Melittin Treats Periprosthetic Osteolysis in a Rat Model by Inhibiting the NF-kB Pathway and Regulating the Ratio of Receptor Activator of Nuclear Factor Kappa B Ligand/Osteoprotegerin.

BACKGROUND: Aseptic loosening around the prosthesis is a common cause of failure in total joint arthroplasty. Polyethylene wear particles trigger the release of inflammatory factors by macrophages. Key mediators involved in osteoclastogenesis include interleukin-6, tumor necrosis factor-α, receptor activator of nuclear factor kappa B (RANK), RANK ligand (RANKL), and bone protection hormone (Osteoprotegerin [OPG]). The purpose of our experiment was to see whether melittin can slow down the release of inflammatory mediators through the NF-kB pathway, regulate the RANKL/OPG ratio, reduce osteoclast formation, and delay the onset of arthritis in rats. METHODS: A total of 20 male Sprague-Dawley rats (10 months, Specific Pathogen Free, 350 g ± 20 g) were randomly divided into 5 groups: sham group, model group, melittin concentration 1 group (0.2 mg/kg), concentration 2 group (0.4 mg/kg), and concentration 3 group (0.6 mg/kg). All rats were implanted with TA2 high-purity titanium rods. A drill was used to create a bone canal along the long axis of the femur in the intercondylar notch. The model group and experimental groups were exposed to polyethylene particles, while the sham group did not receive any particles. RESULTS: The melittin group exhibited significantly increased serum levels of serum P, calcium-phosphorus product, OPG, PINP, PINP/CTX-I, and OPG/RANKKL (P < .05). In the experimental group, micro computed tomography scanning results revealed a decrease in the amount of bone defect around the prosthesis. Immunofluorescence analysis demonstrated a decrease in the expression of IKKα and P65, while the expression of OPG showed an upward trend. Both Hematoxylin-Eosin and Tartrate-Resistant Acid Phosphatase staining revealed less osteoclast and inflammatory cell infiltration in bone resorption pits. CONCLUSIONS: Our study demonstrates that melittin has the ability to inhibit the NF-kB pathway in a rat model, and reduce the impact of RANKL/OPG, thereby delaying osteoclast activity and alleviating periprosthetic osteolysis.

Surgical treatment of acromioclavicular joint dislocation of Rockwood III/IV: a retrospective study on clavicular hook plate versus arthroscopic TightRope loop titanium button.

PURPOSE: To compare the clinical efficacy of arthroscopic TightRope loop titanium button and clavicular hook plate in the treatment of acromioclavicular joint (ACJ) dislocation of Rockwood III/IV. METHODS: A retrospective analysis of patients with ACJ dislocation in our hospital from January 2018 to December 2020 was conducted. The patients were assigned to be treated with arthroscopic TightRope loop titanium button (TR group) or clavicular hook plate (HP group). The preoperative, intraoperative and postoperative data and imaging findings of the two groups were compared. RESULTS: A total of 58 eligible patients were enrolled in this study. Compared with HP group, TR group had shorter incision length and less blood loss during operation. Postoperative follow-up ranged from 12 to 24 months (mean 15.4 months). At 6 months and 12months postoperatively, compared with HP group, TR group had lower VAS and higher CMS, and the difference was statistically significant. At 12 months postoperatively, compared with HP group, TR group had lower ACJ gap and coracoclavicular joint(CCJ) distance, and the difference was statistically significant.In HP group, there were 3 cases of subacromial impact, 1 case of redislocation, 2 cases of traumatic arthritis and 2 cases of wound infection. There was 1 case of redislocation in TR group. CONCLUSIONS: Compared with clavicular hook plate, arthroscopic TightRope loop titanium button is minimally invasive, safe and effective in the treatment of ACJ dislocation, and has a good trend in clinical application.

Knockdown of PRMT1 suppresses the malignant biological behavior of osteosarcoma cells and increases cisplatin sensitivity via c-Myc-mediated BCAT1 downregulation.

