• Title/Summary/Keyword: cell secretion

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Helicobacter pylori Vacuolating Toxin Exhibits Polar Activity of $Cl^-$ Secretion and Secretory Response to Carbachol in T84 Cells

  • Jin, Nan-Ge;Jin, Yong-Ri;So, In-Suk;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • v.8 no.5
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    • pp.289-293
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    • 2004
  • To investigate whether VacA (vacuolating toxin) produced by Helicobacter pylori Korean stain 99 induces intestinal secretion, purified VacA was added to T84 cell monolayers mounted in Ussing chambers, and electrical parameters were monitored. Mucosal addition of low pH-pretreated VacA increased short circuit current (Isc). The effect was time- and dose-dependent and saturable. The time-to-peak Isc was concentration-dependent. Chloride channel inhibitors, niflumic acid or 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB), inhibited VacA-stimulated Isc. Carbachol (CCh)-induced increase of Isc was prolonged by the addition of VacA to the mucosal side only. The effect was unaltered by the addition of niflumic acid. VacA did not show cytopathic effects. These studies indicate that VacA is a nonlethal toxin that acts in a polar manner on T84 monolayers to potentiate $Cl^-$ secretion and the response to CCh secretion without decrease in monolayer resistance. VacA may contribute to diarrhea diseases in human intestinal epithelial cells.

Bacillus subtilis의 단백질 분비기구 SecY의 유전자 수준의 조절이 단백질 분비에 미치는 영향

  • 김상숙;김순옥;서주원
    • Microbiology and Biotechnology Letters
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    • v.24 no.4
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    • pp.408-414
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    • 1996
  • The SecY is a central component of the protein export machinery that mediate the translocation of secretory proteins across the plasma membrane, and has been known to be rate-limiting factor of secretion in Escherichia coli. In order to study the extracellular protein secretion in Gram-positive microorganism, we have, constructed strains harboring more than one copy of the gene for SecY. Firstly, the gene, for B. subtilis SecY and its promoter region was subcloned into pDH32 and the chimeric vector was inserted into amyE locus by homologous recombination. Secondly, low copy number vector, pCED6, was also used for subcloning the secY gene and for constructing a strain which harbors several copies of secY. The KH1 cell which harbor two copies of secY on the chromosome excreted more extracellular proteins than the wild type PB2. Moreover, the KH2 cells which harbor several copies of secY in pCED6 vector excreted more extracellular proteins than the KH1 cells. Here, we found that the capacity of protein secretion is partly controlled by the number of secY and it is suggested that SecY has also an important role in protein secretion in B. subtilis, a gram positive microorganism, as like in E. coli. This will promote the use of B. subtilis as a host for the expression of useful foreign gene and excretion of precious proteins.

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Effect of YCT on Insulin Secretion in RIN-m5F Cells (RIN-m5F 세포에서 야관청혈탕(夜關淸血湯)이 인슐린 분비에 미치는 영향)

  • Kim, Jin-Mi;Cho, Chung-Sik;Kim, Chul-Jung
    • The Journal of Korean Medicine
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    • v.31 no.4
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    • pp.20-37
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    • 2010
  • Objective: This study was performed to investigate the effect of Yagwan-cheunghyeoltang (YCT) on insulin secretion in RIN-m5F cells. Methods: After treatment with various concentrations of YCT to RIN-m5F cells, cell viability, free radical-scavenging activity, SOD activity, and insulin secretion were measured. Additionally, insulin-related gene expressions were measured using real-time RT-PCR. Results: 1. YCT didn't show any influence on RIN-m5F cells viability. 2. YCT showed free radical-scavenging activity by 16% at $100{\mu}g/m{\ell}$ of concentration. 3. YCT showed enhancement of SOD activity by 60% at $100{\mu}g/m{\ell}$ of concentration. 4. YCT significantly increased insulin secretion in RIN-m5F cells in a dose-dependent manner. 5. YCT up-regulated INS-1, INS-2, IRS-1, IRS-2 and IRS-3 mRNA expressions compared to the control group. 6. YCT down-regulated INS-R, GCK, GLP-1R and GLP-2R mRNA expressions compared to the control group. Conclusion: YCT has pharmaceutical properties enhancing insulin production and controlling glucose-associated metabolism, and could be a candidate for drug development after further research.

