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Objective To investigate the effect of Ginkgolide B (BN52021) on lipopolysaccharide (LPS) induced pancreas microvascular endothelialv (MS1) cells, and to explore its molecular mechanism.Methods The optimal concentration and best time point of LPS inhibing MS1 cell survival and the optimal concentration of BN52021 increasing survival of LPS induced MS1 cells were determined by MTT.The mRNA and protein expression of adenylate cyclase (AC), phospholipase A2 (PLA2), phospholipase Cβ (PLCβ),protein tyrosine kinase (PTK) and G protein coupled receptor kinase (GRK) in platelet activating factor receptor(PAFR) signal pathway in MS1 cells were determined by real-time PCR and Western blot.Results It was showed that 10 μg/ml LPS for 24 h was the optimal concentration and best time point to induce the decrease of MS1 cells.50 mmol/L of BN52021 was the optimal concentration of increacing survival of LPS induced MS1 cells.After LPS induction, AC, GRK, PLA2, PLCβ, PTK mRNA expressions of MS1 cells were 4.02 ±0.14, 2.63 ± 0.03, 3.31 ± 0.12, 2.09 ± 0.08, 1.85 ± 0.07, which were significantly higher than those in control group (P ＜ 0.01).After BN52021 treatment, AC, GRK, PLA2, PLCβ mRNA expressions of LPS induced MS1 cells were 2.35 ±0.13, 1.17 ±0.14, 1.87 ±0.11, 1.65 ±0.10, which were significantly lower than those in LPS induction group (P ＜ 0.01).The expression of PTK mRNA was 1.83 ± 0.13, which was not significantly different from that in LPS induction group.Western blot showed that the levels of protein expression were consistent with those of mRNA expression.Conclusions BN52021 can down-regulate the up-regulated genes expression of AC, GRK, PLA2 and PLCβ in the PAFR signal pathway in LPS induced MS1 cells.
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Objective To develop a new type of Raman-enhanced substrate for rapid detection of E.coli based on label-free surface-enhanced Raman scattering( SERS) technology.Methods Stober’ s improved method was used to prepare 360 nm silica ( SiO2 ) nanospheres.Prepared gold core-silver shell nanoparticles( Au@Ag) of different size were attached to 360 nm SiO2 to fabricate the nanocomposites ( SiO2-Au@Ag ) that were characterized by transmission electron microscopy (TEM) and UV-visucl light adsorption spectra (UV-Vis).PATP was detected to select SiO2-Au@Ag with optimal SERS effect.This optimal SiO2-Au@Ag was used to obtain the sensitivity of PATP and E.coli detection after a simple mixed culti-vation.Results TEM images showed that Au@Ag aggregated with the size of Au@Ag attached to 360 nm SiO2 .UV-Vis spectra indicated that the maximum absorption of Au@Ag and SiO2-Au@Ag had a red shift with the invrease of Au@Ag size.The experiment results suggested that detection sensitivity of PATP by SiO2-100 nm Au@Ag 10 -10 mol/L, while the lowest detectable E.coli concentration was 105 CFU/ml.Conclusion The 360 nm SiO2 binding with 100nm Au@Ag exhibits great potential for SERS applications.
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AIM: To explore the effect of receptor tyrosine kinase system mediated by phosphotyrosine phosphatase (PTP) on tau phosphorylation in rat hippocampus. METHODS: Pervanadate (PVN), inhibitor of PTP or inhibitor of glycogen synthase kinase-3 (GSK-3), LiCl were injected into rat hippocampus by stereotaxy technique. The level of tau phosphorylation was detected by Western blot and immunohistochemistry after 24 h of injection. RESULTS: PVN significantly inhibited tau phosphorylation at PHF-1 epitope and the inhibition of tau phosphorylation by PVN was stronger than that of LiCl (P