• Title/Summary/Keyword: anti-blocking

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Characterization of a Novel Monoclonal Antibody (27H2) Recognizing Human CD34 Class III Epitope

  • Hong, Kwon-Pyo;Kang, Sung-Hee;Lee, Kyoung-Mee;Ji, Gil-Yong;Yoon, Sang-Soon;Kim, Jong-Suk;Son, Bo-Ra;Lee, Dong-Geun;Lee, Ok-Jun;Song, Hyung-Geun
    • IMMUNE NETWORK
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    • v.10 no.6
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    • pp.239-246
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    • 2010
  • Background: Monoclonal antibodies (mAbs) recognizing Class III epitope of CD34 are essential for flow cytometric diagnosis of leukemia. Methods: 27H2 mAb was developed from a mouse alternatively immunized with human acute leukemia cell lines, KG1 and Molm-1. Using flow cytometric analysis of various leukemic cell lines and peripheral blood, immunohistochemical study of frozen tonsil, we characterized 27H2 mAb. Antigen immunoprecipitated with 27H2 mAb immunobloted with anti-CD34 mAb. A case of bone marrow sample of acute lymphoblastic leukemia (ALL) patient was obtained at CBNU Hospital. For epitope identification enzyme treatment with neuraminidase and O-sialoglycoprotein endopeptidase (OSGE) and blocking assay with known classIII mAb (HPCA-2) were done. Results: Only KG1 and Molm-1 revealed positive immunoreactivity. Immunohistochemical staining disclosed strong membranous immunoreactivity on high endothelial venules. Antigen immunoprecipitated by 27H2 mAb showed approximately 100 kDa sized band immunoblotted with anti-CD34 under non-reducing conditions. Epitope recognized by 27H2 mAb disclosed resistancy to both neuraminidase and OSGE treatment and completely blocked with known class III mAb preincubation. CD34 positive leukemic cells in BM of pre B cell ALL patient detected by FITC-conjugated 27H2 and HPCA-2 were identified with similar sensitivity. Conclusion: A novel murine mAb recognizing class III epitope of human CD34 with high affinity, which is useful for flow cytometric diagnosis of leukemia, was developed.

Inhibitory Effects of Type IV Collagenase by Disulfiram (Disulfiram에 의한 type IV collagenase 저해효과)

  • Sin, Doo-Il;Park, Jae-Bok;Park, Kwan-Kyu;Cho, Chang-Ho;Oh, Hoon-Kyu;Choi, Chang-Hyuk;Cho, Hyun-Ji;Chang, Young-Chae
    • Journal of Life Science
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    • v.16 no.6
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    • pp.964-971
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    • 2006
  • The cancer cells, characterized by local invasion and distant metastasis, are very dependant on extracellular matrix. The expression of matrix metalloproteinases (MMPs) has been implicated in the invasion and metastasis of cancer cells. Among the human MMPs, matirx metalloproteinase-2 (MMP-2) and matrix metalloproteinse-9 (MMP-9) are key enzymes that degrade type IV collagen of the matrix. Here, we studied the effect of disulfiram, an anti-tumor compound, on the suppression of the tumor invasion and the activity of MMP-2, MMP-9 in human osteosarcoma cells (U2OS). Disulfiram had the type IV collagenase inhibitory activity, the effect of inhibition of gene and protein expression, and these inhibitions were responsible for blocking invasion through cell mediated and non-cell mediated pathways. In conclusion, disulfiram inhibited expression of MMP-2 and MMP-9, and regulated the invasion of U2OS, Caki-1 and Caski. These observations raise the possibility of clinical therapeutic applications for disulfiram used as a potential inhibitor of cancer invasion.

Study on the Immunomodulatory Effects of Ellagic Acid and their Mechanisms Related to Toll-like Receptor 4 in Macrophages (Ellagic acid가 대식세포의 면역조절작용에 미치는 영향과 Toll-like receptor 4 관련 작용기전 연구)

  • NamKoong, Seung;Kim, Ye-Jin;Kim, Taeseong;Sohn, Eun-Hwa
    • Korean Journal of Plant Resources
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    • v.25 no.5
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    • pp.561-567
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    • 2012
  • Ellagic acid (EA) is a phenolic compound in fruits and nuts including raspberries, strawberries, grapes and walnuts. Previous studies have indicated that EA possesses antioxidant activity, growth-inhibition and apoptosis-promoting activity in cancer cells. However, macrophage mediated cytotoxicity and immunomodulating effects on cancer cells have not been clarified. In the present study, we show that EA increased effects on macrophage mediated tumoricidal activity and NO production without direct tumor cell cytotoxicity. To further determine whether TLR4 (toll like receptor 4) is involved in anti-tumor activity, cells were treated TLR4 signaling inhibitor, CLI-095 in the presence of EA. CLI-095 treatment partially reduced macrophage-mediated tumoridial activity. EA also has inhibitory effects of NO production induced by LPS, whereas phagocytic activity was not changed. These results suggest that EA induces macrophage mediated tumoricidal activity which is partially related to TLR4 signaling and has a potential adjuvant in cancer therapy.

