Shikonin, an active ingredient of
, exerts anti-inflammatory and antibacterial effects, and promotes wound healing. We investigated whether shikonin stimulated gingival tissue wound healing in human ...gingival fibroblasts (hGF). In addition, we evaluated the effects of shikonin on the mitogen-activated protein kinase (MAPK) signaling pathway, which has an important role in wound healing. hGF were subjected to primary culture using gingiva collected from patients. The cells were exposed to/treated with Shikonin at concentrations ranging from 0.01 to 100 μM. The optimal concentration was determined by cell proliferation and migration assays. Type I collagen and fibronectin synthesis, the gene expression of vascular endothelial growth factor (VEGF) and FN, and the phosphorylation of Extracellular signal-regulated kinase (ERK) 1/2 were investigated. Identical experiments were performed in the presence of PD98059 our data suggest, a specific ERK 1/2 inhibitor. Shikonin significantly promoted hGF proliferation and migration. Shikonin (1 µM) was chosen as the optimal concentration. Shikonin promoted type I collagen and FN synthesis, increased VEGF and FN expression, and induced ERK 1/2 phosphorylation. These changes were partially suppressed by PD98059. In conclusion, Shikonin promoted the proliferation, migration, type I collagen and FN synthesis, and expression of VEGF and FN via ERK 1/2 signaling pathway in hGFs. Therefore, shikonin may promote periodontal tissue wound healing.
Dental pulp stem cells (DPSCs) play an important role in the homeostasis of the pulp tissue and have a high potential for osteogenic differentiation. Enamel matrix derivative (EMD) has been used in ...periodontal regeneration therapy. Previously, we designed a synthetic amelogenin peptide (AP) derived from EMD. In this study, we investigated the effects of AP on DPSCs and evaluated its usefulness as a dental pulp capping material. DPSCs were cultured in medium supplemented with AP (0 and 100 ng/mL) to examine the effect of DPSCs on cell morphology and the cell migration ability. In addition, DPSCs were cultured with osteogenic medium supplemented with AP at 0 and 100 ng/mL, and their osteogenic differentiation was examined by Alizarin Red staining. AP promoted cell extension by altering cell morphology, and also significantly promoted DPSCs chemotaxis and cell migration. Moreover, the number of calcified nodule formations stained by Alizarin Red increased in the AP group. In summary, AP may be useful as a dental pulp capping material. (J Osaka Dent Univ 2022; 56: 197-201)
Periodontitis is an inflammatory lesion in the periodontal tissue. The behavior of human periodontal ligament stem cells (hPDLSCs), which play an important role in periodontal tissue regeneration, is ...restricted by the influence of inflammatory mediators. Photobiomodulation therapy exerts anti-inflammatory effects. The purpose of this study was to investigate the effects of light-emitting diode (LED) irradiation on the inflammatory responses of hPDLSCs. The light source was a red LED (peak wavelength: 650 nm), and the total absolute irradiance was 400 mW/cm
. The inflammatory response in hPDLSCs is induced by tumor necrosis factor (TNF)-α. Adenosine triphosphate (ATP) levels and pro-inflammatory cytokine (interleukin IL-6 and IL-8) production were measured 24 h after LED irradiation, and the effects of potassium cyanide (KCN) were investigated. LED irradiation at 6 J/cm
significantly increased the ATP levels and reduced TNF-α-induced IL-6 and IL-8 production. Furthermore, the inhibitory effect of LED irradiation on the production of pro-inflammatory cytokines was inhibited by KCN treatment. The results of this study showed that high-intensity red LED irradiation suppressed the TNF-α-stimulated pro-inflammatory cytokine production in hPDLSCs by promoting ATP synthesis. These results suggest that high-intensity red LED is a useful tool for periodontal tissue regeneration in chronically inflamed tissues.
