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Various mechanical loadings, including mechanical stress, orthodontics forces, and masticatory force, affect the functions of periodontal ligament cells. Regulation of periodontal tissue destruction, formation, and differentiation functions are crucial processes for periodontal regeneration therapy. Numerous studies have reported that different types of mechanical loading play a role in maintaining periodontal tissue matrix homeostasis, and osteogenic differentiation of the periodontal ligament cells. This scoping review aims to evaluate the studies regarding the effects of various mechanical loadings on the secretion of extracellular matrix (ECM) components, regulation of the balance between formation and destruction of periodontal tissue matrix, osteogenic differentiation, and multiple differentiation functions of the periodontal ligament. An electronic search for this review has been conducted on two databases; MEDLINE via PubMed and SCOPUS. Study selection criteria included original research written in English that reported the effects of different mechanical loadings on matrix homeostasis and differentiation potential of periodontal ligament cells. The final 204 articles were mainly included in the present scoping review. Mechanical forces of the appropriate magnitude, duration, and pattern have a positive influence on the secretion of ECM components such as collagen, as well as regulate the secretion of matrix metalloproteinases and tissue inhibitors of matrix metalloproteinases. Additionally, these forces regulate a balance between osteoblastic and osteoclast differentiation. Conversely, incorrect mechanical loadings can lead to abnormal formation and destruction of both soft and hard tissue. This review provides additional insight into how mechanical loadings impact ECM homeostasis and multiple differentiation functions of periodontal ligament cells (PDLCs), thus making it valuable for regenerative periodontal treatment. In combination with advancing technologies, the utilization of ECM components, application of different aspects of mechanical force, and differentiation potential of PDLCs could bring potential benefits to future periodontal regeneration therapy. [ABSTRACT FROM AUTHOR]

Betaine, known as trimethylglycine, is a non-toxic natural substance reported to affect cancer cell responses. This study delves into the impact of betaine on the survival, proliferation, and invasion of oral squamous cell carcinoma (OSCC) cells in vitro. Human OSCC cells (HSC-4 and HSC-7) were subjected to varying concentrations of betaine, and their viability and proliferation were assessed through colourimetric MTT and colony-forming unit assays. Cell cycle progression and cell apoptosis were also investigated using flow cytometry, while cell migration and invasion were examined using a transwell migration assay, and the mRNA expression was evaluated by a quantitative polymerase chain reaction. Finally, proteomic analysis was conducted through liquid chromatography-tandem mass spectrometry on the extracted protein component of the cells. Results indicate that betaine effectively suppressed OSCC proliferation and colony formation. It triggered early apoptosis without disrupting cell cycle progression, reduced cell migration, and inhibited invasion. Betaine exposure led to significantly decreased mRNA levels of MMP1, MMP2, and MMP9 while downregulating FN1, a gene linked to epithelial-to-mesenchymal transition. Proteomic analysis revealed 9240 differentially expressed up/downregulated proteins in cells treated with betaine. The significantly upregulated proteins were associated with ATP-binding cassette (ABC) transporters, while the down-regulated proteins were associated with G protein-coupled receptors (GPCR) ligand binding. In conclusion, betaine exhibits potent anti-cancer properties by attenuating OSCC cell proliferation and mitigating invasion. Exploring this natural product as an adjunct for managing oral squamous cell carcinoma shows promise, although further investigations are needed to fully elucidate its functionality. [ABSTRACT FROM AUTHOR]

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]

Background: Various stimuli, that is, mechanical stresses or inflammation, induce the release of adenosine triphosphate (ATP) by human periodontal ligament cells (HPDLCs). Extracellular adenosine triphosphate (eATP) affects HPDLCs' functions such as immunosuppressive action and inflammatory responses. Lipopolysaccharide (LPS) is the key factor involved in periodontal inflammation. However, the possible correlation and detailed mechanism of inflammation‐mediated eATP by LPS and inflammatory cascade formation in HPDLCs is unclarified. This study aims to examine the role of eATP on the HPDLCs' responses concerning inflammatory actions after LPS treatment. Methods: HPDLCs were stimulated with Porphyromonas gingivalis LPS and polyinosinic:polycytidylic acid (poly I:C). The amount of ATP release was measured at different time points using a bioluminescence assay. HPDLCs were treated with eATP. The expression of pro‐inflammatory and anti‐inflammatory genes was determined. Specific P2X purinoreceptor 7 (P2X7) inhibitors (brilliant blue G [BBG] and KN62), a specific P2Y purinoreceptor 1 (P2Y1) inhibitors (MRS2179), calcium chelator (EGTA), protein kinase C (PKC) inhibitors, nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF휅B) activation inhibitors, and cyclic adenosine monophosphate (cAMP)‐dependent protein kinase A (PKA) inhibitors (H89 dihydrochloride) and activators (forskolin) were used to dissect the mechanism of eATP‐induced HPDLCs' inflammatory responses. Results: LPS and poly I:C induced ATP release. A low concentration of eATP (50 µM) increased pro‐inflammatory genes (COX2, IL1B, IL6, IL8, IL12, and TNFA), while a high concentration (500 µM) enhanced anti‐inflammatory genes (IL4 and IL10). BBG, KN62, and NF휅B activation inhibitors impeded eATP‐induced pro‐inflammatory genes. MRS2179 and H89 markedly suppressed eATP‐induced anti‐inflammatory genes. Forskolin induced IL4 and IL10. Conclusion: HPDLCs respond to LPS by releasing ATP. eATP has dose‐dependent dual functions on HPDLCs' inflammatory responses via different pathways. As regulation of inflammation is important in regeneration, eATP may help to limit inflammation and trigger periodontal regeneration. [ABSTRACT FROM AUTHOR]