8-hydroxy-2--deoxyguanosine and Pulmonary-Fibrosis

Myofibroblast differentiation is a key process in the pathogenesis of fibrotic diseases. Transforming growth factor-β

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Biomarkers; Bleomycin; Cell Differentiation; Cells, Cultured; Collagen Type I; Cytoprotection; Deoxyguanosine; DNA; DNA Damage; DNA Glycosylases; DNA, Mitochondrial; Humans; Mice, Knockout; Models, Biological; Myofibroblasts; Pulmonary Fibrosis; Reactive Oxygen Species; Sirtuin 3; Transforming Growth Factor beta1

Maternal nicotine exposure induces lung injuries and fibrosis in rat offspring. Epithelial-mesenchymal transition (EMT) following lung injury is a process in which epithelial cells mediate tissue repair.. To determine the effects of maternal nicotine exposure on EMT in neonatal rat lungs.. Nicotine was administered to pregnant Sprague-Dawley rats using a subcutaneous osmotic minipump that delivered a dose of 6 mg/kg/day on gestational days 7-21 or from gestational day 7 to postnatal day 14. A control group received an equal volume of saline.. The percentage of 8-hydroxy-2'-deoxyguanosine-positive cells in nuclear staining was significantly higher, the E-cadherin protein expression was significantly lower, and the N-cadherin protein expression was significantly higher in rats born to prenatal and postnatal nicotine-treated dams than in those born to prenatal saline- and nicotine-treated dams on postnatal day 7. These characteristics of EMT were associated with a significant increase in α-smooth muscle actin (SMA) expression on postnatal day 21. Rats born to prenatal and postnatal nicotine-treated dams showed significantly higher α-SMA expression and total collagen than those born to prenatal saline- and nicotine-treated dams on postnatal day 21. The number of cells expressing fibroblast-specific protein 1 and vimentin was higher in rats born to prenatal and postnatal nicotine-treated dams than in those born to prenatal saline- and nicotine-treated dams on postnatal days 7 and 21.. Maternal nicotine exposure during gestation and lactation induces EMT and contributes to lung fibrosis in rat offspring.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Actins; Animals; Animals, Newborn; Cadherins; Calcium-Binding Proteins; Collagen; Deoxyguanosine; Epithelial-Mesenchymal Transition; Female; Lactation; Lung; Maternal Exposure; Nicotine; Pregnancy; Pulmonary Fibrosis; Rats; Rats, Sprague-Dawley

Biomarkers predicting for the radiation-induced lung responses of pneumonitis or fibrosis are largely unknown. Herein we investigated whether markers of oxidative stress and intracellular antioxidants, measured within days of radiation exposure, are correlated with the lung tissue injury response occurring weeks later. Mice of the eight inbred strains differing in their susceptibility to radiation-induced pulmonary fibrosis, and in the duration of asymptomatic survival, received 18 Gy whole thorax irradiation and were killed 6 h, 24 h, or 7 days later. Control mice were not irradiated. Lung levels of antioxidants superoxide dismutase, catalase, glutathione peroxidase (GPx), and glutathione, and of oxidative damage [reactive oxygen species (ROS) and 8-hydroxydeoxyguanosine (8-OHdG)], were biochemically determined. GPx was additionally measured through gene expression and immunohistochemical assessment of lung tissue, and activity in serum. ROS and 8-OHdG were increased postirradiation and exhibited significant strain and time-dependent variability, but were not strongly predictive of radiation-induced lung diseases. Antioxidant measures were not dramatically changed postirradiation and varied significantly among the strains. Basal GPx activity (r = 0.73, P = 0.04) in the lung and the pulmonary expression of GPx2 (r = 0.94, P = 0.0003) correlated with postirradiation asymptomatic survival, whereas serum GPx activity was inversely correlated (r = -0.80, P = 0.01) with fibrosis development. In conclusion, pulmonary oxidative stress and antioxidant markers were more affected by inbred strain than radiation over 7 days posttreatment. Lung GPx activity, and GPx2 expression, predicted for survival from lethal pneumonitis, and serum GPx for fibrosis, in this panel of mice.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antioxidants; Blotting, Western; Catalase; Deoxyguanosine; Female; Glutathione Peroxidase; Immunoenzyme Techniques; Mice; Mice, Inbred A; Mice, Inbred AKR; Mice, Inbred C3H; Mice, Inbred C57BL; Mice, Inbred CBA; Oxidative Stress; Pulmonary Fibrosis; Radiation Dosage; Radiation Pneumonitis; Reactive Oxygen Species; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Superoxide Dismutase; Thorax

