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101.
Marie-Odile Parat Marie-Jeanne Richard Marie Th r se Leccia Pierre Amblard Alain Favier Jean Claude B ani 《Free radical research》1995,23(4):339-351
Reactive oxygen species (ROS) are involved in the mechanism of photoaging and carcinogenesis. Skin is endowed with antioxidant enzymes including superoxide dismutases (SOD): cytosolic copper zinc SOD and mitochondrial manganese SOD. The aim of our study was to estimate the protective effect of manganese against oxidative injury on cultured human skin fibroblasts. Dithranol, hydrogen peroxide and UV-A radiation (375 nm) were employed as oxidative stressors. The supply of manganese chloride produced an increase in cellular content of this element up to 24 fold without concomitant elevation of MnSOD activity. Nevertheless, manganese protects cells against two of the three ROS generating systems assessed, namely hydrogen peroxyde and UV-A. This protective effect depends on the concentration of manganese in the medium, 0.1 mM and 0.2 mM protect against UVA cytotoxicity, only 0.2 mM protects against H2O2 cytotoxicity. 相似文献
102.
Overexpression of catalase, but not manganese superoxide dismutase (MnSOD), inhibited glucose deprivation-induced cytotoxicity and c-Jun N-terminal kinase 1 (JNK1) activation in human prostate adenocarcinoma DU-145 cells. Suppression of JNK1 activation by catalase overexpression resulted from inhibition of apoptosis signal-regulating kinase 1 (ASK1) activation by preventing dissociation of thioredoxin (TRX) from ASK1. Overexpression of catalase also inhibited relocalization of Daxx from the nucleus to the cytoplasm as well as association of Daxx with ASK1 during glucose deprivation. Taken together, hydrogen peroxide (H(2)O(2)) rather than superoxide anion (O(2) (*-)) acts as a second messenger of metabolic oxidative stress to activate the ASK1-MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK)-mitogen-activated protein kinase (MAPK) signal transduction pathway. 相似文献
103.
Two kinds of graft chitosan derivatives (CMCTS-g-MAS and HPCTS-g-MAS) were prepared by the graft copolymerization of maleic acid sodium onto etherified chitosans-carboxymethyl chitosan (CMCTS) and hydroxypropyl chitosan (HPCTS), respectively. Superoxide anion scavenging activity of the derivatives was evaluated in a luminal-enhanced autoxidaton of pyrogallol by chemiluminescence techniques. Compared with chitosan, the graft chitosan derivatives have much improved scavenging ability against superoxide anion. They have similar 50% inhibition concentrations (IC50s) as ascorbic acid and superoxide dismutase (SOD). Graft chitosan derivatives with hydroxypropyl groups have relatively higher superoxide anion scavenging ability owing to the incorporation of hydroxyl groups. The graft chitosan derivatives (HPCTS-g-MAS 1, 2, and 3) with different grafting percentages exhibit IC50s values ranging from 243 to 308 μg/mL, which could be related to the contents of active hydroxyl and amino groups in the polymer chains. 相似文献
104.
Interactions of opioid and chemokine receptors: oligomerization of mu,kappa, and delta with CCR5 on immune cells 总被引:6,自引:0,他引:6
In this study, we examined the signaling pathways for extracellular signal-related protein kinase (ERK) activation by three structurally different peroxisome proliferator activated receptor-gamma (PPARgamma) agonists. In murine C2C12 myoblasts, treatment with 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)), ciglitazone, and GW1929 leads to ERK1/2 phosphorylation in a time- and concentration-dependent manner. Consistent with ERK phosphorylation, mitogen activated protein/ERK kinase (MEK) phosphorylation as well as Raf-1 kinase activity are also accordingly stimulated, while the constitutive Ser259 phosphorylation of Raf-1 is decreased. The ERK phosphorylation induced by PPARgamma agonists is not blocked by the PKC inhibitors GF109203X and Ro31-8220, the PI3K inhibitor wortmannin, the Ras inhibitor FPTI, the negative mutant of Ras, or the PPARgamma antagonist bisphenol A diglycidil ether. Expression of PPARgamma2 without DNA binding domain or with a nonphosphorylatable mutant (S112A) fails to change ERK phosphorylation by 15d-PGJ(2). On the contrary, the ERK phosphorylation by PPARgamma agonists is inhibited by the MEK inhibitor PD98059, GSH, and permeable SOD mimetic MnTBAP. Chemiluminescence study reveals that these three PPARgamma agonists are able to induce superoxide anion production, with an efficacy similar to their action on ERK phosphorylation. Consistent with this notion, we also show that superoxide anion donor 2,3-dimethoxy-1,4-naphoquinone elicits ERK phosphorylation. In this study, we for the first time demonstrate a novel mechanism, independent of Ras activation but initiated by superoxide anion production, for PPARgamma agonists to trigger the Raf-MEK-ERK1/2 signaling pathway. 相似文献
105.
