Merlin functions as a critical regulator in Staphylococcus aureus-induced osteomyelitis.

Merlin is known as a tumor suppressor, while its role in osteomyelitis remains unclear. This study aimed to investigate the role of Merlin in Staphylococcus aureus-induced osteomyelitis and its underlying mechanisms. S. aureus-induced osteomyelitis mouse model was established in Merlinfl/fl Lyz2cre/+ and Merlinfl/fl Lyz2+/+ mice. Bone marrow-derived macrophages (BMDMs) were isolated and stimulated by lipopolysaccharide (LPS). Bioassays, including quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blot analysis, and enzyme-linked immunosorbent assays, were conducted to determine the levels of target genes or proteins. Immunoprecipitation was applied to determine the interactions between proteins. DCAF1fl/fl mice were further crossed with Lyz2-Cre mice to establish myeloid cell conditional knockout mice (DCAF1fl/fl Lyz2cre/+ ). It was found that the level of Merlin was elevated in patients with osteomyelitis and S. aureus-infected BMDMs. Merlin deficiency in macrophages suppressed the production of inflammatory cytokines and ameliorated the symptoms of osteomyelitis induced by S. aureus. Merlin deficiency in macrophages also suppressed the production of proinflammatory cytokines in BMDMs induced by LPS. The inhibitory effects of Merlin deficiency on the inflammatory response were associated with DDB1-Cul4-associated factor 1 (DCAF1). In summary, Merlin deficiency ameliorates S. aureus-induced osteomyelitis through the regulation of DCAF1.

Involvement of mechanosensitive ion channels in the effects of mechanical stretch induces osteogenic differentiation in mouse bone marrow mesenchymal stem cells.

Bone marrow mesenchymal stem cells (BMSCs) can be induced to process osteogenic differentiation with appropriate mechanical and/or chemical stimuli. The present study described the successful culture of murine BMSCs under mechanical strain. BMSCs were subjected to 0%, 3%, 8%, 13%, and 18% cyclic tensile strain at 0.5 Hz for 8 hr/day for 3 days. The expression of osteogenic markers and mechanosensitive ion channels was evaluated with real-time reverse transcription-polymerase chain reaction (RT-PCR) and western blot. The expression of alkaline phosphatase (ALP) and matrix mineralization were evaluated with histochemical staining. To investigate the effects of mechanosensitive ion channel expression on cyclic tensile strain-induced osteogenic differentiation, the expression of osteogenic markers was evaluated with real-time RT-PCR in the cells without mechanosensitive ion channel expression. This study revealed a significant augment in osteogenic marker in BMSC strained at 8% compared to other treatments; therefore, an 8% strain was used for further investigations. The ALP expression and matrix mineralization were enhanced in osteogenic induced BMSCs subjected to 8% strain after 7 and 14 days, respectively. Under the same conditions, the osteogenic marker and mechanosensitive ion channel expression were significantly promoted. However, the loss function of mechanosensitive ion channels resulted in the inhibition of osteogenic marker expression. This study demonstrated that strain alone can successfully induce osteogenic differentiation in BMSCs and the expression of mechanosensitive ion channels was involved in the process. The current findings suggest that mechanical stretch could function as efficient stimuli to induce the osteogenic differentiation of BMSCs via the activation of mechanosensitive ion channels.

Inhibition of microRNA-222 up-regulates TIMP3 to promotes osteogenic differentiation of MSCs from fracture rats with type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is the most common diabetes and has numerous complications. Recent studies demonstrated that T2DM compromises bone fracture healing in which miR-222 might be involved. Furthermore, tissue inhibitor of metalloproteinase 3 (TIMP-3) that is the target of miR-222 accelerates fracture healing. Therefore, we assume that miR-222 could inhibit TIMP-3 expression. Eight-week-old rats were operated femoral fracture or sham, following the injection of streptozotocin (STZ) to induce diabetes one week later in fractured rats, and then, new generated tissues were collected for measuring the expression of miR-222 and TIMP-3. Rat mesenchymal stem cells (MSCs) were isolated and treated with miR-222 mimic or inhibitor to analyse osteogenic differentiation. MiR-222 was increased in fractured rats and further induced in diabetic rats. In contrast, TIMP-3 was reduced in fractured and further down-regulated in diabetic rats. Luciferase report assay indicated miR-222 directly binds and mediated TIMP-3. Furthermore, osteogenic differentiation was suppressed by miR-222 mimic and promoted by miR-222 inhibitor. miR-222 is a key regulator that is promoted in STZ-induced diabetic rats, and it binds to TIMP3 to reduce TIMP-3 expression and suppressed MSCs' differentiation.

