• 제목/요약/키워드: DNA-dependent

검색결과 1,346건 처리시간 0.035초

Diversity and Chemical Defense Role of Culturable Non-Actinobacterial Bacteria Isolated from the South China Sea Gorgonians

  • Jiang, Peng;Zhang, Xiaoyong;Xu, Xinya;He, Fei;Qi, Shuhua
    • Journal of Microbiology and Biotechnology
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    • 제23권4호
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    • pp.437-443
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    • 2013
  • The diversity of culturable non-actinobacterial (NA) bacteria associated with four species of South China Sea gorgonians was investigated using culture-dependent methods followed by analysis of the bacterial 16S rDNA sequence. A total of 76 bacterial isolates were recovered and identified, which belonged to 21 species of 7 genera, and Bacillus was the most diverse genus. Fifty-one percent of the 76 isolates displayed antibacterial activities, and most of them belonged to the Bacillus genus. From the culture broth of gorgonian-associated Bacillus methylotrophicus SCSGAB0092 isolated from gorgonian Melitodes squamata, 11 antimicrobial lipopeptides including seven surfactins and four iturins were obtained. These results imply that Bacillus strains associated with gorgonians play roles in coral defense mechanisms through producing antimicrobial substances. This study, for the first time, compares the diversity of culturable NA bacterial communities among four species of South China Sea gorgonians and investigates the secondary metabolites of gorgonian-associated B. methylotrophicus SCSGAB0092.

Ginsenoside Rh2 epigenetically regulates cell-mediated immune pathway to inhibit proliferation of MCF-7 breast cancer cells

  • Lee, Hyunkyung;Lee, Seungyeon;Jeong, Dawoon;Kim, Sun Jung
    • Journal of Ginseng Research
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    • 제42권4호
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    • pp.455-462
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    • 2018
  • Background: Ginsenoside Rh2 has been known to enhance the activity of immune cells, as well as to inhibit the growth of tumor cells. Although the repertoire of genes regulated by Rh2 is well-known in many cancer cells, the epigenetic regulation has yet to be determined, especially for comprehensive approaches to detect methylation changes. Methods: The effect of Rh2 on genome-wide DNA methylation changes in breast cancer cells was examined by treating cultured MCF-7 with Rh2. Pyrosequencing analysis was carried out to measure the methylation level of a global methylation marker, LINE1. Genome-wide methylation analysis was carried out to identify epigenetically regulated genes and to elucidate the most prominent signaling pathway affected by Rh2. Apoptosis and proliferation were monitored to examine the cellular effect of Rh2. Results: LINE1 showed induction of hypomethylation at specific CpGs by 1.6-9.1% (p < 0.05). Genome-wide methylation analysis identified the "cell-mediated immune response"-related pathway as the top network. Cell proliferation of MCF-7 was retarded by Rh2 in a dose-dependent manner. Hypermethylated genes such as CASP1, INSL5, and OR52A1 showed downregulation in the Rh2-treated MCF-7, while hypomethylated genes such as CLINT1, ST3GAL4, and C1orf198 showed upregulation. Notably, a higher survival rate was associated with lower expression of INSL5 and OR52A1 in breast cancer patients, while with higher expression of CLINT1. Conclusion: The results indicate that Rh2 induces epigenetic methylation changes in genes involved in immune response and tumorigenesis, thereby contributing to enhanced immunogenicity and inhibiting the growth of cancer cells.

Effects of Flavonol Derivatives on the Micronudei Formation by N-methyl-N'-nitro-N-nitrosoguanidine and the Enhancement of Bleomycin-induced Chromosome Aberration by N-methyl-N'-nitro-N-nitrosoguanidine

