• Title/Summary/Keyword: 유전자독성

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Inhibitory effects of heavy metals on CYP1A expression in eel hepatocyte cultures (뱀장어 배양 간세포에서의 Cytochrome P4501A (CYP1A) 유전자 발현에 대한 중금속들의 억제효과)

  • Kwon, Hyuk-Chu;Maeng, Joon-Ho;Choi, Seong-Hee
    • Journal of fish pathology
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    • v.23 no.2
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    • pp.245-254
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    • 2010
  • Effects of heavy metal ions on the gene expression of cytochrome P4501A (CYP1A) were examined in cultured eel hepatocytes. When the expression of CYP1A mRNA was measured by RT-PCR after incubation of eel hepatocytes with benzo[$\alpha$]pyrene (B[$\alpha$]P) at concentrations of 10-8~10-5 M, the CYP1A expression increased with B[$\alpha$]P treatment in a dose dependent manner, showing significant increase at concentrations more than 10-7 M. When the eel hepatocyte was treated with cadmium (10-6 and 10-5 M), the expression of CYP1A was inhibited and especially at higher concentration (10-5 M). The inhibition of CYP1A expression by cadmium was also observed in cells treated with B[$\alpha$]P. In another study, effects of heavy metal ions on the expression of CYP1A were examined in cultured hepatocytes isolated from eel which was treated previously with B[$\alpha$]P in vivo. Hepatocytes isolated from the liver of eel taken at 48 hours after injection of B[$\alpha$]P (10 mg/kg) were cultured for 2 days with cadmium, copper, lead or zinc (10-6 and 10-5 M). The expression of CYP1A was found to be suppressed by the metal ions compared with the control in which CYP1A was induced with previous treatment of B[$\alpha$]P in vivo. The present results may provide an important basic information for studying the effects of heavy metal ions on CYP1A expression in other species of fish and studying toxicological mechanisms of heavy metal ions in aquatic livings.

The Beneficial Effects of Extract of Pinus densiflora Needles on Skin Health (솔잎추출물의 피부건강 개선효과)

  • Choi, Jieun;Kim, Woong;Park, Jaeyoung;Cheong, Hyeonsook
    • Microbiology and Biotechnology Letters
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    • v.44 no.2
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    • pp.208-217
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    • 2016
  • Pinus densiflora Sieb. et Zucc. (P. densiflora) contains several phenolic compounds that exhibit biological activities, such as antimicrobial, antioxidant, and antihypertensive effects. However, the anti-inflammatory effect of P. densiflora on skin has rarely been reported. Malassezia furfur (M. furfur) is a commensal microbe that induces skin inflammation and is associated with several chronic disorders, such as dandruff, seborrheic dermatitis, papillomatosis, and sepsis. The aim of our study was to identify the anti-inflammatory effects of P. densiflora needle extracts on skin health subjected to M. furfur-induced inflammation. The methanolic extract of the pine needles was partitioned into n-hexane, EtOAc, n-BuOH, and water layers. We measured the anti-inflammatory effects (in macrophages) as well as the antioxidant, antifungal, and tyrosinase inhibitory activity of each of these layers. The antioxidant activity of the individual layers was in the order EtOAc layer > n-BuOH layer > water layer. Only the n-BuOH, EtOAc, and n-hexane layers showed antifungal activity. Additionally, all the layers possessed tyrosinase inhibition activity similar to that of ascorbic acid, which is used as a commercial control. The EtOAc layer was not cytotoxic toward the RAW 264.7 cell line. Interleukin 1 beta and tumor necrosis factor (TNF)-α expression levels in M. furfur-stimulated RAW 264.7 cells treated with the EtOAc layer were decreased markedly compared to those in cells treated with the other layers. Taken together, we believe that the needle extracts of P. densiflora have potential application as alternative anti-inflammatory agents or cosmetic material for skin health improvement.

