• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.246-247
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• 2011

• BMB Reports
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• v.52 no.5
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• pp.295-303
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• 2019

Breakthroughs in stem cell technology have contributed to disease modeling and drug screening via organoid technology. Organoid are defined as three-dimensional cellular aggregations derived from adult tissues or stem cells. They recapitulate the intricate pattern and functionality of the original tissue. Insulin is secreted mainly by the pancreatic ${\beta}$ cells. Large-scale production of insulin-secreting ${\beta}$ cells is crucial for diabetes therapy. Here, we provide a brief overview of organoids and focus on recent advances in protocols for the generation of pancreatic islet organoids from pancreatic tissue or pluripotent stem cells for insulin secretion. The feasibility and limitations of organoid cultures derived from stem cells for insulin production will be described. As the pancreas and gut share the same embryological origin and produce insulin, we will also discuss the possible application of gut organoids for diabetes therapy. Better understanding of the challenges associated with the current protocols for organoid culture facilitates development of scalable organoid cultures for applications in biomedicine.

• BMB Reports
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• v.50 no.3
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• pp.138-143
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• 2017

Ovariectomy-induced bone loss is related to an increased deposition of osteoclasts on bone surfaces. We reported that the 36-amino-acid-long neuropeptide Y (NPY) could mobilize hematopoietic stem/progenitor cells (HSPCs) from the bone marrow to the peripheral blood by regulating HSPC maintenance factors and that mobilization of HSPCs ameliorated low bone density in an ovariectomy-induced osteoporosis mouse model by reducing the number of osteoclasts. Here, we demonstrated that new NPY peptides, recombined from the cleavage of the full-length NPY, showed better functionality for HSPC mobilization than the full-length peptide. These recombinant peptides mediated HSPC mobilization with greater efficiency by decreasing HSPC maintenance factors. Furthermore, treatment with these peptides reduced the number of osteoclasts and relieved ovariectomy-induced bone loss in mice more effectively than treatment with full-length NPY. Therefore, these results suggest that peptides recombined from full-length NPY can be used to treat osteoporosis.

• Molecules and Cells
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• v.37 no.6
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• pp.473-479
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• 2014

Spermatogonial stem cells (SSCs, also called germline stem cells) are self-renewing unipotent stem cells that produce differentiating germ cells in the testis. SSCs can be isolated from the testis and cultured in vitro for long-term periods in the presence of feeder cells (often mouse embryonic fibroblasts). However, the maintenance of SSC feeder culture systems is tedious because preparation of feeder cells is needed at each subculture. In this study, we developed a Matrigel-based feeder-free culture system for long-term propagation of SSCs. Although several in vitro SSC culture systems without feeder cells have been previously described, our Matrigel-based feeder-free culture system is time- and cost-effective, and preserves self-renewability of SSCs. In addition, the growth rate of SSCs cultured using our newly developed system is equivalent to that in feeder cultures. We confirmed that the feeder-free cultured SSCs expressed germ cell markers both at the mRNA and protein levels. Furthermore, the functionality of feeder-free cultured SSCs was confirmed by their transplantation into germ cell-depleted mice. These results suggest that our newly developed feeder-free culture system provides a simple approach to maintaining SSCs in vitro and studying the basic biology of SSCs, including determination of their fate.

• International Journal of Stem Cells
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• v.10 no.1
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• pp.1-11
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• 2017

Human cardiomyocytes (CMs) cease to proliferate and remain terminally differentiated thereafter, when humans reach the mid-20s. Thus, any damages sustained by myocardium tissue are irreversible, and they require medical interventions to regain functionality. To date, new surgical procedures and drugs have been developed, albeit with limited success, to treat various heart diseases including myocardial infarction. Hence, there is a pressing need to develop more effective treatment methods to address the increasing mortality rate of the heart diseases. Functional CMs are not only an important in vitro cellular tool to model various types of heart diseases for drug development, but they are also a promising therapeutic agent for cell therapy. However, the limited proliferative capacity entails difficulties in acquiring functional CMs in the scale that is required for pathological studies and cell therapy development. Stem cells, human pluripotent stem cells (hPSCs) in particular, have been considered as an unlimited cellular source for providing functional CMs for various applications. Notable progress has already been made: the first clinical trials of hPSCs derived CMs (hPSC-CMs) for treating myocardial infarction was approved in 2015, and their potential use in disease modeling and drug discovery is being fully explored. This concise review gives an account of current development of differentiation, purification and maturation techniques for hPSC-CMs, and their application in cell therapy development and pharmaceutical industries will be discussed with the latest experimental evidence.