  • Heo, Moon-Young;Kwon, Chang-Ho;Sohn, Dong-Hun;Lee, Su-Jun;Kim, Sung-Wan;Kim, Jung-Han;William W. Au
    • Archives of Pharmacal Research
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    • 제16권3호
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    • pp.196-204
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    • 1993
  • Flavonol derivatives were tested for their anticlastogenic effect against induction of micronuclei by n-methyl-n'-nitor-n-nitorsoguanidine(MNNG), and against induction of chromosome aberration by bleomycin or MNNG.belomycin. For micronudeus assay, each flavonol derivative (0, 0.001, 0.01, 0.1, 1, 10 and 100 mg/kg) was administered orally twice with 24 h interval, together with intraperitioneally administered MNNG(150 mg/kg). The result showed that msot flavonol derivatives tested were effective in suppresing the frequencies of micronude induced by MNNG. For chromosome aberration assy, each flavonol derivative (0, 0.1, 1, 10m and 100 mg/kg)was administered to mice orally in vivo, and then mice were sacrificed and spleen lymphocyte cultures were made. Bleomycin $(3\;\mu$g/ml) was treated to the mouse spleen hymphocyte cultures at 24 h after con A initiation. There wre nomarked decrease tendencies in chromosome aberration unless all doses of galangin and some doses of several flavonol derivatives tested. In the another experiment, we have evaluated the effect of flavonol derivatives on the enhancement of bleomycin-induced chromsome aberration by MNNG. Most of flavonol derivtives reduced the incidence of chromosome aberration induced by in vitro treatment of bleomycin followed by in vivo treatment of MNNG. Galangin particulary showed a dose-dependent decrease tendency. Other flavonol derivative showed slightly suggest that most of flavonol derivatives may be capable of protecting the inhibition of suggest that most of flavonol derivatives may be capable of protecting the inhibition of DNA-repair by MNNG. Our data indicate clearly that flavonol derivatives can suppress MNNG-induced genotoxicity such as an induction of MNPCEs. Therfore, our results could suggest that flavonol derivtives may be useful as a chemopreventive agent of MNNG.

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Ethanol Extracts of Angelica decursiva Induces Apoptosis in Human Oral Cancer Cells

  • Lee, Myoung-Hwa;Kim, Myung-Mi;Kook, Joong-Ki;Kim, Do-Kyung;Kim, Hye-Ryun;Kim, Heung-Joong;Kim, Chun-Sung
    • International Journal of Oral Biology
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    • 제35권4호
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    • pp.215-220
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    • 2010
  • Angelica decursiva has been used in Korean traditional medicine as an antitussive, an analgesic, an antipyretic and a cough remedy. However, its anti-cancer properties have not yet been well defined. In our current study, we report the cytotoxic activity and the mechanism of cell death induced by ethanol extracts of Angelica decursiva (EEAD) against the human oral cancer cell line, KB. Treatment of KB cells with EEAD induced apoptotic cell death in both a dose- and time-dependent manner as determined by MTT assay and DNA fragmentation. However, no cytotoxic effects of EEAD against human normal oral keratinocytes (HNOK) were evident. By western blot analysis, we found that apoptosis in KB cells is associated with a decrease in procaspase-7 and -9. In addition, the activation of caspase-7 was detectable in living KB cells by fluorescence microscopy. These results suggest that EEAD exhibits anti-cancer activity in KB cells via apoptosis and thus has potential as an anticancer agent in future drug development strategies.

방사선조사가 MC3T3-E1 조골세포주의 type I collagen과 alkaline phosphatase mRNA 발현에 미치는 영향 (The effects of irradiation on the mRNA expression of type I collagen and alkaline phosphatase in the MC3T3-E1 osteoblastic cell line)

  • 최선영;고광준
    • Imaging Science in Dentistry
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    • 제33권1호
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    • pp.51-57
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    • 2003
  • Purpose: To investigate the effects of irradiation on the phenotypic expression of the MC3T3-El osteoblastic cell line, particularly an the expression of type I collagen and alkaline phosphatase mRNA. Materials and Methods: Cells were irradiated with a single dose of 0.5, 1, 2, 4, and 8 Gy at a dose rate of 5.38 Gy/min using a cesium 137 irradiator. The specimens were then harvested and RNA extraction was carried out at 1 and 3 days after irradiation. The extracted RNA strands were reverse-transcribed and the resulting cDNA fragments were amplified by PCR. Results: The irradiated cells demonstrated a dose-dependent increase in type I collagen mRNA expression relative to the control group, with a maximum level of type I collagen mRNA expression occurring at 8 Gy. The degree of type I collagen mRNA expression increased significantly at 1 day after irradiation, but little differences were found between the control group and at the 3rd day. The amount of alkaline phosphatase mRNA expression increased significantly at land 3 days after irradiation in the 1 Gy exposed group compared with the control group. Conclusion: The amount of type I collagen and alkaline phosphatase mRNA expression increased significantly 1 day after irradiation when compared with the control group.

