8-hydroxy-2--deoxyguanosine and Necrosis

The present research was designed to evaluate the protective effects and underlying mechanisms of propionate, a bioactive food additive, on mitochondrial disruption, neuron necrosis and neurological deficits after epilepsy seizures. Epilepsy seizures was induced by repetitive injections of pentylenetetrazol at a dose of 37 mg per kg. Propionate (37.5, 50 and 75 mg/kg) as well as sodium valproate (300 mg/kg) were administrated intragastrically (i.g.) 1 h before each PTZ injection and continued for 40 days. The influence of propionate was assessed by many biochemical assays and neurobehavioral experiments. The results of gas chromatography (GC) analysis indicated that increased concentration of propionate can be explored in hippocampus area of propionate + PTZ treated animals. Propionate decreased epilepsy seizure intensity, increased latency of seizures. Meanwhile, propionate treatment reversed the structure disruption of the mitochondria, improved ATP level and lessened 8-OHdG level in the brains of animals with seizures. In addition, we find propionate pretreated can increase activities of the antioxidant enzymes (CAT, SOD, as well as GSH-Px) in mitochondria. Additionally, propionate reduced neuronal loss in hippocampus and our results suggest that HIF-1α/ERK pathway and neuron necrosis exists potential linkage during epileptogenesis. Moreover, as a result, propionate administration can significantly improve the neurological function estimated by a battery of functional tests. In conclusion, treatment with propionate attenuates mitochondrial disruption, hippocampal apoptosis and neurological deficits in a mouse model of epilepsy seizures. Therefore, propionate, currently used as a food preservative, has a potential additional advantage of ameliorating epilepsy seizures.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adenosine Triphosphate; Animals; Catalase; Exploratory Behavior; Female; Hippocampus; Mice; Mitochondria; Necrosis; Neurons; Pentylenetetrazole; Propionates; Seizures

Reactive oxygen species (ROS) has a key role in the pathogenesis of sepsis. We wanted to evaluate ROS-associated lymphocyte necrosis and apoptosis.. A total of 51 patients were included in the study, 29 in the patient group and 22 in the control group. Blood samples were taken from patients in the patient group during severe sepsis or septic shock, then again once they had recovered. Oxidative DNA damage was evaluated by 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels. Peripheral blood lymphocytes from patients were evaluated with a microscope immediately. The rate of apoptosis and necrosis of lymphocytes were evaluated according to the number of cells in the peripheral.. The level of 8-OHdG increased with severe sepsis or septic shock. There were significant differences between the pre- and post-treatment values for apoptotic cell frequency (4.21±3.15 vs. 3.82±3.07, P<0.05) and necrotic cell frequency (4.75±3.61 vs. 4.09±3.37, P<0.05). Apoptosis and necrosis was increased during severe sepsis and septic shock, and apoptosis increase also continued after recovery, but necrosis decreased following disease recovery. CONCLUSıONS: In patients with severe sepsis or septic shock, apoptosis and necrosis were increased along with increased 8-OHdG level.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aged; Apoptosis; Biomarkers; Deoxyguanosine; DNA Damage; Female; Humans; Lymphocytes; Male; Middle Aged; Necrosis; Reactive Oxygen Species; Sepsis; Shock, Septic

