MicroRNA-223 negatively regulates LPS-induced inflammatory responses by targeting NLRP3 in human dental pulp fibroblasts.

AIM: To investigate the effect of miR-223 on NLRP3, subsequently regulating the production of the NLRP3/CASP1 inflammasome pathway-mediated proinflammatory cytokines IL-1ß and IL-18 in human dental pulp fibroblasts (HDPFs). METHODOLOGY: Human dental pulp tissue (HDPT) and HDPFs were obtained from impacted third molars. The miR-223 mimics and inhibitor or NLRP3 plasmid were used to upregulate or downregulate miR-223 or NLRP3 in HDPFs, respectively. Computational prediction via TargetScan 5.1 and a luciferase reporter assay was conducted to confirm target association. The mRNA and protein expression of NLRP3, caspase-1, IL-1ß and IL-18 was determined by qRT-PCR and Western blotting, respectively. The release of IL-1ß and IL-18 was analysed by ELISA. The significance of the differences between the experimental and the control groups was determined using one-way analysis of variance; P < 0.05 indicated statistical significance. RESULTS: A decrease in miR-223 and an increase in NLRP3 in HDPT occurred during the transformation of reversible pulpitis into irreversible pulpitis compared to that in healthy pulp tissue (P < 0.05). The computational prediction and luciferase reporter assay confirmed that NLRP3 was a direct target of miR-223 in HDPFs. The miR-223 inhibitor further promoted ATP plus LPS-induced NLRP3/CASP1 inflammasome pathway activation compared to the ATP plus LPS-induced group (P < 0.05). In contrast, the miR-223 mimic significantly inhibited the NLRP3/CASP1 inflammasome pathway activation induced by ATP plus LPS compared to the ATP plus LPS-induced group (P < 0.05). CONCLUSION: MiR-223 served as a negative regulator involved in the control of the production and secretion of proinflammatory cytokines mediated by the NLRP3/CASP1 inflammasome pathway by targeting NLRP3. These data provide insight into the potential regulatory effects of miRNAs on the NLRP3 inflammasome, thus opening up novel potential therapeutic avenues for future endodontic treatment.

Computer-aided three-dimensional assessment of periodontal healing distal to the mandibular second molar after coronectomy of the mandibular third molar: a prospective study.

BACKGROUND: The periodontal healing distal to the mandibular second molar (M2M) after coronectomy of the M3M has shown controversial results. We aimed to combine a digital method with cone-beam computed tomography (CBCT) and estimate periodontal healing of M2M after M3M coronectomy. An accurate and stable indicator in three dimensions was also explored tentatively. METHODS: Patients with a M3M in contact with the inferior alveolar canal were included. CBCT was applied immediately after coronectomy (baseline) and 6-months later. Data were investigated with digital software for registration. Previously reported and coronectomy-related factors were included for univariate and multivariate analyses. RESULTS: A total of 181 patients (213 M3Ms) completed 6-month follow-up. Significant reduction in the distal intra-bony defect (DBD) depth of the M2M was shown (1.28 ± 1.24 mm, P < 0.001). DBD depth of the M2M at baseline was the most influential factor (r = 0.59), followed by preoperative M3M condition, age, rotation and migration of the root complex. Remaining enamel (OR = 6.93) and small retromolar space (0.67) contributed to re-contact of the root complex and M2M. Bone volume regenerated in the distal 2 mm was associated significantly with DBD-depth reduction (r = 0.74, P < 0.001). CONCLUSIONS: Bone volume regenerated in the distal 2 mm of the M2M denoted stability of distal periodontal healing of the M2M. DBD depth at baseline was the most influential factor for healing of a DBD of the M2M after M3M coronectomy. The remaining enamel and a small retromolar space could contribute to re-contact of the root complex and the M2M. TRIAL REGISTRATION: China Clinical Trial Center, ChiCTR1800014862 . Registered 10 February 2018.

[Feasibility of Delaire cephalometric analysis to predict the ideal sagittal position of the maxilla and chin for surgery-first patients in orthognathic surgery].

