In our previous studies, the cardiac xenotransplantation from an alpha-1,3-galactosyltransferase knockout pig (GT-MCP-MCP) to cynomolgus monkeys showed a mean survival of 38 days. The objective of this study is to genetically upgrade the GT-MCP-MCP pig, to further enhance membrane cofactor protein (MCP) expression and to express an endothelial specific thrombomodulin (TBM). MCP is a complement regulatory protein and TBM is a coagulation inhibitor. As the dicistronic cassette for wild-type-based MCP and TBM concurrent expressions does not show any increase of MCP, we optimized the MCP codon usage (mMCP) and substituted mMCP for MCP. When the mMCP-TBM cassette was transfected to HeLa cells, we were able to find an increased expression of MCP and endothelial cell-specific TBM expression. The cassette was then transfected into ear-skin fibroblasts isolated from one-month-old #23-4 of a GT-MCP-MCP pig, and the cell populations expressing MCP were obtained by MACS cell sorting. We performed a single cell culture of the selected cells, and obtained clones over expressing 90% MCP. The cells of a clone were used as a donor for nuclear transfer and generated GT-MCP/-MCP/mMCP/TBM pig. The transgenic pig was confirmed to be carrying the cells expressing MCP and functioning as an inhibitor against the cytotoxic effect of normal monkey serum, comparable with donor cells. Thus, we believe that the GT-MCP/-MCP/mMCP/TBM transgenic pig would be potential for the prolongation of xenograft survival in the recipients.

The aim of this study was performed to evaluate the effects of ice-binding protein from the arctic yeast Leucosporidium (LeIBP) supplementation on cryopreservation of boar sperm. The collected semen was diluted (1.5×108/ml) in lactose egg yolk (LEY) and cooled at 5°C for 3 h. The cooled semen was then diluted (1×108/ml) in LeIBP containing LEY with 9% glycerol and maintained at 5°C for 30 min. The semen was divided into six experimental groups (control, 0.001, 0.005, 0.01, 0.05 and 0.1 mg/ml of LeIBP). The straws were kept on above the liquid nitrogen (LN2) vapors for 20 minutes and then plunged into LN2. After thawing, computer-assisted sperm analysis was used for sperm motility and flow cytometry was performed to assess the viability, acrosome integrity (FITC-PSA/PI), ROS (DCF/PI), lipid peroxidation (BODIPY C11/PI) and apoptosis (Annexin V/PI), respectively. No significant responses were observed for sperm motility. However, sperm viability was significantly increased on 0.05 and 0.1 mg/ml of LeIBP groups compared to control (P < 0.05). In addition, acrosome integrity was significantly increases LeIBP groups (P < 0.05) and both ROS and lipid peroxidation level were lower in all LeIBP groups than those of control (P < 0.05). On the other hand, a significant higher apoptosis rate was observed in 0.05 and 0.1 mg/ml of LeIBP groups compared to control (P < 0.05). It can be assumed that a supplementation of LeIBP in boar sperm freezing extender is an effective method to increase the sperm qualities after cryopreservation.

The identification of biomarkers of a living tissues is essentially required to understand specific functions of the cells. In previous study, we reported IGFBP 3 as one of the putative biomarkers, by showing specific expression at porcine spermatogonial stem cells (SSCs) of early stage of porcine testis. In this study, we analyzed the expression of seven members of IGFBP family (IGFBPs) in SSCs and histological expression pattern of pregnancy-associated plasma protein-A (PAPP-A), which plays a role on the growth promoting enzyme by cleavage of IGFBPs in testis of 5 days old pig. RT-PCR analysis showed that IGFBP 1, 2, 3, 4, and 6 were expressed at high level specifically in porcine SSCs compared with whole testis. We performed immunohisotochemical staining of testis sections with PAPP-A and protein gene product 9.5 (PGP9.5) which are the known biomarkers for SSCs. We were not able to find co-expression of PAPP-A and PGP9.5; PAPP-A was expressed only in Sertoli cells and PGP9.5 expression was confirmed in spermatogonium. Additionally, we were able to confirm the GATA4 expression in Sertoli and Leydig cells as a regulator of Sertoli cell function was not detected PGP9.5 expressing cells, indicating indirect evidence of that cytolocalization of PAPP-A expression is limited in Sertoli cells. These results suggested that the PAPP-A expressed in Sertoli cells may play role on regulation of development and differentiation of testicular cells through the IGF axis in neonatal porcine testis.

