• 제목/요약/키워드: Knockout

검색결과 384건 처리시간 0.03초

The Probiotic Lactobacillus Prevents Citrobacter rodentium-Induced Murine Colitis in a TLR2-Dependent Manner

  • Ryu, Seung-Hyun;Park, Jong-Hyung;Choi, Soo-Young;Jeon, Hee-Yeon;Park, Jin-Il;Kim, Jun-Young;Ham, Seung-Hoon;Choi, Yang-Kyu
    • Journal of Microbiology and Biotechnology
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    • 제26권7호
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    • pp.1333-1340
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    • 2016
  • The main objective of this study was to investigate whether Lactobacillus rhamnosus GG (LGG) ameliorated the effects of Citrobactor rodentium infection in Toll-like receptor 2 (TLR2) knockout (KO) and TLR4 KO mice, as well as in wild-type C57BL/6 (B6) mice. TLR2 KO, TLR4 KO, and B6 mice were divided into three groups per each strain. Each group had an uninfected control group (n = 5), C. rodentium-infected group (n = 8), and LGG-pretreated C. rodentium-infected group (n = 8). The survival rate of B6 mice infected with C. rodentium was higher when pretreated with LGG. Pretreatment with LGG ameliorated C. rodentium-induced mucosal hyperplasia in B6 and TLR4 KO mice. However, in C-rodentium-infected TLR2 KO mice, mucosal hyperplasia persisted, regardless of pretreatment with LGG. In addition, LGG-pretreated B6 and TLR4 KO mice showed a decrease in spleen weight and downregulation of tumor necrosis factor alpha, interferon gamma, and monocyte chemotactic protein 1 mRNA expression compared with the non-pretreated group. In contrast, such changes were not observed in TLR2 KO mice, regardless of pretreatment with LGG. From the above results, we conclude that pretreatment with LGG ameliorates C. rodentium-induced colitis in B6 and TLR4 KO mice, but not in TLR2 KO mice. Therefore, LGG protects mice from C. rodentium-induced colitis in a TLR2-dependent manner.

Emerging Genomics Technologies in Nutritional Sciences : Applications to Obesity and Hypertension Research

  • Moustaid-Moussa;Sumithra Urs;Kim, Suyeon;Heo, Young-Ran
    • 한국영양학회:학술대회논문집
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    • 한국영양학회 2002년도 춘계 심포지움초록
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    • pp.598-603
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    • 2002
  • While the sequencing of several genomes was underway, several advanced techniques in genetics, molecular biology and protein chemistry emerged. Within the notritional sciences, while the focus on nutrition education, epidemiology and public health aspects remains essential; it is crucial to incorporate the new advances in gene and protein discovery in nutritional studies. Nutrition is a discipline that has always integrated social, biochemical and physiological sciences from the studies at the molecule level to studies at the population level. for this reason, nutritionists are in a prime position to readily incorporate the current genomics approaches in nutrition research. All the available analytical techniques can and should be used in modem nutritional sciences. These include genetics, genomics, proteomics and metabolomics which also require integration and use of bioinformatics and computational methods for data analysis and management. These applications will be briefly reviewed with a primary focus on what the genomics and genetics approaches offer to nutritionists. We will use one of our research focus areas to illustrate uses of some of these applications in obesity-hypertension research. Our central hypothesis is that adipose tissue is an endocrine organ that plays a major role in obesity and related hypertension. We are primarily studying the renin angiotensin system (RAS). We provide evidence from our own studies and others for the paracrine as well as endocrine role of adipocyte-derived angiotensin II in adipocyte gene expression, adiposity and blood pressure regulation. Both cell culture studies as well as knockout and transgenic mice models are used to test our hypothesis. Genomics and proteomics technologies are currently developed to complement our physiological and molecular studies on the RAS and for a fine analysis of this system and its function in health and disease.

