The roles of mDia2 in hematopoietic stem and progenitor cell engraftment and migration

mDia2 在造血干细胞和祖细胞植入和迁移中的作用

• 批准号: 10591568
• 负责人: Peng Ji
• 金额: $ 50.69万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10591568
• 关键词: Acetylation; Actins; Adhesions; Affect; Agonist; Benign; Biochemical; Biological Assay; Blood Cells; Bone Marrow; Bone Marrow Cell Transplantation; Bone Marrow Transplantation; CD18 Antigens; CD34 gene; CSF3 gene; Cell Adhesion; Cell Lineage; Cell Transplantation; Cells; Collaborations; Colony-Stimulating Factors; Compensation; Complex; Cytoskeleton; Data; Deacetylase; Deacetylation; Defect; Disease; Engraftment; F-Actin; Failure; Family; Genes; Genetic; Goals; Graft Rejection; HDAC6 gene; Hematological Disease; Hematopoietic; Hematopoietic Stem Cell Mobilization; Hematopoietic Stem Cell Transplantation; Hematopoietic stem cells; Human; ITGAM gene; ITGB2 gene; Immune; In Vitro; Integrins; Investigation; Knock-out; Knockout Mice; Lysine; Malignant - descriptor; Mammals; Mediating; Microfilaments; Mus; Pathway interactions; Pattern; Phosphorylation; Play; Polymers; Post-Translational Protein Processing; Pre-Clinical Model; Process; Progenitor Cell Engraftment; Protein Family; Proteins; Publishing; Regulation; Reporting; Research Personnel; Rho-associated kinase; Role; Serum Response Factor; Signal Pathway; Signal Transduction Pathway; Testing; Transcriptional Regulation; Transplantation; Wasps; Xenograft procedure; cell motility; clinical translation; differential expression; experimental study; gang; hematopoietic engraftment; improved; in vivo; migration; mouse model; mutant; new therapeutic target; non-histone protein; novel; overexpression; polymerization; response; stem cell engraftment; stem cell function; stem cell migration; stem cell population; targeted treatment; translational potential

PROJECT SUMMARY Failure in engraftment is one of the major limitations of hematopoietic stem cell transplantation, which is critical for the treatment of many benign and malignant hematologic disorders. Besides immune-mediated rejection of the transplanted cells, ineffective migration, adhesion, and engraftment of the hematopoietic stem and progenitor cells (HSPCs) to the bone marrow niche are important causes of engraftment failure. The intracellular signaling pathways regulating HSPC engraftment and migration to the bone marrow often directly or indirectly target the actin cytoskeleton network through proteins that regulate actin polymerization. The mDia formins are a major actin-nucleating family, but their functions in HSPCs are unknown. Our preliminary studies using our recently generated mDia2 hematopoietic-specific knockout mice showed that loss of mDia2 resulted in significant defects in HSPC adhesion and bone marrow engraftment in competitive transplantation assays. Loss of mDia2 also markedly reduced G-CSF-induced HSPC mobilization out of the bone marrow. We also found that beta2 integrins including CD11a/CD18 (LFA1) and CD11b/CD18 (Mac1) were significantly downregulated with the loss of mDia2. These results led us to hypothesize that mDia2 is critical for the engraftment, adhesion, and migration of the hematopoietic stem and progenitor cells. We proposed three specific aims to test this hypothesis. First, we will determine the functional roles of mDia2 in HSPC engraftment, adhesion, and migration to the bone marrow. Specifically, we will investigate the role of mDia2 in the in vitro and in vivo migration and adhesion of HSPCs and their relationship with the bone marrow niche. We will also use an mDia activator in vivo to explore a pre-clinical model of mDia activation for enhancing stem cell mobilization and engraftment. In these experiments, relatively pure SLAM+ hematopoietic stem cell population will also be tested. Second, we will determine the mechanisms of mDia2 in regulating HSPC engraftment, adhesion, and migration through a novel mDia2-MAL-SRF-LFA1/Mac1 pathway. Third, based on our preliminary studies that acetylation of mDia2 affects its activity in actin polymerization, we will determine whether and how acetylation or other post-translational modifications of mDia2 influence its functions in HSPC engraftment and migration. The overall goal of this proposed study is to understand the roles of mDia2 in HSPC engraftment, adhesion, and migration and elucidate its mechanisms using in vivo mouse models and transplantation assays. A better understanding of these processes may lead to the identification of novel targets for therapeutic strategies in hematopoietic stem cell transplantation.

项目摘要 植入失败是造血干细胞移植的主要局限性之一，这很关键 用于治疗许多良性和恶性血液学疾病。除了免疫介导的拒绝 移植的细胞，无效的迁移，粘附和造血茎的植入和植入 祖细胞（HSPC）到骨髓生态位是植入失败的重要原因。这 细胞内信号通路调节HSPC植入和迁移到骨髓的迁移通常直接直接 或通过调节肌动蛋白聚合的蛋白质间接靶向肌动蛋白细胞骨架网络。 MDIA 造型是一个主要的肌动蛋白核蛋白质家族，但它们在HSPC中的功能尚不清楚。我们的初步研究 使用我们最近产生的MDIA2造血特异性敲除小鼠，显示MDIA2的损失导致 在竞争移植测定中，HSPC粘附和骨髓植入的显着缺陷。 MDIA2的丧失还显着降低了G-CSF诱导的HSPC动员从骨髓中移动。我们也是 发现包括CD11A/CD18（LFA1）和CD11b/CD18（MAC1）的β2整合素显着 因MDIA2的损失而下调。这些结果使我们假设MDIA2对 造血茎和祖细胞的植入，粘附和迁移。我们提出了三个 具体旨在检验这一假设的目的。首先，我们将确定MDIA2在HSPC中的功能作用 植入，粘附和迁移到骨髓。具体而言，我们将研究MDIA2在 HSPC的体外和体内迁移和粘附及其与骨髓小裂的关系。 我们还将使用体内MDIA激活剂来探索MDIA激活的临床前模型以增强茎 细胞动员和植入。在这些实验中，相对纯净的大满贯+造血干细胞 人口也将进行测试。其次，我们将确定MDIA2在调节HSPC中的机制 通过新型的MDIA2-MAL-SRF-LFA1/MAC1途径植入，粘附和迁移。第三，基于 我们的初步研究，即MDIA2的乙酰化影响其在肌动蛋白聚合中的活性，我们将确定 MDIA2的乙酰化或其他翻译后修饰如何影响其在HSPC中的功能 植入和迁移。这项拟议的研究的总体目标是了解MDIA2在 HSPC植入，粘附和迁移，并使用体内小鼠模型和 移植测定。更好地理解这些过程可能会导致新颖的识别 造血干细胞移植中治疗策略的靶标。