• Title/Summary/Keyword: Degradation pathway

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Neuroprotective Effects of Cheongnoemyeongsin-hwan against Hydrogen Peroxide-induced DNA Damage and Apoptosis in Human Neuronal-Derived SH-SY5Y Cells (인체 신경세포에서 청뇌명신환(淸腦明神丸)의 산화적 스트레스에 대한 세포보호 효과)

  • Pi, Guk Hyun;Hwang, Won Deuk
    • Herbal Formula Science
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    • v.25 no.1
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    • pp.51-68
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    • 2017
  • Objectives : Oxidative stress due to excessive accumulation of reactive oxygen species (ROS) is one of the risk factors for the development of several chronic diseases, including neurodegenerative diseases. Methods : In the present study, we investigated the protective effects of cheongnoemyeongsin-hwan (CNMSH) against oxidative stress‑induced cellular damage and elucidated the underlying mechanisms in neuronal-derived SH-SY5Y cells. Results : Our results revealed that treatment with CNMSH prior to hydrogen peroxide (H2O2) exposure significantly increased the SH-SY5Y cell viability, indicating that the exposure of the SH-SY5Y cells to CNMSH conferred a protective effect against oxidative stress. CNMSH also effectively attenuated H2O2‑induced comet tail formation, and decreased the phosphorylation levels of the histone ${\gamma}H2AX$, as well as the number of apoptotic bodies and Annexin V‑positive cells. In addition, CNMSH exhibited scavenging activity against intracellular ROS generation and restored the mitochondria membrane potential (MMP) loss that were induced by H2O2, suggesting that CNMSH prevents H2O2‑induced DNA damage and cell apoptosis. Moreover, H2O2 enhanced the cleavage of caspase-3 and degradation of poly (ADP-ribose)-polymerase, a typical substrate protein of activated caspase-3, as well as DNA fragmentation; however, these events were almost totally reversed by pretreatment with CNMSH. Furthermore, CNMSH increased the levels of heme oxygenase-1 (HO-1), which is a potent antioxidant enzyme, associated with the induction of nuclear factor-erythroid 2-related factor 2 (Nrf2). According to our data, CNMSH is able to protect SH-SY5Y cells from H2O2-induced apoptosis throughout blocking cellular damage related to oxidative stress through a mechanism that would affect ROS elimination and activating Nrf2/HO-1 signaling pathway. Conclusions : Therefore, we believed that CNMSH may potentially serve as an agent for the treatment and prevention of neurodegenerative diseases caused by oxidative stress.

Characterization of Pseudomonas putida 1K1 Capable of Growing on Extremely High Concentration of Toluene (고농도 Toluene에서 생육 가능한 Pseudomonas putida 1K1의 특성)

  • Cho, Kyung-Yun;Chun, Hyo-Kon;Han, Dong-Cho;Kho, Yung-Hee
    • Microbiology and Biotechnology Letters
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    • v.17 no.3
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    • pp.236-240
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    • 1989
  • The isolated bacterial strain 1K1 able to grow on extremely high concentration of toluene was morphologically and physiologically best described as Pseudomonas putida. This strain could grow on at least eight aromatic compounds, e.g., benzene, benzoate, phenol, o-cresol, m-cresol, toluene, m-tolunte, and xylene, but did not Brow on alkanes, such as hexane, octane, decane, and cyclohexane. Strain 1K1 could grow on above 95% toluene, but it could not grow on above 1% of other aromatic compounds. In the point of survival, strain 1K1 was resistant to high concentration of alkanes, appreciably resistant to toluene and xylene, and damaged by to other aromatic compounds. Strain 1K1 which grew on high concentration of toluene had irregular cell shape in comparing with normal cell shape of the genus Pseudomonas. Strain 1K1 was shown to have at least two aromatic compound dissimilation pathway, one for benzoate and the other for toluene.

