Construction of Zwitterionic Coatings with Lubricating and Antiadhesive Properties for Invisible Aligner Applications.

Invisible aligners have been widely used in orthodontic treatment but still present issues with plaque formation and oral mucosa abrasion, which can lead to complicated oral diseases. To address these issues, hydrophilic poly(sulfobetaine methacrylate) (polySBMA) coatings with lubricating, antifouling, and antiadhesive properties have been developed on the aligner materials (i.e., polyethylene terephthalate glycol, PETG) via a simple and feasible glycidyl methacrylate (GMA)-assisted coating strategy. Poly(GMA-co-SBMA) is grafted onto the aminated PETG surface via the ring-opening reaction of GMA (i.e., "grafting to" approach to obtain G-co-S coating), or a polySBMA layer is formed on the GMA-grafted PETG surface via free radical polymerization (i.e., "grafting from" approach to obtain G-g-S coating). The G-co-S and G-g-S coatings significantly reduce the friction coefficient of PETG surface. Protein adsorption, bacterial adhesion, and biofilm formation on the G-co-S- and G-g-S-coated surfaces are significantly inhibited. The performance of the coatings remains stable after storage in air or artificial saliva for 2 weeks. Both coatings demonstrate good biocompatibility in vitro and is not caused irritation to the oral mucosa of rats in vivo over 2 weeks. This study proposes a promising strategy for the development of invisible aligners with improved performance, which is beneficial for oral health treatment.

Mild hyperthermia enhanced synergistic uric acid degradation and multiple ROS elimination for an effective acute gout therapy.

BACKGROUND: Acute gouty is caused by the excessive accumulation of Monosodium Urate (MSU) crystals within various parts of the body, which leads to a deterioration of the local microenvironment. This degradation is marked by elevated levels of uric acid (UA), increased reactive oxygen species (ROS) production, hypoxic conditions, an upsurge in pro-inflammatory mediators, and mitochondrial dysfunction. RESULTS: In this study, we developed a multifunctional nanoparticle of polydopamine-platinum (PDA@Pt) to combat acute gout by leveraging mild hyperthermia to synergistically enhance UA degradation and anti-inflammatory effect. Herein, PDA acts as a foundational template that facilitates the growth of a Pt shell on the surface of its nanospheres, leading to the formation of the PDA@Pt nanomedicine. Within this therapeutic agent, the Pt nanoparticle catalyzes the decomposition of UA and actively breaks down endogenous hydrogen peroxide (H2O2) to produce O2, which helps to alleviate hypoxic conditions. Concurrently, the PDA component possesses exceptional capacity for ROS scavenging. Most significantly, Both PDA and Pt shell exhibit absorption in the Near-Infrared-II (NIR-II) region, which not only endow PDA@Pt with superior photothermal conversion efficiency for effective photothermal therapy (PTT) but also substantially enhances the nanomedicine's capacity for UA degradation, O2 production and ROS scavenging enzymatic activities. This photothermally-enhanced approach effectively facilitates the repair of mitochondrial damage and downregulates the NF-κB signaling pathway to inhibit the expression of pro-inflammatory cytokines. CONCLUSIONS: The multifunctional nanomedicine PDA@Pt exhibits exceptional efficacy in UA reduction and anti-inflammatory effects, presenting a promising potential therapeutic strategy for the management of acute gout.

The complex of tannic acid and cetylpyridinium chloride: An antibacterial and stain-removal cleaner for aligners.

