Role of reactive oxygen species in zinc deficiency-induced hepatic stellate cell activation.
We previously reported that zinc deficiency caused a reduction in intracellular glutathione at 8 h after the addition of zinc chelator, diethylenetriamine pentaacetic acid (DTPA), compared with control levels in rat hepatic stellate cells. In this study, we investigated the role of reactive oxygen species and glutathione on the mechanism of zinc deficiency-induced hepatic stellate cell activation, via assessing collagen synthesis. Isolated hepatic stellate cells were incubated with or without DTPA. Type I collagen expression in hepatic stellate cells was detected by immunohistochemistry, and then quantification of the intensity of type I collagen expression was analyzed using a computer with NIH image. Intracellular glutathione was measured using HPLC. H(2)O(2) release from hepatic stellate cells into the overlying medium was assayed using a fluorimetric method. H(2)O(2) release by DTPA-treated hepatic stellate cells significantly increased from 4 h, but returned to control levels after zinc supplementation. When catalase was added to the culture at 6 h after the addition of DTPA, the staining for type I collagen was as weak as at control levels. Diphenyliodonium chloride, the inhibitor of NADPH oxidase, produced a marked reduction in zinc deficiency-induced H(2)O(2) release. The results of this study show that the depletion of intracellular glutathione levels triggers a progression of collagen synthesis in zinc deficient-hepatic stellate cells and this depletion may be induced by the stimulation of cellular production of H(2)O(2).
Kojima-Yuasa
Akiko
A
Department of Food and Human Health Sciences, Graduate School of Human Life Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan. kojima@life.osaka-cu.ac.jp
Umeda
Kanako
K
Ohkita
Tomoko
T
Opare Kennedy
David
D
Nishiguchi
Shuhei
S
Matsui-Yuasa
Isao
I
D000818:Animals; D001713:Biphenyl Compounds / Q000494:pharmacology; D002374:Catalase / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000378:metabolism; D024042:Collagen Type I / Q000378:metabolism; D019587:Dietary Supplements; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007150:Immunohistochemistry; D007477:Ions; D008099:Liver / Q000166:cytology* / Q000378:metabolism; D008297:Male; D019255:NADPH Oxidases / Q000378:metabolism; D009861:Onium Compounds / Q000494:pharmacology; D004369:Pentetic Acid / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species; D013997:Time Factors; D015032:Zinc / Q000172:deficiency* / Q000378:metabolism
D001713:Biphenyl Compounds; D024042:Collagen Type I; D004791:Enzyme Inhibitors; D007477:Ions; D009861:Onium Compounds; D017382:Reactive Oxygen Species; C031291:diphenyliodonium; D004369:Pentetic Acid; D003094:Collagen; D006861:Hydrogen Peroxide; D002374:Catalase; D019255:NADPH Oxidases; D005978:Glutathione; D015032:Zinc