Acute vascular rejection has been known as a main barrier occurring in a xenograted tissue of alpha 1,3-galactosyltransferase knock-out (GalT KO) pig into a non-human primate (NHP). Adenosine which is a final metabolite following sequential hydrolysis of nucleotide by ecto-nucleotidases such as CD39 and CD73, act as a regulator of coagulation, and inflammation. Thus xenotransplantation of CD39 and CD73 expressing pig under the GalT KO background could lead to enhanced survival of recipient NHP. We constructed a human CD39 and CD73 expression cassette designed for endothelial cell-specific expression using porcine Icam2 promoter (pIcam2-hCD39/hCD73). We performed isolation of endothelial cells (pAEC) from aorta of 4 week-old GalT KO and membrane cofactor protein expressing pig (GalT-MCP/-MCP). We were able to verify that isolated cells were endothelial-like cells using immunofluorescence staining analysis with von Willebrand factor antibody, which is well known as an endothelial maker, and tubal formation assay. To find optimal condition for efficient transfection into pAEC, we performed transfection with GFP expression vector using four programs of nucleofection, M-003, U-023, W-023 and Y-022. We were able find that the program W-023 was optimal for pAEC with regard to viability and transfection efficiency by flow cytometry and fluorescent microscopy analyses. Finally, we were able to obtain GalT-MCP/-MCP/CD39/CD73 pAEC expressing CD39 and CD73 at levels of 33.3% and 26.8%, respectively. We suggested that pACE isolated from GalT-MCP/-MCP pig might be provided as a basic resource to understand biochemical and molecular mechanisms of the rejections and as an alternative donor cells to generate GalT-MCP/-MCP/CD39/CD73 pig expressing CD39 and CD73 at endothelial cells.

Phosphoprotein Enriched in Astrocytes (PEA15) is a 15kD-sized intracellular signaling protein, highly expressed in astrocytes and constitutively expressed in peripheral tissues. Recently it was found that PEA15 expression was elevated in patients suffering type 2 diabetes and suggested to be involved in the syndrome of insulin resistance. To investigate the functional role of PEA15 for the control of blood glucose level, we produced a transgenic pig over-expressing mouse PEA15 (mPEA15). As a model animal, pig has many advantages. They have a higher fecundity and a short generation time and are physiologically similar to human. Using the transgenic pig, we carried out a series of experiments to establish a link between PEA15 expression and the insulin resistance. Our results suggested that, compared with control pig, mPEA15 pig has, (1) a higher blood resistin level, (2) a lower cell membrane-embeded GLUT4 level, and (3) a lower glucose clearing ability based on oral glucose tolerance test (OGTT). When our results combined, it can be concluded that mPEA15 over-expressing pig has many symptoms of insulin resistance and these pigs will become a useful disease model to investigate diabetes mellitus in the near future.

Oct4 and Nanog are well-known transcription factors related with self renewal of embryonic stem cell. In low-dose of Nanog, transcription of oct4 is increased; however, oct4 is down-regulated upon high-dose of Nanog. There is a negative feedback loop between oct4 and Nanog. To identify this regulation, we generated 4 nested sets for mouse oct4 promoter. Luciferase activities of oct4 were declined upon high-dose Nanog in all constructs. The declined effects of oct4 upon high-dose Nanog were moderated with DNMT and HDAC inhibitors (5-AZA-cytidine and trichostatin A) in 3 constructs (1867, 1346, 754). But, one construct (2179) was only sensitive to TSA. Taken together, these effects were also represented in semi-quantitative RT-PCR and Western blotting data. These data suggest that negative regulation of oct4 gene upon high-dose Nanog would be accomplished by DNMT and HDAC. Further, it will be studied whether these constraining molecules bind to CR1-4 region of oct4 promoter upon low- and high-dose of Nanog.

The overexpression of Phosphoprotein Enriched in Astrocytes (PEA15) gene is commonly found in human diabetic patients. The overexpression of this gene in skeletal muscle and fat tissues have been reported to cause insulin resistance, thereby impairing insulin stimulated glucose uptake. We introduced a gene of mouse PEA15 (mPEA15) and enhanced green fluorescent protein (EGFP) into fertilized one cell pig zygotes using microinjection, and produced a piglet that showed overexpression of mPEA15 in the muscle tissues and expression of EGFP in the ear tissues and hooves. RT-PCR RFLP, southern blot and FISH analysis showed that the tissues carried the transgene. Real-time RT-PCR and western blots demonstrated that PEA15 gene was overexpressed in the various tissues and muscle tissues, respectively. These facts suggest that expression vector system is normally expressed in the trnasgenic (TG) pigs. To use as animal diseases model for type 2 diabetes, further study is necessary to confirm whether diabetes occur in these TG pigs, especially insulin resistance.

Previously, we reported that the osmolarity conditions in the satellite region were affected CpG DNA methylation status while Pre-1 sequence was not affected CpG DNA methylation in pNT blastocyst stage. This study was conducted to investigate the DNA methylation status of repeat sequences in pig nuclear transfer (pNT) embryos produced under different osmolarity culture conditions. Control group of pNT embryos was cultured in PZM-3 for six days. Other two treatment groups of pNT embryos were cultured in modified PZM-3 with 138 mM NaCl or 0.05 M sucrose (mPZM-3, 320 mOsmol) for two days, and then cultured in PZM-3 (270 mOsmol) for four days. The DNA methylation status of the Pre-1 sequences in blastocysts was characterized using a bisulfite-sequencing method. Intriguingly, in the present study, we found the unique DNA methylation at several non-CpG sequences at the Pre-1 sequences in all groups. The non-CpG methylation was hypermethylated in all three groups, including in vivo group (86.90% of PZM- 3; 83.87% of NaCl; 84.82% of sucrose; 90.94% of in vivo embryos). To determine whether certain non-CpG methylated sites were preferentially methylated, we also investigated the methylation degree of CpA, CpT and CpC. Excepting in vivo group, preference of methylation was CpT>CpC>CpA in all three groups investigated. These results indicate that DNA methylation of Pre-1 sequences was hypermethylated in CpG as well as non-CpG site, regardless modification of osmolarity in a culture media.

