• International Journal of Oral Biology
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• v.34 no.4
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• pp.177-183
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• 2009

Human mesenchymal stem cell (hMSCs) isolated from human adult bone marrow have self-renewal capacity and can differentiate into multiple cell types in vitro and in vivo. A number of studies have now demonstrated that MSCs can differentiate into various neuronal populations. Due to their autologous characteristics, replacement therapy using MSCs is considered to be safe and does not involve immunological complications. The basic helix-loop-helix (bHLH) transcription factor Olig2 is necessary for the specification of both oligodendrocytes and motor neurons during vertebrate embryogenesis. To develop an efficient method for inducing neuronal differentiation from MSCs, we attempted to optimize the culture conditions and combination with Olig2 gene overexpression. We observed neuron-like morphological changes in the hMSCs under these induction conditions and examined neuronal marker expression in these cells by RTPCR and immunocytochemistry. Our data demonstrate that the combination of Olig2 overexpression and neuron-specific conditioned medium facilitates the neuronal differentiation of hMSCs in vitro. These results will advance the development of an efficient stem cell-mediated cell therapy for human neurodegenerative diseases.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.6
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• pp.886-892
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• 2017

Objective: Transgenic technology is widely used for industrial applications and basic research. Systems that allow for genetic modification play a crucial role in biotechnology for a number of purposes, including the functional analysis of specific genes and the production of exogenous proteins. In this study, we examined and verified the cumate-inducible transgene expression system in chicken DF1 and quail QM7 cells, as well as loxP element-mediated transgene recombination using Cre recombinase in DF1 cells. Methods: After stable transfer of the transgene with piggyBac transposon and transposase, transgene expression was induced by an appropriate concentration of cumate. Additionally, we showed that the transgene can be replaced with additional transgenes by co-transfection with the Cre recombinase expression vector. Results: In the cumate-GFP DF1 and QM7 cells, green fluorescent protein (GFP) expression was repressed in the off state in the absence of cumate, and the GFP transgene expression was successfully induced in the presence of cumate. In the cumate-MyoD DF1 cells, MyoD transgene expression was induced by cumate, and the genes controlled by MyoD were upregulated according to the number of days in culture. Additionally, for the translocation experiments, a stable enhanced green fluorescent protein (eGFP)-expressing DF1 cell line transfected with the loxP66-eGFP-loxP71 vector was established, and DsRed-positive and eGFP-negative cells were observed after 14 days of co-transfection with the DsRed transgene and Cre recombinase indicating that the eGFP transgene was excised, and the DsRed transgene was replaced by Cre recombination. Conclusion: Transgene induction or replacement cassette systems in avian cells can be applied in functional genomics studies of specific genes and adapted further for efficient generation of transgenic poultry to modulate target gene expression.

• Toxicological Research
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• v.33 no.1
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• pp.71-77
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• 2017

Hormone replacement therapy (HRT) consists of highly effective prescription medications for treating menopausal symptoms; however, these agents have exhibited side effects including the risk of estrogen-induced carcinogenesis. Therefore, interest in phytotherapy-based materials as a natural source of alternatives to estrogen therapy has increased. However, some of these herbal medicines have been reported to increase the risk of estrogen-induced cancer. Herbal formulations composed of a combination of Cynanchum wilfordii Hemsley (CW), Phlomis umbrosa Turczaninow (PU), and Angelica gigas Nakai (AG) extracts (CPAE) have been used for treating menopausal symptoms. Therefore, in this study, we aimed to examine the safety of CPAE by determining its potential adverse estrogenic activity using the Organization for Economic Cooperation and Development (OECD) test guideline 455 (TG455) in a stably transfected transcriptionally activated human estrogen receptor ${\alpha}$ ($hER{\alpha}$)-HeLa9903 cell model. We found that CPAE did not how any estrogenic activity or stimulate promoters containing estrogen response elements in MCF-7 cells. In addition, CPAE showed no significant selective activity against $hER{\alpha}$ and $hER{\beta}$, non-selective activity against the ER, or effects on ER target gene expression. Furthermore, CPAE did not significantly induce MCF-7 cell proliferation and uterine weight increase in ovariectomized rats. These results demonstrate that CPAE can be used as beneficial herbal drug for prevention and therapeutic intervention of estrogen carcinogenesis in menopausal women.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.7-8
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• 2003

