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Kim EY, Kim SB, Kim EJ, Kim M, Ryu GH, Shin H, Lim SE, Sohn Y, Jung HS. Phyllostachys nigra Munro var alleviates inflammatory chemokine expression and DNCB-induced atopic-like dermatitis in BALB/c mice. J Ethnopharmacol 2024; 318:116953. [PMID: 37506780 DOI: 10.1016/j.jep.2023.116953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/20/2023] [Accepted: 07/21/2023] [Indexed: 07/30/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Phyllostachys nigra (PN) is an herbal medicine that originates from the inner bark of Phyllostachys nigra Munro var. henosis Stapf or Phyllostachys bambusoides Siebold et Zuccarini. It has long been used to relieve fever and to treat diarrhea and inflammation. PN has been shown to possess inhibitory effects on pneumonia, intestinal inflammation, tumors, and fatigue. However, its potential efficacy in the treatment of atopic dermatitis (AD) has not been extensively studied or reported. AIM OF THE STUDY The objective of this research was to investigate the impact of PN on HaCaT and HMC-1 cells, as well as its potential in an experimental model of AD induced by 1-chloro-2,4-dinitrobenzene (DNCB). METHODS We analyzed the anti-inflammatory efficacy of PN in HaCaT cells and HMC-1 cells using ELISA and PCR, and investigated invasion of inflammatory cell, change of dermis and epidermis, and the SCORAD index in AD-like mice model. We also measured the MAPK signaling pathway using the dorsal tissue of mice. RESULTS Our results show that PN reduced the expressions of TARC, GM-CSF, TNF-α, MCP-1, and IL-6 in vitro. PN also decreased the SCORAD index, thickening of epidermis and dermis, and inhibited the invasions of mast cells and eosinophils as well as CD4+ T and CD8+ T cells. Furthermore, PN suppressed the level of IgE and IL-6, and also inhibited the MAPK phosphorylation in the dorsal skin. CONCLUSION These results demonstrate that PN could be an effective alternative medicine for allergic inflammatory disease.
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Affiliation(s)
- Eun-Young Kim
- Department of Anatomy, College of Korean Medicine, Kyung Hee University, 26, Kyunghee dae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Sang-Bae Kim
- Department of Anatomy, College of Korean Medicine, Kyung Hee University, 26, Kyunghee dae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Eom Ji Kim
- Department of Anatomy, College of Korean Medicine, Kyung Hee University, 26, Kyunghee dae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Myunghyun Kim
- Department of Anatomy, College of Korean Medicine, Kyung Hee University, 26, Kyunghee dae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Gwang-Hyun Ryu
- Department of Anatomy, College of Korean Medicine, Kyung Hee University, 26, Kyunghee dae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Hwajeong Shin
- Department of Anatomy, College of Korean Medicine, Kyung Hee University, 26, Kyunghee dae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Seo-Eun Lim
- Department of Anatomy, College of Korean Medicine, Kyung Hee University, 26, Kyunghee dae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Youngjoo Sohn
- Department of Anatomy, College of Korean Medicine, Kyung Hee University, 26, Kyunghee dae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Hyuk-Sang Jung
- Department of Anatomy, College of Korean Medicine, Kyung Hee University, 26, Kyunghee dae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
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Jun JY, Kim JH, Kim M, Hong S, Kim M, Ryu GH, Park JH, Jung HS, Sohn Y. Persicae Semen Promotes Bone Union in Rat Fractures by Stimulating Osteoblastogenesis through BMP-2 and Wnt Signaling. Int J Mol Sci 2023; 24:ijms24087388. [PMID: 37108563 PMCID: PMC10138545 DOI: 10.3390/ijms24087388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/30/2023] [Accepted: 04/04/2023] [Indexed: 04/29/2023] Open
Abstract
Fractures cause extreme pain to patients and impair movement, thereby significantly reducing their quality of life. However, in fracture patients, movement of the fracture site is restricted through application of a cast, and they are reliant on conservative treatment through calcium intake. Persicae semen (PS) is the dried mature seeds of Prunus persica (L.) Batsch, and in this study the effects of PS on osteoblast differentiation and bone union promotion were investigated. The osteoblast-differentiation-promoting effect of PS was investigated through alizarin red S and Von Kossa staining, and the regulatory role of PS on BMP-2 (Bmp2) and Wnt (Wnt10b) signaling, representing a key mechanism, was demonstrated at the protein and mRNA levels. In addition, the bone-union-promoting effect of PS was investigated in rats with fractured femurs. The results of the cell experiments showed that PS promotes mineralization and upregulates RUNX2 through BMP-2 and Wnt signaling. PS induced the expression of various osteoblast genes, including Alpl, Bglap, and Ibsp. The results of animal experiments show that the PS group had improved bone union and upregulated expression of osteogenic genes. Overall, the results of this study suggest that PS can promote fracture recovery by upregulating osteoblast differentiation and bone formation, and thus can be considered a new therapeutic alternative for fracture patients.
