Apoptotic body-inspired nanotherapeutics efficiently attenuate osteoarthritis by targeting BRD4-regulated synovial macrophage polarization.

Bromodomain-containing protein 4 (BRD4) is the most well-studied BET protein that is important for the innate immune response. We recently revealed that targeting BRD4 triggers apoptosis in tumor-associated macrophages, but its role in synovial macrophages and joint inflammation is largely unknown. Herein, we demonstrated that BRD4 was highly expressed in the iNOS-positive M1 macrophages in the human and mouse osteoarthritis (OA) synovium, and conditional knockout of BRD4 in the myeloid lineage using Lyz2-cre; BRD4flox/flox mice significantly abolished anterior cruciate ligament transection (ACLT)-induced M1 macrophage accumulation and synovial inflammation. Accordingly, we successfully constructed apoptotic body-inspired phosphatidylserine-containing nanoliposomes (PSLs) loaded with the BRD4 inhibitor JQ1 to regulate inflammatory macrophages. JQ1-loaded PSLs (JQ1@PSLs) exhibited a higher cellular uptake by macrophages than fibroblast-like synoviocytes (FLSs) in vitro and in vivo, as well as the reduction in proinflammatory M1 macrophage polarization. Intra-articular injections of JQ1@PSLs showed prolonged retention within the joint, and remarkably reduced synovial inflammation and joint pain via suppressing M1 polarization accompanied by reduced TRPA1 expression by targeted inhibition of BRD4 in the macrophages, thus attenuating cartilage degradation during OA development. The results show that BRD4-inhibiting JQ1@PSLs can targeted-modulate macrophage polarization, which opens a new avenue for efficient OA therapy via a "Trojan horse".

Trim21 depletion alleviates bone loss in osteoporosis via activation of YAP1/ß-catenin signaling.

Despite the diverse roles of tripartite motif (Trim)-containing proteins in the regulation of autophagy, the innate immune response, and cell differentiation, their roles in skeletal diseases are largely unknown. We recently demonstrated that Trim21 plays a crucial role in regulating osteoblast (OB) differentiation in osteosarcoma. However, how Trim21 contributes to skeletal degenerative disorders, including osteoporosis, remains unknown. First, human and mouse bone specimens were evaluated, and the results showed that Trim21 expression was significantly elevated in bone tissues obtained from osteoporosis patients. Next, we found that global knockout of the Trim21 gene (KO, Trim21-/-) resulted in higher bone mass compared to that of the control littermates. We further demonstrated that loss of Trim21 promoted bone formation by enhancing the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and elevating the activity of OBs; moreover, Trim21 depletion suppressed osteoclast (OC) formation of RAW264.7 cells. In addition, the differentiation of OCs from bone marrow-derived macrophages (BMMs) isolated from Trim21-/- and Ctsk-cre; Trim21f/f mice was largely compromised compared to that of the littermate control mice. Mechanistically, YAP1/ß-catenin signaling was identified and demonstrated to be required for the Trim21-mediated osteogenic differentiation of BMSCs. More importantly, the loss of Trim21 prevented ovariectomy (OVX)- and lipopolysaccharide (LPS)-induced bone loss in vivo by orchestrating the coupling of OBs and OCs through YAP1 signaling. Our current study demonstrated that Trim21 is crucial for regulating OB-mediated bone formation and OC-mediated bone resorption, thereby providing a basis for exploring Trim21 as a novel dual-targeting approach for treating osteoporosis and pathological bone loss.

Treatment of Morel-Lavallée Lesions (MLLs) with Mesh Incisions Combined with Quilting Sutures and Negative Pressure Wound Therapy (NPWT).

