Conjugated Linoleic Acid Reduces Phorbol Ester-Induced Prostaglandin F_2α Production by Bovine Endometrial Cells¹

Abstract 

Recent interest in conjugated linoleic acid (CLA) research stems from the well-documented anticarcinogenic, antiatherogenic, antidiabetic, and antiobesity properties of CLA in animal models. The objective of this study was to examine the effects of 2 CLA isomers (cis-9,trans-11 and trans-10,cis-12) on phorbol 12,13-dibutyrate (PDBu)-induced PGF_2α production in cultured bovine endometrial (BEND) cells. Confluent BEND cells were incubated in the absence (control) or presence of 100μM each of linoleic acid, cis-9,trans-11 CLA, or trans-10,cis-12 CLA for 24h. After incubation, cells were rinsed and then stimulated with PDBu (100 ng/mL) for 6h. Compared with untreated cells, PDBu stimulated PGF_2α secretion (+25-fold) within 6h. The increases in PGF_2α secretion were paralleled by signifi-cant induction of prostaglandin endoperoxide synthase-2 (PGHS-2) mRNA (+63-fold) and protein (+1.6-fold) expression. In spite of stimulatory effects on PGHS-2 and peroxisome proliferator-activated receptor δ (PPARδ) mRNA responses, CLA greatly decreased PGF_2α production by PDBu-stimulated BEND cells. There was no evidence for PDBu or CLA modulation of PPARδ protein synthesis in cultured BEND cells. Results indicated that CLA modulation of PGF_2α production by BEND cells was not mediated through PGHS-2 or PPARδ gene repression.

Key words: conjugated linoleic acid, uterus, prostaglandin F_2α, cow