Liver ischemia-reperfusion (I/R) injury is a severe complication of liver surgery, and steatosis is a risk factor for liver damage. Reactive oxygen species generated by nicotinamide adenine dinucleotide phosphate oxidase (NOX) contribute to liver dysfunction. Here we examined the role of NOX in I/R injury of fatty livers.. Rats were fed a methionine and choline-deficient diet to induce a fatty liver. Rats then underwent surgically induced partial hepatic ischemia followed by reperfusion.. The overall survival rate after I/R was lower in rats with fatty livers than with normal livers (P < 0.01). Necrotic area and the concentrations of 8-hydroxy-2'-deoxyguanosine (8-OHdG), TNFα, and IL-6 were higher in fatty liver tissue than in normal liver tissue (P < 0.01). The number of p47phox-positive cells was significantly higher in fatty liver tissue than in normal liver tissue after reperfusion and peaked 24 hours after reperfusion. The number of TLR-4 positive cells was significantly higher in fatty liver tissue than in normal liver tissue after reperfusion and peaked 4 and 24 hours after reperfusion coupled with a decreased number of high-mobility group box 1-positive hepatocytes. Apocynin significantly improved the survival rate, necrotic area, and concentrations of 8-hydroxy-2'-deoxyguanosine, TNFα, and IL-6 (P < 0.01). The protective effect of apocynin on fatty livers was greater than on normal livers.. Ischemia-reperfusion injury was associated with increased high-mobility group box 1, TLR4, and NOX2. Inhibition of NOX activity improved oxidative stress and may prevent I/R injury in fatty liver.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Cells, Cultured; Choline Deficiency; Deoxyguanosine; Disease Models, Animal; Enzyme Inhibitors; Fatty Liver; HMGB1 Protein; Inflammation Mediators; Interleukin-6; Liver; Macrophages; Male; Membrane Glycoproteins; Methionine; NADPH Oxidase 2; NADPH Oxidases; Necrosis; Oxidative Stress; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury; Signal Transduction; Time Factors; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Currently, there is no effective antidote to prevent skin injuries by sulfur mustard (SM) and nitrogen mustard (NM), which are vesicating agents with potential relevance to chemical warfare, terrorist attacks, or industrial/laboratory accidents. Our earlier report has demonstrated the therapeutic efficacy of silibinin, a natural flavanone, in reversing monofunctional alkylating SM analog 2-chloroethyl ethyl sulfide-induced toxic effects in mouse skin. To translate this effect to a bifunctional alkylating vesicant, herein, efficacy studies were carried out with NM. Topical application of silibinin (1 or 2mg) 30 min after NM exposure on the dorsal skin of male SKH-1 hairless mice significantly decreased NM-induced toxic lesions at 24, 72 or 120 h post-exposure. Specifically, silibinin treatment resulted in dose-dependent reduction of NM-induced increase in epidermal thickness, dead and denuded epidermis, parakeratosis and microvesication. Higher silibinin dose also caused a 79% and 51%reversal in NM-induced increases in myeloperoxidase activity and COX-2 levels, respectively. Furthermore, silibinin completely prevented NM-induced H2A.X phosphorylation, indicating reversal of DNA damage which could be an oxidative DNA damage as evidenced by high levels of 8-oxodG in NM-exposed mouse skin that was significantly reversed by silibinin. Together, these findings suggest that attenuation of NM-induced skin injury by silibinin is due to its effects on the pathways associated with DNA damage, inflammation, vesication and oxidative stress. In conclusion, results presented here support the optimization of silibinin as an effective treatment of skin injury by vesicants.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Administration, Cutaneous; Animals; Antidotes; Apoptosis; Cyclooxygenase 2; Cytoprotection; Deoxyguanosine; DNA Damage; Dose-Response Relationship, Drug; Histones; Irritants; Male; Mechlorethamine; Mice, Hairless; Necrosis; Oxidative Stress; Peroxidase; Phosphorylation; Signal Transduction; Silybin; Silymarin; Skin; Time Factors

Additional approaches to control malignancies are needed due to the emerging trends in the incidence of cancer of different organ sites. Due to the high frequency of hepatocellular carcinoma (HCC) and its poor prognosis, preventing HCC is an urgent priority. To explore the antioxidant and apoptotic pathways of grape seed extract (GSE) we induce HCC experimentally by diethylnitrosoamine (DEN) and treated the animals with low and high doses of GSE. The results indicate good therapeutic possibilities for GSE use in treatment of HCC., This was evidenced via regression of liver enzymes' function (ALT&AST), the HCC markers; α-fucosidase, α-fetoprotein and carcinoembrionic antigen (CEA) in HCC groups treated with the grape seed extract. Also, tumor necrosis factor (TNF-α) showed a significant decrease using GSE in HCC bearing animals. Regarding the apoptotic pathways of GSE, we found a significant down regulation of apoptosis enhancing nuclease (Aen), Bcl2-associated X protein (Bax), B-cell translocation gene 2(Btg2), Cyclin G1 (Ccng1) and Cyclin-dependent kinase inhibitor 1A (Cdkn1a) gene expression in HCC+GSE groups as compared to HCC bearing group. In the same trend, the necrotic/apoptotic rates were significantly higher in the HCC groups treated with GSE vs. the HCC bearing group. Finally, the 8-OHdG/2-dG generation decreased by 73.8% and 52.9% in HCC+GSE at low and high doses, respectively. Based on these encouraging observations, grape seed extract could be a promising natural remedy for attenuating hepatocellular carcinoma that has a great future in approaches directed towards control of HCC.

Topics: 8-Hydroxy-2'-Deoxyguanosine; alpha-L-Fucosidase; Animals; Antioxidants; Apoptosis; Carcinoma, Hepatocellular; Deoxyguanosine; Down-Regulation; Gene Expression Regulation; Grape Seed Extract; Humans; Liver Neoplasms; Male; Necrosis; Oxygen; Prognosis; Rats; Rats, Sprague-Dawley; Real-Time Polymerase Chain Reaction; Tumor Necrosis Factor-alpha

