Photoliberating inositol-1,4,5-trisphosphate triggers ATP release that is blocked by the connexin mimetic peptide gap 26
Photoliberating inositol-1,4,5-trisphosphate triggers ATP release that is blocked by the connexin mimetic peptide gap 26
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DOI：
10.1016/s0143-4160(02)00180-x
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发表时间：
2003-01-01
期刊：
影响因子：
4
通讯作者：
Leybaert, L
中科院分区：
文献类型：
--
作者：
Braet, K;Vandamme, W;Leybaert, L
Calcium signals can be communicated between cells by the diffusion of a second messenger through gap junction channels or by the release of an extracellular purinergic messenger.我们通过光释放细胞内笼状前体中的 InSP3 或钙，并用荧光素/荧光素酶测定记录所产生的细胞间钙波或释放的 ATP，研究了这两种途径在内皮细胞系中的贡献。汇合培养物中单个细胞中光释放的 InSP3 触发细胞间钙波，该钙波受到间隙连接阻断剂 α-甘草次酸 (α-GA)、连接蛋白模拟肽间隙 26、嘌呤能抑制剂苏拉明、PPADS 和腺苷三磷酸双磷酸酶以及嘌呤能受体脱敏的抑制。 InsP(3) 触发的钙波能够穿过 20 微米宽的无细胞区。光释放的 InSP3 触发 ATP 释放，该释放可通过用 BAPTA 缓冲细胞内钙和应用间隙 26 来阻断。然而，根据光漂白后的荧光恢复测量，间隙 26 并没有抑制细胞之间的间隙连接耦合。光释放钙不会引发细胞间钙波或 ATP 释放。我们得出结论，InSP3 通过连接蛋白半通道触发 ATP 释放有助于钙信号的细胞间传播。 (C) 2003 Elsevier Science Ltd. 保留所有权利。
Calcium signals can be communicated between cells by the diffusion of a second messenger through gap junction channels or by the release of an extracellular purinergic messenger. We investigated the contribution of these two pathways in endothelial cell lines by photoliberating InSP3 or calcium from intracellular caged precursors, and recording either the resulting intercellular calcium wave or else the released ATP with a luciferin/luciferase assay. Photoliberating InSP3 in a single cell within a confluent culture triggered an intercellular calcium wave, which was inhibited by the gap junction blocker alpha-glycyrrhetinic acid (alpha-GA), the connexin mimetic peptide gap 26, the purinergic inhibitors suramin, PPADS and apyrase and by purinergic receptor desensitisation. InsP(3)-triggered calcium waves were able to cross 20 mum wide cell-free zones. Photoliberating InSP3 triggered ATP release that was blocked by buffering intracellular calcium with BAPTA and by applying gap 26. Gap 26, however, did not inhibit the gap junctional coupling between the cells as measured by fluorescence recovery after photobleaching. Photoliberating calcium did not trigger intercellular calcium waves or ATP release. We conclude that InSP3-triggered ATP release through connexin hemichannels contributes to the intercellular propagation of calcium signals. (C) 2003 Elsevier Science Ltd. All rights reserved.