Novel Growth Factor Regulators of Early Erythropoieisis

项目摘要 红细胞生成是由造血干细胞形成红细胞的严格调控过程 细胞在临床上，唯一可用于治疗贫血的红细胞生成刺激剂是 激素促红细胞生成素（Epo）和糖皮质激素，留下了它们无效或禁忌的空白。 在这个跨学科的项目中，我们将使用红细胞生成应激的体内小鼠模型，小鼠遗传学， 尖端的scRNA-Seq方法探索非Epo生长因子信号传导的一个基本未知领域 和早期红系祖细胞中的调节机制。我们将特别关注一个强有力的新监管机构 我们已经发现：细胞因子IL-17，我们发现它刺激人类和小鼠红细胞 祖细胞，通过其受体IL-17 RA特异性地起作用。 我们首先通过克服一个重要的技术挑战，将IL 17鉴定为一种新的红细胞生成调节剂。 研究红细胞生成直到最近，鉴定新的红细胞生成调节因子的主要挑战是 缺乏有关干细胞向红细胞分化的最早阶段的信息。早期的祖先可以 仅通过其红细胞集落形成潜力，即“爆发”形成单位， 集落形成单位[分别为BFU-e（红细胞）和CFU-e]。基于FACS的计划可以丰富BFU-e/ CFU-e，但不能纯化它们。我们现在第一次前瞻性地分离出不同的早期阶段， 红细胞生成，通过新的单细胞RNA测序（scRNA-Seq）技术和使用FACS指导。我们 发现这些新定义的祖细胞表达多种以前没有的生长因子受体， 被认为是红细胞调节因子，我们确定了前三个这样的红细胞生成调节作用， 生长因子受体，包括IL-17。 我们的项目是围绕三个目标结构：我们将确定IL-17通路的组成部分，参与 红系和非红系细胞对IL-17的细胞生物学和转录反应 最后，我们将研究IL-17 RA激活调节红细胞生成的能力， 处于压力和疾病中的小鼠，包括贫血状况。在这个过程中，我们将应用scRNA-seq技术 揭示造血/红细胞生成层次在生理、疾病和 以及这些干细胞和祖细胞层次对IL-17信号传导的敏感性。

Project Summary Erythropoiesis is the tightly regulated process by which red blood cells are formed from hematopoietic stem cells. Clinically, the only erythropoiesis-stimulating agents available for the treatment of anemia are the hormone erythropoietin (Epo), and glucocorticoids, leaving a gap where they are ineffective or contraindicated. In this inter-disciplinary project, we will use in vivo mouse models of erythropoietic stress, mouse genetics, and cutting-edge scRNA-Seq approaches to explore a largely uncharted area of non-Epo growth factor signaling and regulatory mechanisms in early erythroid progenitors. We will specifically focus on a potent new regulator that we have discovered: the cytokine IL-17, which we found stimulates both human and mouse erythroid progenitors, acting specifically through its receptor IL-17RA. We first identified IL17 as a novel erythropoietic regulator by overcoming an important technical challenge in studying erythropoiesis. Until recently, a major challenge in identifying novel erythropoietic regulators was a lack of information about the earliest stages of erythroid differentiation from stem cells. Early progenitors could only be defined retrospectively by their erythroid colony forming potential, namely “burst” forming units and colony forming units [BFU-e(rythroid) and CFU-e respectively]. FACS-based schemes could enrich for BFU-e/ CFU-e, but not purify them. We have now, for the first time, prospectively isolated distinct early stages of erythropoiesis, guided by novel single cell RNA sequencing (scRNA-Seq) technology and using FACS. We found that these newly defined progenitors express multiple growth factor receptors that were not previously recognized as erythroid regulators, and we identified an erythropoietic regulatory role for the first three such growth-factor receptors that we tested, including IL-17. Our project is structured around three aims: we will determine IL-17 pathway components involved in erythropoietic control, the cell biological and transcriptional responses to IL-17 in erythroid and non-erythroid blood progenitors, and finally, we will investigate the ability of IL-17RA activation to modulate erythropoiesis in mice in stress and disease, including anemic conditions. In the process, we will apply scRNA-seq technology to reveal the dynamic structure of the hematopoietic/erythropoietic hierarchies in physiology, disease and during stress, and the sensitivity of these stem and progenitor cell hierarchies to IL-17 signaling.