The objectives of this study were to assess cytokinesis-block micronucleus cytome (CBMN Cyt) assay parameters and also oxidative DNA damage in patients with active acromegaly and controls and to assess the relationship between age, serum insulin-like growth factor 1 (IGF-1) levels, pituitary adenoma diameters, 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels and CBMN Cyt assay parameters in patients with active acromegaly.. The study population included 30 patients with active acromegaly and 30 age- and sex-matched healthy controls. CBMN Cyt assay parameters in peripheral blood lymphocytes of patients with active acromegaly and controls were evaluated and plasma 8-OHdG levels were measured.. Frequencies of micronucleus (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) in lymphocytes of patients with acromegaly were found to be significantly higher than those in controls (p<0.001, p<0.001, p<0.001, respectively). The frequencies of apoptotic and necrotic cells in lymphocytes of patients with acromegaly were found to be significantly higher than those in controls (p<0.001 and p<0.001 respectively). No statistically significant differences in the number of cells in metaphase, the number of bi-nucleated cells (M2), the number of tri-nucleated cells (M3), the number of tetra-nucleated cells (M4) and nuclear division index (NDI) values were observed between patients and controls (p>0.05). Plasma 8-OHdG (ng/ml) levels in patients with acromegaly were found to be significantly higher than those in controls (p<0.005). MN frequency in the lymphocytes of patients with acromegaly increased with elevated serum IGF-1 levels (p<0.05), whereas the number of NPBs and the frequency of apoptotic cells decreased with elevated serum IGF-1 levels (p<0.01 and p<0.05 respectively).. Both the increase in chromosomal/oxidative DNA damage and the positive association between MN frequency and serum IGF-1 levels may predict an increased risk of malignancy in acromegalic patients. Long-term follow-up of patients with acromegaly will be necessary to establish the degree of cancer risk in this population.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acromegaly; Adult; Aged; Aged, 80 and over; Apoptosis; Biomarkers; Case-Control Studies; Cell Nucleus; Deoxyguanosine; DNA Damage; Female; Follow-Up Studies; Genomic Instability; Humans; Insulin-Like Growth Factor I; Lymphocytes; Male; Micronucleus Tests; Middle Aged; Necrosis; Prognosis

Birth and early life stages are critical periods characterized by severe alterations of the redox balance and by "physiological" genomic changes in lung cells, which may be responsible for cancer and other diseases in adulthood. Oxidative stress is a major mechanism accounting for the carcinogenicity of cigarette smoke (CS), which becomes more potently carcinogenic in mice when exposure starts at birth and continues early in life. We compared herewith a variety of end-points related to oxidative stress, mitochondrial alterations, and cell turnover in the lung of Swiss H mice, either sham-exposed or CS-exposed for 4 weeks, starting either at birth or at 4 months of age. The results showed that the physiological levels of certain end-points are affected by age. In fact, the baseline proportion of hypodiploid cells and the mitochondrial potential and mass were higher in adults, whereas 8-hydroxy-2'-deoxyguanosine (8-oxo-dGuo) levels, the proportion of necrotic cells, and the extent of autophagy were higher early in life. Adult mice were more responsive to CS by increasing the proportion of necrotic cells and of cells in S/G2 phase, whereas young mice maintained a high extent of autophagy, exhibited a greater increase of lipid peroxidation products and 8-oxo-dGuo levels, and had a higher frequency of micronucleated cells. In addition, exposure to CS affected the mitochondrial potential/mass, especially in young mice. In conclusion, these data provide evidence that oxidative stress and the resulting DNA damage provide a major contribution to the high susceptibility of mice to CS early in life.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aneuploidy; Animals; Autophagy; Cell Cycle; Deoxyguanosine; Female; Inhalation Exposure; Lipid Peroxidation; Lung; Male; Mice; Micronuclei, Chromosome-Defective; Mitochondria; Necrosis; Nicotiana; Oxidative Stress; Smoke

Investigation of the genotoxic potential of nanomaterials is essential to evaluate if they pose a cancer risk for exposed workers and consumers. The Chinese hamster ovary cell line CHO-K1 is recommended by the OECD for use in the micronucleus assay and is commonly used for genotoxicity testing. However, studies investigating if this cell line is suitable for the genotoxic evaluation of nanomaterials, including induction of DNA adduct and micronuclei formation, are rare and for silver nanoparticles (Ag NPs) missing. Therefore, we here systematically investigated DNA and chromosomal damage induced by BSA coated Ag NPs (15.9±7.6 nm) in CHO-K1 cells in relation to cellular uptake and intracellular localization, their effects on mitochondrial activity and production of reactive oxygen species (ROS), cell cycle, apoptosis and necrosis. Ag NPs are taken up by CHO-K1 cells and are presumably translocated into endosomes/lysosomes. Our cytotoxicity studies demonstrated a concentration-dependent decrease of mitochondrial activity and increase of intracellular reactive oxygen species (ROS) in CHO-K1 cells following exposure to Ag NPs and Ag⁺ (0-20 μg/ml) for 24h. Annexin V/propidium iodide assay showed that Ag NPs and Ag⁺ induced apoptosis and necrosis, which is in agreement with an increased fraction of cells in subG1 phase of the cell cycle. Genotoxicity studies showed that Ag NPs but also silver ions (Ag⁺) induced bulky-DNA adducts, 8-oxodG and micronuclei formation in a concentration-dependent manner, however, there were quantitative and qualitative differences between the particulate and ionic form of silver. Taken together, our multi-platform genotoxicity and cytotoxicity analysis demonstrates that CHO-K1 cells are suitable for the investigation of genotoxicity of nanoparticles like Ag NPs.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Apoptosis; Cell Cycle; CHO Cells; Coloring Agents; Cricetinae; Cricetulus; Deoxyguanosine; DNA Adducts; Flow Cytometry; Mass Spectrometry; Micronucleus Tests; Microscopy, Electron, Transmission; Microscopy, Fluorescence; Mutagenicity Tests; Mutagens; Nanoparticles; Necrosis; Reactive Oxygen Species; Silver; Tetrazolium Salts; Thiazoles

