• 제목/요약/키워드: in vitro suppression

검색결과 370건 처리시간 0.028초

효율적인 비천연 아민노산 도입을 위한 효모균 타이로신-tRNA 합성효소와 대장균 시작 tRNA 변이체의 엠버써프레션 활성증가 (Improving amber suppression activity of an orthogonal pair of Saccharomyces cerevisiae tyrosyl-tRNA synthetase and a variant of E. coli initiator tRNA, fMam tRNACUA, for the efficient incorporation of unnatural amino acids)

  • 이욥테칼린;오주연;박중찬
    • 미생물학회지
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    • 제54권4호
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    • pp.420-427
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    • 2018
  • 효모균 타이로실-tRNA 합성효소(Sc YRS)와 엠버 멈춤코돈을 인식하는 대장균 시작tRNA 변이체(fMam $tRNA_{CUA}$)쌍은 대장균에서 단백질 생합성시 원하는 특정 위치에 비천연아미노산을 도입하는데 활용된다. Sc YRS/fMam $tRNA_{CUA}$쌍의 엠버써프레션 활성을 높이기 위해 fMam $tRNA_{CUA}$의 첫번째 안티코돈 염기를 인식하는 Sc YRS의 320번, 321번 아미노산 잔기를 암호화하는 염기서열을 무작위로 돌연변이시킨 라이브러리를 제작하였다. 엠버써프레션에 의한 클로람페니콜 저항성을 이용해 라이브러리를 탐색하여 활성이 향상된 2개의 돌연변이주를 선별하였다. 이들의 클로람페니콜 저항성 성장의 $IC_{50}$값은 야생형 YRS보다 1.7~2.3배 높았으며, in vivo 엠버써프레션 활성을 비교한 결과 3~6.5배의 활성 증가가 나타났다. 높은 활성을 보인 mYRS-3 (P320A/D321A) 단백질의 fMam $tRNA_{CUA}$에 대한 in vitro aminoacylation kinetics 분석은 야생형보다 약 7배 높은 효소활성을 보였으며, 이는 주로 기질인 fMam $tRNA_{CUA}$에 대한 결합 친화도가 증가하여 나타났다. 이런 접근법을 이용하여 다양한 종류의 비천연 아미노산 도입에 활용되는 aminoacyl-tRNA 합성효소의 엠버써프레션 활성을 높임으로써 엠버 멈춤코돈을 이용한 비천연 아미노산 도입 효율성을 높일 수 있을 것이다.

마우스 EAE, GVHD 질환에서 CTLA4Ig 융합단백의 면역치료 효과 (Immunotherapeutic Effects of CTLA4Ig Fusion Protein on Murine EAE and GVHD)

  • 장성옥;홍수종;조훈식;정용훈
    • IMMUNE NETWORK
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    • 제3권4호
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    • pp.302-309
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    • 2003
  • Background: CTLA4 (CD152), which is expressed on the surface of T cells following activation, has a much higher affinity for B7 molecules comparing to CD28, and is a negative regulator of T cell activation. In contrast to stimulating and agonistic capabilities of monoclonal antibodies specific to CTLA-4, CTLA4Ig fusion protein appears to act as CD28 antagonist and inhibits in vitro and in vivo T cell priming in variety of immunological conditions. We've set out to confirm whether inhibition of the CD28-B7 costimulatory response using a soluble form of human CTLA4Ig fusion protein would lead to persistent inhibition of alloreactive T cell activation. Methods: We have used CHO-$dhfr^-$ cell-line to produce CTLA4Ig fusion protein. After serum free culture of transfected cell line we purified this recombinant molecule by using protein A column. To confirm characterization of fusion protein, we carried out a series of Western blot, SDS-PAGE and silver staining analyses. We have also investigated the efficacy of CTLA4Ig in vitro such as mixed lymphocyte reaction (MLR) & cytotoxic T lymphocyte (CTL) response and in vivo such as experimental autoimmune encephalomyelitis (EAE), graft versus host disease (GVHD) and skin-graft whether this fusion protein could inhibit alloreactive T cell activation and lead to immunosuppression of activated T cell. Results: In vitro assay, CTLA4Ig fusion protein inhibited immune response in T cell-specific manner: 1) Human CTLA4Ig inhibited allogeneic stimulation in murine MLR; 2) CTLA4Ig prevented the specific killing activity of CTL. In vivo assay, human CTLA4Ig revealed the capacities to induce alloantigen-specific hyporesponsiveness in mouse model: 1) GVHD was efficiently blocked by dose-dependent manner; 2) Clinical score of EAE was significantly decreased compared to nomal control; 3) The time of skin-graft rejection was not different between CTLA4Ig treated and control group. Conclusion: Human CTLA4Ig suppress the T cell-mediated immune response and efficiently inhibit the EAE, GVHD in mouse model. The mechanism of T cell suppression by human CTLA4Ig fusion protein may be originated from the suppression of activity of cytotoxic T cell. Human CTLA4Ig could not suppress the rejection in mouse skin-graft, this finding suggests that other mechanism except the suppression of cytotoxic T cell may exist on the suppression of graft rejection.

