Ovulation resembles a tissue remodeling process such as a blood coagulation. The present study was aimed to examine the involvement of tissue factor, a primary factor for extrinsic coagulation pathway, in the ovulation. Northern blot analysis revealed that mRNA levels of tissue factor and tissue factor pathway inhibitor 2 (TFPI-2) in the ovary were stimulated by human chorionic gonadotropin (hCG) treatment in surperovulation model, of immature rats. Real-time PCR analysis demonstrated that the expression of tissue factor and TFPI-2 was stimulated in granulosa and theca cells of preovulatory follicles, respectively. The induction of tissue factor mRNA was blocked by the progesterone receptor antagonist RU486. Tissue factor protein was not detected in the ovary by Western blot and immunohistochemical analysis due to the lack of a specific antibody. Interestingly, the levels of tissue factor and TFPI-2 mRNA were increased in the ovarian cells of rats induced ovarian hyperstimulation syndrome (OHSS) and in granulosa cells of OHSS patients undergiong in vitro fertilization. The present findings indicate the stimulation of tissue factor system during ovulation, and in OHSS patients, implicating the possible involvement of tissue factor system in OHSS.

Ovulation resembles a tissue remodeling process such as a blood coagulation. The present study was aimed to examine the involvement of tissue factor, a primary factor for extrinsic coagulation pathway, in the ovulation. Northern blot analysis revealed that mRNA levels of tissue factor and tissue factor pathway inhibitor 2 (TFPI-2) in the ovary were stimulated by human chorionic gonadotropin (hCG) treatment in surperovulation model, of immature rats. Real-time PCR analysis demonstrated that the expression of tissue factor and TFPI-2 was stimulated in granulosa and theca cells of preovulatory follicles, respectively. The induction of tissue factor mRNA was blocked by the progesterone receptor antagonist RU486. Tissue factor protein was not detected in the ovary by Western blot and immunohistochemical analysis due to the lack of a specific antibody. Interestingly, the levels of tissue factor and TFPI-2 mRNA were increased in the ovarian cells of rats induced ovarian hyperstimulation syndrome (OHSS) and in granulosa cells of OHSS patients undergiong in vitro fertilization. The present findings indicate the stimulation of tissue factor system during ovulation, and in OHSS patients, implicating the possible involvement of tissue factor system in OHSS.

The follicle loss of transplanted ovarian tissue (OT) is caused by ischemia and slow revascularization. To shorten the ischemic period and promote angiogenesis, some angiogenic factors have been treated for transplanted tissues. Angiopoietin-2 (ANG-2) is one of the major angiogenic factors and has been reported to promote blood vessels and increase vascular permeability in the ischemic and/or hypoxic environment. So, this study was designed to assess the impact of ANG-2 on follicle integrity and revascularization of mouse OT grafts. The 5-week-old B6D2F1 female mice were divided into 3 groups (a control and 2 ANG-2 groups) followed by ovary collection and vitrification. After warming, the ovaries were autotransplanted into kidney capsules with/without ANG-2 injection (50 or 500 ng/kg), and then killed at day(D)2, 7, 21 and 42 after transplantation. Total 2,437 follicles in OT grafts were assessed for the follicular density, integrity and classification by H&E staining. Apoptosis, revascularization, and serum FSH levels were evaluated by TUNEL assay, CD31 immunohistochemistry, and ELISA respectively. All the ANG-2 groups showed remarkable increase of morphologically intact follicle ratio across all the grafting duration except D21 (no statistical difference). The numbers of CD31(+) vessels (the sum of 3 fields at ×400 magnification) were significantly increased in both ANG-2 groups compared with the control group at all the grafting duration. Especially at D42, the 500ng ANG-2 group showed significantly more vessels than the 50 ng ANG-2 group as well as the control group. However the mean follicle numbers of grafts, apoptosis ratio and serum FSH levels showed no significant difference among the groups. In this study, remarkably well preserved follicles and larger amount of vessels were appeared in ANG-2 treated groups. So we thought that ANG-2 treatment is effective for OT transplantation and improve transplantation outcomes.

Polyethyleneglycol-adsorbed–superoxide dismutase (PEG-SOD), has been proposed as an effective agent for reducing free radical-mediated injury. The objective of this study was to investigate a protective effect of PEG-SOD supplementation on ovarian tissue during transplantation. Ovaries from F-1 mice were collected and vitrified. After warming, ovaries were autotransplanted under kidney capsule. Mice were randomly divided into four groups according to dose of PEG-SOD, (0 U/ml, 100 U/ml, 1,000 U/ml and 10,000 U/ml respectively). Grafted ovaries were retrieved 2, 7 and 21 days later. PEG-SOD was treated by intraperitoneal injection once every 48 hours and especially for 21 days group, after first week treatment, PEG-SOD was treated once every 4 days. Morphology of ovaries was assessed histological analysis and ELISA for FSH was performed to evaluate restoration of ovarian function. In 2 days groups, morphologically intact follicle ratio of 10,000 U/ml group was significantly higher than other groups. In 7 days groups, morphologically intact follicle ratio was significantly higher in all treatment groups. In 21 days groups, there was no significant difference of intact follicle ratio in total follicles in all groups but intact primordial, primary and secondary follicles ratio was higher in 10,000 U/ml group. FSH levels in blood serum were decrease as time goes on, but there is no statistical difference in each groups. In conclusion, the data of the present study show that PEG-SOD has a beneficial effect on preservation of the morphologically intact follicle.

