Induction of bone formation by <i>Escherichia coli</i>‐expressed recombinant human bone morphogenetic protein‐2 using block‐type macroporous biphasic calcium phosphate in orthotopic and ectopic rat models

Park, J‐,C.,So, S‐,S.,Jung, I‐,H.,Yun, J‐,H.,Choi, S‐,H.,Cho, K‐,S.,Kim, C‐,S. Blackwell Publishing Ltd 2011 Journal of periodontal research Vol.46 No.6

<P><I>Park J‐C, So S‐S, Jung I‐H, Yun J‐H, Choi S‐H, Cho K‐S, Kim C‐S. Induction of bone formation by</I> Escherichia coli<I>‐expressed recombinant human bone morphogenetic protein‐2 using block‐type macroporous biphasic calcium phosphate in orthotopic and ectopic rat models. J Periodont Res 2011; 46: 682–690. © 2011 John Wiley & Sons A/S</I></P><P><B>Background and Objective: </B> The potential of the <I>Escherichia coli</I>‐expressed recombinant human bone morphogenetic protein‐2 (ErhBMP‐2) to support new bone formation/maturation using a block‐type of macroporous biphasic calcium phosphate (bMBCP) carrier was evaluated in an orthotopic and ectopic rat model.</P><P><B>Material and Methods: </B> Critical‐size (Φ 8 mm) calvarial defects and subcutaneous pockets in 32 Sprague–Dawley rats received implants of rhBMP‐2 (2.5 μg) in a bMBCP carrier or bMBCP alone (control). Implant sites were evaluated using histological and histometric analysis following 2‐ and 8‐wk healing intervals (eight animals/group/interval).</P><P><B>Results: </B> ErhBMP‐2/bMBCP supported significantly greater bone formation at 2 and 8 wk (10.8% and 25.4%, respectively) than the control at 2 and 8 wk (5.3% and 14.0%, respectively) in calvarial defects (<I>p</I> < 0.01). Bone formation was only observed for the ErhBMP‐2/bMBCP ectopic sites and was significantly greater at 8 wk (7.5%) than at 2 wk (4.5%) (<I>p</I> < 0.01). Appositional and endochondral bone formation was usually associated with a significant increase in fatty marrow at 8 wk. The bMBCP carrier showed no evidence of bioresorption.</P><P><B>Conclusion: </B> ErhBMP‐2/bMBCP induced significant bone formation in both calvarial and ectopic sites. Further study appears to be required to evaluate the relevance of the bMBCP carrier.</P>

Radiosynthesis and <i>in vitro</i> evaluation of 1‐(tetrahydro‐5‐hydroxy‐6‐(hydroxymethyl)‐2H‐pyran‐3‐yl)‐5‐[¹²⁵I]iodouracil: A new potential agent for HSV1‐tk

Jo, Nam Hyun,Kim, Jung Young,El‐,Gamal, Mohammed I.,Choi, Won‐,Kyoung,Park, Jin‐,Hun,Kim, Eun Jung,Cho, Jung‐,Hyuck,Ha, Hyun‐,Joon,Choi, Tae Hyun,Oh, Chang‐,Hyun John Wiley Sons, Ltd. 2011 Journal of labelled compounds & radiopharmaceutica Vol.54 No.2

<P><B>Abstract</B></P><P>Synthesis, radiolabelling, and <I>in vitro</I> evaluation of a new <SUP>125</SUP>I‐labelled iodouracil hexitol nucleoside analogue are reported. The target compound was successfully synthesized by an iodination–destannylation method and then purified by reverse phase HPLC. The radiochemical purity of the product was >99% with decay‐corrected yields of 48±3%. <I>In vitro</I> cellular uptake testing was carried out using MCA and MCA‐tk cell lines for comparison of compound 1 with [<SUP>18</SUP>F]FHBG. The newly synthesized compound 1 showed higher accumulation in herpex simplex virus type 1 thymidine kinase (HSV1‐tk) gene expression cell line (MCA‐tk cell line) than in the wild type MCA cell line compared with [<SUP>18</SUP>F]FHBG. The MCA‐tk to MCA cellular uptake ratio for compound 1 was higher than that of [<SUP>18</SUP>F]FHBG from 2 h after incubation. The radioiodine‐labelled compound 1 (I‐125, <I>t</I><SUB>1/2</SUB>=59.37 days) has a longer physical half‐life than F‐18‐(<I>t</I><SUB>1/2</SUB>=110 min) labelled FHBG. Radioiodine‐labelled compound 1 could be used for monitoring gene expression for a long time. The selectivity for MCA‐tk cell line makes compound 1 a promising imaging agent for HSV1‐tk expression. Copyright © 2010 John Wiley & Sons, Ltd.</P>

