• Title/Summary/Keyword: binding treatment

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Inhibitory Effect of Carnosol on Phthalic Anhydride-Induced Atopic Dermatitis via Inhibition of STAT3

  • Lee, Do Yeon;Hwang, Chul Ju;Choi, Ji Yeon;Park, Mi Hee;Song, Min Ji;Oh, Ki Wan;Son, Dong Ju;Lee, Seung Hwa;Han, Sang Bae;Hong, Jin Tae
    • Biomolecules & Therapeutics
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    • v.25 no.5
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    • pp.535-544
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    • 2017
  • Carnosol is a phenolic antioxidant present in rosemary (Rosmarinus officinalis). It is known for anti-inflammatory effects, analgesic activity and anti-cancer effects. However, no study has been dedicated yet to its effect on atopic dermatitis (AD). Here, we show that carnosol effectively inhibited LPS-induced nitric oxide (NO) generation and expression of inflammatory marker proteins (iNOS and COX-2) in RAW 264.7 cells. In addition, carnosol effectively inhibits the phosphorylation of STAT3 and DNA binding activity in RAW 264.7 cells. Pull down assay and docking model analysis showed that carnosol directly binds to the DNA binding domain (DBD) of STAT3. We next examined the anti-atopic activity of carnosol ($0.05{\mu}g/cm^2$) using 5% Phthalic anhydride (PA)-induced AD model in HR1 mice. Carnosol treatment significantly reduced 5% PA-induced AD like skin inflammation in skin tissues compared with control mice. Moreover, carnosol treatment inhibits the expression of iNOS and COX-2 in skin tissue. In addition, the levels of $TNF-{\alpha}$, $IL-1{\beta}$, and Immunoglobulin-E in blood serum was significantly decreased in carnosol treated mice compared with those of 5% PA treated group. Furthermore, the activation of STAT3 in skin tissue was decreased in carnosol treated mice compared with control mice. In conclusion, these findings suggest that carnosol exhibited a potential anti-AD activity by inhibiting pro-inflammatory mediators through suppression of STAT3 activation via direct binding to DBD of STAT3.

Cisplatin-induced Alterations of $Na^+$-dependent Phosphate Uptake in Renal Epithelial Cells

  • Lee, Sung-Ju;Kwon, Chae-Hwa;Kim, Yong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.11 no.2
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    • pp.71-77
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    • 2007
  • Cisplatin treatment increases the excretion of inorganic phosphate in vivo. However, the mechanism by which cisplatin reduces phosphate uptake through renal proximal tubular cells has not yet been elucidated. We examined the effect of cisplatin on $Na^+$-dependent phosphate uptake in opossum kidney (OK) cells, an established proximal tubular cell line. Cells were exposed to cisplatin for an appropriate time period and phosphate uptake was measured using $[^{32}P]$-phosphate. Changes in the number of phosphate transporter in membranes were evaluated by kinetic analysis, $[^{14}C]$phosphonoformic acid binding, and Western blot analysis. Cisplatin inhibited phosphate uptake in a time- and dose-dependent manner, and also the $Na^+$-dependent uptake without altering $Na^+$-independent uptake. The cisplatin inhibition was not affected by the hydrogen peroxide scavenger catalase, but completely prevented by the hydroxyl radical scavenger dimethylthiourea. Antioxidants were ineffective in preventing the cisplatin-induced inhibition of phosphate uptake. Kinetic analysis indicated that cisplatin decreased Vmax of $Na^+$-dependent phosphate uptake without any change in the Km value. $Na^+$-dependent phosphonoformic acid binding was decreased by cisplatin treatment. Western blot analysis showed that cisplatin caused degradation of $Na^+$-dependent phosphate transporter protein. Taken together, these data suggest that cisplatin inhibits phosphate transport in renal proximal tubular cells through the reduction in the number of functional phosphate transport units. Such effects of cisplatin are mediated by production of hydroxyl radicals.

