• 제목/요약/키워드: transmembrane protein

검색결과 284건 처리시간 0.021초

Induction of Human Hepatocellular Carcinoma HepG2 Cell Apoptosis by Naringin

  • Banjerdpongchai, Ratana;Wudtiwai, Benjawan;Khaw-on, Patompong
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권7호
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    • pp.3289-3294
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    • 2016
  • Naringin, a bioflavonoid found in Citrus seeds, inhibits proliferation of cancer cells. The objectives of this study were to investigate the mode and mechanism(s) of hepatocellular carcinoma HepG2 cell death induced by naringin. The cytotoxicity of naringin towards HepG2 cells proved dose-dependent, measured by MTT assay. Naringin-treated HepG2 cells underwent apoptosis also in a concentration related manner, determined by annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) employing flow cytometry. Mitochondrial transmembrane potential (MTP) measured using 3,3'-dihexyloxacarbocyanine iodide ($DiOC_6$) and flow cytometer was reduced concentration-dependently, which indicated influence on the mitochondrial signaling pathway. Caspase-3, -8 and -9 activities were enhanced as evidenced by colorimetric detection of para-nitroaniline tagged with a substrate for each caspase. Thus, the extrinsic and intrinsic pathways were linked in human naringin-treated HepG2 cell apoptosis. The expression levels of pro-apoptotic Bax and Bak proteins were increased whereas that of the anti-apoptotic Bcl-xL protein was decreased, confirming the involvement of the mitochondrial pathway by immunoblotting. There was an increased expression of truncated Bid (tBid), which indicated caspase-8 proteolysis activity in Bid cleavage as its substrate in the extrinsic pathway. In conclusion, naringin induces human hepatocellular carcinoma HepG2 cell apoptosis via mitochondria-mediated activation of caspase-9 and caspase-8-mediated proteolysis of Bid. Naringin anticancer activity warrants further investigation for application in medical treatment.

No Association of XRCC1 and CLPTM1L Polymorphisms with Non-small Cell Lung Cancer in a Non-Smoking Han Chinese Population

  • Sun, Yan;Zhang, Yong-Jun;Kong, Xiang-Ming
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권9호
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    • pp.5171-5174
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    • 2013
  • Background: This study aimed to explore potential associations between single nucleotide polymorphisms (SNPs) of the x-ray repair cross-complementing group 1 (XRCC1) and cleft lip and palate transmembrane protein 1-like (CLPTM1L) and non-small cell lung cancer (NSCLC) susceptibility in non-smoker Chinese patients. Methods: A total of 200 NSCLC patients and 200 healthy controls with matched age and gender were recruited for genotyping of XRCC1 SNPs (rs2256507 and rs1001581) and CLPTM1L SNPs (rs401681 and rs4975616). Association of these SNPs with NSCLC risk was evaluated by computing the odds ratio (OR) and 95% confidence interval (CI) from multivariate unconditional logistic regression analyses with adjustment for gender and age. Results: The frequencies of genotype and allele in these four loci (rs2256507, rs1001581, rs401681, and rs4975616) were not significantly different between the cases and controls, or between either of the histological subgroups (adenocarcinoma and squamous cell carcinoma) and controls. Conclusions: Although these SNPs are associated with NSCLC risk in patients with a tobacco-smoking habit, this study demonstrated that XRCC1 and CLPTM1L gene SPNs are not linked with NSCLC risk in non-smoking patients, indicating that molecular mechanisms of NSCLC betwee tobacco smokers and non-smokers may be different. Future studies are needed to uncover the underlying molecular mechanisms for NSCLC in non-smokers.

Genomic Organization of Penicillium chrysogenum chs4, a Class Ⅲ Chitin Synthase Gene

  • 박윤동;이명숙;남경준;박범찬;배경숙;박희문
    • 미생물학회지
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    • 제38권4호
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    • pp.230-230
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    • 2002
  • Class Ⅲ chitin synthases in filamentous fungi are important for hyphal growth and differentiation of several filamentous fungi. A genomic clone containing the full gene encoding Chs4, a class Ⅲ chitin synthase in Penicillium chrysogenum, was cloned by PCR screening and colony hybridization from the genomic library. Nucleotide sequence analysis and transcript mapping of chs4 revealed an open reading frame (ORF) that consisted of 5 exons and 4 introns and encoded a putative protein of 915 amino acids. Nucleotide sequence analysis of the 5′flanking region of the ORF revealed a potential TATA box and several binding sites for transcription activators. The putative transcription initiation site at -716 position was identified by primer extension and the expression of the chs4 during the vegetative growth was confirmed by Northern blot analysis. Amino acid sequence analysis of the Chs4 revealed at least 5 transmembrane helices and several sites for past-transnational modifications. Comparison of the amino acid sequence of Chs4 with those of other fungi showed a close relationship between P chrysogenum and genus Aspergillus.

