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.

项目摘要/摘要 造血干细胞（HSC）的自我更新和多条道分化的调节是 对于终身维持造血的必不可少的，特别是在造血应激条件下或 移植。 HSC重新流动活性的缺陷导致免疫缺陷，贫血和A 增加对髓样恶性肿瘤的敏感性。 HSC通常存在于静态状态，但要自我更新 他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，了解如何调节HSC的静止和增殖将提供有关如何如何调节的关键见解 HSC功能可以保持在衰老，造血应激条件下或在移植过程中。 我们已经证明MCL-1是正常造血和 在从压力中恢复期间。这些功能与MCL-1在外部的促生存功能有关 线粒体膜；但是，也可以将MCL-1导入到线粒体矩阵中 调节线粒体代谢和裂变/融合动力学。我们已经产生了一种突变的鼠标 表达截短的MCL-1蛋白（MCL-1MOM），该蛋白阻断凋亡，但不能进口到 线粒体基质。当受到髓能胁迫时，MCL1OMM小鼠会出现缺陷的再生和 大多数动物死亡。此外，来自MCL1OMM小鼠的骨髓细胞表现出深刻的竞争力 移植实验中的缺点。 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促进了他们自我更新和促进压力恢复的能力。以下目标将测试 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： 确定缺乏线粒体基质-MCL-1如何影响线粒体动力学和氧化 磷酸化。 AIM 3：询问矩阵-MCL-1的强制表达是否促进HSC功能。 我的实验室已经提出了许多开创性的发现，以定义MCL-1在促进生存中的作用 正常造血和白血病。我们有独特的位置，可以成功地执行这些研究 我们已经生成了关键的新型模型系统，这将使我们能够在功能上剖析Mcl-1的功能 线粒体。在这项研究结束时，我们将阐明MCL-1在 调节HSC功能。