title: Expression of mRNAs for interleukin-4, interleukin-6 and their receptors in porcine corpus luteum during the estrous cycle.
abstract: 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-17beta (E(2)) and prostaglandin (PG) F2alpha 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 PGF2alpha 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.
authors.affiliation: Department of Physiology and Genetic Regulation, National Institute of Agrobiological Sciences, Ibaraki 305-8602, Japan. sakumoto@affrc.go.jp <sakumoto@affrc.go.jp>
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Sakumoto
authors.forename: Tokushi
authors.initials: T
authors.lastname: Komatsu
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kasuya
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Saito
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Okuda
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000502:physiology*; D015237:Dinoprost / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D030762:Estrous Cycle / Q000502:physiology*; D005260:Female; D015847:Interleukin-4 / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D008184:Luteal Cells / Q000187:drug effects / Q000378:metabolism; D011374:Progesterone / Q000032:analysis / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D019948:Receptors, Interleukin-4 / Q000096:biosynthesis / Q000235:genetics*; D019947:Receptors, Interleukin-6 / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D013552:Swine / Q000502:physiology*
chemical_list: D015850:Interleukin-6; D012333:RNA, Messenger; D019948:Receptors, Interleukin-4; D019947:Receptors, Interleukin-6; D015847:Interleukin-4; D011374:Progesterone; D004958:Estradiol; D015237:Dinoprost