The Effect of Boar Seminal Plasma on the Release of Prostaglandins and Interleukin‐6 by Porcine Endometrial and Cervical Cells and Bovine Endometrial Cells

Abstract

Artificial insemination (AI) of sows results in a significant elevation of prostaglandin F(2α) metabolite (PGFM) levels in peripheral plasma, whereas in mated sows such elevation is not seen. The aim of this study was to investigate whether boar seminal plasma (SP) has any effect on the release of PGFM, prostaglandin F(2α) (PGF(2α) ), prostaglandin E(2) (PGE(2) ) or interleukin-6 (IL-6) by in vitro cultured porcine endometrial (epithelial - pUE and stromal - pUS), cervical (pCE and pCS) and bovine endometrial epithelial cells (bUE). This study shows that boar SP inhibits the release of PGFM, PGF(2α) and PGE(2) by porcine endometrial and cervical cells and bovine endometrial cells after 3 and 24 h incubation. Boar SP stimulated IL-6 release by pUE, pUS and even bUE after 3 h incubation. Tumour necrosis factor α (TNFα) stimulated the release of IL-6 by pUS only after 24 h incubation, but in the presence of boar SP, this stimulation was attenuated. The overall results from these in vitro studies give us possibility to understand the difference in prostaglandin response between mated and inseminated sows. Furthermore, we demonstrated that frozen-stored epithelial and stromal cells from pig endometrium, as well as from the cervix are suitable for studying the effect of SP on the release of prostaglandins. The only prerequisite is to incubate these thawed cells with arachidonic acid as a source for the synthesis of prostaglandins. A similar effect of boar SP on porcine and bUE cells may suggest inter-species reactivity.

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 potent biological activity of boar seminal plasma to inhibit the release of prostaglandins and to stimulate IL-6 release by porcine endometrial, cervical and bovine endometrial cells has been demonstrated previously [1]. It is well known that prostaglandins F 2α and E 2 , which are of endometrial origin, regulate a number of important physiological functions during the estrous cycle and pregnancy in pigs [2,3].…”

“…The cells were separated as described earlier [25][26][27][28] and recently modified by us [1]. Briefly, uterus and cervix were transported to the laboratory within 60 min after slaughter in ice-cold phosphate buffered saline (PBS), pH 7.4, saturated with O 2 :CO 2 (95%:5%) and supplemented with antibiotics.…”

“…Cryopreservation and thawing of separated cervical stromal cells from gilt no. g08 (pCS-80) was performed as described earlier in our work [1].…”

“…The practical limit of sensitivity for the assay analysing 0.1 ml of medium was approximately 10 pg⁄ml. Bovine IL-6 (bIL-6) was measured using the xMAP™ technology as applied by Dernfalk, et al [29] and modified by Madej, et al [1].…”

“…Our previous observations that AI resulted in an increase in the prostaglandin F 2 metabolite (PGFM) concentrations in sows, whereas in mated sows no such elevation in PGFM occurred [21][22][23] led us to the hypothesis that seminal plasma might be responsible for the inhibition of prostaglandins. To test our hypothesis we have done a series of experiments in vitro [1] and demonstrated that boar seminal plasma inhibit prostaglandins (PGFM, PGF 2α , PGE 2 ) release and stimulate IL-6 release by not only porcine endometrial and cervical cells but also by bovine endometrial cells. Thus, the aim of the present study was to investigate the effect of heparin-binding proteins separated by fast protein liquid chromatography (FPLC) from boar SP on the release of PGF 2α , PGE 2 and IL-6 from porcine endometrial and cervical cells and bovine endometrial cells.…”