• Korean Journal of Veterinary Service
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• v.38 no.3
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• pp.205-209
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• 2015

A 7 years old, female and neutered ferret (Mustela putorius furo) was presented to local animal hospital due to lethargy, anorexia and hypothermia. Radiography, ultrasonography and blood test were performed. On the basis of clinical signs and tests, this case was presumed to be lymphoma. In consideration of this ferret's condition, chemotherapy was carried out for the treatment. However, the ferret died a few days. After necropsy, metastatic tumors were observed over abdomen. All tumors were packed with homologous lymphocytes with pleomorphic changes and numerous mitotic figures. Consequently, this masses were diagnosed as B-cell gastrointestinal lymphoma, which were negative for CD3 on immunohistochemistry.

• Molecules and Cells
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• v.27 no.4
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• pp.491-492
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• 2009

We present the result of our research on the tumorigenic ability of single cell clones isolated from an aggressive murine breast cancer cell line in a matched allografting mouse model. Tumor formation is basically dependent on the cell numbers injected per location. We argue that in vivo tumor formation from single cell clones, isolated in vitro from cancer cell lines, may not provide conclusive evidence to disprove the cancer stem cell (CSC) theory without additional data.

• International Journal of Stem Cells
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• v.17 no.1
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• pp.51-58
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• 2024

With the activity of intestinal stem cells and continuous turnover, the gut epithelium is one of the most dynamic tissues in animals. Due to its simple yet conserved tissue structure and enteric cell composition as well as advanced genetic and histologic techniques, Drosophila serves as a valuable model system for investigating the regulation of intestinal stem cells. The Drosophila gut epithelium is in constant contact with indigenous microbiota and encounters externally introduced "non-self" substances, including foodborne pathogens. Therefore, in addition to its role in digestion and nutrient absorption, another essential function of the gut epithelium is to control the expansion of microbes while maintaining its structural integrity, necessitating a tissue turnover process involving intestinal stem cell activity. As a result, the microbiome and pathogens serve as important factors in regulating intestinal tissue turnover. In this manuscript, I discuss crucial discoveries revealing the interaction between gut microbes and the host's innate immune system, closely associated with the regulation of intestinal stem cell proliferation and differentiation, ultimately contributing to epithelial homeostasis.

• The Korean Journal of Zoology
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• v.33 no.4
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• pp.446-453
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• 1990

In order to investigate the retinoic acid indticed-differentiation of F9 teratocarcinoma stem cell, we have analyzed the change of cell morphology and laminin expression after exposure to retinoic add and cyclic AMP. It is shown that undifferentiated F9 stem cells grow as closely packed colonies, and it is difficult to distinguish cell-cell boundaries. After retinoic add and dibutyryl cyclic AMP treatment, F9 cells assume a flat morphology characterized by perinuclear granules and arrest growth. According to Northern blot analysis, laminin expression was increased markedly after retinoic acid treatment. Laminin Bi gene expression was increased at least 30-fold and laminin B2 gene expression was increased approximately 20-fold during differentiation process. Employing immunofluoresence analysis, it was proved that the synthesis of laminin protein was low level in F9 stem cell whereas it became high level in retinoic acid treated F9 cell and the laminin protein was largely accumulated in the cell surface. Our results suggest that induction of laminin Bi and B2 genes m F9 cells is retinoic acid-mediated control, and morphological change and differentiation of F9 cells might be associated with laminin gene expression.

• Molecules and Cells
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• v.45 no.12
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• pp.923-934
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• 2022

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have great potential in applications such as regenerative medicine, cardiac disease modeling, and in vitro drug evaluation. However, hPSC-CMs are immature, which limits their applications. During development, the maturation of CMs is accompanied by a decline in their proliferative capacity. This phenomenon suggests that regulating the cell cycle may facilitate the maturation of hPSC-CMs. Aurora kinases are essential kinases that regulate the cell cycle, the role of which is not well studied in hPSC-CM maturation. Here, we demonstrate that CYC116, an inhibitor of Aurora kinases, significantly promotes the maturation of CMs derived from both human embryonic stem cells (H1 and H9) and iPSCs (induced PSCs) (UC013), resulting in increased expression of genes related to cardiomyocyte function, better organization of the sarcomere, increased sarcomere length, increased number of mitochondria, and enhanced physiological function of the cells. In addition, a number of other Aurora kinase inhibitors have also been found to promote the maturation of hPSC-CMs. Our data suggest that blocking aurora kinase activity and regulating cell cycle progression may promote the maturation of hPSC-CMs.