INTRODUCTION: Effective aligner hygiene is recognized as an important part of orthodontic treatments and oral hygiene. However, there is no effective cleansing method for removable aligners. METHODS: In this study, we incorporated tannic acid (TA) with cetylpyridinium chloride (CPC) to develop the TA-CPC complex. The antibacterial properties of 15.8 mg/mL TA-CPC against Escherichia coli and Staphylococcus aureus were evaluated in vitro, which were compared with 5.1 mg/mL TA, 10.7 mg/mL CPC, a commercial denture cleansing solution (YA; 15 mg/mL), and water. As for the assessment of stain-removal ability, the aligners stained by coffee were soaked in cleansing solutions, and the color changes (ΔE∗) were calculated on the basis of the CIE L∗a∗b∗ color system, and the National Bureau of Standards system was used for the clinical interpretation of the color change. Atomic force microscope examination, tensile property assessment, and wavelength dispersive x-ray fluorescence analysis were performed to investigate the material compatibility of TA-CPC, and Cell Counting Kit-8 assay and live/dead assay were used to test the cytotoxicity of TA-CPC. RESULTS: The results showed that TA-CPC had a positive zeta-potential, and cation-π interaction changed the chemical environments of the phenyl group in TA-CPC, resulting in greater inhibition zones of S. aureus and E. coli than other cleaners. The quantification of the biofilm biomass and the fluorescent intensities also reflected that the TA-CPC solution exhibited better antibacterial ability. As for the ability of stain removal, ΔE∗ value of group TA-CPC was 2.84 ± 0.55, whereas those of stained aligners immersed with deionized distilled water, TA, YA, and CPC were 10.26 ± 0.04, 9.54 ± 0.24, 5.93 ± 0.36, and 4.69 ± 0.35, respectively. The visual inspection and National Bureau of Standards ratings also showed that the color of stained aligners cleansed by TA-CPC was much lighter than those of the other groups. Meanwhile, TA-CPC had good compatibility with the aligner material and cells. CONCLUSIONS: TA-CPC is a promising strategy to inhibit the formation of biofilms and remove the stains on the aligners safely, which may disinfect the aligners to improve oral health and help keep the transparent appearances of aligners without impacting the morphology and mechanical properties.

miR-20a-5p regulated SMAD6 to inhibit chondrogenesis of hDPSCs.

OBJECTIVES: Chondrogenic differentiation of human dental pulp stem cells (hDPSCs) is highly promising for cartilage repair. The specific mechanism, however, still needs to be explicated. MATERIALS AND METHODS: In this study, we isolated hDPSCs and transfected cells with lentiviruses containing an over-expression, knock-down, or negative control of miR-20a-5p. Three-D pellet cultures of hDPSCs were used for the chondrogenic induction. Following the pellet culture period, chondrogenesis was assessed by histological and immunohistochemical analysis and expression of chondrogenic-related genes. Dual-luciferase report assay was performed to determine potential targeted genes of miR-20a-5p, and the phosphorylation levels of P65 and IκBα were explored. Animal experiments were performed to determine the effect of miR-20a-5p on cartilage regeneration. RESULTS: miR-20a-5p was showed to repress the expression of SMAD6 to inhibit the chondrogenic differentiation of hDPSCs. Accordingly, the knock-down of miR-20a-5p promoted cartilage regeneration in the osteochondral defects of rats. Mechanically, it is indicated that NF-κB signaling is the potential down-stream network of miR-20a-5p/Smad6 crosstalk during chondrogenic differentiation. CONCLUSIONS: miR-20a-5p could target SMAD6 to activate NF-κB signaling pathway, and thus inhibit chondrogenesis of hDPSCs, which provided promising therapeutic target for cartilage defects clinically.

Effect of photobiomodulation therapy on mini-implant stability: a systematic review and meta-analysis.

