Norepinephrine induces MAIL mRNA expression in primary cultured hepatocytes through IL-1β released from non-parenchymal cells

The molecule possessing ankyrin-repeats induced by lipopolysaccharide (MAIL) protein is a novel member of the Ikappaβ family. In the present study, we examined the effect of norepinephrine NE) on MAIL mRNA expression in primary cultured mouse hepatocytes and non-parenchymal liver cells. MAIL mRNA expression in hepatocytes and non-parenchymal liver cells was not directly influenced by NE. However, MAIL mRNA expression in hepatocytes was significantly induced by incubation with a culture medium of non-parenchymal liver cells, treated with NE. Pretreatment with an interleukin (IL)-1 receptor antagonist significantly attenuated the stimulatory effect of the medium. Moreover, exogenous IL-1β induced MAIL mRNA expression in hepatocytes, while IL-6 and tumor necrosis factor α did not. The concentration of IL-1β in the medium of non-parenchymal liver cells was significantly increased after NE-treatment. These results suggest that NE can induce MAIL mRNA expression in hepatocytes through IL-1β, released from non-parenchymal liver cells.