Systems biology of ERK signaling networks

ERK信号网络可以调节各种细胞过程。信号网络的显著特征之一是，相同的信号网络可以调节多种细胞功能。在PC 12细胞中，EGF和NGF分别诱导瞬时和持续的ERK激活，导致细胞增殖和分化。本研究从系统生物学的角度分析了ERK信号网络是如何通过不同的时间激活模式来调控细胞增殖和分化的。首先，我们试图分析分化过程。我们进行了不连续刺激测定，其由第一次瞬时刺激，随后是间隔，然后是第二次持续刺激组成，并定量了神经突延伸水平（Chung，J.等人，2010）。因此，我们观察到一个时间依赖性的行动，神经生长因子对细胞分化，和不连续的神经生长因子刺激同样诱导分化。第一次刺激并没有导致 ...更多信息 UCE神经突延伸，而第二次刺激诱导快速神经突延伸;因此，第一次刺激可能需要作为先决条件。这些观察结果表明，神经生长因子的作用可以分为两个过程：初始刺激驱动的潜伏过程和第二刺激驱动的延伸过程。潜伏过程似乎需要ERK和转录的活性，但不需要PI 3 K，而延伸过程需要ERK和PI 3 K的活性，但不需要转录。我们筛选了可能参与潜伏过程的基因，并确定了3个可能的候选基因。我们开发了一种完全自动化的测定技术，称为定量图像细胞术，其整合了定量免疫染色技术和用于细胞鉴定的高精度图像处理算法（Ozaki，Y.等人，2010）。在自动化样品制备系统的帮助下，该设备可以以一分钟的间隔以亚细胞分辨率定量蛋白质表达、磷酸化和定位。我们将研究ERK通路在PC 12细胞中的信号动力学，使用QIC进行演示。少

ERK signaling networks can regulate various cellular processes. One of the remarkable features of signaling networks is that the same signaling networks can regulate multiple cellular functions. In PC12 cells, EGF and NGF induces transient and sustained ERK activation, leading to cell proliferation and differentiation, respectively. In this study, we analyzed how ERK signaling networks can regulate cell proliferation and differentiation, depending on the distinct temporal activation patterns by use of systems biology approach. First, we tried to analyze the differentiation processes. We performed a discontinuous stimulation assay consisting of a first transient stimulation followed by an interval and then a second sustained stimulation and quantified the neurite extension level (Chung, J. et al, 2010). Consequently, we observed a timing-dependent action of NGF on cell differentiation, and discontinuous NGF stimulation similarly induced differentiation. The first stimulation did not ind … More uce neurite extension, whereas the second stimulation induced fast neurite extension ; therefore, the first stimulation is likely required as a prerequisite condition. These observations indicate that the action of NGF can be divided into two processes : an initial stimulation-driven latent process and a second stimulation-driven extension process. The latent process appears to require the activities of ERK and transcription, but not PI3K, whereas the extension-process requires the activities of ERK and PI3K, but not transcription. We screened the possible genes involved in the latent process, and identified 3 genes as a possible candidates. We developed a fully automatable assay technique, termed quantitative image cytometry, which integrates a quantitative immunostaining technique and a high precision image-processing algorithm for cell identification (Ozaki, Y. et al, 2010). With the aid of an automated sample preparation system, this device can quantify protein expression, phosphorylation and localization with subcellular resolution at one-minute intervals. We will investigate the signaling dynamics of the ERK pathway in PC12 cells, demonstrating using QIC. Less