• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1202-1207
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• 2003

In order to clarify the neuroprotective effect of Cornu Saigae Tataricae(CST) water extract on cultured mouse spinal motor neuron damaged by hydrogen peroxide (H₂O₂), MTT [3-(4,5-dimethylthiazole-2-yl)- 2,5-diphenyltetrazolium bromide] assay, LDH (Lactate Dehydrogenase) activity assay and SRB (Sulforhodamine B) assay were carried out after the cultured mouse spinal motor neuron were preincubated with various concentrations of CST water extract for 3 hours prior to exposure of hydrogen peroxide Cell viability of cultured mouse spinal motor neurons exposed to various concentrations of hydrogen peroxide for 6 hours was decreased in a dose-dependent manner. MTT50 values were 40 uM hydrogen peroxide. Cultured mouse spinal motor neurons in the medium containing various concentration of hydrogen peroxide for 6 hours showed increasing of LDH activity and decreasing of total protein synthesis. We know that hydrogen peroxide was toxic on cultured spinal motor neurons. Pretreatment of CST water extract for 3 hours following hydrogen peroxide prevented the hydrogen peroxide-induced neurotoxicity such as increasing of LDH activity and decreasing of total protein synthesis. These results suggest that hydrogen peroxide shows toxic effect on cultured spinal motor neurons and CST water extract is highly effective in protecting the neurotoxicity induced by hydrogen peroxide.

• Journal of Microbiology and Biotechnology
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• v.22 no.2
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• pp.199-206
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• 2012

Naturally immobilized tannase (tannin acyl hydrolase, E.C. 3.1.1.20) has many advantages, as it avoids the expensive and laborious operation of isolation, purification, and immobilization, plus it is highly stable in adverse pH and temperature. However, in the case of cell-associated enzymes, since the enzyme is associated with the biomass, separation of the pure biomass is necessary. However, tannic acid, a known inducer of tannase, forms insoluble complexes with media proteins, making it difficult to separate pure biomass. Therefore, this study optimizes the production of cell-associated tannase using a "protein-tannin complex" free media. An exploratory study was first conducted in shake-flasks to select the inducer, carbon source, and nitrogen sources. As a result it was found that gallic acid induces tannase synthesis, a tryptose broth gives higher biomass, and lactose supplementation is beneficial. The medium was then optimized using response surface methodology based on the full factorial central composite design in a 3 l bioreactor. A $2^3$ factorial design augmented by 7 axial points (${\alpha}$ = 1.682) and 2 replicates at the center point was implemented in 17 experiments. A mathematical model was also developed to show the effect of each medium component and their interactions on the production of cell-associated tannase. The validity of the proposed model was verified, and the optimized medium was shown to produce maximum cell-associated tannase activity of 9.65 U/l, which is 93.8% higher than the activity in the basal medium, after 12 h at pH 5.0, $30^{\circ}C$. The optimum medium consists of 38 g/l lactose, 50 g/l tryptose, and 2.8 g/l gallic acid.

• Journal of Life Science
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• v.26 no.2
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• pp.265-274
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• 2016

Toxin-antitoxin (TA) systems are ubiquitous genetic modules that are evolutionally conserved in bacteria and archaea. TA systems composed of an intracellular toxin and its antidote (antitoxin) are currently classified into five types. Commonly, activation of toxins under stress conditions inhibits diverse cellular processes and consequently induces cell death or reversible growth inhibition. These effects of toxins play various physiological roles in such as regulation of gene expression, growth control (stress response), programmed cell arrest, persister cells, programmed cell death, phage protection, stabilization of mobile genetic elements or postsegregational killing of plasmid-free cells. Accordingly, bacterial TA systems are commonly considered as stress-responsive genetic modules. However, molecule screening for activation of toxin in TA system is available as development of antimicrobial agents. In addition, cytotoxic effect induced by toxin is used as effective cloning method with antitoxic effect of antitoxin; consequently cells containing cloning vector inserted a target gene can survive and false-positive transformants are removed. Also, TA system is applicable to efficient single protein production in biotechnology industry because toxins that are site-specific ribonuclease inhibit protein synthesis except for target protein. Furthermore, some TA systems that induce apoptosis in eukaryotic cells such as cancer cells or virus-infected cells would have a wide range of applications in eukaryotes, and it will lead to new ways of treating human disease. In this review, we summarize the current knowledge on bacterial TA systems and their applications.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.687-693
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• 2007