Increasing evidence indicated that protein arginine methyltransferase-1 (PRMT1) is an oncogene in multiple malignant tumors, including osteosarcoma (OS). The aim of this study was to investigate the underlying mechanism of PRMT1 in OS. The effects of PRMT1 or BCAT1, branched-chain amino acid transaminase 1 (BCAT1) on OS cell proliferation, invasion, autophagy, and apoptosis in vitro were examined. Moreover, molecular control of PRMT1 on c-Myc or transactivation of BCAT1 on c-Myc was assessed by chromatin immunoprecipitation and quantitative reverse transcription PCR assays. The effects of PRMT1 in vivo were examined with a xenograft tumor model. The results showed that PRMT1 was potently upregulated in OS tissues and cells. Upregulation of PRMT1 markedly increased OS cell proliferation and invasion in vitro and reduced cell apoptosis, whereas PRMT1 silencing showed the opposite effects. Cisplatin, one of the most effective chemotherapeutic drugs, improved cell survival rate by inducing the expression of PRMT1 to downregulate the cisplatin sensitivity. Meanwhile, the cisplatin-induced upregulation of PRMT1 expression caused dramatically autophagy induction and autophagy-mediated apoptosis by inactivating the mTOR signaling pathway, which could be reversed by 3-methyladenine, an autophagy inhibitor, or PRMT1 silencing. PRMT1 could activate c-Myc transcription and increase c-Myc-mediated expression of BCAT1. Furthermore, BCAT1 overexpression counteracted the effects of PRMT1 knockdown on cell proliferation, invasion, and apoptosis. Of note, deficiency of PRMT1 suppressed tumor growth in vivo. PRMT1 facilitated the proliferation and invasion of OS cells, inhibited cell apoptosis, and decreased chemotherapy sensitivity through c-Myc/BCAT1 axis, which may become potential target in treating OS.

The hydroxyapatite modified 3D printed poly L-lactic acid porous screw in reconstruction of anterior cruciate ligament of rabbit knee joint: a histological and biomechanical study.

BACKGROUND: 3D printing technology has become a research hotspot in the field of scientific research because of its personalized customization, maneuverability and the ability to achieve multiple material fabrications. The focus of this study is to use 3D printing technology to customize personalized poly L-lactic acid (PLLA) porous screws in orthopedic plants and to explore its effect on tendon-bone healing after anterior cruciate ligament (ACL) reconstruction. METHODS: Preparation of PLLA porous screws with good orthogonal pore structure by 3D printer. The hydroxyapatite (HA) was adsorbed on porous screws by electrostatic layer-by-layer self-assembly (ELSA) technology, and PLLA-HA porous screws were prepared. The surface and spatial morphology of the modified screws were observed by scanning electron microscopy (SEM). The porosity of porous screw was measured by liquid displacement method. Thirty New Zealand male white rabbits were divided into two groups according to simple randomization. Autologous tendon was used for right ACL reconstruction, and porous screws were inserted into the femoral tunnel to fix the transplanted tendon. PLLA group was fixed with porous screws, PLLA-HA group was fixed with HA modified porous screws. At 6 weeks and 12 weeks after surgery, 5 animals in each group were sacrificed randomly for histological examination. The remaining 5 animals in each group underwent Micro-CT and biomechanical tests. RESULTS: The pores of PLLA porous screws prepared by 3D printer were uniformly distributed and connected with each other, which meet the experimental requirements. HA was evenly distributed in the porous screw by ELSA technique. Histology showed that compared with PLLA group, mature bone trabeculae were integrated with grafted tendons in PLLA-HA group. Micro-CT showed that the bone formation index of PLLA-HA group was better than that of PLLA group. The new bone was uniformly distributed in the bone tunnel along the screw channel. Biomechanical experiments showed that the failure load and stiffness of PLLA-HA group were significantly higher than those of PLLA group. CONCLUSIONS: The 3D printed PLLA porous screw modified by HA can not only fix the grafted tendons, but also increase the inductivity of bone, promote bone growth in the bone tunnel and promote bone integration at the tendon-bone interface. The PLLA-HA porous screw is likely to be used in clinic in the future.

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.

Circular RNA VMA21 ameliorates IL-1ß-engendered chondrocyte injury through the miR-495-3p/FBWX7 signaling axis.

