• Toxicological Research
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• v.18 no.3
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• pp.293-300
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• 2002

Chemical carcinogen-induced alteration of aldehyde metabolic enzymes were examined in clone 9 cell. Diethylnitrosamine (DENA), N-nitrosoethylurea (NEU) and N-nitrosomorpholine (NNM) were wed as model carcinogens. Changes in enzyme activities by repetitive treatment of DENA, NEU or NNM were analyzed in terms of specific activities and activity stainings of the enzymes on the gel. Upon treatment of DENA, lipid peroxide level increased upto 10 fold, indicating strong oxidative stress state of the cell. Notable enhancement of ADH and ALDH activity occurred after DENA treatment, while glutathione-S-transferase activity was slightly increased. Furthermore, about 2.5 fold higher superoxide dismutase (SOD) activity was detected during deactivation of catalase (CAT) activity by repetitive treatment of DENA. However in NEU-treated cell, about 2.3 fold higher ALDH activity was found while ADH activity was slightly increased. Notable increase CAT and SOD could also be found. In contrast, maximum 3.5 fold higher CAT activity occurred during SOD deactivation in NNM-treated cell. These results suggest that there might be different enzymatic responses in relation to cell protection against DENA, NEU or NNM.

• Journal of Periodontal and Implant Science
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• v.23 no.1
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• pp.1-15
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• 1993

P. gingivalis has been implicated as a strong pathogen in periodontal disease and known to have three serotypes of P. gingivalis. The purpose of this study is to investigate on the relationship between virulence, metabolic acids and genetic heterogeneity of P. gingivalis. P. gingivalis W50 standard strain and five strains of P. gingivalis serotype b Korean isolates were used in this study. For in vitro virulence test, lyophilized whole cell P. gingivalis were suspended, and sonicated with ultrasonic dismembranometer. Sonicated samples were applied to cultured cells derived from periodontal ligament, and cell activity was assayed with growth and survival assay. The metabolic acids were also extracted, and determined by High Performance Liquid Chromatography. Pst I-digested bacterial genomic DNA was electrophoresed, and densitometric analysis was performed to study the genetic heterogeneity. All of the P. gingivalis serotype b produced butyric acid. In cell activity study, butyric acid inhibited the cell activity irrespective of its concentration. Densitometric analysis showed restriction fragment length polymorphism. These results suggested that there existed heterogeneity of the metabolic acids and the virulence of P. gingivalis and such heterogeneity might be related to genetic heterogeneity.

• Molecules and Cells
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• v.46 no.12
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• pp.727-735
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• 2023

Stem cells require high amounts of energy to replicate their genome and organelles and differentiate into numerous cell types. Therefore, metabolic stress has a major impact on stem cell fate determination, including self-renewal, quiescence, and differentiation. Lysosomes are catabolic organelles that influence stem cell function and fate by regulating the degradation of intracellular components and maintaining cellular homeostasis in response to metabolic stress. Lysosomal functions altered by metabolic stress are tightly regulated by the transcription factor EB (TFEB) and TFE3, critical regulators of lysosomal gene expression. Therefore, understanding the regulatory mechanism of TFEB-mediated lysosomal function may provide some insight into stem cell fate determination under metabolic stress. In this review, we summarize the molecular mechanism of TFEB/TFE3 in modulating stem cell lysosomal function and then elucidate the role of TFEB/TFE3-mediated transcriptional activity in the determination of stem cell fate under metabolic stress.

• Journal of Magnetics
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• v.18 no.3
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• pp.289-296
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• 2013

This work presents results of the study which concerns the influence of the rotating magnetic field (RMF) on the growth rate, cell metabolic activity and ability to form biofilms by E. coli and S. aureus. Liquid cultures of the bacteria were exposed to the RMF (RMF frequency f = 1-50 Hz, RMF magnetic induction B = 22-34 mT, time of exposure t = 60 min, temperature of incubation $37^{\circ}C$). The present study indicate the exposition to the RMF, as compared to the unexposed controls causing an increase in the growth dynamics, cell metabolic activities and percentage of biofilm-forming bacteria, in both S. aureus and E. coli cultures. It was also found that the stimulating effects of the RMF exposition enhanced with its increasing frequencies and magnetic inductions.

• Journal of Ginseng Research
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• v.43 no.3
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• pp.431-441
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• 2019

Background: The efficacy of ginseng, the representative product of Korea, and its chemical effects have been well investigated. The ginsenoside RG3 has been reported to exhibit apoptotic, anticancer, and antidepressant-like effects. Methods: In this report, the putative effect of RG3 on several cellular function including cell survival, differentiation, development and aging process were evaluated by monitoring each specific marker. Also, mitochondrial morphology and function were investigated in ultraviolet (UV)-irradiated normal human dermal fibroblast cells. Results: RG3 treatment increased the expression of extracellular matrix proteins, growth-associated immediate-early genes, and cell proliferation genes in UV-irradiated normal human dermal fibroblast cells. And, RG3 also resulted in enhanced expression of antioxidant proteins such as nuclear factor erythroid 2-related factor-2 and heme oxygenase-1. In addition, RG3 affects the morphology of UV-induced mitochondria and plays a role in protecting mitochondrial dysfunction. Conclusioin: RG3 restores mitochondrial adenosine triphosphate (ATP) and membrane potential via its antioxidant effects in skin cells damaged by UV irradiation, leading to an increase in proteins linked with the extracellular matrix, cell proliferation, and antioxidant activity.

