Interleukin-6 sustains hepatic regeneration in cirrhotic rat.

BACKGROUND/AIMS: In the liver IL-6 displays growth-inducing and pro-survival activities. We studied the pro-proliferative and protective mechanisms of IL-6 treatment in a model of liver cirrhosis in wild type rat, investigating the theoretical basis for a potential pharmacologic role of IL-6 in cirrhosis. METHODOLOGY: We analyzed IL-6 receptors levels in cirrhotic liver. We also studied the activation of signaling pathways downstream IL-6 receptors by analyzing the DNA-binding activity of transcription factors STAT3, AP-1, HNF-1 and NF-kappaB and the phosphorylation status of AKT and eNOS. We also analyzed hepato-cell proliferation, by determining BrdU incorporation into DNA, and liver mass expansion. RESULTS: We show that liver cells from cirrhotic animals have ncreased expression of the IL-6 receptor alpha/gp80. In addition, we show that in cirrhosis the main molecular pathways downstream the receptors are intact and that IL-6 activates STAT3, AP-1 and NF-kappaB transcription factors, induces AKT and eNOS phosphorylation and increases hepato-cell proliferation and liver mass expansion in a dose-dependent manner. CONCLUSIONS: Our data demonstrate that the theoretical basis exists for the therapeutic employment of IL-6 in liver cirrhosis.