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Affiliation(s)
- Jae-Yun Jun
- Department of Anatomy, College of Korean Medicine, Seoul 02447, Republic of Korea
| | - Jae-Hyun Kim
- Department of Anatomy, College of Korean Medicine, Seoul 02447, Republic of Korea
| | - Minsun Kim
- Department of Anatomy, College of Korean Medicine, Seoul 02447, Republic of Korea
| | - Sooyeon Hong
- Department of Anatomy, College of Korean Medicine, Seoul 02447, Republic of Korea
| | - Myunghyun Kim
- Department of Anatomy, College of Korean Medicine, Seoul 02447, Republic of Korea
| | - Gwang-Hyun Ryu
- Department of Anatomy, College of Korean Medicine, Seoul 02447, Republic of Korea
| | - Jae Ho Park
- Department of Pharmaceutical Science, Jungwon University, Goesan-eup 28024, Republic of Korea
| | - Hyuk-Sang Jung
- Department of Anatomy, College of Korean Medicine, Seoul 02447, Republic of Korea
| | - Youngjoo Sohn
- Department of Anatomy, College of Korean Medicine, Seoul 02447, Republic of Korea
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Bertinshaw J, Gurung N, Jorba P, Liu H, Schmid M, Mantadakis DT, Daghofer M, Krautloher M, Jain A, Ryu GH, Fabelo O, Hansmann P, Khaliullin G, Pfleiderer C, Keimer B, Kim BJ. Unique Crystal Structure of Ca_{2}RuO_{4} in the Current Stabilized Semimetallic State. Phys Rev Lett 2019; 123:137204. [PMID: 31697510 DOI: 10.1103/physrevlett.123.137204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 07/26/2019] [Indexed: 06/10/2023]
Abstract
The electric-current stabilized semimetallic state in the quasi-two-dimensional Mott insulator Ca_{2}RuO_{4} exhibits an exceptionally strong diamagnetism. Through a comprehensive study using neutron and x-ray diffraction, we show that this nonequilibrium phase assumes a crystal structure distinct from those of equilibrium metallic phases realized in the ruthenates by chemical doping, high pressure, and epitaxial strain, which in turn leads to a distinct electronic band structure. Dynamical mean field theory calculations based on the crystallographically refined atomic coordinates and realistic Coulomb repulsion parameters indicate a semimetallic state with partially gapped Fermi surface. Our neutron diffraction data show that the nonequilibrium behavior is homogeneous, with antiferromagnetic long-range order completely suppressed. These results provide a new basis for theoretical work on the origin of the unusual nonequilibrium diamagnetism in Ca_{2}RuO_{4}.