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Enhancement of Antigen-specific Antibody and $CD8^+$ T Cell Responses by Codelivery of IL-12-encapsulated Microspheres in Protein and Peptide Vaccination

  • Park, Su-Hyung;Chang, Jun;Yang, Se-Hwan;Kim, Hye-Ju;Kwak, Hyun-Hee;Kim, Byong-Moon;Lee, Sung-Hee;Sung, Young-Chul
    • IMMUNE NETWORK
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    • 제7권4호
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    • pp.186-196
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    • 2007
  • Background: Although IL-12 has been widely accepted to playa central role in the control of pathogen infection, the use of recombinant IL-12 (rIL-12) as a vaccine adjuvant has been known to be ineffective because of its rapid clearance in the body. Methods: To investigate the effect of sustained release of IL-12 in vivo in the peptide and protein vaccination models, rIL-12 was encapsulated into poly ($A_{DL}$-lactic-co-glycolic acid) (PLGA). Results: We found that codelivery of IL-12-encapsulated microspheres (IL-12EM) could dramatically increase not only antibody responses, but also antigen-specific $CD4^+\;and\;CD8^+$ T cell responses. Enhanced immune responses were shown to be correlated with protective immunity against influenza and respiratory syncytial virus (RSV) virus challenge. Interestingly, the enhancement of $CD8^+$ T cell response was not detectable when $CD4^+$ T cell knockout mice were subjected to vaccination, indicating that the enhancement of the $CD8^+$ T cell response by IL-12EM is dependent on $CD4^+$ T cell "help". Conclusion: Thus, IL-12EM could be applied as an adjuvant of protein and peptide vaccines to enhance protective immunity against virus infection.

Next-generation gene targeting in the mouse for functional genomics

  • Gondo, Yoichi;Fukumura, Ryutaro;Murata, Takuya;Makino, Shigeru
    • BMB Reports
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    • 제42권6호
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    • pp.315-323
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    • 2009
  • In order to elucidate ultimate biological function of the genome, the model animal system carrying mutations is indispensable. Recently, large-scale mutagenesis projects have been launched in various species. Especially, the mouse is considered to be an ideal model to human because it is a mammalian species accompanied with well-established genetic as well as embryonic technologies. In 1990', large-scale mouse mutagenesis projects firstly initiated with a potent chemical mutagen, N-ethyl-N-nitrosourea (ENU) by the phenotype-driven approach or forward genetics. The knockout mouse mutagenesis projects with trapping/conditional mutagenesis have then followed as Phase II since 2006 by the gene-driven approach or reverse genetics. Recently, the next-generation gene targeting system has also become available to the research community, which allows us to establish and analyze mutant mice carrying an allelic series of base substitutions in target genes as another reverse genetics. Overall trends in the large-scale mouse mutagenesis will be reviewed in this article particularly focusing on the new advancement of the next-generation gene targeting system. The drastic expansion of the mutant mouse resources altogether will enhance the systematic understanding of the life. The construction of the mutant mouse resources developed by the forward and reverse genetic mutagenesis is just the beginning of the annotation of mammalian genome. They provide basic infrastructure to understand the molecular mechanism of the gene and genome and will contribute to not only basic researches but also applied sciences such as human disease modelling, genomic medicine and personalized medicine.

Trehalose Metabolism: Gate to Stress Signaling and Seed Development in Plant\ulcorner

  • Chung, H-J;Kim, Y-S;Lee, E-J;Kim, J-S;Shin, Y-M;Cho, I-S;Jin, H-O;Cho, J-W;Chung, C-H
    • 식물조직배양학회지
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    • 제27권5호
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    • pp.415-421
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    • 2000
  • The disaccharide trehalose ($\alpha$-D-glucopyranosyl-$\alpha$-D-glucopyranoside) is found in variety of organ-isms that are able to withstand almost complete desiccation. In order to identify the function of trehalose in plants, we isolated Arabidopsis trehalase (AtTRE) gene that encodes the enzyme able to hydrolyze trehalose to glucose, and trehalose-6-phosphate synthase isolog, TPS3 gene by RT-PCR. The AtTRE had the substrate specificity to hydrolyze only trehalose, and a broad pH range of enzyme activity. The AtTRE promoter/GUS reporter gene was expressed in cotyledons, mature leaf tissues including guard cells, and developing siliques. The GUS expression driven by AtTPS3 promoter was significant in root tissues, and the level of GUS activity was much higher than that of the pBll 21 control seedlings. The knockout of AtTPS3 gene in Arabidopsis resulted in the retarded root development, whereas the overexpression of AtTPS3 increased the root elongation in the presence of sucrose in MS medium. Possible functions of AtTRE and AtTPS3 in plant will be discussed. In addition, ectopic expression of yeast TPS1 driven by the inducible promoters in tobacco and potato conferred the plants on the drought and freezing tolerances.

