Light environment affects the efficiency of surgical suture training.

BACKGROUND: Suture knotting is the basis of surgical skills. In the process of surgical skills learning, the surrounding environment, especially the light, will affect the efficiency of learning. This study investigated the effect of optical environment on the learning of stitching and knotting skills. METHODS: A total of 44 medical students were randomly divided into four groups and participated in the study of suture knotting in four different optical environments. During the process, we assess objective pressure level by testing salivary amylase activity Likert scale and objective structured clinical examination (OSCE) was used to estimate the subjective psychological state and overall skill mastery in surgical suturing respectively. RESULTS: Under high illumination conditions (700 lx), the salivary amylase activity of the high color temperature group (6000 K) was significantly higher than that of the low color temperature group (4000 K) (p < 0.0001). Similarly, under low illumination (300 lx), the salivary amylase activity of the high color temperature group was also significantly higher than that of the low color temperature group (p < 0.05). The student under high illumination conditions (700 lx) and the low color temperature (6000 K) have an autonomy score between 37-45, which is significantly higher compared to the other three groups (p < 0.0001). Group 2 has an average OSCE score of 95.09, which were significantly higher than those of the other three groups (p < 0.05). CONCLUSION: High illumination combined with low color temperature is considered as the optimal training conditions, promoting trainees' optimism, reducing stress levels, and enhancing learning efficiency. These results highlight the pivotal role of light environment in improving the quality and efficiency of surgical skills training.

Associations of residential greenness with bone mineral density and osteoporosis: the modifying effect of genetic susceptibility.

OBJECTIVES: To investigate the associations of residential greenness with bone mineral density and incident osteoporosis, and further evaluate the potential modifying effect of genetic susceptibility. METHODS: We used the Normalised Difference Vegetation Index (NDVI) at various buffer distances, including 300 m (NDVI300m), 500 m (NDVI500m), 1000 m (NDVI1000m) and 1500 m (NDVI1500m), to serve as indicators of greenness. We fitted linear regression, logistic regression and Cox proportional hazard models to assess the associations of residential greenness with estimated bone mineral density (eBMD), prevalent osteoporosis and incident osteoporosis, respectively. With the Polygenic Risk Score (PRS) for osteoporosis, we further assessed the joint effects of genetic risk and greenness on the risk of osteoporosis. We conducted causal mediation analyses to explore potential mediators. RESULTS: Each IQR increase in NDVI300m was associated with 0.0007 (95% CI 0.0002 to 0.0013) increase in eBMD, 6% lower risk of prevalent osteoporosis (OR 0.94; 95% CI 0.92 to 0.97) and 5% lower risk of incident osteoporosis (HR 0.95; 95% CI 0.93 to 0.98). The joint effects of greenness and PRS on the risk of osteoporosis displayed a clear dose-response pattern. Compared with individuals exposed to low NDVI levels and high genetic risk, those exposed to high NDVI levels and low genetic risk had a 56% (95% CI 51% to 61%) lower risk of osteoporosis. The primary mediators in the association between greenness and incident osteoporosis were identified as PM2.5 and NO2. CONCLUSIONS: Residential greenness was associated with higher bone mineral density and decreased risk of incident osteoporosis.

Inhibition of NF-κB and ERK signaling pathways in osteoclasts and M1 macrophage polarization: Mechanistic insights into the anti-osteoporotic effects of Pseudolaric acid B.

