Background: The regulation of maternal immunity is critical for the establishment and maintenance of successful pregnancy. Among many cell types regulating the immune system, innate lymphoid cells (ILCs) are known to play an important role in innate immunity. Although some reports show that ILCs are present at the maternalconceptus interface in humans and mice, the expression and function of ILCs in the endometrium have not been studied in pigs. Methods: Thus, we determined the expression, localization, and regulation of ILC markers, CD127 (a common marker for ILCs), BCL11B (a ILC2 marker), and RORC (a ILC3 marker) at the maternal-conceptus interface in pigs. Results: The expression of BCL11B and RORC, but not CD127, in the endometrium changed during pregnancy in a stage-specific manner and the expression of CD127, BCL11B, and RORC was greatest on Day 15 during pregnancy. CD127, BCL11B, and RORC were also expressed in conceptus tissues during early pregnancy and in chorioallantoic tissues during the later stage of pregnancy. BCL11B and RORC proteins were localized to specific cells in endometrial stroma. The expression of CD127 and BCL11B, but not RORC, was increased by the increasing doses of interferon-γ (IFNG) in endometrial explants. Conclusions: These results suggest that ILCs present at the maternal-conceptus interface may play a role in the establishment and maintenance of pregnancy by regulating the innate immunity in pigs.

The cellular communication network factor (CCN) family proteins regulate many biological events such as angiogenesis, tumor growth, placentation, implantation, and embryogenesis. The expression and function of CCN1, CCN2, and CCN3 at the maternal-conceptus interface are established in humans and rodents, but little is known about the role of CCN4 to CCN6 in the reproductive organs in any other species. Several studies in transcriptome analysis in pigs have shown that the expression of CCN4 and CCN6 increases in the endometrium during early pregnancy. However, their expression, regulation, and function in the endometrium throughout the estrous cycle and pregnancy have not been fully understood in pigs. Thus, we determined the expression, localization, and regulation of CCN4 and CCN6 during the estrous cycle and at the maternal-conceptus interface in pigs. We found that the levels of CCN4, but not CCN6, changed during the estrous cycle. The levels of CCN4 were greater during mid- to late pregnancy than in the early stage, and the levels of CCN6 were greatest on Day 15 of pregnancy. CCN4 and CCN6 were detected in conceptus tissues during early pregnancy and in chorioallantoic tissues during the later stage of pregnancy. CCN4 mRNA was mainly localized to epithelial cells, CCN6 mRNAs to epithelial and stromal cells in the endometrium. In endometrial explant cultures, CCN4 expression was increased by progesterone, and CCN6 expression by interferon-γ. These results suggest that CCN4 and CCN6 may play roles in the establishment and maintenance of pregnancy by regulating the endometrial epithelial cell functions in pigs.

The aim of this study was to investigate effect of heat stress on expression levels of plasminogen activators (PAs) related mRNAs and proteins, and changes of PAs activity in porcine endometrial explants. The endometrial explants (200 ± 50 mg) were isolated from middle part of uterine horn at follicular phase (Day 19-21) and were pre-incubated in serum-free culture medium at 38.5oC in 5% CO2 for 18 h. Then, the tissues were transferred into fresh medium and were cultured at different temperature (38.5, 39.5, 40.5 or 41.5oC) for 24 h. The expression level of urokinase-type PA (uPA), type-1 PA inhibitor (PAI-1), type-2 PAI (PAI-2), and heat shock protein-90 (HSP-90) mRNA were analysis by reverse-transcription PCR and proteins were measured by western blotting. The supernatant were used for measurement of PAs activity. In results, mRNA and protein levels of HSP-90 was higher in 41.5oC treatment groups than other treatment groups (p < 0.05). The expression of uPA, PAI-1, and PAI-2 mRNA were slightly increased by heat stress, however, there were no significant difference. Heat stress condition suppressed expression of active uPA and PAI-2 proteins (p < 0.05), whereas PAI-1 protein was increased (p < 0.01). Although PAI-1 protein was increased and active uPA was decreased, PAs activity was greatly enhanced by exposure of heat stress (p < 0.05). These results suggest that heat stress condition could change intrauterine microenvironment through regulation of PAs activity and other factors regarding with activation of PAs might be regulate by heat stress. Therefore, more studies regarding with regulatory mechanism of PAs activation are needed.

