• Title/Summary/Keyword: molecular pathogenesis

검색결과 584건 처리시간 1.852초

Identification of a lead small-molecule inhibitor of anthrax lethal toxin by using fluorescence-based high-throughput screening

  • Wei, Dong;Bu, Zhaoyun;Yu, Ailian;Li, Feng
    • BMB Reports
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    • 제44권12호
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    • pp.811-815
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    • 2011
  • Inhalational anthrax is caused by B. anthracis, a virulent sporeforming bacterium which secretes anthrax toxins consisting of protective antigen (PA), lethal factor (LF) and edema factor (EF). LF is a Zn-dependent metalloprotease and is the main determinant in the pathogenesis of anthrax. Here we report the identification of a lead small-molecule inhibitor of anthrax lethal factor by screening an available synthetic small-molecule inhibitor library using fluorescence-based high-throughput screening (HTS) approach. Seven small molecules were found to have inhibitory effect against LF activity, among which SM157 had the highest inhibitory activity. All theses small molecule inhibitors inhibited LF in a noncompetitive inhibition mode. SM157 and SM167 are from the same family, both having an identical group complex, which is predicted to insert into S1' pocket of LF. More potent small-molecule inhibitors could be developed by modifying SM157 based on this identical group complex.

nArgBP2 as a hub molecule in the etiology of various neuropsychiatric disorders

  • Lee, Sang-Eun;Chang, Sunghoe
    • BMB Reports
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    • 제49권9호
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    • pp.457-458
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    • 2016
  • Recent studies have strongly implicated postsynaptic scaffolding proteins such as SAPAP3 or Shank3 in the pathogenesis of various mood disorders, including autism spectrum disorder, bipolar disorder (BD), and obsessive-compulsive disorders. Neural Abelson-related gene-binding protein 2 (nArgBP2) was originally identified as a protein that interacts with SAPAP3 and Shank3. Recent study shows that the genetic deletion of nArgBP2 in mice leads to manic/bipolar-like behavior resembling symptoms of BD. However, the function of nArgBP2 at synapse, or its connection with the synaptic dysfunctions, is completely unknown. This study provides compelling evidence that nArgBP2 regulates the spine morphogenesis through the activation of Rac1/WAVE/PAK/cofilin pathway, and that its ablation causes a robust and selective inhibition of excitatory synapse formation, by controlling actin dynamics. Our results revealed the underlying mechanism for the synaptic dysfunction caused by nArgBP2 downregulation that associates with analogous human BD. Moreover, since nArgBP2 interacts with key proteins involved in various neuropsychiatric disorders, our finding implies that nArgBP2 could function as a hub linking various etiological factors of different mood disorders.

The pathophysiological role of dendritic cell subsets in psoriasis

  • Kim, Tae-Gyun;Kim, Dae Suk;Kim, Hyoung-Pyo;Lee, Min-Geol
    • BMB Reports
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    • 제47권2호
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    • pp.60-68
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    • 2014
  • Psoriasis is a chronic inflammatory disorder characterized by an erythematous scaly plaque of the skin and is occasionally accompanied by systemic complications. In the psoriatic lesions, an increased number of cytokine-producing dendritic cells and activated T cells are observed, which indicate that psoriasis is a prototype of an immune-mediated dermatosis. During the last decade, emerging studies demonstrate novel roles for the dendritic cell subsets in the process of disease initiation and maintenance of psoriasis. In addition, recently discovered anti-psoriatic therapies, which specifically target inflammatory cytokines produced by lesional dendritic cells, bring much better clinical improvement compared to conventional treatments. These new therapies implicate the crucial importance of dendritic cells in psoriasis pathogenesis. This review will summarize and discuss the dendritic cell subsets of the human skin and their pathophysiological involvement in psoriasis based on mouse- and patient-oriented studies.

소청용탕이 기관지천식 환자의 혈청 IL-4, IL-5, $IFN-{\gamma}$변화에 미치는 영향 (The Effects of Sochongryong-tang on Serum IL-4, IL-5, and $IFN-{\gamma}$ in Asthmatic Patients)