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Analysis of Gene Expression in Carcinogen-induced Acute Hepatotoxicity

  • Oh, Jung-Hwa;Park, Han-Jin;Lee, Eun-Hee;Heo, Sun-Hee;Cho, Jae-Woo;Kim, Yong-Bum;Yoon, Seok-Joo
    • Molecular & Cellular Toxicology
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    • 제5권1호
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    • pp.58-66
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    • 2009
  • The 2-year rodent carcinogenicity test involves long-term, repetitive dosing of animals that is both time consuming and expensive. Alternative approaches have been attempted using specific transgenic or knockout mice or toxicogenomics to predict carcinogenicity without conducting a 2-year rodent test. In addition, toxicogenomic analysis of carcinogen-treated animals could also enhance our understanding of molecular mechanisms and aid in the diagnosis of acute toxicity induced by carcinogens. Therefore, we investigated transcription profiles after administering the carcinogens 4,4-dimethylformamide (DMF) and 4-biphenylamine (ABP). BALB/c male mice were treated once with DMF (650 mg/kg i.p.) or ABP (120 mg/kg p.o.). Standard blood biochemistry and histological changes were observed. Gene expression profiles in the livers of mice treated with either vehicle or the carcinogens were analyzed using the Affymetrix $GeneChip^{(R)}$ assay. In all, 1,474 differentially expressed genes in DMF- or ABP-treated mice were identified as being either up- or down-regulated over 1.5-fold (P< 0.01), and these genes were analyzed using hierarchical clustering and Ingenuity Pathways Analysis. Of these, 107 genes were consistently regulated in both carcinogen-treated groups. Genes associated with cancer were upregulated (Por, S100a10, Tes, Ctcf, Ddx21, Eapp, Nel, and Pa2g4) or downregulated (Cbs and Gch1). Toxicological function analysis also identified genes involved in organ toxicity, including hepatotoxicity. These data may help to identify molecular markers for acute hepatotoxicity induced by carcinogens.

고속 ATM망을 위한 파장 분할 광교환기 구조 (Optical Switching Architectures using WDM for High-Speed ATM Networks)

  • 소원호;이청훈;김영선;김영천
    • 전자공학회논문지S
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    • 제35S권8호
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    • pp.12-20
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    • 1998
  • 전광 통신망(All-Optical Network)은 근거리와 원거리 통신망을 위한 차세대 광대역 통신먕이며 이를 위한 많은 광교환기들이 제안되고 있다. 특히 파장 분할 다중화 기법을 적용한 광교환기는 전광 통신망에서 B-ISDN 서비스를 위한 망의 투명성과 토폴로지 측면에서 많은 장점을 갖는다. 본 논문에서는 광링크 기반의 고속 ATM 망을 위한 두 종류의 넉아웃 광교환기 구조를 제안하였다. 제안된 구조는 파장 분할 다중화 기법을 이용하여 전광 영역에서 동작할 수 있도록 하였으며, 구조-Ⅰ과 구조-Ⅱ로 명명하였다. 각 구조는 구성 소자수 및 소자 종류에 의하여 다른 특성을 갖으며, 시스템의 성능과 복잡도도 많은 영향을 받는다. 제안된 두 종류의 광교환기 구조에 대한 해석적 분석과 시뮬레이션을 실시하였으며, 셀 손실률, 구성 소자의 복잡도, 요구되는 버퍼링 속도 관점에서 성능을 비교 분석하였다.

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선택적 iNOS 억제에 의한 골격근 재관류 손상의 감소 (Selective iNOS Inhibition Attenuates Skeletal Muscle Reperfusion Injury)