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Affiliation(s)
- J Bertinshaw
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - N Gurung
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - P Jorba
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
| | - H Liu
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - M Schmid
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
- Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - D T Mantadakis
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - M Daghofer
- Institute for Functional Matter and Quantum Technologies, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
- Center for Integrated Quantum Science and Technology, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany
| | - M Krautloher
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - A Jain
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
- Solid State Physics Division, Bhabha Atomic Research Center, Mumbai 400 085, India
| | - G H Ryu
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - O Fabelo
- Institut Laue Langevin, BP 156, F-38042 Grenoble cedex 9, France
| | - P Hansmann
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
- Max Planck Institute for Chemical Physics of Solids, Nöthnitzerstr Straße 40, D-01187 Dresden, Germany
| | - G Khaliullin
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - C Pfleiderer
- Physik-Department, Technische Universität München, D-85748 Garching, Germany
| | - B Keimer
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
| | - B J Kim
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, D-70569 Stuttgart, Germany
- Department of Physics, Pohang University of Science and Technology, Pohang 790-784, South Korea
- Center for Artificial Low Dimensional Electronic Systems, Institute for Basic Science (IBS), 77 Cheongam-Ro, Pohang 790-784, South Korea
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Yu G, Zhang GY, Ryu GH, Lin CT. Structure and superconductivity of (Li1-x Fe x )OHFeSe single crystals grown using A x Fe2-y Se2 (A = K, Rb, and Cs) as precursors. J Phys Condens Matter 2016; 28:015701. [PMID: 26656943 DOI: 10.1088/0953-8984/28/1/015701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We present results on the hydrothermal growth of ([Formula: see text])OHFeSe single crystals using floating-zone-grown [Formula: see text] (A = K, Rb, and Cs) as precursors. The growth proceeds by the hydrothermal ion exchange of Li/Fe-O-H for K, Rb, and Cs, resulting in a stacking layer of ([Formula: see text])OH sandwiched between the FeSe layers. Optimal growth parameters are achieved using high quality A 0.80Fe1.81Se2 single crystals added to the mixtures of LiOH, H2O, Fe and C(NH2)2Se in an autoclave and subsequently heated to 120 °C for 2 d, to obtain highest quality single crystals. The obtained crystals have lateral dimensions up to centimeters, with the final size related to that of the precursor crystal used. All ([Formula: see text])OHFeSe single crystals show a superconducting transition temperature T c > 42 K, regardless of the phase of the precursor such as superconducting K0.80Fe1.81Se2 (T c = 29.31 K) or non-superconducting Rb0.80Fe1.81Se2 or poor-superconducting Cs0.80Fe1.81Se2 (T c = 28.67 K). The T c and transition width ΔT vary in the obtained single crystals, due to the inhomogeneity of the ionic exchange. X-ray diffraction analysis demonstrates that the 245 insulating phase is absent in the ion-exchanged single crystals, while it is observed in the [Formula: see text] precursors. Comparative studies of the structure, magnetization, and superconductivity on the parent A 0.80Fe1.81Se2 and the ion-exchanged ([Formula: see text])OHFeSe crystals are discussed. A phase diagram including antiferromagnetic spin density wave and superconducting phases is also proposed.
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Affiliation(s)
- G Yu
- Max Planck Institute for Solid State Research, D 70569 Stuttgart, Germany. Shijiazhuang Tiedao University, Shijiazhuang 050043, People's Republic of China
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Li MT, Chen L, Li ZW, Ryu GH, Lin CT, Zhang JC. Enhancement of phase separation and superconductivity in Mn-doped K0.8Fe2-yMnySe2 crystals. J Phys Condens Matter 2013; 25:335701. [PMID: 23880791 DOI: 10.1088/0953-8984/25/33/335701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Single crystals of K0.8Fe2-yMnySe2 with slight Mn doping have been grown by a self-flux method. X-ray diffraction measurements show enhanced phase separation with increasing Mn doping in the compounds. The superconducting transition temperature increases to Tc,onset ∼ 46.1 K for the sample with y ∼ 0.03, as observed by electrical transport measurements. Our results demonstrate that the doping of Mn does not suppress the superconductivity, and on the contrary increases the superconducting shield fraction and transition temperature, an effect which may originate from the Mn dopant's high preference to fill into iron vacancies in the Mn-doped samples. It suggests that the Mn dopant can induce a local lattice strain or distortion that profitably modifies the microstructure of the superconducting/metallic phase, leading to superconductivity of the compound.
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Affiliation(s)
- M T Li
- Department of Physics, Shanghai University, Shanghai 200444, People's Republic of China
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Lee JW, Jung MC, Park HD, Park KD, Ryu GH. Synthesis and characterization of thermosensitive chitosan copolymer as a novel biomaterial. J Biomater Sci Polym Ed 2005; 15:1065-79. [PMID: 15461190 DOI: 10.1163/1568562041526496] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Novel water-soluble thermosensitive chitosan copolymers were prepared by graft polymerization of N-isopropylacrylamide (NIPAAm) onto chitosan using cerium ammonium nitrate (CAN) as an initiator. The physicochemical properties of the resulting chitosan-g-NIPAAm copolymers were characterized by Fourier transform infrared (FT-IR) spectroscopy, 1H-nuclear magnetic resonance, X-ray diffraction measurement, thermogravimetric analysis (TGA) and solubility test. Sol-gel transition behavior was investigated by the cloud point measurement of the chitosan-g-NIPAAm aqueous solution. The gelling temperature was examined using the vial inversion method. The percentage of grafting (%) and efficiency of grafting (%) were investigated according to concentrations of monomer and initiator. The maximum grafted chitosan copolymer was obtained with 0.4 M NIPAAm and 6 x 10(-3) M CAN. Water-soluble chitosan-g-NIPAAm copolymers were prepared successfully and they formed thermally reversible hydrogel, which exhibits a lower critical solution temperature (LCST) around 32 degrees C in aqueous solutions. A preliminary in vitro cell study showed nontoxic and biocompatible properties. These results suggest that chitosan-g-NIPAAm copolymer could be very useful in biomedical and pharmaceutical applications as an injectable material for cell and drug delivery.
