Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Investigations of the odontoblast phenotype are hindered by obstacles such as the limited number of odontoblasts within the dental pulp and the difficulty in purification of these cells. Therefore, it is necessary to develop a cell culture system in which the local environment is inductive and can promote dental pulp stem cells (DPSCs) to differentiate into odontoblast lineage. In this study, we investigated the effect of conditioned medium from developing tooth germ cells (TGCs) on the differentiation and dentinogenesis of DPSCs both in vitro and in vivo. DPSCs were enzymatically isolated from the lower incisors of 4-week-old Sprague-Dawley rats and co-cultured with TGC conditioned medium (TGC-CM). The cell phenotype of induced DPSCs presents many features of odontoblasts, as assessed by the morphologic appearance, cell cycle modification, increased alkaline phosphatase level, synthesis of dentin sialoprotein, type I collagen and several other noncollagenous proteins, expression of the dentin sialophosphoprotein and dentin matrix protein 1 genes, and the formation of mineralized nodules in vitro. The induced DPSC pellets in vivo generated a regular-shaped dentin-pulp complex containing distinct dentinal tubules and predentin, while untreated pellets spontaneously differentiated into bone-like tissues. To our knowledge, this is the first study to mimic the dentinogenic microenvironment from TGCs in vitro, and our data suggest that TGC-CM creates the most odontogenic microenvironment, a feature essential and effective for the regular dentinogenesis mediated by DPSCs.
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PMID:Differentiation of dental pulp stem cells into regular-shaped dentin-pulp complex induced by tooth germ cell conditioned medium. 1751 25

Dental pulp stem cells harbor great potential for tissue-engineering purposes. However, previous studies have shown variable results, and some have reported only limited osteogenic and odontogenic potential.Because bone morphogenetic proteins (BMPs) are well-established agents to induce bone and dentin formation,in this study STRO-1-selected rat dental pulp-derived stem cells were transfected with the adenoviral mediated human BMP-2 gene. Subsequently, the cells were evaluated for their odontogenic differentiation ability in medium not containing dexamethasone or other stimuli. Cultures were investigated using light microscopy and scanning electron microscopy (SEM) and evaluated for cell proliferation, alkaline phosphatase(ALP) activity, and calcium content. Real-time polymerase chain reaction (PCR) was performed for gene expression of Alp, osteocalcin, collagen type I, bone sialoprotein, dentin sialophosphoprotein, and dentin matrix acidic phosphoprotein 1. Finally, an oligo-microarray was used to profile the expression of odontogenesis-related genes. Results of ALP activity, calcium content, and real-time PCR showed that only BMP2-transfected cells had the ability to differentiate into the odontoblast phenotype and to produce a calcified extracellular matrix. SEM and oligo-microarray confirmed these results. In contrast, the non-transfected cells represented a less differentiated cell phenotype. Based on our results, we concluded that the adenovirus can transfect STRO-1 selected cells with high efficacy. After BMP2 gene transfection, these cells had the ability to differentiate into odontoblast phenotype, even without the addition of odontogenic supplements to the medium.
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PMID:STRO-1 selected rat dental pulp stem cells transfected with adenoviral-mediated human bone morphogenetic protein 2 gene show enhanced odontogenic differentiation. 1782 31

Recombinant human bone morphogenetic protein-7 (BMP-7) has been shown to stimulate new reparative dentin formation in animal models. However, little is known about whether BMP-7 could promote the odontoblast-like differentiation and the formation of mineralized nodules in human dental pulp cells. Here, we reported that the infection with adenovirus-BMP-7 (Ad-BMP-7), a BMP-7-expressing adenoviral vector, induced the expression of BMP-7 in primarily cultured human dental pulp cells in the long term with little effect on their proliferation and viability. Importantly, BMP-7 expression significantly increased alkaline phosphatase activity and induced the dentin sialophosphoprotein expression in a dose- and time-dependent manner, suggesting that BMP-7 promoted the odontoblast differentiation. Furthermore, BMP-7 expression stimulated the formation of many mineralized dentin-like calcified nodules. Our data suggest that Ad-BMP-7-mediated BMP-7 expression can promote the differentiation of human pulp cells into odontoblast-like cells and mineralization in vitro, which may provide insight for the design of new gene therapy for the pulp capping in the clinic.
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PMID:Adenovirus-mediated recombinant human bone morphogenetic protein-7 expression promotes differentiation of human dental pulp cells. 1787 77

