Interferon-τ Modulates Phorbol Ester-Induced Production of Prostaglandin and Expression of Cyclooxygenase-2 and Phospholipase-A2 from Bovine Endometrial Cells1

Antiluteolytic actions of bovine interferon-tau (bIFN-tau) require suppression of prostaglandin F(2 alpha) (PGF(2 alpha)) production. Our objective was to test whether bIFN-tau could block PGF(2 alpha) production and synthesis of phospholipase A(2) (PLA(2)) and cyclooxygenase-2 (COX-2) enzymes induced by a protein kinase C (PKC) stimulator (phorbol 12,13 dibutyrate; PDBu). Bovine endometrial epithelial (BEND) cells were treated with PDBu in the presence or absence of bIFN-tau. Medium samples were analyzed for concentrations of PGF(2 alpha), whole-cell extracts were analyzed for abundance of PLA(2) and COX-2 by immunoblotting, and RNA extracts were examined for steady-state levels of COX-2 mRNA by Northern blotting. The PDBu stimulated production of PGF(2 alpha) between 3 and 12 h, levels of COX-2 mRNA by 3 h and protein expression of COX-2 and PLA(2) by 6 and 12 h, respectively. Added concomitantly with PDBu, bIFN-tau suppressed PGF(2 alpha) production, steady-state levels of COX-2 mRNA, and expression of COX-2 and PLA(2) proteins. Added after a 3-h stimulation with PDBu alone, bIFN-tau suppressed PGF(2 alpha) production after 1 h. Bovine IFN-tau inhibited intracellular mechanisms responsible for PGF(2 alpha) production in BEND cells, and this could be through both cytosolic and nuclear actions.