Glycolytic and oxidative muscles under acute glucose supplementation differ in their metabolic responses to fatty acyl-CoA synthetase gene suppression

  • Jung, Yun Hee;Bu, So Young
    • Journal of Nutrition and Health
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    • 제55권1호
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    • pp.70-84
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    • 2022
  • Purpose: Skeletal muscles display significant heterogeneity in metabolic responses, owing to the composition of metabolically distinct fiber types. Recently, numerous studies have reported that in skeletal muscles, suppression of genes related to fatty acid channeling alters the triacylglycerol (TAG) synthesis and switches the energy substrates. However, such responses may differ, depending on the type of muscle fiber. Hence, we conducted in vitro and animal studies to compare the metabolic responses of different types of skeletal muscle fibers to the deficiency of fatty acyl-CoA synthetase (Acsl)6, one of the main fatty acid-activating enzymes. Methods: Differentiated skeletal myotubes were transfected with selected Acsl6 short interfering RNA (siRNA), and C57BL/6J mice were subjected to siRNA to induce Acsl6 deficiency. TAG accumulation and expression levels of insulin signaling proteins in response to acute glucose supplementation were measured in immortalized cell-based skeletal myotubes, oxidative muscles (OM), and glycolytic muscles (GM) derived from the animals. Results: Under conditions of high glucose supplementation, suppression of the Acsl6 gene resulted in decreased TAG and glycogen synthesis in the C2C12 skeletal myotubes. The expression of Glut4, a glucose transporter, was similarly downregulated. In the animal study, the level of TAG accumulation in OM was higher than levels determined in GM. However, a similar decrease in TAG accumulation was obtained in the two muscle types in response to Acsl6 suppression. Moreover, Acsl6 suppression enhanced the phosphorylation of insulin signaling proteins (Foxo-1, mTORc-1) only in GM, while no such changes were observed in OM. In addition, the induction ratio of phosphorylated proteins in response to glucose or Acsl6 suppression was significantly higher in GM than in OM. Conclusion: The results of this study demonstrate that Acsl6 differentially regulates the energy metabolism of skeletal muscles in response to glucose supplementation, thereby indicating that the fiber type or fiber composition of mixed muscles may skew the results of metabolic studies.

Mouse cell에서 선방활명음(仙方活命飮)의 항산화작용과 항알러지 및 항염증 효과 (The Effects of Sunbanghwalmyung-eum Extract on Anti-oxidant, Anti-allergic and Anti-inflammatory ability in mouse cell)

  • 박민철;홍승욱
    • 한방안이비인후피부과학회지
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    • 제21권2호
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    • pp.46-53
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    • 2008
  • Background and Objectives : The aim of this study was to investigate the anti-oxidant, anti-allergic and anti-inflammatory ability of the Taglisodog-eum(SHE) extract on the RAW 264.7 and EL4 cells Materials and Methods : Three types of experiments were implemented for this study: first, the experiment to study the anti-oxidant effect of SHE using Riboflavin; second, in vitro experiment to investigate the inhibition of Th 2 cell differentiation by SHE using EL4 cells (IL-4 mRNA expression); third, the suppression of $NF-{\kappa}B$ activation using RAW 264.7 cells (iNOS and COX-2 mRNA expression). Results : The anti-oxidant ability of SHE were dose-dependantly increased. From in vitro, the LPS-induced iNOS and COX-2 mRNA expression were dose-dependantly decreased in the RAW264.7 cells treated with SHE and the PMA-induced IL-4 mRNA expression were also dose-dependantly decreased in EL4 cells. $NF-{\kappa}B$ activation was suppressed, and iNOS & COX-2 production were inhibited by SHE Conclusion : The results suggest that SHE has dose-dependant anti-oxidant ability, and has anti-allergic and anti-inflammatory effects through the suppression of $NF-{\kappa}B$ activation and the inhibition of Th 2 cell differentiation.

