Induction and nuclear translocation of thioredoxin by oxidative damage in the mouse kidney: independence of tubular necrosis and sulfhydryl depletion.
Adult T-cell leukemia-derived factor (ADF), originally defined as an interleukin-2 receptor inducer, is a human thioredoxin (TRX). ADF/TRX is a conserved multifunctional reductant presumably associated with redox regulation of the cellular environment; it works in vitro as a cytokine, free radical scavenger, activator of transcription factors, and substrate for several enzymes. In the present series of experiments, we studied the expression and intracellular localization of ADF/TRX in mouse kidney from two different renal tubular injury models: a free radical-associated model with ferric nitrilotriacetate (Fe-NTA) and a free radical-independent model with HgCl2. Markers of oxidative damage, such as 8-hydroxy-2'-deoxyguanosine, thiobarbituric acid-reactive substances, and 4-hydroxy-2-nonenal-modified proteins, were significantly increased in kidney from male C57B/6 mice 1 hour after a single intraperitoneal injection of Fe-NTA (5 mg iron/kg). However, in kidney from mice given a subcutaneous injection of HgCl2 (5 mg Hg/kg), none of these markers were increased, despite tubular necrosis with sulfhydryl depletion. In the Fe-NTA model only, Northern and Western blot analyses of the kidney revealed induction of ADF/TRX (> 2.5-fold) after 16 hours and translocation of ADF/TRX from the cytoplasmic to nuclear fraction (> 3.5-fold) after 24 hours. Immunohistochemistry showed a patchy distribution of ADF/TRX in the normal renal proximal tubules. In ex vivo experiments using serial normal kidney frozen sections, it was found that renal proximal tubules with low expression of ADF/TRX were more vulnerable to oxidative stress mediated by Fe-NTA. Collectively, these data suggest that: (a) ADF/TRX is induced and translocated to nuclei by oxidative damage mediated by Fe-NTA in the renal proximal tubules; (b) induction of ADF/TRX is independent of tubular necrosis or sulfhydryl depletion; and (c) ADF/TRX is involved in the cellular defense mechanisms in vivo against oxidative damage.
Tanaka
T
T
Department of Pathology and Biology of Diseases, Graduate School of Medicine, Kyoto University, Japan.
Nishiyama
Y
Y
Okada
K
K
Hirota
K
K
Matsui
M
M
Yodoi
J
J
Hiai
H
H
Toyokuni
S
S
D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism*; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D005290:Ferric Compounds / Q000633:toxicity; D007150:Immunohistochemistry; D007684:Kidney Tubules / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D015227:Lipid Peroxidation; D008297:Male; D008627:Mercuric Chloride / Q000633:toxicity; D051379:Mice; D008810:Mice, Inbred C57BL; D009336:Necrosis; D009363:Neoplasm Proteins / Q000378:metabolism*; D009571:Nitrilotriacetic Acid / Q000031:analogs & derivatives / Q000633:toxicity; D018384:Oxidative Stress; D013438:Sulfhydryl Compounds / Q000032:analysis*; D013879:Thioredoxins / Q000378:metabolism*
D016207:Cytokines; D005290:Ferric Compounds; D009363:Neoplasm Proteins; D013438:Sulfhydryl Compounds; C055533:adult T cell leukemia-derived factor; D013879:Thioredoxins; D008627:Mercuric Chloride; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine; D009571:Nitrilotriacetic Acid; C020326:ferric nitrilotriacetate