Insulin-like growth factor-I(IGF-I) has significant insulin-like anabolic effects which include the stimulation of glucose and amino acid uptake, as well as protein and glycogen synthesis. IGFs exist in serum and other biological fluids as complexes bound to a family of structurally related insulin-like growth factor binding proteins(IGFBPs). Six human IGFBPs can modulate the effects of IGFs on target tissues by several mechanisms, including altering the serum's half-life and the transcapillary transport of IGFs, as well as changing the availability of IGFs to specific cell surface receptors. Human fibroblasts secrete IGFBPs that can modify IGF-I action. Previous to our study using either Northern blotting, and Western blotting have shown that fibroblasts express mRNA IGFBP-3, -4, and -5, and synthesize these proteins. In addition, fibroblast cell lysates revealed that the IGFBP-3 was most abundant. For these reasons, we undertook to gain further insight into the effects of high and low glucose incubation condition on metabolism and IGFBP-3 expression. In results of metabolites and IGFBP-3 expression in GM10 cells cultivated with various glucose concentration, the consumption of glucose and accumulation of triglyceride were increased in condition of high glucose, and total protein level was decreased. in the course of time. After 5 days incubation, levels of free amino acid in medium containing glucose of high concentration glucose were higher than in conditions of low glucose. Although the levels of IGFBP-3 protein and mRNA levels were increased in low glucose, and IGFBP-3 was not affected by any pretense. Taken together, we suggest that the study of growth factors, like IGFs, might be a possible model of diabetes militus in cell, although the results in cell models were not in accord with in vivo.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.375-379
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• 1997

Two ribosome-inactivating proteins, PRIP 1 and PRIP 2 have been isolated from the leaves of $Cucurbita\;moschata\;D_{UCHESNE}$. Crude extracts were purified through ammonium sulfate precipitation and column chromatography using DE-52 cellulose, S-Sepharose, FPLC Suprose 12 HR and FPLC Mono-S. The molecular weights of PRIP 1 and PRIP 2 were 31,000 and 30,500, respectively. PRIP 2 was thermostabe and maintained its activity even after the incubation of the protein at $50^{\circ}C$ for 30 min. In a cell free in vitro translation system using rabbit reticulocyte lysate, protein synthesis was inhibited by the addition of PRIP 1 and PRIP 2. The $IC_{50}$ of PRIP 1 and PRIP 2 were 0.82 nM and 0.79 nM, respectively. The comparison of N-terminal amino acid sequences of the PRIP 1 and PRIP 2 with known RIPs revealed that PRIP 1 shows sequence similarity with Luffin B from Luffa cylindrica and Trichokirin from Trichosanthes kirilowii Maximowicz and PRH) 2 has sequence similarity with Momordin II and MAP 30 from Momordica charantia.

• Animal cells and systems
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• v.1 no.4
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• pp.641-646
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• 1997

Lysophosphatidic acid (LPA; 1-acyl-glycerol-3-phosphate) has been known as an intercellular phospholipid messenger with a wide range of biological activities. In this study, the effect of LPA on both the proliferation and differentiation of rat E63 myoblasts has been investigated. In the serum-free Insulin-Transferrin-Selenium (ITS) media, the proliferation of E63 cells was largely restricted. Addition of LPA into the ITS media strongly promoted the cell proliferation and resulted in two to four fold increase of cell number. Furthermore, it appeared to increase the percent fusion in a dose-dependent manner up to 15 ug/ml. The synthesis of myosin heavy chain (MHC) was increased by LPA as well. These results indicate that LPA is able to promote both cell proliferation and differentiation in rat E63 myoblasts. Suramin, known to have uncoupling activity on growth factor-receptor interaction, was tested for antagonistic activity in myoblast proliferation and differentiation. Myoblasts grown in the ITS medium containing LPA were able to proliferate well even in the presence high concentration of suramin whereas myoblast differentiation was completely blocked by 30 ug/ml of suramin. The inhibitory effect of suramin on the myoblast differentiation was completely reversible by removing the suramin. This result indicates that the intracellular signaling pathway of LPA leading to cell proliferation might be distinct from that leading to cell differentiation on E63 myoblasts. Also, the antagonistic effect of suramin suggests that the differentiation activity elicited by LPA might be mediated by a specific G protein-coupled receptor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.428-436
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• 2003

Epidemiological studies have observed a negative association between increased consumption of green and yellow vegetables and cancer incidence. These vegetables contain carotenoids, which are reported to exhibit anticarcinogenic effects. Overexpression of ErbB2 and ErbB3 genes is a frequent event in several human cancers. The present study was performed to determine whether $\alpha$-carotene, $\beta$-carotene, lutein, or lycopene inhibits cell growth and to assess such an effect is related to changes in the levels of the ErbB receptor family and tile ErbB3 receptor signaling pathway in HT-29 cells. HT-29 cells were cultured in serum-free medium in the presence of various concentrations (0~100 $\mu$M) of the individual carotenoids. $\alpha$ -Carotene and lycopene significantly inhibited cell growth in a dose-dependent manner, whereas lutein slightly inhibited cell growth and $\beta$-carotene increased cell growth. Lycopene is more potent than $\alpha$ -carotene in inhibiting HT-29 cell growth. Lycopene inhibited DNA synthesis and induced apoptosis of HT-29 cells. The ErbB3 ligand heregulin (HRG) increased cell growth but did not prevent the lycopene-induced inhibition of cell growth. Lycopene decreased ErbB2 protein levels in a dose-dependent manner. Immunoprecipitation/Western blot studies revealed that lycopene inhibited HRG-induced phosphorylation of ErbB3, recruitment of the 985 regulatory subunit of phosphatidylinositol 3-kinase (PI3K) to the ErbB3 receptor, and phosphorylation of Akt. These results indicate that downregulation of ErbB2/ErbB3/PI3K/Akt signaling may be one of the mechanisms by which lycopene inhibits HT-29 cell pro-liferation and induces apoptosis.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.443-448
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• 2010

