Towards Understanding Molecular Mechanisms of Human Hematopoietic Stem Cells' Quiescence

总结/摘要 造血干细胞（HSC）产生所有的血液谱系，并补充血液以应对损失或损伤 在生活中。与大多数成体干细胞一样，HSC主要是静止的。静止是为了保护 HSC免受复制和代谢应激，否则会影响健康和寿命， 使它们能够维持组织内稳态并允许修复有缺陷/受损的组织， 他们的一生。基于HSC的疗法的进展部分地受到缺乏可靠的方法来调节HSC表达的影响。 HSC静止和活动。因此，理解HSC静止的核心分子机制是 这是改善HSC健康和长寿的基础，并对临床具有重大的转化意义。 通过应用一种基于线粒体膜电位（MMP）的新方法，我们确定了最 人和小鼠HSC的休眠亚群。使用这种方法，我们最近发现， 溶酶体活性是维持小鼠HSC静止的关键。我们的发现表明 溶酶体动态地调节造血干细胞在静止和活动状态之间的转换。 在这里，我们建议研究溶酶体的功能和调节溶酶体活性的影响， 人HSC的潜能。这些研究可能会提供扩大供应的手段， 人HSC。总的来说，将我们的研究结果转化为人类HSC将为进一步研究奠定基础。 细胞疗法

SUMMARY/ABSTRACT Hematopoietic stem cells (HSCs) produce all blood lineages and replenish blood in response to loss or injury throughout life. HSCs like most adult stem cells, are mainly quiescent. Quiescence is proposed to protect HSCs from replicative and metabolic stress that would otherwise impact health and longevity, thereby enabling them to maintain tissue homeostasis and allowing for the repair of defective/damaged tissue during their lifetime. Progress in HSC-based therapies is partly hindered by lack of reliable approaches to modulate HSC quiescence and activity. Thus, understanding the core molecular mechanisms of HSC quiescence is fundamental for improving HSC health and longevity and has major translational implications for the clinic. By applying a new approach based on mitochondrial membrane potential (MMP), we identified the most dormant subsets of both human and mouse HSCs. Using this approach, we recently discovered that lysosomal activity is pivotal for the maintenance of mouse HSC quiescence. Our findings suggest that lysosomes dynamically regulate the hematopoietic stem cell switch between quiescent and active states. Here, we propose to investigate lysosomal function and the effects of modulation of lysosomal activity on the potency of human HSCs. These studies are likely to provide means towards extending the availability of human HSCs. Overall, translation of our findings to human HSCs will build the foundation towards advancing cell therapy.