Pycnogenol Supplementation Retards Immune Dysfunction in Murine AIDS (MAIDS) After LP-BM5 Leukemia Virus Infection by Modulating Cytokine Secretion

  • Lee, Jeong-Min;Park, Kun-Young;Hwang, Kwon-Tack;Watson, Ronald R.
    • Preventive Nutrition and Food Science
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    • v.10 no.2
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    • pp.161-166
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    • 2005
  • We investigated the effect of pycnogenol (PYC) supplementation on retarding the immune dysfunction of CS7BL/6 mice after murine AIDS (MAIDS) development. Dysfunction of T and B cell mitogenesis from primary cultured splenocytes has been observed with retrovirus infection and PYC supplementation partially recovered the dysfunction of T and B cells. There was an abnormal shift of cytokine pattern with retrovirns infection, which was designated by the decreased secretion of Th1 cytokines and increased secretion of Th2 cytokines. PYC supplementation increased IL-2 and $IFN-\gamma$ secretion and decreased IL-4, IL-6, and $TNF-\alpha$ secretion, but it was not sufficient enough to maintain the normal level of these cytokines. Hepatic vitamin E level was significantly decreased by retrovirns infection, in accordance with increased hepatic lipid peroxidation level, whereas PYC supplementation normalized the hepatic level of vitamin E and lipid peroxidation. This study suggests that PYC supplementation may partially help retard the incidence of symptoms during MAIDS.

Effects of Mutagenesis for Glycosylation Sites of Recombinant Human EPO During Production from Cultured CHO Cell

  • Lee, Hyun-Gi;Seong, Hwan-Hoo;Im, Seok-Ki;Chung, Hee-Kyoung;Lee, Poongyeon;Lee, Yeun-Kun;Min, Kwan-Sik;Chang, Won-Kyoung;Lee, Hoon-Taek
    • Proceedings of the Korean Society of Embryo Transfer Conference
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    • 2002.11a
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    • pp.97-97
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    • 2002
  • Human eryhropoietin (EPO) is acidic glycoprotein hormone that plays key role in hematopoiesis by facilitating differentiation of erythrocyte and formation of hemoglobin (Hb) and is used for the treatment of anemia. Human EPO is consist of 166 amino acids which is modified by three N-glycosylations (24, 38, 83) and single O-glycosylation (126). N-glycosylation is reported to be related to the cellular secretion and activity of EPO. In this study, we examined effects of mutagenesis in glycosylation site of recombinat hEPO for the cellular secretion during production from cultured CHO cell. We produced rhEpo which was cloned by PCR from human liver cDNA (TaKaRa) in cultured CHO cell. Using supernatant of the culture, ELISA assay and western analysis were performed. To estimate biological activity, 20IU of rhuEpo was subcutaneously injected into four ICR mice. After 8 days, HCT level was increased average 13 per cent, RBC was increased ca. 2${\times}$10$\^$6//${\mu}\ell$. In disease model Rat (anemia c-kit, WSRC-WS/WS), HCT was increased ca. 12%, RBC was increased ca. 1.6${\times}$10$\^$6//${\mu}\ell$. These results suggests that rhEpo we produced has biological activity. To remove glycosylation site by substituting 24, 38, 83, and 126th asparagine (or serine) with glutamic acid, overlapping -extension site-directed mutagenesis was performed. To add novel glycosylation sites, 69, 105th leucine was mutated to asparagine. Mutant EPO construct was transfected into CHO cell. Supernatant of the cell culture was analyzed using ELISA assay with monoclonal anti-EPO antibody (Medac, Germany). Since, several reports for mutagenesis of glycosylation sites showed case-by-case results, we examined both transient expression and stable expression. Addition of novel glycosylation sites resulted no secretion while deletion mutants had little effect except some double deletion mutants (24/83 and 38/83) and triple mutant. We suggest that not single but combination of glycosyl group affect secretion of EPO.