Purpose: The objective of this retrospective study was to evaluate the clinical effects of a novel treatment approach for Morel-Lavallée lesions (MLL) using a combination of suturing techniques and Negative Pressure Wound Therapy (NPWT) with mesh incisions. To summarize the clinical effects of a combination of suturing techniques and (Negative Pressure Wound Therapy) NPWT on the wall of Morel-Lavallée lesions (MLL) fibrotic pseudocapsules with mesh incisions in the treatment of MLLs. A retrospective analysis was performed on MLL patients from April 2017 to March 2021. Methods: This a retrospective case-control study and thirteen MLL patients were included in this retrospective analysis conducted between April 2017 and March 2021, who were treated with mesh incisions on the wall of the pseudocapsule, quilting suturing to degloved soft tissues, and NPWT. Physical examination, MRI, or ultrasound before surgery confirmed the diagnosis. Wound healing, secondary infection, recurrence, visual analog scale (VAS) scores before and after surgery, and skin and soft tissue condition were observed and evaluated. Results: The combination of mesh incisions, quilting sutures, and NPWT led to successful wound healing in 11 out of 13 cases without recurrent hematoma or secondary infection. Visual analog scale (VAS) scores significantly decreased after the operation, and the aesthetic and tactile qualities of the injured area improved. One case of skin and soft tissue necrosis infection before the operation, which healed after second-stage full-thickness skin grafting, 1 case healed after a dressing change, and the remaining 11 cases had wounds that healed by the first stage without secondary infection or recurrent hematoma formation. VAS scores decreased significantly after the operation, the appearance of the injured area was as expected, and the skin feel and elasticity recovered satisfactorily. Conclusion: The study demonstrates that the mesh incision technique, along with mattress sutures and NPWT, presents a feasible and effective approach for treating MLL with fibrotic pseudocapsules. This could shorten healing times, reduce risk of complications, and improve patient satisfaction.

Preliminary study of short-term outcomes and learning curves of robotic-assisted THA: comparison between closed platform robotic system and open platform robotic system.

BACKGROUND: Both closed platform and open platform robotic-assisted total hip arthroplasty (THA) have recently been recommended as a viable treatment option for achieving accurate positioning of components. Yet, limited studies paid attention to the differences between the closed platform robotic system and the open platform robotic system. Hence, this study aimed to investigate clinical outcomes, radiographic outcomes, complication rates and learning curve of two systems. MATERIALS AND METHODS: We retrospectively included 62 patients (31 closed robotic system and 31 open robotic system) who underwent THA between February 2021 and January 2023. The demographics, operating time, cup positioning, complications and hip Harris score were evaluated. Learning curves of operation time was conducted using cumulative sum (CUSUM) analysis. RESULTS: There were no differences in surgical time (76.7 ± 12.1 min vs. 72.3 ± 14.8 min), estimated blood loss (223.2 ± 13.2 ml vs. 216.9 ± 17 ml) and Harris Hip score (HHS) between closed platform robotic system and the open platform robotic system. The closed robotic system and the open robotic system were associated with a learning curve of 9 cases and 7 cases for surgical time respectively, based on the satisfying rate of Lewinnek's safe zone outliers (1/31, 96.8%) and no occurrence of complication. Both robotic systems had significant reduction in overall surgical time, the duration of acetabulum registration, and estimated blood loss between learning phase and proficiency phase. CONCLUSION: The authors suggest that the surgical outcomes and safe zone outlier rate of the open robotic-assisted THA were similar to those of the closed robotic-assisted THA. These two robotic-assisted are associated with comparable learning curves and both have the precise positioning of acetabular component. From learning phase to proficiency phase, the rate of positions within the safe zone differed only marginally (88.9-100% vs. 85.7-100%) based on a rather low number of patients. This is not a statistically significant difference. Therefore, we suggest that THA undergoing with the robotic-assisted system is the relatively useful way to achieve planned acetabular cup position so far.

Versatile Nano-PROTAC-Induced Epigenetic Reader Degradation for Efficient Lung Cancer Therapy.

Recent evidence has indicated that overexpression of the epigenetic reader bromodomain-containing protein 4 (BRD4) contributes to a poor prognosis of lung cancers, and the suppression of its expression promotes cell apoptosis and leads to tumor shrinkage. Proteolysis targeting chimera (PROTAC) has recently emerged as a promising therapeutic strategy with the capability to precisely degrade targeted proteins. Herein, a novel style of versatile nano-PROTAC (CREATE (CRV-LLC membrane/DS-PLGA/dBET6)) is developed, which is constructed by using a pH/GSH (glutathione)-responsive polymer (disulfide bond-linked poly(lactic-co-glycolic acid), DS-PLGA) to load BRD4-targeted PROTAC (dBET6), followed by the camouflage with engineered lung cancer cell membranes with dual targeting capability. Notably, CREATE remarkably confers simultaneous targeting ability to lung cancer cells and tumor-associated macrophages (TAMs). The pH/GSH-responsive design improves the release of dBET6 payload from nanoparticles to induce pronounced apoptosis of both cells, which synergistically inhibits tumor growth in both subcutaneous and orthotopic tumor-bearing mouse model. Furthermore, the efficient tumor inhibition is due to the direct elimination of lung cancer cells and TAMs, which remodels the tumor microenvironment. Taken together, the results elucidate the construction of a versatile nano-PROTAC enables to eliminate both lung cancer cells and TAMs, which opens a new avenue for efficient lung cancer therapy via PROTAC.

