Glutathione peroxidase 4 restrains temporomandibular joint osteoarthritis progression by inhibiting ferroptosis.

There are few effective therapeutic strategies for temporomandibular joint osteoarthritis (TMJOA) due to the unclear pathology and mechanisms. We aimed to confirm the roles of GPX4 and ferroptosis in TMJOA progression. ELISA assay was hired to evaluate concentrations of ferroptosis-related markers. The qRT-PCR assay was hired to assess gene mRNA level. Western blot assay and immunohistochemistry were hired to verify the protein level. CCK-8 assay was hired to detect cell viability. Human fibroblast-like synoviocytes (FLSs) were cultured to confirm the effects of GPX4 and indicated inhibitors, and further verified the effects of GPX4 and ferroptosis inhibitors in TMJOA model rats. Markers of ferroptosis including 8-hidroxy-2-deoxyguanosine (8-OHdG) and iron were notably increased in TMJOA tissues and primary OA-FLSs. However, the activity of the antioxidant system including the glutathione peroxidase activity, glutathione (GSH) contents, and glutathione/oxidized glutathione (GSH/GSSG) ratio was notably inhibited in TMJOA tissues, and the primary OA-FLSs. Furthermore, the glutathione peroxidase 4 (GPX4) expression was down-regulated in TMJOA tissues and primary OA-FLSs. Animal and cell experiments have shown that ferroptosis inhibitors notably inhibited ferroptosis and promoted HLS survival as well as up-regulated GPX4 expression. Also, GPX4 knockdown promoted ferroptosis and GPX4 overexpression inhibited ferroptosis. GPX4 also positively regulated cell survival which was the opposite with ferroptosis. In conclusion, GPX4 and ferroptosis regulated the progression of TMJOA. Targeting ferroptosis might be an effective therapeutic strategy for TMJOA patients in the clinic.

DP7-C/mir-26a system promotes bone regeneration by remodeling the osteogenic immune microenvironment.

OBJECTIVE: This study investigates the DP7-C/miR-26a complex as a stable entity resulting from the combination of miR-26a with the immunomodulatory peptide DP7-C. Our focus is on utilizing DP7-C loaded with miR-26a to modulate the immune microenvironment in bone and facilitate osteogenesis. METHODS: The DP7-C/miR-26a complex was characterized through transmission electron microscopy, agarose electrophoresis, and nanoparticle size potentiometer analysis. Transfection efficiency and cytotoxicity of DP7-C were assessed using flow cytometry and the CCK-8 assay. We validated the effects of DP7-C/miR-26a on bone marrow mesenchymal stem cells (BMSCs) and macrophages RAW 264.7 through gene expression and protein synthesis assays. A comprehensive evaluation of appositional bone formation involved micro-CT imaging, histologic analysis, and immunohistochemical staining. RESULTS: DP7-C/miR-26a, a nanoscale, and low-toxic cationic complex, demonstrated the ability to enter BMSCs and RAW 264.7 via distinct pathways. The treatment with DP7-C/miR-26a significantly increased the synthesis of multiple osteogenesis-related factors in BMSCs, facilitating calcium nodule formation in vitro. Furthermore, DP7-C/miR-26a promoted M1 macrophage polarization toward M2 while suppressing the release of inflammatory factors. Coculture studies corroborated these findings, indicating significant repair of rat skull defects following treatment with DP7-C/miR-26a. CONCLUSION: The DP7-C/miR-26a system offers a safer, more efficient, and feasible technical means for treating bone defects.

The association between plain water intake and periodontitis in the population aged over 45: a cross-sectional study based on NHANES 2009-2014.