• Analytical Science and Technology
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• v.35 no.4
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• pp.181-188
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• 2022

This paper describes a comparative analysis of yeast cell viability at exponential and stationary growth phases using multiple conventional techniques and statistical tools. Overall, cellular responses to various viability assays were asynchronous. Results of optical density measurement and direct cell counting were asynchronous both at exponential and stationary phases. Proliferative capacity measurement using SP-SDS indicated that cells at the end of the stationary phase were proliferative as much as exponentially growing cells. Metabolic activity assays using two different dyes concluded that the inside of cells at stationary phase is slightly less reducing compared to that of exponentially growing cells, implying that the metabolic activity imperceptibly declined as cells were aged. These results will be helpful to understand the details of yeast cell viability at exponential and stationary growth phases.

• Korean Journal of Microbiology
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• v.25 no.3
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• pp.189-197
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• 1987

The aim of the present study was to investigate the effect of glutamate on the biosynthesis of tylosin. Activities of enzymes involved in the metabolic pathway of glutamate to form tylactone, an essential precursor of tylosin, were determined using Streptomyces fradiae grown at different concentration of glutamate. As results, it was found that cell growth and tylactone formation was controlled by the metabolic flux of oxaloacetate. It was clear that cell growth was favored by the activities of citrate synthase and aspartate aminotransferase, while the tylactone synthesis was stimulated by the activity of methylmalonyl-CoA carboxyltransferase. Therefore it was concluded that channelling of oxaloacetate was a point for favoring either cell growth or tylosin biosynthesis.

• Biotechnology and Bioprocess Engineering:BBE
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• v.8 no.1
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• pp.41-46
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• 2003

Difficulties associated with bioartificial liver (BAL) preservation limit not only the commercialization of BAL, but also its clinical trials. In this study, the possibility of cold preservation of BAL cartridges containing porcine hepatocytes was examined at 4$^{\circ}C$. In an in vitro perfusion culture System, BAL cartridges maintained cytochrome P450 metabolic function for at least 50 days. However, all BAL cartridges completely lost their ammonia eliminating ability when stored at 4$^{\circ}C$. We a1so studied the effect of cell density on the maintenance of BAL liver function In a highly differentiated and healthy state. As expected, BALs containing a larger number of hepatocytes demonstrated higher metabolic functions. When metabolic functions were compared per gram of hepatotytes, no large differences were observed between devices containing different densities of hepatocytes. Decreased cell density did not Successfully prolong BAL function. The viability and function of isolated hepatotytes highly depend on the culture conditions, such as cell density, substrata, culture media, and additives to the culture media. Perfusion culture of BAL cartridges at 4$^{\circ}C$ gave a promosing result with respect to the maintenance of P450 activity. However, as indicated by the rapid loss of ammonia metabolic activity, many factors still remain to be optimized for preservation of BAL keeping high metabolic functions for a longer time.

• Proceedings of the Korean Society of Toxicology Conference
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• 2002.05a
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• pp.105-105
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• 2002

A wide range of chemicals derived from plant and human-made xenobiotics are reported to have hormonal activity. The present studies were performed to examine the estrogenic effect of Kwao Keur, Pueraria mirifica (PM), that has been used a rejuvenating folk medicine from Thailand, using recombinant yeast, MCF-7 cell proliferation and HepG2 cell transient transfection assay.(omitted)

• Molecules and Cells
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• v.37 no.5
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• pp.365-371
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• 2014

Recent findings, notably on adipokines and adipose tissue inflammation, have revised the concept of adipose tissues being a mere storage depot for body energy. Instead, adipose tissues are emerging as endocrine and immunologically active organs with multiple effects on the regulation of systemic energy homeostasis. Notably, compared with other metabolic organs such as liver and muscle, various inflammatory responses are dynamically regulated in adipose tissues and most of the immune cells in adipose tissues are involved in obesity-mediated metabolic complications, including insulin resistance. Here, we summarize recent findings on the key roles of innate (neutrophils, macrophages, mast cells, eosinophils) and adaptive (regulatory T cells, type 1 helper T cells, CD8 T cells, B cells) immune cells in adipose tissue inflammation and metabolic dysregulation in obesity. In particular, the roles of natural killer T cells, one type of innate lymphocyte, in adipose tissue inflammation will be discussed. Finally, a new role of adipocytes as antigen presenting cells to modulate T cell activity and subsequent adipose tissue inflammation will be proposed.