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Affiliation(s)
- J W Lee
- Department of Molecular Science and Technology, Ajou University, Suwon 442-749, South Korea
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Park YH, Han DW, Suh H, Ryu GH, Hyon SH, Cho BK, Park JC. Protective effects of green tea polyphenol against reactive oxygen species-induced oxidative stress in cultured rat calvarial osteoblast. Cell Biol Toxicol 2003; 19:325-37. [PMID: 14703119 DOI: 10.1023/b:cbto.0000004986.51081.c5] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The injurious effects of reactive oxygen species on osteoblasts and the potential protective role played by green tea polyphenols (GtPP) were investigated using primarily cultured rat calvarial osteoblasts. Oxidative stress was induced in cultured osteoblasts, either by adding 100 mmol/L H2O2 or by the action of 40 U/L xanthine oxidase (XO) in the presence of xanthine (250 micromol/L). After incubation, the cellular viability, function and morphology were evaluated. Both treatments produced a significant reduction in osteoblast viability, as assessed by a two-colored fluorescence staining method combined with flow cytometric analysis and MTT assay. A significant reduction in the alkaline phosphatase activity was observed after H2O2 addition, whereas XO did not have the same effect. On the microscopic observations, the morphological changes and intracellular ultrastructural damages were remarkably induced by both treatments. The H2O2-induced alterations were prevented by pre-incubating the osteoblasts with 200 microg/ml GtPP for 1 h. When the oxidative stress was induced by XO, the cellular viability and morphology was also maintained at the same polyphenol concentration. These results demonstrate that GtPP can act as a biological antioxidant in a cell culture experimental model and protect cells from oxidative stress-induced toxicity.
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Affiliation(s)
- Y H Park
- Department of Medical Engineering, Cardiovascular Research Institute, Yonsei University College of Medicine Seoul, Korea
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Pedrazzi G, Perrera C, Blaser H, Kuster P, Marra G, Davies SL, Ryu GH, Freire R, Hickson ID, Jiricny J, Stagljar I. Direct association of Bloom's syndrome gene product with the human mismatch repair protein MLH1. Nucleic Acids Res 2001; 29:4378-86. [PMID: 11691925 PMCID: PMC60193 DOI: 10.1093/nar/29.21.4378] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Bloom's syndrome (BS) is a rare genetic disorder characterised by genomic instability and cancer susceptibility. BLM, the gene mutated in BS, encodes a member of the RecQ family of DNA helicases. Here, we identify hMLH1, which is involved in mismatch repair (MMR) and recombination, as a protein that directly interacts with BLM both in vivo and in vitro, and that the two proteins co-localise to discrete nuclear foci. The interaction between BLM and hMLH1 appears to have been evolutionarily conserved, as Sgs1p, the Saccharomyces cerevisiae homologue of BLM, interacts with yeast Mlh1p. However, cell extracts derived from BS patients show no obvious defects in MMR compared to wild-type- and BLM-complemented BS cell extracts. We conclude that the hMLH1-BLM interaction is not essential for post-replicative MMR, but, more likely, is required for some aspect of genetic recombination.
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Affiliation(s)
- G Pedrazzi
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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Lee KH, Kim DW, Bae SH, Kim JA, Ryu GH, Kwon YN, Kim KA, Koo HS, Seo YS. The endonuclease activity of the yeast Dna2 enzyme is essential in vivo. Nucleic Acids Res 2000; 28:2873-81. [PMID: 10908349 PMCID: PMC102684 DOI: 10.1093/nar/28.15.2873] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2000] [Accepted: 06/14/2000] [Indexed: 11/12/2022] Open
Abstract
Dna2 is a multifunctional enzyme in yeast that possesses endonuclease activity well suited to remove RNA-DNA primers of Okazaki fragments, raising the question of whether endonuclease activity is essential for in vivo Dna2 function. Systematic site-directed mutations of amino acid residues in Saccharomyces cerevisiae DNA2 conserved in the central region of many eukaryotic DNA2 homologs allowed us to identify mutant dna2 alleles that were divided into three groups based on the viability of the mutant cells: (i) viable; (ii) inviable only when expression was repressed; (iii) inviable. Biochemical analyses of recombinant mutant Dna2 proteins isolated from the latter two groups revealed that they possessed normal ATPase/helicase activity, but were impaired in their endonuclease activity. Cells expressing mutant Dna2 enzymes partially impaired in endonuclease activity were viable, but were unable to grow when expression of their mutant Dna2 enzymes was further reduced. Their growth was restored when the mutant Dna2 proteins decreased in nuclease activity were induced to overexpress. In contrast, mutant Dna2 proteins lacking endonuclease activity did not allow cells to grow under any conditions tested. These in vivo and in vitro results demonstrate that the endonuclease activity of Dna2 is essential for Okazaki fragment processing.
