Characterizing transient hematopoietic multipotent and megakaryocyte progenitor cells during postnatal development

出生后发育过程中短暂造血多能和巨核细胞祖细胞的特征

基本信息

批准号：
10708838
负责人：
Ryan Mack
金额：
$ 3.43万
依托单位：
LOYOLA UNIVERSITY CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-01 至 2026-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10708838
关键词：
4-Hydroxy-Tamoxifen Address Adult Animals Aorta Arteries B-Lymphocytes Biological Biological Assay Biology Birth Blood Cells Blood Island Blood Platelets Bone Marrow Cell Maturation Cells Childhood Leukemia Clonal Evolution Data Development Disease Embryo Embryonic Development Erythrocytes Fetal Development Fetal Liver Flow Cytometry Future Gene Expression Profile Generations Gonadal structure Green Fluorescent Proteins Hematologic Neoplasms Hematological Disease Hematopoiesis Hematopoietic Hematopoietic stem cells In Vitro Infant Infant Development Infant Leukemia Injections Label MPP1 gene MPP2 gene Megakaryocytes Mesonephric structure Modeling Molecular Mouse Protein Multipotent Stem Cells Mus Myelogenous Myeloproliferative disease Neonatal Organism Palmitoylated Membrane Protein 2 Pathogenesis Pathologic Perinatal Phenotype Ploidies Population Process Property Reporter Spleen T-Lymphocyte Techniques Testing Tomatoes Transplantation Validation Yolk Sac experimental study fetal fetal immunity granulocyte hematopoietic stem cell expansion hemogenic endothelium in vivo insight leukemia migration monocyte mouse model neonatal mice novel pediatric patients postnatal postnatal development progenitor protein expression reconstitution self-renewal stem cells success transcriptome sequencing young adult

项目摘要

Abstract Fetal hematopoiesis has properties distinct from adult hematopoiesis, explaining the unique features of infant myeloproliferative disorders and leukemia. Adult-type hematopoietic stem cells (HSCs) are generated in the major arteries in the aorta-gonad-mesonephros region at embryonic day (E)9.5-E11.5 in mice, colonize the fetal liver (FL) and fetal bone marrow (BM), and remain in adult BM for an organism’s lifetime. Previous studies hypothesized that the fetal-to-adult hematopoietic transition is a gradual maturation process of adult type HSCs. However, two fetal-type hematopoietic progenitors (HPCs) originate from the yolk sac hematopoiesis (E7.5 and E8.5) that also colonize the FL and fetal BM, overlap with maturing HSCs, and are the primary contributors to hematopoiesis during fetal development. Increased evidence suggests this transition is a combined process of declining fetal-type HPCs and maturation of adult-type HSCs. However, the cellular and molecular mechanisms regulating the hematopoietic transition are still largely unknown. Green fluorescent protein (GFP) expression in Ctnnal1-GFP reporter mice was shown to specifically label HSCs in young adults, but not downstream multipotent progenitors (MPPs) or megakaryocyte progenitors (MkPs). In addition to HSCs in neonatal mice, I found GFP labels a subset of MPP1, MPP2 and MkPs. These GFP+ HPCs gradually decline until absent by week 4 post-birth, while GFP- MPP1, MPP2, and MkPs remain. As adult HSC maturation occurs during this period, GFP+ subsets represent novel developmentally restricted HPCs with unknown origin, function, and regulatory mechanisms. In vitro study demonstrates that GFP+ MPP1, MPP2 and MkPs are distinct from their GFP- counterparts and display many properties of fetal type HPCs. For example, although both GFP+ and GFP- MPP2s differentiate to monocytes, granulocytes and megakaryocytes (Mk), GFP+ MPP2s are biased to monocyte and Mk differentiation like fetal HPCs, while GFP- MPP2s are biased to granulocytic differentiation. Compared to Mks produced by GFP- MkPs, GFP+ MkPs produce smaller, lower ploidy Mks similar to Mks found in fetal BM. I hypothesize that Ctnnal1-GFP+ MPP1, MPP2, and MkPs are phenotypically and functionally distinct from their Ctnnal1-GFP- counterparts, are derived from fetal type HPCs independent of adult HSCs, and represent novel transient populations that are capable of initiating infant hematological diseases. I intend to address this hypothesis by (1) fully characterizing the biology and function of GFP+ MPP1, MPP2, and MkPs; and (2) determining where they arise and if they are derived from fetal type HPCs independent of adult HSCs. To do so, I will use three mouse models: Ctnna1-GFP mice for in vitro and flow cytometry experiments, Ctnna1-GFP/Rosa26-tdTomato mice for transplantations, and Cdh5Cre-Ert/Ctnnal1- GFP/Rosa26-tdTomato mice to determine the origin of GFP+ cells. Success of this study will not only help to understand the mechanism of fetal to adult hematopoietic transition, but also serve as a model for hypothesis generation related to the development of infant/pediatric leukemia.

