Discover the signaling basis for OPC homeostasis

在这个提案中，我们将解决胶质生物学中一个根本上的重要问题：少突胶质细胞如何 前体细胞(OPC)强劲地维持着它们的数量？以前的活体成像实验证明 OPC相互接触时相互抑制，相邻时迅速进入细胞周期 OPC要么分化，要么死亡，当达到内稳态时，再次停止增殖。然而， OPC动态平衡背后的分子基础在很大程度上仍不清楚。最近，使用一种老鼠遗传系统 我们的实验室用马赛克双标记分析(MADM)来建立胶质瘤的模型，发现OPC是一种 胶质瘤的起源，并揭示了突变的OPC实际上超过了竞争对手，而不是被动地过度扩张 WT OPC，并最终接管整个大脑。最重要的是，当我们从基因上阻止细胞 突变型OPC的竞争，可以完全预防胶质瘤。把OPC的观察结果 健康中的动态平衡和胶质瘤中的OPC竞争一起，我们意识到这是两者 同一枚硬币的两面，而且OPC的增殖存在一种阴阳机制来制衡 彼此健康，但在癌症中却被放松了管制。当RTK信令的杨氏网络被很好地研究时， 人们对阴氏网络的了解要少得多，更不用说他们的反互动了。在这里，我们假设 使用高灵敏度的OPC进行磷酸蛋白质组/蛋白质组学分析和后续候选验证 竞争平台应该让我们能够机械地洞察这个阴阳网络。为了测试这一点 假设，我们已经组建了一个关于OPC纯化和培养、蛋白质组学图谱的专家团队 有限的材料，并使用高级统计和非监督学习方法来预测信号 基于磷酸蛋白质组/蛋白质组图谱的网络。作为一个团队，我们已经成功地进行了一次试点 这项实验产生了几个候选基因。在本提案的目标1中，我们将验证以下各项的作用 OPC竞赛的候选基因。在本提案的目标2中，我们将执行进一步的深入剖析 实验以全面了解控制OPC动态平衡的信号网络和 竞争。我们项目的发现应该会激励进一步的功能研究，以清楚地描绘出 整个过程，加深了我们对OPC动态平衡的理解，并为范式转换提供了启示 基于OPC竞争理念的胶质瘤治疗策略。

In this proposal, we will address a fundamentally important problem in glia biology: how do oligodendrocyte precursor cells (OPCs) robustly maintain their numbers? Previous intravital imaging experiments demonstrated that OPCs exert mutual inhibition when they contact each other, but promptly enter cell cycle when neighboring OPCs either differentiate or die, and halt proliferation again when homeostasis is achieved. However, the molecular basis behind OPC homeostasis remains largely unknown. Recently, using a mouse genetic system called Mosaic Analysis of Double Markers (MADM) to model glioma, our lab discovered that OPC is a cell of origin for glioma, and revealed that, instead of passively over-expanding, mutant OPCs actually outcompete WT OPCs and eventually take over the entire brain. Most importantly, when we genetically blocked cell competition of mutant OPCs, glioma can be completely prevented. Putting the observations of OPC homeostasis in health and OPC competition in gliomagenesis together, we realized that these are the two sides of the same coin, and that there is a Yin/Yang mechanism for OPC proliferation that counterbalances each other in health but gets deregulated in cancer. While the Yang network of RTK signaling is well studied, the Yin network is much less understood, let alone their counter-interactions. Here, we hypothesize that phospho-proteomic/proteomic profiling and subsequent candidate validation using highly sensitive OPC competition platforms should enable us to provide mechanistic insights into this Yin/Yang network. To test this hypothesis, we have assembled a team of experts on OPC purification and culture, proteomic profiling with limited materials, and using advanced statistical and unsupervised learning approaches to predict signaling network based on phospho-proteomic/proteomic profiles. As a team, we have successfully performed a pilot experiment that led to a handful of candidate genes. In Aim 1 of this proposal, we will validate the role of these candidate genes in OPC competition. In Aim 2 of this proposal, we will perform further in-depth profiling experiments to gain a comprehensive insight into the signaling network that controls OPC homeostasis and competition. The findings from our project should motivate further functional studies to clearly delineate the entire pathway, deepen our understanding of OPC homeostasis, and shed light on paradigm-shifting therapeutic strategies for glioma based on the concept of OPC competition.