• 대한생식의학회:학술대회논문집
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• 대한불임학회 2005년도 제49차 추계학술대회
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• pp.85-85
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• 2005

• 한국가금학회:학술대회논문집
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• 한국가금학회 2001년도 제18차 정기총회 및 학술발표 PROCEEDINGS
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• pp.40-46
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• 2001

The use of pluripotent stem cells has tremendous advantages for various purposes but these cell lines with proven germ-line transmission have been completely established only in the mouse. Embryonic germ (EG) cell lines are also pluripotent and undifferentiated stem cells established from primordial germ cells (PGCs). This study was conducted to establish and characterize the chicken EG cells derived from gonadal primordial germ cells. We isolated gonadal PGCs from 5.5-day-old (stage 28) White leghorn (WL) embryos and established chicken EG cells lines with EG culture medium supplemented with human stem cell factor (hSCF), murine leukemia inhibitory factor (mLIF), bovine basic fibroblast growth factor (bFGF), human interleukin-11 (hIL-11), and human insulin-like growth factor-I (hIGF-I). These cells grew continuously for 4 months (10 passages) on a feeder layer of mitotically active chicken embryonic fibroblasts. These cells were characterized by screening with the Periodic acid-Shiff＇s reaction, anti-SSEA-1 antibody, and a proliferation assay after several passages. As the results, the chicken EG cells maintained characteristics of undifferentiated stem cells as well as that of gonadal PGCs. When cultured in suspension, the chicken EG cells successfully formed an embryoid body and differentiated into a variety of cell types when re-seeded onto culture dish. The chicken EG cells were injected into blastodermal layer at stage X and dorsal aorta of recipient embryo at stage 14 (incubation of 53hrs) and produced chimeric chickens with various differentiated tissues derived from the EG cells. The germline chimeras were also successfully induced by using EG cells. Thus, Chicken EG cells will be useful for the production of transgenic chickena and for studies of germ cell differentiation and genomic imprinting.

• Molecules and Cells
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• 제19권1호
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• pp.46-53
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• 2005

Human embryonic stem (hES) cells, unlike most cells derived from adult or fetal human tissues, represent a potentially unlimited source of various cell types for basic clinical research. To meet the increased demand for characterized hES cell lines, we established and characterized nine new lines obtained from frozen-thawed pronucleus-stage embryos. In addition, we improved the derivation efficiency from inner cell masses (to 47.4%) and optimized culture conditions for undifferentiated hES cells. After these cell lines had been maintained for over a year in vitro, they were characterized comprehensively for expression of markers of undifferentiated hES cells, karyotype, and in vitro/in vivo differentiation capacity. All of the cell lines were pluripotent, and one cell line was trisomic for chromosome 3. Improved culture techniques for hES cells should make them a good source for diverse applications in regenerative medicine, but further investigation is needed of their basic biology.

• Molecules and Cells
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• 제23권1호
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• pp.49-56
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• 2007

One of the goals of stem cell technology is to control the differentiation of human embryonic stem cells (hESCs), thereby generating large numbers of specific cell types for many applications including cell replacement therapy. Although individual hESC lines resemble each other in expressing pluripotency markers and telomerase activity, it is not clear whether they are equivalent in their developmental potential in vitro. We compared the developmental competence of three hESC lines (HSF6, Miz-hES4, and Miz-hES6). All three generated the three embryonic germ layers, extraembryonic tissues, and primordial germ cells during embryoid body (EB) formation. However, HSF6 and Miz-hES6 readily formed neuroectoderm, whereas Miz-hES4 differentiated preferentially into mesoderm and endoderm. Upon terminal differentiation, HSF6 and Miz-hES6 produced mainly neuronal cells whereas Miz-hES4 mainly formed mesendodermal derivatives, including endothelial cells, leukocyte progenitors, hepatocytes, and pancreatic cells. Our observations suggest that independently-derived hESCs may differ in their developmental potential.

