PO.BCS01.17 · 生物信息与计算
时间序列单细胞RNA-seq的状态转换模型识别慢性髓系白血病(CML)疾病微状态稳定性的基因层面起源
State-transition model of time-series single-cell RNA-seq identifies gene-level origins of disease microstate stability in chronic myeloid leukemia (CML)
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
CML的定义特征是从慢性期(CP)演变为急变期时疾病负担增加,但产生这些疾病状态并导致状态间转换的细胞机制尚不明确。我们此前使用状态转换模型表明,CML的演变并未编码于单细胞转录微状态中,而是仅当基因表达聚合为群体层面的宏状态(其中出现不同的表型疾病状态)时才显现。在此,我们扩展这一框架,探究拮抗性的基因团队及其调控网络所定义的稳态如何产生这些宏状态。利用来自CP和急变危象(BC)可诱导CML小鼠模型的每周时间序列单细胞RNA测序,我们通过识别拮抗性的基因团队,评估了每种细胞类型中表型疾病宏状态的起源。我们为每种细胞类型谱系识别这些团队,方法是选择那些其在状态空间构建中的特征值与其观察到的表达变化相结合,表明该基因强烈促进(促CML)或强烈拮抗(抗CML)白血病的基因。为了对每个谱系产生的大量基因进行粗粒化,我们应用加权基因共表达网络分析(WGCNA)来定义基因模块和模块特征基因,以界定协同的转录程序。该过程产生的每个模块都强烈富集于促CML或抗CML,这提示它们定义了白血病发展中的功能单元。随后,我们使用受来自经整理的相互作用和调控数据库的先验知识约束的贝叶斯网络推断,为这些模块推断基因调控网络。这产生了对B细胞、T细胞、髓系和干细胞区室各不相同的模块层面网络。对于每个推断出的网络,我们计算稳态(吸引子),并将稳定的转录构型投射到状态空间,以确定基因衍生的吸引子是否与状态空间中谱系特异性的宏状态相一致。初步分析显示,模块网络能够重现我们此前研究中观察到的早期、过渡期和晚期CML宏状态。此外,我们对网络进行了计算机模拟扰动,以预测吸引子占据情况的变化,并再现了我们此前的发现,即B细胞和髓系区室对疾病进展的主导性贡献。这些结果支持一种关于白血病的机制观点,即CML宏状态源于组织成低维调控网络的细胞类型特异性基因团队。这些网络层面的吸引子状态可提供一种识别与疾病表型直接相关的治疗靶点的新方法,从而为预防CML疾病演变提供新途径。
查看英文原文 English abstract
CML is defined by evolution from chronic phase (CP) to increased disease burden during blastic phase, but the cellular mechanisms that create these disease states and produce the transition between states is not understood. We previously used state-transition models to show that CML evolution is not encoded in single-cell transcriptional microstates but instead emerges only when gene expression is aggregated into population-level macrostates where distinct phenotypic disease states emerge. Here, we extend this framework to ask how antagonistic teams of genes and their regulatory network defined steady states give rise to these macrostates. Using weekly time-series single-cell RNA sequencing from both CP and blast crisis (BC) inducible CML mouse models, we assessed the origin of phenotypic disease macrostates in each cell type by identifying antagonistic teams of genes. We identified these teams for each cell type lineage by selecting the genes where their eigenvalue in the state-space construction and their observed expression change combine to indicate that the gene either strongly promoted (pro-CML) or strongly opposed (anti-CML) leukemia. To coarse grain the large number of resulting of genes per lineage, we applied weighted gene coexpression network analysis (WGCNA) to define gene modules and module eigengenes that define coordinated transcriptional programs. Each module produced by this process were strongly enriched for either pro- or anti-CML which suggests that they define functional units in leukemia development. We then inferred gene regulatory networks for these modules using Bayesian network inference constrained by prior knowledge from curated interaction and regulatory databases. This produced module-level networks that were unique for each of the B, T, myeloid, and stem cell compartments. For each inferred network, we computed steady states (attractors) and projected the stable transcriptional configurations into the state-space to determine whether the gene derived attractors align with lineage-specific macrostates in the state-space. Preliminary analyses reveal that module networks can reproduce the early, transitional, and late CML macrostates observed from our previous study. Further, we performed in silico perturbations of the networks to predict shifts in attractor occupancy and recapitulate our previous findings that the dominant contributions of B and myeloid compartments to disease progression observed previously. These results support a mechanistic view of leukemia where CML macrostates arise from cell type-specific teams of genes organized into low-dimensional regulatory networks. These network level attractor states could provide a new approach to identify therapeutic targets that are directly related to disease phenotypes and, therefore, new approaches for preventing CML disease evolution.
利益披露 Disclosure
D. E. Frankhouser, None..
A. Dey, None..
J. R. Ambriz, None..
Z. Chen, None..
D. O'Meally, None..
Y. Fu, None..
J. Irizarry, None..
T. Kanesa Ybarra, None..
R. Sathianathen, None..
J. Trent, None..
S. J. Forman, None..
Y. Kuo, None..
B. Zhang, None..
A. L. MacLean, None..
G. Marcucci, None.