• The Journal of Korean Medicine
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• v.21 no.4
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• pp.64-72
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• 2000

Objectives : This study was designed to investigate the neuroprotective effect of Hwansodan(Huanshao-dan) on the apoptosis induced by withdrawal of neurotrophic support. Methods : PCl2 pheochromocytoma cells have been used extensively as a model for studying the cellular and molecular effects of neuronal cells. The viability of cells was measured by MTT assay. We used DNA fragmentation and caspase 3-like protease activation assay. Results : The water extract of Hwansodan(Huanshao-dan) significantly showed protective effects on serum and glucose deprivation-induced apoptotic death. Hwansodan(Huanshao-dan) also prevents DNA fragmentation and caspase 3-like protease activation, representing typical neuronal apoptotic phenomena in PCl2 pheochromocytoma cells and induces tyrosine phosphorylation of proteins around 44 kDa, which was identified as ERK1 with electrophoretic gel mobility shift by Western blot. In addition, MAPK kinase(MEK) inhibitor PD98059 and Ras inactivator, ${\alpha}-hydroxyfarnesylphosphonic$ acid attenuated the neuroprotective effects of Hwansodan(Huanshao-dan) in serum-deprived PCl2 cells. Conclusions : These results indicate that Ras/MEK/ERK signaling pathway plays a key role in neuroprotective effects of Hwansodan(Huanshao-dan) in serum-deprived PCl2 cells. Taken together, we suggest the possibility that Hwansodan(Huanshao-dan) might provide a neurotrophic-like activity in PCl2 cells.

• Journal of Microbiology and Biotechnology
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• v.13 no.4
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• pp.487-494
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• 2003

2,3-Dihydroxybiphenyl 1,2-dioxygenase (23DBDO), an enzyme of the biphenyl biodegradation pathway encoded by the bphC gene of Comnmonas sp. SMN4, was expressed and purified using column chromatographies. SDS-PAGE of purified 23DBDO showed a single band with a molecular mass of 32 kDa, which was consistent with the data from the gel filtration chromatography (GFC). The purified enzyme exhibited a maximum 23DBDO activity at pH 9.0 and was stable at pH 8.0. The enzyme showed maximum activity at $40^{\circ}C$ and maintained activity at $30^{\circ}C$ for 24 h. Kinetic parameters represented by Michaelis-Menten constants such as $K_m\;and\;V_{max}$ values for various substrates were determined by Lineweaver-Burk plots: The purified enzyme 23DBDO from Comamonas sp. SMN4 had the highest catalytic activity for 2,3-dihydroxybiphenyl and 3-methylcatechol, and had very poor activity with catechol and 4-methylcatechol.

• Nutrition Research and Practice
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• v.9 no.2
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• pp.117-122
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• 2015

BACKGROUND/OBJECTIVES: Curcumin, a major component of the Curcuma species, contains antioxidant and anti-inflammatory properties. Although it was found to induce apoptosis in cancer cells, the functional role of curcumin as well as its molecular mechanism in anti-inflammatory response, particularly in intestinal cells, has been less investigated. The intestine epithelial barrier is the first barrier and the most important location for the substrate coming from the lumen of the gut. SUBJECTS/METHODS: We administered curcumin treatment in the human intestinal epithelial cell lines, T84 and Caco-2. We examined endoplasmic reticulum (ER) stress response by thapsigargin, qPCR of XBP1 and BiP, electrophysiology by wild-type cholera toxin in the cells. RESULTS: In this study, we showed that curcumin treatment reduces ER stress and thereby decreases inflammatory response in human intestinal epithelial cells. In addition, curcumin confers protection without damaging the membrane tight junction or actin skeleton change in intestine epithelial cells. Therefore, curcumin treatment protects the gut from bacterial invasion via reduction of ER stress and anti-inflammatory response in intestinal epithelial cells. CONCLUSIONS: Taken together, our data demonstrate the important role of curcumin in protecting the intestine by modulating ER stress and inflammatory response post intoxication.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2129-2144
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• 2015

