• 제목/요약/키워드: Mechanism synthesis

검색결과 989건 처리시간 0.033초

목과(木瓜), 호장근(虎杖根) 및 유향(乳香) 추출물이 Raw 264.7 cell에서 LPS로 유도된 nitric oxide 생성에 미치는 영향 (Effects of Water Extracts from Chaenomeles sinensis, Polygonum cuspidatum and Boswellia carterii on LPS-Induced Nitric Oxide Production in Raw 264.7 Cell)

  • 이태진;우경진;서성일;신상우;김상찬;권영규;박종욱;권택규
    • 동의생리병리학회지
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    • 제20권3호
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    • pp.603-608
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    • 2006
  • In activated macrophage, large amounts of nitric oxide (NO) are generated by inducible nitric oxide synthase (iNOS), resulting in acute or chronic inflammatory disorders. In Raw 264.7 cells stimulated with lipopolysaccharide (LPS) to mimic inflammation, water extracts from the fruit of Chaenomeles sinensis, the root of Polygonum cuspidatum and Boswellia carterii inhibited the LPS-induced NO production in a parallel dose-dependent manner. To investigate the mechanism by which those extracts inhibits NO production, we examined the expression of iNOS and COX-2 in both mRNA and protein levels. We observed a significant change in the iNOS expression between LPS alone and LPS plus those extracts-treated cells. However, water extracts from Chaenomeles sinensis, Polygonum cuspidatum and Boswellia carterii did not inhibit COX-2 expression which was induced by LPS treatment in Raw 264.7 cells. These data suggest that water extracts from Chaenomeles sinensis, Polygonum cuspidatum and Boswellia carterii can modulate anti-inflammatory immune response, which may be in part associated with the regulation of NO synthesis through the regulation of iNOS expression in mouse macrophage cells.

DOWN REGULATION OF TGF-$\beta$ GENE EXPRESSION BY ANTISENSE OLIGO-DEOXYNUCLEOTIDES INCREASE rIFN-${\gamma}$-INDUCED NITRIC OXIDE SYNTHESIS IN MURINE PERITONEAL MACROPHAGES

  • Jun, Chang-Duk;Kim, Su-Ung;Lee, Seong-Yong;Chung, Hun-Taeg
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1995년도 춘계학술대회
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    • pp.78-78
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    • 1995
  • Increasing evidence indicates that the production of nitric oxide (NO) by inducible NO synthase (NOS) is tightely regulated. Transforming growth factor-${\beta}$ (TGF-${\beta}$) is a homodimeric protein secreted during macrophage activation, but several lines of evidence suggest that TGF-${\beta}$ is selectively suppressive for macrophage NO production. We therefore reasoned that a strategy employing oligodeoxynucleotides(ODNs) complemently to TGF-${\beta}$ mRNA (antisense ODNs) might increase NO production in IFN-${\gamma}$-treated murine peritoneal macrophages. To evaluate this concept, we tested the effects of antisense ODNs targeted to TGF-${\beta}$ mRNA (25-mer ODNs complemently to TGF-${\beta}$mRNA sequences) by introducing it into the medium of cultured macrophages. Phosphorothiolation of ODNs were employed to retard their degradation. Antisense ODNs had no effect on NO production by itself, whereas IFN-${\gamma}$ alone had modest effect. When antisense ODNs were used in combination with IFN-${\gamma}$, there was a marked cooperative induction of NO production, These effects of antisense ODNs were associated with decreased TGF-${\beta}$ expression in activated macrophages. ODNs with the same nucleotides but a scrambled sequence had no effect. Adding anti-TGF-${\beta}$ antibodies to the IFN-${\gamma}$-treated macrophages mimicked the positive effect of antisense ODNs on NO production. In addition, the effects of either antisense ODNs or anti-TGF-${\beta}$ antibodies were blocked by adding TGF-${\beta}$ in cultured macrophages. These results indicate that the generation of TGF-${\beta}$ by activated macrophages provides a self-regulating mechanism by which the temporal and perhaps spatial production of NO, a reactive and potentially toxic mediator, can be finely regulated.

