• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.93-93
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• 2004

• Clinical and Experimental Reproductive Medicine
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• v.38 no.4
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• pp.179-185
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• 2011

The ultimate function of the endometrium is to allow the implantation of a blastocyst and to support pregnancy. Cycles of tissue remodeling ensure that the endometrium is in a receptive state during the putative 'implantation window', the few days of each menstrual cycle when an appropriately developed blastocyst may be available to implant in the uterus. A successful pregnancy requires strict temporal regulation of maternal immune function to accommodate a semi-allogeneic embryo. To preparing immunological tolerance at the onset of implantation, tight temporal regulations are required between the immune and endocrine networks. This review will discuss about the action of steroid hormones on the human endometrium and particularly their role in regulating the inflammatory processes associated with endometrial receptivity.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1307-1314
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• 2015

Leukemia inhibitory factor (LIF) is a member of the IL-6 cytokine family, having pleiotropic actions such as maintaining stem cell pluripotency and enabling blastocyst implantation. Because the action of LIF is mediated by a ligand-receptor interaction with the LIF receptor (LIF-R), an antagonist for LIF-R has been developed to inhibit LIF-induced signaling. In this study, we present a novel method for the production and purification of an antagonist to human LIF-R (hLA). His-tagged hLA was expressed in E. coli, and simple purification methods without any endopeptidase cleavage were designed. In addition, we determined the optimal temperature conditions for enhancing the production of soluble hLA. Finally, the bioactivity of His-tagged hLA was examined using STAT3 phosphorylation and receptivity of human endometrial ECC-1 cells. Our strategy provides a rapid and efficient method to produce biologically active recombinant hLA.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.4
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• pp.248-258
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• 2022

Objective: This research investigated the effects of human chorionic gonadotropin (HCG)-producing peripheral blood mononuclear cells (PBMCs) on the implantation rate and embryo attachment in mice. Methods: In this experimental study, a DNA fragment of the HCG gene was cloned into an expression vector, which was transfected into PBMCs. The concentration of the produced HCG was measured using enzyme-linked immunosorbent assay. Embryo attachment was investigated on the co-cultured endometrial cells and PBMCs in vitro. As an in vivo experiment, intrauterine administration of PBMCs was done in plaque-positive female mice. Studied mice were distributed into five groups: control, embryo implantation dysfunction (EID), EID with produced HCG, EID with PBMCs, and EID with HCG-producing PBMCs. Uterine horns were excised to characterize the number of implantation sites and pregnancy rate on day 7.5 post-coitum. During an implantation window, the mRNA expression of genes was evaluated using real-time polymerase chain reaction. Results: DNA fragments were cloned between the BamHI and EcoRI sites in the vector. About 465 pg/mL of HCG was produced in the transfected PBMCs. The attachment rate, pregnancy rate, and the number of implantation sites were substantially higher in the HCG-producing PBMCs group than in the other groups. Significantly elevated expression of the target genes was observed in the EID with HCG-producing PBMCs group. Conclusion: Alterations in gene expression following the intrauterine injection of HCG-producing PBMCs, could be considered a possible cause of increased embryo attachment rate, pregnancy rate, and the number of implantation sites.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.3
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• pp.243-251
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• 2005

Objective: Low-dose aspirin have been proposed to improving endometrial receptivity and pregnancy rate in COH-IVF by increasing endometrial perfusion. However, the effect of low-dose aspirin in COH-IVF could be negligible because there have been large quantity of other important factors responsible for changing endometrial perfusion accompanied by COH procedure. In contrast, in frozen-thawed embryo transfer cycles which were not accompanied by COH procedure, the effects of low-dose aspirin in endometrial blood flow seems to be more certain than in COH-IVF cycles. In this study, we analyzed the effect of low-dose aspirin treatment on implantation and pregnancy rates in patients undergoing frozen-thawed embryo transfer Methods: From January 2003 to December 2003, total 264 cycles from 264 patients who attended infertility clinic at Samsung Cheil Hospital were enrolled in this study. All cases included in this study, embryos were frozen and thawed at the pronuclear stage and three days after incubation, at least 2 or more good quality embryos were transferred into uterus. In study group, low dose aspirin (100 mg/day) was administrated from the first or second date of menstrual day to 9 days after embryo transfer. On the other hand, control group did not take any medicine except estradiol valerate for endometrial priming. Several variables including implantation and pregnancy rates were compared in both groups. After then, each groups were stratified by endometrial thickness checked at embryo transfer (ET) day such as (28 mm versus <8 mm) and same variables above described were compared between study and control groups. Results: The mean age, infertility duration, endometrial thickness at embryo transfer day and mean number of transferred embryo were not significantly different in both groups. Also, implantation rates (study group: 15.8%, control group: 20.5%) and pregnancy rate (study group: 45.1%, control group: 43.5%) were not significantly different between two groups. (p>0.05) After we analyzed same variables stratified by endometrial thickness checked at embryo transfer day, we could not found any significant difference between study and control groups. Conclusions: Low-dose aspirin treatment seems to have no advantage of improving implantation and pregnancy rates in patients undergoing frozen-thawed embryo transfer.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.390-400
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• 2000

