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Journal of Dental Research Apr 1985
Topics: Animals; Calcium; Cell Membrane; Cytoplasm; Dentin; Dentin, Secondary; Dentinogenesis; Freeze Fracturing; Histological Techniques; Humans; Microscopy, Electron, Scanning; Odontoblasts; Organoids; Radioisotopes; Sensory Receptor Cells; Staining and Labeling; Tooth Calcification
PubMed: 2580872
DOI: 10.1177/002203458506400403 -
Journal of Dental Research Apr 1985Origin, cell kinetics, and phenotypic aspects of odontoblast cell lineage are described. Epithelial-mesenchymal interactions regulate odontoblast differentiation. These...
Origin, cell kinetics, and phenotypic aspects of odontoblast cell lineage are described. Epithelial-mesenchymal interactions regulate odontoblast differentiation. These interactions appear to be mediated by the extracellular matrix. Possible molecular mechanisms of cell-matrix interactions are discussed. Questions still unanswered are recommended for investigation.
Topics: Animals; Basement Membrane; Cell Cycle; Cell Differentiation; Culture Techniques; Cytoplasm; Dental Papilla; Epithelial Cells; Epithelium; Humans; Intercellular Junctions; Kinetics; Mesoderm; Mice; Neural Crest; Odontoblasts; Phenotype
PubMed: 3857251
DOI: 10.1177/002203458506400402 -
Chemico-biological Interactions Jan 2021Resin-based dental materials consist of filler particles and different monomers that are light cured in situ to re-establish dental function and aesthetics. Due to the...
Resin-based dental materials consist of filler particles and different monomers that are light cured in situ to re-establish dental function and aesthetics. Due to the degree of conversion of adhesive polymers, the monomers triethyleneglycol dimethacrylate (TEGDMA) and 2-hydroxyethyl methacrylate (HEMA) are released in relatively high amounts and are susceptible to degradation, acting as bioactive compounds and affecting cell and tissues. This study aimed to assess the effect of HEMA and TEGDMA exposure on metabolic activity, membrane integrity, and cell survival of human odontoblast-like cell (hOLCs). Exposure to resin monomers for 24 h induced major changes in cell membrane integrity, metabolic activity, and survival, which were measured by the calcein method and lactate dehydrogenase release. Increased and early reactive oxygen species (ROS) production was observed leading to degradative oxidation of membrane lipids identified as malondialdehyde production. Severe alteration in mitochondria occurred due to transmembrane mitochondrial potential collapse, possibly inducing activation of apoptotic cell death. hOLCs exposure to resin monomers modified the cell redox potential, with consequences on membrane permeability and integrity, including mitochondrial function. Lipid peroxidation appears to be a key phenomenon for the membrane structures oxidation after HEMA and TEGDMA exposure, leading to cell death and cytotoxicity. hOLCs respond early by differential induction of adaptive mechanisms to maintain cell homeostasis. Modulation of oxidative stress-induced response involves the regulation of genes that encode for antioxidant proteins such as catalase and heme oxygenase-1; regulation that functions as a critical protection mechanism against oxidative cell damage induced by HEMA and TEGDMA. Ascorbic acid as an antioxidant substance mitigates the oxidative damage associated with exposure to monomers.
Topics: Apoptosis; Catalase; Cell Membrane; Gene Expression Regulation, Enzymologic; Heme Oxygenase-1; Humans; Methacrylates; Mitochondria; Odontoblasts; Oxidative Stress; Polyethylene Glycols; Polymethacrylic Acids; Reactive Oxygen Species; Resins, Synthetic
PubMed: 33248029
DOI: 10.1016/j.cbi.2020.109336 -
Connective Tissue Research Mar 2019Neurotrophin receptor-interacting MAGE homologue (Nrage) plays an important role in bone development and the metabolism of normal skeletal structures. Our previous study...
PURPOSE
Neurotrophin receptor-interacting MAGE homologue (Nrage) plays an important role in bone development and the metabolism of normal skeletal structures. Our previous study showed that Nrage inhibited the odontogenic differentiation of mouse dental pulp cells. However, the potential roles and mechanism of Nrage in regulating odontogenic differentiation are unknown. The aim of this study was to investigate the molecular mechanism of Nrage in odontogenic differentiation of mouse odontoblast-like cells.
MATERIALS AND METHODS
Endogenous expression of Nrage was stably downregulated by lentivirus-mediated shRNA. Mineralized nodules formation was detected by alizarin red S staining. Dmp-1, Dspp, and ALP mRNA and protein levels were detected by qRT-PCR and western blotting, respectively. In addition, ALPase activity was detected. Confocal microscopy and co-immunoprecipitation (co-IP) were used to analyze the interactions between NRAGE and NF-κB signaling molecules. An IKK inhibitor was also used in the study.