OBJECTIVE: There is no universally accepted method for determining the ideal sagittal position of the maxilla in orthognathic surgery. The purpose of this study was to compare how well the Delaire's cephalometric analysis correlated with postoperatively findings in patients who underwent orthognathic surgery planned using other cephalometric analyses, as well as to evaluate the feasibility of the Delaire's cephalometric analysis in predicting the ideal sagittal position of the maxilla and chin. METHODS: In the study, 35 patients with skeletal Class III malocclusion were involved and met the criteria. Treatment plans were developed using photographs, 3-D photographs, radiographs, and standard cephalometric measurements. The Delaire's cephalometric analysis data, like the phase measurements (∠C1-L1 and ∠C1-L2) of the sagittal positions of the maxillary and the chin separating the reference line (L1) of NP point and the reference line (L2) of Me point, were analyzed using Dolphin Imaging software. At the same time, the analyses on standard measurements were also performed. Four orthognathic doctors, 4 orthodontic doctors and 4 college students from non-medical majors were selected as aesthetic evaluators to assess the patients' profile aesthetic by visual analogue scale (VAS). The results through the Delaire's cephalometric analysis were statistically compared with that through standard methods. RESULTS: The mean of ∠C1-L1 was 83.93°±2.99° and∠C1-L2 was 89.08° ±2.48° for males postoperatively, and 85.67° ±3.60° and 88.30° ±4.20° for females postoperatively. Compared with the reference values of Chinese goodlooking people, there was no significant difference of NP point, whereas there was a significant difference of Me point. The postoperative aesthetic scores were: the mean was 6.71±0.25 of upper jaws, 6.81±0.30 of chins and 6.90±0.29 of the overall for males; and 7.19±0.22, 7.26±0.34 and 7.39±0.29 for females. Compared with preoperative scores, there was a significant improvement. Furthermore, the scores of chins and the overall scores were related to the sagittal position of the chins. CONCLUSION: Compared with standard cephalometric analysis, the Deliare's cephalometric analysis well unravel the preoperative deformity and the final esthetic sagittal positions of maxillary and chin in the present sample, and could be a useful tool for the planning of surgery-first approach in orthognathic surgery.

[Accuracy analysis of computer assisted navigation for condylectomy via intraoral approach].

OBJECTIVE: To explore the application accuracy of virtual preoperative plan after the condylectomy via intraoral approach under computer assisted surgical navigation, and to analyze the location and cause of the surgical deviation to provide reference for the surgical procedure improvement in the future. METHODS: In the study, 23 cases with condylar hypertrophy (11 with condylar osteochondroma and 12 with condylar benign hypertrophy) in Department of Oral and Maxilloficial Surgery, Peking University School and Hospital of Atomatology from December 2012 to December 2016 were treated by condylectomy via intraoral approach under computer assisted surgical navigation. The patient's spiral CT data were imported into ProPlan software before operation, and the affected mandibular ramus was reconstructed three-dimensionally. The condylar osteotomy line was designed according to the lesion range, and the preoperative design model was generated and introduced into the BrainLab navigation system. Under the guidance of computer navigation, the intraoral approach was used to complete the condylar resection according to the preoperative design of the osteotomy line. Cranial spiral CT of the craniofacial region was taken within one week after operation. three-dimensional reconstruction of the mandibular ramus at the condylectomy side was performed, and the condylar section was divided into six segments (anterolateral, anterior, anteromedial, posteromedial, posterior, and posterolateral) and the corresponding regional measurement points P1 to P6 were defined. Then the preoperative virtual model and the postoperative actual model were matched by Geomagic studio 12.0 to compare the differences and to analyze the accuracy of the operation. RESULTS: All the patients had successfully accomplished the operation and obtained satisfactory results. Postoperative CT showed that the condyle lesion was completely resected, and the condylar osteotomy line was basically consistent with the surgical design. No tumor recurrence or temporomandibular joint ankylosis during the follow-up period. The postoperative accuracy analysis of the condylar resection showed that the confidence intervals measured by the six groups of P1 to P6 were (-2.26 mm, -1.89 mm), (-2.30 mm, -1.45 mm), (-3.37 mm, -2.91 mm), (-2.83 mm, -1.75 mm), (-1.13 mm, 0.99 mm), and(-1.17 mm, 0.17 mm), where P3 group was different from the other 5 groups. There was no significant difference between the P5 and P6 groups and the difference between the other four groups was statistically significant. CONCLUSION: Under the guidance of computer navigation, the intraoral approach can be performed more accurately. The surgical deviation of each part of the osteotomy surface is mainly due to excessive resection. The anterior medial area of the anterior medial condyle represents the most excessive resection. The posterior and posterior lateral measurement points represent the posterior condylar area. The average deviation is not large, but the fluctuation of the deviation value is larger than that of the other four groups. The accuracy of computer-assisted subtotal resection has yet to be improved.

