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Aseptic loosening of an implant after total joint arthroplasty is still a major complication that results from periprosthetic osteolysis. Fibroblasts in the interface membrane express receptor activator of nuclear factor kappa B ligand (RANKL) and stimulate osteoclast formation. Studies demonstrate that through the control of osteoclastic bone loss bisphosphonates inhibit wear particle-induced bone resorption around total hip arthroplasty. The majority of bisphosphonates studies have focused on their effects on osteoblasts and osteoclasts. Little attention has been paid to their action on fibroblasts.~Purpose~Objective~We isolated fibroblasts from the interface membrane that was obtained when revision hip arthroplasty was performed because of aseptic loosening. Fibroblasts were stimulated with alendronate. RANKL and osteoprotegerin (OPG) assays were performed using enzyme-linked immunosorbent assay kit and real time Reverse Transcription- Polymerase Chain Reaction (RT-PCR).~Methods~Methods~We found that alendronate stimulated OPG mRNA and protein expression in a time and dose dependent manner. By contrast, alendronate did not affect RANKL expression.~Results~Results~The results indicate that alendronate modulated OPG production by fibroblasts from periprosthetic membrane, which may prove helpful for the inhibition of bone loss during aseptic loosening following total joint arthroplasty.~Conclusions~Conclusions [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to investigate the regulative activity of (5R)-5-hydroxytriptolide (LLDT-8) on receptor activator of nuclear factor κ-B ligand (RANKL)/receptor activator of nuclear factor κ-B (RANK)/Osteoprotegerin (OPG) system in rheumatoid arthritis (RA) and its anti-osteoclastogenesis mechanism. Methods: The expression of OPG, RANK and RANKL in CD3+ T leukomonocytes in both peripheral blood and synovial fluid of RA patients was evaluated by flow cytometry. The levels of interleukin (IL) 1β, IL-6, IL-10, IL-21 and IL-23 in the supernatants of peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) were assayed by ELISA. Tartaric acid phosphatase (TRAP) staining was used to identify the osteoclast-like cells derived from RAW264.7. Western blotting analysis was used to check the downstream molecules of RANKL. Results: LLDT-8 increased the rate of OPG expression in CD3+ T leukomonocytes in peripheral blood as well as the ratio of OPG/RANKL in both peripheral blood and synovial fluid. LLDT-8 inhibited IL-1 β, IL-6, IL-21 and IL-23 secretion, but promoted the secretion of IL-10 in the supernatants of PBMCs and SFMCs. In addition, LLDT-8 decreased the number of TRAP-positive cells derived from RAW264.7 in the presence of RANKL and M-CSF. Furthermore, LLDT-8 also inhibited the expression of p-lκB, a key regulator of RANKL signaling pathway. Conclusions: LLDT-8 exerts its anti-osteoclastogenesis effect in RA probably through regulating RANKL/RANK/OPG system and its downstream signaling pathway as well as cytokine productions. [ABSTRACT FROM AUTHOR]

Summary: Association between 22 single nucleotide polymorphisms (SNPs) in the TNFSF11, TNFRSF11A, and TNFRSF11B genes in the RANKL/RANK/OPG pathway with bone mineral density (BMD) in 881 post-menopausal women. Our results suggest that TNFSF11 and TNFRSF11A, but not TNFRSF11B, genetic polymorphisms influence BMD mainly in the femoral neck in post-menopausal Chinese women. Introduction: The aim of this study was to assess the relationship of polymorphisms in the TNFSF11, TNFRSF11A, and TNFRSF11B genes in the RANKL/RANK/OPG pathway with bone mineral density (BMD) in a cohort of Chinese post-menopausal women. Methods: A cross-sectional study was conducted in 881 post-menopausal women aged 50-89 years. All participants underwent lumbar spinal (LS) and femoral neck (FN) BMD evaluation by dual-energy X-ray absorptiometry. Twenty-two TNFSF11, TNFRSF11A, and TNFRSF11B SNPs were genotyped. We tested whether a single SNP or a haplotype was associated with BMD variations. Results: Two SNPs in the TNFSF11 gene (rs2277439 and rs2324851) and one in the TNFRSF11A gene (rs7239261) were found to be significantly associated with FN BMD ( p = 0.014, 0.013, and 0.047, respectively). Haplotype TGACGT of TNFSF11 rs9525641-rs2277439-rs2324851-rs2875459-rs2200287-rs9533166 was a genetic risk factor toward a lower FN BMD (beta = −0.1473; p = 0.01126). In contrary, haplotype TAGCGT of TNFSF11 rs9525641-rs2277439-rs2324851-rs2875459-rs2200287-rs9533166 was genetic protective factor for LS BMD (beta = 0.3923; p = 0.04917). Conclusions: Our findings suggest that TNFSF11 and TNFRSF11A, but not TNFRSF11B, genetic polymorphisms influence BMD mainly in the femoral neck in post-menopausal Chinese women. This contributes to the understanding of the role of genetic variation in this pathway in determining bone health. [ABSTRACT FROM AUTHOR]

