Remotely Temporal Scheduled Macrophage Phenotypic Transition Enables Optimized Immunomodulatory Bone Regeneration.

Precise timing of macrophage polarization plays a pivotal role in immunomodulation of tissue regeneration, yet most studies mainly focus on M2 macrophages for their anti-inflammatory and regenerative effects while the essential proinflammatory role of the M1 phenotype on the early inflammation stage is largely underestimated. Herein, a superparamagnetic hydrogel capable of timely controlling macrophage polarization is constructed by grafting superparamagnetic nanoparticles on collagen nanofibers. The magnetic responsive hydrogel network enables efficient polarization of encapsulated macrophage to the M2 phenotype through the podosome/Rho/ROCK mechanical pathway in response to static magnetic field (MF) as needed. Taking advantage of remote accessibility of magnetic field together with the superparamagnetic hydrogels, a temporal engineered M1 to M2 transition course preserving the essential role of M1 at the early stage of tissue healing, as well as enhancing the prohealing effect of M2 at the middle/late stages is established via delayed MF switch. Such precise timing of macrophage polarization matching the regenerative process of injured tissue eventually leads to optimized immunomodulatory bone healing in vivo. Overall, this study offers a remotely time-scheduled approach for macrophage polarization, which enables precise manipulation of inflammation progression during tissue healing.

Osmolarity controls the differentiation of adipose-derived stem cells into nucleus pulposus cells via histone demethylase KDM4B.

Adipose-derived stem cells (ADSCs) are an ideal source of cells for intervertebral disc (IVD) regeneration, but the effect of an increased osmotic microenvironment on ADSC differentiation remains unclear. Here, we aimed to elucidate whether hyperosmolarity facilitates ADSC nucleus pulposus (NP)-like differentiation and whether histone demethylase KDM4B is involved in this process. ADSCs were cultured under standard and increased osmolarity conditions for 1-3 weeks, followed by analysis for proliferation and viability. Differentiation was then quantified by gene and protein analysis. Finally, KDM4B knockdown ADSCs were generated using lentiviral vectors. The results showed that increasing the osmolarity of the differentiation medium to 400 mOsm significantly increased NP-like gene expression and the synthesis of extracellular matrix (ECM) components during ADSC differentiation; however, further increasing the osmolarity to 500 mOsm suppressed the NP-like differentiation of ADSCs. KDM4B, as well as the IVD formation regulators forkhead box (Fox)a1/2 and sonic hedgehog (Shh), were found to be significantly upregulated at 400 mOsm. KDM4B knockdown reduced Foxa1/2, Shh, and NP-associated markers' expression, as well as the synthesis of ECM components. The reduction in NP-like differentiation caused by KDM4B knockdown was partially rescued by Purmorphamine, a specific agonist of Shh. Moreover, we found that KDM4B can directly bind to the promoter region of Foxa1/2 and decrease the content of H3K9me3/2. In conclusion, our results indicate that a potential optimal osmolarity window might exist for successful ADSC differentiation. KDM4B plays an essential role in regulating the osmolarity-induced NP-like differentiation of ADSCs by interacting with Foxa1/2-Shh signaling.

Malignant fibrous neoplasms of long bones: analysis of the surveillance, epidemiology, and end results database from 1973 to 2015.