Effects of ultrasonic removal of fractured files from the middle third of root canals on dentinal cracks: a micro-computed tomography study.

AIM: To evaluate the frequency of dentinal microcracks after ultrasonic removal of fractured files from the middle third of root canals using micro-computed tomography (micro-CT). METHODOLOGY: Eighteen bilaterally matched pairs of human mandibular incisors extracted for periodontal reasons were included. The matched pairs of teeth were then divided into a control group and an experimental group, with one member of each pair assigned to each group. In the control group, the canals were instrumented using the ProTaper Next (PTN) system. In the experimental group, size 20 K-files were fractured in the middle third of the root canals, followed by their ultrasonic removal. Subsequently, the canals were instrumented with the PTN system. All teeth were scanned using high-resolution micro-CT before (preoperative) and after (intraoperative) file removal and after (postoperative) root canal preparation. Pre-, intra-, and postoperative cross-sectional images of the roots were screened to identify the presence of dentinal defects. Two experienced observers evaluated the images twice in a blinded manner. The incidence of dentinal microcracks was noted and statistically analysed using Fisher's exact and McNemar's tests (P = 0.05), with the root cross-section and the tooth root as the units of analysis, respectively. RESULTS: All fractured files in the experimental group were removed successfully. New microcracks were detected in 0.56% (93/16 472) cross-sections (8/18 specimens) generated after file removal in the experimental group. These microcracks were detected 4-6 mm below the root canal orifice and exhibited a width and length of 12-36 µm and 48-72 µm, respectively. They did not disappear or propagate after canal preparation. No new dentinal microcracks were observed in the control group. There was a significant difference in the incidence of new microcracks between the two groups (P < 0.05). CONCLUSIONS: Ultrasonic removal of fractured files from root canals resulted in the formation of short microcracks in a small number of cross-sections in approximately half the specimens. Further studies are necessary to determine the cause and consequences of this finding.

Effects of histone deacetylase inhibitors on regenerative cell responses in human dental pulp cells.

AIM: To investigate the growth, migratory and adhesive effects of trichostatin A (TSA) and valproic acid (VPA), two histone deacetylase inhibitors (HDACis), on human dental pulp stem cells (hDPSCs). METHODOLOGY: To verify that TSA or VPA functions as an HDAC inhibitor, the expressions of histones H3 and H4 were examined using Western blotting analysis. hDPSC growth and metabolic activity was evaluated by MTT viability analysis at different time-points and by cell count experiments. The expression of cell cycle regulatory proteins and apoptosis-associated proteins was examined by Western blot analysis. Migration effects were investigated using wound healing and transwell migration assays. An adhesion assay was also performed in the presence and absence of HDACis. The levels of chemokines and adhesion molecules relevant to repair in hDPSCs were also assessed by qRT-PCR and Western blot analysis. The data were analysed, where appropriate, using Student's t-test or one-way anova followed by the Student-Newman-Keuls test using SPSS software. RESULTS: Trichostatin A and VPA enhanced acetylation of histones H3 and H4 (P < 0.05). Significant increases (P < 0.05) in MTT levels in hDPSCs were observed after treatment with TSA (2 and 20 nmol L-1 ) or VPA (1 and 10 mmol L-1 ). Cell numbers were not significantly affected at the concentration of TSA (0.2-10 nmol L-1 ) or VPA (0.01-100 mmol L-1 ) applied compared with the control at 3, 5 or 7 days (P > 0.05). At the same time, the expression of Cdx2 and cyclin A was upregulated by 2 nmol L-1 TSA and 1 mmol L-1 VPA (P < 0.05). Higher TSA or VPA concentrations induced apoptosis in hDPSCs in the cell count and apoptosis experiments (P < 0.05). Moreover, TSA and VPA significantly depressed the expression of Cdx2 and cyclin A (P < 0.05), whilst it significantly improved the level of p21 (P < 0.05). TSA and VPA promoted migration and adhesion of hDPSCs (P < 0.05). The levels of chemokines and adhesion molecules were significantly upregulated after exposure of hDPSCs to 20 nmol L-1 TSA or 1 mmol L-1 VPA (P < 0.05). CONCLUSIONS: Histone deacetylase inhibitors at specific concentrations promoted proliferation, migration and adhesion of hDPSCs, which may contribute to novel regenerative therapies for pulpal disease treatment.

The effect of magnesium on early osseointegration in osteoporotic bone: a histological and gene expression investigation.