The study aimed to assess trials investigating the effect of PBMT on mini-implant stability. Electronic searches of seven databases and manual search were conducted up to May 2020. Randomized controlled trials and controlled clinical trials evaluating the effect of PBMT on mini-implant stability were included. The risks of bias of individual studies were performed using ROB 2.0 and ROBINS-I-tool based on different study design. Meta-analysis was conducted to compare mini-implant stability exposed to PBMT with control ones at different time points after implantation. Among the 518 records initially identified, seven studies were included in this study. Six studies investigated low-level laser therapy (LLLT) and one study evaluated light-emitting diode (LED) therapy. Two studies were eligible for meta-analysis, which showed that LLLT significantly improved mini-implant stability 60 days after initial implantation (MD - 3.01, 95% CI range [- 4.68, - 1.35], p = 0.0004). High energy density of LLLT began to show beneficial effect on mini-implant stability as early as 3 days after implantation, while the significant effect of low energy density displayed later than 30 days after insertion. LED therapy could improve mini-implant stability after 2 months post-insertion. In conclusion, PBMT appears to be beneficial in ameliorating mini-implant stability. High energy density of LLLT might exert more rapid effect than low energy density. More high-quality clinical trials are needed to further demonstrate PBMT' effects on orthodontic mini-implants.

Effect of clear aligners on oral health-related quality of life: A systematic review.

Clear aligners have been frequently applied in orthodontic clinic practice. However, its effect on oral health-related quality of life (OHRQoL) compared with fixed appliance treatment (FAT) remains inconclusive. This systematic review aimed to compare the impacts of clear aligner treatment (CAT) with FAT on patients' OHRQoL. Electronic searches of databases (PubMed, Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, Embase, Medline, two Chinese databases and six grey literature databases) were conducted up to July 2019. Randomized controlled trials, controlled clinical trials, cohort studies and cross-sectional studies comparing the impact of CAT and FAT on OHRQoL with validated instruments were included. Extraction of data and assessment of the risk of bias were conducted using ROBINS-I-tool, Newcastle-Ottawa Scale and ROB 2.0 based on study design. Of the 1112 records initially identified, 2 studies were included in this review. One study evaluated OHRQoL at the last debonding appointment, while the other made evaluation at the early stage of treatment. In the aspect of functional dimensions, both studies reported less eating disturbance in CAT patients than FAT ones. Based on currently limited information, the effect of CAT on the overall OHRQoL compared to FTA was still inconclusive. In individual dimensions, however, weak evidence supported that CAT might cause less eating disturbance than FAT. More high-quality clinical trials using validated OHRQoL instruments are needed to draw more reliable conclusions in the effect of CAT and FAT on OHRQoL.

The impact of surgery-first approach on the oral health-related quality of life: a systematic review and meta-analysis.

BACKGROUND: The oral health-related quality of life (OHRQoL) is affected by dentofacial deformity. Patients with dentofacial deformity are normally treated with orthognathic surgery, including conventional three-stage method (CTM) and surgery first approach (SFA). The aim of this systematic review and meta-analysis was to compare the impact of SFA with CTM on the OHRQoL of patients with severe dentofacial deformity. METHODS: Five English databases, three Chinese databases, and six grey literature databases were searched (January 2000 to July 2018). Randomized controlled trials, controlled clinical trials, and cohort studies assessing the OHRQoL of patients who underwent SFA or CTM were included. After selecting studies, extracting data, and assessing risk-of-bias according to the Cochrane Handbook for Systematic Reviews of Interventions and the Newcastle-Ottawa Scale, meta-analysis was performed to elucidate the effects of SFA on the changes of OHRQoL of patients with dentofacial deformity at each stage and made a comparison with CTM. RESULTS: There were 4 studies with 122 participants were selected for the final analysis. Three among these studies were included in meta-analysis, 2 of which were included in each forest plot. All the included studies were graded as moderate value of evidence according to GRADE quality analysis. Over the period of 2-year follow-up after bonding, the OHRQoL of the patients in SFA group showed an improving trend and was better than those in CTM group generally. After debonding, the summary scores of the 14-item Oral Health Impact Profile (OHIP-14) (- 2.92, P = 0.12) and Orthognathic Quality of Life Questionnaire (OQLQ) (- 5.59, P = 0.01) were smaller in SFA group than CTM group. CONCLUSIONS: Clinical evidence indicates that SFA can contribute to the better OHRQoL in patients with dentofacial deformity immediately and persistently.

Glucosamine oral administration as an adjunct to hyaluronic acid injection in treating temporomandibular joint osteoarthritis.

