Department of Physiology and Cell Biology, Tokyo Medical and Dental University, Graduate School, Tokyo 113-8519, Japan.
Department of Biochemistry and Biophysics, Tokyo Medical and Dental University, Graduate School, Tokyo 113-8510, Japan.
Int J Mol Sci. 2019 Mar 2;20(5):1079. doi: 10.3390/ijms20051079.
Pericytes are mesenchymal cells that surround the endothelial cells of small vessels in various organs. These cells express several markers, such as NG2, CD146, and PDGFRβ, and play an important role in the stabilization and maturation of blood vessels. It was also recently revealed that like mesenchymal stem cells (MSCs), pericytes possess multilineage differentiation capacity, especially myogenic, adipogenic, and fibrogenic differentiation capacities. Although some previous studies have reported that pericytes also have osteogenic potential, the osteogenesis of pericytes can still be further elucidated. In the present study, we established novel methods for isolating and culturing primary murine pericytes. An immortalized pericyte line was also established. Multilineage induction of the pericyte line induced osteogenesis, adipogenesis, and chondrogenesis of the cells in vitro. In addition, pericytes that were injected into the fracture site of a bone fracture mouse model contributed to callus formation. Furthermore, in vivo pericyte-lineage-tracing studies demonstrated that endogenous pericytes also differentiate into osteoblasts and osteocytes and contribute to bone fracture healing as a cellular source of osteogenic cells. Pericytes can be a promising therapeutic candidate for treating bone fractures with a delayed union or nonunion as well as bone diseases causing bone defects.
周细胞是一种间质细胞，存在于各种器官中小血管的内皮细胞周围。这些细胞表达多种标志物，如 NG2、CD146 和 PDGFRβ，在血管的稳定和成熟中发挥重要作用。最近的研究还表明，与间充质干细胞（MSCs）一样，周细胞具有多能分化能力，特别是成肌、成脂和成纤维分化能力。尽管一些先前的研究报告称周细胞也具有成骨潜能，但周细胞的成骨作用仍有待进一步阐明。在本研究中，我们建立了分离和培养原代小鼠周细胞的新方法。还建立了一种永生化的周细胞系。周细胞系的多能诱导在体外诱导细胞的成骨、成脂和成软骨分化。此外，注射到骨折小鼠模型骨折部位的周细胞有助于骨痂形成。此外，体内周细胞系示踪研究表明，内源性周细胞也分化为成骨细胞和骨细胞，并作为成骨细胞的细胞来源促进骨折愈合。周细胞有望成为治疗延迟愈合或不愈合的骨折以及导致骨缺损的骨病的有前途的治疗候选物。