This study explored the function of circular RNA VMA21 (circVMA21) in osteoarthritis (OA). IL-1ß inducement reduced the expression of circVMA21 in C28/I2 cells and human primary chondrocytes. Forced expression of circVMA21 heightened cell viability and attenuated cell apoptosis, accompanied by upregulation of Bcl-2, and downregulation of Bax and C-caspase-3 in C28/I2 cells in response to IL-1ß exposure. CircVMA21 overexpression diminished the expression of MMP1 and MMP13, augmented the expression of COL2A1, and impeded the production of IL-6, TNF-α, prostaglandin E2 (PGE2) and NO. CircVMA21 served as a competitive endogenous RNA by sponging miR-495-3p. F-box and WD40 domain protein 7 (FBWX7) was identified as a target of miR-495-3p. The compensation experiments affirmed that circVMA21-mediated protective effects on IL-1ß-irritated chondrocytes through the miR-495-3p/FBWX7 axis. The role of circVMA21 was also confirmed in an OA rat model. Collectively, these findings revealed a protective effect of circVMA21in OA by intercepting the miR-495-3p/FBWX7 crosstalk.

Hypoxia inducible factor-3α promotes osteosarcoma progression by activating KDM3A-mediated demethylation of SOX9.

Hypoxia/oxygen-sensing signally is closely associated with many tumor progressions, including osteosarcoma (OS). Previous research principally focused on the function of hypoxia-inducible factor (HIF)-1α and HIF-2α as the major hypoxia-associated transcription factors in OS, however, the role of HIF-3α has not been investigated. Our study found that HIF-3α was upregulated in OS tissues and cell lines. HIF-3α overexpression facilitated cell proliferation and invasion, and inhibited apoptosis, whereas HIF-3α knockdown showed the opposite results. Chromatin immunoprecipitation analysis revealed that lysine demethylase 3A (KDM3A) expression was transcriptionally activated by HIF-3α under hypoxia, and KDM3A occupied the SRY-box transcription factor 9 (SOX9) gene promoter region through H3 lysine 9 dimethylation (H3K9me2). Additionally, rescue results revealed that KDM3A or SOX9 overexpression reversed the effects of HIF-3α silence on cell functions. The Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway inhibitor cucurbitacin I suppressed the promotive effects of HIF-3α overexpression on cell proliferation, invasion and TAK2/STAT3 pathway. Finally, OS cell line MG-63 transfected with HIF-3α short hairpin RNA (HIF-3α shRNA) were subcutaneously injected into nude mice, and the results found that HIF-3α knockdown significantly inhibited the xenograft tumor growth of OS in vivo. In conclusion, this study reveals that HIF-3α promotes OS progression in vitro and in vivo by activating KDM3A-mediated SOX9 promoter demethylation, which may provide a potential therapeutic mechanism for OS.

A network pharmacology approach to determine the underlying mechanisms of action of Yishen Tongluo formula for the treatment of oligoasthenozoospermia.

Oligoasthenozoospermia is a complex disease caused by a variety of factors, and its incidence is increasing yearly worldwide. Yishen Tongluo formula (YSTLF), created by Professor Sun Zixue, has been used to treat oligoasthenozoospermia in clinical practice for several decades with a good therapeutic effect. However, the chemical and pharmacological profiles of YSTLF remain unclear and need to be elucidated. In this study, a network pharmacology approach was applied to explore the potential mechanisms of YSTLF in oligoasthenozoospermia treatment. All of the compounds in YSTLF were retrieved from the corresponding databases, and the bioactive ingredients were screened according to their oral bioavailability (OB) and drug-likeness (DL). The potential proteins of YSTLF were obtained from the traditional Chinese medicine systems pharmacology (TCMSP) database and the Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM) database, while the potential genes of oligoasthenozoospermia were obtained from the GeneCards database and the DisGeNET database. The STRING database was used to construct an interaction network according to the common targets identified by the online tool Venny for YSTLF and oligoasthenozoospermia. The topological characteristics of nodes were visualized and analyzed through Cytoscape. Biological functions and significant pathways were determined and analyzed using the Gene Ontology (GO) knowledgebase, the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Metascape. Finally, the disease-formula-compound-target-pathway network was constructed by Cytoscape. A total of 106 bioactive ingredients and 134 potential targets from YSTLF were associated with oligoasthenozoospermia or considered to be therapeutically relevant. Pathway analysis indicated that the PI3K/Akt, MAPK and apoptosis signaling pathways were significant pathways involved in oligoasthenozoospermia. In conclusion, the current study expounded the pharmacological actions and molecular mechanisms of YSTLF in treating oligoasthenozoospermia from a holistic viewpoint. The potential molecular mechanisms were closely related to antioxidative stress, antiapoptosis and anti-inflammation, with TNF, CCND1, ESR1, NFKBIA, NR3C1, MAPK8, and IL6 being possible targets. This network pharmacology prediction may offer a helpful tool to illustrate the molecular mechanisms of the Chinese herbal compound YSTLF in oligoasthenozoospermia treatment.