High Expression of Water-Soluble Recombinant Antigenic Domains of Toxoplasma gondii Secretory Organelles

  • Yang, Zhaoshou;Ahn, Hye-Jin;Nam, Ho-Woo
    • Parasites, Hosts and Diseases
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    • 제52권4호
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    • pp.367-376
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    • 2014
  • Recombinant antigenic proteins of Toxoplasma gondii are alternative source of antigens which are easily obtainable for serodiagnosis of toxoplasmosis. In this study, highly antigenic secretory organellar proteins, dense granular GRA2 and GRA3, rhoptrial ROP2, and micronemal MIC2, were analyzed by bioinformatics approach to express as water-soluble forms of antigenic domains. The transmembrane region and disorder tendency of 4 secretory proteins were predicted to clone the genes into pGEX-4T-1 vector. Recombinant plasmids were transformed into BL21 (DE3) pLysS E. coli, and GST fusion proteins were expressed with IPTG. As a result, GST fusion proteins with $GRA2_{25-105}$, $GRA3_{39-138}$, $ROP2_{324-561}$, and $MIC2_{1-284}$ domains had respectively higher value of IgG avidity. The $rGST-GRA2_{25-105}$ and $rGST-GRA3_{39-138}$ were soluble, while $rGST-ROP2_{324-561}$ and $rGST-MIC2_{1-284}$ were not. $GRA2_{31-71}$, intrinsically unstructured domain (IUD) of GRA2, was used as a linker to enhance the solubility. The $rGST-GRA2_{31-71}-ROP2_{324-561}$, a chimeric protein, appeared to be soluble. Moreover, $rGST-GRA2_{31-71}-MIC2_{1-284}$ was also soluble and had higher IgG avidity comparing to $rGST-MIC2_{1-284}$. These 4 highly expressed and water-soluble recombinant antigenic proteins may be promising candidates to improve the serodiagnosis of toxoplasmosis in addition to the major surface antigen of SAG1.

Indacaterol Inhibits Tumor Cell Invasiveness and MMP-9 Expression by Suppressing IKK/NF-κB Activation

  • Lee, Su Ui;Ahn, Kyung-Seop;Sung, Min Hee;Park, Ji-Won;Ryu, Hyung Won;Lee, Hyun-Jun;Hong, Sung-Tae;Oh, Sei-Ryang
    • Molecules and Cells
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    • 제37권8호
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    • pp.585-591
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    • 2014
  • The ${\beta}_2$ adrenergic receptor (ADRB2) is a G protein-coupled transmembrane receptor expressed in the human respiratory tract and widely recognized as a pharmacological target for treatments of asthma and chronic obstructive pulmonary disorder (COPD). Although a number of ADRB2 agonists have been developed for use in asthma therapy, indacaterol is the only ultra-long-acting inhaled ${\beta}_2$-agonist (LABA) approved by the FDA for relieving the symptoms in COPD patients. The precise molecular mechanism underlying the pharmacological effect of indacaterol, however, remains unclear. Here, we show that ${\beta}$-arrestin-2 mediates the internalization of ADRB2 following indacaterol treatment. Moreover, we demonstrate that indacaterol significantly inhibits tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-induced NF-${\kappa}B$ activity by reducing levels of both phosphorylated-IKK and -$I{\kappa}B{\alpha}$, thereby decreasing NF-${\kappa}B$ nuclear translocation and the expression of MMP-9, an NF-${\kappa}B$ target gene. Subsequently, we show that indacaterol significantly inhibits TNF-${\alpha}$/NF-${\kappa}B$-induced cell invasiveness and migration in a human cancer cell line. In conclusion, we propose that indacaterol may inhibit NF-${\kappa}B$ activity in a ${\beta}$-arrestin2-dependent manner, preventing further lung damage and improving lung function in COPD patients.