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Affiliation(s)
- K H Lee
- National Creative Research Initiative Center for Cell Cycle Control, Sungkyunkwan University School of Medicine, 300 Chunchun-Dong, Changan-Ku, Suwon-Si, Kyunggi-Do 440-746, Korea
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Han SJ, Lee YC, Gim BS, Ryu GH, Park SJ, Lane WS, Kim YJ. Activator-specific requirement of yeast mediator proteins for RNA polymerase II transcriptional activation. Mol Cell Biol 1999; 19:979-88. [PMID: 9891034 PMCID: PMC116029 DOI: 10.1128/mcb.19.2.979] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The multisubunit Mediator complex of Saccharomyces cerevisiae is required for most RNA polymerase II (Pol II) transcription. The Mediator complex is composed of two subcomplexes, the Rgr1 and Srb4 subcomplexes, which appear to function in the reception of activator signals and the subsequent modulation of Pol II activity, respectively. In order to determine the precise composition of the Mediator complex and to explore the specific role of each Mediator protein, our goal was to identify all of the Mediator components. To this end, we cloned three previously unidentified Mediator subunits, Med9/Cse2, Med10/Nut2, and Med11, and isolated mutant forms of each of them to analyze their transcriptional defects. Differential display and Northern analyses of mRNAs from wild-type and Mediator mutant cells demonstrated an activator-specific requirement for each Mediator subunit. Med9/Cse2 and Med10/Nut2 were required, respectively, for Bas1/Bas2- and Gcn4-mediated transcription of amino acid biosynthetic genes. Gal11 was required for Gal4- and Rap1-mediated transcriptional activation. Med11 was also required specifically for MFalpha1 transcription. On the other hand, Med6 was required for all of these transcriptional activation processes. These results suggest that distinct Mediator proteins in the Rgr1 subcomplex are required for activator-specific transcriptional activation and that the activation signals mediated by these Mediator proteins converge on Med6 (or the Srb4 subcomplex) to modulate Pol II activity.
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Affiliation(s)
- S J Han
- Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University College of Medicine, Seoul 135-230, Korea
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Abstract
Adsorption of proteins (fibrinogen, albumin, and gamma globulin) from plasma onto surface-modified PUs (PU-PEO, PU-SO3, and PU-PEO-SO3) was evaluated. Adsorbed fibrinogen at steady state decreased in the order PU-SO3 > PU > PU-PEO-SO3 > PU-PEO, suggesting that sulfonate groups have specific high affinity to fibrinogen. The intermediate fibrinogen adsorption on PU-PEO-SO3 can be explained by the compensatory effect between the low protein binding affinity of the PEO chain and the high fibrinogen binding affinity of the sulfonate group. In addition, PU-PEO-SO3 showed a very fast fibrinogen adsorption due to the high accessibility of the sulfonate group to fibrinogen by the poly(ethylene oxide) (PEO) spacer. The kinetic profiles of their surfaces showed that as the adsorption time increases, fibrinogen initially adsorbed was decreased and a plateau reached, demonstrating that all the surfaces exhibited the Vroman effect (the fibrinogen displacement phenomenon). PU-PEO showed the least fibrinogen and albumin adsorption among PUs, confirming the known nonadhesive property of PEO chains. It is very interesting that PU-PEO-SO3 exhibited the highest adsorption of albumin and the lowest adsorption of IgG. Therefore, it may be concluded that such adsorption behaviors of proteins to PU-PEO-SO3 contribute to improved blood compatibility.