Enhanced adipogenic differentiation and reduced collagen synthesis induced by human periodontal ligament stem cells might underlie the negative effect of recombinant human bone morphogenetic protein‐2 on periodontal regeneration

Song, D‐,S.,Park, J‐,C.,Jung, I‐,H.,Choi, S‐,H.,Cho, K‐,S.,Kim, C‐,K.,Kim, C‐,S. Blackwell Publishing Ltd 2011 Journal of periodontal research Vol.46 No.2

<P> <I>Song D‐S, Park J‐C, Jung I‐H, Choi S‐H, Cho K‐S, Kim C‐K, Kim C‐S. Enhanced adipogenic differentiation and reduced collagen synthesis induced by human periodontal ligament stem cells might underlie the negative effect of recombinant human bone morphogenetic protein‐2 on periodontal regeneration. J Periodont Res 2011; 46: 193–203. © 2010 John Wiley & Sons A/S</I> </P><P><B>Background and Objective: </B> Recombinant human bone morphogenetic protein‐2 (rhBMP‐2) is a potent inducer for the regeneration of mineralized tissue, but has a limited effect on the regeneration of cementum and periodontal ligament (PDL). The aim of the present study was to determine the effects of rhBMP‐2 on the <I>in vitro</I> and <I>in vivo</I> biologic activity of well‐characterized human PDL stem cells (hPDLSCs) and to elucidate the underlying mechanism of minimal periodontal regeneration by rhBMP‐2.</P><P><B>Material and Methods: </B> hPDLSCs were isolated and cultured, and then transplanted into an ectopic subcutaneous mouse model using a carrier treated either with or without rhBMP‐2. Comprehensive histologic, histometric and immunohistochemical analyses were performed after an 8‐wk healing period. The effects of rhBMP‐2 on the adipogenic and osteogenic/cementogenic differentiation of hPDLSCs were also evaluated. The effect of rhBMP‐2 on both soluble and insoluble collagen synthesis was analyzed, and the expression of mRNA and protein for collagen types I, II, III and V was assessed.</P><P><B>Results: </B> In the present study, rhBMP‐2 promoted both adipogenic and osteogenic/cementogenic differentiation of hPDLSCs <I>in vitro</I>, and the <I>in vivo</I> potential of hPDLSCs to form mineralized cementum and organized PDL tissue was down‐regulated following treatment with rhBMP‐2. Collagen synthesis, which plays a crucial role in the regeneration of cementum and the periodontal attachment, was significantly reduced, with associated modification of the relevant mRNA and protein expression profiles.</P><P><B>Conclusion: </B> In summary, the findings of the present study suggest that enhanced adipogenic differentiation and inhibition of collagen synthesis by hPDLSCs appear to be partly responsible for the minimal effect of rhBMP‐2 on cementum and PDL tissue regeneration by hPDLSCs.</P>

Characterization and expression analysis of a goose-type lysozyme from the rock bream Oplegnathus fasciatus, and antimicrobial activity of its recombinant protein

Whang, I.,Lee, Y.,Lee, S.,Oh, M.J.,Jung, S.J.,Choi, C.Y.,Lee, W.S.,Kim, H.S.,Kim, S.J.,Lee, J. Academic Press 2011 Fish & shellfish immunology Vol.30 No.2