Effect of Diabetes Mellitus on Implant Osseointegration of Titanium Screws: An Animal Experimental Study.

OBJECTIVE: To explore the effect of diabetes mellitus (DM) on implant osseointegration of titanium screws. METHODS: Sixty rats were randomly divided into a DM group and a control group (each group, n = 30). DM group rats were injected with 1% Streptozotocin solution at 65 mg/kg to establish a DM model. Titanium screws were implanted into the rats' distal femurs in both groups. The rats were sacrificed for micro-CT scanning, micro-indentation, biomechanical detection, confocal Raman microspectroscopy, and histological and histomorphometric analysis at 4, 8, and 12 weeks post-implantation, respectively. Messenger RNA (mRNA) expression and protein expression of the related growth factors around the implant were analyzed using real-time polymerase chain reaction and Western blots. RESULTS: At 4, 8 and 12 weeks, micro-CT scanning, hematoxylin-eosin (HE) staining, Gieson's acid-magenta staining, and fluorescent labeled staining showed disorder in the bone tissue arrangement, a lack of new bone tissue, poor maturity and continuity, and poor trabecular bone parameters around the implant in the DM group. At 4, 8, and 12 weeks, the interfacial bone binding rate in the DM group was significantly lower (16.2% ± 4.8%, 25.7% ± 5.7%, 42.5% ± 5.8%, respectively) than that in the control group (23.6% ± 5.2%, 40.8% ± 6.3%, 64.2% ± 7.3%, respectively; P < 0.05). At 8 and 12 weeks, the elastic modulus (17.0 ± 1.8 and 15.1 ± 1.5 GPa, respectively) and trabecular bone hardness (571 ± 39 and 401 ± 37 MPa, respectively) in the DM group were significantly lower than the elastic modulus (23.4 ± 2.3 and 23.8 ± 1.8 GPa, respectively) and trabecular bone hardness (711 ± 45 and 719 ± 46 MPa, respectively) in the control group (P < 0.05). The maximum load required for the prosthesis pull-out experiment in the DM group at 4, 8, and 12 weeks (55.14 ± 6.74 N, 73.34 ± 8.43 N, and 83.45 ± 8.32 N, respectively) was significantly lower than that in the control group (77.45 ± 7.48 N, 93.28 ± 8.29 N, and 123.62 ± 9.43 N, respectively, P < 0.05). At 8 and 12 weeks, the mineral-to-collagen ratio in the DM group (6.56 % ± 1.35% and 4.45%± 1.25%, respectively) was significantly higher than that in the control group (5.31% ± 1.42% and 3.62% ± 1.33%, respectively, P < 0.05). At 12 weeks, mRNA and protein expression levels of bone morphogenetic protein 2, transforming growth factor-ß1, vascular endothelial growth factor, osteopontin, osteocalcin, and runt-related transcription factor 2 in the DM group were significantly lower than that in the control group. CONCLUSIONS: DM can negatively affect bone osseointegration, manifesting as disorder in bone tissue arrangement around the implant, a lack of new bone tissue, poor maturity and continuity, poor trabecular bone parameters and lower expression of the related growth factors.

YAP/miR-524-5p axis negatively regulates TXNIP expression to promote chondrosarcoma cell growth.

Chondrosarcoma (CHS) is the second most common bone malignant tumor and currently has limited treatment options. We have recently demonstrated that thioredoxin interacting protein (TXNIP) plays a crucial role in the oncogenesis of bone sarcoma, yet its implication in CHS is underdetermined. In the present study, we first found that knockdown of TXNIP promotes the proliferation of CHS cell largely through increasing their glycolytic metabolism, which is well-known as Warburg effect for providing energy. Consistent with our previous report that YAP is fundamental for CHS cell growth, herein we revealed that YAP functioned as an upstream molecule of TXNIP, and that YAP negatively regulated TXNIP mRNA and protein expression both in vitro and in vivo. Mechanistically, although knockdown of YAP upregulated both the nuclear and cytoplasmic TXNIP expression, we did not observe any obvious interaction between YAP and TXNIP; instead, miRNA-524-5p was demonstrated to be required for YAP-regulated TXNIP expression and thus controlling CHS cell growth. Together, our study reveals that TXNIP is a tumor suppressor in terms of CHS, and that the YAP/miRNA-524-5p/TXNIP signaling axis may provide a novel clue for CHS targeted therapy.