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Hypothermia Inhibits Endothelium-Independent Vascular Contractility via Rho-kinase Inhibition

  • Chung, Yoon Hee;Oh, Keon Woong;Kim, Sung Tae;Park, Eon Sub;Je, Hyun Dong;Yoon, Hyuk-Jun;Sohn, Uy Dong;Jeong, Ji Hoon;La, Hyen-Oh
    • Biomolecules & Therapeutics
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    • 제26권2호
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    • pp.139-145
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    • 2018
  • The present study was undertaken to investigate the influence of hypothermia on endothelium-independent vascular smooth muscle contractility and to determine the mechanism underlying the relaxation. Denuded aortic rings from male rats were used and isometric contractions were recorded and combined with molecular experiments. Hypothermia significantly inhibited fluoride-, thromboxane $A_{2-}$, phenylephrine-, and phorbol ester-induced vascular contractions regardless of endothelial nitric oxide synthesis, suggesting that another pathway had a direct effect on vascular smooth muscle. Hypothermia significantly inhibited the fluoride-induced increase in pMYPT1 level and phorbol ester-induced increase in pERK1/2 level, suggesting inhibition of Rho-kinase and MEK activity and subsequent phosphorylation of MYPT1 and ERK1/2. These results suggest that the relaxing effect of moderate hypothermia on agonist-induced vascular contraction regardless of endothelial function involves inhibition of Rho-kinase and MEK activities.

Marker-assisted Genotype Analysis of Bulb Colors in Segregating Populations of Onions (Allium cepa)

  • Kim, Sunggil;Bang, Haejeen;Yoo, Kil-Sun;Pike, Leonard M.
    • Molecules and Cells
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    • 제23권2호
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    • pp.192-197
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    • 2007
  • Bulb color in onions (Allium cepa) is an important trait whose complex inheritance mechanism involves epistatic interactions among major color-related loci. Recent studies revealed that inactivation of dihydroflavonol 4-reductase (DFR) in the anthocyanin synthesis pathway was responsible for the color differences between yellow and red onions, and two recessive alleles of the anthocyanidin synthase (ANS) gene were responsible for a pink bulb color. Based on mutations in the recessive alleles of these two genes, PCR-based markers for allelic selection were developed. In this study, genotype analysis of onions from segregating populations was carried out using these PCR-based markers. Segregating populations were derived from the cross between yellow and red onions. Five yellow and thirteen pink bulbs from one segregating breeding line were genotyped for the two genes. Four pink bulbs were heterozygous for the DFR gene, which explains the continuous segregation of yellow and pink colors in this line. Most pink onions were homozygous recessive for the ANS gene, except for two heterozygotes. This finding indicated that the homozygous recessive ANS gene was primarily responsible for the pink color in this line. The two pink onions, heterozygous for the ANS gene, were also heterozygous for the DFR gene, which indicated that the pink color was produced by incomplete dominance of a red color gene over that of yellow. One pink line and six other segregating breeding lines were also analyzed. The genotyping results matched perfectly with phenotypic color segregation.

Effects of phenolics from Oplismenus undulatifolius in α-MSH-stimulated B16F10 melanoma cells

  • Park, Hye-Jin;Lee, Eun-Ho;Jung, Hee-Young;Kang, In-Kyu;Cho, Young-Je
    • Journal of Applied Biological Chemistry
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    • 제63권1호
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    • pp.89-93
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    • 2020
  • In this study, the efficacy of melanoma cell B16F10 was investigated using the Korean native plant Oplismenus undulatifolius (OU). First, the cell viability of the extract was more than 90% when treated with 15 ㎍/mL of phenolics from OU. The results showed that melanin biosynthesis and cellular tyrosinase synthesis were inhibited by treatment with α-melanocyte-stimulating hormone-stimulated mouse melanoma cell B16F10 at a concentration of 15 ㎍/mL of phenolics for cell-line efficacy. The expression of tyrosinase, tyrosinase-related protein (TRP)-1, TRP-2, and microphthalmia transcription factor (MITF) protein was confirmed by western blot to investigate the effect of phenolics from OU on melanin biosynthesis. When treated with phenolics from OU 15 ㎍/mL, tyrosinase, TRP-1, TRP-2, and MITF decreased the protein expression level. In particular, tyrosinase, TRP-1, and MITF inhibited the production amount to a level similar to that of the non-treated normal group, indicating that the effect was excellent. Therefore, phenolics from OU acts as an inhibitor of tyrosinase, TRP-1, TRP-2, and its transcription factor MITF, and participates in melanin biosynthesis mechanism. These results suggested the potential for development as a material.