A high-fat diet aggravates osteonecrosis through a macrophage-derived IL-6 pathway.

Inflammation plays an important role in osteonecrosis. Obesity, a risk factor for osteonecrosis, leads to a chronic inflammatory status. We hypothesized that inflammation mediated the effects of obesity on osteonecrosis and tested our hypothesis in a mouse model of osteonecrosis. We fed mice with a high-fat diet (HFD) for 12 weeks before osteonecrosis induction by methylprednisolone and examined bone structure and IL-6 expression. Then we investigated the effects of IL-6 deletion in mice with osteonecrosis on the HFD. Next, we isolated bone marrow cells and determined the cell types responsible for HFD-induced IL-6 secretion. Finally, we investigated the roles of macrophages and macrophage-driven IL-6 in HFD-mediated effects on osteonecrosis and osteogenesis of bone marrow stromal cells (BMSCs). The HFD lead to exacerbated destruction of the femoral head in mice with osteonecrosis and increased IL-6 expression in macrophages. Il-6 knockout or macrophage depletion suppressed the effects of the HFD on bone damage. When co-cultured with macrophages isolated from HFD-fed mice with osteonecrosis, BMSCs showed reduced viability and suppressed osteogenic differentiation. Our results suggest that macrophage-driven IL-6 bridges obesity and osteonecrosis and inhibition of IL-6 or depletion of macrophage may represent a therapeutic strategy for obesity-associated osteonecrosis.

IL-15 deficiency alleviates steroid-induced osteonecrosis of the femoral head by impact osteoclasts via RANKL-RANK-OPG system.

BACKGROUND: Whether IL-15 is involved in the development of steroid-induced osteonecrosis of the femoral head (ONFH) is investigated. METHODS: C57BL/6 J and l15-/-mice were injected with methylprednisolone to induce wide type osteonecrosis (WT ON) and IL-15 deficiency osteonecrosis (IL-15-/- ON). Hematoxylin-Eosin (H&E) staining and micro-computed tomography (micro-CT) scanning was used to detect the microstructure. The differentiation and formation of osteoclasts were determined with colony-forming unit-granulocyte macrophages (CFU-GM), colony-forming unit-macrophage/mononuclear (CFU-M) per tibia, and tartrate-resistant acid phosphatase (TRACP or TRAP) positive cells. Serum interleukin (IL)-15, osteocalcin, bone alkaline phosphatase (BAP), bone Gla protein (BGP), and TRACP were assayed with enzyme-linked immunosorbent assay (ELISA). The receptor activator of nuclear factor-κB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) in the femoral heads were detected by Western blot. CD34 staining was performed to detect microvascular density. RESULTS: IL-15 secretion was increased in the femoral heads and the serum of steroid-induced ONFH mice. IL-15 deficiency may lead to up-regulated vessel remodeling, improved microstructure, and up-regulated serum osteocalcin, BAP, and BGP secretion. Both the expression of RANKL/RANK/OPG and osteoclast differentiation and formation can be down-regulated by IL-15 deficiency. CONCLUSION: IL-15 deficiency alleviates steroid-induced ONFH by impact osteoclasts via RANKL-RANK-OPG system.

The promotion of bone regeneration through CS/GP-CTH/antagomir-133a/b sustained release system.

