Expression of mRNAs for interleukin-4, interleukin-6 and their receptors in porcine corpus luteum during the estrous cycle

• Published in: Domestic animal endocrinology 2006-10, Vol.31 (3), p.246-257
• Main Authors: Sakumoto, Ryosuke, Komatsu, Tokushi, Kasuya, Etsuko, Saito, Toshiyuki, Okuda, Kiyoshi
• Format: Article
• Language: English
• Subjects: Animals; Cells, Cultured; Corpus luteum; Corpus Luteum - physiology; Cytokine; cytokines; Dinoprost - secretion; estradiol; Estradiol - secretion; estrous cycle; Estrous Cycle - physiology; Female; hormone secretion; interleukin receptors; interleukin-4; Interleukin-4 - biosynthesis; Interleukin-4 - genetics; Interleukin-4 - pharmacology; interleukin-6; Interleukin-6 - biosynthesis; Interleukin-6 - genetics; Interleukin-6 - pharmacology; luteal cells; Luteal Cells - drug effects; Luteal Cells - secretion; messenger RNA; Pig; progesterone; Progesterone - analysis; Progesterone - immunology; prostaglandins; Real-time PCR; Receptor; receptors; Receptors, Interleukin-4 - biosynthesis; Receptors, Interleukin-4 - genetics; Receptors, Interleukin-6 - biosynthesis; Receptors, Interleukin-6 - genetics; Reverse Transcriptase Polymerase Chain Reaction - veterinary; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; steroidogenesis; swine; Swine - physiology
• ISSN: 0739-7240; 1879-0054
• DOI: 10.1016/j.domaniend.2005.11.001

There is increasing evidence that inflammatory cytokines regulate corpus luteum (CL) function in many species. The purpose of the present study was to determine whether interleukin (IL)-4 and IL-6 are expressed in the porcine CL, and whether these cytokines influence porcine luteal steroidogenesis. The gene expressions of IL-4, IL-6 and their specific receptors were determined in the CL of Chinese Meishan pigs during the estrous cycle. Moreover, the effects of these cytokines on progesterone (P 4), estradiol-17β (E 2) and prostaglandin (PG) F2α secretion by cultured luteal cells were investigated. IL-4 and IL-6 mRNAs were detected in the CL at all luteal stages. Furthermore, mRNAs of the receptors for IL-4 and IL-6 were clearly expressed in the CL throughout the estrous cycle. Real-time PCR analysis revealed that IL-6 receptor (IL-6R) mRNA expression was higher in the regressed CL (days 19–21 after ovulation) than in the CL at other stages ( P < 0.01). Exposure of cultured luteal cells obtained from mid-stage CL (days 8–11) to IL-6 (1–100 ng/ml), it inhibited P 4 and E 2 secretion by the cells ( P < 0.05). Although IL-4 (1–100 ng/ml) did not significantly alter P 4 secretion, it inhibited E 2 secretion by the cells ( P < 0.05). Neither IL-4 nor IL-6 had any effect on PGF2α secretion by the cells. These results suggest that IL-4 and IL-6 are locally produced in the porcine CL, and that they inhibit steroid production from luteal cells via their specific receptors. Collectively, both IL-4 and IL-6 may play roles in regulating porcine CL function throughout the estrous cycle.