Characterization of DNA methylation as well as mico-RNA expression and screening of epigenetic markers in adipogenesis.

This study aimed to use bioinformatics methods to characterize epigenetic changes in terms of micro-RNA(miRNA) expression and DNA methylation during adipogenesis. The mRNA and miRNA expression microarray and DNA methylation dataset were obtained from the GEO database. Differentially expressed genes (DEGs), differentially expressed miRNAs (DEMs) and differentially methylated probes (DMPs) were filtered using the limma package. The R language cluster profile package was used for functional and enrichment analysis. A protein-protein interaction (PPI) network was constructed using STRING and visualized in Cytoscape. The Connection map (CMap) website tool was used to screen potential therapeutic drugs for adipogenesis. When comparing the early and late stages of adipogenesis, 111 low miRNA targeted upregulated genes and 64 high miRNA targeted downregulated genes were obtained, as well as 663 low-methylated high-expressed genes and 237 high-methylated low-expressed genes. In addition, 41 genes (24 upregulated and 17 downregulated) were simultaneously regulated by abnormal miRNA changes and DNA methylation. Ten chemicals were identified as putative therapeutics for adipogenesis. In addition, among the dual-regulated genes identified, CANX, HNRNPA1, MCL1, and PPIF may play key roles in the epigenetic regulation of adipogenesis and may serve as aberrant methylation or miRNA targeting biomarkers.

CX3CL1 in the red bone marrow promotes renal cell carcinoma to metastasize to the spine by involving the Src-related pathway.

Spinal metastasis (SM) frequently occurs in renal cell carcinoma (RCC) patients. Our preliminary work showed that CX3CL1 plays a positive role in SM. The objective of the present study was to verify whether CX3CL1 activates the downstream pathway by binding to CX3CR1 in RCC cells, ultimately promoting RCC to metastasize to the spine. The expression of CX3CL1 and CX3CR1 in tissue samples was detected by immunohistochemistry and western blotting. ELISA was used to quantify the concentration of CX3CL1 in the serum. The expression level of CX3CR1 in RCC cell lines was also detected. The CellTiter-Glo assay and flow cytometry were used to analyze cell viability and apoptosis of RCC cells. Transwell and wound healing assay were used to analyze the effect of CX3CL1 on the invasion and migration ability of RCC cells. Specific inhibitors were used to interfere with key molecules in the signaling pathway to further explore the signal transduction in RCC cells after CX3CL1 stimulation. The expression of CX3CR1 in SM from RCC was higher than that in limb bone metastases. Among the five RCC cell lines, 786O cells expressed the highest level of CX3CR1. CX3CL1 neither inhibited the proliferation of 786O cells nor promoted the apoptosis of 786O cells. However, it promoted the migration and invasion of RCC cells. After CX3CL1 stimulation, Src and Focal adhesion kinase (FAK) phosphorylation levels increased in RCC cells. Bosutinib and PF-00562271 inhibited Src/FAK phosphorylation and cell motility and invasion triggered by CX3CL1 stimulation. CX3CL1 in the red bone marrow of spinal cancellous bone enhances migration and invasion abilities of RCC cells, thereby promoting RCC metastasize to the spine. The migration and invasion of RCC cells activated by CX3CL1 are at least partially dependent on Src/FAK activation.

The Bare Area of the Proximal Ulna: An Anatomic Study With Relevance to Chevron Osteotomy.