To determine whether ultrasound oscillations in the anterior chamber cause corneal endothelial injury by free radicals.. A phacoemulsification probe was introduced into the anterior chamber of rabbits' eyes through a limbal incision, and ultrasound oscillation was performed without emulsifying the lens. Rabbits were assigned to 4 treatment groups: (1) no treatment (controls); (2) only irrigation with a salt solution; (3) ultrasound only; and (4) ultrasound oscillations with a salt solution of 0.001M ascorbic acid. The corneas were immunohistochemically examined for oxidative stress using 8-hydroxy-2-deoxyguanosine (8-OHdG), apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) staining, and ultrastructural changes by electron microscopy. The lipid peroxide levels in the aqueous humor were also measured.. In the ultrasound-only group, 8-OHdG-positive cells and TUNEL-positive cells were detected at 24 hours; necrotic cells were detected at 12 to 24 hours. Also, lipid peroxide levels were significantly increased at later times in the ultrasound group. Such changes were not observed in other groups.. Free radicals induced by ultrasound oscillation can cause corneal endothelial damages. Clinical Relevance Clinicians should be aware that free radicals associated with ultrasound oscillation can injure the corneal endothelial cells.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Anterior Chamber; Aqueous Humor; Deoxyguanosine; Endothelium, Corneal; Free Radicals; Immunohistochemistry; In Situ Nick-End Labeling; Lipid Peroxides; Male; Microscopy, Electron; Microscopy, Electron, Scanning; Necrosis; Phacoemulsification; Rabbits; Time Factors; Ultrasonics; Up-Regulation

For the past 20 years, super-oxidised solutions (SOSs) have been shown to be potent antimicrobials and disinfectants via oxidative damage. However, the potential toxicity of SOSs on eukaryotic cells has not been documented in vitro. This is relevant because oxygen and chlorine reactive species may possibly induce ageing and irreversible cellular dysfunctions that eventually produce cell death. The present study investigates the cytotoxicity and oxidative stress induced by a novel, pH-neutral SOS (i.e. Microcyn, MCN) on young, primary diploid - human dermal fibroblast (HDF) cultures. For this purpose, hydrogen peroxide (HP) was used as a positive control of oxidative damage. When these solutions were used at concentrations indicated for wound care (i.e. undiluted MCN or 880 mM HP), HP was significantly more toxic than MCN. After 5 and 30 minutes of exposure, cell viability was 38% and 5%, respectively, in 880 mM HP-treated cells versus 75% and 70% in MCN-treated populations, respectively. HP induced both apoptosis and necrosis, whereas MCN induced only necrosis. Genotoxic and ageing studies were then conducted at sublethal HP concentrations as previously reported in the literature. Cellular DNA and RNA were partially degraded only in HDFs exposed to 500 microM HP for 30 minutes but not in those exposed to undiluted MCN. At this same concentration, HP induced the formation of 8-hydroxy-2'deoxyguanosine adducts in HDFs but this effect was neither observed in control- nor observed in MCN-treated cells. HDFs were further exposed to 5 microM HP or 10% MCN for 1 month. The expression of senescence-associated-beta-galactosidase was only significantly elevated in cells chronically exposed to 5 microM HP. Altogether, these results show that MCN is significantly less cytotoxic than antiseptic HP concentrations (i.e. 880 mM) and that, in vitro, it does not induce genotoxicity or accelerated ageing.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Anti-Infective Agents, Local; Apoptosis; beta-Galactosidase; Cell Survival; Cells, Cultured; Deoxyguanosine; Disinfectants; DNA Adducts; DNA Damage; Fibroblasts; Humans; Hydrogen Peroxide; Hydrogen-Ion Concentration; Necrosis; Oxidative Stress; RNA Stability; Skin

Our goal was to elucidate roles of Nrf2 in in vivo defense against pentachlorophenol (PCP), an environmental pollutant and hepatocarcinogen in mice. We examined oxidative stress and cell proliferation, along with other hepatotoxicological parameters, in the livers of nrf2-deficient (wild:+/+, heterozygous:+/-, homozygous:-/-) animals fed PCP in their diet at doses of 0, 150, 300, 600, or 1200 ppm for 4 weeks. For measurement of methoxyresorufin-O-demethylase (CYP 1A2), NAD(P):quinone oxidoreductase 1 (NQO1), and UDP-glucuronosyltransferase (UDP-GT), an additional study was performed with all but the 150-ppm dose. Significant elevation of 8-hydroxydeoxyguanosine (8-OH-dG) levels in the liver DNA was observed only in -/- mice treated with PCP at 1200 ppm. Levels of thiobarbituric-acid-reactive substances (TBARS) were also raised significantly compared to those of the relevant +/+ mice. Bromodeoxyuridine labeling indices (BrdU-LIs) of hepatocytes in -/- mice were significantly higher at all doses than those in the relevant +/+ mice. Relative liver weights were unchanged in mice lacking Nrf2, whereas liver weight in +/+ and +/- mice was increased. Significant elevations of serum ALP activity, but not ALT and AST activity, occurred at 600 ppm and above in -/- mice compared to the relevant +/+ mice. Histopathologically, centrilobular hepatocyte necrosis was severe in the -/- mice that received 600 ppm. Although CYP 1A2 activity was elevated in all treated mice, increases in NQO1 levels and UDP-GT activities did not occur only in -/- mice. These data suggest that Nrf2 plays a key role in prevention of PCP-induced oxidative stress and cell proliferation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Alkaline Phosphatase; Animals; Cell Proliferation; Cytochrome P-450 CYP1A2; Deoxyguanosine; Diet; DNA Damage; Dose-Response Relationship, Drug; Environmental Pollutants; Glucuronosyltransferase; Hepatocytes; Liver; Mice; Mice, Inbred ICR; Mice, Knockout; NAD(P)H Dehydrogenase (Quinone); NADPH Dehydrogenase; Necrosis; NF-E2-Related Factor 2; Organ Size; Oxidative Stress; Pentachlorophenol