NF-${\kappa}B$ Activation and cIAP Expression in Radiation-induced Cell Death of A549 Lung Cancer Cells (A549 폐암세포주의 방사선-유도성 세포사에서 NF-${\kappa}B$ 활성화 및 cIAP 발현)

  • Lee, Kye Young;Kwak, Shang-June
    • Tuberculosis and Respiratory Diseases
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    • v.55 no.5
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    • pp.488-498
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    • 2003
  • Background : Activation of the transcription factor NF-${\kappa}B$ has been shown to protect cells from tumor necrosis factor-alpha, chemotherapy, and radiation-induced apoptosis. NF-${\kappa}B$-dependent cIAP expression is a major antiapoptotic mechanism for that. NF-${\kappa}B$ activation and cIAP expression in A549 lung cancer cells which is relatively resistant to radiation-induced cell death were investigated for the mechanism of radioresistance. Materials and methods : We used A549 lung cancer cells and Clinac 1800C linear accelerator for radiation. Cell viability test was done by MTT assay. NF-${\kappa}B$ activation was tested by luciferase reporter gene assay, Western blot for $I{\kappa}B{\alpha}$ degradation, and electromobility shift assay. For blocking ${\kappa}B$, MG132 and transfection of $I{\kappa}B{\alpha}$-superrepressor plasmid construct were used. cIAP expression was analyzed by RT-PCR and cIAP2 promoter activity was performed using luciferase assay system. Results : MTT assay showed that cytotoxicity even 48 hr after radiation in A549 cells were less than 20%. Luciferas assay demonstrated weak NF-${\kappa}B$ activation of $1.6{\pm}0.2$ fold compared to PMA-induced $3.4{\pm}0.9$ fold. Radiation-induced $I{\kappa}B{\alpha}$ degradation was observed in Western blot and NF-${\kappa}B$ DNA binding was confirmed by EMSA. However, blocking NF-${\kappa}B$ using MG132 and $I{\kappa}B{\alpha}$-superrepressor transfection did not show any sensitizing effect for radiation-induced cell death. The result of RT-PCR for cIAP1 & 2 expression was negative induction while TNF-${\alpha}$ showed strong expression for cIAP1 & 2. The cIAP2 promoter activity also did not show any change compared to positive control with TNF-${\alpha}$. Conclusion : We conclude that activation of NF-${\kappa}B$ does not determine the intrinsic radiosensitivity of cancer cells, at least for the cell lines tested in this study.

Production of hTPO Transgenic Chickens using Tetracycline-Inducible Expression System (Tetracycline-Inducible Expression System을 이용한 Human Thrombopoietin (hTPO) 형질전환 닭의 생산)

  • Kwon, M.S.;Koo, B.C.;Kim, D.H.;Kim, M.J.;Kim, T.
    • Korean Journal of Poultry Science
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    • v.36 no.2
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    • pp.177-186
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    • 2009
  • It is well-known that unregulated over-expression of foreign gene may have unwanted physiological or toxic effects in transgenic animals. To circumvent these problems, we constructed retrovirus vector designed to express the foreign gene under the control of the tetracycline-inducible promoter. However, gene expressions in the tetracycline-inducible expression system (Tet system) are not completely regulated but a little leaky due to the inherent defects in conventional Tet-based systems. A more tightly controllable regulatory system can be achieved when the advanced versions ($rtTA2^SM2$) of rtTA and a minimal promoter in responsive components (pTRE-tight) are used in combination therein. In this study, we tried to produce human thrombopoietin (hTPO) from various target cells and transgenic chickens using the retrovirus vector combined with Tet system. hTPO is the primary regulator of platelet production and has an important role in the survival and expansion of hematopoietic stem cells. In a preliminary experiment in vitro, higher hTPO expression and tighter expression control were observed in chicken embryonic fibroblast (CEF) cells. We also measured the biological activity of the hTPO using Mo7e cells whose proliferation is dependant on hTPO. The biological activity of the recombinant hTPO from CEF was higher than both its commercial counterpart and hTPO from other target cells. The recombinant retrovirus was injected beneath the blastoderm of non-incubated chicken embryos (stage X). Out of 138 injected eggs, 15 chicks hatched after 21 days of incubation. Among them, 8 hatched chicks were hTPO positive. When the Go transgenic chicken was fed doxycycline (0.5 mg per 1 gram of feed), a tetracycline derivative, hTPO concentration of the transgenic chicken blood was 200 ng/mL. Germline transmission of the transgene was confirmed in sperm of the Go transgenic roosters. These results are informative to establish transgenic chickens as bioreactors for the mass production of commercially valuable and biological active human cytokine proteins.