Lysozyme (muramidase) represents an important defense molecule of the fish innate immune system. Known for its bactericidal properties, lysozyme catalyzes the hydrolysis of β-(1,4)-glycosidic bonds between the N-acetyl glucosamine and N-acetyl muramic acid in the peptidoglycan layer of bacterial cell walls. In this study, the complete coding sequence of a g-type lysozyme (RBgLyz) was identified in the Oplegnathus fasciatus rock bream fish genome by means of multi-tissue normalized cDNA pyrosequencing using Roche 454 GS-FLX(TM) technology. RBgLyz is composed of 669 bp, with a 567 bp open reading frame that encodes 188 amino acids. Protein motif searches indicated that RBgLyz contains the soluble lytic transglycosylase domain involved in maintaining cell wall integrity. Furthermore, RBgLyz shares significant identity (81.4%) with Chinese perch Siniperca chuatsi. Quantitative real-time RT-PCR analysis results showed that RBgLyz transcripts are constitutively expressed in various tissues from healthy rock breams. In order to determine RBgLyz function in immunity, its expression was analyzed in head kidney following exposure to known immune stimulants or pathogens. RBgLyz transcripts were significantly up-regulated in response to challenge with lipopolysaccharide (LPS) and Edwardsiella tarda, as compared to non-injected control fish. Polyinosinic:polycytidylic acid (poly I:C) dsRNA stimulated a moderate expression of RBgLyz, as did Streptococcus iniae but to a lesser extent. There were no specific time-dependent effects on RBgLyz mRNA expression observed in response to rock bream iridovirus (RBIV) infection. Taken together, the gene expression results indicated that g-type lysozyme plays a role in the innate immune response to LPS, poly I:C, E. tarda and S. iniae in rock bream. Thus, we generated recombinant RBgLyz in an Escherichia coli expression system and characterized its antimicrobial activity. Our results indicated that recombinant RBgLyz had lytic activity against Gram-negative Vibrio salmonicida, Gram-positive Listeria monocytogenes, S. iniae and Micrococcus lysodeikticus. In addition, observations by scanning electron microscope (SEM) confirmed that the cell morphology of M. lysodeikticus was altered in the presence of recombinant RBgLyz.

Caspase-cleaved tau exhibits rapid memory impairment associated with tau oligomers in a transgenic mouse model

Kim, Y.,Choi, H.,Lee, W.,Park, H.,Kam, T.I.,Hong, S.h.,Nah, J.,Jung, S.,Shin, B.,Lee, H.,Choi, T.Y.,Choo, H.,Kim, K.K.,Choi, S.Y.,Kayed, R.,Jung, Y.K. Blackwell Science ; Academic Press 2016 Neurobiology of disease Vol.87 No.-

<P>In neurodegenerative diseases like AD, tau forms neurofibrillary tangles, composed of tau protein. In the AD brain, activated caspases cleave tau at the 421th Asp, generating a caspase-cleaved form of tau, TauC3. Although TauC3 is known to assemble rapidly into filaments in vitro, a role of TauC3 in vivo remains unclear. Here, we generated a transgenic mouse expressing human TauC3 using a neuron-specific promoter. In this mouse, we found that human TauC3 was expressed in the hippocampus and cortex. Interestingly, TauC3 mice showed drastic learning and spatial memory deficits and reduced synaptic density at a young age (2-3 months). Notably, tau oligomers as well as tau aggregates were found in TauC3 mice showing memory deficits. Further, i.p. or i.c.v. injection with methylene blue or Congo red, inhibitors of tau aggregation in vitro, and i.p. injection with rapamycin significantly reduced the amounts of tau oligomers in the hippocampus, rescued spine density, and attenuated memory impairment in TauC3 mice. Together, these results suggest that TauC3 facilitates early memory impairment in trans genic mice accompanied with tau oligomer formation, providing insight into the role of TauC3 in the AD pathogenesis associated with tau oligomers and a useful AD model to test drug candidates. (C) 2015 Elsevier Inc. All rights reserved.</P>

HOXB13 downregulates intracellular zinc and increases NF-κB signaling to promote prostate cancer metastasis

Kim, Y-R,Kim, I-J,Kang, T W,Choi, C,Kim, K K,Kim, M S,Nam, K I,Jung, C Macmillan Publishers Limited 2014 Oncogene Vol.33 No.37

Characteristically, prostate cancer (PCa) cells exhibit marked decrease in intracellular zinc; however, the mechanism responsible is not clearly understood. HOXB13 is involved in PCa progression and is overexpressed in castration-resistant PCa. DNA microarray analysis of LNCaP Pca cells showed that ZnT zinc output transporters were strikingly upregulated among androgen-independent HOXB13 target genes. Furthermore, exogenous HOXB13 caused intracellular zinc concentrations to fall in PCa cells, stimulated NF-κB-mediated signaling by reducing inhibitor of NF-κB alpha (IκBα) and enhanced the nuclear translocation of RelA/p65. Human prostate tumors also exhibited strong inverse correlation between the protein expressions of HOXB13 and IκBα. Consequently, HOXB13 stimulated PCa cell invasion, and this was inhibited by the suppression of ZnT4. In addition, studies in a PC3 orthotopic mouse model of PCa metastasis showed that HOXB13 is a strong metastatic stimulator. Taken together, these results show that HOXB13 promotes PCa invasion and metastasis by decreasing intracellular zinc levels, thus stimulating NF-κB signals, and suggest that HOXB13 acts as a modulator of intracellular zinc levels that promotes the malignant characteristics of PCa.