BACKGROUND: Numerous studies have demonstrated the impact of beverage consumption on overall health and oral health. Specifically, high consumption of sugar-sweetened beverages and coffee has been associated with an increased risk of metabolic disorders and periodontitis. Conversely, high intake of plain water has been linked to various health benefits, including weight management and reduced energy intake. However, no previous studies have explored the potential association between plain water intake and the risk of periodontitis. OBJECTIVES: Our objective was to investigate the relationship between plain water consumption and periodontitis in a middle-aged and elderly population. METHODS: The present cross-sectional study was conducted among participants aged ≥ 45 in the 2009-2014 National Health and Nutrition Examination Surveys. Multivariable regression analysis, subgroup analysis and smooth fitting tests were conducted to explore the independent relationship between plain water intake and periodontitis. RESULTS: A total of 5,882 participants were enrolled,62.02% have periodontitis. Periodontitis patients have lower plain water intake. The multivariable regression tests showed that the risk of periodontitis decreased with increased plain water intake quartiles (Q4 OR = 0.78; 95%CI 0.62-0.96) after fully adjustment. Subgroup analysis and interaction tests showed that gender, age, smoking, diabetes, hypertension or BMI does not significantly interact with the association. However, the relation was significant in males (Q4 OR = 0.64; 95%CI 0.47-0.86) but not in females (Q4 OR = 0.97;95% CI 0.71-1.31). In the smoothed curve fits stratified by gender, the curve for male participants displayed as a U-shape, with an optimal plain water intake at 1200 ml/day. For males drinking plain water less than 1200 ml/day, the risk of periodontitis decreased by 24% with each increase of 500 ml plain water intake (OR = 0.76, 95%CI 0.66-0.87, p < 0.001). CONCLUSIONS: Together, the results showed that plain water intake is negatively associated with periodontitis risk in US middle aged and elderly population. Further studies are needed to investigate the mechanism unites this association. Attention should be given to adequate plain water intake when considering dietary suggestions to the population at high risk of developing periodontitis, especially for men.

Lycium barbarum polysaccharide-glycoprotein promotes osteogenesis in hPDLSCs via ERK activation.

OBJECTIVE: A lack of relevant research on Lycium barbarum polysaccharide-glycoprotein (LBP) application in oral diseases. Here, we focused on the effect of LBP on osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) and periodontitis bone loss. METHODS: Human periodontal ligament stem cells (hPDLSCs) were isolated and identified by flow cytometry. Alkaline phosphatase (ALP) activity, Alizarin Red staining, and combined qPCR and Western blot analyses were performed to elucidate the effects of LBP on the osteogenic potential of hPDLSCs. In vivo experiments were performed with the treatment of LBP in rat periodontal model. MicroCT scanning and histological analysis were conducted to evaluate osteogenesis in situ. RESULTS: Human periodontal ligament stem cells (hPDLSCs) were successfully isolated and identified with CD90, CD29, and CD45. LBP enhanced hPDLSCs proliferation and migration and promoted RUNX2, ALP, Collagen I, and Osteocalcin expression through activating the ERK1/2 signaling pathway in vitro. The inflammatory factors, including interleukin 6 (IL-6) and interleukin 8 (IL-8) were reduced after LBP treatment. Alveolar bone resorption was significantly decreased in the LBP-treated groups in vivo, and osteoclast was markedly decreased by LBP application. CONCLUSION: LBP promoted hPDLSC osteogenesis by targeting the ERK1/2 signaling pathway and reverse bone loss by reducing inflammation. These findings provided latent hope for LBP application in periodontal therapy.

Bone marrow mesenchymal stem cell-derived exosomes loaded with miR-26a through the novel immunomodulatory peptide DP7-C can promote osteogenesis.

PURPOSE: As small bioactive molecules, exosomes can deliver osteogenesis-related miRNAs to target cells and promote osteogenesis. This study aimed to investigate miR-26a as a therapeutic cargo to be loaded into bone marrow stromal cell exosomes through a novel immunomodulatory peptide (DP7-C). METHODS: After transfecting BMSCs with DP7-C as a transfection agent, exosomes were extracted by ultracentrifugation from the culture supernatant of miR-26a-modified BMSCs. We then characterized and identified the engineered exosomes. The effect of the engineered exosomes on osteogenesis was then evaluated in vitro and in vivo, including transwell, wound healing, modified alizarin red staining, western blot, real-time quantitative PCR, and experimental periodontitis assays. Bioinformatics and data analyses were conducted to investigate the role of miR-26a in bone regeneration. RESULTS: The DP7-C/miR-26a complex successfully transfected miR-26a into BMSCs and stimulated them to release more than 300 times the amount of exosomes overexpressing miR-26a compared with the ExoNC group. Furthermore, exosomes loaded with miR-26a could enhance proliferation, migration, and osteogenic differentiation of BMSCs in vitro compared with the ExoNC and blank groups. In vivo, the ExomiR-26a group inhibited the destruction of periodontitis compared with the ExoNC and blank groups, as revealed by HE staining. Micro-CT indicated that treatment of ExomiR-26a increased the percent bone volume and the bone mineral density compared with those of the ExoNC (P < 0.05) and blank groups (P < 0.001). Target gene analysis indicated that the osteogenic effect of miR-26a is related to the mTOR pathway. CONCLUSION: miR-26a can be encapsulated into exosomes through DP7-C. Exosomes loaded with miR-26a can promote osteogenesis and inhibit bone loss in experimental periodontitis and serve as the foundation for a novel treatment strategy.