Secretory leukocyte protease inhibitor (SLPI), also known as neutrophil elastase and cathepsin-G protease inhibitor, functions in protection of epithelial cells from proteases. SLPI is expressed and secreted by many mucosal tissues, including lungs, seminal vesicles and cervix in women. SLPI plays an important role in protection of endometrial epithelial cells during pregnancy from degradation by degradation by proteases derived from trophoblast at the maternal-conceptus interface. In pigs, SLPI mRNA is known to be expressed in endometrial tissues, but the expression of SLPI in the endometrium throughout the estrous cycle and pregnancy has not been determined. Therefore, we analyzed the expression and regulation of SLPI mRNA in the endometrium throughout the whole stages of the estrous cycle and pregnancy in pigs. We obtained endometrial tissues from gilts on Days 0 (day of estrus), 3, 6, 9, 12, 15, and 18 of the estrous cycle and on Days 10, 12, 15, 30, 60, 90, and 114 of pregnancy. Real-time RT-PCR analysis showed that the expression of SLPI mRNA in the endometrium increases during midt-o late pregnancy. During the estrous cycle, levels of SLPPI mRNA in estrus and proestrus were higher than those in diestrus and metestrus. In situ hybridization analysis showed that SLPI mRNA was specifically localized to the glandular epithelial cells in the endometrium during pregnancy with strong signal intensity during mid-to late pregnancy. SLPI mRNA was not detectable in conceptus tissues on Days 12 and 15 of pregnancy, but SLPI mRNA was expressed in chorioallantoic tissues during mid-to term pregnancy with increasing levels toward term pregnancy. To determine the effects of steroid hormones, estrogen and progesterone, on the expression of SLPI mRNA, endometrial explant tissues from immature pigs were treated with increasing doses of estradiol-17β (E2) and progesterone (P4). Increasing doses of E2 and P4 increased the expression of SLPI mRNA in endometrial tissues. These results showed that SLPI was expressed in the endometrium in a pregnancy stage-and cell type-specific manner and the expression of SLPI was regulated by E2 and P4 in endometrial tissues, suggesting that SLPI may play an important role in regulating the endometrial epithelial cell function during mid-to late pregnancy in pigs. Further analysis to determine the roles of SLPI at the maternal-conceptus interface is still needed.

Our study has analyzed whether inappropriate gonadotropin secretion affects the morphological changes due to the activation of intrauterine MMP. Methods A total of each 6 mice were injected with PMSG, Progesterone, and Androgen in 5 IU of intraperitoneal injection every 2 days after estrus synchronization, and morphological and MMPs expression patterns were compared after inducing hormone secretion. Also, cell survival and death related genes were compared and analyzed. The endometrium was highly developed in the PMSG, and the androgen was not developed at all. In particular, the diameter of the uterus of the Androgen group was also very narrow. MMPs activity assay in the case of PMSG was confirmed that showed low activity, whereas, progesterone and androgen In showed high activity and, in particular, very high activity of MMPs in the case of androgen in glandular cell. The expression of VEGF in the tissues of each group was different from that of MMPs. In the PMSG group, the activity of VEGF was increased in both the Myo-metrium and the endo-metrium, whereas the progesterone group showed low overall expression in the endo-metrium. Therefore, the present study showed that the activities of the endo-metrial cells and the restructuring of the endometrial cells differed according to the type of the abnormal secretory hormone. In particular, the secretion of androgen increased the activity of MMPs throughout the uterus, The endo-metrial epithelial cells are affected by the progesterone group. In conclusion, this study suggests that inappropriate gonadotropin secretion increases the functional changes of the uterus and this reconstruction may be caused by increased activity of MMPs