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Preparation Method for Escherichia coliS30 Extracts Completely Dependent upon tRNA Addition to Catalyze Cell-free Protein Synthesis

  • Ahn, Jin-Ho;Hwang, Mi-Yeon;Oh, In-Seok;Park, Kyung-Moon;Hahn, Geun-Hee;Choi, Cha-Yong;Kim, Dong-Myung
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제11권5호
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    • pp.420-424
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    • 2006
  • A simple method for depleting E. coliS30 extracts of endogenous tRNA has been developed. An $ethanolamine-Sepharose^{(R)}$ column equilibrated with water selectively captured the tRNA molecules in E. coli S30 extracts. As a result, S30 extracts filtered through this column became completely dependent upon the addition of exogenous tRNA to mediate cell-free protein synthesis reactions. We anticipate that the procedures developed and described will be particularly useful for in vitro suppression reaction studies designed to introduce unnatural amino acids into protein molecules.

건강 열수추출액이 Cyclophosphamide에 의해 유도된 면역억제조절에 미치는 영향 (Immunomodulatory Effect of Aqueous Extracted Zingiberis Rhizoma on Cyclophosphamide - Induced Immune Suppression)

  • 이영선;이금홍;권영규;박종현;신상우
    • 동의생리병리학회지
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    • 제21권2호
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    • pp.485-490
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    • 2007
  • Zingiberis rhizoma(ZB) has been used to treat a various condition and disease in many traditional preparation. The present study was conducted to investigate the immunomodulatory effect on cyclophosphamide(CY)-induced immunotoxicity of aqueous-extracted ZB(ZBE) using in vitro and in vivo experiment. In vitro experiment, the mouse spleen cells proliferation and nitric oxide(NO) production in RAW 264.7 mouse macrophage cells were investigated. ZBE enhanced mitogenic activity in mouse spleen cells. The suppression of CY-induced mouse speen cell proliferation was significantly restored by ZBE treatment. ZBE inhibited NO production, iNOS mRNA and protein levels in LPS-stimulated RAW 264.7 cells. In vivo experiment, ZBE was orally administrated(single dose of 150mg/kg for 12 days) and CY i.p(150mg/kg) injected to SD rats. In CY alone injected group, body weights and spleen weights, and a various hematological parameters were reduced when compared with control group, whereas those values were increased by concomitant treatment of CY and ZBE when compared with CY alone injected group. These results indicated that ZBE can modulate CY-induced immune suppression through immune cell proliferation, the regulation of NO production and the inhibition of CY-induced immunotoxicity.

Comparison of Gene Expression between Cumulus Oocyte Complexes and Naked Oocytes by Suppression Subtractive Hybridization in Swine

  • Xiang, Zhi Feng;Zhang, Jin Zhou;Li, Xue Bin;Xie, Hong Bin;Wang, Qing Hua
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권1호
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    • pp.17-24
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    • 2010
  • In the antral follicle phase, several layers of cumulus cells surround the oocyte and play an important support and regulation role in oocyte development and maturation via intercellular communications and interactions between oocytes and cumulus cells. However, information on stage specific gene expression in swine during the phase is not well understood. To investigate the function of cumulus cells during in vitro maturation of porcine oocytes and gene expression, suppression subtractive hybridization (SSH) was performed to screen genes that were differentially expressed between cumulus-oocyte complexes (COCs) and naked oocytes (NOs). Utilizing mRNAs from in vitro maturation oocytes, a SSH cDNA library from COCs as the tester and NOs as the driver was constructed. The SSH cDNA library was then screened using dot blot analysis. Results showed that a total of 70 clones randomly selected from the library were differentially expressed. Among these, 41 exhibited high homology to known genes and 11 were novel expressed sequences tags (ESTs). Four differentially expressed genes, including bfgf, sprouty 2, egr and btc, were further studied by real time quantitative PCR; results confirmed an increased expression of respective mRNA in COCs compared with NOs, which suggests that these factors may play an important role in oocyte development and maturation.