A novel porous hydroxyapatite scaffold (pHAMG) enhances angiogenesis and osteogenesis around dental implants by regulating the immune microenvironment.

OBJECTIVE: The purpose was to evaluate whether a novel porous hydroxyapatite (HA) scaffold with a 25-30-µm groove structure (pHAMG) may improve bone osteogenesis, angiogenesis, and bone integration of titanium dental implants in animal models. METHODS: The pHAMG was prepared by chemical precipitation method and its elemental composition and crystal structure were evaluated. The ability of the scaffolds to induce ectopic osteogenesis and the ability of scaffolds combined with titanium dental implants to induce orthotopic peri-implant angiogenesis, osteogenesis, and osteointegration were tested after implantation into the femur muscle pocket in rats and the mandibular defects in beagle dogs, respectively. The elemental composition was evaluated by SEM-EDS; the expression of the relevant osteogenic/inflammation marker and the anti-/pro-inflammation markers was evaluated by immunostaining and immunofluorescence, respectively. RESULTS: In animal experiments with ectopic and peri-implant osteogenesis, pHAMG resulted in significantly larger neovascularization by hematoxylin-eosin staining, as well as deposition of collagen fibers by Masson staining than HA. Meanwhile, microgrooves in pHAMG upregulate more bone morphogenetic protein (BMP) 2 and interleukin-4 (IL-4) and -10 (IL-10) and downregulate more IL-1ß and tumor necrosis factor-α (TNF-α) than that in HA. The pHAMG showed greater expression of arginase (Arg)-1 and lower expression of inducible nitric oxide synthase (iNOS) than HA. CONCLUSION: The novel pHAMG can better repair bone defects in ectopic and orthotopic model. It also transfers macrophages to anti-inflammatory phenotypes, promoting angiogenic and osteogenesis in scaffolds, and bone integration in implants. CLINICAL RELEVANCE: The novel pHAMG induce greater osteogenesis and angiogenesis which could be utilized in the clinical treatment.

A grooved porous hydroxyapatite scaffold induces osteogenic differentiation via regulation of PKA activity by upregulating miR-129-5p expression.

BACKGROUND AND OBJECTIVE: Hydroxyapatite scaffolds with different morphologies have been widely used in bone tissue engineering. Moreover, microRNAs (miRNAs) have been proven to be extensively involved in regulating bone regeneration. We developed grooved porous hydroxyapatite (HAG) scaffolds with good osteogenic efficiency. However, little is known about the role of miRNAs in HAG scaffold-mediated promotion of bone regeneration. The objective of this study was to reveal the mechanism from the perspective of differential miRNA expression. METHODS: Scanning electron microscopy (SEM) was used to perform the coculture of cells and scaffolds. The miRNA profiles were generated by a microarray assay. A synthetic miR-129-5p mimic and inhibitor were used for overexpression or inhibition. The expression of osteogenic marker mRNAs and proteins was detected by quantitative real-time PCR (qRT-PCR), Western blotting, and immunofluorescence. An ALP activity kit and alizarin red staining (ARS) were used to measure ALP activity and mineral deposition formation. Cell migration ability was examined by wound healing and transwell assays. Protein kinase A (PKA) activity was measured by enzyme-linked immunosorbent assay (ELISA) after miR-129-5p transfection. Target genes were identified by a dual-luciferase reporter assay. H89 preculture evaluated the cross talk between miR-129-5p and PKA activity. Heterotopic implantation models, hematoxylin-eosin (HE), immunohistochemistry staining, and micro-CT were used to evaluate miR-129-5p osteogenesis in vivo. RESULTS: miRNAs were differentially expressed during osteogenic differentiation induced by HAG in vitro and in vivo. miR-129-5p was the only highly expressed miRNA both in vitro and in vivo. miR-129-5p overexpression promoted osteoblast differentiation and cell migration, while its inhibition weakened the effect of HAG. Moreover, miR-129-5p activated PKA to regulate the phosphorylation of ß-catenin and cAMP-response element binding protein (CREB) by inhibiting cAMP-dependent protein kinase inhibitor alpha (Pkia). H89 prevented the effects of miR-129-5p on osteogenic differentiation and cell migration. HE, immunohistochemistry staining and micro-CT results showed that miR-129-5p promoted in vivo osteogenesis of the HAG scaffold. CONCLUSION: The HAG scaffold activates Pka by upregulating miR-129-5p and inhibiting Pkia, resulting in CREB-dependent transcriptional activation and accumulation of ß-catenin and promoting osteogenic marker expression.

