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：
9096081
负责人：
Marie-Dominique Filippi
金额：
$ 42.03万
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/9096081
关键词：
Activities of Daily Living Affect Applications Grants B-Lymphocytes Biological Assay Blood Blood Cells CD34 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 Health 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 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 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 mitochondrial fitness mitochondrial metabolism novel novel therapeutic intervention novel therapeutics overexpression prevent reconstitution regenerative rho rho GTP-Binding Proteins rho GTPase-activating protein self-renewal small molecule inhibitor 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（由应用程序提供）：本授予应用的总体目标是了解控制造血造血症中造血干细胞（HSC）再生能力的调节途径。仍然缺乏对HSC自我更新和分化以平衡有效造血再生的清晰理解。目前尚不清楚信号通路如何控制HSC自我更新与其他调节元素。缺乏知识阻碍了我们防止与压力造血相关的HSC再生能力下降的能力，因此，基于HSC的疗法的成功限制了需要大量HSC的HSC疗法的成功。我们最近发现了HSC自我更新的新型且临床上重要的调节网络，涉及Rho GTPase信号通路和线粒体功能之间的串扰，从而限制了HSC再生能力。我们报道了P190-B Rho GTPase激活蛋白的遗传缺失（P190-B Rhogap [P190-B]）；小鼠中Rho GTPase活性的抑制剂增强了长期HSC植入，并防止了HSC在串行竞争重生中的耗竭。人类CD34+细胞中的p190-b敲除在离体培养过程中保留了HUCD34+功能。单细胞分析表明，P190-B损失促进了HSC在分裂过程中分化的自我更新决策。但是HSC的静止和血统的发育没有影响。从机械上讲，P190-B损耗通过限制线粒体氧化应激和随后的自分泌TGFß/p38mapk应力信号传导途径的异常激活来增强HSC自我更新。我们建议P190-B使用线粒体将氧化应激转化为自分泌细胞因子信号，以指导HSC再生期间HSC命运决策。 AIM 1将确定将P190-B和RHO信号与AutocrineTGFß1途径联系起来的机制，以进行HSC自我更新。 AIM 2将定义P190-B如何使用线粒体和氧化能来调节TGFß-介导的HSC自我更新。 AIM3将测试这些途径对异种移植模型中人CD34+适应性的药理抑制作用。拟议的研究具有创新性，因为它探讨了主要应力途径在HSC生物学的不忽视的基本方面的作用 - 即HSC决定自我更新或分化独立于成熟的谱系分化或HSC静态的决定。预计这项工作将产生通过信号传导和线粒体代谢之间串扰HSC自我更新机理的新见解。这项研究最终可能导致鉴定出新型药物干预的新靶标。