PURPOSE: A chevron osteotomy of the ulna is widely used to obtain intra-articular access to the elbow in the treatment of type C distal humerus fractures. The trochlear notch of the proximal ulna is divided into 2 articular parts by the "bare area." Ideally, the olecranon osteotomy should be centered on the bare area to minimize damage to the joint cartilage. The goals of this study were to describe the anatomy of the bare area and design an ideal chevron-shaped osteotomy. METHODS: We dissected 38 cadaver elbows and measured the width of the bare area, the distance between the tip of the triceps insertion and the area on the olecranon cortex corresponding to the bare area. We then designed a chevron osteotomy to stay within the bare area and measured the distance from the tip of the triceps insertion to the osteotomy apex as well as the angle of the osteotomy plane and the angle of the chevron cuts. RESULTS: The bare area existed in all 38 cadavers. The mean longitudinal and transverse widths were 4.0 mm (range, 1.0-8.6 mm) and 19.0 mm (range, 16.9-23.8 mm), respectively. The mean distance between the tip of the triceps insertion and the area on the olecranon cortex corresponding to the bare area was 19.0 mm (range, 16.0-23.0 mm). The mean transverse and longitudinal widths of the cortical notch were 3.0 mm (range, 1.6-4.5 mm) and 8.0 mm (range, 6.5-14.8 mm), respectively. The mean distance between the tip of the triceps insertion and the osteotomy apex was 22.0 mm (range, 18.0-24.0 mm) and the mean angle between the osteotomy surface and the vertical plane corresponding to the tangent plane was 20° (range, 10° to 25°). The mean angle of the V shape was 140° (range, 130° to 150°). CONCLUSIONS: Using the narrowest edge lacking cartilage (lateral or medial side) as a point of reference to locate the bare area, the designed chevron osteotomy entered the joint in the bare area in most specimens and decreased associated damage to the joint cartilage. CLINICAL RELEVANCE: This study describes the anatomy of the bare area and the design of the ideal chevron-shaped osteotomy to treat type C distal humerus fractures.

Leaf Extract of Perilla frutescens (L.) Britt Promotes Adipocyte Browning via the p38 MAPK Pathway and PI3K-AKT Pathway.

The leaf of Perilla frutescens (L.) Britt (PF) has been reported to negatively affect adipocyte formation, inhibit body-fat formation, and lower body weight. However, its effect on adipocyte browning remains unknown. Thus, the mechanism of PF in promoting adipocyte browning was investigated. The ingredients of PF were acquired from the online database and filtered with oral bioavailability and drug-likeness criteria. The browning-related target genes were obtained from the Gene Card database. A Venn diagram was employed to obtain the overlapped genes that may play a part in PF promoting adipocyte browning, and an enrichment was analysis conducted based on these overlapped genes. A total of 17 active ingredients of PF were filtered, which may regulate intracellular receptor-signaling pathways, the activation of protein kinase activity, and other pathways through 56 targets. In vitro validation showed that PF promotes mitochondrial biogenesis and upregulates brite adipocyte-related gene expression. The browning effect of PF can be mediated by the p38 MAPK pathway as well as PI3K-AKT pathway. The study revealed that PF could promote adipocyte browning through multitargets and multipathways. An in vitro study validated that the browning effect of PF can be mediated by both the P38 MAPK pathway and the PI3K-AKT pathway.

Harmine loaded Au@MSNs@PEG@Asp6 nano-composites for treatment of spinal metastasis from lung adenocarcinoma by targeting ANXA9 in vivo experiment.

Background: Annexin A9 (ANXA9) has been proved to be concerned with cancer development. However, to explore the clinical consequences of ANXA9 in lung adenocarcinoma (LUAD), especially its correlation to spinal metastasis (SM) has no in-depth study. The study was expected to elucidate the mechanism of ANXA9 in regulating SM of LUAD and create a productive nano-composites delivery system targeting this gene for treatment of SM. Methods: Harmine (HM), a ß-carboline extracted from the traditional Chinese herb Peganum harmala, loaded Au@MSNs@PEG@Asp6 (NPS) nano-composites were synthesized. Bioinformatics analysis and clinical specimens' tests were used to verify the association between ANXA9 and prognosis of LUAD with SM. The immunohistochemistry (IHC) was employed to detect the expression levels of the ANXA9 protein in LUAD tissues with or without SM, and its significance in clinic was also explored. ANXA9­siRNA was applied to investigate the molecular mechanism of ANXA9 in tumor behaviors. The HM release kinetics was detected by high performance liquid chromatography (HPLC) method. The cellular uptake efficiency of nanoparticles by A549 cells was observed by fluorescence microscope. Antitumor effects of nanoparticles were assessed in the nude mouse model of SM. Results: The genomic amplification of ANXA9 was prevalent in LUAD tissues and closely associated with poor outcome and SM (P<0.01). The experimental result manifested that high expression of ANXA9 could lead to wretched prognosis and ANXA9 was an independent risk factor for survival (P<0.05). After impeding expression of ANXA9, the proliferation and metastatic ability of tumor cells obviously decreased, and expression of matrix metallopeptidase 2 (MMP-2) and matrix metallopeptidase 9 (MMP-9) were considerably downregulated, while the expression of associated oncogene pathway were downregulated (P<0.01) as well. The synthesized HM-loaded NPS nano-composites could target to cancer and response to reactive oxygen species (ROS) to release HM slowly. Notably, in comparison to free HM, the nano-composites showed excellent targeting and anti-tumor effects in the A549 cell-bearing mouse model. Conclusions: ANXA9 may serve as a novel biomarker for predicting poor prognosis in LUAD, and we provided an efficient and targeting drug delivery nano-composites system for precise treatment of SM from LUAD.