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Gamma Irradiation Up-regulates Expression of B Cell Differentiation Molecule CD23 by NF-κB Activation

  • Rho, Hyun-Sook;Park, Soon-Suk;Lee, Choong-Eun
    • BMB Reports
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    • 제37권4호
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    • pp.507-514
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    • 2004
  • Gamma irradiation ($\gamma$-IR) is reported to have diverse effects on immune cell apoptosis, survival and differentiation. In the present study, the immunomodulatory effect of a low dose $\gamma$-IR (5~10 Gy) was investigated, focusing on the role of NF-${\kappa}B$ in the induction of the B cell differentiation molecule, CD23/FceRII. In the human B cell line Ramos, $\gamma$-IR not only induced CD23 expression, but also augmented the IL-4-induced surface CD23 levels. While $\gamma$-IR did not cause STAT6 activation in these cells, it did induce both DNA binding and the transcriptional activity of NF-${\kappa}B$ in the $I{\kappa}B$ degradation-dependent manner. It was subsequently found that different NF-${\kappa}B$ regulating signals modulated the $\gamma$-IR-or IL-4-induced CD23 expression. Inhibitors of NF-${\kappa}B$ activation, such as PDTC and MG132, suppressed the $\gamma$-IR-mediated CD23 expression. In contrast, Ras, which potentiates $\gamma$-IR-induced NF-${\kappa}B$ activity in these cells, further augmented the $\gamma$-IR- or IL-4-induced CD23 levels, The induction of NF-${\kappa}B$ activation and the subsequent up-regulation of CD23 expression by $\gamma$-IR were also observed in monocytic cells. These results suggest that $\gamma$-IR, at specific dosages, can modulate immune cell differentiation through the activation of NF-${\kappa}B$, and this potentially affects the immune inflammatory response that is mediated by cytokines.

Anti-Inflammatory Effects of N1-Benzyl-4-Methylbenzene-1,2-Diamine (JSH-21) Analogs on Nitric Oxide Production and Nuclear Factor-kappa B Transcriptional Activity in Lipopolysaccharide-Stimulated Macrophages RAW 264.7

  • Min, Kyung-Rak;Shin, Hyun-Mo;Lee, Jee-Hyun;Kim, Byung-Hak;Chung, Eun-Yong;Jung, Sang-Hun;Kim , Young-Soo
    • Archives of Pharmacal Research
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    • 제27권10호
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    • pp.1053-1059
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    • 2004
  • $N^1$-Benzyl-4-methylbenzene-1,2-diamine (JSH-21) and its analogs were chemically synthesized and their anti-inflammatory potentials investigated. JSH-21 inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated macrophages RAW 264.7 in a dose-dependent manner, with an $IC_{50}$ value of 9.2 ${\mu}M$, where pyrrolidine dithiocarbamate and parthenolide as positive controls exhibited $IC_{50}$ values of 29.3 and 3.6 ${\mu}M$, respectively. The inhibitory effect of JSH-21 on the NO production was attributable to its down-regulatory action on LPS-inducible NO synthase (iNOS), which was documented by iNOS promoter activity. In the mechanism of the anti-inflammatory action, JSH-21 exhibited inhibitory effects on LPS-induced DNA binding activity and transcriptional activity of nuclear factor-kappa B (NF-$_KB$). Structural analogs of JSH-21 also inhibited both the LPS-induced NO production and NF-$_KB$). transcriptional activity, where diamine substitution at positions 1 and 2 of JSH-21 seems to play an important role in the anti-inflammatory activity.

The Study of $NF-{\kappa}B(P50)$ Suppression mechanism with main Component of Bee Venom and Melittin on Human Synoviocyte

  • Kwon, Soon-Jung;Song, Ho-Sueb
    • Journal of Acupuncture Research
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    • 제22권2호
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    • pp.123-132
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    • 2005
  • Melittin,cationic 26-amino acid, is the principal component of the bee venom (BV) which has been used for treatment of inflammatory disease such as arthritis rheumatism NF-kB is activated by subsequent release of inhibitory IkB via activation of a multisubunit IkB kinase (IKK). We previously found that melittin bind to the sulfhydryl group of p50, a subunit of NF-kB. Since sulfhydryl group is present in kinase domain of IKKa and IKKb, melittin could modify IKK activity by protein-protein interaction. We therefore examined effect of melittin on IKK activities in sodium nitroprusside (SNP)-stimulated synoviocyte obtained from RA patients. Melittin suppressed the SNP-induced release of IkB resulted in inhibition of DNA binding activity of NF-kB and NF-kB-dependent luciferase activity. Consistent with the inhibitory effect on NF-kB activation, IKKa and IKKb activities were also suppressed by melittin. Surface plasmon resonance analysis realized that melitin binds to IKKa $(Kd\;=\;1.34{\times}10-9M)$ and IKKb$(Kd\;=\;1.0{\times}10-9M)$. Inhibition of IKKa and IKKb resulted in reduction of the SNP-induced production of inflammatory mediators NO and PGE2 generation. The inhibitory effect of melittin on the IKKs activities, binding affinity of melittin to IKKs, and NO and PGE2 generation were blocked by addition of reducing agents dithiothreitol and glutathione. In addition, melittin did not show inhibitory effect in the transfected Synoviocytes with plasmid carrying dominant negative mutant IKKa (C178A) and IKKb (C179A). These results demonstrate that melittin directly binds to sulfhydryl group of IKKs resulting in IkBrelease, thereby inhibits activation of NF-kB and expression of genes involving in the inflammatory responses.

