• Biomolecules & Therapeutics
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• v.25 no.4
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• pp.362-366
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• 2017

Direct conversion by trans-differentiation is of growing interest in cell therapy for incurable diseases. The efficiency of cell reprogramming and functionality of converted cells are important considerations in cell transplantation therapy. Here, we compared two representative protocols for the generation of induced-oligodendrocyte progenitor cells (iOPCs) from mouse and rat fibroblasts. Then, we showed that induction of Nkx6.2, Olig2, and Sox10 (NOS) was more effective in mouse fibroblasts and that induction of Olig2, Sox10, and Zfp536 (OSZ) was more effective at reprogramming iOPCs from rat fibroblasts. However, OSZ-iOPCs did not show greater proliferation than NOS-induced cells. Because the efficiency of iOPCs generation appears to differ between cell species depending on transcription factors and culture conditions, it is important to select appropriate methods for efficient reprogramming.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2004.10a
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• pp.57-58
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• 2004

• Genomics & Informatics
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• v.17 no.1
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• pp.8.1-8.10
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• 2019

Alveolar type II cells constitute a small fraction of the total lung cell mass. However, they play an important role in many cellular processes including trans-differentiation into type I cells as well as repair of lung injury in response to toxic chemicals and respiratory pathogens. Transcription factors are the regulatory proteins dynamically modulating DNA structure and gene expression. Transcription factor profiling in microarray datasets revealed that several members of AP1, ATF, $NF-{\kappa}B$, and C/EBP families involved in diverse responses were expressed in mouse lung type II cells. A transcriptional factor signature consisting of Cebpa, Srebf1, Stat3, Klf5, and Elf3 was identified in lung type II cells, Sox9+ pluripotent lung stem cells as well as in mouse lung development. Identification of the transcription factor profile in mouse lung type II cells will serve as a useful resource and facilitate the integrated analysis of signal transduction pathways and specific gene targets in a variety of physiological conditions.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.541-548
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• 2013

Purpose: Marrow stromal cells (MSCs) have been known for their potential to trans-differentiate into neural and glial cells in vitro and in vivo. To investigate the influence of the developing host environment on the survival and morphological and molecular differentiation, murine MSCs transplanted into the eye of Brazilian opossum (Monodelphis domestica). Methods: Enhanced green fluorescent protein (GFP) - expressing MSCs were transplanted into developing Brazilian opossums. Animals were allowed to survive for up to 4 weeks after transplantation, at which time the eyes were prepared for immunohistochemical analysis. Results: Some transplanted MSCs survived and showed morphological differentiation into neural cells with some processes within the host vitreous chamber. Some transplanted cells expressed class III ${\beta}$-tubulin (TuJ1, a marker for neuronal cells) or glial fibrillary acid protein (GFAP, a marker for glial cells) or Nestin (a marker for neural stem cells). In addition, some transplanted cells were located in ganglion cell layer but did not show morphological and molecular differentiation. Conclusions: Our result show that the most effective stage of development for transplantation into the retina was postnatal day 16, which retinas developmentally corresponded to postnatal day 4-5 days mouse retina based on cell differentiation and lamination patterns. The present findings suggest that the age of the host appears to play a key role in determining cell fate in vivo.

• Journal of Life Science
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• v.16 no.5
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• pp.759-766
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• 2006

Acute promyelocytic leukemia (APL) is a myeloid leukemia caused by over-expression of fusion protein, PML/RAR$({\alpha})$, which was the result of chromosomal translocation and induces the blockage of differentiation of affected promyelocytes. Pharmacological dose of retinoic acid induces the activation of and subsequent degradation of PML/RAR$({\alpha})$ fusion protein, and then APL cells undergo through the normal differentiation pathway. Arsenic trioxide has proved effective in causing remission of acute promyelocytic leukemia by inducing apoptosis of this tumor cells, whereas the heterogeneity of cellular susceptibility to this cytotoxic agent limited its usage on more types of tumors in clinic. This work showed that arsenic trioxide could induce apoptosis of a panel of acute promyelocytic leukemic cell lines, all-trans-retinoic acid (ATRA) sensitive NB4 cells and ATRA resistant UF-1 cell. They were investigated with regard to the correlation between the inherent or intrinsic cellular level of GSH and the apoptotic susceptibility of the cells to arsenic trioxide. We manifested, in two cell types, the inherently existed difference in intracellular GSH level reactive to the arsenic trioxide, and a positive correlation between the GSH level and their apoptotic sensitivity to arsenic trioxide. And it showed that arsenic trioxide could differentiate promyelocytic cancer cells to the cells possessed of dendritic cell surface markers. Unravelling the cause of the different susceptibility between leukemic cells and proving that promyelocyte could be differentiated to dendritic cells by arsenic trioxide will help not only to understand the mechanism underlying the complete remission of acute promyelocytic leukemia induced by arsenic trioxide, but also to expand its clinical usage.