• Biomolecules & Therapeutics
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• v.24 no.4
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• pp.363-370
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• 2016

Cardiovascular disease is the most common cause of death in diabetic patients. Hyperglycemia is the primary characteristic of diabetes and is associated with many complications. The role of hyperglycemia in the dysfunction of human cardiac progenitor cells that can regenerate damaged cardiac tissue has been investigated, but the exact mechanism underlying this association is not clear. Thus, we examined whether hyperglycemia could regulate mitochondrial dynamics and lead to cardiac progenitor cell dysfunction, and whether blocking glucose uptake could rescue this dysfunction. High glucose in cardiac progenitor cells results in reduced cell viability and decreased expression of cell cycle-related molecules, including CDK2 and cyclin E. A tube formation assay revealed that hyperglycemia led to a significant decrease in the tube-forming ability of cardiac progenitor cells. Fluorescent labeling of cardiac progenitor cell mitochondria revealed that hyperglycemia alters mitochondrial dynamics and increases expression of fission-related proteins, including Fis1 and Drp1. Moreover, we showed that specific blockage of GLUT1 improved cell viability, tube formation, and regulation of mitochondrial dynamics in cardiac progenitor cells. To our knowledge, this study is the first to demonstrate that high glucose leads to cardiac progenitor cell dysfunction through an increase in mitochondrial fission, and that a GLUT1 blocker can rescue cardiac progenitor cell dysfunction and downregulation of mitochondrial fission. Combined therapy with cardiac progenitor cells and a GLUT1 blocker may provide a novel strategy for cardiac progenitor cell therapy in cardiovascular disease patients with diabetes.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.5
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• pp.459-466
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• 2021

Cardiovascular disease (CVD) and its complications are the leading cause of morbidity and mortality in the world. Because of the side effects and incomplete recovery from current therapy, stem cell therapy emerges as a potential therapy for CVD treatment, and endothelial progenitor cell (EPC) is one of the key stem cells used for therapeutic applications. The effect of this therapy required the expansion of EPC function. To enhance the EPC activation, proliferation, and angiogenesis using dronedarone hydrochloride (DH) is the purpose of this study. DH received approval for atrial fibrillation treatment and its cardiovascular protective effects were already reported. In this study, DH significantly increased EPC proliferation, tube formation, migration, and maintained EPCs surface marker expression. In addition, DH treatment up-regulated the phosphorylation of AKT and reduced the reactive oxygen species production. In summary, the cell priming by DH considerably improved the functional activity of EPCs, and the use of which might be a novel strategy for CVD treatment.

• BMB Reports
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• v.55 no.3
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• pp.142-147
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• 2022

Human pluripotent stem cells (PSCs) have been utilized as a promising source in regenerative medicine. However, the risk of teratoma formation that comes with residual undifferentiated PSCs in differentiated cell populations is most concerning in the clinical use of PSC derivatives. Here, we report that a monoclonal antibody (mAb) targeting PSCs could distinguish undifferentiated PSCs, with potential teratoma-forming activity, from differentiated PSC progeny. A panel of hybridomas generated from mouse immunization with H9 human embryonic stem cells (hESCs) was screened for ESC-specific binding using flow cytometry. A novel mAb, K312, was selected considering its high stem cell-binding activity, and this mAb could bind to several human induced pluripotent stem cells and PSC lines. Cell-binding activity of K312 was markedly decreased as hESCs were differentiated into embryoid bodies or by retinoic acid treatment. In addition, a cell population negatively isolated from undifferentiated or differentiated H9 hESCs via K312 targeting showed a significantly reduced expression of pluripotency markers, including Oct4 and Nanog. Furthermore, K312-based depletion of pluripotent cells from differentiated PSC progeny completely prevented teratoma formation. Therefore, our findings suggest that K312 is utilizable in improving stem cell transplantation safety by specifically distinguishing residual undifferentiated PSCs.

• BMB Reports
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• v.49 no.2
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• pp.93-98
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• 2016

Germline stem cells (GSCs) are the best understood adult stem cell types in the nematode Caenorhabditis elegans, and have provided an important model system for studying stem cells and their cell fate in vivo, in mammals. In this review, we propose a mechanism that controls GSCs and their cell fate through selective activation, repression and mobilization of the specific mRNAs. This mechanism is acutely controlled by known signal transduction pathways (e.g., Notch signaling and Ras-ERK MAPK signaling pathways) and P granule (analogous to mammalian germ granule)-associated mRNA regulators (FBF-1, FBF-2, GLD-1, GLD-2, GLD-3, RNP-8 and IFE-1). Importantly, all regulators are highly conserved in many multi-cellular animals. Therefore, GSCs from a simple animal may provide broad insight into vertebrate stem cells (e.g., hematopoietic stem cells) and their cell fate specification.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.135-135
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• 2002

Nowadays a huge variety of products that aim to assist to quit smoking or reduce addictive symptoms are developed and manufactured with safety evaluation, but the safety of the most recent products of interest which do not contain tobacco and nicotine, and shape cigarettes is not evaluated and guaranteed relatively.(omitted)