In porcine production, porcine litter size is a quantitative trait and its heritability is especially low. So it is necessary to identify porcine reproductive gene and protein. The establishment of pregnancy requires performance of a receptive endometrium and ovary. The endometrium and ovary go through transformations in response to physiological changes initiated by local factors including ovarian hormones and uterine environment that make it for possible pregnancy. The endometrium and ovary secrete a wide array of growth factors, cytokines and proteins. Based on these background, we analyzed the endometrial tissue protein of porcine and would find out biomarker proteins related to porcine litter size. We sorted the two groups according to litter size of porcine: a small litter size group (SLSG) (n=2) and a large litter size group (LLSG) (n=2). The porcine endometrial tissue and ovary samples were preprocessed for proteomic analysis. In order to comparison, samples of each 2mg endometrium protein and ovary protein were separated form pI and molecular weight in the same conditions by applying a pH 3.0-10.0 IPG gels for the first dimension and then 8-16% SDS-PAGE gel for the second dimension. After proteins were visualized by staining with Commassie brilliant blue (CBB), image analysis was performed with Image Master detect variations in protein spots between large litter size group and small litter size group endometrium. And then differential proteins were identified using MALDI-TOF analysis. The master images of 2-DE gel images obtained from 2mg samples of large litter size group and small litter size group endometrial proteins at pH 3.0-10.0 revealed more than 400 protein spots in pH 3.0-10.0 range. When we analyzed the levels of expression of proteins that protein spots appeared more than 1.5-fold difference in endometrial tissue from porcine. In comparison of SLSG(small litter size group) with LLSG(large litter size group), a total of 18 protein spots differentially expressed on porcine endometrial tissue 2-DE gels, among which 9 spots were up-regulated proteins as retinol dehydrogenase 16-like isoform 1, Acrosin-binding protein, alpha-N-acetylgalactosaminidase. phosphoglycerate kinase 2, Acrosin-binding protein in LLSG. And 8 spots were up-regulated proteins as phosphoglycerate kinase 2, prenylcysteine oxidase in SLSG.

Caspases are a family of cysteine protease enzymes composed of more than 10 members that play essential roles in apoptosis and inflammation. It has been reported that caspases play a critical role in regulating apoptosis at the maternal-conceptus interface in many species. However, the expression and regulation of caspases have not been determined in the endometrium in pigs. Therefore, we analyzed the expression, localization, and regulation of caspases in the endometrium during the estrous cycle and pregnancy in pigs. Real-time RT-PCR analysis showed that caspases were expressed in the endometrium during the estrous cycle and pregnancy. The expression of CASP6, CASP7, and CASP8 during the estrous cycle and CASP3, CASP6, CASP7, and CASP10 changed during pregnancy. Levels of CASP3 mRNA in the endometrium were higher on Day 12 of pregnancy than the estrous cycle and levels of CASP7 mRNAs were highest on Day 15 of estrous cycle and pregnancy. Immunohistochemistry analysis showed that CASP3 protein was localized to endometrial epithelial cells on Days 12 and 15 the estrous cycle and pregnancy, but cleaved CASP3 was localized only to luminal epithelial (LE) cells on Days 12 and 15 of pregnancy in the endometrium. CASP7 protein was localized to endometrial LE cells only on Day 15 of pregnancy. CASP3, CASP6, CASP7, CASP8, and CASP10 mRNAs were detectable in conceptus on D12 and D15 of pregnancy, and chorioallantoic tissues expressed CASP3, CASP6, CASP7, CASP8, CASP8, and CASP10 with increasing levels toward term pregnancy, except CASP3 mRNA. The effect of steroid hormones and interleukin-1βß (IL1B) on CASP3 expression and the effect of interferon-γ(IFNG) on CASP7 expression was determined by endometrial explant cultures and we found that CASP3 expression was increased by IL1B and CASP7 expression was increased by IFNG in a dose-dependent manner. These results showed that caspases were expressed in the endometrium during the estrous cycle and pregnancy in a stage- and/or pregnancy-specific dependent manner and some caspases were regulated by IL1B or IFNG in the endometrial tissues, suggesting that caspase may play an important role in regulating apoptosis for the establishment and maintenance of pregnancy at the maternal-conceptus interface in pigs.

Porcine litter size is a quantitative trait and its heritability is especially low. So it is necessary to identify porcine reproductive gene and protein. The establishment of pregnancy requires performance of a receptive endometrium. We analyzed the endometrial tissue protein of porcine and would find out biomarker proteins related to porcine litter size. We sorted the two groups according to litter size of porcine: a small litter size group (SLSG) (n=2) and a large litter size group (LLSG) (n=2). The porcine endometrial tissue samples were analyzed separately using 2-dimensional electrophoresis (2-DE) within the isoelectric point ranges of 3.0 to 10.0, and then differential proteins were identified using MALDI-TOF analysis. In comparison of SLSG(small litter size group) with LLSG(large litter size group), a total of 9 protein spots differentially expressed on porcine endometrial tissue 2-DE gels, among which 5 spots were up-regulated proteins as retinol dehydrogenase 16-like isoform 1, Acrosin-binding protein, alpha-N-acetylgalactosaminidase. phosphoglycerate kinase 2, Acrosin-binding protein in LLSG. And 4 spots were up-regulated proteins as phosphoglycerate kinase 2, prenylcysteine oxidase in SLSG.

