Odontoblastic Differentiation Of Dental Pulp Stem Cells Research Articles

Dopamine is involved in reparative dentin formation through odontoblastic differentiation of dental pulp stem cells

Conventional direct pulp-capping materials induce pulp cells to secrete various biomolecules in pulp tissues that promote reparative dentin formation through induction of odontoblastic differentiation of dental pulp stem cells (DPSCs). However, these biomolecules sometimes induce bone-like dentin with poor sealing properties. Therefore, exploration of biomolecules that allow tight sealing by tubular reparative dentin is required. We recently reported that dopamine (DA) is involved in dentinogenesis. Hence, we investigated the effect of DA on odontoblastic differentiation of DPSCs and reparative dentin formation. Both tyrosine hydroxylase (TH), a DA synthetase, and DA were expressed in odontoblast-like cells in vivo. In vitro, their expression was increased during odontoblastic differentiation of DPSCs. Furthermore, TH-overexpressing DPSCs had promoted odontoblastic differentiation and DA production. Moreover, DA stimulation promoted their differentiation and induced tubular reparative dentin. These results suggest that DA produced by TH is involved in odontoblastic differentiation of DPSCs and has an inductive capacity for reparative dentin formation similar to primary dentin. This study may lead to the development of therapy to preserve vital pulp tissues.

LncKCNQ1OT1 Promotes the Odontoblastic Differentiation of Dental Pulp Stem Cells via Regulating hsa-miR-153-3p/RUNX2 Axis.

This study aimed to explore the role of LncKCNQ1OT1/hsa-miR-153-3p/RUNX2 in the odontoblastic differentiation of human dental pulp stem cells (DPSCs) and its possible mechanism. The expression of LncKCNQ1OT1, hsa-miR-153-3p, and RUNX2 in the odontoblastic differentiation was detected by qRT-PCR. Interaction between LncKCNQ1OT1 and hsa-miR-153-3p and interaction between hsa-miR-153-3p and RUNX2 were detected by dual-luciferase assay. The cell viability of DPSCs was detected by CCK-8, and the effect of LncKCNQ1OT1 and hsa-miR-153-3p on the odontoblastic differentiation of DPSCs was observed by alizarin red staining, alkaline phosphatase (ALP) activity assay, and Western blot for RUNX2, DSPP, and DMP-1. The results showed, during odontoblastic differentiation of DPSCs, the expression of LncKCNQ1OT1 increased, hsa-miR-153-3p expression decreased, and RUNX2 expression increased. Dual-luciferase assay showed that LncKCNQ1OT1 sponges hsa-miR-153-3p and hsa-miR-153-3p targets on RUNX2. After LncKCNQ1OT1 and hsa-miR-153-3p expressions of DPSCs were changed, the cell viability was not notably changed, but the odontoblastic differentiation was notably changed, which was confirmed with Alizarin Red staining, ALP activity, and Western blot for RUNX2, DSPP, and DMP-1. The results indicate that LncKCNQ1OT1 promotes the odontoblastic differentiation of DPSCs via regulating hsa-miR-153-3p/RUNX2 axis, which may provide a therapeutic clue for odontogenesis.

MicroRNA-125a-3p participates in odontoblastic differentiation of dental pulp stem cells by targeting Fyn.

Fyn is a member of the protein tyrosine kinase family and its overexpression is associated with various types of inflammation. MicroRNAs can regulate the expression of target genes and play an important role in varied physiological and pathological processes. Based on the important role of Fyn and microRNA-125a-3p (miR-125a-3p) in inflammation, and combined with the bioinformatics studies, we performed in this study and chose miR-125a-3p as the focus of our research. During the progression of inflammation, we found that the expression of miR-125a-3p was decreased while the expression of Fyn was up-regulated. Fyn formed a complex with Neuropilin-1, which inhibited odontoblastic differentiation and expanded inflammatory responses through nuclear factor-κB signal pathways in dental pulp stem cells (DPSCs). These findings suggested that miR-125a-3p plays an important role in odontoblastic differentiation of DPSCs by targeting Fyn, implying its therapeutic potential in dental caries.

CKIP-1 suppresses odontoblastic differentiation of dental pulp stem cells via BMP2 pathway and can interact with NRP1

ABSTRACTAim: Casein kinase 2 interacting protein-1 (CKIP-1) is a recently discovered intracellular regulator of bone formation, muscle cell differentiation, and tumor cell proliferation. Our study aims to identify the inhibition of BMP2-Smad1/5 signaling by CKIP-1 in odontoblastic differentiation of human dental pulp stem cells (DPSCs). Materials and Methods: DPSCs infected CKIP-1 siRNA or transfected CKIP-1 full-length plasmid were cultured in odontoblastic differentiation medium or added noggin (200 ng/mL) for 21 days. We examined the effects of CKIP-1 on odontoblastic differentiation, mineralized nodules formation, and interaction by western blot, real-time polymerase chain reaction (RT-PCR), alkaline phosphatase (ALP) staining, alizarin red S staining, and immunoprecipitation. Results: Firstly, we have demonstrated that CKIP-1 expression markedly decreased time-dependently along with cell odontoblastic differentiation. Indeed, the silence of CKIP-1 upregulated odontoblastic differentiation via BMP2-Smad1/5 signaling, while CKIP-1 over-expression had a negative effect on odontoblastic differentiation of DPSCs. Furthermore, CKIP-1 could interact with Neuropilin-1 (NRP1). Conclusions: This work provides data that advocates a novel perception on odontoblastic differentiation of DPSCs. Therefore, inhibiting the expression of CKIP-1 may be of great significance to the development of dental caries.