OBJECTIVE: To investigate the therapeutic effect of oral glucosamine (GS) as an adjunct to hyaluronic acid (HA) injection on patients with temporomandibular joint osteoarthritis (TMJ OA). METHODS: In this clinical trial, 136 participants, diagnosed as TMJ OA clinically and radiographically, were enrolled and randomized into two groups (group GS + HA: oral GS + HA injection; group placebo + HA: oral placebo + HA injection). Pain, maximum interincisal mouth opening (MMO), the levels of IL-1ß, IL-6, and TGF-ß in TMJ synovial were defined as the outcome measurements and conducted before operation, and at 1-month and 1-year follow-up. RESULTS: In both groups, pain scores were decreased and MMOs were increased at 1-month and 1-year follow-up, the changes at 1-year follow-up showed statistically significant intergroup differences. At 1-month follow-up, only IL-6 concentration was lower in group GS + HA than that in group placebo + HA. One year later, TGF-ß concentration was higher and IL-6 and IL-1ß concentrations were lower in group GS + HA than those in group placebo + HA. CONCLUSIONS: Both strategies alleviated symptoms in short term, but the patients treated with GS benefited more than those with placebo in long term, which may be due to the suppression of IL-1ß and IL-6 and the stimulation of TGF-ß.

Is There a Difference in Intra-Articular Injections of Corticosteroids, Hyaluronate, or Placebo for Temporomandibular Osteoarthritis?

PURPOSE: Corticosteroids are widely used for treatment of temporomandibular joint (TMJ) osteoarthritis (OA). This study investigated the effects of corticosteroids on TMJOA compared with placebo or hyaluronate. MATERIALS AND METHODS: The authors designed and implemented a systematic review and meta-analysis to compare the effects of intra-articular injection of corticosteroid, hyaluronate, or placebo for patients with TMJOA. The authors searched related randomized controlled studies electronically in multiple English- and Chinese-language electronic databases. The predictor variable was intra-articular injection with corticosteroid, hyaluronate, or placebo. Primary outcome variables were pain intensity and maximal mouth opening. Other variables included success rate and adverse events. Meta-analyses were performed with Rev Man 5.3. RESULTS: Eight studies met the inclusion criteria. Meta-analysis showed that corticosteroid injections after arthrocentesis were superior to placebo in relieving pain as assessed with the visual analog scale (mean difference [MD], -0.74; 95% confidence interval [CI], -1.34 to -0.13; P = .02; I2 = 0%) in the long-term, but was inferior in increasing maximal mouth opening (MD, -2.06; 95% CI, -2.76 to -1.36; P < .00001; I2 = 28%). Although corticosteroid and hyaluronate injections without arthrocentesis decreased pain and improved maximal mouth opening, the corticosteroid group had a significantly lower success rate (odds ratio = 0.41; 95% CI, 0.17-1.00; P = .05; I2 = 0%) than the hyaluronate group in the short term. CONCLUSION: Corticosteroid injections after arthrocentesis are recommended for patients with TMJOA to relieve joint pain rather than increase maximal mouth opening. Corticosteroid and hyaluronate have marked effectiveness on TMJOA; however, hyaluronate might be the better alternative to some extent.

Effect of protraction facemask on the temporomandibular joint: a systematic review.

