• Title/Summary/Keyword: membrane function

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Expression of MEK1 Fusion Protein in Yeast for Developing Cell Based Assay System, a Major Substrate of LeTx (Yeast내에서 MEK1 융합 단백질 발현 및 Lethal Factor 활성 검증)

  • Hwang, Hye-Hyun;Kim, Joung-Mok;Choi, Kyoung-Jae;Park, Hae-Chul;Han, Sung-Hwan;Chung, Hoe-Il;Koo, Bon-Sung;Park, Joon-Shik;Yoon, Moon-Young
    • Korean Journal of Microbiology
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    • v.42 no.3
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    • pp.195-198
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    • 2006
  • Lethal toxin is a critical virulence factor of anthrax. It is composed two protein: protective antigen (PA) and lethal factor (LF). PA binds to specific cell surface receptors and, forms a membrane channel that mediates entry of LF into the cell. LF is a zinc-dependent metalloprotease, which cleaves MKKs [MAPK (mitogen-activated protein kinase) kinases] at peptide bonds very close to their N-termini. In this study, we suggest application of cell-based assays in the early phase of drug discovery, with a particular focus on the use of yeast cells. We constructed MEK1 expression system in yeast to determine LF activity and approached cell-based assay system to screen inhibitors, in which the results covering the construction of LF-substrate in yeast expression vector, expression, and LF-mediated proteolysis of substrate were described. These results could provided the basic steps in design of cell-based assay system with the high efficiency, rapidly and easy way to screening of inhibitors.

An Experimental Study and Value Analysis for Performance Assessment of the Embo-thane Membrane Waterproofing Method (엘보탄도막방수공법의 성능평가를 위한실험적 연구 및 VE분석)

  • Yoon, Cha-Woong;Lee, Seung-Soo;Kim, Sang-Rok;Seo, Jong-Won
    • Korean Journal of Construction Engineering and Management
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    • v.10 no.5
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    • pp.123-134
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    • 2009
  • Since 1970s, urethane waterproofing method is broadly used in rooftops, underground spaces, and sports stadium for its outstanding ultraviolet blockage, watertightness, and elasticity. However, development of slippage-resistance and endurance, improvement of function considering convenience and visually pleasing of users, urethane waterproofing method is necessary, since rooftops and underground spaces have slippage and external force risks. Therefore, many improved waterproofing methods are being developed and, recently, embo-thane waterproofing method, which applies embo-spray coating system, has been developed. This paper explains exposure, nonexposure, and floor-material of embo-thane waterproofing method, and then perform experimental study for comparison with urethane waterproofing method about tensile strength, coefficient of expansion, performance of bond, anti-abrasion, and slippage-resistance. In addition, the performance index was presented for the superiority of embo-thane waterproofing method compared to urethane by setting up evaluation criteria considering not only physical performance but also design side of embo-thane waterproofing method, and Value Analysis applying AHP. Also for an assessment considering uncertain result, Monte Carlo Simulation Method was used to operate reliability analysis through statistic approach method.

The Evaluation of Artificial Lung Using Blood Substitutes (대체혈액을 이용한 인공폐의 평가에 관한 연구)

  • Kim K.B.;Hong S C.;Kim M.H.;Jheong G.R.;Lee S.C.
    • Journal of Biomedical Engineering Research
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    • v.21 no.3 s.61
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    • pp.311-320
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    • 2000
  • In this paper a newly designed oxygenator module was used to perform the experiments for pressure drop and oxygen transport in order to evaluate the efficiency of the artificial lung. Also, distilled water. sodium sulfite solutions used in this experiment were evaluated for the performance of other artificial lungs. Substituted bloods have many advantages over whole blood in studying pressure drop and oxygen uptake. They are relatively inexpensive, and require fewer variables to be controlled. Furthermore, deoxygenation is not necessary when those solutions are used. In addition to these advantages. assays and interpretation of the experimental results are relatively easy. In the case of using the sodium sulfite solution having the same oxygen partial pressure as whole blood. the oxygen transfer rate of the sodium sulfite solution was basically same as that of whole blood. It was concluded in evaluating the function of artificial lungs that the sodium sulfite solution was suited for measuring oxygen transfer rate. In our module, artificial blood was flowed into the outside of hollow fiber membrane. The artificial lung created in this experiment showed that pressure drop was reduced to $1/3\~1/6$ of that compared to the inside-flow case.