Few studies reported the application of miRNA in bone regeneration. In this study, the expression of miR133a and miR133b in murine BMSCs was inhibited via antagomiR-133a/b and the osteogenic differentiation in murine BMSCs was evaluated. The RT-PCR, flow cytometry, cell counting kit-8, and annexin V-FITC/PI double staining assays were performed. Double knockdown miR133a and miR133b can promote BMSC osteogenic differentiation. At optimum N/P ration (15:1), the loading efficiency can reach over 90%. CTH-antagomiR-133a/b showed no cytotoxicity to BMSCs and diminished miR133a and miR133b expression in BMSCs. Furthermore, chitosan-based sustained delivery system can facilitate continuous dosing of antagomiR-133a/b, which enhanced calcium deposition and osteogenic specific gene expression in vitro. The new bone formation was enhanced after the sustained delivery system containing CTH-antagomiR-133a/b nanoparticles was used in mouse calvarial bone defect model. Our results demonstrate that CTH nanoparticles could facilitate continuous dosing of antagomiR133a/b, which can promote osteogenic differentiation.

Effects of Mindfulness-Based Stress Reduction on Depression, Anxiety, and Pain in Patients With Postherpetic Neuralgia.

The aim of this study was to explore the effects of mindfulness-based stress reduction (MBSR) on reducing the psychological and physical symptoms in patients with postherpetic neuralgia (PHN). A total of 50 patients with PHN from January 2017 to September 2018 were selected into the intervention group and the control group. Both groups received routine care, whereas the intervention group also was given an 8-week of MBSR. Psychological (depression and anxiety) and physical (pain) symptoms were assessed before and after the intervention. The study demonstrated evidence of MBSR effectiveness in reducing depression (p < 0.01), anxiety (p < 0.01), and pain (p < 0.01) scores after intervention for herpetic patients with neuralgia. MBSR can effectively alleviate depression, anxiety, and pain in patients with PHN. Our results provide clinical effectiveness evidence that MBSR works to improve the psychological and physical symptoms with the greatest improvement occurring during the 8-week program.

Puerarin Attenuates Osteoarthritis via Upregulating AMP-Activated Protein Kinase/Proliferator-Activated Receptor-γ Coactivator-1 Signaling Pathway in Osteoarthritis Rats.

BACKGROUND/AIMS: Osteoarthritis is the most common degenerative joint disease and causes major pain and disability in adults. It has been reported that mitochondrial dysfunction in chondrocytes was associated with osteoarthritis. Puerarin has multiple effects including restoring mitochondrial function. In this study, the potential effects of puerarin on osteoarthritis and osteoarthritis associated mitochondrial dysfunctions were evaluated. METHODS: Osteoarthritis rats were treated with puerarin and the severity of osteoarthritis and cartilage damages was evaluated. The mitochondrial biogenesis and functions were analyzed by measuring related proteins expression, mitochondrial DNA content, ATP production, and oxygen consumption. The dependence of AMP-activated protein kinase (AMPK) pathway on puerarin-regulated mitochondrial function was analyzed by applying AMPK inhibitor Compound C. RESULTS: Puerarin treatment alleviated mechanical hyperalgesia and cartilage damage in osteoarthritis rats. Puerarin increased mitochondrial biogenesis and attenuated mitochondrial dysfunctions in osteoarthritis rats. AMPK inhibitor Compound C abolished puerarin's effects. CONCLUSION: Puerarin attenuates osteoarthritis by upregulating the AMPK/proliferator-activated receptor-γ coactivator signaling pathway in osteoarthritis rats.

Curcumin protects human adipose-derived mesenchymal stem cells against oxidative stress-induced inhibition of osteogenesis.

The detrimental effects of oxidative stress on the skeletal system have been documented, and understanding the mechanisms is important to design a therapeutic strategy. As an antioxidant and anti-inflammatory agent, the active ingredient of turmeric curcumin has been used as medication for numerous complications including bone loss. However, it is unclear if curcumin could influence the osteogenic potential of mesenchymal stem cells (MSCs), particularly in oxidative injuries. Here we demonstrate that curcumin treatment protects cell death caused by hydrogen peroxide (H2O2) exposure in human adipose-derived MSCs in vitro. Importantly, curcumin is able to enhance the osteoblast differentiation of human adipose-derived MSCs that is inhibited by H2O2. Notably, both oxidative stress and the inhibition of Wnt/ß-catenin signaling are attenuated by curcumin treatment. These results suggest that curcumin can promote osteoblast differentiation of MSCs and protect the inhibitory effect elicited by oxidative injury. The findings support potential use of curcumin or related antioxidants in MSC-based bone regeneration for disease related with oxidative stress-induced bone loss.