• Journal of Yeungnam Medical Science
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• v.36 no.3
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• pp.231-240
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• 2019

Background: We sought to determine the value of combining diffusion-weighted (DW) and perfusion-weighted (PW) sequences with a conventional magnetic resonance (MR) sequence to assess solid components of borderline ovarian tumors (BOTs) and stage I carcinomas. Methods: Conventional, DW, and PW sequences in the tumor imaging studies of 70 patients (BOTs, n=38; stage I carcinomas, n=32) who underwent surgery with pathologic correlation were assessed. Two independent radiologists calculated the parameters apparent diffusion coefficient (ADC), $K^{trans}$ (vessel permeability), and $V_e$ (cell density) for the solid components. The distribution on conventional MR sequence and mean, standard deviation, and 95% confidence interval of each DW and PW parameter were calculated. The inter-observer agreement among the two radiologists was assessed. Area under the receiver operating characteristic curve (AUC) and multivariate logistic regression were performed to compare the effectiveness of DW and PW sequences for average values and to characterize the diagnostic performance of combined DW and PW sequences. Results: There were excellent agreements for DW and PW parameters between radiologists. The distributions of ADC, $K^{trans}$, and $V_e$ values were significantly different between BOTs and stage I carcinomas, yielding AUCs of 0.58 and 0.68, 0.78 and 0.82, and 0.70 and 0.72, respectively, with ADC yielding the lowest diagnostic performance. The AUCs of the DW, PW, and combined PW and DW sequences were $0.71{\pm}0.05$, $0.80{\pm}0.05$, and $0.85{\pm}0.05$, respectively. Conclusion: Combining PW and DW sequences to a conventional sequence potentially improves the diagnostic accuracy in the differentiation of BOTs and stage I carcinomas.

• Animal cells and systems
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• v.4 no.2
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• pp.157-163
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• 2000

Yeast pheromone a-factor is a 13-amino acid peptide hormone that is synthesized as a part of a larger precursor, prepro-$\alpha$-factor, consisting of a signal peptide and a proregion of 64 amino acids. The carboxy-terminal half of the precursor contains four tandem copies of mature $\alpha$-factor. To investigate the molecular basis of intracellular sorting, proteolytic processing, and storage of the peptide hormone, yeast prepro-$\alpha$-factor precursors were heterologously expressed in rat pituitary $GH_3 cells. When cells harboring the precursor were metabolically labeled, a species of approximately 27 kD appeared inside the cells. Digestion with peptide: N-glycosidase F (PNG-F) shifted the molecular mass to a 19 kD, suggesting that the 27 kD protein was the glycosylated form as in yeast cells. The nascent polypeptide is efficiently targeted to the ER in the $GH_3 cells, where it undergoes cleavage of its signal peptide and core glycosylation to generate glycosylated pro-a-factor. To look at the post ER intracellular processing, the pulse-labelled cells were chased up to 2 hrs. The nascent propeptides disappeared from the cells at a half life of 30 min and only 10-25% of the newly synthesized, unprocessed precursors were stored intracellularly after the 2 h chase. However, about 20% of the pulse-labeled pro-$\alpha$-factor precursors were secreted into the medium in the pro-hormone form. With increasing chase time, the intracellular level of propeptide decreased, but the amount of secreted propeptide could not account for the disappearance of intracellular propeptide completely. This disappearance was insensitive to lysosomotropic agents, but was inhibited at $16^{circ}C or 20^{\circ}C$, suggesting that the turnover of the precursors was not occurring in the secretory pathway to trans Golgi network (TGN) or dependent on acidic compartments. From these results, it is concluded that a pan of these heterologous precursors may be processed at its paired dibasic sites by prohormone processing enzymes located in TGN/secretpry vesicles producing small peptides, and that the residual unprocessed precursors may be secreted into the medium rather than degraded intracellularly.

