Heparin-binding proteins from boar seminal plasma affecting the release of prostaglandins and interleukin-6 by porcine endometrial and cervical cells and bovine endometrial cells

The objectives of this study were to explore whether heparin-binding proteins, separated by fast protein liquid chromatography from boar seminal plasma influence the release of pros- taglandins F2α, (PGF2α), E2 (PGE2) and interleu- kin-6 (IL-6) by porcine endometrial and cervical cells and even bovine endometrial cells. In Ex- periment I, we showed that release of PGF2α by endometrial epithelial, endometrial stromal and cervical stromal cells to the medium was inhi- bited (p < 0.05) to 9.0% - 60.6% after 24 h incu- bation with 125 μg of heparin-binding proteins. Tumor necrosis factor α (TNFα) stimulated re- lease of IL-6 by endometrial and cervical stromal cells after 24 h incubation, but in the presence of heparin-binding proteins, this stimulation was attenuated. Release of PGF2α by cryopreserved (Experiment II) and primary (Experiment III) cer- vical stromal cells was significantly inhibited after 3 h incubation with 66 - 95.4 μg of heparin- binding proteins. A significant inhibition of PGE2 release by cryopreserved and primary cervical stromal cells was already achieved after incuba-tion with 16.5 - 23.9 μg of heparin-binding pro-teins. The release of IL-6 by cryopreserved cells was stimulated after 3 h incubation with heparin- binding proteins in a dose dependent manner in contrast to the release of IL-6 by freshly isolated cervical stromal cells. We also found (Experi-ment IV) that porcine heparin-binding seminal plasma proteins inhibited release of PGF2α and stimulated release of IL-6 by bovine endometrial epithelial cells. In conclusion, a group of hepa- rin-binding proteins separated by fast protein liquid chromatography from boar seminal plas- ma inhibit PGF2α, PGE2 and stimulate IL-6 re-lease by porcine endometrial and cervical cells, and even by bovine endometrial cells. Thus, these proteins have a similar effect as the entire seminal plasma.