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Oxidation of Glutathione by Hypochlorous Acid in theAirways of Children with Cystic Fibrosis
would attenuate Hbs vasculotoxic effects and progression towards pulmonary arterial hypertension.
Pulmonary Diseases
slow
the
Methods: Using programmable micro-pumps, male Sprague Dawley rats were exposed for 5 weeks to either the combination of Hb (35 mg/day) and chronic hypoxia or hypoxia alone in the presence or absence of haptolglobin therapy (300 mg per week). Blood pressures, cardiac output, right ventricular hypertrophy, indices of pulmonary vascular remodeling and markers of inflammation were evaluated.
Metabolic Shift in Lung Mitochondria After Toxic Exposure to Cigarette Smoke Amit Agarwal1 and Enrique Cadenas1 1 University of Southern California, United States Cigarette smoking (CS) leads to alteration in cellular redox status, a hallmark in the pathogenesis of chronic obstructive pulmonary disease (COPD). the current study was undertaken to determine the role of CS in the development of mitochondrial dysfunction due to oxidative stress as a consequence of altered redox status. Male A/J mice were exposed to CS generated by a smoking machine for 4 or 8 wk. a recovery group was exposed to CS for 8 wk and allowed to recover for 2 wk. Our data indicates that shortterm cigarette smoke exposure leads to altered metabolism of glucose due to oxidative modification of GAPDH, a central glycolytic enzyme and a concurrent increase in the pentose phosphate pathway of glucose metabolism. on the other hand, the activity and expression of mitochondrial respiratory chain complexes II, IV, and V were found to increase after 8 weeks of CS exposure. Microarray analysis of gene expression in mouse lungs after exposure to CS for 8 wk revealed upregulation of a group of genes involved in metabolism, electron transfer chain, oxidative phosphorylation, mitochondrial transport and dynamics, and redox regulation. to follow up on the source of substrates for mitochondrial respiratory chain mediated oxidative phosphorylation, we studied the effect of cigarette smoke, on primary alveolar Type II cells from mice exposed to cigarette smoke. the Type II alveolar cells showed a decrease in mitochondrial respiration on glucose and increased respiration on fatty acids (palmitate). the cells also showed an increase in expression of FAT/CD36 and CPT1 after CS exposure. Phosphatidylcholine was found to decrease after CS exposure along-with an increase in the cytosolic PLA2 activity. Thus, palmitate present in alveolar cells for surfactant synthesis could serve as an energy substrate in the event of altered glucose metabolism in alveolar cells.
doi: 10.1016/j.freeradbiomed.2013.10.534
Haptoglobin Therapy in a Rodent Model of Severe Pulmonary Vascular Disease Mediated by Hemoglobin Reduces Disease Progression David Irwin1, Paul Buehler2, Paul Eigenberger1, Christina Lisk1, Joanne Maltzhan3, Kathryn Hassel1, Eva Nozik-Grayck1, and Zoe Loomis1 1 University of Colorado Denver, United States, 2FDA, United States, 3University of Colorado Denver, United States Introduction: Cell-free hemoglobin exposure is a pathogenic modifier of vascular and peripheral organ dysfunction and when combined with tissue hypoxia, as typifies many disease and injury states, its effects are more pronounced. Haptaglobin is an acute phase protein responsible for binding and clearing Hb through the macrophage CD163 receptor mechanism. Haptoglobin infusion may be a viable therapy to attenuate vascular diseases associated with chronic exposure to Hb. We hypothesized that in a rodent model of severe pulmonary vascular disease mediated by Hb in the presence of tissue hypoxia, haptoglobin therapy
Results: Rats exposed to the combination of Hb and hypoxia had lower cardiac outputs, increased systemic and pulmonary vascular resistance, right ventricular hypertrophy, and pulmonary vascular remodeling compared to rats exposed to hypoxia. Further, when compared to hypoxia alone, the combination of Hb and hypoxia had increased lung perivascular leukocytes, CD163 positive macrophages, and ICAM-1 expression. Haptoglobin treatment attenuated all these responses in the rats exposed to Hb and hypoxia, but did not completely restore these indices to those values observed in animals exposed to hypoxia alone. Conclusion: This study demonstrated the proof of concept that haptoglobin therapy reduces the vascular toxicity and disease modifying effects of free Hb by slowing the progression of pulmonary vascular disease to pulmonary hypertension.