  • 정승기;허태석;황우석;주창엽;김영우;정희재
    • 대한한의학회지
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    • 제23권2호
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    • pp.70-77
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    • 2002
  • Background : Asthma is considered to be an inflammatory disease characterized by airway hyperresponsiveness and pulmonary eosinophilia. Production of cytokines by bronchial epithelial cells may contribute to the local accumulation of inflammatory cells in patients with bronchial asthma. In many recent studies molecular biological methods have been used to investigate the role of cytokines in pathogenesis and new therapeutic targets of asthma. Objective : We aimed to identify the effects of Sochongryong-tang on Serum IL-4, IL-5, $IFN-{\gamma}$ in asthmatic patients. Material and Methods: The subjects consisted of 15 patients with asthma who had been treated with Sochongryong-tang for two weeks from February 2001 through June 2001. Sochongryong-tang is an herbal decoction which has traditionally been used as a therapeutic agent for asthma. Results : The serum IL-4 in asthmatic patients was increased significantly compared to the serum IL-4 in the normal control group. However, the serum IL-5, $IFN-{\gamma}$ in asthmatic patients showed no significant difference from the serum IL-5, $IFN-{\gamma}$ in the normal control group. The patients were treated with Sochongryong-tang for two weeks with no significant difference in the serum IL-4, IL-5, and $IFN-{\gamma}$. Conclusion : This study shows that the serum IL-4 may be a new therapeutic target of asthma. Further long-term studies must be made in a larger number of asthmatic patients.

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Effects of Mannose on Pathogenesis of Acanthamoeba castellanii

  • Yoo, Kyung-Tae;Jung, Suk-Yul
    • Parasites, Hosts and Diseases
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    • 제50권4호
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    • pp.365-369
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    • 2012
  • Acanthamoeba spp. are single-celled protozoan organisms that are widely distributed in the environment. In this study, to understand functional roles of a mannose-binding protein (MBP), Acanthamoeba castellanii was treated with methyl-alpha-D-mannopyranoside (mannose), and adhesion and cytotoxicity of the amoeba were analyzed. In addition, to understand the association of MBP for amoeba phagocytosis, phagocytosis assay was analyzed using non-pathogenic bacterium, Escherichia coli K12. Amoebae treated with mannose for 20 cycles exhibited larger vacuoles occupying the most area of the amoebic cytoplasm in comparison with the control group amoebae and glucose-treated amoebae. Mannose-selected amoebae exhibited lower levels of binding to Chinese hamster ovary (CHO) cells. Exogenous mannose inhibited >50% inhibition of amoebae (control group) binding to CHO cells. Moreover, exogenous mannose inhibited amoebae (i.e., man-treated) binding to CHO cells by <15%. Mannose-selected amoebae exhibited significantly decreased cytotoxicity to CHO cells compared with the control group amoebae, 25.1% vs 92.1%. In phagocytic assay, mannose-selected amoebae exhibited significant decreases in bacterial uptake in comparison with the control group, 0.019% vs 0.03% (P<0.05). Taken together, it is suggested that mannose-selected A. castellanii trophozoites should be severely damaged and do not well interact with a target cell via a lectin of MBP.

Analysis for nucleotide sequence of the small membrane (sM) protein gene of porcine epidemic diarrhea virus Chinju99 isolated in Korea

  • Yeo, Sang-Geon;Lee, Changhee
    • 대한수의학회지
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    • 제47권2호
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    • pp.169-174
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    • 2007
  • To provide information for the molecular pathogenesis and antigenic structures of Korean isolates of porcine epidemic diarrhea virus (PEDV), the small membrane (sM) protein gene of Chinju99 strain, which was previously isolated from piglets suffering from severe diarrhea was characterized and further analyzed with other PEDV strains. The sM gene of Chinju99 generated by reverse transcription and polymerase chain reaction had a single open reading frame with 231 bases consisting of 24.2% adenine, 18.6% cytosine, 18.1% guanine and 39.0% thymine nucleotides. Nucleotide sequence of the gene revealed 97.8% homology to those of Belgian strain CV777 and British strain Br1/87, and 97.0% to Chinese strain LZC. The gene encoded a protein with 76 amino acids, and putative amino acid sequence of the gene revealed 98.7% homology to those of CV777 and Br1/87, and 96.1% to LZC. The amino acids of Chinju99 sM gene consisted of mostly hydrophobic residues, and there were one potential N-myristylation site and one potential threonine (T)-linked phosphorylation site recognized. Also, there was a transmembrane region with 46 amino acids, and Chinju99 was more close to CV777 and Br1/87 than to LZC in phylogenetic analysis on the sM amino acid sequences.

Structural and Quantitative Expression Analyses of HERV Gene Family in Human Tissues

  • Ahn, Kung;Kim, Heui-Soo
    • Molecules and Cells
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    • 제28권2호
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    • pp.99-103
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    • 2009
  • Human endogenous retroviruses (HERVs) have been implicated in the pathogenesis of several human diseases as multi-copy members in the human genome. Their gene expression profiling could provide us with important insights into the pathogenic relationship between HERVs and cancer. In this study, we have evaluated the genomic structure and quantitatively determined the expression patterns in the env gene of a variety of HERV family members located on six specific loci by the RetroTector 10 program, as well as real-time RT-PCR amplification. The env gene transcripts evidenced significant differences in the human tumor/normal adjacent tissues (colon, liver, uterus, lung and testis). As compared to the adjacent normal tissues, high levels of expression were noted in testis tumor tissues for HERV-K, in liver and lung tumor tissues for HERV-R, in liver, lung, and testis tumor tissues for HERV-H, and in colon and liver tumor tissues for HERV-P. These data warrant further studies with larger groups of patients to develop biomarkers for specific human cancers.

