Prostaglandins (PGs) mediate insect immune responses. However, their biosynthesis in insects is little understood due to lack of cyclooxygenase (COX) ortholog. This study aimed to identify PG-biosynthetic factor(s) in Spodoptera exigua, which has been a well-known insect in possessing immune responses mediated via PGs. Peroxidases (POXs) are a sister group of COX genes. Ten putative POXs (POX-A ∼POX-J) were expressed in S. exigua. Especially, expressions of POX-F and POX-H were inducible to bacterial challenge and expressed in hemocytes and fat body. Individual RNA interference (RNAi) of each of ten POXs was performed by hemocoelic injection of their specific double-strnaded RNAs (dsRNAs). Only RNAi of POX-F or POX-H specifically suppressed hemocyte-spreading behavior and nodule formation. Addition of PGE2 significantly nescued the immunosuppression in either dsRNA treatment of POX-F or POX-H. Structural analysis indicated that both POX-F and POX-H have conserved domain and residues corresponding to peroxinectin of Drosophila melanogaster, which mimics COX-like activity. These results suggest that POX-E and POX-H are involved in PG biosynthesis in S. exigua.

The purpose of the present study was to investigate the effect of IFN- on prostaglandin synthesis, cyclooxygenase-2 (COX-2) gene expression in vitro and concentration of progesterone (P4) in endometrial cells. Epithelial and stromal cells cultured in vitro were isolated from bovine endometrium and stimulated with increasing doses of IFN- (0, 0.02, 0.2 and 2 ug/ml). Human chorionic gonadotropin (hCG, 1.5 IU/ml) was used as a positive control. Prostaglandin and levels in the culture media were analyzed by enzyme immunoassays and total RNA was extracted from the cells for RT-PCR. P4 concentrations of blood samples were assayed by chemiluminescent immuno assays system. In epithelial cells, COX-2 gene expression was increased in the presence of IFN- (p<0.05), but it was not significantly different in all groups of stromal cells except for 2 ug/ml IFN- group (p<0.05). Although IFN- did not affect and production in epithelial cells, it decreased and production significantly in stromal cells (p<0.05). In vivo experiment, blood concentration of P4 was significantly increased after addition of IFN- (1 ug/ml). The results indicate that PG production was mediated by COX-2 expression in stromal cells but it was not affected in epithelial cells and this suggest that treatment of IFN- could improve the implantation environment of uterine by maintenance of high P4 concentration.

In ruminants, Interferon-τ (IFN-τ) has the role of recognizing pregnancy signals produced by the embryo and it may have an important role during the luteolysis. Therefore, the purpose of the present study was to investigate the effect of IFN-τ on prostaglandin synthesis, cyclooxygenase-2 (COX-2) gene expression in vitro and secretion of progesterone (P4) in vivo. The epithelial and stromal cells isolated from bovine endometrium were cultured with different doses of IFN-τ (0, 0.02, 0.2 and 2 μg/ml). Human chorionic gonadotropin (hCG, 1.5 IU/ml) was used as a positive control. Prostaglandin E2 and F2α levels in the culture media were analyzed by enzyme immunoassays, and total RNA was extracted from the cells for RT-PCR. P4 concentrations in blood samples were assayed by chemiluminescent immunoassay system. In epithelial cells, COX-2 gene expression was increased in the presence of IFN-τ (p<0.05), but it was not significantly different in all groups of stromal cells except 2 μg/ml IFN-τ group (p<0.05). Although IFN-τ did not affect PGE2 and PGF2α production in epithelial cells, it decreased PGE2 and PGF2α production significantly in stromal cells (p<0.05). In vivo experiment, the P4 concentrations in blood sample was significantly increased after injection of 1 μg/ml IFN-τ. These results indicate that PG production was mediated by COX-2 expression in the stromal cells but it did not affect in the epithelial cells, and suggest that treatment of IFN-τ was to improve the implantation environment of uterine by maintenance of high P4 concentration. * This work was carried out with the support of “Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ907008)” Rural Development Administration, Republic of Korea.

본 연구는 소 체외 수정란의 팽창 및 hatching시 prostaglandin 와 prostaglandin 의 영향에 대하여 검토하였다. 체외 수정란의 체외 배양시 다음과 같이 (1) 0, 1, 10 및 100ng/ml , (2) 0, 1, 10 및 100ng/ml , (3) low (1ng/ml : 1ng/ml), (4) low , (5) high (10ng/ml : 1ng/ml), (6) high : high (10ng/ml : 10ng/ml)로

Lipid metabolites involved in cellular regulation as signaling mediators. Prostaglandins (PGs), metabolites of lipid are involved to pregnancy at the time of implantation but the functional roles of PGs on embryo development are still controversy and largely unknown. In previous report, the levels of and at embryos of morula stage and blastocyst stage were explored (Cheon et al., 1998). In this study, the previous suggestion was confirmed and the possible downstream mediator of prostaglandin and prostaglandin on the expansion and hatching of mouse embryo was examined. As expected, developmental rate of the blastocyst to expanded stage was a concentration-response curve that showed the highest expansion rate at 10 , but at 100 , the rate was decreased. In contrast to the , stimulated expansion without toxicity at highest concentration. Cotreatment of PGs with indomethacin overcame the inhibitory effects of indomethacin in expansion. Exogenous PGs also improved the development of expanded embryos to the hatching stage. Besides, PGs receptors' transcripts detected at blastocyst. was caused of calcium fluctuation in the blastocyst but did not. The changes of intracellular calcium concentration were different between indomethacin pretreated embryos and non-treated embryos. Based on these results it is suggested that PGs work as paracrine and/or autocrine factors through calcium and the others which were not identified in this study.

부화 및 착상에서 prostaglandins의 역할에 대한 연구는 많으나 배아단계에 따라 포배의 팽창과 부화에 미치는 영향에 대한 연구는 미미하다. 따라서 본 실험에서는 다양한 농도의 prostaglandins를 발생단계에 따라 처리하거나, indomethacin과 prostaglandins의 양 변화를 통해 팽창과 부화에 미치는 영향을 알아보고, 배아 단계별 PG 와 PG 의 생합성양 변화양상을 알아보았다. 100M이 상 농도의 PG 처리시 거의 모든