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Objective To investigate the effect of metformin on the osteogenic differentiation of human mesenchymal stem cells exposed to PMMA particles. Methods Human placental mesenchymal stem cells were iso-lated and cultured in vitro. The effect of metformin with different concentrations on cell viability was determined by CCK8 assay. The effect of metformin on the mRNA expression of osteogenic genes was detected by using real-time RT-PCR. Calcified nodules were stained by alizarin S. The effect of metformin on the expression of eNOS was also detected by using real-time RT-PCR. Results PMMA particles could inhibit the viability of mesenchymal stem cells. Metformin(0.05 mmol/L)could promote the viability of mesenchymal stem cells exposed to PMMA particles. Metformin(0.05 mmol/L)could increase the expression of osteogenic genes,including OCN,RNUX2,and ALP, in human mesenchymal stem cells exposed to PMMA particles. The calcium deposit was also increased after metfor-min treatment. Results of real-time RT-PCR showed that metformin could increase the expression of eNOS in human mesenchymal stem cells exposed to PMMA particles. Conclusions Metformin can increase the osteogenic differentiation of human mesenchymal stem cells exposed to PMMA particles,partially by inducing eNOS expression.
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Objective:To establish a pristine-induced rheumatoid arthritis model in mice,and to evaluate its histological and immunological distinction.Methods:Thirty female BALB/c mice,6-8 weeks old,were randomly divided into 2 groups,a control group and pristine group.The mice in pristine group were injected intraperitoneally with 0.5 ml pristine three times at 0,9,and 18 weeks, while mice in the control group receiving saline at the same time.Arthritis score and paw thickness were measured and histopathological assessment of joint sections was performed.The expression of phagocytes,dendritic,neutrophils,T and B cells markers in spleen were determined by flow cytometry.Results:In model-marking group,11 mice were presented with macroscopic evidence of arthritis such as erythema or swelling.The paw thickness in pristine-induced mice was significant higher than that in the control groups[(2.90±0.51) mm vs(1.29±0.47 mm),P<0.05].In addition,arthritis score in pristine-induced mice was 9.55±2.80 at 21 weeks after first injection with 0.5 ml pristine.H&E staining revealed a significant increase of synovial inflammation, cartilage and bone destruction after stimulated with pristine.Meanwhile,the expression levels of CD11b,CD11c,GR1,CD4,CD8 and CD154 were obviously increased in model-marking group when compared with that in control group.Conclusion: The pristine-induced model presents the similar histological and immunological distinctions with human rheumatism arthritis,which can mimic the pathogenesis of rheumatism arthritis.
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Objective To investigate the anti-inflammatory mechanism by which curcumin affects TNF-αand IL-8 production in Propionibactierium acnes-induced THP-1 cells. Methods THP-1 cell viability was determined by CCK8 assay. The productions of TNF-α and IL-8 were detected by ELISA assay. Total RNA and proteins were collected for real-time PCR and Western blot analysis, respectively. Results Curcumin didn′t significantly affect the cell viability at 12 h. It decreased Propionibactierium acnes-induced productions of TNF-αand IL-8 in THP-1 cells. Moreover, it decreased TLR2, NF-κB p65, and P-NF-κB p65 expressions in THP-1 cells. Conclusions Curcumin may reduce TNF-α and IL-8 expressions in Propionibactierium acnes-induced THP-1 cells by inhibiting TLR2/NF-κB signaling pathway.
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Objective To explore the effects of polymethylmethacrylate(PMMA)-induced autophagy osteoclasts on bone disso-lution animal models ,and study the mechanism of PMMA particle-induced pyrophosphate osteolysis .Methods 30 8-week-old BALB / c mice were randomly divided into two groups ,sterile air with back injection on mice to form airbag and homologous skulls were implanted into experimental group mice were injected with PMMA particles ,the control group were injected with physiological saline .After 14 d ,the mice were killed ,osteoclast activation related gene (RANK / RANKL ) and autophagy morphological exami-nation of the the airbags tissue and the skull were detect .Results The tartrate-resistant enzyme staining (TRAP)-positive osteo-clasts(21 .31 ± 6 .32)s of experiment group is significantly higher than that of the control group (7 .45 ± 3 .23) ,immunohisto-chemistry showed that autophytic protein microtubule-associated protein 1 light chain 3(LC3) and Beclin 1 antibody staining score level in experimental group was significantly higher than that of control group .RT-PCR showed that the RANK mRNA level(1 .35 ± 0 .05) of experimental group was significantly increased(P< 0 .05) .Conclusion The autophagy induce by PMMA is involved in the formation of osteolysis .