Pulmonary fibrosis, a progressive and lethal lung disease characterized by inflammation and accumulation of extracellular matrix components, is a major therapeutic challenge for which new therapeutic strategies are warranted. Cyclooxygenase (COX) inhibitors have been previously utilized to reduce inflammation. Histamine H4 receptor (H4R), largely expressed in hematopoietic cells, has been identified as a novel target for inflammatory and immune disorders. The aim of this study was to evaluate the effect of JNJ7777120 (1-[(5-chloro-1H-indol-2-yl)carbonyl]-4-methylpiperazine), a selective H4R antagonist, and naproxen, a well known nonsteroidal anti-inflammatory drug, and their combination in a murine model of bleomycin-induced fibrosis. Bleomycin (0.05 IU) was instilled intratracheally to C57BL/6 mice, which were then treated by micro-osmotic pump with vehicle, JNJ7777120 (40 mg/kg b.wt.), naproxen (21 mg/kg b.wt.), or a combination of both. Airway resistance to inflation, an index of lung stiffness, was assessed, and lung specimens were processed for inflammation, oxidative stress, and fibrosis markers. Both drugs alone were able to reduce the airway resistance to inflation induced by bleomycin and the inflammatory response by decreasing COX-2 and myeloperoxidase expression and activity and thiobarbituric acid-reactive substance and 8-hydroxy-2'-deoxyguanosine production. Lung fibrosis was inhibited, as demonstrated by the reduction of tissue levels of transforming growth factor-β, collagen deposition, relative goblet cell number, and smooth muscle layer thickness. Our results demonstrate that both JNJ7777120 and naproxen exert an anti-inflammatory and antifibrotic effect that is increased by their combination, which could be an effective therapeutic strategy in the treatment of pulmonary fibrosis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Anti-Inflammatory Agents; Bleomycin; Collagen; Cyclooxygenase 2; Deoxyguanosine; Disease Models, Animal; Goblet Cells; Indoles; Lung; Mice; Muscle, Smooth; Naproxen; Oxidative Stress; Peroxidase; Piperazines; Pneumonia; Pulmonary Fibrosis; Thiobarbituric Acid Reactive Substances; Transforming Growth Factor beta

Cyclooxygenase (COX)-inhibiting nitric oxide (NO) donors (CINODs) are designed to inhibit COX-1 and COX-2 while releasing NO. COX inhibition is responsible for anti-inflammatory and pain-relieving effects, whereas NO donation can improve microcirculation and exert anti-inflammatory and antioxidant actions. In an in vivo mouse model of bleomycin-induced lung fibrosis, we evaluated whether a prototype CINOD compound, (S)-(5S)-5,6-bis(nitrooxy)hexyl)2-(6-methoxynaphthalen-2-yl)propanoate (NCX 466), may show an advantage over naproxen, its congener drug not releasing NO. Bleomycin (0.05 IU) was instilled intratracheally to C57BL/6 mice, which were then treated orally with vehicle, NCX 466 (1.9 or 19 mg/kg), or an equimolar dose of naproxen (1 or 10 mg/kg) once daily for 14 days. Afterward, airway resistance, assumed as lung stiffness index, was assayed, and lung specimens were collected for analysis of lung inflammation and fibrosis. NCX 466 and naproxen dose-dependently prevented bleomycin-induced airway stiffness and collagen accumulation. NCX 466, at the highest dose, was significantly more effective than naproxen in reducing the levels of the profibrotic cytokine transforming growth factor-β and the oxidative stress markers thiobarbituric acid reactive substance and 8-hydroxy-2'-deoxyguanosine. NCX 466 also decreased myeloperoxidase activity, a leukocyte recruitment index, to a greater extent than naproxen. A similar inhibition of prostaglandin E₂ was achieved by both compounds. In conclusion, NCX 466 has shown a significantly higher efficacy than naproxen in reducing lung inflammation and preventing collagen accumulation. These findings suggest that COX inhibition along with NO donation may possess a therapeutic potential in lung inflammatory diseases with fibrotic outcome.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Anti-Inflammatory Agents; Antibiotics, Antineoplastic; Bleomycin; Collagen; Cyclooxygenase Inhibitors; Deoxyguanosine; Dinoprostone; Inflammation; Lung; Male; Mice; Mice, Inbred C57BL; Naproxen; Nitrates; Nitric Oxide; Nitric Oxide Donors; Oxidative Stress; Peroxidase; Propionates; Prostaglandin-Endoperoxide Synthases; Pulmonary Fibrosis; Thiobarbiturates; Transforming Growth Factor beta