Ganoderma lucidum has long been used as a potent medicinal plant. In addition, recent studies showed that G. lucidum is used to prevent or treat various human diseases such as allergy, hepatopathy, hypertension, cancer and diabetes. In this study showed that ethanol extract from G. lucidum have potential inhibitory effects of glycerol 3-phosphat acyltransferase (GPAT) activity and increase of glucose uptake on skeletal muscle cells. Inhibition of GPAT, which catalyze the first step in de novo TAG synthesis, has been proposed as one of the drug targets for insulin resistance and type-2 diabetes. G. lucidum extract inhibited GPAT activity. Bioassay-guided fractionation and isolation of bio-active substances from ethanol extracts of G. lucidum were carried out by using chromatographic techniques and in vitro GPAT enzyme assay. One of bioactive molecules, ergosterol peroxide, was isolated and identified by physical and spectral properties. In this study showed that ethanol extract from G. lucidum and ergosterol peroxide have potential anti- diabetes effects through the increase of glucose uptake. This was as sociated with increased activity AMP-activated protein kinase(AMPK). AMPK is another regulatory protein in the glucose uptake pathway and energy metabolism. The result was that the increase of glucose uptake by G. lucidum extract might be mediated by AMPK.

This study was performed to comprehend the plasma proteins expressed specifically during early pregnancy in pregnant or non-pregnant Hanwoo using proteomic analysis technique. Plasma samples (0, 2, 3, 4, 7, and 11 weeks after AI) were obtained from pregnant (P, n=3) or non-pregnant (NP, n=4) Hanwoo, respectively. To evaluate proteins differentially expressed, 2-dimensional electrophoresis (2DE) was conducted. Normalized protein spots were selected for the significant expression variation deviated over two fold in its expression level between two groups. Molecular functions of the proteins were DNA binding, protein binding, hemoglobin binding, ferrochelatase and transporter activity and arylestera, respectively. According to western blotting, haptoglobin was specifically expressed only in NP group during early pregnancy; however, paraoxonase 1 was highly expressed in pregnant group. Based on these results, pregnancy was maintained successfully by the activation of specific plasma proteins associated with immune system and antioxidant regulation during early pregnancy in Hanwoo

Osmolarity of culture media is one of the most important factors affecting in vitro development. This study was conducted to investigate the DNA methylation status of Pre-1 and satellite sequence in pig nuclear transfer (pNT) embryos produced under different osmolarity culture conditions. Control group of pNT embryos was cultured in PZM-3 for six days. Other two treatment groups of pNT embryos were cultured in modified PZM-3 with 138 mM NaCl or 0.05M sucrose (mPZM-3, 320 mOsmol) for two days, and then cultured in PZM-3 (270 mOsmol) for four days. Previous our studies have reported that pNT embryos cultured in both hypertonic media showed significantly higher blastocyst formation rate than that of control. The DNA methylation status of the satellite sequences in blastocyst was characterized using bisulfite-sequencing technology. The satellite region had a similar methylation pattern of in vivo blastocyst among two culture groups excepting the control group. Each level of methylation is that the satellite DNA moderately methylated (43.10% of PZM-3; 56.12% of NaCl; 55.06% of sucrose; 60.00% of in vivo embryos). As a result of the sequence of PRE-1, CpG methylation pattern was similar to three groups, including in vivo group. In case of the satellite DNA region, the osmolarity conditions were affected CpG DNA methylation status while PRE-1 sequence was not affected CpG DNA methylation in pNT blastocyst stage. These results indicate that the modification of osmolarity in a culture media may influence to spatially change of DNA methylation of repetitive sequence for pNT embryo development.

Abnormal development and fetal loss during the post‐implantation period are key concerns in the production of cloned animals by somatic cell nuclear transfer (SCNT). We hypothesized that the problems in cloned porcine offspring derived from SCNT are related to interactions between the conceptus and the endometrial environment. In the present study, we investigated expression patterns in the formation of placenta‐related genes (Cdx2 and GATA6) in whole in vivo normal porcine embryos (from single cell to blastocyst) and each tissue of a normal fetus at Days 25, 35 and 55 by quantitative mRNA expression analysis using real‐time PCR. The expression of Cdx2 and GATA6 mRNA increased to around the blastocyst stage. These genes were gradually decreased from the peri‐implantation to post‐implantation stage. Moreover, we examined the expression patterns of Cdx2 and GATA6 in Day 35 normal and SCNT cloned fetuses by the same methods. And, the level of Cdx2 and GATA6 gene expression in the extraembryonic tissue of SCNT was significantly higher than that of control tissues. From the present results, it can be postulated that the aberrant expression of Cdx2 and GATA6 genes in the endometrial and extraembryonic tissues at pre‐ and peri‐implantation stages may be closely related to the lower fficiency of animal cloning.