• 제목/요약/키워드: Reporter gene assay

검색결과 218건 처리시간 0.04초

Detection of the cell wall-affecting antibiotics at sublethal concentrations using a reporter Staphylococcus aureus harboring drp35 promoter - lacZ transcriptional fusion

  • Mondal, Rajkrishna;Chanda, Palas K.;Bandhu, Amitava;Jana, Biswanath;Lee, Chia-Y.;Sau, Subrata
    • BMB Reports
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    • 제43권7호
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    • pp.468-473
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    • 2010
  • Previously, various inhibitors of cell wall synthesis induced the drp35 gene of Staphylococcus aureus efficiently. To determine whether drp35 could be exploited in antistaphylococcal drug discovery, we cloned the promoter of drp35 ($P_d$) and developed different biological assay systems using an engineered S. aureus strain that harbors a chromosomally-integrated $P_d$ - lacZ transcriptional fusion. An agarose-based assay showed that $P_d$ is induced not only by the cell wall-affecting antibiotics but also by rifampicin and ciprofloxacin. In contrast, a liquid medium-based assay revealed the induction of $P_d$ specifically by the cell wall-affecting antibiotics. Induction of $P_d$ by sublethal concentrations of cell wall-affecting antibiotics was even assessable in a microtiter plate assay format, indicating that this assay system could be potentially used for high-throughput screening of new cell wall-inhibiting compounds.

Agrobacterium tumefaciens 에 의한 민들레의 형질전환 (Transformation of Taraxacum mongolicum Hand by Agrobacterium tumefaciens)

  • 여상언;노광수
    • KSBB Journal
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    • 제16권5호
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    • pp.480-485
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    • 2001
  • 국화과에 속하는 다년생 초본식물의 민들레가 Agrobacteria 에 대한 숙주로서의 가능성을 조사하고 여러 가지 유용한 유전자를 민들레로 도입시키기 위해, 민들레잎 절편을 pBI121으로 형질전환된 Agrobacterium tumefaciens LBA4404와 10분동안 공동배양하여 형질전환시킨 후, 1$\mu$M IAA, 1$\mu$M BA. 50 $\mu$g/ML Km과 100$\mu$g/ML Cb이 함유된 MS 배지에서 약 2주후에 multiple shoot를 유가시켰다. 유기된 shoot로 부터 유식식물체를 얻었으며, 형질전환을 확인하기 위해 GUS활성을 측정한 결과 양성 반응을 보였다.

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형질전환효모를 이용한 내분비계장애물질검색과 Nonylphenol의 Estrogen 유사작용에 대한 DEHP의 상협작용 (Modification of Estrogenic Effect of Nonylphenol Combined with DEHP in Yeast-based Bioassay)

  • 박미선;정해관;박현신;한의식;김종원;엄미옥;정상희;오혜영
    • Toxicological Research
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    • 제17권1호
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    • pp.65-71
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    • 2001
  • The key targets of endocrine disruptors are nuclear hormone receptors, which bind to steroid hormones and regulate their gene transcription. A yeast-based steroid hormone receptor gene trascription assay was previously developed for the evaluation of chemicals with endocrine modulating activity. The yeast transformants used in this assay contain the human estrogen receptor along with the appropriate steroid response elements upstream of the $\beta$-galactosidase reporter gene. We tried to evaluate several natural and synthetic steroids of their potential to interact directly with the steroid receptor. Some putative endocrine disruptors, including nonylphenol, are weakly estrogenic. But the combined treatment oj these chemicals with di-(2-ethylhexyl)phthalate (DEHP) significantly increased the $\beta$-galactosidase activity in the yeast transformant. These results suggest that we also have to consider the synergistic effects of endocrine disruptors. In this study, we showed that yeast-based bioassay is a valuable tool for screening potential endocrine disruptors and quantitative determination of estrogenicity. And the possibility that the estrogen receptor binds multiple environmental chemicals adds another level of complexity to the interaction between the endocrine disruptors and the human hormone system.

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Magnolol Inhibits LPS-induced NF-${\kappa}B$/Rel Activation by Blocking p38 Kinase in Murine Macrophages

