Mechanisms of liver injury. III. Role of glutathione redox status in liver injury.
GSH is the most abundant redox molecule in cells and thus the most important determinant of cellular redox status. Thiols in proteins can undergo a wide range of reversible redox modifications (e.g., S-glutathionylation, S-nitrosylation, and disulfide formation) during times of increased exposure to reactive oxygen and nitrogen species, which can affect protein activity. These reversible thiol modifications regulated by GSH may be nanoswitches to turn on and off proteins, similar to phosphorylation, in cells. In the cytoplasm, an altered redox state can activate (e.g., MAPKs and NF-E2-related factor-2) and inhibit (e.g., phosphatases and caspases) proteins, whereas in the nucleus, redox alterations can inhibit DNA binding of transcription factors (e.g., NF-kappaB and activator protein-1). The consequences include the promotion of expression of antioxidant genes and alterations of hepatocyte survival as well as the balance between necrotic versus apoptotic cell death. Therefore, the understanding of the redox regulation of proteins may have important clinical ramifications in understanding the pathogenesis of liver diseases.
Han
Derick
D
University of Southern California (USC) Research Center for Liver Diseases, USC-University of California-Los Angeles Research Center for Alcohol Liver and Pancreatic Diseases, Keck School of Medicine, USC, Los Angeles, CA 90089-9121, USA. derickh@usc.edu
Hanawa
Naoko
N
Saberi
Behnam
B
Kaplowitz
Neil
N
D000818:Animals; D056486:Chemical and Drug Induced Liver Injury; D016207:Cytokines / Q000276:immunology; D062787:Drug Overdose / Q000276:immunology; D005786:Gene Expression Regulation / Q000276:immunology; D005978:Glutathione / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D008099:Liver / Q000276:immunology*; D008107:Liver Diseases / Q000276:immunology*; D018448:Models, Immunological; D010084:Oxidation-Reduction; D010100:Oxygen / Q000276:immunology; D011041:Poisoning / Q000276:immunology; D017382:Reactive Oxygen Species / Q000276:immunology*
D016207:Cytokines; D017382:Reactive Oxygen Species; D005978:Glutathione; D010100:Oxygen