Metabolic syndrome parameters in adolescents may be determinants for the future periodontal diseases.

AIM: The prevalence of metabolic syndrome (MetS) increases even in adolescents. The evidence that MetS is associated with the periodontal diseases in adolescents has been understudied. Therefore, our aim was to assess the association between MetS parameters and gingivitis in adolescents. MATERIAL AND METHODS: A total of 941 participants (590 boys, 351 girls), aged 12-18 years was selected from the Fourth Korea National Health and Nutrition Examination Survey, a cross-sectional and nationally representative survey, which had had information on waist circumference, blood pressure, serum triglyceride, high-density lipoprotein (HDL) cholesterol, and the fasting blood sugar and community periodontal Index (CPI). RESULTS: The number of positive parameters of MetS showed significant positive correlation with gingivitis; adjusted and crude ORs with one positive parameters of MetS were 1.92 (95% CI: 1.21-3.04) and 1.88(95% CI: 1.28-2.76), respectively. And adjusted OR with three or more positive parameters of MetS was 3.29 (95% CI: 1.24-8.71). Among five parameters of MetS, Low HDL-cholesterol showed significant association with gingivitis (crude OR 2.12, 95% CI 1.20-3.73; adjusted OR 1.96, 95% CI 1.24-3.12). CONCLUSIONS: Having more positive parameters of MetS and low HDL-cholesterol parameter had an independent relationship with the prevalence of gingivitis, which may be determinants for the future periodontal diseases even in adolescents.

Establishment of SV40T-transformed human dermal papilla cells and identification of dihydrotestosterone-regulated genes by cDNA microarray.

BACKGROUND: Recent studies suggest that androgens are the main regulator of changes in human hair growth, and dermal papilla (DP) is known to secret factors which regulate the growth and activity of the cells in the follicle in response to androgens. However, published data of androgen-regulated genes in human dermal papilla cells is limited and genome-wide large scale screening has not been reported. OBJECTIVE: To identify the dihydrotestosterone (DHT)-regulated genes in human dermal papilla cells. METHODS: SV40T-transformed human dermal papilla cell line (SV40T-DPC) was established and DHT-regulated genes were screened by cDNA microarray analysis. RESULTS: SV40T-DPC maintained early passage morphology and expressed functional androgen receptors. cDNA microarray followed by RT-PCR analysis showed that a number of genes are regulated by DHT in SV40T-DPC. CONCLUSION: The DHT-regulated genes reported in this study may be involved in androgen-mediated regulation of hair growth.

Effect of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) nanofiber matrices cocultured with hair follicular epithelial and dermal cells for biological wound dressing.

We tested the effects on the early-stage wound healing of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofiber matrices cultured with hair follicular cells. PHBV only, PHBV/collagen, and PHBV/gelatin at a 7/3 weight ratio were produced by electrospinning, and their in vitro cell culture and in vivo wound healing as biological dressings were examined. In cell attachment and growth on matrices, dermal sheath (DS) cells attached to hydrophilic PHBV/collagen and PHBV/gelatin faster than hydrophobic PHBV at the early incubation stage (up to 6 h). From 6- to 24-h incubation, PHBV/collagen showed the best results in cell culture. Furthermore, PHBV/collagen cocultured for 3-5 days with DS and epithelial outer root sheath (ORS) cells expressed more extracellular materials, such as type I collagen, elastin, and alpha-smooth muscle actin, than cocultured PHBV with the same cells. However, there was no significant difference between PHBV and PHBV/collagen in the amounts of cytokeratin 8 expressed. Grafting of PHBV and PHBV/collagen matrices cocultured with ORS/DS cells for 3-5 days showed that PHBV promoted wound closure and re-epithelization more obviously than PHBV/collagen in both cocultured matrices and matrices alone. Cocultured matrices would heal wounds better than the corresponding matrices alone. Thus, PHBV cocultured with ORS/DS cells could be used as a cell-seeded biological dressing, thereby reducing preparation time as well as regenerating the epidermis efficiently during the early stage of wound healing.

Polycan suppresses osteoclast differentiation and titanium particle-induced osteolysis in mice.

Particle-induced osteolysis is a major issue, and it is most likely the result of enhanced osteoclast activation in the pathogenesis of various skeletal diseases. This study investigated whether the inhibitory effect that Polycan has on osteoclast differentiation can be used to treat osteolysis induced by titanium (Ti) particles. To this end, the effects of Polycan were examined in terms of the cytotoxicity, osteoclast differentiation, cytokine expression, and Ti-induced calvarial osteolysis. Polycan had no significant cytotoxic effects on bone marrow macrophages (BMMs) but instead increased BMM proliferation. High levels of interleukin (IL)-6, IL-12, and macrophage colony-stimulating factor (M-CSF) were expressed in BMM cells in the presence of Polycan, suggesting that Polycan drives the differentiation of BMMs into M1 macrophages. Polycan significantly inhibited osteoclast differentiation induced by M-CSF and the receptor activator of nuclear factor kappa-B ligand (RANKL). The expression levels of the osteoclast marker genes significantly decreased, and Polycan induced and maintained the expression of IL-12, which suppressed osteoclast differentiation. In contrast, the RANKL signaling pathway was not inhibited by Polycan. An in vivo calvarial osteolysis model revealed that Polycan significantly decreased the osteoclast numbers and suppressed osteolysis. Our results suggest that the natural compound Polycan is a good candidate for therapeutic intervention against enhanced osteoclast differentiation and Ti particle-induced osteolysis. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1170-1175, 2016.

