• Title/Summary/Keyword: cell surface protein

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P2 Receptor-mediated Inhibition of Vasopressin-stimulated Fluid Transport and cAMP Responses in AQP2-transfected MDCK Cells

  • Kim, Yang-Hoo;Choi, Young-Jin;Bae, Hae-Rahn;Woo, Jae-Suk
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.1
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    • pp.9-14
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    • 2009
  • We cultured canine kidney(MDCK) cells stably expressing aquaporin-2(AQP2) on collagen-coated permeable membrane filters and examined the effect of extracellular ATP on arginine vasopressin(AVP)-stimulated fluid transport and cAMP production. Exposure of cell monolayers to basolateral AVP resulted in stimulation of apical to basolateral net fluid transport driven by osmotic gradient which was formed by addition of 500 mM mannitol to basolateral bathing solution. Pre-exposure of the basolateral surface of cell monolayers to ATP(100 ${\mu}M$) for 30 min significantly inhibited the AVP-stimulated net fluid transport. In these cells, AVP-stimulated cAMP production was suppressed as well. Profile of the effects of different nucleotides suggested that the $P2Y_2$ receptor is involved in the action of ATP. ATP inhibited the effect of isoproterenol as well, but not that of forskolin to stimulate cAMP production. The inhibitory effect of ATP on AVP-stimulated fluid movement was attenuated by a protein kinase C inhibitor, calphostin C or pertussis toxin. These results suggest that prolonged activation of the P2 receptors inhibits AVP-stimulated fluid transport and cAMP responses in AQP2 transfected MDCK cells. Depressed responsiveness of the adenylyl cyclase by PKC-mediated modification of the pertussis-toxin sensitive $G_i$ protein seems to be the underlyihng mechanism.

Estrogenic Activity of Sanguiin H-6 through Activation of Estrogen Receptor α Coactivator-binding Site

  • Trinh, Tuy An;Park, Eun-Ji;Lee, Dahae;Song, Ji Hoon;Lee, Hye Lim;Kim, Ki Hyun;Kim, Younghoon;Jung, Kiwon;Kang, Ki Sung;Yoo, Jeong-Eun
    • Natural Product Sciences
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    • v.25 no.1
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    • pp.28-33
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    • 2019
  • A popular approach for the study of estrogen receptor ${\alpha}$ inhibition is to investigate the protein-protein interaction between the estrogen receptor (ER) and the coactivator surface. In our study, we investigated phytochemicals from Rubus coreanus that were able to disrupt $ER{\alpha}$ and coactivator interaction with an $ER{\alpha}$ antagonist. The E-screen assay and molecular docking analysis were performed to evaluate the effects of the estrogenic activity of R. coreanus extract and its constituents on the MCF-7 human breast cancer cell line. At $100{\mu}g/mL$, R. coreanus extract significantly stimulated cell proliferation ($574.57{\pm}8.56%$). Sanguiin H6, which was isolated from R. coreanus, demonstrated the strongest affinity for the $ER{\alpha}$ coactivator-binding site in molecular docking analysis, with a binding energy of -250.149. The initial results of the study indicated that sanguiin H6 contributed to the estrogenic activity of R. coreanus through the activation of the $ER{\alpha}$ coactivator-binding site.

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.

Anti-Oral Microbial Activity and Anti-Inflammatory Effects of Rosmarinic Acid in Lipopolysaccharide-Stimulated MC3T3-E1 Osteoblastic Cells on a Titanium Surface

  • Jeong, Moon-Jin;Lim, Do-Seon;Heo, Kyungwon;Jeong, Soon-Jeong
    • Journal of dental hygiene science
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    • v.20 no.4
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    • pp.221-229
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    • 2020
  • Background: The purpose of this study was to investigate the anti-oral microbial activity and anti-inflammatory effects of rosmarinic acid (RA) in lipopolysaccharide (LPS)-stimulated MC3T3-E1 osteoblastic cells on a titanium (Ti) surface during osseointegration, and to confirm the possibility of using RA as a safe natural substance for the control of peri-implantitis (PI) in Ti-based dental implants. Methods: A disk diffusion test was conducted to confirm the antimicrobial activity of RA against oral microorganisms. In order to confirm the anti-inflammatory effects of RA, inflammatory conditions were induced with 100 ng/ml of LPS in MC3T3-E1 osteoblastic cells on the Ti surface treated with or without 14 ㎍/ml of RA. The production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated MC3T3-E1 osteoblastic cells on the Ti surface was confirmed using an NO assay kit and PGE2 enzyme-linked immunosorbent assay kit. Reverse transcription polymerase chain reaction and western blot analysis were performed to confirm the expression of interleukin (IL)-1β and tumor necrosis factor (TNF)-α in total RNA and protein. Results: RA showed weak antimicrobial effects against Streptococcus mutans and Escherichia coli, but no antimicrobial activity against the bacteria Aggregatibacter actinomycetemcomitans and the fungus Candida albicans. RA reduced the production of pro-inflammatory mediators, NO and PGE2, and proinflammatory cytokines, TNF-α and IL-1β, in LPS-stimulated MC3T3-E1 osteoblastic cells on the Ti surface at the protein and mRNA levels. Conclusion: RA not only has anti-oral microbial activity, but also anti-inflammatory effects in LPS-stimulated MC3T3-E1 osteoblasts on the Ti surface, therefore, it can be used as a safe functional substance derived from plants for the prevention and control of PI for successful Ti-based implants.