Clinical practice has been reducing in recent years due to the COVID-19 pandemic. The study will compare the impact of COVID-19 pandemic on the effectiveness of pre-graduate clinical education over a ...three-year period from 2019 to 2021. The subject was to remove supragingival marginal dental calculus from a model using a curette scaler for fifth-year students of the School of dentistry of Osaka Dental University. Three items were evaluated, and the evaluation was performed by three faculty members. For dental calculus removal, the results for each year were varied. However, there were generally no students who scored zero on teeth and gingival damage, criteria. It is recognized that the improvement of periodontal treatment is due to the educational effect of clinical practice even during the COVID-19 pandemic. We suggest that the on-demand teaching materials combined with practice on models contributed to the improvement of students' clinical skills. (J Osaka Dent Univ 2024; 58: 135-137)
Photodynamic therapy using lisht emitting diodes (LEDs) and lasers has been shown effective for periodontal treatment. In previous research, we found that high‐intensity red LEDs promote hard tissue ...formation of human periodontal ligament stem cells and human bone marrow mesenchymal stem cells (BMSCs). On the other hands, it has been suggested that LED might induce cytotoxicity and inflammtion. Therefore, we investigated the biological effect of high‐intensity red LEDs on BMSCs, including cytotoxicity and inflammation. A high‐intensity red LED manufactured by Led Engin was used as a light source, and the irradiation energy was adjusted by changing the irradiation time. We performed cell proliferation and cytotoxicity assays, and examined the mineralization by alizarin red staining and the expression of IL‐6 and IL‐8. LED irradiation suppressed cell proliferation, and promoted cytotoxicity in an energy dose‐dependent manner at 48 hours of irradiation. The mineralization tended to be promoted most at 6J/cm2. LED irradiation promoted the expression of IL‐6 at 48 hours, and the expression of IL‐8 at 24 and 48 hours. In conclusion, high‐intensity red LED might promote the calcification of BMSCs, while promoting the cytotoxicity and gene expression of inflammatory cytokines. (J Osaka Dent Univ 2021; 55: 225‐230)
Diabetes mellitus (DM) leads to an increased risk of tooth loss. Dental implants are a standard treatment for partial or full edentulism, and various implant surface treatments have been developed to ...increase their stability. However, some studies have reported that DM reduces osseointegration and dental implant success. The purpose of this study was to determine the effects of high glucose levels on hard tissue formation on an alkali‐treated titanium surface. Titanium disks were heated at 600°C for 1 h prior to treatment with 10 M NaOH solution and incubated with type II DM rat bone marrow mesenchymal cells (BMMCs) prior to exposure to glucose at 5.5, 8.0, 12.0 or 24.0 mM. We evaluated the effect of different glucose concentrations on the osteogenesis of BMMCs on the titanium surface. Alkaline phosphatase activity decreased with increasing glucose concentration. In contrast, although osteocalcin production, calcium deposition and the calcium/phosphate ratio deposition were significantly decreased at 8.0 mM, they increased when the concentration was greater than 8.0 mM. The RANKL/OPG ratio decreased with increasing glucose concentration. Although high glucose concentrations increased hard tissue formation, the quality of the mineralized tissue decreased. (J Osaka Dent Univ 2021; 55: 255‐261)
Enamel matrix derivative (EMD) is used in periodontal tissue regeneration therapy. In our previous study, we constructed a synthetic oligopeptide (SP) derived from EMD that enhanced the cell ...proliferation of gingival fibroblasts and periodontal ligament cells. SP also induced hard tissue formation in artificial periodontal tissue defects in a rat experimental model. Mesenchymal stem cells (MSCs) are highly proliferative and have a high potential of osteogenic differentiation, and thus contribute to the regeneration of hard tissues. However, the molecular effect of SP is not fully understood. In this study, we investigated the effect of SP on cell proliferation and osteogenic differentiation of human MSCs. Additionally, we examined the activation of the extracellular signal-related kinases (ERK) 1/2 pathway to investigate its molecular biological mechanism. Our results indicated that SP promotes cell proliferation and osteogenic differentiation, and induces ERK 1/2 activation in MSCs. Therefore, SP might promote cell proliferation and osteogenic differentiation through the ERK 1/2 pathway in MSCs, thus possibly contributing to periodontal tissue regeneration. (J Osaka Dent Univ 2022; 56: 115-120)
Enamel matrix derivative (EMD) is applied for periodontal therapy. We created a synthetic amelogenin peptide (SP) derived from EMD, and have previously investigated the biological function of SP. ...However, it is unknown whether SP affects odontoblastic differentiation. In this study, we tested the effects of SP in the odontoblast-like cells, KN-3 cells. KN-3 cells were cultured with SP (0 to 1000 ng/mL) and then cultured for 3, 8, 24, or 48 h in order to determine the effects of SP on cell proliferation and detect its optimum concentration. KN-3 cells were treated with SP in odontogenic differentiation medium cultured for 3 or 7 days. Odontogenic markers were measured by the detection of alkaline phosphatase (ALP) activity and dentin sialo phosphoprotein (DSPP) expression, the calcified nodule formation, and calcium deposition. The addition of SP significantly promoted cell proliferation at 100 ng/mL, generating the greatest change in cell proliferation. SP also showed increased odontogenic expression markers and mineralization. These results suggest that SP, derived from EMD, could have potential for application in dental pulp capping.
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