Magnetic nanoparticles(MNPs) are promising materials for various biomedical applications,including magnetic resonance imaging,stem cell tracking,gene/drug delivery,and cancer treatment.To increase the effectiveness of...Magnetic nanoparticles(MNPs) are promising materials for various biomedical applications,including magnetic resonance imaging,stem cell tracking,gene/drug delivery,and cancer treatment.To increase the effectiveness of MNPs,high capture efficiency and controlled uptake of the particles by cells is required.In this paper we report the cytotoxicity and cellular uptake into SPC-A1 cells of oxidized glutathione(GSSG)-modified MNPs(GSSG@Fe3O4).Experimental findings indicated that GSSG@Fe3O4 were biocompatible,and could be efficiently taken up by SPC-A1 cells(up to 160 pg iron per cell).The internalized GSSG@Fe3O4 was retained in the cell cytoplasm for 6 generations.The uptake of GSSG@Fe3O4 into SPC-A1 cells was energy-,concentration-and time-dependent.Pinocytosis may be involved in the internalization process of GSSG@Fe3O4 into SPC-A1 cells,but this mechanism remains to be elucidated.The controlled and efficient localization of GSSG@Fe3O4 into the cytosol and long intracellular retention provides theoretical and experimental insight into the biomedical applications for these molecules.展开更多
极端环境微生物嗜酸氧化亚铁硫杆菌的谷胱甘肽还原酶(GR)可能在它的抵抗极端酸性,有毒和氧化性的生物浸出环境中发挥至关重要的作用。通过同源模建技术和分子动力学模拟,它的一个三维结构被构建,优化和检验了。获得的结构被进一步用于...极端环境微生物嗜酸氧化亚铁硫杆菌的谷胱甘肽还原酶(GR)可能在它的抵抗极端酸性,有毒和氧化性的生物浸出环境中发挥至关重要的作用。通过同源模建技术和分子动力学模拟,它的一个三维结构被构建,优化和检验了。获得的结构被进一步用于搜索绑定位点,跟辅因子黄素腺嘌呤二核苷酸(FAD)和底物谷胱甘肽(GSSG)进行分子柔性对接,并以此识别关键残基。对接结果显示,位于活性残基Cys42和Cys47之间的二硫键夹在FAD的活性位点和底物GSSG的二硫键之间。它们之间的距离非常靠近,这跟底物反应机理的初始步骤的情况十分一致。相互作用能表明8个酶中残基Cys42,Cys47,Glu443B,Glu444B,His438B, Ser14,Thr447B和Lys51是固定或激活GSSG的关键残基,这跟以前的实验事实相吻合。此外,根据相互作用能我们还新发现7个重要残基(Arg449B,Pro439B,Thr440B,Thr310,Val43,Gly46 and Val48)。所有这些残基在其它物种中的相应物中也都是保守的。这些结果有助于进一步的实验研究和理解其催化机理,进而揭示这种细菌的抗毒机理,服务于工业应用。展开更多
Zinc oxide nanoparticles（ZnO NPs） are among the most commonly utilized nanomaterials. They are used in a wide range of applications, including medicine, sunscreens, cosmetics, paints, catalysis, electronics, as well...Zinc oxide nanoparticles（ZnO NPs） are among the most commonly utilized nanomaterials. They are used in a wide range of applications, including medicine, sunscreens, cosmetics, paints, catalysis, electronics, as well as biosensors, and hence, it is crucial to illustrate their biological effects and risks. In the present study, the effects and mechanism of ZnO NPs（≤5 nm） were investigated in rat glioma C6 cells in vitro. The results of transmission electron microscopy（TEM） and X-ray difffaction（XRD） show that ZnO NPs are pure with a uniform diameter of ca. 5 nm 3-（4,5-Dimethylthiazol-2yl）-2,5-diphenyltetrazolium bromide（MTT） assays on C6 cells show that ZnO NPs, at different concentrations（0-5 I^g/mL）, can induce significant cytotoxicity in C6 cells in a dose-dependent manner. An increased level of reactive oxygen species（ROS）, a decreased level of glutathione（GSH）, and an elevated level of glutathione disulfide（GSSG） and the toxicity mechanism are primarily attributed to the induced cellular oxidative stress. 4＇,6-Diamidino-2-phenylindole（DAPI） staining was used to observe the apoptosis. The results show that C6 cells treated with the ZnO NPs at various concentrations（0, 1.25, 2.5 and 5 μg/mL） can induce apoptosis in a dose-dependent manner. These results suggest that ZnO NPs are the killers of the rat glioma C6 cells, and oxidative stress is the underlying mechanism of this process.展开更多