Inhibition Effects of Galla Chinenisis Extract on Adipocyte Differentiation in OP9 Cells (오미자 추출물의 지방세포 분화 억제 효과)

  • Park, Sun-Young;Hwang, Hong-Yeon;Seo, Eun-A;Kwon, Kang-Beom;Ryu, Do-Gon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.26 no.4
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    • pp.455-461
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    • 2012
  • Obesity is associated with numerous diseases such as type 2 diabetes, hypertension and cancer. Inhibition of adipogenesis is a effectite strategy to anti-obesity. In this study, Galla Chinenisis extract (GCE) inhibited adipocyte differentiation in OP9 cells. There was no cytotoxicity when cells were treated with GCE in designated time intervals, unaffected by concentration. In this cell model, increases in fat storage were inhibited by 2 days treatment with various concentration of GCE, visualized by Oil red-O, BODIPY and DAPI staining. To understand the underlying mechanism at the molecular level, the effects of GCE were examined on the expression of the genes involved in adipogenesis by real-time PCR. In the progress of adipocyte differentiation with GCE-treated, the mRNA level of adipogenic genes such as peroxisome-proliferator-activated receptors gamma ($PPAR{\gamma}$), computer-assisted axial tomography/enhancer binding protein-alpha ($C/EBP{\alpha}$) were decreased. Also, GCE treatment inhibited increase of mRNA expression, which is adipogenic factor such as fatty acid synthase (FAS), hormone-sensitve lipase (HSL), lipoprotein lipase (LPL), and adipocyte-specific lipid binding protein (aP2). Therefore, the result of this study suggest that Galla Chinenisis extract can prevent adipocyte differentiation and GCE may have a great potential as a novel anti-adipogenic agent.

The Cytotoxic and Apoptotic Effect of Pseudomonas aeruginosa Exotoxin A on Human Leukemia K-562 Cells (인간 백혈병 세포에서 Psuedomonas aeruginosa exotoxin A에 대한 세포독성과 세포자멸사 효과)

  • Chang, Jeong-Hyun;Kwon, Heun-Young
    • Korean Journal of Clinical Laboratory Science
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    • v.39 no.2
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    • pp.68-75
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    • 2007
  • After reports on regression of cancer in humans and animals infected with microbial pathogens date back more than 100 years, much effort has been spent over the years in developing a wild type or attenuated bacterial and purified bacterial proteins for the treatment of cancer. Pseudomonas aeruginosa exotoxin A (ETA) is known to inhibit cell growth and trigger significant cell death in various cancer cells. Although ETA induces apoptosis of cancer cells, its exact mechanism of action is not known yet. Four different assays were performed in this study: morphological assessment of apoptotic cells, cell cytotoxity, annexin-V binding assay, and cell cycle analysis. The proliferation and survival of the K-562 cells treated with ETA were decreased in a dose dependent manner. In addition, the apoptotic body of K-562 cells was induced by ETA treatment in a dose dependent manner. The ETA-induced apoptosis was confirmed by annexin-V binding assay. Flow cytometric analysis was examined to ascertain whether ETA could arrest the cell cycle at the sub-G1 phase. Our results suggest that P. aeruginosa ETA inhibits cell growth and induces apoptosis in human leukemia K-562 cells.

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Reduction-Sensitive and Cysteine Residue-Mediated Streptococcus pneumoniae HrcA Oligomerization In Vitro

  • Kwon, Hyog-Young;Kim, Eun-Hye;Tran, Thao Dang Hien;Pyo, Suhk-Neung;Rhee, Dong-Kwon
    • Molecules and Cells
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    • v.27 no.2
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    • pp.149-157
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    • 2009
  • In both gram-positive and several gram-negative bacteria, the transcription of dnaK and groE operons is negatively regulated by HrcA; however, the mechanism modulating HrcA protein activity upon thermal stress remains elusive. Here, we demonstrate that HrcA is modulated via reduction and oligomerization in vitro. Native-PAGE analysis was used to reveal the oligomeric structure of HrcA. The oligomeric HrcA structure became monomeric following treatment with the reducing agent dithothreitol, and this process was reversed by treatment with hydrogen peroxide. Moreover, the mutant HrcA C118S exhibited reduced binding to CIRCE elements and became less oligomerized, suggesting that cysteine residue 118 is important for CIRCE element binding as well as oligomerization. Conversely, HrcA mutant C280S exhibited increased oligomerization. An HrcA double mutant (C118S, C280S) was monomeric and exhibited a level of oligomerization and CIRCE binding similar to wild type HrcA, suggesting that cysteine residues 118 and 280 may function as checks to one another during oligomer formation. Biochemical fractionation of E. coli cells overexpressing HrcA revealed the presence of HrcA in the membrane fraction. Together, these results suggest that the two HrcA cysteine residues at positions 118 and 280 function as reduction sensors in the membrane and mediate oligomerization upon stress.

