Angiogenesis Research Laboratory, Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, MI 48109, USA.
Department of Molecular, Cellular and Developmental Biology, University of Michigan College of Literature, Science and the Arts, Ann Arbor, MI 48109, USA.
Cells. 2021 Oct 20;10(11):2804. doi: 10.3390/cells10112804.
Understanding how Mesenchymal Stem Cells (MSCs) form blood vessels is critical for creating mechanism-based approaches for the therapeutic use of these cells. In addition, understanding the determinants and factors involved in lineage hierarchy is fundamental to creating accurate and reliable techniques for the study of stem cells in tissue engineering and repair. Dental Pulp Stem Cells (DPSC) from permanent teeth and Stem cells from Human Exfoliated Deciduous teeth (SHED) are particularly interesting sources for tissue engineering as they are easily accessible and expandable. Previously, we have shown that DPSCs and SHEDs can differentiate into endothelial cells and form functional blood vessels through vasculogenesis. Here, we described how we created the "pulpbow" (pulp + rainbow), a multicolor tag experimental model that is stable, permanent, unique to each cell and passed through generations. We used the pulpbow to understand how dental pulp stem cells contributed to blood vessel formation in 3D models in in vitro and ex vivo live cell tracking, and in vivo transplantation assays. Simultaneous tracking of cells during sprout formation revealed that no single multicolor-tagged cell was more prone to vasculogenesis. During this process, there was intense cell motility with minimal proliferation in early time points. In later stages, when the availability of undifferentiated cells around the forming sprout decreased, there was local clonal proliferation mediated by proximity. These results unveiled that the vasculogenesis process mediated by dental pulp stem cells is dynamic and proximity to the sprouting area is critical for cell fate decisions.
了解间充质干细胞（MSCs）如何形成血管对于创造基于机制的治疗这些细胞的方法至关重要。此外，了解谱系层次结构中涉及的决定因素和因素对于创建用于组织工程和修复中干细胞研究的准确可靠技术至关重要。来自恒牙的牙髓干细胞（DPSC）和来自人类脱落乳牙的干细胞（SHED）是组织工程特别有趣的来源，因为它们易于获取和扩增。以前，我们已经表明，DPSC 和 SHED 可以通过血管生成分化为内皮细胞并形成功能性血管。在这里，我们描述了如何创建“牙髓彩虹”（牙髓+彩虹），这是一种稳定、永久、每个细胞独有的多色标记实验模型，并通过代际传递。我们使用牙髓彩虹来了解牙髓干细胞如何在体外和体内 3D 模型中的血管生成中发挥作用，进行活细胞跟踪和体内移植实验。在芽形成过程中同时跟踪细胞表明，没有单个多色标记细胞更倾向于血管生成。在此过程中，早期阶段细胞迁移活跃，增殖很少。在后期阶段，当形成芽周围未分化细胞的可用性减少时，通过接近介导局部克隆增殖。这些结果揭示了牙髓干细胞介导的血管生成过程是动态的，并且与发芽区域的接近度对于细胞命运决定至关重要。