Albumin's Influence on Carprofen Enantiomers-Hymecromone Interaction.

Hymecromone is an important coumarin drug, and carprofen is one of the most important nonsteroidal antiinflammatory drugs (NSAIDs). The present study aims to determine the influence of bovine serum albumin (BSA) on the carprofen-hymecromone interaction. The inhibition of carprofen enantiomers on the UDP-glucuronosyltransferase (UGT) 2B7-catalyzed glucuronidation of hymecromone was investigated in the UGTs incubation system with and without BSA. The inhibition capability of increased by 20% (P < 0.001) of (R)-carprofen after the addition of 0.5% BSA in the incubation mixture. In contrast, no significant difference was observed for the inhibition of (S)-carprofen on UGT2B7 activity in the absence or presence of 0.5% BSA in the incubation system. The Lineweaver-Burk plot showed that the intersection point was located in the vertical axis, indicating the competitive inhibition of (R)-carprofen on UGT2B7 in the incubation system with BSA, which is consistent with the inhibition kinetic type of (R)-carprofen on UGT2B7 in the incubation system without BSA. Furthermore, the second plot using the slopes from the Lineweaver-Burk versus the concentrations of (R)-carprofen showed that the fitting equation was y=39.997x+50. Using this equation, the inhibition kinetic parameter was calculated to be 1.3 µM. For (S)-carprofen, the intersection point was located in the horizontal axis in the Lineweaver-Burk plot for the incubation system with BSA, indicating the noncompetitive inhibition of (S)-carprofen on the activity of UGT2B7. The fitting plot of the second plot was y=24.6x+180, and the inhibition kinetic parameter was 7.3 µM. In conclusion, the present study gives a short summary of BSA's influence on the carprofen enantiomers-hymecromone interaction, which will guide the clinical application of carprofen and hymecromone.

Late surgery for acetabular fractures in a Chinese level I trauma centre: surgical experience and outcomes.

PURPOSE: Delayed surgical management of acetabular fractures, often necessary due to life-threatening concomitant injuries, is a great challenge because delays may potentially increase complications and decrease outcomes. We report clinical outcomes of 61 acetabular fractures treated by delayed open reduction and internal fixation (ORIF) with an injury-to-surgery interval (ISI) of 22-399 days. METHODS: Operations were performed between April 2001 and December 2008. There were 61 cases (42 men 19 women), with an average age of 38 years. All patients were followed for an average of 82 months. Demographic data, fracture pattern, ISI, concomitant injuries, surgical approach, complications and clinical outcomes were recorded and analysed. There were 16 simple fractures (26.2%) and 45 associated fractures (73.8%). Matta criteria were used to evaluate reduction quality. The Merle d'Aubigné and Postel scoring system was employed to assess post-operative functionality. RESULTS: Anatomical reduction was achieved in 45 cases (73.8%). The clinical result was excellent in 38 cases, good in 13, fair in six and poor in four. Osteonecrosis of the femoral head was observed in three cases, and heterotopic ossification was found in 28 cases. Four patients had transient palsy of the sciatic nerve. CONCLUSIONS: ORIF for fresh acetabular fractures might yield a better prognosis; however, for delayed acetabular fractures, clinical outcomes are also predictable when sophisticated surgical techniques are employed. Our results indicate that delayed ORIF could yield satisfactory clinical outcomes in the majority of patients with acetabular fractures.

Subtrochanteric femur fracture treated by intramedullary fixation.

