Phospholipase A2 activation and increases in specific prostaglandins in the oxidatively stressed 14CoS/14CoS mouse hepatocyte line.

ABSTRACT

This laboratory has previously shown that increases in the expression of several genes in SV40-transformed hepatocyte cultures derived from the untreated newborn c14CoS/c14CoS mouse, and in newborn mouse liver--when compared with the cch/cch wild-type--are associated with enhanced levels of reactive oxygenated metabolites (ROMs) and reduced glutathione (GSH). We show here that, in contrast to the ch/ch wild-type levels, the oxidatively stressed 14CoS/14CoS liver cell line displays 2- to 5-fold increases in 1) phospholipase A2 (PLA2) enzyme activity, 2) Ca2+ dependent Group II secreted PLA2 mRNA levels, 3) arachidonic acid release, and 4) arachidonic acid metabolites co-eluting with prostaglandins D2, E2, and F2 alpha. These findings suggest that the cyclooxygenase-2 (COX2) pathway, and possible involvement of the "inflammatory" and/or "acute phase response" signal transduction pathways, might be activated during the endogenous ROM-mediated oxidative stress response in 14CoS/14CoS cells.