Hydrogen sulfide protects against particle-induced inflammatory response and osteolysis via SIRT1 pathway in prosthesis loosening.

Wear debris-induced osteolysis and ensuing aseptic loosening is the main cause of implant failure and revision surgery. Wear debris-induced inflammatory response plays key roles in peri-implant osteolysis. Recently, substantial of evidence suggests that hydrogen sulfide (H2 S), the third gasotransmitter, is a critical player regulating inflammation. However, the role and therapeutic potential of H2 S in wear debris-induced inflammation and osteolysis remains to be defined. In the present study, we investigated the effect of H2 S on wear debris-induced pro-inflammatory cytokines expression and osteolysis in vitro and in vivo. With a slow-releasing H2 S donor GYY4137, our study demonstrated that H2 S attenuated wear debris-induced osteolysis and osteoclastogenesis in murine calvaria resorption models. The expression of tumor necrosis factor-alpha (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) that stimulated by wear particles were significantly reduced by GYY4137. Further, the level of sirtuin 1 (SIRT1), which possesses anti-inflammation property, was examined in vivo and in macrophages. And we found that wear debris decreased the expression of SIRT1. Cotreated macrophages with GYY4137 in part reversed the decline of SIRT1. More importantly, with the SIRT1 recombinant lentivirus and small interfering RNAs (siRNA) against SIRT1, our data indicated that SIRT1 mediated the inhibitory effects of GYY4137 on wear debris-induced inflammation. Collectively, these results suggested that exogenous H2 S production (via H2 S donors) may represent a potential approach for the treatment of wear particle-induced osteolysis.

Associations between ERα/ß gene polymorphisms and osteoporosis susceptibility and bone mineral density in postmenopausal women: a systematic review and meta-analysis.

BACKGROUND: Many studies have reported associations between estrogen receptor (ER) gene polymorphisms and postmenopausal osteoporosis (PMOP) risk and bone mineral density (BMD), but the results are controversial. The aim of the present meta-analysis is to verify the association between ERα and ERß gene polymorphisms and osteoporosis susceptibility and BMD in postmenopausal women. METHODS: PubMed, EMBASE, Web of Science, the Cochrane Library and China WeiPu Library were searched. OR and WMD with 95% CI were calculated to assess the association. RESULTS: Overall, no significant association was observed between ERα XbaI, ERα PvuII and PMOP susceptibility in either overall, Caucasian or Asian populations. ERα G2014A was significantly associated with a decreased risk of PMOP in Caucasian populations. There was a significant association between ERß RsaI and PMOP risk in both overall and Asian populations. Caucasian PMOP women with ERα XbaI XX and Xx genotypes had a higher LS Z value than women with xx genotype. ERα XbaI XX genotype was associated with increased FN BMD in overall and Caucasian populations, an increased FN Z value in Asians, and a decreased FN Z value in Caucasians. There was also a significant association between ERα XbaI Xx genotype and an increased FN Z value in either Asians or Caucasians. ERα PvuII PP genotype was associated with a low LS Z value in Caucasians and a low FN BMD and Z value in Asians. Pp genotype in PMOP women was significantly correlated with low LS BMD in overall populations, a low FN Z value in either overall, Caucasian or Asian populations. CONCLUSION: Each ERα and ERß gene polymorphism might have different impact on PMOP risk and BMD in various ethnicities.

Negative Pressure Therapy in the Regeneration of the Sciatic Nerve Using Vacuum - Assisted Closure in a Rabbit Model.

BACKGROUND The aim of this study was to investigate the effects of negative pressure therapy in the regeneration of the rabbit sciatic nerve using vacuum assisted closure (VAC). MATERIAL AND METHODS Thirty male New Zealand white rabbits underwent surgical injury of the sciatic nerve, followed by negative pressure therapy using vacuum assisted closure (VAC), in three treatment groups: Group A: 0 kPa; Group B: -20 kPa; Group C: -40 kPa. At 12 weeks following surgery, the following factors were studied: motor nerve conduction velocity (MNCV); the number of myelinated nerve fibers; the wet weight of the gastrocnemius muscle. Gastrocnemius muscle and sciatic nerve tissue samples were studied for the expression of S100, and brain-derived neurotrophic factor (BDNF) using Western blot. RESULTS At 12 weeks following VAC treatment, the MNCV, number of myelinated nerve fibers, and wet weight of the gastrocnemius muscle showed significant differences between the groups (p<0.05), in the following order: Group B >Group A >Group C. The sciatic nerve at 12 weeks following VAC in Group B and Group C showed a significant increase in expression of S100 and BDNF when compared with Group A; no significant differences were detected between Group B and Group C results from Western blot at 12 weeks. CONCLUSIONS The findings of this study, using negative pressure therapy in VAC in a rabbit model of sciatic nerve damage, have shown that moderate negative pressure was beneficial, but high values did not benefit sciatic nerve repair.