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Helicobacter pylori Chaperone-Like Protein CagT Plays an Essential Role in the Translocation of CagA into Host Cells

  • Ding, Honglei;Zeng, Hao;Huang, Linping;Dong, Yandong;Duan, Yijun;Mao, Xuhu;Guo, Gang;Zou, Quanming
    • Journal of Microbiology and Biotechnology
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    • v.22 no.10
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    • pp.1343-1349
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    • 2012
  • Most of the Helicobacter pylori strains containing the cag pathogenicity island (PAI) have been associated with more severe gastric disease in infected humans. The cag PAI is composed of 27 proteins, and some of the components are required for CagA translocation into host cells as well as induction of proinflammatory cytokines, such as interleukin-8 (IL-8); however, the exact function of most of the components remains unknown or poorly characterized. In this study, we demonstrated that CagT (HP0532), which is an essential structural component of the cag PAI apparatus, plays an important role in the translocation of CagA into host epithelial cells. In addition to being located on the bacterial surface, CagT is also partially localized in the inner membrane, where it acts as a chaperone-like protein and promotes CagA translocation. However, CagT secretion was not detected by immunoprecipitation analysis of cell culture supernatants. Meanwhile, CagT was related to the introduction of IL-8 of the host cell. These results suggest that CagT is expressed on both the inner and outer bacterial membranes, where it serves as a unique type IV secretion system component that is involved in CagA secretion and cag PAI apparatus assembly.

Synthetic Cannabinoid-Induced Immunosuppression Augments Cerebellar Dysfunction in Tetanus-Toxin Treated Mice

  • Yun, Jaesuk;Gu, Sun Mi;Lee, Tac-hyung;Song, Yun Jeong;Seong, Seonhwa;Kim, Young-Hoon;Cha, Hye Jin;Han, Kyoung Moon;Shin, Jisoon;Oh, Hokyung;Jung, Kikyung;Ahn, Chiyoung;Park, Hye-Kyung;Kim, Hyung Soo
    • Biomolecules & Therapeutics
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    • v.25 no.3
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    • pp.266-271
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    • 2017
  • Synthetic cannabinoids are one of most abused new psychoactive substances. The recreational use of abused drug has aroused serious concerns about the consequences of these drugs on infection. However, the effects of synthetic cannabinoid on resistance to tetanus toxin are not fully understood yet. In the present study, we aimed to determine if the administration of synthetic cannabinoids increase the susceptibility to tetanus toxin-induced motor behavioral deficit and functional changes in cerebellar neurons in mice. Furthermore, we measured T lymphocytes marker levels, such as CD8 and CD4 which against tetanus toxin. JWH-210 administration decreased expression levels of T cell activators including cluster of differentiation (CD) $3{\varepsilon}$, $CD3{\gamma}$, CD74p31, and CD74p41. In addition, we demonstrated that JWH-210 induced motor impairment and decrement of vesicle-associated membrane proteins 2 levels in the cerebellum of mice treated with tetanus toxin. Furthermore, cerebellar glutamatergic neuronal homeostasis was hampered by JWH-210 administration, as evidenced by increased glutamate concentration levels in the cerebellum. These results suggest that JWH-210 may increase the vulnerability to tetanus toxin via the regulation of immune function.

Water Extract of Allium sativum L. Induces Apoptosis in Human Leukemia U937 Cells through Reactive Oxygen Species Generation (마늘 열수 추출물의 활성산소종 생성을 통한 인체백혈병세포의 apoptosis 유발)

