• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.1-8
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• 2011

Techniques to evaluate gene expression profiling, such as sufficiently sensitive cDNA microarrays or real-time quantitative PCR, are efficient methods for monitoring human pluripotent stem cell (hESC/iPSC) cultures. However, most of these high-throughput tests have a limited use due to high cost, extended turn-around time, and the involvement of highly specialized technical expertise. Hence, there is an urgency of rapid, cost-effective, robust, yet sensitive method development for routine screening of hESCs/hiPSCs. A critical requirement in hESC/hiPSC cultures is to maintain a uniform undifferentiated state and to determine their differentiation capacity by showing the expression of gene markers representing all three germ layers, including ectoderm, mesoderm, and endoderm. To quantify the modulation of gene expression in hESCs/hiPSC during their propagation, expansion, and differentiation via embryoid body (EB) formation, we developed a simple, rapid, inexpensive, and definitive multimarker, semiquantitative multiplex RT-PCR platform technology. Among the 9 gene primers tested, 5 were pluripotent markers comprising set 1, and 3 lineage-specific markers were combined as set 2, respectively. We found that these 2 sets were not only effective in determining the relative differentiation in hESCs/hiPSCs, but were easily reproducible. In this study, we used the hES/hiPS cell lines to standardize the technique. This multiplex RT-PCR assay is flexible and, by selecting appropriate reporter genes, can be designed for characterization of different hESC/hiPSC lines during routine maintenance and directed differentiation.

• Korean Journal of Animal Reproduction
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• v.26 no.4
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• pp.377-384
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• 2002

To investigate the expression patterns of proteins and growth factor signals in differentiated rabbit embryonic stem (ES) cells, ES cells with confluent stage grown of feeder layer and differentiated cells into embryoid bodies (EB) without feeder cell were applied to protein gel and Western blotting analysis. There were 66kDa and 28kDa specifically expressed in differentiated ES cell but not in undifferentiated ES cell while 25kDa protein band showed up in only undifferentiated ES cells. Also there were some difference of protein bands in several area of gel between differentiated and undifferentiated ES cells such as about 100 kDa, 50kDa and 27kDa areas, but there was no difference in band pattern of one-dimensional gel analysis between mouse ES cells and rabbit ES cells. IGF-I receptor and EGF receptor were expressed in differentiated cells and undifferentiated cells. And ICF-I and EGF were not expressed in both differentiated and undifferentiated cells. These results indicated that ES cells express their own proteins to inhibit differentiation while EB cells synthesize different proteins to differentiate, and 16F-I receptor and EGF receptor were expressed in both ES and EB cells probably for the different functions.

• Korean Journal of Animal Reproduction
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• v.25 no.3
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• pp.219-225
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• 2001

To establish rabbit Embryonic Stem (ES) cells, rabbit one-cell embryos were collected and cultured in vitro to blastocysts. Blastocysts were co-cultured with mouse embryonic fibroblasts (MEF), rabbit embryonic fibroblasts (REF) or 570 cells expressing LIF (SNL). Although rabbit ES cells were isolated with low efficiencies, total 8 ES cell lines were kept in vitro with normal colony shape. The MEF was the best feeder for rabbit ES cell isolation in regard to growth rate and undifferentiated morphology. The doubling time of rabbit ES cells in MEF was about 84 hours and the undifferentiated morphology was maintained following passing and freezing processes. These rabbit ES cells were differentiated into embryoid body following the culture in the uncoated dishes, indicating that they were undifferentiated stem cells.

• Molecules and Cells
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• v.40 no.10
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• pp.737-751
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• 2017

Histone-modifying enzymes are key players in the field of cellular differentiation. Here, we used GSK-J4 to profile important target genes that are responsible for neural differentiation. Embryoid bodies were treated with retinoic acid ($10{\mu}M$) to induce neural differentiation in the presence or absence of GSK-J4. To profile GSKJ4-target genes, we performed RNA sequencing for both normal and demethylase-inhibited cells. A total of 47 and 58 genes were up- and down-regulated, respectively, after GSK-J4 exposure at a log2-fold-change cut-off value of 1.2 (p-value < 0.05). Functional annotations of all of the differentially expressed genes revealed that a significant number of genes were associated with the suppression of cellular proliferation, cell cycle progression and induction of cell death. We also identified an enrichment of potent motifs in selected genes that were differentially expressed. Additionally, we listed upstream transcriptional regulators of all of the differentially expressed genes. Our data indicate that GSK-J4 affects cellular biology by inhibiting cellular proliferation through cell cycle suppression and induction of cell death. These findings will expand the current understanding of the biology of histone-modifying enzymes, thereby promoting further investigations to elucidate the underlying mechanisms.

• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.270-270
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• 2004

이 연구는 Ⅰ) 혈관 폐색에 의한 인지 및 기억장애 동물모델에서 뇌졸중 치료제로써 인간배아줄기 세포의 신경세포 보호효과 및 작용기간을 밝히며, Ⅱ) 행동 약리학적 연구를 통해 기억력증진에 미치는 효과에 대해 밝히고 혈관 폐색에 의한 동물모델에서의 기억기능 증진 및 세포효과를 검증하고자 실시하였다. 중대 뇌동맥 폐색에 의한 쥐의 동물모델은 Sprague Dawley계 흰 쥐(260∼300 g)의 국소 중대뇌동맥을 일시적으로 폐색시켜 만들었다. 본 연구(미국 국립보건원에 등록된 MB03세포)에 사용된 인간배아줄기세포는 3×10⁴ cells/㎠ 밀도의 배양접시 내에서 4일 동안 embryoid bodies(EBs)의 형성을 위해 집합체를 이루도록 유도하였다. (중략)

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.84-84
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• 2002

This study was to investigate generation of the specific neuronal cell in vitro from the neural progenitors derived from human embryonic stem (hES, MB03) cells. For the neural progenitor cell formation, we produced embryoid bodies (EB: for 5 days, without mitogen) from hES cells and then neurospheres (for 7-10 days, 20 ng/㎖ of bFGF added N2 medium) from EB. And then for the differentiation into neuronal cells, neural progenitor cells were cultured in N2 medium (without bFGF) supplemented with brain derived neurotrophic factor (BDNF, 5 ng/㎖) or platelet derived growth factor-bb (pDGF-bb, 20ng/㎖) for 2 weeks. (omitted)

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.20-20
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• 2002

This study was to establish the use of parthenogenetic mouse ES (P-mES02) cells as a reproducible differentiation system for mouse cardiomyocytes. To induce differentiation, P-mES02 cells were dispersed by dissociation and the formation of ES cell aggregates in differentiation medium. After 7 days in differentiation culture, the embryoid bodies (EBs) were plated onto gelatin-coated dish. Cultures were observed daily using an inverted light microscope to determine the day of contraction onset and total duration of continuous contractile activity for each contracting focus. (omitted)

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.18-18
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• 2002

This study was to investigate the effect of neurotrophic factors on neural cell differentiation in vitro derived from human embryonic stem (hES, MB03) cells. For neural progenitor cell formation derived from hES cells, we produced embryoid bodies (EB: for 5 days, without mitogen) from hES cells and then neurospheres (for 7 - 10 days, 20 ng/㎖ of bFGF added N2 medium) from EB. And then finally for the differentiation into mature neuron cells, neural progenitor cells were cultured in ⅰ) N2 medium (without bFGF), ⅱ) N2 supplemented with brain derived neurotrophic factor (BDNF, 5ng/㎖) or ⅲ) N2 supplemented with platelet derived growth factor-bb (PDGF-bb, 20ng/㎖) for 2 weeks. (omitted)

• Proceedings of the Korean Society of Toxicology Conference
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• 2005.05a
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• pp.159-159
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• 2005

• Journal of Ginseng Research
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• v.6 no.2
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• pp.162-167
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• 1982

Calli and leaflets of ginseng (Panax ginseng C.A. Meyer) were cultured on 1/2MS media supplement. with kinetin, 2 iP, NAA, 2,4-D and IBA to assess their capacity to regenerate embryoids and organs. Root calli produced numerous embryoids and shoots in 1/2MS medium supplemented with 2 mg/l NAA and 2mg/s 2iP, and the combination of 2 iP and NAA was more effective than the combination of kinetin and NAA in induction of embryoid and shoot from root calli. Culture of leaflet in the medium supplemented with IBA resulted in profuse root regeneration.