Bone Mesenchymal Stem Cells Contribute to Ligament Regeneration and Graft-Bone Healing after Anterior Cruciate Ligament Reconstruction with Silk-Collagen Scaffold.

Anterior cruciate ligament (ACL) reconstruction was realized using a combination of bone mesenchymal stem cells (BMSCs) and silk-collagen scaffold, and an in vivo evaluation of this combination was performed. By combining type I collagen and degummed silk fibroin mesh, silk-collagen scaffolds were prepared to simulate ligament components. BMSCs isolated from bone marrow of rabbits were cultured for a homogenous population and seeded on the silk-collagen scaffold. In the scaffold and BMSC (S/C) group, scaffolds were seeded with BMSCs for 72 h and then rolled and used to replace the ACL in 20 rabbits. In the scaffold (S) group, scaffolds immersed only in culture medium for 72 h were used for ACL reconstruction. Specimens were collected at 4 and 16 weeks postoperatively to assess ligament regeneration and bone integration. HE and immunohistochemical staining (IHC) were performed to assess ligament regeneration in the knee cavity. To assess bone integration at the graft-bone interface, HE, Russell-Movat staining, micro-CT, and biomechanical tests were performed. After 4 weeks, vigorous cell proliferation was observed in the core part of the scaffold in the S/C group, and a quantity of fibroblast-like cells and extracellular matrix (ECM) was observed in the center part of the graft at 16 weeks after surgery. At 4 and 16 weeks postoperatively, the tenascin-C expression in the S/C group was considerably higher than that in the S group (4 w, p < 0.01; 16 w, p < 0.01). Furthermore, bone integration was better in the S/C group than in the S group, with histological observation of trabecular bone growth into the graft and more mineralized tissue formation detected by micro-CT (4 w, bone volume fraction (BV/TV), p = 0.0169, bone mineral density (BMD), p = 0.0001; 16 w, BV/TV, p = 0.1233, BMD, p = 0.0494). These results indicate that BMSCs promote ligament regeneration in the knee cavity and bone integration at the graft-bone interface. Silk-collagen scaffolds and BMSCs will likely be combined for clinical practice in the future.

Anterior cruciate ligament reconstruction in a rabbit model using a silk-collagen scaffold modified by hydroxyapatite at both ends: a histological and biomechanical study.

BACKGROUND: To investigate osteointegration at the graft-bone interface and the prevention of osteoarthritis after anterior cruciate ligament (ACL) reconstruction using a silk-collagen scaffold with both ends modified by hydroxyapatite (HA) in a rabbit model. METHODS: The HA/silk-collagen scaffold was fabricated using a degummed, knitted silk scaffold, collagen I matrix, and simulated body fluid (SBF). The HA/silk-collagen scaffold was rolled up to make a graft for replacing the native ACL in the experimental group (HA group), and the silk-collagen scaffold was used in the control (S group). All specimens were harvested at 16 weeks postoperatively to evaluate graft-bone healing and osteoarthritis prevention. RESULTS: Histological staining revealed the massive formation of more mature bone at the tendon-bone interface, and immunohistochemistry staining revealed more collagen I and osteocalcin deposition in the HA group than in the S group. Higher signals indicating more bone mineral formation were detected in the HA group than in the S group, which was consistent with the results of biomechanical testing. Better osteoarthritis prevention was also observed in the HA group, indicating a more stable knee joint in the HA group than in the S group. CONCLUSION: The HA/silk-collagen scaffold promotes osteointegration at the tendon-bone interface after ACL reconstruction and has great potential for clinical applications.

A systematic review of undisplaced femoral neck fracture treatments for patients over 65 years of age, with a focus on union rates and avascular necrosis.