BACKGROUND: Malignant fibrous neoplasms (MFN) of long bones are rare lesions. Moreover, the prognostic determinants of MFN of long bones have not been reported. This study aimed to present epidemiological data and analyse the prognostic factors for survival in patients with MFN. MATERIALS AND METHODS: The Surveillance, Epidemiology, and End Results (SEER) programme database was used to screen patients with malignant fibrous neoplasms (MFN) of long bones from 1973 to 2015, with attention to fibrosarcoma, fibromyxosarcoma, periosteal fibrosarcoma and malignant fibrous histiocytoma. The prognostic values of overall survival (OS) and cancer-specific survival (CSS) were assessed using the Cox proportional hazards regression model with univariate and multivariate analyses. The Kaplan-Meier method was used to obtain OS and CSS curves. RESULTS: A total of 237 cases were selected from the SEER database. Malignant fibrous histiocytoma was the most common form of lesion in long bones. Multivariate analysis revealed that independent predictors of OS included age, stage, tumour size and surgery. Age, stage, tumour size and surgery were also independent predictors of CSS. Additionally, the most significant prognostic factor was whether metastasis had occurred at the time of initial diagnosis. CONCLUSION: Among patients with MFN of long bones, age (> 60 years), tumour size (> 10 cm), distant stage, and non-surgical treatment are factors for poor survival.

Intra-Articular Viscosupplementation for Patients with Hip Osteoarthritis: A Meta-Analysis and Systematic Review.

BACKGROUND The aim of this study was to review the efficacy and safety of intra-articular (IA) viscosupplementation (VS) for hip osteoarthritis (OA). MATERIAL AND METHODS We searched Medline, Clinical Trial Register Center, EMBASE, and Cochrane databases for randomized controlled trials (RCTs) comparing VS with placebo injection for hip OA. We included suitable studies, assessed the quality of studies, and extracted data on pain reduction, function improvement at different time points, and safety profiles. The comparisons of pain and function outcome were performed by meta-analysis. RESULTS Five high-quality randomized controlled studies trials (RCTs) with 591 patients with hip OA were identified. Although several trials demonstrated a significant decline in pain in VS groups during follow-up compared to baseline, without severe adverse events, the pooled analysis did not show VS was superior to placebo at any time windows [7-14 days: standardized mean difference (SMD): -0.18; 95% CI, -0.47 to 0.10, p=0.21; 28-30 days: 0.02 (-0.15, 0.19), p=0.82; or at final visit: -0.14 (-0.46, 0.18), p=0.38]. Similar results were also observed in the combined data of functional results. CONCLUSIONS IA VS does not reduce pain or improve function significantly better than placebo in a short-term follow-up. The benefits and safety of VS should be further assessed by sufficiently-sized, methodologically sound studies with validated assessment of more clinically relevant end-points.

Survival Analysis of Patients with Osseous Malignant Vascular Tumors: Results of the Surveillance, Epidemiology, and End Results (SEER) Database from 1973 to 2015.

BACKGROUND Osseous malignant vascular tumors (OMVTs) are rare lesions. Moreover, the prognostic determinants of OMVTs have not been reported. This study aimed to present epidemiological data and analyze the prognostic factors of survival in OMVT patients. MATERIAL AND METHODS OMVT patients who were diagnosed between 1973 and 2015 were screened using the Surveillance, Epidemiology, and End Results (SEER) program database, with special attention paid to osseous hemangiosarcoma (OAS) and osseous hemangioendothelioma (OHE). We assessed the prognostic values of cancer-specific survival (CSS) and overall survival (OS) rates with a Cox proportional hazards regression model and univariate and multivariate analyses. OS and CSS curves were obtained using the Kaplan-Meier method. RESULTS A total of 202 cases were selected from the SEER database. The specific histopathological diagnoses were osseous hemangiosarcoma (n=127) and osseous hemangioendothelioma (n=75). Among OMVT patients, histology was an important factor in determining survival. Using multivariate analysis, old age, distant tumor stage, surgery, and low tumor grade were predictors of OS for OAS patients. Old age, surgery, and low tumor grade were predictors of CSS. Using multivariate analysis, old age and surgery were predictors of OS and CSS for OHE patients. CONCLUSIONS This study is the largest population-based study to show the demographic characteristics and analyze the prognosis of OMVT patients. Independent predictors of OS for patients with AS included old age, distant tumor stage, low tumor grade, and surgery. Old age, surgery, and low tumor grade were also predictors of CSS for patients with OAS. Independent predictors of CSS and OS for patients with OHE included old age and surgery.