• The Korean Journal of Physiology and Pharmacology
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• v.19 no.2
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• pp.105-109
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• 2015

NgR1, a Nogo receptor, is involved in inhibition of neurite outgrowth and axonal regeneration and regulation of synaptic plasticity. P19 embryonal carcinoma cells were induced to differentiate into neuron-like cells using all trans-retinoic acid and the presence and/or function of cellular molecules, such as NgR1, NMDA receptors and STAT3, were examined. Neuronally differentiated P19 cells expressed the mRNA and protein of NgR1, which could stimulate the phosphorylation of STAT3 when activated by Nogo-P4 peptide, an active segment of Nogo-66. During the whole period of differentiation, mRNAs of all of the NMDA receptor subtypes tested (NR1, NR2A-2D) were consistently expressed, which meant that neuronally differentiated P19 cells maintained some characteristics of neurons, especially central nervous system neurons. Our results suggests that neuronally differentiated P19 cells expressing NgR1 may be an efficient and convenient in vitro model for studying the molecular mechanism of cellular events that involve NgR1 and its binding partners, and for screening compounds that activate or inhibit NgR1.

• The Korean Journal of Physiology and Pharmacology
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• v.5 no.1
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• pp.79-86
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• 2001

Recent clinical studies have shown that a high proportion of patients with acute promyelocytic leukemia (APL) achieve complete remission after treatment with all-trans retinoic acid (ATRA). However, most patients who receive continuous treatment with ATRA relapse and develop ATRA-resistant leukemia. Dendritic cells (DCs) are important antigen-presenting cells in the development of antileukemic T-cell responses. In this study, we investigated the strategies to overcome ATRA resistance of APL cells by inducing the differentiation of DCs from human leukemic cell lines for the developtment of adoptive immunotherapy. CD83 was used as a mature DC marker in this study and the expression of CD83 mRNA was determined by RT-PCR method. The promyelocytic leukemic cell line HL-60, B lymphoblast cell lines RPMI 7666 and NC-37 could be induced to dendritic cells in vitro. Treatment of HL-60 with phorbol 12-myristate 13-acetate (PMA) resulted in the expression of myeloid-related DC phenotypes, while treatment of RPMI 7666 with fms-like tyrosine kinase 3 ligand (Flt3-ligand, FL) and treatment of NC-37 with PMA and FL led to the expression of lymphoid-related DC phenotypes. In conclusion, myeloid-related DC phenotypes and lymphoid-related DC phenotypes could be generated from HL-60, NC-37 and RPMI 7666 cell lines, respectively. These DC phenotypes can potentially be used to generate antileukemic T cells in vitro for adoptive immunotherapy.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.6
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• pp.463-472
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• 2020

Direct reprogramming, also known as a trans-differentiation, is a technique to allow mature cells to be converted into other types of cells without inducing a pluripotent stage. It has been suggested as a major strategy to acquire the desired type of cells in cell-based therapies to repair damaged tissues. Studies related to switching the fate of cells through epigenetic modification have been progressing and they can bypass safety issues raised by the virus-based transfection methods. In this study, a protocol was established to directly convert fully differentiated fibroblasts into diverse mesenchymal-lineage cells, such as osteoblasts, adipocytes, chondrocytes, and ectodermal cells, including neurons, by means of DNA demethylation, immediately followed by culturing in various differentiating media. First, 24 h exposure of 5-azacytidine (5-aza-CN), a well-characterized DNA methyl transferase inhibitor, to NIH-3T3 murine fibroblast cells induced the expression of stem-cell markers, that is, increasing cell plasticity. Next, 5-aza-CN treated fibroblasts were cultured in osteogenic, adipogenic, chondrogenic, and neurogenic media with or without bone morphogenetic protein 2 for a designated period. Differentiation of each desired type of cell was verified by quantitative reverse transcriptase-polymerase chain reaction/western blot assays for appropriate marker expression and by various staining methods, such as alkaline phosphatase/alizarin red S/oil red O/alcian blue. These proposed procedures allowed easier acquisition of the desired cells without any transgenic modification, using direct reprogramming technology, and thus may help make it more available in the clinical fields of regenerative medicine.