Magnesium has a key role in osteoporosis and could enhance implant osseointegration in osteoporotic patients. Titanium implants impregnated with Mg ions were installed in the tibia of ovariectomized rats. The release of Mg induced a significant increase of bone formation and the expression of anabolic markers in the peri-implant bone. INTRODUCTION: The success of endosseous implants is highly predictable in patients possessing normal bone status, but it may be impaired in patients with osteoporosis. Thus, the application of strategies that adjuvate implant healing in compromized sites is of great interest. Magnesium has a key role in osteoporosis prevention and it is an interesting candidate for this purpose. In this study, the cellular and molecular effects of magnesium release from implants were investigated at the early healing stages of implant integration. METHODS: Osteoporosis was induced in 24 female rats by means of ovariectomy and low-calcium diet. Titanium mini-screws were coated with mesoporous titania films and were loaded with magnesium (test group) or left as native (control group). The implants were inserted in the tibia and femur of the rats. One, 2 and 7 days after implantation, the implants were retrieved and histologically examined. In addition, expression of genes was evaluated in the peri-implant bone tissue at day 7 by means of quantitative polymerase chain reactions with pathway-oriented arrays. RESULTS: The histological evaluation revealed that new bone formation started already during the first week of healing for both groups. However, around the test implants, new bone was significantly more abundant and spread along a larger surface of the implants. In addition, the release of magnesium induced a significantly higher expression of BMP6. CONCLUSIONS: These results provide evidence that the release of magnesium promoted rapid bone formation and the activation of osteogenic signals in the vicinity of implants placed in osteoporotic bone.

Inferior alveolar nerve function recovers after decompression of large mandibular cystic lesions.

OBJECTIVE: The treatment of large mandibular cystic lesions (diameter > 35 mm) is controversial. Few studies determine the inferior alveolar nerve function after decompression which is one of the major options for treating such lesions. We aim to investigate the recovery of inferior alveolar nerve function after decompression. METHODS: Twenty-two patients with large mandibular cystic lesions, diagnosed as keratocystic odontogenic tumor, ameloblastoma, or dentigerous cyst, were included. Inferior alveolar nerve function was observed by monitoring the pulp vitality of involved teeth (n = 64) with electric pulp test before decompression and 1, 3, 6, 9, 12, and 24 months after decompression, respectively. RESULTS: The pulp vitality of the involved teeth was significantly decreased before decompression. Recovery of pulp vitality could be observed after decompression, indicating the recovery of inferior alveolar nerve function. A majority (96.9%) of the vital pulp was preserved in the involved teeth after decompression. CONCLUSIONS: Recovery of inferior alveolar nerve function was remarkable in patients with large mandibular cystic lesions after decompression, indicated by the recovery of pulp vitality of involved teeth. When decompression is preferred, conservative therapy rather than root canal therapy is recommended for the teeth with root tip exposed in the cystic lesions and without pulposis.

Osteoimmunology in orthodontic tooth movement.

The skeletal and immune systems share a multitude of regulatory molecules, including cytokines, receptors, signaling molecules, and signaling transducers, thereby mutually influencing each other. In recent years, several novel insights have been attained that have enhanced our current understanding of the detailed mechanisms of osteoimmunology. In orthodontic tooth movement, immune responses mediated by periodontal tissue under mechanical force induce the generation of inflammatory responses with consequent alveolar bone resorption, and many regulators are involved in this process. In this review, we take a closer look at the cellular/molecular mechanisms and signaling involved in osteoimmunology and at relevant research progress in the context of the field of orthodontic tooth movement.

A systematic review and meta-analysis on the efficacy of low-level laser therapy in the management of complication after mandibular third molar surgery.

