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Odontology Jul 2013This study aimed to examine the dynamics of odontoblast-lineage cells following cavity preparation with erbium:yttrium-aluminum-garnet (Er:YAG) laser in rat molars....
This study aimed to examine the dynamics of odontoblast-lineage cells following cavity preparation with erbium:yttrium-aluminum-garnet (Er:YAG) laser in rat molars. Cavity preparation was made with Er:YAG laser in the mesial surface of the maxillary left first molar of 8-week-old Wistar rats. Contralateral first molar served as unirradiated control. Immediately, 6 and 12 h and 1, 2, 3, 5 and 7 days after the lasing (n = 5, each), specimens were collected and processed for immunohistochemistry for heat-shock protein (HSP)-25 and nestin as markers for odontoblast-lineage cells. Cell proliferation assay using bromodeoxyuridine (BrdU) labeling was also performed. Unirradiated teeth showed HSP-25- and nestin-immunoreactivity in odontoblasts. At 6-12 h after irradiation, the odontoblastic layer was disorganized and some of odontoblasts lost the immunoreactivity to HSP-25 and nestin. At 1-2 days, however, HSP-25- and nestin-immunoreactivities in the odontoblast layer showed a noticeable recovery, resulting in the rearrangement of odontoblast-like cells intensely immunoreactive to HSP-25 and nestin at 3-7 days. BrdU-positive cells showed a significant increase at 2 days (P < 0.05 vs. immediate previous time point; one-way analysis of variance and Scheffé post hoc test), peaked at 3 days and then decreased significantly (P < 0.05). It was concluded that under the present experimental condition in rat molars, cavity preparation with Er:YAG laser induced mild and reversible damage to odontoblasts. The reparative process was characterized by the rearrangement of HSP-25- and nestin-immunoreactive odontoblast-like cells, which took place subsequent to the odontoblastic layer disorganization with partial loss of these immunoreactivities.
Topics: Animals; Bromodeoxyuridine; HSP27 Heat-Shock Proteins; Immunohistochemistry; Lasers; Molar; Odontoblasts; Rats; Rats, Wistar
PubMed: 22736273
DOI: 10.1007/s10266-012-0078-x -
Cellular Reprogramming Aug 2018Wedelolactone is a multitarget natural plant compound with many pharmacological activities, including anti-inflammatory, anticancer, and antiosteoporosis. In this study,...
Wedelolactone is a multitarget natural plant compound with many pharmacological activities, including anti-inflammatory, anticancer, and antiosteoporosis. In this study, dental pulp stem cells (DPSCs) were treated with or without wedelolactone. We found that wedelolactone stimulated odontoblast differentiation and mineralization. At the molecular level, wedelolactone directly promoted the nuclear accumulation of β-catenin, and thereafter stimulated the expression of odontoblast-related marker genes containing dentin matrix protein-1 (DMP1), dentin sialophosphoprotein (DSPP), and runt-related transcription factor 2 (Runx2). Furthermore, wedelolactone upregulated the expression of IκBα and inhibited phosphonation and nuclear migration of p65. As a result, wedelolactone remarkably induced odontoblast differentiation through semaphorin 3A (Sema3A)/neuropilin-1 (NRP1) pathway-mediated β-catenin activation and nuclear factor kappa B (NF-κB) pathway inhibition. Our findings provide novel perceptions on odontogenic differentiation of DPSCs.
Topics: Adult; Cell Differentiation; Cells, Cultured; Coumarins; Gene Expression Regulation; Healthy Volunteers; Humans; NF-kappa B; Odontoblasts; Wnt Proteins; Young Adult; beta Catenin
PubMed: 30089027
DOI: 10.1089/cell.2018.0004 -
Head & Face Medicine Dec 2017The revitalization or regeneration of the dental pulp is a preferable goal in current endodontic research. In this study, human dental pulp cell (DPC) spheres were...