• Mass Spectrometry Letters
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• 제7권4호
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• pp.85-90
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• 2016

Post-translational modifications (PTMs) of proteins regulate self-renewal and differentiation in embryonic stem cells (ESCs). Nitration of tyrosine residues of proteins in ESCs modulates their downstream pathways, which can affect self-renewal and differentiation. However, protein tyrosine nitration (PTN) in ESCs has been rarely studied. We reviewed 23 nitrated sites in stem cell proteins. Functional enrichment analysis showed that these nitrated proteins are involved in signal transduction, cell adhesion and migration, and cell proliferation in ESCs. Comparison between the nitrated and known phosphorylated sites revealed that 7 nitrated sites had overlapping phosphorylated sites, indicating functional links of PTNs to their associated signaling pathways in ESCs. Therefore, nitrated proteome provides a basis for understanding potential roles of PTN in self-renewal and differentiation of ESCs.

• Reproductive and Developmental Biology
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• 제35권1호
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• pp.9-15
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• 2011

The functional cardiovascular system is comprised of distinct mesoderm-derived lineages including endothelial cells, vascular smooth muscle cells and other mesenchymal cells. Recent studies in the human embryonic stem cell differentiation model have provided evidence indicating that these cell lineages are developed from the common progenitors such as hemangioblasts and cardiovascular progenitor cells. Also, the studies have suggested that these progenitors have a common primordial progenitor, which expresses KDR (human Flk-1, also known as VEGFR2, CD309). We demonstrate here that sustained activation of BMP4 (bone morphogenetic protein 4) in hESC line, CHA15 hESC results in $KDR^+$ mesoderm specific differentiation. To determine whether the $KDR^+$ population derived from hESCs enhances potential to differentiate along multipotential mesodermal lineages than undifferentiated hESCs, we analyzed the development of the mesodermal cell types in human embryonic stem cell differentiation cultures. In embryoid body (EB) differentiation culture conditions, we identified an increased expression of $KDR^+$ population from BMP4-stimulated hESC-derived EBs. After induction with additional growth factors, the $KDR^+$ population sorted from hESCs-derived EBs displays mesenchymal, endothelial and vascular smooth muscle potential in matrix-coated monolayer culture systems. The populations plated in monolayer cultures expressed increased levels of related markers and exhibit a stable/homologous phenotype in culture terms. In conclusion, we demonstrate that the $KDR^+$ population is stably isolated from CHA15 hESC-derived EBs using BMP4 and growth factors, and sorted $KDR^+$ population can be utilized to generate multipotential mesodermal progenitors in vitro, which can be further differentiated into cardiovascular specific cells.

• 생약학회지
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• 제46권1호
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• pp.52-58
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• 2015

Neural stem cells (NSCs), with self-renewal and neuronal differentiation capacity, are a feasible resource in cell-based therapies for various neurodegenerative diseases and neural tissue injuries. In this study, we investigated the effects of Schisandrae Fructus (SF) on proliferation and differentiation of human embryonic NSCs. Treatment with 70% ethanol extract of SF increased the viability of NSCs derived from human embryonic stem cells, which was accompanied by increased mRNA expression of cyclin D1. Whereas 70% ethanol extract of SF also decreased the mRNA expression of nestin, it increased class III ${\beta}$-tublin (Tuj-1) and MAP2 in both growth and differentiation media. Lastly, we found increased mRNA expression of BDNF in SF-treated NSCs. In conclusion, our study demonstrates for the first time that SF induced proliferation and neuronal differentiation of NSCs and increased mRNA expression of BDNF, suggesting its potential as a regulator of NSC fate in NSC-based therapy for neuronal injuries from various diseases.