Objective : To investigate the effects of Simvastatin and Methylprednisolone on ovarian tissue cryopreservation and transplantation using mouse models. Methods : The mice were randomly distributed into 1 control and 3 experimental groups. The B6D2F1 mice were given oral Simvastatin (5 mg/kg), intravenous Methylprednisolone (15 mg/kg), or a combination of both at 2 hours before ovariectomy. Same volume of normal saline was given perorally in the control group at 2 hours before ovariectomy. The ovarian tissues were vitrified accrording to our protocols. The vitrified ovaries were warmed 1 week later and auto-transplanted under bilateral kidney capsules. The ovaries and blood sera were collected at 2, 7 or 21 days after transplantation. Histological analysis, TUNEL assay, immuno-histochemistry for CD31, serum AMH level and embryonic development after in vitro fertilization were assessed for evaluation. Results : With regard to the total grade 1 follicle rate, both Simvastatin or Methylprednisolone treated groups were significantly increased at 2, 7 or 21 days after transplantation (except Simvastatin treated group at 7 days). A combination of Simvastatin and Methylprednisolone group was significantly improved in terms of the total G1 follicle rate, apoptotic follicle rate, CD31 positive area and serum AMH after ovarian tissue transplantation. However, there were no statistically difference with respect to the oocyte maturation rate, blastulation rate, and the other embryonic development parameters after in vitro fertilization procedure among the four groups. Conclusion : Our results suggest that combined donor Simvastatin and Methylprednisolone have beneficial effects on the quality and function of transplanted ovarian tissues.

Study question: What is the optimal vitrification protocol according to the cryoprotective agent (CPA) for ovarian tissue (OT) cryopreservation? Summary answer: The two-step protocol with 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO) for 10 min then 20% EG, 20% DMSO and 0.5 M sucrose for 5 min showed the best results in mouse OT vitrification. What is known already: Establishing the optimal cryopreservation protocol is one of the most important steps to improve OT survival. However, only a few studies have compared vitrification protocols with different CPAs and investigated the effect of in vitro culture (IVC) on vitrified–.warmed OT survival. Some recent papers proposed that a combination of CPAs has less toxicity than one type of CPA. However, the efficacy of different types and concentrations of CPA are not yet well documented. Study design, size, duration: A total of 644 ovaries were collected from 4-week-old BDF1 mice, of which 571 ovaries were randomly assigned to 8 groups and vitrified using different protocols according to CPA composition and the remaining 73 ovaries were used as controls. After warming, each of the eight groups of ovaries was further randomly divided into four subgroups and in vitro cultured for 0, 0.5, 2 and 4 h, respectively. Ovaries of the best two groups among the eight groups were autotransplanted after IVC. Participants/materials, setting, methods: The CPA solutions for the eight groups were composed of EDS, ES, ED, EPS, EF, EFS, E and EP, respectively (E, EG; D, DMSO; P, propanediol; S, sucrose; F, Ficoll). The IVC medium was composed of a-minimal essential medium, 10% fetal bovine serum and 10 mIU/ml follicle-stimulating hormone (FSH). Autotransplantation of vitrified–.warmed OTs after IVC (0 to 4 h) using the EDS or ES protocol was performed, and the grafts were recovered after 3 weeks. Ovarian follicles were assessed for morphology, apoptosis, proliferation and FSH level. Main results and the role of chance: The percentages of the morphologically intact (G1) and apoptotic follicles in each group at 0, 0.5, 2 and 4 h of IVC were compared. For G1 follicles at 0 and 4 h of IVC, the EDS group showed the best results at 63.8 and 46.6%, respectively, whereas the EP group showed the worst results at 42.2 and 12.8%, respectively. The apoptotic follicle ratio was lowest in the EDS group at 0 h (8.1%) and 0.5 h (12.7%) of IVC. All of the eight groups showed significant decreases in G1 follicles and increases in apoptotic follicles as IVC duration progressed. After autotransplantation, the EDS 0 h group showed a significantly higher G1 percentage (84.9%) than did the other groups (42.4–.58.8%), while only the ES 4 h group showed a significant decrease in the number of proliferative cells (80.6%, 87.6–.92.9%). However, no significant differences in apoptotic rates and FSH levels were observed between the groups after autotransplantation. Limitations, reasons for caution: The limitation of this study was the absence of in vitro fertilization using oocytes obtained from OT grafts, which should be performed to confirm the outcomes of ovarian cryopreservation and transplantation. Wider implications of the findings: We compared eight vitrification protocols according to CPA composition and found the EDS protocol to be the optimal method among them. The data presented herein will help improve OT cryopreservation protocols for humans or other animals.