Risk factors for anterior shoulder instability: a matched case-control study.

BACKGROUND: Anatomic skeletal features of the shoulder play important roles in anterior shoulder dislocation. However, studies on the effect of the humeral structure are few. This case-control study aimed to analyze the risk factors of anterior shoulder instability, including glenoid and humeral factors. METHODS: Anterior shoulder instability was found in 64 of 10,035 individuals who underwent magnetic resonance imaging. Propensity score matching was used to select controls matched for age, sex, height, and weight. We analyzed the glenoid and humeral structural data using conditional logistic regression analysis and identified cutoff points using receiver operating characteristic curve analysis. RESULTS: Significant differences were found between the control and dislocation groups in the depth-to-width ratio (0.119 ± 0.034 vs. 0.105 ± 0.037, P = .021), height-to-width ratio (1.51 ± 0.13 vs. 1.67 ± 0.16, P < .001), humeral head diameter-to-glenoid fossa diameter ratio (1.56 ± 0.11 vs. 1.64 ± 0.20, P < .001), and humeral containing angle (67.3° ± 5.9° vs. 60.4° ± 5.9°, P < .001). The humeral containing angle (odds ratio, 0.95; P = .024) and the glenoid height-to-width ratio (odds ratio, 7.88; P = .002), adjusted for the depth-to-width ratio and diameter ratio, were associated with anterior shoulder instability. The cutoff point for the humeral containing angle was 64° and for the height-to-width ratio was 1.60. CONCLUSIONS: This study revealed significant risk factors for shoulder instability in the Chinese Han population. The humeral containing angle and the glenoid height-to-width ratio were risk factors for anterior shoulder instability.

Effect of Low-Frequency Pulsed Ultrasound on Drug Delivery, Antibacterial Efficacy, and Bone Cement Degradation in Vancomycin-Loaded Calcium Phosphate Cement.

BACKGROUND Calcium phosphate cement (CPC) has been applied as a biodegradable antibiotic carrier in osteomyelitis. However, the drug delivery, antibacterial efficacy, and degradation rate of CPC are insufficient and require further improvement in clinical application. MATERIAL AND METHODS Vancomycin-loaded CPC columns were prepared, and eluted in simulated body fluid. The drug delivery was assessed in the ultrasound group and control group by fluorescence polarization immunoassay. The antibacterial efficacy of vancomycin in the ultrasound group and control groups was investigated by standard plate count method. Low-frequency pulsed ultrasound (46.5 kHz, 900 mW/cm²) was used to produce a sinusoidal wave in the ultrasound groups. The percentage of residual weight was evaluated to assess the degradation of CPC. RESULTS The concentration and cumulatively released percentage of vancomycin in the ultrasound group were higher than that in the control group at each time point (p<0.05). The duration of vancomycin concentration over the level of minimum inhibitory concentration was significantly prolonged in the ultrasound group (p<0.05). Antibacterial efficacy of vancomycin in the ultrasound group was significantly greater than that in the control group with same concentration of vancomycin (p<0.05). The percentage of residual weight in the ultrasound group was significantly less than that in the control group (p<0.05). CONCLUSIONS Low-frequency pulsed ultrasound can enhance vancomycin release, prolong the duration of vancomycin concentration at high levels, and accelerate the degradation rate of vancomycin-loaded CPC.

Effect of bisphosphonates on periprosthetic bone loss after total knee arthroplasty: a meta-analysis of randomized controlled trials.

