Virulence genes of Streptococcus mutans and dental caries

Streptococcus mutans is one of the important bacteria that forms dental biofilm and cause dental caries. Virulence genes in S. mutans can be classified into the genes involved in bacterial adhesion, extracellular polysaccharide formation, biofilm formation, sugar uptake and metabolism, acid tolerance, and regulation. The genes involved in bacterial adhesion are gbps (gbpA, gbpB, and gbpC) and spaP. The gbp genes encode glucan-binding protein (GBP) A, GBP B, and GBP C. The spaP gene encodes cell surface antigen, SpaP. The genes involved in extracellular polysaccharide formation are gtfs (gtfB, gtfC, and gtfD) and ftf, which encode glycosyltransferase (GTF) B, GTF C, and GTF D and fructosyltransferase, respectively. The genes involved in biofilm formation are smu630, relA, and comDE. The smu630 gene is important for biofilm formation. The relA and comDE genes contribute to quorum-sensing and biofilm formation. The genes involved in sugar uptake and metabolism are eno, ldh, and relA. The eno gene encodes bacterial enolase, which catalyzes the formation of phosphoenolpyruvate. The ldh gene encodes lactic acid dehydrogenase. The relA gene contributes to the regulation of the glucose phosphotransferase system. The genes related to acid tolerance are atpD, aguD, brpA, and relA. The atpD gene encodes F1F0-ATPase, a proton pump that discharges H⁺ from within the bacterium to the outside. The aguD gene encodes agmatine deiminase system and produces alkali to overcome acid stress. The genes involved in regulation are vicR, brpA, and relA.

Cytotoxicity of Various Calcium Silicate-based Materials with Stem Cells from Deciduous Teeth / 대한소아치과학회지

The purpose of this study was to compare and evaluate the cytotoxicity of 3 calcium silicate-based materials (CSMs) on stem cells from human exfoliated deciduous teeth (SHEDs). The powder of Retro MTA® (RM), EZ-Seal™ (EZ) and ENDOCEM Zr® (EN) was eluted with SHED culture media and then filtered. The SHEDs were cultured in the presence of the various concentrations of the eluate. To investigate the effect of the 3 CSMs on SHED proliferation, the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay was performed. Flow cytometry analysis was also performed to identify any changes in the cellular phenotype. The absorbance values of the SHEDs cultured in the eluate of samples at a 10% concentration showed the following relation: RM > EN > EZ (p = 0.0439). However, the SHEDs maintained their mesenchymal phenotype regardless of product exposure. Although the 3 CSMs did not alter the SHED stem cell markers, EZ may be a less cytocompatible than RM and EN.

Expression and Localization of Keap1 During Amelogenesis in the Developing Molar Germ of Rats

The objective of this study was to examine the expression pattern of Kelch-like ECH-associated protein 1 (Keap1) in the maxillary 2(nd) molar germs of rats. We used the maxillary 2(nd) molar germs in rats' pup at postnatal day 3 (bell stage), 6 (crown formation stage) and 9 (root formation stage). The investigation on mRNA and protein levels were done using reverse transcription - polymerase chain reaction and western blot. Localization of Keap 1 in the maxillary 2(nd) molar germs were revealed through immunofluorescence staining. Keap1 from the maxillary 2nd molar germs were mostly manifested on postnatal day 3 and dramatically decreased on postnatal day 6 and 9 at mRNA and protein levels, while amelogenin and ameloblastin increased during the development of maxillary 2nd molar germs. During immunofluorescence analysis, the strong immunoreactivity against Keap1 was detected in the apical side of ameloblasts at the presecretory and secretory stages. However, Keap1 expression was hardly observed in the ameloblasts at the maturation stage. These results shows that Keap1 is strongly expressed in the presecretory and secretory ameloblasts of amelogenesis, and suggest that Keap1 may be a crucial molecule for the regulatory mechanisms tasked with the formation of enamel layer.

The Ethanol Extract of Croton Seed Inhibits the Oral Pathogen, Streptococcus mutans

It is noted that Streptococcus mutans (S. mutans) triggers dental caries establishment by two major factors: the synthesis of organic acids, which demineralize dental enamel, and the synthesis of glucans, which mediate the attachment of bacteria to the tooth surface. Therefore, it is noted that the development of a more effective, substantial and safe preventive agent that works against dental caries and periodontal disease is required at this time. For this reason, the present study was designed to investigate the effect of croton seed ethanol extracts on the growth, acid production, adhesion, and insoluble glucan synthesis of S. mutans. In this case, the ethanol extract of croton seed showed concentration dependent inhibitory activity against the growth, acid production and adhesion of S. mutans. Especially, it is important to note that it has produced significant inhibition at the concentration of 0.1 and 0.2 mg/ml as compared to the control group. Moreover, these results suggest that the application of croton seed extract may be considered to be a useful method for the prevention of dental caries.