  • Li, Mei Hong;Kothandan, Gugan;Cho, Seung-Joo;Huong, Pham Thi Thu;Nan, Yong Hai;Lee, Kun-Yeong;Shin, Song-Yub;Yea, Sung-Su;Jeon, Young-Jin
    • The Korean Journal of Physiology and Pharmacology
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    • 제14권6호
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    • pp.353-358
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    • 2010
  • This study demonstrates the ability of magnolol, a hydroxylated biphenyl compound isolated from Magnolia officinalis, to inhibit LPS-induced expression of iNOS gene and activation of NF-${\kappa}B$/Rel in RAW 264.7 cells. Immunohisto-chemical staining of iNOS and Western blot analysis showed magnolol to inhibit iNOS gene expression. Reporter gene assay and electrophoretic mobility shift assay showed that magnolol inhibited NF-${\kappa}B$/Rel transcriptional activation and DNA binding, respectively. Since p38 is important in the regulation of iNOS gene expression, we investigated the possibility that magnolol to target p38 for its anti-inflammatory effects. A molecular modeling study proposed a binding position for magnolol that targets the ATP binding site of p38 kinase (3GC7). Direct interaction of magnolol and p38 was further confirmed by pull down assay using magnolol conjugated to Sepharose 4B beads. The specific p38 inhibitor SB203580 abrogated the LPS-induced NF-${\kappa}B$/Rel activation, whereas the selective MEK-1 inhibitor PD98059 did not affect the NF-${\kappa}B$/Rel. Collectively, the results of the series of experiments indicate that magnolol inhibits iNOS gene expression by blocking NF-${\kappa}B$/Rel and p38 kinase signaling.

Function identification of bovine Nramp1 promoter and intron 1

  • Hao, Linlin;Zhang, Libo;Li, Mingtang;Nan, Wang;Liu, Songcai;Zhong, Jifeng
    • Animal cells and systems
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    • 제15권3호
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    • pp.227-233
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    • 2011
  • The Nramp1/Slc11a1 locus encodes a proton-coupled divalent cation transporter, expressed in late endosomes/lysosomes of macrophages, that constitutes a component of the innate immune response to combat intracellular pathogens and it was shown to play an important role in regulating inherent immunity. The previously identified Z-DNA forming polymorphic repeat(GT)n in the promoter region of the human Nramp1 gene does act as a functional polymorphism influencing gene expression. Research has shown that INF-${\gamma}$, TNF-${\alpha}$, IL-$1{\beta}$ and bacteria LPS increase the level of Nramp1 expression. However, the molecular mechanism for Nramp1 gene regulation is unclear. In this research, bovine Nramp1 5'-flanking region (-1748~+769) was cloned and analyzed by bioinformatics. Then to find the core promoter and the cis-acting elements, deletion analysis of promoter was performed using a set of luciferase reporter gene constructs containing successive deletions of the bovine Nramp1 5'-flanking regions. Promoter activity analysis by the dual luciferase reporter assay system showed that the core promoter of Nramp1 was located at +58~-89 bp. Some positive regulatory elements are located at -89~-205 bp and -278~-1495 bp. And the repressor elements were in region -205~-278 bp, intron1 and -1495~-1748 bp. LPS-responsive regions were located at -1495~-1748 bp and -278~-205 bp. The present study provides an initial effort to explore the molecular mechanism of transcriptional activation of the bovine Nramp1 gene and should facilitate further studies to decode the complex regulatory process and for molecular breeding for disease resistance in bovines.

The Homologous Region 3 from Bombyx mori Nucleopolyhedrovirus Enhancing the Transcriptional Activity of Drosophila hsp70 Promoter

  • Tang, Shun-Ming;Yi, Yong-Zhu;Zhou, Ya-Jing;Zhang, Zhi-Fang;Li, Yi-Ren;He, Jia-Lu
    • International Journal of Industrial Entomology and Biomaterials
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    • 제9권2호
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    • pp.235-239
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    • 2004
  • Drosophila melanogaster heat shock protein 70 gene promoter (Dhsp70p) is widely used in transgenic insect to drive exogenous gene, and the homologous region 3 from Bombyx mori nucleopolyhedrovirus (BmNPVhr3) functions as an enhancer for several promoters. To test whether BmNPVhr3 can enhance the Dhsp70ps transcriptional activity, the reporter plasmids, which contain the Dhsp70p, the reporter $\beta$-galactosidase gene with SV40 terminator and BmNPVhr3 fragment, are constructed and transfected into the insect cell lines (Bm-N cells and Sf-21 cells) by lipofectin-mediated method. The results from the transient expression assay show that BmNPVhr3 significantly increases transcriptional activity of Dhsp70p both under the normal condition and under the heat-shock treatment, although the effects are significantly different between in Bm-N cells and in sf-21 cells. The enhancing behavior of BmNPVhr3 on the Dhsp70p is in an orientation-independent manner. Meanwhile, the effects of heat-shock treatment on Dhsp70p alone or Dhsp70p/BmNPVhr3 combination present no significant difference, indicating that BmNPVhr3 only enhances the transcriptional activity of Dhsp70p, but cant alter its characteristic of the response to the heat-shock stress. The above results suggest that the Dhsp70p/BmNPVhr3 combination is more effective one to drive exogenous gene for transgene or stable cell expression system in insects.

