p38 Signaling Mediates Naringin-Induced Osteogenic Differentiation of Porcine Metanephric Mesenchymal Cells.

OBJECTIVE: To explore the potential of metanephric mesenchymal cells (MMCs) for osteogenesis and naringin's ability to enhance this process and its molecular mechanism. METHODS: Porcine MMCs at 70 days of gestation were used as tool cells, cultured in osteogenic induction medium, identified by immunocytochemistry staining. Osteogenic potential of porcine MMCs and naringin's ability to enhance this process was tested by detecting changes in cell viability, alkaline phosphatase (ALP) activity, the expression of runt-related transcription factor 2 (Runx2), osteopontin (OPN) and osteocalcin (OCN), and the formation of mineralized nodules, and the application of the p38 signaling pathway inhibitor SB203580 vitiated the osteogenesis-promoting effect of naringin. RESULTS: Immunocytochemical staining showed that the cells were Vimentin and Six2(+), E-cadherin and CK-18(-). Naringin can activate the p38 signaling pathway to enhance the osteogenesis of porcine MMCs by increasing cell viability, ALP activity, the expressions of Runx2, OPN and OCN, and the formation of mineralized nodules (P<0.05). The application of p38 signaling pathway inhibitor SB203580 vitiated the osteogenesis-promoting effect of naringin, manifested by decreased ALP activity, the expressions of Runx2, OPN and OCN, and the formation of mineralized nodules (P<0.05). CONCLUSION: Naringin, the active ingredient of Chinese herbal medicine Rhizoma Drynariae for nourishing Shen (Kidney) and strengthening bone, enhances the osteogenic differentiation of renal MMCs through the p38 signaling pathway.

Quorum Sensing Inhibition and Metabolic Intervention of 4-Hydroxycinnamic Acid Against Agrobacterium tumefaciens.

The natural product 4-hydroxycinnamic acid (HA) was firstly isolated from the metabolites of Phomopsis liquidambari, one endophytic fungus from Punica granatum leaves. The anti-QS potential of HA was evaluated by ß-galactosidase assay and acylated homoserine lactones (AHL) analysis. The MIC of HA was > 1.20 mM. Exposure to HA at sub-MIC concentrations (0.30-0.60 mM) remarkably reduced the ß-galactosidase activity and AHL secretion. Transcriptional analysis by qRT-PCR and docking simulation indicated that HA functions as an anti-QS agent by inhibiting the transcriptional levels of traI and traR rather than signal mimicry. The blocked QS lead to suppressed biofilm formation, motilities, and flagella formation after exposure to HA at concentrations ranging from 0.30 to 0.80 mM. The dysfunctional QS also resulted in repressed antioxidant enzymes and intensified oxidative stress. The intensified oxidative stress destroyed membrane integrity, induced energy supply deficiency, resulted in disorder of protein and nuclear acid metabolism, and ultimately weakened pathogenicity of A. tumefaciens. HA may have promising potential for controlling A. tumefaciens.

Inactivation of Pseudomonas aeruginosa biofilms by thymoquinone in combination with nisin.

Pseudomonas aeruginosa is one of the most important foodborne pathogens that can persist in leafy green vegetables and subsequently produce biofilms. In this study, the synergistic effect of thymoquinone and nisin in reducing biofilm formation of P. aeruginosa on lettuce was evaluated, and their anti-virulence and anti-biofilm mechanisms were also investigated. At concentrations ranging from 0.5 to 2 mg/ml, thymoquinone inhibited the production of autoinducers and virulence factors, and enhanced the susceptibility of P. aeruginosa biofilms to nisin as evidenced by the scanning electron microscopy and confocal laser scanning microscopy. Integrated transcriptomics, metabolomics, and docking analyses indicated that thymoquinone treatment disrupted the quorum sensing (QS) system, altered cell membrane component, and down-regulated the expressions of genes related to virulence, efflux pump, and antioxidation. The changed membrane component and repressed efflux pump system enhanced membrane permeability and facilitated the entrance of nisin into cells, thus improving the susceptibility of biofilms to nisin. The dysfunctional QS and repressed antioxidant enzymes lead to the enhancement of oxidative stress. The enhanced oxidative stress disrupted energy metabolism and protein metabolism and ultimately attenuated the virulence and pathogenicity of P. aeruginosa PAO1. Our study indicated that thymoquinone has the potential to function as a QS-based agent to defend against foodborne pathogens in combination with nisin.

