The production of toxic, partially reduced species of oxygen is greatly enhanced in hyperoxic lungs and may eventually overwhelm the endogenous cellular capacity of antioxidant defenses resulting in lung cell damage. This kind of pulmonary injury is observed not only in experimental animals, but also in humans receiving oxygen therapy for respiratory insufficiency. Previously studies have demonstrated that augmentation of intracellular antioxidant enzyme activities [superoxide dismutase (SOD) and/or catalase] in cells or animals by treating them with liposome-encapsulated antioxidant enzymes, or exposing animals to a sublethal concentration of oxygen would provide dramatic protection to the recipient cells or animals against hyperoxic insults. In this application, a novel approach will be undertaken to further evaluate the effectiveness of each of the antioxidant enzymes in protecting lung cells from oxygen-mediated injury. Initially, five lines of transgenic mice each carrying a specific antioxidant enzyme transgene will be generated. These transgenes are being designed to be under the control of a human beta-actin promoter to insure high levels of transcription in all types of cells in animals. Additionally, mice containing a combination of two transgenes will also be obtained by mating two transgenic founder mice each bearing a different transgene. Expression of these transgenes in different tissues including the lung will be examined at both mRNA and protein levels. Immunocytochemistry will be used to identify the cellular sites, distribution and concentrations of the antioxidant enzymes in both control and exposure will be used to determine the degree of protection provided by the augmented antioxidant enzyme activities. Antioxidant enzymes are critical for cellular defense against oxidant stress. Unravelling the effectiveness of each antioxidant enzyme should help design more efficient antioxidant therapies to block or reduce oxygen- mediated lung injury. the transgenic mice generated in this study also can be used for elucidating the role of antioxidant enzymes in other diseases associated with the over-production of partially reduced oxygen species, such as some types of lung fibrosis and reperfusion injury of ischemic heart tissue.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
1R01HL044571-01
Application #
3363375
Study Section
Pathology A Study Section (PTHA)
Project Start
1990-04-01
Project End
1995-03-31
Budget Start
1990-04-01
Budget End
1991-03-31
Support Year
1
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Duke University
Department
Type
Schools of Medicine
DUNS #
071723621
City
Durham
State
NC
Country
United States
Zip Code
27705
Chen, Z; Chua, C C; Ho, Y S et al. (2001) Overexpression of Bcl-2 attenuates apoptosis and protects against myocardial I/R injury in transgenic mice. Am J Physiol Heart Circ Physiol 280:H2313-20
Chen, Z; Oberley, T D; Ho, Y et al. (2000) Overexpression of CuZnSOD in coronary vascular cells attenuates myocardial ischemia/reperfusion injury. Free Radic Biol Med 29:589-96
Chen, Z; Siu, B; Ho, Y S et al. (1998) Overexpression of MnSOD protects against myocardial ischemia/reperfusion injury in transgenic mice. J Mol Cell Cardiol 30:2281-9
Ho, Y S; Vincent, R; Dey, M S et al. (1998) Transgenic models for the study of lung antioxidant defense: enhanced manganese-containing superoxide dismutase activity gives partial protection to B6C3 hybrid mice exposed to hyperoxia. Am J Respir Cell Mol Biol 18:538-47
Yoshida, T; Maulik, N; Engelman, R M et al. (1997) Glutathione peroxidase knockout mice are susceptible to myocardial ischemia reperfusion injury. Circulation 96:II-216-20
Cheng, W H; Ho, Y S; Ross, D A et al. (1997) Cellular glutathione peroxidase knockout mice express normal levels of selenium-dependent plasma and phospholipid hydroperoxide glutathione peroxidases in various tissues. J Nutr 127:1445-50
Cheng, W H; Ho, Y S; Ross, D A et al. (1997) Overexpression of cellular glutathione peroxidase does not affect expression of plasma glutathione peroxidase or phospholipid hydroperoxide glutathione peroxidase in mice offered diets adequate or deficient in selenium. J Nutr 127:675-80
Yen, H C; Oberley, T D; Vichitbandha, S et al. (1996) The protective role of manganese superoxide dismutase against adriamycin-induced acute cardiac toxicity in transgenic mice. J Clin Invest 98:1253-60
Yoshida, T; Watanabe, M; Engelman, D T et al. (1996) Transgenic mice overexpressing glutathione peroxidase are resistant to myocardial ischemia reperfusion injury. J Mol Cell Cardiol 28:1759-67
Ho, Y S (1994) Transgenic models for the study of lung biology and disease. Am J Physiol 266:L319-53

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