Pyrrosia lingua (Thunb.) Farw is a common plant that has been widely used as a traditional herbal medicine in China and Korea to treat patients suffering from pain, vaginal bleeding and urolithiasis. However, the pharmacological effects of P. lingua on bone remain unknown. We investigated the anti-osteoporotic effects of an ethanolic extract of P. lingua (EEPL). We found that EEPL suppressed osteoclast differentiation by directly acting on osteoclast precursor cells. EEPL suppressed the expression of receptor activator of nuclear factor-κB ligand (RANKL)-induced nuclear factor of activated T cells 1, a major transcription factor for osteoclastogenesis, by inhibiting RANKL-induced expression of aryl hydrocarbon receptor/c-Fos, and activation of nuclear factor-κB and mitogen-activated protein kinases. Moreover, administration of EEPL inhibited trabecular bone loss and weight gain in ovariectomized mice. Furthermore, we identified phytochemicals in EEPL that are known to exert anti-osteoclastogenic or anti-osteoporotic effects using ultra-high-performance liquid chromatography–tandem mass-spectrometry analysis. Overall, the results of this study suggest that EEPL is effective therapeutic candidate that can be used to prevent or treat postmenopausal osteoporosis. [Display omitted] • Ethanolic extract of Pyrrosia lingua (Thunb.) Farw. (EEPL) inhibits RANKL-induced osteoclastogenesis in vitro. • EEPL prevents OVX-induced bone loss in vivo. • EEPL could be explored as a potential therapeutic candidate for postmenopausal osteoporosis. [ABSTRACT FROM AUTHOR]

Serum IGF-I level was negatively correlated with OPG and OPG/RANKL ratio, but positively correlated with RANKL. Serum OPG level in the highest quintile of IGF-I was significantly lower than that in the lowest. We conclude that the effect of IGF-I on bone remodeling may be mediated by the OPG/RANKL system. Insulin-like growth factor I (IGF-I) is an important factor in coupling bone remodeling, activating both formation and resorption. Compared with the many studies on the role of IGF-I in bone formation, the information regarding its effects on bone resorption is limited and conflicting. The balance of the two peptides produced by osteoblasts, osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL), is critical for the bone resorption process. Our study was designed to analyze the relationships of serum concentrations of IGF-I with OPG, RANKL, OPG/RANKL ratio as well as BMDs in healthy Chinese women. BMDs at lumbar spine and proximal femur in 504 pre- and postmenopausal women were measured by DXA. Serum levels of IGF-I, OPG and RANKL were also measured. Pearson’s correlation and partial correlation analysis, ANOVA, covariance analysis and stepwise multiple regression analysis were used as appropriate. Age was negatively correlated with serum levels of IGF-I (r = −0.702, p < 0.001). IGF-I was negatively correlated with OPG and OPG/RANKL ratio, but positively correlated with RANKL. The relationship between IGF-I and BMDs disappeared after adjustment for age. In postmenopausal women, IGF-I was lower in women with osteoporosis than in those with normal BMD ( p = 0.056), but no differences were found among OPG, RANKL and OPG/RANKL ratio. Serum levels of OPG in the highest quintile of IGF-I were significantly lower than those in the lowest quintile of IGF-I, while no difference was found in RANKL. In the multiple regression analysis model, serum levels of IGF-I were the main determinants of the bone mass in Chinese women. In conclusion, the relationship between decreasing IGF-I and BMDs in healthy Chinese women influenced by age, whereas the effect of IGF-I on bone remodeling (bone resorption) may be mediated by the OPG/RANKL system. [ABSTRACT FROM AUTHOR]

The nuclear factor of activated T lymphocytes (NFATC1) signaling has been demonstrated to play important roles in cardiac valve and septal development. Genetic variants in genes involved in NFATC1 signaling may affect their expression and promote the formation of congenital heart disease (CHD). The goal of this study was to investigate the associations of single nucleotide polymorphism (SNP) in seven genes (NFATC1, VEGFR, VEGF, RANKL, FGFR1, BCL-6 and ZNRD1) with the risk of CHD. Twenty-nine polymorphisms were genotyped by using MassARRAY RS1000 platform in 277 CHD child patients and 293 controls from the Henan Province in China. Fours SNPs were excluded for the association analysis because of deviation from the Hardy-Weinberg equilibrium. Of the 25 SNPs, only two were found to be significantly associated with increased CHD risk after Bonferroni correction (RANKL, rs4531631: homozygous, AA vs. GG; OR 2.38, 95 % CI 1.40-4.07, p = 0.001; recessive, AA vs. AG + GG; OR 2.54, 95 % CI 1.53-4.22, p = 0.0003; FGFR1, rs13317: recessive, CC vs. CT + TT; OR 2.06, 95 % CI 1.30-3.25, p = 0.00196). Our findings suggest rs4531631 and rs13317 may be potential biomarkers for genetic diagnosis and treatment of CHD.

Background: Omentin-1, as a newly discovered adipocytokine, plays an important role in bone metabolism. However, the association between circulating omentin-1 level and bone mineral density (BMD) in Chinese women has never been investigated., Methods: Serum omentin-1, adiponectin, leptin, bone turnover biochemical markers, BMD were determined in 225 premenopausal women and 285 postmenopausal women., Results: In premenopausal Chinese women, omentin-1 level was significantly higher compared to postmenopausal women. The multiple linear stepwise regression analysis showed that lean mass, omentin-1 and weight were independent predictors of BMD in premenopausal women. Omentin-1 was negatively correlated with bone-specific alkaline phosphatase (BAP) and bone cross-linked N-terminal telopeptides of type I collagen (NTX) in premenopausal women. However the omentin-1 was not the predictor of BMD in postmenopausal women., Conclusions: Omentin-1 is an independent predictor of BMD in premenopausal Chinese women, and shows a negative correlation with bone turnover biochemical markers. Our results suggest that omentin-1 may exert a negative effect on bone mass by inhibiting bone formation in premenopausal women., (© 2013.)