Outcomes of dual mobility articulation total hip arthroplasty in ipsilateral residual poliomyelitis.

BACKGROUND: Patients with poliomyelitis underwent total hip arthroplasty (THA) are known to be at higher risk of dislocation on account of muscular atrophy. This study aimed to investigate clinical outcomes, radiographic outcomes, complication rates, and survivorship of dual mobility THA in displaced femoral neck fractures of elderly with poliomyelitis. MATERIALS AND METHODS: We retrospectively included 17 patients (17 hips) with residual poliomyelitis who underwent THA with dual mobility articulation. Clinical outcomes were assessed with the visual analog scale (VAS) pain score, Oxford hip score, and University of California Los Angeles activity (UCLA) score. Radiographic outcomes were examined by radiographs. Complications and re-operations following THA were recorded. RESULTS: The mean follow-up period was 77.05 months. The mean VAS, Oxford hip score, and UCLA score were improved significantly. In all but one patient, no complications were occurred. Re-operation was carried out in one patient due to posterior dislocation. The Kaplan-Meier survivorship with an end point of re-operation for any reason was 94.1%. CONCLUSIONS: THA with dual mobility system is proved to be effective in strengthening stability and reducing the risk of dislocation, which is suitable for patients with neuromuscular disease. Hence, in elderly with residual poliomyelitis, dual mobility THA is a valid choice as a treatment for displaced femoral neck fractures.

Arthroscopic Hip Surgery versus Conservative Therapy on Femoroacetabular Impingement Syndrome: A Meta-Analysis of RCTs.

To determine the outcome and differences between arthroscopic hip surgery and conservative therapy in patients suffering from femoroacetabular impingement syndrome, we searched articles from PubMed, Embase, Cochrane, Web of Science and Clinicaltrials.gov using a Boolean search algorithm. Only randomized controlled trials comparing arthroscopic hip surgery and conservative therapy were included in this meta-analysis of femoroacetabular impingement syndrome management. Two authors determined eligibility, extracted the needed data and assessed the risk of bias of eligible studies independently. Then we meta-analyzed three articles to assess pooled estimate size (ES) and 95% confidence interval for Hip Outcome Score of activities of daily living (HOS ADL subscale), Hip Outcome Score sport (HOS sports subscale) and International Hip Outcome Tool (iHOT-33) analyses were performed by using STATA version 14.0 MP (STATA, College Station, TX, USA) with the principal summary measures are mean between group difference, sample size, and standard deviation. We collected 52 articles in total after removing duplicates and screened by titles and abstracts. A total of three RCTs were included finally. There was definite evidence of additional benefit of arthroscopic hip surgery against conservative therapy in the field of improving quality of life (three trials, 575 participants, ES = 2.109, 95% CI: 1.373 to 2.845, I2  = 42.8%, P = 0.000) and activity of daily living (two trials, 262 participants, ES = 9.220, 95% CI: 5.931 to 12.508, I2  = 16.5%, P = 0.000). However, no significant difference could be seen in sports function improvement (two trials, ES = 7.562, 95% CI: -2.957 to 18.082, I2  = 60.1%, P = 0.159). In conclusion, this meta-analysis suggests that arthroscopic hip surgery provided essential benefit compared with conservative therapy in improving activity of daily living and quality of life.

Diabetes mellitus accelerates the progression of osteoarthritis in streptozotocin-induced diabetic mice by deteriorating bone microarchitecture, bone mineral composition, and bone strength of subchondral bone.

