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ABSTRACT: It is suggested that dental pulp stem cells (DPSCs) possess pluripotent differentiation and self-renewal capacity and play a crucial role in maintaining dental pulp homeostasis. However, little is known about the age-related changes of DPSCs, and whether aging and its microenvironment are associated with DPSCs remains a question. In this study, age-related changes in proliferation and osteogenic differentiation ability of rat DPSCs were assessed.
To examine the influence of microenvironment factors on different ages of DPSCs, we exposed adult rat DPSCs to juvenile rat dental pulp cell-conditioned medium (DPC-CM), and juvenile DPSCs were exposed to adult DPC-CM. Morphologic appearance, colony-forming assay, cell cycle analysis, 3-(4,5-dimethyl-thyazol-2-yl)-2,5-diphenyltetrazolium, gene expression, and mineralization assay after osteogenic induction of DPSCs were evaluated.
DPSCs isolated from the juvenile donors displayed increased proliferation and decreased osteogenic differentiation ability compared with the adult DPSCs. Interestingly, adult DPSCs induced by juvenile DPC-CM demonstrated enhanced proliferation but decreased osteogenic differentiation ability, whereas DPSCs from juvenile donors induced by adult DPC-CM showed decreased proliferation but enhanced osteogenic differentiation ability.
Our data suggest that age-related changes of DPSCs should be taken into account when DPSCs are intended to be used for investigations and application. Furthermore, the activity of DPSCs can be modulated by the extrinsic microenvironment.
Journal of endodontics 11/2009; 35(11):1546-53. · 2.95 Impact Factor
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ABSTRACT: Estrogens have been suggested to play an important role in the development of temporomandibular disorders (TMD). However, a growing body of epidemiological, clinical and experimental researches focusing on the relationship between TMD and exogenous estrogen or serum estrogen has produced conflicting results. Recently, locally synthesized estrogens have been found and proved to contribute greatly to the function of cartilage. We hypothesize that estrogens synthesized locally in condylar cartilage have a profound effect on the development of TMD. Future investigation of local estrogen in condylar cartilage may give, at least partially, valuable evidences for the etiology and treatment strategy of TMD. In our opinion, regulating the amount and effect of locally synthesized estrogen seems to hold interesting future prospects for the treatment of TMD.
Medical Hypotheses 03/2009; 72(6):720-2. · 1.39 Impact Factor
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ABSTRACT: Previous studies have suggested that periodontal ligament stem cells (PDLSCs) play crucial role in regeneration of periodontal defects, and recently tissue engineering based on PDLSCs to enhance periodontal regeneration has been the focus of periodontal research. A theoretical way to achieve this goal would be to provide a "stimulatory'' environment to rapidly expand PDLSCs in vitro to expedite tissue engineering of periodontium. We hypothesize that three-dimensional (3D) dynamic simulated microgravity (SMG) culture system have effect on periodontal stem cells, and would benefit periodontal stem cells proliferation and differentiation, but up to now, there are no related reports on this aspect. In this study, we investigated the biological effect of three-dimensional dynamic SMG induced by rotary cell culture system (RCCS) on human periodontal ligament stem cells (hPDLSCs) in vitro. hPDLSCs were isolated from surgically extracted human teeth and enriched by collecting multiple colonies. hPDLSCs were inoculated on Cytodex 3 microcarriers and cultured in RCCS. The results showed that SMG affected the biology of hPDLSCs as indicated by promotion of proliferation and viability, alterations of morphology, and disorganization of microfilament system. Besides, SMG-treated hPDLSCs presented increased matrix mineralization and up-regulated expression of mineralization associated genes after incubation in osteogenic medium. For it is the first time to investigate effects of SMG on PDLSCs, the research may lend insight into variations of cell response in 3D environment, and contribute to achievement of desirable periodontal regeneration utilizing PDLSCs-based tissue engineering approaches.
Stem cells and development 02/2009; 18(9):1273-82. · 4.15 Impact Factor
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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.
Tissue Engineering Part A 11/2008; 14(12):2059-68. · 4.64 Impact Factor
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ABSTRACT: Dental pulp stem cells from teeth can be used for tooth regeneration. Although nondental stem cells derived from bone marrow can differentiate into odontoblast-like cells when recombined with embryonic oral epithelium, these cells can lose their ability to differentiate after an extended number of cell culture passages. There has been limited research to identify stem cells from other tissue sources to regenerate teeth. As another candidate source for mesenchymal stem cells, hair follicle has obtained much more attention recently because of its easy accessibility. In this study, cultured vibrissae follicle dermal papilla mesenchymal cells (FDPMCs) from adult C57BL/6 GFP mice can differentiate into adipocytes and osteoblasts in vitro. Moreover, in the inductive microenvironment generated by apical bud and dental mesenchyme from 7-day-old C57 mice, FDPMCs in vitro demonstrated odontogenic potential, as indicated by the morphological transformation, cell-cycle change and expression of tooth-specific markers. Under the same microenvironment, FDPMCs were incubated in vivo for 3 weeks. Coexpression of GFP and DSP proteins in the odontoblast layer was detected in the recovered implants, suggesting that GFP(+) FDPMCs can function as odontoblasts in vivo. Together, our data indicate for the first time that whisker FDPMCs from adult mice can differentiate to odontoblast-like cells.
Stem cells and development 09/2008; 18(4):583-9. · 4.15 Impact Factor
