Contribution of macrophages in the HSC niche

巨噬细胞在 HSC 生态位中的贡献

• 批准号: 10374928
• 负责人: Ulrich Steidl
• 金额: $ 56.04万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-01 至 2025-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10374928
• 关键词: Animals; Applications Grants; Blood Vessels; Bone Marrow; CD47 gene; CRISPR/Cas technology; CSF3 gene; CXCL12 gene; Cell Communication; Cell Maintenance; Cells; Cellular Structures; Collaborations; Connexin 43; Connexins; Data; Development; Embryo; Equilibrium; Erythroblasts; Erythrocytes; Erythroid; Funding; GJB3 gene; Generations; Genes; Genetic; Genetic Models; Hematological Disease; Hematopoietic; Hematopoietic Stem Cell Mobilization; Hematopoietic Stem Cell heterogeneity; Hematopoietic stem cells; Image; Immunofluorescence Immunologic; In Transferrin; Iron; Island; Laboratories; Lead; Light; Liver X Receptor; Mediating; Methods; Molecular; Mus; Myelogenous; National Heart, Lung, and Blood Institute; Natural regeneration; Pathway interactions; Phagocytes; Population; Process; Production; Regulation; Role; Series; Signal Transduction; Singapore; Stromal Cells; Structure; Synapses; TFRC gene; Universities; Work; blood treatment; erythroid differentiation; experimental study; genotoxicity; gut microbiota; hematopoietic stem cell differentiation; hematopoietic stem cell niche; hematopoietic stem cell self-renewal; macrophage; metal transporting protein 1; microbiota; novel; novel therapeutic intervention; progenitor; regeneration function; residence; senescence; spatial relationship; stem cell function; stem cells; transcriptome sequencing

PROJECT SUMMARY: Previous studies from our laboratory have suggested that CD169+ macrophages of the bone marrow (BM) contribute to the hematopoietic stem cell (HSC) niche activity by regulating CXCL12 synthesis in stromal cells and their retention in the BM. Preliminary results reveal two novel functions of macrophages in directly regulating the HSC function. First, we provide evidence that macrophages are critical for HSC regeneration after genotoxic challenge via the regulation of iron availability mediated by signals from the gut microbiota. Second, we have found that BM macrophages can transfer to HSCs/progenitors key retention signals that confer residence in BM. Indeed, HSCs that have received the transfer from macrophages are retained in the BM, whereas only those that have not are mobilized from the BM microenvironment following G-CSF administration. These results raise important new questions as to whether the various functions of macrophages in regulating HSCs, RBC production, or clearance are achieved by the same cells or whether the BM macrophages have specialized functions. In this proposal, we will explore the hypothesis that macrophage can directly contribute to niche activities by regulating HSCs’ ability to regenerate and to egress from the BM. In Specific Aim 1, we will investigate how macrophages interact with the microbiota to promote HSC regeneration. We will use genetic models to manipulate iron delivery pathways in HSCs and macrophages to dissect the mechanism by which iron is supplied to HSCs/progenitors during hematopoietic regeneration. We will also evaluate how BM macrophages can sense signals from the microbiota. In Specific Aim 2, we will investigate the mechanisms by which macrophages assign bone marrow residence. We will assess the role of connexins in the cell-cell communication using CRISPR/Cas9-mediated targeting and determine the role of trogocytosis as transfer mechanism. In Specific Aim 3, we will further define the bone marrow-resident macrophage population. We will evaluate the spatial relationship of these macrophages with vascular structures, HSCs and erythroblasts using immunofluorescence imaging. We will investigate the origin (embryonic or hematopoietic) of BM- resident macrophages using genetic tracing methods. These studies will shed light into the critical functions of an under-appreciated component of the HSC niche and uncover new therapeutic approaches for blood disorders.

项目概要： 我们实验室之前的研究表明，骨髓 (BM) 的 CD169+ 巨噬细胞 通过调节基质细胞中的 CXCL12 合成来促进造血干细胞 (HSC) 生态位活性， 他们保留在 BM 中。初步结果揭示了巨噬细胞在直接调节 HSC 功能。首先，我们提供证据表明巨噬细胞对于基因毒性后 HSC 再生至关重要 通过肠道微生物群信号介导的铁可用性调节来应对挑战。其次，我们有 发现 BM 巨噬细胞可以将关键保留信号转移到 HSC/祖细胞，从而赋予其在 BM 中的驻留。 事实上，接受巨噬细胞转移的 HSC 会保留在 BM 中，而只有那些接受巨噬细胞转移的 HSC 才会保留在 BM 中。 G-CSF 给药后尚未从 BM 微环境中动员出来。这些结果提高了 关于巨噬细胞在调节 HSC、RBC 中的各种功能是否具有重要的新问题 生产或清除是由相同的细胞实现的，或者 BM 巨噬细胞是否有专门的 功能。在本提案中，我们将探讨巨噬细胞可以直接贡献生态位的假设 通过调节 HSC 的再生能力和从 BM 排出的能力来进行活动。在具体目标 1 中，我们将 研究巨噬细胞如何与微生物群相互作用以促进 HSC 再生。我们将利用基因 操纵 HSC 和巨噬细胞中铁输送途径的模型，以剖析铁的机制 在造血再生过程中供应给 HSC/祖细胞。我们还将评估 BM 巨噬细胞如何 可以感知来自微生物群的信号。在具体目标 2 中，我们将研究其机制 巨噬细胞分配骨髓居住地。我们将评估连接蛋白在细胞间通讯中的作用 使用 CRISPR/Cas9 介导的靶向并确定 trogocytosis 作为转移机制的作用。具体来说 目标 3，我们将进一步定义骨髓驻留巨噬细胞群。我们将评估空间 使用免疫荧光法观察这些巨噬细胞与血管结构、HSC 和成红细胞的关系 成像。我们将利用遗传学研究 BM 驻留巨噬细胞的起源（胚胎或造血） 追踪方法。这些研究将揭示一个未被充分认识的组成部分的关键功能。 HSC 利基并发现血液疾病的新治疗方法。