Tao Ke Filipe Marques Gonçalves Cinara Ludvig Gonçalves Alessandra Antunes dos Santos João B.T. Rocha Marcelo Farina Anatoly Skalny Aristidis Tsatsakis Aaron B. Bowman Michael Aschner 《生物化学与生物物理学报:疾病的分子基础》2019,1865(8):2068-2081
Mercury (Hg) exposure remains a major public health concern due to its widespread distribution in the environment. Organic mercurials, such as MeHg, have been extensively investigated especially because of their congenital effects. In this context, studies on the molecular mechanism of MeHg-induced neurotoxicity are pivotal to the understanding of its toxic effects and the development of preventive measures. Post-translational modifications (PTMs) of proteins, such as phosphorylation, ubiquitination, and acetylation are essential for the proper function of proteins and play important roles in the regulation of cellular homeostasis. The rapid and transient nature of many PTMs allows efficient signal transduction in response to stress. This review summarizes the current knowledge of PTMs in MeHg-induced neurotoxicity, including the most commonly PTMs, as well as PTMs induced by oxidative stress and PTMs of antioxidant proteins. Though PTMs represent an important molecular mechanism for maintaining cellular homeostasis and are involved in the neurotoxic effects of MeHg, we are far from understanding the complete picture on their role, and further research is warranted to increase our knowledge of PTMs in MeHg-induced neurotoxicity. 相似文献
106.
Granulocyte colony-stimulating factor potentiates anti-Candida albicans growth inhibitory activity of polymorphonuclear cells 总被引:2,自引:0,他引:2
Yoshimasa Yamamoto Thomas W. Klein Herman Friedman Sadao Kimura Hideyo Yamaguchi 《FEMS immunology and medical microbiology》1993,7(1):15-22
Abstract Granulocyte colony-stimulating factor (G-CSF) stimulates a subset of granulocyte colony forming cells and when administered to neutropenic individuals results in recovery of blood neutrophil numbers to normal levels. Therefore, G-CSF may be a useful therapeutic agent for infections in immunocompromised hosts. However, to date there has been only limited information that G-CSF activates the antimicrobial activity of neutrophils. In the present study, we found that recombinant G-CSF promotes the anti- Candida albicans activity of normal human blood polymorphonuclear (PMN) cells in vitro using both a 3 H-glucose uptake procedure and a Candida colony counting assay. As little as 0.1 ng/ml G-CSF induced significant anti-Candida activity in the PMN cultures. G-CSF treatment also enhanced superoxide anion production by the PMNs in response to f-MLP as determined by the superoxide dismutase inhibitable cytochrome C reduction method. Such results show that G-CSF can promote the antimicrobial activity of peripheral blood PMNs against C. albicans . 相似文献
107.
Ying-Jin Yuan Jing-Chuan Li Zhi-Qiang Ge Jin-Chuan Wu 《Journal of Molecular Catalysis .B, Enzymatic》2002,18(4-6):251-260
Generation of reactive oxygen species (ROS) induced by Ce4+ in suspension cultures of Taxus cuspidata was investigated. The burst of superoxide anions (O2√−) occurred rapidly after the addition of Ce4+ and reached maximum at 4.3 h, while the total level of the cellular reactive oxygen species maintained unchanged. The intracellular superoxide dismutase (SOD) and catalase (CAT) were activated while the intra/extracellular peroxidases (PODs) were inhibited accompanying the O2√− burst. The pretreatment of the suspension cultures with diphenylene iodonium (DPI), a suicide inhibitor of the NADPH oxidase, blocked the O2√− burst, inhibiting the cell apoptosis and taxol production induced by Ce4+. These results show that NADPH oxidase played a key role in O2√− burst and O2√− served as a mediator of Ce4+ for cell apoptosis and taxol production. The pretreatments of the suspension cultures with anthracene-9-carboxylate, an ion-channel blocker, nifedipine, a Ca2+-channel blocker, neomycin, a phospholipase C (PLC) inhibitor, or suramin, a G-protein inhibitor, decreased O2√− burst induced by Ce4+. It is thus inferred that Ce4+-induced O2√− burst, which mediated cell apoptosis and taxol production by activating the ion-channels, PLC, G-proteins and NADPH oxidase. 相似文献
108.
大豆肽体外抗氧化活性研究 总被引:4,自引:0,他引:4
研究大豆肽的体外抗氧化的作用。采用邻二氮菲-Fe^2+检测大豆肽对羟自由基(·OH)的清除作用,邻苯三酚检测大豆肽对超氧阴离子(·O2^-)的清除作用,用硫代巴比妥酸法测定小鼠肝匀浆丙二醛(MDA)的含量,用比色法测定小鼠红细胞溶血度,来研究大豆肽的抗氧化效果。结果表明:大豆肽可以清除·OH和·O2^-,抑制·OH所致的丙二醛的产生,减少H2O2所致的红细胞溶血,在2~15g/L内均具有明显的量效关系。表明大豆肽在体外具有明显的抗氧化效果。 相似文献
109.
等电聚焦表明,北京鸭红细胞铜锌超氧化物歧化酶由等电点分别为5.0,5.3,5.9,6.1和6.5的五个主要的活性组分(电荷异构体)构成,利用分析型聚丙烯酰胺凝胶等电聚焦电泳进行电荷异构体的制备级分离,采用三氯乙酸沉淀法快速确定蛋白条带的位置,电渗洗脱法回收蛋白,获得其中两个电荷异构体,对比研究结果表明电荷异构体的活性,氨基酸组成,二级结构等性质无明显差异。 相似文献
110.
两个品种的大豆叶圆片经10-4mol/L和10-3mol/L的H2O2处理12h后,超氧物歧化酶(SOD)、过氧化氢酶(CAT)与谷胱甘肽还原酶(GR)活性明显增加,但10-2mol/L的H2O2处理却使这些酶活性降低。抗旱性较强的大豆品种小粒豆1号较抗旱性较弱的鲁豆4号能维持较高的叶绿素含量和较高的SOD、CAT及GR活性,对H2O2的抗性较强。50μmol/L的亚胺环已酮(CHM)能消除H2O2对SOD、CAT与GR活性的刺激作用,而同样浓度的放线菌素D(AMD)则不能。 相似文献