BACKGROUND: Aseptic loosening and osteolysis are the most common indications after TKA for revision surgery. This meta-analysis which included high-quality randomized controlled trials (RCTs) aimed to analyze the effect of bisphosphonates (BPs) on maintaining periprosthetic bone mineral density (BMD) after total knee arthroplasty. METHODS: PubMed, AMED, EMBASE, the Cochrane library, ISI Web of Science, and China National Knowledge Infrastructure were systematically searched, five RCTs were included and the total number of participants was 188. The weighted mean differences with 95% confidence interval were calculated to evaluate the efficacy of BPs on total BMD of knee and the BMD of different periprosthetic regions. A descriptive review was performed for BP-related adverse effects. RESULTS: The BPs group presented significantly higher total BMD in proximal part of the tibia than the control group at 3 and 6 months (P < 0.05), but no significant difference at 12 months (P = 0.09). The BPs group presented significantly higher BMD in the distal aspect of the femur than that in the control group at 3, 6, 12 months. The BPs group presented significantly higher periprosthetic BMD than that in the control group at 3, 6 and 12 months in tibial medial and lateral metaphyseal region, and femoral anterior, central and posterior metaphyseal region (p < 0.05), but no significant difference for tibial diaphyseal region at 3, 6, and 12 months. None of the included studies described severe or fatal adverse effects related to BPs. CONCLUSION: BPs have a short-term effect on reducing periprosthetic bone loss after total knee arthroplasty. Compared with diaphyseal region, BPs are more effective on the preservation of BMD in medial lateral metaphyseal regions of proximal tibia and in anterior, central, and posterior metaphyseal region of distal femur.

Cartilage oligomeric matrix protein gene multilayers inhibit osteogenic differentiation and promote chondrogenic differentiation of mesenchymal stem cells.

There are still many challenges to acquire the optimal integration of biomedical materials with the surrounding tissues. Gene coatings on the surface of biomaterials may offer an effective approach to solve the problem. In order to investigate the gene multilayers mediated differentiation of mesenchymal stem cells (MSCs), gene functionalized films of hyaluronic acid (HA) and lipid-DNA complex (LDc) encoding cartilage oligomeric matrix protein (COMP) were constructed in this study via the layer-by-layer self-assembly technique. Characterizations of the HA/DNA multilayered films indicated the successful build-up process. Cells could be directly transfected by gene films and a higher expression could be obtained with the increasing bilayer number. The multilayered films were stable for a long period and DNA could be easily released in an enzymatic condition. Real-time polymerase chain reaction (RT-PCR) assay presented significantly higher (p<0.01) COMP expression of MSCs cultured with HA/COMP multilayered films. Compared with control groups, the osteogenic gene expression levels of MSCs with HA/COMP multilayered films were down-regulated while the chondrogenic gene expression levels were up-regulated. Similarly, the alkaline phosphatase (ALP) staining and Alizarin red S staining of MSCs with HA/COMP films were weakened while the alcian blue staining was enhanced. These results demonstrated that HA/COMP multilayered films could inhibit osteogenic differentiation and promote chondrogenic differentiation of MSCs, which might provide new insight for physiological ligament-bone healing.

Identification of a Diagnostic Multiomics-Based Biomarker Cluster in a Mouse Model of Pulmonary Tuberculosis.

BACKGROUND: Tuberculosis (TB) stands as the second most prevalent infectious agent-related cause of death worldwide in 2022, trailing only COVID-19. With 1.13 million reported deaths, this figure is more than half of the mortality associated with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), which accounted for 0.63 million deaths. Diagnosing Mycobacterium tuberculosis (MTB) infection remains a formidable challenge due to the inability to isolate and detect MTB in sputum and within the human body. The absence of universally reliable diagnostic criteria for MTB infection globally poses a significant obstacle to preventing the progression of tuberculosis from the MTB infection stage. METHODS: In this study, our objective was to formulate a diagnostic biomarker cluster capable of discerning the progression of MTB infection and disease. This was achieved through a comprehensive joint multiomics analysis, encompassing transcriptome, proteome, and metabolome, conducted on lung tissue samples obtained from both normal control mice and those infected with MTB. RESULTS: A total of 1690 differentially expressed genes and 94 differentially expressed proteins were systematically screened. From this pool, 10 core genes were singled out. Additionally, eight long non-coding ribonucleic acids and eight metabolites linked to these core genes were identified to establish a cohesive cluster of biomarkers. This multiomics-based biomarker cluster demonstrated its capability to differentiate uninfected samples from MTB-infected samples effectively in both principle component analysis and the construction of a random forest model. CONCLUSION: The outcomes of our study strongly suggest that the multiomics-based biomarker cluster holds significant potential for enhancing the diagnosis of MTB infection.