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Sulforaphane-Induced Apoptosis was Regulated by p53 and Caspase-3 Dependent Pathway in Human Chondrosarcoma, HTB-94 (Sulforaphane에 의한 p53 및 caspase-3 의존 신호전달계를 통한 인간 연골암 세포주 HTB-94에서의 세포사멸 기전 연구)

  • Lee, Won-Kil;Kim, Song-Ja
    • Journal of Life Science
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    • v.21 no.6
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    • pp.851-857
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    • 2011
  • Sulforaphane (SFN) is an isothiocyanate, isolated from glucoraphanin in broccoli and other cruciferaous vegetables. Recent studies have revealed that SFN induces anti-proliferation and apoptosis by cell cycle arrest in various cancer cells. In this study, we investigated the effect of SFN induced apoptosis in chondrosarcoma HTB-94 cells. SFN caused suppression of proliferation and apoptosis in a dose-dependent manner as determined by cell phenotype, MTT assay and FACS analysis in HTB-94 cells. Treatment of SFN led to caspase-3 activation and p53 accumulation as determined by Western blot analysis. Also, SFN significantly induced DNA fragmentation and nuclear degradation though activation of caspase-3, as detected by DNA electrophoresis and immunostaining, respectively. Our results indicate that SFN-induced apoptosis was regulated by p53 and caspase-3 dependent pathways. Furthermore, SFN may act as a potent anti-proliferation agent, and as a promising candidate for molecular-targeting chemotherapy against human chondrosarcoma cells.

Induction of Apoptosis by Citri Pericarpium Methanol Extract through Reactive Oxygen Species Generation in U937 Human Leukemia Cells (진피 메탄올 추출물의 활성산소종 생성을 통한 인체 백혈병 세포의 apoptosis 유발)

  • Kim, Ga Hee;Lee, Moon Hee;Han, Min Ho;Park, Cheol;Hong, Su Hyun;Choi, Yung Hyun
    • Journal of Life Science
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    • v.23 no.8
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    • pp.1057-1063
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    • 2013
  • Citri Pericarpium is one of the most commonly used traditional herbal medicines in Korea, China, and Japan. Its extracts have many properties including the treatment of indigestion and inflammatory respiratory syndromes such as bronchitis and asthma. However, the underlying molecular mechanisms of anti-cancer activity and molecular targets are not fully understood. In this work, we investigated the anti-proliferative activity of Citri Pericapium (EMCP) methanol extract on reactive oxygen species (ROS) production and the association of these effects with apoptotic cell death using U937 human leukemia cells in vitro. EMCP treatment decreased cell proliferation in a dose-dependent manner following an increase of the sub-G1 phase, the down-regulation of Bax proteins, the activation of caspases, the degradation of poly (ADP-ribose) polymerase proteins (PARP), and the induction of ROS generation. However, the quenching of ROS generation by N-acetyl-L-cysteine administration, a scavenger of ROS, reversed the EMCP-induced apoptosis effects. In addition, heme oxygenase-1 expression also recovered by inhibiting the nuclear translocation of phosphorylated NF-E2-related factor 2. Taken together, our data indicate that ROS are involved as key mediators in the early molecular events in the EMCP-induced apoptotic pathway.

Different Responses to Arsenic Trioxide between NB4 and UF-1, Acute Promyelocytic Leukemia Cell Lines (급성 전골수성 백혈병 세포주간의 삼산화비소에 대한 반응)

  • Kim, Hye-Ran;Choi, Yoon-Jeong;Ryu, Seong-Yeoll;Lee, Young-Seok;Lee, Sang-Hwa
    • Journal of Life Science
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    • v.16 no.5
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    • pp.759-766
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    • 2006
  • Acute promyelocytic leukemia (APL) is a myeloid leukemia caused by over-expression of fusion protein, PML/RAR$({\alpha})$, which was the result of chromosomal translocation and induces the blockage of differentiation of affected promyelocytes. Pharmacological dose of retinoic acid induces the activation of and subsequent degradation of PML/RAR$({\alpha})$ fusion protein, and then APL cells undergo through the normal differentiation pathway. Arsenic trioxide has proved effective in causing remission of acute promyelocytic leukemia by inducing apoptosis of this tumor cells, whereas the heterogeneity of cellular susceptibility to this cytotoxic agent limited its usage on more types of tumors in clinic. This work showed that arsenic trioxide could induce apoptosis of a panel of acute promyelocytic leukemic cell lines, all-trans-retinoic acid (ATRA) sensitive NB4 cells and ATRA resistant UF-1 cell. They were investigated with regard to the correlation between the inherent or intrinsic cellular level of GSH and the apoptotic susceptibility of the cells to arsenic trioxide. We manifested, in two cell types, the inherently existed difference in intracellular GSH level reactive to the arsenic trioxide, and a positive correlation between the GSH level and their apoptotic sensitivity to arsenic trioxide. And it showed that arsenic trioxide could differentiate promyelocytic cancer cells to the cells possessed of dendritic cell surface markers. Unravelling the cause of the different susceptibility between leukemic cells and proving that promyelocyte could be differentiated to dendritic cells by arsenic trioxide will help not only to understand the mechanism underlying the complete remission of acute promyelocytic leukemia induced by arsenic trioxide, but also to expand its clinical usage.

