Roch Aline, Giger Sonja, Girotra Mukul, Campos Vasco, Vannini Nicola, Naveiras Olaia, Gobaa Samy, Lutolf Matthias P
Institute of Bioengineering, School of Life Sciences and School of Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015, Lausanne, Switzerland.
Department of Medicine, Centre Hospitaler Universitaire Vaudois (CHUV), CH-1015, Lausanne, Switzerland.
Nat Commun. 2017 Aug 9;8(1):221. doi: 10.1038/s41467-017-00291-3.
The in vitro expansion of long-term hematopoietic stem cells (HSCs) remains a substantial challenge, largely because of our limited understanding of the mechanisms that control HSC fate choices. Using single-cell multigene expression analysis and time-lapse microscopy, here we define gene expression signatures and cell cycle hallmarks of murine HSCs and the earliest multipotent progenitors (MPPs), and analyze systematically single HSC fate choices in culture. Our analysis revealed twelve differentially expressed genes marking the quiescent HSC state, including four genes encoding cell-cell interaction signals in the niche. Under basal culture conditions, most HSCs rapidly commit to become early MPPs. In contrast, when we present ligands of the identified niche components such as JamC or Esam within artificial niches, HSC cycling is reduced and long-term multipotency in vivo is maintained. Our approach to bioengineer artificial niches should be useful in other stem cell systems.Haematopoietic stem cell (HSC) self-renewal is not sufficiently understood to recapitulate in vitro. Here, the authors generate gene signature and cell cycle hallmarks of single murine HSCs, and use identified endothelial receptors Esam and JamC as substrates to enhance HSC growth in engineered niches.
长期造血干细胞（HSC）的体外扩增仍然是一项重大挑战，这主要是因为我们对控制HSC命运选择机制的了解有限。利用单细胞多基因表达分析和延时显微镜技术，我们在此定义了小鼠HSC以及最早的多能祖细胞（MPP）的基因表达特征和细胞周期特征，并系统分析了培养过程中单个HSC的命运选择。我们的分析揭示了十二个标记静止HSC状态的差异表达基因，其中包括四个编码龛中细胞间相互作用信号的基因。在基础培养条件下，大多数HSC会迅速分化为早期MPP。相反，当我们在人工龛中提供已鉴定的龛成分（如JamC或Esam）的配体时，HSC的细胞周期会缩短，并且体内长期多能性得以维持。我们构建人工龛的方法在其他干细胞系统中应该也有用。造血干细胞（HSC）的自我更新尚未被充分了解，难以在体外进行重现。在此，作者生成了单个小鼠HSC的基因特征和细胞周期特征，并使用已鉴定的内皮受体Esam和JamC作为底物，以增强工程龛中HSC的生长。