To clarify mechanisms of pulp wound healing and regeneration, it is important to establish continuous odontoblast-lineage cell lines. In this study, we established the proliferating pulp progenitor cell lines from dental papilla cells of rat incisor. These cell lines showed high levels of alkaline phosphatase (ALP) activity, expression of Runx2 and dentin sialophosphoprotein (DSPP), and extracellular formation of mineralized nodules. By using the cell line with high expression level of DSPP and the prominent mineral deposition, we examined whether bacterial lipopolysaccharide (LPS) had effects on its odontoblastic properties and found that ALP activity, expression of DSPP and Runx2, and the formation of mineralized nodules were suppressed in LPS dose-dependent manner. These results indicate that our established pulp progenitor cell line exhibits odontoblastic properties, which were suppressed by LPS, suggesting that gram-negative bacterial infection might downregulate the odontoblast function.
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PMID:Effects of lipopolysaccharide on newly established rat dental pulp-derived cell line with odontoblastic properties. 1788 87

Dentin sialophosphoprotein (DSPP) is an extracellular matrix, typically dentin- and bone-specific gene, which plays an important role in dentin mineralization and tooth development. Adipose-derived stromal cells (ADSCs) are considered to contain a group of pluripotent mesenchymal stem cells which are capable of mineralization either in vitro or in vivo. In the present study, we hypothesized that overexpression of DSPP would promote mineralization in ADSCs. Our results showed that infection of DSPP-expressing adenovirus (Ad-DSPP) enhanced expression of genes related to mineralization, such as Cbfa1,Osx,BSP, OCN and DMP1 in ADSCs. Alkaline phosphatase activity was also confirmed in Ad-DSPP-infected ADSCs by cytochemistry and alkaline phosphatase activity assay. Mineralization assay indicated that Ad-DSPP-infected ADSCs were able to form mineralized nodules. Another finding in this study is that early odontogenic marker genes such as Msx1, Msx2, Lhx7 and Pax9 were expressed in DSPP-overexpressed ADSCs. Thus, our results suggested that overexpression of DSPP promoted mineralization of ADSCs, and together with the expression of early odontogenic marker genes, implied that these cells may differentiate into functional odontoblast-like cells.
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PMID:Dentin sialophosphoprotein-promoted mineralization and expression of odontogenic genes in adipose-derived stromal cells. 1795 93

The aim of this study was to compare the ability of hard tissue regeneration of four types of stem cells or precursors under both in vitro and in vivo situations. Primary cultures of rat bone marrow, rat dental pulp, human bone marrow, and human dental pulp cells were seeded onto a porous ceramic scaffold material, and then either cultured in an osteogenic medium or subcutaneously implanted into nude mice. For cell culture, samples were collected at weeks 0, 1, 3, and 5. Results were analyzed by measuring cell proliferation rate and alkaline phosphatase activity, scanning electron microscopy, and real-time PCR. Samples from the implantation study were retrieved after 5 and 10 weeks and evaluated by histology and real-time PCR. The results indicated that in vitro abundant cell growth and mineralization of extracellular matrix was observed for all types of cells. However, in vivo matured bone formation was found only in the samples seeded with rat bone marrow stromal cells. Real-time PCR suggested that the expression of Runx2 and the expression osteocalcin were important for the differentiation of bone marrow stromal cells, while dentin sialophosphoprotein contributed to the odontogenic differentiation. In conclusion, the limited hard tissue regeneration ability of dental pulp stromal cells questions their practical application for complete tooth regeneration. Repeated cell passaging may explain the reduction of the osteogenic ability of both bone- and dentinal-derived stem cells. Therefore, it is essential to develop new cell culture methods to harvest the desired cell numbers while not obliterating the osteogenic potential.
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PMID:Hard tissue formation in a porous HA/TCP ceramic scaffold loaded with stromal cells derived from dental pulp and bone marrow. 1833 81

Although dental pulp stem cells (DPSC) have been isolated from adult dental pulp tissues, knowledge on how to use them to make teeth lags behind. To date, little is known about the effects of epithelial-mesenchymal cell ratios on the bioengineered odontogenesis mediated by DPSCs. In this study, we investigated the effects of apical bud cells (ABC) from dental epithelial stem cell niche of rat incisors on the differentiation and morphogenesis of molar DPSCs at different proportions (DPSC/ABC cell ratios=1:10, 1:3, 1:1, 3:1, 10:1, respectively). In vitro mixed DPSCs/ABCs at 1:1, 1:3, and 3:1 ratios displayed several crucial characteristics of odontoblast/ameloblast lineages, as indicated by accelerated mineralization, upregulated alkaline phosphatase activity, protein/gene expression for dentin sialophosphoprotein and ameloblastin. In vivo transplantation of reassociated DPSC and ABC pellets at different ratios was also carried out. Histological analyses demonstrated that only DPSC/ABC recombinants at 1:1 ratio generated typical molar crown-shaped structures, whereas recombinations at other ratios presented an atypical crown morphogenesis with unbalanced distribution of amelogenesis and dentinogenesis. Together, these findings revealed that the proportions of dental epithelial and mesenchymal cell populations can determine the odontogenic differentiation of DPSCs/ABCs in vitro as well as the bioengineered tooth morphogenesis in vivo.
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PMID:Epithelial-mesenchymal cell ratios can determine the crown morphogenesis of dental pulp stem cells. 1851 62