Anti-cariogenic Properties of α-Pinene, a Monoterpene in Plant Essential Oil

Dental caries is the most common chronic disease in the dental field. Streptococcus mutans (S. mutans) is the most important bacteria in the formation of dental plaque and dental caries. In a previous study, we confirmed that the essential oil of Chrysanthemum boreale has antibacterial activity against S. mutans. Alpha-pinene is one of the major chemical components of Chrysanthemum boreale essential oil. In the present study, we investigated the inhibitory effects of α-pinene on cariogenic properties such as growth, acid production, biofilm formation, and bactericidal activity on S. mutans. Alpha-pinene at a concentration range of 0.25-0.5 mg/mL significantly inhibited the growth of S. mutans and acid production of S. mutans. Biofilm formation was significantly inhibited at < 0.0625 mg/mL α-pinene, similar to the data from scanning electronic microscopy. Under confocal laser scanning microscopy, the bacterial viability was decreased by α-pinene in a dose-dependent manner. These results suggested that α-pinene may be a useful agent for inhibiting the cariogenic properties of S. mutans.

Effect of the Ethanol Extract of Propolis on Formation of Streptococcus mutans Biofilm

Streptococcus mutans (S. mutans) is one of the most important bacteria in the formation of dental plaque and dental caries. S. mutans adheres to an acquired pellicle formed on the tooth surface, and aggregates with many oral bacteria. It initiates plaque formation by synthesizing glucan from sucrose, which is catalyzed by glucosyltransferases. Propolis is a resinous mixture produced by honeybees, by mixing saliva and beeswax with secretions gathered from wood sap and flower pollen. Bees prevent pathogenic invasions by coating the propolis to the outer and inner surface of the honeycomb. Propolis has traditionally been used for the treatment of allergic rhinitis, asthma and dermatitis. We investigated the inhibitory effects of propolis ethanol extract on biofilm formation and gene expression of S. mutans. The biofilm formation of S. mutans was determined by scanning electron microscopy (SEM) and safranin staining. We observed that the extract of propolis had an inhibitory effect on the formation of S. mutans biofilms at concentrations higher than 0.2 mg/ml. Real-time PCR analysis showed that the gene expression of biofilm formation, such as gbpB, spaP, brpA, relA and vicR of S. mutans, was significantly decreased in a dose dependent manner. The ethanol extract of propolis showed concentration dependent growth inhibition of S. mutans, and significant inhibition of acid production at concentrations of 0.025, 0.05, 0.1 and 0.2 mg/ml, compared to the control group. These results suggest that the ethanol extract of propolis inhibits gene expression related to biofilm formation in S. mutans

Retinoic Acid Increases the Cell Cycle Progression of Human Gingival Fibroblasts by Increasing Cyclin E and CDK 2 Expression and Decreasing p21WAF1/CIP1 and p16INK4A Expression

Retinoic acid plays an important role in the regulation of cell growth and differentiation. In our present study, we evaluated the effects of all-trans retinoic acid (RA) on cell proliferation and on the cell cycle regulation of human gingival fibroblasts (HGFs). Cell proliferation was assessed using the MTT assay. Cell cycle analysis was performed by flow cytometry, and cell cycle regulatory proteins were determined by western blot. Cell proliferation was increased in the presence of a 0.1 nM to 1 microM RA dose range, and maximal growth stimulation was observed in cells exposed to 1 nM of RA. Exposure of HGFs to 1 nM of RA resulted in an augmented cell cycle progression. To elucidate the molecular mechanisms underlying cell cycle regulation by RA, we measured the intracellular levels of major cell cycle regulatory proteins. The levels of cyclin E and cyclin-dependent kinase (CDK) 2 were found to be increased in HGFs following 1 nM of RA treatment. However, the levels of cyclin D, CDK 4, and CDK 6 were unchanged under these conditions. Also after exposure to 1 nM of RA, the protein levels of p21WAF1/CIP1 and p16INK4A were decreased in HGFs compared with the control group, but the levels of p53 and pRb were similar between treated and untreated cells. These results suggest that RA increases cell proliferation and cell cycle progression in HGFs via increased cellular levels of cyclin E and CDK 2, and decreased cellular levels of p21WAF1/CIP1 and p16INK4A.

