• 한국동물위생학회지
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• 제38권3호
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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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• 제27권4호
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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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• 제17권1호
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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.

• 한국동물학회지
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• 제33권4호
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• pp.446-453
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• 1990

본 실험은 레티노익산에 의해 F9 Teratocarcinoma Stem Cell의 분화를 유도하고 이분화과정에서 세포형태의 변화와 라미닌유전자의 발현을 조사 하였다. 분화되지 않은 F9 Stem Cell은 지속적으로 증식을 하며 세포간의 간격을 구분하기 어령루 뿐만 아니라 불규칙적인 모양을 하고 있으나,레티노익산과 dibutyryl cyclic AMP처리후의 분화된 F9세포는 둥글고 평평한 모양을 나타내며 세포성장은 중지되었다. Northern blot분석에 의하여 레티노익산과 cyclic AMP처리 후의 F9세포내에서 라미닌 유전자의 발현은 현저하게 증가하였다. 즉, 라미닌 B1유전자 발현은 분화과정 동안 최소한 30배, 라미닌 B2 유전자의 발현은 약 20배 증가하였다. 또한 라미닌 항체를 이용한 면역형광 분석결과는 Northern 분석결과와 일치하게 분화 후에 라미닌 단백질 합성이 크게 증가되었으며, 생성된 라미닌 단백질은 거의 세포표면에 분포된 것으로 나타났다. 이러한 결과로부터, 레티노익산에 의해 F9 Stem Cell의 분화가 유도되며 이 분화과정에서의 형태적인 변화와 진행은 라미닌의 생성과 밀접한 관련이 있다고 추측된다.

• Molecules and Cells
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• 제45권12호
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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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• 제24권4호
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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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• 제25권5호
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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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• 제55권3호
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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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• 제49권2호
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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.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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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)