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.

项目总结/摘要 造血干细胞（HSCs）自我更新和多向分化的调控是造血干细胞研究的热点之一。 对造血的终身维持至关重要，尤其是在造血应激的条件下， 移植HSC再生活性的缺陷导致免疫缺陷、贫血和免疫缺陷。 对骨髓恶性肿瘤的易感性增加。HSC通常以静止状态存在，但为了自我更新， 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的静止和增殖是如何调节的，将为我们提供关键的见解， HSC功能可以在衰老、造血应激条件下或移植期间维持。 我们已经证明MCL-1是正常造血中HSC存活的重要介质， 从压力中恢复过来这些功能与MCL-1在细胞外膜上的促生存功能有关。 然而，MCL-1也可以被输入到线粒体基质中， 调节线粒体代谢和裂变/融合动力学。我们培育了一种突变小鼠， 表达截短的MCL-1蛋白（MCL-1 OMM），其阻断细胞凋亡，但不能被导入细胞内。 线粒体基质当经受清髓性应激时，Mcl 1 OMM小鼠表现出有缺陷的再生， 大多数动物死亡。此外，来自Mcl 1 OMM小鼠的骨髓细胞表现出强烈的竞争性。 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促进其自我更新和促进从压力中恢复的能力。以下目标将检验这一点 假设：目的1：分析来自缺乏线粒体基质-MCL-1的小鼠的HSC表型/功能。目标二： 确定线粒体基质-MCL-1的缺乏如何影响线粒体动力学和氧化 磷酸化目的3：探讨基质MCL-1的强表达是否促进HSC功能。 我的实验室已经做出了许多开创性的发现，定义了MCL-1在促进生存过程中的作用。 正常造血和白血病。我们处于独特的地位，能够成功地进行这些研究， 我们已经生成了关键的、新颖的模型系统，使我们能够从功能上剖析MCL-1的功能， 线粒体在本研究的最后，我们将阐明MCL-1在以下方面的一个先前未被认识的作用： 调节HSC功能。