BACKGROUND: It remains unclear whether conservative treatment should be used to treat the common undisplaced femoral neck fractures that develop in the elderly. Herein, we systematically review the rates of union and avascular necrosis after conservative and surgical treatment of undisplaced femoral neck fractures. METHODS: We searched the EMBASE, PubMed, OVID, Cochrane Library, Web of Science, and Scopus databases for randomized controlled trials or observational studies that assessed the outcomes of conservative or surgical treatments of undisplaced femoral neck fractures. No language or publication year limitation was imposed. Statistical analyses were performed with the aid of the chi-squared test. We evaluated the quality of each publication and the risk of bias. RESULTS: Twenty-nine studies involving 5071 patients were ultimately included; 1120 patients were treated conservatively and 3951 surgically. The union rates were 68.8% (642/933) and 92.6% (635/686) in the former and latter groups, respectively (p < 0.001). The avascular necrosis rate in the conservatively treated group was 10.3% (39/380), while it was 7.7% (159/2074) in the surgically treated group (p = 0.09). CONCLUSIONS: Surgery to treat undisplaced femoral neck fractures was associated with a higher union rate and a tendency toward less avascular necrosis than conservative treatment.

Combination of platelet-rich plasma and bone marrow mesenchymal stem cells enhances tendon-bone healing in a rabbit model of anterior cruciate ligament reconstruction.

BACKGROUND: The objective of this study was to investigate the potency of platelet-rich plasma (PRP) combined with bone marrow mesenchymal stem cells (BMSCs) to promote tendon-bone healing in a rabbit model. METHODS: In the in vitro study, the effects of PRP on osteogenic induction of BMSCs were analysed. Later, PRP with or without BMSCs was used in the rabbit model of anterior cruciate ligament reconstruction. Specimens were harvested 8 weeks postoperatively to evaluate tendon-bone healing by histology, radiology, and biomechanical testing. RESULTS: The in vitro study revealed that collagen I, osteocalcin, and osteopontin expression was higher in BMSCs co-cultured with PRP for 14 days. The in vivo study revealed a more mature tendon-bone interface using light microscopy, a more newly formed bone at the bone tunnel walls detected by micro-computed tomography, and a significantly higher failure load as assessed by biomechanical testing in the BMSC + PRP group than in the control and PRP groups. CONCLUSIONS: These results indicate that the combination of PRP and BMSCs promotes tendon-bone healing and has potential for clinical use.

Intermittent Administration of Parathyroid Hormone [1-34] Prevents Particle-Induced Periprosthetic Osteolysis in a Rat Model.

We examined whether intermittent administration of parathyroid hormone [1-34] (PTH[1-34]; 60 µg/kg/day) can prevent the negative effects of titanium (Ti) particles on implant fixation and periprosthetic osteolysis in a rat model. Eighteen adult male rats (12 weeks old, bones still growing) received intramedullary Ti implants in their bilateral femurs; 6 rats from the blank group received vehicle injections, and 12 rats from the control group and PTH treatment group received Ti particle injections at the time of operation and intra-articular injections 2 and 4 weeks postoperatively. Six of the rats that received Ti particles from the PTH group also received PTH[1-34] treatment. Six weeks postoperatively, all specimens were collected for assessment by X-ray, micro-CT, biomechanical, scanning electron microscopy (SEM), and dynamic histomorphometry. A lower BMD, BV/TV, Tb.N, maximal fixation strength, and mineral apposition rate were observed in the control group compared to the blank group, demonstrating that a periprosthetic osteolysis model had been successfully established. Administration of PTH[1-34] significantly increased the bone mineral density of the distal femur, BV/TV, Tb.N, Tb.Th, Tb.Sp, Con.D, SMI, and maximal fixation strength in the PTH group compared to that in the control group. SEM revealed higher bone-implant contact, thicker lamellar bone, and larger trabecular bone area in the PTH group than in the control group. A higher mineral apposition rate was observed in the PTH group compared to both the blank and control groups. These findings imply that intermittent administration of PTH[1-34] prevents periprosthetic osteolysis by promoting bone formation. The effects of PTH[1-34] were evaluated at a suprapharmacological dosage to the human equivalent in rats; therefore, additional studies are required to demonstrate its therapeutic potential in periprosthetic osteolysis.

Anterior cruciate ligament reconstruction in a rabbit model using silk-collagen scaffold and comparison with autograft.

