Increase of c- jun mRNA upon hypo-osmotic cell swelling of rat hepatoma cells

Abstract

c- jun mRNA levels were increased in rat hepatoma cells (H4-II-E-C3) when exposed to hypotonie medium (205 mosmol l ) with a maximal induction observed after 1 h of hypotonie exposure. At this time point an approximate 5-fold increase in c- jun expression could be detected in relation to nonnotonic control incubations (305 mosmol l ). Hypertonic exposure (405 mosmol/1) had only a slight effect on c- jun expression. In contrast to the increased c- jun mRNA levels under hypotonic conditions, expression of the c- fos proto-oncogene was unaffected by changes in the osmolarity. The hypotonicity-induced increase in c- jun expression was also detectable in the presence of a protein kinase C (PKC) inhibitor. This indicates that PKC is not involved in the signal transduction pathway leading to c- jun expression upon hypotonic cell swelling in these cells.