• Reproductive and Developmental Biology
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• 제37권3호
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• pp.109-115
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• 2013

Until recently the most popular tetracycline-inducible gene expression system has been the one developed by Gossen and Bujard. In this study, we tested the latest version of same system and the results are summarized as follows: Compared with previous one, the difference of new system are minor changes of nucleotide sequences in transactivator and tetracycline response element (TRE) regions. Sensitivity to the doxycycline (a tetracycline derivative) was improved. Leakiness of GFP marker gene expression in non-inducible condition was significantly decreased. Higher expression of the marker gene was observed when the cells were fed with doxycycline-containing medium. Optimal insertion site of woodchuck posttranscriptional regulatory element (WPRE) sequence which was known to increase gene expression was different depending on the origin of cells. In chicken embryonic fibroblast, location of WPRE sequence at 3' end of TRE resulted in the highest GFP expression. In bovine embryonic fibroblasts, 3' end of transactivator was the best site for the GFP expression.

• International Journal of Oral Biology
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• 제34권2호
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• pp.105-113
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• 2009

Dentin, a major component of teeth, is formed by odontoblasts which produce the dentin matrix beneath the dental epithelium and induce the mineralization of dentin. To date, the biochemical properties of dentin matrix proteins have been well characterized, but upstream regulators of these proteins are not yet well known. Recently in this regard, several transcription factors have been identified as potential regulators of matrix proteins. Most transcription factors are generally involved in diverse biological processes and it is essential to identify those that are odontoblast-specific transactivators to further understand the process of dentin formation. We thus analyzed the expression pattern of dentin matrix proteins and the activities of established transactivators containing a Cre-locus. Expression analyses using in situ hybridization showed that dentin matrix proteins are sequentially expressed in differentiating odontoblasts, including type-I collagen, Dmp-1 and Dspp. The activities of the transactivators were evaluated using ${\beta}$-galactosidase following the generation of double transgenic mice with each transactivator and the ROSA26R reporter line. The ${\beta}$-galactosidase activity of each transactivator paralled the expression of the matrix proteins. These results thus showed that these transactivators could be utilized for odontoblastspecific conditional gene targeting. In addition, time- and tissue-specific conditional gene targeting might also be achieved using a combination of these transactivators. Odontoblast-specific conditional gene targeting with these transactivators will likely also provide new insights into the molecular mechanisms underlying dentin formation.

• IMMUNE NETWORK
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• 제8권2호
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• pp.39-45
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• 2008

Background: Down regulation of major histocompatibility complex class II transactivator (CIITA) has been identified as a major factor of immunosuppression in sepsis and the level of CIITA expression inversely correlates with the degree of severity. However, it has not been fully elucidated whether the lower expression of CIITA is a cause of disease process or a just associated sign. Here we determined whether the CIITA deficiency decreased survival rate using murine sepsis model. Methods: Major histocompatibility complex class II (MHC-II) deficient, CIITA deficient and wild type B6 mice were subjected to cecal ligation puncture (CLP) surgery. CIITA and recombination activation gene (RAG)-1 double deficient mice were generated to test the role of lymphocytes in CIITA-associated sepsis progression. Results: Sepsis mortality was enhanced in CIITA deficient mice, not by impaired bacterial clearance resulted from CD4 T cell depletion, but hyper-inflammatory response such as excessive release of a pro-inflammatory cytokine, high-mobility group box 1 (HMGB1). Conclusion: Our results demonstrate that CIITA deficiency affects the course of sepsis via the unexpected function of CIITA, regulation of cytokine release.

• BMB Reports
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• 제41권8호
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• pp.575-580
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• 2008

Thymocyte-specific transcriptional regulatory systems can be used to better understand the relationship between transcription and V(D)J recombination during early T cell development. In this study, we generated transgenic mice expressing the transactivator Gal4-VP16 or the Gal4 DNA binding domain (Gal4-DBD) under the control of the lck proximal promoter, which is only active in immature thymocytes. From these studies Gal4-VP16 and Gal4-DBD expression was shown to significantly alter thymic cellularity and differentiation without significantly changing the $CD3^+$ thymocyte distribution. Furthermore, the presence of Gal4-VP16 or Gal4-DBD in the transgenic thymocytes retarded the mobility of the Gal4 DNA binding motif as determined by a gel mobility shift assay, suggesting that the developmental alteration did not affect the functional property of the transgenic proteins. These results indicated that lck promoter-driven Gal4-VP16 or Gal4-DBD expression did not affect $CD3^+$ mature thymocytes, thus this system can be applied to study transcriptional regulation of transresponder genes in bigenic mouse model thymocytes.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2001년도 International Symposium on Signal transduction in Toxicology
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• pp.41-83
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• 2001

Under low oxygen tension, cells increase the transcription of specific genes that are involved in angiogenesis, erythropoiesis and glycolysis. Hypoxia-induced gene expression primarily depends on the stabilization of the subunit of Hypoxia-Inducible Factor-1 (HIF-1), which acts as a heterodimeric transactivator.(omitted)

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1103-1108
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• 2009

The human immunodeficiency virus (HIV)-l protein Tat acts as a transcription transactivator that stimulates expression of the infected viral genome. It is released from infected cells and can similarly affect neighboring cells. The nucleocapsid is an important protein that has a related significant role in early mRNA expression, and which contributes to the rapid viral replication that occurs during HIV-1 infection. To investigate the interaction between the Tat and nucleocapsid proteins, we utilized cDNA micro arrays using pTat and flag NC cotransfection in HEK 293T cells and reverse transcription-polymerase chain reaction to validate the micro array data. Four upregulated genes and nine downregulated genes were selected as candidate genes. Gene ontology analysis was conducted to define the biological process of the input genes. A proteomic approach using PathwayStudio determined the relationship between Tat and nucleocapsid; two automatically built pathways represented the interactions between the upregulated and downregulated genes. The results indicate that the up- and downregulated genes regulate HIV-1 replication and proliferation, and viral entry.