Type-III-A structure of mycobacteria CRISPR-Csm complexes involving atypical crRNAs.

Tuberculosis (TB), a leading cause of mortality globally, is a chronic infectious disease caused by Mycobacterium tuberculosis that primarily infiltrates the lung. The mature crRNAs in M. tuberculosis transcribed from the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) locus exhibit an atypical structure featured with 5' and 3' repeat tags at both ends of the intact crRNA, in contrast to typical Type-III-A crRNAs that possess 5' repeat tags and partial crRNA sequences. However, this structural peculiarity particularly concerning the specific binding characteristics of the 3' repeat end within the mature crRNA within the Csm complex, has not been comprehensively elucidated. Here, our Mycobacteria CRISPR-Csm complexes structure represents the largest Csm complex reported to date. It incorporates an atypical Type-III-A CRISPR RNA (crRNA) (46 nt) with 5' 8-nt and 3' 4-nt repeat sequences in the stoichiometry of Mycobacteria Csm1125364151. The PAM-independent single-stranded RNAs (ssRNAs) are the most suitable substrate for the Csm complex. The 3'-repeat end trimming of mature crRNA was not necessary for its cleavage activity in Type-III-A Csm complex. Our work broadens our understanding of the Type-III-A Csm complex and identifies another mature crRNA processing mechanism in the Type-III-A CRISPR-Cas system based on structural biology.

EspB and HtpG interact with the type III-A CRISPR/Cas system of Mycobacterium tuberculosis.

Introduction: Mycobacterium tuberculosis (MTB) has a type III-A clustered regularly interspaced short palindromic repeat/CRISPR-associated protein (CRISPR/Cas) system consisting of a Csm1-5 and CRISPR RNA (crRNA) complex involved in the defense against invading nucleic acids. However, CRISPR/Cas system in the MTB still is clearly unknown and needs to be further explored. Methods: In our work, two non-Cas system proteins EspB and HtpG protein were found and identified by LC-MS/MS. The effect of EspB and HtpG on Type III-A CRISPR/Cas System of M. tuberculosis was examined by using Plasmid interference assay and Co-immunoprecipitation analyses. We explored that EspB could interact with the crRNA RNP complex, but HtpG could inhibit the accumulation of the MTB Csm proteins and defense the mechanism of CRISPR/Cas system. Results: The proteins ESAT-6 secretion system-1(Esx-1) secreted protein B (EspB) and high-temperature protein G (HtpG), which were not previously associated with CRISPR/Cas systems, are involved in mycobacterial CRISPR/Cas systems with distinct functions. Conclusion: EspB is a novel crRNA-binding protein that interacts directly with the MTB crRNP complex. Meanwhile, HtpG influences the accumulation of MTB Csm proteins and EspB and interferes with the defense mechanism of the crRNP complex against foreign DNA in vivo. Thereby, our study not only leads to developing more precise clinical diagnostic tool to quickly detect for MTB infection, but also knows these proteins merits for TB biomarkers/vaccine candidates.

Is there really no benefit of vertebroplasty for osteoporotic vertebral fractures? A meta-analysis.

