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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要植入失败是造血干细胞移植的主要限制之一，这一点至关重要用于治疗许多良性和恶性血液疾病。除了免疫介导的排斥反应移植的细胞，造血干细胞的无效迁移、粘附和植入祖细胞（HSPC）进入骨髓生态位是植入失败的重要原因。这细胞内信号通路通常直接调节 HSPC 植入和迁移至骨髓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。米迪亚福尔明是一个主要的肌动蛋白成核家族，但其在 HSPC 中的功能尚不清楚。我们的初步研究使用我们最近生成的 mDia2 造血特异性基因敲除小鼠表明，mDia2 的丢失导致在竞争性移植试验中，HSPC 粘附和骨髓植入存在显着缺陷。 mDia2 的缺失也显着减少了 G-CSF 诱导的 HSPC 从骨髓中的动员。我们也发现包括 CD11a/CD18 (LFA1) 和 CD11b/CD18 (Mac1) 在内的 β2 整合素显着随着 mDia2 的丢失而下调。这些结果使我们推测 mDia2 对于造血干细胞和祖细胞的植入、粘附和迁移。我们提出了三个具体目的是检验这一假设。首先，我们将确定 mDia2 在 HSPC 中的功能作用植入、粘附和迁移至骨髓。具体来说，我们将研究 mDia2 在 HSPCs 的体外和体内迁移和粘附及其与骨髓生态位的关系。我们还将在体内使用 mDia 激活剂来探索 mDia 激活的临床前模型，以增强干细胞的活性。细胞动员和植入。在这些实验中，相对纯净的SLAM+造血干细胞人口也将接受测试。其次，我们将确定mDia2调节HSPC的机制通过新的 mDia2-MAL-SRF-LFA1/Mac1 途径进行植入、粘附和迁移。三、基于我们的初步研究表明 mDia2 的乙酰化会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是否以及如何影响其在 HSPC 中的功能植入和迁移。这项研究的总体目标是了解 mDia2 在 HSPC 植入、粘附和迁移，并利用体内小鼠模型阐明其机制移植测定。更好地理解这些过程可能会导致识别新的造血干细胞移植治疗策略的目标。