• Journal of Information Technology Services
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• v.17 no.2
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• pp.111-128
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• 2018

About 3.9 million apps and 24 primary categories can be approved on Apple iTunes Store. Making accurate categorization can potentially receive many benefits for developers, app stores, and users, such as improving discoverability and receiving long-term revenue. However, current categorization problems may cause usage inefficiency and confusion, especially for cross-attribution, etc. This study focused on evaluating the reliability of app categorization on Apple iTunes Store by using several rounds of inter-rater reliability statistics, locating categorization problems based on Machine Learning, and making more accurate suggestions about representative functionality stems for each primary category. A mixed methods research was performed and total 4905 popular apps were observed. The original categorization was proved to be substantial reliable but need further improvement. The representative functionality stems for each category were identified. This paper may provide some fusion research experience and methodological suggestions in categorization research field and improve app store's categorization in discoverability.

• Development and Reproduction
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• v.27 no.2
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• pp.57-65
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• 2023

Kidney disease affects a significant portion of the global population, yet effective therapies are lacking despite advancements in identifying genetic causes. This limitation can be attributed to the absence of adequate in vitro models that accurately mimic human kidney disease, hindering targeted therapeutic development. However, the emergence of human induced pluripotent stem cells (PSCs) and the development of organoids using them have opened up a way to model kidney development and disease in humans, as well as validate the effects of new drugs. To fully leverage their capabilities in these fields, it is crucial for kidney organoids to closely resemble the structure and functionality of adult human kidneys. In this review, we aim to discuss the potential of using human PSCs or adult kidney stem cell-derived kidney organoids to model genetic kidney disease and renal cancer.

• International Journal of Stem Cells
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• v.16 no.1
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• pp.108-116
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• 2023

γδ T cells are a rare and unique prototype of T cells that share properties with natural killer cells in secondary lymphoid organs. Although many studies have revealed the function and importance of adult-derived γδ T cells in cancer biology and regenerative medicine, the low numbers of these cells hamper their application as therapeutic cell sources in the clinic. To solve this problem, pluripotent stem cell-derived γδ T cells are considered alternative cell sources; however, few studies have reported the generation of human pluripotent stem cell-derived γδ T cells. In the present study, we investigated whether lymphoid lineage γδ T cells were successfully generated from human pluripotent stem cells via hemogenic endothelium under defined culture conditions. Our results revealed that pluripotent stem cells successfully generated γδ T cells with an overall increase in transcriptional activity of lymphoid lineage genes and cytolytic factors, indicating the importance of the optimization of culture conditions in generating lymphoid lineage γδ T cells. We uncovered an initial step in differentiating γδ T cells that could be applied to basic and translational investigations in the field of cancer biology. Based on our result, we will develop an appropriate method to purify γδ T cells with functionality and it helpful for the study of basic mechanism of γδ T cells in pathophysiologic condition as well as clinic application.

• Journal of Microbiology and Biotechnology
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• v.33 no.5
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• pp.680-686
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• 2023

Aging is a complex series of multi-organ processes that occur in various organisms. As such, an in vivo study using an animal model of aging is necessary to define its exact mechanisms and identify anti-aging substances. Using Drosophila as an in vivo model system, we identified Crataegus pinnatifida extract (CPE) as a novel anti-aging substance. Regardless of sex, Drosophila treated with CPE showed a significantly increased lifespan compared to those without CPE. In this study, we also evaluated the involvement of CPE in aging-related biochemical pathways, including TOR, stem cell generation, and antioxidative effects, and found that the representative genes of each pathway were induced by CPE administration. CPE administration did not result in significant differences in fecundity, locomotion, feeding amount, or TAG level. These conclusions suggest that CPE is a good candidate as an anti-aging food substance capable of promoting a healthy lifespan.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.4
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• pp.285-291
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• 2021

Mesenchymal stem cells (MSCs) have been recognized as a therapeutic tool for various diseases due to its unique ability for tissue regeneration and immune regulation. However, poor survival during in vitro expansion and after being administrated in vivo limits its clinical uses. Accordingly, protocols for enhancing cell survivability is critical for establishing an efficient cell therapy is needed. CDDO-Me is a synthetic C-28 methyl ester of 2-cyano-3,12-dioxoolean-1,9-dien-28-oic acid, which is known to stimulate nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway. Herein, report that CDDO-Me promoted the proliferation of MSCs and increased colony forming units (CFU) numbers. No alteration in differentiation into tri-lineage mesodermal cells was found after CDDO-Me treatment. We observed that CDDO-Me treatment reduced the cell death induced by oxidative stress, demonstrated by the augment in the expression of Nrf2-downstream genes. Lastly, CDDO-Me led to the nuclear translocation of NRF2. Our data indicate that CDDO-Me can enhance the functionality of MSCs by stimulating cell survival and increasing viability under oxidative stress.