BACKGROUND: Bone marrow-derived mononuclear cells (BM-MNCs) hold the potential of differentiating into osteoclasts. Polygonatum sibiricum polysaccharide (PSP) may inhibit the differentiation of BM-MNCs into osteoclasts and it is expected to become a new drug for the treatment of osteoporosis. OBJECTIVE: To investigate the effect of PSP on the differentiation of mouse BM-MNCs into osteoclasts induced by receptor activator of nuclear factor kappa-B ligand (RANKL) and bone resorption in vivo. METHODS: Mouse bone marrow-derived macrophages cultured in vitro, the effect of macrophage colony stimulating factor and PSP (5, 10, 20, 40, 80,160, 320, 640, 1280, 2560 mg/L) on the proliferation of mouse BM-MNCs was detected by cell counting kit-8 assay to determine the PSP concentration range; the mouse BMMs were cultured and induced in DMEM medium containing macrophage colony stimulating factor, RANKL and 5, 10, 20, 40, 80,160, 320, 640 mg/L PSP, respectively; those cultured without PSP served as control group. The morphological changes of cells were observed under an inverted microscope.; the number of osteoclasts was detected by tartrate-resistant acid phosphatase staining; the mRNA expression levels of osteoclast-related genes including tartrate-resistant acid phosphatase, matrix metalloproteinase-9, cathepsin K, and nuclear factor of activated T cells c1 were evaluated by quantitative real-time PCR. A mouse model of calvarial osteolysis induced by lipopolysaccharide was established to receive PSP intervention, and then micro CT scanning, three-dimensional reconstruction and relevants software were used for quantitative analysis of bone volume/volume percentage, trabecular number, trabecular bone spacing and thickness. The number of osteoclasts was identified by tartrate-resistant acid phosphatase staining and quantitative analysis of bone resorption area was conducted. RESULTS AND CONCLUSION: Compared with the control group, the concentration of PSP below 640 mg/L showed no significant effect on the proliferation of BMMs (P > 0.05). Different concentrations of PSP (40-640 mg/L) significantly reduced the number of osteoclasts, osteoclast differentiation and maturation, and the mRNA expression levels of tartrate-resistant acid phosphatase, matrix metalloproteinase-9, cathepsin K, and nuclear factor of activated T cells c1 TRAP, MMP-9, CtsK and NFATc1 (P < 0.05). Compared with lipopolysaccharide, PSP could effectively alleviate the lipopolysaccharide-induced calvarial osteolysis, and the bone volume/volume percentage, trabecular number, and trabecular bone spacing were significantly decreased (P < 0.05); additionally, the number of osteoclasts and the area of bone resorption were decreased significantly (P < 0.01). To conclude, PSP can inhibit the differentiation and maturation of mouse BMMs to osteoclasts and alleviate lipopolysaccharide-induced calvarial osteolysis.

BACKGROUND: miRNA plays a critical regulatory role in the development and plasticity of spinal cord, and pathological changes after spinal cord injury. OBJECTIVE: To study the effect of miR-136-5p on the A20 expression in mouse astrocytes stimulated by interleukin-17 (IL-17). METHODS: C57BL/6 mouse astrocytes were cultured in vitro, identified by immunofluorescence staining, and then stimulated by 100 μg/L IL-17 for 0, 3, 6, 12 and 24 hours, respectively. The relative mRNA expression levels of IL-6 and tumor necrosis factor-α were detected by RT-PCR to determine the optimal stimulation time of IL-17. The mouse astrocytes were respectively stimulated by 10, 20, 50, 100 and 200 μg/L IL-7 for 6 hours, and similarly, the relative mRNA expression levels of IL-6 and tumor necrosis factor-α were detected to determine the optimal concentration of IL-17. At 6 hours after IL-17 (50 μg/L) stimulation, the mRNA expression levels of miR-136-5p and A20 in mouse astrocytes were detected by RT- PCR, and the protein expression level of A20 was detected by western blot assay. In addition, the lentiviral expression vector (miR-136-5p-inhibition) was constructed and transfected into the mouse astrocytes that were also stimulated by IL-7 to detect the expression levels of miR-136-5p, A20 mRNA and A20 protein. RESULTS AND CONCLUSION: Compared with the blank control group, the expression level of miR-136-5p in the miR-136-5p-inhibition group was significantly decreased after 6-hour IL-17 stimulation (P < 0.05). The expression levels of A20 mRNA and protein in each group were significantly decreased after 6-hour IL-17 (50 μg/L) stimulation (P < 0.05). The expression levels of A20 mRNA and protein in the miR-136-5p-inhibition group were significantly higher than those in the blank control group (P < 0.05), while there were no significant differences in the expression level of A20 protein between blank control and negative groups (P > 0.05). To conclude, miR-136-5p makes certain effect on the expression of A20 protein in astrocytes after IL-17 stimulation.

