Effects of lipopolysaccharide on proliferation, migration and osteogenic differentiation of apical papilla cells from early and late stage of root development.

The aim of this study was to investigate the effects of lipopolysaccharide on cell proliferation, migration and osteogenic differentiation of apical papilla cells from early and late stage of root development. After challenging with various lipopolysaccharide concentrations to apical papilla cells from both stages of root development for 168 h, cell proliferation and migration were investigated. Osteogenic differentiation was examined by Alizarin red staining, and gene expressions of bone/cementum or dentin-related genes were examined by polymerase chain reaction. Lipopolysaccharide did not affect cell proliferation and migration in both groups. Lipopolysaccharide at 1 and 5 µg mL-1 increased Alizarin red staining in apical papilla cells from early-stage but not the late-stage cells. Bone sialoprotein (bone/cementum marker) gene expression increased in both early and late stage of root development at 5 µg mL-1 . These results might explain bone/cementum generation in regenerative endodontic procedures.

Antitumor Effects of Fucoidan Via Apoptotic and Autophagic Induction on HSC-3 Oral Squamous CellCarcinoma.

OBJECTIVE: Many studies suggested that fucoidan has anticancer potential. The objective of the present study was to determine the cytotoxic effects and mechanism of cell death induced by fucoidan extracted from Fucus vesiculosus on HSC-3 oral squamous cell carcinoma. METHODS: HSC-3 cells were treated with 0, 100, 200, and 400 µg/mL of fucoidan. Cell viability was measured using MTT assay. Apoptosis and cell cycle were measured with a flow cytometry-based assay. Chromatin condensation and nuclear fragmentation were determined using Hoechst 33342 staining. Mitochondrial membrane potential (ΔΨm) was determined using the JC-1 kit. The apoptotic, anti-apoptotic, and autophagic markers study were done by western blot analysis. RESULTS: the viable cell number of treated HSC-3 cells was decreased. Moreover, treated cells were arrested in the G0/G1 phase. Annexin V/PI staining revealed that fucoidan could induce apoptosis in HSC-3 cells. Western blot analysis suggested the up-regulation of apoptotic markers including cleaved caspase-3, cleaved PARP, Bax, and autophagic markers including LC3-II and Beclin-1 but down-regulation of anti-apoptotic markers, Bcl-2. Fucoidan could disturb ΔΨm and induce chromatin condensation with nuclear fragmentation. CONCLUSION: fucoidan has potential in anticancer properties against HSC-3 cells manifested by the induction of apoptosis, cell cycle arrest, and autophagy.
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Effects of Lipopolysaccharide on the Proliferation and Osteogenic Differentiation of Stem Cells from the Apical Papilla.

INTRODUCTION: Stem cells from the apical papilla (SCAPs) were suggested as the stem cell source in regenerative endodontic procedures. However, bone and/or cementum-like structure were observed in root canals. Lipopolysaccharide (LPS) in infected root canals might alter SCAPs' osteogenic differentiation pattern. The objectives of this study were to investigate the effects of LPS on SCAPs' proliferation and osteogenic differentiation. METHODS: The mesenchymal stem cell characteristics of SCAPs were confirmed. Cell viability was tested with Porphyromonas gingivalis LPS at concentration between 0.001 and 5 µg/mL. SCAPs were pretreated with those concentrations for 168 hours. Then SCAPs were further investigated for cell proliferation by resazurin-based assay. Mineralization capacity was determined by alizarin red S staining. Odontoblast marker was determined by DSPP gene expression. General bone and cementum markers, BSP and OPN, were also determined. Determination of the expression levels of these genes was performed by polymerase chain reaction. RESULTS: SCAPs demonstrated the mesenchymal stem cell characteristics. All LPS concentrations did not affect cell viability. Pretreatment with LPS also did not affect cell proliferation and mineralization in every concentration. There was no significant difference between DSPP and OPN gene expression levels at all concentrations. However, LPS at 5 µg/mL significantly increased BSP gene expression. CONCLUSIONS: Under the limitations of this in vitro study, LPS did not affect SCAP proliferation and mineralization. However, LPS at high concentration, 5 µg/mL, increased BSP gene expression.

Comparison of stem cell behaviors between indigenous high and low-CD24 percentage expressing cells of stem cells from apical papilla (SCAPs).