BACKGROUND: The purpose of this study was to develop an optimal diabetes-osteoarthritis (DM-OA) mouse model to validate that diabetes aggravates osteoarthritis (OA) and to evaluate the microarchitecture, chemical composition, and biomechanical properties of subchondral bone (SB) as a consequence of the DM-OA-induced damage induced. METHODS: Mice were randomly divided into three groups: DM-OA group, OA group, and sham group. Blood glucose levels, body weight, and food intake of all animals were recorded. Serum calcium (Ca) and osteocalcin (OCN) levels were compared in the three groups. The messenger ribonucleic acid (mRNA) and protein expression of key regulators for bone metabolism were detected. A semi-quantitative grading system [Osteoarthritis Research Society International (OARSI)] was used to evaluate cartilage and SB degeneration. Microspectroscopy, microindentations, micro-computed tomography (CT) imaging, and fracture load of compression testing were also used to evaluate trabecular SB properties. RESULTS: Glycemic monitoring and pancreas pathological results indicated stable high blood glucose and massive destruction of pancreas and islet cells in the DM-OA group. Serum levels of bone specific alkaline phosphatase (ALP-B) and tartrate-resistant acid phosphatase 5b (TRACP-5b) in the DM-group were higher than those of the other two groups while levels of serum Ca and OCN were lower. Meanwhile, the protein and mRNA expression of osteoblast-specific biomarkers [osteoprotegerin/receptor activator of nuclear factor kappa-B ligand (OPG/RANKL) ratio, collagen type I (COL-I), Runt-related transcription factor 2 (RUNX-2), OCN] were suppressed, and osteoclast-specific biomarkers [sclerostin (SOST)] was elevated in the DM-OA group. The mineral-to-collagen ratio, microindentation elastic modulus, hardness, micro-architectural parameters, bone mineral density, and fracture load of SB trabecular bone of the DM-OA group joint were lower than those of the other two groups. On the other hand, The OARSI score, trabecular spacing, and structural model index of the DM-OA group joint were higher than those of the other two groups. CONCLUSIONS: The glycemic and pancreatic pathological results indicated that the DM-OA model was a simple and reliable model induced by streptozotocin (STZ) and surgery. The results revealed the mechanisms through which diabetes accelerates OA; that is, by damaging and deteriorating the functions of SB, including its microarchitecture, chemical composition, and biomechanical properties.

Sequential targeting of YAP1 and p21 enhances the elimination of senescent cells induced by the BET inhibitor JQ1.

Chondrosarcoma (CHS) is the second most common bone malignancy with limited therapeutic approaches. Our previous study has found that Yes associated protein 1 (YAP1) is downregulated in CHS cells treated with bromodomain and extraterminal domain (BET) inhibitor JQ1. However, the precise role of YAP1 in CHS is largely unknown. Herein, we found that YAP1 expression was upregulated in CHS tissues, and positively correlated with its grading score. Loss of YAP1 inhibited CHS proliferation and induced cellular senescence, while expression of YAP1 mutants revealed YAP1/TEA domain family member (TEAD)-dependent negative regulation of p21 and subsequent cellular senescence. These results were validated by in vivo experiments using stable shYAP1 cell lines. Mechanistically, negative regulation of p21 by YAP1 occurred post-transcriptionally via Dicer-regulated miRNA networks, specifically, the miR-17 family. Furthermore, we demonstrated that sequential targeting of YAP1 and p21 enhanced the elimination of JQ1-induced senescent cells in a Bcl-2-like 1 (Bcl-XL)/Caspase-3 dependent manner. Altogether, we unveil a novel role of YAP1 signaling in mediating CHS cell senescence and propose a one-two punch approach that sequentially targets the YAP1/p21 axis to eliminate senescent cells.

Visualization of GLUT1 Trafficking in Live Cancer Cells by the Use of a Dual-Fluorescence Reporter.

Glucose metabolism is an essential process for energy production and cell survival for both normal and abnormal cellular metabolism. Several glucose transporter/solute carrier 2A (GLUT/SLC2A) superfamily members, including glucose transporter 1 (GLUT1), have been shown to mediate the cellular uptake of glucose in diverse cell types. GLUT1-mediated glucose uptake is a transient and rapid process; thus, the real-time monitoring of GLUT1 trafficking is pivotal for a better understanding of GLUT1 expression and GLUT1-dependent glucose uptake. In the present study, we established a rapid and effective method to visualize the trafficking of GLUT1 between the plasma membrane (PM) and endolysosomal system in live cells using an mCherry-EGFP-GLUT1 tandem fluorescence tracing system. We found that GLUT1 localized at the PM exhibited both red (mCherry) and green (EGFP) fluorescence (yellow when overlapping). However, a significant increase in red punctate fluorescence (mCherry is resistant to acidic pH), but not green fluorescence (EGFP is quenched by acidic pH), was observed upon glucose deprivation, indicating that the mCherry-EGFP-GLUT1 functional protein was trafficked to the acidic endolysosomal system. Besides, we were able to calculate the relative ratio of mCherry to EGFP by quantification of the translocation coefficient, which can be used as a readout for GLUT1 internalization and subsequent lysosomal degradation. Two mutants, mCherry-EGFP-GLUT1-S226D and mCherry-EGFP-GLUT1-ΔC4, were also constructed, which indirectly confirmed the specificity of mCherry-EGFP-GLUT1 for monitoring GLUT1 trafficking. By using a series of endosomal (Rab5, Rab7, and Rab11) and lysosomal markers, we were able to define a model of GLUT1 trafficking in live cells in which upon glucose deprivation, GLUT1 dissociates from the PM and experiences a pH gradient from 6.8-6.1 in the early endosomes to 6.0-4.8 in the late endosomes and finally pH 4.5 in lysosomes, which is appropriate for degradation. In addition, our proof-of-concept study indicated that the pmCherry-EGFP-GLUT1 tracing system can accurately reflect endogenous changes in GLUT1 in response to treatment with the small molecule, andrographolide. Since targeting GLUT1 expression and GLUT1-dependent glucose metabolism is a promising therapeutic strategy for diverse types of cancers and certain other glucose addiction diseases, our study herein indicates that pmCherry-EGFP-GLUT1 can be utilized as a biosensor for GLUT1-dependent functional studies and potential small molecule screening.

