Department of Craniofacial Development and Comprehensive Biomedical Research Centre, Dental Institute, Kings College London, London SE1 9RT, United Kingdom.
Proc Natl Acad Sci U S A. 2011 Apr 19;108(16):6503-8. doi: 10.1073/pnas.1015449108. Epub 2011 Apr 4.
In many adult tissues, mesenchymal stem cells (MSCs) are closely associated with perivascular niches and coexpress many markers in common with pericytes. The ability of pericytes to act as MSCs, however, remains controversial. By using genetic lineage tracing, we show that some pericytes differentiate into specialized tooth mesenchyme-derived cells--odontoblasts--during tooth growth and in response to damage in vivo. As the pericyte-derived mesenchymal cell contribution to odontoblast differentiation does not account for all cell differentiation, we identify an additional source of cells with MSC-like properties that are stimulated to migrate toward areas of tissue damage and differentiate into odontoblasts. Thus, although pericytes are capable of acting as a source of MSCs and differentiating into cells of mesenchymal origin, they do so alongside other MSCs of a nonpericyte origin. This study identifies a dual origin of MSCs in a single tissue and suggests that the pericyte contribution to MSC-derived mesenchymal cells in any given tissue is variable and possibly dependent on the extent of the vascularity.
在许多成人组织中，间充质干细胞（MSCs）与血管周围龛密切相关，并与周细胞共同表达许多共同的标志物。然而，周细胞作为 MSCs 的能力仍然存在争议。通过使用遗传谱系追踪，我们发现一些周细胞在牙齿生长过程中以及体内受到损伤时分化为专门的牙间质衍生细胞——成牙本质细胞。由于周细胞衍生的间充质细胞对成牙本质细胞分化的贡献并不能解释所有的细胞分化，我们确定了另一种具有 MSC 样特性的细胞来源，这些细胞被刺激向组织损伤区域迁移并分化为成牙本质细胞。因此，尽管周细胞能够作为 MSCs 的来源并分化为间充质来源的细胞，但它们与其他非周细胞来源的 MSC 一起发挥作用。这项研究在单个组织中确定了 MSC 的双重起源，并表明周细胞对特定组织中 MSC 衍生的间充质细胞的贡献是可变的，可能取决于血管化程度。