Osteoporosis, characterized by bone metabolism disruption leading to gradual bone loss and increased fracture susceptibility, is linked to the excessive activation of osteoclasts. Pseudolaric acid B (PAB), identified as an NF-κB signaling inhibitor crucial for osteoclastogenesis, is explored here for its protective effects in osteoporosis. Noncytotoxic PAB's impact on osteoclast differentiation was assessed through cell viability and osteoclast formation assays, with subsequent testing of osteoclast function via bone resorption assays. Quantitative real-time polymerase chain reaction evaluated PAB's genetic-level impact on osteoclastogenesis. Network pharmacology, western blot, and luciferase reporter gene assays were employed to elucidate PAB's regulatory mechanism. In an in vivo model of osteoporosis induced by ovariectomy (OVX) in mice, micro-CT, H&E staining, and TRAP staining facilitated histomorphometry analysis, while flow cytometry verified macrophage polarization. PAB demonstrated inhibitory effects on osteoclast formation and bone resorption in BMM and RAW264.7 cells, suppressing osteoclast-specific genes. Bioinformatic analysis, western blot, and luciferase assay results indicated PAB's inhibition of IκBα phosphorylation in the NF-κB signaling pathway and ERK in MAPKs, elucidating its mechanism. In vivo experiments confirmed PAB's attenuation of osteoporosis by reducing osteoclast formation in OVX mice. PAB further facilitated macrophage conversion from M1 to M2 and suppressed IL-1ß, TNF-α, and IL-6 synthesis. In conclusion, PAB prevents osteoporosis by inhibiting RANKL-induced osteoclastogenesis through NF-κB and ERK signaling pathway suppression, coupled with macrophage polarization. These findings indicate the potential therapeutic role of PAB in osteoporosis.

TiO2 nanotube topography enhances osteogenesis through filamentous actin and XB130-protein-mediated mechanotransduction.

TiO2 nanotube topography, as nanomechanical stimulation, can significantly promote osteogenesis and improve the osteointegration on the interface of implants and bone tissue. However, the underlying mechanism has not been fully elucidated. XB130 is a member of the actin filament-associated protein family and is involved in the regulation of cytoskeleton and tyrosine kinase-mediated signalling as an adaptor protein. Whether XB130 is involved in TiO2 nanotubes-induced osteogenic differentiation and how it functions in mechano-biochemical signalling transduction remain to be elucidated. In this study, the role of XB130 on TiO2 nanotube-induced osteogenesis and mechanotransduction was systematically investigated. TiO2 nanotube topography was fabricated via anodic oxidation and characterized. The osteogenic effect was significantly accelerated by the TiO2 nanotube surface in vitro and vivo. XB130 was significantly upregulated during this process. Moreover, XB130 overexpression significantly promoted osteogenic differentiation, whereas its knockdown inhibited it. Filamentous actin depolymerization could change the expression and distribution of XB130, thus affecting osteogenic differentiation. Mechanistically, XB130 could interact with Src and result in the activation of the downstream PI3K/Akt/GSK-3ß/ß-catenin pathway, which accounts for the regulation of osteogenesis. This study for the first time showed that the enhanced osteogenic effect of TiO2 nanotubes could be partly due to the filamentous actin and XB130 mediated mechano-biochemical signalling transduction, which might provide a reference for guiding the design and modification of prostheses to promote bone regeneration and osseointegration. STATEMENT OF SIGNIFICANCE: TiO2 nanotubes topography can regulate cytoskeletal rearrangement and thus promote osteogenic differentiation of BMSCs. However, how filamentous actin converts mechanical stimulus into biochemical activity remains unclear. XB130 is a member of actin filament-associated protein family and involves in the regulation of tyrosine kinase-mediated signalling. Therefore, we hypothesised that XB130 might bridge the mechano-biochemical signalling transduction during TiO2 nanotubes-induced osteogenic differentiation. For the first time, this study shows that TiO2 nanotubes enhance osteogenesis through filamentous actin and XB130 mediated mechanotransduction, which provides new theoretical basis for guiding the design and modification of prostheses to promote bone regeneration and osseointegration.

Predicting recurrence and survival in patients with non-metastatic renal-cell carcinoma after nephrectomy: a prospective population-based study with multicenter validation.