Glutathione (GSH), γ-Glu-Cys-Gly, is one of the most abundant small non-protein thiol molecules in mammalian tissues, particu- larly in the liver. Although glutathione is present in thiol-reduced (GSH) and disulfide ...Glutathione (GSH), γ-Glu-Cys-Gly, is one of the most abundant small non-protein thiol molecules in mammalian tissues, particu- larly in the liver. Although glutathione is present in thiol-reduced (GSH) and disulfide oxidized (GSSG) forms, the predominant form is GSH and its content can exceed 10 mmol/L in liver cells. As an important intracellular reductant, GSH has many biological functions in cells. Its major function is as an anti-oxidant as it can protect proteins from oxidation by reversible posttranslational modification (glutathionylation) and decrease reactive oxygen species-mediated damage. However, it does have numerous other functions, including to chelate metal irons; enhance the absorption of iron, selenium and calcium; participate in lipid and insulin metabolism; regulate cellular events such as gene expression, DNA and protein synthesis, cell proliferation and apoptosis, redox-dependent signal transduction pathways, cytokine production and the immune response; and control protein glutathionylation. Therefore, GSH plays important roles in cell survival and health, and an imbalance in the GSH level can lead to many diseases. In this review, we provide an overview of the function of GSH in mammalian cells and discuss future research of GSH.展开更多
Objective To explore the changes and clinical significance of plasma redox status in patients with acute myocardial infarction,angina pectoris and people with normal coronary artery.Methods According to the
基金supported by the International Cooperation Project (20080068and 075207012)the National Natural Science Foundation of China(81000656)
文摘Magnetic nanoparticles(MNPs) are promising materials for various biomedical applications,including magnetic resonance imaging,stem cell tracking,gene/drug delivery,and cancer treatment.To increase the effectiveness of MNPs,high capture efficiency and controlled uptake of the particles by cells is required.In this paper we report the cytotoxicity and cellular uptake into SPC-A1 cells of oxidized glutathione(GSSG)-modified MNPs(GSSG@Fe3O4).Experimental findings indicated that GSSG@Fe3O4 were biocompatible,and could be efficiently taken up by SPC-A1 cells(up to 160 pg iron per cell).The internalized GSSG@Fe3O4 was retained in the cell cytoplasm for 6 generations.The uptake of GSSG@Fe3O4 into SPC-A1 cells was energy-,concentration-and time-dependent.Pinocytosis may be involved in the internalization process of GSSG@Fe3O4 into SPC-A1 cells,but this mechanism remains to be elucidated.The controlled and efficient localization of GSSG@Fe3O4 into the cytosol and long intracellular retention provides theoretical and experimental insight into the biomedical applications for these molecules.
