Extracellular ATP activates ERK1/ERK2 via a metabotropic P2Y1 receptor in a Ca2+ independent manner in differentiated human skeletal muscle cells
Extracellular ATP activates ERK1/ERK2 via a metabotropic P2Y1 receptor in a Ca2+ independent manner in differentiated human skeletal muscle cells
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DOI：
10.1016/j.bcp.2006.02.003
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发表时间：
2006-05-14
影响因子：
5.8
通讯作者：
Hohenegger, M
中科院分区：
文献类型：
--
作者：
May, C;Weigl, L;Hohenegger, M
ATP在神经肌肉接头处释放以调节发育和增殖。P2 X和P2 Y受体的顺序表达与许多物种和细胞系中的这些效应相关。因此，我们研究了ATP介导的信号在分化的原代人骨骼肌细胞。ATP能够通过P2 Y受体触发这些细胞中的Ca 2+瞬变，这不是由于通过P2 X受体的Ca 2+内流。相反，ATP促进磷酸肌醇（IP）的形成，EC 50为21.3 μ M。由ATP引起的Ca 2+瞬变被磷脂酶C（PLC）抑制剂U 73122废除约75%。有趣的是，ryanodine敏感的Ca 2+池不参与ATP触发的Ca 2+释放。在mRNA水平和药理学方法上，我们证实了P2 Y（1）、P2 Y（2）、P2 Y（4）和P2 Y（6）受体的存在。基本上，ATP通过P2 Y1受体激活IP形成。此外，ATP引起细胞外信号调节激酶（ERK）1/2磷酸化的时间和浓度依赖性的方式，再次主要通过P2 Y，受体。ATP介导的ERK 1/2磷酸化严格依赖于磷脂酶C和P13激酶活性。重要的是，ATP介导ERK 1/2磷酸化。Ca 2+不依赖。常规蛋白激酶C抑制剂不能抑制ATP触发的ERK 1/2磷酸化的发现证实了这一观察结果。总之，这些观察结果突出了ATP作为神经肌肉接头处的辅助神经递质通过双重信号传导的重要性，即IP 3受体介导的Ca 2+，瞬变和ERK 1/2的Ca 2+，不敏感磷酸化。(c)2006爱思唯尔公司All rights reserved.
ATP is released at the neuromuscular junction to regulate development and proliferation. The sequential expression of P2X and P2Y receptors has been correlated to these effects in many species and cell lines. We have therefore investigated ATP mediated signalling in differentiated primary human skeletal muscle cells. ATP was capable to trigger Ca2+ transients in these cells via P2Y receptors which were not attributable to Ca2+, influx via P2X receptors. Instead, ATP propagated the formation of inositol phosphate (IP) with an EC50 of 21.3 mu M. The Ca2+, transient provoked by ATP was abrogated roughly 75% by the phospholipase C (PLC) inhibitor, U73122. Interestingly, the ryanodine sensitive Ca2+ pool was not involved in ATP triggered Ca2+ release. On mRNA level and by a pharmacological approach we confirmed the presence of the P2Y(1), P2Y(2), P2Y(4) and P2Y(6) receptors. Substantially, ATP activated IP formation via a P2Y, receptor. In addition, ATP elicited extracellular signal regulated kinase (ERK)1/2 phosphorylation in a time and concentration dependent manner, again mainly via P2Y, receptors. The ATP mediated ERK1/2 phosphorylation was strictly dependent on phospholipase C and P13 kinase activity. Importantly, ATP mediated ERK1/2 phosphorylation. was Ca2+ independent. This observation was corroborated by the finding that conventional protein kinase C inhibitors did not Suppress ATP triggered ERK1/2 phosphorylation. Taken together, these observations highlight the importance of ATP as a co-neurotransmitter at the neuromuscular junction via dual signalling, i.e. IP3 receptor mediated Ca2+, transients and Ca2+, insensitive phosphorylation of ERK1/2. (c) 2006 Elsevier Inc. All rights reserved.