Deep learning of bone metastasis in small cell lung cancer: A large sample-based study.

Introduction: Bone is a common metastatic site for small cell lung cancer (SCLC). Bone metastasis (BM) in patients have are known to show poor prognostic outcomes. We explored the epidemiological characteristics of BM in SCLC patients and create a new deep learning model to predict outcomes for cancer-specific survival (CSS) and overall survival (OS). Materials and Methods: Data for SCLC patients diagnosed with or without BM from 2010 to 2016 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox proportional hazards regression models were used to evaluate the effects of prognostic variables on OS and CSS. Through integration of these variables, nomograms were created for the prediction of CSS and OS rates at 3-month,6- month,and 12-month. Harrell's coordination index, calibration curves,and time- dependent ROC curves were used to assess the nomograms' accuracy. Decision tree analysis was used to evaluate the clinical application value of the established nomogram. Results: In this study, 4201 patients were enrolled. Male sex, tumor size 25 but <10, brain and liver metastases, as well as chemotherapy were associated with a high risk for BM. Tumor size, Age, N stage, gender, liver metastasis, radiotherapy as well as chemotherapy were shown to be prognostic variables for OS, and the prognostic variables for CSS were added to the tumor number in addition. Based on these results, nomograms for CSS and OS were established separately. Internal as well as external validation showed that the C-index, calibration cuurve and DCA had good constructive correction effect and clinical application value. Decision tree analysis further confirmed the prognostic factors of OS and CSS. Discussion: The nomogram and decision tree models developed in this study effectively guided treatment decisions for SCLC patients with BM. The creation of prediction models for BM SCLC patients may be facilitated by deep learning models.

Epigenetic Biomarkers Screening of Non-Coding RNA and DNA Methylation Based on Peripheral Blood Monocytes in Smokers.

This study aims to use bioinformatics methods to determine the epigenetic changes in microRNA expression and DNA methylation caused by cigarette smoking. The data of mRNA, miRNA expression, and methylation microarray were obtained from the GEO database to filter differentially expressed genes (DEGs), differentially expressed miRNAs (DEMs), and methylated CpG probes (DMPs) through the limma package. The R clusterProfile package was used for functional annotation and enrichment analysis. The protein-protein interaction (PPI) network was constructed by the String database and visualized in Cytoscape software. Starbase database was employed to predict lncRNA and CirRNA based on the sequence of miRNA, and to establish a regulatory network of ceRNA. By overlapping DEG and DEM, 107 down-miRNA-targeted up-regulated genes and 65 up-miRNA-target down-regulated genes were obtained, which were mainly enriched in autophagy signaling pathways and protein ubiquitination pathways, respectively. In addition, 324 genes with low methylation and high expression and 204 genes with high methylation and low expression were respectively related to the degeneration of the nervous system and the function of the cardiovascular system. Interestingly, 43 genes were up-regulated under the dual regulation of reduced miRNA and hypomethylation, while 14 genes were down-regulated under the dual regulation of increased miRNA and hypermethylation. Ten chemicals have been identified as putative therapeutic agents for pathological conditions caused by smoking. In addition, among these genes, HSPA4, GRB2, PRKCA, and BCL2L1 could play a fundamental role in related diseases caused by smoking and may be used as the biomarkers for precise diagnosis and targets for future therapies of smoking-related diseases.