Factors influencing serum progesterone level on triggering day in stimulated in vitro fertilization cycles

  • Park, Ju Hee;Jee, Byung Chul;Kim, Seok Hyun
    • Clinical and Experimental Reproductive Medicine
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    • 제42권2호
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    • pp.67-71
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    • 2015
  • Objective: Elevated serum progesterone (P) levels on triggering day have been known to affect the pregnancy rate of in vitro fertilization (IVF). This study aimed to identify the possible factors influencing serum P levels on triggering day in stimulated IVF cycles. Methods: Three hundred and thirty consecutive fresh IVF cycles were included in the study. All cycles were first attempts and were performed in a single infertility center. The indications for IVF were male factor infertility (n=114), ovulatory infertility (n=84), endometriosis (n=61), tubal infertility (n=59), unexplained infertility (n=41), and uterine factor infertility (n=39). A luteal long protocol of a gonadotropin-releasing hormone (GnRH) agonist (n=184) or a GnRH antagonist protocol (n=146) was used for pituitary suppression. Ovarian sensitivity was defined as the serum estradiol level on triggering day per 500 IU of administered gonadotropins (OS[a]) or the retrieved oocyte number per 500 IU of administered gonadotropins (OS[b]). Results: Univariate analysis revealed that the serum P level on triggering day was associated with the serum estradiol level on triggering day (r=0.379, p<0.001), the number of follicles ${\geq}14mm$ (r=0.247, p<0.001), the number of retrieved oocytes (r=0.384, p<0.001), and ovarian sensitivity (OS[a]: r=0.245, p<0.001; OS[b]: r=0.170, p=0.002). The woman's age, body mass index, antral follicle count, and basal serum follicle stimulating hormone and estradiol levels were not associated with serum P level on triggering day. The serum P level on triggering day did not show significant variation depending on the type or cause of infertility, pituitary suppression protocol, or the type of gonadotropins used. Conclusion: The serum P level on triggering day was closely related to the response to ovarian stimulation.

밤속껍질에서 기능성 음료의 개발(II) -밤차, 현미녹차 및 결명자차가 생체기능활성화에 미치는 효과- (The Development of Functional Beverage from the Inner Skin of the Chestnut Castanea crenata ( II ) -Physiological Effects of Chestnut Inner Skin Tea, Brown Rice-preen Tea and Cassia tora Tea in Mouse and Rat-)

  • 전병관;정현우;이종률;지준명
    • 한국식품영양학회지
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    • 제13권5호
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    • pp.411-418
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    • 2000
  • 결명자차, 녹차 및 밤차가 인체의 생체기능활성화에 미치는 영향을 알아보기 위하여 국소뇌혈류량 및 혈압, in vitro상에서의 면역세포의 활성화, 그리고 암세포가 이식된 동물에서의 면역세포 활성화와 암세포의 증식억제 효과를 관찰한 결과 다음과 같은 결론을 얻었다. 1. 단당류는 현미녹차와 결명자차에는 glucose, ga-lactose등이 들어 있으나 밤차에는 glucose, gal-actose, mannose가 들어 있다. 2. 아미노산은 현미녹차, 밤차, 결명자차 순으로 들어 있다. 3. 카페인은 현미녹차에는 들어 있으나 밤차와 결명자차에는 들어 있지 않았다. 4. 결명자 차는 국소뇌혈류량을 증가시킨 반면 밤차는 감소시켰다. 5. 녹차는 혈압을 증가시켰다. 6. 밤차는 in vitro 상에서 흉선세포와 비장세포의 증식을 유의성있게 증가시켰다. 7. 결명자차와 녹차는 in bitro 상에서 흉선세포의 증식을 감소시켰다. 8. 결명자차와 녹차는 L1210세포가 이식된 동물의 흉선세포 증식을 감소시켰다. 9. 밤차는 L1210세포가 이식된 동물의 비장세포 증식을 촉진시켰다. 10. 밤차와 결명자차는 L1210세포가 이식된 동물의 암세포 증식을 억제하였다.

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