Mitochondrial matrix-localized MCL-1 regulates hematopoietic stem cell self-renewal and regeneration

线粒体基质定位的MCL-1调节造血干细胞的自我更新和再生

• 批准号: 10705365
• 负责人: JOSEPH T. OPFERMAN
• 金额: $ 45.5万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-22 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10705365
• 关键词: Affect; Aging; Anemia; Animal Model; Animals; Apoptosis; Apoptotic; Biological Models; Bone Marrow Cells; Cell Count; Cell Cycle; Cell Line; Cell Maintenance; Cell Respiration; Cell division; Cell model; Cell physiology; Cellular Stress; Data; Defect; Disadvantaged; Exhibits; Goals; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Immune; Impairment; Induction of Apoptosis; Informal Social Control; Laboratories; Lead; Link; MCL1 gene; Maintenance; Mediator of activation protein; Mitochondria; Mitochondrial Matrix; Mus; Mutant Strains Mice; Myeloproliferative disease; Natural regeneration; Outer Mitochondrial Membrane; Oxidative Phosphorylation; Phenotype; Positioning Attribute; Predisposition; Production; Proteins; Reactive Oxygen Species; Recovery; Regenerative capacity; Regulation; Research; Respiration; Role; Saint Jude Children' s Research Hospital; Seminal; Stress; Testing; Transplantation; United States National Institutes of Health; daughter cell; exhaustion; experimental study; hematopoietic stem cell differentiation; hematopoietic stem cell quiescence; hematopoietic stem cell self-renewal; in vivo; insight; leukemia; mitochondrial metabolism; mouse model; novel; prevent; self-renewal; stem cell function; stem cell survival; stem cells; transplantation therapy

PROJECT SUMMARY/ABSTRACT The regulation of self-renewal and multi-lineage differentiation of hematopoietic stem cells (HSCs) is essential for lifelong maintenance of hematopoiesis, especially under conditions of hematopoietic stress or transplantation. Defects in HSC repopulating activity contribute to immune deficiencies, anemia, and an increased susceptibility to myeloid malignancies. HSCs typically exist in a quiescent state, but to self-renew they must enter the cell cycle. This is associated with an activation of mitochondrial oxidative metabolism. Thus, understanding how HSC quiescence and proliferation are regulated will provide key insights into how HSC function can be maintained in aging, under conditions of hematopoietic stress, or during transplantation. We have demonstrated that MCL-1 is an essential mediator of HSC survival in normal hematopoiesis and during recovery from stress. These functions are associated with MCL-1's pro-survival function on the outer mitochondrial membrane; however, MCL-1 can also be imported into the mitochondrial matrix where it regulates mitochondrial metabolism and fission/fusion dynamics. We have generated a mutant mouse that expresses a truncated MCL-1 protein (MCL-1OMM) which blocks apoptosis, but cannot be imported into the mitochondrial matrix. When subjected to myeloablative stress, Mcl1OMM mice exhibit defective regeneration and most animals die. Furthermore, bone marrow cells from the Mcl1OMM mice exhibit a profound competitive disadvantage in transplantation experiments. Our central hypothesis is that matrix-localized MCL-1 regulates mitochondrial dynamics and respiration in HSCs promoting their ability to self-renew and promote recovery from stress. The following aims will test this hypothesis: Aim 1: Analyze the HSC phenotype/function from mice lacking mitochondrial matrix-MCL-1. Aim 2: Determine how lack of mitochondrial matrix-MCL-1 affects mitochondrial dynamics and oxidative phosphorylation. Aim 3: Interrogate whether enforced expression of matrix-MCL-1 promotes HSC function. My laboratory has made many seminal findings defining the role of MCL-1 in promoting survival during normal hematopoiesis and in leukemia. We are uniquely positioned to successfully perform these studies as we have generated critical, novel model systems that will allow us to functionally dissect MCL-1's functions at the mitochondria. At the end of this study, we will illuminate a previously unrecognized role for MCL-1 in regulating HSC function.

项目概要/摘要 造血干细胞（HSC）的自我更新和多谱系分化的调节是 对于终生维持造血功能至关重要，特别是在造血应激或造血应激的条件下 移植。 HSC 再生活性缺陷会导致免疫缺陷、贫血和贫血 增加对骨髓恶性肿瘤的易感性。 HSC 通常处于静止状态，但可以自我更新 它们必须进入细胞周期。这与线粒体氧化代谢的激活有关。 因此，了解 HSC 静止和增殖是如何调控的将为了解如何调控 HSC 提供重要见解。 HSC 功能可以在衰老、造血应激条件下或移植过程中维持。 我们已经证明，MCL-1 是正常造血和造血干细胞存活的重要介质。 从压力中恢复期间。这些功能与 MCL-1 外层的促生存功能相关。 线粒体膜；然而，MCL-1 也可以被导入线粒体基质中，在那里它 调节线粒体代谢和裂变/融合动力学。我们已经培育出一只突变小鼠 表达截短的 MCL-1 蛋白 (MCL-1OMM)，该蛋白可阻止细胞凋亡，但不能导入到细胞中 线粒体基质。当遭受清髓应激时，Mcl1OMM 小鼠表现出再生缺陷和 大多数动物都会死亡。此外，来自 Mcl1OMM 小鼠的骨髓细胞表现出深刻的竞争性 移植实验的缺点。 我们的中心假设是基质定位的 MCL-1 调节线粒体动力学和呼吸 HSC 促进自我更新和促进压力恢复的能力。以下目标将对此进行测试 假设：目标 1：分析缺乏线粒体基质-MCL-1 的小鼠的 HSC 表型/功能。目标 2： 确定线粒体基质 MCL-1 缺乏如何影响线粒体动力学和氧化 磷酸化。目标 3：探究基质-MCL-1 的强制表达是否会促进 HSC 功能。 我的实验室取得了许多开创性的发现，定义了 MCL-1 在促进存活期间的作用 正常造血和白血病。我们具有独特的优势，可以成功地开展这些研究 我们已经生成了关键的新颖模型系统，使我们能够在功能上剖析 MCL-1 的功能 线粒体。在本研究结束时，我们将阐明 MCL-1 在 调节 HSC 功能。