CVD-grown monolayer graphene induces osteogenic but not odontoblastic differentiation of dental pulp stem cells

ObjectiveThe objective was to investigate the potential of graphene (Gp) to induce odontogenic and osteogenic differentiation in dental pulp stem cells (DPSC). MethodsGp was produced by chemical vapor deposition. DPSC were seeded on Gp or glass (Gl). Cells were maintained in culture medium for 28 days. Every two days, culture medium from Gp was used to treat cells on Gl and vice versa. Mineralization and differentiation of DPSC on all substrates were evaluated after 14 and 28 days by alizarin red S staining, qPCR, immunofluorescence and FACS. Statistics were performed with two-way ANOVA and multiple comparisons were performed using Tukey's post hoc test at a pre-set significance level of 5%. ResultsAfter 14 and 28 days, Gp induced higher levels of mineralization as compared to Gl. Odontoblastic genes (MSX-1, PAX and DMP) were down-regulated and osteogenic genes and proteins (RUNX2, COL and OCN) were significantly upregulated on Gp comparing to Gl (p<0.05 for all cases). Medium from Gp induced downregulation of odontoblastic genes and increased bone-related gene and protein on Gl. SignificanceGraphene induced osteogenic and not odontoblastic differentiation of DPSC without the use of chemical inducers for osteogenesis. Graphene has the potential to be used as a substrate for craniofacial bone tissue engineering research.

Connexin43-containing gap junctions potentiate extracellular Ca2+-induced odontoblastic differentiation of human dental pulp stem cells via Erk1/2

Extracellular Ca2+ can promote dentin sialophosphoprotein (DSPP) expression and odontoblastic differentiation of dental pulp stem cells (DPSCs). Gap junctions mediated by connexin43 (Cx43) allow diffusion of small molecules (such as Ca2+) among cells to regulate cell-to-cell communications. However, it is unclear whether Cx43 is required for the Ca2+-induced cell differentiation. Here, we found that the influx of extracellular Ca2+ through L-type Ca2+ channels increases intracellular free Ca2+ levels to promote DSPP expression. Cx43 overexpression potentiated the extracellular Ca2+-induced DSPP expression via Erk1/2. Flow cytometry analyses showed that Cx43 increased the percentage of p-Erk1/2 positive cells in response to Ca2+, indicating that Cx43 in DPSCs possibly acts as a traditional gap junction channel, which permits the sharing of signals among coupled cells to make more DPSCs respond to Ca2+. Furthermore, inhibition of Cx43 function and gap junction communication decreased Ca2+-induced the expression of DSPP, suggesting that cell-to-cell contacts are required for Cx43 to promote the Ca2+-induced cell differentiation. Similarly, the study performed on DPSCs cultured at low-density and high-density revealed that intercellular contacts are required to potentiate Erk1/2 activity and DSPP expression. In total, this study indicates that Cx43 increases Ca2+-induced DSPP expression and odontoblastic differentiation of DPSCs via Erk1/2 through gap junction-mediated cell-to-cell contacts.

Promotion of dentin regeneration via CCN3 modulation on Notch and BMP signaling pathways

Dentin regeneration remains a great challenge in clinic. Dental pulp stem cells (DPSCs) actively contribute to dentinogenesis, which is orchestrated by a spectrum of signaling factors. However, the exact mechanism underlying the reparative dentin regeneration process is largely unknown and the application of DPSCs in the repair of dentin defect is thus limited. Here, using a rat reparative dentin regeneration model, we observed that DPSCs underwent a proliferation phase followed by a differentiation phase after dental injury. A transient elevation of nephroblastoma overexpressed (NOV, or CCN3) expression correlated with this progressive dental tissue restoration process. Further studies revealed that over-expression of CCN3 promoted human DPSCs proliferation via activation of Notch. Moreover, using cocultured cells (DPSCs/CCN3 and DPSCs) in vitro and the cocultured cells-poly (lactic-co-glycolic acid) (PLGA) scaffold complex in vivo, we demonstrated that CCN3 was capable of promoting mineralization in a non-cell autonomous manner through promoting secretion of BMP2. CCN3 can promote dentinogenesis by coordinating proliferation and odontoblastic differentiation of DPSCs via modulating Notch and BMP2 signaling pathways and CCN3 is a promising therapeutic target in dentin tissue engineering.

Effects of FGF2 and TGFβ1 on the differentiation of human dental pulp stem cells in vitro

Two crucial growth factors, FGF2 and TGFbeta1, were investigated in this study to determine their inductive effects on the odontoblastic differentiation of human dental pulp stem cells (DPSCs) in vitro. DPSCs were isolated by immunomagnetic bead selection using the STRO-1 antibody, and then co-cultured respectively with FGF2, TGFbeta1 and FGF2+TGFbeta1. The results showed that FGF2 can exert a significant effect on the cell proliferation, while TGFbeta1 or FGF2+TGFbeta1 can initiate an odontoblast-like differentiation of DPSCs. Moreover, FGF2 can synergistically upregulate the effects of TGFbeta1 on the odontoblastic differentiation of DPSCs, as indicated by the increased alkaline phosphatase activity, the polarized cell appearance and secretary ultrastructural features, the formation of mineralized nodules and the gene/protein expression of dentin sialoprotein and dentin matrix protein-1. Together, FGF2 acted primarily on the cell proliferation, while TGFbeta1 and FGF2+TGFbeta1 mainly stimulated the odontoblastic differentiation of DPSCs. This study provides interesting progress in the odontoblastic differentiation of DPSCs induced by FGF2 and TGFbeta1.