• Title/Summary/Keyword: molecular pathogenesis

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Purification of Heat-Stable Enterotoxin of Enterotoxigenic Escherichia coli eKT-53 (장독성 대장균 eKT-53 균주의 내열성 장독소 정제)

  • Do, Dea-Hong;Kim, Kyo-Chang;Kim, Do-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.21 no.1
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    • pp.76-83
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    • 1992
  • Enterotoxigenic E. coli is one of the major causative agents of the infantile diarrhea and traveler's diarrhea. The heat-stable enterotoxin (ST) is thought to be a virulence factor in the pathogenesis of the diarrhea and to be a maker for identification of the enterotoxigenic E. coli from non pathogenic E. coli. ST producing E. coli KM-7 strain was isolated from the swine and molecular cloning of ST gene of KM-7 strain. Transformant eKT-53 $(ST^+,\;LT^-)$ was selected by infant mouse assay (IMA). The culture supernatant of eKT-53 strain was performed purification by multipled steps. The culture supernatant (crude ST) was purified by sequentially applying batch adsorption chromatography on Amberlite XAD-2 resin, ion exchange chromatography on DEAE-Sephacel anion exchanger, gel filtration chromatography on Bio-Gel P-6 and preparative polyacrylamide slab gel electrophoresis. About 113-fold purification was achieved with a yield of about 11% of crude ST and the minimum effective dose(MED) of this purified ST was about 2.8ng in IMA. Homogeneity of purified ST was demonstrated by showing a single band in analytical SDS polyacrylamide disc gel electrophoresis.

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The Effects of BGG on Various Immunological Factors Related to Pathogenesis of Allergic Dermatitis in NC/Nga Mice Induced by Der-f (보음거풍지양탕(補陰祛風止痒湯)이 아토피 피부염을 유발(誘發)한 NC/Nga 생쥐의 면역(免疫) 조절작용(調節作用)에 미치는 영향(影響))

  • Bang, Chan-Kuk;Choi, Jeong-Jun;Eom, Dong-Myung;Kim, Dong-Hee
    • Journal of Haehwa Medicine
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    • v.16 no.2
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    • pp.147-169
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    • 2007
  • To evaluate the therapeutic effects of BGG on atopic dermatitis, we investigated the composition of immune cells of lymph node, PBMC and skin of Dermatophagoides farinae-induced NC/Nga mice. The levels of immunoglobulins in serum were analyzed at the protein level and the amount of pathologic cytokines were investigated using CD3/CD28 stimulated splenocytes. The results are summarized below; 1. BGG showed no cytotoxic effect up to $200\;{\mu}g/m{\ell}$ on mLFC in vitro. 2. BGG showed no hepatotoxicity in vivo based on the levels of ALT and AST. 3. Atopic dermatitis was improved through naked eye examination. BGG reduced the skin clinical index from 2.9 to 1.3 (p<0.01). 4. H&E and toluidine blue staining of tissue biopsies revealed that BGG inhibited the infiltration of lymphocytes and mast cells to skin. 5. BGG reduced the number of CD19 positive B cells in PBMCs by 16% (p<0.01), whereas cells were increased by 26% (p<0.05) in lymph nodes. 6. BGG reduced the numbers of B220+/CD23+ cells by 15% (p<0.01) and 33% in PBMCs and lymph node, respectively. 7. BGG reduced the numbers of B220+/IgE+ cells in PBMCs and lymph node by 21% and 33% (p<0.01), respectively. 8. BGG suppressed the levels of IgE (13%, p<0.001) as well as IgM (34%, p<0.001), IgG2a (40%, p<0.001) and IgG2b (26%, p<0.05). 9. BGG reduced the levels of IL-4 and IFN-$\gamma$ by 7% (p<0.05) and 13% (p<0.001) in anti-CD3 and anti-CD28-activated splenocytes, respectively. 10. BGG considerably inhibited the production of TNF-$\alpha$ and IL-6 by 42% (p<0.01) and 15% in the serum, respectively. Based on the results above, we concluded that BGG has therapeutic effects on atopic dermatitis by regulating the differentiation of B cells and isotype switching of IgE. Further investigations on the molecular mechanisms of BGG on atopic dermatitis are anticipated.