Application of Oryza sativa (Rice) Bran Oil as an Anti-pollution Cosmetic Material (쌀겨오일의 안티폴루션 화장품 소재로써의 응용)

  • Kang, Hae-Ran;Jung, So Young;Heo, Hyojin;Cha, Byungsun;Brito, Sofia;Lee, So Min;Yeo, Hye Lim;Yoo, Kyung Wan;Kwak, Jun Soo;Kwak, Byeong-Mun;Lee, Mi-Gi;Bin, Bum-Ho
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.47 no.3
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    • pp.237-245
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    • 2021
  • Particulate matter and ultra-particle matters generally refer to very small floating dust, such as 1/6 to 1/7 and 1/20 to 1/30, respectively, compared to the thickness of human hair, and contain various types of heavy metal ions. In addition to breathing, particle matters (PM) that flows in through the gaps in the pores of the skin can induce health problems in the body's tissues and skin, so it must be removed by blocking the inflow or by washing. Through this study, we confirmed the possibility that heavy metal ions can be adsorbed and removed by using Oryza sativa (Rice) bran oil (OSBO). In addition, the cell viability is much higher than that of grain-derived components through cytotoxicity experiments, and the cytoprotective effect of an external stimulus source can be expected. It was confirmed that the expression amount of COL1A1 mRNA increased, and accordingly, it was believed that wrinkles that might be caused by moisture lost by heavy metal ions in fine dust could be alleviated. Based on the results of these experiments, we tried to present a cosmetics containing OSBO, which is a wash-off formulation, in order to finally remove heavy metals.

Proteasome Inhibitor-Induced IκB/NF-κB Activation is Mediated by Nrf2-Dependent Light Chain 3B Induction in Lung Cancer Cells

  • Lee, Kyoung-Hee;Lee, Jungsil;Woo, Jisu;Lee, Chang-Hoon;Yoo, Chul-Gyu
    • Molecules and Cells
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    • v.41 no.12
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    • pp.1008-1015
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    • 2018
  • $I{\kappa}B$, a cytoplasmic inhibitor of nuclear factor-${\kappa}B$ ($NF-{\kappa}B$), is reportedly degraded via the proteasome. However, we recently found that long-term incubation with proteasome inhibitors (PIs) such as PS-341 or MG132 induces $I{\kappa}B{\alpha}$ degradation via an alternative pathway, lysosome, which results in $NF-{\kappa}B$ activation and confers resistance to PI-induced lung cancer cell death. To enhance the anti-cancer efficacy of PIs, elucidation of the regulatory mechanism of PI-induced $I{\kappa}B{\alpha}$ degradation is necessary. Here, we demonstrated that PI up-regulates nuclear factor (erythroid-derived 2)-like 2 (Nrf2) via both de novo protein synthesis and Kelch-like ECH-associated protein 1 (KEAP1) degradation, which is responsible for $I{\kappa}B{\alpha}$ degradation via macroautophagy activation. PIs increased the protein level of light chain 3B (LC3B, macroautophagy marker), but not lysosome-associated membrane protein 2a (Lamp2a, the receptor for chaperone-mediated autophagy) in NCI-H157 and A549 lung cancer cells. Pretreatment with macroautophagy inhibitor or knock-down of LC3B blocked PI-induced $I{\kappa}B{\alpha}$ degradation. PIs up-regulated Nrf2 by increasing its transcription and mediating degradation of KEAP1 (cytoplasmic inhibitor of Nrf2). Overexpression of dominant-negative Nrf2, which lacks an N-terminal transactivating domain, or knock-down of Nrf2 suppressed PI-induced LC3B protein expression and subsequent $I{\kappa}B{\alpha}$ degradation. Thus, blocking of the Nrf2 pathway enhanced PI-induced cell death. These findings suggest that Nrf2-driven induction of LC3B plays an essential role in PI-induced activation of the $I{\kappa}B$/$NF-{\kappa}B$ pathway, which attenuates the anti-tumor efficacy of PIs.

