Mechanisms of Liver Injury. I. TNF-alpha-induced liver injury: role of IKK, JNK, and ROS pathways.
TNF-alpha activates several intracellular pathways to regulate inflammation, cell death, and proliferation. In the liver, TNF-alpha is not only a mediator of hepatotoxicity but also contributes to the restoration of functional liver mass by driving hepatocyte proliferation and liver regeneration. This review summarizes recent advances in TNF-alpha signaling mechanisms that demonstrate how the IKK, ROS, and JNK pathways interact with each other to regulate hepatocyte apoptosis and proliferation. Activation of these pathways is causatively linked to liver injury induced by concanavalin A, TNF-alpha, and ischemia-reperfusion and to liver regeneration and hepatocarcinogenesis. In light of recent findings, pharmacological inhibitors of JNK and IKK and antioxidants may be promising new tools for the treatment of hepatitis, ischemia-reperfusion injury, and hepatocellular carcinoma.
Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA. rfs2102@columbia.edu
Robert F
RF
Schwabe
David A
DA
Brenner
D000818:Animals; D006801:Humans; D051550:I-kappa B Kinase / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000293:injuries / Q000378:metabolism*; D048670:MAP Kinase Kinase 4 / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015427:Reperfusion Injury / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D051550:I-kappa B Kinase; D048670:MAP Kinase Kinase 4