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At least 757 records · Page 42Linked to original sources
PubMed2004

Up-regulation of reactive oxygen species (ROS) and resistance to Fas-mediated apoptosis in the C33A cervical cancer cell line transfected with IL-18 receptor.

Cervical cancer cells were transfected with a newly discovered interleukin (IL)-18 receptor to investigate the effect of endogenous IL-18 on the regulation of immune-related factors such as Fas (CD95/Apo-1)/Fas ligand and intercellular adhesion molecules. Transfection of the IL-18 receptor selectively induced a slight enhancement of the Fas via the up-regulation of intracellular reactive oxygen species and IL-18 in cervical carcinoma C33A cells, whereas there were no effects on the expression of p53, intercellular adhesion molecules-1 and Fas ligand. Neither IL-18 receptor transfection nor recombinant IL-18 enhanced interferon-gamma production in C33A cells. Thus, IL-18 receptor transfection induced IL-18 expression and enhanced intracellular reactive oxygen species and Fas expression in C33A cells in an interferon-gamma-independent pathway. However, treatment with agonistic anti-Fas antibody did not induce the apoptosis of C33A/IL-18 receptor transfectants, suggesting that either reactive oxygen species play a key role in resisting the Fas-induced apoptosis of C33A cells, or Fas was not functional. These results show that C33A/IL-18 receptor cells are resistant to the apoptosis and thus can survive against the immune surveillance and activated immune cells. Our results thus suggest that IL-18 and IL-18 receptor, together, may play a role in immunoregulation or in inflammation by augmenting the levels of IL-18 and reactive oxygen species in C33A cells.

Antibodies, Monoclonal↗
PubMed2005

Oxidation by reactive oxygen species (ROS) alters the structure of human insulin and decreases the insulin-dependent D-glucose-C14 utilization by human adipose tissue.

The formation of dityrosine of human insulin oxidized by metal-catalyzed oxidation system (H2O2/Cu) was estimated by fluorescent methods. The oxidation of tyrosine and phenylalanine residues present on the insulin molecule was evident after 2 minutes of in vitro oxidation due to the formation of protein-bound dityrosine. The success of oxidative protein modification was followed until available aromatic residues were consumed (60 minutes), measured by their emission at 405 nm. The structural and chemical changes on insulin molecule are related to the loss of biological activity as assessed by measuring the increase of U-14C-glucose utilization by human adipose tissue in a radiorespirometry system. The oxidation of glucose (14CO2 production) of the adipose cells was increased 35 % (301 +/- 119 to 407 +/- 182 cpm/mg in dry weight. P < 0.05) in presence of 0.1 IU and 69 % (301 +/- 119 to 510 +/- 266 cpm/dry weight. P < 0.05) for 1.0 IU of insulin. The recombinant human insulin oxidized for 5 minutes only increased the glucose oxidation by 25 %. In conclusion, these observations show that dityrosine formation and other oxidative chemical changes of insulin due to its in vitro oxidation decrease and can abolish its biological activity.

Adipose Tissue↗
PubMed1994

Colorimetric evaluation of cultured osteoblast-like cells (ROS 17/2.8).

We have developed a colorimetric method for evaluating the number of osteoblastic cells in culture without destroying the cells. This assay is based on the staining of basophilic cellular compounds with methylene blue. The dye bound by the cells is released at low pH and measured in a spectrophotometer at 662 nm. Linear correlations exist between the absorbance measured by the methylene blue assay and the number of cells seeded, the total cellular protein content, and thymidine labeling. This colorimetric method has the advantage of preserving cell integrity. After destaining, scanning electron microscopy can be performed on well preserved cell morphology.

Animals↗
PubMed2003

Absolute quantitation of normal and ROS-induced patterns of gene expression: an in vivo real-time PCR study in mice.

Most studies using real-time PCR are taken semiquantitatively and assume a steady level of expression forthe so-called housekeeping genes. By absolute real-time PCR we demonstrate that the transcript amounts of two of the most popular internall controls (coding GAPDH and beta-actin) fluctuate dramatically across diverse mouse or human tissues. This raises the question about the inaccuracy of these genes a squantitative references in tissue-specific mRNA profiling. Target genes chosen for absolute real-time PCR analysis are involved in DNA repair, regulation of gene expression, and oxidative stress response. Hence, they code for 8-oxoG-DNA glycosylase/AP-lyase, major AP-endonuclease, and heme oxygenase-1. Quantitations reported: i) determine mouse-to-mouse variability in basal gene expression, ii) establish organ- and embryo-associated differences in mouse, iii) compare mouse and human tissue-specific profiles, iv) examine the time course (30-240 min) expression in liver and lung of mice treated with paraquat (superoxide generator) at 30 mg kg(-1) (one half LD50 value), and v) explore the utility of absolute real-time PCR in field studies with genetically diverse mice. We conclusively establish that real-time PCR is a highly sensitive and reproducible technique for absolute quantitation of transcript levels in vivo and propose its use to quantitate gene expression modulation under mild physiological exposures and for field epidemiological studies.