The successful reduction of postoperative discomfort is of great significance. This review aims to evaluate the efficacy of low-level laser therapy (LLLT) for the reduction of complication caused by impacted mandibular third molars extraction. An extensive literature search up to October 2013 for randomized controlled trials (RCTs) was performed through CENTRAL, PubMed, Embase, Medline, and CNKI. Six RCTs in which involves 193 participants are included in the meta-analysis. Among them, three RCTs exhibit a moderate risk of bias, while the other three show a high bias risk. Compared with placebo laser/control group, pain is significantly reduced with LLLT on the first day (mean difference [MD] = -2.63, 95% confidence interval [CI] -4.46 to -0.79, P = 0.005). The superiority of LLLT in pain control persists on the second day (MD = -2.34, 95% CI -4.61 to -0.06, P = 0.04) and the third day (MD = -3.40, 95% CI -4.12 to -2.68, P < 0.00001). Moreover, LLLT reduces an average of 4.94 mm (MD = 4.94, 95 % CI 1.53 to 8.34, P = 0.004) of trismus compared with placebo laser irradiation in the first 3 days. On the seventh day, the superiority of LLLT also persists (MD = 3.24, 95% CI 0.37 to 6.12, P = 0.03). In the first 3 days after surgery, extraoral irradiation (MD = -0.69, 95% CI -1.30 to -0.08, P = 0.03) and intraoral combined with extraoral irradiation (MD = -0.65, 95% CI -1.15 to -0.15, P = 0.01) reduced facial swelling significantly. On the seventh day, the intraoral combined with extraoral irradiation group (MD = -0.32, 95% CI -0.59 to -0.06, P = 0.02) still showed benefit in relieving facial swelling. However, because of the heterogeneity of intervention and outcomes assessment and risk of bias of included trials, the efficacy is proved with limited evidence. In the future, well-designed RCTs with larger sample size will be required to provide clearer recommendations.

Efficacy of low-level laser therapy for accelerating tooth movement during orthodontic treatment: a systematic review and meta-analysis.

This review aimed to evaluate the efficacy of low-level laser therapy (LLLT) for accelerating tooth movement during orthodontic treatment. An extensive electronic search was conducted by two reviewers. Randomized controlled trials (RCTs) and quasi-RCTs concerning the efficacy of LLLT for accelerating tooth movement during orthodontic treatment were searched in CENTRAL, Medline, PubMed, Embase, China Biology Medicine Disc (CBM), China National Knowledge Infrastructure (CNKI), and Google Scholar. Six RCTs and three quasi-RCTs, involving 211 patients from six countries, were selected from 173 relevant studies. All nine articles were feasible for the systematic review and meta-analysis, five of which were assessed as moderate risk of bias, while the rest were assessed as high risk of bias. The mean difference and the 95 % confidence interval (95 % CI) of accumulative moved distance of teeth were observed among all the researches. The results showed that the LLLT could accelerate orthodontic tooth movement (OTM) in 7 days (mean difference 0.19, 95 % CI [0.02, 0.37], p = 0.03) and 2 months (mean difference 1.08, 95 % CI [0.16, 2.01], p = 0.02). Moreover, a relatively lower energy density (5 and 8 J/cm(2)) was seemingly more effective than 20 and 25 J/cm(2) and even higher ones.

Effect of sphingosine-1-phosphate and myoblast transplantation on rat acute myocardial infarction.

In this study, we investigated the effects of sphingosine-1-phosphate (S1P) combined with myoblast transplantation on the treatment of acute myocardial infarction and provided a foundation for its clinical application. A rat model of acute myocardial infarction was established by ligating the anterior descending branch of the coronary artery. Serum-free media, myoblasts, myoblasts with S1P liposomes, or myoblasts with liposomes were then injected into the infarcted area. Apoptosis of the transplanted cells was assessed after 24 and 48 h, and changes in heart function and myocardial infarction area were assessed after 4 weeks. After transplantation of S1P into myoblasts, myocardial function was improved compared to that in the other groups. Specifically, the apoptosis of transplanted cells and the area of myocardial infarction decreased significantly (P < 0.01), while cardiac function significantly improved (P < 0.01). The efficacy of S1P and myoblast transplantation on acute myocardial infarction was significantly better than that in the control group (i.e., injection of myoblasts and liposomes) and the serum-free medium group, demonstrating the feasibility of joint S1P and myoblast transplantation for treating myocardial infarction.

Phenotype-genotype correlations in patients with Marinesco-Sjögren syndrome.

Marinesco-Sjögren syndrome (MSS; MIM 248800) is an autosomal recessive disorder characterized by congenital cerebellar ataxia, early cataracts, developmental delay, myopathy and short stature. Alterations in the gene SIL1 cause MSS in some patients with typical findings. In this study, molecular investigations including sequencing of the SIL1 gene, western blotting and microscopic investigations in fibroblast cultures were carried out in a cohort of 15 patients from 14 unrelated families, including the large, inbred family reported by Superneau et al., having the clinical features of MSS to provide insights into the pathophysiology of the disorder. A total of seven different mutations were found in eight of the patients from seven families. The mutations caused loss of the BIP-associated protein (BAP) protein in four patients by western blot. Novel clinical features such as dental abnormalities, iris coloboma, eczema and hormonal abnormalities were noticed in some patients, but there was no clear way to distinguish those with and without SIL1 mutations. Cultured fibroblasts contained numerous cytoplasmic inclusion bodies, similar to those identified in the brain of the whoozy mouse in five unrelated patients, three with and two without SIL1 mutations, suggesting some SIL1 negative patients share a common cellular pathogenesis with those who are SIL1 positive.

