RNA was extracted from human gestational membranes and villous placental tissue following spontaneous delivery (n=15) or elective caesarean section (n=15) at term. The samples were subjected to Northern analysis, using a 2 kb cDNA probe for peroxisome proliferator activated receptor (PPAR)-gamma. The mRNA was detectable in all choriodecidual and villous placental samples, irrespective of mode of delivery, but was only rarely detectable in the amnion. The JEG3 choriocarcinoma cell line also expressed PPAR gamma. In order to evaluate PPAR mediated transcriptional activation in JEG3 cells, the cells were transfected with pTK-PPREx3-luc, a PPAR response element (PPRE) containing luciferase reporter construct. Subsequent treatment with 10 mu M 15-deoxy-Delta(12,14)prostaglandin J(2) (15dPGJ(2)) resulted in an eight-fold stimulation of luciferase production relative to controls transfected with the same construct lacking the PPRE. This stimulation was concentration-dependent. These results suggest roles for PPAR gamma and its ligand in lipid, steroid and inflammatory mediator homeostasis and in remodelling of gestational tissues. (C) 2000 Harcourt Publishers Ltd.