• Title/Summary/Keyword: Expression vectors

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Baculovirus Vector Reconstructed with Useful Genes (유용한 유전자들로 재구성된 베큘로바이러스 벡터)

  • Kim, Ji-Young;Kim, Hyun Joo;Sa, Young-Hee;Hong, Seong-Karp
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2016.05a
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    • pp.711-714
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    • 2016
  • Recombinant baculovirus was reconstructed with useful genes of polyhedron promoter, vesicular stomatitis virus G (VSVG), polyA, cytomegalovirus (CMV) promoter, enhanced green fluorescent protein (EGFP), and protein transduction domain (PTD). This reconstructed vector was infected into various cell lines and tissues. We investigated gene transfer and gene expression of this reconstructed vector in comparison to other vectors and recognized that this reconstructed vector was higher effective than any other control vector.

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Pilot Sequence Assignment for Spatially Correlated Massive MIMO Circumstances

  • Li, Pengxiang;Gao, Yuehong;Li, Zhidu;Yang, Dacheng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.1
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    • pp.237-253
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    • 2019
  • For massive multiple-input multiple-output (MIMO) circumstances with time division duplex (TDD) protocol, pilot contamination becomes one of main system performance bottlenecks. This paper proposes an uplink pilot sequence assignment to alleviate this problem for spatially correlated massive MIMO circumstances. Firstly, a single-cell TDD massive MIMO model with multiple terminals in the cell is established. Then a spatial correlation between two channel response vectors is established by the large-scale fading variables and the angle of arrival (AOA) span with an infinite number of base station (BS) antennas. With this spatially correlated channel model, the expression for the achievable system capacity is derived. To optimize the achievable system capacity, a problem regarding uplink pilot assignment is proposed. In view of the exponential complexity of the exhaustive search approach, a pilot assignment algorithm corresponding to the distinct channel AOA intervals is proposed to approach the optimization solution. In addition, simulation results prove that the main pilot assignment algorithm in this paper can obtain a noticeable performance gain with limited BS antennas.

The optimal conditions to improve retrovirus-mediated transduction efficiency to NIH 3T3 cells (레트로바이러스(retrovirus)의 NIH 3T3 세포로의 유전자 전달효율을 증가시키기 위한 적절한 조건들)

  • Lee, Jun Ah;Lee, Kang-Min;Lee, Hyun Jae;Lee, Yun Jeong;Kim, Dong Ho;Lim, Jung Sub;Park, Kyung-Duk
    • Clinical and Experimental Pediatrics
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    • v.50 no.10
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    • pp.1011-1017
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    • 2007
  • Purpose : We tried to assess the optimal conditions to improve low transduction efficiency and their effect on target cells. Methods : Cultured NIH 3T3 cells were incubated with retroviral vectors bearing an enhanced green fluorescent protein (eGFP) gene. We varied the ratio of viral vectors to target cells (1:1-1:8) and the number of transfections (${\times}1$, ${\times}2$), and compared transduction efficiencies. Also, the effects of polybrene on transduction efficiency and viability of target cells were assessed. Transduction of the eGFP gene was evaluated by observing NIH 3T3 cells under a fluorescence microscope and efficiencies were measured by the percentage of eGFP positive cells using FACscan. Results : As the ratio of retroviral vectors to target cells increased, transduction efficiency was greatly improved, from 7% (1:1) to 38% (1:4). However, transduction efficiency did not increase any more when the ratio increased from 1:4 to 1:8. Cells transfected twice showed higher transduction efficiencies than cells transfected once, at a ratio of 1:8. The eGFP gene transduced to NIH 3T3 cells sustained its expression during repeated passages. However, after the third passage (day 9), the percentage of eGFP positive cells began to decline. The degree of this decline in eGFP expression was lower in cells transfected twice than in cells transfected once (P<0.05). The addition of polybrene did not have any toxic effect on NIH 3T3 cells and greatly increased transduction efficiency (P=0.007). In addition to vector component, transduction efficiency was very sensitive to culture confluence. Cells cultured and transfected in 24-well plate showed higher transduction efficiency, although cells cultured in 6- well plate proliferated more (P=0.024). Conclusion : Our data could be used as a basis for retrovirus-based gene therapy. Further study will follow using human cells as target cells.

