• Title/Summary/Keyword: intracellular pH

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Studies on the Anti-cancer Effect and the Mechanism of Apoptosis by Baekduong-tang in Human Colon Cancer Cell Line HCT-116 (백두옹탕(白頭翁湯)의 대장암 세포주 HCT-116 항암효과와 세포자멸사에 관한 연구)

  • Kim, Jong-Uk;Moon, Goo;Park, Chan-Ny;Lee, Jeong-Han;Ji, Hye-Min
    • The Journal of Internal Korean Medicine
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    • v.31 no.2
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    • pp.273-289
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    • 2010
  • Objectives : To investigate the anti-cancer effect of Baekduong-tang(BDOT) against cancer cells, the signaling pathway of apoptosis was explored in human colon cancer cells. Materials and Methods : Human colon cancer cell lines, including HT-29 and HCT-116 cells, were used. Cell viability was measured by MTT assay. Apoptosis was determined by DAPI nuclei staining and flow cytometry in HCT-116 cells treated with 0.25 mg/$m{\ell}$ Baekduong-tang for 48 hrs. Results : Baekduong-tang induced the apoptosis of p53 positive HCT-116 cells with G2/M phase arrest. Treatment with Baekduong-tang led to increased expression and phosphorylation of p53 and decreased expression of CDK2 and CDK6 in HCT-116 cells. It also activated caspase-3 through caspase-10 and caspase-9 activation. Finally, Baekduong-tang induced production $H_2O_2$, superoxide anion ($O_2^-$) and NO and modulated proteins expression including SOD, NOS, Bax and Bcl-2. Conclusions : These results indicate Baekduong-tang induces apoptotic death of HCT-116 cells through G2/M phase arrest and disturbance of intracellular redox status in a p53-dependent manner.

Anti-Inflammatory and Antioxidative Effects of Gracilaria textorii Ethanol Extract in LPS-PG-Stimulated Human Gingival Fibroblast-1 Cells (사람 치은섬유모세포에서 잎꼬시래기 에탄올 추출물의 항염증 및 항산화 효과)

  • Park, Chungmu;Yoon, Hyunseo
    • Journal of The Korean Society of Integrative Medicine
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    • v.7 no.4
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    • pp.61-69
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    • 2019
  • Purpose : Human gingival fibroblast cell is one of the the main cell types in periodontal tissue, which they can show anti-inflammatory activity through the production of numerous lines of inflammatory mediators such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and interleukins. Porphyromonas gingivalis, one of the oral pathogens, has reported to play a critical role in the development of periodontal diseases. This study aimed to investigate anti-inflammatory and antioxidative activities of Gracilaria textorii ethanol extract (GTEE) in P. gingivalis derived lipopolysaccharide (LPS-PG) stimulated human gingival fibroblast (HGF)-1 cell line. Methods : In order to analyze anti-inflammatory and antioxidative activities of GTEE in HGF-1 cell line, NOS enzyme activity, expression levels of iNOS, COX-2, NAD(P)H quinone dehydrogenase (NQO)1 and their transcription factors were estimated by Griess reaction and western hybridization. Results : LPS-PG induced overexpression of iNOS and COX-2, which was significantly attenuated by GTEE treatment in a dose-dependent manner without any cytotoxicity. In addition, intracellular NOS activity was in accordance with the result of iNOS expression. Due to important role in the regulation of inflammatory responses, phosphorylated status of p65 and c-jun, each subunit of nuclear factor (NF)-κB and activator protein (AP)-1, was also dose-dependently ameliorated by GTEE treatment. One of phase II enzymes, NQO1, and its transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), were analyzed since elevated phase II enzyme expression inhibited inflammatory response, which was significantly elevated by GTEE treatment in HGF-1 cell line. Conclusion : In conclusion, GTEE mitigated LPS-PG-stimulated inflammatory responses by attenuating NF-κB and AP-1 activation as well as accelerating NQO1 and Nrf2 expression in HGF-1 cell line. These results indicate that GTEE might be utilized a promising strategy for potential anti-inflammatory agent in periodontal diseases.