Since it was first reported in 1997, somatic cell cloning has been demonstrated in several other mammalian species. On the mouse, it can be cloned from embryonic stem (ES) cells, fetus-derived cells, and adult-derived cells, both male and female. While cloning efficiencies range from 0 to 20%, rates of just 1-2% are typical (i.e. one or two live offspring per one hundred initial embryos). Recently, abnormalities in mice cloned from somatic cells have been reported, such as abnormal gene expression in embryo (Boiani et al., 2001, Bortvin et al., 2003), abnormal placenta (Wakayama and Yanagimachi 1999), obesity (Tamashiro et ai, 2000, 2002) or early death (Ogonuki et al., 2002). Such abnormalities notwithstanding, success in generating cloned offspring has opened new avenues of investigation and provides a valuable tool that basic research scientists have employed to study complex processes such as genomic reprogramming, imprinting and embryonic development. On the other hand, mouse ES cell lines can also be generated from adult somatic cells via nuclear transfer. These 'ntES cells' are capable of differentiation into an extensive variety of cell types in vitro, as well assperm and oocytes in vivo. Interestingly, the establish rate of ntES cell line from cloned blastocyst is much higher than the success rate of cloned mouse. It is also possible to make cloned mice from ntES cell nuclei as donor, but this serial nuclear transfer method could not improved the cloning efficiency. Might be ntES cell has both character between ES cell and somatic cell. A number of potential agricultural and clinical applications are also are being explored, including the reproductive cloning of farm animals and therapeutic cloning for human cell, tissue, and organ replacement. This talk seeks to describe both the relationship between nucleus donor cell type and cloning success rate, and methods for establishing ntES cell lines. (중략)

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.85.1-85
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• 2003

In most ascomycetes, a single mating type locus, MAT, with two alternate forms (MAT1-1 and MAT1-2) called idiomorphs, controls mating ability. In heterothallic ascomycetes these alternate idiomorphs reside in different nuclei. In contrast, most homothallic ascomycetes carry both MAT1-1 and MAT1-2 in a single nucleus, usually closely linked. An example of the latter is Gibberella zeae, a producer of mycotoxins such as trichothecene and zearalenone that threaten human and animal health. We asked if G. zeae could be made strictly heterothallic by manipulation of MAT. Targeted gene replacement was used to differentially delete MAT1-1 or MAT1-2 from a wild type haploid MAT1-1 MAT1-2 strain, resulting in MAT1-1；mat1-2, mat1-1；MAT1-2 strains that were self-sterile, yet able to cross to wild type testers and more importantly, to each other. These results indicated that differential deletion of MAT idiomorphs eliminates selfing ability of G. zeae, but the ability to outcross is retained. To our knowledge, this is the first report of complete conversion of fungal reproductive strategy from homothallic to heterothallic by targeted manipulation of MAT. Practically, this approach opens the door to simple and efficient procedures for obtaining sexual recombinants of G. zeae that will be useful for genetic analyses of mycotoxin production and other traits, such as ability to cause disease.

• Journal of Ecology and Environment
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• v.36 no.1
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• pp.39-47
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• 2013

The expression of transgenic traits in genetically modified crops is sometimes associated with decreases in crop performance or fitness. These decreases in performance or fitness of transgenic plants in unfavourable conditions may provide valuable information about the ecological consequences of transgene escape. In a glasshouse trial, we tested the cost associated with resistance to herbicides by comparing the growth, yield, and competitive ability of transgenic rice with its parental non-transgenic line. This new line was developed for constitutive overexpression of protoporphyrinogen oxidase (PPO) to increase resistance to herbicides. We evaluated nine agronomic traits of transgenic and non-transgenic rice grown in a replacement series design over four densities. Competitive ability was also assessed between transgenic and non-transgenic plants by analyzing their relative yields based on biomass and seed weight data. Our results indicated that non-transgenic plants showed greater performance than did the transgenic plants when those genotypes were grown in mixtures. The non-transgenic rice plants exhibited superior competitive ability at certain combinations of planting densities and genotype proportions. These results suggest that PPO-herbicide resistance incurs some costs in plant performance and competitive ability.

• Reproductive and Developmental Biology
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• v.32 no.2
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• pp.135-140
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• 2008

Recent studies on nuclear transfer and induced pluripotent stem cells have demonstrated that differentiated somatic cells can be returned to the undifferentiated state by reversing their developmental process. These epigenetically reprogrammed somatic cells may again be differentiated into various cell types, and used for cell replacement therapies through autologous transplantation to treat many degenerative diseases. To date, however, reprogramming of somatic cells into undifferentiated cells has been extremely inefficient. Hence, reliable markers to identify the event of reprogramming would assist effective selection of reprogrammed cells. In this study, a transgene construct encoding enhanced green fluorescent protein (EGFP) under the regulation of human Oct4 promoter was developed as a reporter for the reprogramming of somatic cells. Microinjection of the transgene construct into pronuclei of fertilized mouse eggs resulted in the emission of green fluorescence, suggesting that the undifferentiated cytoplasmic environment provided by fertilized eggs induces the expression of EGFP. Next, the transgene construct was introduced into human embryonic fibroblasts, and the nuclei from these cells were transferred into enucleated porcine oocytes. Along with their in vitro development, nuclear transfer embryos emitted green fluorescence, suggesting the reprogramming of donor nuclei in nuclear transfer embryos. The results of the present study demonstrate that expression of the transgene under the regulation of human Oct4 promoter coincides with epigenetic reprogramming, and may be used as a convenient marker that non-invasively reflects reprogramming of somatic cells.