CD24 was suggested as a marker to SCAPs and has been reported for a decade. CD24 has been shown to involve stem cell activities such as self-renewal, proliferation and differentiation. However, the percentage variations of CD24 positive cells were reported among the studies. It is possible that this variation may affect these SCAPs behaviors. In this study, the variation was confirmed. To elucidate the influence of CD24 positive cells quantity on SCAPs stem cell behaviors, the 3 cell lines with the most maximum and the least numbers of CD24 positive cells (High-CD24 and Low-CD24 group) were selected to study. Both groups expressed the same mesenchymal stem cell markers and negative to hematopoietic marker. High-CD24 group demonstrated less self-renewal capacity by lower colony-forming-unit count and pluripotency marker gene expressions. However, cell proliferation was not different. In contrast, osteogenic and adipogenic differentiation were better than Low-CD24 group. The early stage of root development demonstrated higher CD24 expressing cells than later stage. In conclusion, quantity of CD24 expressing cells influenced SCAPs self-renewal and multi-lineage differentiation but did not influence on cell proliferation. Stage of root development influenced to CD24 expressing cell numbers.

Notch signaling is involved in neurogenic commitment of human periodontal ligament-derived mesenchymal stem cells.

Notch signaling plays critical roles in stem cells by regulating cell fate determination and differentiation. The aim of this study was to evaluate the participation of Notch signaling in neurogenic commitment of human periodontal ligament-derived mesenchymal stem cells (hPDLSCs) and to examine the ability to control differentiation of these cells using modified surfaces containing affinity immobilized Notch ligands. Neurogenic induction of hPDLSCs was performed via neurosphere formation. Cells were aggregated and form spheres as early 1 day in culture. In addition, the induced cells exhibited increased mRNA and protein expression of neuronal markers that is, ß3-tubulin and neurofilament. During neuronal differentiation, a significant increase of Hes1 and Hey1 mRNA expression was noted. Using pharmacological inhibition (γ-secretase inhibitor) or genetic manipulation (overexpression of dominant negative mastermind-like transcription co-activators), neurosphere formation was attenuated and a marked decrease in neurogenic mRNA expression was observed. To confirm the role of Notch signaling in neuronal differentiation of hPDLSCs, the Notch ligand, Jagged-1, is bound to the surface using an affinity immobilization technique. The hPDLSC cultured on a Jagged-1-modified surface had increased expression of Notch signaling target genes, Hes-1 and Hey-1, confirming the activity and potency of surface-bound Jagged-1. Further, hPDLSC on surface-bound Jagged-1 under serum-free conditions showed multiple long and thin neurite-like extensions, and an increase in the expression of neurogenic mRNA markers was observed. Pretreatment of the cells with γ-secretase inhibitor, DAPT, before seeding on the Jagged-1-modified surface blocked development of the neurite-like morphology. Together, the results in this study suggest the involvement of Notch signaling in neurogenic commitment of hPDLSCs.

Vital pulp therapy in vital permanent teeth with cariously exposed pulp: a systematic review.

INTRODUCTION: This systematic review aims to illustrate the outcome of vital pulp therapy, namely direct pulp capping, partial pulpotomy, and full pulpotomy, in vital permanent teeth with cariously exposed pulp. METHODS: Electronic database MEDLINE via Ovid, PubMed, and Cochrane databases were searched. Hand searching was performed through reference lists of endodontic textbooks, endodontic-related journals, and relevant articles from electronic searching. The random effect method of weighted pooled success rate of each treatment and the 95% confidence interval were calculated by the DerSimonian-Laird method. The weighted pooled success rate of each treatment was estimated in 4 groups: >6 months-1 year, >1-2 years, >2-3 years, and >3 years. All statistics were performed by STATA version 10. The indirect comparison of success rates for 4 follow-up periods and the indirect comparison of clinical factors influencing the success rate of each treatment were performed by z test for proportion (P < .05). RESULTS: Overall, the success rate was in the range of 72.9%-99.4%. The fluctuation of the success rate of direct pulp capping was observed (>6 months-1 year, 87.5%; >1-2 years, 95.4%; >2-3 years, 87.7%; and >3 years, 72.9%). Partial pulpotomy and full pulpotomy sustained a high success rate up to more than 3 years (partial pulpotomy: >6 months-1 year, 97.6%; >1-2 years, 97.5%; >2-3 years, 97.6%; and >3 years, 99.4%; full pulpotomy: >6 months-1 year, 94%; >1-2 years, 94.9%; >2-3 years, 96.9%; and >3 years, 99.3%). CONCLUSIONS: Vital permanent teeth with cariously exposed pulp can be treated successfully with vital pulp therapy. Current best evidence provides inconclusive information regarding factors influencing treatment outcome, and this emphasizes the need for further observational studies of high quality.