gamma-Glutamyltranspeptidase-dependent metabolism of 4-hydroxynonenal-glutathione conjugate.
A major pathway for detoxification of the highly reactive lipid peroxidation product, 4-hydroxy-2,3-trans-nonenal (HNE) is through the conjugation with glutathione (GSH). We have studied the metabolism of GS-HNE conjugate by the enzyme gamma-glutamyltranspeptidase (GGT) using its purified form, as well as a GGT-overexpressing fibroblast cell line (V79 GGT). Using mass spectrometry analysis we identified for the first time cysteinylglycine-HNE (CysGly-HNE) as the GGT metabolite of GS-HNE. Furthermore, the GGT-dependent metabolism of GS-HNE in the V79 GGT cell line was associated with a considerable increase of cytotoxicity as compared to a control cell line which does not express GGT (V79 Cl). The cytotoxic effect was dose- and time-dependent (100% cellular death at 200 microM GS-HNE after 24 h incubation) in V79 GGT cells, whereas no decrease of viability was observed in V79 Cl cells. A similar cytotoxic effect was obtained when cells were incubated directly with CysGly-HNE, demonstrating that this GGT-dependent metabolite unlike GS-HNE, exhibits cytotoxic properties.
Enoiu
Milica
M
EA 3117, Faculty of Pharmacy, University Henri Poincaré Nancy 1, 54001 Nancy Cedex, France.
Herber
Régine
R
Wennig
Robert
R
Marson
Claude
C
Bodaud
Haline
H
Leroy
Pierre
P
Mitrea
Niculina
N
Siest
Gérard
G
Wellman
Maria
M
D000447:Aldehydes / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D002851:Chromatography, High Pressure Liquid; D004396:Coloring Agents / Q000494:pharmacology; D006224:Cricetinae; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000378:metabolism; D005978:Glutathione / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D013058:Mass Spectrometry; D008956:Models, Chemical; D011485:Protein Binding; D013053:Spectrophotometry; D013778:Tetrazolium Salts / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D013997:Time Factors; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
D000447:Aldehydes; D004396:Coloring Agents; D015853:Cysteine Proteinase Inhibitors; D013778:Tetrazolium Salts; D013844:Thiazoles; D005723:gamma-Glutamyltransferase; C022616:thiazolyl blue; D005978:Glutathione; C027576:4-hydroxy-2-nonenal