BACKGROUND: Osteoporotic vertebral compressed fractures (VCFs) are the most common osteoporotic fractures. Although percutaneous vertebroplasty (PVP) reportedly relieves pain and improves function, a recent pooled analysis from two multicenter randomized controlled trials concluded the improvement in pain and disability treated with PVP was similar to those with sham surgery. QUESTIONS/PURPOSE: Using meta-analysis we therefore asked whether compared with either nonoperative therapy or a sham injection for patients with VCF, PVP would (1) better relieve pain, (2) provide greater improvement in pain-related disability, and (3) increase the recurrence of vertebral fractures. METHODS: We searched PubMed, EMBASE, Medline, and the Cochrane library using the keywords "vertebroplasty AND osteoporosis OR fracture". We included nine of the 469 articles identified. Using a random effects model, we calculated the weighted mean differences to evaluate the pain reduction at different times as the primary outcome. Pain-related disability was assessed by a quality of life (QOL) measure. Improvement of QOL and recurrence of vertebral fractures were the secondary outcomes. We used subgroup analysis to reinvestigate pain relief and function improvement of PVP based on two different controls: nonoperative therapy and sham injection. The total number of patients was 886. RESULTS: Pain scoring was similar between the PVP group and the sham injection group at 1 to 29 days and 90 days. However, compared with nonoperative therapy, PVP reduced pain at all times studied. QOL in the PVP group was improved or tended to be improved compared with QOL for both control groups. The risk of new fractures was similar between the PVP groups and both control groups. CONCLUSIONS: Different control groups may have accounted for the different conclusions in the literature regarding the ability of PVP to relieve pain and restore function recovery. Compared with nonoperative treatment PVP relieved pain better and improved QOL. PVP did not increase the risk of new fractures. LEVEL OF EVIDENCE: Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Therapeutic Potential of POU3F3, a Novel Long Non-coding RNA, Alleviates the Pathogenesis of Osteoarthritis by Regulating the miR-29a- 3p/FOXO3 Axis.

BACKGROUND: Osteoarthritis (OA) is the predominant threat to the health of the elderly, and it is crucial to understand the molecular pathogenetic mechanisms involved in it. This study aims to investigate the role of a well-studied cancer-related long non-coding RNA (lncRNA)-POU3F3 in OA and its implicated molecular mechanisms. METHODS: The expression of POU3F3 and miR-29a-3p was examined in osteoarthritis patients, as well as destabilization of the medial meniscus (DMM) mouse OA model and IL- 1ß induced chondrocytes cell OA model, by quantitative real-time PCR. The interaction between POU3F3, miR-29a-3p and transcription factor forkhead box O3 (FOXO3) was verified via dual-luciferase reporter analysis and RNA immunoprecipitation analyses. Cell proliferation and apoptosis were evaluated by cell viability assay and flow cytometry, respectively. Cartilage extracellular matrix (ECM) degradation was investigated with ELISA and western blotting. In addition, the in vivo regulation of POU3F3 in OA was verified by intra-articular injection of lentivirus overexpression POU3F31 in mice models. RESULTS: The expression level of POU3F3 was decreased in OA patients/animal cartilage tissues and IL-1ß-stimulated in vitro chondrocyte model. POU3F3 overexpression inhibited IL-1ß-induced injury of chondrocytes, enhancing cell viability, suppressing apoptosis and inflammatory cytokine secretion, rescuing metabolic dysfunction, and restraining autophagy in vitro. Mechanistically, Luciferase reporter and RNA immunoprecipitation (RIP) assays indicated that miR-29a-3p could directly bind to POU3F3, and FOXO3 was a target gene of miR-29a-3p. Functional rescue assays confirmed this POU3F3/miR-29a-3p/FOXO3 axis in chondrocytes during OA occurrence. Furthermore, intraarticularly delivery of lentivirus containing POU3F3 alleviates the damage in mouse OA model in vivo. CONCLUSION: In conclusion, this work highlights the role of the POU3F3/miR-29a-3p/FOXO3 axis in the OA pathogenesis, suggesting this axis as a potential therapeutic target for OA.

Additive Effect of Parathyroid Hormone and Zoledronate Acid on Prevention Particle Wears-Induced Implant Loosening by Promoting Periprosthetic Bone Architecture and Strength in an Ovariectomized Rat Model.