BACKGROUND: Accurate prognostication of oncological outcomes is crucial for the optimal management of patients with renal cell carcinoma (RCC) after surgery. Previous prediction models were developed mainly based on retrospective data in the Western populations, and their predicting accuracy remains limited in contemporary, prospective validation. We aimed to develop contemporary RCC prognostic models for recurrence and overall survival (OS) using prospective population-based patient cohorts and compare their performance with existing, mostly utilized ones. METHODS: In this prospective analysis and external validation study, the development set included 11  128 consecutive patients with non-metastatic RCC treated at a tertiary urology center in China between 2006 and 2022, and the validation set included 853 patients treated at 13 medical centers in the USA between 1996 and 2013. The primary outcome was progression-free survival (PFS), and the secondary outcome was OS. Multivariable Cox regression was used for variable selection and model development. Model performance was assessed by discrimination [Harrell's C-index and time-dependent areas under the curve (AUC)] and calibration (calibration plots). Models were validated internally by bootstrapping and externally by examining their performance in the validation set. The predictive accuracy of the models was compared with validated models commonly used in clinical trial designs and with recently developed models without extensive validation. RESULTS: Of the 11  128 patients included in the development set, 633 PFS and 588 OS events occurred over a median follow-up of 4.3 years [interquartile range (IQR) 1.7-7.8]. Six common clinicopathologic variables (tumor necrosis, size, grade, thrombus, nodal involvement, and perinephric or renal sinus fat invasion) were included in each model. The models demonstrated similar C-indices in the development set (0.790 [95% CI 0.773-0.806] for PFS and 0.793 [95% CI 0.773-0.811] for OS) and in the external validation set (0.773 [0.731-0.816] and 0.723 [0.731-0.816]). A relatively stable predictive ability of the models was observed in the development set (PFS: time-dependent AUC 0.832 at 1 year to 0.760 at 9 years; OS: 0.828 at 1 year to 0.794 at 9 years). The models were well calibrated and their predictions correlated with the observed outcome at 3, 5, and 7 years in both development and validation sets. In comparison to existing prognostic models, the present models showed superior performance, as indicated by C-indices ranging from 0.722 to 0.755 (all P <0.0001) for PFS and from 0.680 to 0.744 (all P <0.0001) for OS. The predictive accuracy of the current models was robust in patients with clear-cell and non-clear-cell RCC. CONCLUSIONS: Based on a prospective population-based patient cohort, the newly developed prognostic models were externally validated and outperformed the currently available models for predicting recurrence and survival in patients with non-metastatic RCC after surgery. The current models have the potential to aid in clinical trial design and facilitate clinical decision-making for both clear-cell and non-clear-cell RCC patients at varying risk of recurrence and survival.

Unraveling the potential mechanisms of the anti-osteoporotic effects of the Achyranthes bidentata-Dipsacus asper herb pair: a network pharmacology and experimental study.