BACKGROUND
The revitalization or regeneration of the dental pulp is a preferable goal in current endodontic research. In this study, human dental pulp cell (DPC) spheres were applied to human root canal samples to evaluate their potential adoption for physiological tissue-like regeneration of the dental root canal by odontoblastic differentiation as well as cell-induced mineral formation.
METHODS
DPC were cultivated into three-dimensional cell spheres and seeded on human root canal specimens. The evaluation of sphere formation, tissue-like behavior and differentiation as well as mineral formation of the cells was carried out with the aid of optical light microscopy, immunohistochemical staining and scanning electron microscopy (SEM).
RESULTS
Spheres and cells migrated out of the spheres showed an intense cell-cell- and cell-dentin-contact with the formation of extra cellular matrix. In addition, the ingrowth of cell processes into dentinal tubules and the interaction of cell processes with the tubule walls were detected by SEM-imaging. Immunohistochemical staining of the odontoblast specific matrix proteins, dentin matrix protein-1, and dentin sialoprotein revealed an odontoblast-like cell differentiation in contact with the dentin surface. This differentiation was confirmed by SEM-imaging of cells with an odontoblast specific phenotype and cell induced mineral formation.
CONCLUSIONS
The results of the present study reveal the high potential of pulp cells organized in spheres for dental tissue engineering. The odontoblast-like differentiation and the cell induced mineral formation display the possibility of a complete or partial "dentinal filling" of the root canal and the opportunity to combine this method with other current strategies.
Topics: Adult; Bicuspid; Cell Differentiation; Cell Movement; Dental Pulp; Dental Pulp Cavity; Dentin; Female; Humans; In Vitro Techniques; Male; Middle Aged; Minerals; Molar; Odontoblasts; Regeneration; Root Canal Therapy; Tissue Engineering; Tissue Scaffolds
PubMed: 29221472
DOI: 10.1186/s13005-017-0156-y -
Molecular Medicine Reports Dec 2017The present study aimed to investigate the effect of SOX2 on odontoblast differentiation of dental pulp stem cells (DPSCs), and to examine the potential application of...
The present study aimed to investigate the effect of SOX2 on odontoblast differentiation of dental pulp stem cells (DPSCs), and to examine the potential application of DPSCs on dental restoration. SRY‑box 2 (SOX2) overexpression in human DPSCs (DPSCs‑SOX2) was established by retroviral infection. The empty vector‑infected DPSCs were regarded as a control group (DPSCs‑vector group). Odontoblast differentiation culture medium was used to induce the differentiation of DPSCs. The degree of odontoblast differentiation of DPSCs was analyzed by flow cytometry. A genomic expression microarray and reverse transcription‑quantitative polymerase chain reaction were used to analyze the molecular mechanism of SOX2 affecting odontoblast differentiation of DPSCs. After induction by odontoblast differentiation culture medium, the DPSC, DPSCs‑vector and DPSCs‑SOX2 groups all could carry out odontoblast differentiation. After induction for 3 weeks, all groups expressed dentin sialophosphoprotein (DSPP) and dentin matrix protein‑1 (DMP‑1) to a certain degree. However, after induction differentiation, the expression efficiency of DSPP and DMP‑1 in the DPSCs‑SOX2 group was highest compared with the normal DPSC and DPSCs‑vector groups, which demonstrated the advantages of DPSC‑SOX2 in odontoblast differentiation. Mechanism analysis indicated that in the DPSCs‑SOX2 group, the activation of the Wnt signaling pathway and the upregulation of Wnt genes may be important mechanisms underlying SOX2 promoting odontoblast differentiation of DPSCs. These results preliminarily indicate that SOX2 has a certain promoting effect on odontoblast differentiation of DPSCs.