doi: 10.1016/j.freeradbiomed.2013.10.535
Loss of Vascular EC-SOD Increases the ProInflammatory Cytokine IL-18 in Chronic HypoxiaInduced Pulmonary Hypertension Laura Alejandra Guerra1, Keyla Tumas2, Timothy Stidham2, Richard Johnson2, Crystal Woods2, John Hartney3, Russell Bowler3, Rashmin Savani4, Eva Nozik-Grayck2, and Leah Villegas2 1 University of Texas at El Paso, United States, 2University of Colorado Anschutz Medical Campus, United States, 3National Jewish Hospital, United States, 4University of Texas Southwestern Medical Center, United States The antioxidant enzyme extracellular superoxide dismutase (ECSOD or SOD3) contains a positively charged C-terminal heparinbinding domain (HBD) that enables it to bind to the extracellular matrix, contributing to its strong vascular localization. a single nucleotide polymorphism (SNP) in the HBD (R213G) in humans decreases the matrix binding affinity of EC-SOD and increases risk of cardiovascular disease. Loss of EC-SOD contributes to injury in animal models of lung and vascular disease characterized by inflammation and fibrosis, including pulmonary hypertension (PH). We recently reported that chronic hypoxia increases lung expression of the proinflammatory cytokine IL-18 and that the increase in IL-18 is blocked by treatment with an ECSOD mimetic. We thus hypothesized that a loss of vascular ECSOD due to decreased production or redistribution will modulate IL-18 expression. We tested the following mouse strains exposed to normoxia (Nx), 14 days (14dHX), or 21 days (21dHX) of hypobaric hypoxia: wild type (WT), total body knockout of ECSOD (KO), and a new strain with knock-in of the human EC-SOD with the R213G SNP (R213G). in R213G mice, there was an allele dependent decrease in PA EC-SOD expression and concomitant increase in plasma EC-SOD. Lung IL-18 mRNA and protein expression at baseline, analyzed by QPCR and western blot, were higher in KO, and hypoxia lead to an earier rise and higher levels of IL-18 compared to WT. While lung IL-18 protein content was higher in R213G at baseline compared to WT, it did
6)5%0
6
Pulmonary Diseases
slow
the
Methods: Using programmable micro-pumps, male Sprague Dawley rats were exposed for 5 weeks to either the combination of Hb (35 mg/day) and chronic hypoxia or hypoxia alone in the presence or absence of haptolglobin therapy (300 mg per week). Blood pressures, cardiac output, right ventricular hypertrophy, indices of pulmonary vascular remodeling and markers of inflammation were evaluated.
Metabolic Shift in Lung Mitochondria After Toxic Exposure to Cigarette Smoke Amit Agarwal1 and Enrique Cadenas1 1 University of Southern California, United States Cigarette smoking (CS) leads to alteration in cellular redox status, a hallmark in the pathogenesis of chronic obstructive pulmonary disease (COPD). the current study was undertaken to determine the role of CS in the development of mitochondrial dysfunction due to oxidative stress as a consequence of altered redox status. Male A/J mice were exposed to CS generated by a smoking machine for 4 or 8 wk. a recovery group was exposed to CS for 8 wk and allowed to recover for 2 wk. Our data indicates that shortterm cigarette smoke exposure leads to altered metabolism of glucose due to oxidative modification of GAPDH, a central glycolytic enzyme and a concurrent increase in the pentose phosphate pathway of glucose metabolism. on the other hand, the activity and expression of mitochondrial respiratory chain complexes II, IV, and V were found to increase after 8 weeks of CS exposure. Microarray analysis of gene expression in mouse lungs after exposure to CS for 8 wk revealed upregulation of a group of genes involved in metabolism, electron transfer chain, oxidative phosphorylation, mitochondrial transport and dynamics, and redox regulation. to follow up on the source of substrates for mitochondrial respiratory chain mediated oxidative phosphorylation, we studied the effect of cigarette smoke, on primary alveolar Type II cells from mice exposed to cigarette smoke. the Type II alveolar cells showed a decrease in mitochondrial respiration on glucose and increased respiration on fatty acids (palmitate). the cells also showed an increase in expression of FAT/CD36 and CPT1 after CS exposure. Phosphatidylcholine was found to decrease after CS exposure along-with an increase in the cytosolic PLA2 activity. Thus, palmitate present in alveolar cells for surfactant synthesis could serve as an energy substrate in the event of altered glucose metabolism in alveolar cells.