PURPOSE: To discuss surgical technique, operative efficacy and clinical outcome of intramedullary fixation in the treatment of subtrochanteric femur fractures. METHODS: From February 2011 to February 2013, 76 cases of subtrochanteric femur fractures were treated by intramedullary fixation in our hospital, including 53 males and 23 females, with the age range of 37 -72 years (mean 53.5 years). According to Seinsheimer classification, there were 2 cases of type I, 7 type II, 15 type III, 23 type IV and 29 type V. Firstly, all patients underwent closed reduction with the guidance of C-arm fluoroscopy in a traction table. Two cases of type I and 3 cases of type III fractures had ideal closed reduction followed by internal fixation. The others needed additional limited open reduction. Radiographic examination was used to evaluate callus formation and fracture healing in postoperative 1, 3, 6 and 12 months follow-up. Functional recovery was evaluated by Harris Hip Scoring (HHS) system. RESULTS: Patients were followed up for 6-12 months. All fractures were healed except one patient with delayed union. The average bone union time was 4.5 months. According to HHS system, 65 cases were considered as excellent in functional recovery, 8 good, 2 fair and 1 poor. The proportion of the patients with excellent and good recovery was 96.05%. CONCLUSION: Intramedullary fixation is feasible for the treatment of subtrochanteric femur fracture. The accuracy of intraoperative reduction and surgical skill are important for the clinical outcome and the patients' prognosis.

Prognostic significance of VEGF expression in osteosarcoma: a meta-analysis.

Vascular endothelial growth factor (VEGF) is considered as a prime mediator of angiogenesis and has been implicated in carcinogenesis and metastasis. Various studies examined the relationship between VEGF overexpression with the clinical outcome in patients with osteosarcoma but yielded conflicting results. Electronic databases updated to April 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between VEGF overexpression and survival of patients with osteosarcoma. Survival data were aggregated and quantitatively analyzed. We performed a meta-analysis of eight studies that evaluated the correlation between VEGF overexpression and survival in patients with osteosarcoma. Combined hazard ratios suggested that VEGF overexpression had an unfavorable impact on overall survival (hazard ratio (HR) = 1.75, 95% confidence interval (CI): 1.21-2.28) in patients with osteosarcoma for overall populations, 2.37 (1.35-3.39) in Asian studies but not in non-Asian studies (HR = 1.51, 95% CI: 0.89-2.14). No significant heterogeneity was observed among all studies. VEGF overexpression indicates a poor prognosis for patients with osteosarcoma. However, the prognostic value of VEGF on survival in osteosarcoma patients still needs further large-scale prospective trials to be clarified.

Association of the CTLA-4 +49A/G polymorphism with rheumatoid arthritis in Chinese Han population.

Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is an important molecule in the regulation of T cells, so the CTLA-4 gene has been considered as a strong candidate associated with T cell-mediated autoimmune diseases such as rheumatoid arthritis (RA). CTLA-4 has many variants and polymorphic forms, among which the +49A/G polymorphism, causing a non-synonymous substitution, has been studied most. However, previous studies of the association between the +49A/G polymorphism of the CTLA-4 gene and RA have provided conflicting results. The aim of this study was to determine the potential relationship of the CTLA-4 +49A/G polymorphism and the risk of RA in Chinese Han population. TaqMan assay was used to genotype the +49A/G polymorphism in 1,489 RA patients and 1,200 healthy controls. Furthermore, a meta-analysis of all studies relating this polymorphism in Chinese population to the risk of RA was performed. The genotype and allele frequencies of the CTLA-4 +49A/G in patients with RA differed significantly from those of controls (P = 0.03 and P = 0.007, respectively). The meta-analysis also revealed that the CTLA-4 +49G allele was associated with an increased risk of RA in Chinese population. Our results suggested that the CTLA-4 gene might contribute to the pathogenesis of RA, and the +49A/G polymorphism of this gene was a risk factor associated with increased RA susceptibility in Chinese Han population.

Minimally invasive treatment for pubic ramus fractures combined with a sacroiliac joint complex injury.