Inhibitory Effect of Continentalic Acid from Aralia continentalis on Streptococcus mutans Biofilm

In our present study, we investigated the effects of continentalic acid on Streptococcus mutans (S. mutans) biofilm. Methanol extract of Aralia continentalis (A. continentalis) was suspended in water and sequentially partitioned with CHCl3, ethyl acetate (EtOAc), and n-butanol (n-BuOH). The CHCl3 fraction showed the highest activity and an antibacterial compound against S. mutans was isolated from this preparation through various chromatography methods by bioassay guided fractionation. MS, 1H-NMR and 13C-NMR analysis showed that the active principle was continentalic acid which was confirmed to show significant inhibitory effects against S. mutans biofilm. These results may provide some scientific rationale for the traditional use these extracts for the treatment of dental diseases.

Inhibitory effects of Caesalpinia sappan on growth and invasion of methicillin-resistant Staphylococcus aureus

No abstract available.

Cytotoxic effects of prevotella nigrescens on cultured cells / 대한치과보존학회지

No abstract available.

The Effect Of Hyaluronic Acid On Mouse Calvaria Pre-Osteoblasts Osteogenesis In Vitro

Hyaluronic acid (HA) is an almost essential component of extracellular matrices. Early in embryogenesis mesenchymal cells migrate, proliferate and differentiate, in part, because of the influence of HA. Since the features of embryogenesis are revisited during wound repair, including bone fracture repair, this study was initiated to evaluate whether HA has an effect on calcification and bone formation in an in vitro system of osteogenesis. Mouse calvaria Pre-osteoblast (MC3T3-E1) cells were cultured in alpha-MEM medium with microorganism-derivative hyaluronic acid that was produced by Strep. zooepidemicus which of molecular weight was 3 million units. The dosages were categorized in each 0.5, 1.0 and 2.0 mg/ml concentration experimental groups. After 2 and 4 days cultures in expeirmental and control groups, the tendency of cell proliferation, MTT assay, protein synthesis ability, collagen synthesis and alkaline phosphatase activity were analysed and bone nodule formation capacity were measured with Alizarin Red S stain after 29 days cultures. The cell proliferation was increased in time, especially the group of 0.5 and 1.0 mg/ml concentration of HA were showed prominent cell proliferation. After 2 and 4 days culture, experimental groups in general were greater cell activity in MTT assay. The protein synthesis was increased in all experimental groups compared to control group, especially most prominent in 1.0 mg/ml concentration group. The collagen synthesis capacity were increased in HA experimental groups, especially prominent in 1.0 mg/ml group and the activity of alkaline phosphatase were increased, especially also prominent in 1.0 mg/ml group, compared to control group. Above these, the activity of mouse carvarial pre-osteoblast cells was showed greater bone osteogenesis activity in all applied HA experimental group, especially group of 1.0 mg/ml concentration of HA.

Antibacterial Effects Of Berberine On Antibiotic-Resistant Staphylococcus Aureus

Voltage-Dependent Sodium And Potassium Currents In Acutely Isolated Rat Trigeminal Caudal Neurons

Effects of Replicative Senescence on the Cell Cycle Regulation in Human Gingival Fibroblasts / 대한치주과학회지

Gingival fibroblasts are major cellular component of gingiva. However, the molecular mechanisms of senescence of human gingival fibroblasts are unknown. Human fibroblasts undergo replicative senescence in vitro after a limited number of population doublings. A reduced rate of proliferation is a prominent phenomenon observed in senescent fibroblasts. This phenomenon is happened with cell cycle arrest that was controled by cell cycle regulatory proteins. The purpose of present study was to investigate the effect of replicative senescence on cell cycle progression and to find out its molecular mechanisms in human gingival fibroblasts. Replicative senescence of gingival fibroblasts were induced by subsequent cultures that were repeated up to 18 passage. In the present study, I examined change of cell proliferation, cell activity, cell viability and cell cycle progression during the replicative process. Also, I examined expression of cell cycle regulatory proteins which was estimated by western blot analysis. Cell proliferation, cell activity and cell viability of gingival fibroblasts were notably decreased with increase of population doubling level(PDL). S phase was decreased and G1 phase was increased with increase of PDL. Western blot analysis showed that levels of p16, p21 and p53 of senescent gingival fibroblasts(PDL41, PDL58) were higher than young fibroblasts(PDL27) and cdk4 were lower than young fibroblasts(PDL27). In conclusion, these results suggest that proliferative function of human gingival fibroblasts may be decreased by replicative senescence and its molecular mechanisms may be activatied with p16, p21, p53 and pRB, and repressed wtih cdk4.