Dental amalgam exposure can elevate urinary mercury concentrations in children.

OBJECTIVES: Owing to its cost-effectiveness and operative convenience, dental amalgam remains in use as a restorative material for tooth caries in children in many countries. The aim of this study was to evaluate the relationship between dental amalgam exposure and urinary mercury (U-Hg) concentrations in children. METHODS: In this longitudinal study, 463, 367 and 348 children, 8-11 years of age, were evaluated at baseline, and at the first and second follow-up visits, respectively. The interval between each survey was 6 months. For the oral examination and urine sample, the amalgam-filled tooth surface (TS), and U-Hg and creatinine concentrations of participants were determined, and the cumulative amalgam-filled TS and cumulative creatinine-adjusted U-Hg were calculated. To assess potential covariates, socio-demographic factors, oral health behaviour and dietary factors were surveyed by questionnaire. Data were analysed by the t-test, correlation analysis and mixed-model analysis. The statistical analyses were performed using SPSS 18.0. RESULTS: Children with more than one amalgam-filled TS exhibited significantly higher creatinine-adjusted U-Hg concentrations than those without, in all three survey periods (P < 0.001). The results for the current and cumulative amalgam-filled TS significantly correlated with those for the current and cumulative creatinine-adjusted U-Hg concentration, respectively, in all surveys (P < 0.001). In the repeated-measures mixed model analysis, current and cumulative amalgam-filled TS was significantly related to current and cumulative creatinine-adjusted U-Hg concentration, respectively (P < 0.001). CONCLUSIONS: Amalgam-filled TS was significantly correlated with U-Hg concentrations in children. Therefore, dental amalgam exposure can affect the systemic mercury concentration in children.

Dihydrotestosterone-inducible dickkopf 1 from balding dermal papilla cells causes apoptosis in follicular keratinocytes.

Recent studies suggest that androgen-driven alteration to the autocrine and paracrine factors produced by scalp dermal papilla (DP) cells may be a key to androgen-potentiated balding. Here, we screened dihydrotestosterone (DHT)-regulated genes in balding DP cells and found that dickkopf 1 (DKK-1) is one of the most upregulated genes. DKK-1 messenger RNA is upregulated in 3-6 hours after 50-100 nM DHT treatment and ELISA showed that DKK-1 is secreted from DP cells in response to DHT. A co-culture system using outer root sheath (ORS) keratinocytes and DP cells showed that DHT inhibits the growth of ORS cells, and neutralizing antibody against DKK-1 significantly reversed the growth inhibition of ORS cells. Analysis of co-cultured ORS cells showed a significant increment of sub-G1 apoptotic cells in response to DHT. Also, recombinant human DKK-1 inhibited the growth of ORS cells and triggered apoptotic cell death. In addition, DHT-induced epithelial cell death in cultured hair follicles was reversed by neutralizing DKK-1 antibody. Moreover, immunoblotting showed that the DKK-1 level is up in the bald scalp compared with the haired scalp of patients with androgenetic alopecia. Altogether, our data strongly suggest that DHT-inducible DKK-1 is involved in DHT-driven balding.

Analysis of cellular changes resulting from forced expression of Dickkopf-1 in hepatocellular carcinoma cells.

PURPOSE: Recent studies have shown that Dickkopf-1 (DKK-1) is overexpressed in some tumors, including hepatocellular carcinoma. However, the role of increased DKK-1 in these tumors is not known. In this study, the DKK-1 expression in hepatocellular carcinoma (HCC) cell lines was evaluated and the effect of DKK-1 overexpression in HCC cell lines was studied. MATERIALS AND METHODS: The expression of DKK-1 in hepatocellular carcinoma cell lines was evaluated by RT-PCR. Stable cell lines that overexpressed DKK-1 were established. Cell growth, adhesion, migration and invasion assays were performed. RESULTS: RT-PCR analysis showed that 5 out of 8 HCC cell lines expressed DKK-1. The forced expression of DKK-1 suppressed the growth of cells and increased the population of cells in the sub-G1 phase. In addition, DKK-1 reduced the cellular adhesion capacity to collagen type I and fibronectin, and it increased migratory capacity. However, overexpression of DKK-1 did not increase the invasion capacity of the HCC cell line. CONCLUSION: Collectively, our data suggest that overexpression of DKK-1 affects the biology of HCC cells.