Chrysotile (CH) is a pathogenic waste building material that can potentially be rendered innocuous via conversion to forsterite (FO) by heating at high temperatures. We compared the ability of FO and CH to cause oxidative DNA damage and lung injury. A single 1-mg intratracheal dose of CH or FO was administered to rats. Significant changes were observed 3 to 7 days after CH injection in alveolar macrophages, neutrophils, eosinophils, lymphocytes, total protein, and lactate dehydrogenase. High concentrations of 8-hydroxy-29-deoxyguanosine (8-OHdG) were also observed in the macrophages, other infiltrating inflammatory cells, granulomas, and in bronchiolar and alveolar epithelial cells. The overexpression of 8-OHdG was limited to airway epithelial and inflammatory cells surrounding the fibrotic foci 540 days after injection, indicating that the inflammatory effects of CH were persistent yet decreased with time. Compared to the CH group, acute lung inflammation observed in the FO group was less apparent and exhibited no progressive fibrosing lesions. The expression of 8-OHdG was transient and weak in the bronchiolar epithelial cells as well as in the inflammatory cells, consistent with low concentrations of 8-OHdG observed in the lungs. These findings confirm that FO causes significantly less inflammation and oxidative DNA damage in the lungs than CH.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Air Pollutants; Animals; Asbestos, Serpentine; Bronchoalveolar Lavage Fluid; Deoxyguanosine; DNA Damage; Intubation, Intratracheal; L-Lactate Dehydrogenase; Lung; Macrophages, Alveolar; Magnesium; Male; Oxidation-Reduction; Proteins; Pulmonary Fibrosis; Rats; Rats, Wistar; Silicon Compounds

Oxidative stress plays a critical role in the development of pulmonary fibrosis. However, the effects of treatment with anti-oxidant agents against pulmonary fibrosis have not yet been thoroughly investigated. In this study, the effect of MCI-186, a novel free radical scavenger, on bleomycin-induced pulmonary fibrosis was investigated. Bleomycin (0.05units/mouse) was administered intratracheally into C57Bl/6 mice. MCI-186 was given to bleomycin-treated mice intraperitoneally from (i) day -3 to day 7, or from (ii) day 10 to day 28 after bleomycin administration in successive days. At 28 days after bleomycin administration, pulmonary fibrosis was then assessed by lung histology and hydroxyproline. MCI-186 inhibited H(2)O(2)-induced DNA damage in bronchial epithelium in vitro. MCI-186 decreased the lipid peroxide content, a marker for DNA damage, in the lung and reduced 8-OHdG positive cells in the lung in vivo. During the early period (day -3 to day 7) administration, MCI-186 partially attenuated bleomycin-induced pulmonary fibrosis. However, during the late period (day 10 to day 28) MCI-186 exacerbated pulmonary fibrosis, based on the histology and hydroxyproline content. In this condition, MCI-186 in the late period decreased the number of apoptosis cells induced by bleomycin, and therefore it might contribute to the deterioration of pulmonary fibrosis. These data indicate that MCI-186, radical scavenger, has a biphasic effect on bleomycin-induced pulmonary fibrosis in mice. Careful attention should be paid before clinical application of new remedies for pulmonary fibrosis.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Antipyrine; Apoptosis; Bleomycin; Bronchi; Bronchoalveolar Lavage Fluid; Deoxyguanosine; Dose-Response Relationship, Drug; Edaravone; Epithelial Cells; Free Radical Scavengers; Hydroxyproline; Immunohistochemistry; Injections, Intraperitoneal; Intubation, Intratracheal; Lipid Peroxides; Lung; Male; Mice; Mice, Inbred C57BL; Pulmonary Fibrosis; Time Factors

To determine whether comparative proteomics could detect differential protein expression after lung irradiation in two mouse strains with different radiation responses, lung proteins were subjected to two-dimensional orthogonal liquid-phase separations, with chromatofocusing in the first dimension and nonporous silica reverse-phase high-performance liquid chromatography (NPS-RP-HPLC) in the second. Five weeks after 12 Gy whole-lung irradiation, 15 and 31 proteins had significantly altered expression levels in C3H/HeJ (less likely to develop lung fibrosis) and C57BL/6J mice (more likely to develop lung fibrosis), respectively. These proteins were analyzed by HPLC-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) and identified by matching sequences in a peptide database. The proteins are associated with redox, energy consumption, glycolysis, or chromatin/ RNA structure formation. Five of the six redox-related proteins, including superoxide dismutase 1 (SOD1), cytochrome c oxidase, glutamate dehydrogenase, biliverdin reductase, peroxiredoxin and carbonyl reductase, were down-regulated in the irradiated C57BL/6J mice, whereas SOD1, sulfurtransferase and carbonyl reductase increased in the irradiated C3H/ HeJ mice. Thus decreased antioxidant proteins in the irradiated C57BL/6J mice may be correlated with increased early lung toxicity. Changes in SOD1 and 8-hydroxydeoxy-guanosine (8-OHdG, an oxidative stress marker) were further confirmed by immunohistochemistry and/or Western blot analysis. These data suggest that a proteomics approach has the potential to detect protein changes relevant to early lung toxicity after irradiation.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Deoxyguanosine; Lung; Male; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Proteomics; Pulmonary Fibrosis; Radiation Tolerance; Superoxide Dismutase; Superoxide Dismutase-1

