Modulation of ERK 1/2 and p38 MAPK signaling pathways by ATP in osteoblasts:: Involvement of mechanical stress-activated calcium influx, PKC and Src activation
Modulation of ERK 1/2 and p38 MAPK signaling pathways by ATP in osteoblasts:: Involvement of mechanical stress-activated calcium influx, PKC and Src activation
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DOI：
10.1016/j.biocel.2006.05.018
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发表时间：
2006-01-01
影响因子：
4
通讯作者：
Santillan, G.
中科院分区：
文献类型：
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作者：
Katz, S.;Boland, R.;Santillan, G.
有证据表明，细胞外核苷酸，通过多种P2受体，可能发挥重要作用，通过激活细胞内信号级联调节骨代谢。我们研究了丝裂原活化蛋白激酶（MAPK）信号通路的调节及其与ATP诱导的ROS-A17/2.8成骨细胞内[Ca ~（2+）]i变化的关系。ATP和UTP（10 μ M）增加[Ca 2 +]i的阳离子释放从细胞内存储。我们已经发现，当细胞随后受到机械应力（介质扰动）时，会发生瞬时钙内流。ADP刺激后未观察到这种机械应力激活的钙内流（MSACI），表明MSACI需要P2 Y（2）受体激活。此外，ERK 1/2和p38 MAPK被ATP以剂量和时间依赖性方式激活。使用新霉素（2.5 mM）（一种磷酸肌醇-磷脂酶C（PI-PLQ，Ro 318220（1 μ M），一种蛋白激酶C（PKC）抑制剂）和PP 1（50 μ M）（一种Src家族酪氨酸激酶的有效和选择性抑制剂）几乎完全阻断这种激活。无Ca 2+的细胞外培养基（含有0.5 mM EGTA）和使用抑制MSACI的钆（5 μ M）阻止ATP引起的ERK 1/2和p38磷酸化。总之，这些结果代表了迄今为止的第一个证据，表明ATP刺激成骨细胞中的P2 Y（2）受体使机械应力激活的钙通道敏感，导致钙内流和ERK 1/2和p38 MAPK途径的快速激活。这种作用还涉及上游介质，如PI-PLC，PKC和Src家族激酶。(c)2006爱思唯尔有限公司保留所有权利。
There is evidence that extracellular nucleotides, acting through multiple P2 receptors, may play an important role in the regulation of bone metabolism by activating intracellular signaling cascades. We have studied the modulation of mitogen-activated protein kinase (MAPK) signaling pathways and its relationship to changes in intracellular calcium concentration ([Ca2+]i) induced by ATP in ROS-A 17/2.8 osteoblastic cells. ATP and UTP (10 mu M) increased [Ca2+]i by cation release from intracellular stores. We have found that when the cells are subsequently subjected to mechanical stress (medium perturbation), a transient calcium influx occurs. This mechanical stress-activated calcium influx (MSACI) was not observed after ADP stimulation, indicating that P2Y(2) receptor activation is required for MSACI. In addition, ERK 1/2 and p38 MAPK were activated by ATP in a dose- and time-dependent manner. This activation was almost completely blocked using neomycin (2.5 mM), an inhibitor of phosphoinositide-phospholipase C (PI-PLQ, Ro 318220 (1 mu M), a protein kinase C (PKC) inhibitor, and PP1 (50 mu M), a potent and selective inhibitor of the Src-family tyrosine kinases. Ca2+-free extracellular medium (containing 0.5 mM EGTA) and the use of gadolinium (5 mu M), which suppressed MSACI, prevented ERK 1/2 and p38 phosphorylation by ATP. Altogether, these results represent the first evidence to date suggesting that P2Y(2) receptor stimulation by ATP in osteoblasts sensitizes mechanical stress activated calcium channels leading to calcium influx and a fast activation of the ERK 1/2 and p38 MAPK pathways. This effect also involves upstream mediators such as PI-PLC, PKC and Src family kinases. (c) 2006 Elsevier Ltd. All rights reserved.