• Toxicological Research
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• v.19 no.1
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• pp.21-27
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• 2003

A teratogenic study of dimethyl dimethoxy biphenylate derivative (DDB-S) was carried out on Sprague-Dawley rats. DDB-S dissolved in saline was administered to male and female rats by intravenously injection at daily doses of 50 mg/kg, 75 mg/kg, and 100 mg/kg. A half of dams were sacrificed at 20th day of gestation to scrutinize the pregnant performances and fetal development. And the remaining dams were allowed to deliver. The growth, reflex, behaviour and reproductive function of F1 offsprings were examined. There was no treatment-related difference in body weight, food consumption and necropsy findings of dams. No gross, skeletal and visceral abnormalities was observed in F1 fetuses from dams treated with DDB-S. F1 offsprings did not show any treatment-related difference in growth, reflex, behaviour and reproductive performance. At caesarean section of F1 dams, no growth retardation and gross abnormality was observed in F2 fetuses. In conclusion, DDB-S did not show any potential teratogenic effect in rats.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.2
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• pp.111-117
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• 2004

Objectives: To investigate the effect of LH receptor in folliculogenesis, we confirm the expression level of LH receptor (LH-R) mRNA in human granulosa cells (GCs) and its expression levels were analyzed by comparison to embryo developmental rate and pregnancy rate. Materials and Methods: GCs were obtained at the time of oocyte retrieval from the patients undergoing IVF-ET program. The patients were divided into two groups: Group I (n=20) is poor responder (retrieved oocyte(s)$\leq$3ea), Group II (n=80) is normal responder (retrieved oocytes>3ea). After the extraction of total RNA, semiquantitative RT-PCR was performed and the expression level of LH-R mRNA was normalized by $\beta$-actin. Statistical analysis was performed by using $X^2$ test, Student's t-test and Pearson correlation. Results: In Group II, the relative values of LH-R mRNA (0.680 vs. 0.463, p<0.005) and pregnancy rate (54.7% vs. 23.1%, p<0.05) were significantly higher than in Group I. Number of retrieved oocyte(s) was gradually increased when the expression of LH-R mRNA was increased (p<0.05). But the quality of retrieved oocyte and transferred embryo were not related with the expression of LH-R mRNA. When the pregnancy rate was compared with FSH only group and FSH combined with hMG group in the ovarian stimulation protocol, FSH combined with hMG group was significantly higher than FSH only group in Group I (37.5% vs. 0%), and the expression of LH-R mRNA was significantly higher in hMG combined group than FSH only group (p<0.05). Conclusion: Expression level of LH-R mRNA has important role in ovarian function related with the response to gonadotrophin in human folliculogenesis. Furthermore these data might provide the evidence that additional use of hMG is helpful to poor responders.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.2
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• pp.89-100
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• 2009

SLE 등의 자가면역질환 병인론에 있어서 $CD4^+$ T 조력 림프구 (T helper cell)의 기능과 항상성 조절의 이상이 중요하다는 것은 알려진 사실이지만 $CD4^+$ T 조력 림프구 (T helper cell)의 발달과 기능에 대한 성호르몬의 정확한 역할에 대하여는 아직 확립되어 있지 않은 실정이다. 에스트로겐의 $CD4^+$ T 림프구에 대한 여러 방면의 작용에 대한 결과는 에스트로겐 매개 신호가 전달되는 정황에 매우 의존적이라고 할 수 있으며, 또한 에스트로겐이 B 림프구와 항원발현세포들 같이 T 림프구 기능을 변화시킬 수 있는 다른 분획 세포들의 기능에 대해서도 영향을 미칠 수 있다는 사실을 고려한다면, 에스트로겐이 $CD4^+$ T 림프구매개반응에 미치는 작용은 매우 복잡하다고 할 수 있다. 현재로선 이런 과정들과 관련된 에스트로겐의 정확한 기전에 대한 연구 성과는 현재로선 아직걸음마 단계에 지나지 않는다고 볼 수 있다. 일부 분자학적 표적들의 발견에도 불구하고 ER-$\alpha$와 ER-$\beta$, 또는 이런 표적들의 조절에 대한 유전자적 또는 비유전자적 경로의 상대적 역할에 대해서는 현재로선 알려진 바가 많지 않은 것 또한 사실이며, T 림프구 자체의 미세 환경과 ER 매개 전사반응에 영향을 미칠 수 있는 방법 역시 아직까진 알려진 바가 없다. 따라서 에스트로겐의 $CD4^+$ T 림프구에 대한 다각적 영향을 규명하는 데 있어 이런 경로들에 대한 보다 체계적이고 상세한 연구가 반드시 필요하다. 최근 골다공증의 병인에 있어 에스트로겐에 의한 TNF 및 RANK-RANKL계 억제에 대해 연구가 심도 있게 진행됨으로써 결과적으로 다른 시토카인과 면역세포들에 대한 영향이 간접적으로 규명되고 있는 점은 매우 고무적인 현상이라고 여겨진다. 이러한 연구들은 추후 에스트로겐의 면역 및 염증체계에 대한 특징적 작용을 규명하는데 있어서 밑거름이 될 수 있을 것이다. 나아가 호르몬 자체, 또는 SERM 같은 준호르몬제제들이 면역계에 미치는 영향을 분자학적으로 규명함으로써 향후 이러한 지식들이 또한 류마티스성 자가면역질환이나 만성염증성질환, 또는 전신성 감염질환에 있어 면역글로불린이나 기타 다른 기존 치료 약제들을 대체 보완할 수 있는 호르몬 치료로 이어질 수 있는 결정적인 단서를 제공할 수 있을 것이라 기대할 수 있을 것이다.