Toxoplasma gondii: Ultrastructural localization of specific antigens and inhibition of intracellular multiplication by monoclonal antibodies

  • Lee, Boo-Young;Ahn, Myoung-Hee;Kim, Hyun-Chul;Min, Duk-Young
    • Parasites, Hosts and Diseases
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    • v.39 no.1
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    • pp.67-76
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    • 2001
  • This experiment was focused on the characterization of anti- Toxoplasma monoclonal antibodies (mAbs) and the effect of mAbs on the parasite invasion of mouse peritoneal macrophages. Twenty eight mAbs including M110, M556, R7A6 and M62l were characterized by Ab titer, immunoglobulin isotyping and western blot pattern. Antibody titer (optical density) of 4 mAbs. Ml 10. M556. R7A6 and M62l. were 0.53,0.67, 0.45 and 0.39 (normal mouse serum; 0.19) with the same IgGl isotypes shown by Enzyme-linked immunosorbent assay (ELISA). Western blot analysis showed that Ml 10. M556. R7A6 and M62l reacted with the 33 kDa (p30),31 kDa (p28),43 kDa and 36 kDa protein. Immuno-gold labelling of mAbs M110, M556, R7A6 and M621 reacted with the surface membrane, dense granules and parasitophorous vacuolar membrane (PVM) , rhoptries and cytoplasm of tachyzoite, respectively. For in vitro assay, preincubation of tachyzoties with four mAbs, Ml 10, M556, R7A6 and M62l resulted in the decrease of the number of infected macrophages (p < 0.05) and the suppression of parasite multiplication at 18 h post-infection. Four monoclonal antibodies including Ml 10 (SAGI) were found to have an important role in the inhibition of macrophage invasion and T. gondii multiplication in vitro, and these mAbs may be suitable for vaccine candidates, diagnostic kit and for chemotherapy.

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OPTHiS Identifies the Molecular Basis of the Direct Interaction between CSL and SMRT Corepressor

  • Kim, Gwang Sik;Park, Hee-Sae;Lee, Young Chul
    • Molecules and Cells
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    • v.41 no.9
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    • pp.842-852
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    • 2018
  • Notch signaling is an evolutionarily conserved pathway and involves in the regulation of various cellular and developmental processes. Ligand binding releases the intracellular domain of Notch receptor (NICD), which interacts with DNA-bound CSL [CBF1/Su(H)/Lag-1] to activate transcription of target genes. In the absence of NICD binding, CSL down-regulates target gene expression through the recruitment of various corepressor proteins including SMRT/NCoR (silencing mediator of retinoid and thyroid receptors/nuclear receptor corepressor), SHARP (SMRT/HDAC1-associated repressor protein), and KyoT2. Structural and functional studies revealed the molecular basis of these interactions, in which NICD coactivator and corepressor proteins competitively bind to ${\beta}-trefoil$ domain (BTD) of CSL using a conserved ${\varphi}W{\varphi}P$ motif (${\varphi}$ denotes any hydrophobic residues). To date, there are conflicting ideas regarding the molecular mechanism of SMRT-mediated repression of CSL as to whether CSL-SMRT interaction is direct or indirect (via the bridge factor SHARP). To solve this issue, we mapped the CSL-binding region of SMRT and employed a 'one- plus two-hybrid system' to obtain CSL interaction-defective mutants for this region. We identified the CSL-interaction module of SMRT (CIMS; amino acid 1816-1846) as the molecular determinant of its direct interaction with CSL. Notably, CIMS contains a canonical ${\varphi}W{\varphi}P$ sequence (APIWRP, amino acids 1832-1837) and directly interacts with CSL-BTD in a mode similar to other BTD-binding corepressors. Finally, we showed that CSL-interaction motif, rather than SHARP-interaction motif, of SMRT is involved in transcriptional repression of NICD in a cell-based assay. These results strongly suggest that SMRT participates in CSL-mediated repression via direct binding to CSL.