The objective of the present study was to perform an in vivo assessment of a novel silk-collagen scaffold for anterior cruciate ligament (ACL) reconstruction. First, a silk-collagen scaffold was fabricated by combining sericin-extracted knitted silk fibroin mesh and type I collagen to mimic the components of the ligament. Scaffolds were electron-beam sterilized and rolled up to replace the ACL in 20 rabbits in the scaffold group, and autologous semitendinosus tendons were used to reconstruct the ACL in the autograft control group. At 4 and 16 weeks after surgery, grafts were retrieved and analyzed for neoligament regeneration and tendon-bone healing. To evaluate neoligament regeneration, H&E and immunohistochemical staining was performed, and to assess tendon-bone healing, micro-CT, biomechanical test, H&E and Russell-Movat pentachrome staining were performed. Cell infiltration increased over time in the scaffold group, and abundant fibroblast-like cells were found in the core of the scaffold graft at 16 weeks postoperatively. Tenascin-C was strongly positive in newly regenerated tissue at 4 and 16 weeks postoperatively in the scaffold group, similar to observations in the autograft group. Compared with the autograft group, tendon-bone healing was better in the scaffold group with trabecular bone growth into the scaffold. The results indicate that the silk-collagen scaffold has considerable potential for clinical application.

SeMet mediates anti-inflammation in LPS-induced U937 cells targeting NF-κB signaling pathway.

In previous studies, selenium (Se) was reported to play critical roles in anti-inflammatory activities. Nevertheless, limited information could be obtained during inflammation about selenomethionine (SeMet) in U937 human macrophage cells. The purpose of this study was to investigate the effects of SeMet on the inflammatory responses to lipopolysaccharide (LPS)-induced U937 macrophage cells and the signaling pathways targeted. U937 cells were pretreated with SeMet (1 µM) and subsequently induced with LPS (1 µg/ml) for 24 h. In the cell counting kit-8 assay (CCK-8), SeMet significantly inhibits the proliferation of U937 cells. SeMet also inhibited the production of nitric oxide (NO) and prostaglandin E2 (PGE2) stimulated by LPS. In the Western blot assay and real-time polymerase chain reaction (RT-PCR), SeMet significantly reduced protein expression and production of inducible NO synthase (iNOS), tumor necrosis factor-alpha (TNF-α), and COX-2 in U937 cells. Furthermore, SeMet markedly suppressed the LPS-mediated activation of nuclear factor-kappa B (NF-κB) by blocking the degradation of inhibitor-κB proteins (IκBα) and lessening the translocations of P50 subunit content of NF-κB in the nucleus. These findings suggested the anti-inflammatory activity of SeMet in U937 cells; indicating that SeMet might be a potential treatment for inflammation therapy.

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.

Effects of cartilage oligomeric matrix protein on bone morphogenetic protein-2-induced differentiation of mesenchymal stem cells.

OBJECTIVE: To investigate the effect of overexpression of cartilage oligomeric matrix protein (COMP) on bone morphogenetic protein-2 (BMP-2) induced osteogenic and chondrogenic differentiation of mesenchymal stem cells (MSCs). In this study, we used liposomes to transfect MSCs with plasmid encoding COMP and then induced the transfected MSCs to differentiate in osteogenic and chondrogenic differentiation media containing BMP-2. METHODS: MSCs transfected with plasmid DNA encoding recombinant human COMP were induced to differentiate into osteocytes and chondrocytes by BMP-2. Real-time polymerase chain reaction (PCR) assays of osteogenesis-related markers (collagen type I alpha 1, runt-related transcription factor 2, osteopontin, bone gla protein) and chondrogenesis-related markers (collagen type II alpha 1, sry-related high-mobility group box 9, Aggrecan) was performed to evaluate the process of cell differentiation. Cell differentiation was evaluated by alkaline phosphatase (ALP) and Alizarin red S stains for osteogenic differentiation and alcian blue staining for chondrogenic differentiation. RESULTS: Real-time PCR assay showed significantly greater COMP expression by MSCs when COMP gene had been transfected into the cells (P < 0.01). Overexpression of COMP down-regulated expression of osteogenesis-related markers and up-regulated expression of chondrogenesis-related markers. ALP staining and Alizarin red S staining were weakened, whereas alcian blue staining was enhanced. CONCLUSION: Overexpression of COMP inhibits BMP-2-induced osteogenic differentiation and promotes BMP-2-induced chondrogenic differentiation. These findings may provide new insights for cartilage tissue engineering. The experiments in the present study were all in vitro, which has potential limitations. Further in vivo studies to investigate the effects of COMP in animal models are necessary, which will be the next step in our research.

Intermittently administered parathyroid hormone [1-34] promotes tendon-bone healing in a rat model.

