Objective： To study the role of nuclear factor-kappa B（NF- κB） in cholesterol efflux from THP-1 derived-foam cells treated with Angiotensin Ⅱ（Ang Ⅱ ）. Methods：Cultured THP-1 derived-foam cells were treated wi...Objective： To study the role of nuclear factor-kappa B（NF- κB） in cholesterol efflux from THP-1 derived-foam cells treated with Angiotensin Ⅱ（Ang Ⅱ ）. Methods：Cultured THP-1 derived-foam cells were treated with Ang Ⅱ or preincubated with tosyl-phenylalanine chloromethyl-ketone（TPCK） NF- κB inhibitor. The levels of activated NF- κB in the cells were examined by sandwich ELISA, Cellular cholesterol content was studied by electron microscopy scanning and zymochemistry via fluorospectrophotometer and cholesterol effiux was detected by scintillation counting technique. ABCA1 mRNA and protein were quantified by RT-PCR and Western blotting. Results：Addition of TPCK to the cells before Ang Ⅱ stimulation attenuated the response of NF- κB p65 nuclear translocation induced by Ang Ⅱ and showed no peak in foam cells group and caused a reduction in cholesterol content and an increase in cholesterol efflux by 24.1%（P〈 0.05） and 41.1%（P〈 0.05） respectively, when compared with Ang Ⅱ group. In accordance, the ABCA1 mRNA and protein were increased by 30% and 19%（P 〈 0.05） respectively, when compared with Ang Ⅱ group. Conclusion：Ang Ⅱ can downregulate ABCA1 in THP-1 derived-foam cells via NF- K B, which leads to less cholesterol effiux and the increase of cholesterol content with the consequence of the promotion of atherosclerosis.展开更多
Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negati...Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negatively about 0.14 V, initial electrolytic potential reduced 0.2 V and reduction peak current increased. At the same conditions,the conversion of Mn(Ⅱ) was increased. The optimum conditions for electrooxidation were 0.3 mol/L solution of Mn(Ⅱ), 6 mol/L H 2SO 4, electrolysis potential 2.3 V and 44 W ultrasound.展开更多
The electrochemical behavior of Mn (Ⅲ)/Mn(Ⅱ)ion-pair on platinum electrode in acid media were studied by cyclic voltammetry.It was demonstrated that the redox process of Mn(Ⅲ)/Mn(Ⅱ) pair was a simple pseudo-revers...The electrochemical behavior of Mn (Ⅲ)/Mn(Ⅱ)ion-pair on platinum electrode in acid media were studied by cyclic voltammetry.It was demonstrated that the redox process of Mn(Ⅲ)/Mn(Ⅱ) pair was a simple pseudo-reversible one-electron reaction between Mn(Ⅲ) and Mn(Ⅱ).The electrochemical kinetics of the redox reaction on static Pt electrode was a mass transfer controlled one.The calculated diffusion coefficient of Mn(Ⅱ) was 1.48×10 -6cm 2/s.展开更多
基金the National Basic Research and Development Program of China(973 Program, No.2007CB512000) (Sub-Project,No.2007CB512005)
文摘Objective： To study the role of nuclear factor-kappa B（NF- κB） in cholesterol efflux from THP-1 derived-foam cells treated with Angiotensin Ⅱ（Ang Ⅱ ）. Methods：Cultured THP-1 derived-foam cells were treated with Ang Ⅱ or preincubated with tosyl-phenylalanine chloromethyl-ketone（TPCK） NF- κB inhibitor. The levels of activated NF- κB in the cells were examined by sandwich ELISA, Cellular cholesterol content was studied by electron microscopy scanning and zymochemistry via fluorospectrophotometer and cholesterol effiux was detected by scintillation counting technique. ABCA1 mRNA and protein were quantified by RT-PCR and Western blotting. Results：Addition of TPCK to the cells before Ang Ⅱ stimulation attenuated the response of NF- κB p65 nuclear translocation induced by Ang Ⅱ and showed no peak in foam cells group and caused a reduction in cholesterol content and an increase in cholesterol efflux by 24.1%（P〈 0.05） and 41.1%（P〈 0.05） respectively, when compared with Ang Ⅱ group. In accordance, the ABCA1 mRNA and protein were increased by 30% and 19%（P 〈 0.05） respectively, when compared with Ang Ⅱ group. Conclusion：Ang Ⅱ can downregulate ABCA1 in THP-1 derived-foam cells via NF- K B, which leads to less cholesterol effiux and the increase of cholesterol content with the consequence of the promotion of atherosclerosis.
文摘Cyclic voltammetric behavior of electrooxidation of Mn(Ⅱ) under ultrasound and without ultrasound were compared. With the ultrasound irradiation the reduction peak potential of Pb(Ⅳ)/ Pb(Ⅱ) was found shifted negatively about 0.14 V, initial electrolytic potential reduced 0.2 V and reduction peak current increased. At the same conditions,the conversion of Mn(Ⅱ) was increased. The optimum conditions for electrooxidation were 0.3 mol/L solution of Mn(Ⅱ), 6 mol/L H 2SO 4, electrolysis potential 2.3 V and 44 W ultrasound.
文摘The electrochemical behavior of Mn (Ⅲ)/Mn(Ⅱ)ion-pair on platinum electrode in acid media were studied by cyclic voltammetry.It was demonstrated that the redox process of Mn(Ⅲ)/Mn(Ⅱ) pair was a simple pseudo-reversible one-electron reaction between Mn(Ⅲ) and Mn(Ⅱ).The electrochemical kinetics of the redox reaction on static Pt electrode was a mass transfer controlled one.The calculated diffusion coefficient of Mn(Ⅱ) was 1.48×10 -6cm 2/s.
基金supported by the National Natural Science Foundation of China(20972015)the Natural Science Foundation of Beijing(Grant2082016)a joint project of Beijing Municipal Education Commission(China)