Functional Characterization of the Extracts from Nipa Palm, Molokhia, and Finger Root for Cosmetic Ingredients (니파팜, 몰로키아, 핑거루트 추출물의 화장품 소재로서의 기능적 특성 분석)

  • Jun, Yue Jin;Lee, Sohyun;Heo, Sojeong;Jin, Byung Suk
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.3
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    • pp.821-829
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    • 2019
  • This study was conducted to evaluate the applicability of the extracts from nipa palm, molokhia, and finger root in functional cosmetics as a natural active ingredient. The extracts were obtained through the processes of heating under reflux with ethanol, filtration, concentration, and freeze-drying. UV absorption and blocking effects of the extracts were examined by using the UV-vis spectrophotometer equipped with an integrating sphere. Antioxidant activity and its stability between the extracts were compared using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. Also, total polyphenol content in the extracts was determined quantitatively using the Folin-Ciocalteu reagent, with gallic acid as the standard. Antibacterial activity of the extracts was investigated by the disc diffusion test against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative). Finally, collagenase inhibitor assay was performed to examine the anti-wrinkle effect of the extracts. From the results of this study, the extract of nipa palm showed the potential for use in cosmetics as an antioxidant and anti-wrinkle agent, and the extract of finger root as a sunscreen and antibacterial agent.

Anthocyanins from Hibiscus syriacus L. Attenuate LPS-Induced Inflammation by Inhibiting the TLR4-Mediated NF-κB Signaling Pathway

  • Karunarathne, Wisurumuni Arachchilage Hasitha Maduranga;Molagoda, Ilandarage Menu Neelaka;Lee, Kyoung Tae;Choi, Yung Hyun;Kang, Chang-Hee;Jeong, Jin-Woo;Kim, Gi-Young
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.10a
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    • pp.92-92
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    • 2019
  • Excessive or chronic inflammation contributes to the pathogenesis of many inflammatory diseases such as sepsis, rheumatoid arthritis, and ulcerative colitis. Hibiscus syriacus L. has been used as a medicinal plant in many Asian countries, even though its anti-inflammatory activity has been unclear. Therefore, we investigated the anti-inflammatory effect of anthocyanin fractions from the H. syriacus L. varieties Pulsae (PS) on the lipopolysaccharide (LPS)-induced expression of proinflammatory mediators and cytokines in RAW264.7 macrophages. PS suppressed LPS-induced nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) secretion concomitant with downregulation of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) expression. Furthermore, PS inhibited the production of proinflammatory cytokines such as tumor necrosis factor-alpha ($TNF-{\alpha}$), interleukin-6 (IL-6), and IL-12 in LPS-stimulated RAW264.7 macrophages. Further study showed that PS significantly decreased LPS-induced nuclear translocation of the nuclear $factor-{\kappa}B$ ($NF-{\kappa}B$) subunits, p65 and p50. Molecular docking data showed that many anthocyanins from PS fit into the hydrophobic pocket of MD2 and bound to Toll-like receptor 4 (TLR4), indicating that PS inhibits the TLR4-MD2-mediated inflammatory signaling pathway. Especially, apigenin-7-O-glucoside most powerfully bound to MD2 and TLR4 through LYS122, LYS122, and SER127 at a distance of $2.205{\AA}$, $3.098{\AA}$, and $2.844{\AA}$ and SER441 at a distance of $2.873{\AA}$ (docking score: -8.4) through hydrogen bonding, respectively. Additionally, PS inhibited LPS-induced TLR4 dimerization/expression on the cell surface, which consequently decreased MyD88 recruitment and IRAK4 phosphorylation. PS completely blocked LPS-mediated mortality in zebrafish larvae by diminishing the recruitment of neutrophil and macrophages accompanied by low levels of proinflammatory cytokines. Taken together, our results indicate that PS attenuates LPS-mediated inflammation in both in vitro and in vivo by blocking the TLR4/MD2-MyD88/IRAK4-$NF-{\kappa}B$ axis. Therefore, PS might be used as a novel modulatory candidate for effective treatment of LPS-mediated inflammatory diseases.

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Antimicrobial Peptide CopA3 Induces Survivin Expression in Human Colonocytes Through the Transcription Factor Sp1 (인간 대장상피세포에서 항균펩타이드 CopA3에 의한 survivin 발현 조절 기작 규명)

  • Kim, Ho
    • Journal of Life Science
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    • v.32 no.1
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    • pp.23-28
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    • 2022
  • CopA3 (LLCIALRKK), an antimicrobial peptide isolated from the Korean dung beetle, has been shown to suppress apoptosis in various cell types. CopA3 inhibits not only bacterial toxin-induced colonocyte apoptosis but also 6-hydroxy dopamine-induced neural cell apoptosis. Our recent study revealed that CopA3 directly binds to caspases (key regulators of apoptosis) and inhibits the proteolytic cleavage required for their activation. But molecular mechanisms underlying CopA3-mediated inhibition of apoptosis in multiple cell types remain unknown. Here we assessed possible effects of CopA3 on expression of survivin, which is known to inhibit apoptosis. In HT29 human colonocytes, CopA3 exposure markedly upregulated survivin expression in a concentration- and time-dependent manner. RT-PCR revealed that CopA3-mediated upregulation of survivin was attributable to increased gene transcription, and further showed that CopA3 also increased expression of Sp1, one of many transcription factors known to be involved in transcription of the survivin gene. Notably, blocking Sp1 by treatment with the Sp1 inhibitor, tolfenamic acid, significantly reduced CopA3-mediated upregulation of survivin. These results collectively suggest that CopA3 induces Sp1 expression, which in turn is involved in upregulation of survivin in human colonocytes. These novel findings establish another pathway for explaining the anti-apoptotic effects of CopA3 against various cellular apoptosis systems.