The 'D-M-C' strategy for conventional ameloblastoma of the mandible: a retrospective study.

The purpose of this multicentre study was to evaluate the efficacy of the 'dredging-marsupialization-curettage' (D-M-C) strategy in the treatment of conventional intraosseous ameloblastoma of the mandible. A total of 31 patients from three institutions, who had a pathological diagnosis of conventional ameloblastoma of the mandible, were treated with the D-M-C strategy. The surgical protocol comprised a dredging and marsupialization (D-M) step, with additional D-M steps as required. The patients then underwent curettage (C) once an obvious effect of the D-M step had been achieved during follow-up. Eight patients were followed up for ≥36 months but <60 months, while 23 were followed up for ≥60 months. Nineteen of the 23 patients followed up for ≥60 months were disease-free at the last follow-up, with no evidence of recurrence. The D-M step is effective for reducing the tumour size and preserving vital structures. The D-M-C surgical strategy may be a feasible treatment option for conventional ameloblastoma of the mandible.

Casp11 Deficiency Alters Subgingival Microbiota and Attenuates Periodontitis.

Periodontitis (PD) is the primary cause of tooth loss in adults. Porphyromonas gingivalis (P.g), a keystone pathogen, has been identified as a crucial contributor to this process. Pyroptosis activation in PD is acknowledged, with accumulating evidence underscoring the crucial role of Caspase-11 (described as Caspase-4/5 in humans)-mediated noncanonical pyroptosis. However, the mechanism behind its impact on PD remains unclear. In this study, we delved into the interplay between the Caspase-11-mediated noncanonical pyroptosis, subgingival microbiota alteration, and macrophage polarization. Clinical samples from PD patients revealed heightened expression of Caspase-4, gasdermin-D, and their active fragments, pointing to the activation of the noncanonical pyroptosis. Single-cell sequencing analysis linked Caspase-4 with gingival macrophages, emphasizing their involvement in PD. In vitro cell experiments confirmed that P.g-induced pyroptosis was activated in macrophages, with Casp11 deficiency attenuating these effects. In an experimental PD mouse model, Casp11 deficiency led to an alteration in subgingival microbiota composition and reduced alveolar bone resorption. Casp11-/- mice cohousing with wild-type mice confirmed the alteration of the subgingival microbiota and aggravated the alveolar bone resorption. Notably, Casp11 deficiency led to decreased M1-polarized macrophages, corresponding with reduced alveolar bone resorption, uncovering a connection between subgingival microbiota alteration, macrophage M1 polarization, and alveolar bone resorption. Taken together, we showed that Caspase-11 fulfilled a crucial role in the noncanonical pyroptosis in PD, potentially influencing the subgingival microbiota and linking to M1 polarization, which was associated with alveolar bone resorption. These findings underscored the pivotal role of the Caspase-11-mediated noncanonical pyroptosis in PD pathogenesis and may provide critical insights into potential therapeutic avenues for mitigating PD.

LPS induces IL-8 expression through TLR4, MyD88, NF-kappaB and MAPK pathways in human dental pulp stem cells.