Construction of Xylose-Inducible Expression Vector Using xylA Promoter of Escherichia coli (대장균 xylA 프로모터를 이용한 xylose 유도성 발현벡터의 구축)

  • Kim, Hyun-Ho;So, Jai-Hyun;Rhee, In-Koo
    • Journal of Applied Biological Chemistry
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    • v.53 no.1
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    • pp.1-7
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    • 2010
  • xylA promoter is a major promoter in xylose operon of Escherichia coli. xylA promoter is sufficient as the promoter for the construction of new expression vector because this promoter was tightly controlled and induced by the addition of xylose. For the construction of xylose-inducible expression vector, 600 bp of xylA promoter was ligated between AatII and HindIII of pUC18, named pXA600. In order to investigate the effect of XylR protein encoded by xylR gene on the xylA promoter, 1,988 bp of xylR gene including its promoter was ligated into downstream of multiple cloning site to the opposite direction of xylA promoter in pXA600, named pXAR600. For the measurement of expression level, 3,048 bp of lacZ structural gene was fused into xylA promoter in both plasmids pXA600 and pXAR600 as a reporter gene, named pXA600-lacZ and pXAR600-lacZ, respectively. The $\beta$-galactosidase activity of pXA600-lacZ and pXAR600-lacZ in E. coli JM109 was determined to be 1,641 and 2,304 unit by the induction with xylose in LB medium, respectively. The $\beta$-galactosidase activity of pXAR600-lacZ/JM109 was about 1.4 times higher by the induction with xylose than that of pXA600-lacZ/JM109. The $\beta$-galactosidase activity of pXA600-lacZ and pXAR600-lacZ in E.coli JM109 showed 6,282 and 9,320 unit by the induction with xylose in DM minimal medium, respectively. A regulator, xylR protein works as an activator for the gene expression by the addition of xylose in the xylose-inducible vectors because the level of gene expression in pXA600 is increased by the insertion of xylR gene into the same vector. The xynA gene of Streptomyces thermocyaneoviolaceus cloned in pXA600 and pXAR600 was successfully expressed in E. coli BLR(DE3). As a result, plasmids pXA600 and pXAR600 using xylA promoter are sufficient as new expression system to produce a foreign protein in E. coli.

Effect of Zanthoxylum piperitum Extract on Human Skin Protection from UVB by Regulation of COP1 and PPAR-α (초피나무 열매 추출물의 COP1 및 PPAR-α 조절을 통한 자외선에 대한 피부 보호 효과)

  • Kim, Yun-Sun;Kim, Yumi;Lee, Sanghwa
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.42 no.4
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    • pp.393-401
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    • 2016
  • Ultraviolet (UV) irradiation from the sun is the primary environmental factor that causes skin damages including skin cancer and premature skin aging. Because, even the most powerful sunscreen can't always afford enough protection, it is necessary to enhance the defensive power of skin against UV. Recently, constitutive photomorphogenic protein-1 (COP1) has shown to contribute to the regulation of UVB response of keratinocytes. In this study, we represent that COP1 and its associated protein, de-etiolated 1 (DET1), might participate in photoaging process in human skin as Arabidopsis COP1 does sun-protective function in plants. After UVB irradiation, the decrease of COP1 and DET1 mRNA expression was followed by the increase of c-Jun total protein. Moreover, transfection with DNA vectors expressing COP1 and DET1 down-regulated the c-Jun total protein. We found that Zanthoxylum piperitum extract (ZE) up-regulated the expression of COP1 and DET1 on human keratinocytes, and inhibited the expression of MMP1 which is one of the genes regulated by c-Jun signal. In addition, ZE has been reported to stimulate PPAR-${\alpha}$ and strengthen the skin barrier. We found that ZE decreased the UVB-induced IL-6 and IL-8 in NHEK cells. In human study, ZE protected skin against UV-B induced erythema and erythema-induced pigmentation. These results indicate that ZE could be useful for the protection against the adverse effects of UV irradiation through various mechanisms.