A Peptide-Based Small RNA Delivery System to Suppress Tumor Growth by Remodeling the Tumor Microenvironment.

MicroRNAs can regulate a variety of physiological and pathological processes and are increasingly recognized as being involved in regulating the malignant progression of cancer, which is an important direction for the study and treatment of cancer. In addition, the tumor microenvironment has gradually become an important direction of study for combating cancer. Researchers can inhibit tumor growth by remodeling and suppressing an immunosuppressive phenotype in the tumor microenvironment. Therefore, the combination of microRNA delivery and tumor microenvironment remodeling may be a potential research direction. In a previous study, we developed a novel cationic and hydrophilic antimicrobial peptide, DP7, by computer simulation. It was found that cholesterol-modified DP7 (DP7-C) has dual functions as a carrier and an immune adjuvant. In this experiment, we used DP7-C to deliver microRNAs or inhibitors intratumorally, where it played a dual role as a carrier and an immune adjuvant. As a delivery vector, DP7-C has more advantages in terms of transfection efficiency and cytotoxicity than Lipo2000 and PEI25K. Components of the DP7-C/RNA complex can effectively escape endosomes after uptake via caveolin- and clathrin-dependent pathways. As an immune adjuvant, DP7-C can activate dendritic cells and promote macrophage polarization. Moreover, it can transform the immunosuppressive tumor microenvironment into an immune-activated tumor microenvironment, indicating its potential as an anticancer therapy. In conclusion, this study identifies a novel microRNA and inhibitor delivery system that can remodel the tumor microenvironment and introduces an alternative scheme for antitumor treatment.

A novel in silico antimicrobial peptide DP7 combats MDR Pseudomonas aeruginosa and related biofilm infections.

BACKGROUND: Antimicrobial peptides are promising alternative antimicrobial agents to combat MDR. DP7, an antimicrobial peptide designed in silico, possesses broad-spectrum antimicrobial activities and immunomodulatory effects. However, the effects of DP7 against Pseudomonas aeruginosa and biofilm infection remain largely unexplored. OBJECTIVES: To assess (i) the antimicrobial activity of DP7 against MDR P. aeruginosa; and (ii) the antibiofilm activity against biofilm infection. Also, to preliminarily investigate the possible antimicrobial mode of action. METHODS: The MICs of DP7 for 104 clinical P. aeruginosa strains (including 57 MDR strains) and the antibiofilm activity were determined. RNA-Seq, genome sequencing and cell morphology were conducted. Both acute and chronic biofilm infection mouse models were established. Two mutants, resulting from point mutations associated with LPS and biofilms, were constructed to investigate the potential mode of action. RESULTS: DP7, at 8-32 mg/L, inhibited the growth of clinical P. aeruginosa strains and, at 64 mg/L, reduced biofilm formation by 43% to 68% in vitro. In acute lung infection, 0.5 mg/kg DP7 exhibited a 70% protection rate and reduced bacterial colonization by 50% in chronic infection. DP7 mainly suppressed gene expression involving LPS and outer membrane proteins and disrupted cell wall structure. Genome sequencing of the DP7-resistant strain DP7R revealed four SNPs controlling LPS and biofilm production. gshA44 and wbpJ139 mutants displayed LPS reduction and motility deficiency, conferring the reduction of LPS and biofilm biomass of strain DP7R and indicating that LPS was a potential target of DP7. CONCLUSIONS: These results demonstrate that DP7 may hold potential as an effective antimicrobial agent against MDR P. aeruginosa and related infections.

Impact of Hyperbaric Oxygen on the Healing of Teeth Extraction Sockets and Alveolar Ridge Preservation.