Anticancer Activities of the Methanolic Extract from Lemon Leaves in Human Breast Cancer Stem Cells (인간 유방암 줄기세포에서 레몬잎 메탄올 추출물의 항암 효능)

  • Moon, Jeong Yong;Nguyen, Linh Thi Thao;Hyun, Ho Bong;Osman, Ahmed;Cho, Minwhan;Han, Suyeong;Lee, Dong-Sun;Ahn, Kwang Seok
    • Journal of Applied Biological Chemistry
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    • v.58 no.3
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    • pp.219-226
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    • 2015
  • The anticancer activity of a methanolic extract from lemon leaves (MLL) was assessed in MCF-7-SC human breast cancer stem cells. MLL induced apoptosis in MCF-7-SC, as evidenced by increased apoptotic body formation, sub-G1 cell population, annexin V-positive cells, Bax/Bcl-2 ratio, as well as proteolytic activation of caspase-9 and caspase-3, and degradation of poly (ADP-ribose) polymerase (PARP) protein. Concomitantly, MLL induced the formation of acidic vesicular organelles, increased LC3-II accumulation, and reduced the activation of Akt, mTOR, and p70S6K, suggesting that MLL initiates an autophagic progression in MCF-7-SC via the Akt/mTOR pathway. Epithelial-mesenchymal transition (EMT), a critical step in the acquisition of the metastatic state, is an attractive target for therapeutic interventions directed against tumor metastasis. At low concentrations, MLL induced anti-metastatic effects on MCF-7-SC by inhibiting the EMT process. Exposure to MLL also led to an increase in the epithelial marker E-cadherin, but decreased protein levels of the mesenchymal markers Snail and Slug. Collectively, this study provides evidence that lemon leaves possess cytotoxicity and anti-metastatic properties. Therefore, MLL may prove to be beneficial as a medicinal plant for alternative novel anticancer drugs and nutraceutical products.

Formation of Hydrogen Peroxide by the Ozonation of Aqueous Humic Acid (수중 부식산의 오존처리시 생성되는 과산화수소의 농도 변화에 대한 연구)

  • Kim, Kei Woul;Rhee, Dong Seok
    • Analytical Science and Technology
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    • v.13 no.5
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    • pp.659-665
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    • 2000
  • The changes in $UV_{254}$ and concentrations of $H_2O_2$ formed by ozonation of aqueous humic acid in ozone/high pH, peroxone process and in the presence of radical scavenger, $HCO_3{^-}$ were investigated. This study confirmed that the formation of $H_2O_2$ by ozonation may undergo different reaction pathways compared to those of $UV_{254}$ reduction in the degradation of the humic acid. The concentration of $H_2O_2$ produced by ozonation was found to be increased with decreasing pH of the sample solution due to the higher stability of ozone molecules at acidic conditions. On the while, $UV_{254}$ reduction was found to be higher at alkaline conditions or larger amount of $H_2O_2$ additions as a radical promoter in which the producing of ${\cdot}OH$, ${\cdot}HO_2$ radicals can be more favorable. From the results, it has been suggested that the formation of $H_2O_2$ by ozonation depends mainly on the direct reactions of ozone with humic acid molecules, while $UV_{254}$ reduction is affected by both the indirect reactions of the radicals and direct reactions of ozone with humic acid.

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Heterologous Expression of Yeast Prepro-$\alpha$-factor in Rat $GH_3$ Cells