Inverted distal clavicle anatomic locking plate for displaced medial clavicle fracture.

Fractures of the medial clavicle are rare injuries. Recently, open reduction and internal fixation has been recommended for displaced medial clavicle fractures in order to prevent non-union and dysfunction. Because of the rarity of this injury, the optimal fixation device has not yet been established. In this report, we describe a case of a 40-year-old male patient who sustained a significantly displaced medial clavicle fracture treated by open reduction and internal fixation using an inverted distal clavicle anatomic locking plate. At the 12 months follow-up, the patient recovered well, had returned to pre-injury job, and was quite satisfied with the outcome. Internal fixation of medial clavicle fracture using an inverted distal clavicle anatomic locking plate of the ipsilateral side appears to be a good treatment option.

Effects of osteoblast autophagy on glucocorticoid-induced femoral head necrosis.

OBJECTIVES: This study aims to explore the mechanism by which osteoblast autophagy participated in glucocorticoid-induced femoral head necrosis (FHN). MATERIALS AND METHODS: Thirty male specific-pathogen-free C57 mice (age, one month; weighing 20-25 g) were randomly divided into blank control, dexamethasone and rapamycin-dexamethasone groups (n=10). After six weeks of intervention, right femoral head was obtained to observe morphology and to calculate percentage of empty lacunae. MC3T3-E1 cells were randomly divided into normal, dexamethasone, rapamycin and dexamethasone-rapamycin groups, and cultured for 24 h. Microtubule-associated protein 1 light chain 3 (LC3)-I, LC3-II, mammalian target of rapamycin (mTOR) and Beclin-1 protein expressions were detected by Western blot. RESULTS: In rapamycin-dexamethasone group, some bone trabeculae in medullary cavity ruptured and atrophied, and subchondral bone underwent local necrosis. The total apoptosis rates of dexamethasone and rapamycin-dexamethasone groups surpassed that of blank control group, and the former two groups had significantly different rates (p<0.001). LC3-II/LC3-I of dexamethasone group was lower than those of rapamycin and dexamethasone-rapamycin groups (p<0.001), and the ratio of rapamycin group surpassed that of dexamethasone-rapamycin group (p<0.001). Dexamethasone group had higher mTOR protein expression than those of rapamycin and dexamethasone- rapamycin groups (p<0.001), and the expression of rapamycin group was lower than that of dexamethasone-rapamycin group (p<0.001). The Beclin-1 protein expression of dexamethasone group was lower than those of rapamycin and dexamethasone- rapamycin groups (p<0.001), and the expression of rapamycin group exceeded that of dexamethasone-rapamycin group (p<0.05). CONCLUSION: Osteoblast autophagy may play a crucial protective role in dexamethasone-induced FHN. The attenuation of autophagy may be related to the affected expressions of key autophagy regulators mTOR and Beclin-1.

An analysis of the expression and function of myeloid differentiation factor 88 in human osteosarcoma.