RESULTS
NRAGE expression in odontoblasts was downregulated during mouse first maxillary molar development. Moreover, NRAGE expression was downregulated during odontogenic differentiation of odontoblast-like cells. NRAGE knockdown significantly upregulated DMP1 and DSP expression, increased ALPase activity, and promoted mineralized nodule formation. In addition, NRAGE knockdown increased the translocation of NF-κB1 to the nucleus and phosphorylation levels of p65. Co-IP results showed that NRAGE bound to IKKβ. Most importantly, the promoting effect of Nrage knockdown on odontoblastic differentiation was reduced after treatment with an IKK inhibitor.
CONCLUSIONS
Our data confirmed that NRAGE is an important regulator of odontogenic differentiation of odontoblasts by inhibiting the NF-κB signaling pathway through binding to IKKβ.
ABBREVIATIONS
Nrage: neurotrophin receptor-interacting MAGE homologue; DSP: dentin sialophospho protein; DMP-1: dentin matrix protein-1; BMP: bone morphogenetic protein; Wnt: wingless; NF-κB: nuclear factor of activated B cells; DAPI: 4',6-diamidino-2-phenylindole; KO: knockout; DPCs: dental pulp cells; AA: ascorbic acid; β-Gly: β-glycerophosphate; Dex: dexamethasone; co-IP: co-immunoprecipitation; IκB: inhibitor of NF-κB; IKK: IκB kinase.
Topics: Alkaline Phosphatase; Animals; Biomarkers; Calcification, Physiologic; Cell Differentiation; Cell Line; Down-Regulation; Extracellular Matrix Proteins; Gene Knockdown Techniques; I-kappa B Kinase; Mice, Inbred C57BL; NF-kappa B; Neoplasm Proteins; Odontoblasts; Odontogenesis; Protein Binding; Signal Transduction
PubMed: 29448842
DOI: 10.1080/03008207.2018.1439484 -
International Endodontic Journal Jul 2021To explore the role of DNA methylation in the innate immunity of the dental pulp, this study investigated the effect of 5-aza-2'-deoxycytidine (AZA) on lipoteichoic acid...
AIM
To explore the role of DNA methylation in the innate immunity of the dental pulp, this study investigated the effect of 5-aza-2'-deoxycytidine (AZA) on lipoteichoic acid (LTA)-induced cytokine production and related intracellular signalling pathways in human odontoblast-like cells (hOBs).
METHODOLOGY
hOBs were cultured and differentiated from human dental pulp tissue, and the odontoblastic phenotype of the cells was detected using immunofluorescence, qRT-PCR and Western blotting. hOBs were pretreated with AZA and then stimulated with 10 μg mL LTA. The levels of 42 cytokines related to immunity and inflammation were examined using a cytokine antibody array and verified using qRT-PCR and ELISA. The effect of AZA on the LTA-induced NF-κB and MAPK signalling pathways was explored using Western blotting. The cells were treated with the specific NF-κB inhibitor PDTC and MAPK inhibitors (the ERK inhibitor U0126, the p38 inhibitor SB203580, and the JNK inhibitor SP600125) to further confirm the role of the signalling pathways in LTA-treated hOBs. DNA immunoprecipitation-PCR was used to examine the dynamic methylation status of the gene promoters of myeloid differentiation primary response 88 (MyD88) and tumour necrosis factor receptor-associated factor 6 (TRAF6) in the LTA-induced hOBs. Statistical analyses of the differences between two groups were performed using Student's t-test. One-way analysis of variance (anova) or repeated-measures anova with a post hoc Dunnett's test was used to assess the differences between multiple sets of data. P < 0.05 was considered to be statistically significant.
RESULTS
The odontoblastic markers were significantly higher in hOBs than those in human dental pulp cells (hDPCs) (P < 0.05). According to the cytokine antibody array results, hOBs pretreated with AZA had significantly increased production of several inflammatory cytokines (P < 0.05), in which the expression levels of IL-6 and IL-8 were the most dramatically increased upon LTA stimulation (P < 0.01). Furthermore, AZA resulted in the significant upregulation of p-IKKα/β, p-IκBα, p-p65, p-p38 and p-ERK in LTA-stimulated hOBs (P < 0.01). Treatment with the NF-κB pathway inhibitor suppressed both IL-6 and IL-8 expression (P < 0.05), whereas inhibitors of the MAPK pathway (SB203580 and SP600125) did not. In LTA-treated hOBs, AZA significantly increased the expression levels of TRAF6 and MyD88 (P < 0.05). AZA induced MyD88 promoter hypomethylation but did not affect TRAF6 methylation.