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Vimentin Is Involved in Peptidylarginine Deiminase 2-Induced Apoptosis of Activated Jurkat Cells

  • Hsu, Pei-Chen;Liao, Ya-Fan;Lin, Chin-Li;Lin, Wen-Hao;Liu, Guang-Yaw;Hung, Hui-Chih
    • Molecules and Cells
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    • v.37 no.5
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    • pp.426-434
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    • 2014
  • Peptidylarginine deiminase type 2 (PADI2) deiminates (or citrullinates) arginine residues in protein to citrulline residues in a $Ca^{2+}$-dependent manner, and is found in lymphocytes and macrophages. Vimentin is an intermediate filament protein and a well-known substrate of PADI2. Citrullinated vimentin is found in ionomycin-induced macrophage apoptosis. Citrullinated vimentin is the target of anti-Sa antibodies, which are specific to rheumatoid arthritis, and play a critical role in the pathogenesis of the disease. To investigate the role of PADI2 in apoptosis, we generated a Jurkat cell line that overexpressed the PADI2 transgene from a tetracycline-inducible promoter, and used a combination of 12-O-tetradecanoylphorbol-13-acetate and ionomycin to activate Jurkat cells. We found that PADI2 overexpression reduced the cell viability of activated Jurkat cells in1a dose- and time-dependent manner. The PADI2-overexpressed and -activated Jurkat cells presented typical manifestations of apoptosis, and exhibited greater levels of citrullinated proteins, including citrullinated vimentin. Vimentin overexpression rescued a portion of the cells from apoptosis. In conclusion, PADI2 overexpression induces apoptosis in activated Jurkat cells. Vimentin is involved in PADI2-induced apoptosis. Moreover, PADI2-overexpressed Jurkat cells secreted greater levels of vimentin after activation, and expressed more vimentin on their cell surfaces when undergoing apoptosis. Through artificially highlighting PADI2 and vimentin, we demonstrated that PADI2 and vimentin participate in the apoptotic mechanisms of activated T lymphocytes. The secretion and surface expression of vimentin are possible ways of autoantigen presentation to the immune system.

Overexpression of Rcan1-1L Inhibits Hypoxia-Induced Cell Apoptosis through Induction of Mitophagy

  • Sun, Lijun;Hao, Yuewen;An, Rui;Li, Haixun;Xi, Cong;Shen, Guohong
    • Molecules and Cells
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    • v.37 no.11
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    • pp.785-794
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    • 2014
  • Mitophagy, a cellular process that selectively targets dysfunctional mitochondria for degradation, is currently a hot topic in research into the pathogenesis and treatment of many human diseases. Considering that hypoxia causes mitochondrial dysfunction, which results in cell death, we speculated that selective activation of mitophagy might promote cell survival under hypoxic conditions. In the present study, we introduced the Regulator of calcineurin 1-1L (Rcan1-1L) to initiate the mitophagy pathway and aimed to evaluate the effect of Rcan1-1L-induced mitophagy on cell survival under hypoxic conditions. Recombinant adenovirus vectors carrying Rcan1-1L were transfected into human umbilical vein endothelial cells and human adult cardiac myocytes. Using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide MTT assay and Trypan blue exclusion assay, Rcan1-1L overexpression was found to markedly reverse cell growth inhibition induced by hypoxia. Additionally, Rcan1-1L overexpression inhibited cell apoptosis under hypoxic conditions, as detected by annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) apoptosis assay. Meanwhile, the mitochondria-mediated cell apoptotic pathway was inhibited by Rcan1-1L. In contrast, knockdown of Rcan1-1L accelerated hypoxia-induced cell apoptosis. Moreover, Rcan1-1L overexpression significantly reduced mitochondrial mass, decreased depolarized mitochondria, and downregulated ATP and reactive oxygen species production. We further delineated that the loss of mitochondrial mass was due to the activation of mitophagy induced by Rcan1-1L. Rcan1-1L overexpression activated autophagy flux and promoted translocation of the specific mitophagy receptor Parkin into mitochondria from the cytosol, whereas inhibition of autophagy flux resulted in the accumulation of Parkin-loaded mitochondria. Finally, we demonstrated that mitochondrial 1permeability transition pore opening was significantly increased by Rcan1-1L overexpression, which suggested that Rcan1-1L might evoke mitophagy through regulating mitochondrial permeability transition pores. Taken together, we provide evidence that Rcan1-1L overexpression induces mitophagy, which in turn contributes to cell survival under hypoxic conditions, revealing for the first time that Rcan1-1L-induced mitophagy may be used for cardioprotection.