The objective of this study was to investigate whether intermittent administration of parathyroid hormone [1-34] (PTH[1-34]) promotes tendon-bone healing after anterior cruciate ligament (ACL) reconstruction in vivo. A rat model of ACL reconstruction with autograft was established at the left hind leg. Every day, injections of 60 µg PTH[1-34]/kg subcutaneously were given to the PTH group rats (n=10) for four weeks, and the controls (n=10) received saline. The tendon-bone healing process was evaluated by micro-CT, biomechanical test, histological and immunohistochemical analyses. The effects of PTH[1-34] on serum chemistry, bone microarchitecture and expression of the PTH receptor (PTH1R) and osteocalcin were determined. Administration of PTH[1-34] significantly increased serum levels of calcium, alkaline phosphatase (AP), osteocalcin and tartrate-resistant acid phosphatase (TRAP). The expression of PTH1R on both osteocytes and chondrocyte-like cells at the tendon-bone interface was increased in the PTH group. PTH[1-34] also enhanced the thickness and microarchitecture of trabecular bone according to the micro-CT analysis. The results imply that systematically intermittent administration of PTH[1-34] promotes tendon-bone healing at an early stage via up-regulated PTH1R. This method may enable a new strategy for the promotion of tendon-bone healing after ACL reconstruction.

The external rotation immobilisation does not reduce recurrence rates or improve quality of life after primary anterior shoulder dislocation: a systematic review and meta-analysis.

PURPOSE: Conducting a systematic review and meta-analysis of prospective randomised controlled trials directly comparing (1) the rates of recurrence and (2) patient-based quality-of-life assessments after the external rotation (ER) or internal rotation (IR) immobilisation after primary anterior shoulder dislocation. METHODS: PubMed, EMBASE, the Cochrane Library and ISI Web of Science were searched up to January 2013, using the Boolean operators as follows: (bankart lesion OR shoulder anterior dislocation) AND ((external rotation AND internal rotation) OR immobilisation). All prospective randomised controlled trials directly comparing recurrence rate and patient-based quality-of-life assessments between the ER and IR immobilisations were retrieved. No limitation of the language or publication year existed in our analysis. RESULTS: Seven of 896 studies involving 663 patients were included, 338 in the ER group and 325 in the IR group. No significant difference was observed in the recurrence rate at all ages (risk ratio (RR)=0.65; 95% confidence interval, 0.41-1.03; p=0.067), at the age stratum of ≤30 years (RR=0.70; 95% confidence interval, 0.38-1.29; p=0.250) and >30 years (RR=0.86; 95% confidence interval, 0.38-1.97; p=0.722). Four trials adopted quality-of-life assessments, using the Constant-Murlay functional scoring system, the Rowe scoring system, the Western Ontario Shoulder Instability index (WOSI), the Disabilities of arm, shoulder and hand (DASH) and the American Shoulder and Elbow Surgeons evaluation form (ASES). Only one trial demonstrated borderline statistical significance (p=0.05) and probable superiority of the ER group based on the ASES. No significant difference was observed in other three trials. CONCLUSION: Based on the results of our analysis, the ER immobilisation could not reduce the rates of recurrence after primary anterior shoulder dislocation or improve the quality of life compared with the IR immobilisation. More rigorous and adequately powered prospective randomised controlled trials with long-term follow-ups are required to elucidate a more objective outcome.

Association between single nucleotide polymorphisms of DOT1L gene and risk of knee osteoarthritis in a Chinese Han population.

To investigate associations between single nucleotide polymorphisms rs12982744 and rs12459350 in the DOT1L gene and knee osteoarthritis (OA) susceptibility in a Chinese Han population. DOT1L rs12982744 and rs12459350 polymorphisms were genotyped in patients with knee OA and age- and sex-matched OA-free controls from a Chinese Han population. A total of 605 patients with knee OA and 615 controls were enrolled in the study. GC and CC genotypes of rs12982744, and variant C, were associated with a significantly increased risk of knee OA. On stratification analysis, the association between the risk of OA and rs12982744 GC heterozygotes compared with GG homozygotes was stronger in females and those aged >65 years. In contrast, the GA and AA genotypes of rs12459350 were not significantly associated with the risk of knee OA, even after further stratification analysis according to age or sex. Our results showed that DOT1L rs12982744 G to C change and variant C genotype may contribute to knee OA risk in a Chinese Han population.