Chatbot Design Method Using Hybrid Word Vector Expression Model Based on Real Telemarketing Data

  • Zhang, Jie;Zhang, Jianing;Ma, Shuhao;Yang, Jie;Gui, Guan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.14 no.4
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    • pp.1400-1418
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    • 2020
  • In the development of commercial promotion, chatbot is known as one of significant skill by application of natural language processing (NLP). Conventional design methods are using bag-of-words model (BOW) alone based on Google database and other online corpus. For one thing, in the bag-of-words model, the vectors are Irrelevant to one another. Even though this method is friendly to discrete features, it is not conducive to the machine to understand continuous statements due to the loss of the connection between words in the encoded word vector. For other thing, existing methods are used to test in state-of-the-art online corpus but it is hard to apply in real applications such as telemarketing data. In this paper, we propose an improved chatbot design way using hybrid bag-of-words model and skip-gram model based on the real telemarketing data. Specifically, we first collect the real data in the telemarketing field and perform data cleaning and data classification on the constructed corpus. Second, the word representation is adopted hybrid bag-of-words model and skip-gram model. The skip-gram model maps synonyms in the vicinity of vector space. The correlation between words is expressed, so the amount of information contained in the word vector is increased, making up for the shortcomings caused by using bag-of-words model alone. Third, we use the term frequency-inverse document frequency (TF-IDF) weighting method to improve the weight of key words, then output the final word expression. At last, the answer is produced using hybrid retrieval model and generate model. The retrieval model can accurately answer questions in the field. The generate model can supplement the question of answering the open domain, in which the answer to the final reply is completed by long-short term memory (LSTM) training and prediction. Experimental results show which the hybrid word vector expression model can improve the accuracy of the response and the whole system can communicate with humans.

Inhibitory Mechanism on NF-${\kappa}B$ Transactivation by Dexamethasone in Pulmonary Epithelial Cells (폐상피세포에서 Dexamethasone에 의한 NF-${\kappa}B$ Transactivation 억제기전에 관한 연구)

  • Lee, Kye-Young;Kim, Yoon-Seop;Ko, Mi-Hye;Park, Jae-Seok;Jee, Young-Koo;Kim, Keun-Youl;Kwak, Sahng-June
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.5
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    • pp.682-698
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    • 2000
  • Glucocorticoid receptor (GR) functions as a suppressor of inflammation by inhibiting the expression of many cytokine genes activated by NF-${\kappa}B$. The goal of this study is to investigate the mechanism by which GR repress NF-${\kappa}B$ activation in lung epithelial cells. We used A549 and BEAS-2B lung epithelia! cell lines. Using Ig$G{\kappa}$-NF-${\kappa}B$ luciferase reporter gene construct, we found that dexamethasone significantly suppressed TNF-$\alpha$-induced NF-${\kappa}B$ activation and the overexpression of GR showed dose-dependent reduction of TNF-$\alpha$-induced NF-${\kappa}B$ activity in both cell lines. However, DNA binding of NF-${\kappa}B$ induced by TNF-$\alpha$ in electromobility shift assay was not inhibited by dexamethasone. Super shift assay with anti-p65 antibody demonstrated the existence of p65 in NF-${\kappa}B$ complex induced by $\alpha$ Western blot showed that $I{\kappa}B{\alpha}$ degradation induced by TNF-$\alpha$ was not affected by dexamethasone and $I{\kappa}B{\kappa}$ was not induced by dexamethasone, neither. To evaluate p65 specific transactivation, we adopted co-transfection study of Gal4-p65TA1 or TA2 fusion protein expression system together with 5xGal4-luciferase vector. Co-transfection of GR with Gal4-p65TA1 or TA2 repressed luciferase activity profoundly to the level of 10-20% of p65TA1- or TA2-induced transcriptional activity. And this transrepressional effect was abolished by co-transfection of CBP of SRC-1 expression vectors. These results suggest that GR-mediated transrepression of NF-${\kappa}B$ in lung epithelial cells is through competing for binding to limiting amounts of transcriptional coactivators, CBP or SRC-1.

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Prognostic Significance of CD44v6/v7 in Acute Promyelocytic Leukemia