Topics: Biomarkers; Cell Differentiation; Cells, Cultured; Dental Pulp; Gene Expression; Humans; Odontoblasts; Osteogenesis; SOXB1 Transcription Factors; Signal Transduction; Stem Cells
PubMed: 29039570
DOI: 10.3892/mmr.2017.7812 -
The International Journal of... Feb 1995Reactionary dentinogenesis is the secretion of a tertiary dentine matrix by surviving odontoblast cells in response to an appropriate stimulus. Whilst this stimulus may... (Review)
Review
Reactionary dentinogenesis is the secretion of a tertiary dentine matrix by surviving odontoblast cells in response to an appropriate stimulus. Whilst this stimulus may be exogenous in nature, it may also be from endogenous tissue components released from the matrix during pathological processes. Implantation of isolated dentine extracellular matrix components in unexposed cavities of ferret teeth led to stimulation of underlying odontoblasts and a response of reactionary dentinogenesis. Affinity chromatography of the active components prior to implantation and assay for growth factors indicated that this material contained significant amounts of TGF-beta 1, a growth factor previously shown to influence odontoblast differentiation and secretory behavior. Reactionary dentinogenesis during dental caries probably results from solubilization of growth factors, TGF-beta in particular, from the dentine matrix which then are responsible for initiating the stimulatory effect on the odontoblasts. Compositional differences in tertiary dentine matrices beneath carious lesions in human teeth have also been shown indicating modulation of odontoblast secretion during reactionary and reparative dentinogenesis.
Topics: Animals; Dentinogenesis; Extracellular Matrix; Humans; Odontoblasts; Phenotype
PubMed: 7626417
DOI: No ID Found -
Cell and Tissue Research Apr 2016Odontoblasts differentiate from dental mesenchyme during dentin formation and mineralization. However, the molecular mechanisms controlling odontoblast differentiation...
Odontoblasts differentiate from dental mesenchyme during dentin formation and mineralization. However, the molecular mechanisms controlling odontoblast differentiation remain poorly understood. Here, we show that expression of testicular acid phosphatase (ACPT) is restricted in the early stage of odontoblast differentiation in proliferating dental mesenchymal cells and secretory odontoblasts. ACPT is expressed earlier than tissue-nonspecific alkaline phosphatase (TNAP) and partly overlaps with TNAP in differentiating odontoblasts. In MDPC-23 odontoblastic cells, expression of ACPT appears simultaneously with a decrease in β-catenin activity and is abolished with the expression of Phex and Dsp. Knockdown of ACPT in MDPC-23 cells stimulates cell proliferation together with an increase in active β-catenin and cyclin D1. In contrast, the overexpression of ACPT suppresses cell proliferation with a decrease in active β-catenin and cyclin D1. Expression of TNAP, Osx, Phex and Dsp is reduced by knockdown of ACPT but is enhanced by ACPT overexpression. When ACPT is blocked with IgG, alkaline phosphatase activity is inhibited but cell proliferation is unchanged regardless of ACPT expression. These findings suggest that ACPT inhibits cell proliferation through β-catenin-mediated signaling in dental mesenchyme but elicits odontoblast differentiation and mineralization by supplying phosphate during dentin formation. Thus, ACPT might be a novel candidate for inducing odontoblast differentiation and mineralization for dentin regeneration.
Topics: Acid Phosphatase; Animals; Antigens, Differentiation; Calcification, Physiologic; Cell Differentiation; Cell Line; Gene Expression Regulation, Enzymologic; Gene Knockdown Techniques; Male; Mice; Odontoblasts
PubMed: 26547858
DOI: 10.1007/s00441-015-2310-9 -
European Journal of Cell Biology Jan 2019Cell polarity identifies the asymmetry of a cell. Various types of cells, including odontoblasts and epithelial cells, polarize to fulfil their destined functions.... (Review)
Review
Cell polarity identifies the asymmetry of a cell. Various types of cells, including odontoblasts and epithelial cells, polarize to fulfil their destined functions. Odontoblast polarization is a prerequisite and fundamental step for tooth development and tubular dentin formation. Current knowledge of odontoblast polarization, however, is very limited, which greatly impedes the development of novel approaches for regenerative endodontics. Compared to odontoblasts, epithelial cell polarization has been extensively studied over the last several decades. The knowledge obtained from epithelia polarization has been found applicable to other cell types, which is particularly useful considering the remarkable similarities of the morphological and compositional features between polarized odontoblasts and epithelia. In this review, we first discuss the characteristics, the key regulatory factors, and the process of epithelial polarity. Next, we compare the known facts of odontoblast polarization with epithelial cells. Lastly, we clarify knowledge gaps in odontoblast polarization and propose the directions for future research to fill the gaps, leading to the advancement of regenerative endodontics.