Effects of Olibanum Extracts on the Activity and Differentiation of MC3T3-E1 Cells / 대한치주과학회지

Recently, many natural medicines, which have advantage of less side effects and possibility of long-term use have been studied for their capacity of anti-bacterial, anti-inflammatory and regenerative potential of periodontal tissues. Olibanum has the effects to hemostasis, analgesic and anti-inflammatory, and it also has been traditionally used as a drug for the treatment of bone disease in oriental medicine. The purpose of the present study was to investigate the effects of Olibanum extracts on the activity and differentiation of MC3T3-E1 cells, alkaline phosphatase(ALP) synthesis, formation of bone nodules and expression of type I collagen of MC3T3-E1 cells. To examine the cellular activity, MC3T3-E1 cells were cultured with alpha-MEM(control) and each concentration of Olibanum for 2 days and 4 days. To compare the ALP synthesis, MC3T3-E1 cells were cultured with alpha-MEM(negative control), dexamethasone(positive control), and each concentration of Olibanum for 2 days and 4 days. To compare the bone nodule formation, MC3T3-E1 cells were cultured for 21 days, and to compare the type I collagen expression, MC3T3-E1 cells were cultured for 4 days. The cellular activity of MC3T3-E1 cells treated with 1 microgram/ml of Olibanum extracts was significantly increased at 4-day(p<0.05) to control. The activity of ALP in MC3T3-E1 cells treated with 1 microgram/ml Olibanum extracts was significantly increased at 4-day(p<0.05). All the experimental groups showed much more bone nodule formation than control groups. The group treated with 1 microgram/ml of Olibanum extracts was the highest bone nodule formation, and showed much more type I collagen expression than negative control. These results indicate that Olibanum extracts may be considered effective in the activity and differentiation of MC3T3-E1 cells.

Effects of Nicotine on the Expression of Cell Cycle Regulatory Proteins of Human Gingival Fibroblasts / 대한치주과학회지

Normal gingival fibroblasts functioning is fundamental for the maintenance of periodontal connective tissue as well as wound healing. Nicotine have been found to affect DNA synthesis and cell proliferation, which appear to depend on the type of cells. This in vitro study was done to determine the effects of nicotine, a major component of tobacco, on cell proliferation, viability, activity, cell cycle distribution, and expression of cell cycle regulatory proteins in human gingival fibroblasts. Nicotine has been tested for 2 days or 4 days in 5 different concentrations; 0.1 microgram/ml; 1 microgram/ml; 10 microgram/ml; 100 microgram/ml; 1000 microgram/ml. To assess cell proliferation and viability, viable and non-viable cells were counted by hemocytometer; to evaluate cellular activity, MTT assay was employed; to analyze cell cycle distribution, fluorescent propidium iodide-DNA complex were measured using fluorocytometer; to determine the expression of cell cycle regulatory proteins, western blot analysis was performed. After 2 days and 4 days incubation respectively, at concentrations of 1 microgram/ml - 1000 microgram/ml, nicotine significantly inhibited proliferation comparing to non-supplemented controls. The cell viability was significantly decreased after 2 days and 4 days at concentrations of 1 microgram/ml - 1000 microgram/ml and at 10 microgram/ml - 1000 microgram/ml respectively. After 2 days and 4 days, the cellular activity was significantly decreased at concentrations of 10 microgram/ml - 1000 microgram/ml. Treatment with 100 microgram/ml nicotine for 48 hours caused an increase in the proportion of G1-phase cells (from 46.41% to 53.46%) and a decrease in the proportion of S-phase cells (from 17.80% to 14.27%). The levels of cyclin D1 and CDK 4 proteins in nicotine-treated fibroblasts were lower than that of controls, whereas the levels of p16 and pRB were higher than that of controls. These results suggest that the decrease of cell proliferation and lengthened Gap phases (G1) by nicotine may due to the increased expression of p16 and pRB as well as decreased expression of cyclin D1 and CDK 4 in human gingival fibroblasts.