Background: Osteoporosis is a prevalent bone metabolism disease characterized by a reduction in bone density, leading to several complications that significantly affect patients' quality of life. The Achyranthes bidentata-Dipsacus asper (AB-DA) herb pair is commonly used in Traditional Chinese Medicine (TCM) to treat osteoporosis. This study aimed to investigate the therapeutic compounds and potential mechanisms of AB-DA using network pharmacology, molecular docking, molecular dynamics simulation, and experimental verification. Methods: Identified compounds of AB-DA were collected from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), Traditional Chinese Medicine Information Database (TCM-ID), TCM@Taiwan Database, BATMAN-TCM, and relevant literature. The main bioactive ingredients were screened based on the criteria of "OB (oral bioavailability) ≥ 30, DL (drug-likeness) ≥ 0.18." Potential targets were predicted using the PharmMapper and SwissTargetPrediction websites, while disease (osteoporosis)-related targets were obtained from the GeneCards, DisGeNET, and OMIM databases. The PPI network and KEGG/GO enrichment analysis were utilized for core targets and pathway screening in the STRING and Metascape databases, respectively. A drug-compound-target-pathway-disease network was constructed using Cytoscape software to display core regulatory mechanisms. Molecular docking and dynamics simulation techniques explored the binding reliability and stability between core compounds and targets. In vitro and in vivo validation experiments were utilized to explore the anti-osteoporosis efficiency and mechanism of sitogluside. Results: A total of 31 compounds with 83 potential targets for AB-DA against osteoporosis were obtained. The PPI analysis revealed several hub targets, including AKT1, CASP3, EGFR, IGF1, MAPK1, MAPK8, and MAPK14. GO/KEGG analysis indicated that the MAPK cascade (ERK/JNK/p38) is the main pathway involved in treating osteoporosis. The D-C-T-P-T network demonstrated therapeutic compounds that mainly consisted of iridoids, steroids, and flavonoids, such as sitogluside, loganic acid, and ß-ecdysterone. Molecular docking and dynamics simulation analyses confirmed strong binding affinity and stability between core compounds and targets. Additionally, the validation experiments showed preliminary evidence of antiosteoporosis effects. Conclusion: This study identified iridoids, steroids, and flavonoids as the main therapeutic compounds of AB-DA in treating osteoporosis. The underlying mechanisms may involve targeting core MAPK cascade (ERK/JNK/p38) targets, such as MAPK1, MAPK8, and MAPK14. In vivo experiments preliminarily validated the anti-osteoporosis effect of sitogluside. Further in-depth experimental studies are required to validate the therapeutic value of AB-DA for treating osteoporosis in clinical practice.

The incidence, risk factors and outcomes of wound complications after preoperative radiotherapy and surgery for high grade extremity soft tissue sarcomas: A 14-year retrospective study.

OBJECTIVE: The aim of this study was to analyze the wound complication (WC) rate and to determine the risk factors for WC in patients with soft tissue sarcoma treated with preoperative radiotherapy followed by surgical resection. METHODS: Using the database of Oxford University Hospital (OUH) we retrospectively studied 126 cases of soft tissue sarcomas treated with preoperative radiotherapy and surgery between 2007 and 2021. WC were defined as minor wound complication (MiWC) not requiring surgical intervention or major wound complication (MaWC) if they received a secondary surgical intervention. Univariate and multiple regression analyses were performed using frequency of WC and MaWC as a dependent variable. RESULTS: The incidence of WC and MaWC was 43.7% (55/126) and 19% (24/126). Age (OR:1.03, 95%CI: 1.00-1.06, p = 0.016), tumor size (OR:1.11, 95%CI:1.01-1.21, p = 0.027) and tumor site namely proximal lower limb vs upper limb (OR:10.87, 95%CI 1.15-103.03, p = 0.038) were risk factors on multivariate analysis. In nested case control analysis, the incidence of MaWC was 43.6% (24/55), the mean recovery time is 143 days in patients with MaWC. Smoking increases the risk for MaWC (OR:8.32, 95%CI:1.36-49.99, p = 0.022). The time interval between surgery and wound complication reduces the risk for MaWC (OR:0.91, 95%CI:0.84-0.99, p = 0.028) in multivariate analysis. CONCLUSIONS: Age, tumor site and size are risk factors for WC requiring preoperative radiotherapy. Smoking and the time interval between surgery and wound complication are risk factors for MaWC as compared with MiWC. MaWC rate (19%) are comparable to those in postoperative radiotherapy and surgery alone.

Toosendanin inhibits osteoclast formation and alleviate postmenopausal osteoporosis by regulating the p38 signaling pathway.

Disruption of the balance between osteoclasts and osteoblasts could lead to bone diseases including osteoporosis. It's well known that RANKL-RANK signaling plays a vital role in activating osteoclasts. Herein, we explored the therapeutic effects of toosendanin (TSN) in osteoporosis, showing that TSN attenuated RANKL-stimulated osteoclastogenesis and osteoclast-specific gene expression in vitro. Bioinformatics predicted that TSN could interfere p38 subunits and regulate the MAPK cascade, and we further verified and demonstrated that TSN significantly inhibited RANKL-induced p38 signaling through western blot. In ovariectomized mouse model, TSN effectively inhibited the formation of TRAP-positive osteoclasts and exhibited protective effect against bone loss. Altogether, these data indicate that TSN targeted p38 activation to inhibit osteoclastogenesis, suggesting the possible therapeutic use of TSN in osteoporosis in the future.