The mesenchymal stem cells (MSC) has been investigated as a source of stem cell therapy to replace and treat damaged cells. Human endometrial epithelial and stromal cells was isolated from hysterectomy tissue and the direct evidence of stem/progenitor cells in the human endometrium was identified. Endometrium derived stem cells (EnMSCs) are known to have a high proliferative ability, genetic stability, lack of tumorigenicity and low immnunogenicity during long-term cultivation. Here, we aimed to identify MSC in canine endometrium and characterize its potential to differentiate into decidua cells. EnMSCs were isolated from thrown-away spayed uterus of adult canine depending on their estrus cycle, and identified by flow cytometry, immunocytochemistry and flow cytometry with MSC specific markers. We then characterized the ability of EnMSCs by the doubling-time analysis, colony-forming units and MSC differentiation assays. Isolated EnMSCs expressed stem cell specific genes (Sox2, Oct4, Nanog, MCAM, Endoglin, Susd2 and IGTB) and MSC surface markers (CD90, CD44 and CD117). EnMSCs are also differentiated into adipogenic, osteogenic and chondrogenic cells morphologically under modified conditions with the expression of lineage specific genetic markers. EnMSCs showed higher proliferation ability than canine amniotic fluid derived MSCs which were used as a positive control. EnMSCs were cultured at low density (10, 20, cells/cm2) and initiated to form small colonies of loosely-arranged cells and gradually formed large colonies of densely-packed cells which underwent self-renewal with high proliferative potential which is similar to the clonogenicity feature of human endometrium-derived stem cells. EnMSCs were then induced to differentiate into decidua cells with 0.5 mM dbcAMP. After 14 days, EnMSCs changed their morphology into the elongated and rounded shape. The induced decidual cells expressed PRL and IGFBP1 which are typically expressed in decidua cells. In conclusion, we successfully isolated and characterized MSC in the canine endometrium which differentiated into decidua cells. These results showed that endometrium may be a promising source of stem cells, and furthermore raise the possibility of canine EnMSCs as a novel hypothetical decidualisation model of infertility associated with decidualisation insufficiency and implantation failure.

Pro-inflammatory cytokines, interleukin-1β (IL1B), IL6, and tumor necrosis factor-alpha (TNF), are known to play important roles in regulating the endometrial function in the uterus during the estrous cycle and pregnancy in several species. However, the expression and function of these cytokines and their receptors in the uterine endometrium during the estrous cycle have not been studied in pigs. Thus, this study determined the expression and regulation of IL1B, IL6, TNF and their respective receptors, IL1R1, IL1RAP, IL6R, GP130, TNFRSF1A, and TNFRSF1B during the estrous cycle in pigs. To analyze levels of each gene expression in the uterine endometrium we obtained from endometrial tissues on Days 0, 3, 6, 9, 12, 15, and 18 of the estrous cycle. Real-time RT-PCR analysis showed that levels of IL1B, IL1RAP, IL6R, GP130, TNF, TNFRSF1A, and TNFRSF1B mRNAs were highest on Day 15 or 18 of the estrous cycle, which corresponds to the proestrus period. Levels of IL1R1 were highest on Day 0, while levels of IL6 were biphasic with high levels on Day 6 and Day 15. The abundance of IL1B, IL6, IL6R, and TNF mRNAs was decreased by progesterone, while levels of GP130 were increased by progesterone in endometrial tissue explants. These results showed that expression of pro-inflammatory cytokines and their receptors changed stage-specifically during the estrous cycle and regulated by progesterone in the uterine endometrium in pigs, suggesting that these pro-inflammatory cytokines may be involved in the regulation endometrial function during the estrous cycle in pigs.

