Shi Songtao, Gronthos Stan
Craniofacial and Skeletal Diseases Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA.
J Bone Miner Res. 2003 Apr;18(4):696-704. doi: 10.1359/jbmr.2003.18.4.696.
Mesenchymal stem cell populations have previously been identified in adult bone marrow and dental pulp that are capable of regenerating the bone marrow and dental pulp microenvironments, respectively. Here we show that these stem cell populations reside in the microvasculature of their tissue of origin. Human bone marrow stromal stem cells (BMSSCs) and dental pulp stem cells (DPSCs) were isolated by immunoselection using the antibody, STRO-1, which recognizes an antigen on perivascular cells in bone marrow and dental pulp tissue. Freshly isolated STRO-1 positive BMSSCs and DPSCs were tested for expression of vascular antigens known to be expressed by endothelial cells (von Willebrand factor, CD146), smooth muscle cells, and pericytes (alpha-smooth muscle actin, CD146), and a pericyte-associated antigen (3G5), by immunohistochemistry, fluorescence-activated cell sorting (FACS), and/or immunomagnetic bead selection. Both BMSSCs and DPSCs lacked expression of von Willebrand factor but were found to be positive for alpha-smooth muscle actin and CD146. Furthermore, the majority of DPSCs expressed the pericyte marker, 3G5, while only a minor population of BMSSCs were found to be positive for 3G5. The finding that BMSSCs and DPSCs both display phenotypes consistent with different perivascular cell populations, regardless of their diverse ontogeny and developmental potentials, may have further implications in understanding the factors that regulate the formation of mineralized matrices and other associated connective tissues.
间充质干细胞群先前已在成人骨髓和牙髓中被鉴定出来，它们分别能够再生骨髓和牙髓微环境。在此我们表明，这些干细胞群存在于其起源组织的微血管系统中。通过使用抗体STRO-1进行免疫筛选，分离出人类骨髓基质干细胞（BMSSCs）和牙髓干细胞（DPSCs），该抗体可识别骨髓和牙髓组织中血管周围细胞上的一种抗原。通过免疫组织化学、荧光激活细胞分选（FACS）和/或免疫磁珠分选，对新鲜分离的STRO-1阳性BMSSCs和DPSCs进行检测，以确定已知由内皮细胞表达的血管抗原（血管性血友病因子、CD146）、平滑肌细胞和周细胞（α平滑肌肌动蛋白、CD146）以及一种周细胞相关抗原（3G5）的表达情况。BMSSCs和DPSCs均缺乏血管性血友病因子的表达，但被发现α平滑肌肌动蛋白和CD146呈阳性。此外，大多数DPSCs表达周细胞标志物3G5，而仅发现一小部分BMSSCs对3G5呈阳性。BMSSCs和DPSCs均表现出与不同血管周围细胞群一致的表型这一发现，无论它们不同的个体发生和发育潜能如何，可能对理解调节矿化基质和其他相关结缔组织形成的因素具有进一步的意义。
