Synergistic induction of apoptosis in primary rat decidual cells by INF-gamma and TNF.

In the rat, in response to blastocyst implantation, stromal cells of the endometrium proliferate and differentiate into decidual cells, forming the decidua. After reaching its maximum development, the decidua undergoes regression. This phenomenon appears to be due to an active process involving apoptosis. As there is sparse knowledge concerning the mechanisms of induction of decidual cell death, the potential role of cytokines present in the uterine environment during pregnancy, such as tumor necrosis factor (TNF) and interferon-gamma (INF-gamma) was explored in primary cultures of rat decidual cells. The effects of these factors upon cellular viability, nuclear morphologic alterations, expression, and enzymatic activities of the effector caspases-3/7 were evaluated. The results obtained demonstrated that in contrast to TNF, which did not induce any alteration, INF-gamma and in association with TNF caused a decrease in cell viability and an increase in the appearance of apoptotic bodies in a time-dependent manner that was augmented in the co-presence of TNF. An increase in caspase-3/7 activities after 12 hr of TNF/INF-gamma treatment was also observed. These findings suggest that INF-gamma expressed in the uterine environment may play an important role in regulating apoptosis through potential synergistic mechanisms with TNF and thereby modulate decidual stability and regression during pregnancy.