F9 기형암종세포에서 Ursolic acid의 apoptosis 유도기작 (Induction of Apoptosis by Ursolic Acid in F9 Teratocarcinoma Cells)

  • 강창모;백진현;김규원
    • 생명과학회지
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    • 제8권1호
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    • pp.51-59
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    • 1998
  • Ursolic acid(UA)의 apoptosis 유도능을 F9 생쥐 기형암종세포를 대상으로 조사하였다. UA는 피부암화의 억제, tumor의 분화유도, tumor promotion의 억제 등의 항암 효과를 나타내는 pentacyclic triterpene acid로 물질로 알려져 있다. UA를 F9세포에 처리하였을 때 농도비례로 성장억제를 나타냈다. 또한 apoptosis과정에서 관찰되는 전형적인 DNA 분절을 관찰할 수 있었고, 전자현미경을 이용한 세포의 미세구조를 관찰한 결과, 역시 apoptosis과정에서 관찰되는 전형적인 형태인 염색질 응축, 핵의 분절들을 관찰할 수 있어, UA에 의한 항암 효과는 apoptosis에 의한 것임을 시사한다. UA에 의한 apoptosis는 단백질 합성저해제인 cycloheximide에 의해 저해됨을 관찰할 수 있었다. UA를 F4쎄포에 처리한 후 oncogene의 발현양상을 조사한 결과, c-myc과 laminin B1은 apoptosis과정동안 점점 감소하고 c-jun은 증가함을 관찰할 수 있었다. 이상의 결과로서 UA에 의한 F9 세포의 apoptosis에는 새로운 단백질의 합성이 요구되며, c-myc 및 laminin의 발현 감소와 c-jumd의 발현 증가가 관여하고 있음을 시사한다.

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솔루션 플라즈마를 이용한 이종 원소 카본 나노시트의 합성 (Synthesis of Heteroatom-Carbon Nanosheets by Solution Plasma Process)

  • 현광룡;정광후;박일초;이정형;한민수;김성종
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2018년도 춘계학술대회 논문집
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    • pp.114-114
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    • 2018
  • 탄소 재료는 뛰어난 물성에서 다양한 재료로의 응용이 기대되고 있다. 특히, 이종 원소 함유 카본 재료는 전기적 특성과 촉매성의 발현 등 새로운 기능을 카본 재료에 부여할 수 있어서 연료 전지, 에너지 저장, 태양 전지 등에의 응용이 기대되고 있다. 최근, 용액 중의 저온 플라즈마인 솔루션 플라즈마(solution plasma process)를 이용하여 벤젠 용액 등에서 탄소 재료 합성에 성공하였다. 그러나 기존의 연구에서는 솔루션 플라즈마 프로세스를 이용하여 합성한 이종원소 카본은 전도성이 낮아 이종원소의 함유량을 낮추는 고온의 열처리가 필요했다. 따라서 본 연구에서는 우수한 물리적 전기적 특성을 갖는 그래핀(graphene)과 같은 이종 원소 카본 나노시트(heteroatom carbon nanosheets)의 합성 및 메커니즘(mechanism)에 대해 검토하였다. 다양한 이종원소를 포함한 유기용매 안에 바이폴라 펄스 전원에 의한 전압을 두 텅스텐 전극 간에 인가하고, 솔루션 플라즈마를 생성하여 이종원소 카본 재료를 합성했다. 플라즈마 생성은 텅스텐 봉을 전극으로 사용하고 전압을 2.0 kV, 펄스 주파수를 200 kHz, 펄스 폭을 $1.0{\mu}s$, 전극 간 거리를 1.5 mm에서 일정하게 유지하며 200 mL 유기용매 중에서 방전시키는 것으로 재료를 합성했다. 플라즈마 방전 후, 필터을 이용하여 흡인 여과한 뒤 $200^{\circ}C$에서 1 시간 동안 건조 시켰다. 건조 후의 이종원소 카본의 물리적 특성을 원소 분석, X선 회절 법(XRD), 저항률 측정, 투과형 전자 현미경(TEM) 및 라만 분광법, 전자 현미경(SEM), X-선광전자분광기(XPS)등을 이용하여 카본의 형상 및 특성을 분석하였다. 그 결과 다양한 이종원소를 포함한 유기용매 중 2-pyrrolidone을 사용했을 때, 이종 원소 카본 나노시트를 합성하는데 성공하였다. 또한, 이 연구방법을 통해서 솔루션 플라즈마 프로세스를 통한 카본 나노시트 합성의 메커니즘을 규명하였다.

