The general goal of the prospective studies is to understand the causes of the aging process in animals. Endogenously-generated oxygen free radicals have been widely postulated to play a causal role in the aging process; however, few studies have been conducted to directly test the validity of this hypothesis. The purpose of the proposed experiments is to directly test the main prediction of this hypothesis: that a decrease in the level of oxidative stress should slow down the aging process. Extra copies of genes that play key roles in the antioxidative system will be introduced into the Drosophila melanogaster genome and the impact of overexpression on age-related biochemical and physiological changes will be assessed. Effects of the overexpression of the Mn superoxide dismutase, glutathione reductase, glutamylcysteine synthetase and glucose-6-phosphate dehydrogenase will be studied; we have previously examined the effects of Cu-Zn superoxide dismutase and catalase. Because the overexpression of single antioxidative genes may create a biochemical imbalance in an inter- related defense mechanism, a major effort will be made to construct transgenic strains with balanced antioxidative defenses. Results of this study should critically test the veracity of the free radical hypothesis of aging by indicating if the major defenses against reactive oxygen species play a causal role in the aging process of Drosophila. Knowledge gained from this study should help in developing strategies for the manipulation of the aging process in mammalian systems.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG008459-07
Application #
2050218
Study Section
Molecular Cytology Study Section (CTY)
Project Start
1989-07-01
Project End
1997-06-30
Budget Start
1995-07-01
Budget End
1996-06-30
Support Year
7
Fiscal Year
1995
Total Cost
Indirect Cost
Name
Southern Methodist University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
City
Dallas
State
TX
Country
United States
Zip Code
75205
Candas, M; Sohal, R S; Radyuk, S N et al. (1997) Molecular organization of the glutathione reductase gene in Drosophila melanogaster. Arch Biochem Biophys 339:323-34
Orr, W C; Orr, E C; Legan, S K et al. (1996) Molecular analysis of the Drosophila catalase gene. Arch Biochem Biophys 330:251-8
Sohal, R S; Agarwal, A; Agarwal, S et al. (1995) Simultaneous overexpression of copper- and zinc-containing superoxide dismutase and catalase retards age-related oxidative damage and increases metabolic potential in Drosophila melanogaster. J Biol Chem 270:15671-4
Orr, W C; Sohal, R S (1994) Extension of life-span by overexpression of superoxide dismutase and catalase in Drosophila melanogaster. Science 263:1128-30
Sohal, R S (1993) The free radical hypothesis of aging: an appraisal of the current status. Aging (Milano) 5:3-17
Orr, W C; Sohal, R S (1993) Effects of Cu-Zn superoxide dismutase overexpression of life span and resistance to oxidative stress in transgenic Drosophila melanogaster. Arch Biochem Biophys 301:34-40
Sohal, R S; Brunk, U T (1992) Mitochondrial production of pro-oxidants and cellular senescence. Mutat Res 275:295-304
Sohal, R S; Orr, W C (1992) Relationship between antioxidants, prooxidants, and the aging process. Ann N Y Acad Sci 663:74-84
Orr, W C; Sohal, R S (1992) The effects of catalase gene overexpression on life span and resistance to oxidative stress in transgenic Drosophila melanogaster. Arch Biochem Biophys 297:35-41
Orr, W C; Arnold, L A; Sohal, R S (1992) Relationship between catalase activity, life span and some parameters associated with antioxidant defenses in Drosophila melanogaster. Mech Ageing Dev 63:287-96

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