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Effects of Water Extract of Liriope platyphylla on the mRNA Expression and Protein Secretion of Nerve Growth Factors (맥문동 유수추출물이 NGF의 mRNA발현과 단백질 분비에 미치는 영향)

  • Choi, Sun-Il;Park, Jee-Hee;Her, Youn-Kyng;Lee, Yoen-Kyung;Kim, Ji-Eun;Nam, So-Hee;Goo, Jun-Seo;Jang, Min-Ju;Lee, Hee-Sup;Son, Hong-Ju;Lee, Chung-Yeol;Hwang, Dae-Youn
    • Korean Journal of Medicinal Crop Science
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    • v.18 no.5
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    • pp.291-297
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    • 2010
  • Liriope platyphylla has been though as an useful medical plant to improve the cough, sputum, neurodegenerative disorders, obesity, and diabetes in Korea and China from old times. In order to investigate the effects of Liriope platyphylla on expression and secretion of nerve growth factor (NGF), the mRNA expression and protein secretion were detected in the neuronal cell (B35) and neuroglial cell (C6) cultured with three differences concentration (5%, 10%, 15%) of Liriope platyphylla. In MTT assay and FACS anslysis, the some death of some B35 and C6 cells were observed in 15% extract-treated group, while other groups did not induce the death. Also, the mRNA expression of NGF were significantly increased in 5% and 10% extracts treated-group. Furthermore, the NGF protein concentration in supernatant collected from cultured cells showed the very similar pattern with mRNA expression. In order to verify the activity of secreted NGF, the culture supernatant collected from B35 and C6 cells cultured with Liriope platyphylla extracts for 24 hrs were treated into undifferentiated PC12 cells, and the differentiation level of PC12 cell were also observed with microscopes. The differentiation level of PC12 cell were significantly increased depend on the dose of extract. Therefore, these results suggested that the water extracts of Liriope platyphylla may contribute the regulation of NGF expression and secretion in the neuronal cell and be considered as an excellent candidate for a neurodegenerative disease-therapeutic drug.

Effect of Glycyrrhizae Radix Pharmacopuncture on PCA and Secretion of ${\beta}$-Hexosaminidase and Cytokines in RBL-2H3 Cells (감초약침(藥鍼)이 PCA반응과 비만세포의 ${\beta}$-Hexosaminidase 및 Cytokine 분비에 미치는 영향)

  • Lee, Hang-Do;Song, Choon-Ho
    • Korean Journal of Acupuncture
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    • v.28 no.3
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    • pp.73-83
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    • 2011
  • Objectives : The purpose of this study is to investigate anti-allergic effects of Glycyrrhizae Radix(GR) pharmacopuncture and GR extract. Methods : In vivo, animals were gotten GR pharmacopunctures at both sides of ST36s three times for 5 days. Then, we investigated anti-DNP IgE-induced passive cutaneous anaphylaxis of Sprague Dawley rats. In vitro, we measured cell viability, ${\beta}$-hexosaminidase release, and the secretion of interleukin-4(IL-4) and tumor necrosis factor-alpha(TNF-${\alpha}$) in RBL-2H3 cells after treatment of various concentrations of GR extract. Results : In vivo, we observed inhibition of passive cutaneous anaphylaxis after GR pharmacopuncture treatments at both sides of ST36s and optional points. In vitro, GR extract treatments did not affect cell viability, but inhibited ${\beta}$-hexosaminidase release and the secretion of IL-4 and TNF-${\alpha}$. Conclusions : These results suggest that GR pharmacopuncture and GR extract should be beneficial in the inhibition of allergic inflammatory response.