Structural and functional characterization of <i>Caenorhabditis elegans</i> α-catenin reveals constitutive binding to β-catenin and F-actin

Kang, Hyunook,Bang, Injin,Jin, Kyeong Sik,Lee, Boyun,Lee, Junho,Shao, Xiangqiang,Heier, Jonathon A.,Kwiatkowski, Adam V.,Nelson, W. James,Hardin, Jeff,Weis, William I.,Choi, Hee-Jung American Society for Biochemistry and Molecular Bi 2017 The Journal of biological chemistry Vol.292 No.17

<P>Intercellular epithelial junctions formed by classical cadherins, beta-catenin, and the actin-binding protein alpha-catenin link the actin cytoskeletons of adjacent cells into a structural continuum. These assemblies transmit forces through the tissue and respond to intracellular and extracellular signals. However, the mechanisms of junctional assembly and regulation are poorly understood. Studies of cadherin-catenin assembly in a number of metazoans have revealed both similarities and unexpected differences in the biochemical properties of the cadherin center dot catenin complex that likely reflect the developmental and environmental requirements of different tissues and organisms. Here, we report the structural and biochemical characterization of HMP-1, the Caenorhabditis elegans alpha-catenin homolog, and compare it with mammalian alpha-catenin. HMP-1 shares overall similarity in structure and actin-binding properties, but displayed differences in conformational flexibility and allosteric regulation from mammalian alpha-catenin. HMP-1 bound filamentous actin with an affinity in the single micromolar range, even when complexed with the beta-catenin homolog HMP-2 or when present in a complex of HMP-2 and the cadherin homolog HMR-1, indicating that HMP-1 binding to F-actin is not allosterically regulated by the HMP-2.HMR-1 complex. The middle (i.e. M) domain of HMP-1 appeared to be less conformationally flexible than mammalian alpha-catenin, which may underlie the dampened effect of HMP-2 binding on HMP-1 actin-binding activity compared with that of the mammalian homolog. In conclusion, our data indicate that HMP-1 constitutively binds beta-catenin and F-actin, and although the overall structure and function of HMP-1 and related alpha-catenins are similar, the vertebrate proteins appear to be under more complex conformational regulation.</P>

CVD 법에 의한 강의 TiN 피복에 관하여

정성희,양훈영,최진일 대한금속재료학회(대한금속학회) 1985 대한금속·재료학회지 Vol.23 No.2

Chemical vapor deposition on the various substrates such as electrolytic iron, carbon steel and stainless steel (STS 304) has been carried out with gaseous mixture of TiCl₄, H₂and N₂in order to study the effect of temperature, composition of reaction gas and gas and gas flow rate on the amount and state of TiN coating. Wear resistance of the TiN coated specimens has also been studied. Better TiN deposition was resulted with gas flow rate of 100/min N₂, 90㎖/min H₂and l.l㎖/hr TiCl₄, and elevated temperature. TiN coated layer of electrolytic iron was superior, followed by carbon steel and stainless steel. Wear resistance of the TiN coated specimens improved markedly, and that of stainless steel was prominent.

정상위와 위암 조직에서 발현의 차이를 보이는 유전자의 검색

정명호,김성천,전경아,김승현,김영열,최경숙,박상익,조명국,김규찬 국립보건연구원 2000 국립보건원보 Vol.37 No.-

호기성침전막 생물반응기를 이용한 유기물 및 질소 제거특성

최영익,하상안,정병길 동아대학교 환경문제연구소 2008 硏究報告 Vol.30 No.1

The objectives of this research are to remove dissolved organic matter and nitrogen compounds by using aerated submerged bio-film (ASBF) reactors in batch systems and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynarnic relationships between heterotrophic and autotrophic bacteria in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. These structures are designed to encourage the growth of a nitrifying bacterial bio-film on a submerged surface. Specially, the effects of cold temperatures on the dissolved organic matter and amrnonia nitrogen performance of the ASBF pilot plant was investigated for the batch system. It is anticipated that the ASBF would be used for a design of biological treatment for removing of dissolved organic matter and nitrogen compounds in new wastewater treatment plants as well as existing wastewater treatment plants.