BACKGROUND: The aim of this study was to assess the influence of protraction facemask (PFM) on temporomandibular joint (TMJ) of skeletal Class III malocclusion patients. METHOD: Literature searches were carried out electronically in five English and three Chinese databases (Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, PubMed, Embase, MEDLINE (via Ovid), Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and VIP Database). The date of the most recent search was 22 March 2017. Randomized controlled trials, controlled clinical trials, cohort studies, and before-after studies comparing the effect of PFM and other treatments on TMJ were included. The data were collected and extracted by three authors. The risk of bias in the RCTs was assessed in accordance with the Cochrane Handbook for Systematic Reviews of Interventions. For the nonrandomized studies, the risk of bias was judged with Newcastle-Ottawa Scale. RESULTS: For the 261 articles identified, 13 studies with 522 participants were included for the final qualitative analysis. Three studies were graded as high value of evidence, while seven studies and the other three studies were graded as moderate value and low value respectively. According to the available evidence, PFM contributed to the significant increase of CondAx-SBL and the significant decrease of CondAx-ML. Thin-plate spline (TPS) analysis showed a horizontal compression in condyles. Condyles tended to move superiorly and posteriorly. Concerning the occurrence of temporomandibular disorders (TMD), PFM was not involved in aggravating TMJ symptoms and signs. CONCLUSIONS: Clinical evidence suggests that PFM might contribute to the morphologic adaptation of TMJs and displacement of condyles, and PFM may well be not a risk factor for the development of TMD.

Knowledge of orthodontic tooth movement through the maxillary sinus: a systematic review.

BACKGROUND: To investigate the feasibility, safety and stability of current interventions for moving teeth through the maxillary sinus (MTTMS) by performing a systematic review of the literature. METHODS: The electronic databases PubMed, Embase, CENTRAL, Web of Science, CBM, CNKI and SIGLE were searched without a language restriction. The primary outcomes were parameters related to orthodontic treatment, including orthodontic protocols, magnitude of forces, type of tooth movement, duration and rate of tooth movement, and remolding of alveolar bone and the maxillary sinus floor. The secondary outcomes were safety and stability, including root resorption, perforation of the sinus floor, loss of pulp vitality and periodontal health and relapse. RESULTS: Nine case reports with 25 teeth were included and systematically analyzed. Fifty to two hundred g of force was applied to move teeth through the maxillary sinus. Bodily movement was accomplished, but initial tipping was observed in 7 cases. The rate was 0.6-0.7 mm/month for molar intrusion and 0.16-1.17 and 0.05-0.16 mm/month for mesial-distal movement of premolars and molars, respectively. Bone formation and remolding of the sinus floor occurred in 7 cases. Root resorption within 6 to 30 months was observed in 3 cases, while no cases of perforation of the sinus floor, loss of pulp vitality, periodontal health impairment or relapse were reported. CONCLUSIONS: At the present stage, no evidence-based protocol could be recommended to guide MTTMS. The empirical application of constant and light to moderate forces (by TAD, segment and multibrackets) to slowly move teeth through or into the maxillary sinus in adults appears to be practical and secure. Bodily movement was accomplished, but teeth appear to be easily tipped initially, potentially resulting in root resorption. However, this conclusion should be interpreted with caution as the currently available evidence is based on only a few case reports or case series and longitudinal or controlled studies are lacking in this area.

Biomimetic zwitterionic copolymerized chitosan as an articular lubricant.

Restoration of the lubrication functions of articular cartilage is an effective treatment to alleviate the progression of osteoarthritis (OA). Herein, we fabricated chitosan-block-poly(sulfobetaine methacrylate) (CS-b-pSBMA) copolymer via a free radical polymerization of sulfobetaine methacrylate onto activated chitosan segment, structurally mimicking the lubricating biomolecules on cartilage. The successful copolymerization of CS-b-pSBMA was verified by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and 1H nuclear magnetic resonance. Friction test confirmed that the CS-b-pSBMA copolymer could achieve an excellent lubrication effect on artificial joint materials such as Ti6Al4V alloy with a coefficient of friction as low as 0.008, and on OA-simulated cartilage, better than the conventional lubricant hyaluronic acid, and the adsorption effect of lubricant on cartilage surface was proved by a fluorescence labeling experiment. In addition, CS-b-pSBMA lubricant possessed an outstanding stability, which can withstand enzymatic degradation and even a long-term storage up to 4 weeks. In vitro studies showed that CS-b-pSBMA lubricant had a favorable antibacterial activity and good biocompatibility. In vivo studies confirmed that the CS-b-pSBMA lubricant was stable and could alleviate the degradation process of cartilage in OA mice. This biomimetic lubricant is a promising articular joint lubricant for the treatment of OA and cartilage restoration.

