An essential role for the SHIP2-dependent negative feedback loop in neuritogenesis of nerve growth factor-stimulated PC12 cells.
An essential role for the SHIP2-dependent negative feedback loop in neuritogenesis of nerve growth factor-stimulated PC12 cells.
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依赖Ship2的负反馈回路在神经生长因子刺激的PC12细胞的神经发生中的重要作用。
DOI：
10.1083/jcb.200609017
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发表时间：
2007-06-04
影响因子：
7.8
通讯作者：
Matsuda, Michiyuki
中科院分区：
文献类型：
--
作者：
Aoki, Kazuhiro;Nakamura, Takeshi;Inoue, Takanari;Meyer, Tobias;Matsuda, Michiyuki
磷脂酰肌醇（3，4，5）三磷酸（PIP 3）的局部积累和由此引起的Rac 1/Cdc 42的激活在神经生长因子（NGF）诱导的神经突生长中起关键作用。为了进一步探索其机制，我们通过荧光共振能量转移（FRET）成像在NGF刺激的PC 12细胞中观察了PIP 3、磷脂酰肌醇（3，4）二磷酸和Rac 1/Cdc 42的活性。基于获得的FRET图像，并在计算机动力学反应模型的帮助下，我们预测，PI-5-磷酸酶负调节PIP 3在NGF刺激。与此模型一致，Src同源2结构域含有肌醇多磷酸5-磷酸酶2（SHIP 2）的耗竭显着增强了NGF诱导的Rac 1/Cdc 42激活和PIP 3积累，并大大增加了磷酸盐和张力蛋白同源物耗竭的PC 12细胞中神经突的数量和长度。计算模型的进一步改进预测了Rac 1对PI 3-激酶和SHIP 2的调节，这也得到了实验验证。我们认为，SHIP 2介导的PIP 3负反馈与PI 3激酶介导的正反馈协同作用，形成一个初始的扩张模式，然后，打断PIP 3积累，以维持适当的神经突生长。
The local accumulation of phosphatidylinositol (3,4,5) trisphosphate (PIP3) and resulting activation of Rac1/Cdc42 play a critical role in nerve growth factor (NGF)–induced neurite outgrowth. To further explore the mechanism, we visualized PIP3, phosphatidylinositol (3,4) bisphosphate, and Rac1/Cdc42 activities by fluorescence resonance energy transfer (FRET) imaging in NGF-stimulated PC12 cells. Based on the obtained FRET images, and with the help of in silico kinetic reaction model, we predicted that PI-5-phosphatase negatively regulates PIP3 upon NGF stimulation. In agreement with this model, depletion of Src homology 2 domain–containing inositol polyphosphate 5-phosphatase 2 (SHIP2) markedly potentiated NGF-induced Rac1/Cdc42 activation and PIP3 accumulation and considerably increased the number and the length of neurites in phosphate and tensin homologue–depleted PC12 cells. Further refinement of the computational model predicted Rac1 regulation of PI3-kinase and SHIP2, which was also validated experimentally. We propose that the SHIP2-mediated negative feedback on PIP3 coordinately works with the PI3-kinase–mediated positive feedback to form an initial protrusive pattern and, later, to punctuate the PIP3 accumulation to maintain proper neurite outgrowth.