PURPOSE: Fractures of the pubic rami due to low energy trauma are common in the elderly, with an incidence of 26 per 100,000 people per year in those aged more than 60 years. The purpose of this study was to evaluate the clinical application of this minimally invasive technique in patients with pubic ramus fractures combined with a sacroiliac joint complex injury, including its feasibility, merits, and limitations. METHODS: Fifteen patients with pubic ramus fractures combined with sacroiliac joint injury were treated with the minimally invasive technique from June 2008 until April 2012. The quality of fracture reduction was evaluated according to the Matta standard. RESULTS: Fourteen cases were excellent (93.3 %), and one case was good (6.7 %). The fracture lines were healed 12 weeks after the surgery. The 15 patients had follow-up visits between four to 50 months (mean, 22.47 months). All patients returned to their pre-injury jobs and lifestyles. One patient suffered a deep vein thrombosis during the peri-operative period. A filter was placed in the patient before the surgery and was removed six weeks later. There was no thrombus found at the follow-up visits of this patient. CONCLUSION: The minimally invasive technique in patients with pubic ramus fractures combined with a sacroiliac joint complex injury provided satisfactory efficacy.

Umbrella-shaped, memory alloy femoral head support device for treatment of avascular osteonecrosis of the femoral head.

PURPOSE: Avascular necrosis (AVN) of the femoral head is a common orthopaedic disease that is difficult to treat. The purpose of this study was to explore the preliminary efficacy of a self-designed umbrella-shaped memory alloy femoral head support device in the treatment of adult patients with avascular osteonecrosis of the femoral head. METHODS: The minimally-invasive approach involved curettage of the necrotic tissue of the femoral head, and a self-designed umbrella-shaped, memory alloy femoral head support device was implanted into the collapsed necrotic area to support the collapsed femoral head. Autologous iliac bone and artificial bone were implanted into the support device for the treatment of adult patients with avascular osteonecrosis of the femoral head. RESULTS: The clinical device was used in ten patients and 18 hip joints. The support device failed in one hip joint, which subsequently underwent joint replacement surgery, and the remaining 17 implanted devices were followed up for four to 19 months. The 17 postoperative hip joints were evaluated using the percent-efficacy evaluation method for avascular osteonecrosis of the femoral head in adult patients, and the efficacy rate was 82.35 %. CONCLUSION: The umbrella-shaped femoral head support device can be used in Ficat stage I, stage II, and stage III adult patients with avascular osteonecrosis of the femoral head.

Inhibiting wear particles-induced osteolysis with naringin.

PURPOSE: The purpose of this study was to determine the effects of naringin on osteoclastogenesis and osteolysis both in vitro and in vivo. METHODS: In this research osteoclasts were generated from mouse bone marrow monocytes with the receptor activator of NF-КB ligand and the macrophage colony stimulating factor. Naringin, at a concentration of 1, 10, 50, and 100 µg/mL, was respectively added to the medium. Seven days later, the osteoclasts were determined through tartrate-resistant acid phosphatase (TRAP) staining. Mature osteoclasts were isolated from newborn rabbits and cultured for three days on bone slices. Naringin at a concentration of 1, 10, 50, and 100 µg/mL was respectively added to the medium. The resorption bone slices were quantified, and the area was calculated after toluidine blue and Mayer-hematoxylin staining. Polymethyl methacrylate (PMMA) particles were implanted on the calvariae of C57BL/J6 mice. Naringin, at a dose of 50 µg/kg and 100 µg/kg, was respectively given intraperitoneally for seven. Seven days later, the calvariae were removed and processed for pathological analysis. RESULTS: The result indicated that naringin treatment effectively inhibited in vitro osteoclastogenesis and inhibited mature osteoclasts. In vivo data indicated that naringin strongly inhibited PMMA-induced osteolysis. CONCLUSION: Naringin can effectively inhibit osteoclastogenesis and suppress wear particles-induced osteolysis and might be useful in the treatment or prevention of wear particles-induced osteolysis and aseptic loosening for its effect on osteoclast generation and function.

Effects of astragaloside IV on glucocorticoid-induced avascular necrosis of the femoral head via regulating Akt-related pathways.