AIM: To evaluate the effects of lipopolysaccharide (LPS) on interleukin-8 (IL-8) and related intracellular signalling pathways in human dental pulp stem cells (hDPSCs). METHODOLOGY: Human pulp tissues were isolated from human impacted third molars, and the hDPSCs were cultured and characterized. The effects of LPS on IL-8 and Toll-like receptor 4 (TLR4) gene expression in hDPSCs were investigated using real-time quantitative RT-PCR and ELISA. Whether TLR4/MyD88/NF-кB was involved in the LPS-induced up-regulation of IL-8 in hDPSCs was determined using transient transfection, luciferase assay and ELISA. The involvement of MAPKs in the LPS-induced up-regulation of IL-8 in hDPSCs was investigated via transient transfection, luciferase assay, ELISA and western blot. The data were statistically analysed using Student's t-test or one-way anova followed by the Student-Neumann-Keuls test. RESULTS: Cells exposed to LPS not only displayed an enhanced expression of TLR4 but also showed an elevated IL-8 gene expression; exposure to LPS also resulted in the induction of IL-8 gene transcription via promoter activation. The LPS-induced IL-8 promoter activation was inhibited through dominant-negative mutations in TLR4 and MyD88, but not in TLR2. The LPS-induced IL-8 protein release was attenuated through the administration of TLR4-neutralizing antibody or MyD88 inhibitory peptide and a dominant-negative mutation in IκBα. In contrast, IL-8 protein release was enhanced through the expression of NF-κB p65. Treatment with PDTC, TPCK or Bay117082 effectively antagonized LPS-induced IL-8 protein release. Moreover, both the promoter activity and the LPS-induced release of IL-8 were diminished upon the administration of U0126 and SB203580, but not SP600125. Moreover, the exposure to LPS activated ERK1/2 and p38 MAPK phosphorylation in cells. CONCLUSIONS: This study reports the LPS-mediated transcriptional and post-translational up-regulation of IL-8, which is a process that also involves TLR4, MyD88, NF-κB and MAPK.

CpG ODN-induced matrix metalloproteinase-13 expression is mediated via activation of the ERK and NF-κB signalling pathways in odontoblast cells.

AIM: To investigate the effects of CpG ODN (CpG oligodeoxynucleotides) to model the action of bacterial challenge on pulpal matrix metalloproteinase-13 (MMP-13) expression and elucidate the associated intracellular signalling pathways. METHODOLOGY: Real-time PCR was used to detect the effects of CpG ODN on MMP-13 mRNA expression levels in a murine odontoblast-lineage cell line (OLCs). The possible involvement of TLR9/MyD88, NF-κB or MAPK pathways involved in the CpG ODN-induced MMP-13 expression was examined by real-time PCR, transient transfection, luciferase activity assay and ELISA. Western blotting was performed to assay the phosphorylation of ERK at a range of time points. RESULTS: MMP-13 was constitutively expressed in OLCs, and their exposure to CpG ODN significantly increased MMP-13 expression. Pre-treatment of OLCs with the inhibitory peptide MyD88, or chloroquine, attenuated the CpG ODN-induced expression of MMP-13. Treatment of the OLCs with CpG ODN increased NF-κB-luciferase activity. This activity was decreased by the over-expression of a nondegrading mutant of IκBα (IκBαSR), although enhanced by the over-expression of NF-κB p65. MMP-13 expression induced by CpG ODN was markedly suppressed by NF-κB inhibitors (pyrrolidine dithiocarbamate, PDTC), IκBα phosphorylation inhibitors (Bay 117082) or IκB protease inhibitor (L-1-tosylamido-2-phenylethyl chloromethyl ketone, TPCK). The inhibitor of ERK1/2, U0126, but not inhibitors of p38 MAPK and JNK, SB203580 and SP600125, decreased CpG ODN-mediated MMP-13 expression. CONCLUSION: The CpG ODN-induced MMP-13 expression in OLCs is mediated through TLR9, NF-κB and the ERK pathway indicating that potentially the recognition of CpG ODN by TLR9 on odontoblasts may regulate the remodelling of injured dental pulp and hard tissues by inducing MMP-13 expression.

Efficacy of low-level laser therapy in the management of orthodontic pain: a systematic review and meta-analysis.

This review aimed to identify the efficacy of low-level laser therapy (LLLT) in the management of orthodontic pain. This systematic review and meta-analysis was carried out in accordance with Cochrane Handbook and the PRISMA statement. An extensive literature search for RCTs, quasi-RCTs, and CCTs was performed through CENTRAL, PubMed, Embase, Medline, CNKI, and CBM up to October 2011. Risk of bias assessment was performed via referring to the Cochrane tool for risk of bias assessment. Meta-analysis was implemented using Review Manager 5.1. As a result, four RCTs, two quasi-RCTs, and two CCTs were selected from 152 relevant studies, including 641 patients from six countries. The meta-analysis demonstrated that 24% risk of incidence of pain was reduced by LLLT (RR = 0.76, 95% CI range 0.63-0.92, P = 0.006). In addition, compared to the control group, LLLT brought forward "the most painful day" (MD = -0.42, 95% CI range -0.74- -0.10, P = 0.009). Furthermore, the LLLT group also implied a trend of earlier end of pain compared with the control group (MD = -1.37, 95% CI range -3.37-0.64, P = 0.18) and the pseudo-laser group (MD = -1.04, 95% CI range -4.22-2.15, P = 0.52). However, because of the methodological shortcomings and risk of bias of included trials, LLLT was proved with limited evidence in delaying pain onset and reducing pain intensity. In the future, larger and better-designed RCTs will be required to provide clearer recommendations.

