Endothelin 2 (EDN2) induces follicular rupture by constricting periovulatory follicles. In this study, it was investigated the mechanisms of EDN2 action on follicular rupture with respect of receptor using the conditionally granulosa cell specific EDN2 receptor type A (ETa) KO mice (gcETaKO; ETaflox/-․Amhr2Cre). It was generated the gcETaKO mice by breeding with ETaflox/- mice after mono-alleic ETa knockout by ZP3Cre and Amhr2Cre mice. Fertility, ovulation and maturation rates of ovulated oocytes after super ovulation were investigated in the gcETaKO mice compared with wild-type mice (ETaflox/flox and ETaflox/-) as a control group. In the gcETaKO mice, normal fertility after breeding with male mice was shown compared with wild-type mice. And, there was no significant differences in ovulation rates after super ovulation, however its maturation rates was lower than that of wild type mice. These findings show that EDN2 in follicular rupture for ovulation is related with an other ETa not in granulosa cells. Further studies are needed to investigate how EDN2 is acted in ovarian follicular rupture for ovulation.

The aim of this study was to evaluate the changes of protein patterns in granulosa cells and corpus luteum during the estrus cycle in bovine ovary by proteomics ^techniques. Our study was devided into five steps for follicular, ovulatory, early-lteal, midluteal and late-luteal. The protein was extracted from glanulosa cell and corpus luteum proteins by using M-PER Mammalian Protein Extraction Reagent. Proteins were refined by clean-up kit and quantified by Bradford method until total protein was 700 μg. Immobilized pH gradient (IPG) strip was used 18 cm and 3 11 NL. SDS-PAGE was used 10% acrylamide gel. The protein spots were visualized by Coomassie Brilliant Blue (CBB) staining, analyzed by MALDI mass spectrometry and searched on NCIBlnr. As the result, 61 spots of total 85 spots were repeated on follicular stage and 51 spots of total 114 spots were repeated on ovulatory stage. 40 spots of total 129 were repeated on early-luteal and 49 spots of total 104 spots were repeated on mid-luteal stage. Also 41 spots of total 60 spots were repeated on last-luteal stage. There were differences in the ovulation (follicular∼ovultory stage) in which the spots of follicular stage 19 was only and in ovulation stage was 10 spots. The difference between the luteinization (ovultory∼mid-luteal stage) was the spots counted in each stage. The spots of ovulatory stage was 1, early-luteal stage was 1 and in mid-luteal stage was 2. Eleven spots were found in mid-luteal stage and 2 spots were found in last-luteal stage. In conclusion, we confirmed that there were 7 spots in ovulation, 4 spots in luteinization and 2 spots in luteolysis. Spot No. 89-93 from ovulation were transferrin, and spot No.94 and 95 were HSP60. Spot No. 103 were Dusty PK, spot No. 135 were OGDC-E2, and spot No. 175, 176 were Rab GDI beta from luteinization. Spot No. 178 and 179 from luteolysis were vimentin.

Early growth response 1 (Egr1) is an inducible zinc finger transcription factor. Egr1 binds specific GC-rich region. Egr1 mRNA is rapidly and transiently expressed in pre-ovulatory follicles by LH and expressed in decidual cell by estrogen. Progesterone receptor (PR) is a nuclear transcription factor that is induced in granulosa cells of pre-ovulatory follicles following the LH surge. PR regulates ADAMTS1, which downstream gene of PR. In previous study, we observed ADAMTS1 mRNA expression pattern changed in Egr1 KO mice. Therefore, we expected that progesterone receptor gene expression is directly regulated by early growth response 1 in mouse ovarian granulosa cell. We could found the ER binding domain, Egr1 binding domain and CAAT box in PR promoter using the web tool AliBaba 2.1. We construct the PR promoter vectors truncated ER binding domain, Egr1 binding domain, CAAT box, respectively. We also construct the Egr1 expression vector using pcDNA 3.1 (+) vector. Granulosa cells are isolated from female ICR mice after 12h PMSG injection. To confirm the Egr1 overexpression, we performed western blot. For reporter assay, we used Dual-Luciferase reporter assay system. In conclusion, Egr1 may regulate PR expression in granulosa cell.

To study the regulation of porcine follicular cell apostosis by gonadotropin, steroid, and nitric oxide, we analyzed DNA fragmentation, the hallmark of apoptosis, and nitrite production of porcine granulosa cells. Dissected indiidual follicles from ovary were separated in size (small, 2-3 mm; medium, 5-6 mm; large, 7-8 mm) and isolated granulosa cells were classified morpholocally as atretic or nonatretic. Nitrite concentration was measured by mixing follicular fluids with an equal volume of Griess reagent. Follicular nitric oxide (NO) concentration of healthy follicles was higher than that of atretic follicles. Apoptotic DNA fragmentation was suppressed in non-apoptotic granulosa cells. Follicular apoptosis was induced by androgen but prevented by gonadotropin in vitro. Apoptosis was confined to the granulosa cells. But it was not clear whether apoptosis of granulosa cells were isolated, incubated with or without gonadotropin, androgen and sodium nitroprusside (SNP), respectively at for 24 hrs. Cultured granulosa cells were used to extract genomic DNA and culture media was asssayed for nitrite concentration. Nitrite production of culture media was increased, while apoptotic DNA fragmentation was suppressed in PMSG, hCG, testosterone+SNP and SNP treated groups. Nitrite concentration in culture media was decreased, but apoptotic DNA fragmentation was induced in testosterone treated group. These data suggest that NO production and apoptosis may be involved of granulosa cell apoptosis induced by testosterone.