Investigation of the Binding Site of CCR2 using 4-Azetidinyl-1-aryl-cyclohexane Derivatives: A Membrane Modeling and Molecular Dynamics Study

  • Kothandan, Gugan;Gadhe, Changdev G.;Cho, Seung Joo
    • Bulletin of the Korean Chemical Society
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    • 제34권11호
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    • pp.3429-3443
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    • 2013
  • Chemokine receptor (CCR2) is a G protein-coupled receptor that contains seven transmembrane helices. Recent pharmaceutical research has focused on the antagonism of CCR2 and candidate drugs are currently undergoing clinical studies for the treatment of diseases like arthritis, multiple sclerosis, and type 2 diabetes. In this study, we analyzed the time dependent behavior of CCR2 docked with a potent 4-azetidinyl-1-aryl-cyclohexane (4AAC) derivative using molecular dynamics simulations (MDS) for 20 nanoseconds (ns). Homology modeling of CCR2 was performed and the 4AAC derivative was docked into this binding site. The docked model of selected conformations was then utilized to study the dynamic behavior of the 4AAC enzyme complexes inside lipid membrane. MDS of CCR2-16b of 4AAC complexes allowed us to refine the system since binding of an inhibitor to a receptor is a dynamic process and identify stable structures and better binding modes. Structure activity relationships (SAR) for 4AAC derivatives were investigated and reasons for the activities were determined. Probable binding pose for some CCR2 antagonists were determined from the perspectives of binding site. Initial modeling showed that Tyr49, Trp98, Ser101, Glu291, and additional residues are crucial for 4AAC binding, but MDS analysis showed that Ser101 may not be vital. 4AAC moved away from Ser101 and the hydrogen bonding between 4AAC and Ser101 vanished. The results of this study provide useful information regarding the structure-based drug design of CCR2 antagonists and additionally suggest key residues for further study by mutagenesis.

쥐의 콜라겐 유도 관절염에 대한 유근피의 효과 및 기전 (Anti-inflammatory Effects and Mechanisms of Ulmus Davidiana Planch(Ulmaceae) in Collagen-induced Arthritis Rats)

  • 송인광;이승덕;김갑성
    • Journal of Acupuncture Research
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    • 제24권2호
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    • pp.83-100
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    • 2007
  • 목적 : 쥐의 콜라겐 유도 관절염에 대한 유근피 추출액의 면역 반응 효과 및 그 기전을 살펴보고자 하였다. 방법 : 유근피 추출액의 면역 반응을 관찰하기 위하여 콜라겐 유도 관절염 쥐가 사용되었다. 실험에 쓰인 쥐 뒷다리의 부종 용적은 volume meter로 측정하였고, lymphocyte 증식, 표1, 표2 및 TNF-${\alpha}$ 레벨은 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolirun bromide(MTT) assay에의해 측정하였다. 활막세포의 cAMP 레벨은 경쟁적 단백 결합검사 (CPBA)를 통하여 측정하였다. 2형 콜라겐에 대한 항체는 효소면역 협착검사법(ELISA)을 반복 사용하여 측정하였다. 결과 : 실험에서 유근피 추출액( 20, 80, 150mg/kg, ig ${\times}$ 7days)의 시술은 면역 반응을 억제하고 콜라겐 유도관절염 쥐의 체중과 면역 기관의 무게를 유지하였다. 콜라겐 유도 관절염 쥐에서 림프구의 증식과 IL-2의 생산은 복막의 대식세포 및 활막세포의 IL-1 , TNF-${\alpha}$와 함께 증가하였고, 유근피 추출액 (20, 80, 150mg/kg, ig ${\times}$ 7days)의 시술은 이러한 변화를 유의성 있게 감소시켰다. 0.5, 2.5, 12.5, 62.5, 125mg/l 농도에서의 유근피 추출액은 활막세포의 cAMP 레벨을 증가시킨데 반해 콜라겐 유도관절염 쥐에서의 시험관 실험결과에서는 감소시켰다. 유근피 추출액은 2형 콜라겐 항체의 농도에 대하여는 효과가 없었다. 결론 : 유근피 추출액은 항염증 작용과 면역조절 작용을 갖고 있고, 활막세포의 G protein-AC-cAMP transmembrane signal transduction 형질 도입 신호에의한 콜라겐 유도관절염 쥐의 치료 효과를 가지고 있는 것으로 여겨진다.

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Xenopus laevis oocytes에서 진세노사이드에 의하여 활성화되는 Ca2+-activated Cl- 이온 통로의 유전자 클로닝, 조직 분포 및 채널 특성 (Gene cloning, tissue distribution, and its characterization of Ca2+-activated Cl- channel activated by ginsenosides in Xenopus laevis oocytes)

