Hepatocyte isolation stimulates formation of interferon stimulatory response element DNA-protein complexes

We have examined the relationship between intracellular signalling pathways and loss of differentiated function during hepatocyte isolation and cultur e. We have shown that isolation induces the activation of the interferon st imulatory response element (ISRE). This activation was transient and peaked at 3 h before it returned to basal by 24 h of culture. Interferon regulato ry factor-1 (IRF-1) was shown to be important for generation of ISRE comple xes by electromobility shift assays and supershift intervention. IRF-1 was translocated to the nucleus in parallel with changes to ISRE complex format ion. The p38 kinase inhibitor, SE 203580, diminished the formation of ISRE binding complexes. Hence p38 kinase may be involved in the activation and b inding of IRF-1 or related proteins to the ISRE motif. Changes in ISRE acti vation levels in cultured hepatocytes may have important implications in pr imary hepatocyte differentiation and loss of function. (C) 1999 Academic Pr ess.