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Objectives: This study investigated the miRNA expression profile in Notch‐activated human dental stem pulp stem cells (DPSCs) and validated the functions of miRNAs in modulating the odonto/osteogenic properties of DPSCs. Methods: DPSCs were treated with indirect immobilized Jagged1. The miRNA expression profile was examined using NanoString analysis. Bioinformatic analysis was performed, and miRNA expression was validated. Odonto/osteogenic differentiation was examined using alkaline phosphatase staining, Alizarin Red S staining, as well as odonto/osteogenic‐related gene and protein expression. Results: Fourteen miRNAs were differentially expressed in Jagged1‐treated DPSCs. Pathway analysis revealed that altered miRNAs were associated with TGF‐β, Hippo, ErbB signalling pathways, FoxO and Ras signalling. Target prediction analysis demonstrated that 7604 genes were predicted to be targets for these altered miRNAs. Enrichment analysis revealed relationships to various DNA bindings. Among differentially expressed miRNA, miR‐296‐3p and miR‐450b‐5p were upregulated under Jagged1‐treated conditions. Overexpression of miR‐296‐3p and miR‐450b‐5p enhanced mineralization and upregulation of odonto/osteogenic‐related genes, whereas inhibition of these miRNAs revealed opposing results. The miR‐296‐3p and miR‐450b‐5p inhibitors attenuated the effects of Jagged1‐induced mineralization in DPSCs. Conclusions: Jagged‐1 promotes mineralization in DPSCs that are partially regulated by miRNA. The novel understanding of these miRNAs could lead to innovative controlled mechanisms that can be applied to modulate biology‐targeted dental materials. [ABSTRACT FROM AUTHOR]

Objective: Periostin (PN), a major matricellular periodontal ligament (PDL) protein, modulates the remodeling of the PDL and bone, especially under mechanical stress. This study investigated the requirement of PN‐integrin signaling in force‐induced expression of transforming growth factor‐beta 1 (TGF‐β1) and alpha‐smooth muscle actin (α‐SMA) in human PDL stem cells (hPDLSCs). Methods: Cells were stimulated with intermittent compressive force (ICF) using computerized controlled apparatus. Cell migration was examined using in vitro scratch assay. The mRNA expression was examined using real‐time polymerase chain reaction. The protein expression was determined using immunofluorescent staining and western blot analysis. Results: Stimulation with ICF for 24 h increased the expression of PN, TGF‐β1, and α‐SMA, along with increased SMAD2/3 phosphorylation. Knockdown of POSTN (PN gene) decreased the protein levels of TGF‐β1 and pSMAD2/3 upon force stimulation. POSTN knockdown of hPDLSCs resulted in delayed cell migration, as determined by a scratch assay. However, migration improved after seeding these knockdown cells on pre‐PN‐coated surfaces. Further, the knockdown of αVβ5 significantly attenuated the force‐induced TGF‐β1 expression. Conclusion: Our findings indicate the importance of PN‐αVβ5 interactions in ICF‐induced TGF‐β1 signaling and the expression of α‐SMA. Findings support the critical role of PN in maintaining the PDL's tissue integrity and homeostasis. [ABSTRACT FROM AUTHOR]

Objective: To investigate the role of phosphatase and tensin homolog (PTEN) in dental pulp cells (hDPs) and adipose‐derived mesenchymal stem cells (hADSCs). Materials and Methods: Genetic variant was identified with exome sequencing. The hDPs isolated from a patient with Cowden syndrome were investigated for their proliferation, osteogenesis, adipogenesis, and gene expression compared with controls. The normal hDPs and hADSCs were treated with the PTEN inhibitor, VO‐OHpic trihydrate (VOT), to investigate the effect of PTEN inhibition. Results: A heterozygous nonsense PTEN variant, c.289C>T (p.Gln97*), was identified in the Cowden patient's blood and intraoral lipomas. The mutated hDPs showed significantly decreased proliferation, but significantly upregulated RUNX2 and OSX expression and mineralization, indicating enhanced osteogenic ability in mutated cells. The normal hDPs treated with VOT showed the decreases in proliferation, colony formation, osteogenic marker genes, alkaline phosphatase activity, and mineral deposition, suggesting that PTEN inhibition diminishes proliferation and osteogenic potential of hDPs. Regarding adipogenesis, the VOT‐treated hADSCs showed a reduced number of cells containing lipid droplets, suggesting that PTEN inhibition might compromise adipogenic ability of hADSCs. Conclusions: PTEN regulates proliferation, enhances osteogenesis of hDPs, and induces adipogenesis of hADSCs. The gain‐of‐function PTEN variant, p.Gln97*, enhances osteogenic ability of PTEN in hDPs. [ABSTRACT FROM AUTHOR]