The multiple roles of Thy-1 in cell differentiation and regeneration.

Thy-1 is a 25-37 kDa glycophosphatidylinositol (GPI)-anchored cell surface protein that was discovered more than 50 years ago. Recent findings have suggested that Thy-1 is expressed on thymocytes, mesenchymal stem cells (MSCs), cancer stem cells, hematopoietic stem cells, fibroblasts, myofibroblasts, endothelial cells, neuronal smooth muscle cells, and pan T cells. Thy-1 plays vital roles in cell migration, adhesion, differentiation, transdifferentiation, apoptosis, mechanotransduction, and cell division, which in turn are involved in tumor development, pulmonary fibrosis, neurite outgrowth, and T cell activation. Studies have increasingly indicated a significant role of Thy-1 in cell differentiation and regeneration. However, despite recent research, many questions remain regarding the roles of Thy-1 in cell differentiation and regeneration. This review aimed to summarize the roles of Thy-1 in cell differentiation and regeneration. Furthermore, since Thy-1 is an outer leaflet membrane protein anchored by GPI, we attempted to address how Thy-1 regulates intracellular pathways through cis and trans signals. Due to the complexity and mystery surrounding the issue, we also summarized the Thy-1-related pathways in different biological processes, and this might provide novel insights in the field of cell differentiation and regeneration.

Gap balancing versus measured resection in primary total knee arthroplasty: A retrospective cohort study protocol.

BACKGROUND: Recently, controversy still exists regarding the clinical effects of measured resection or gap-balancing technique in total knee arthroplasty (TKA). The objective of this retrospective study was to compare the clinical outcomes of conventional measured resection technique and computer-assisted gap-balancing technique in TKA. METHODS: Strengthening the Reporting of Observational studies in Epidemiology checklist. Patients underwent primary TKA by a single surgeon between 2014 and 2016 were reviewed. This study was approved by the institutional review board in our hospital and was registered in the Research Registry. Outcome measures included surgical time, intraoperative complications, patient satisfaction, Oxford Knee Score, range of motion, postoperative complications, and revision. RESULTS: This study had limited inclusion and exclusion criteria and a well-controlled intervention. CONCLUSION: We were able to directly compare the outcomes of measured resection versus gap-balancing techniques and might reveal a better technique in TKA. TRIAL REGISTRATION: This study protocol was registered in Research Registry (researchregistry5441).

Hemiarthroplasty compared with internal fixation for treatment of nondisplaced femoral neck fractures in elderly patients: a retrospective study.

INTRODUCTION: Internal fixation (IF) with cannulated screws is the most widely accepted operation method for nondisplaced femoral neck fractures (FNFs) in elderly patients. However, there were higher rate of reoperation, severe complications and poorer functional outcomes reported in these patients treated with IF. The purpose of this research is to compare the prognosis, complications, reoperation and mortality of bipolar hemiarthroplasty (HA) with IF of cannulated screws in elderly patients. METHODS: All elderly patients (>75 years of age) with nondisplaced FNFs from January 2010 to December 2015 at our institution were included in this study. Patients treated with HA and IF with cannulated screws were compared. Outcome measures included the surgical complications, perioperative parameters, hip joint function, reoperation and mortality. RESULTS: The blood loss of HA group (150.0 ± 55.1 mL) was statistically more than IF group (40.5 ± 15.7 mL, p = 0.001). However, the blood transfusion rate was similar between two groups (p = 0.102). At the last follow-up, there were total 14 (34.1%) severe surgical complications in the IF group, compared to 9 (10.1%) in the HA group (P = 0.001). No difference was detected between two groups with respect to the HHS and VAS at the last follow-up. Compared with the HA group, the IF group had much more reoperation in the follow up period (p = 0.001). There was no statistically differences of mortality rate between HA group (39.3%, 35/89) and IF group (34.1%, 14/41) (p=0.571). CONCLUSIONS: As a treatment option for nondisplaced intracapsular FNFs in elderly patients, HA showed the merits of a less surgical complications and less reoperations, while IF demonstrated a shorter surgical time and less intraoperative blood loss. Meanwhile, there was no significant difference in the hip joint function and mortality rate in midterm follow-up. Further evaluation with a longer follow-up is recommended to strengthen these findings.