• Clinical and Experimental Pediatrics
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• v.55 no.2
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• pp.48-53
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• 2012

Purpose: Gaucher disease is caused by a ${\beta}$-glucocerebrosidase (GBA) deficiency. The aim of this study is to investigate the clinical and genetic characteristics according to subtypes of Gaucher disease in the Korean population. Methods: Clinical findings at diagnosis, $GBA$ mutations, and clinical courses were reviewed in 20 patients diagnosed with Gaucher disease. Results: Eleven patients were diagnosed with non-neuronopathic type, 2 with acute neuronopathic type, and 7 with chronic neuronopathic type. Most patients presented with hepatosplenomegaly, thrombocytopenia, and short stature. In the neuronopathic group, variable neurological features, such as seizure, tremor, gaze palsy, and hypotonia, were noted at age $8.7{\pm}4.3$ years. B cell lymphoma, protein-losing enteropathy, and hydrops fetalis were the atypical manifestations. Biomarkers, including chitotriosidase, acid phosphatase, and angiotensin-converting enzyme, increased at the initial evaluation and subsequently decreased with enzyme replacement treatment (ERT). The clinical findings, including hepatosplenomegaly, thrombocytopenia, and skeletal findings, improved following ERT, except for the neurological manifestations. L444P was the most common mutation in our cohort. One novel mutation, R277C, was found. Conclusion: Although the clinical outcome for Gaucher disease improved remarkably following ERT, the outcome differed according to subtype. Considering the high proportion of the neuronopathic form in the Korean population, new therapeutic strategies targeting the central nervous system are needed, with the development of a new scoring system and biomarkers representing clinical courses in a more comprehensive manner.

• BMB Reports
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• v.38 no.4
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• pp.414-419
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• 2005

The production of recombinant antibodies has been generally recognized as time-consuming and labor-intensive. The aim of our study is to construct mammalian expression vectors containing the cDNA encoding the human constant regions and murine variable regions to massively and cost-effectively produce full-length chimeric antibodies. Unique restriction sites flanking the Ig variable region were designed to allow for the replacement of variable regions generated by PCR. Western blot analysis of the chimeric antibodies revealed that the expressed products were of the predicted size, structure and specificity. The usefulness of the vectors was confirmed by construction of human-mouse chimeric antibody-HCAb which secretes murine antibody against the human colorectal cancer. Selected in medium containing gradually increasing methotrexate (MTX), clones with increased expression of the product gene can be efficiently generated. The secretion of recombinant chimeric antibody-HCAb yielded $30\;pg\;cell^{-1}\;day^{-1}$ at $10^{-6}\;M$ MTX. With this high-level expression from pools, the convenient and rapid production of over 100 milligram amounts per liter of recombinant antibodies may be achieved, which indicates the significant roles of pYR-GCEVH and pYR-GCEVL in the production of chimeric antibodies.

• Journal of mucopolysaccharidosis and rare diseases
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• v.4 no.1
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• pp.26-36
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• 2018

Mucopolysaccharidosis IIIA is a heritable neurodegenerative disorder resulting from the dysfunction of the lysosomal hydrolase sulphamidase. This leads to the primary accumulation of the complex carbohydrate heparan sulphate in a wide range of tissues and CNS degeneration. Characterization of animal model is the beginning point of the therapeutic clinical trial. Mouse model has a limitation in that it is not a human and does not have all of the disease phenotypes. Therefore, delineate of the phenotypic characteristics of MPS IIIA mouse model prerequisite for the enzyme replace treatment for the diseases. We designed 6-month duration of phenotypic characterization of MPS IIIA mouse biochemically, behaviorally and histologically. We compared height and weight of MPS IIIA mouse with wild type from 4 weeks to 6 months in both male and female. At 6 months, we measured GAG storage in urine kidney, heart, liver, lung and spleen. The brain GAG storage is presented with Alcian blue staining, immunohistochemistry, and electron-microscopy. The neurologic phenotype is evaluated by brain MRI and behavioral study including open field test, fear conditioning, T-maze test and Y-maze test. Especially behavioral tests were done serially at 4month and 6month. This study will show the result of the MPS IIIA mouse model phenotypic characterization. The MPS IIIA mouse provides an excellent model for evaluating pathogenic mechanisms of disease and for testing treatment strategies, including enzyme or cell replacement and gene therapy.