The biological effect of dentin noncollagenous proteins (DNCPs) on the human periodontal ligament stem cells (HPDLSCs) in vitro and in vivo.
ABSTRACT It was recognized that periodontal progenitor cells penetrate disintegrated Hertwig's epithelial root sheath, and contact with root dentin give rise to periodontium formation. Clinically, direct contact of the conditioned or denuded root surfaces with periodontal cells seems to be a prerequisite for periodontal regeneration. In this study, we investigated the biological effect of dentin noncollagenous proteins (DNCPs) on the human periodontal ligament stem cells (HPDLSCs) in vitro and in vivo. Chemical-conditioned root dentin (CCRD) was prepared by process of partly demineralization and deproteinization. Treated HPDLSCs with DNCPs showed increased proliferation and adhesion ability. Induced HPDLSCs presented several features of cementoblast differentiation, as indicated by morphologic changes, enhanced alkaline phosphatase (ALP) activity, increased matrix mineralization, and upregulated expression of mineralization-associated genes. Incubation of treated HPDLSC aggregate in vivo revealed that cementum-like tissues formed along the CCRD surface with fibrous tissue adjacent to or inserted into it, but untreated HPDLSCs cannot form similar structure. To our knowledge, this is the first study to apply active proteins derived from dentin with periodontal stem cells to construct periodontal structure, which may shed light on human periodontal tissue regeneration.
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ABSTRACT: Aim: The objective of this study was to evaluate the effects of enamel matrix derivative (EMD), transforming growth factor-β1 (TGF-β1), and a combination of both factors (EMD+TGF-β1) on periodontal ligament (PDL) fibroblasts.Material and methods: Human PDL fibroblasts were obtained from three adult patients with a clinically healthy periodontium, using the explant technique. The effects of EMD, TGF-β1, or a combination of both were analysed on PDL cell proliferation, adhesion, wound healing, and total protein synthesis, and on alkaline phosphatase (ALP) activity and bone-like nodule formation.Results: Treatment with EMD for 4, 7, and 10 days increased cell proliferation significantly compared with the negative control (p<0.05). At day 10, EMD and EMD+TGF-β1 showed a higher cell proliferation compared with TGF-β1 (p<0.01). Cell adhesion was significantly up-regulated by TGF-β1 compared with EMD and EMD+TGF-β1 (p<0.01). EMD enhanced in vitro wound healing of PDL cells compared with the other treatments. Total protein synthesis was significantly increased in PDL cells cultured with EMD compared with PDL cells treated with TGF-β1 or EMD+TGF-β1 (p<0.05). EMD induced ALP activity in PDL fibroblasts, which was associated with an increase of bone-like nodules.Conclusion: These findings support the hypothesis that EMD and TGF-β1 may play an important role in periodontal regeneration. EMD induced PDL fibroblast proliferation and migration, total protein synthesis, ALP activity, and mineralization, while TGF-β1 increased cellular adhesion. However, the combination of both factors did not positively alter PDL fibroblast behaviour.Journal Of Clinical Periodontology 05/2007; 34(6):514 - 522. · 3.69 Impact Factor
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ABSTRACT: Dentin contains numerous polypeptides and signaling molecules sequestered in a mineralized matrix. The exposure and release of these molecules occur as a consequence of injury to the pulp and periodontal ligament, which may result from luxation, orthodontic movement or infections of tooth and periodontal structures. When released at these sites, dentin constituents have the potential to act on different surrounding cells, including periodontal cells, osteoblasts, osteoclasts and inflammatory cells, and to affect the course of dental disease. Experimental studies have highlighted the interactions between dentin and cells from tooth and periodontal tissues and reveal dentin to be a cell adhesive, signaling and migratory stimulus for various mesenchymal and inflammatory cells. These results support the hypothesis that dentin molecules might function as regulatory signals for the healing and resorption of dental and periodontal tissues. Data from recent and classical investigations are summarized, many open questions are discussed, and current hypotheses concerning the mechanisms of tooth resorption and periodontal healing are outlined. Many questions regarding the importance of dentin as a source of multifunctional molecules remain unanswered and provide important directions for future studies.Oral Diseases 04/2004; 10(2):63-74. · 2.38 Impact Factor
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ABSTRACT: Identification, characterization, and potential application of mesenchymal stem cells (MSC) derived from human dental tissues. Dental pulp and periodontal ligament were obtained from normal human impacted third molars. The tissues were digested in collagenase/dispase to generate single cell suspensions. Cells were cultured in alpha-MEM supplemented with 20% fetal bovine serum, 2 mM l-glutamine, 100 microM l-ascorbate-2-phosphate. Magnetic and fluorescence activated cell sorting were employed to characterize the phenotype of freshly isolated and ex vivo expanded cell populations. The developmental potential of cultured cells was assessed following co-transplantation with hydroxyapetite/tricalcium phosphate (HA/TCP) particles into immunocompromised mice for 8 weeks. MSC were identified in adult human dental pulp (dental pulp stem cells, DPSC), human primary teeth (stem cells from human exfoliated deciduous teeth, SHED), and periodontal ligament (periodontal ligament stem cells, PDLSC) by their capacity to generate clongenic cell clusters in culture. Ex vivo expanded DPSC, SHED, and PDLSC populations expressed a heterogeneous assortment of makers associated with MSC, dentin, bone, smooth muscle, neural tissue, and endothelium. PDLSC were also found to express the tendon specific marker, Scleraxis. Xenogeneic transplants containing HA/TCP with either DPSC or SHED generated donor-derived dentin-pulp-like tissues with distinct odontoblast layers lining the mineralized dentin-matrix. In parallel studies, PDLSC generated cementum-like structures associated with PDL-like connective tissue when transplanted with HA/TCP into immunocompromised mice. Collectively, these data revealed the presence of distinct MSC populations associated with dental structures with the potential of stem cells to regenerate living human dental tissues in vivo.Orthodontics and Craniofacial Research 09/2005; 8(3):191-9. · 1.19 Impact Factor