• Reproductive and Developmental Biology
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• v.31 no.3
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• pp.181-186
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• 2007

Inhibitor of DNA binding protein or inhibitor of differentiation(Id) is largely considered as positive and/or negative regulators of proliferation, differentiation, angiogeneisis, and apoptosis. The four Id genes(Id1, Id2, Id3, and Id4) were known in mammals. However, little is known about the expression and function of these genes in reproductive physiology. Among them, this study was conducted to analyze the expression pattern of Id3 mRNA on folliculogenesis in rat ovary. After PMSG administration, the ovaries were obtained at 3, 6, 12, 24, 36, and 48hrs, fixed, dehydrated, and paraffin embedded. For in situ hybridization, anti-sense and sense Id3 cRNA probes were prepared and applied to the ovarian section. The ovarian sections were coated with NTB-2 emulsion. After that, the slides were developed and counterstained with hematoxylin and eosin staining. The hybridization signal was estimated on a scale of 1+ to 4+. In oocyte, the intensity of Id3 mRNA in primordial and primary follicles was scored at ${\geq}2+$, but the intensity was less than 1+ in secondary, dominant, and preovulatory follicles. In granulosa cells, the Id3 mRNA was strongly expressed(3+ or 4+) in dominant and preovulatory follicles. Taken together, Id3 mRNA was expressed specifically at follicle stages and follicular tissue and might be closely related with follicle development.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.3
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• pp.181-191
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• 2008

Objective: Environmental chemicals alter reproduction, growth, and survival by changing the normal function of the endocrine system. Bisphenol A (BPA), one of the endocrine disruptors, is known to be an estrogen receptor agonist. Therefore, we hypothesized that BPA may affect male reproduction including spermatogenesis in the mouse testis. Methods: We used 7-week-old ICR mice. The first experiment group received BPA in sesame oil (vehicle, 1 mg/kg, 10 mg/kg, and 100 mg/kg) by i.p. injection and mice were sacrificed 24 hr later. The second experiment group received BPA (vehicle, 10 ${\mu}g/kg$, 1 mg/kg, and 100 mg/kg) daily for 14 days by subcutaneous injection. Expression of cell type-specific marker genes in the testis was evaluated by RT-PCR. Histological analysis, immunofluorescence staining, and TUNEL staining were also performed. Results: RT-PCR analyses showed that expression of luteinizing hormone receptor (LHR), a marker gene for the Leydig cell, was notably decreased in the testes of high dose-exposed mice. No obvious difference in the histology of testes was noted among treatment groups. Immunostaining of LHR in the first experiment group did not show noticeable difference in LHR protein expression in Leydig cells. Immunohistochemistry also revealed heightened expression of the immunoreactive Bax in the treatment group, and this was accompanied by positive TUNEL staining in the interstitial area within testis where Leydig cells reside. Conclusions: Our result suggests that BPA affects Leydig cell functions by altering gene expression and by increasing apoptosis in the mouse testis.