OBJECTIVES: The purpose of this study was to investigate the role of hyperbaric oxygen (HBO) in the healing of teeth extraction sockets and in alveolar ridge preservation. This may provide an experimental basis for the widespread application of HBO in oral implantation. METHODS: A total of 32 beagle dogs were included in the study and randomly divided equally between an HBO group treated with hyperbaric oxygen (100% O2, 2.4 atm, 90 min/day, 5 times/week, 6 weeks) and a normobaric oxygen (NBO) group treated with normal air in the same chamber. The lateral incisors of the maxillary and mandible of each dog were extracted, and the right upper and lower incisor extraction sockets (A2C2) were allowed to heal naturally, while left upper and lower incisor sockets (B2D2) received implants of a commercial bone substitute. At 4 and 8 weeks after surgery, clinical observation, cone-beam computerized tomography (CBCT), histomorphology observation, and expression levels of vascular endothelial growth factor (VEGF) and bone morphogenetic protein 2 (BMP-2) were analyzed to evaluate new bone formation, mineralization, and reconstruction. RESULTS: After 4 and 8 weeks, bone width and lip contour of the extraction socket in the NBO group were significantly reduced and collapsed in comparison with the HBO group. CBCT showed that the difference in vertical height between the alveolar crest of the labial tongue and palatal side of the extraction sockets was smaller in the HBO than NBO group. There was a significant difference in new bone formation (P < 0.05) and bone mineral density (P < 0.05) between the HBO and NBO groups, and the HBO group showed significantly greater new bone and bone reconstruction based on histology. Furthermore, the expression levels of VEGF and BMP-2 were higher in the HBO group. CONCLUSION: HBO reduced bone resorption and promoted early bone formation, bone mineralization, and reconstruction in the extraction sockets. HBO greatly reduced the healing time of the extraction sockets and promoted alveolar ridge preservation, thus showing promise for the clinic.

Groove structure of porous hydroxyapatite scaffolds (HAS) modulates immune environment via regulating macrophages and subsequently enhances osteogenesis.

Researches have revealed the vital roles of the generated immune environment via the response of immune cells growing on biomaterial surfaces in the bone healing process. HAS and novel constructed microgrooved patterns of HAS (HAS-G) are widely used as biocompatible ceramic, especially as a mimic of the natural bone matrix. However, it is unclear whether osteoimmune response induced by HAS and HAS-G affects the osteogenic differentiation of bone marrow stromal cells (BMSCs). RAW264.7 cells were seeded on different surface of materials and cytokines released by macrophages were detected by enzyme-linked immunosorbent assay. The cell viability and mitochondrial function of macrophages seeded on different surface of materials were detected. Then, the effects of modified inflammatory microenvironment by macrophages on osteogenesis of BMSCs were measured by performing ALP staining, Alizarin Red S staining, and western blot. We confirmed that HAS-G is more favorable for RAW cell attaching and subsequently regulated the expression and release of cytokines/chemokines. Decrease in interleukin-6 (IL-6) release was further confirmed for contributing significantly to improve mitochondrial function in RAW cells. HAS-G-conditioned medium promoted osteogenic differentiation in BMSCs and was reversed by IL-6 addition. Decrease in IL-6 contributes to downregulation of miR-214 and subsequently upregulated p38/JNK pathway, which is potentially contributes to osteogenic promotion by HAS-G. This study is the first report to reveal the effects of HAS-G on osteogenesis via immune response, which could lead to a new insight into novel material for the advantage of biomaterials for tissue engineering applications.

Impact of Hyperbaric Oxygen on Tissue Healing around Dental Implants in Beagles.

BACKGROUND The impact of hyperbaric oxygen (HBO) on the healing of soft tissues around dental implants was studied in a beagle model. MATERIAL AND METHODS Beagle dogs were randomized to receive implants, followed by postoperative HBO therapy or not (n=10 per group). On postoperative days 3, 7, and 14, tissue specimens were paraffin-embedded and analyzed by hematoxylin-eosin and Masson staining, as well as immunohistochemistry against CD31. RESULTS Scores for inflammation pathology based on hematoxylin-eosin staining and mean optical density of collagen fibers were significantly different between the HBO and control groups on postoperative days 3 and 7 (P<0.05), but not on day 14. Mean optical density due to anti-CD31 staining was significantly higher in the HBO group on postoperative days 3, 7, and 14 (P<0.05). CONCLUSIONS These results suggest that HBO may promote early osteogenesis and soft tissue healing after implantation.