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Mitochondrial Efficiency-Dependent Viability of Saccharomyces cerevisiae Mutants Carrying Individual Electron Transport Chain Component Deletions

  • Kwon, Young-Yon;Choi, Kyung-Mi;Cho, ChangYeon;Lee, Cheol-Koo
    • Molecules and Cells
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    • 제38권12호
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    • pp.1054-1063
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    • 2015
  • Mitochondria play a crucial role in eukaryotic cells; the mitochondrial electron transport chain (ETC) generates adenosine triphosphate (ATP), which serves as an energy source for numerous critical cellular activities. However, the ETC also generates deleterious reactive oxygen species (ROS) as a natural byproduct of oxidative phosphorylation. ROS are considered the major cause of aging because they damage proteins, lipids, and DNA by oxidation. We analyzed the chronological life span, growth phenotype, mitochondrial membrane potential (MMP), and intracellular ATP and mitochondrial superoxide levels of 33 single ETC component-deleted strains during the chronological aging process. Among the ETC mutant strains, 14 ($sdh1{\Delta}$, $sdh2{\Delta}$, $sdh4{\Delta}$, $cor1{\Delta}$, $cyt1{\Delta}$, $qcr7{\Delta}$, $qcr8{\Delta}$, $rip1{\Delta}$, $cox6{\Delta}$, $cox7{\Delta}$, $cox9{\Delta}$, $atp4{\Delta}$, $atp7{\Delta}$, and $atp17{\Delta}$) showed a significantly shorter life span. The deleted genes encode important elements of the ETC components succinate dehydrogenase (complex II) and cytochrome c oxidase (complex IV), and some of the deletions lead to structural instability of the membrane-$F_1F_0$-ATP synthase due to mutations in the stator stalk (complex V). These short-lived strains generated higher superoxide levels and produced lower ATP levels without alteration of MMP. In summary, ETC mutations decreased the life span of yeast due to impaired mitochondrial efficiency.

대장균 내에서의 Bdi I Methylase 유전자의 클로닝과 발현 (Cloning and Expression of the Bdi Methylase Gene in E. coli)

  • 전희숙;김용석;최경래;노현모
    • 미생물학회지
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    • 제25권1호
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    • pp.40-45
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    • 1987
  • B Brevibacterium divaricatum FERM 5948 균주로부터 Bdi I RIM 체계에 속하는 BdiI methylase 유천자를 클로닝하여 발현을 조사하였다. Bdi I methylase 유전자의 클로닝을 위해 pBR 322의 EcoRI, BamHl, Sal I 3 군데의 클로닝 site를 이 용했고 1 차 형질전환후 나온 플라스미드를 BdiI으로 자른 뒤 ligation 시키지 않고 형질전환시키는 방법을 이용하였다. 유전 자을 가지는 행질전환체의 선별은 Bdi I methylase에 의해 수정된 채조합 플라스미드는 BdiI 제한효소에 방호된다는 것에 기 초하여 선별하였는데 5.6kb의 EcoRI insert DNA를 가지는 pBDIM 116이 Bdil methylase 유전자플 가지는 것으로 판명 되었다. pBDIM 11&을 가지는 숙주셰포에서 추출한 추출용액에는 S-adenosylmethionine이 있으면 BdiI의 인지부위인 A ATCGAT에만 특정한 methylase 활성이 측정되였다. 11개의 제한효소를 이용하이 제한효소지도를 작성하였고, BdiI r restriction -modification 체계에 관해서 도 논의하였다.

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