Biomechanical restoration of metastatic cancer-induced peri-acetabular bone defects by ablation-osteoplasty-reinforcement-internal fixation technique (AORIF): To screw or not to screw?

BACKGROUND: Minimally invasive percutaneous polymethyl methacrylate cement augmentation procedures offer numerous clinical advantages for patients with periacetabular osteolytic metastatic bone defects in contrast to open reconstructive procedures that are associated with many complications. Several techniques, such as Ablation-Osteoplasty-Reinforcement-Internal Fixation (AORIF), cementoplasty alone, and screw fixation alone are currently used. There is no consensus on optimal skeletal reinforcement of diseased bones. The purpose of this study was to determine the most effective technique of percutaneous acetabular augmentation for joint preservation, with respect to resilience on cyclic loading and fracture pattern at maximal load to failure. METHODS: Five cohorts of hemipelvis composite bones with uniform periacetabular defects and various types of reinforcement techniques were utilized to simulate osteolytic metastasis in the weight bearing dome of the acetabulum. Five groups of hemipelves underwent finite element analysis and biomechanical testing for load to failure, energy absorption to failure, stress relaxation on cyclic loading, and fracture locations. RESULTS: The combination of screws and bone cement augmentation demonstrated significant higher energy absorption than the cement or screw only groups (p < 0.05), and better protection of acetabulum from displaced intraarticular fractures than the screws alone oror cement only groups (p < 0.05). Resilience to cyclic loading was higheest in the screw with cement fixation group than the screw only repair (p < 0.01), though not the cement fixation only group. INTERPRETATION: These data support the hypothesis that cementoplasty combined with screw augmentation such as the AORIF technique provides the best protection of acetabulum from massive metastatic cancer-induced acetabular fractures compared to augmentation with screws or cement alone.

Preoperative prediction of microvascular invasion in non-metastatic hepatocellular carcinoma based on nomogram analysis.

PURPOSE: The presence of microvascular invasion (MVI) is an unfavorable prognostic factor for hepatocellular carcinoma (HCC). This study aimed to construct a nomogram-based preoperative prediction model of MVI, thereby assisting to preoperatively select proper surgical procedures. METHODS: A total of 714 non-metastatic HCC patients undergoing radical hepatectomy were retrospectively selected from Zhongshan Hospital between 2010 and 2018, followed by random assignment into training (N = 520) and validation cohorts (N = 194). Nomogram-based prediction model for MVI risk was constructed by incorporating independent risk factors of MVI presence identified from multivariate backward logistic regression analysis in the training cohort. The performance of nomogram was evaluated by calibration curve and ROC curve. Finally, decision curve analysis (DCA) was used to determine the clinical utility of the nomogram. RESULTS: In total, 503 (70.4%) patients presented MVI. Multivariate analysis in the training cohort revealed that age (OR: 0.98), alpha-fetoprotein (≥400 ng/mL) (OR: 2.34), tumor size (>5 cm) (OR: 3.15), cirrhosis (OR: 2.03) and γ-glutamyl transpeptidase (OR: 1.61) were significantly associated with MVI presence. The incorporation of five risk factors into a nomogram-based preoperative estimation of MVI risk demonstrated satisfactory discriminative capacity, with C-index of 0.702 and 0.690 in training and validation cohorts, respectively. Calibration curve showed good agreement between actual and predicted MVI risks. Finally, DCA revealed the clinical utility of the nomogram. CONCLUSION: The nomogram showed a satisfactory discriminative capacity of MVI risk in HCC patients, and could be used to preoperatively estimate MVI risk, thereby establishing more rational therapeutic strategies.

Forkhead box F2 as a novel prognostic biomarker and potential therapeutic target in human cancers prone to bone metastasis: a meta-analysis.

