Activation of the PI3K/Akt signaling pathway through P2Y2 receptors by extracellular ATP is involved in osteoblastic cell proliferation
Activation of the PI3K/Akt signaling pathway through P2Y2 receptors by extracellular ATP is involved in osteoblastic cell proliferation
复制标题
DOI：
10.1016/j.abb.2011.06.013
复制
发表时间：
2011-09-15
影响因子：
3.9
通讯作者：
Boland, Ricardo
中科院分区：
文献类型：
--
作者：
Katz, Sebastian;Ayala, Victoria;Boland, Ricardo
我们研究了PI3K/Akt信号通路的调节及其参与细胞外ATP对ROS 17/2.8成骨细胞样细胞增殖的刺激。观察到Akt-Ser 473磷酸化（p-Akt）呈剂量和时间依赖性增加。ATP γ S和UTP可使p-Akt升高，但ADP β S不能使其升高。PI3K抑制剂可使Akt活性消失，PI-PLC、Src、calmodulin （CaM）抑制剂可使Akt活性降低，但CaMK抑制剂不能使Akt活性降低。细胞在无Ca2+培养基中孵育后，p-Akt减少，但使用l型钙通道阻滞剂后p-Akt没有减少。在PKC抑制剂Ro318220的存在下，ATP诱导的细胞内Ca2+升高被增强，并被已知的PKC激活剂TPA减弱。在含Ca2+的培养基中，atp依赖性的p-Akt被TPA降低，而在无Ca2+的培养基中，Ro318220则增强。ATP通过PI3K/Akt刺激ROS 17/2.8细胞和大鼠成骨细胞的增殖。在初代成骨细胞中，ATP通过PI3K诱导碱性磷酸酶活性，表明核苷酸促进成骨细胞分化。这些结果表明，ATP通过PI-PLC连接的p2y(2)受体和涉及Ca2+、CaM和Src的PI3K/Akt通路激活刺激成骨细胞增殖。PKC似乎通过Src和Ca2+内流/CaM途径调节Akt的激活。(C) 2011爱思唯尔公司版权所有。
We studied the PI3K/Akt signaling pathway modulation and its involvement in the stimulation of ROS 17/2.8 osteoblast-like cell proliferation by extracellular ATP. A dose- and time-dependent increase in Akt-Ser 473 phosphorylation (p-Akt) was observed. p-Akt was increased by ATP gamma S and UTP, but not by ADP beta S. Akt activation was abolished by PI3K inhibitors and reduced by inhibitors of PI-PLC, Src, calmodulin (CaM) but not of CaMK. p-Akt was diminished by cell incubation in a Ca2+-free medium but not by the use of L-type calcium channel blockers. The rise in intracellular Ca2+ induced by ATP was potentiated in the presence of Ro318220, a PKC inhibitor, and attenuated by the TPA, a known activator of PKC. ATP-dependent p-Akt was diminished by TPA and augmented by Ro318220 treatment in a Ca2+-containing but not in a Ca2+-free medium. ATP stimulated the proliferation of both ROS 17/2.8 cells and rat osteoblasts through PI3K/Akt. In the primary osteoblasts, ATP induces alkaline phosphatase activity via PI3K, suggesting that the nucleotide promotes osteoblast differentiation. These results suggest that ATP stimulates osteoblast proliferation through PI-PLC linked-P2Y(2) receptors and PI3K/Akt pathway activation involving Ca2+, CaM and Src. PKC seems to regulate Akt activation through Src and the Ca2+ influx/CaM pathway. (C) 2011 Elsevier Inc. All rights reserved.