Effective inhibition of melanoma tumorigenesis and growth via a new complex vaccine based on NY-ESO-1-alum-polysaccharide-HH2.

BACKGROUND: A safe and effective adjuvant plays an important role in the development of a vaccine. However, adjuvants licensed for administration in humans remain limited. Here, for the first time, we developed a novel combination adjuvant alum-polysaccharide-HH2 (APH) with potent immunomodulating activities, consisting of alum, polysaccharide of Escherichia coli and the synthetic cationic innate defense regulator peptide HH2. METHODS: The adjuvant effects of APH were examined using NY-ESO-1 protein-based vaccines in prophylactic and therapeutic models. We further determined the immunogenicity and anti-tumor effect of NY-ESO-1-APH (NAPH) vaccine using adoptive cellular/serum therapy in C57/B6 and nude mice. Cell-mediated and antibody-mediated immune responses were evaluated. RESULTS: The APH complex significantly promoted antigen uptake, maturation and cross-presentation of dendritic cells and enhanced the secretion of TNF-α, MCP-1 and IFN-γ by human peripheral blood mononuclear cells compared with individual components. Vaccination of NAPH resulted in significant tumor regression or delayed tumor progression in prophylactic and therapeutic models. In addition, passive serum/cellular therapy potently inhibited tumor growth of NY-ESO-1-B16. Mice treated with NAPH vaccine produced higher antibody titers and greater antibody-dependent/independent cellular cytotoxicity. Therefore, NAPH vaccination effectively stimulated innate immunity, and boosted both arms of the adaptive humoral and cellular immune responses to suppress tumorigenesis and growth of melanoma. CONCLUSIONS: Our study revealed the potential application of APH complex as a novel immunomodulatory agent for vaccines against tumor refractory and growth.

Emulsion template fabricated gelatin-based scaffold functionalized by dialdehyde starch complex with antibacterial antioxidant properties for accelerated wound healing.

Gelatin and starch are considered as promising sustainable materials for their abundant production and good biodegradability. Efforts have been made to explore their medical application. Herein, scaffolds based on gelatin and starch with a preferred microstructure and antibacterial antioxidant property were fabricated by the emulsion template method. The dialdehyde starch was firstly combined with silver nanoparticles and curcumin to carry out the efficient hybrid antibacterial agent. Then, the gelatin microsphere of appropriate size was prepared by emulsification and gathered by the above agent to obtain gelatin-based scaffolds. The prepared scaffolds showed porous microstructures with high porosity of over 74 % and the preferred pore sizes of ∼65 µm, which is conducive to skin regeneration. Moreover, the scaffolds possessed a good swelling ability of over 640 %, good degradability of over 18 days, excellent blood compatibility, and cell compatibility. The promising antibacterial and antioxidant properties came from the hybrid antibacterial agent were affirmed. As expected, the gelatin-based scaffolds fabricated by the emulsion template method with a preferred microstructure can facilitate more adhered fibroblasts. In summary, gelatin-based scaffolds functionalized by starch-based complex expanded the application of abundant sustainable materials in the biomedical field, especially as antibacterial antioxidant wound dressings.

Emulsion template fabricated heterogeneous bilayer gelatin-based scaffolds with sustained-delivery of lycium barbarum glycopeptide for periodontitis treatment.

Periodontitis is a chronic inflammatory disease raising the risks of tooth-supporting structures destruction and even tooth loss. The way to reconstruct periodontal bone tissues in inflammatory microenvironment has been long in demand for periodontitis treatment. In this study, the lycium barbarum glycopeptide (LbGP) loaded gelatin-based scaffolds were fabricated for periodontitis treatment. Gelatin microspheres with suitable size were prepared by emulsification and gathered by oxidized sodium alginate to prepare heterogeneous bilayer gelatin-based scaffolds, and then they were loaded with LbGP. The prepared scaffolds possessed interconnected porous microstructures, good degradation properties, sufficient mechanical properties, sustained release behavior and well biocompatibility. In vitro experiments suggested that the LbGP loaded gelatin-based scaffolds could inhibit the expression of inflammatory factors (IL-1ß, IL-6, and TNF-α), promote the expression of anti-inflammatory factor (IL-10), and the expression of osteogenic markers (BMP2, Runx2, ALP, and OCN) in PDLSCs under the LPS-stimulated inflammatory microenvironment. Moreover, in rat periodontitis models, the LbGP gelatin-based scaffolds would reduce the alveolar bone resorption of rats, increase the collagen fiber content of periodontal membrane, alleviate local inflammation and improve the expression of osteogenesis-related factors. Therefore, the LbGP loaded gelatin-based scaffolds in this study will provide a potential therapeutic strategy for periodontitis treatment.