基金supported by the National Natural Science Foundation of China(50321402)the National Basic Research Program of China(2004CB619201)+1 种基金the Mittal student Foundation of Central South University(No.07MX27)the post-graduate foundation of Hunan province(No.2340-74236000003)~~
文摘极端环境微生物嗜酸氧化亚铁硫杆菌的谷胱甘肽还原酶(GR)可能在它的抵抗极端酸性,有毒和氧化性的生物浸出环境中发挥至关重要的作用。通过同源模建技术和分子动力学模拟,它的一个三维结构被构建,优化和检验了。获得的结构被进一步用于搜索绑定位点,跟辅因子黄素腺嘌呤二核苷酸(FAD)和底物谷胱甘肽(GSSG)进行分子柔性对接,并以此识别关键残基。对接结果显示,位于活性残基Cys42和Cys47之间的二硫键夹在FAD的活性位点和底物GSSG的二硫键之间。它们之间的距离非常靠近,这跟底物反应机理的初始步骤的情况十分一致。相互作用能表明8个酶中残基Cys42,Cys47,Glu443B,Glu444B,His438B, Ser14,Thr447B和Lys51是固定或激活GSSG的关键残基,这跟以前的实验事实相吻合。此外,根据相互作用能我们还新发现7个重要残基(Arg449B,Pro439B,Thr440B,Thr310,Val43,Gly46 and Val48)。所有这些残基在其它物种中的相应物中也都是保守的。这些结果有助于进一步的实验研究和理解其催化机理,进而揭示这种细菌的抗毒机理,服务于工业应用。
文摘Zinc oxide nanoparticles（ZnO NPs） are among the most commonly utilized nanomaterials. They are used in a wide range of applications, including medicine, sunscreens, cosmetics, paints, catalysis, electronics, as well as biosensors, and hence, it is crucial to illustrate their biological effects and risks. In the present study, the effects and mechanism of ZnO NPs（≤5 nm） were investigated in rat glioma C6 cells in vitro. The results of transmission electron microscopy（TEM） and X-ray difffaction（XRD） show that ZnO NPs are pure with a uniform diameter of ca. 5 nm 3-（4,5-Dimethylthiazol-2yl）-2,5-diphenyltetrazolium bromide（MTT） assays on C6 cells show that ZnO NPs, at different concentrations（0-5 I^g/mL）, can induce significant cytotoxicity in C6 cells in a dose-dependent manner. An increased level of reactive oxygen species（ROS）, a decreased level of glutathione（GSH）, and an elevated level of glutathione disulfide（GSSG） and the toxicity mechanism are primarily attributed to the induced cellular oxidative stress. 4＇,6-Diamidino-2-phenylindole（DAPI） staining was used to observe the apoptosis. The results show that C6 cells treated with the ZnO NPs at various concentrations（0, 1.25, 2.5 and 5 μg/mL） can induce apoptosis in a dose-dependent manner. These results suggest that ZnO NPs are the killers of the rat glioma C6 cells, and oxidative stress is the underlying mechanism of this process.
基金the National Natural Science Foundation of China (30970630)the New Century Talents Program (NCET-08-0912)the Key Project of the Chinese Ministry of Education (210010)
文摘Glutathione (GSH), γ-Glu-Cys-Gly, is one of the most abundant small non-protein thiol molecules in mammalian tissues, particu- larly in the liver. Although glutathione is present in thiol-reduced (GSH) and disulfide oxidized (GSSG) forms, the predominant form is GSH and its content can exceed 10 mmol/L in liver cells. As an important intracellular reductant, GSH has many biological functions in cells. Its major function is as an anti-oxidant as it can protect proteins from oxidation by reversible posttranslational modification (glutathionylation) and decrease reactive oxygen species-mediated damage. However, it does have numerous other functions, including to chelate metal irons; enhance the absorption of iron, selenium and calcium; participate in lipid and insulin metabolism; regulate cellular events such as gene expression, DNA and protein synthesis, cell proliferation and apoptosis, redox-dependent signal transduction pathways, cytokine production and the immune response; and control protein glutathionylation. Therefore, GSH plays important roles in cell survival and health, and an imbalance in the GSH level can lead to many diseases. In this review, we provide an overview of the function of GSH in mammalian cells and discuss future research of GSH.
文摘Objective To explore the changes and clinical significance of plasma redox status in patients with acute myocardial infarction,angina pectoris and people with normal coronary artery.Methods According to the