Susceptibility to oxidative stress by X-ray irradiation was examined in splenic cells of BDF1 mouse and fetal human lung fibroblasts, TIG-7. Survival rates of splenic cells irradiated with X-rays were lower than those of TIG-7 cells irradiated similarly. The content of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) immediately after X-ray irradiation in the DNA of splenic cells increased until 2 Gy irradiation, but remained constant above 2 Gy. The 8-oxodG contents rose in proportion to the dose of X-rays in TIG-7 cells. Although the survival rate of splenic cells exposed to 1 Gy irradiation decreased with time, the survival rate of TIG-7 cells remained unchanged. The 8-oxodG content in splenic cells irradiated with X-rays did not decrease even 48 h after irradiation, while that in TIG-7 cells decreased with time, and recovered to the pre-irradiation level after 48 h. A DNA ladder was observed in splenic cells 2 h after X-ray irradiation, but the ladder was not found in fibroblasts. Furthermore, caspase-3 activity increased after X-ray irradiation of splenic cells. These results indicate that splenic cells are sensitive to oxidative stress induced by X-ray irradiation and that splenic cells damaged by even low doses of X-rays are removed through apoptosis rather than by a repair pathway.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Apoptosis; Caspase 3; Caspases; Cell Survival; Cells, Cultured; Deoxyguanosine; DNA; DNA Damage; Fibroblasts; Male; Mice; Necrosis; Oxidation-Reduction; Spleen; X-Rays

Mortality due to ischemic cardiovascular diseases is significantly higher in elderly than in young adults. Myocardial ischemia-reperfusion (MI/R) can induce oxidative stress and an inflammatory response. We hypothesized that increased vulnerability of aged myocardium to reperfusion injury could be caused by decreased antioxidative capacity, rather than increased oxidant production, after MI/R. Aged (20-mo-old) and young (4-mo-old) male F344BN rats were subjected to 30 min of myocardial ischemia by ligation of the left main coronary artery followed by release of the ligature and 4 h of reperfusion. Four experimental groups were studied: young sham-operated rats, aged sham-operated rats, young rats subjected to MI/R, and aged rats subjected to MI/R. MI/R significantly increased infiltrated leukocyte number and myeloperoxidase (MPO) activity in perinecrotic areas of hearts of young rats compared with aged MI/R rats. These changes in infiltrated leukocyte number and MPO activity were associated with an increase in superoxide generation in perinecrotic areas from hearts of young rats compared with aged rats. Plasma levels of TNF-alpha and IL-1beta were significantly higher in young than in aged MI/R rats. However, plasma 8-hydroxy-2'-deoxyguanosine levels and creatine kinase activity were increased in aged compared with young MI/R rats. Increased reperfusion damage in aged rats was associated with a significant decrease in plasma ratio of GSH to GSSG. Our results suggest that enhanced ischemia-reperfusion injury in aged rat hearts may be related to reduced antioxidative capacity, rather than increased reactive oxygen species production. These findings contribute to a better understanding of effects of aging on oxidative stress and inflammatory responses of the heart after MI/R.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Aging; Animals; Antioxidants; Blood Pressure; Creatine Kinase; Deoxyguanosine; Disease Models, Animal; Gene Expression; Heart Rate; Interleukin-1; Leukocyte Count; Myocardial Reperfusion Injury; Myocardium; Necrosis; Peroxidase; Rats; Rats, Inbred F344; Superoxides; Tumor Necrosis Factor-alpha