• Reproductive and Developmental Biology
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• 제38권4호
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• pp.137-142
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• 2014

A tremendous increase in the human population has put poultry industry under an increased pressure to meet steep increase in the demand. Poultry is contributing 25% of the total world's meat production and lesser cost of investment per bird makes it more suitable for the further breeding programmes. Major poultry diseases frequently lead to cardiac damage and cause huge economic losses to poultry industry due to mortality. The in vitro embryonic stem cell (ESC) technology has a futuristic approach for homogeneous populace of differentiated cells, for their further transplantations. During in vitro conditions the differentiated cell populace can be used in grafting and transplantation processes to regenerate damaged tissues. Therefore, the current study targeted the use of spermatogonial stem cells (SSCs) in the poultry production system through cardiac regeneration. The current study will also open new boulevard for the similar kind of research in other livestock species for the management of heart diseases.

• Clinical and Experimental Reproductive Medicine
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• 제38권4호
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• pp.216-221
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• 2011

Objective: To differentiate the human embryonic stem cells (hESCs) into the retinal pigment epithelium (RPE) in the defined culture condition and determine its therapeutic potential for the treatment of retinal degenerative diseases. Methods: The embryoid bodies were formed from hESCs and attached on the matrigel coated culture dishes. The neural structures consisting neural precursors were selected and expanded to form rosette structures. The mechanically isolated neural rosettes were differentiated into pigmented cells in the media comprised of N2 and B27. Expression profiles of markers related to RPE development were analyzed by reverse transcription-polymerase chain reaction and immunostaining. Dissociated putative RPE cells ($10^5$ cells/5 ${\mu}L$) were transplanted into the subretinal space of rat retinal degeneration model induced by intravenous sodium iodate injection. Animals were sacrificed at 1, 2, and 4 weeks after transplantation, and immnohistochemistry study was performed to verify the survival of the transplanted cells. Results: The putative RPE cells derived from hESC showed characteristics of the human RPE cells morphologically and expressed molecular markers and associated with RPE fate. Grafted RPE cells were found to survive in the subretinal space up to 4 weeks after transplantation, and the expression of RPE markers was confirmed with immunohistochemistry. Conclusion: Transplanted RPE cells derived from hESC in the defined culture condition successfully survived and migrated within subretinal space of rat retinal degeneration model. These results support the feasibility of the hESC derived RPE cells for cell-based therapies for retinal degenerative disease.

• 한국미생물·생명공학회지
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• 제39권4호
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• pp.364-373
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• 2011

인간배아줄기세포는 인간배아줄기세포가 가지는 전 분화능 등의 특이적 특성으로 인해 재생의학 분야에서 세포 치료제의 근원으로 널리 각광받고 있다. 그러나, 미분화 상태의 인간배아줄기세포를 세포치료제로 이용하기 위해서는 인간배아줄기세포 주 유래 기능성 세포를 확립이 반드시 요구된다. 본 연구에서는, 미분화 상태의 인간배아줄기세포주로부터 기능성 세포의 확립을 위해, 혈관계통의 세포로 분화를 유도하였으며, 분화 유도 후 세포의 크기 차이를 이용하여 특정 세포군 만을 분리하여 그 기능성을 비교 분석하였다. 그 결과, VEGF를 이용하여 분화 시킨 세포군에서 약 10%의 PECAM 양성 세포군을 확인할 수 있었으며, 분리 및 세포 이식을 위해 세포를 단일 세포군으로 만들었다. 단일 세포군의 형성 후, 유세포 분석기를 이용한 세포 분리 기법을 이용하여 FCS를 기준으로 한 세포 크기의 차이를 이용하여 특정 세포군 만을 분리하여, 하지 허혈 동물 모델로의 이식을 통해, 비 분리 세포군과 치료 효능을 비교 분석을 실시하였다. 세포 이식 4주 후, 혈류량 복구율이 FSC 기준 분리 군의 경우 54%, 비 분리군의 경우 17%를 보이는 것을 확인하였다. 이 결과는, 초기 분화 유도 후 세포 크기차이를 이용한 세포 분리법이 기능성 세포 획득에 이용될 수 있음을 시사한다. 이와 같은 방법을 통해 다양한 종류의 기능성 세포 분리에 이용될 수 있을 것이라 생각된다.