Expression profile of lipoxygenases in gingival tissues of human periodontitis.

OBJECTIVES: This study aimed to clarify the expression profile and significance of lipoxygenases in periodontitis. MATERIALS AND METHODS: The mRNA levels of lipoxygenases in gingival tissues from 14 patients with periodontitis and 14 healthy individuals were determined by real-time PCR, and validated in datasets, GSE16134 and GSE10334, and by Western blotting. Correlation of differentially expressed lipoxygenases with clinical parameters and expression of tumor necrosis factor-α (TNF-α), interleukin-1ß, matrix metalloproteinase (MMP)-8, MMP-9, and receptor activator of nuclear factor-κB ligand (RANKL) was investigated in patients with periodontitis by Spearman's correlation analysis. RESULTS: The expression of ALOX5 (2.1-fold, p < .05), ALOX12B (2.9-fold, p < .001), and ALOX15B (9.4-fold, p < .001) was upregulated in gingival tissues from patients with periodontitis, which was validated by dataset analysis and Western blotting. Positive correlations were observed between ALOX5 and probing depth, and ALOX15B and probing depth and clinical attachment loss. Furthermore, ALOX5 expression was positively correlated with TNF-α, MMP-8, MMP-9, and RANKL expression, and ALOX15B was positively correlated with MMP-8 and RANKL. CONCLUSIONS: Our findings indicated the upregulation of ALOX5 and ALOX15B in periodontitis and suggested that ALOX5 and ALOX15B may be involved in periodontitis pathogenesis, including inflammation, connective tissue destruction, and abnormal bone metabolism.

Supercritical CO2 foamed composite scaffolds incorporating bioactive lipids promote vascularized bone regeneration via Hif-1α upregulation and enhanced type H vessel formation.

Bone tissue engineering has substantial potential for the treatment of massive bone defects; however, efficient vascularization coupled with bone regeneration still remains a challenge in this field. In the current study, supercritical carbon dioxide (scCO2) foaming technique was adopted to fabricate mesoporous bioactive glasses (MBGs) particle-poly (lactic-co-glycolic acid) (PLGA) composite scaffolds with appropriate mechanical and degradation properties as well as in vitro bioactivity. The MBG-PLGA scaffolds incorporating the bioactive lipid FTY720 (designated as FTY/MBG-PLGA) exhibited simultaneously sustained release of the bioactive lipid and ions. In addition to providing a favorable microenvironment for cellular adhesion and proliferation, FTY/MBG-PLGA scaffolds significantly facilitated the in vitro osteogenic differentiation of rBMSCs and also markedly stimulated the upregulation of Hif-1α expression via the activation of the Erk1/2 pathway, which mediated the osteogenic and pro-angiogenic effects on rBMSCs. Furthermore, FTY/MBG-PLGA extracts induced superior in vitro angiogenic performance of HUVECs. In vivo evaluation of critical-sized rat calvarial bone defects indicated that FTY/MBG-PLGA scaffolds potently promoted vascularized bone regeneration. Notably, the significantly enhanced formation of type H vessels (CD31hiEmcnhi neo-vessels) was observed in newly formed bone tissue in FTY/MBG-PLGA group, strongly suggesting that FTY720 and therapeutic ions released from the scaffolds synergistically induced more type H vessel formation, which indicated the coupling of angiogenesis and osteogenesis to achieve efficiently vascularized bone regeneration. Overall, the results indicated that the foamed porous MBG-PLGA scaffolds incorporating bioactive lipids achieved desirable vascularization-coupled bone formation and could be a promising strategy for bone regenerative medicine. STATEMENT OF SIGNIFICANCE: Efficacious coupling of vascularizationandbone formation is critical for the restoration of large bone defects. Anoveltechnique was used to fabricate composite scaffolds incorporating bioactive lipids which possessedsynergistic cues of bioactive lipids and therapeutic ions to potently promotebone regenerationas well as vascularization. The underlying molecular mechanism for the osteogenic and pro-angiogenic effects of the compositescaffolds was unveiled. Interestingly, the scaffolds were furtherfoundto enhance the formation oftype H capillarieswithin the bone healing microenvironment to couple angiogenesis to osteogenesis to achieve satisfyingvascularizedbone regeneration.These findings provide a novel strategy to develop efficiently vascularized engineering constructs to treat massive bone defects.