Effect of Different Infusion Frequency of Liquid Nitrogen on Actin Filament, Mitochondria, Apoptosis and Development in Mouse 2-Cell Embryo after Freezing and Thawing (생쥐 배아 동결시 액체질소의 분사속도가 해빙후 배아의 발달, 미세섬유, 미토콘드리아 및 세포자연사에 미치는 영향)

  • 손인표;안학준;계명찬;최규완;민철기;강희규;이호준;권혁찬
    • Development and Reproduction
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    • v.4 no.2
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    • pp.161-173
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    • 2000
  • The aim of this study was to assess the effect of the frequency of the L$N_2$ infusion on the ultrastructure, metabolism and development of the embryo after freezing and thawing by computerized cell freezer. Two-cell embryos of ICR mouse were randomly allocated into fresh (control), high-frequency freezing (group 1) and low-frequency freezing (group 2). For fresh and frozen-thawed intact 2-cell embryos, total ceil number in the blastocyst was counted by fluorescent microscope after Hoechst 33258 staining. Relative amount of $H_2O$$_2$ was measured by DCHFDA. Intracellular location and membrane potential of the mitochondria were evaluated by staining with rhodamine 123 and JC-1. The structure of actin filament was also evaluated by confocal microscope. DNA fragmentation was assessed by TUNEL method after development into blastocyst. The survival rate of intact embryo was higher in group 1 than group 2 (50.7% vs. 34.6% respectively, p<0.05). The blastocyst developmental rate was significantly low in group 2 (86.7%, 76.7% vs. 44.0% for control, group 1 and group 2 respectively, p<0.05). Total cell number in the blastocyst was also significantly lower in group 2 than control (79.5$\pm$12.9, 71.6$\pm$8.0, and 62.5$\pm$4.7 for control, group 1 and group 2 respectively, p<0.05). The relative amount of $H_2O$$_2$ was higher in group 2 than other groups (15.3$\pm$3.0, 16.6$\pm$1.6 vs. 23.4$\pm$1.8, p<0.05). After JC-1 staining, relative intensity of mitochondria with high membrane potential was significantly lower in group 2 than control and group 1 (17.2$\pm$3.8, 17.4$\pm$1.3 vs. 13.2$\pm$2.0, p<0.05). In group 2, partial deletion and aggregation of the actin filament was found. DNA fragmentation rate was also hieher for group 2 versus other groups (30.8%, 36.0% vs. 65.6%, p<0.05). The frequency of the L$N_2$ infusion is an important factor for the development of frozen-thawed mouse embryo. High-frequency infusion may prevent damages of cytoskeleton and mitochondria in the embryo probably by preventing the temperature fluctuation during dehydration phase. We speculate that the application of high-frequency infusion method in human embryo may be promising.

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Protective Effect of Propofol against Hypoxia-reoxygenation Injury in HaCaT Human Keratinocytes

  • Kim, Yong-Ho;Kang, Jin-Mo;Kim, In-Ryoung;Lee, Bo-Young;Yoon, Ji-Young;Kim, Cheul-Hong;Park, Bong-Soo
    • International Journal of Oral Biology
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    • v.39 no.2
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    • pp.97-105
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    • 2014
  • The aim of this study was to determine the beneficial effect of propofol on human keratinocytes that have undergone hypoxia reoxygenation (H/R) injury and to investigate whether autophagy is associated with the protective mechanism. Thus, we evaluated how propofol influences the intracellular autophagy and apoptosis during the H/R process in the HaCaT cells. The cultured human keratinocyte cells were exposed to 24 h of hypoxia (5% $CO_2$, 1% $O_2$, 94% $N_2$) followed by 12 h of reoxygenation (5% $CO_2$, 21% $O_2$, 74% $N_2$). The experiment was divided into 4 groups: (1) Control=Normoxia ; (2) H/R=Hypoxia Reoxygenation ; (3) PPC+H/R=Propofol Preconditioning+Hypoxia Reoxygenation; (4) 3-MA+PPC+ H/R=3-MA-Methyladenine+Propofol Preconditioning+ Hypoxia Reoxygenation. In addition, Western blot analysis was performed to identify the expression of apoptotic pathway parameters, including Bcl-2, Bax, and caspase 3 involved in mitochondrial-dependent pathway. Autophagy was determined by fluorescence microscopy, MDC staining, AO staining, and western blot. The H/R produced dramatic injuries in keratinocyte cells. In our study, the viability of Propofol in H/R induced HaCaT cells was first studied by MTT assay. The treatment with 25, 50, and $100{\mu}M$ Propofol in H/R induced HaCaT cells enhanced cell viability in a dose-dependent manner and $100{\mu}M$ was the most effective dose. The Atg5, Becline-1, LC3-II, and p62 were elevated in PPC group cells, but H/R-induced group showed significant reduction in HaCaT cells. The Atg5 were increased when autophagy was induced by Propofol, and they were decreased when autophagy was suppressed by 3-MA. These data provided evidence that propofol preconditioning induced autophagy and reduced apoptotic cell death in an H/R model of HaCaT cells, which was in agreement with autophagy playing a very important role in cell protection.

