The main purpose of the proposed studies is to test the validity of the oxidative stress hypothesis of aging, which postulates that the age-associated loss of functional capacity is substantially due to the accrual of molecular oxidative damage. The focus of this study is to investigate one of the main predictions of this hypothesis, namely, that variations in the level of oxidative stress, induced by experimental alterations in antioxidative defenses, should correspondingly affect the rate of the aging process. Specifically, this study will determine the effects of an increased, or a decreased ability of cells to synthesize and regenerate reduced glutathione, on the aging process of Drosophila melanogaster. Flies that have an increased ability to synthesize and regenerate glutathione will be created by the transgenic overexpression of gamma-glutamylcysteine synthetase (the rate-limiting enzyme in glutathione synthesis) and glutathione reductase (which converts oxidized glutathione to reduced glutathione), respectively. In contrast, flies with a decreased ability to synthesize and regenerate glutathione will be obtained by isolating mutant alleles of these genes. The effects of over- and under-expression of these genes on life span and a variety of biochemical/physiological alterations, related to the aging process, will be determined. Subsequently, the effects of co-overexpression of these two genes, along with other antioxidative genes (Cu/Zn-SOD, Mn-SOD, and catalase), on the aging process of the flies will be determined. It is suggested that the results should provide a direct test of (i) the validity of the oxidative stress hypothesis of aging, and (ii) the role of the genes, involved in the maintenance of glutathione, in the aging process.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG015122-03
Application #
6124242
Study Section
Special Emphasis Panel (ZRG4-ORTH (01))
Program Officer
Mccormick, Anna M
Project Start
1997-12-01
Project End
2000-11-30
Budget Start
1999-12-15
Budget End
2000-11-30
Support Year
3
Fiscal Year
2000
Total Cost
$207,895
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
Orr, William C; Radyuk, Svetlana N; Sohal, Rajindar S (2013) Involvement of redox state in the aging of Drosophila melanogaster. Antioxid Redox Signal 19:788-803
Radyuk, Svetlana N; Klichko, Vladimir I; Michalak, Katarzyna et al. (2013) The effect of peroxiredoxin 4 on fly physiology is a complex interplay of antioxidant and signaling functions. FASEB J 27:1426-38
Radyuk, Svetlana N; Gambini, Juan; Borras, Consuelo et al. (2012) Age-dependent changes in the transcription profile of long-lived Drosophila over-expressing glutamate cysteine ligase. Mech Ageing Dev 133:401-13
Sohal, Rajindar S; Orr, William C (2012) The redox stress hypothesis of aging. Free Radic Biol Med 52:539-555
Radyuk, Svetlana N; Rebrin, Igor; Klichko, Vladimir I et al. (2010) Mitochondrial peroxiredoxins are critical for the maintenance of redox state and the survival of adult Drosophila. Free Radic Biol Med 49:1892-902
Radyuk, Svetlana N; Rebrin, Igor; Luchak, James M et al. (2009) The catalytic subunit of Drosophila glutamate-cysteine ligase is a nucleocytoplasmic shuttling protein. J Biol Chem 284:2266-74
Legan, Susan K; Rebrin, Igor; Mockett, Robin J et al. (2008) Overexpression of glucose-6-phosphate dehydrogenase extends the life span of Drosophila melanogaster. J Biol Chem 283:32492-9
Toroser, Dikran; Yarian, Connie S; Orr, William C et al. (2006) Mechanisms of gamma-glutamylcysteine ligase regulation. Biochim Biophys Acta 1760:233-44
Orr, William C; Radyuk, Svetlana N; Prabhudesai, Leena et al. (2005) Overexpression of glutamate-cysteine ligase extends life span in Drosophila melanogaster. J Biol Chem 280:37331-8
Rebrin, Igor; Bayne, Anne-Cecile V; Mockett, Robin J et al. (2004) Free aminothiols, glutathione redox state and protein mixed disulphides in aging Drosophila melanogaster. Biochem J 382:131-6

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