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Affiliation(s)
- D K Han
- Polymer Chemistry Laboratory, Korea Institute of Science and Technology, Seoul, Korea
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12
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Abstract
The composition and molecular organization of adsorbed protein films are strongly correlated with thrombogenesis on artificial surfaces. In particular, the antibody-detectable (that is, conformationally intact) bound fibrinogen, but not that the total amount of adsorbed fibrinogen, is correlated with platelet reactivity. In this work, the authors quantified the adsorbed plasma protein distribution inside the left ventricular assist device. They also evaluated the effect of wall shear stress on protein adsorption and conformational change of adsorbed fibrinogen. Conformational change of adsorbed fibrinogen was measured by exposing the fibrinogen preadsorbed polyurethane to three anti-fibrinogen monoclonal antibodies; the 134B-29 detectable alpha 566-580 domain of fibrinogen was increased with increasing concentration of adsorbed fibrinogen, whereas the other two fibrinogen domains were almost saturated when increasing the concentration of adsorbed fibrinogen. The adsorbed amounts of total fibrinogen and monoclonal antibody detectable fibrinogen was decreased with increasing shear rate. Results of in vivo plasma protein adsorption on polyurethane surfaces disclosed that the adsorbed amount of fibrinogen, as well as albumin and globulin, was also decreased with increasing shear rate. In conclusion, less protein was adsorbed in the higher shear region and the effect of shear level on fibrinogen adsorption and its conformational change was strongly dependent upon the surface characteristics of the biomaterials. The monoclonal antibody 134B-29 against the 566-580 domain of fibrinogen was the most reactive with the fibrinogen adsorbed on polyurethane surfaces in this experiment.
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Affiliation(s)
- G H Ryu
- Department of Biomedical Engineering, Seoul National University College of Medicine, Korea
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Abstract
Cardiac dysfunctions such as myocardial functional failure and ventricular arrhythmia have been largely attributed to intracellular Ca2+ overload. One of the mechanisms of intracellular Ca2+ overload involves a rapid influx of Ca2+ via Na(+)-Ca2+ exchange during the reperfusion which utilizes the accumulation of Na+ in myocytes during ischemic cardiac arrest. Possible sources of the intracellular Na+ accumulation include Na+ channel, Na(+)-H+ exchange, Na(+)-Ca2+ exchange, and Na+ background current. In this study, we studied the role of the Na+ background current in intracellular Na+ accumulation during the cardiac arrest by measuring the Na+ background current in guinea pig ventricular myocytes with whole cell clamp method and evaluating the effects of cardioprotective drugs on the Na+ background current. The results were as follows: (1) The Na+ background inward current at -40 mV membrane potential was larger at Ca2+ free solution than 1.8 mM Ca2+ solution. (2) The Na+ background current was not affected by verapamil. (3) 2 microM O-(N, N-hexamethylene)-amiloride (HMA) decreased the Na+ background current at negative membrane potential. (4) The new cardioprotective drug, R 56865, decreased the Na+ background current. These results suggest that the Na+ background current plays a role in increasing the intracellular Na+ activity during high K+ cardioplegia and the blocking effect of myoprotective drugs, such as R 56865, on the Na+ background current may contribute to myocardial protection after cardioplegia.
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Affiliation(s)
- S R Park
- Department of Physiology, Inha University College of Medicine, Inchon, Korea
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Ryu GH, Han DK, Park S, Kim M, Kim YH, Min B. Surface characteristics and properties of lumbrokinase-immobilized polyurethane. J Biomed Mater Res 1995; 29:403-9. [PMID: 7615590 DOI: 10.1002/jbm.820290315] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Potent and novel fibrinolytic enzymes (lumbrokinase [LK]) were extracted from the earthworm, Lumbricus rubellus. These enzymes were very stable and showed greater antithrombotic activity than other currently used fibrinolytic proteins. An LK fraction showing the most potent fibrinolytic activity was immobilized onto a polyurethane (PU) surface to investigate its enzymatic activity and antithrombotic activity. A methanol-extracted PU surface was coated with 3% (wt/vol) maleic anhydride methylvinyl ether copolymer (MAMEC)/tetrahydrofuran (THF) solution, and the surface was incubated in an LK solution/phosphate-buffered saline (PBS, pH 7.4). The surface properties were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), electron spectroscopy for chemical analysis (ESCA), and dynamic contact angle. The stability of immobilized LK was determined by caseinolytic activity assay and the specificity of immobilized LK on fibrinogen/fibrin was observed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The antithrombotic activity of immobilized LK was evaluated using an ex vivo rabbit A-A shunt experiment. LK immobilization was confirmed by ATR-FTIR and ESCA. Immobilized LK demonstrated stable proteolytic activity during various incubation periods. Immobilized LK proteolyzed fibrinogen and fibrin almost specifically, while it hardly hydrolyzed other plasma proteins including plasminogen and albumin. In the ex vivo A-A shunt experiment, the LK-immobilized surface significantly prolonged occlusion time over control surfaces. This is primarily due to the high thrombolytic activity of immobilized LK. In this work, a highly efficient surface modification method on the PU surface was developed, and this LK immobilization technique will be very useful in improving the blood compatibility of blood-contacting devices.