Bacitracin Inhibits the Migration of U87-MG Glioma Cells via Interferences of the Integrin Outside-in Signaling Pathway

  • Li, Songyuan;Li, Chunhao;Ryu, Hyang-Hwa;Lim, Sa-Hoe;Jang, Woo-Youl;Jung, Shin
    • Journal of Korean Neurosurgical Society
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    • v.59 no.2
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    • pp.106-116
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    • 2016
  • Objective : Protein disulfide isomerase (PDI) acts as a chaperone on the cell surface, and it has been reported that PDI is associated with the tumor cell migration and invasion. The aims of this study are to investigate the anti-migration effect of bacitracin, which is an inhibitor of PDI, and the associated factor in this process. Methods : U87-MG glioma cells were treated with bacitracin in 1.25, 2.5, 3.75, and 5.0 mM concentrations. Western blot with caspase-3 was applied to evaluate the cytotoxicity of bacitracin. Adhesion, morphology, migration assays, and organotypic brain-slice culture were performed to evaluate the effect of bacitracin to the tumor cell. Western blot, PCR, and gelatin zymography were performed to investigate the associated factors. Thirty glioma tissues were collected following immunohistochemistry and Western blot. Results : Bacitracin showed a cytotoxicity in 3rd (p<0.05) and 4th (p<0.001) days, in 5.0 Mm concentration. The cell adhesion significantly decreased and the cells became a round shape after treated with bacitracin. The migration ability, the expression of phosphorylated focal adhesion kinase (p-FAK) and matrix metalloproteinase-2 (MMP-2) decreased in a bacitracin dose- and time-dependent manner. The U87-MG cells exhibited low-invasiveness in the 2.5 mM, compared with the untreated in organotypic brain-slice culture. PDI was expressed in the tumor margin, and significantly increased with histological glioma grades (p<0.001). Conclusion : Bacitracin, as a functional inhibitor of PDI, decreased the phosphorylated FAK and the secreted MMP-2, which are the downstream of integrin and play a major role in cell migration and invasion, might become one of the feasible therapeutic strategies for glioblastoma.

The Effect of Moutan Cortex on Pro-inflammatory Cytokines through NF-κB & MAPKs pathway in HMC-l (목단피의 NF-κB와 MAPKs 억제를 통한 Pro-inflammatory Cytokines 활성에 미치는 효과)

  • Park, Joo-Ho;Kim, Kyung-Jun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.22 no.2
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    • pp.1-18
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    • 2009
  • Objective : Moutan Cortex (the root bark of Paeonia suffruticosa Andr.) is widely used in oriental medicine as a remedy for inflammation. However, as yet there is no clear explanation of how MC(Moutan Cortex) affects the production of inflammatory cytokine. This study was to determine the effects of Essence extracted MC on the mast cell-mediated inflammatory responses. Method : We observed the effect of MC on compound 48/80-induced histamine release of rat peritoneal mast cells and the effect of administering MC on PCA in rat. We measured the amount of inflammatory cytokine production induced by the phorbol myristate acetate (PMA) plus calcium ionophore(A23187) in the human mast cell line (HMC-1) incubated with various concentrations of MC. The TNF-$\alpha$ protein levels were analysised by Western blot. The TNF-$\alpha$, IL-6 and IL-8 secreted protein levels were measured by the ELISA assay. The TNF-$\alpha$, IL-6 and IL-8 mRNA levels were measured by the RT-PCR analysis. NF-$\kappa$B, phospho-I$\kappa$B and MAPKs were exmined by Western blot analysis. The NF-$\kappa$B promoter activity was examined by luciferase assay. Result : 1. Enzyme immunoassay indicated that MC suppressed histamine secretion of rat peritoneal mast cells. 2. In PCA dependent on IgE, MC had anti-allergic effect of the internal surface of rat skin. 3. Western blot indicated that MC decreased TNF-$\alpha$ protein levels. 4. ELISA indicated that MC decreased TNF-$\alpha$, IL-6 but MC had no significant effect on IL-8 in HMC-1 cells. 5. RT-PCR indicated that MC decreased TNF-$\alpha$, IL-8 but MC had no significant effect on IL-6 in HMC-l cells. 6. Western blot indicated that MC suppressed the induction of MAPKs, NF-$\kappa$B & phospho-I$\kappa$B activity in HMC-1 cells. 7. Luciferase assay indicated that MC suppressed the PMA plus A23187-induced NF-$\kappa$B promoting activityin HMC-1 cells. Conclusion : In this study, we have found that MC is an inhibitor of NF-$\kappa$B, MAPKs & cytokines on the mast cell-mediated inflammatory responses.

