Regulation of hematopoietic stem cell self-renewal by GTPase activating protein signaling

GTP酶激活蛋白信号传导调节造血干细胞自我更新

基本信息

批准号：
8987948
负责人：
Marie-Dominique Filippi
金额：
$ 42.63万
依托单位：
CINCINNATI CHILDRENS HOSP MED CTR
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-07-01 至 2019-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8987948
关键词：
Activities of Daily Living Affect Applications Grants B-Lymphocytes Biological Assay Blood Blood Cells CD34 gene CNTNAP1 gene Cell Respiration Cell Therapy Cell division Cell physiology Cells Clinical Cytokine Signaling Daughter Development Devices Disease Engraftment Equilibrium Failure Functional disorder Future GTPase-Activating Proteins Genetic Goals Hematological Disease Hematopoiesis Hematopoietic Hematopoietic Stem Cell Transplantation Hematopoietic System Hematopoietic stem cells Human In Vitro Intervention Knock-out Knowledge Lead Life Ligands Link MAPK14 gene Malignant Neoplasms Mediating Metabolism Mitochondria Modeling Mus Natural regeneration Organelles Oxidative Stress Pancytopenia Pathway interactions Process Production Protocols documentation Regenerative Medicine Regulation Regulatory Element Regulatory Pathway Reporting Role Signal Pathway Signal Transduction Stem cell transplant Stem cells Stress Testing Therapeutic Tissues Transforming Growth Factor beta Transplantation Work Xenograft procedure autocrine cost design fitness functional outcomes hematopoietic stem cell fate in vivo inhibitor/antagonist innovation insight knock-down leukemia novel novel therapeutic intervention novel therapeutics overexpression prevent public health relevance reconstitution regenerative rho rho GTP-Binding Proteins rho GTPase-activating protein self-renewal small molecule stem cell biology success

项目摘要

DESCRIPTION (provided by applicant): The overall goal of this grant application is to understand the regulatory pathways that control the regenerative capacity of hematopoietic stem cells (HSCs) during stress hematopoiesis. A clear understanding of how signaling pathways are used to balance HSC self-renewal and differentiation for efficient hematopoietic regeneration is still lacking. It is unclear how signaling pathways control HSC self-renewal in concert with other regulatory elements. This lack of knowledge has hampered our ability to prevent the decline in HSC regenerative capacity associated with stress hematopoiesis and, consequently, has limited the success of HSC-based therapies that require high numbers of HSC. We have recently discovered a novel and clinically important regulatory network of HSC self-renewal, involving crosstalk between Rho GTPase signaling pathways and mitochondria functions that limit HSC regenerative capacity. We reported that genetic deletion of p190-B Rho GTPase Activating Protein (p190-B RhoGAP [p190-B]); a suppressor of Rho GTPase activity, in mice enhanced long-term HSC engraftment and prevented HSC depletion over serial competitive repopulation. P190-B knock-down in human CD34+ cells preserved huCD34+ functions during ex vivo culture. Single cell assays revealed that p190-B loss promoted HSC self-renewal decision over differentiation during divisions; but HSC quiescence and blood lineage development were not affected. Mechanistically, p190-B loss enhanced HSC self-renewal by limiting mitochondrial oxidative stress and subsequent abnormal activation of an autocrine TGFß/p38MAPK stress signaling pathway. We propose that p190-B uses mitochondria to convert oxidative stress into autocrine cytokine signals to instruct HSC fate decision during HSC regeneration. Aim 1 will determine mechanism linking p190-B and Rho signaling to autocrine TGFß1 pathway for HSC self-renewal via. Aim 2 will define how p190-B uses mitochondria and oxidative energy to modulate TGFß - mediated HSC self-renewal. Aim3 will test the effects of pharmacological inhibition of these pathways on human CD34+ fitness in xeno-transplant models. The proposed studies are innovative because it explores the role of major stress pathways in an underexplored fundamental aspect of HSC biology - i.e. a HSC decision to self-renew or to differentiate independent on mature lineage differentiation or HSC quiescence. The work is expected to yield novel insights in mechanism of HSC self-renewal by crosstalk between signaling and mitochondrial metabolism. This study may ultimately lead to the identification of novel targets for pharmacological intervention in regenerative medicine.

描述（由申请人提供）：本资助申请的总体目标是了解在应激造血过程中控制造血干细胞（HSC）再生能力的调控途径，清楚地了解如何利用信号途径来平衡 HSC 自身。有效造血再生的更新和分化仍然缺乏，目前尚不清楚信号通路如何与其他调控元件一起控制造血干细胞的自我更新，这种知识的缺乏阻碍了我们防止衰退的能力。与应激造血相关的 HSC 再生能力，因此限制了需要大量 HSC 的基于 HSC 的治疗的成功。我们最近发现了一种新颖的、临床上重要的 HSC 自我更新调节网络，涉及 Rho GTPase 之间的串扰。我们报道了 p190-B Rho GTP 激活蛋白 (p190-B RhoGAP) 的基因缺失。 [p190-B])；Rho GTPase 活性的抑制剂在小鼠体内增强 HSC 植入并防止人 CD34+ 细胞中连续竞争性再增殖过程中的 HSC 耗竭，从而在离体培养过程中保留了 huCD34+ 功能。细胞分析表明，p190-B 的缺失促进了 HSC 在分裂过程中的自我更新决策；但 HSC 的静止和血统发育并未受到影响。从机制上讲，p190-B 的缺失通过限制线粒体氧化应激和随后的自分泌 TGFβ/p38MAPK 应激信号通路的异常激活来增强 HSC 的自我更新，我们认为 p190-B 使用线粒体将氧化应激转化为自分泌细胞因子信号来指导 HSC 的命运。 HSC 再生过程中的决定将确定 p190-B 和 Rho 信号传导与自分泌 TGFβ1 途径的联系机制。 HSC 自我更新通过 Aim 2 将定义 p190-B 如何使用线粒体和氧化能量来调节 TGFβ 介导的 HSC 自我更新，Aim3 将测试这些途径的药理学抑制对异种移植模型中的人类 CD34+ 适应性的影响。拟议的研究具有创新性，因为它探讨了主要应激途径在 HSC 生物学尚未充分探索的基本方面的作用，即 HSC 决定自我更新或分化独立于成熟谱系分化或 HSC 静止，这项工作有望通过信号传导和线粒体代谢之间的相互作用对 HSC 自我更新机制产生新的见解。。