Long exposure to high glucose concentration impairs the responsive expression of gamma-glutamylcysteine synthetase by interleukin-1beta and tumor necrosis factor-alpha in mouse endothelial cells.
To elucidate the pathological metabolism of glutathione synthesis in diabetic endothelial cells, we studied the expression of gamma-glutamylcysteine synthetase (gamma-GCS) using a mouse vascular endothelial cell line. Exposing normoglycemic endothelial cells to tumor necrosis factor-alpha (TNF-alpha) or interleukin-1beta (IL-1beta) increased the activity and the mRNA expression of gamma-GCS. The addition of inhibitors for nuclear factor kappaB (NF-kappaB) to the cells caused a loss of the gamma-GCS mRNA expression in response to TNF-alpha. A shift of the concentration of glucose in the medium from 5.5 to 28 mM glucose and a following incubation for 7 days decreased the expression of gamma-GCS mRNA. These cells showed no apparent responses of gamma-GCS mRNA or the activity of NF-kappaB to TNF-alpha or IL-beta. Increase in the GSH concentration of the cells treated with 28 mM glucose restored the expression of gamma-GCS mRNA and its response to TNF-alpha or IL-beta, suggesting that redox regulation is involved in the expression of gamma-GCS. In summary, the expression of gamma-GCS is regulated by TNF-alpha or IL-1beta in endothelial cells mediated by NF-kappaB stimulation, and impairment of the regulation of gamma-GCS in hyperglycemic cells may be a cause of medical complications that develop in diabetes mellitus.
Urata
Y
Y
Department of Pathological Biochemistry, Nagasaki University School of Medicine, Nagasaki 852, Japan.
Yamamoto
H
H
Goto
S
S
Tsushima
H
H
Akazawa
S
S
Yamashita
S
S
Nagataki
S
S
Kondo
T
T
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D003920:Diabetes Mellitus / Q000378:metabolism; D004730:Endothelium, Vascular / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D005947:Glucose / Q000494:pharmacology*; D005721:Glutamate-Cysteine Ligase / Q000096:biosynthesis*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006390:Hemangioendothelioma; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008099:Liver / Q000201:enzymology; D051379:Mice; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000037:antagonists & inhibitors; D015345:Oligonucleotide Probes; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D011480:Protease Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D013482:Superoxide Dismutase / Q000378:metabolism; D013964:Thyroid Neoplasms; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects*; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007375:Interleukin-1; D016328:NF-kappa B; D015345:Oligonucleotide Probes; D016376:Oligonucleotides, Antisense; D011480:Protease Inhibitors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D000255:Adenosine Triphosphate; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005982:Glutathione Transferase; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione; D005947:Glucose