Partial Characterization of Proteases from Culture Filtrate of Mycobacterium tuberculosis

  • Na, Byoung-Kuk;Song, Chul-Yong;Park, Young-Kill;Bai, Gill-Han;Ki, Sang-Jae
    • Journal of Microbiology
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    • 제34권2호
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    • pp.198-205
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    • 1996
  • Two proteases were partially characterized from culture filtrate of Mycobacterium, tuberculosis KIT110. Their molecular weights were approximately 200 and 180 kDa, respectively and they exhibited similar enzymatic characteristics. These enzymes were inhibited significantly by EDTA and to some extent by EGTA. Their activity was enhanced by $Ca^{2+}$ and $Mg^{2+}$ to some degree. However, $Cu^{2+}$ and $Ag^{2+}$ completely inhibited the enzyme activity at the concentration of 2.5 and 5 mM, respectively. The optimal pH was 7.0 and optimal temperature was around $40^{\circ}C$. These enzymes were rapidly inactivated at $80^{\circ}C$. Therefore, they were heat-labile, neutral metalloproteases. These enzymes exhibited antigenicity shown by their reacting with sera from the partients with pulmonary tuberculosis. These enzymes were able to degrade serum proteins including hemoglobin, bovine serum albumin, lysozyme and immunoglobulin G and structural matrix protein such as type I collagen. Therefore, these enzymes may be thought to contribute to tissue necrosis and pathogenesis during infection.

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플라보노이드에 의한 사람 Low Density Lipoprotein 변형에 대한 항산화 효과 (Antioxidative Effects of Flavonoids toward Modification of Human Low Density Lipoprotein)

  • 류병호
    • 한국식품영양학회지
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    • 제12권3호
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    • pp.320-327
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    • 1999
  • The flavonoids are one of the most numberous and widespread groups of natural consituents. The low molecular weight of benzo-${\gamma}$-pyrone derivative are ubiquitous in plants and are vegetables nuts, seeds, leaves, flowers, and bark. The flavonoids constitute of a large class of compounds ubiquitous in plants containing a number of phenolic hydroxyl groups attached to ring structures conferring the antioxidant activity. Epidemiologic studies suggest that the dietary intake of antioxidants constitutes a risk factor for vasclar disease indicating that oxidation may be important in the pathogenesis of human athero-sclerosis. Elevated plasma low density lipoprotein (LDL) cholesterol concentration are associated with accelerated atherosclerosis, LDL is oxidized by smooth muscle cells resulting in several chemicals and physical changes of LDL. Oxidized LDL is responsible for cholesterol loading of macrophages foam cells formation and atherogenesis. There have been insulficient tests of the protective effects of flavonoids against LDL oxidation to make definitive statements about their structure activity relationships. How-ever hydroxylation of the flavone uncleas can appears to be advantageous because polyhydroxylated aglycone flavonoids are potent inhibitor of LDL modification. This identification may lead to new and more effective antioxidant strategies for abrogating the atherosclerotic process the leading cause of death and disability in industrialized societies.

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Molecular Cloning and Characterization of Alkaliphilic Phospholipase B (VFP58) from Vibrio fluvialis

  • AHN SUN HEE;JEONG SEUNG HA;KIM JIN MAN;KIM YOUNG OK;LEE SANG JUN;KONG IN SOO
    • Journal of Microbiology and Biotechnology
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    • 제15권2호
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    • pp.354-361
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    • 2005
  • Vibrio fluvialis, an enteropathogenic bacterium, produces a phospholipase which is thought to be an important factor in the pathogenesis of disease. In this study, the phospholipase gene (vfp) was identified from V fluvialis (KCTC 2473) and its sequence was determined. The entire open reading frame was composed of 1,689 nuc1eotides and 563 amino acids. The phospholipase gene (vfp) was overexpressed in Escherichia coli as a his-tag fused protein. This recombinant protein (rVFP58) was solubilized with 6 M urea and purified by Ni-NTA affinity chromatography. The action mode of rVFP58 was determined by TLC and GC-MS, and it showed phospholipase B activity, which had both phospholipase A and lysophospholipase activities. The rVFP58 showed a maximum activity at pH around 9- 10 and temperature of about 40OC, and it was stable under alkaline condition over pH 9. The cytotoxicity of rVFP58 was evaluated, using a fish cell line, CHSE-2l4, and was found to cause significant cell death after 14 h of exposure to 250 $\mu$g of the protein.