  • Choi, Woo-Young;Chung, Kyung-Tae;Yoon, Tae-Kyung;Choi, Byung-Tae;Lee, Yong-Tae;Lee, Won-Ho;Ryu, Chung-Ho;Choi, Yung-Hyun
    • Journal of Life Science
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    • v.17 no.12
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    • pp.1709-1716
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    • 2007
  • The health benefits of garlic (Allium sativum L.) are derived from a wide variety of components and from the different ways it is administered. The known health benefits of garlic include cardiovascular protective effects, stimulation of immune function, reduction of blood glucose level, protection against microbial, viral and fungal infections, as well as anticancer effects. In the present study, it was examined the effects of water extract of A. sativum (WEAS) on the growth of cultured human tumor cells in order to investigate its anti-proliferative mechanism. Treatment of WEAS to tumor cells resulted in the growth inhibition, especially in leukemia cells, which was associated with induction of G2/M arrest of the cell cycle and apoptosis. In order to further explore the critical events leading to apoptosis in WEAS-treated U937 human leukemia cells, the following effects of WEAS on components of the mitochondrial apoptotic pathway were examined: generation of reactive oxygen species (ROS), alteration of the mitochondrial membrane potential (MMP), and the expression changes of Bcl-2 and IAP family proteins. The cytotoxic effect of WEAS was mediated by its induction of apoptosis as characterized by the occurrence of DNA ladders, apoptotic bodies and chromosome condensation in U937 cells. The WEAS-induced apoptosis in U937 cells was correlated with the generation of intracellular ROS, collapse of MMP, activation of caspase-3 and down-regulation of anti-apoptotic proteins. The quenching of ROS generation with antioxidant N-acetyl-L-cysteine conferred significant protection against WEAS-elicited ROS generation, caspase-3 activation, G2/M arrest and apoptosis. In conclusion, the present study reveals that the cellular ROS generation plays a pivotal role in the initiation of WEAS-triggered apoptotic death in U937 cells.

Time-based Expression Networks of Genes Related to Cold Stress in Brassica rapa ssp. pekinensis (배추의 저온 스트레스 처리 시간대별 발현 유전자 네트워크 분석)

  • Lee, Gi-Ho;Yu, Jae-Gyeong;Park, Young-Doo
    • Horticultural Science & Technology
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    • v.33 no.1
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    • pp.114-123
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    • 2015
  • Plants can respond and adapt to cold stress through regulation of gene expression in various biochemical and physiological processes. Cold stress triggers decreased rates of metabolism, modification of cell walls, and loss of membrane function. Hence, this study was conducted to construct coexpression networks for time-based expression pattern analysis of genes related to cold stress in Chinese cabbage (Brassica rapa ssp. pekinensis). B. rapa cold stress networks were constructed with 2,030 nodes, 20,235 edges, and 34 connected components. The analysis suggests that similar genes responding to cold stress may also regulate development of Chinese cabbage. Using this network model, it is surmised that cold tolerance is strongly related to activation of chitinase antifreeze proteins by WRKY transcription factors and salicylic acid signaling, and to regulation of stomatal movement and starch metabolic processes for systemic acquired resistance in Chinese cabbage. Moreover, within 48 h, cold stress triggered transition from vegetative to reproductive phase and meristematic phase transition. In this study, we demonstrated that this network model could be used to precisely predict the functions of cold resistance genes in Chinese cabbage.

A Study on Safety and Performance Evaluation of Smart All-in-one Cardiopulmonary Assist Device (스마트올인원 심폐순환보조장치의 안전성 및 성능평가에 관한 연구)

  • Park, Junhyun;Ho, YeJi;Lee, Yerim;Lee, Duck Hee;Choi, Jaesoon
    • Journal of Biomedical Engineering Research
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    • v.40 no.5
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    • pp.197-205
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    • 2019
  • The existing Extracorporeal membrane oxygenation(ECMO) and Cardiopulmonary bypass system(CPB) have been developed and applied to various devices according to their respective indications. However, due to the complicated configuration and difficult usage method, it causes inconvenience to users and there is a risk of an accident. Therefore, smart all-in-one cardiopulmonary circulation device is being developed recently. The smart all-in-one cardiopulmonary assist device consists of a blood pump for cardiopulmonary bypass, a blood oxidizer for cardiopulmonary bypass, a blood circuit for cardiopulmonary bypass, and an artificial cardiopulmonary device. It is an integrated cardiopulmonary bypass device that can be used for a variety of purposes such as emergency, intraoperative, post-operative intensive care, and long-term cardiopulmonary assist, combined with CPB used in open heart surgery and ECMO used when patient's cardiopulmonary function does not work normally. The smart all-in-one cardiopulmonary assist device does not exist as a standard and international standard applicable to advanced medical devices. Therefore, in this study, we will refer to the International Standard for Blood Components, the International Standard for Blood, the Guideline for Blood Products, and prepare applicable performance and safety guidelines to help quality control of medical devices, and contribute to the improvement of the health of people. The guideline, which is the result of conducted a survey of the method of safety and performance test, is based on the principle of all-in-one cardiopulmonary aiding device, related domestic foreign standards, the status of domestic and foreign patents, related literature, blood pump(ISO 18242), blood oxygenator (ISO 7199), and blood circuit (ISO 15676) for cardiopulmonary bypass.The items on blood safety are as follows: American Society for Testing and Materials ASTM F1841-97R17), and in the 2010 Food and Drug Administration's Safety Assessment Guidelines for Medical Assisted Circulatory Devices. In addition, after reviewing the guidelines drawn up through expert consultation bodies including manufacturers / importers, testing inspectors, academia, etc. the final guideline was established through revision and supplementation process. Therefore, we propose guidelines for evaluating the safety and performance of smart all-in-one cardiopulmonary assist devices in line with growing technology.

