Stimulation of the P2Y Purinergic Receptor on Type 1 Astroglia Results in Inositol Phosphate Formation and Calcium Mobilization
Stimulation of the P2Y Purinergic Receptor on Type 1 Astroglia Results in Inositol Phosphate Formation and Calcium Mobilization
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DOI：
10.1111/j.1471-4159.1992.tb11339.x
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发表时间：
1992-04
影响因子：
4.7
通讯作者：
C. Helen;C. Kastritsis;A. Salm;K. McCarthy
中科院分区：
文献类型：
--
作者：
C. Helen;C. Kastritsis;A. Salm;K. McCarthy
摘要：培养的星形胶质细胞表达嘌呤能受体，启动磷酸肌醇代谢和钙动员。进行实验来表征 1 型星形胶质细胞上负责刺激这些第二信使系统的嘌呤能受体亚型。用 ATP 或嘌呤受体亚型选择性 ATP 类似物刺激后，测量磷酸肌醇 (IP) 积累和钙动员。 ATP (10–5M) 使 IP 积累增加数倍。监测星形胶质细胞 IP 积累的剂量效应测定揭示了定义 P2Y 受体的效力顺序：2-甲硫腺苷 5′-三磷酸 > ATP > αβ-亚甲基腺苷 5′-三磷酸 > βγ-亚甲基腺苷 5′-三磷酸。使用钙指示剂染料 fura-2 检查 ATP 对个体 1 型星形胶质细胞细胞内钙水平的影响。剂量效应实验表明，ATP 对于生成磷酸肌醇和增加细胞钙具有同等效力。对 ATP 最普遍的反应（占总反应的 87%）包括钙的快速增加至峰值水平，大约是刺激前水平的五倍。该峰值之后下降至显着高于基线的稳定水平。钙增加的平台期在 ATP 存在下维持至少 5 分钟，并且依赖于外部钙。许多 (23%) 星形胶质细胞表现出自发的钙振荡，其频率和幅度在添加 10-5M ATP 后增加。免疫细胞化学染色表明反应发生在神经胶质纤维酸性蛋白阳性细胞中。我们得出结论，1 型星形胶质细胞表达 P2Y 嘌呤能受体，调节 IP 产生和钙动员。
Abstract: Cultured astroglia express purinergic receptors that initiate phosphoinositide metabolism and calcium mobilization. Experiments were conducted to characterize the purinergic receptor subtype on type 1 astroglia responsible for stimulating these second‐messenger systems. Inositol phosphate (IP) accumulation and calcium mobilization were measured after stimulation with ATP or purinergic receptor subtype‐selective ATP analogues. ATP (10–5M) increased IP accumulation severalfold. Dose–effect assays monitoring astroglial IP accumulation revealed the order of potency that defines the P2Y receptor: 2‐methylthioadenosine 5′‐triphosphate > ATP > αβ‐methyleneadenosine 5′‐triphosphate > βγ‐methyleneadenosine 5′‐triphosphate. The influence of ATP on intracellular calcium levels in individual type 1 astroglia was examined using the calcium indicator dye, fura‐2. Dose–effect experiments indicated that ATP was equally potent for generating inositol phosphates and increasing cellular calcium. The most prevalent response (87% of total responses) to ATP consisted of a rapid increase in calcium to a peak level that was approximately five times greater than the prestimulation level. This peak was followed by a decline to a plateau level that was significantly above baseline. This plateau phase of the calcium increase was maintained for at least 5 min in the presence of ATP and was dependent on external calcium. Many (23%) astroglia exhibited spontaneous calcium oscillations whose frequency and magnitude increased after the addition of 10–5M ATP. Immunocytochemical staining indicated that the responses occurred in glial fibrillary acidic protein positive cells. We conclude that type 1 astroglia express the P2Y purinergic receptor which regulates IP production and calcium mobilization.