PRMT5-TRIM21 interaction regulates the senescence of osteosarcoma cells by targeting the TXNIP/p21 axis.

Osteosarcoma (OS) is the most common bone malignancy in adolescents and has poor clinical outcomes. Protein arginine methyltransferase 5 (PRMT5) has recently been shown to be aberrantly expressed in various cancers, yet its role in OS remains elusive. Here, we found that PRMT5 was overexpressed in OS and its overexpression predicted poor clinical outcomes. PRMT5 knockdown significantly triggered pronounced senescence in OS cells, as evidenced by the increase in senescence-associated ß-galactosidase (SA-ß-gal)-stained cells, induction of p21 expression, and upregulation of senescence-associated secretory phenotype (SASP) gene expression. In addition, we found that PRMT5 plays a key role in regulating DNA damaging agents-induced OS cell senescence, possibly, via affecting the repair of DNA damage. Furthermore, we found that TXNIP acts as a key factor mediating PRMT5 depletion-induced DNA damage and cellular senescence. Mechanistically, TRIM21, which interacts with PRMT5, was essential for the regulation of TXNIP/p21 expression. In summary, we propose a model in which PRMT5, by interaction with TRIM21, plays a key role in regulating the TXNIP/p21 axis during senescence in OS cells. The present findings suggest that PRMT5 overexpression in OS cells might confer resistance to chemotherapy and that targeting the PRMT5/TRIM21/TXNIP signaling may enhance the therapeutic efficacy in OS.

HSP90 regulates osteosarcoma cell apoptosis by targeting the p53/TCF-1-mediated transcriptional network.

Osteosarcoma (OS) is the most common bone tumor that occurs predominantly in children and teenagers. Although many genes, such as p53 and Rb1, have been shown to be mutated, deregulation of the canonical Wnt/ß-catenin signaling pathway is frequently observed in OS. We recently demonstrated that heat shock protein 90 (HSP90) is involved in the regulation of runt-related transcription factor 2 via the AKT/GSK-3ß/ß-catenin signaling pathway in OS. However, the precise role of T cell factors/lymphoid enhancer-binding factor (TCFs/LEF) family members, which are the major binding complex of ß-catenin, in OS is poorly understood. In the present study, we first demonstrated that TCF-1 is overexpressed in OS compared with other bone tumors. Knockdown of TCF-1 significantly induced cell cycle arrest, severe DNA damage, and subsequent caspase-3-dependent apoptosis. Interestingly, coexpression of HSP90 and TCF-1 was observed in OS, and mechanistically, we demonstrated that TCF-1 expression is regulated by HSP90 either through a ß-catenin-dependent mechanism or a direct degradation of the proteasome. We also found that overexpression of TCF-1 partially abolishes the apoptosis induced by HSP90 inhibition. Furthermore, we provided evidence that p53, but not miR-34a, plays a crucial role in the HSP90-regulated TCF-1 expression and subsequent apoptosis. Given the diverse combination regimens of HSP90 inhibition with some other treatments, we propose that the p53 status and the expression level of TCF-1 should be taken into consideration to enhance the therapeutic efficacy of HSP90 inhibition.

Transcriptional regulation of Runx2 by HSP90 controls osteosarcoma apoptosis via the AKT/GSK-3ß/ß-catenin signaling.