Hepatocyte growth factor (HGF) is a potent mitogenic and angiogenic factor involved in the development of many tissues including the teeth. We previously reported that dental pulp cells express the HGF receptor c-met and that HGF can enhance cell proliferation and differentiation. The purpose of this study was to determine whether HGF could stimulate proliferation and/or differentiation of murine dental papilla cells (MDPCs). MDPCs were isolated from neonatal mice, and the mitogenic potential of HGF on MDPCs was measured by 3-(4, 5-dimethyl-thyazol-2-yl)-2, 5-diphenyltetrazolium and flow cytometry. Differentiation of MDPCs in the presence of HGF was characterized by mineralization assay, alkaline phosphatase (ALP) activity and reverse-transcription polymerase chain reaction. We reported that MDPCs expressed both HGF and c-met and that HGF enhanced proliferation of MDPCs by concentrations ranging from 5 ng/mL to 20 ng/mL, with 10 ng/mL as the optimal concentration (p < 0.05). HGF prolonged S phase and shortened G1 phase of MDPCs, increased ALP activity significantly over the control (p < 0.05), and enhanced the formation of mineral nodules. ALP, dentin sialophosphoprotein, and dentin matrix protein-1 expression were significantly increased in the presence of HGF (p < 0.05), as were the expression of Msx1, Runx2, and Pax9. Our data suggest that HGF plays an important role in tooth development, by promoting the proliferation and differentiation of MDPCs.
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PMID:Hepatocyte growth factor exerts promoting functions on murine dental papilla cells. 1924

The ultimate goal of this study is to regenerate lost dental pulp and dentin via stem/progenitor cell-based approaches and tissue engineering technologies. In this study, we tested the possibility of regenerating vascularized human dental pulp in emptied root canal space and producing new dentin on existing dentinal walls using a stem/progenitor cell-mediated approach with a human root fragment and an immunocompromised mouse model. Stem/progenitor cells from apical papilla and dental pulp stem cells were isolated, characterized, seeded onto synthetic scaffolds consisting of poly-D,L-lactide/glycolide, inserted into the tooth fragments, and transplanted into mice. Our results showed that the root canal space was filled entirely by a pulp-like tissue with well-established vascularity. In addition, a continuous layer of dentin-like tissue was deposited onto the canal dentinal wall. This dentin-like structure appeared to be produced by a layer of newly formed odontoblast-like cells expressing dentin sialophosphoprotein, bone sialoprotein, alkaline phosphatase, and CD105. The cells in regenerated pulp-like tissue reacted positively to anti-human mitochondria antibodies, indicating their human origin. This study provides the first evidence showing that pulp-like tissue can be regenerated de novo in emptied root canal space by stem cells from apical papilla and dental pulp stem cells that give rise to odontoblast-like cells producing dentin-like tissue on existing dentinal walls.
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PMID:Stem/progenitor cell-mediated de novo regeneration of dental pulp with newly deposited continuous layer of dentin in an in vivo model. 1973 72

Direct application of dentin bonding agents onto the exposed pulp has been advocated, but in vivo studies indicate a lack of reparative dentin formation. Our objective was to investigate the role of triethylene glycol dimethacrylate (TEGDMA), a commonly used compound in dentin bonding agents, as a potential inhibitor of mineralization. Human pulp cells were exposed to different concentrations of TEGDMA, and expression of the mineralization-related genes collagen I, alkaline phosphatase, bone sialoprotein, osteocalcin, Runx2, and dentin sialophosphoprotein was analyzed. Gene expression studies by real-time polymerase chain-reaction revealed a concentration- and time-dependent decrease of mineralization markers. A subtoxic TEGDMA concentration (0.3 mM) reduced expression levels by 5 to 20% after 4 hrs and by 50% after 12 hrs. Furthermore, alkaline phosphatase activity and calcium deposition were significantly lower in dental pulp cells treated with TEGDMA over 14 days. These findings indicate that even low TEGDMA concentrations might inhibit mineralization induced by dental pulp cells, thus impairing reparative dentin formation after pulp capping with dentin bonding agents.
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PMID:TEGDMA reduces mineralization in dental pulp cells. 2113 93


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