Metabolic regulation of human erythropoiesis

项目3 人红细胞生成的代谢调控 造血干细胞（HSC）的自我更新能力受细胞代谢状态的控制， 营养物质进入和代谢有助于HSC向细胞分化的可能性， 直到最近才考虑淋巴样、髓样或红细胞系的命运。这个项目的总体目标是 该项目是发展一个机制的理解细胞代谢的作用，在生理和 红细胞生成障碍我们的研究提出了这样一个假设，即营养物质的运输和利用调节着 正常和病理性人红细胞分化。我们之前的数据显示， 转运蛋白Glut 1仅在人红细胞分化的最后有丝分裂期间上调（Montel， 哈根等人，细胞2008），而谷氨酰胺转运蛋白ASCT 2在所有HSC上表达。我们 确定ASCT 2的下调或阻断谷氨酰胺代谢会消除红细胞 造血干细胞的分化并使红细胞生成素处理的HSC偏向于髓样命运。相反，转移葡萄糖 进入戊糖磷酸途径，远离糖酵解，加速红细胞生成（Oburoglu等人，Cell Stem Cell 2014）。在目标1中，我们将使用我们独特的逆转录病毒包膜受体结合结构域集合 （RBD），其作为溶质载体（SLC）营养转运蛋白的特异性配体，以表征阶段- 转运蛋白的特异性表达和功能，并确定调节转运蛋白的阵列 在正常条件下以及在具有改变的核纤层蛋白的红系祖细胞中的红细胞生成（具有 项目4），在TET 2缺陷型骨髓增生异常综合征模型中，以及在RPL 5和RPL 11缺陷型 Diamond Blackfan贫血模型（项目1）。在目标2中，我们将评估从稳定的 葡萄糖，谷氨酰胺和脂肪酸同位素示踪剂，阐明代谢网络和代谢物， 调节正常和紊乱的红细胞生成。这些研究将批判性地解决我们的假设， 资源利用控制着早期和终末红细胞分化，其水平超出了简单地提供 细胞分裂所需的ATP、氨基酸和脂质。我们认为新陈代谢的变化 有助于阶段特异性表观遗传、转录和翻译红细胞调节程序， 将与项目2一起评估。我们预计，这些数据在计划项目中的整合将 确定控制阶段特异性红细胞转变的营养通量和利用， 红系疾病中转运蛋白生物标志物的发现，并促进营养素的操纵 定向生理和病理红系细胞分化的转运蛋白和代谢网络 和生存

Project 3 Abstract Metabolic regulation of human erythropoiesis The self renewal capacity of hematopoietic stem cells (HSCs) is controlled by the cells' metabolic state but the possibility that nutrient entry and metabolism contribute to the differential commitment of an HSC to a lymphoid, myeloid or erythroid lineage fate was not considered until very recently. The overall goal of this project is to develop a mechanistic understanding of the role of cell metabolism in physiological and disordered erythropoiesis. Our studies address the hypothesis that nutrient transport and utilization regulate both normal and pathological human erythroid differentiation. Our previous data show that the glucose transporter Glut1 is only upregulated during the final mitoses of human erythroid differentiation (Montel- Hagen et al. Cell 2008) whereas the glutamine transporter ASCT2 is expressed on all HSCs. We determined that down regulation of ASCT2 or blocking glutamine metabolism abrogates erythroid differentiation and skews erythropoietin-treated HSCs towards a myeloid fate. In contrast, diverting glucose into the pentose phosphate pathway, away from glycolysis, accelerates erythropoiesis (Oburoglu et al. Cell Stem Cell 2014). In Aim 1, we will use our unique collection of retroviral envelope receptor binding domains (RBDs), that function as specific ligands of solute carrier (SLC) nutrient transporters, to characterize stage- specific expression and function of transporters and determine the array of transporters regulating erythropoiesis in normal conditions as well as in erythroid progenitors with altered nuclear lamins (with Project 4), in a TET2-deficient model of myelodysplastic syndrome, and in RPL5- and RPL11-deficient models of Diamond Blackfan anemia (with Project 1). In Aim 2, we will assess metabolic fluxes from stable glucose, glutamine, and fatty acid isotope tracers, elucidating the metabolic networks and metabolites that regulate normal and perturbed erythropoiesis. These studies will critically address our hypothesis that fuel resource utilization governs early and terminal erythroid differentiation, at a level beyond simply providing the ATP, amino acids and lipids that are required for cell division. We propose that metabolic changes contribute to stage-specific epigenetic, transcriptional and translational erythroid regulatory programs which will be evaluated with Project 2. We anticipate that integration of these data within the Program Project will identify the nutrient fluxes and utilization that control stage-specific erythroid transitions, pioneer nutrient transporter biomarker discovery in erythroid disorders, and promote the manipulation of nutrient transporters and metabolic networks that orient physiological and pathological erythroid cell differentiation and survival.