Osteosarcoma (OS) is the most malignant primary bone tumor in children and adolescents with limited treatment options and poor prognosis. Recently, aberrant expression of Runx2 has been found in OS, thereby contributing to the development, and progression of OS. However, the upstream signaling molecules that regulate its expression in OS remain largely unknown. In the present study, we first confirmed that the inhibition of HSP90 with 17-AAG caused significant apoptosis of OS cells via a caspase-3-dependent mechanism, and that inhibition or knockdown of HSP90 by 17-AAG or siRNAs significantly suppressed mRNA and protein expression of Runx2. Furthermore, we provided evidence that Runx2 was transcriptionally regulated by HSP90 when using MG132 and CHX chase assay. We also demonstrated that ß-catenin was overexpressed in OS tissue, and that knockdown of ß-catenin induced pronounced apoptosis of OS cells in the presence or absence of 17-AAG. Interestingly, this phenomenon was accompanied with a significant reduction of Runx2 and Cyclin D1 expression, indicating an essential role of Runx2/Cyclin D1 in 17-AAG-induced cells apoptosis. Moreover, we demonstrated that the apoptosis of OS cells induced by 17-AAG did require the involvement of the AKT/GSK-3ß/ß-catenin signaling pathway by using pharmacological inhibitor GSK-3ß (LiCl) or siGSK-3ß. Our findings reveal a novel mechanism that Runx2 is transcriptionally regulated by HSP90 via the AKT/GSK-3ß/ß-catenin signaling pathway, and by which leads to apoptosis of OS cells.

Andrographolide Induces Cell Cycle Arrest and Apoptosis of Chondrosarcoma by Targeting TCF-1/SOX9 Axis.

Chondrosarcoma is the second most malignant bone tumor with poor prognosis and limited treatment options. Thus, development of more effective treatments has become urgent. Recently, natural compounds derived from medicinal plants have emerged as promising therapeutic options via targeting multiple key cellular molecules. Andrographolide (Andro) is such a compound, which has previously been shown to induce cell cycle arrest and apoptosis in several human cancers. However, the molecular mechanism through which Andro exerts its anti-cancer effect on chondrosarcoma remains to be elucidated. In the present study, we showed that Andro-induced G2/M cell cycle arrest of chondrosarcoma by fine-tuning the expressions of several cell cycle regulators such as p21, p27, and Cyclins, and that prolonged treatment of cells with Andro caused pronounced cell apoptosis. Remarkably, we found that SOX9 was highly expressed in poor-differentiated chondrosarcoma, and that knockdown of SOX9 suppressed chondrosarcoma cell growth. Further, our results showed that Andro dose-dependently down-regulated SOX9 expression in chondrosarcoma cells. Concomitantly, an inhibition of T cell factor 1 (TCF-1) mRNA expression and an enhancement of TCF-1 protein degradation by Andro were observed. In contrast, the expression and subcellular localization of ß-catenin were not altered upon the treatment of Andro, suggesting that ß-catenin might not function as the primary target of Andro. Additionally, we provided evidence that there was a mutual regulation between TCF-1 and SOX9 in chondrosarcoma cells. In conclusion, these results highlight the potential therapeutic effects of Andro in treatment of chondrosarcoma via targeting the TCF-1/SOX9 axis. J. Cell. Biochem. 118: 4575-4586, 2017. © 2017 Wiley Periodicals, Inc.

The BET Bromodomain Inhibitor JQ1 Suppresses Chondrosarcoma Cell Growth via Regulation of YAP/p21/c-Myc Signaling.

Chondrosarcoma, the second-most frequent primary bone malignancy, is generally more resistant to conventional chemotherapy and radiotherapy. Therefore, the development of an effective adjuvant therapy is necessary. Recently, targeting the epigenetic regulator such as bromodomain and extraterminal domain (BET) proteins has achieved great success. For instance, the bromodomain inhibitor JQ1 has been shown to inhibit the growth of several cancer cells both in vitro and in vivo. Herein, we demonstrated that JQ1 significantly inhibited chondrosarcoma cell growth and colony formation. JQ1 also induced marked G1-phase cell cycle arrest coincided with the up-regulation of p21WAF1/CIP1 , p27Kip1 , and Cyclin D1 expression, and the down-regulation of Cyclin E2 expression. Moreover, JQ1 induced the premature senescence of SW 1353 cells, and that prolong treatment of JQ1 caused cell apoptosis. Mechanistically, the JQ1-induced cell growth inhibition was correlated with the suppression of c-Myc and Bcl-xL, which are the prime genes for cell cycle control and anti-apoptosis. Furthermore, we demonstrated that p21 negatively regulated the expression of c-Myc and Bcl-xL upon JQ1 treatment, and that the growth inhibition of SW 1353 and Hs 819.T cells and induction of p21 were predominantly regulated by the LATS1/YAP signaling but not through a p53-dependent manner. In conclusion, we disclosed a novel mechanism that JQ1 inhibits cell proliferation, induces cell senescence and apoptosis of chondrosarcoma cells through the regulation of the YAP/p21/c-Myc/Bcl-xL signaling axis. J. Cell. Biochem. 118: 2182-2192, 2017. © 2017 Wiley Periodicals, Inc.