Plumbagin from Plumbago Zeylanica L Induces Apoptosis in Human Non-small Cell Lung Cancer Cell Lines through NF-κB Inactivation

  • Xu, Tong-Peng;Shen, Hua;Liu, Ling-Xiang;Shu, Yong-Qian
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2325-2331
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    • 2013
  • Objective: To detect effects of plumbagin on proliferation and apoptosis in non-small cell lung cancer cell lines, and investigate the underlying mechanisms. Materials and Methods: Human non-small cell lung cancer cell lines A549, H292 and H460 were treated with various concentrations of plumbagin. Cell proliferation rates was determined using both cell counting kit-8 (CCK-8) and clonogenic assays. Apoptosis was detected by annexin V/propidium iodide double-labeled flow cytometry and TUNEL assay. The levels of reactive oxygen species (ROS) were detected by flow cytometry. Activity of NF-${\kappa}B$ was examined by electrophoretic mobility shift assay (EMSA) and luciferase reporter assay. Western blotting was used to assess the expression of both NF-${\kappa}B$ regulated apoptotic-related gene and activation of p65 and $I{\kappa}B{\kappa}$. Results: Plumbagin dose-dependently inhibited proliferation of the lung cancer cells. The IC50 values of plumbagin in A549, H292, and H460 cells were 10.3 ${\mu}mol/L$, 7.3 ${\mu}mol/L$, and 6.1 ${\mu}mol/L$ for 12 hours, respectively. The compound concentration-dependently induced apoptosis of the three cell lines. Treatment with plumbagin increased the intracellular level of ROS, and inhibited the activation of NK-${\kappa}B$. In addition to inhibition of NF-${\kappa}B$/p65 nuclear translocation, the compound also suppressed the degradation of $I{\kappa}B{\kappa}$. ROS scavenger NAC highly reversed the effect of plumbagin on apoptosis and inactivation of NK-${\kappa}B$ in H460 cell line. Treatment with plumbagin also increased the activity of caspase-9 and caspase-3, downregulated the expression of Bcl-2, upregulated the expression of Bax, Bak, and CytC. Conclusions: Plumbagin inhibits cell growth and induces apoptosis in human lung cancer cells through an NF-${\kappa}B$-regulated mitochondrial-mediated pathway, involving activation of ROS.

Production of Xylooligo-Saccharides and Purification of Extracellular Xylanase from Streptomyces chibaensis J-59 (방선균 Streptomyces chibaensis J-59 Xylanase의 정제 및 자일로 올리고당(Xylooligo-Saccharides)의 생산)

  • Joo, Gil-Jae;Rhee, In-Koo
    • Current Research on Agriculture and Life Sciences
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    • v.14
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    • pp.111-122
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    • 1996
  • S. chibaensis J-59 produced an extracellular xylanase in a CSL medium composed of 1.5% com steep liquor, 0.1% $MgSO_4{\cdot}7H_2O$, 0.012% $CoCl_2{\cdot}6H_2O$, and 0.15% glucose containing xylan. but it did not produce in the culture medium containing xylose. The production of enzyme reached to a maximum level (0.83 uints/ml) when bacteria were cultured in 2.5 l jar fermentor for 48hrs at $30^{\circ}C$ and pH 7.0. Furthermore, S. chibaensis J-59 produced an intracellular glucose isomerase in a medium containing xylan and/or xylose. Xylanase was purified 29-fold over the culture supernatants of S. chibaensis J-59 by ammonium sulfate fractionation, chromatography on DEAE-Sephadex A-50, and gel filtration on Sephadex G-200. The purified enzyme is a monomeric enzyme with a native molecular mass of 25 kDa and a subunit molecular mass of 25 kDa. The purified enzyme requires $Mg^{2+}$ for activity, $Ca^{2+}$, $Co^{2+}$ is not an inhibitor but inhibit by $Fe^{3+}$, $Hg^{2+}$, and $Cu^{2+}$, sodium dodecyl sulfate, N-bromosuccinide. Pattern of hydrolysis demonstrated that the xylanase was an endo-splitting enzyme able to break down birchwood xylan at random giving xylobiose, xylotriose and xylotetrose as the main end products.