Sequentially activating macrophages M1 and M2 phenotypes by lipopolysaccharide-containing Mg-Fe layered double hydroxides coating on the Ti substrate.

As cells of innate immunity, macrophages are a class of innate immune cells existing in almost all tissues and play a crucial role in bone repair. However, it remains a challenge to modulate the sequential activation of the deferent phenotypes in macrophage when designing the titanium (Ti) implants. In this study, the Mg-Fe layered double hydroxides (LDHs) was coated on Ti substrate through hydrothermal treatment. Further on lipopolysaccharide (LPS) was introduced onto the LDHs through adsorption and ions exchange. The adsorption efficiency of the coating on LPS reached 72.8% in 24 h due to the anion exchange and electrostatic interactions between the LPS and the LDH layers in deionized water. The LDHs-LPS coating released a large amount of LPS in the early stage, which induced macrophages into M1 phenotype via activating TLR-4 → MyD88 and TLR-4 → Ticam-1/2 signal pathways. Subsequently, the M1 macrophages were transformed into M2 phenotype by regulating the integrin α5ß1 of cells by the nanostructures, wetting angle and Mg2+ of the coating. The LDHs-LPS coating endows Ti with the ability of stage immunomodulation, indicating the positive osteoimmunomodulatory property.

Nomogram Predicting the Risk of Postoperative Major Wound Complication in Soft Tissue Sarcoma of the Trunk and Extremities after Preoperative Radiotherapy.

Preoperative radiotherapy increases the risk of postoperative wound complication in the treatment of soft tissue sarcoma (STS). This study aims to develop a nomogram for predicting major wound complication (MaWC) after surgery. Using the Oxford University Hospital (OUH) database, a total of 126 STS patients treated with preoperative radiotherapy and surgical resection between 2007 and 2021 were retrospectively reviewed. MaWC was defined as a wound complication that required secondary surgical intervention. Univariate and multivariate regression analyses on the association between MaWC and risk factors were performed. A nomogram was formulated and the areas under the Receiver Operating Characteristic Curves (AUC) were adopted to measure the predictive value of MaWC. A decision curve analysis (DCA) determined the model with the best discriminative ability. The incidence of MaWC was 19%. Age, tumour size, diabetes mellitus and metastasis at presentation were associated with MaWC in the univariate analysis. Age, tumour size, and metastasis at presentation were independent risk factors in the multivariate analysis. The sensitivity and specificity of the predictive model is 0.90 and 0.76, respectively. The AUC value was 0.86. The nomogram constructed in the study effectively predicts the risk of MaWC after preoperative radiotherapy and surgery for STS patients.

Sequential activation of M1 and M2 phenotypes in macrophages by Mg degradation from Ti-Mg alloy for enhanced osteogenesis.