Objective To investigate PSP on bone microstructures,Ca,P,OPG and RANKL of osteoporotic rat model.Methods Thirty female rats randomly divided into five groups:Sham,OVX,H-,M-,L-PSP.Sham and OVX were irrigated stomachsaline;PSP solution was gavaged to other groups.After 8-week,bone microstructures of tibial metaphyseal,Ca,P,OPG and RANKL were measured.Results Body weight,Ca,P,RANKL,Tb.Sp of OVX were significantly increased compared to Sham,OPG,BV/TV,Tb.Th,Tb.N decreased.Body weight of H-,M-PSP,Ca and Tb.Sp of PSP,P and RANKL in H-PSP were decreased compared to OVX,OPG in H-,M-PSP,BV/TV,Tb.Th,Tb.N of PSP group increased.The differences were statistically significant (P ＜ 0.05).Conclusion PSP prevents osteoporosis by improving the microstructure of trabecular bone,reducing bone turnover,increasing OPG and reducing RANKL expression.

BACKGROUND:Our previous studies have found that polygonatum sibiricum polysaccharide (PSP) promotes osteogenic differentiation of bone marrow mesenchymal stem cel s (BMSCs) by Wnt/β-catenin signaling pathway, but the molecular mechanism is unclear.OBJECTIVE:To investigate the effect of PSP promoting the osteogenic differentiation via Wnt signaling pathways in BMSCs after LRP5 silencing. METHODS:LRP5 interference vectors were constructed and then transfected into C57BL/6 mouse BMSCs cultured in vitro. The transfection efficiency of cel s was calculated under fluorescence inverted microscope and the expression of LRP5 protein was detected by western blot assay. The osteogenic potential of BMSCs after LRP5-siRNA transfection was analyzed by alkaline phosphatase staining, alizarin red staining and western blot assay. Effect of PSP on the osteogenic differentiation of LIRP5-silenced mouse BMSCs was detected by real-time PCR and dual luciferase assay. RESULTS AND CONCLUSION:Compared with the control group, the mineralization ability, the mRNA expressions of Runx2 and Osterix, and the protein expression of LRP5 were significantly decreased in the LRP5-siRNA group (P<0.05). PSP could promote LRP5-siRNA transfected mouse BMSCs differentiating into osteoblasts and significantly upregulated the expressions ofβ-catenin and Osterixin, and also induced the high expression of luciferase reporter gene (TOPFlash) containing wild type TCF binding sites (P<0.05). To conclude, LRP5 plays an important role in the process of mouse BMSCs differentiating into osteoblasts. PSP can promote the osteogenic differentiation of mouse BMSCs by activating the Wnt/β-catenin signaling pathway independent on LRP5.

AIM:To study the effect of NEDD8-conjugating enzyme UBE2F on lung adenocarcino-ma metastasis.METHODS:The expression of UBE2F in lung adenocarcinoma was analyzed using TIMER2.0,UALCAN and HPA databases.Kaplan-Mei-er Plotter database was used to analyze the rela-tionship between UBE2F expression and survival rate of lung adenocarcinoma.A UBE2F-knockout lung adenocarcinoma cell line was constructed us-ing CRISPR/Cas9 technology,and a UBE2F-knockout lung adenocarcinoma metastasis model was con-structed in nude mice to verify the effect of UBE2F knockout on lung adenocarcinoma metastasis.The effects of UBE2F knockout on invasion and migra-tion of lung adenocarcinoma cells were examined by cell scratch assay and Transwell invasion and mi-gration assays.The effect of down-regulated UBE2F expression on snail expression,a key marker of epi-thelial-mesenchymal transition(EMT),was detect-ed by Western blot and Real time PCR.RESULTS:Multiple database analysis showed that UBE2F was highly expressed in lung cancer,and Kaplan-Meier Plotter analysis showed that high expression of UBE2F in lung adenocarcinoma had better progno-sis than low expression.In vivo experiments showed that compared with control group,the number of nodules metastasized on the lung sur-face of nude mice after UBE2F knockout was signifi-cantly increased(P<0.05).Cell scratch assay and Transwell assay showed that UBE2F enhanced the migration and invasion ability of lung cancer cells after knockout,and the difference were statistically significant(P<0.05).Western blot and Real time PCR results indicated that the level of EMT tran-scription factor snail protein and mRNA increased after UBE2F knockout.CONCLUSION:In lung ade-nocarcinoma cells,UBE2F down-regulation leads to Snail accumulation and promotes invasion and me-tastasis of lung adenocarcinoma cells.