Apoptosis-modulating effect of prostaglandin E2 in coelomocytes of holothurian Eupentacta fraudatrix depends on the cell antioxidant enzyme status

The effects of prostaglandin PGE₂ on apoptosis and antioxidant enzyme activities were studied in two coelomocyte fractions of holothurian Eupentacta fraudatrix in vitro and in vivo. PGE₂ (10^?8–10^?6M) modulated apoptosis in a time-and concentration-dependent manner in both fractions studied in vitro. In vivo, PGE₂ induced apoptosis at concentrations of 0.1–1 μg/g in the fraction enriched with morula-like cells. Phagocytes were more sensitive to the regulating effect of PGE₂. In this fraction, PGE₂ induced apoptosis at concentrations from 0.01 to 1 μg/g, while PGE₂ at 10 μg/g demonstrated an antiapoptotic effect. In all experiments, apoptosis development was accompanied by a disbalance of the antioxidant enzyme system, primarily, decreased catalase activity.