  • 박종웅;이광석;김성곤;박정호;왕준호;전우주;이정일
    • Archives of Reconstructive Microsurgery
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    • 제15권1호
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    • pp.1-9
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    • 2006
  • The purpose of this study is to determine the effects of selective inducible nitric oxide synthase (iNOS) inhibitor N-[3-aminomethyl]benzyl]acetamidine (l400W) on the reperfused cremaster muscle. The extracellular superoxide dismutase knockout ($EC-SOD^{-/-}$) mice was used to make the experimental window for ischemia-reperfusion injury. The muscle was exposed to 4.5 h of ischemia followed by 90 min of reperfusion and the mice received either 3 mg/kg of 1400W or the same amount of phosphate buffered saline (PBS) subcutaneously at 10 min before the start of reperfusion. The results showed that 1400W treatment markedly improved the recovery of the vessel diameter and blood flow in the reperfused cremaster muscle compared to that of PBS group. Histological examination showed reduced edema in the interstitium and muscle fiber, and reduced nitrotyrosine formation (a marker of total peroxinitrite ($ONOO^-$) in 1400W-treated muscle compared to PBS. Our results suggest that iNOS and $ONOO^-$ products are involved in skeletal muscle I/R injury. Reduced I/R injury by using selective inhibition of iNOS is perhaps via limiting cytotoxic $ONOO^-$ generation, a reaction product of nitric oxide (NO) and superoxide anion ($O_2^-$). Thus, inhibition of iNOS appears to be a good treatment strategy in reducing clinical I/R injury.

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Babesia bovis rap-1 및 B equi ema-1 intergenic 뉴클레오타이드에서 프로모터로 추정되는 위치 분석 (Analysis of putative promoter sites in Babesia bovis rap-l and B equi ema-l intergenic nucleotides)

  • 곽동미
    • 한국동물위생학회지
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    • 제27권1호
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    • pp.95-101
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    • 2004
  • Babesia bovis rap-1 and B equi ema-1 intergenic(IG) nucleotides were analyzed and compared for identifying putative promoter sites using computer programs. The reason to initiate this research was to determine if IG nucleotides of Babesia genes that are predicted to be involved in erythrocyte invasion have functions regulating gene transcription and translation, which can be applied to functional gene knockout. Four IG sequences used included BbIG5(B bovis rap-1 5' IG), BblG3(B bovis rap-1 3' IG), BeIG5(B equi ema-1 5' IG) and BeIG3(B equi ema-1 3' IG). BbIG5 contained a putative promoter at nucleotide 197-246 with a predicted TATA-box and a transcription start site. BbIG3 had a putative promoter at nucleotide 270-320 with two predicted TATA-boxes and a transcription start site. BeIG3 had a putative promoter at nucleotide 155-205 with a predicted TATA-box and a transcription start site. Putative promoter sites in these three sequences mentioned above were identified with score cutoff 0.8, which means detection of about 40% recognized promoters with 0.1-0.4% false positives. In contrast, BeIG5 had a putative promoter at nucleotide 163-213 with score cutoff 0.8, but neither TATA-box nor transcription start site were recognized. However, BeIG5 had a putative promoter at nucleotide 388-438 with a predicted TATA-box and a transcription start site when score cutoff was decreased to 0.18, which means detection of about 70% recognized promoters with 2.2-5.3% false positives. These sequences with putative promoters can be tested if they have functions regulating gene transcription and translation.

Multiple roles of phosphoinositide-specific phospholipase C isozymes

  • Suh, Pann-Ghill;Park, Jae-Il;Manzoli, Lucia;Cocco, Lucio;Peak, Joanna C.;Katan, Matilda;Fukami, Kiyoko;Kataoka, Tohru;Yun, Sang-Uk;Ryu, Sung-Ho
    • BMB Reports
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    • 제41권6호
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    • pp.415-434
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    • 2008
  • Phosphoinositide-specific phospholipase C is an effector molecule in the signal transduction process. It generates two second messengers, inositol-1,4,5-trisphosphate and diacylglycerol from phosphatidylinositol 4,5-bisphosphate. Currently, thirteen mammal PLC isozymes have been identified, and they are divided into six groups: PLC-$\beta$, -$\gamma$, -$\delta$, -$\varepsilon$, -$\zeta$ and -$\eta$. Sequence analysis studies demonstrated that each isozyme has more than one alternative splicing variant. PLC isozymes contain the X and Y domains that are responsible for catalytic activity. Several other domains including the PH domain, the C2 domain and EF hand motifs are involved in various biological functions of PLC isozymes as signaling proteins. The distribution of PLC isozymes is tissue and organ specific. Recent studies on isolated cells and knockout mice depleted of PLC isozymes have revealed their distinct phenotypes. Given the specificity in distribution and cellular localization, it is clear that each PLC isozyme bears a unique function in the modulation of physiological responses. In this review, we discuss the structural organization, enzymatic properties and molecular diversity of PLC splicing variants and study functional and physiological roles of each isozyme.