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Affiliation(s)
- G H Ryu
- Department of Biomedical Engineering, College of Medicine, Seoul National University, Korea
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Kim SW, Ryu GH, Lee I, Koh JJ, Min BG, Lee HK. Adhered platelet morphology in diabetes mellitus. Diabete Metab 1995; 21:50-3. [PMID: 7781844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We compared the morphology of platelets obtained from diabetic patients in various stages of retinopathy and nephropathy with those of control patients. The platelets were collected on to polyethylene films, processed and observed under scanning electron microscopy. Different platelet morphologies were observed within the diabetic group, correlating with the severity of complications, whereas platelets appeared normal in the control group. After more extensive follow-up and comparative studies, these preliminary observations could provide another diagnostic tool for detecting and evaluating severe complications associated with diabetes.
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Affiliation(s)
- S W Kim
- Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City 84108, USA
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Abstract
Lumbrokinase is a potent fibrinolytic enzyme purified from the earthworm, Lumbricus rubellus. We immobilized 18 IU/cm2 of lumbrokinase to polyurethane using maleic anhydride methylvinyl ether copolymer (MAMEC) as an enzyme carrier, and the proteolytic and fibrinolytic activities of immobilized lumbrokinase were assayed. Immobilized lumbrokinase retained about 34% of its activity, compared with soluble lumbrokinase activity. Immobilized lumbrokinase showed stability against thermal inactivation and degradation and within a various pH range. The optimal pH of immobilized lumbrokinase shifted 1.0 pH unit upward compared with soluble enzyme. Upon exposure to the human whole blood, less amount of 125I-fibrinogen was adsorbed to lumbrokinase-immobilized surface than to the polyurethane control surface. The lumbrokinase-immobilized surface showed less platelet adhesion than did the MAMEC-grafted surface. At the early stage of platelet adhesion, the number of adhered platelets increased on the lumbrokinase-immobilized surface with increasing time; yet, the platelet number drastically decreased on the lumbrokinase-immobilized surface after 80 min incubation. This suggests that lumbrokinase-immobilized polyurethane digested the adsorbed fibrinogen and inhibited platelet adhesion on the surface, probably by inhibiting fibrinogen adsorption to be highly antithrombogenic. Clinical applications of this material to artificial organs should be developed in the near future.
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Affiliation(s)
- G H Ryu
- Department of Biomedical Engineering, College of Medicine, Seoul National University, Korea
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Ryu GH, Park S, Han DK, Kim YH, Min B. Antithrombotic activity of a lumbrokinase immobilized polyurethane surface. ASAIO J 1993; 39:M314-8. [PMID: 8268550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Six fractions of strong and novel fibrinolytic enzymes (lumbrokinase, LK) were extracted from the earthworm Lumbricus rubellus. The enzymes in these fractions appeared to be very stable and showed greater antithrombotic activity than other currently used antithrombotics. The authors immobilized an LK fraction that shows the most potent fibrinolytic activity on a polyurethane (PU) surface to investigate its enzymatic and antithrombotic activity. The methanol extracted PU surface was treated with a 3% (wt/vol) maleic anhydride methylvinyl ether copolymer (MAMEC) solution and finally incubated in an LK solution in PBS (pH 7.4). The immobilized LK activity was estimated by the fibrin plate method and caseinolytic activity assay. The antithrombotic activity was evaluated by in vitro 125I-fibrinogen adsorption in fresh whole blood and 99mTc platelet adhesion tests. In addition, the occlusion time was determined through ex vivo rabbit A-A shunt experiments. The content and unit activity of immobilized LK were found to be 24 micrograms/cm2 and 18 IU/cm2, respectively. The relative activity ratio of immobilized LK to soluble LK was found to be approximately 34%. Immobilized LK was stable within a various pH range and resistant to inhibitors and thermal inactivation. Less fibrinogen was adsorbed and fewer platelets adhered on an LK-immobilized surface than on PU and PU-MAMEC controls. The ex vivo occlusion time of untreated PU and PU-MAMEC surfaces were only 32 and 42 minutes, respectively. But that of LK-immobilized PU was extended to 140 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- G H Ryu
- Department of Biomedical Engineering, College of Medicine, Seoul National University, Korea