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Soft lithographic patterning of proteins and cells inside a microfluidic channel (소프트 리소그라피를 이용한 마이크로유체 채널 내의 단백질 및 세포 패터닝)

  • Suh, Kahp-Yang
    • Journal of the Korean Vacuum Society
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    • v.16 no.1
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    • pp.65-73
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    • 2007
  • The control of surface properties and spatial presentation of functional molecules within a microfluidic channel is important for the development of diagnostic assays, microreactors, and for performing fundamental studies of cell biology and fluid mechanics. Here, we present soft lithographic methods to create robust microchannels with patterned microstructures inside the channel. The patterned regions were protected from oxygen plasma by controlling the dimensions of the poly(dimethylsiloxane)(PDMS) mold as well as the sequence of fabrication steps. The approach was used to pattern a non-biofouling polyethylene glycol(PEG)-based copolymer or the polysaccharide hyaluronic acid(HA) within microfluidic channels. These non-biofouling patterns were then used to fabricate arrays of fibronectin(FN) and bovine serum albumin(BSA) as well as mammalian cells.

Identification of Amino Acid Residues Involved in the Interaction between Measles Virus Haemagglutin (MVH) and Its Human Cell Receptor(Signaling Lymphocyte Activation Molecule, SLAM)

  • Xu, Qin;Zhang, Peng;Hu, Chunling;Liu, Xin;Qi, Yipeng;Liu, Yingle
    • BMB Reports
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    • v.39 no.4
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    • pp.406-411
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    • 2006
  • Signaling lymphocyte activation molecule (SLAM; also known as CD150) is a newly identified cellular receptor for measles virus (MV). The interaction between MV Haemagglutin (MVH) and SLAM is an initial step for MV entry. We have identified several novel SLAM binding sites at residues S429, T436 and H437 of MVH protein and MVH mutants in these residues dramatically decrease the ability to interaction with the cell surface SLAM and fail to co-precipitation with SLAM in vivo as well as malfunction in syncytium formation. At the same time, K58, S59 and H61 of SLAM was also identified to be critical for MVH and SLAM binding. Further, these residues may be useful targets for the development of measles therapy.

Antibody Induced by the JY-Pol Pneumococcal Conjugate Protects Mice Against systemic Infection Due to Streptococcus pneumoniae (JY-Pol 접합백신으로 유도된 항페렴구균 항체의 보호효과)

  • Lee, Jue-Hee;Han, Yong-Moon
    • YAKHAK HOEJI
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    • v.48 no.6
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    • pp.369-373
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    • 2004
  • We previously reported that Streptococcus pneumoniae capsule attached to the surface protein (JY-Pol) was protective to systemic pneumococcal infection. The JY -Pol antigen induced IgM, IgG, and IgA in mice and provoked cell-mediated immunity. In this current study, we investigated the effect of anti JY-Pol antiserun and monoclonal antibody C2 (Mab C2) specific for the JY-Pol antigen against the pneumococcal disease. Mice that were given the antiserum survived longer than mice that received antiserum pre-absorbed with S.pneumoniae cells or DPBS as a negative control. Heat-treated anti JY-Pol antiserum resulted in survival rates similar to intact fresh JY-Pol antiserum. Mab C2 isolated from JY-Pol-immunized mice also enhanced resistance of naive mice against the pneumococcal diseaser. This protection by Mab C2 appeared to be mediated by opsonization as determined in a RAW 264.7 monocyte/macrophage cell line. Epitope analysis showed that Mab C2 epitope consisted of glucuronic acid and glucose that blocked the interaction of JY-Pol to the C2. Taken together, these data indicate that the antiserum induced by the JY-Pol, a naturally pneumococcal conjugate formula, mediated the protection by passive transfer, which was confirmed by protective effect of Mab C2.

A Study on the Quality Properties of Jeungpyun Added with Soybean Yogurt (두유 요구르트 분말을 첨가한 증편의 품질특성)

  • Lee, Young-Woo;Kim, Myung-Hee;Kim, Kang-Sung;Lee, Kyung-Ae
    • Korean journal of food and cookery science
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    • v.25 no.3
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    • pp.387-394
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    • 2009
  • This study was performed to determine the quality characteristics of Jeungpyun with the addition of soy yogurt (0%,3%, 6%, 9%, 12%). The proximate composition analysis showed that moisture contents of Jeungpyun were 49.87${\sim}$51.60%, and crush protein, lipid and ash contents were 2.58%, 0.21${\sim}$0.33% and 0.58${\sim}$1.05%, respectively. The pH ofJeungpyun was higher as the additive increased. Volume and symmetry index were higher as the additive increased, but uniformity index was no significant difference. L value and a value were the lowest in control group and increased with soy yogurt addition, while b value was decreased as amount of soy yogurt. Hardness, cohesiveness, gumminess were the highest in 9% group, springiness was the lowest in 9% group. In surface structure of Jeungpyun observed by SEM, cell size was the smallest and the cell uniformity was most regular in 12% group. According to sensory evaluation, appearance, taste and overall acceptance were highest in Jeungpyun with 9% soy yogurt. Therefore, Jeungpyun containing 9% soy yogurt was most preferable.