BACKGROUND: Even though the modulatory effects of Magnisum (Mg) and its alloys on bone-healing cells have been widely investigated during the last two decades, relatively limited attention has been paid on their inflammation-modulatory properties. Understanding the activation process of macrophages in response to the dynamic degradation process of Mg as well as the relationship between macrophage phenotypes and their osteogenic potential is critical for the design and development of advanced Mg-based or Mg-incorporated biomaterials. METHODS: In this work, a Ti-0.625 Mg (wt.%) alloy fabricated by mechanical alloying (MA) and subsequent spark plasma sintering (SPS) was employed as a material model to explore the inflammatory response and osteogenic performance in vitro and in vivo by taking pure Ti as the control. The data analysis was performed following Student's t-test. RESULTS: The results revealed that the macrophages grown on the Ti-0.625 Mg alloy underwent sequential activation of M1 and M2 phenotypes during a culture period of 5 days. The initially increased environmental pH (~ 8.03) was responsible for the activation of M1 macrophages, while accumulated Mg2+ within cells contributed to the lateral M2 phenotype activation. Both M1 and M2 macrophages promoted osteoblast-like SaOS-2 cell maturation. In vivo experiment further showed the better anti-inflammatory response, regenerative potentiality and thinner fibrous tissue layer for the Ti-0.625 Mg alloy than pure Ti. CONCLUSION: The results highlighted the roles of Mg degradation in the Ti-0.625 Mg alloy on the sequential activation of macrophage phenotypes and the importance of modulating M1-to-M2 transition in macrophage phenotypes for the design and development of inflammation-modulatory biomaterials.

[Bioinformatics Analysis on Key Genes and Immune Infiltration of Osteosarcoma].

Objective To screen the potential key genes of osteosarcoma by bioinformatics methods and analyze their immune infiltration patterns. Methods The gene expression profiles GSE16088 and GSE12865 associated with osteosarcoma were obtained from the Gene Expression Omnibus(GEO),and the differentially expressed genes(DEGs)related to osteosarcoma were screened by bioinformatics tools.Gene Ontology(GO)annotation,Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment,and analysis of immune cell infiltration were then carried out for the DEGs.The potential Hub genes of osteosarcoma were identified by protein-protein interaction network,and the expression of Hub genes in osteosarcoma and normal tissue samples was verified via the Cancer Genome Atlas(TCGA). Results A total of 108 DEGs were screened out.GO annotation and KEGG pathway enrichment revealed that the DEGs were mainly involved in integrin binding,extracellular matrix (ECM) structural components,ECM receptor interactions,and phosphatidylinositol 3-kinase/protein kinase B(PI3K/Akt)signaling pathway.Macrophages were the predominant infiltrating immune cells in osteosarcoma.Secreted phosphoprotein 1(SPP1),matrix metallopeptidase 2(MMP2),lysyl oxidase(LOX),collagen type V alpha(II)chain(COL5A2),and melanoma cell adhesion molecule(MCAM)presented differential expression between osteosarcoma and normal tissue samples(all P<0.05). Conclusions SPP1,MMP2,LOX,COL5A2,and MCAM are all up-regulated in osteosarcoma,which may serve as potential biomarkers of osteosarcoma.Macrophages are the key infiltrating immune cells in osteosarcoma,which may provide new perspectives for the treatment of osteosarcoma.

Punicalin Attenuates Breast Cancer-Associated Osteolysis by Inhibiting the NF-κB Signaling Pathway of Osteoclasts.

Background: Breast cancer bone metastasis and osteoporosis are both severe diseases that seriously threaten human health. These diseases are closely associated with osteolytic lesions. And osteoclasts are the key targets of this pathological process. Given the lack of effective preventive or treatment options against these diseases, the exploitation of new pharmacological agents is critically required. Method: We assessed the efficacy of punicalin on receptor activator of nuclear factor-κB ligand (RANKL)-mediated osteoclast formation, F-actin ring formation, gene expression, bone resorption, nuclear factor-κB (NF-κB) as well as on mitogen-activated protein kinase (MAPK) signaling pathways and molecular docking in vitro. The impact of punicalin on breast cancer-induced osteoclastogenesis, breast cancer cell proliferation, and apoptosis were examined. Transwell assays were also performed. Moreover, we evaluated in vivo effects of punicalin in postmenopausal osteoporosis models and breast cancer bone metastasis model by micro-CT scanning and histomorphometry. Results: Punicalin inhibited osteoclast formation, F-actin ring formation, bone resorption, as well as osteoclast-related gene expression by suppressing the NF-κB signaling pathway. In vitro, punicalin also suppressed the breast cancer-induced osteoclastogenesis, and proliferation, migration as well as invasion of MDA-MB-231 cells and dose-dependently promoted their apoptosis. In vivo, punicalin significantly suppressed breast cancer-induced osteolysis, breast cancer-associated bone metastasis, and ovariectomized (OVX)-mediated osteoporosis by repressing osteoclast and breast cancer cell. Conclusion: Punicalin is expected to offer a novel treatment for the prevention of osteolysis diseases, including osteoporosis and breast cancer-associated osteolysis.