Exosomal miR-196a derived from cancer-associated fibroblasts confers cisplatin resistance in head and neck cancer through targeting CDKN1B and ING5.

BACKGROUND: Cisplatin resistance is a major challenge for advanced head and neck cancer (HNC). Understanding the underlying mechanisms and developing effective strategies against cisplatin resistance are highly desired in the clinic. However, how tumor stroma modulates HNC growth and chemoresistance is unclear. RESULTS: We show that cancer-associated fibroblasts (CAFs) are intrinsically resistant to cisplatin and have an active role in regulating HNC cell survival and proliferation by delivering functional miR-196a from CAFs to tumor cells via exosomes. Exosomal miR-196a then binds novel targets, CDKN1B and ING5, to endow HNC cells with cisplatin resistance. Exosome or exosomal miR-196a depletion from CAFs functionally restored HNC cisplatin sensitivity. Importantly, we found that miR-196a packaging into CAF-derived exosomes might be mediated by heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1). Moreover, we also found that high levels of plasma exosomal miR-196a are clinically correlated with poor overall survival and chemoresistance. CONCLUSIONS: The present study finds that CAF-derived exosomal miR-196a confers cisplatin resistance in HNC by targeting CDKN1B and ING5, indicating miR-196a may serve as a promising predictor of and potential therapeutic target for cisplatin resistance in HNC.

Evaluation of highly carbonated hydroxyapatite bioceramic implant coatings with hierarchical micro-/nanorod topography optimized for osseointegration.

BACKGROUND: Optimal osseointegration has been recognized as a pivotal factor in determining the long-term success of biomedical implants. MATERIALS AND METHODS: In the current study, highly carbonated hydroxyapatite (CHA) with carbonate contents of 8, 12 and 16 wt% and pure hydroxyapatite (HA) were fabricated via a novel hydrothermal method and deposited on the titanium substrates to generate corresponding CHA bioceramic coatings (designated as C8, C12 and C16, respectively) and HA bioceramic coatings (designated as C0). RESULTS: C8, C12 and C16 were endowed with nanoscale, hierarchical hybrid micro-/nanoscale and microscale surface topographies with rod-like superstructures, respectively. Compared with C0, the micro-/nanotextured CHA bioceramic coatings (C8, C12 and C16) possessed excellent surface bioactivity and biocompatibility, as well as better wettability, which mediated improved protein adsorption, giving rise to simultaneous enhancement of a biological cascade of events of rat bone-marrow-derived mesenchymal stem cells including cell adhesion, proliferation, osteogenic differentiation and, notably, the production of the pro-angiogenic growth factor, vascular endothelial growth factor-A. In particular, C12 with biomimetic hierarchical hybrid micro-/nanorod topography exhibited superior fractal property and predominant performance of protein adsorption, cell adhesion, proliferation and osteogenesis concomitant with angiogenesis. CONCLUSION: All these results suggest that the 12 wt% CHA bioceramic coating with synergistic modification of surface chemistry and topography has great prospect for future use as implant coating to achieve optimum osseointegration for orthopedic and dental applications.

Microstructures, mechanical, and biological properties of a novel Ti-6V-4V/zinc surface nanocomposite prepared by friction stir processing.

BACKGROUND: The interaction between the material and the organism affects the survival rate of the orthopedic or dental implant in vivo. Friction stir processing (FSP) is considered a new solid-state processing technology for surface modification. PURPOSE: This study aims to strengthen the surface mechanical properties and promote the osteogenic capacity of the biomaterial by constructing a Ti-6Al-4V (TC4)/zinc (Zn) surface nanocomposites through FSP. METHODS: FSP was used to modify the surface of TC4. The microstructures and mechanical properties were analyzed by scanning electron microscopy, transmission electron microscopy, nanoindentation and Vickers hardness. The biological properties of the modified surface were evaluated by the in vitro and in vivo study. RESULTS: The results showed that nanocrystalline and numerous ß regions, grain boundary α phase, coarser acicular α phase and finer acicular martensite α' appeared because of the severe plastic deformation caused by FSP, resulting in a decreased elastic modulus and an increased surface hardness. With the addition of Zn particles and the enhancement of hydrophilicity, the biocompatibility was greatly improved in terms of cell adhesion and proliferation. The in vitro osteogenic differentiation of rat bone marrow stromal cells and rapid in vivo osseointegration were enhanced on the novel TC4/Zn metal matrix nanocomposite surface. CONCLUSION: These findings suggest that this novel TC4/Zn surface nanocomposite achieved by FSP has significantly improved mechanical properties and biocompatibility, in addition to promoting osseointegration and thus has potential for dental and orthopedic applications.