Implant-generated particle wears are considered as the major cause for the induction of implant loosening, which is more susceptible to patients with osteoporosis. Monotherapy with parathyroid hormone (PTH) or zoledronate acid (ZOL) has been proven efficient for preventing early-stage periprosthetic osteolysis, while the combination therapy with PTH and ZOL has exerted beneficial effects on the treatment of posterior lumbar vertebral fusion and disuse osteopenia. However, PTH and ZOL still have not been licensed for the treatment of implant loosening to date clinically. In this study, we have explored the effect of single or combined administration with PTH and ZOL on implant loosening in a rat model of osteoporosis. After 12 weeks of ovariectomized surgery, a femoral particle-induced periprosthetic osteolysis model was established. Vehicle, PTH (5 days per week), ZOL (100 mg/kg per week), or combination therapy was utilized for another 6 weeks before sacrifice, followed by micro-CT, histology, mechanical testing, and bone turnover examination. PTH monotherapy or combined PTH with ZOL exerted a protective effect on maintaining implant stability by elevating periprosthetic bone mass and inhibiting pseudomembrane formation. Moreover, an additive effect was observed when combining PTH with ZOL, resulting in better fixation strength, higher periprosthetic bone mass, and less pseudomembrane than PTH monotherapy. Taken together, our results suggested that a combination therapy of PTH and ZOL might be a promising approach for the intervention of early-stage implant loosening in patients with osteoporosis.

Cepharanthine Ameliorates Chondrocytic Inflammation and Osteoarthritis via Regulating the MAPK/NF-κB-Autophagy Pathway.

Osteoarthritis is a worldwide joint disease caused by abnormal chondrocytic metabolism. However, traditional therapeutic methods aimed at anti-inflammation for early-stage disease are palliative. In the present study, we demonstrated that cepharanthine (CEP), extracted from the plant Stephania cepharantha, exerted protective medicinal efficacy on osteoarthritis for the first time. In our in vitro study, CEP suppressed the elevated expression of matrix metalloproteinases (MMPs), a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5) and inducible nitric oxide synthase (iNOS) stimulated by IL-1ß or TNF-α by inhibiting the activation of MAPK and NF-κB signaling pathways, and upregulated the protein expression of aggrecan, collagen II, and Sox9. Also, CEP could reverse the reduced level of cellular autophagy in IL-1ß or TNF-α-induced chondrocytes, indicating that the protective effect of CEP on osteoarthritis was achieved by restoring MAPK/NF-κB-mediated autophagy. Furthermore, in a murine OA model, CEP mitigated cartilage degradation and prevented osteoarthritis in the CEP-treated groups versus the OA group. Hence, our results revealed the therapeutic prospect of CEP for anti-osteoarthritic treatment.

HemoglobinA1c Is a Risk Factor for Changes of Bone Mineral Density: A Mendelian Randomization Study.

Background: As a valuable blood glucose measurement, HemoglobinA1c (HbA1c) is of great clinical value for diabetes. However, in previous observational studies, studies on its effect on bone mineral density (BMD) have different results. This study aimed to use Mendelian randomization (MR) to assess the effect of HbA1c on bone mineral density and fracture risk, and try to further explore whether this association was achieved through glycemic or non-glycemic factors. Methods: Take HbA1c measurement as exposure, and BMD estimated from quantitative heel ultrasounds (eBMD) and bone fractures as outcomes. Two-Sample MR Analysis was conducted to assess the causal effect of HbA1C on heel BMD and risk fracture. Then, we performed the analysis using two subsets of these variants, one related to glycemic measurement and the other to erythrocyte indices. Results: Genetically increased HbA1C was associated with the lower heel eBMD [odds ratio (OR) 0.91 (95% CI 0.87, 0.96) per %-unit, P = 3 × 10-4(IVW)]. Higher HbA1C was associated with lower heel eBMD when using only erythrocytic variants [OR 0.87 (0.82, 0.93), P=2× 10-5(IVW)]; However, when using only glycemic variants, this casual association does not hold. In further MR analysis, we test the association of erythrocytic traits with heel eBMD. Conclusion: Our study revealed the significant causal effect of HbA1c on eBMD, and this causal link might achieve through non-glycemic pathways (erythrocytic indices).