Single-cell transcriptional profiling reveals immunomodulatory properties of stromal and epithelial cells in periodontal immune milieu with diabetes in rats.

Periodontitis is the sixth major complication of diabetes. Gingiva, as an important component of periodontal tissues, serves as the first defense barrier against infectious stimuli. However, relatively little is known about cellular heterogeneity and cell-specific changes in gingiva in response to diabetes-associated periodontitis. To characterize molecular changes linking diabetes with periodontitis, we profiled single-cell transcriptome analyses of a total of 45,259 cells from rat gingiva with periodontitis under normoglycemic and diabetic condition. The single-cell profiling revealed that stromal and epithelial cells of gingiva contained inflammation-related subclusters enriched in functions of immune cell recruitment. Compared to normoglycemic condition, diabetes led to a reduction in epithelial basal cells, fibroblasts and smooth muscle cells in gingiva with periodontitis. Analysis of differentially expressed genes indicated that stromal and epithelial populations were reprogrammed towards pro-inflammatory phenotypes promoting immune cell recruitment in diabetes-related periodontitis. In aspect of immune cells, diabetes prominently enhanced neutrophil and M1 macrophage infiltration in periodontitis lesions. Cell-cell communications revealed enhanced crosstalk between stromal/epithelial cells and immune cells mediating by chemokine/chemokine receptor interplay in diabetes-associated periodontitis. Our findings deconvolved cellular heterogeneity of rat gingiva associated with periodontitis and diabetes, uncovered altered immune milieu caused by the disease, and revealed immunomodulatory functions of stromal and epithelial cells in gingival immune niche. The present study improves the understanding of the link between the diabetes and periodontitis and helps in formulating precise therapeutic strategies for diabetes-enhanced periodontitis.

Drug delivery systems for treatment of temporomandibular joint osteoarthritis.

The number of people suffering from temporomandibular joint osteoarthritis (TMJOA) has been increasing. TMJOA cause joint noise, pain on TMJ and/or masticatory muscles, and restricted mandibular movement, which disturb eating, laughing and conversation, and impose serious lifestyle impediments. Chondrocyte apoptosis, extracellular matrix degradation, synovitis, and subchondral bone remodeling are the main pathological features of TMJOA. Various drug delivery systems are developed to controlled release at specific activation sites with high bioactivity and inhibit rapid dilution to enable long-term therapeutic response, which present great potential for the treatment of TMJOA. This review focuses on recently developed drug delivery systems by different administration in the TMJOA treatment, and summarizes their effects, duration, safety, and limitations, which would pave the way for development of TMJOA therapy.

Quantitative proteomic analysis of gingival crevicular fluids to identify novel biomarkers of gingival recession in orthodontic patients.