Suppression of Monosodium Urate-induced NLRP3 Inflammasome Activation by Garlic-derived Sulfur-containing Phytochemicals is Associated with Blocking ROS Generation in RAW 264.7 Macrophages (RAW 264.7 대식세포에서 마늘 유래 황 함유 화합물에 의한 요산 유도 inflammasome 활성화의 억제는 ROS 생성 차단과 연관성이 있음)

  • Min Yeong Kim;Yung Hyun Choi
    • Journal of Life Science
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    • v.33 no.4
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    • pp.349-356
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    • 2023
  • Gout, a chronic inflammatory arthritic disease, is characterized by hyperuricemia. Gout can be induced by an inflammatory response to monosodium urate (MSU) crystals mediated by pro-inflammatory cytokine release following activation of the NOD-like receptor protein 3 (NLRP3) inflammasome. Many sulfur-containing phytochemical compounds in garlic (Allium sativum L.) are considered active ingredients because of their potential pharmacological benefits for various diseases, but their efficacy in NLRP3 inflammasome activation-mediated gout has not been demonstrated. In this study, we investigated whether diallyl disulfide (DADS) and diallyl trisulfide (DATS), representative garlic-derived sulfur compounds, have an inhibitory effect on MSU-induced NLRP3 inflammasome activation. Our results showed that under non-cytotoxic conditions, DADS and DATS significantly blocked nitric oxide production and interleukin (IL)-1β release in response to MSU in lipopolysaccharide (LPS)-primed RAW 264.7 macrophages. DADS and DATS also attenuated enhanced expression of NLRP3 and its adapter protein, apoptosis-associated speck-like protein, which was associated with downregulation of and caspase-1 p20 and IL-1β expression, suggesting that MSU-induced LRP3 inflammasome activation was counteracted by DADS and DATS. Furthermore, DADS and DATS blocked oxidative stress, an upstream event for NLRP3 inflammasome activation, as evidenced by the fact that they scavenged reactive oxygen species (ROS) production. Taken together, our findings demonstrate that DADS and DATS suppressed NLRP3 inflammasome activation by inhibiting the ROS/NLRP3 pathway and that they have potential as treatments for NLRP3-dependent gouty arthritis.

Differential Intracellular Localization of Mitotic Centromere-associated Kinesin (MCAK) During Cell Cycle Progression in Human Jurkat T Cells (인체 Jurkat T 세포에 있어서 세포주기에 따른 MCAK 단백질의 세포 내 위치변화)

  • Jun Do Youn;Rue Seok Woo;Kim Su-Jung;Kim Young Ho
    • Journal of Life Science
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    • v.15 no.2 s.69
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    • pp.253-260
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    • 2005
  • Mitotic centromere-associated kinesin (MCAK), which is a member of the Kin I (internal motor domain) subfamily of kinesin-related proteins, is known to play a role in mitotic segregation of chromosome during M phase of the cell cycle. In the present study, we have produced a rat polyclonal antibody using human MCAK (HsMCAK) expressed in E. coli as the antigen. The antibody specifically recognized the HsMCAK protein (81 kDa), and could detect its nuclear localization in human Jurkat T cells and 293T cells by Western blot analysis. The specific stage of the cell cycle was obtained through blocking by either hydroxyl urea or nocodazole and subsequent releasing from each blocking for 2, 4, and 7 h. While the protein level of HsMCAK reached a maximum level in the S phase with slight decline in the $G_{2}-M$ phase, the electrophoretic mobility shift from $p81^{MCAK}\;to\;p84^{MCAK}$ began to be induced in the late S phase and reached a maximum level in the $G_{2}/M $ phase, and then it disappeared as the cells enter into the $G_{1}$ phase. Immunocytochemical analysis revealed that HsMCAK protein localized to centrosome and nucleus at the interphase, whereas it appeared to localize to the spindle pole, centromere of the condensed mitotic DNA, spindle fiber, or midbody, depending on the specific stage of the M phase. These results demonstrate that a rat polyclonal antibody raised against recombinant HsMCAK expressed in E. coli specifically detects human MCAK, and indicate that the electrophoretic mobility shift from $p81^{MCAK}\;to\;p84^{MCAK}$, which may be associated with its differential intracellular localization during the cell cycle, fluctuates with a maximum level of the shift at the $G_{2}-M$ phase.