The roles of lipid metabolism in the maintenance of hematopoietic stem cells

脂质代谢在造血干细胞维持中的作用

• 批准号: 8481961
• 负责人: Keisuke Ito
• 金额: $ 29.06万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8481961
• 关键词: Ablation; Acetylation; Activities of Daily Living; Acute Promyelocytic Leukemia; Agonist; Arsenic Trioxide; Biological Assay; Bone Marrow Cells; Cancer Center; Carnitine; Cell Cycle; Cell Maintenance; Cell physiology; Cells; Clinic; Clinical Trials; Commit; Cues; Data; Defect; Development; Dose; Drug Targeting; Effectiveness; Embryo; Energy Metabolism; Engraftment; Equilibrium; Exhibits; Fibroblasts; Gene Expression Profile; Gene Targeting; Genetic; Genetically Engineered Mouse; Goals; Health; Hematology; Hematopoietic; Hematopoietic stem cells; Homeostasis; Human; Image; In Vitro; Institutional Review Boards; Invertebrates; Knock-in Mouse; Knock-out; Knockout Mice; Lead; Link; Longevity; Maintenance; Measures; Medicine; Metabolic; Metabolic Diseases; Metabolic Pathway; Metabolism; Modeling; Molecular; Mus; Nature; Normal Cell; Organism; PPAR delta; PPAR gamma; Pathology; Pathway interactions; Patients; Pattern; Peroxisome Proliferator-Activated Receptors; Personal Satisfaction; Play; Prevention; Regulation; Regulatory Element; Research; Research Design; Role; Signal Transduction; Source; Stem cells; System; Technology; Testing; Time; Tissues; Transferase; Transplantation; Vertebrates; Work; Xenograft procedure; clinical application; daughter cell; exhaustion; fatty acid metabolism; fatty acid oxidation; human stem cells; in vivo; inhibitor/antagonist; leukemia; leukemic stem cell; lipid metabolism; malignant breast neoplasm; mouse model; novel; novel therapeutic intervention; novel therapeutics; obesity treatment; oncology; pre-clinical; progenitor; programs; promoter; public health relevance; reconstitution; response; self-renewal; stem; stem cell division; stem cell fate; stem cell niche; transcriptome sequencing

DESCRIPTION (provided by applicant): Hematopoietic stem cells are the source of all hematopoietic cells, and replenish the hematopoietic compartment as required throughout organism lifespan. Since alterations in the equilibrium of this compartment greatly impact stem cell maintenance, the molecular mechanisms regulating the cell fate decisions of stem cells hold great promise for clinical applications. Studies of genetically-engineered mouse models suggest that metabolic cues contribute to the governance of these cells' self-renewal capacity. To date, however, little is known regarding the role of lipid metabolism in stem cell homeostasis. To better understand the key metabolic pathways involved in stem cell fate and maintenance, we propose the following Specific Aims: 1. To investigate the effects of inactivation of PPAR-fatty acid oxidation in stem cells; We have previously shown that stem cells exhibit higher Ppard expression and fatty acid oxidation than committed progenitor cells, and have hypothesized that lipid metabolism plays a role in their repopulation capacity. In accordance with this premise, we have also found that inhibition of fatty acid oxidation in vitro leads to a reduction of long-term culture-initiating cell capacity. Furthermore, Ppard-ablation leads to reduction of fatty acid oxidation in the hematopoietic stem cell compartment. The current proposal aims to elucidate the effect of genetic loss of Ppard in vivo on the reconstitution ability of stem cells in a transplantation setting. Stem cell division assays with Ppard knockout models will allow us to test whether Ppard-ablation leads to increased commitment of stem cells during their division. 2. To enable long-term engraftment with minimal donor cells by the activation of PPAR signaling; we will employ different activators of PPAR¿ at low doses in vivo to observe their effects on the long-term maintenance of murine stem cells from Ppard wild-type and knockout mice. This will provide a definitive proof, in a PPAR¿-dependent manner, of the potential benefit of PPAR¿ activators in the stem cell compartment. We will then determine, through the use of xenograft mouse models transplanted with human bone marrow cells, whether pharmacological activation of PPAR signaling induces a transplanted minimum number of human hematopoietic stem cells to maximize their long-term repopulation capacity in vivo. 3. To identify cell fate determinants that maintain stem cell-ness through division balance control; in stark contrast to what is known about symmetric and asymmetric division of normal cells in invertebrates, it has been extremely difficult to image the division pattern of most purified stem cell compartments in vertebrates. We therefore propose to generate knock-in mouse lines for real-time imaging of stem cell divisions and to study the intrinsic and extrinsic signals regulating stem cell decision. Combined with the data from our whole transcriptome analysis by RNA-seq in the purified stem cell compartment, the results from these mouse models will lead to a deeper understanding of the cell fate determinants of stem cells. These proposed studies will identify a novel metabolic switch for the cell fate decisions of stem cells, and in turn open new therapeutic avenues for the manipulation of hematopoietic stem cell function, and possibly the function of leukemia stem cells. This work will be conducted with the support of the following experts; Drs. Michael A. Brownlee (Metabolism), Chih-Hao Lee (Metabolism), David E. Avigan (Hematology/Oncology), Julie Teruya-Feldstein (Hemato- pathology), Toshio Suda (Stem Cells), Jan Vijg (Genetics), and Winfried Edelman (Gene Targeting). Importantly, Dr. Paul S. Frenette (Stem Cell niche) is closely supporting our research program along with Dr. Arthur Skoultchi (Hematology).