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Tat-mediated Protein Transduction of Human Brain Pyridoxine-5-P Oxidase into PC12 Cells

  • Kim, So-Young;An, Jae-Jin;Kim, Dae-Won;Choi, Soo-Hyun;Lee, Sun-Hwa;Hwang, Seok-Il;Kwon, Oh-Shin;Kang, Tae-Cheon;Won, Moo-Ho;Cho, Sung-Woo;Park, Jin-Seu;Eum, Won-Sik;Lee, Kil-Soo;Choi, Soo-Young
    • BMB Reports
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    • v.39 no.1
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    • pp.76-83
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    • 2006
  • Pyridoxine-5-P oxidase catalyses the terminal step in the biosynthesis of pyridoxal-S-P, the biologically active form of vitamin $B_6$ Which acts as an essential cofactor. Here, a human brain pyridoxine-5-P oxidase gene was fused with a gene fragment encoding the HIV-1 Tat protein transduction domain (RKKRRQRRR) in a bacterial expression vector to produce a genetic in-frame Tat-pyridoxine-5-P oxidase fusion protein. Expressed and purified Tat-pyridoxine-5-P oxidase fusion protein transduced efficiently into PC12 cells in a time- and dose-dependent manner when added exogenously to culture media. Once inside the cells, the transduced Tat-pyridoxine-5-P oxidase protein showed catalytic activity and was stable for 48 h. Moreover, the formation of pyridoxal-5-P was increased by adding exogenous Tat-pyridoxine-5-P oxidase to media pre-treated with the vitamin $B_6$ precursor pyridoxine. In addition, the intracellular concentration of pyridoxal-S-P was markedly increased when Tat-pyridoxal kinase was transduced together with Tat-pyridoxine-5-P oxidase into cells. These results suggest that the transduction of Tat-pyridoxine-5-P oxidase fusion protein presents a means of regulating the level of pyridoxal-5-P and of replenishing this enzyme in various neurological disorders related to vitamin $B_6$.

Esterase Production and Culture Characteristics of Bacteria Isolated from Acid Hydrolysed Soybean Protein (산분해 대두 단백질로부터 분리된 Esterase 생성균의 생육 및 효소생성 특성)

  • Oh, Nam-Soon
    • Applied Biological Chemistry
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    • v.40 no.6
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    • pp.484-489
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    • 1997
  • The characteristics of growth and esterase activity of bacterial strains isolated from acid hydrolysed soybean protein were examined. All the isolated strains having decomposition activity of p-hydroxybenzoic acid butyl ester and esterase producing activity were identified as Bacillus sp. by morphological and biochemical methods. The specific growth rates, esterase activities and p-hydroxybenzoic acid butyl ester decomposition activities of isolated strains were $0.844{\sim}1.213\;h^{-1}$, $21{\sim}222\;mU/ml$ and $5.4{\sim}8.1\;mU/ml$, respectively. In the fermentation of Bacillus sp. KB8 strain which had the highest esterase producing activity, growth, extracellular excretion and intracellular synthesis of esterase were inhibited by adding NaCl in the culture broth. Esterase producing activity gradually increased after late exponential growth phase, until maximum value of 420 mU/ml reached after 64 hours culture period. Esterase of Bacillus sp. KB8 strain was stable up to $50^{\circ}C$ for 30 minutes, but was inactivated by heating for 30 minutes at $70^{\circ}C$. The enzyme activity exponentially decreased during the incubation time at the temperatures of $60^{\circ}C$ and $65^{\circ}C$.

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