Oxygen metabolism release toxic products called free radicals which are implicated in many human diseases including autoimmune, ischemia/stroke, drug/toxin damage, atherosclerosis, arthritis, diabetes, ALS, aging, and cancer. Protection against free radical damage is provided by antioxidant enzymes including GSH-dependent enzymes. The cytosolic selenium-dependent glutathione peroxidase (GPXl) is one of the most important GSH-dependent protective enzymes. While detailed biochemical studies on GPXl regulation have been accomplished, little is known of regulatory control at a molecular level, notably in regard to induction of GPXl during stress. This proposal will investigate the regulation of GPXl by characterizing novel negative and positive regulatory elements in the flanking 5-nontranslated (5'NTR) or promoter region of the gene. Studies include DNA footprinting, nucleotide mutagenesis, and serial nucleotide deletion from 5'NTR GPXl/reporter chimeric constructs to identify nucleotides comprising the elements. The DNA-binding protein to the major oxidant-responsive element (ORE3) will be isolated. A novel element ORE4 is identified in the 5'UTR of GPX1 that may repress GPXl mRNA translation until oxidative stress occurs, similar to the iron-responsive element (IRE) in ferritin. Studies will determine the functional role of this element and its corresponding binding protein (ORE4-BP (previously isolated). The elements responsible for basal or core GPXl expression, as well as tissue-specific elements responsible for the unusual tissue expression of GPXl, will be identified. The mouse GPXl gene will be characterized to allow comparison to human GPXl in regards to basal, oxidative-responsive, and tissue-specific elements. These studies will provide critical information regarding cellular response to oxidative stress and aid in determining if a common regulatory mechanism exists for GSH-dependent enzymes.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
5R01ES004989-08
Application #
6125051
Study Section
Special Emphasis Panel (ZRG4-ALTX-1 (01))
Program Officer
Packenham, Joan P
Project Start
1997-12-01
Project End
2002-11-30
Budget Start
1999-12-01
Budget End
2000-11-30
Support Year
8
Fiscal Year
2000
Total Cost
$244,439
Indirect Cost
Name
University of California San Diego
Department
Pathology
Type
Schools of Medicine
DUNS #
077758407
City
La Jolla
State
CA
Country
United States
Zip Code
92093
Estonius, M; Forsberg, L; Danielsson, O et al. (1999) Distribution of microsomal glutathione transferase 1 in mammalian tissues. A predominant alternate first exon in human tissues. Eur J Biochem 260:409-13
de Haan, J B; Bladier, C; Griffiths, P et al. (1998) Mice with a homozygous null mutation for the most abundant glutathione peroxidase, Gpx1, show increased susceptibility to the oxidative stress-inducing agents paraquat and hydrogen peroxide. J Biol Chem 273:22528-36
de Haan, J B; Wolvetang, E J; Cristiano, F et al. (1997) Reactive oxygen species and their contribution to pathology in Down syndrome. Adv Pharmacol 38:379-402
Kelner, M J; Estes, L; Rutherford, M et al. (1997) Heterologous expression of carbonyl reductase: demonstration of prostaglandin 9-ketoreductase activity and paraquat resistance. Life Sci 61:2317-22
de Haan, J B; Cristiano, F; Iannello, R et al. (1996) Elevation in the ratio of Cu/Zn-superoxide dismutase to glutathione peroxidase activity induces features of cellular senescence and this effect is mediated by hydrogen peroxide. Hum Mol Genet 5:283-92
Kelner, M J; Stokely, M N; Stovall, N E et al. (1996) Structural organization of the human microsomal glutathione S-transferase gene (GST12). Genomics 36:100-3
Kelner, M J; Uglik, S F (1995) Superoxide dismutase abolishes the platelet-derived growth factor-induced release of prostaglandin E2 by blocking induction of nitric oxide synthase: role of superoxide. Arch Biochem Biophys 322:31-8
Kelner, M J; Bagnell, R D; Uglik, S F et al. (1995) Heterologous expression of selenium-dependent glutathione peroxidase affords cellular resistance to paraquat. Arch Biochem Biophys 323:40-6
Kelner, M J; Bagnell, R; Montoya, M et al. (1995) Transfection with human copper-zinc superoxide dismutase induces bidirectional alterations in other antioxidant enzymes, proteins, growth factor response, and paraquat resistance. Free Radic Biol Med 18:497-506
Kelner, M J; Uglik, S F (1994) Mechanism of prostaglandin E2 release and increase in PGH2/PGE2 isomerase activity by PDGF: involvement of nitric oxide. Arch Biochem Biophys 312:240-3

Showing the most recent 10 out of 12 publications