doi: 10.1016/j.freeradbiomed.2013.10.534
Haptoglobin Therapy in a Rodent Model of Severe Pulmonary Vascular Disease Mediated by Hemoglobin Reduces Disease Progression David Irwin1, Paul Buehler2, Paul Eigenberger1, Christina Lisk1, Joanne Maltzhan3, Kathryn Hassel1, Eva Nozik-Grayck1, and Zoe Loomis1 1 University of Colorado Denver, United States, 2FDA, United States, 3University of Colorado Denver, United States Introduction: Cell-free hemoglobin exposure is a pathogenic modifier of vascular and peripheral organ dysfunction and when combined with tissue hypoxia, as typifies many disease and injury states, its effects are more pronounced. Haptaglobin is an acute phase protein responsible for binding and clearing Hb through the macrophage CD163 receptor mechanism. Haptoglobin infusion may be a viable therapy to attenuate vascular diseases associated with chronic exposure to Hb. We hypothesized that in a rodent model of severe pulmonary vascular disease mediated by Hb in the presence of tissue hypoxia, haptoglobin therapy
Results: Rats exposed to the combination of Hb and hypoxia had lower cardiac outputs, increased systemic and pulmonary vascular resistance, right ventricular hypertrophy, and pulmonary vascular remodeling compared to rats exposed to hypoxia. Further, when compared to hypoxia alone, the combination of Hb and hypoxia had increased lung perivascular leukocytes, CD163 positive macrophages, and ICAM-1 expression. Haptoglobin treatment attenuated all these responses in the rats exposed to Hb and hypoxia, but did not completely restore these indices to those values observed in animals exposed to hypoxia alone. Conclusion: This study demonstrated the proof of concept that haptoglobin therapy reduces the vascular toxicity and disease modifying effects of free Hb by slowing the progression of pulmonary vascular disease to pulmonary hypertension.
doi: 10.1016/j.freeradbiomed.2013.10.535
Loss of Vascular EC-SOD Increases the ProInflammatory Cytokine IL-18 in Chronic HypoxiaInduced Pulmonary Hypertension Laura Alejandra Guerra1, Keyla Tumas2, Timothy Stidham2, Richard Johnson2, Crystal Woods2, John Hartney3, Russell Bowler3, Rashmin Savani4, Eva Nozik-Grayck2, and Leah Villegas2 1 University of Texas at El Paso, United States, 2University of Colorado Anschutz Medical Campus, United States, 3National Jewish Hospital, United States, 4University of Texas Southwestern Medical Center, United States The antioxidant enzyme extracellular superoxide dismutase (ECSOD or SOD3) contains a positively charged C-terminal heparinbinding domain (HBD) that enables it to bind to the extracellular matrix, contributing to its strong vascular localization. a single nucleotide polymorphism (SNP) in the HBD (R213G) in humans decreases the matrix binding affinity of EC-SOD and increases risk of cardiovascular disease. Loss of EC-SOD contributes to injury in animal models of lung and vascular disease characterized by inflammation and fibrosis, including pulmonary hypertension (PH). We recently reported that chronic hypoxia increases lung expression of the proinflammatory cytokine IL-18 and that the increase in IL-18 is blocked by treatment with an ECSOD mimetic. We thus hypothesized that a loss of vascular ECSOD due to decreased production or redistribution will modulate IL-18 expression. We tested the following mouse strains exposed to normoxia (Nx), 14 days (14dHX), or 21 days (21dHX) of hypobaric hypoxia: wild type (WT), total body knockout of ECSOD (KO), and a new strain with knock-in of the human EC-SOD with the R213G SNP (R213G). in R213G mice, there was an allele dependent decrease in PA EC-SOD expression and concomitant increase in plasma EC-SOD. Lung IL-18 mRNA and protein expression at baseline, analyzed by QPCR and western blot, were higher in KO, and hypoxia lead to an earier rise and higher levels of IL-18 compared to WT. While lung IL-18 protein content was higher in R213G at baseline compared to WT, it did
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