Nobiletin attenuates neurotoxic mitochondrial calcium overload through K+ influx and ∆Ψm across mitochondrial inner membrane

  • Lee, Ji Hyung;Amarsanaa, Khulan;Wu, Jinji;Jeon, Sang-Chan;Cui, Yanji;Jung, Sung-Cherl;Park, Deok-Bae;Kim, Se-Jae;Han, Sang-Heon;Kim, Hyun-Wook;Rhyu, Im Joo;Eun, Su-Yong
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.3
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    • pp.311-319
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    • 2018
  • Mitochondrial calcium overload is a crucial event in determining the fate of neuronal cell survival and death, implicated in pathogenesis of neurodegenerative diseases. One of the driving forces of calcium influx into mitochondria is mitochondria membrane potential (${\Delta}{\psi}_m$). Therefore, pharmacological manipulation of ${\Delta}{\psi}_m$ can be a promising strategy to prevent neuronal cell death against brain insults. Based on these issues, we investigated here whether nobiletin, a Citrus polymethoxylated flavone, prevents neurotoxic neuronal calcium overload and cell death via regulating basal ${\Delta}{\psi}_m$ against neuronal insult in primary cortical neurons and pure brain mitochondria isolated from rat cortices. Results demonstrated that nobiletin treatment significantly increased cell viability against glutamate toxicity ($100{\mu}M$, 20 min) in primary cortical neurons. Real-time imaging-based fluorometry data reveal that nobiletin evokes partial mitochondrial depolarization in these neurons. Nobiletin markedly attenuated mitochondrial calcium overload and reactive oxygen species (ROS) generation in glutamate ($100{\mu}M$)-stimulated cortical neurons and isolated pure mitochondria exposed to high concentration of $Ca^{2+}$ ($5{\mu}M$). Nobiletin-induced partial mitochondrial depolarization in intact neurons was confirmed in isolated brain mitochondria using a fluorescence microplate reader. Nobiletin effects on basal ${\Delta}{\psi}_m$ were completely abolished in $K^+-free$ medium on pure isolated mitochondria. Taken together, results demonstrate that $K^+$ influx into mitochondria is critically involved in partial mitochondrial depolarization-related neuroprotective effect of nobiletin. Nobiletin-induced mitochondrial $K^+$ influx is probably mediated, at least in part, by activation of mitochondrial $K^+$ channels. However, further detailed studies should be conducted to determine exact molecular targets of nobiletin in mitochondria.

The Effect of the Bojungikgi-tang in a Mouse Model of Allergic Rhinitis (포중익기탕(補中益氣湯)이 알레르기 비염(鼻炎) 유발 마우스에 미치는 효과(效果))

  • Kim, Sun-Min;Sim, Sung-Youn;Byun, Hak-Sung;Kim, Kyung-Jun
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.18 no.3
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    • pp.26-36
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    • 2005
  • Objectives: Maier symptoms of allergic rhinitis are nasal obstructions, sneezing and watery rhinorrhea. When exposed to certain allergens, the IgE covered mast cells degranulate and release inflammatory mediators and cytokines which result in a local inflammatory reaction. In many recent studies, molecular biological methods have been used to investigate the role of cytokines in pathogenesis and new therapeutic targets of allergic rhinitis. This experimental study was done to reveal the effects of the Bojungikgi-tang on the allergic rhinitis. We have studied effect of mice on OVA-induced production of IL-4, IL-5, $INF-{\gamma}$ by murine splenocytes and effect of OVA-induced Total IgE and OVA-specific IgE Meterial and Metheds: 21 BALB/c rats were divided into three groups: normal group, control group, experimental group. To induce the allergic rhinitis in control group and experimental group, rats were sentitized intraperitioneally with 0.1% ovalbumin solution 3 times at intervals of 2 weeks. Then intranasal sensitization was performed by diffusing 0.1% ovalbumin solution 3 times at intervals of 2 days for a week. After that time, rats in experimental group were oral administration treated by the Bojuogikgi-tang fer 28 days. We observed changes of IL-4, IL-5, $INF-{\gamma}$, Total IgE and OVA-specific IgE. We used independent-test statistically. Results: 1. In IL-4 study, Bojungikgi-tang treated group didn't show significant differences. 2. In IL-5 study, Bojungikgi-tang treated group shows significant differences. 3. In $INF-{\gamma}$ study, Bojungikgi-tang treated group shows significant differences. 4. In Total IgE, Bojungikgi-tang treated group shows significant differences. 5. In OVA-specific IgE, Bojungikgi-tang treated group didn't show significant differences. According to this result, Bojungikgi-tang was concluded to be effective on lowering the total IgE. Through this. Bojungikgi tang seems to reduce the symptoms of allergic rhinitis. More studies are required to know exact mechanism of Bojungikgi tang to show the anti allergenic effect.