  • 정상민;이준호;윤인수;나승열
    • Journal of Ginseng Research
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    • 제29권4호
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    • pp.167-175
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    • 2005
  • The $Ca^{2+}-activated$ chloride channel (CLCA) was activated by ginseng total saponin (GTS) in Xenopus oocytes. The reverse transcription PCR (RT-PCR) method was performed with gene specific primers on oocytes. The gene specific primers were deduced from spleen cDNA in expressed sequence tags (EST) database showing high homology to the mouse CLCA. Full length of cDNA sequence was completed by linkage of several 5' and 3'-half cDNA fragments have been sequenced. We named the full cDNA to oCLCA transiently. The oCLCA gene encodes a protein of 911 amino acids with $48.9\%$ identity overall to that of mouse CLCA (mCLCA4). A predicted oCLCA amino acids sequence shows the molecular weight of 108 kDa and has four or more transmembrane domains, and also the one hydrophobic C­terminal domain. oCLCA gene was expressed ubiquitously in various tissues included oocytes, also interfered in oocytes by siRNA for oCLCA. Here, we suggest that oCLCA is a endogenous chloride channel gene in oocytes. We are studying for the identification of oCLCA gene and further physiological research.

Loss of FAT Atypical Cadherin 4 Expression Is Associated with High Pathologic T Stage in Radically Resected Gastric Cancer

  • Jung, Hae Yoen;Cho, Hyundeuk;Oh, Mee-Hye;Lee, Ji-Hye;Lee, Hyun Ju;Jang, Si-Hyong;Lee, Moon Soo
    • Journal of Gastric Cancer
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    • 제15권1호
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    • pp.39-45
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    • 2015
  • Purpose: Recent studies have revealed recurrent alterations in the cell adhesion gene FAT4, a candidate tumor suppressor gene, in cancer. FAT atypical cadherin 4 (FAT4) is a transmembrane receptor involved in the Hippo signaling pathway, which is involved in the control of organ size. Here, we investigated the loss of FAT4 expression and its association with clinicopathological risk factors in gastric cancer. Materials and Methods: We assessed the expression of FAT4 by using immunohistochemistry on three tissue microarrays containing samples from 136 gastric cancer cases, radically resected in the Soonchunhyang University Cheonan Hospital between July 2006 and June 2008. Cytoplasmic immunoexpression of FAT4 was semi-quantitatively scored using the H-score system. An H-score of ${\geq}10$ was considered positive for FAT4 expression. Results: Variable cytoplasmic expressions of FAT4 were observed in gastric cancers, with 33 cases (24.3%) showing loss of expression (H-score <10). Loss of FAT4 expression was associated with an increased rate of perineural invasion (H-score <10 vs. ${\geq}10$, 36.4% vs. 16.5%, P=0.015), high pathologic T stage (P=0.015), high tumor-node-metastasis stage (P=0.017), and reduced disease-free survival time (H-score <10 vs. ${\geq}10$, mean survival $62.7{\pm}7.3$ months vs. $79.1{\pm}3.1$ months, P=0.025). However, no association was found between the loss of FAT4 expression and tumor size, gross type, histologic subtype, Lauren classification, lymphovascular invasion, or overall survival. Conclusions: Loss of FAT4 expression appears to be associated with invasiveness in gastric cancer.

Klotho : Expression and Regulation at the Maternal-Conceptus Interface in Pigs

  • Choi, Yohan;Seo, Heewon;Shim, Jangsoo;Hyun, Sang-Hwan;Lee, Eunsong;Ka, Hakhyun
    • 한국수정란이식학회지
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    • 제29권4호
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    • pp.375-383
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    • 2014
  • Klotho (KL) is a single transmembrane protein composed of KL1 and KL2 repeats possessing ${\beta}$-glucuronidase activity and maintains calcium homeostasis in physiological state. It has been implicated in pigs that calcium is important for the establishment and maintenance of pregnancy, and our previous study has shown that transient receptor potential vanilloid type 6 (TRPV6), a calcium ion transporter, is predominantly expressed in the uterine endometrium during pregnancy in pigs. However, expression and function of KL in the uterine endometrium has not been determined in pigs. Thus, the present study determined expression and regulation of KL in the uterine endometrium during the estrous cycle and pregnancy in pigs. Real-time RT-PCR analysis showed that levels of KL mRNA decreased between Days 12 to 15 of the estrous cycle, and its expression showed a biphasic manner during pregnancy. KL mRNA was expressed in conceptuses and in chorioallantoic tissues during pregnancy. Explant culture study showed that expression levels of KL were not affected by treatment of steroid hormones or interleukin-1beta during the implantation period. Furthermore, levels of KL mRNA in the uterine endometrium from gilts carrying somatic cell nuclear transfer (SCNT)-derived embryos were significantly lower than those from gilts carrying natural mating-derived embryos on Day 12 of pregnancy. These results exhibited that KL was expressed at the maternal-conceptus interface in a pregnancy status- and stage-specific manner, and its expression was affected by SCNT procedure, suggesting that KL may play an important role in the establishment and maintenance of pregnancy in pigs.