OBJECTIVE: To undertake a systematic review and meta-analysis to evaluate the prognostic value of Forkhead box F2 (FOXF2) levels in different types of cancers prone to bone metastasis. METHODS: A systematic search of publications listed in electronic databases (The Web of Science, EMBASE®, PubMed®, PMC, Science Direct and CNKI) from inception to 5 November 2020 was conducted. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were used to assess the relationship between FOXF2 levels and patient prognosis including overall survival (OS) and disease-free survival (DFS). RESULTS: Sixteen studies enrolling 8461 participants were included in the meta-analysis. High levels of FOXF2 were a predictor of OS (HR: 0.66; 95% CI 0.51, 0.86) and DFS (HR: 0.60; 95% CI 0.48, 0.76). The trim-and-fill analysis, sensitivity analysis and subgroup analyses stratified by the study characteristics confirmed the robustness of the results. CONCLUSION: These current findings indicate that high FOXF2 levels could be an indicator of a good prognosis in cancer patients with tumours that are prone to bone metastasis. FOXF2 levels might be a clinically important prognostic biomarker.

LGR5 enhances the osteoblastic differentiation of MC3T3-E1 cells through the Wnt/ß-catenin pathway.

Leucine-rich repeat-containing G-protein coupled receptor 5 (LGR5) is a Wnt-associated gene that contributes to cell proliferation and self-renewal in various organs. LGR5 is expressed in Ewing sarcoma, and LGR5-overexpressing mesenchymal stem cells promote fracture healing. However, the effects of LGR5 on osteoblastic differentiation remain unclear. The aim of the present study was to explore the function of LGR5 in osteoblastic differentiation. LGR5 was overexpressed or knocked down in the MC3T3-E1 pre-osteoblastic cell line via lentiviral transfection and its function in osteoblastic differentiation was investigated. The mRNA expression levels of the osteoblast differentiation markers alkaline phosphatase (ALP), osteocalcin and collagen type I a1 were determined, and ALP and Alizarin red staining were performed. In addition, the effects of LGR5 modulation on ß-catenin and the expression of target genes in the Wnt pathway were investigated. The results revealed that the overexpression of LGR5 promoted osteoblastic differentiation. This was associated with enhancement of the stability of ß-catenin and its levels in the cell nucleus, which enabled it to activate Wnt signaling. By contrast, the inhibition of LGR5 decreased the osteogenic capacity of MC3T3-E1 cells. These results indicate that LGR5 is a positive regulator of osteoblastic differentiation, whose effects are mediated through the Wnt/ß-catenin signaling pathway. This suggests suggesting that the regulation of LGR5/Wnt/ß-catenin signaling has potential as a therapy for osteoporosis.

Modified pedicle screw-rod versus anterior subcutaneous internal pelvic fixation for unstable anterior pelvic ring fracture: a retrospective study and finite element analysis.

OBJECTIVES: This study compared the stability and clinical outcomes of modified pedicle screw-rod fixation (MPSRF) and anterior subcutaneous internal pelvic fixation (INFIX) for the treatment of anterior pelvic ring fractures using the Tornetta and Matta grading system and finite element analyses (FEA). METHODS: In a retrospective review of a consecutive patient series, 63 patients with Orthopaedic Trauma Association (OTA)/Arbeitsgemeinschaft für Osteosynthesefragen (AO) type B or C pelvic ring fractures were treated by MPRSF (n = 30) or INFIX (n = 33). The main outcome measures were the Majeed score, incidence of complications, and adverse outcomes, and fixation stability as evaluated by finite element analysis. RESULTS: Sixty-three patients were included in the study, with an average age of 34.4 and 36.2 in modified group and conventional group, respectively. Two groups did not differ in terms of the injury severity score, OTA classification, cause of injury, and time to pelvic surgery. However, the MPSRF group had a rate of higher satisfactory results according to the Tornetta and Matta grading system than the conventional group (73.33% vs 63.63%) as well as a higher Majeed score (81.5 ± 10.4 vs 76.3 ± 11.2), and these differences were statistically significant at 6 months post-surgery. FEA showed that MPSRF was stiffer and more stable than INFIX and had a lower risk of implant failure. CONCLUSIONS: Both MPSRF and INFIX provide acceptable biomechanical stability for the treatment of unstable anterior pelvic ring fractures. However, MPSRF provides better fixation stability and a lower risk of implant failure, and can thus lead to better clinical outcomes. Therefore, MPSRF should be more widely applied to anterior pelvic ring fractures.