Long noncoding RNA PANDAR blocks CDKN1A gene transcription by competitive interaction with p53 protein in gastric cancer.

Emerging evidence indicates that lncRNAs play important roles in cancer tumourigenesis and could be used as potential diagnostic biomarkers or therapeutic targets. However, the clinical significance and molecular mechanism of lncRNAs in gastric cancer (GC) is still unclear. The aim of this study was to explore the expression and role of lncRNAs in GC. The relative expression level of lncRNAs in GC samples was examined by an lncRNA microarray analysis, northern blot analysis and qRT-PCR analysis. A Kaplan-Meier survival analysis and univariate and multivariate Cox proportional hazards models were performed to evaluate the clinical and prognostic significance of PANDAR (promoter of CDKN1A antisense DNA damage activated RNA) in GC patients. The binding activity of PANDAR with the p53 protein was analysed by an RNA immunoprecipitation analysis and RNA pull-down analysis. The depletion of PANDAR was conducted using the CRISPR/Cas9 system for PANDAR. The biological functions of PANDAR in GC cells were determined both in vitro and in vivo. Upregulated PANDAR in GC patients was positively correlated with increased tumour size, advanced TNM classification and a poor survival rate in GC patients. The ROC curves identified that the PANDAR level was a marker for discriminating the early-stage tumour group from the healthy group, the metastasis group from the non-metastasis group and the chemoresistance group from the chemosensitive group in GC patients. As a target, the CDKN1A gene was successfully downregulated by PANDAR. PANDAR controlled the transcription of the CDKN1A gene by competitively binding with p53 protein. In combination with a p53 activator (nutlin3), the knockout of PANDAR by CRISPR/Cas9 technology synergistically inhibited GC tumour growth in vivo. Our results suggest that the PANDAR is a powerful diagnostic and therapeutic marker for patients with GC and, combined with other chemotherapeutics, may have distinct antitumour effects.

Plumbagin suppresses chronic periodontitis in rats via down-regulation of TNF-α, IL-1ß and IL-6 expression.

Chronic periodontitis (CP) is one of the most common oral diseases, which causes alveolar bone absorption and tooth loss in adults. In this study we aimed to investigate the potential of plumbagin (PL), a widely-investigated active compound extracted from the traditional Chinese herb Plumbago zeylanica L in treating CP. Human periodontal ligament stem cells (PDLSCs) were used for in vitro studies, whereas an animal model of CP was established in SD rats by ligation+Porphyromonas gingivalis (Pg) stimulation. The rats were injected with PL (2, 4, and 6 mg·kg-1·d-1, ip) for 4 weeks. Treatment of PDLSCs with TNF-α (10 ng/mL) markedly stimulated the expression of the proinflammatory cytokines TNF-α, IL-1ß and IL-6, as well as the chemokines CCL-2 and CCL-5, which were dose-dependently suppressed by co-treatment with PL (1.25-5 µmol/L). Furthermore, PL (3.75 µmol/L) markedly suppressed TNF-α-induced activation of the MAPK, NF-κB and JAK/STAT signaling pathways in PDLSCs. In consistence with the in vitro studies, PL administration significantly decreased the expression of TNF-α, IL-1ß and IL-6 in gingiva of the rat with CP, with the dosage 4 mg·kg-1·d-1 showing the best anti-inflammatory effect. Moreover, PL administration decelerated bone destruction in the rat with CP, evidenced by the aveolar bone loss (ABL) and H&E staining results. In conclusion, PL suppresses CP progression in rats by downregulating the expressions of TNF-α, IL-1ß and IL-6 and inhibiting the MAPK, NF-κB and JAK/STAT signaling pathways.

Effects of oestrogen deficiency on the alveolar bone of rats with experimental periodontitis.

