Seminal plasma modulates expression of endometrial inflammatory meditators in the bovine†

Abstract

Seminal plasma has conventionally been viewed as a transport and survival medium for mammalian sperm; however, its role now extends beyond this process to actively targeting female tissues. Studies in rodents, swine, and humans demonstrate that seminal plasma induces molecular and cellular changes within the endometrium or cervix following insemination. Seminal-plasma-induced alterations to the maternal environment have been theorized to facilitate embryo development, modulate maternal immunity toward the conceptus, and potentially improve pregnancy success. It is unknown if bovine seminal plasma modulates the uterine environment following insemination in the cow, where routine use of artificial insemination reduces maternal exposure to seminal plasma. We hypothesize that seminal plasma modulates the expression of inflammatory mediators in the endometrium, altering the maternal environment of early pregnancy. In vitro, seminal plasma altered intact endometrial explant expression of CSF2, IL1B, IL6, IL17A, TGFB1, IFNE, PTGS2, and AKR1C4. Furthermore, endometrial epithelial cell CSF2, CXCL8, TGFB1, PTGS2, and AKR1C4 expression were increased after seminal plasma exposure, while endometrial stromal cell CSF2, IL1B, IL6, CXCL8, IL17A, TGFB1, PTGS2, and AKR1C4 expression were increased following seminal plasma exposure. Endometrial expression of IL1B was increased in the cow 24 h after uterine infusion of seminal plasma, while other evaluated inflammatory mediators remained unchanged. These data indicate that seminal plasma may induce changes in the bovine endometrium in a temporal manner. Understanding the role of seminal plasma in modulating the maternal environment may aid in improving pregnancy success in cattle.

Keywords: endometrial epithelium; endometrial stroma; endometrium; inflammation; insemination; seminal plasma.