[Effects of Diallyl Disulfide on the Proliferation and Apoptosis of Epithelial Ovarian Cancer Cells by Inducing G2/M Arrest].

Objective To explore the effects of diallyl disulfide(DADS)-induced G2/M phase arrest on proliferation and apoptosis of ovarian cancer cells and its possible molecular mechanism.Methods DADS was used to incubate SK-OV-3 and OVCAR-3 cells,respectively,in different concentrations. Cell proliferation was measured by MTT assay and cell apoptosis rate was detected by flow cytometry assay. Xenograft model assay were performed to analyze the antitumor effect in vivo. Cell cycle phase distribution was detected by flow cytometry. Expressions of cell cycle G2/M phase as well as proliferation- and apoptosis-related proteins were measured by Western blotting.Results MTT assay showed that,after treatment of SK-OV-3(F=247.86,P=0.000)and OVCAR-3 cells(F=302.54,P=0.000)with different concentrations of DADS,the cell proliferation inhibition rate was significantly elevated with the increase of DADS concentrations in a concentration-dependent manner. The inhibition rate of SK-OV-3(F=335.12,P=0.000)and OVCAR-3 cells(F=347.43,P=0.000)at 24 h was significantly higher than that at 12 h and 48 h,showing a significant time-dependence manner. Flow cytometry showed that,after SK-OV-3 and OVCAR-3 cells were treated with different concentrations of DADS,the apoptosis rates increased significantly with the increase of DADS concentration in a concentration-dependent manner(P<0.05). The apoptotic rates of SK-OV-3 and OVCAR-3 cells treated with DADS at 24 h was significantly higher than that at 12 h and 48 h in a significant time-dependence manner(P<0.05). Compared with the blank treatment group,intraperitoneal injection of DADS solution significantly inhibited the xenograft volume of ovarian cancer cells in nude mice(F=548.23,P=0.000;F=311.84,P=0.000). After 30 mg/L of DADS was applied to SK-OV-3 and OVCAR-3 cells for 24 h,the percentage of cells in G2 phase of SK-OV-3 and OVCAR-3 cells increased significantly(F=375.11,P=0.000;F=256.48,P=0.000),compared with the blank cells. After 30 mg/L DADS was applied to SK-OV-3 and OVCAR-3 cells for 24 h,the expressions of p-Chk1(ser345)(F=108.89,P=0.013;F=97.58,P=0.018),p-CDC25C(ser216)(F=87.25,P=0.025;F=114.25,P=0.009),p-P53(ser15)(F=112.41,P=0.011;F=255.87,P=0.000),P21WAF1(F=246.38,P=0.001;F=141.36,P=0.005)and p-CDK1(Thr14/Tyr15)protein(F=298.12,P=0.000;F=233.15,P=0.000)were significantly increased,whereas the expressions of CDK1(F=308.24,P=0.000;F=257.55,P=0.000)and CyclinB1 protein(F=223.15,P=0.001;F=241.28,P=0.000)were significantly reduced.The expressions of proliferation and apoptosis-related proteins PCNA(F=77.36,P=0.031;F=157.28,P=0.001),Ki-67(F=205.64,P=0.007;F=315.22,P=0.000)and Survivin(F=122.13,P=0.013;F=188.24,P=0.000)were significantly decreased and Cleaved-caspase3 protein was significantly increased(F=86.46,P=0.023;F=99.11,P=0.009).Conclusion DADS can inhibit the proliferation of ovarian cancer cells and induce their apoptosis,which may be related to the activation of Chk1-CDC25C and P53-P21WAF1 signaling pathways in G2/M checkpoint,decreased kinase activity of CDK1,down-regulated expressions of CDK1 and CyclinB1 proteins,and ultimately cell cycle arrest at G2/M phase.

An ethical evaluation index system for clinical approval of medical technology in China: A structural equation model study.

OBJECTIVE: To construct a quantitative ethical evaluation index system for the clinical approval of medical technology in China. METHODS: Exploratory factor analysis (EFA) and first-order confirmatory factor analysis (CFA) based on a structure equation model (SEM), higher-order CFA and normalisation were used to establish an ethical evaluation index system for the clinical approval of medical technology. Data were processed in SPSS 13.0 and Lisre l5.3. RESULTS: There were 52 third class indices, 15 second class indices, and 3 first class indices in this ethical evaluation index system. The weight of each index was calculated by normalisation. CONCLUSION: This study developed a three-level ethical evaluation index system, comprising 70 indices, for the clinical approval of medical technology.