We investigated the role of astragaloside IV (AS-IV) in preventing glucocorticoid-induced avascular necrosis of the femoral head (ANFH) and the underlying molecular mechanisms. Network pharmacology was used to predict the molecular targets of AS-IV. Molecular dynamic simulations were performed to explore the binding mechanism and interaction mode between AS-IV and Akt. Rat models of glucocorticoid-induced ANFH with AS-IV intervention were established, and osteogenesis, angiogenesis, apoptosis and oxidative stress were evaluated before and after blocking the PI3K/Akt pathway with LY294002. The effects of glucocorticoid and AS-IV on bone marrow mesenchymal stem cells and human umbilical vein endothelial cells incubated with and without LY294002 were determined. Downregulated p-Akt expression could be detected in the femoral heads of glucocorticoid-induced ANFH patients and rats. AS-IV increased trabecular bone integrity and vessel density of the femoral head in the model rats. AS-IV increased Akt phosphorylation and upregulated osteogenesis-, angiogenesis-, apoptosis- and oxidative stress-related proteins and mRNA and downregulated Bax, cleaved caspase-3 and cytochrome c levels. AS-IV promoted human umbilical vein endothelial cell migration, proliferation and tube formation ability; bone marrow mesenchymal stem cell proliferation; and osteogenic differentiation under glucocorticoid influence. AS-IV inhibited apoptosis. LY294002 inhibited these effects. AS-IV prevented glucocorticoid-induced ANFH by promoting osteogenesis and angiogenesis via the Akt/Runx2 and Akt/HIF-1α/VEGF pathways, respectively, and suppressing apoptosis and oxidative stress via the Akt/Bad/Bcl-2 and Akt/Nrf2/HO-1 pathways, respectively.

Minimally invasive percutaneous osteosynthesis for proximal humeral shaft fractures with the PHILOS through the deltopectoral approach.

PURPOSE: The aim of this study was to evaluate clinical outcomes and complications following minimally invasive plate osteosynthesis (MIPO) with the proximal humeral internal locking system (PHILOS) for treating proximal humeral shaft fracture through the deltopectoral approach. METHODS: Between November 2008 and March 2010, 74 patients with unilateral proximal humeral shaft fractures were treated using the MIPO technique with the PHILOS through the deltopectoral approach. Patients received an average follow-up of 16.9 (range, 12-24) months, and the final follow-up included anteroposterior and lateral imaging and recording of postoperative complications. The Constant-Murley shoulder score was used to evaluate function. RESULTS: No intraoperative complications occurred. Postoperative complications included subacromial impingement in four patients. There was no deep infection, neurovascular damage, breakage or implant loosening. All fractures united in an average time of 17.4 (15-25) weeks. In terms of function, the Constant-Murley score was 85.8 points on average (range, 67-100). The range of motion of the involved shoulder was satisfactory, and pain-free in 83.8 % of patients. CONCLUSIONS: Using the MIPO technique with the PHILOS through the deltopectoral approach is a valid and safe method of treating proximal humeral shaft fractures.

IL-34 Aggravates Steroid-Induced Osteonecrosis of the Femoral Head via Promoting Osteoclast Differentiation.

IL-34 can promote osteoclast differentiation and activation, which may contribute to steroid-induced osteonecrosis of the femoral head (ONFH). Animal model was constructed in both BALB/c and IL-34 deficient mice to detect the relative expression of inflammation cytokines. Micro-CT was utilized to reveal the internal structure. In vitro differentiated osteoclast was induced by culturing bone marrow-derived macrophages with IL-34 conditioned medium or M-CSF. The relative expression of pro-inflammation cytokines, osteoclast marker genes, and relevant pathways molecules was detected with quantitative real-time RT-PCR, ELISA, and Western blot. Up-regulated IL-34 expression could be detected in the serum of ONFH patients and femoral heads of ONFH mice. IL-34 deficient mice showed the resistance to ONFH induction with the up-regulated trabecular number, trabecular thickness, bone value fraction, and down-regulated trabecular separation. On the other hand, inflammatory cytokines, such as TNF-α, IFN-γ, IL-6, IL-12, IL-2, and IL-17A, showed diminished expression in IL-34 deficient ONFH induced mice. IL-34 alone or works in coordination with M-CSF to promote osteoclastogenesis and activate ERK, STAT3, and non-canonical NF-κB pathways. These data demonstrate that IL-34 can promote the differentiation of osteoclast through ERK, STAT3, and non-canonical NF-κB pathways to aggravate steroid-induced ONFH, and IL-34 can be considered as a treatment target.