Epigenetic modifications of tumor necrosis factor-alpha in joint cartilage tissue from osteoarthritis patients - CONSORT.

BACKGROUND: Osteoarthritis (OA) remains one of the most common osteopathy for centuries, which can be attributed to multiple risk factors including mechanical and biochemical ones. More and more studies verified that inflammatory cytokines play important roles in the progression of OA, such as tumor necrosis factor-alpha (TNF-α). In this study, we aimed to investigate the relationship between epigenetic manifestations of TNF-? and the pathogenesis of OA. METHODS: Totally, 37 OA patients' cartilage was collected through the knee joint and 13 samples of articular cartilage as healthy control was collected through traumatic amputation. Real-time PCR, Western blot and ELISA analysis were performed to observe the expression of target genes and proteins in collected samples. RESULTS: Compared with the healthy control group, TNF-? was over-expressing in cartilage which was collected from OA patients. DNA hypomethylation, histone hyperacetylation and histone methylation were observed in the TNF-? promoter in OA compared with normal patients, and we also studied series of enzymes associated with epigenetics. The results showed that by increasing DNA methylation and decreasing histone acetylation in the TNF-? promoter, and TNF-? over-expression in OA cartilage was suppressed, histone methylation has no significant correlation with OA. CONCLUSION: In conclusion, the changes of epigenetic status regulate TNF-α expression in the cells, which are pivotal to the OA disease process. These results may give us a better understanding of OA and may provide new therapeutic options.

Cimifugin Suppresses NF-κB Signaling to Prevent Osteoclastogenesis and Periprosthetic Osteolysis.

Background: Aseptic loosening of prosthesis (ALP) is one of the most common long-term complications of knee and hip arthroplasty. Wear particle-induced osteoclastogenesis and subsequent periprosthetic osteolysis account for the morbidity of ALP. Here, we investigate the potential of cimifugin (CIM), a natural extract from Cimicifuga racemosa and Saposhnikovia divaricata, as a bone-protective drug in the treatment of ALP. Method: First, we performed cell viability and osteoclast formation assays to assess the effect of noncytotoxic CIM on osteoclast differentiation in vitro. Bone slice resorption and F-actin ring immunofluorescence assays were adopted to assess the effects of CIM on bone-resorption function. Then, quantitative real-time polymerase chain reaction (qRT-PCR) analysis was performed to further assess the repressive effects of CIM on osteoclastogenesis at the gene expression level. To elucidate the mechanisms underlying the above findings, Western blot and luciferase reporter gene assays were used to assess the regulatory effects of CIM on the NF-κB and MAPK signaling pathways. Moreover, a Ti particle-induced murine calvarial osteolysis model and subsequent histomorphometric analysis via micro-CT and immunohistochemical staining were used to elucidate the effect of CIM on periprosthetic osteolysis in vivo. Result: CIM dose-dependently inhibited both bone marrow-derived macrophage (BMM)- and RAW264.7 cell-derived osteoclastogenesis and bone resorption pit formation in vitro, which was further supported by the reduced expression of F-actin and osteoclast-specific genes. According to the Western blot analysis, inhibition of IκBα phosphorylation in the NF-κB signaling pathway, not the phosphorylation of MAPKs, was responsible for the suppressive effect of CIM on osteoclastogenesis. Animal experiments demonstrated that CIM alleviated Ti particle-induced bone erosion and osteoclast accumulation in murine calvaria. Conclusion: The current study suggested for the first time that CIM can inhibit RANKL-induced osetoclastogenesis by suppressing the NF-κB signaling pathway in vitro and prevent periprosthetic osteolysis in vivo. These findings suggest the potential of CIM as a therapeutic in ALP.