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Microbiological and Immunological Investigation on the Bacteroides gingivalis in Rapidly Progressive and Adult Periodontitis in Korean (한국인 급성진행성 및 성인성 치주염의 원인균인 Bacteroides gingivalis에 대한 미생물 및 면역학적 연구)

  • Chung, Chong-Pyoung;Lee, Jong-Heun;Chung, Hyun-Ju
    • The Journal of the Korean Society for Microbiology
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    • v.22 no.3
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    • pp.309-321
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    • 1987
  • For the investigation of microbiological and immunological specificity of Bacteroides gingivalis, Bacteroides gingivalis were isolated, enumerated and characterized from 13 Korean rapidly progressive periodontitis and 7 healthy control by anaerobic culture technique. The total proportion of black-pigmented Bacteroides from Korean R.P.P. patients and healthy control were 8.78% and 0.92%, respectively, among total isolated black-pigmented Bacteroides. In antibiotic susceptibility test, Bacteroides gingivalis isolated from R.P.P. patients were sensitive to Ampicillin and Tetracycline, and resistant to Gentamicin and Erythromycin in disc diffusion method. In antibiotic broth dilution method, the minimum inhibitory concentration(MIC) to Bacteroides gingivalis was 2 unit/ml of Penicillin and $0.25{\sim}1{\mu}g/ml$ of Tetracycline, respectively. The concentration of serum IgG in rapidly progressive periodontitis patients were sigificantly higher than that of healthy control, and concentration of diluted gingival crevicular IgG has not any significant differences between two groups. Serum and gingival crevicular IgG antibody to Bacteroides gingivalis were significantly higher titer in rapidly progressive periodontitis patients to compare with healthy control. The lipopolysaccharide profiles of 2 Korean B. gingivalis in silver stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis were similar to type strains of B. gingivalis and typical LPS band were appeared around the 24-Kd molecular weight. Immunodiffusion test and immunoelectrophoresis of the L.P.S. extracted from 2 Korean B. gingivalis and 2 kinds of type strains of B. gingivalis showed that B. gingivalis Korean-1 was reacted identically to B. gingivalis ATCC 33277. In trypsin and ${\alpha}$-glucosidase activity test of 2 Korean B. gingivalis, both of them revealed positive trypsin and negative ${\alpha}$-glucosidase activity, respectively. These investigation suggested that B. gingivalis is important pathogenic plaque bacteria for the pathogenesis of periodontitis and further study is needed to purify and characterize of the species-specific antigens of this organisms to develop monoclonal antibody and potential diagnostic reagents.

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Differential Hrd1 Expression and B-Cell Accumulation in Eosinophilic and Non-eosinophilic Chronic Rhinosinusitis With Nasal Polyps

  • Chen, Kun;Han, Miaomiao;Tang, Mengyao;Xie, Yadong;Lai, Yuting;Hu, Xianting;Zhang, Jia;Yang, Jun;Li, Huabin
    • Allergy, Asthma & Immunology Research
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    • v.10 no.6
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    • pp.698-715
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    • 2018
  • Purpose: Hrd1 has recently emerged as a critical regulator of B-cells in autoimmune diseases. However, its role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) remains largely unexplored. This study aimed to examine Hrd1 expression and B-cell accumulation and their possible roles in CRSwNP. Methods: Quantitative real-time polymerase chain reaction, immunohistochemistry, enzyme-linked immunosorbent assay and Western blotting were used to assess gene and protein expression in nasal tissue extracts. Cells isolated from nasal tissues and peripheral blood mononuclear cells were characterized by flow cytometry. Local antibody production was measured in tissue extracts with a Bio-Plex assay. Additionally, changes in Hrd1 expression in response to specific inflammatory stimuli were measured in cultured dispersed polyp cells. Results: Nasal polyps (NPs) from patients with eosinophilic CRSwNP (ECRS) had increased levels of Hrd1, B-cells and plasma cells compared with NPs from patients with non-eosinophilic CRSwNP (non-ECRS) or other control subjects (P < 0.05). The average Hrd1 levels in B-cells in NPs from ECRS patients were significantly higher than those from non-ECRS patients and control subjects (P < 0.05). NPs also contained significantly increased levels of several antibody isotypes compared with normal controls (P < 0.05). Interestingly, Hrd1 expression in cultured polyp cells from ECRS patients, but not non-ECRS patients, was significantly increased by interleukin-$1{\beta}$, lipopolysaccharide and Poly(I:C) stimulation, and inhibited by dexamethasone treatment (P < 0.05). Conclusions: Differential Hrd1 expression and B-cell accumulation between the ECRS and non-ECRS subsets suggests that they can exhibit distinct pathogenic mechanisms and play important roles in NP.