CONCLUSION
AZA regulated the LTA-induced inflammatory response through the NF-κB signal pathway in hOBs. This study highlights the important role of DNA methylation in the immunity defence of odontoblasts during the dental pulp immunity response to caries.
Topics: Cytokines; Decitabine; Humans; Lipopolysaccharides; NF-kappa B; Odontoblasts; Signal Transduction
PubMed: 33539038
DOI: 10.1111/iej.13488 -
Journal of Endodontics Nov 1984
Topics: Adolescent; Adult; Bicuspid; Child; Humans; Molar, Third; Odontoblasts; Odontogenesis; Tooth Root
PubMed: 6594421
DOI: 10.1016/S0099-2399(84)80139-9 -
International Endodontic Journal May 2016To fabricate a keratin hydrogel, characterize its functionality as a biomaterial and investigate the effects of keratin on growth and differentiation of odontoblast-like...
AIM
To fabricate a keratin hydrogel, characterize its functionality as a biomaterial and investigate the effects of keratin on growth and differentiation of odontoblast-like cells.
METHODOLOGY
Keratins were extracted from sheep wool using a well-established technique. The extracted proteins were purified by dialysis, quantified by gel electrophoresis, mass spectrometry, amino acid analysis and inductively coupled mass spectrometry. The microstructure of the fabricated keratin hydrogels was studied by scanning electron microscopy, flow characteristics by rheometer, hydrolytic stability and cytocompatibility by Live/Dead(®) cell assay. Furthermore, the influence of keratin on odontoblast-like cells (MDPC-23) was assessed to confirm their bioactivity at different dilutions. Cell proliferation was studied using alamarBlue(®) assay and differentiation by alkaline phosphatase enzyme activity, alizarin red staining and calcium quantification, reverse transcription polymerase chain reaction (rt-PCR) and immunocytochemical staining for dentine matrix protein- 1 (DMP-1) expression. anova with Tukey's tests was performed for statistical comparison.
RESULTS
The characterized hydrogel was injectable with a highly porous architecture that underwent slow degradation, and its cytocompatibility was statistically equivalent to collagen hydrogel (P > 0.05). Cell proliferation and differentiation were enhanced at the optimal keratin concentration of 0.1 mg mL(-1) . At this concentration, the influence of keratin on cell differentiation was demonstrated by marked elevation in alkaline phosphatase activity (P < 0.05), calcium deposition (P < 0.01), gene expression (P < 0.01) and positive immunostaining for DMP-1.
CONCLUSION
The presence of keratin enhanced odontoblast cell behaviour. Keratin hydrogels may be a potential scaffold for pulp-dentine regen-eration.
Topics: Animals; Cell Differentiation; Cell Proliferation; Dental Pulp; Keratins; Odontoblasts; Sheep; Wool
PubMed: 26016886
DOI: 10.1111/iej.12476 -
Journal of Dental Research Apr 2009TGF-beta1 exerts diverse functions in tooth development and tissue repair, but its role in microbial defenses of the tooth is not well-understood. Odontoblasts extending... (Comparative Study)
Comparative Study
TGF-beta1 exerts diverse functions in tooth development and tissue repair, but its role in microbial defenses of the tooth is not well-understood. Odontoblasts extending their cellular processes into the dentin are the first cells to recognize signals from TGF-beta1 and bacteria in carious dentin. This study aimed to determine the role of TGF-beta1 in modulating odontoblast responses to oral bacteria. We show that these responses depend upon the expression levels of microbial recognition receptors TLR2 and TLR4 on the cell surface. Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum activated both TLRs, but TLR4 played a greater role. Lack of cell-surface TLR2 was associated with poor response to Streptococcus mutans, Enterococcus faecalis, and Lactobacillus casei. TGF-beta1 inhibited TLR2 and TLR4 expression and attenuated odontoblast responses. Our findings suggest that the balance between TLR-mediated inflammation and TGF-beta1 anti-inflammatory activity plays an important role in pulpal inflammation.
Topics: Clone Cells; Dental Caries; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Odontoblasts; Pulpitis; RNA Interference; RNA, Small Interfering; Regression Analysis; Signal Transduction; Toll-Like Receptor 2; Toll-Like Receptor 4; Transforming Growth Factor beta1
PubMed: 19407153
DOI: 10.1177/0022034509334846 -
International Endodontic Journal Jul 2016To investigate the effect of RGD peptides derived from dentine phosphophoryn (DPP) on odontoblast-like cell in terms of differentiation and mineralization.
AIM
To investigate the effect of RGD peptides derived from dentine phosphophoryn (DPP) on odontoblast-like cell in terms of differentiation and mineralization.