Facile synthesis of multi-functional nano-composites by precise loading of Cu2+ onto MgO nano-particles for enhanced osteoblast differentiation, inhibited osteoclast formation and effective bacterial killing.

Biomaterials with multi-functions including enhancing osteogenesis, inhibiting osteoclastogenesis and effectively removing bacteria are urgently needed in the treatment of osteoporotic bone defects. In this study, MgO nano-particles were employed as a platform for precise Cu2+ loading. By immersing MgO into CuSO4 solution with a pre-defined concentration (0.1, 1 or 10 mM), 1 mg MgO adsorbed 3.25, 32.5 or 325 µg Cu2+ from the solution. As-synthesized nano-composites were referred as MgO-0.1Cu, MgO-1Cu or MgO-10Cu depending on the concentration of employed CuSO4 solution. The results revealed that MgO-xCu (x = 0.1, 1 and 10) nano-composites were lamella-shaped and composed of amorphous Cu(OH)2, crystalline Mg(OH)2 and minor MgO. The extracellular release of Cu2+ was rather limited due the capture of Cu2+ by Mg(OH)2. In vitro results revealed that MgO-xCu (x = 0.1, 1 and 10) nano-composites modulated osteoblast, osteoclast and bacterium response in a Cu2+ loading amount-dependent manner. MgO-0.1Cu nano-composite exhibited stimulatory function on osteoblast proliferation without influencing osteoblast maturation, osteoclast formation and bacterial survival. MgO-1Cu nano-composite enhanced osteoblast proliferation and differentiation, inhibited osteoclast formation and effectively killed bacteria. When larger amount of Cu2+ was loaded, MgO-10Cu nano-composite exhibited stronger stimulatory effect on osteoblast maturation, enhanced inhibitory function on osteoclast formation and promoted bactericidal performance, although it showed a certain degree of initial cyto-toxicity. Together, the results suggest that MgO nano-particles could be employed as potential platform for precise Cu2+ loading and intracellular Cu2+ delivery. MgO-xCu (x = 1 and 10) nano-composites are promising to be employed as multi-functional fillers in bone tissue engineering scaffolds for osteoporotic bone regeneration.

MiR-99b-5p suppressed proliferation of human osteoblasts by targeting FGFR3 in osteoporosis.

Osteoporosis is a common skeletal disease characterized by reduced bone mass partially caused by an imbalance between bone resorption and formation. Considering the potential role of microRNAs (miRNAs) in osteoporosis, we attempted to identify deregulated miRNA that participates in the pathogenesis of osteoporosis. We analyzed online datasets for differentially expressed miRNAs and predicted deregulated miRNA target genes, applied these genes for signaling pathway enrichment annotation, and selected the possible miR-99b-5p/FGFR3 axis. Within osteoporosis bone tissues, miR-99b-5p was upregulated and FGFR3 was downregulated. miR-99b-5p overexpression inhibited osteoblast proliferation and osteogenesis-related genes expression, whereas FGFR3 overexpression exerted opposite effects upon the proliferation of osteoblasts and osteogenesis-related genes expression. By direct targeting, miR-99b-5p inhibited FGFR3 expression. Moreover, FGFR3 silencing significantly reversed the roles of miR-99b-5p inhibition in the proliferation of osteoblasts and osteogenesis-related genes expression. In conclusion, we identify a deregulated miRNA/mRNA axis in osteoporosis and osteogenic differentiation, namely the miR-99b-5p/FGFR3 axis; through targeting FGFR3, miR-99b-5p inhibits osteoblast proliferation and activity, which might subsequently affect the bone formation in osteoporosis progression.