Effect of Biochanin A on the Aryl Hydrocarbon Receptor and Cytochrome P450 1A1 in MCF-7 Human Breast Carcinoma Cells

  • Han, Eun-Hee;Kim, Ji-Young;Jeong, Hye-Gwang
    • Archives of Pharmacal Research
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    • v.29 no.7
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    • pp.570-576
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    • 2006
  • Phytoestrogen biochanin A is an isoflavone derivative isolated from red clover Trifolium pratense with anticarcinogenic properties. This study examined the action of biochanin A with the carcinogen activation pathway that is mediated by the aryl hydrocarbon receptor (AhR) in MCF-7 breast carcinoma cells. Treating the cells with biochanin A alone caused the accumulation of CYP1A1 mRNA and an increase in CYP1A1-specific 7-ethoxyresorufin O-deethylase (EROD) activity in a dose dependent manner. A concomitant treatment with 7,12-dimethylbenz[a]anthracene (DMBA) and biochanin A markedly reduced the DMBA-inducible EROD activity and CYP1A1 mRNA level. In addition, the biochanin A treatment alone activated the DNA-binding capacity of the AhR for the dioxin-response element (DRE) of CYP1A1, as measured by the electrophoretic-mobility shift assay (EMSA). EMSA revealed that biochanin A reduced the level of the DMBA-inducible AhR-DRE binding complex. Furthermore, biochanin A competed with the prototypical AhR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), for binding to the AhR in an isolated rat cytosol. The biochanin A competitively inhibited the metabolic activation of DMBA, as measured by the formation of the DMBA-DNA adducts. These results suggest that biochanin A may thus be a natural ligand to bind on AhR. Therefore, biochanin A may be due to act an antagonist/agonist of the AhR pathway.

Druggability for COVID-19: in silico discovery of potential drug compounds against nucleocapsid (N) protein of SARS-CoV-2

  • Ray, Manisha;Sarkar, Saurav;Rath, Surya Narayan
    • Genomics & Informatics
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    • v.18 no.4
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    • pp.43.1-43.13
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    • 2020
  • The coronavirus disease 2019 is a contagious disease and had caused havoc throughout the world by creating widespread mortality and morbidity. The unavailability of vaccines and proper antiviral drugs encourages the researchers to identify potential antiviral drugs to be used against the virus. The presence of RNA binding domain in the nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could be a potential drug target, which serves multiple critical functions during the viral life cycle, especially the viral replication. Since vaccine development might take some time, the identification of a drug compound targeting viral replication might offer a solution for treatment. The study analyzed the phylogenetic relationship of N protein sequence divergence with other 49 coronavirus species and also identified the conserved regions according to protein families through conserved domain search. Good structural binding affinities of a few natural and/or synthetic phytocompounds or drugs against N protein were determined using the molecular docking approaches. The analyzed compounds presented the higher numbers of hydrogen bonds of selected chemicals supporting the drug-ability of these compounds. Among them, the established antiviral drug glycyrrhizic acid and the phytochemical theaflavin can be considered as possible drug compounds against target N protein of SARS-CoV-2 as they showed lower binding affinities. The findings of this study might lead to the development of a drug for the SARS-CoV-2 mediated disease and offer solution to treatment of SARS-CoV-2 infection.

Novel Anti-Mesothelin Nanobodies and Recombinant Immunotoxins with Pseudomonas Exotoxin Catalytic Domain for Cancer Therapeutics