The emergence of new prognostic scores in lung cancer patients with spinal metastasis: A 12-year single-center retrospective study.

Objective: Lung cancer patients exhibit spinal metastases from a specific population, and with this study, we aimed to develop a model that can predict this particular group's survival. Methods: Data were retrospectively collected from 83 lung cancer patients who underwent spinal metastasis surgery at our center from 2009 to 2021. After the initial assessment of treatment and scoring effects, a nomogram for survival prediction was created by identifying and integrating critical prognostic factors, followed by a consistency index (C-index) to measure consistency, and finally, a subject working characteristic curve (ROC) to compare the predictive accuracy of the three existing models. Results: The mean postoperative survival was 14.7 months. Surgical treatment significantly improved the VAS and Frankel scores in lung cancer patients with spinal metastases. The revised Tokuhashi score underestimated the life expectancy of these patients. Six independent prognostic factors, including age, extraspinal bone metastasis foci, visceral metastasis, Frankel score, targeted therapy, and radiotherapy, were identified and incorporated into the model. Calibration curves for 3-, 6-, and 12-month overall survival showed a good concordance between predicted and actual risk. The nomogram C-index for the cohort study was 0.800 (95% confidence interval [CI]: 0.757-0.843). Model comparisons showed that the nomogram's prediction accuracy was better than revised Tokuhashi and Bauer's scoring systems. Conclusions: Spine surgery offered patients the possibility of regaining neurological function. Having identified shortcomings in existing scoring systems, we have recreated and validated a new nomogram that can be used to predict survival outcomes in patients with spinal metastases from lung cancer, thereby assisting spinal surgeons in making surgical decisions and personalizing treatment for these patients.

Inflammatory conversion of quiescent osteoblasts by metastatic breast cancer cells through pERK1/2 aggravates cancer-induced bone destruction.

Disruption of bone homeostasis caused by metastatic osteolytic breast cancer cells increases inflammatory osteolysis and decreases bone formation, thereby predisposing patients to pathological fracture and cancer growth. Alteration of osteoblast function induces skeletal diseases due to the disruption of bone homeostasis. We observed increased activation of pERK1/2 in osteolytic breast cancer cells and osteoblasts in human pathological specimens with aggressive osteolytic breast cancer metastases. We confirmed that osteolytic breast cancers with high expression of pERK1/2 disrupt bone homeostasis via osteoblastic ERK1/2 activation at the bone-breast cancer interface. The process of inflammatory osteolysis modulates ERK1/2 activation in osteoblasts and breast cancer cells through dominant-negative MEK1 expression and constitutively active MEK1 expression to promote cancer growth within bone. Trametinib, an FDA-approved MEK inhibitor, not only reduced breast cancer-induced bone destruction but also dramatically reduced cancer growth in bone by inhibiting the inflammatory skeletal microenvironment. Taken together, these findings suggest that ERK1/2 activation in both breast cancer cells and osteoblasts is required for osteolytic breast cancer-induced inflammatory osteolysis and that ERK1/2 pathway inhibitors may represent a promising adjuvant therapy for patients with aggressive osteolytic breast cancers by altering the shared cancer and bone microenvironment.

MicroRNA-744 promotes proliferation of osteosarcoma cells by targeting PTEN.