抽象的胎儿造血具有与成人造血不同的特性，解释了胎儿造血的独特特征婴儿骨髓增殖性疾病和白血病是在成人型造血干细胞 (HSC) 中产生的。小鼠胚胎日 (E)9.5-E11.5 的主动脉-性腺-中肾区域的主要动脉，定植于先前的研究显示，胎儿肝脏 (FL) 和胎儿骨髓 (BM) 中存在，并在生物体的一生中保留在成人 BM 中。认为胎儿向成人造血转变是成人型造血干细胞逐渐成熟的过程。然而，两种胎儿型造血祖细胞（HPC）起源于卵黄囊造血（E7.5和 E8.5）也定植于 FL 和胎儿 BM，与成熟的 HSC 重叠，并且是越来越多的证据表明，这种转变是胎儿发育期间的造血过程的综合过程。然而，胎儿型 HPC 的下降和成人型 HSC 的成熟，其细胞和分子机制。调节造血转变仍然很大程度上未知。 Ctnnal1-GFP 报告小鼠中的绿色荧光蛋白 (GFP) 表达可特异性标记年轻人中的 HSC，但下游多能祖细胞 (MPP) 或巨核细胞祖细胞不存在 (MkPs) 除了新生小鼠中的 HSC 之外，我还发现 GFP 标记了 MPP1、MPP2 和 MkPs 的一个子集。 GFP+ HPC 逐渐下降，直至出生后第 4 周消失，而 GFP- MPP1、MPP2 和 MkP 仍然存在。成人 HSC 成熟发生在这一时期，GFP+ 亚群代表新型发育受限的 HPC 来源、功能和调控机制未知。体外研究表明 GFP+ MPP1、MPP2。和 MkP 与其 GFP 单位不同，并显示出胎儿型 HPC 的许多特性。尽管 GFP+ 和 GFP- MPP2 均分化为单核细胞、粒细胞和巨核细胞 (Mk)，但 GFP+ MPP2 与胎儿 HPC 一样偏向于单核细胞和 Mk 分化，而 GFP-MPP2 则偏向于单核细胞和 Mk 分化。与 GFP- MkP 产生的 Mks 相比，GFP+ MkP 产生的粒细胞分化更小、更低。倍性 Mks 与胎儿 BM 中发现的 Mks 相似，我敢说 Ctnnal1-GFP+ MPP1、MPP2 和 MkPs 是。表型和功能上与其 Ctnnal1-GFP- 盟友不同，源自胎儿型 HPC 独立于成人 HSC，并且代表能够启动婴儿的新型临时群体我打算通过（1）充分描述血液疾病的生物学和功能来解决这一假设。 GFP+ MPP1、MPP2 和 MkP；以及 (2) 确定它们出现的位置以及它们是否源自胎儿类型；为此，我将使用三种小鼠模型：用于体外和体外的 Ctnna1-GFP 小鼠。流式细胞术实验，Ctnna1-GFP/Rosa26-tdTomato 小鼠移植，以及 Cdh5Cre-Ert/Ctnna1- GFP/Rosa26-tdTomato 小鼠确定 GFP+ 细胞的起源这项研究的成功不仅有助于了解胎儿到成人造血转变的机制，同时也可以作为假设的模型与婴儿/儿童白血病发展相关的一代。