• Molecules and Cells
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• v.19 no.1
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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.

• Journal of Convergence for Information Technology
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• v.8 no.2
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• pp.61-65
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• 2018

Our experiment studied that grafted stem cells reduced behavioral deficiency in rodent animal models of clip compressive surgery inducing spinal cord infarction. Our research proved the effect of embryonic stem cells to the spinal cord infarction caused by compressing T9-10 with an aneurysm clip, focusing the application of grafted stem cells for reduction of infarction and regeneration of spinal cord nervous injury. Therefore, our research suggests manifest results that implantation of mouse embryonic stem cell could show behavioral improvement after severe spinal cord damage. Therefore, mouse embryonic stem cell (mESC) could be useful application for the method in neurological injury. Conclusively, stem cell implant therapy may enhance the effectiveness of stem cell implant for central nervous system injury.

• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.126-140
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• 2022

Stem cells can be applied usefully in basic research and clinical field due to their differentiation and self-renewal capacity. The aim of this study was to establish an effective novel therapeutic cellular source and create its molecular expression profile map to elucidate the possible therapeutic mechanism and signaling pathway. We successfully obtained a mesenchymal stem cell population from human embryonic stem cells (hESCs) cultured on chemically defined feeder-free conditions and treated with connective tissue growth factor (CTGF) and performed the expressive proteomic approach to elucidate the molecular basis. We further selected 12 differentially expressed proteins in CTGF-induced hESC-derived mesenchymal stem cells (C-hESC-MSCs), which were found to be involved in the metabolic process, immune response, cell signaling, and cell proliferation, as compared to bone marrow derived-MSCs(BM-MSCs). Moreover, these up-regulated proteins were potentially related to the Wnt/β-catenin pathway. These results suggest that C-hESC-MSCs are a highly proliferative cell population, which can interact with the Wnt/β-catenin signaling pathway; thus, due to the upregulated cell survival ability or downregulated apoptosis effects of C-hESC-MSCs, these can be used as an unlimited cellular source in the cell therapy field for a higher therapeutic potential. Overall, the study provided valuable insights into the molecular functioning of hESC derivatives as a valuable cellular source.

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.11-15
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• 2004

Embryonic stem (ES) cells are derived from the inner cell mass of the blastocyst-stage embryos that can be propagated indefinitely and, at the same time, can be differentiated into all the cell types that constitute the body. Current research using ES cells is mainly focused on the efficient generation of specific cell types by employing optimal differentiation conditions, which often requires the genetic manipulation of ES cells. As a way of developing an efficient system to regulate foreign gene expression in ES cells, we have inserted the gene encoding Corynebacterium diphtheria toxin-A (DTA) into an autonomously induced plasmid under positive doxycycline control ('Tet-on' system). In this study, we demonstrate that this system can lead to the cell death of mouse ES cells by the induction of DTA expression when exposed to the tetracycline derivative, doxycycline. MTT assay showed that this induction resulted in the apoptosis of ES cells.

• BMB Reports
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• v.51 no.2
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• pp.92-97
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• 2018

B cell leukemia/lymphoma 3 (Bcl3) plays a pivotal role in immune homeostasis, cellular proliferation, and cell survival, as a co-activator or co-repressor of transcription of the $NF-{\kappa}B$ family. Recently, it was reported that Bcl3 positively regulates pluripotency genes, including Oct4, in mouse embryonic stem cells (mESCs). However, the role of Bcl3 in the maintenance of pluripotency and self-renewal activity is not fully established. Here, we report the dynamic regulation of the proliferation, pluripotency, and self-renewal of mESCs by Bcl3 via an influence on Nanog transcriptional activity. Bcl3 expression is predominantly observed in immature mESCs, but significantly decreased during cell differentiation by LIF depletion and in mESC-derived EBs. Importantly, the knockdown of Bcl3 resulted in the loss of self-renewal ability and decreased cell proliferation. Similarly, the ectopic expression of Bcl3 also resulted in a significant reduction of proliferation, and the self-renewal of mESCs was demonstrated by alkaline phosphatase staining and clonogenic single cell-derived colony assay. We further examined that Bcl3-mediated regulation of Nanog transcriptional activity in mESCs, which indicated that Bcl3 acts as a transcriptional repressor of Nanog expression in mESCs. In conclusion, we demonstrated that a sufficient concentration of Bcl3 in mESCs plays a critical role in the maintenance of pluripotency and the self-renewal of mESCs via the regulation of Nanog transcriptional activity.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.1
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• pp.48-54
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• 2022

Parthenogenesis is maternally uniparental reproduction through the embryonic development of oocytes without fertilization. Artificial activation of mature oocytes could generate homozygous haploid embryos with the extrusion of the second polar body. However, the haploid embryos showed low embryo development in preimplantation embryos. In this study, we investigated whether the electronic fusion of the haploid embryos could enhance embryo development and ESC establishment in mice. Haploid embryos showed the developmental delay from 4-cell to the blastocyst stage. The haploid blastomeres of the 2-cell stage were fused electronically, resulting in that the fused embryos showed a significantly higher rate of blastocysts compared to non-fused haploid embryos (55% vs. 37%). Further, the embryonic stem cells (ESCs) derived from the fused embryos were confirmed to be diploid. The rate of ESC establishment in fused embryos was significantly higher compared to non-fused ones. Based on the results, we concluded that the electronic fusion of haploid embryos could be efficient to generate homozygous ESCs.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.175-182
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• 2021

Pluripotent stem cells could self-renew and differentiate into various cells. In particular, porcine pluripotent stem cells are useful for preclinical therapy, transgenic animals, and agricultural usage. These stem cells have naïve and primed pluripotent states. Naïve pluripotent stem cells represented by mouse embryonic stem cells form chimeras after blastocyst injection. Primed pluripotent stem cells represented by mouse epiblast stem cells and human embryonic stem cells. They could not produce chimeras after blastocyst injection. Populations of embryonic stem cells are not homogenous; therefore, reporter systems are used to clarify the status of stem cells and to isolate the cells. For this reason, studies of the OCT4 reporter system have been conducted for decades. This review will discuss the naïve and primed pluripotent states and recent progress in the development of porcine OCT4 reporter systems.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.1
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• pp.37-44
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• 2011

Parthenogenetic embryonic stem (pES) cells could provide a valuable model for research into genomic imprinting and X-linked diseases. In this study, pES cell lines were established from oocytes of hybrid offspring of Kunming and 129/Sv mice, and pluripotency of pES cells was evaluated. The pES cells maintained in the undifferentiated state for more than 50 passages had normal karyotypes with XX sex chromosomes and exhibited high activities of alkaline phosphatase (AKP) and telomerase. Meanwhile, these cells expressed ES cell molecular markers SSEA-1, Oct-4, Nanog, and GDF3 but not SSEA-3 detected by immunohistochemistry and RT-PCR. The pES cells could be differentiated into various types of cells from three germ layers in vitro by analysis of embryoid bodies (EBs) with immunohistochemistry and RT-PCR, and in vivo by observation of pES cell-derived teratoma sections. Therefore, the established pES cell lines contained all features of mouse ES cells. This work provides a new strategy for isolating pES cells from Kunming mice, and the pES cell lines could be applied as the cell model in research into genomic imprinting and epigenetic regulation of Kunming mice.

• 대한생식의학회:학술대회논문집
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• 2007.11a
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• pp.117-117
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• 2007

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2003.10a
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• pp.121-121
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• 2003