An important role of redox regulation in myocardial diseases and heart failure has been postulated. Thioredoxin (TRX) is a redox-regulating protein. Recent studies indicated a possible association between plasma TRX concentrations and the severity of heart failure. Accordingly, we investigated the myocardial expression of TRX in patients with myocarditis and cardiomyopathies. Four cases of hypertrophic cardiomyopathy (HCM), 10 of dilated cardiomyopathy (DCM), 6 of myocarditis, and 5 of controls were studied. Right and left ventricular endomyocardial biopsy samples were obtained at the diagnostic cardiac catheterization. The samples were processed for immunohistological staining for TRX, which was done by the indirect immunoperoxidase technique. 8-hydoxy-2'-deoxyguanosine (8-OHdG), one of the major DNA base-modified products, was also detected for an established marker for oxidative stress. TRX immunoreactivity was none or trivial in control specimens. Positive TRX staining was found in 6 cases; 3 in active myocarditis and 3 in DCM. The positive staining was found in infiltrating cells and damaged myocytes in the perinecrotic lesions. Damaged myocytes were also positive for 8-OHdG All the 3 cases of DCM positive for TRX stain showed severe left ventricular hypertrophy on electrocardiogram and highly elevated left ventricular end-diastolic pressure (> 24 mmHg), suggesting the overload of oxidative stress by hemodynamic impairment. Myocardial TRX was upregulated in myocarditis and cardiomyopathies with active necrotic stage associated with DNA damage, which may reflect the oxidative stress overload in hemodynamically uncontrolled status.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Biopsy; Cardiomyopathies; Deoxyguanosine; Diastole; DNA; DNA Damage; Heart Ventricles; Humans; Hypertrophy; Immunohistochemistry; Myocarditis; Myocardium; Necrosis; Oxidation-Reduction; Oxidative Stress; Pressure; Thioredoxins; Up-Regulation

Reactive oxygen radicals play an important role in various forms of liver injury. In this study, we evaluated the efficacy of edaravone, a newly synthesized free radical scavenger, in its clinical dosage on an experimental model of acute liver injury in rats.. The clinical dose of edaravone (3 mg/kg) was intravenously administered immediately and 3 h after intraperitoneal administration of carbon tetrachloride (CCl4) in rats. Histological evaluation including apoptosis and cytokine profiles were examined.. Fatty degeneration and necrosis with marked elevation of serum alanine aminotransferase and lactate dehydrogenase levels developed after CCl4 administration were significantly reduced by edaravone. In addition, the apoptotic index assessed by TUNEL method was significantly lowered in the edaravone treated group. Serum and liver transcription levels of interleukin-6, tumor necrosis factor-alpha, interleukin-4, and interleukin-10 were increased following CCl4 administration, and they were attenuated by edaravone treatment. The formation of malondialdehyde, 4-hydroxynonenal adduct and one of the markers for oxidative DNA damage, 8-hydroxy-2'-deoxyguanosine, was also inhibited by edaravone treatment.. Edaravone has a remarkable protective effect on acute liver injury caused by oxygen radicals through not only attenuating the membrane lipid peroxidation, but also inhibiting the production of inflammatory cytokines. We theorize that edaravone may have a clinical benefit in the treatment of various liver injuries.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acute Disease; Alanine Transaminase; Aldehydes; Animals; Antipyrine; Apoptosis; Cell Death; Cytokines; Deoxyguanosine; Edaravone; Free Radical Scavengers; Growth Inhibitors; Immunohistochemistry; In Situ Nick-End Labeling; Interleukin-10; Interleukin-4; Interleukin-6; Liver; Male; Models, Chemical; Necrosis; Oxygen; Rats; Rats, Wistar; Reactive Oxygen Species; Reverse Transcriptase Polymerase Chain Reaction; Tumor Necrosis Factor-alpha

8-Hydroxydeoxyguanosine (8-OHdG) is a promutagenic DNA lesion produced by oxygen radicals and is recognized as a useful marker in estimating DNA damage induced by oxidative stress.. Hepatic expression of 8-OHdG was immunohistochemically investigated in control and diseased human livers.. While no positive immunolabeling for 8-OHdG was observed in control livers, 8-OHdG was widely evident in diseased livers. Nuclear expression of 8-OHdG in the hepatocytes and bile duct cells were found in various forms of chronic hepatitis. 8-OHdG-positive hepatocytes were especially abundant in the periportal area with piecemeal necrosis and prominent cell infiltration. The number of positive hepatocytes significantly increased with the progression of severity of chronic hepatitis activity (r(s)=0.68, P<0.05). In alcoholic liver disease, nuclear expression of 8-OHdG was detected in the hepatocytes in the area of alcoholic hepatitis. Regarding primary biliary cirrhosis, 8-OHdG was preferentially detected in the nuclei of injured bile ducts (11 of 12 cases, 91.7%) and occasionally (2 of 12 cases, 16.7%) in the nuclei of hepatocytes around the bile duct lesions.. These results indicate that oxidative DNA damage is common in various forms of chronic liver disease suggesting a possible link between chronic inflammation and hepatocarcinogenesis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adult; Aged; Bile Duct Diseases; Biomarkers; Deoxyguanosine; DNA Damage; Hepatitis; Hepatitis B, Chronic; Hepatitis C, Chronic; Humans; Immunohistochemistry; Liver; Liver Cirrhosis, Biliary; Liver Diseases; Liver Diseases, Alcoholic; Middle Aged; Mitotic Index; Necrosis; Oxidation-Reduction