Programmed cell death (PCD) or apoptosis is a mechanism which is crucial for all multicellular organisms to control cell proliferation and maintain tissue homeostasis as well as eliminate harmful or unnecessary cells from an organism. Defects in the physiological mechanisms of apoptosis may contribute to different human diseases like cancer. Identification of the mechanisms of apoptosis and its effector proteins as well as the genes responsible for apoptosis has provided a new opportunity to discover and develop novel agents that can increase the sensitivity of cancer cells to undergo apoptosis or reset their apoptotic threshold. These novel targeted therapies include those targeting anti-apoptotic Bcl-2 family members, p53, the extrinsic pathway, FLICE-inhibitory protein (c-FLIP), inhibitor of apoptosis (IAP) proteins, and the caspases. In recent years a number of these novel agents have been assessed in preclinical and clinical trials. In this review, we introduce some of the key regulatory molecules that control the apoptotic pathways, extrinsic and intrinsic death receptors, discuss how defects in apoptotic pathways contribute to cancer, and list several agents being developed to target apoptosis.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.441-451
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• 2016

Squalene is a linear triterpene formed via the MVA or MEP biosynthetic pathway and is widely distributed in bacteria, fungi, algae, plants, and animals. Metabolically, squalene is used not only as a precursor in the synthesis of complex secondary metabolites such as sterols, hormones, and vitamins, but also as a carbon source in aerobic and anaerobic fermentation in microorganisms. Owing to the increasing roles of squalene as an antioxidant, anticancer, and anti-inflammatory agent, the demand for this chemical is highly urgent. As a result, with the exception of traditional methods of the isolation of squalene from animals (shark liver oil) and plants, biotechnological methods using microorganisms as producers have afforded increased yield and productivity, but a reduction in progress. In this paper, we first review the biosynthetic routes of squalene and its typical derivatives, particularly the squalene synthase route. Second, typical biotechnological methods for the enhanced production of squalene using microbial cell factories are summarized and classified. Finally, the outline and discussion of the novel trend in the production of squalene with several updated events to 2015 are presented.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.2
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• pp.129-135
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• 2020

SHP2 is an unusual protein phosphatase that functions as an activator for several signaling pathways, including the RAS pathway, while most other phosphatases suppress their downstream signaling cascades. The physiological and pathophysiological roles of SHP2 have been extensively studied in the field of cancer research. Mutations in the PTPN11 gene which encodes SHP2 are also highly associated with developmental disorders, such as Noonan syndrome (NS), and cognitive deficits including learning disabilities are common among NS patients. However, the molecular and cellular mechanism by which SHP2 is involved in cognitive functions is not well understood. Recent studies using SHP2 mutant mice or pharmacological inhibitors have shown that SHP2 plays critical role in learning and memory and synaptic plasticity. Here, we review the recent studies demonstrating that SHP2 is involved in synaptic plasticity, and learning and memory, by the regulation of the expression and/or function of glutamate receptors. We suggest that each cell type may have distinct paths connecting the dots between SHP2 and glutamate receptors, and these paths may also change with aging.

• Nutrition Research and Practice
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• v.14 no.5
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• pp.453-462
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• 2020

BACKGROUND/OBJECTIVES: Platycodon grandiflorum (PG), an oriental herbal medicine, has been known to improve liver function, and has both anti-inflammatory and antimicrobial properties. However, little is known about the immune-enhancing effects of PG and its mechanism. In this study, we aimed to investigate whether fermented PG extract (FPGE), which has increased platycodin D content, activates the immune response in a murine macrophage cell line, RAW 264.7. MATERIALS/METHODS: Cell viability was determined by Cell Counting Kit-8 assay and the nitric oxide (NO) levels were measured using Griess reagent. Cytokine messenger RNA levels of were monitored by quantitative reverse transcription polymerase chain reaction. To investigate the molecular mechanisms underlying immunomodulatory actions of FPGE in RAW 264.7 cells, we have conducted luciferase reporter gene assay and western blotting. RESULTS: We found that FPGE treatment induced macrophage cell proliferation in a dose-dependent manner. FPGE also modulated the expression of NO and pro-inflammatory cytokines, such as tumor necrosis factor-α, interleukin (IL)-1β, and IL-6. The activation and phosphorylation levels of nuclear factor kappa B (NF-κB) were increased by FPGE treatment. Moreover, 5-aminoimidazole-4-carboxamide ribonucleotide, an activator of AMP-activated kinase (AMPK), significantly reduced both lipopolysaccharides- and FPGE-induced NF-κB reporter gene activity. CONCLUSIONS: Taken together, our findings suggest that FPGE may be a novel immune-enhancing agent acting via AMPK-NF-κB signaling pathway.