[The influence of zinc on apoptosis and cell proliferation in palatal shelves during the fusion phase in mice and identification of a special protein family based on gene expression in cleft palate].

Objective: To investigate the effect of the trace element zinc (Zn) on apoptosis and cell proliferation in palate shelvesduring the fusion phase, and to screen candidate genes of the Zn-finger special protein (Sp) family that were differentially expressed between the cleft palate and the normal palate to explore the mechanism of Zn in the development of cleft palate. Methods: Zn-rich, normal-Zn, low-Zn, and Zn-deficient diets were fed to female mice and, for the resultant fetuses, paraffin slices of their heads were made at embryonicdays 14.5 and 16.5. Using terminaldeoxynucleotidyltransferase-mediated dUTP nick-end labeling, the number of apoptotic cells in the palatal shelves was counted, and cell proliferation activity was detected using proliferating cell nuclear antigen staining. Total RNA from the palatal shelves of fetal mice was extracted from the Zn-rich diet, normal Zn-diet, and Zn-deficient-diet groups. We used microarray analysis to examine the expression of genes to identify intergroup differential gene expression and polymerase chain reaction tests to validate the results. Results: At ED14.5, the incidence of cleft palate in the regular zinc group, zinc rich group, low zinc group, and zinc deficient group was 8% (3/36), 2% (1/39), 29% (12/41), and 39% (15/38), respectively. The HE staining results at ED14.5 showed that both the left and right palatal processes in the zinc group had been lifted up and were in contact and connected with each other. In the zinc deficiency group, the left and right palatine processes remained vertically downwards on both sides of the tongue, ultimately forming cleft palate; In the low zinc group, the left and right palatine processes were raised but not in contact, ultimately resulting in cleft palate. There is no significant difference between the zinc rich group and the regular zinc group. At ED14.5, the positive rates of proliferative cells in the palatal process of fetal mice in the regular zinc group (80.29% ± 7.39%) and the zinc rich group (87.69% ± 6.62%) were significantly higher than those in the zinc deficient group (56.05% ± 16.13%) and the low zinc group (56.22% ± 9.61%) (t=4.32, P<0.05). The apoptosis index of fetal rat palatal process cells in the zinc deficient group (38.80% ± 3.10%) and the low zinc group (28.80% ± 6.19%) were significantly higher than those in the regular zinc group (16.80% ± 1.82%) (t=19.35, P<0.001; t=5.81, P<0.001). There were 663 differentially expressed genes in the zinc rich group and the zinc deficient group, with 513 up-regulated genes and 150 down-regulated genes, among which Sp5 was found to be located. The real time PCR results showed that compared with the regular zinc group (2.22 ± 0.36), the expression level of Sp5mRNA in the palatal process tissue of the zinc deficient group (1.23 ± 0.38) significantly increased (P<0.05), while the zinc rich group (3.68 ± 0.90) significantly decreased (P<0.05). Conclusions: Trace element Zn content was found to be closely related to the occurrence of cleft palate in mice offspring, with a lack of Zn leading to cleft palate.

[New advances in vital pulp therapy and pulp regeneration for the treatment of pulpitis: from basic to clinical application].

In recent years, great progress has been made in research on the treatment of pulpitis, mainly due to the rapid development of basic and clinical researches in this field, and some achievement from basic research has been applied in clinical practice. Advances in the diagnostic methods for pulpitis can help the clinicians to recognize the true state of pulpitis more accurately and to adopt the corresponding treatment methods including indirect/direct pulp capping, pulpotomy, pulp regeneration and root canal therapy. The new theory of pulpitis diagnosis and the studies on immune defense, repair function of dental pulp and new pulp capping materials have significantly improved the success rate of vital pulp therapy. For diffuse coronary pulpitis or radicular pulpitis, which is difficult to achieve vital pulp therapy successfully, methods of pulp revascularization, cell homing and pulp stem cells-mediated pulp regeneration can also be used as treatment options in addition to root canal therapy. The present article focuses on the research progress on pulpitis treatments and related clinical transformation practices, in order to provide reference on vital pulp therapy and pulp regeneration for clinicians.