Hematopoietic Stem Cell Biology

目标1.原始人类造血细胞群体的单细胞转录谱。 目标2.分化小鼠造血细胞的转录和表观遗传特征与作为ENCODE的一部分收集的人类可用数据的比较。 在目标1中，我们已经确定，转录和表观遗传谱确定小鼠巨核细胞，淋巴细胞，中性粒细胞和单核细胞造血祖细胞的原始群体之前，他们已经提交给他们的特定谱系。我们现在已经将这些研究扩展到人类造血干细胞和祖细胞。正常人HSPC的分化可以通过其转录谱在单细胞水平上追踪（Roy et al.）。此外，我们已经表明，在红细胞分化的钻石黑扇贫血的细胞缺陷发生在非常早期的过程中，早在细胞已经获得了一个独特的红细胞转录谱。 这些数据现已存入有关数据库。该项目将于9月结束。2022年30日 在目标2中，我们发现人MEP群体包含三个谱系致敏细胞亚群，其可以通过表面标志物表达前瞻性地分离。 小鼠和人类造血细胞分化的转录和表观遗传特征的比较远远超出了任何单一实验室的能力。因此，我们与ENCODE联手提供学科专业知识和分选的人类细胞进行分析，以及经过验证的造血表观基因组联盟（VISION）的系统整合。VISION专注于鼠标系统有几个原因。小鼠和人类造血，虽然在某些方面高度保守，但在许多重要方面也有差异。通过比较小鼠和人类的表观遗传谱，我们将确定重叠（共同）模式以及与小鼠和人类红细胞生成的不同特性相关的不同模式，这将产生比研究单个物种中的造血更有说服力的假设。例如，人类中核糖体蛋白的单倍不足导致红细胞生成的阻断，导致Diamond Blackfan贫血，而小鼠中核糖体蛋白的单倍不足是良性的。我们相信，确定小鼠和人RP基因调控的差异（例如）可能会确定一个小鼠样的途径，可以有针对性地治疗DBA患者。 这些数据现已存入有关数据库。该项目将于9月结束。2022年30日

Aim 1. Single cell transcriptional profiling of primitive human hematopoietic cell populations. Aim 2. Comparison of the transcriptional and epigenetic profiles of differentiating mouse hematopoietic cells to the available data in humans gathered as part of ENCODE. In Aim 1, we have determined that transcriptional and epigenetic profiles are determined for mouse megakaryocytic, lymphocytes, neutrophils and monocytes primitive populations of hematopoietic progenitor cells before they have committed to their specific lineages. We have now extended these studies to human hematopoietic stem and progenitor cells. The differentiation of normal human HSPC can be traced at the single cell level by their transcriptional profiles (Roy et al.). In addition, we have shown that the cellular defect in erythroid differentiation in Diamond Blackfan Anemia occurs very early in the process, well before the cells have acquired a distinct erythroid transcription profile. These data have now been deposited in the appropriate databases. This project will terminate on Sept. 30, 2022. In Aim 2, we found that the human MEP population contains three subpopulations of lineage primed cells that could be prospectively separated by surface marker expression. The comparison of the transcriptional and epigenetic profiles of differentiating mouse and human hematopoietic cells is well beyond the capacities of any single lab. Thus we have joined forces with both ENCODE to provide subject expertise and sorted human cells for analysis as well as the ValIdated Systematic IntegratiON of hematopoietic epigenomes consortium (VISION). VISION has focused on the mouse system for several reasons. Mouse and human hematopoiesis, while highly conserved in some respects, also differ in many significant ways. By comparing the mouse and human epigenetic profiles, we will identify overlapping (common) patterns as well as distinct patterns that can be associated with the different properties of mouse and human erythropoiesis, which will generate more informed hypotheses than would be possible by studying hematopoiesis in a single species. For example, haploinsufficiency of ribosomal proteins in humans leads to a block in erythropoiesis resulting in Diamond Blackfan anemia, while haploinsufficiency of ribosomal proteins in mice is benign. We believe that identifying the differences (for example) in mouse and human RP gene regulation may identify a mouse like pathway that could be targeted to treat DBA patients. These data have now been deposited in the appropriate databases. This project will terminate on Sept. 30, 2022.