The objective of this study was to determine the effect of zoledronic acid on mandibular bone quality in osteoporotic model mice. Zoledronic acid was administered to ovariectomized mice, and mandibular bone was harvested. Polished specimens were prepared, and the biological apatite (BAp) crystal alignment and changes in collagen fiber bundles in the alveolar and basal regions of the mandible were analyzed. It was found that ovariectomy increased BAp crystal alignment. The administration of zoledronic acid post-ovariectomy normalized BAp crystal alignment in the basal region of the mandible. However, BAp crystal alignment in the alveolar region decreased significantly. Ovariectomy decreased the diameters of collagen fiber bundles in both the alveolar and basal regions and significantly increased their lengths. The administration of zoledronic acid post-ovariectomy decreased both the diameters and lengths of collagen fiber bundles. These results showed that the microarchitecture of the mandibular bone changes to compensate for osteoporosis-induced loss of bone mass and adapts to the load environment resulting from mastication. Interestingly, they suggested that zoledronic acid severely reduces the bone quality of osteoporotic alveolar bone in a site-specific manner.

Periodontitis, a chronic oral inflammatory disease, induces progressive damage to periodontal ligament and leads to tooth loss. Proviral insertion in murine lymphomas 2 (PIM2) promotes activation of NF-κB signaling, and functions as negative regulator of osteoblastogenesis. However, the role of PIM2 in periodontitis remains elusive. Firstly, cell model of periodontitis was established through incubating human periodontal ligament cells (PDLCs) with lipopolysaccharide. Lipopolysaccharide treatment decreased cell viability of PDLCs, promoted the cell apoptosis and enhanced the production of TNF-α, IL-8, and IL-6. Secondly, PIM2 expression was up-regulated in gingival tissues of patients with chronic periodontitis and lipopolysaccharide-treated PDLCs. Knockdown of PIM2 enhanced cell viability of lipopolysaccharide-treated PDLCs, and suppressed the cell apoptosis. Moreover, silence of PIM2 attenuated lipopolysaccharide-induced increase of TNF-α, IL-8, and IL-6 in PDLCs. Thirdly, the downregulated protein expression of collagen type I alpha 1 (COL1A1), osteopontin (OPN), and runt-related transcription factor 2 (RUNX2) was increased by knockdown of PIM2 in lipopolysaccharide-treated PDLCs was. Lastly, interference of PIM2 up-regulated phosphorylation of AMP-activated protein kinase (AMPK), while down-regulated phosphorylation of p65 in lipopolysaccharide-treated PDLCs. In conclusion, knockdown of PIM2 exerted anti-apoptotic and anti-inflammatory effects against lipopolysaccharide-treated PDLCs, promoted the osteogenic differentiation through activation of AMPK signaling and inactivation of NF-κB signaling.

Surface modifications of implants can improve the rate of osseointegration. The aim of this study was to determine the effect of super-hydrophilic modification on tetragonal zirconia polycrystals (TZP) implant surface and its subsequent effect on the rate of osseointegration. The TZP implants were rendered super-hydrophilic by the use of ultraviolet light (UV) or via atmospheric-pressure plasma treatments (PL), on their surface and were compared to control specimen that any surface modification wasn’t performed (NC). According to the surface wettability and x-ray photoelectron spectroscopy (XPS) analysis, the contact angle of water droplets on the surface of UV and PL was 0 degree, and their C1s peak was less than that of NC. The push-in test and histological analysis revealed that the super-hydrophilic modification enhanced the bone-implant integration and the formation of new bone around the TZP implants. Additionally, carbon removal and surface wettability enhancement likely improved the osseointegration rate. The study, therefore, demonstrates the design of future TZP implants, particularly for dental applications.

Multiple experimental pieces of evidence have confirmed that fully understanding the regulatory mechanisms of osteogenic differentiation of periodontal ligament stem cells (PDLSCs) can better promote and improve the ability of periodontal tissues to regenerate and alleviate periodontal diseases. This study aimed to reveal whether the long noncoding RNA (lncRNA) ZNF710-AS1 plays a role in the osteogenic differentiation of PDLSCs and its molecular mechanisms. Microarray datasets GSE159507 and GSE159508 were retrieved from the Gene Expression Omnibus database and differentially expressed genes were identified using R language (limma package). The results revealed that the expression of ZNF710-AS1 and bone morphogenetic protein 6 (BMP6) was upregulated whereas that of miR-146a-5p/miR-146b-5p was downregulated during the osteogenic differentiation of PDLSCs. PDLSCs were successfully isolated and cultured in vitro. Osteogenic and adipogenic differentiation abilities were evaluated by performing alizarin red staining and oil red O staining, respectively. Overexpression of ZNF710-AS1 significantly increased the osteogenic differentiation ability of PDLSCs by upregulating the expression of BMP6 and phosphorylation-SMAD family member 1/5/9 (p-Smad1/5/9) and competitively sponging miR-146a-5p/miR-146b-5p and acting as a competing endogenous RNA (ceRNA). This study demonstrated that ZNF710-AS1 promotes the osteogenic differentiation of PDLSCs by upregulating BMP6/Smad1/5/9 expression and acting as a ceRNA for miR-146a-5p and miR-146b-5p.

