Fibroblastic cells derived from bovine periodontal ligaments have the phenotypes of osteoblasts

Abstract

We examined the possibility that periodontal ligament (PDL) cells can differentiate into osteoblasts and/or cementoblasts in freshly isolated PDL tissues and in cultured cells derived from PDL. PDL tissues were obtained from the incisor teeth of bovine lower jaws; gingival connective tissues of the same animals were used as controls. Freshly isolated PDL tissues and cultured PDL cells showed an intense alkaline phosphatase (ALPase) activity both histochemically and biochemically. The production of 3',5'-cyclic adenosine monophosphate (cAMP) was greatly increased in response to human parathyroid hormone [PTH(1-34)], in both freshly isolated PDL tissues and cultured PDL cells. In contrast, neither ALPase activity nor PTH-dependent cAMP production was detected in gingival connective tissues and cultured gingival fibroblasts. Furthermore, cultured PDL cells synthesized a protein immunologically cross-reactive with bovine bone gla protein (BGP), a highly reliable marker of osteoblastic cells. When 10(-8) M 1a, 25-dihydroxyvitamin D3 [1a,25(OH)2D3] was added to the PDL cell cultures, the synthesis of the BGP-like protein was increased 2- to 3-fold. The maximal level of the synthesis was obtained 72 h after the addition of 1a,25(OH)2D3. Gingival fibroblasts cultured with or without 1a,25(OH)2D3 did not produce any appreciable amounts of the BGP-like protein. These results indicate that the PDL cells have phenotypes typical of osteoblasts, indicating that they may differentiate into osteoblasts and/or cementoblasts.

Generation of Functional Mesenchymal Stem Cells from Different Induced Pluripotent Stem Cell Lines

“…The PDL functions to attach the tooth into the alveolar bone, while enabling a degree of movement, and it is involved in tooth nutrition, homeostasis, and repair [42][43][44]. In vitro studies have demonstrated that specific cells isolated from PDL exhibit an osteoblast-like phenotype and have the capacity to form mineralized [45][46][47]. In addition, MSC-like cells isolated from PDL have the capacity to form ligamentous structures resembling Sharpey's fibers and mineralized tissues similar to bone and cementum in vivo [8].…”

A cell line with characteristics of the periodontal ligament fibroblasts is negatively regulated for mineralization and Runx2/Cbfa1/Osf2 activity, part of which can be overcome by bone morphogenetic protein-2

“…demonstrated that cells isolated from the PDL have osteoblastlike properties, such as alkaline phosphatase (ALPase) activity (Yamashita et al, 1987), being responsive to PTH (Nojima et al, 1990) and producing bone sialoprotein in response to 1,25-dihydroxyvitamin D3 (Nojima et al, 1990). In addition, primary rat PDL cells in culture formed mineralized nodules in vitro, although the mineralized nodules appeared to be different from those produced by osteoblasts (Cho et al, 1992).…”

Recombinant Human Plasminogen Activator Inhibitor-1 Promotes Cementogenic Differentiation of Human Periodontal Ligament Stem Cells

“…[5][6][7][8] Recent studies indicate that PDLSCs have many osteoblast-and cementoblast-like properties and can differentiate into mineral-forming cells that express bone-and cementum-associated markers, such as alkaline phosphatase (ALP), bone sialoprotein (BSP), type 1 collagen (Col1), osteopontin (OPN), and osteocalcin (OCN). 7,[9][10][11][12][13] Cementum protein 1 (CEMP1) was first isolated and characterized as a human cementoblastoma-derived protein that is expressed in cementoblasts, and studies suggested that CEMP1 might play a critical role as a local regulator of cementoblast differentiation.…”