描述（申请人提供）：造血干细胞是所有造血细胞的来源，并在生物体整个生命周期中根据需要补充造血室。由于该区室平衡的改变极大地影响干细胞的维持，因此调节干细胞细胞命运决定的分子机制在临床应用中具有广阔的前景。基因工程小鼠模型的研究表明，代谢信号有助于控制这些细胞的自我更新能力。然而，迄今为止，人们对脂质代谢在干细胞稳态中的作用知之甚少。为了更好地了解干细胞命运和维持的关键代谢途径，我们提出以下具体目标： 1. 研究PPAR-脂肪酸氧化失活对干细胞的影响；我们之前已经证明，干细胞比定向祖细胞表现出更高的 Ppard 表达和脂肪酸氧化，并假设脂质代谢在其增殖能力中发挥作用。根据这个前提，我们还发现体外抑制脂肪酸氧化会导致长期培养起始细胞能力的降低。此外，Ppard 消融导致造血干细胞室中脂肪酸氧化的减少。目前的提案旨在阐明 Ppard 体内遗传缺失对移植环境中干细胞重建能力的影响。使用 Ppard 敲除模型进行干细胞分裂测定将使我们能够测试 Ppard 敲除是否会导致干细胞在分裂过程中的承诺增加。 2. 通过激活 PPAR 信号传导，以最少的供体细胞实现长期植入；我们将在体内使用低剂量的不同 PPAR 激活剂，观察它们对 Ppard 野生型和基因敲除小鼠干细胞长期维持的影响。这将以 PPAR? 依赖性方式提供 PPAR? 激活剂在干细胞区室中的潜在益处的明确证据。然后，我们将通过使用移植了人骨髓细胞的异种移植小鼠模型来确定 PPAR 信号传导的药理激活是否会诱导移植最小数量的人造血干细胞，以最大限度地提高其体内长期再增殖能力。 3. 鉴定通过分裂平衡控制维持干细胞特性的细胞命运决定因素；与无脊椎动物中正常细胞的对称和不对称分裂的已知形成鲜明对比的是，对脊椎动物中大多数纯化的干细胞区室的分裂模式进行成像是极其困难的。因此，我们建议生成用于干细胞分裂实时成像的敲入小鼠系，并研究调节干细胞决策的内在和外在信号。结合我们在纯化的干细胞室中通过 RNA-seq 进行的全转录组分析的数据，这些小鼠模型的结果将有助于更深入地了解干细胞的细胞命运决定因素。这些拟议的研究将确定干细胞细胞命运决定的新代谢开关，进而为操纵造血干细胞功能以及可能的白血病干细胞功能开辟新的治疗途径。这项工作将在以下专家的支持下进行；博士。 Michael A. Brownlee（代谢）、Chih-Hao Lee（代谢）、David E. Avigan（血液学/肿瘤学）、Julie Teruya-Feldstein（血液病理学）、Toshio Suda（干细胞）、Jan Vijg（遗传学）和 Winfried Edelman（基因靶向）。重要的是，Paul S. Frenette 博士（干细胞领域）与 Arthur Skoultchi 博士（血液学）密切支持我们的研究项目。