  • Minh Quan Nguyen;Do Hyung Kim;Hye Ji Shim;Huynh Kim Khanh Ta;Thi Luong Vu;Thi Kieu Oanh Nguyen;Jung Chae Lim;Han Choe
    • Molecules and Cells
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    • v.46 no.12
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    • pp.764-777
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    • 2023
  • Recombinant immunotoxins (RITs) are fusion proteins consisting of a targeting domain linked to a toxin, offering a highly specific therapeutic strategy for cancer treatment. In this study, we engineered and characterized RITs aimed at mesothelin, a cell surface glycoprotein overexpressed in various malignancies. Through an extensive screening of a large nanobody library, four mesothelin-specific nanobodies were selected and genetically fused to a truncated Pseudomonas exotoxin (PE24B). Various optimizations, including the incorporation of furin cleavage sites, maltose-binding protein tags, and tobacco etch virus protease cleavage sites, were implemented to improve protein expression, solubility, and purification. The RITs were successfully overexpressed in Escherichia coli, achieving high solubility and purity post-purification. In vitro cytotoxicity assays on gastric carcinoma cell lines NCI-N87 and AGS revealed that Meso(Nb2)-PE24B demonstrated the highest cytotoxic efficacy, warranting further characterization. This RIT also displayed selective binding to human and monkey mesothelins but not to mouse mesothelin. The competitive binding assays between different RIT constructs revealed significant alterations in IC50 values, emphasizing the importance of nanobody specificity. Finally, a modification in the endoplasmic reticulum retention signal at the C-terminus further augmented its cytotoxic activity. Our findings offer valuable insights into the design and optimization of RITs, showcasing the potential of Meso(Nb2)-PE24B as a promising therapeutic candidate for targeted cancer treatment.

Effects of Salviae miltiorrhizae Radix Extract on Gene Expression of Dendritic cells. (단삼이 수지상 세포의 유전자 발현에 미치는 영향)

  • Chiang, Wen-Lih;Kim, Jong-Han;Choi, Jeong-Hwa;Park, Su-Yeon
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.21 no.3
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    • pp.52-68
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    • 2008
  • Objectives and Methods : Salviae miltiorrhizae Radix (SMR) promotes blood circulation to remove blood stasis, cools the blood to relieve carbuncle, clears away heat from the heart and tranquilizes the mind. This study was designed to investigate the effects of SMR on immuno-potentiative action in terms of changes in the genetic profile of dendritic cells (DC) using by microarray analysis. Results and Conclusion: In this experiment, treatments with more than 250 ${\mu}g/ml$ upto 1000 ${\mu}g/ml$ of SMR elevated the proliferation rates of DC. Microscopic observations confirmed the tendency on proliferation rates. Expression levels of genes related with cellular methabolic process, cell communication, and macromolecule metabolic process were elevated by treatment with SMR in comparison of functional distribution in a Biological Process. In molecular functions, expression levels of genes related with receptor activation, nucleotide binding and nucleic acid binding were elevated. In cellular components, expression levels of genes related to cellular membrane-bound organelles were elevated. In addition, expression levels of genes related to Wnt signalling pathways and the glycerophospholipid metabolism were elevated through analysis using pathway analysis between up-and down-regulated genes in cells treated with SMR. Finally, genes related to JAK2, GRB2, CDC42, SMAD4, B2M, FOS and ESRI located the center of Protein interaction network of genes through treatment with SMR.

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Differential Role of Ethanol, Glycerol, 4-Methylpyrazole and Isoniazid on Human CYP2E1 Activity in Intact HepG2 Cells (HepG2 세포에서 Ethanol, Glycerol, 4-Methylpyrazole 및 Isoniazid에 의한 Human CYP2E1 활성변화)

  • 최달웅
    • Toxicological Research
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    • v.19 no.3
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    • pp.235-240
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    • 2003
  • The modification of CYP2E1 activity is of considerable interest because of its role in the metabolic activation of a variety of toxic chemicals. In the present studies, the time-course of changes in human CYP2E1 activities was determined after treatment with ethanol, glycerol, 4-methylpyrazole or isoniazid using intact HepG2 cells transfected by human CYP2E1. Hydroxylation of chlorzoxazone was chosen for the measurement of CYP2E1 activity. CYP2E1 protein levels were increased upon cultivation of cells in the presence of ethanol, glycerol, 4-methylpyrazole or isoniazid for 24 hr. After 24 hr cultivation, ethanol or glycerol increased CYP2E1 activities, whereas 4-methylpyrazole or isoniazid inhibited. This different effect of the chemical inducers on CYP2E1 activi-ties persisted to subsequent 24 hr. Competitive inhibition study suggested that 4-methylpyrazole or isoniazid has stronger binding affinity to CYP2E1 than ethanol or glycerol. These results demonstrate that different binding affinity of the chemical inducers to the active site of CYP2E1 plays important role in determining real CYP2E1 activity in intact cells after treatment with the chemical inducers. Present study would be helpful in precise understanding of human CYP2E1-mediated toxicity.