Cullin3 aggravates the inflammatory response of periodontal ligament stem cells via regulation of SHH signaling and Nrf2.

It is found that the activation of Sonic Hedgehog (SHH) signaling pathway is related to the degree of inflammation in patients suffering from periodontitis. Cullin3 (CUL3), an important ubiquitin ligase, can control SHH signaling. In this study, we were dedicated to clarify the roles of SHH and CUL3 in P. gingivalis-LPS (Pg-LPS)-treated periodontal ligament stem cells (PDLSCs). In this study, cell viability was detected using cell counting kit-8 (CCK-8). The inflammatory cytokines of PDLSCs were estimated by enzyme-linked immunosorbent assay (ELISA). With the application of western blots, the protein levels of SHH, Gli1 and NF-E2-related factor 2 (Nrf2) were determined. Alkaline phosphatase staining and Alizarin red staining were performed to evaluate the differentiation and mineralization capabilities of PDLSCs. The apoptotic cells were screened using TUNEL staining. The results showed that Pg-LPS inhibited cell viability and triggered inflammation of PDLSCs. Overexpression of CUL3 weakened the differentiation and mineralization capabilities of PDLSCs. Moreover, CUL3 overexpression aggravated inflammation and cell apoptosis induced by Pg-LPS. It is worth noting that although the protein levels of SHH, Gli1 and Nrf2 were elevated in PDLSCs treated with Pg-LPS, overexpression of CUL3 decreased the expressions of Gli1 and Nrf2. Overall, SHH/Gli1 and Nrf2 were involved in the inflammation and cell apoptosis of PDLSCs, which was dominated by CUL3.

[Study on the mechanism of endothelial progenitor cells in periodontal revascularization during orthodontic tooth movement].

PURPOSE: To investigate the mechanism of endothelial progenitor cells(EPCs) bone remodeling during orthodontic tooth movement. METHODS: Experimental tooth movement model was established. EPCs were isolated, cultured, and labeled with 10 µmol/L Brdu and injected into rats through tail vein to observe the distribution in periodontal tissue. VEGF was added to EPCs culture medium, cell proliferation ability was measured by MTT assay, cell adhesion was observed under microscope. Transwell assay was used to observe cell migration ability, and VEGF immunohistochemical staining sections of model rats at different time points were made. The expression of VEGF in periodontal tissues at different time points was defected. All data were imputed into SPSS 20.0 software package for statistical analysis. RESULTS: A rat model of tooth movement was successfully established. EPCs were isolated from cardiac blood. Some spindle-shaped EPCs were observed under microscope and injected into model rats using Brdu-labeled EPCs. With the increase of time, the intensity of fluorescence gradually increased. In the 3d specimen, the fluorescence intensity reached the strongest. The gap between the first and second molars in the experimental group was lower than that in the control group at each time point, with significant difference(P<0.05). The results of VEGF immunohistochemical staining showed that both the tension side and the pressure side of the experimental group were significantly higher than the control group(P<0.05). The expression of VEGF in both osteoblasts and osteoclasts reached a maximum at 14 days. EPCs proliferation and adhesion experiments demonstrated that VEGF promoted proliferation of EPCs and enhanced their adhesion. Transwell experiments showed that VEGF promoted chemotaxis of EPCs.VEGF regulated the biological effects of EPCs. CONCLUSIONS: EPCs can be accumulated in periodontal tissues and participate in periodontal bone remodeling. After EPCs chemotizing to periodontal tissues, they participate in the remodeling of periodontal tissues through mutual regulation of VEGF and other factors, and promote periodontal tissue repair and bone remodeling.

Effects of Quartz Splint Woven fiber periodontal fixtures on evaluating masticatory efficiency and efficacy.

Masticatory efficiency is altered by mobile teeth resulting from periodontal disease. The goal of our study was to investigate changes before and after fixation of mobile teeth with a Quartz Splint Woven high-strength quartz fiber splint and evaluate the fixation effect.Forty-two patients with chronic severe periodontal disease and 2 to 3 degree tooth mobility underwent fixation with Quartz Splint Woven quartz fiber splints. Masticatory efficiency was determined before and 1 month after periodontal treatment, and 1 month after fixation. Changes in periodontal probing depth (PD) and periodontal attachment level (AL) were measured and clinical efficacy was evaluated.Masticatory efficiency significantly increased from 39.32% to 50.95% after treatment (P < .001). One month post-fixation, mastication efficiency increased to 67.99% (P < .001). At 3 months post-fixation, efficacy was 100% and at 6 months it was 95.24%; PD decreased from (4.91 ±â€Š0.63) to (4.19 ±â€Š0.60) mm at 1 month post-periodontal treatment, and significantly decreased to (3.73 ±â€Š0.60) mm 1 month post-fixation (P < .001); AL decreased from (4.43 ±â€Š0.58) to (3.96 ±â€Š0.51) mm 1 month after periodontal treatment. One month post-fixation, AL reduced to (3.64  ±â€Š0.46) mm (P < .001).Masticatory efficiency improved after periodontal treatment. Using Quartz Splint Woven quartz fiber periodontal splint for mobile tooth fixation can further improve mastication efficiency and periodontal condition. A stable and ideal fixation can be achieved within 6 months, which provides a clinical basis for treatment and preserving mobile teeth in severe periodontal disease. Mastication efficiency may be recommended as the index for evaluating curative effects of periodontal disease treatment.

[Use of visual analogue scale and pain-related factors to evaluate the impact of different orthodontic forces on human dental pulp in patients who underwent fixed dental treatment].

PURPOSE: To investigate the role of visual analogue scale (VAS) and pain-related factors, like tumor necrosis factor-alpha (TNF-α), interleukin-8 (IL- 8), interleukin-6 (IL-6) and interleukin-1 beta (IL-1ß) in evaluation of the impact of different orthodontic forces on human dental pulp in patients who underwent fixed dental treatment. METHODS: From January 2014 to April 2015, 156 patients with maxillary bilateral premolar treated with tooth fixed were randomly divided into 4 groups, 42 patients in control group, 40 patients in 100 g-force group, 40 patients in 150 g-force group, and 39 in 200 g-force group. VAS was used to evaluate before and after removed. TNF-α, IL-8, IL-6 and IL-1ß in pulp tissues were measured by ELISA and pathological changes of pulp were observed on HE staining sections. The data were analyzed with SPSS 13.0 software package. RESULTS: Except for the control group, all patients in other groups had pain after 1-7 days, and the pain peaked at 3~5 days. The pain reaction disappeared on 10th day, and VAS increased in a force dependent manner (P<0.05). TNF-α, IL-8, IL-6 and IL-1ß were higher in different force groups than in control group after 1~2 weeks of treatment, and in a force dependent manner (P<0.05). After 3~4 weeks, the expression of IL-8, IL-6 and IL-1ß returned to normal (P>0.05). Except for the control group, blood vessels on the pulp tissue increased and thickened at 1 week after application of force. Occasionally, odontoblast nucleus was enlarged and the nuclear chromatin and cytoplasmic basophilic staining were enhanced, some odontoblasts displayed vacuolar degeneration, connective tissue in the central pulp presented edema; with the increase of applied force, the changes above mentioned became more obvious, in a force dependent way. CONCLUSIONS: The larger the sustained force, the pain, pain-related factors and pathological changes became more obvious, but restored to normal within 3 weeks.