Mitochondria mediated intercellular metabolic coupling in bone marrow regeneration

摘要 造血干细胞和祖细胞(HSPC)移植(HSCT)是治疗急性髓系白血病的常规方法 先天错误的治疗。体外基因编辑/治疗正在成为一种成功的治疗手段 有骨髓衰竭(BMF)和免疫缺陷的患者。然而，完整的 在这些患者中植入HSC需要比预期更大的细胞剂量和HSC移植 对改善成骨不全等骨骼疾病很有用。这些意想不到的观察 没有经过严格的机械论分析。 线粒体是众所周知的新陈代谢传感器，它连接转录信号和细胞 功能。HSC的线粒体含量升高，但优先使用糖酵解和低 大量实验数据支持的HSC中的线粒体活性表明 线粒体呼吸对于HSC来说比对他们的细胞后代更可有可无。 我们的初步数据表明，在造血细胞和它们之间存在线粒体转移 周围微环境对造血和间充质功能的影响 骨髓清除术后再生。我们的数据表明存在精细化的构型 线粒体命运决定HSC和微环境在再生骨髓中的命运 代谢偶联受两个主要分子节点控制。我们推测HSPC线粒体 HSPC和BM的MSC/P之间的代谢偶联需要转移。这样做的目的是 建议是定义控制线粒体内容和从 造血移植细胞及其对骨髓间充质再生的影响。我们将澄清 BM生态位中线粒体转移的机制及其功能相关性 功能得失、列举和功能分析的药理工具 线粒体在HSC生态位中流动的生化后果。线粒体转移 对受体BM MSC/P的代谢组进行重新编程，这种重新编程对于 骨髓间充质细胞的增殖及骨间充质龛的重建 骨髓清髓后的骨髓再生。我们将确定a)负调节角色是否 Cx43在线粒体转移中依赖于细胞与细胞之间的接触；b)线粒体从BM转移 HSPC转BM MSC/P诱导间充质微环境代谢重编程 导致造血再生；以及，c)骨髓需要阻止AMPK的激活 间充质和造血再生。这项提议将在分子基础上提供光明 移植后依赖造血的间充质再生，并将确定其作用 造血细胞Cx43与宿主AMPK活性对骨髓代谢偶联的影响

ABSTRACT Hematopoietic stem and progenitor cell (HSPC) transplantation (HSCT) is routinely used for the treatment of inborn errors. Ex vivo gene editing/therapy is becoming a successful tool for treatment of patients with bone marrow (BM) failure (BMF) and immunodeficiencies. However, the complete engraftment of HSC in these patients requires larger-than-expected cell doses and HSC transplantation is useful in ameliorating bone diseases like osteogenesis imperfecta. These unexpected observations have not been followed by a stringent mechanistic analysis. Mitochondria are well known metabolic sensors that bridge transcriptional signatures and cellular functions. The mitochondrial content of HSC is elevated but the preferential use of glycolysis and low mitochondrial activity in HSC as supported by a large cohort of experimental data suggest that mitochondrial respiration is more dispensable for HSC than for their cell progeny. Our preliminary data indicate that mitochondrial transfer exists between hematopoietic cells and their surrounding microenvironment with functional consequences on hematopoietic and mesenchymal regeneration after myeloablation. Our data suggests the existence of refined configuration of the mitochondrial fate defining the HSC and microenvironment fate in the regenerating bone marrow by metabolic coupling controlled by two major molecular nodes. We hypothesize that HSPC mitochondria transfer is required for metabolic coupling between HSPC and MSC/P of the BM. The goal of this proposal is to define the mechanisms that control the mitochondrial content and transfer from hematopoietic engrafting cells and their impact on BM mesenchymal regeneration. We will elucidate the mechanisms of mitochondrial transfer in the BM niche and their functional relevance using genetic and pharmacological tools of gain- and loss-of-function and enumeration and functional analysis of biochemical consequences of the traffic of mitochondria in the HSC niche. The mitochondrial transfer reprograms the metabolome of recipient BM MSC/P and this reprogramming is necessary for mesenchymal proliferation and reconstitution of the mesenchymal niche of the BM as well as bone regeneration of the BM after myeloablation. We will determine whether a) the negative regulator role of Cx43 in mitochondrial transfer depends on cell-to-cell contact; b) the mitochondrial transfer from BM HSPC to BM MSC/P induces metabolic reprogramming of the mesenchymal microenvironment resulting in hematopoietic regeneration; and, c) the prevention of AMPK activation is required for BM mesenchymal and hematopoietic regeneration. This proposal will provide light on the molecular basis of hematopoietic-dependent mesenchymal regeneration after transplantation and will identify the role of hematopoietic Cx43 and host AMPK activity on bone marrow metabolic coupling.