MicroRNAs (miRNAs/miRs) are non-coding RNAs that regulate protein synthesis by targeting mRNAs for translational repression or degradation. Previous studies have reported that aberrant expression of miR­744 may be involved in human osteosarcoma; however, the underlying mechanisms remain elusive. In the present study, the expression levels of miR­744 and its downstream signals were determined by reverse transcription­quantitative PCR and western blotting. Cell proliferation was assessed using the bromodeoxyuridine assay, and the target of miR­744 was investigated using a dual­luciferase activity assay. The present study identified a significant upregulation of miR­744 in osteosarcoma tissues compared with adjacent non­tumor tissues. Furthermore, it was demonstrated that ectopic overexpression of miR­744 induced by a miR­744 precursor significantly enhanced proliferation of the osteosarcoma cell line MG63, whereas opposite results were observed following suppression of miR­744 with its inhibitor. Moreover, as a unique anti­oncogene, PTEN was identified as a direct target of miR­744. It was confirmed that miR­744 downregulated PTEN expression in MG63 cells by targeting the PTEN 3'untranslated region, and that the downstream AKT signal was also regulated by miR­744. Collectively, the present results suggested that miR­744 promoted proliferation of human osteosarcoma cells by directly regulating the PTEN/AKT signaling pathway.

Finite element analysis of dual small plate fixation and single plate fixation for treatment of midshaft clavicle fractures.

BACKGROUND: Midshaft clavicle fractures are one of the most familiar fractures. And, dual small plate fixation has been reported as can minimize hardware-related complications. However, the biomechanical properties of the dual small plate fixation have not yet been thoroughly evaluated. Here, we report the results of a finite element analysis of the biomechanical properties of midshaft clavicle fractures treated with dual small plating and superior and anteroinferior single plate fixation. METHODS: A three-dimensional (3D) finite element model of the midshaft clavicle fractures was created, whose 4-mm transverse fracture gap, having an angle < 30 degree and devoid of overlapping triangles, was simulated between the fractured segments of the middle-shaft of the clavicle. The equivalent von Mises stress and displacement of the model was used as the output measures for analysis. RESULTS: No significant differences were found between dual plating, superior or anteroinferior single plating in cantilever bending, axial compression, and axial torsion. Dual plating with a smaller plate-screw construct is biomechanically eligible to compare with superior and anteroinferior single plate fixation using larger plate-screw constructs. CONCLUSIONS: This study demonstrated that larger plate-screw constructs for the treatment of simple are placed clavicular fractures; however, weight-bearing and exorbitant shoulder activity should be avoided after the operation. Therefore, dual plating may provide a viable option for fixing midshaft clavicle fractures and, thus, may be preferred for patients who need early activity.

Systemic Parathyroid Hormone Enhances Fracture Healing in Multiple Murine Models of Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) is a multisystemic disease that afflicts more than 415 million people globally-the incidence and prevalence of T2DM continues to rise. It is well-known that T2DM has detrimental effects on bone quality that increase skeletal fragility, which predisposes subjects to an increased risk of fracture and fracture healing that results in non- or malunion. Diabetics have been found to have perturbations in metabolism, hormone production, and calcium homeostasis-particularly PTH expression-that contribute to the increased risk of fracture and decreased fracture healing. Given the perturbations in PTH expression and the establishment of hPTH (1-34) for use in age-related osteoporosis, it was determined logical to attempt to ameliorate the bone phenotype found in T2DM using hPTH (1-34). Therefore, the present study had two aims: (i) to establish a suitable murine model of the skeletal fragility present in T2DM because no current consensus model exists; and (ii) to determine the effects of hPTH (1-34) on bone fractures in T2DM. The results of the present study suggest that the polygenic mouse of T2DM, TALLYHO/JngJ, most accurately recapitulates the diabetic osteoporotic phenotype seen in humans and that the intermittent systemic administration of hPTH (1-34) increases fracture healing in T2DM murine models by increasing the proliferation of mesenchymal stem cells. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Inhibition of Y1 Receptor Promotes Osteogenesis in Bone Marrow Stromal Cells via cAMP/PKA/CREB Pathway.