ADCY6 is a potential prognostic biomarker and suppresses OTSCC progression via Hippo signaling pathway.

Oral tongue squamous cell carcinoma (OTSCC) is a malignant tumor. Recently, studies have found that adenylate cyclase 6 (ADCY6) plays a pivotal role in many lethal tumors formation processes. The role of ADCY6 in OTSCC remains unknown. The expression of ADCY6 in OTSCC tissue samples was detected. The clinical significance of ADCY6 in OTSCC was analyzed by statistical methods. OTSCC cell lines were selected to analyze the biological function of ADCY6. Meanwhile, the effect of ADCY6 on the growth of OTSCC in vivo was explored using subcutaneous tumorigenesis assay. WB assay was used to detect the underlying signaling pathway. Cell function recovery test used to investigate the mechanism of ADCY6-promoting OTSCC malignant biological behavior via Hippo signaling pathway. We report that ADCY6 was obviously downregulated in OTSCC tissue samples and cell lines. Importantly, lower expression of ADCY6 indicates a poorer prognosis in patients with OTSCC, and its expression is significantly correlated with TNM stage and tumor size. Functionally, forced expression of ADCY6 can significantly inhibit the proliferation, migration, invasion, and promote apoptosis of OTSCC cells. Mechanistically, we demonstrated that ADCY6 upregulation impaired Hippo signaling pathway to reduce the malignant biological behavior of OTSCC. Generally, our findings suggest that ADCY6 suppressed Hippo signaling pathway to regulate malignant biological behavior in OTSCC, which provide new cues for further exploring the mechanism of occurrence and development of OTSCC.

Hexapeptide decorated ß-cyclodextrin delivery system for targeted therapy of bone infection.

Successfully treating bone infections is a major orthopedic challenge. Clinically, oral, intravenous, or intramuscular injections of drugs are usually used for direct or complementary treatment. However, once the drug enters the system, it circulates throughout the body, leading to an insufficient local dose and limiting the therapeutic effect because of the lack of targeting in the drug system. In this study, ß-cyclodextrin, modified with poly (ethylene glycol) [PEG] and aspartic acid hexapeptide (Asp6-ß-CD), was used to specifically target the hydroxyapatite (HA) component of the bone. It was then loaded with norfloxacin (NFX) to treat bone infections. The antibacterial ability of NFX was enhanced by loading it into Asp6-ß-CD, because the solubility of Asp6-ß-CD@NFX increased significantly. Moreover, Asp6-ß-CD could target bone tissue in nude mice and showed significantly enhanced accumulation (10 times) than the unmodified ß-CD. In addition, in a rat model of osteomyelitis, Asp6-ß-CD@NFX targeted HA well and exerted its antibacterial activity, which reduced inflammation and promoted bone tissue repair. This study indicates that the Asp6-ß-CD based drug delivery system can efficiently target bone tissue to enable potential applications for treating bone-related diseases.

Differential Expression Profiling of microRNAs in Human Placenta-Derived Mesenchymal Stem Cells Cocultured with Grooved Porous Hydroxyapatite Scaffolds.

Scaffold materials used for bone defect repair are often limited by osteogenic efficacy. Moreover, microRNAs (miRNAs) are involved in regulating the expression of osteogenic-related genes. In previous studies, we verified the enhancement of osteogenesis using a grooved porous hydroxyapatite scaffold (HAG). In the present study, we analyzed the contribution of HAG to the osteogenic differentiation of human placenta-derived mesenchymal stem cells (hPMSCs) from the perspective of miRNA differential expression. Furthermore, results showed that miRNAs were differentially expressed in the osteogenic differentiation of hPMSCs cocultured with HAG. In detail, 16 miRNAs were significantly upregulated and 29 miRNAs were downregulated with HAG. In addition, bioinformatics analyses showed that the differentially expressed miRNAs were enriched in a variety of biological processes, including signal transduction, cell metabolism, cell junctions, cell development and differentiation, and that they were associated with osteogenic differentiation through axon guidance, mitogen-activated protein kinase, and the transforming growth factor beta signaling pathway. Furthermore, multiple potential target genes of these miRNAs were closely related to osteogenic differentiation. Importantly, overexpression of miR-146a-5p (an upregulated miRNA) promoted the osteogenic differentiation of hPMSCs, and miR-145-5p overexpression (a downregulated miRNA) inhibited the osteogenic differentiation of hPMSCs.