Periodontitis is an inflammatory disease characterized by loss of connective tissue and alveolar bone, and osteoporosis is a common disease characterized by a systemic impairment of bone mass and microarchitecture. To date, the association between periodontitis and osteoporosis has remained to be fully elucidated. In the present study, an experimental rat model of periodontitis was used to explore the effects of oestrogen deficiency­induced osteoporosis on the maxillary alveolar bone. Forty­four female, six­month­old Sprague­Dawley rats were randomly divided into four groups: Control, ligature, ovariectomized (OVX), and OVX + ligature. One month after ovariectomy, rats in the ligature and OVX + ligature groups received ligatures on their first and second maxillary molars for 1 month. Fluorescent labelling was performed prior to sacrificing the animals. At the end of the experiment, the maxillae and serum were collected and subjected to micro­computed tomography analysis, confocal laser­scanning microscopic observation, Van Gieson's fuchsin staining, tartrate­resistant acid phosphatase staining and ELISA. Ligatures slightly reduced the alveolar bone mineral density (BMD) and bone formation rate, but significantly reduced alveolar crest height (ACH). Ovariectomy reduced the alveolar BMD, impaired the trabecular structure, reduced the bone formation rate and increased the serum levels of bone resorption markers. Animals in the OVX + ligature group exhibited a lower alveolar BMD, a poorer trabecular structure, a reduced ACH, a lower bone formation rate and higher serum levels of bone resorption markers compared with those in the control group. The results of the present study showed that ovariectomy enhanced alveolar bone loss and reduced the ACH of rats with experimental periodontitis. Thus, post­menopausal osteoporosis may influence the progression of periodontitis.

Sclerostin antibody treatment causes greater alveolar crest height and bone mass in an ovariectomized rat model of localized periodontitis.

INTRODUCTION: Periodontitis and osteoporosis are bone destructive diseases with a high prevalence in the adult population. The concomitant presence of osteoporosis may be a risk factor of progression of periodontal destruction. We studied the effect of sclerostin-neutralizing monoclonal antibody (Scl-Ab) on alveolar bone endpoints in an ovariectomized (OVX) rat model of induced experimental periodontitis. METHODS: Sixty female, 4-month-old Sprague-Dawley rats underwent sham operation or bilateral OVX and were left untreated for 2 months. Experimental periodontitis (ligature) was established by placing silk sutures subgingival to the right maxillary first and second molar teeth for 4 weeks, and feeding the rats food and high-sugar drinking water during this period. Thereafter, ligatures were removed and 25mg/kg vehicle or Scl-Ab was administered subcutaneously twice weekly for 6 weeks. Rats were randomized into four groups: (1) Control (Sham+Vehicle), (2) Sham+Ligature+Vehicle, (3) OVX+Ligature+Vehicle, and (4) OVX + Ligature + Scl-Ab. Terminal blood and right maxilla specimens were collected for analyses. RESULTS: Group 3 rats showed lower bone volume fraction (BVF) of alveolar bone with higher bone resorption and lower bone formation than Group 2 rats. Group 4 rats had higher alveolar crest height, as assessed by linear distance of cementoenamel junction to the alveolar bone crest and greater alveolar bone mass using Micro CT, than Group 3 rats. Significantly higher values of mineral apposition rate (MAR) and mineralizing surface/bone surface (MS/BS) were also observed in Group 4 rats by analyzing polychrome sequential labeling data. Increased serum osteocalcin and osteoprotegerin, and deceased serum tartrate-resistant acid phosphatase and CTx-1 illustrate the ability of Scl-Ab to increase alveolar bone mass by enhancing bone formation and decreasing bone resorption in an animal model of estrogen deficiency osteopenia plus periodontitis. CONCLUSION: Scl-Ab could be a potential bone anabolic agent for improving alveolar crest height and higher alveolar bone mass in conditions where alveolar bone loss in periodontitis is compounded by estrogen deficiency osteopenia.

Endoscopic lift of the maxillary sinus floor in Beagles.

The aim of this study was to introduce a modified endoscopic lift of the floor of the maxillary sinus in Beagles. Twelve operations (bilateral and randomly chosen) were done in 6 Beagles each in the test group (modified endoscopic operation), and the control group, in which the operation was done with an osteotome. All operations were evaluated by two indices of safety (perforation of the sinus membrane and nasal bleeding) and 3 effective indices (the intraoperative height after lifting, volume of bone grafts, and dislocation of the sinus grafts). The sinus membrane was not perforated and there were no nasal bleeds in either group. The intraoperative height after lifting was 13.7 (0.8) mm in the test group and 9.1 (0.5) mm in the control group, so it was significantly higher in the test group than the control group (p=0.0001). Similarly, the volume of bone graft was 0.9 (0.04) ml in the test group and 0.5 (0.02) ml in the control group (p=0.0001). The volume of the anterior and posterior bone grafts in the implant cavity in the test group did not differ significantly (p=0.102), while there were significant differences in the control group (p=0.002). Endoscopic lifting of the floor of the maxillary sinus is a safe and effective approach based on direct observation in Beagles.

