Towards Understanding Molecular Mechanisms of Human Hematopoietic Stem Cells' Quiescence

摘要/摘要 造血干细胞(HSCs)产生所有的血统，并在失去或受伤时补充血液。 在一生中。像大多数成体干细胞一样，HSCs主要是静止的。建议通过静默来保护 来自复制和代谢压力的HSCs，否则将影响健康和寿命，从而 使它们能够维持组织动态平衡，并允许修复有缺陷/受损的组织 他们的一生。缺乏可靠的调节方法在一定程度上阻碍了基于HSC的治疗的进展 HSC处于静止和活跃状态。因此，了解HSC静止的核心分子机制是 对改善HSC的健康和长寿至关重要，并对临床具有重大的翻译意义。 通过应用一种基于线粒体膜电位(MMPs)的新方法，我们识别了大多数 人类和小鼠HSCs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肝星状细胞静止状态的关键。我们的发现表明 溶酶体动态调节造血干细胞在静止和活跃状态之间的切换。 在这里，我们建议研究溶酶体的功能以及溶酶体活性的调节对 人类造血干细胞的效力。这些研究很可能为扩大可获得性提供手段 人类的造血干细胞。总体而言，将我们的发现转化为人类造血干细胞将为推动 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.