Mineral trioxide aggregate upregulates odonto/osteogenic capacity of bone marrow stromal cells from craniofacial bones via JNK and ERK MAPK signalling pathways.

The aim of this study was to investigate effects of mineral trioxide aggregate (MTA) on odonto/osteogenic differentiation of bone marrow stromal cells (BMSCs) from craniofacial bones. Craniofacial BMSCs were isolated from rat mandible and effects of MTA on their proliferation, differentiation and MAPK pathway involvement were subsequently investigated, in vitro. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2,5-tetrazoliumbromide) assay was performed to evaluate proliferation of the MTA-treated cells. Alkaline phosphatase (ALP) activity, alizarin red staining, real-time reverse transcription polymerase chain reaction and western blot assays were used to assess differentiation capacity as well as MAPK pathway involvement. 0.02 mg/ml MTA-treated BMSCs had significantly higher ALP activity and formed more mineralized nodules than the untreated group. Odonto/osteoblastic marker genes/proteins (Alp, Runx2/RUNX2, Osx/OSX, Ocn/OCN and Dspp/DSP respectively) in MTA-treated cells were remarkably upregulated compared to untreated ones. Mechanistically, phosphorylated Jun N-terminal kinase (P-JNK) and phosphorylated extracellular regulated protein kinases (P-ERK) in MTA-treated BMSCs increased significantly in a time-dependent manner, while inhibition of JNK and ERK MAPK pathways dramatically blocked MTA-induced odonto/osteoblastic differentiation, as indicated by reduced ALP levels, weakened mineralization capacity and downregulated levels of odonto/osteoblastic marker genes (Alp, Runx2, Osx, Ocn and Dspp). Mineral trioxide aggregate promoted odonto/osteogenic capacity of craniofacial BMSCs via JNK and ERK MAPK signalling pathways.

Wang Y ，Li J ，Song W ，Yu J ... -  《-》

Mineral trioxide aggregate enhances the odonto/osteogenic capacity of stem cells from inflammatory dental pulps via NF-κB pathway.

This study was designed to investigate the effects of mineral trioxide aggregate (MTA) on the osteo/odontogenic differentiation of inflammatory dental pulp stem cells (iDPSCs). inflammatory DPSCs were isolated from the inflammatory pulps of rat incisors and cocultured with MTA-conditioned medium. MTT assay and flow cytometry were performed to evaluate the proliferation of iDPSCs. Alkaline phosphatase (ALP) activity, alizarin red staining, real-time RT-PCR, and Western blot assay were used to investigate the differentiation capacity as well as the involvement of NF-κB pathway in iDPSCs. Mineral trioxide aggregate-treated iDPSCs demonstrated the higher ALP activity and formed more mineralized nodules than the untreated group. The odonto/osteoblastic markers (Alp, Runx2/RUNX2, Osx/OSX, Ocn/OCN, and Dspp/DSP, respectively) in MTA-treated iDPSCs were significantly upregulated as compared with untreated iDPSCs. Mechanistically, cytoplastic phos-P65 and nuclear P65 in MTA-treated iDPSCs were significantly increased in a time-dependent manner. Moreover, the inhibition of NF-κB pathway suppressed the MTA-induced odonto/osteoblastic differentiation of iDPSCs, as indicated by decreased ALP levels, weakened mineralization capacity and downregulated levels of odonto/osteoblastic genes (Osx, Ocn, and Dspp). Mineral trioxide aggregate enhances the odonto/osteogenic capacity of DPSCs from inflammatory sites via activating the NF-κB pathway.

Wang Y ，Yan M ，Fan Z ，Ma L ，Yu Y ，Yu J ... -  《-》

Mineral trioxide aggregate enhances the osteogenic capacity of periodontal ligament stem cells via NF-κB and MAPK signaling pathways.

Mineral trioxide aggregate (MTA), as a bioactive material, has a widespread application in clinical practice. To date, the effects of MTA on the proliferation and differentiation of human periodontal ligament stem cells (hPDLSCs) remain unclear. hPDLSCs were isolated from human periodontal ligament tissues and cultured with MTA conditioned media. Cell counting kit-8 (CCK-8) assay was performed to assess the proliferation capacity of MTA-treated hPDLSCs. Immunofluorescence assay, alkaline phosphatase (ALP) activity, alizarin red staining, real-time RT-PCR, and western blot analyses were used to investigate the odonto/osteogenic capacity of hPDLSCs as well as the involvement of NF-κB and MAPK pathways. ALP activity assay revealed that 2 mg/ml was the optimal concentration for the induction of hPDLSCs by MTA. The protein expression of DSP, RUNX2, OCN, OSX, OPN, DMP1, ALP, and COL-I in MTA-treated hPDLSCs was significantly higher than those in control group (p < 0.01). When hPDLSCs were treated with the inhibitors of NF-κB and MAPK pathways (U0126, SP600125, SB203580, and BMS345541), the effects of MTA on the differentiation of hPDLSCs were suppressed. Mechanistically, P65 was detected to transfer from cytoplasm to nuclei, as indicated by western blot and immunofluorescence assay. Moreover, MAPK-related proteins and its downstream transcription factors were also upregulated in MTA-treated hPDLSCs. Together, mineral trioxide aggregate can promote the odonto/osteogenic capacity of hPDLSCs via activating the NF-κB and MAPK pathways.

Wang Y ，Zhou Y ，Jin L ，Pang X ，Lu Y ，Wang Z ，Yu Y ，Yu J ... -  《-》

Effect of Biodentine and Bioaggregate on odontoblastic differentiation via mitogen-activated protein kinase pathway in human dental pulp cells.

To compare the mineralization inductive capacity of Biodentine and Bioaggregate with Mineral trioxide aggregate (MTA) and to investigate possible signaling pathways of mineralization in human dental pulp cells (HDPCs). Viability of HDPCs in response to Biodentine, Bioaggregate, and MTA was measured using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide. To investigate their potential to induce odontoblast differentiation, expression of dentine sialophosphoprotein (DSPP) and dentine matrix protein1 (DMP1) mRNA level was evaluated by RT-PCR. For the mineralized nodule assay, Alizarin red staining was performed. To determine the role of MAPK signaling in the odontoblastic differentiation of HDPCs, activated MAPKs were investigated by Western blot and the effect of MAPK inhibitor was examined by Alizarin red S staining. The results were statistically analysed using one-way anova and the Bonferroni test. The effects of MTA, Biodentine, and Bioaggregate on cell viability were similar. Biodentine and Bioaggregate enhanced DSPP and DMP1 mRNA expression compared to the control group, but to the same extent as MTA (P < 0.05). MTA, Biodentine, and Bioaggregate increased the area of calcified nodules compared to the control (P < 0.01). MTA, Biodentine, and Bioaggregate increased phosphorylation of extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK). MAPK inhibitors attenuated mineralized nodule formation, which was increased by MTA, Biodentine, and Bioaggregate, respectively (P < 0.01). Biodentine and Bioaggregate stimulated odontoblastic differentiation and mineralization nodule formation by activating the MAPK pathway as did MTA. This suggests that the new materials could be useful for regenerative endodontic procedures.

Jung JY ，Woo SM ，Lee BN ，Koh JT ，Nör JE ，Hwang YC ... -  《-》

Mineral trioxide aggregate promotes odontoblastic differentiation via mitogen-activated protein kinase pathway in human dental pulp stem cells.

Zhao X ，He W ，Song Z ，Tong Z ，Li S ，Ni L ... -  《-》