Ostrowski M, Paulevé L, Schaub T, Siegel A, Guziolowski C
University of Potsdam, Potsdam, Germany.
CNRS, Université Paris-Sud LRI-UMR 8623, Orsay, France.
Biosystems. 2016 Nov;149:139-153. doi: 10.1016/j.biosystems.2016.07.009. Epub 2016 Jul 30.
Boolean networks (and more general logic models) are useful frameworks to study signal transduction across multiple pathways. Logic models can be learned from a prior knowledge network structure and multiplex phosphoproteomics data. However, most efficient and scalable training methods focus on the comparison of two time-points and assume that the system has reached an early steady state. In this paper, we generalize such a learning procedure to take into account the time series traces of phosphoproteomics data in order to discriminate Boolean networks according to their transient dynamics. To that end, we identify a necessary condition that must be satisfied by the dynamics of a Boolean network to be consistent with a discretized time series trace. Based on this condition, we use Answer Set Programming to compute an over-approximation of the set of Boolean networks which fit best with experimental data and provide the corresponding encodings. Combined with model-checking approaches, we end up with a global learning algorithm. Our approach is able to learn logic models with a true positive rate higher than 78% in two case studies of mammalian signaling networks; for a larger case study, our method provides optimal answers after 7min of computation. We quantified the gain in our method predictions precision compared to learning approaches based on static data. Finally, as an application, our method proposes erroneous time-points in the time series data with respect to the optimal learned logic models.
布尔网络(以及更通用的逻辑模型)是研究跨多条信号通路信号转导的有用框架。逻辑模型可以从先验知识网络结构和多重磷酸化蛋白质组学数据中学习得到。然而,大多数高效且可扩展的训练方法都聚焦于两个时间点的比较,并假设系统已达到早期稳态。在本文中,我们对这样的学习过程进行了推广,以考虑磷酸化蛋白质组学数据的时间序列轨迹,从而根据布尔网络的瞬态动力学对其进行区分。为此,我们确定了布尔网络动力学必须满足的一个必要条件,以便与离散化的时间序列轨迹一致。基于此条件,我们使用回答集编程来计算与实验数据最匹配的布尔网络集的过近似,并提供相应的编码。结合模型检查方法,我们最终得到了一种全局学习算法。在哺乳动物信号网络的两个案例研究中,我们的方法能够以高于78%的真阳性率学习逻辑模型;对于一个更大的案例研究,我们的方法在计算7分钟后提供了最优答案。我们量化了与基于静态数据的学习方法相比,我们的方法在预测精度上的提升。最后,作为一个应用,我们的方法针对最优学习到的逻辑模型,在时间序列数据中提出错误的时间点。