The aim of the present study was to investigate the expression and function of myeloid differentiation factor 88 (MyD88) in osteosarcoma. Immunohistochemical staining was used to detect MyD88 protein in osteosarcoma tissues and matched normal bone tissues. The association between MyD88 expression and the clinical characteristics of patients with osteosarcoma was analyzed. Furthermore, survival analysis of patients with osteosarcoma was performed to study the association between MyD88 expression and patient prognosis. Finally, the effect of the MyD88 inhibitor, ST2825, on the proliferation and apoptosis of the human osteosarcoma cell line U2OS was examined. Additionally, cell proliferation, invasion and apoptosis were examined using an MTT assay, Transwell assay and Annexin V-fluorescein isothiocyanate staining kit, respectively. The expression of proteins associated with the NF-κB signaling pathway was analyzed by western blotting. The positive expression rate of MyD88 in osteosarcoma and normal bone tissues was 71.4 and 6.1%, respectively. Statistical analysis demonstrated that MyD88 was not associated with gender, age, histological type or tumor location, but that it was associated with Enneking stage and tumor metastasis (P<0.05). According to the survival analysis, patients with osteosarcoma in the high MyD88 expression group displayed a reduced overall survival rate (P<0.05). Furthermore, inhibition of MyD88 by ST2825 in U2OS cells resulted in a marked decrease in cellular proliferation and migration, and an increase in the rate of apoptosis (P<0.05). Notably, ST2825 significantly decreased cyclin D1, matrix metallopeptidase-9 and nucleus p65 expression, but increased cleaved-caspase 3 expression in ST2825-treated U2OS cells (P<0.05). The results of the present study indicated that MyD88 expression is associated with the progression of osteosarcoma and may be a potential therapeutic target for the treatment of osteosarcoma.

CPNE1 silencing inhibits the proliferation, invasion and migration of human osteosarcoma cells.

Osteosarcoma (OS) is the most common primary malignancy of the bone affecting children and adolescents. Copine 1 (CPNE1) is a highly conserved calcium-dependent phospholipid-binding protein and may function in regulating signal transduction and membrane trafficking. In the present study, we investigated CPNE1 expression in osteosarcoma tissues and cells, and studied the effects of small interfering RNA (siRNA)-targeting CPNE1 on proliferation, metastasis and chemosensitivity of the osteosarcoma cells. The results demonstrated that CPNE1 was highly expressed in the osteosarcoma tissues and cell lines. Moreover, functional investigations confirmed that CPNE1 knockdown significantly inhibited cell proliferation, colony formation, invasion and metastasis in Saos-2 and HOS cells. Western blot analysis indicated that CPNE1 silencing downregulated the expression of many proteins associated with tumorigenesis and development, including Ras, MEK-1/2, WNT1, ß-catenin, cyclin A1, IRAK2 and cIAP2. In addition, CPNE1 downregulation enhanced the sensitivity of Saos-2 cells towards cisplatin and adriamycin. The present study provides deep insight into the clinical use of lentiviral-mediated CPNE1 silencing for osteosarcoma therapy.

Anxa2 attenuates osteoblast growth and is associated with hip BMD and osteoporotic fracture in Chinese elderly.

Low bone mineral density (BMD) is a risk factor of osteoporotic fracture (OF). Peripheral blood monocytes (PBM) can differentiate into osteoclasts to resorb bone. It was known that PBM-expressed Anxa2 protein is associated with BMD, and extracellular Anxa2 protein promotes osteoclastogenesis. This study aimed to test 1) whether Anxa2 protein level in PBM differs significantly between subjects with OF and without fracture history (NF); 2) whether Anxa2 level in plasma is associated with BMD; 3) how Anxa2 protein at various concentrations would affect osteoblastic activity in vitro. All the study subjects were Chinese Han elderly. Firstly, Anxa2 protein in PBM was identified and quantitated by LC-MS/MS and compared between 45 OF cases and 42 healthy controls. Secondly, plasma Anxa2 protein level was quantitated by ELISA and compared between unrelated subjects with extremely low vs. high hip BMD (0.63±0.10 vs. 1.05±0.10 g/cm2, n = 75). Furthermore, in vitro functional assay was utilized to test the effects of extracellular Anxa2 protein on osteoblastic growth. We found that Anxa2 protein expression in PBM was significantly up-regulated in OF vs. NF subjects (fold change [FC)] = 1.16, P<0.05). Plasma Anxa2 protein concentration (range: 31.69-227.35ng/ml) was significantly elevated in low vs. high BMD subjects (84.85 vs. 66.15ng/ml, FC = 1.28, P<0.05). Cellular dynamical monitoring demonstrated that the general shape of dose-response relationship is the inverse U-shaped curve. Specifically, lower dose of Anxa2 protein may promote osteoblast growth and the optimal concentration for osteoblastic growth was around 50ng/ml, but even higher concentration could attenuate hFOB1.19 osteoprogenitor cell growth. We concluded that Anxa2 protein could attenuate osteoblast growth and be associated with hip BMD and OF in Chinese elderly.