We investigated the anti-inflammatory effect of hydroxyethyl starch (HES) 6% 200/0.5 on lipopolysaccharide (LPS)-induced RAW264.7 cells based on the high mobility group protein B1/nuclear transcription factor-κB (HMGB1/NF-κB) signaling pathway. The mouse monocyte macrophage RAW264.7 cells were divided into control group (no additional treatment), LPS group (0.2 pg/ml LPS), LPS+HES group (0.2 pg/ml LPS+6% HES) and LPS+TAK-242 (HMGB1/NF-κB signal pathway blocker) group (0.2 pg/ml LPS The LPS+HES+TAK-242 group (0.2 pg/ml LPS+6% HES+1 μ mol/l TAK-242) was cultured for 48 hours. Griess method and ELISA were used to detect the levels of nitric oxide (NO), tumor necrosis factor α (TNF-α), interleukin (IL)-6 and IL-1β in cell supernatant. The level of intracellular reactive oxygen species (ROS) was detected by flow cytometry. The mitochondrial membrane potential was detected by immunofluorescence. The mRNA expressions of inducible nitric oxide synthase (iNOS), HMGB1, Toll-like receptor 4 (TLR4), nuclear factor-κ b inhibitory protein α (IκBα) and NF-κB were detected by qRT-PCR. The expressions of HMGB1, TLR4, IκBα, phosphorylated IκBα (p-IκBα), NF-κB and phosphorylated NF-κB (p-NF-κB) were detected by western blotting. Compared with the control group, the expression levels of NO, TNF-α, IL-6, IL-1β, ROS, iNOS, HMGB1, TLR4, NF-κB mRNA, HMGB1, TLR4 and p-NF-κB proteins in the LPS group, LPS+HES group, LPS+TAK-242 group and LPS+HES+TAK-242 group increased (P<0.05), the expression levels of mitochondrial membrane potential, IκBα mRNA and p-IκBα protein decreased (P<0.05). Compared with LPS group, the expression levels of NO, TNF-α, IL-6, IL-1β, ROS, iNOS, HMGB1, TLR4, NF-κB mRNA, HMGB1, TLR4 and p-NF-κB proteins in the LPS+HES group, LPS+TAK-242 group and LPS+HES+TAK-242 group increased (P<0.05), the expression levels of mitochondrial membrane potential, IκBα mRNA and p-IκBα protein decreased (P<0.05). The expression levels of mitochondrial membrane potential, IκBα mRNA and p-IκBα protein increased (P<0.05). Six % HES 200/0.5 could down-regulate the expression of molecules related to HMGB1/NF-кB signaling pathway, and reduce the inflammatory response of RAW264.7 cells induced by LPS.

Bone morphogenetic protein (BMP) is the only cytokine that induces heterotopic new bone. BMP has been classified as a subfamily of the TGF superfamily. The most important and essential aspect for the clinical application of BMP is the replenishment and reinforcement of bone defects and fragile areas with new bone. However, it is difficult to ascertain long term clinical results. In this study, we examined the osteogenic potential in mouse femoral fascia of crude BMP extracted from bovine bone that had been stored at room temperature for 25 years. The results showed vigorous osteogenesis. This study demonstrates the long-term stability of crude BMP.

We aimed to explore the effects of microRNA 21 (miR-21) downregulation on the expression of RECK and the proliferation and metastasis of oral squamous cell carcinoma (OSCC) cells. Sixty-five tumor tissue (TT) and corresponding paracancerous tissue (PT) specimens were excised from patients with OSCC. The mRNA levels of miR-21 and RECK in TTs and PTs were determined using qPCR. To assess the effects of miR-21-mediated modulation of RECK expression on tumor behavior, the OSCC cell line CAL-27 was transfected with miR-21 mimic, miR-21 inhibitor, or negative control (miR-NC). Compared with PTs, TTs showed increased levels of miR-21 and decreased mRNA and protein levels of RECK. Compared with CAL-27 cells transfected with miR-NC, those transfected with miR-21 inhibitor had upregulated RECK mRNA and protein expression, whereas those transfected with miR-21 mimic had downregulated RECK expression. After 48–72 h of transfection, the miR-21 mimic group exhibited higher cell proliferation rate than other groups. miR-21 was upregulated and RECK expression was downregulated in OSCC. The downregulation of miR-21 upregulates RECK expression via disinhibition, thereby suppressing the proliferation and migration and accelerating the apoptosis of OSCC cells. Thus, the downregulation of miR-21 may be an effective strategy against OSCC.

Fracture healing is a complex dynamic process that involves the balance between osteoblasts and osteoclasts. Several microRNAs (miRNAs) have been shown to participate in fracture healing. In this study, we investigated the role of miR-324-3p in osteoblast differentiation. MC3T3-E1 cell differentiation was induced by icariin, and miR-324-3p expression levels during cell differentiation were measured using qRT-PCR. Cell proliferation and differentiation were assessed to evaluate the function of miR-324-3p. Luciferase activity was used for target gene verification. During MC3T3-E1 differentiation, miR-324-3p levels gradually increased over time. Further experiments showed that miR-324-3p overexpression significantly promoted cell viability, whereas miR-324-3p downregulation showed the opposite effect. For cells with miR-324-3p mimic, the levels of bone sialoprotein, Runx2, osteocalcin, and alkaline phosphatase activity were significantly elevated. SMAD7 is the target gene of miR-324-3p, and its level is gradually downregulated during MC3T3-E1 cell differentiation. MiR-324-3p may promote MC3T3-E1 cell differentiation by targeting SMAD7.