Rapid induction of mRNA for Tec genes by hepatopoietin and partial hepatectomy

Abstract

OBJECTIVE: To investigate how hepatopoietin (HPO) and partial hepatectomy induce the expression of immediate early genes.METHODS: mRNA expression related to liver regenera­tion was investigated within 1 h after a two‐thirds partial hepatectomy by representational difference analysis and with the addition of HPO in a primary cultured hepatocyte system by reverse transcription polymerase chain reaction.RESULTS: In the expressed sequence tag library, most of the genes identified were immediate early genes, and one Tec gene that might be associated with liver regeneration was found. Moreover, the Tec gene was rapidly induced after partial hepatectomy, with peak expression (7−10‐fold) within 1−2 h after the operation as identified by northern blotting. Hepato­poietin was able to rapidly induce the expression of immediate early genes (e.g. c‐fos, LRF‐1, Tec) in primary cultured rat hepatocytes. The c‐fos and LRF‐1 mRNA were also known to be induced during the early hours of liver regeneration, and increased after treatment of isolated hepatocytes with HPO. Addition of HPO resulted in rapid and transient induction of Tec mRNA with a peak at 0.5−2 h (3−5‐fold), which might be one of the molecular mechanisms of the effect of HPO on the stimulation of hepatocyte proliferation.CONCLUSION: Hepatopoietin and partial hepa­tectomy can rapidly induce the expression of the immediate early genes. Our results suggest that the Tec gene is an immediate early gene related to liver regeneration.