Welder's pneumoconiosis has generally been determined to be benign and unassociated with respiratory symptoms based on the absence of pulmonary-function abnormalities in welders with marked radiographic abnormalities. In previous studies, the current authors suggested a three-phase lung fibrosis process to study the pathological process of lung fibrosis and found that the critical point for recovery was after 30 days of welding-fume exposure at a high dose, at which point early and delicate fibrosis was observed in the perivascular and peribronchiolar regions. Accordingly, the current study investigated the inflammatory and genotoxic responses during a 30-day period of welding-fume exposure to elucidate the process of fibrosis. As such, rats were exposed to manual metal arc-stainless steel (MMA-SS) welding fumes at concentrations of 65.6 +/- 2.9 (low dose) and 116.8 +/- 3.9 mg/m3 (high dose) total suspended particulate for 2 h per day in an inhalation chamber for 30 days. Animals were sacrificed after the initial 2 h exposure, and after 15 and 30 days of exposure. The rats exposed to the welding fumes exhibited a statistically significant (P < 0.05) decrease in body weight when compared to the control during the 30-day exposure period, yet an elevated cellular differential count and higher levels of albumin, LDH, and beta-NAG, but not elevated TNF-alpha, and IL-1beta in the acellular bronchoalveolar lavage fluid. In addition, the DNA damage resulting from 30 days of welding-fume exposure was confirmed by a comet assay and the inmmunohistochemistry for 8-hydroxydeoxyguanine (8-OH-dG). Consequently, the elevated inflammatory and genotoxic indicators confirmed the lung injury and inflammation caused by the MMA-SS welding-fume exposure.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Acetylglucosaminidase; Air Pollutants, Occupational; Albumins; Animals; Body Weight; Bronchoalveolar Lavage Fluid; Comet Assay; DNA; DNA Damage; Dose-Response Relationship, Drug; Guanine; Inhalation Exposure; L-Lactate Dehydrogenase; Leukocyte Count; Lung; Macrophages, Alveolar; Male; Pulmonary Fibrosis; Rats; Rats, Sprague-Dawley; Specific Pathogen-Free Organisms; Stainless Steel; Welding

Occupational exposure to silica has often been associated with the development of pulmonary fibrosis and, occasionally, lung cancer. Their development may be mediated by oxidant-induced cellular injury. The short- and long-term effects of a single intratracheal instillation of silica in rats (10 mg/200 microliters/saline per rat) was assessed by measuring 8-hydroxy-2'-deoxyguanosine (oh8dG) levels in lung tissue and peripheral blood leukocytes. Cell differentials, reduced glutathione (GSH), and superoxide dismutase (SOD), lipid peroxide, and total phospholipids in peripheral blood and/or bronchoalveolar lavage fluid (BALF) were also measured. The pulmonary oh8dG levels increased approximately 2.24- 2.86-fold from 1 to 5 days after exposure to silica. It was still elevated 1 and 4 weeks after installation, but the difference was no longer statistically significant. The oh8dG levels in peripheral blood leukocytes were never significantly different, but they were generally higher than in the controls. The low SOD levels in the BALF of exposed rats in the early stage and the higher GSH levels in the late stage may represent protective reactions against the generation of oxygen species. A significant increase in oh8dG levels in lung tissue suggested the possible carcinogenicity of silica.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Bronchoalveolar Lavage Fluid; Cell Differentiation; Deoxyguanosine; Disease Models, Animal; DNA Damage; Glutathione; Leukocytes; Lipid Peroxidation; Lung; Lung Neoplasms; Male; Occupational Exposure; Oxidative Stress; Phospholipids; Pulmonary Fibrosis; Rats; Rats, Wistar; Silicon Dioxide; Specific Pathogen-Free Organisms; Superoxide Dismutase; Trachea