Regulatory Role of N6-methyladenosine (m6A) Modification in Osteosarcoma.

Osteosarcoma is the most common primary bone malignancy, typically occurring in childhood or adolescence. Unfortunately, the clinical outcomes of patients with osteosarcoma are usually poor because of the aggressive nature of this disease and few treatment advances in the past four decades. N6-methyladenosine (m6A) is one of the most extensive forms of RNA modification in eukaryotes found both in coding and non-coding RNAs. Accumulating evidence suggests that m6A-related factors are dysregulated in multiple osteosarcoma processes. In this review, we highlight m6A modification implicated in osteosarcoma, describing its pathophysiological role and molecular mechanism, as well as future research trends and potential clinical application in osteosarcoma.

Mycobacterium tuberculosis CRISPR/Cas system Csm1 holds clues to the evolutionary relationship between DNA polymerase and cyclase activity.

Prokaryotic CRISPR/Cas systems confer immunity against invading nucleic acids through effector complexes. Csm1, the signature protein of Type III effector complexes, catalyses cyclic oligoadenylate synthesis when in the effector complex, but not when alone, activating the Csm6 nuclease and switching on the antiviral response. Here, we provide biochemical evidence that M. tuberculosis Csm1 (MtbCsm1) has ion-dependent polymerase activity when independent of the effector complex. Structural studies provide supporting evidence that the catalytic core of the MtbCsm1 palm2 domain is almost identical to that of classical DNA polymerase Pol IV, and that the palm1 and B domains function as the other structural elements required (thumb and fingers) for DNA polymerase activity. MtbCsm1 polymerase activity is relatively weak in vitro and its functional relevance in vivo is unknown. Our structural and mutagenesis data suggest that residue K692 in the palm2 domain has been significant in the evolution of Csm1 from a polymerase to a cyclase, and support the notion that the cyclase activity of Csm1 requires the presence of other elements provided by the CRISPR/Cas effector complex. This structural rationale for Csm1 polymerase (alone) and cyclase (within the effector complex) activity should benefit future functional investigations and engineering.

Virtual screening identified natural Keap1-Nrf2 PPI inhibitor alleviates inflammatory osteoporosis through Nrf2-mir214-Traf3 axis.

Overactive osteoclastogenesis is involved in the inflammatory bone loss and could be target for therapy. Here, we applied transcription factor enrichment analysis using public inflammatory osteolysis datasets and identified Nrf2 as the potential therapeutic target. Additionally, in-silico screening was performed to dig out Nrf2-Keap1 PPI inhibitor and Forsythoside-ß was found to be the best-performing PHG compound. We firstly tested the effect of Forsythoside-ß in inflammatory osteoporosis models and found it was able to attenuate the bone loss by inhibiting osteoclastogenesis and activating Nrf2-signaling in vivo. Forsythoside-ß was capable to suppress the differentiation of osteoclast in time and dose-dependent manners in vitro. Further, Forsythoside-ß could inhibit the production of reactive oxygen species and induce Nrf2 nuclear-translocation by interrupting Nrf2-Keap1 PPI. Recently, Nrf2 was identified as the epigenetic regulator modulating levels of miRNA in various diseases. We discovered that Forsythoside-ß could suppress the expression of mir-214-3p, one of most variable miRNAs during osteoclastogenesis. To clarify the undermining mechanism, by utilizing chip-seq dataset, we found that Nrf2 could bind to promoter of mir-214-3p and further regulate this miRNA. Collectively, Forsythoside-ß was able to prevent bone loss through Nrf2-mir-214-3p-Traf3 axis, which could be a promising candidate for treating inflammatory bone loss in the future.