Contribution of macrophages in the HSC niche

巨噬细胞在 HSC 生态位中的贡献

• 批准号: 10213515
• 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/10213515
• 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.

项目摘要： 我们实验室的先前研究表明，骨髓（BM）的CD169+巨噬细胞 通过调节基质细胞中的CXCL12合成和 他们保留在BM中。初步结果揭示了直接调节巨噬细胞的两个新功能 HSC功能。首先，我们提供证据表明巨噬细胞对于遗传毒性后HSC再生至关重要。 通过调节肠道菌群信号介导的铁可用性的挑战。第二，我们有 发现BM巨噬细胞可以转移到BM会议居住地的HSC/祖先关键保留信号。 实际上，从巨噬细胞转移的HSC保留在BM中，而只有那些 G-CSF给药后，尚未从BM微环境中动员。这些结果提高了 关于巨噬细胞在调节HSC中的各种功能，RBC的重要新问题 同一单元格或BM巨噬细胞是否专业实现生产或清除率 功能。在此提案中，我们将探讨巨噬细胞可以直接有助于利基的假设 通过规范HSC的再生能力和从BM出口的能力来进行活动。在特定目标1中，我们将 研究巨噬细胞如何与菌群相互作用以促进HSC再生。我们将使用遗传 在HSC和巨噬细胞中操纵铁发射途径的模型，以剖析铁的机制 在造血再生期间提供给HSC/祖细胞。我们还将评估BM巨噬细胞的方式 可以感觉到微生物群的信号。在特定的目标2中，我们将研究的机制 巨噬细胞分配骨髓住所。我们将评估连接蛋白在细胞电池通信中的作用 使用CRISPR/CAS9介导的靶向，并确定trogocytosis作​​为转移机制的作用。具体 AIM 3，我们将进一步定义骨髓居民巨噬细胞种群。我们将评估空间 这些巨噬细胞与使用免疫荧光的血管结构，HSC和红细胞的关系 成像。我们将使用通用性研究BM居民巨噬细胞的起源（胚胎或造血） 跟踪方法。这些研究将介绍到未注重的成分的关键功能中 HSC利基市场和血液疾病的新治疗方法。