  • Chen, Ping;Huang, Hui-Fang;Lu, Rong;Wu, Yong;Chen, Yuan-Zhong
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.8
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    • pp.3791-3794
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    • 2012
  • CD44v, especially splice variants containing exon v6, has been shown to be related closely to development of different tumors. High levels of CD44v6/v7 have been reported to be associated with invasiveness and metastasis of many malignancies. The objective of this study was to detect expression of CD44v6-containing variants in patients with acute promyelocytic leukemia (APL) and evaluate the potential of CD44v6/v7 for risk stratification. Reverse transcription polymerase chain reaction (RT-PCR) followed by PCR product purification, ligation into T vectors and positive clone sequencing were used to detect CD44 v6-containing variant isoforms in 23 APL patients. Real-time quantitative PCR of the CD44v6/v7 gene was performed in patients with APL and in NB4 cells that were treated with all-trans retinoic acid (ATRA) or arsenic trioxide ($As_2O_3$). Sequencing results identified four isoforms (CD44v6/v7, CD44v6/v8/v10, CD44v6/v8/v9/v10, and CD44v6/v7/v8/v9/v10) in bone marrow mononuclear cells of 23 patients with APL. The level of CD44v6/v7 in high-risk cases was significantly higher than those with low-risk. Higher levels of CD44v6/v7 were found in three patients with central nervous system relapse than in other patients inthe same risk group. Furthermore, in contrast to ATRA, only $As_2O_3$ could significantly down-regulate CD44v6/v7 expression in NB4 cells. Our data suggest that CD44v6/v7 expression may be a prognostic indicator for APL.

Promoter Cloning of Human SETDB1 Gene Utilizing Bioinformatic Programs (생물정보 프로그램을 활용한 SETDB1 유전자 프로모터 클로닝)

  • Noh, Hee-Jung;Kim, Keun-Cheol
    • Journal of Life Science
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    • v.24 no.1
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    • pp.1-7
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    • 2014
  • Eukaryotic gene expression is an important process, which is initiated by several transcription factors and RNA polymerases that occupy the promoter region of genomic DNA. Although there are many experiments to identify the promoter region in a gene, it is time and labor consuming to finalize it. In this study, we utilized bioinformatic programs, including Ensembl, NCBI, and CpG plots, to identify the cloning promoter region in SETDB1 genomic DNA. We performed PCR amplification to obtain the SETDB1 promoter on an approximately 2 kb region upstream from the TSS named SETDB1-P1. The PCR product was ligated with TA cloning vectors, and we confirmed the insert size using restriction enzyme digestion. Sequentially, the insert was subcloned into a pGL3-luc vector to produce pGL3-SETDB1- P1-luc and then confirmed by DNA sequencing. We also obtained a fragmented PCR product called P2 and P3 and performed a luciferase assay using pGL3-SETDB1-P1-luc transfection. We found that several anticancer drugs, including taxol, 4-FU, and doxorubicin, decreased the promoter activity of SETDB1. We obtained consistent data on the regulation of SETDB1 gene expression after anticancer drug treatment using Western blot analysis and RT-PCR. Our results suggest that promoter cloning of the human SETDB1 gene utilizing bioinformatics is a very useful and timesaving approach to study gene expression.

Effects of the cis-Acting Element in the 3' End of Porcine $\beta$-Casein Gene on the Expression in Mammary Epithelial Cells (돼지 $\beta$-Casein 유전자의 3' 말단 부위의 cis-Acting Element가 유선 상피 세포내의 발현에 미치는 영향)

  • Lee, Hwi-Cheul;Kim, Byoung-Ju;Byun, Sung-June;Lee, Seung-Hoon;Kim, Min-Ji;Chung, Hee Kyoung;Lee, Hyun-Gi;Jo, Su-Jin;Chang, Won-Kyong;Park, Jin-Ki;Lee, Poong-Yeon
    • Reproductive and Developmental Biology
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    • v.32 no.3
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    • pp.153-158
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    • 2008
  • Tissue-specific and temporal regulation of milk protein gene expression is advantageous when creating transgenic animal that produces foreign protein into milk. Gene expression, i.e. protein production, is regulated not only by promoter strength but also mRNA stability. Especially, poly A tail length by polyadenylation affects in vivo and in vitro mRNA stability and translation efficiency of the target gene. In the present study, nucleotide sequence of 3'-UTR was analyzed to evaluate the effects of mRNA stability on the target gene expression. Based on the poly A signal of 3' -untranslated region (UTR), nucleotide sequences of putative cytoplasmic polyadenylation elements (CPEs) and downstream elements (DSEs: U-rich, G-rich, GU-rich) were analyzed and used to construct 15 luciferase reporter vectors. Each vector was transfected to HC11 and porcine mammary gland cell (PMGC) and measured for dual luciferase expression levels after 48 hours of incubation. Luciferase expression was significantly higher in construct #6 (with CPE 2, 3 and DSE 1 of exon 9) and #11 (with CPE 2, 3 and DSE 1, 2 and 3 of exon 9) than construct #1 in the PMGC. These results suggest that expression of target genes in PMGC may be effectively expressed by using the construct #6 and #11 on production of transgenic pig.