OBJECTIVE: To identify gingival recession-related biomarkers in orthodontic patients, we compared the proteome of gingival crevicular fluids (GCF) from healthy gingiva without orthodontic treatment (GH), healthy gingiva undergoing orthodontic treatment (OGH), and recessed gingiva undergoing orthodontic treatment (OGR). METHODS: GCF samples were obtained from the anterior teeth of 15 volunteers (n = 5/group). Quantitative proteomic analysis was performed using DIA-based liquid chromatography-tandem mass spectrometry (LC-MS/MS). Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were used to annotate differentially expressed proteins (DEPs). Receiver-operating characteristic (ROC) analysis was performed to detect and filter biomarker candidates, while Protein-Protein Interaction (PPI) Networks were utilized to determine the interactions between these DEPs. RESULTS: A total of 253, 238, and 101 DEPs were found in OGR vs. OGH, OGR vs. GH, and OGH vs. GH groups, respectively. Based on the Venn diagram of three groups, 128 DEPs in OGR vs. OGH group were identified as specific proteins associated with progressive gingival recession (GR) during orthodontic treatment. Molecular function analysis showed that 128 DEPs were enriched in "molecular binding", including antigen binding, RNA binding, double-stranded RNA binding, cadherin binding involved in cell-cell adhesion, vinculin binding, S100 protein binding, and Ral GTPase binding. The majority of these DEPs were also involved in cytoskeletal regulation. In addition, biological process analysis showed an enrichment in translation, while cellular component analysis indicated that 128 DEPs were related to extracellular exosome. Furthermore, Ribosome and Phagosome were the top two terms in KEGG analysis. The results of ROC analysis demonstrated that 26 proteins could be potential biomarker candidates for GR. PPI networks analysis predicted that IQGAP1, ACTN1, TLN1, VASP, FN1, FERMT3, MYO1C, RALA, RPL35, SEC61G, KPNB1, and NPM1 could be involved in the development of GR via cytoskeletal regulation. CONCLUSIONS: In summary, we identified several GCF proteins associated with GR after orthodontic treatment. These findings could contribute to the prevention of GR in susceptible patients before the initiation of orthodontic treatment. SIGNIFICANCE: Orthodontic patients with GR often report esthetic defects or root hypersensitivity during orthodontic treatment, especially at the anterior teeth site. GCF, rich in protein, is an easily accessible source of potential biomarkers for the diagnosis of periodontal diseases; however, little is known about the changes in GCF proteome associated with GR in orthodontic patients. In this study we firstly used DIA-based LC-MS/MS to evaluate the proteome and to identify the biomarker candidates for GR in orthodontic patients. These findings will improve our understanding of GR during orthodontic treatment, and could contribute to an earlier diagnosis, or even prevention, of GR in susceptible populations before orthodontic treatment.

CircRFWD2 Promotes Osteogenic Differentiation of human Dental Pulp Stem Cells by Targeting miR-6817-5p Through BMP-Smad and p38 MAPK Pathway.

Dental pulp stem cells (DPSCs) are one promising cell source of mesenchymal stem cells in bone tissue engineering. However, it remains unknown that the molecules and signaling pathways involved in osteogenesis of DPSCs. Hence, this study investigated the functional roles and underlying mechanisms of circRFWD2 during osteogenesis of DPSCs. Knockdown of circRFWD2 suppressed osteogenesis of DPSCs significantly. Mechanistically, circRFWD2 could crosstalk with miR-6817-5p, which was an inhibitor of DPSCs osteogenesis. MiR-6817-5p functioned as a sponge of BMPR2, which regulated the phosphorylation of Smad5 and p38 to impact osteogenesis activity of DPSCs. Collectively, circRFWD2/miR-6817-5p/BMPR2 axis could regulate DPSCs osteogenesis via BMP-Smad and p38 MAPK pathway, which are novel mechanisms in the osteogenic differentiation of DPSCs and suggest potential therapeutic methods for bone defects regeneration.

miR-20a-5p contributes to osteogenic differentiation of human dental pulp stem cells by regulating BAMBI and activating the phosphorylation of Smad5 and p38.