Cloning and Characterization of a 5-Enolpyruvyl Shikimate 3-Phosphate Synthase (EPSPS) Gene from Korean Lawn Grass (Zoysia japonica) (들잔디 5-Enolpyruvyl Shikimate 3-Phosphate Synthase(EPSPS) 유전자 클로닝 및 특성)

  • Lee, Hye-Jung;Lee, Geung-Joo;Kim, Dong-Sub;Kim, Jin-Beak;Ku, Ja-Hyeong;Kang, Si-Yong
    • Horticultural Science & Technology
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    • v.28 no.4
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    • pp.648-655
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    • 2010
  • This study is the first comprehensive report on the molecular cloning, structural characterization, sequence comparison between wild and mutant types, copy number in the genome, expression features and activities of a gene encoding 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in Korean lawn grass ($Zoysia$ $japonica$). The full length cDNA of the EPSPS from Korean lawn grass ($zj$EPSPS) obtained from a 3' and 5' RACE method was 1540 bp, containing a 1176 bp ORF, a 144 bp leader sequence (5' UTR) and a 220 bp 3' UTR, which was eventually decoded 391 amino acid residues with a molecular mass of 41.74 kDa. The Southern blot detection of the $zj$EPSPS showed that the gene exists as a single copy in the Korean lawn grass genome. Sequence comparison of the $zj$EPSPS gene demonstrated that the glyphosate-tolerant mutant (GT) having a Pro-53 to Ser substitution in the gene seems to have a preferred binding activity of the enzyme to phosphoenol pyruvate(PEP) over glyphosate, which allows the continuous synthesis of aromatic amino acids in the shikimate pathway. From the Northern blotting analysis, the $zj$EPSPS was found to be highly expressed, with continuous increase until 36 hours after 0.5% glyphosate treatment in both wild and mutant samples, but 1.5-fold higher EPSP synthase activity was observed in the tolerant mutant when exposed to the glyphosate treatment. The molecular information of the $zj$EPSPS gene obtained from this study needs to be further dissected to be more effectively applied to the development of gene-specific DNA markers and zoysiagrass cultivars; nevertheless, the glyphosate-tolerant mutant having the featured $zj$EPSPS gene can be provided to turfgrass managers for weed problems with timely adoptable management options.

Role of Oxygen Free Radical in the Expression of Interleukin-8 and Interleukin-$1{\beta}$ Gene in Mononuclear Phagocytic Cells (내독소에 의한 말초혈액 단핵구의 IL-8 및 IL-$1{\beta}$ 유전자 발현에서 산소기 역할에 관한 연구)