• Journal of Microbiology and Biotechnology
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• v.13 no.5
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• pp.819-822
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• 2003

Polyketides are an extensive class of secondary metabolites with diverse molecular structures and biological activities. A plasmid-based minimal polyketide synthase (PKS) expression cassette was constructed using a subset of actinorhodin (act) biosynthetic genes (actI-orfl, actI-orf2, actI-orf3, actIII, actⅦ, and actIV) from Streptomyces coelicolor, which specify the construction of an orange-fluorescent anthraquinone product aloesaponarin II, a type II polyketide compound derived from one acetyl coenzyme A and 7 malonyl coenzyme A extender units. This system was designed as an indicator pathway in S. parvulus to generate a hybrid type II polyketide compound via gene-specific replacement. The act ${\beta}-ketoacyl$ synthase unit (actI-orfl and actI-orf2) in the expression cassette was specifically replaced with oxytetracycline ${\beta}-ketoacyl$ synthase otcY-orfl and otcY-orf2). This plasmid-based hybrid PKS cassette generated a novel orange-fluorescent compound structurally different from aloesaponarin II in both S. lividans and S. parvulus. In addition, several additional distinctive blue-fluorescent compounds were detected, when this hybrid PKS cassette was expressed in S. coelicolor B78 (actI-orf2 mutant), implying that the expression of plasmid-based hybrid PKS cassette in Streptomyces species should be an efficient way of generating hybrid type II polyketide compounds.

• Journal of Microbiology and Biotechnology
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• v.23 no.11
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• pp.1544-1553
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• 2013

Despite the importance of acetate kinase in the metabolism of bacteria, limited structural studies have been carried out on this enzyme. In this study, a three-dimensional structure of the Escherichia coli acetate kinase was constructed by use of molecular modeling methods. In the next stage, by considering the structure of the catalytic intermediate, trifluoroethanol (TFE) and trifluoroethyl butyrate were proposed as potential inhibitors of the enzyme. The putative binding mode of these compounds was studied with the use of a docking program, which revealed that they can fit well into the enzyme. To study the role of these potential enzyme inhibitors in the metabolic pathway of E. coli, their effects on the growth of this bacterium were studied. The results showed that growth was considerably reduced in the presence of these inhibitors. Changes in the profile of the metabolic products were studied by proton nuclear magnetic resonance spectroscopy. Remarkable changes were observed in the quantity of acetate, but other products were less altered. In this study, inhibition of growth by the two inhibitors as reflected by a change in the metabolism of E. coli suggests the potential use of these compounds (particularly TFE) as bacteriostatic agents.

• Journal of Microbiology and Biotechnology
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• v.23 no.10
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• pp.1372-1380
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• 2013

Different endophytic fungi isolated from Himalayan Yew plants were tested for their ability to produce taxol. The BAPT gene (C-13 phenylpropanoid side chain-CoA acetyl transferase) involved in the taxol biosynthetic pathway was used as a molecular marker to screen taxol-producing endophytic fungi. Taxol extracted from fungal strain TBPJ-B was identified by HPLC and MS analysis. Strain TBPJ-B was identified as Fusarium redolens based on the morphology and internal transcribed spacer region of nrDNA analysis. HPLC quantification of fungal taxol showed that F. redolens was capable of producing $66{\mu}g/l$ of taxol in fermentation broth. The antitumour activity of the fungal taxol was tested by potato disc tumor induction assay using Agrobacterium tumefaciens as the tumor induction agent. The present study results showed that PCR amplification of genes involved in taxol biosynthesis is an efficient and reliable method for prescreening taxol-producing fungi. We are reporting for the first time the production of taxol by F. redolens from Taxus baccata L. subsp. wallichiana (Zucc.) Pilger. This study offers important information and a new source for the production of the important anticancer drug taxol by endophytic fungus fermentation.