Inhibition of neuropeptide Y1 receptor stimulates osteogenesis in vitro and in vivo. However, the underlying mechanisms involved in these effects remain poorly understood. Here we identify the effects of Y1 receptor deficiency on osteogenic differentiation in human bone marrow stromal cells (BMSCs) by using genetic and pharmacological regulation, and to explore the pathways mediating these effects. In BMSCs, inhibition of Y1 receptor stimulates osteogenesis and upregulates the expression levels of the master transcriptional factor RUNX2. Mechanistically, Y1 receptor deficiency increases the levels of intracellular cAMP, which via protein kinase A (PKA) mediated pathways results in activation of phospho-CREB (p-CREB). We find RUNX2 activation induced by Y1 receptor deficiency is reversed by H-89, a PKA inhibitor. These results indicate Y1 receptor deficiency activates PKA-mediated phosphorylation of CREB, leading to activation of RUNX2 and enhances osteogenic differentiation in BMSCs. In conclusion, these data indicate that Y1 receptor deficiency promotes osteogenic differentiation by RUNX2 stimulation through cAMP/PKA/CREB pathway.

Tetrandrine Prevents Bone Loss in Ovariectomized Mice by Inhibiting RANKL-Induced Osteoclastogenesis.

Postmenopausal osteoporosis (PMOP) is a metabolic bone disease characterized by decreased bone density and strength due to the imbalance between osteogenesis and osteoclastogenesis. Postmenopausal estrogen withdrawal increases proinflammatory cytokines and increases the serum level of Receptor activator of NF-kB ligand (RANKL)/Osteoprotegerin (OPG), which then leads to the overactivation of osteoclastogenesis. Tetrandrine, a bis-benzylisoquinoline alkaloid, has been widely used in the treatment of rheumatoid arthritis clinically in China. Here, we demonstrate that tetrandrine significantly prevented ovariectomy-induced bone loss and inhibited RANKL-induced osteoclastogenesis. In vivo, we found that intraperitoneal injection of tetrandrine (30 mg/kg) every other day markedly reduced bone loss in ovariectomized mice and the serum levels of TRAcp5b, TNF-a, IL-6, CTX-I, and RANKL/OPG were significantly decreased. In vitro, we found that tetrandrine significantly inhibited osteoclast differentiation in bone marrow monocytes (BMMs) and RAW264.7 cells according to the results of osteoclastogenesis-related gene expression, tartrate-resistant acid phosphatase (TRAP) staining and actin-ring formation as well as bone resorption assay. Mechanistically, tetrandrine inhibited RANKL-induced osteoclastogenesis by suppressing NF-kB, Ca2+, PI3K/AKT, and MAPKs signaling pathways. Taken together, our findings suggest that tetrandrine suppresses osteoclastogenesis through modulation of multiple pathways and has potential value as a therapeutic agent for PMOP, especially for those suffering from RA and PMOP at the same time.

Finite element analysis of intramedullary nailing and double locking plate for treating extra-articular proximal tibial fractures.

BACKGROUND: Proximal tibia fractures are one of the most familiar fractures. Surgical approaches are usually needed for anatomical reduction. However, no single treatment method has been widely established as the standard care. Our present study aims to compare the stress and stability of intramedullary nails (IMN) fixation and double locking plate (DLP) fixation in the treatment of extra-articular proximal tibial fractures. METHODS: A three-dimensional (3D) finite element model of the extra-articular proximal tibial fracture, whose 2-cm bone gap began 7 cm from the tibial plateau articular surface, was created fixed by different fixation implants. The axial compressive load on an adult knee during single-limb stance was imitated by an axial force of 2500 N with a distribution of 60% to the medial compartment, while the distal end was fixed effectively. The equivalent von Mises stress and displacement of the model was used as the output measures for analysis. RESULTS: The maximal equivalent von Mises stress value of the system in the IMN model was 293.23 MPa, which was higher comparing against that in the DLP fixation model (147.04 MPa). And the mean stress of the model in the IMN model (9.25 MPa) was higher than that of the DLP fixation system in terms of equivalent von Mises stress (EVMS) (P < 0.0001). The maximal value of displacement (sum) in the IMN system was 8.82 mm, which was lower than that in the DLP fixation system (9.48 mm). CONCLUSIONS: This study demonstrated that the stability provided by the locking plate fixation system was superior to the intramedullary nails fixation system and served as an alternative fixation for the extra-articular proximal tibial fractures of young patients.