Porcine tissue factor promoter induces specific expression of target gene in response to human serum in porcine aortic endothelial cells

  • No, Jin Gu;Lee, Haesun;Lee, Na Hyun;Sun, Wu-Sheng;Hwang, In-Sul;Lee, Minguk;Oh, Keon Bong
    • 농업과학연구
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    • 제48권2호
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    • pp.353-365
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    • 2021
  • Previously, we reported that tissue factor (Tf) was included in the list of differentially expressed genes as an upregulated gene in a rejected porcine heart after xenotransplantation into monkey. In this study, we analyzed that expression of Tf in aortic endothelial cells (pAEC) isolated from alpha 1,3-galactosyltransferase knockout pig in response to allogeneic porcine serum and xenogeneic human serum. The consequence was significant upregulation of Tf expression by responding to human serum compared with porcine serum. To analyze the function of Tf gene as a promoter, we constructed reporter vectors for expression of luciferase linked to 1,246 and 787 base pairs of porcine Tf (pTF1246 and pTF787), and 535 base pairs of human TF (hTF535) sequences including putative promoter regions and AP-1 biding site at the 5' end. The reporter vectors were transfected into pAEC including cytomegalovirus enhancer/chicken β-actin (CAG)-luciferase vector as a control. Luciferase assay showed that all of the promoters were insufficient to express luciferase compared with CAG promoter in basic culture conditions. Notably, pTF1246, pTF787, and hTF535 led to a significant increase of luciferase expression in response to human serum compared with porcine serum while no change of CAG. pTF1246 and pTF787 showed higher expression than hTF535. Taken together, our findings suggest that pTF1246 and pTF787 promoters could mediate target gene expression specifically at xenogeneic stress condition.

Antiestrogenic Effects of Marijuana Smoke Condensate and Cannabinoid Compounds

  • Lee Soo Yeun;Oh Seung Min;Lee Sang Ki;Chung Kyu Hyuck
    • Archives of Pharmacal Research
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    • 제28권12호
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    • pp.1365-1375
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    • 2005
  • The antiestrogenic effects of marijuana smoke condensate (MSC) and three major cannabinoids, i.e., $\bigtriangleup^{9}$-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN), were evaluated using in vitro bioassays, viz., the human breast cancer cell proliferation assay, the recombinant human estrogen receptor (ER) competitive binding assay, and the reporter gene assay. The inhibitory effects on estrogen were also examined using the ethoxyresorufin-O­deethylase (EROD) assay, the aromatase assay, and the 17$\beta$-estradiol ($E_{2}$) metabolism assay. The results showed that MSC induced the antiestrogenic effect via the ER-mediated pathway, while THC, CBD, and CBN did not have any antiestrogenic activity. This suggests that the combined effects of the marijuana smoke components are responsible for the antiestrogenicity of marijuana use. In addition, MSC induced the CYP1A activity and the $E_{2}$ metabolism, but inhibited the aromatase activity, suggesting that the antiestrogenic activity of MSC is also related to the indirect ER-dependent pathway, as a result of the depletion of the in situ $E_{2}$ level available to bind to the ER. In conclusion, pyrogenic products including polycyclic aromatic hydrocarbons (PAHs) in the non-polar fraction, which is the most biologically active fraction among the seven fractions of MSC, might be responsible for the antiestrogenic effect.

청조구폐탕(淸燥救肺湯)의 Nrf2 매개 항산화 효능 (Cheogjogupye-Tang has Anti-oxidant Potential through the Activation of Nrf2)

  • 이광규;이학인;정한솔
    • 동의생리병리학회지
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    • 제29권2호
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    • pp.174-179
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    • 2015
  • Transcription factor, Nrf2 was well known to protect cell from oxidative stress by up-regulating it's dependent anti-oxidative genes such as HO-1 and NQO1. Cheongjogupye-tang (CJGPT), a traditional herbal formula was originally recorded in 『EuiMunBeopRyul』, still having been used to treat pulmonary disease such as asthma and pulmonary inflammation, in Eastern Asian countries. However, the underlying therapeutic mechanisms remain elusive. The purpose of this study is to investigate the anti-inflammatory or anti-oxidative effects of CJGPT on the RAW 264.7 cells. To examine the anti-inflammatory or anti-oxidative effects of CJGPT, MTT assay, immunoblotting, RT-PCR and reporter gene assays were performed. Although CJGPT slightly suppressed the nuclear NF-κB expression, it did not decreased the expression of pro-inflammatory genes in LPS-stimulated RAW 264.7 cells. Moreover, it did not increased the transcriptional activity of NF-κB in reporter gene assay. However, CJGPT upregulated the nuclear expression of Nrf2, as well as increased the expression of Nrf2-dependent genes such as HO-1 and NQO1. In addition, CJGPT incresed the transcriptional activity of Nrf2. Taken together, our results showed that CJGPT exerts functions as an anti-oxidant mainly by activating Nrf2.