Elucidation of molecular mechanism underlying smooth muscle-like differentiation of fibroblastic cells derived from periodontal ligament.

血液供应对于受损或丢失的牙周膜（PDL）组织的再生是必不可少的。来源于PDL的细胞的间充质干细胞样活性已经通过它们形成纤维和骨组织以及牙骨质的能力来鉴定。然而，这些细胞是否具有构建血管毛细血管网络的能力仍有待澄清。本研究评价了来源于PDL的细胞构建血管样结构的潜力，并研究了生长因子如何控制细胞的多能性，评价了猪PDL成纤维细胞系TesPDL 3构建血管样结构的能力。此外，在I型胶原包被的塑料板上评价细胞形成矿化结节的能力。在某些情况下，向这些培养物中加入成纤维细胞生长因子（FGF）-2和骨形态发生蛋白（BMP）-2。通过RT-PCR、Western blotting和免疫荧光分析检测细胞中血管和成骨细胞特异性标志物的表达情况，发现TesPDL 3细胞不仅在BMP-2刺激下形成矿化结节，而且在FGF-2刺激下形成管状结构。有趣的是，FGF-2抑制BMP-2诱导的矿化结节形成。相反，BMP-2抑制FGF-2诱导的管状结构形成。因此，PDL成纤维细胞不仅具有分化为成骨细胞的潜力，而且具有分化为血管细胞谱系的潜力。BMP-2和FGF-2共同调控细胞的命运。

A blood supply is indispensable for the regeneration of damaged or lost periodontal ligament (PDL) tissue. Mesenchymal stem cell-like activity of cells derived from the PDL has been identified by their capacity to form fibrous and osseous tissue, and cementum. However, it remains to be clarified whether the cells have an ability to build the capillary network of blood vessels. This study evaluated the potential of cells derived from the PDL to construct a blood vessel-like structure, and examined how growth factors controlled the multipotency of the cells.The ability of a swine PDL fibroblast cell line, TesPDL3, to construct a blood vessel-like structure was evaluated. In addition, the ability of the cells to form mineralized nodules was evaluated on type I collagen-coated plastic plates. In some cases, fibroblast growth factor (FGF)-2 and bone morphogenetic protein (BMP)-2 were added to these cultures. The status of the expression of vascular and osteoblastic cell-specific markers in the cells was evaluated using reverse transcriptase-polymerase chain reaction (RT-PCR), western blotting and immunofluorescent analyses.TesPDL3 cells not only formed mineralized nodules in response to BMP-2 stimulation but also constructed tube-like structures in response to FGF-2 stimulation. Intriguingly, FGF-2 inhibited the BMP-2-induced mineralized nodule-formation. Conversely, BMP-2 inhibited the FGF-2-induced tube-like structure-formation. Thus, PDL fibroblasts have the potential to differentiate not only into osteoblastic but also into vascular cell lineages. The destiny of the cells was reciprocally regulated by BMP-2 and FGF-2.