  • Kang, Min-Jong;Kim, Jae-Yeol;Park, Jae-Seok;Lee, Seung-Joon;Yoo, Chul-Gyu;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.6
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    • pp.862-870
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    • 1995
  • Background: Oxygen free radicals have generally been considered as cytotoxic agents. On the other hand, recent results suggest that small nontoxic amounts of these radicals may act a role in intracellular signal transduction pathway and many efforts to reveal the role of these radicals as secondary messengers have been made. It is evident that the oxygen radicals are released by various cell types in response to extracellular stimuli including LPS, TNF, IL-1 and phorbol esters, all of which translocate the transcription factor $NF{\kappa}B$ from cytoplasm to nucleus by releasing an inhibitory protein subunit, $I{\kappa}B$. Activation of $NF{\kappa}B$ is mimicked by exposure to mild oxidant stress, and inhibited by agents that remove oxygen radicals. It means the cytoplasmic form of the inducible tanscription factor $NF{\kappa}B$ might provide a physiologically important target for oxygen radicals. At the same time, it is well known that LPS induces the release of oxygen radicals in neutrophil with the activation of $NF{\kappa}B$. From above facts, we can assume the expression of IL-8 and IL-$1{\beta}$ gene by LPS stimulation may occur through the activation of $NF{\kappa}B$, which is mediated through the release of $I{\kappa}B$ by increasing amounts of oxygen radicals. But definitive evidence is lacking about the role of oxygen free radicals in the expression of IL-8 and IL-$1{\beta}$ gene in mononuclear phagocytic cells. We conducted a study to determine whether oxygen radicals act a role in the expression of IL-8 and IL-$1{\beta}$ gene in mononuclear phagocytic cells. Method: Human peripheral blood monocytes were isolated from healthy volunteers. Time and dose relationship of $H_2O_2$-induced IL-8 and IL-$1{\beta}$ mRNA expression was observed by Northern blot analysis. To evaluate the role of oxygen radicals in the expression of IL-8 and IL-$1{\beta}$ mRNA by LPS stimulation, pretreatment of various antioxiants including PDTC, TMTU, NAC, ME, Desferrioxamine were done and Northern blot analysis for IL-8 and IL-$1{\beta}$ mRNA was performed. Results: In PBMC, dose and time dependent expression of IL-8 and IL-$1{\beta}$ mRNA by exogenous $H_2O_2$ was not observed. But various antioxidants suppressed the expression of LPS-induced IL-8 and IL-$1{\beta}$ mRNA expression of PBMC and the suppressive activity was most prominant when the pretreatment was done with TMTU. Conclusion: Oxygen free radical may have some role in the expression of IL-8 and IL-$1{\beta}$ mRNA of PBMC but that radical might not be $H_2O_2$.

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Triptolide Mimics the Effect of Dietary Restriction on Lifespan and Retards Age-related Diseases in Caenorhabditis elegans (트립톨라이드가 식이제한에 의한 수명연장과 노화관련 질환에 미치는 영향)

  • Beak, Sun-Mi;Park, Sang-Kyu
    • Journal of Life Science
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    • v.28 no.8
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    • pp.931-937
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    • 2018
  • Triptolide is a compound found in Tripterygium wilfordii and reported to have an anti-inflammatory and anti-oxidant activities. A previous study shows that the dietary supplementation with triptolide increases resistance to environmental stressors, including oxidative stress, heat shock, and ultraviolet irradiation, and extends lifespan in C. elegans. Here, we investigated the underlying mechanisms involved in the lifespan-extending effect of triptolide. The effect of triptolide on age-related diseases, such as diabetes mellitus and Alzheimer's disease, was also examined using animal disease models. The longevity phenotype conferred by triptolide was not observed in the eat-2 mutant, a well-known genetic model of dietary restriction, while there was an additional lifespan extension with triptolide in age-1 and clk-1 mutants. The long lifespan of age-1 mutant is resulted from a reduced insulin/IGF-1-like signaling and the clk-1 mutant lives longer than wild-type due to dysfunction of mitochondrial electron transport chain reaction. The effect of dietary restriction using bacterial dilution on lifespan also overlapped with that of triptolide. The toxicity of high glucose diet or transgenic human amyloid beta gene was significantly suppressed by the supplementation with triptolide. These findings suggest that triptolide can mimic the effect of dietary restriction on lifespan and onset of age-related diseases. We conclude that triptolide can be a strong candidate for the development of dietary restriction mimetics.