Beyond the Molecular Facilitator, CD82: Roles in Metastasis Suppressor, Stem Cell Niche, Muscle Regeneration, and Angiogenesis (분자 촉진제를 넘어, CD82: 전이억제자, 줄기세포 니쉬, 근육 재생 및 혈관신생에서의 역할)

  • Lee, Hyun-Chae;Han, Jung-Hwa;Hur, Jin
    • Journal of Life Science
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    • v.31 no.9
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    • pp.856-861
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    • 2021
  • CD82/KAI1, identified as a metastasis suppressor, was initially known only as a molecular facilitator, but its various functions have recently been revealed. CD82 plays an important role in the stem-progenitor cell, angiogenesis, and muscle. We would like to introduce the recently reported functions and roles of CD82 in this review. CD82 is a member of the tetraspanin family, which consists of four transmembrane domains. The interaction between CD82 and cell adhesion molecules suppresses the metastasis of cancer. CD82 regulates the cell cycle of stem-progenitor cells in the stem cell niche. In the bone marrow, CD82 is expressed on long-term repopulating hematopoietic stem cells (LT-HSCs), which show multipotent differentiation potential. The interaction between CD82 and Duffy antigen receptor for chemokines (DARC) induces quiescence in LT-HSCs. CD82 also regulates Rac1 activity, resulting in the homing and engraftment of HSCs into the bone marrow niche. Besides, CD82 maintains the differentiation potential of muscle stem cells and prevents angiogenesis by inhibiting the expression of cytokines, such as IL-6 and VEGF and adhesion molecules in endothelial cells. CD82 is a key membrane protein that distinguishes the hierarchy of stem-progenitor cells, and is also important for amplification and verification of cellular resources. Further studies on the function of CD82 in various organs and cells are expected to advance cell biology and cell therapy.

Treatment of Mid-trimester Oligohydramnios Using Gami-danggui-san (임신중기(姙娠中期)에 나타난 양수과소증(oligohydramnios)에 가미당귀산(加味當歸散)을 투여하여 효과를 보인 증례보고)

  • Kim, Hyo-Jung;Kim, Eun-Seop;Jin, Dae-Hwan;Hwang, Deok-Sang;Lee, Jin-Moo;Lee, Chang-Hoon;Jang, Jun-Bock
    • The Journal of Korean Obstetrics and Gynecology
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    • v.32 no.1
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    • pp.85-93
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    • 2019
  • Objectives: The aim of this study was to demonstrate the benefit of Traditional Korean Medicine as an adjuvant therapy in management of mid-trimester oligohydramnios. Methods: It is a case report of a 31 year-old woman hospitalized for oligohydramnios at $24^{+4/7}$weeks of gestation. This patient diagnosed with special oligohydramnios had no abnormal findings such as fetal urinary abnormalities or other anomalies. Also, symptom of PPROM (preterm premature rupture of membrane) was not confirmed. The decoction, Gami-danggui-san (DG) was prescribed for the purpose of reducing unnecessary contraction of uterine muscle during pregnancy and promoting blood circulation and metabolism, thereby improving placental function and contributing to the increase of the fluid. DG decoction was administered twice a day until 19th of June, which was 10 days in total. During the treatment, level of amniotic fluid had been monitored by measuring AFI (amnioti fluid index). Results: After these conventional therapies, the amount of amniotic fluid increased steadily, and eventually reached the optimal level. AFI was found to be 3.2 on the $24^{+4/7}$ weeks, 8 on the $26^{+1/7}$ weeks, 11.5 on the $27^{+0/7}$ weeks of gestation. In the same periods, EFW (expected fetal weight) was also found to be increasing gradually: 545 g, 630, and 760 g. Conclusions: Our report implies the potential of herbal medicine as a effective therapy for oligohydramnios tratment. Further studies are needed to assess the efficacy of TKM herbal medicine and reveal the mechanisms of the decoction.