Project 3 - Transcriptional and epigenetic heterogeneity of stem/progenitor cells

项目总结 造血一直被认为是血细胞形成的一个严格等级的有序过程； 然而，现在很明显，内在和外在的细胞力影响着一个复杂的细胞生态系统 差异化。而反复发生的突变在白血病前期环境中会导致细胞自主中断，比如克隆性 造血潜能不确定(CHIP)和骨髓增生异常综合征(MDS)，克隆选择也 依赖于微环境中的外在力量，如炎症。在这种情况下，理解如何 癌前克隆对促炎因子反应的扰动成为治疗的基础 进步。我们的项目试图建立一个分子和细胞框架来表征克隆 以及单细胞分辨率的炎性造血。我们已经发现，成熟的先天变化 免疫细胞有助于扰乱炎症环境，更具体地说，是促进 通过细胞内信号的差异激活进行CHIP突变克隆的克隆扩增。基于我们的 初步数据，我们认为这个独特的细胞因子信号网络调节细胞功能，甚至更多。 细胞代谢，特别是突变干细胞。野生型干细胞中同样的激活促进了 分化和增殖，失去茎。我们的研究确定了信号转导和激活器 转录因子3(STAT3)是介导芯片克隆功能的主要细胞内信号之一。正在进行中 在研究中，我们将明确STAT3对克隆细胞维持的具体机制。我们建议定义如何 细胞因子信号通路介导克隆性扩张(目标1)。我们将对该函数和 用芯片突变临床前模型研究造血干/祖细胞的转录特征 通过归纳和微扰来确定维持转化的分子驱动因素 炎症期间的造血干细胞(目标2)。这些实验将定义新的监管网络 通过建立并将细胞因子与活跃的信号和细胞代谢联系起来。这些结果将提供 了解克隆造血过程中的炎症如何调节线粒体的研究基础 新陈代谢以获得选择性优势。这些发现将使我们能够利用这些相互作用来阻止前 改变骨髓微环境靶向信号轴和细胞代谢的恶性克隆 (目标3)。展望未来，这些发现可能导致改善细胞反应的治疗干预 减轻CHIP和改变血液病的转归。

PROJECT SUMMARY Hematopoiesis has been considered an ordered process of blood cell formation from a strict hierarchy; however, it is now clear that intrinsic and extrinsic cellular forces influence a complex cellular ecosystem of differentiation. While recurrent mutations cause cell autonomous disruptions in pre-leukemic settings like clonal hematopoiesis of indeterminate potential (CHIP) and myelodysplastic syndrome (MDS), clonal selection is also dependent on extrinsic forces in the microenvironment like inflammation. In this context, understanding how perturbations in pre-malignant clones respond to pro-inflammatory factors becomes fundamental in therapeutic advancement. Our project seeks to establish a molecular and cellular framework for characterization of clonal and inflammatory hematopoiesis at single-cell resolution. We have found that alterations in mature innate immune cells contribute to a perturbed inflammatory environment, and more specifically factors that promote clonal expansion of CHIP mutant clones through differential activation of intracellular signlaing. Based on our preliminary data, we propose that this unique cytokine signaling network mediates cellular function and more so cellular metabolism specifically in mutant stem cells. The same activation in wild-type stem cells promotes differentiation and proliferation, with loss of stemness. Our research identified Signal Transducer And Activator Of Transcription 3 (STAT3) as one of the major intracellular signals mediating CHIP clonal function. In ongoing studies, we will to define STAT3 specific mechanisms of clonal cell maintenance. We propose to define how cytokine signaling pathways mediate clonal expansion (Aim 1). We will characterize the function and transcriptional characteristics of hematopoietic stem and progenitor cells using CHIP mutant pre-clinical models following induction and perturbation to define the molecular drivers for maintenance of transformed hematopoietic stem cells during inflammation (Aim 2). These experiments will define new regulatory networks by establishing and linking cytokine to active signaling and cellular metabolism. These results will provide the basis for studies to understand how inflammation during clonal hematopoiesis regulates mitochondrial metabolism for a selective advantage. These findings will allow us to exploit these interactions to impede pre- malignant clones by altering the marrow microenvironment and targeting signaling axis and cellular metabolism (Aim 3). Moving forward, these findings could lead to therapeutic interventions for improved cellular response mitigating CHIP and changing outcomes in hematological disease.