Effects of Rubus coreanus and Artemisia princeps Extracts on the Ultraviolet B-Induced DNA Damage Responses in HaCaT Cells (HaCaT 세포에서 자외선 B에 의해 유도된 DNA 상해반응에 대한 복분자와 쑥 추출물의 효과)

  • Lee, Seok Hee;Ha, Se Eun;Lee, Jun Kyoung;Park, Jong Kun
    • Journal of Life Science
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    • v.24 no.2
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    • pp.112-117
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    • 2014
  • We investigated the effects of extracts from Rubus coreanus (RC) and Artemisia princeps var. orientalis (AP) on DNA damage response in ultraviolet B (UVB)-exposed HaCaT cells. Cell activity upon treatment for 24 h with RC or AP alone was similar to or greater than that of the nontreated control. When UVB-exposed cells were postincubated for 24 h in medium containing RC or AP, cell activity increased in a concentration-dependent manner. Nuclear fragmentation analysis showed that postincubation with RC or AP decreased UVB-induced apoptosis by about 20% and 15%, respectively, of that in cells postincubated with growth medium. When UVB-exposed cells were postincubated for 24 h in medium containing RC or AP, the level of cyclobutane pyrimidine dimer decreased in a concentration- dependent manner. Western blot analysis showed that treatment of cells not exposed to UVB with RC or AP alone did not significantly change the levels of phospho-p53 and GADD45 protein. Interestingly, when UVB-exposed cells were postincubated for 24 h in medium containing RC or AP, phospho-p53 and GADD45 levels decreased in a concentration dependent manner. Our results suggest that RC and AP extract assist the survival of UVB-exposed cells in parallel with a decrease in levels of UVB-induced DNA damage and damage-response proteins, such as p53 and GADD45.

Evaluation of DNA Damage Induced by Mercury Chloride (II) and Ionizing Radiation in the Earthworm (염화수은(II)과 이온화 방사선 처리에 따른 토양 내 환형동물의 DNA 손상 측정)

  • Ryu, Tae-Ho;Nili, Mohammad;An, Kwang-Guk;Kim, Jin-Kyu
    • Korean Journal of Environmental Biology
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    • v.28 no.4
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    • pp.212-217
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    • 2010
  • Soil pollution by heavy metals has become a significant environmental concern due to a variety of human activities. Specially toxicity caused by excessive mercury exposure is now being recognized as a widespread environmental problem and is continuing to attract a great deal of public concerns. The earthworms are very important animals that aerate the soil with their burrowing action and enrich the soil by decomposing organic matters. Especially the earthworm Eisenia fetida is routinely used in ecotoxicological studies. The levels of DNA damage in earthworms treated with HgCl2 and ionizing radiation were investigated in this study. Genotoxic effects were evaluated in the earthworm's coelomocytes using the comet assay (Single Cell Gel Electrophoresis; SCGE). The results showed that the mercury chloride and radiation were responsible for the genotoxic effects on earthworms. The level of DNA damage significantly increased after the treatment of mercury chloride combined with ionizing radiation. The combined treatment of $HgCl_2$ and ionizing radiation had a greater genotoxicity. This study is amenable to further study such as enzyme activation assay.

Anti-Inflammatory Effects of Vegetable Soup in Murine Macrophage RAW 264.7 Cells (야채스프의 RAW 264.7 세포에서 항염증 효과)

  • Sim, Jae-Geun;Lee, Jae-Hyeok;Shin, Tae-Yong;Shin, Hye-Young;Jeong, Sook-Hee;Kim, Mi-Hye;Ku, Ho-Jun;Park, Jeong-Suk
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.8
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    • pp.1097-1101
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    • 2010
  • The aim of the present study is to investigate the anti-inflammatory effect of a vegetable soup (VS). The present study was designed to determine the effect of the vegetable soup on pro-inflammatory factors such as NO, iNOS and TNF-$\alpha$ in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. The cell toxicity was determined by MTS assay. To evaluate the anti-inflammatory effect of vegetable soup, amount of NO was measured using the NO detection kit and the iNOS expression was measured by reverse transcriptase polymerase chain reaction (RT-PCR). Also, proinflammatory cytokines were measured by ELISA kit. The results showed that the vegetable soup reduced NO, iNOS and TNF-$\alpha$ production without cytotoxicity. Our results suggest that the vegetable soup may have an anti-inflammatory property through suppressing inflammatory mediator productions and appears to be useful to develop the functional food realted to anti-inflammation.