BACKGROUND: Human dental pulp stem cells (hDPSCs) are the preferable choice of seed cells for craniomaxillofacial bone tissue regeneration. As a member of the miR-17-92 cluster, miR-20a-5p functions as an important regulator during bone remodeling. This study aimed to investigate the roles and mechanisms of miR-20a-5p during osteogenesis of hDPSCs. METHODS: Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was conducted to determine the expression of miR-20a-5p during osteogenesis of hDPSCs. We interfered with the expression of miR-20a-5p in hDPSCs to clarify the function of miR-20a-5p on osteogenesis both in vitro and vivo. Direct bind sites between miR-20a-5p and BAMBI were confirmed by dual-luciferase reporter assay, and the underlying mechanisms were investigated with cell co-transfections. RESULTS: The expression of miR-20a-5p was showed to be upregulated during osteogenesis of hDPSCs. Inhibition of miR-20a-5p could weaken the intensity of ALP/ARS staining and downregulate the expression of mRNAs and proteins of osteogenic markers, while overexpression of miR-20a-5p could enhance the intensity of ALP/ARS staining and the expression of osteogenic markers. Both micro-CT reconstruction images and histological results showed that miR-20a-5p could promote the regeneration of calvarial defects. miR-20a-5p directly targeted bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI), and the latter one was an inhibitor of hDPSC osteogenesis. Silencing BAMBI partially reversed the suppression effect of miR-20a-5p knockdown on osteogenesis. Phosphorylation of Smad5 and p38 was decreased when miR-20a-5p was silenced, whereas p-Smad5 and p-p38 were upregulated when miR-20a-5p was overexpressed or BAMBI was silenced. CONCLUSIONS: It is demonstrated that miR-20a-5p functioned as a regulator of BAMBI to activate the phosphorylation of Smad5 and p38 during osteogenic differentiation of hDPSCs.

The functions of mechanosensitive ion channels in tooth and bone tissues.

Tooth and bone are independent tissues with a close relationship. Both are composed of a highly calcified outer structure and soft inner tissue, and both are constantly under mechanical stress. In particular, the alveolar bone and tooth constitute an occlusion system and suffer from masticatory and occlusal force. Thus, mechanotransduction is a key process in many developmental, physiological and pathological processes in tooth and bone. Mechanosensitive ion channels such as Piezo1 and Piezo2 are important participants in mechanotransduction, but their functions in tooth and bone are poorly understood. This review summarizes our current understanding of mechanosensitive ion channels and their roles in tooth and bone tissues. Research in these areas may shed new light on the regulation of tooth and bone tissues and potential treatments for diseases affecting these tissues.

circAKT3 positively regulates osteogenic differentiation of human dental pulp stromal cells via miR-206/CX43 axis.

BACKGROUND: Human dental pulp stromal cells (hDPSCs) are promising sources of mesenchymal stem cells (MSCs) for bone tissue regeneration. Circular RNAs (circRNAs) have been demonstrated to play critical roles in stem cell osteogenic differentiation. Herein, we aimed to investigate the role of circAKT3 during osteogenesis of hDPSCs and the underlying mechanisms of its function. METHODS: We performed circRNA sequencing to investigate the expression profiles of circular RNAs during osteogenesis of hDPSCs. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was performed to detect the expression pattern of circAKT3 and miR-206 in hDPSCs during osteogenesis. We knocked down circAKT3 and interfered the expression of miR-206 to verify their regulatory role in hDPSC osteogenesis. We detected hDPSCs mineralization by alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining and used dual-luciferase reporter assay to validate the direct binding between circAKT3 and miR-206. To investigate in vivo mineralization, we performed subcutaneous transplantation in nude mice and used hematoxylin and eosin, Masson's trichrome, and immunohistochemistry staining. RESULTS: Totally, 86 circRNAs were differentially expressed during hDPSC osteogenesis, in which 29 were downregulated while 57 were upregulated. circAKT3 was upregulated while miR-206 was downregulated during hDPSC osteogenesis. Knockdown of circAKT3 inhibited ALP/ARS staining and expression levels of osteogenic genes. circAKT3 directly interacted with miR-206, and the latter one suppressed osteogenesis of hDPSCs. Silencing miR-206 partially reversed the inhibitory effect of circAKT3 knockdown on osteogenesis. Connexin 43 (CX43), which positively regulates osteogenesis of stem cells, was predicted as a target of miR-206, and overexpression or knockdown of miR-206 could correspondingly decrease and increase the expression of CX43. In vivo study showed knockdown of circAKT3 suppressed the formation of mineralized nodules and expression of osteogenic proteins. CONCLUSION: During osteogenesis of hDPSCs, circAKT3 could function as a positive regulator by directly sponging miR-206 and arresting the inhibitive effect of miR-206 on CX43 expression.