The migration, adhesion, and proliferation of conceptuses during pregnancy are tightly controlled processes that are mediated by various factors including cytokines, growth factors, and hormones. Among many factors, chemokines play key roles in lymphocyte trafficking, cellular proliferation, vascularization, and embryogenesis in many mammalian species. Especially, it has been shown that C-X-C chemokine ligand 12 (CXCL12) plays an important role in early pregnancy by promoting trophoblast invasion, proliferation, and differentiation through its receptor, C-X-C chemokine receptor 4 (CXCR4) in humans. However, expression and function of CXCL12 in the uterine endometrium during pregnancy have not been well studied in pigs. Thus, we determined expression of CXCL12 and its receptor, CXCR4, in the uterine endometrium during the estrous cycle and pregnancy in pigs. We obtained endometrial tissues from gilts on day (D) 12 and D15 of the estrous cycle and D12, D15, D30, D60, D90, and D114 of pregnancy, conceptus tissues from D12 and D15 of pregnancy, and chorioallantoic tissues from D30, D60, D90, and D114 of pregnancy. Real-time RT-PCR analysis showed that levels of CXCL12 and CXCR4 mRNAs changed in the uterine endometrium during pregnancy. Levels of CXCL12 and CXCR4 mRNAs on D15 of pregnancy were higher than those on D15 of the estrous cycle. After D15 of pregnancy levels of CXCL12 and CXCR4 mRNAs gradually decreased toward term of pregnancy, and CXCL12 and CXCR4 were expressed in the chorioallantoic tissues during the mid- to late pregnancy. CXCL12 and CXCR4 mRNAs were expressed in chorioallantoic tissues during mid- to late pregnancy, and RT-PCR analysis showed that CXCL12 and CXCR4 mRNAs were detectable in conceptus on D12 and D15 of pregnancy. Immunohistochemistry showed that CXCL12 proteins were localized to endometrial luminal and glandular epithelial cells during the estrous cycle and pregnancy, and to chorionic epithelial cells during mid- to late pregnancy. Abundance of CXCL12 mRNAs, but not CXCR4, in the uterine endometrium was increased by the treatment of IFNG. These results showed that CXCL12 and CXCR4 were expressed in the uterine endometrium, conceptus, and chorioallantoic tissues and IFNG increased endometrial CXCL12 expression in pigs, suggesting that CXCL12 and its receptor may play a key role in regulation of the establishment and maintenance of pregnancy by affecting the conceptus development in pigs. [supported by the Next Generation BioGreen 21 Program (#PJ01110301), Rural Development Administration]

For the establishment and maintenance of successful pregnancy the maternal immune system must tolerate semi-allogenic fetus during pregnancy. Several mechanisms explaining immune tolerance have been proposed. Among those, it has been suggested that the CD40/CD40L system is involved in immune tolerance in several tissues. However, expression and function of CD40/CD40L in the maternal-fetal interface during pregnancy have not been studied in pigs. Thus, this study determined expression and localization of CD40 and CD40L in the uterine endometrium during pregnancy in pigs. We obtained uterine endometrial tissue samples from day (D) 12 and D15 of the estrous cycle and from D12, D15, D30, D60, D90 and D114 of pregnancy. Quantitative real-time PCR analysis showed that levels of CD40L mRNA expression during pregnancy increased on D15 of pregnancy and decreased thereafter whereas levels of CD40 mRNA was highest on D30 of pregnancy. Localization of CD40 and CD40L proteins by immunohistochemistry showed that CD40 was localized to vascular endothelial cells with strongest signal intensity on D15 of pregnancy, and CD40L was localized to luminal epithelial cells on D15 of pregnancy and amniotic membrane during mid- to late pregnancy. To determine the effect of IFNG on CD40 and CD40L expression, we took advantage of endometrial explant culture using tissues from D12 of the estrous cycle, and found that CD40 was up-regulated by IFNG in a dose-dependent manner. These results showed that CD40 and CD40L were expressed in the uterine endometrium in a cell-type and stage-specific fashion during pregnancy, and IFNG induced CD40, indicating that the CD40/CD40L system may be important for establishment and maintenance of pregnancy in pigs. [Supported by the Next Generation BioGreen21 Program (#PJ01110301), Rural Development Administration]