Effects of Cyclosporin A on the Cell Cycle Regulation of Human Gingival Fibroblasts / 대한치주과학회지

Cyclosporin A is a cyclic polypeptide produced by the metabolism of fungi. It is widely used at present as immunosuppressive treatment following organ transplants. It is also used to deal with autoimmune diseases such as rheumatoid arthritis or type II diabetes. Gingival hyperplasia is one of the most frequent side-effects associated with the prescription of Cyclosporin A. The mechanisms involved in Cyclosporin A induced gingival hyperplasia are not yet clear. In vitro Cyclosporin A promotes proliferation of gingival fibroblasts, that Cyclosporin A act as a mitogen. Its action is based on mitosis of gingival fibroblasts regulated by cell cycle regulatory proteins. It was the purpose of the present study to examine the effects of Cyclosporin A on human gingival fibroblasts by means of biological and biochemical criteria. In this present study, we examined change of cell proliferation, cell activity, cell viability and cell cycle progression after application of Cyclosporin A. We also examined expression of cell cycle regulatory proteins by western blot analysis. Human gingival fibroblasts were cultured for 48 hours with application of Cyclosporin A at concentrations of 0.01, 0.1, 1, and 10 ng/ml. Cyclosporin A(1 ng/ml) significantly increased the cell activity of gingival fibroblast. Proliferation and viability of gingival fibroblasts were also increased in group treated with 1 ng/ml of Cyclosporin A compared to control group. In the cell cycle analysis, S phase was increased and G1 phase was decreased in the group treated with 1 ng/ml of Cyclosporin A. Cyclosporin A increased the expression of cdk4 and inhibited the expression of pRB and p21. These results suggest that 1 ng/ml of Cyclosporin A may increase the cell cycle progression of human gingival fibroblasts, and its mechanisms may increase the expression of cdk4 and decrease the expression of pRB and p21.

Effects of Retinoic Acid on Replicative Senescence and Apoptosis of Normal Human Oral Keratinocytes

No abstract available.

Effects of Sophorae Radix Extracts on the Expression of Cell Cycle Regulatory Proteins in Human Gingival Fibroblasts / 대한치주과학회지

Fibroblasts are major cellular components of gingiva and periodontal ligament. They regulate the healing process after surgery or injury. Recently, many natural medicines, whose advantages are less side effects and possibility of long-term use, have been studied for their capacity, their anti-bacterial and anti-inflammatory effects and regenerative potential of periodontal tissues. Sophorae radix have been traditionally used as an antibacterial and anti-inflammatory drug in oriental medicine. The purpose of present study was to investigate the effects of Sophorae radix extract on cell cycle progression and its molecular mechanism in human gingival fibroblasts. Sophorae radix extracts(100microgram/ml) notably increased cell proliferation and cell activity in the human gingival fibroblasts as compared to non-supplemented controls. There was an increase in the S phase and a decrease in the G1 phase in 100microgram/ml of Sophorae radix extracts group as compared to non-supplemented controls. The level of cyclin E and cdk 2 protein in test group was higher than that of control groups. But that of cyclin D, cdk 4, and cdk 6 was not distinguished from controls. The level of p53 protein in test group was lower than that of controls, whereas that of p21 was not different. The level of pRB protein in test group was higher than that of controls, whereas that of p16 was lower. These results indicate that the increase of cell proliferation by Sophorae radix extracts may be due to the increased expression of cyclin E and cdk 2, and the decreased expression of p53 and p16 in human gingival fibroblasts.

Effects of Several Biodegradable Controlled-Release Local Delivery Drugs on the Treatment of Periodontitis / 대한치주과학회지

The present study was performed to evaluate the clinical effects following local application of 30% minocycline strip(polycaprolactone), 2% minocycline gel(hydro-carbon gel) and 12% minocycline strip(polylactide, Minodent) to augment scaling and root planing in patients with chronic adult periodontitis. Forty teeth with periodontitis were enrolled in the study anddistributed into 4 groups including control group. All patients performed standardized oral hygiene instructions and mechanical debridement at the beginning of the study and then each local delivery drugs were inserted into periodontal pocket in each groups. Examinations regarding plaque index(PI), papillary bleeding index (PBI), probing pocket depth (PPD) were carried out at 0, 2, 4 weeks. All experimental groups showed statistically significant differences between baseline and 2 and 4 weeks in every clinical indices. Especially, 30%minocycline strip and Minodent group showed a significant improvement in PBI at 2 weeks and in PPD at 2 and 4 weeks. In conclusion, highly bio-resorbable Minodent delivered subgingivally as an adjunct to scaling and root planing induces better clinical effects for periodontal health than 2% minocycline gel and control group.