miR-210-3p suppresses osteogenic differentiation of MC3T3-E1 by targeting brain derived neurotrophic factor (BDNF).

BACKGROUND AND OBJECTIVE: As an important mediator of intercellular interaction and formation of extracellular bone matrix, porous scaffolds are widely used for bone regeneration. Accumulating evidences demonstrate that microRNA are involved in the regulation of scaffolds-induced bone regeneration. Recently, we revealed that miR-210-3p was highly expressed during osteogenesis induced by HAG. In present study, we further explored the molecular mechanism underlying the effect of miR-210-3p on osteogenic differentiation. MATERIALS AND METHODS: In this study, miR-210-3p mimics and inhibitors were synthesized and transfected into MC3T3-E1 cells to explore their effects on osteogenic differentiation. The expression of osteogenic marker (Alp and Runx2) were detected by real-time quantitative PCR (qRT-PCR) and western blotting. After osteogenesis induction for 7 days, Alp staining were used to detected osteoblast differentiation of MC3T3-E1 cells. CCK8 and Transwell assays were performed to detected cell proliferation and migration. Then, top ranking list of target genes of miR-210-3p obtained from TargetScan and the expression of BDNF were detected by qRT-PCR and ELISA. The relationship between miR-210-3p and BDNF was verified by luciferase report assay. Furthermore, the effect of BDNF on osteoblast differentiation was verified by transfecting siRNA or adding BDNF to the culture medium. RESULTS: MiR-210-3p mimics markedly suppress osteogenic differentiation, cell migration and cell proliferation of MC3T3-E; nevertheless, silencing of miR-210-3p dramatically enhanced MC3T3-E1 osteogenesis, cell migration and proliferation. Furthermore, luciferase reporter assay verified that brain derived neurotrophic factor (BDNF) is a directly target of miR-210-3p. Moreover, BDNF siRNA significantly decreased the expression levels of ALP and cell migration. The addition of BDNF partially rescued the inhibition of osteogenesis by miR-210-3p. CONCLUSION: miR-210-3p inhibited the osteogenic differentiation via targeting BDNF. Our Results provide a promising target for regulating osteogenic differentiation.

Development and characterization of a mouse floxed Bmp2 osteoblast cell line that retains osteoblast genotype and phenotype.

Bone morphogenetic protein 2 (Bmp2) is essential for osteoblast differentiation and osteogenesis. Generation of floxed Bmp2 osteoblast cell lines is a valuable tool for studying the effects of Bmp2 on osteoblast differentiation and its signaling pathways during skeletal metabolism. Due to relatively limited sources of primary osteoblasts, we have developed cell lines that serve as good surrogate models for the study of osteoblast cell differentiation and bone mineralization. In this study, we established and characterized immortalized mouse floxed Bmp2 osteoblast cell lines. Primary mouse floxed Bmp2 osteoblasts were transfected with pSV3-neo and clonally selected. These transfected cells were verified by PCR and immunohistochemistry. To determine the genotype and phenotype of the immortalized cells, cell morphology, proliferation, differentiation and mineralization were analyzed. Also, expression of osteoblast-related gene markers including Runx2, Osx, ATF4, Dlx3, bone sialoprotein, dentin matrix protein 1, osteonectin, osteocalcin and osteopontin were examined by quantitative RT-PCR and immunohistochemistry. These results showed that immortalized floxed Bmp2 osteoblasts had a higher proliferation rate but preserved their genotypic and phenotypic characteristics similar to the primary cells. Thus, we, for the first time, describe the development of immortalized mouse floxed Bmp2 osteoblast cell lines and present a useful model to study osteoblast biology mediated by BMP2 and its downstream signaling transduction pathways.