Animals↗
PubMedDate not supplied

Adamantyl maleimide induced changes in adhesion molecules and ROS are involved in apoptosis of human gastric cancer cells.

BACKGROUND: We have previously found that N-1-adamantyl maleimide (AMI) inhibited the growth of SC-M1 tumors in vitro and in vivo. The cytotoxicity of AMI on SC-M1 was accompanied by a decrease of adherent cells and the suppressive effect was associated with conformational changes in cell membrane protein. In order to determine the cellular targets of AMI in human gastric cancer SC-M1 cells, we examined AMI-induced changes in the levels of adhesion molecules CD29 (beta 1 integrin) and CD54 (ICAM-1) and GSH. In addition, we also analyzed changes of apoptosis markers such as annexin V binding to membrane and caspase 3 activity in SC-M1 cells after treatment with AMI. MATERIALS AND METHODS: Changes in CD29, CD54, annexin V binding and GSH levels were examined using FITC-conjugated antibodies or fluorescence probes and flowcytometry. Caspase 3 activity was assayed with spectrofluorometry. RESULTS: We found that the expression of CD29 and CD54 on SC-M1 was decreased and the caspase 3 activity was increased during the early apoptosis induced by AMI. Moreover, it was found that the GSH content of the cell was depleted within 30 minutes and then recovered. CONCLUSION: These results suggest that the cell membrane proteins, such as adhesion molecules (CD29, CD54) and intracellular GSH, were the targets of AMI on SC-M1 cells. Since these membrane alterations were prior to apoptosis they may have transduced a death signal to SC-M1 cells.

Adamantane↗
PubMedDate not supplied

Role of reactive oxygen species (ROS) in patients with erythema migrans, an early manifestation of Lyme borreliosis.

BACKGROUND: Lyme borreliosis is a tick-transmitted, chronic, zoogenous disease caused by Borrelia burgdorferi spirochete. The clinical picture of Lyme disease is characterized by the variety of tissue and organ involvement and differing severity of symptoms. One of the pathogenic symptoms of early Lyme disease is a skin lesion called erythema migrans. MATERIAL AND METHODS: The purpose of our research was to estimate the parameters of the antioxidant system and the concentration of lipid peroxidation products in the plasma of patients with erythema migrans (EM). The parameters measured included the activity levels of superoxide dismutase (SOD) according to Sykes, gluthatione reductase (GSSG-R) according to Mize and Langdon, glutathione peroxidase (GSH-Px) according to Paglia and Valentine; the concentrations of malondialdehyde (MDA) were examined by means of a Bioxytech LPO-586 kit. The total sulphydryl groups (-SH) according to Ellman and reduced glutathione (GSH) were measured using a Bioxytech GSH-400 test in plasma samples collected from 20 patients with EM aged from 19 to 50, taken before (examination 1) and after (examination 2) therapy with amoxycycline. The control group consisted of 8 healthy people. RESULTS: The results of our examinations prove that beta-lactamase antibiotic therapy brings non-enzymatic antioxidant parameters to control values, though the treatment causes no change in enzymatic antioxidant parameters, resulting in the further activation of free radicals. CONCLUSIONS: In patients with Erythema migrans, the decreased capability to reduce lipid superoxidants leads to maintaining a high concentration of membrane lipid peroxidation products.

Adult↗
PubMed2004

Methyl jasmonate induces apoptosis through induction of Bax/Bcl-XS and activation of caspase-3 via ROS production in A549 cells.

Jasmonates are plant lipid derivatives, similar to mammalian eicosanoid, that play a critical role(s) in plant defenses against herbivores and pathogens through up-regulating the expression of defense-related genes. Recently, jasmonates were shown to induce cell cycle arrest or apoptosis in human leukemia, prostate and breast cancer cells, but not in normal lymphocytes, suggesting that the chemicals can be used as a novel class of anti-cancer drugs. In the present study, we examined the molecular mechanism that contributes to methyl jasmonate-induced apoptosis. Herein we show that methyl jasmonate induces apoptosis through induction of Bax/Bcl-XS and activation of caspase-3 via reactive oxygen species production in A549 human lung adenocarcinoma cells.

Acetates↗