Experimental and epidemiological evidence suggests that lycopene, a carotenoid present in tomatoes, tomato products, and several fruits and vegetables, may play a role in preventing certain cancers in humans. We have investigated the effect of lycopene pretreatment on lipid peroxidation, oxidative damage to DNA, and histopathological changes in liver of animals subjected to intraperitoneal (ip) ferric nitrilotriacetate (Fe-NTA) administration. Compared with control rats, liver of Fe-NTA-treated animals showed a significant increase in the 8-oxo-7,8-dihydro-2'-deoxyguanosine level and a 75% increase in malondialdehyde accumulation concomitant with histopathological changes. Five days of lycopene pretreatment (10 mg/kg body weight, ip) almost completely prevented liver biomolecule oxidative damage and protected the tissue against the observed histological alterations.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Anticarcinogenic Agents; Body Weight; Carcinogens; Carotenoids; Deoxyguanosine; DNA; DNA Damage; Ferric Compounds; Lipid Peroxidation; Liver; Lycopene; Male; Malondialdehyde; Necrosis; Nitrilotriacetic Acid; Radiation-Protective Agents; Rats; Rats, Wistar; Time Factors

Adult T-cell leukemia-derived factor (ADF), originally defined as an interleukin-2 receptor inducer, is a human thioredoxin (TRX). ADF/TRX is a conserved multifunctional reductant presumably associated with redox regulation of the cellular environment; it works in vitro as a cytokine, free radical scavenger, activator of transcription factors, and substrate for several enzymes. In the present series of experiments, we studied the expression and intracellular localization of ADF/TRX in mouse kidney from two different renal tubular injury models: a free radical-associated model with ferric nitrilotriacetate (Fe-NTA) and a free radical-independent model with HgCl2. Markers of oxidative damage, such as 8-hydroxy-2'-deoxyguanosine, thiobarbituric acid-reactive substances, and 4-hydroxy-2-nonenal-modified proteins, were significantly increased in kidney from male C57B/6 mice 1 hour after a single intraperitoneal injection of Fe-NTA (5 mg iron/kg). However, in kidney from mice given a subcutaneous injection of HgCl2 (5 mg Hg/kg), none of these markers were increased, despite tubular necrosis with sulfhydryl depletion. In the Fe-NTA model only, Northern and Western blot analyses of the kidney revealed induction of ADF/TRX (> 2.5-fold) after 16 hours and translocation of ADF/TRX from the cytoplasmic to nuclear fraction (> 3.5-fold) after 24 hours. Immunohistochemistry showed a patchy distribution of ADF/TRX in the normal renal proximal tubules. In ex vivo experiments using serial normal kidney frozen sections, it was found that renal proximal tubules with low expression of ADF/TRX were more vulnerable to oxidative stress mediated by Fe-NTA. Collectively, these data suggest that: (a) ADF/TRX is induced and translocated to nuclei by oxidative damage mediated by Fe-NTA in the renal proximal tubules; (b) induction of ADF/TRX is independent of tubular necrosis or sulfhydryl depletion; and (c) ADF/TRX is involved in the cellular defense mechanisms in vivo against oxidative damage.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Blotting, Western; Cell Nucleus; Cytokines; Deoxyguanosine; Ferric Compounds; Immunohistochemistry; Kidney Tubules; Lipid Peroxidation; Male; Mercuric Chloride; Mice; Mice, Inbred C57BL; Necrosis; Neoplasm Proteins; Nitrilotriacetic Acid; Oxidative Stress; Sulfhydryl Compounds; Thioredoxins

High-performance liquid chromatography with electrochemical detection is a highly sensitive and selective method for detecting oxo8dG and oxo8Gua, biomarkers of oxidative DNA damage. When employed together with the DNA isolation and monoclonal antibody-based immunoaffinity purification methods described, oxo8dG and oxo8Gua in DNA and urine can be readily detected and quantitated, offering a powerful approach for assessing oxidative DNA damage in vivo. Application of the technique to the detection of oxo8dG from DNA permits quantitation of the steady-state levels of this oxidatively modified deoxynucleoside and overcomes the detection problems associated with the extremely low levels present in DNA. In addition, the selectivity gained by this detection method eliminates the problem of separating the signal for oxo8dG from those of normal deoxynucleosides. The quantitation of oxo8dG and oxo8Gua in biological fluids is noninvasive and complements the measurement of oxo8dG in DNA by estimating the rate of oxidative DNA damage occurring within the body or in a population of cells. This analytical approach may allow one to estimate oxidative DNA damage in an animal or individual exposed to prooxidant conditions associated with lifestyle, genetic predisposition, degenerative diseases, or environmental toxins. Furthermore, these assays may allow one to assess the potentially beneficial effects of intervention strategies that protect DNA from such damage.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Apoptosis; Biomarkers; Body Fluids; Carbon Radioisotopes; Cell Nucleus; Cells, Cultured; Chromatography, Affinity; Chromatography, High Pressure Liquid; Cytosol; Deoxyguanosine; DNA; DNA Damage; Electrochemistry; Guanine; Humans; Hydrolysis; Isotope Labeling; Mammals; Necrosis; Oxidation-Reduction; Radioisotope Dilution Technique; Tritium