• Clinical and Experimental Reproductive Medicine
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• v.31 no.3
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• pp.155-168
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• 2004

Objective: Melatonin, which is secreted by pineal gland play an important role in the regulation of ovarian function via seasonal rhythm and sleep in most mammals. It also has a role in the protection of cells by removing toxic oxygen free radicals brought about by metabolism. In the present study, effects of melatonin on the mouse oocyte maturation were examined using two different culture conditions provided with 5% or 21% oxygen concentration. Material and Method: Immature mouse oocytes were obtained from the ovarian follicles of $3{\sim}4$ weeks old ICR strain mice intraperitoneally injected with 5 I.U. PMSG 44 hour before. Under stereomicroscope, morphologically healthy oocytes with distinct germinal vesicle (GV) were liberated from the graafian follicles and collected using mouth-controlled micropipette. They were then cultured for 17 hour at $37^{circ}C$, 5% $CO_2$ and 21% $O_2$ (95% air) or 5% $CO_2$, 5% $O_2$ and 90% $N_2$. New modified Hank's balanced salt solution (New MHBS) was used as a culture medium throughout the experiments. Effects of melatonin were examined at a concentration of $0.0001{\mu}M$, $0.01{\mu}M$ or $1.0{\mu}M$. For the prevention of spontaneous maturation of immature oocytes during culture, dibutyryl cyclic AMP (dbcAMP) and/or hypoxanthine were included in the medium. Results: Under 21% oxygen condition, oocytes cultured in the presence of $0.01{\mu}M$ melatonin showed a significantly higher maturation rates, in terms of germinal vesicle breakdown (95.0% vs 89.0%) and polar body formation (88.1% vs 75.4%), compared to those cultured with $0.0001{\mu}M$ or $1.0{\mu}M$ melatonin. However, no difference was observed in oocytes cultured under 5% oxygen whether they were treated with melatonin or not. In the presence of $0.01{\mu}M$ melatonin, oocytes either cultured under 21% or 5% oxygen exhibited no difference in the polar body formation (85.6% vs 86.7%). However, in the absence of melatonin, oocytes cultured under 21% oxygen exhibited lower polar body formation (74.7%). When oocytes were cultured in the presence of dbcAMP alone or with varying concentrations of melatonin, those treated with both compounds always showed better maturation, i.e., germinal vesicle breakdown and polar body formation, compared to those cultured with dbcAMP alone. At the same concentration of melatonin, however, oocytes exposed to 21% oxygen showed poor maturation than those to 5% oxygen. Similar results were obtained from the experiments using hypoxanthine instead of dbcAMP. Conclusion: Based upon these results, it is suggested that melatonin could enhance the meiotic maturation of mouse oocytes under 21% oxygen concentration, and release oocytes from the meiotic arrest by dbcAMP or hypoxanthine regardless of the concentration of oxygen, probably via the removal of oxygen free radicals.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.3
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• pp.181-189
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• 2010

The placenta, which is a temporary organ derived from the fetus during pregnancy, is critical to support fetus development via optimal regulation between mother and fetus. Trophoblast as a major cell population of the placenta is one of the earliest to differentiate and shows an extensive proliferation or/and differentiation up to the formation of the placenta. The role of the trophoblast show dynamic changes from early embryo implantation to placentation during pregnancy. Implantation of the blastocyst into the endometrium of the maternal uterus is mediated by invasion of the differentiated trophoblast (e.g. syncytiotrophoblast) from the trophectoderm. During pregnancy, the unique role of the trophoblast is to invasion, eroding, and metastasizing in the placenta as well as to ensure appropriate bidirectional nutrient or waste flow required for growth and maturation of the embryo. The dysfunction of the trophoblast during pregnancy can result in several gynecological diseases including preeclampsia and congenital malformation in neonatal medicine. Therefore, trophoblasts act as a conclusive factor in placental and fetal development. This brief review outlines the classification of trophoblast and its function in the placenta during pregnancy. Also, we introduce the latest research in trophoblast for implantation and the placenta development, and the application potential of trophoblast for infertility and obstetrical diseases.