The corpus luteum (CL) is a temporary endocrine gland whose main function is to secrete progesterone to support pregnancy. On the other hand, the cyclic bovine CL has also been shown to be a site of prostaglandin $F_{2{\alpha}}$ ($PGF_{2{\alpha}}$) production. Although there is general agreement that endometrial $PGF_{2{\alpha}}$ is an essential luteolysin in cattle, luteal $PGF_{2{\alpha}}$ seems to play a luteotropic role as an autocrine and/or paracrine factor, especially for the development and maintenance of the CL. This supposition is based on evidence that some of the prerequisites for autocrine/paracrine mechanisms are present, including local production of $PGF_{2{\alpha}}$ and the existence of specific binding sites within the CL. The purpose of this paper is to review the regulation of luteal $PGF_{2{\alpha}}$ secretion, its action on CL as an autocrine and/or paracrine factor and the receptivity of bovine CL to. $PGF_{2{\alpha}}$.

• Development and Reproduction
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• v.13 no.1
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• pp.1-11
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• 2009

Implantation itself is governed by an array of endocrine, paracrine and autocrine modulators, of embryonic and maternal origin. Window of implantation is the unique temporal and spatial expression of factors allows the embryo to implant via signaling, appositioning, attachment, and invasion in a specific time frame of $2{\sim}4$ days. When the embryo has arrived in the uterine cavity, a preprogrammed sequence of events occurs, which involves the production and secretion of a multitude of biochemical factors such as cytokines, growth factors, and adhesion molecules by the endometrium and the embryo, thus leading to the formation of a receptive endometrium. Cytokines such as LIF, CSF-1, and IL-1 have all been shown to play important roles in the cascade of events that leads to implantation. Integrin, L-selectin ligands, glycodelin, mucin-1, HB-EGF and pinopodes are involved in appositioning and attachment. The embryo also produces cytokines and growth factors (ILs, VEGF) and receptors for endometrial signals such as LIF, CSF-1, IGF and HB-EGF. The immune system and angiogenesis play an important role. The usefulness of these factors to assess endometrial receptivity and to estimate the prognosis for pregnancy in natural and artificial cycles remains to be proven. Integrins, pinopodes, glycodelin and LIF (from biopsies) are promising candidates; from uterine flushings, glycodelin and LIF are also candidates. The ideal serum marker is not available, but VEGF, glycodelin and CSF have some clinical implications. Further evaluation that includes larger groups of infertile women and fertile controls are needed to elucidate whether their presence in plasma, flushing fluid, or endometrial samples can be used as some kind of a screening tool to assess endometrial function and prognosis for pregnancy before and after artificial reproductive therapy. A better understanding of their function in human implantation may lead to therapeutic intervention, thereby improving the success rate in reproduction treatment. New molecular techniques are becoming available for measuring both embryonic and endometrial changes prior to and during implantation. The use of predictive sets of markers may prove to be more reliable than a single marker. Ultimately, the aim is to use these tools to increase implantation in artificial cycles and consequently improve live-birth rates.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.1
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• pp.31-37
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• 2000

This study was designed to identify the ultrastructural changes of mouse endometrium during peri-implantation period and obtain the fundamental information for the establishment of 3-dimensional culture system of mouse endometrial cells in vitro. The used female ICR mice ($6{\sim}8$ wks) were conducted on pregnant. The biopsies were obtained from whole uterus at cycle day 1 (D1) and day 5 (D5) after hCG injection and mating. The biopsies materials were fixed 2.5% glutaraldehyde and 1% osmium tetroxide. Subsequently, for observation using light and transmission electron microscopy (LM and TEM), they were dehydrated and embedded in Epon and the embedded biopsies were sectioned and stained. For scanning electron microscopy (SEM), the fixed specimens were dehydrated, dried and coated with gold. 1) For LM, the biopsied materials at D5 (late secretory phase) were appeared the extended stromal layer by increased connective tissues and the fully developed endometrial glands and vessels compared with D1 (early secretory phase). 2) For TEM, the mouse endometrium was consisted of 3-layers, a simple polarized columnar epithelial cells, basement membrane and stromal cells. At D5, the distribution of microvilli, endoplasmic reticulum, Golgi body, lipid and glycogen deposits, secretory granules and surface area of basement membrane were increased. 3) For SEM, the degree of folding and microvilli of surface of mouse epithelial cells was became more and more according to the process of secretory phase, and at D5, implantation time of mouse, the appearance of pinopodes as a specific marker of uterine receptivity was found. The uterine pinopodes of mouse were found in narrow sites at the luminal surface, irregularity and appeared the different stages in the same sample. Therefore, these results indicated that the mouse endometrium was experienced dramatic morphological changes during peri-implantation period.