Progesterone regulates endometrial functions to support implantation, placentation, and fetal/placental development in the uterus. It is known that actions of progesterone are mediated by nuclear progesterone receptor (PGR), using the signaling pathway referred to the genomic pathway. However, all physiological progesterone actions cannot be explained by the genomic pathway via PGR, and it is understood that there are non-genomic actions of progesterone though membrane progesterone receptors, progesterone receptor membrane components (PGRMCs) and progestin and adipoQ receptors (PAQRs). The expression and localization of PGRMCs and PAQRs has been reported in female reproductive tissues of several species such as human, mouse and cattle. Previously, we have shown that PGRMCs and PAQRs are expressed in the porcine uterine endometrium during the estrous cycle and pregnancy. However, the regulatory mechanism for expression of PGRMCs and PAQRs in the uterine endometrium has not been studied in pigs. Thus, to understand the regulatory mechanism of PGRMC1, PGRMC2, PAQR5, PAQR6, PAQR7, PAQR8, and PAQR9 expression in the uterine endometrium during the estrous cycle and pregnancy in pigs, we determined the effect of steroid hormones estrogen and progesterone on expression of PGRMCs and PAQRs using the endometrial tissue explants for immature pigs. Levels of PGRMC1, PGRMC2, PAQR5, PAQR6, PAQR7, PAQR8, and PAQR9 mRNAs were increased by increasing doses of progesterone, but not by estradiol in the uterine endometrium. Blocking PGR by treatment of RU486, a progesterone receptor antagonist, increased levels of endometrial PGRMCs and PAQRs mRNA. These data showed that membrane progesterone receptors were induced by progesterone in the uterine endometrium, suggesting that these membrane progesterone receptors may play an important role in mediating progesterone actions in the uterine endometrium for regulation of the estrous cyclicity and pregnancy. [Supported by the Next Generation Biogreen 21 Program (# PJ01119103), Rural Development Administration, Republic of Korea]

This study was to investigate effect of progesterone (P4) on prostaglandin (PG) synthases and plasminogen activators (PAs) system in bovine endometrium during estrous cycle. Endometrium tissues were collected from bovine uterus on follicular and luteal phase and were incubated with culture medium containing 0 (Control), 0.2, 2, 20 and 200 ng/ml P4 for 24 h. The PGF2α synthase (PGFS), PGE2 synthase (PGES), cyclooxygenase-2 (COX-2), urokinase PA (uPA), and PA inhibitors 1 (PAI-1) mRNA in bovine endometrium were analyzed using reverse transcription PCR and PA activity was measured using spectrophotometry. In results, COX-2 was higher at 2 ng/ml P4 group than control group in luteal phase (p<0.05), but, it did not change in follicular phase. Contrastively, PGES was significantly increased in 2 ng/ml P4 group compared to control group in follicular phase, but there were no significant differ among the treatments in luteal phase. uPA was no significant difference between P4 treatment groups and control group in both of different phase. PAI-1 was decreased in 20 ng/ml P4 group compared to control group in follicular phase (p<0.05). PA activity was decreased in 2 ng/ml P4 group compared to other groups in follicular and luteal phase (p<0.05). In conclusion, we suggest that P4 may influence to translation and post-translation process of PG production and PA activation in bovine endometrium.

Cows may suffer impaired ovarian function, often accompanied by reduced conception rates and increased embryonic loss. Cystic ovarian disease (COD) is one of the most frequently diagnosed gynecological findings in dairy cattle. It causes temporary infertility and is likely to affect reproduction as well as production parameters in cattle. Therefore, the purpose of this study was to determine the expression patterns of apoptosis (Bcl-2, Bax), implantation (E-cadherin) and immune related proteins (TNF-α, IL-10) in uterine endometrium of Hanwoo (Korean native cattle) with ovarian cyst and normal ovarian follicles. In the Western blot analysis, the expression of anti-apoptotic Bcl-2 protein was significantly higher in endometrium with normal ovarian follicles, whereas expression of pro-apoptotic Bax protein was significantly lower. Also, the expressions of E-cadherin and TNF-α proteins were significantly higher in uterine endometrium with normal ovarian follicles. On the other hand, the expression of IL-10 protein was significantly lower in uterine endometrium with normal ovarian follicles. Taken together, our results provided that the expressions of apoptosis, adhesion and immune related proteins in uterine endometrium with ovarian cyst were showed the aberrant patterns, and we suggest that different expression changes of these proteins may be affect to pregnancy ability of cattle.