Casein phosphopeptide (CPP) enhances calcium absorption in humans. Lactic acid bacteria (LAB) are capable of synthesis of cell-surface proteinase, which can hydrolyze milk protein and release several types of peptides in the medium. This study was conducted to characterize proteinase of LAB and to evaluate the CPP production from bovine milk. The content of CPP of milk produced by cell-free extract of LAB was determined based on the quantity of decomposed peptide from casein using the O-phthaldialdehyde (OPA) method. The proteolytic activity of LAB was assayed using fluorescein isothiocyanate (FITC)-labeled casein. Casein appeared to be a better substrate than whey proteins for extracellular proteinases of LAB. During fermentation, milk proteins were hydrolyzed by extracellular proteinase of LAB, resulting in an increase in the amount of free $NH_3$ groups. Overall, the results presented here indicate that CPP produced by LAB may be a promising material for novel applications in the dairy industry.

• Applied Microscopy
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• v.26 no.4
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• pp.431-446
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• 1996

This experiment was performed to study the ultrastructural changes of the juxtaglomerular cell of mice following subcutaneous injection of heavy metallic agents. Male mice were divided into normal and experimental groups. The mice were subcutaneouly injected with $HgCl_2$ (2mg, 5mg or 10 mg/Kg/BW) or with $K_{2}Cr_{2}O_7$(5 mg, 10 mg or 20 mg/Kg/BW). Mice were sacrificed on 6 hours, 3 days and 14 days after the injection. Kidneys were fixed in the 2.5% glutaraldehyde-1.5% paraformaldehyde solution, followed by refixation in the 1% osmium tetroxide solution. Dehydrated blocks were embedded in araldite mixture. The sections were cut on a LKB-V ultratome, and ultrathin sections stained with uranyl acetate and lead citrate were observed with JEM 100CX II electron microscope. The results were as follow: 1. Juxtaglomerular cell of the experimental groups showed some alterations, especially in the structures of protein synthesis including dilations and degradations of granular endoplasmic reticula, atrophy of Golgi complex, and numerous free ribosomes in the cytoplasm. 2. Juxtaglomerular cells treated groups showed a number of vacuoles, protogranules and some myelin figures in the cytoplasm, especially in the earlier groups. 3. Juxtaglomerular cells of treated groups, contained a large number of secretory granules showing variable electron densities and pleomorphism in later groups (2 weeks). From the above results, it was concluded that, the mercuric chloride or potassium bichromate induces acute renin release from juxtaglomerular cells of the mice, but many juxtaglomerular cells may secrete prematured secretory granules, or the synthetic system of the cell can not perform normal function.

• The Microorganisms and Industry
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• v.25 no.1
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• pp.2-9
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• 1999

A study was made on enzymes of carbohydrate metabolism in T. concretivorus grown with and without glucose. The present results show that T. concretivorus possesses high activities of pentose shunt pathway and related enzymes, glucokinase, G-6-P dehydrogenase, 6-PG dehydrogenase, and phosphoglucoisomerase, but low activities of enzymes unique to EMP(fructose-1,6-diphosphate aldolase). Although the synthesis of the latter enzymes remains largely unaffected by the growth enviroment, that of the former is stimulated by glucose. And the failure to detect ED pathway enzymes in cells grown in thiosulate or thiosulfate-glucose medium eliminates the ED pathway as a significant route of glucose catabolism in T.concretivorus. These results suggest that pentose shunt pathway performs an energetic role in glucose metabolism by T.concretivorus with EMP as a subway. The absence of ED pathway and the presence of pentose shunt pathway which is the major route of catabolism in T.concretivorus are similar to those of other obligately chemolitho-trophic thiobacilli. The G-6-P and 6-PG dehydrogenase are both NAD and NADP specific, but MAD predominant. However, the 3-PGAL dehydrogenase is only NAD specific. Since the specific activity of 3-PGAL generated from glucose is converted mainly into pyruvate which is channeled into the TCA cycle. All enzymes of the TCA cycle tested and NADH oxidase are detected in the cells of T.concretivorus grown in thiosulfate. The specific activities of fumarase and isocitrate dehydrogenase are high and others are low. The presence of two isocitrate dehydrogenase (NAD-and NADP-linked) may have important regulatory function for this organism. The activity of NAD-oxidase, which is implicated in the energy generating metabolism, was very high in the crude cell-free extract of T.concretivorus, recording 55.11 m.mu. mole/min/mg protein. This well coincides with the fact that activities of NAD-linked G-6-P dehydrogenase, 6-PG dehydrogenase and 3-PGAL dehydrogenase were high.