+]ielicited by ATP occurred concomitantly with the hydrolysis off [32P]‐phosphatidylinositol 4,5‐bisphosphates and an increase in the level of inositol 1,4,5‐trisphosphate. ATP also caused a time‐ and dose‐dependent increase in levels of [3H]inositol monophosphates in lithium‐treated cells. Separation of the inositol monophosphate isomers by ion chromatography revealed a specific increase in the level of inositol 4‐monophosphate. The magnitude of the increase in [Ca2+]ielicited by ATP correlated with the concentration of the fully ionized form of ATP (ATP4‐) in the medium and not with the concentration of magnesium‐ATP (MgATP2‐). Similar to ATP, UTP also induced polyphosphoinositide breakdown, inositol phosphate formation, and an increase in [Ca2+]i. ADP, ITP, TTP, GTP, ATP‐γS, 2‐methylthio ATP, β,γ‐imidoATP or 3′‐O‐(4‐benzoyl)benzoylATP, but not CTP, AMP, β,γ‐methylene ATP, or adenosine, also caused an increase in [Ca2+]i. In cells labeled with [32P]Pior [14C]‐arachidonic acid, ATP caused a transient increase in levels of labeled phosphatidic acids, but had no effect on levels of arachidonic acid. The increase in phosphatidic acid levels elicited by ATP apparently was not due to activation of a phospholipase D because ATP did not induce the formation of phosphatidylethanol in [14C]myristic acid‐labeled cells incubated in the presence of ethanol. These findings support the hypothesis that a P2nucleotide receptor in NG108‐15 cells is coupled to a signal transduction pathway involving the activation of a phospholipase C and a plasma membrane calcium channel, but not the activation of phospholipases A2and D.