Identification of superoxide dismutase as a potential urinary marker of carbon tetrachloride-induced hepatic toxicity.
The aim of this study was the identification of a novel protein marker of hepatotoxicity in rat urine. Rats were dosed by gavage with carbon tetrachloride (CCl(4)) to induce acute liver injury. Surface enhanced laser desorption/ionisation (SELDI) ProteinChip technology revealed the appearance of a 15.7 kDa protein in the CCl(4)-treated rat urine. One-dimensional sodium dodecyl sulphate polyacrylamide electrophoresis (SDS-PAGE) identified an 18.4 kDa protein in the CCl(4)-treated rat urine. The appearance of either protein was coincident over a time course during which they first appeared at 12h post-dosing, peaked at 36h and had disappeared again within 3 days post-dosing. The protein was identified by in-gel digestion and nano-electrospray (nano-ES)-tandem mass spectrometry as Cu/Zn superoxide dismutase (SOD-1). SOD activity was found to be increased by 61.4-fold in CCl(4)-treated rat urine. Western blots of tissue homogenates from the rats revealed a time-dependent loss of SOD-1 from the livers of CCl(4)-treated rats matching the time course of SOD-1 appearance in urine. SOD-1 is not specifically located in liver; however, its appearance in urine in response to acute CCl(4)-induced hepatotoxicity is a novel finding; this coupled with loss from the liver following injury suggests urinary SOD-1 may be a potential marker of hepatotoxicity.
Smyth
R
R
Department of Pharmaceutical and Biological Chemistry, The School of Pharmacy, University of London, London WC1N 1AX, UK. rosemary.smyth@pharmacy.ac.uk
Turton
J A
JA
Clarke
C J
CJ
York
M J
MJ
Dare
T O
TO
Lane
C S
CS
Munday
M R
MR
D000595:Amino Acid Sequence; D000818:Animals; D015415:Biomarkers / Q000652:urine; D015153:Blotting, Western; D002252:Carbon Tetrachloride Poisoning / Q000473:pathology / Q000652:urine*; D056486:Chemical and Drug Induced Liver Injury / Q000473:pathology / Q000652:urine*; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007668:Kidney / Q000473:pathology; D008099:Liver / Q000473:pathology; D008111:Liver Function Tests; D008969:Molecular Sequence Data; D009929:Organ Size; D011507:Proteinuria / Q000652:urine; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000652:urine*; D053719:Tandem Mass Spectrometry
D015415:Biomarkers; D013482:Superoxide Dismutase