Topics: Animals; Cell Polarity; Epithelial Cells; Models, Biological; Odontoblasts; rho GTP-Binding Proteins
PubMed: 30473389
DOI: 10.1016/j.ejcb.2018.11.003 -
Journal of Endodontics Mar 2019The primary aim was to explore the criteria used in characterization of reparative cells and mineralized matrices formed after treatment of pulp exposures, and the...
INTRODUCTION
The primary aim was to explore the criteria used in characterization of reparative cells and mineralized matrices formed after treatment of pulp exposures, and the sequence of relative events. The secondary aim was to evaluate whether the reparative events depend on the experimental model species, age, and therapeutic intervention.
METHODS
A literature search of databases using different combinations of the key words was undertaken. Data analysis was based only on studies having histological or histochemical assessment of the pulp tissue responses. The search yielded 86 studies, 47 capping material-based and 39 bioactive application-based experiments, which provided data on morphological or functional characterization of the mineralized matrices and the associated cells.
RESULTS
In 64% of capping material-based and 72% of bioactive application-based experiments, a 2-zone mineralized matrix formation (atubular followed by tubular) was detected, whereas characterization of odontoblastic differentiation is provided in only 25.5% and 46.1% of the studies, respectively. In 93.3% of the studies showing odontoblast-like cells, differentiated cells were in association with tubular mineralized matrix formation. Analyses further showed that cell- and matrix-related outcomes do not depend on experimental model species, age, and therapeutic intervention.
CONCLUSIONS
The evidence of the reviewed scientific literature is that dental pulp cells secrete a dentin-like matrix of tubular morphology in relation to primitive forms of atubular or osteotypic mineralized matrix. Furthermore, data analysis showed that dental pulp cells express in vivo the odontoblastic phenotype, and secrete matrix in a predentin-like pattern, regardless of the model species, age, and therapeutic intervention used.
Topics: Aging; Animals; Calcification, Physiologic; Cell Differentiation; Databases, Bibliographic; Dental Pulp; Dentin, Secondary; Dentinogenesis; Extracellular Matrix Proteins; Humans; Odontoblasts; Species Specificity
PubMed: 30803530
DOI: 10.1016/j.joen.2018.12.002 -
Journal of Endodontics Jun 2022Odontoblasts, terminally differentiated dentin-forming cells with their processes that penetrate into dentin, have been considered potential sensory cells. Current...
INTRODUCTION
Odontoblasts, terminally differentiated dentin-forming cells with their processes that penetrate into dentin, have been considered potential sensory cells. Current research suggests that odontoblasts sense external stimuli and transmit pain signals. PIEZO1, as a specific mechanically activated ion channel, may play an important role in mechanical transduction in odontoblasts. In this study, we devoted to investigating the functions and underlying molecular mechanisms of PIEZO1 ion channels in odontoblast mechanotransduction.