Increasing concentrations (1-100 microM) of the redox cycling quinone, 2,3-dimethoxy-1,4-naphthoquinone (DMNQ), stimulated growth, triggered apoptosis, or caused necrosis of pancreatic RINm5F cells, depending on the dose and duration of the exposure. Following the exposure of RINm5F cells to 10 microM DMNQ, ornithine decarboxylase activity and polyamine biosynthesis increased. This was accompanied by enhanced cell proliferation. Conversely, exposure to 30 microM DMNQ for 3 h resulted in the inhibition of ornithine decarboxylase, intracellular polyamine depletion, and apoptotic cell killing. Pretreatment of the cultures with the phorbol ester, 12-O-tetradecanoylphorbol-13-acetate, restored polyamine levels and prevented apoptosis. Exposure to the same DMNQ concentration for only 1 h, with subsequent re-incubation in growth medium, neither caused polyamine depletion nor resulted in apoptosis. Finally, exposure to an even higher DMNQ concentration (100 microM) for either 1 or 3 h caused rapid intracellular Ca2+ overload, ATP, NAD+, and glutathione depletion, and extensive DNA single strand breakage, which resulted in necrotic cell death. Our results show that a disturbance of polyamine biosynthesis occurred prior to cell growth or apoptosis elicited by oxidative stress. In addition, we show that effects as opposite as cell proliferation and deletion, by either apoptosis or necrosis, can be induced, in the same system, by varying the exposure to a prooxidant.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adenosylmethionine Decarboxylase; Animals; Apoptosis; Cell Division; Cell Line; Cell Survival; Deoxyguanosine; Dose-Response Relationship, Drug; Insulin; Insulin Secretion; Islets of Langerhans; Kinetics; Naphthoquinones; Necrosis; Oxidants; Polyamines; Tetradecanoylphorbol Acetate; Time Factors

HPLC analysis revealed that luteoskyrin administered orally to male mice accumulated selectively in the liver, with minor distribution to the serum and kidneys. Elevation of serum GOT and GPT values was maximal 3 days after administration. In mice administered this mycotoxin intravenously, selective accumulation was also observed in the liver, and the half-life of hepatic luteoskyrin in males was significantly longer than that in females. Increment of serum transaminases was also marked in males with maximum accumulation at 24 h after administration. Histopathologically, cellular membrane damage was an early effect of luteoskyrin on cell necrosis, and these morphological changes were also marked in males. Luteoskyrin also elevated hepatic lipid peroxides, the maximum elevation being 8 h after injection; this increase was suppressed by alpha-tocopherol and Bi(NO3)3. HPLC-ECD analysis indicated that the level of 8-hydroxy-deoxyguanosine, one of the markers of hydroxy-radical-mediated modification of DNA guanine residues, was increased in hepatic DNA. These findings indicate that luteoskyrin has a high affinity for the liver, resulting in induction of lipid peroxidation, hepatocellular membrane damage, and elevation of serum transaminase activities. It is suggested that the hydroxy radicals derived from this anthraquinone contribute to these toxicological changes.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Alanine Transaminase; Animals; Aspartate Aminotransferases; Chromatography, High Pressure Liquid; Deoxyguanosine; Free Radical Scavengers; Hydroxylation; Lipid Peroxides; Liver; Male; Mice; Naphthoquinones; Necrosis; Time Factors

Inducibility of oxidative stress in rat liver in vivo by menadione-associated redox cycling activation under redox enzyme modulating conditions was examined by monitoring hepatocyte injury and 8-hydroxydeoxyguanosine (8-OHdG) levels of liver DNA. In addition, the treatment-associated liver tumor initiating activity was assessed in terms of development of gamma-glutamyl-transpeptidase (GGT)- and glutathione S-transferase placental form (GST-P)-positive foci and hyperplastic nodules. With or without following menadione treatment (50 mg/kg, i.g.), redox enzyme modulations of increased cytochrome P450 reductase activity induced by phenobarbital (PB)-Na (100 mg/kg, i.p. for 5 days), inhibition of DT-diaphorase by dicumarol (25 mg/kg, i.p.) and depletion of glutathione by phorone (200 mg/kg, i.p.), with or without further supplement of iron EDTA-Na-Fe(III) (70 mg/kg, i.p.), caused both substantial hepatocyte necrosis and 8-OHdG production in Fischer 344 male rats. Subsequent feeding with a 0.05% PB diet for 64 weeks resulted in slightly increased development of GGT-positive foci but not GST-P positive lesions or hyperplastic nodules, suggesting a lack of tumor-initiating activity of the oxidative DNA damage associated with redox enzyme modulations with or without menadione.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Body Weight; Cytochrome Reductases; Deoxyguanosine; Dicumarol; DNA; DNA Damage; gamma-Glutamyltransferase; Glutathione; Iron; Ketones; Liver; Liver Neoplasms, Experimental; Male; NAD(P)H Dehydrogenase (Quinone); Necrosis; Neoplasms, Experimental; Organ Size; Oxidation-Reduction; Phenobarbital; Quinone Reductases; Rats; Rats, Inbred F344; Time Factors; Vitamin K