  • Lee, Myung-Ae;Cheong, Kwang-Ho;Han, Sang-Yeol;Park, Sang-Dai
    • Animal cells and systems
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    • v.4 no.2
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    • pp.157-163
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    • 2000
  • Yeast pheromone a-factor is a 13-amino acid peptide hormone that is synthesized as a part of a larger precursor, prepro-$\alpha$-factor, consisting of a signal peptide and a proregion of 64 amino acids. The carboxy-terminal half of the precursor contains four tandem copies of mature $\alpha$-factor. To investigate the molecular basis of intracellular sorting, proteolytic processing, and storage of the peptide hormone, yeast prepro-$\alpha$-factor precursors were heterologously expressed in rat pituitary $GH_3 cells. When cells harboring the precursor were metabolically labeled, a species of approximately 27 kD appeared inside the cells. Digestion with peptide: N-glycosidase F (PNG-F) shifted the molecular mass to a 19 kD, suggesting that the 27 kD protein was the glycosylated form as in yeast cells. The nascent polypeptide is efficiently targeted to the ER in the $GH_3 cells, where it undergoes cleavage of its signal peptide and core glycosylation to generate glycosylated pro-a-factor. To look at the post ER intracellular processing, the pulse-labelled cells were chased up to 2 hrs. The nascent propeptides disappeared from the cells at a half life of 30 min and only 10-25% of the newly synthesized, unprocessed precursors were stored intracellularly after the 2 h chase. However, about 20% of the pulse-labeled pro-$\alpha$-factor precursors were secreted into the medium in the pro-hormone form. With increasing chase time, the intracellular level of propeptide decreased, but the amount of secreted propeptide could not account for the disappearance of intracellular propeptide completely. This disappearance was insensitive to lysosomotropic agents, but was inhibited at $16^{circ}C or 20^{\circ}C$, suggesting that the turnover of the precursors was not occurring in the secretory pathway to trans Golgi network (TGN) or dependent on acidic compartments. From these results, it is concluded that a pan of these heterologous precursors may be processed at its paired dibasic sites by prohormone processing enzymes located in TGN/secretpry vesicles producing small peptides, and that the residual unprocessed precursors may be secreted into the medium rather than degraded intracellularly.

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Role of NFAT5 in Osteogenic Differentiation of Human Adipose Tissue-Derived Mesenchymal Stem Cells (인체 지방 유래 중간엽 줄기세포의 골분화 조절 기전에서 NFAT5의 역할)

  • Lee, Sun Young;Yang, Ji won;Jung, Jin Sup
    • Journal of Life Science
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    • v.23 no.4
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    • pp.471-478
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    • 2013
  • Human adipose tissue-derived mesenchymal stem cells (hADSCs) have therapeutic potential, including the ability to self-renew and differentiate into multiple lineages. Understanding of molecular mechanisms of stem cell differentiation is important for improving the therapeutic efficacies of stem cell transplantation. In this study, we determined the role of nuclear factor of activated T cells (NFAT5) in the osteogenic differentiation of hADSCs. The down-regulation of NFAT5 expression by the transfection of a specific siRNA significantly inhibited osteogenic differentiation of hADSCs and decreased the activity of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-${\kappa}B$) promoter without affecting their proliferation and adipogenic differentiation. The inhibition of NFAT5 expression inhibited the basal and Tumor Necrosis Factor ${\alpha}$ (TNF-${\alpha}$) induced activation of NF-${\kappa}B$, but it did not affect TNF-${\alpha}$-induced degradation of the $I{\kappa}B$ protein. These findings indicate that NFAT5 plays an important role in the osteogenic differentiation of hADSCs through the modulation of the NF-${\kappa}B$ pathway.

Correlation between Deoxycytidineuria and CdR-aminohydrolase Activity following X-Irradiation (X線照射에 따르는 Deoxycytidineuria와 CdR-aminohydrolase의 活性變化와의 連關性)

  • Man Sik kang;Rhee, Juong-Gile;Cho, Joong-Myung
    • The Korean Journal of Zoology
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    • v.18 no.4
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    • pp.163-172
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    • 1975
  • This work was undertaken to elucidate some aspects of mechanisms underlying the increased deoxycytidineuria following irradiation in the mice, by observing Dische-positive substances liberated from thissues, the activity of CdR-aminohydrolase of tissues and the CdR excreted in the urine at various times after single whole-body exposure to 400 and 800 R of X-rays. The activity of CdR-aminohydrolase declined markedly at 1 hour in the small intestine and liver, followed by a gradual rise reaching a maximum at 3 days after irradiation. In the case of the spleen and blood, however, only a trace of activity was observed in the control and irradiated animals. The amount of Dische-positive substance liberated from the small intestine postirradiation was elevated from 3 to 12 hours, showing a maximum during 6 to 9 hours after irradiation. On the contrary, the activity of the enzyme in the liver, spleen and kidney was less than one twentieth that of the small intestine, suggesting a prediction that these organs are not attributable to the increased deoxycytidineuria. A maximum deoxycytidineuria was exhibited at 9-12 hours period, attributed a large amount of CdR to the small intestine, which might correlate with the change in the CdR-aminohydrolase activity. Radiation-induced CdR seems to be liberated from the small intestine into the blood when the CdR-aminohydrolase activity declines abruptly. Then, the CdR is rapidly subjected to a filtration in the kidney without undergoing a further degradation pathway in the blood.

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