Systematic modification and evaluation of a canine model for elevation of the floor of the maxillary sinus.

We have modified a canine model for raising the floor of the maxillary sinus by selecting a new surgical approach, and have evaluated the model with computed tomographic (CT) scans and endoscopy. Preoperative CT scans were taken of two beagle cadavers and four healthy, live beagles. The CT data were entered into Simplant software to select a candidate site for a surgical incision located between the first molar and the greater palatine foramen. All animals had the floor of the maxillary sinus raised from the candidate site. During the operation an endoscope was put outside the candidate site and into the maxillary sinus through a lateral puncture to record the condition of the Schneiderian membrane and the position of the candidate site. Postoperative CT scans were used to measure the position of the site, and the positions were compared. Eleven variables were measured on the coronal and sagittal sections. The two most important variables were the mean (SD) horizontal distance from the candidate site to the palatal alveolar ridge (8.1 (0.9)mm) and the residual bone height (2.0 (0.4)mm). There were no significant differences in the anteroposterior or internal-external position of the candidate site. Intraoperative endoscopic views showed the intact, white, and opaque membrane from the candidate site, and the movement of the membrane in the middle of the sinus floor from the lateral puncture. The candidate site is therefore an ideal surgical approach for raising the floor of the maxillary sinus, and the canine model is suitable for research in this area.

Smoking, radiotherapy, diabetes and osteoporosis as risk factors for dental implant failure: a meta-analysis.

BACKGROUND: There are conflicting reports as to the association between smoking, radiotherapy, diabetes and osteoporosis and the risk of dental implant failure. We undertook a meta-analysis to evaluate the association between smoking, radiotherapy, diabetes and osteoporosis and the risk of dental implant failure. METHODS: A comprehensive research on MEDLINE and EMBASE, up to January 2013, was conducted to identify potential studies. References of relevant studies were also searched. Screening, data extraction and quality assessment were conducted independently and in duplicate. A random-effects meta-analysis was used to pool estimates of relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: A total of 51 studies were identified in this meta-analysis, with more than 40,000 dental implants placed under risk-threatening conditions. The pooled RRs showed a direct association between smoking (n = 33; RR = 1.92; 95% CI, 1.67-2.21) and radiotherapy (n = 16; RR = 2.28; 95% CI, 1.49-3.51) and the risk of dental implant failure, whereas no inverse impact of diabetes (n = 5; RR = 0.90; 95% CI, 0.62-1.32) on the risk of dental implant failure was found. The influence of osteoporosis on the risk of dental implant failure was direct but not significant (n = 4; RR = 1.09; 95% CI, 0.79-1.52). The subgroup analysis indicated no influence of study design, geographical location, length of follow-up, sample size, or mean age of recruited patients. CONCLUSIONS: Smoking and radiotherapy were associated with an increased risk of dental implant failure. The relationship between diabetes and osteoporosis and the risk of implant failure warrant further study.

A comparative study of dog models for osteotome sinus floor elevation and dental implants in posterior maxilla subjacent to the maxillary sinus.

OBJECTIVE: The objective of this study was to investigate the suitability of beagles and Labrador retrievers as animal models for osteotome sinus floor elevation (OSFE) and dental implants in posterior maxilla subjacent to sinus. STUDY DESIGN: Ten beagles and 8 Labrador retrievers were included. Their posterior maxillas subjacent to the sinus were studied by a gross survey, CT scan, and histologic analysis. RESULTS: In the posterior maxilla subjacent to sinus, the bone height was significantly higher for Labrador retrievers than for beagles (P < .05). There was no significant difference in sinus size from the coronal section and its location from the sagittal section (P > .05) between Labrador retrievers and beagles. CONCLUSIONS: As an animal model, the Labrador is more suitable for OSFE and dental implants in posterior maxilla subjacent to sinus. The midpoint of the maxillary fourth premolar is an ideal site for implantation.