Prostaglandins (PGs), especially PGE2 and PGF2α, are critical local mediators that play important role in luteolysis and maternal recognition of pregnancy in pigs. Luteolysis during the estrous cycle in pigs is induced by PGF2α synthesized and secreted by the uterine endometrium. In pregnant pigs, PG synthesis is changed in favor of PGE2 synthesis. However, molecular and cellular mechanisms by which PGE2 and PGF2α are produced in the uterine endometrium during pregnancy are poorly understood. Therefore, we determined immunolocalization of PTGES, AKR1B1, CBR1, and HPGD that are involved in synthesis and catabolism of PGE2 and PGF2α in the uterine endometrium during the estrous cycle and pregnancy in pigs. Uterine endometrial tissue samples were collected from day (D) 12 and D15 of the estrous cycle and from D12, D15, D30, D60, D90, and D114 of pregnancy. Spatial expression of all proteins studied was analyzed by immunohistochemistry. PTGES were localized primarily to luminal and glandular epithelial cells. AKR1B1 were localized to luminal epithelial cells during early pregnancy and chorionic membrane during mid- to late pregnancy. CBR1 and HPGD were localized to luminal epithelial cells. Our results showed that expression of proteins responsible for synthesis and catabolism of PGE2 and PGF2α were dynamically regulated in the uterine endometrium during the estrous cycle and pregnancy in pigs. These results indicate that PGs play critical roles to support the establishment and maintenance of pregnancy at the maternal-fetal interface in pigs. This research was supported by the Next Generation BioGreen 21 program (#PJ007997), RDA, Republic of Korea.

Cathepsins (CTSs), a family of lysosomal cysteine proteases, and their inhibitors (CSTs) play a critical role in remodeling of the uterine endometrium and placenta for the establishment and maintenance of pregnancy in many animal species including rodents, sheep, cow and pigs. It has been shown that the high rate of pregnancy failure by somatic cell nuclear transfer (SCNT) is associated with abnormal placental development. Our previous study has shown that CST6 is highly expressed in the uterine endometrium from mid to late pregnancy in pigs. In this study, to understand whether appropriate endometrial and placental tissue remodeling occurs in the uterine endometrium from gilts with conceptuses derived from SCNT during pregnancy in pigs, we investigated expression of CST6 in the uterine endometrium. Uterine endometrial tissues were obtained from gilts that carried SCNT-derived normal conceptuses (NT-No) and abnormal conceptuses (NT-Ab), and from gilts carrying conceptuses from natural mating (Non-NT) on D114 of pregnancy. Immunoblot analysis showed that CST6 protein levels in the endometrial tissues of gilts carrying NT-No were lower than those of gilts carrying Non-NT. The levels of CST6 protein in the endometrial tissues of gilts carrying NT-Ab decreased even more than those of gilts carrying NT-No. These results indicate that decreased expression of CST6 in the endometrium with NT-No and NT-Ab reflects inappropriate endometrial tissue remodeling and pregnancy failure of pigs with SCNT derived conceptuses and that CST6 plays an important role for the maintenance of pregnancy in pigs. * This work was supported by the Next Generation BioGreen 21 program (#PJ007997), RDA, Republic of Korea.

Na+/K+-ATPase, an energy-transducing ion pump, is responsible for maintenance of relatively high concentrations of potassium ions but low concentrations of sodium ions in the cell by transport of these ions across the plasma membrane and participates in transport of various nutrients including glucose, amino acids. and ions. Na+/K+-ATPase consists of α, β, and FXYD subunits, but only α and β subunits are needed for basic functions. FXYD subunit is an auxiliary protein for αβ complex of Na+/K+-ATPase. Our recent study has shown that α (ATP1A1-4) and β (ATP1B1-3) subunits of Na+/K+-ATPase are expressed in the uterine endometrium during the estrous cycle and pregnancy in pigs. In this study, we further determined expression of FXYD (FXYD1-7) subunits of Na+/K+-ATPase in the uterine endometrium during the estrous cycle and pregnancy in pigs. Real-time RT-PCR analysis showed that mRNAs for all subtypes of FXYD subunit were expressed in the uterine endometrium during the estrous cycle and pregnancy in a pregnancy status- and stage-specific fashion. In situ hybridization analysis exhibited that transcripts of all subtypes of FXYD subunit were primarily localized to luminal (LE) and glandular epithelia (GE) during the estrous cycle and early pregnancy and to chorionic membrane (CM) during mid to term pregnancy. RT-PCR analysis showed that FXYD subunits were expressed in conceptuses on D12 and D15 of pregnancy. These results indicate that all subtypes of FXYD subunit are expressed in the uterine endometrium and conceptuses during the estrous cycle and pregnancy in a pregnancy status- and stagespecific manner. These suggest that FXYD may be involved in the establishment and maintenance of pregnancy by regulating the activity of Na+/K+-ATPase in nutrient transport at the maternal-fetal interface in pigs. * This work was supported by the Next Generation BioGreen 21 program (#PJ007997), RDA and the National Research Foundation (NRF #2010-0012304) funded by the Korean Government, Republic of Korea.