Seung Kwon Yoo

Human embryonic stem cells (hESCs) need feeder cells for their maintenance in an undifferentiated state. In conventional culture systems, mouse to maintain hESCs. However, the use of MEFs elevates the risk of transmitting mouse pathogens and thus limits the potential of hESCs in cell replacement therapy. Consequently, the use of human feeder cells would be an important step forward in this in vitro technology. To address this issue, we used fibroblast-like cells differentiated from the Miz-hES6

The mitochondrial pathway of swine influenza virus (SIV)-induced apoptosis was investigated using porcine kidney (PK-15) cells, swine testicle (ST) cells, and HeLa cervical carcinoma cells which are known not to support viral replication. As judged by cell tation, PK-15 and ST cells infected with three different subtypes of SIV (H1N1, H3N2, and H1N2) were obviously killed by apoptosis, not necrosis. SIV infection in PK-15 and HeLa cells was shown to decrease the cellular levels of Bcl-2 protein

Recent evidence has suggested that human skin fibroblasts may represent a novel source of therapeutic stem cells. In this study, we report a 3-stage method to induce the differentiation of skin fibroblasts into insulin-producing cells (IPCs). In stage 1, we establish the isolation, expansion and characterization of mesenchymal stem cells from human labia minora dermis-derived fibroblasts (hLMDFs) (stage 1: MSC expansion). hLMDFs express the typical mesenchymal stem cell marker proteins and can d

We have established in culture a spontaneously immortalized bovine embryonic fibroblast (BEF) cell line that has lost p53 and p16INK4a functions. MyoD is a musclespecific regulator capable of inducing myogenesis in a number of cell types. When the BEF cells were transduced with MyoD they differentiated efficiently to desmin- positive myofibers in the presence of 2% horse serum and 1.7 nM insulin. The myogenic differentiation of this cell line was more rapid and obvious than that of C2C12 cells,

To investigate the ability of 1.8 kb or 3.1 kb bovine beta-casein promoter sequences for the expression regulation of transgene in vivo, transgenic mice were produced with human type II collagen gene fused to 1.8 kb and 3.1 kb of bovine beta-casein promoter by DNA microinjection. Five and three transgenic founder mice were produced using transgene constructs with 1.8 kb and 3.1 kb of bovine beta-casein promoters respectively. Founder mice were outbred with the wild type to produce F1 and F2 prog

Using normal canine embryonic fibroblasts (CaEF) that were shown to be senescent at passages 7th-9th, we established two spontaneously immortalized CaEF cell lines (designated CGFR-Ca-1 and -2) from normal senescent CaEF cells, and an immortal CaEF cell line by exogenous introduction of a catalytic telomerase subunit (designated CGFR-Ca-3). Immortal CGFRCa- 1, -2 and -3 cell lines grew faster than primary CaEF counterpart in the presence of either 0.1% or 10% FBS. Cell cycle analysis demonstrate

Capsaicin is a major constituent of hot chili peppers that influences lipid metabolism in animals. In this study, we explored the effects of capsaicin on adipogenic differentiation of bovine bone marrow mesenchymal stem cells (BMSCs) in a dose- and time-dependent manner. The BMSCs were treated with various concentrations of capsaicin (0, 0.1, 1, 5, and 10 μM) for 2, 4, and 6 days. Capsaicin suppressed fat deposition significantly during adipogenic differentiation. Peroxisome proliferator-activat

Although primary bovine embryonic fibroblast (BEF)cells have previously been used as nucleus-donors fornuclear transfer (NT), it has now been proposed to useBEF cells to generate cloned cows that were geneticallymodified by transgenic or a knock-out system. A majorlimitation to gene targeting somatic cells, however, is theoverall life-span of the cell. In this study, we first examinedin vitro life-span of primary BEF cells. Primary BEFcells were found to be replicative senescent at passage10th−1

One of distinct genetic alterations in spontaneously immortalized DF-1 cells was found to be dysfunction of p53 and E2F-1 as well as altered antioxidant gene expression (upregulation of MnSOD and downregulation of catalase). We have characterized the cellular responses of primary and immortal DF-1 cells to oxidative stress and found that DF-1 cells were more sensitive to oxidative stress than their primary counterparts when treated with antimycin A. The increased DF-1 cell death by oxidative str

We have established three immortal bovine muscularepithelial (BME) cell lines, one spontaneously immortalized(BMES), the second SV40LT-mediated (BMEV)and the third hTERT-mediated (BMET). The morphologyof the three immortal cell lines was similar tothat of early passage primary BME cells. Each of theimmortal cell lines made cytokeratin, a typical epithelialmarker. BMET grew faster than the other immortallines and the BME cells, in 10% FBS-DMEM medium,whereas neither the primary cells nor the thre

GRAS (generally recognized as safe) 하며 열에 민감한 기능성 물질의 전달체로 이용될 수 있는 beta-lactoglobulin (β-Lg) 나노입자 연구는 건강 기능성 유식품 개발에 기여 할 수 있다. 본 연구에서는 protein self-assembly 방법을 이용하여 β-Lg나노입자를 제조하고, 투과 전자 현미경과 분광광도계를 이용하여 β-Lg나노입자 제조 공정요인에 따른 나노입자의 구조 형태 및 화학적 특성 연구가 수행 되었다. 65℃ 열처리 온도와 1mM CaCl₂에서는 β-Lg나노입자가 형성 되지 않았다. 그러나 CaCl₂농도가 2mM에서 5mM로 증가 함 에 따라 나노입자 형성이 관찰 되었고 그 입자 크기도 점차 증가함을 알 수 있었다. 또한 CaCl₂농도가 증가 할수록 turbidity 값이 증가하였다. 이러한 CaCl₂농도 증가에 따른 나노입자의 구조적 변화는 β-Lg와 Ca² 사이의 정전기적 상호작용이 중요한 요인임을 알 수 있었다. 열처

This study was performed to determine the developmental potentials of nuclear transfer (NT) embryos using life-span extended cells transfected with a foreign gene as donor cells. A life-span extended bovine embryonic fibroblast cell line was transfected with an expression vector in which the human type II collagen (BOMAR) and ear fibroblasts were used as a donor cell. Cytogenetic analysis was performed to analyze the chromosomal abnormality of donor cells. The fusion rate of 1.8 kV/cm for 15 ??s

Changes in milk quality during storage of extended shelf life milk (ESL milk) and non-ESL milk were evaluated. No significant differences were observed between ESL and typical ultra high temperature-treated (UHT) milk in physicochemical properties including non-casein nitrogen (NCN) content, whey protein nitrogen index (WPNI), and L-ascorbic acid content. Low temperature and long time-treated milk (LTLT milk) had significantly higher NCN content and WPNI than those of UHT milk. In terms of micro

BACKGROUND: Immunoglobulin A (IgA) nephropathy (IgAN) is one of an important cause of progressive kidney disease and occurs when IgA settles in the kidney resulted in disrupts kidney’s ability to filter waste and excess water. Hydrogels are promising material for medical applications owing to their excellent adaptability and filling ability. Herein, we proposed a hyaluronic acid/gelatin (CHO-HA/Gel-NH2) bioactive hydrogel as a cell carrier for therapeutic kidney regeneration in IgAN. METHODS: CH

The generation of induced pluripotent stem cells (iPSCs) from somatic cells demonstrated that adult mammalian cells can be reprogrammed into a pluripotent state by introducing defined transcription factors. iPSCs show almost identical properties in self-renewal and pluripotency, and can circumvent ethical concerns because they do not use embryonic materials. Therefore, iPSCs from a patient’s somatic cells have great potential in studying drug development and regenerative medicine. Several human