Effect of Oral Administration of Houttuynia Cordata Extract on Benign Prostatic Hyperplasia (전립선비대증의 어성초추출물에 의한 경구투여 효과)

  • Song, Won-Yeong;Choi, Jeong-Hwa
    • Journal of Life Science
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    • v.29 no.6
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    • pp.705-711
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    • 2019
  • Benign prostatic hyperplasia (BPH) is the most common urogenital disorder in men, benign tumor and is a typical disease deteriorating the quality of old men's lives, and its prevalence increases with age. Though the molecular pathogenesis of BPH has not yet been clearly revealed, it is known that the variation and aging of the endocrine including sex hormone may cause BPH. Especially the hypertrophy of the prostate cell by the formation of the excessive dihydrotestosterone (DHT) is estimated to cause BPH. If testosterone exists excessively in blood, a lot of DHT is produced in prostate by $5{\alpha}-reductase$. Thus, in this study we tried to analyze haematological change and histopathological change by using the model rat with BPH caused by hypodermic injection of testosterone to prove the effect of Houttuynia cordata extracts on BPH. Rats were divided into four experimental groups: no treatment group (N), the testosterone injection and D.W treatment group (DO), the testosterone injection and Houttuynia cordata treatment group (HO) and testosterone injection and finasteride treatment group (FO). Prostate weight, volume and weight ratio in the HO and FO groups were significantly lower than the DO group. Testosterone and DHT levels in the HO group were significantly lower than the DO group. The HO and FO groups showed trophic symptoms and were lined by flattened epithelial cells, thus, the stromal proliferation is relatively low as compared to the DO group. These results suggest that Houttuynia cordata may control benign prostatic hyperplasia.

Molecular Detection of Virulence Factors in Carbapenem-Resistant Pseudomonas aeruginosa Isolated from a Tertiary Hospital in Daejeon (대전지역의 3차 병원에서 분리된 Carbapenem 내성 Pseudomonas aeruginosa의 병독성 인자 검출)

  • Cho, Hye Hyun
    • Korean Journal of Clinical Laboratory Science
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    • v.51 no.3
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    • pp.301-308
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    • 2019
  • The emergence and spread of multidrug resistant (MDR) Pseudomonas aeruginosa is a critical problem worldwide. The pathogenesis of P. aeruginosa is due partly to the production of several cell-associated and extracellular virulence factors. This study examined the distribution of virulence factors and antimicrobial resistance patterns of carbapenem-resistant P. aeruginosa (CRPA) isolated from a tertiary hospital in Daejeon, Korea. Antimicrobial susceptibility testing was performed using the disk diffusion method, and PCR and DNA sequencing were performed to determine for the presence of virulence genes. In addition, the sequence type (ST) of MDR P. aeruginosa was investigated by multilocus sequence typing (MLST). Among 32 CRPA isolates, 14 (43.8%) were MDR and the major ST was ST235 (10 isolates, 71.4%). All isolates were positive for the presence of virulence genes and the most prevalent virulence genes were toxA, plcN, and phzM (100%). All isolates carried at least eight or more different virulence genes and nine (28.1%) isolates had 15 virulence genes. The presence of the exoU gene was detected in 71.4% of the MDR P. aeruginosa isolates. These results indicate that the presence of the exoU gene can be a predictive marker for the persistence of MDR P. aeruginosa isolates.