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Proline Accumulation and P5CS ($\Delta^1$-pyrroline-5-carboxylate synthetase) Gene Expression in Response to Salt Stress in Zoysiagrasses

  • Lee, Dong-Joon;Hwang, Cheol-Ho
    • 한국작물학회지
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    • 제48권1호
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    • pp.20-24
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    • 2003
  • Proline is known as an osmotrotectant to enhance tolerance against both salt and dehydration stresses. A P5CS ($\Delta^1$-pyrroline-5-carboxylate synthetase) plays a major role in regulation of synthesis of proline. An overexpression of the mothbean P5CS gene in transgenic tobacco plant increased the levels of proline and osmotolerance. In an attempt to look for the possibility to use content of proline as well as a level of P5CS gene expression as molecular markers for salt tolerance, the amounts of proline and transcript levels of P5CS were measured as functions of either concentration of NaCl or length of treatment period among different species of zoysiagrass. Hybridzoysia showed the highest level of proline ($329\mu\textrm{g}$/g.f.w.) among five different species of zoysiagrass at 250 mM NaCl in 24 hours. The level of P5CS transcript was also the highest in the hybridzoysia at 250 mM NaCl in 24 hours. The transcriptions of P5CS gene were induced at the rates of 1.2, 1.2, 1.8, and 1.8, upon treatment of 250 mM NaCl in Z. japonica, Z. matrella, Z. sinica and hybridzoysia respectively. Based on a correlation between the level of P5CS transcript and the proline content among different species of zoysiagrass, a comparative structural analysis of the gene for P5CS from either Z. sinica or hybridzoysia may lead to an understanding of mechanism for salt tolerance shown differently among zoysiagrasses.

돼지 미성숙 난포란의 체외성숙에 미치는 Thymidine 처리 효과 (Effect of Thymidine on $In$ $Vitro$ Maturation of Immature Porcine Follicular Oocytes)

  • 민성훈;박흠대
    • Reproductive and Developmental Biology
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    • 제36권1호
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    • pp.71-77
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    • 2012
  • The objective of this study was to examine the effect of thymidine treatment during $in$ $vitro$ maturation (IVM) of porcine follicular oocytes on blastocyst development. Porcine oocytes were treated with thymidine (10 mM, 20 mM and 30 mM) for 2 or 6 hr in the preiods of IVM I and/or II. The survival rates of the blastocysts in the 6 hr treatment groups of 10 mM and 20 mM during IVM I period were significantly higher than those of control group ($p$<0.05). However, the survival rate of the blastocysts in the 2 hr treatment group of 20 mM during IVM II period was significantly higher than control group ($p$<0.05). Furthermore, the survival rate of the blastocysts in the 6 hr treatment group of 30 mM during IVM II period was significantly lower than control group ($p$<0.05). Consistent with the previous result, blastocyst development of both IVM I and II treatment group was also showed as similar pattern. Total and apoptotic cell numbers of blastocysts derived from thymidine treated porcine oocytes were examined by using Tunel assay. The results showed that there was no significant differences in total cell number of blastocysts between thymidine treated and untreated groups. However, apoptosis-positive cells in the thymidine treated group (6 hr IVM I) were significantly lower than those of other groups ($p$<0.05). Taken together, these results indicate that high quality oocytes were selected by DNA synthesis mechanism according to high concentration thymidine treatment during porcine oocyte maturation. Therefore, we concluded that presumptive selected oocytes by thymidine treatment during maturation periods improved the further embryo development and embryonic quality of IVF embryos by decreasing the incidence of apoptosis in preimplantation porcine embryos.

Paraquat 독성 경감제 검색 및 그 억제 기전에 관한 연구 (Studies on Screening of Paraquat Toxicity Reducing Agent and its Inhibition Mechanism)

  • 이정훈;구성자;정세영
    • 한국식품과학회지
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    • 제30권1호
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    • pp.192-198
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    • 1998
  • 제초제 paraquat의주된 독성 기전이 인체내 대사과정중 생성되는 superoxide anion radical $(O_{2-})$에 의한 것이라고 최근 보고된 바, 항산화작용을 갖는 taurine을 가지고 paraquat 독성 경감 효과 및 억제 기전에 관한 실험을 하게 되었으며 다음과 같은 결론을 얻게 되었다. 혈액생화학적인자 분석을 종합해 보면 paraquat의 독성 경감효과는 taurine, aloesin, ${\beta}-carotene$ 중 taurine이 가장 우수하였으며, aloesin도 효과가 있는 것으로 나타났다. In vivo에서 taurine은 혈액생화학적 검사에서 paraquat에 의해 유도된 간독성 지표인 sGPT. sGOT치, 신장독성 지표인 BUN, creatinine치 및 조직 손상의 지표인 ALP, MDA치를 정상으로 회복시켰다. 폐조직중의 MDA량, ALP 활성 및 collagen 량이 정상치로 회복이 되었다. 이로써 taurine은 paraquat의 폐독성 및 각 장기의 독성을 효과적으로 경감 시켜 준다는 사실을 확인할 수 있었다.

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