• Clinical and Experimental Reproductive Medicine
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• v.45 no.3
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• pp.143-148
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• 2018

Objective: The favored method of preserving fertility in young female cancer survivors is cryopreservation and autotransplantation of ovarian tissue. Reducing hypoxia until angiogenesis takes place is essential for the survival of transplanted ovarian tissue. The aim of this study was to investigate the role of angiopoietin-1 (Angpt-1), angiopoietin-2 (Angpt-2), and vascular endothelial growth factor (VEGF) in ovarian tissue grafts that were cryopreserved using two methods. Methods: Ovarian tissues harvested from ICR mice were divided into three groups: group I (control), no cryopreservation; group II, vitrification in EFS (ethylene-glycol, ficoll, and sucrose solution)-40; and group III, slow freezing in dimethyl sulfoxide. We extracted mRNA for VEGF, Angpt-1, and Angpt-2 from ovarian tissue 1 week following cryopreservation and again 2 weeks after autotransplantation. We used reverse transcriptase-polymerase chain reaction to quantify the levels of VEGF, Angpt-1, and Angpt-2 in the tissue. Results: Angpt-1 and Angpt-2 expression decreased after cryopreservation in groups II and III. After autotransplantation, Angpt-1 and Angpt-2 expression in ovarian tissue showed different trends. Angpt-1 expression in groups II and III was lower than in group I, but Angpt-2 in groups II and III showed no significant difference from group I. The vitrified ovarian tissues had higher expression of VEGF and Angpt-2 than the slow-frozen ovarian tissues, but the difference was not statistically significant. Conclusion: Our results indicate that Angpt-2 may play an important role in ovarian tissue transplantation after cryopreservation although further studies are needed to understand its exact function.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.1
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• pp.9-16
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• 2021

Under the stressed condition, a complex feedback mechanism for stress is activated to maintain homeostasis of the body and secretes several stress hormones. But these stress hormones impair synthesis and secretion of the reproductive hormones, followed by suppression of ovarian function. Cytochrome P450 1A2 (CYP1A2) plays a major role in metabolizing exogenous substances and endogenous hormones, and its expression is recently identified at not only the liver but also several organs with respect to the pancreas, lung and ovary. Although the expression of CYP1A2 can be also affected by several factors, understanding for the changed pattern of the ovarian CYP1A2 expression upon stress induction is still limited. Therefore, CYP1A2 expression in the ovaries from immobilization stress-induced rats were assessed in the present study. The stress-induced rats in the present study exhibited the physiological changes in terms of increased stress hormone level and decreased body weight gains. Under immunohistological observation, the ovarian CYP1A2 expression in both control and the stressed ovary was localized in the antral to pre-ovulatory follicles. However, its expression level was significantly (p < 0.01) higher in the stress-induced group than control group. In addition, stress-induced group presented more abundant CYP1A2-positive follicles (%) than control group. Since expression of the ovarian CYP1A2 was highly related with follicle atresia, increased expression of CYP1A2 in the stressed ovary might be associated with changes of the ovarian follicular dynamics due to stress induction. We hope that these findings have important implications in the fields of the reproductive biology.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.3
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• pp.217-229
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• 2010

Objective: Apoptosis plays an important role for the maintenance of the normal pregnancy. Expression of X-linked inhibitor of apoptosis (XIAP) is able to effectively prevent apoptosis and controls trophoblast cells death throughout placental development, but it is still unknown in the function of XIAP in trophoblast cells exposed to hypoxic condition, which is one of the factors causing preeclampsia. Therefore, we conducted to compare XIAP expression in normal and pre-eclamptic placenta tissues and analyzed the function of XIAP in HTR-8/SVneo trophoblast cell line exposed to hypoxic condition. Methods: The expression of XIAP was analyzed in placental tissues from the following groups of patients (none underwent labor): 1) term normal placenta (n=15); 2) term with pre-eclamptic placeneta (n=15); and 3) pre-term with pre-eclamptic placenta (n=11) using semi-quantitative RT-PCR, immunohistochemistry, and Western blot. In order to evaluate the function of XIAP in HTR-8/SVneo trophoblast cells under hypoxic condition, HIF-$1{\alpha}$ plasmids, and hypoxic condtion were transfected and treated into HTR-8/SVneo trophoblast cells for 24 hours, respectively. Results: We observed that XIAP are expressed in the syncytiotrophoblasts and syncytial knot of placental villi. The expression of XIAP was significantly decreased in preeclamptic placenta tissues than in normal placenta tissues without labor (p<0.05). Furthermore, we confirmed the XIAP expression in HTR-8/SVneo trophbolast cells exposed to hypoxia was translocated from cytoplasm into nucleus and decreased XIAP by hypoxic condition induced apoptosis in HTR-8/SVneo trophoblast cells through up-regulation of pro-apoptotic proteins. Conclusion: These results suggest that the expression of XIAP is involved in placental development as well as decreased expression of XIAP by hypoxia is associated with pre-eclampsia through inducing trophoblast cells apoptosis.