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韧带(PDL)组织的再生是不可或缺的。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组织、骨组织和牙骨质的能力来鉴定。然而，细胞是否具有构建血管的毛细血管网络的能力仍有待阐明。本研究评估了来源于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。评估了猪PDL成纤维细胞系TesPDL3构建血管样结构的能力。此外，在I型胶原涂层塑料平板上评估细胞形成矿化结节的能力。在某些情况下，成纤维细胞生长因子(FGF)-2和骨形态发生蛋白(BMP)-2被加入这些培养物中。逆转录-聚合酶链式反应、免疫印迹和免疫荧光检测血管和成骨细胞特异性标志物的表达情况。TesPDL3细胞不仅在BMP-2刺激下形成矿化结节，而且在成纤维细胞生长因子-2刺激下形成管状结构。有趣的是，成纤维细胞生长因子-2抑制了BMP-2诱导的矿化结节的形成。反之，BMP-2可抑制成纤维细胞生长因子-2诱导的管样结构形成。因此，PDL成纤维细胞不仅具有向成骨细胞分化的潜能，而且具有向血管细胞分化的潜能。骨形态发生蛋白-2和成纤维细胞生长因子-2相互调控细胞的命运。

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.