Upregulation and biological function of transmembrane protein 119 in osteosarcoma.

Osteosarcoma is suggested to be caused by genetic and molecular alterations that disrupt osteoblast differentiation. Recent studies have reported that transmembrane protein 119 (TMEM119) contributes to osteoblast differentiation and bone development. However, the level of TMEM119 expression and its roles in osteosarcoma have not yet been elucidated. In the present study, TMEM119 mRNA and protein expression was found to be up-regulated in osteosarcoma compared with normal bone cyst tissues. The level of TMEM119 protein expression was strongly associated with tumor size, clinical stage, distant metastasis and overall survival time. Moreover, gene set enrichment analysis (GSEA) of the Gene Expression Omnibus (GEO) GSE42352 dataset revealed TMEM119 expression in osteosarcoma tissues to be positively correlated with cell cycle, apoptosis, metastasis and TGF-ß signaling. We then knocked down TMEM119 expression in U2OS and MG63 cells using small interfering RNA, which revealed that downregulation of TMEM119 could inhibit the proliferation of osteosarcoma cells by inducing cell cycle arrest in G0/G1 phase and apoptosis. We also found that TMEM119 knockdown significantly inhibited cell migration and invasion, and decreased the expression of TGF-ß pathway-related factors (BMP2, BMP7 and TGF-ß). TGF-ß application rescued the inhibitory effects of TMEM119 knockdown on osteosarcoma cell migration and invasion. Further in vitro experiments with a TGF-ß inhibitor (SB431542) or BMP inhibitor (dorsomorphin) suggested that TMEM119 significantly promotes cell migration and invasion, partly through TGF-ß/BMP signaling. In conclusion, our data support the notion that TMEM119 contributes to the proliferation, migration and invasion of osteosarcoma cells, and functions as an oncogene in osteosarcoma.

Silencing of Aurora kinase A by RNA interference inhibits tumor growth in human osteosarcoma cells by inducing apoptosis and G2/M cell cycle arrest.

The overexpression of Aurora kinase A (AURKA), a member of serine/threonine kinase family, has been observed in various types of human cancers. However, the role of AURKA in osteosarcoma (OS), the most common type of primary malignancy arising from bone, has not been clarified. We used AURKA-specific lentivirus-delivered short hairpin RNA (shRNA) to significantly and sustainably silence the endogenous AURKA expression in human OS cells SAOS-2 and U2OS. We found that AURKA downregulation in OS cells prominently decreased colony formation ability in vitro and tumorigenesis ability in vivo. We further evaluated the effect of AURKA silence on cell viability by MTT assay, cell apoptosis and cell cycle by flow cytometer detection. The results showed that AURKA silence inhibited cell viability by inducing cell apoptosis and G2/M cell cycle arrest in OS cells. Taken together, our findings indicate that AURKA plays a crucial role on OS growth by inhibiting cell apoptosis and propelling cell cycle. Inhibition of AURKA by lentivirus-delivered specific shRNA showed the therapeutic potential in treatment of osteosarcoma.

A study on screening of osteosarcoma U2OS cell inhibiting active components from nidus vespae.

This paper mainly examined the anti-osteosarcoma activity of total flavonoids extract from traditional Chinese medicine, nidus vespae. Orthogonal design was used to design the extraction process of total flavonoids. L(3(4)) orthogonal test was performed and the extracts obtained by three optimal extraction processes were used for anti-tumour activity screening in order to determine the optimal anti-tumour effective component of nidus vespae. MTT assay was used to investigate the effect of nidus vespae extract on proliferation activity of osteosarcoma cells. Meanwhile, U2OS cell inhibitory capacities of extracts in three groups with higher total flavonoid contents were investigated and compared, and inhibition rates were calculated. The results showed that the optimal extraction process was ethanol concentration of 95%, 12-fold amount of ethanol relative to the weight of medicinal material, extraction times of 3 times, and extraction time of 2 hours. 9 extraction processes all showed proportional trend of cancer cell inhibition rate to extract concentration.