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 culture. We have shown that isolation induces the activation of the interferon stimulatory response element (ISRE). This activation was transient and peaked at 3 h before it returned to basal by 24 h of culture. Interferon regulatory factor-1 (IRF-1) was shown to be important for generation of ISRE complexes by electromobility shift assays and supershift intervention. IRF-1 was translocated to the nucleus in parallel with changes to ISRE complex formation. The p38 kinase inhibitor, SB 203580, diminished the formation of ISRE binding complexes. Hence p38 kinase may be involved in the activation and binding of IRF-1 or related proteins to the ISRE motif. Changes in ISRE activation levels in cultured hepatocytes may have important implications in primary hepatocyte differentiation and loss of function.