Roles of reactive oxygen species, NF-kappaB, and peroxiredoxins in glycochenodeoxycholic acid-induced rat hepatocytes death.
The aim of this study was to determine the roles of reactive oxygen species (ROS), NF-kappaB and antioxidants in glycochenodeoxycholic acid (GCDC, 0-400 micromol/l, 0.5- 3 h)-induced hepatocytes death. The differential uptake of ethidium bromide and acridine orange revealed that apoptotic death occurred dose-dependently in GCDC-treated hepatocytes whereas necrotic death was prominent especially at higher GCDC concentrations (> or =200 micromol/l). ROS generation measured fluorometrically either by a confocal laser microscope or by a microplate fluorescence reader was increased dose-dependently. The dose-dependent NF-kappaB activation with the significant IkappaB-alpha decrease preceded both hepatocyte cell death and the alteration of antioxidant enzymes. The Cu/Zn-SOD level among several antioxidants, we checked, remained unchanged. In contrast, the catalase level and its enzymatic activity were markedly decreased only at 400 micromol/l. The Prx I and Prx II, newly defined antioxidant enzymes reducing H(2)O(2) levels were decreased at the 200 and 400 micromol/l. These observations point to ROS generation in the GCDC-treated hepatocyte as the proximate event that triggers NF-kappaB activation, IkappaB-alpha proteolysis, Prx depletion, and finally cell death. And oxidative stress may be more related to necrotic cell death in GCDC-treated hepatocytes.
Chu
Sang Hui
SH
Department of Pharmacology, College of Medicine, Ewha Womans University, Seoul, Korea.
Lee-Kang
Jihee
J
Lee
Kweon-Haeng
KH
Lee
Kyungeun
K
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001647:Bile Acids and Salts / Q000009:adverse effects*; D002374:Catalase / Q000378:metabolism; D002478:Cells, Cultured; D005999:Glycochenodeoxycholic Acid / Q000633:toxicity*; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000378:metabolism; D008297:Male; D016328:NF-kappa B / Q000502:physiology*; D010544:Peroxidases / Q000502:physiology*; D054464:Peroxiredoxins; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*
D001647:Bile Acids and Salts; D018398:Homeodomain Proteins; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D005999:Glycochenodeoxycholic Acid; D010544:Peroxidases; D054464:Peroxiredoxins; D002374:Catalase