Effects of Styrax Liquides on the Secretion of ${\beta}$-amyloid Precursor Protein in Neuroblastoma Cells (소합향(蘇合香)이 신경 세포에서 베타 아밀로이드 분비에 미치는 영향)

  • Leem, Jae-Yoon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.1
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    • pp.91-95
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    • 2010
  • Alzheimer's disease (AD) is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of ${\beta}$-amyloid (A${\beta}$) peptides. It is urgent to develop effective therapies for the treatment of AD, since our society rapidly accelerate aging. A${\beta}$ peptides have been believed to be neurotoxic and now are also considered to have affects on the mechanism of memory formation, which are generated by processing of amyloid precursor protein (APP). In this study, effects of Styrax Liquides (SL) on the metabolism of APP were analyzed. SL inhibited the secretion of A${\beta}$ from the Neuro2a cell line (APPswe cell) expressing a mutation of APPswe. Immunoblotting study showed that it inhibited ${\beta}$-site APP cleaving enzyme (BACE) from the APPswe cells. We suggest that SL inhibits APP metabolism and A${\beta}$ generation by the means of BACE inhibitory mechanism. This is the first report that SL inhibits the secretion of A${\beta}$ peptides from neuroblastoma cells.

Prosuction of Cytokine and NO by RAW 264.7 Macrophages and PBMC In Vitro Incubation with Flavonoids

  • Lyu, Su-Yun;Park, Won-Bong
    • Archives of Pharmacal Research
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    • v.28 no.5
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    • pp.573-581
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    • 2005
  • Flavonoids, a group of low molecular weight phenylbenzopyrones, have various pharmacological properties including antioxidant activity, anticancer, and immunomodulatory effects. In the present study, lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate/phytohemagglutinin (PMA/PHA) were used as stimulants for RAW 264.7 macrophages and human peripheral blood mononuclear cell (hPBMC), and tumor necrosis factor (TNF)-${\alpha}$ and interleukin (IL)-2 productions were measured. In addition, flavonoids were examined for their effects on LPS-induced NO production in RAW 264.7 macrophages. The results showed that all compounds were not strongly cytotoxic at the tested concentrations on hPBMC and RAW 264.7 macrophages. On immunomodulatory properties, catechin, epigallocatechin (EGC), naringenin, and fisetin repressed NO production and TNF-${\alpha}$ secretion. Furthermore, catechin, epigallocatechin gallate (EGCG), epicatechin (EC), luteolin, chrysin, quercetin, and galangin increased IL-2 secretion while EGC, apigenin, and fisetin inhibited the secretion. These results indicated that flavonoids have the capacity to modulate the immune response and have a potential anti-inflammatory activity. There was no obvious structure-activity relationship regard to the chemical composition of the flavonoids and their cell biological effects.

The Anti-allergic Effect of Vinegar Treated Small Black Soybean (Glycine max Merr.) is Mediated Through Inhibition of Histamine Release and Inflammatory Cytokine Secretion

  • Shin, Tae-Yong;Shin, Hye-Young;Lim, Jong-Pil;Jeon, Hoon;Kim, Dae-Keun;Chae, Byeong-Suk;Kwon, Young-Ee;Kang, Sin-Myoung;Chang, Ik-Jun;Park, Jeong-Suk;Lee, Jae-Hyeok
    • Natural Product Sciences
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    • v.13 no.4
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    • pp.337-341
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    • 2007
  • In this report, we investigated the effect of aqueous extract of vinegar treated small black soybean (Glycine max Merr.) (Leguminosae) (VSBS) on mast cell-mediated allergic reaction and pro-inflammatory cytokine secretion. VSBS inhibited compound 48/80-induced systemic reactions. VSBS attenuated immunoglobulin (Ig) E-mediated passive cutaneous anaphylaxis. In addition, VSBS decreased the phorbol 12-myristate 13-acetate plus calcium ionophore A23187-stimulated secretion of tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-6 and interleukin (IL)-8 in human mast cells. Our findings provide evidence that VSBS inhibits mast cell-derived allergic reactions.