• 대한화장품학회:학술대회논문집
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• 대한화장품학회 2003년도 IFSCC Conference Proceeding Book I
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• pp.630-644
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• 2003

A human Cu, Zn-superoxide dismutase (Cu, Zn-SOD) was fused with a Tat PTD of HIV-1 to produce a novel anti-aging ingredient, Tat-SOD for cosmeceuticals. Test of stability and evaluation of transduction efficacy and enzymatic activity suggest Tat-SOD is an effective active ingredient for anti-aging treatment.

• 한국식품영양학회지
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• 제10권1호
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• pp.74-81
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• 1997

본 연구에서는 phenol이 암 예방에 어떻게 영향을 미치는가를 규명하고자 시도하였으며 phenol이 TBARS에 미치는 영향, TBRAS와 암과의 상관관계 규명에 촛점을 맞추었다. 식이 phenol이 조직산화와 종양 발생(tumor onset)에 미치는 영향을 측정하기 위하여 영양적으로 우수한 amino acid-based diet와 transgenic mouse model을 이용한 protocol을 사용하였다. Mice는 human lymphotropic virus(type-1) transactivator(texl) gene을 carry하며 동시에 종양이 외불 나타난다. 25마리의 transgenic mice를 대조군, 2, 4, 8 mmol catechin/kg diet 군 및 wine soled 군으로 구분하였으며, 대조군은 catechin과 wine solid를 전혀 주지 않았으며, wine solid 군은 redwine 750 ml/kg을 주었다. Mice는 매일 관찰하여 맨 처음 종양이 발현하는 날짜를 기록하였다. Catechin과 wine solid를 섭취한 mice에서 종양이 발현하는 시기가 대조군보다 유의적으로 낮았으며 더욱이 4 mmol catechin diet 군과 8 mmol catechin diet 군에서는 실험기간동안 각각 1마리에서 종양이 발견되지 않았다. Catechin과 wine solid를 섭취한 mice의 뇌조직과 비장의 TBARS 수준은 대조군 mice의 동일한 조직과 비교하였을 때 유의적으로 낮았다. 또한 조직의 TBARS 수준은 종양 발생과 유의적으로 상관관계가 있었다. 본 연구의 결과는 phenol의 종류에 상관없이 식이 phenol에 조직의 항산화(산화억제)를 통해 암 예방(cancer prevention)에 영향을 미친다는 것을 제시해준다.

• IMMUNE NETWORK
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• 제2권3호
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• pp.150-157
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• 2002

Background: Although Tat plays a role as a potent transactivator in the viral gene expression from the Human Immunodeficiency Virus type 1 long terminal repeat (HIV-1 LTR), it does not function efficiently in rodent cells implying the absence of a human specific factor essential for Tat-medicated transactivation in rodent cells. In previous experiments, we demonstrated that one of chimeric forms of TAR (transacting responsive element) of HIV-1 LTR compensated the restriction in rodent cells. Methods: To characterize the nature of the compensation, we tested the effects of several upstream binding factors of HIV-1 LTR by simple substitution, and also examined the role of the configuration of the upstream binding factor(s) indirectly by constructing spacing mutants that contained insertions between Sp1 and TATA box on Tat-mediated transactivation. Results: Human Sp1 had no effect whereas its associated factors displayed differential effects in human and rodent cells. In addition, none of the spacing mutants tested overcame the restriction in rodent cells. Rather, when the secondary structure of the chimeric HIV-1 TAR construct was destroyed, the compensation in rodent cells was disappeared. Interestingly, the proper interaction between Sp1 and TATA box binding proteins, which is essential for Tat-dependent transcription, was dispensable in rodent cells. Conclusion: This result suggests that the human-specific Tat cofactor acts to allow Tat to interact effectively in a ribonucleoprotein complex that includes Tat, cellular factors, and TAR RNA, rather than be associated with the HIV-1 LTR upstream DNA binding factors.

• Journal of Microbiology and Biotechnology
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• 제27권10호
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• pp.1892-1895
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• 2017

IK can downregulate interferon-gamma-induced major histocompatibility complex (MHC) class II expression through the MHC class II transactivator, which suggests that IK can inhibit the interactions between immune cells. We delivered adeno-associated virus serotype 2 (AAV2) encoding the genes for truncated IK (tIK) or green fluorescent protein (GFP) to DBA1/J mice via intravenous injection. Seven weeks after injection, collagen-induced arthritis was induced in the AAV2-treated mice. AAV2-tIK injection reduced the severity of arthritis and the percentage of pathogenic Th17 cells compared with AAV2-GFP injection. These results suggest a novel gene therapy strategy for treatment of inflammatory arthritis.