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Ryu GH, Kim J, Chang JK, Lee KB, Lee I, Choi JW, Han DK, Kim YH, Min BG. The fluid dynamic effect on protein adsorption in left ventricular assist devices. ASAIO J 1993; 39:M332-6. [PMID: 8268554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Plasma protein adsorption onto an artificial surface is strongly influenced by not only the surface characteristics of materials, but also by the fluid dynamics inside the blood pump, and it would influence subsequent platelet adhesion or activation, which plays a major role in the initiation of thrombus formation at the blood-material interface in vivo. In vitro flow visualization of an electrohydraulic LVAD was performed by a video camera (CCD, Hitachi) and an image processor (PC VISION PLUS) with an IBM PC. The electrohydraulic LVADs were implanted in mongrel dogs of approximately 20 kg. The authors sectioned the blood contacted ventricle after animal death according to the level of shear rate. Because analysis of adsorbed protein might be influenced by the size of the ventricle segment, the number of segments was limited to eight per ventricle. Platelet adhesion and its morphology were observed by scanning electron microscopy (SEM). Adsorbed plasma proteins (fibrinogen, albumin, and IgG) on each segment were quantified by enzyme linked immunosorbent assay (ELISA). The specimens were soaked in 2% (wt/vol) SDS/PBS for 2 days and the released protein concentration assessed. A well developed large vortex was observed at the center of the artificial ventricle. Polyurethane blood pumps displayed different degrees of protein adsorption and subsequent platelet adhesion on each segment.
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Affiliation(s)
- G H Ryu
- Department of Biomedical Engineering, College of Medicine, Seoul National University, Korea
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Han DK, Ryu GH, Park KD, Jeong SY, Kim YH, Min BG. Adsorption behavior of fibrinogen to sulfonated polyethyleneoxide-grafted polyurethane surfaces. J Biomater Sci Polym Ed 1993; 4:401-13. [PMID: 8241058 DOI: 10.1163/156856293x00087] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Fibrinogen adsorptions to surface modified polyurethanes (PU, PU-PEO, and PU-PEO-SO3) were studied from plasma in vitro. PU and PU-PEO surfaces demonstrated that initial adsorption increases with increasing plasma concentration in kinetic profiles and adsorption time in adsorption profiles as a function of plasma concentration, but after the plateau is reached, its adsorption amount decreases as plasma concentration (0.2-2.0%) and adsorption time (1-120 min) increase, respectively. In contrast, PU-PEO-SO3 showed that initial adsorption is almost same regardless of plasma concentration and adsorption time, which is due to the high affinity of surface sulfonate group to fibrinogen. All the surfaces indicated the Vroman effect at about 0.6% plasma concentration; however, the displacement was relatively low. Adsorbed amount of fibrinogen at steady state decreased in the order: PU > PU-PEO-SO3 > PU-PEO, regardless of adsorption time and plasma concentration. The adsorption behavior of PU-PEO-SO3 is attributed to both effect of low binding affinity of PEO chain and high affinity of pendant sulfonate group toward fibrinogen.
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Affiliation(s)
- D K Han
- Polymer Chemistry Laboratory, Korea Institute of Science and Technology, Cheongryang, Seoul
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Min BG, Kim HC, Choi JW, Ryu GH, Seo KP, Rho JR, Ahn H, Kim SW, Diegel PD, Olsen DB. A moving-actuator type electromechanical total artificial heart--Part II: Circular type and animal experiment. IEEE Trans Biomed Eng 1990; 37:1195-200. [PMID: 2289793 DOI: 10.1109/10.64462] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A new type of electromechanical total artificial heart (TAH) based on circular rolling-cylinder mechanism was developed to overcome critical problems in motor-driven artificial hearts such as large size and difficulties in fitting the heart to atrial remnants and arterial vessels. Its performance and reliability were evaluated in mock circulation and in an animal implant experiment. The total weight and volume of the pump is 650 g and 600 mL, respectively. This new pump was implanted in a calf for total heart replacement and 96 h of survival was achieved. The whole system, including pump, controller, and control algorithm performed well enough to improve the prospect of eventual clinical application of our TAH system.
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Affiliation(s)
- B G Min
- Department of Biomedical Engineering, College of Medicine, Seoul National University, Korea
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