METHODS
Human dental pulp stem cells were cultured in vitro and induced to differentiate into odontoblast-like cells (OLCs). The expression of PIEZO1 protein in pulp, dental pulp stem cells, and OLCs was detected by immunohistochemistry or immunofluorescence. The mechanical sensitivity of OLCs was detected by a constructed fluid shear stress model and examined by calcium fluorescence intensity. A single-cell mechanical stimulation model was used to detect the PIEZO1 electrophysiological properties of OLCs. Yoda1 (a PIEZO1-specific agonist), GsMTx4 (a PIEZO1 antagonist), and non-calcium ion extracellular solution were utilized to confirm PIEZO1 mechanotransduction in OLCs in both fluid shear stress and single-cell mechanical stimulation assays. The amount of ATP released by OLCs was measured under stimulation with Yoda1 and GsMTx4. Rat trigeminal ganglion neurons were cultured in vitro and detected by whole-cell patch-clamp recording under ATP stimulation.
RESULTS
PIEZO1 ion channels were positively expressed in OLCs and odontoblastic bodies and processes but weakly expressed in dental pulp cells. After the treatment of OLCs with shearing stress or Yoda1, the fluorescence intensity of intracellular calcium ions increased rapidly but did not noticeably change after treatment with GsMTx4 or the non-calcium ion extracellular solution. When single-cell mechanical stimuli were applied to OLCs, the evoked inward currents were recorded by patch-clamp electrophysiology. The inward currents increased and current inactivation became slower after Yoda1 treatment, but these currents almost completely disappeared after the addition of GsMTx4. The amount of ATP released by OLCs increased significantly after Yoda1 stimulation, while GsMTx4 reversed the release of ATP. Whole-cell patch-clamp detection showed that ATP evoked slow inward currents and increased the frequency of action potentials of trigeminal ganglion neurons.
CONCLUSIONS
Taken together, these findings indicated that odontoblasts evoked a fast inward current via PIEZO1 ion channels after the application of external mechanical stimuli and released ATP to transmit signals to adjacent cells. Thus, PIEZO1 ion channels in odontoblasts mediate mechanotransduction under various pathophysiological conditions in dentin.
Topics: Adenosine Triphosphate; Animals; Calcium; Ion Channels; Mechanotransduction, Cellular; Membrane Proteins; Odontoblasts; Rats
PubMed: 35219748
DOI: 10.1016/j.joen.2022.02.005 -
Calcified Tissue International Feb 2000In order to elucidate the mechanisms involved in human dentin formation, we developed a cell culture system to promote differentiation of dental pulp cells into...
In order to elucidate the mechanisms involved in human dentin formation, we developed a cell culture system to promote differentiation of dental pulp cells into odontoblasts. Explants from human teeth were cultured in Eagle's basal medium supplemented with 10% or 15% fetal calf serum, with or without beta-glycerophosphate (beta GP). Addition of beta GP to the culture medium induced odontoblast features in the cultured pulp cells. Cells polarized and some of them exhibited a typical cellular extension. In some cases, cells aligned with their processes oriented in the same direction and developed junctional complexes similar to the terminal web linking odontoblasts in vivo. Fine structural analyses showed the presence of typical intracellular organelles of the odontoblast body, whereas the process contained only cytoskeleton elements and secretory vesicles. Polarized cells deposited onto the plastic dishes an abundant and organized type I collagen-rich matrix with areas of mineralization appearing thereafter. X-ray microanalysis showed the presence of calcium and phosphorus and the electron diffraction pattern confirmed the apatitic crystal structure of the mineral. High expression of alpha 1 (1) collagen mRNAs was detected in all polarized cells whereas dentin sialoprotein gene was mainly expressed in mineralizing areas. This cell culture system allowed for the differentiation of pulp cells into odontoblasts, at both the morphological and functional level. Moreover, these cells presented a spatial organization similar to the odontoblastic layer.
Topics: Adolescent; Cell Differentiation; Cell Polarity; Culture Media; DNA Probes; Dental Pulp; Electron Probe Microanalysis; Extracellular Matrix; Glycerophosphates; Humans; Microscopy, Electron; Molar, Third; Odontoblasts; Organ Culture Techniques
PubMed: 10652961
DOI: 10.1007/pl00005833