METHODOLOGY
Mouse dental papilla cell line (MDPC-23), a rat odontoblast-like cell line, was used. Briefly, RGD peptides (RGD-1: SESDNNSSSRGDASYNSDES, RGD-2: ANSESDNNSSSRGDA, RGD-3: SRGDASYNSDESKD) were immobilized onto tissue culture polystyrene dishes (TCPS) assisted by carbodiimide chemistry. Surface characterization including carboxyl group quantification and amino acid analysis was carried out to ensure the existence of peptides on plates. Cells were inoculated to those peptides-modified and control dishes. Next, cell morphology was observed under phase contrast microscopy; cell numbers were counted manually using a hemocytometer. Furthermore, differentiation was examined by alkaline phosphatase (ALP) activity quantification, conventional and real-time RT-PCR. Finally, calcific deposition was observed by alizarin red staining and quantified using the cetylpyridinium chloride extraction method. Differences between the experimental groups and the control group were analysed statistically using one-way anova and Tukey's multiple comparison tests.
RESULTS
Peptides were immobilized onto TCPS successfully as evidenced by carboxyl group density and amino acid analysis. Cell morphology remained unchanged between peptides-immobilized groups and control, but adhered cell numbers were higher on those peptides-immobilized dishes (significant differences existed between RGD-1-0.5 with control, RGD-2-0.1 with control, and RGD-3-0.5 with control, respectively). RGD-3-0.5 exhibited the highest ALP activity on day 7 (P < 0.05) and promoted a twofold greater DMP-1 mRNA expression compared to the control on day 10 (P < 0.05). RGD peptides grafted dishes accelerated the mineralization of cells, amongst the experimental groups tested, RGD-3 groups (comprising RGD-3-0.1 and RGD-3-0.5) had significantly higher amounts of calcific deposition as compared to the control (P < 0.05).
CONCLUSIONS
RGD peptides originated from DPP especially RGD-3 promoted MDPC-23 differentiation and mineralization.
Topics: Amino Acid Motifs; Animals; Cell Count; Cell Line; Cells, Cultured; Dentin; Mice; Odontoblasts; Peptides; Phosphoproteins; Rats; Real-Time Polymerase Chain Reaction
PubMed: 26172115
DOI: 10.1111/iej.12498 -
Molecular Medicine Reports Jan 2018The role of dental pulp cells (DPCs) in hard dental tissue regeneration had received increasing attention because DPCs can differentiate into odontoblasts and other...
The role of dental pulp cells (DPCs) in hard dental tissue regeneration had received increasing attention because DPCs can differentiate into odontoblasts and other tissue‑specific cells. In recent years, epigenetic modifications had been identified to serve an important role in cell differentiation, and histone deacetylase (HDAC) inhibitors have been widely studied by many researchers. However, the effects of HDAC4 and HDAC5 on the differentiation of DPCs and the precise molecular mechanisms remain unclear. The present study demonstrated that LMK‑235, a specific human HDAC4 and HDAC5 inhibitor, increased the expression of specific odontoblastic gene expression levels detected by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) in dental pulp cells, and did not reduce cell proliferation tested by MTT assay after 3 days in culture at a low concentration. In addition, the mRNA and protein expression levels of dentin sialophosphoprotein, runt‑related transcription factor 2, alkaline phosphatase (ALP) and osteocalcin were evaluated by RT‑qPCR and western blotting, respectively. The increased gene and protein expression of specific markers demonstrated, indicating that LMK‑235 promoted the odontoblast induction of DPCs. ALP activity and mineralised nodule formation were also enhanced due to the effect of LMK‑235, detected by an ALP activity test and Alizarin Red S staining, respectively. Additionally, the vascular endothelial growth factor (VEGF)/RAC‑gamma serine/threonine‑protein kinase (AKT)/mechanistic target of rapamycin (mTOR) signalling pathway was tested to see if it takes part in the differentiation of DPCs treated with LMK‑235, and it was demonstrated that the mRNA expression levels of VEGF, AKT and mTOR were upregulated. These findings indicated that LMK‑235 may serve a key role in the proliferation and odontoblast differentiation of DPCs, and could be used to accelerate dental tissue regeneration.
Topics: Cell Differentiation; Cell Proliferation; Cells, Cultured; Dental Pulp; Gene Expression; Histone Deacetylase Inhibitors; Humans; Odontoblasts; Proto-Oncogene Proteins c-akt; RNA, Messenger; Signal Transduction; TOR Serine-Threonine Kinases; Vascular Endothelial Growth Factor A
PubMed: 29138868
DOI: 10.3892/mmr.2017.8055