• Title/Summary/Keyword: intracellular degradation

검색결과 143건 처리시간 0.027초

베타 아밀로이드 유도성 Neuro 2A 세포독성에 대한 총명탕의 효과 (Chongmyung-tang Inhibits the Cytotoxicity of Beta-amyloid in Neuro 2A Neuroblastoma Cells)

  • 국윤재;최혁;김태헌;강형원;유영수
    • 동의생리병리학회지
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    • 제18권5호
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    • pp.1418-1425
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    • 2004
  • The water extract of Chongmyung-tang has been traditionally used for treatment of memory-disorder in oriental medicine. This study was designed to investigate the protective mechanisms of Chongmyung-tang on β-amyloid or H₂O₂-induced cytotoxicity in Neuro 2A cells. The water extract of Chongmyung-tang significantly reduced both β-amyloid or H₂O₂-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, it inhibited the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition(MPT) and the modulation in expression of Bcl-2 family proteins in H₂O₂-treated H9c2 cells. Furthermore, pretreatment of quercetin inhibited the activation of caspase-3, in turn, degradation of ICAD/DFF45 were completely abolished in H₂O₂-treated cells. Taken together, that data suggest that the protective effects of the water extract of Chongmyung-tang against β-amyloid induced oxidative injuries may be achieved through modulation of mitochondrial dysfunction.

기니픽 심장에서 histamine H2-수용체 자극에 의한 Mg2+ 유리에 대한 phosphodiesterase 억제제의 효과 (Regulation of histamine H2-receptor mediated Mg2+ release by phosphodiesterase inhibitors in the guinea pig hearts)

  • 강형섭;김진상
    • 대한수의학회지
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    • 제40권3호
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    • pp.479-487
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    • 2000
  • Several recent studies demonstrate that receptor-mediated cAMP (adenosine 3',5'-monophosphate) production evokes marked change in magnesium ($Mg^{2+}$) homeostasis. The effects of dimaprit or/and phosphodiesterase (PDE) inhibitors on the $Mg^{2+}$ release from perfused guinea pig heart and collagenase-dispersed myocytes was studied to clarify an association of $H_2-histaminergic$ receptor-mediated $Mg^{2+}$ regulation with intracellular cAMP-degradation system. $Mg^{2+}$ efflux was stimulated in perfused hearts and myocytes by IBMX (3-isobutyl-1-methylxanthine), a calmodulin-sensitive PDE inhibitor, but not by RO 20-1724(4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone) or papaverine, cAMP-specific PDE inhibitors. $Mg^{2+}$ efflux was also be induced by dimaprit, a H-2-agonist. $Mg^{2+}$ effluxes induced by dimaprit were augmented by the presence of the PDE inhibitors. The augmentation of dimaprit-induced $Mg^{2+}$ effluxes by the PDE inhibitors were inhibited by ranitidine, a $H_2-antagonist$, and imipramine, a $Na^{+}-Mg^{2+}$ exchange inhibitor, in perfused hearts and myocytes and were also inhibited by amiloride in perfused hearts. These results suggest that the $H_2$-stimulated $Mg^{2+}$ effluxes from guinea pig heart can be regulated by the cytosolic nonspecific-dependent PDE systems and that it is induced by the $Na^{+}-Mg^{2+}$ exchanger stimulation.

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Proteomic Analysis of Recombinant Saccharomyces cerevisiae upon Iron Deficiency Induced via Human H-Ferritin Production

  • Seo, Hyang-Yim;Chang, Yu-Jung;Chung, Yun-Jo;Kim, Kyung-Suk
    • Journal of Microbiology and Biotechnology
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    • 제18권8호
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    • pp.1368-1376
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    • 2008
  • In our previous study, the expression of active H-ferritins in Saccharomyces cerevisiae was found to reduce cell growth and reactive oxygen species (ROS) generation upon exposure to oxidative stress; such expression enhanced that of high-affinity iron transport genes (FET3 and FTR1). The results suggested that the recombinant cells expressing H-ferritins induced cytosolic iron depletion. The present study analyzes metabolic changes under these circumstances via proteomic methods. The YGH2 yeast strain expressing A-ferritin, the YGH2-KG (E62K and H65G) mutant strain, and the YGT control strain were used. Comparative proteomic analysis showed that the synthesis of 34 proteins was at least stimulated in YGH2, whereas the other 37 proteins were repressed. Among these, the 31 major protein spots were analyzed via nano-LC/MS/MS. The increased proteins included major heat-shock proteins and proteins related to endoplasmic reticulum-associated degradation (ERAD). On the other hand, the proteins involved with folate metabolism, purine and methionine biosynthesis, and translation were reduced. In addition, we analyzed the insoluble protein fractions and identified the fragments of Idh1p and Pgk1p, as well as several ribosomal assembly-related proteins. This suggests that intracellular iron depletion induces imperfect translation of proteins. Although the proteins identified above result from changes in iron metabolism (i.e., iron deficiency), definitive evidence for iron-related proteins remains insufficient. Nevertheless, this study is the first to present a molecular model for iron deficiency, and the results may provide valuable information on the regulatory network of iron metabolism.

Zinc Inhibits Amyloid ${\beta}$ Production from Alzheimer's Amyloid Precursor Protein in SH-SY5Y Cells

  • Lee, Jin-U;Kim, Chul-Hoon;Kim, Dong-Goo;Ahn, Young-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • 제13권3호
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    • pp.195-200
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    • 2009
  • Zinc released from excited glutamatergic neurons accelerates amyloid ${\beta}$ (A ${\beta}$) aggregation, underscoring the therapeutic potential of zinc chelation for the treatment of Alzheimer's disease (AD). Zinc can also alter A ${\beta}$ concentration by affecting its degradation. In order to elucidate the possible role of zinc influx in secretase-processed A ${\beta}$ production, SH-SY5Y cells stably expressing amyloid precursor protein (APP) were treated with pyrrolidine dithiocarbamate (PDTC), a zinc ionophore, and the resultant changes in APP processing were examined. PDTC decreased A ${\beta}$ 40 and A ${\beta}$ 42 concentrations in culture media bathing APP-expressing SH-SY5Y cells. Measuring the levels of a series of C-terminal APP fragments generated by enzymatic cutting at different APP-cleavage sites showed that both ${\beta}$-and ${\alpha}$-cleavage of APP were inhibited by zinc influx. PDTC also interfered with the maturation of APP. PDTC, however, paradoxically increased the intracellular levels of A ${\beta}$ 40. These results indicate that inhibition of secretase-mediated APP cleavage accounts -at least in part- for zinc inhibition of A ${\beta}$ secretion.

Adenophora remotiflora protects human skin keratinocytes against UVB-induced photo-damage by regulating antioxidative activity and MMP-1 expression

  • Kim, Hye Kyung
    • Nutrition Research and Practice
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    • 제10권4호
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    • pp.371-376
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    • 2016
  • BACKGROUND/OBJECTIVES: Chronic ultraviolet (UV) exposure-induced reactive oxygen species (ROS) are commonly involved in the pathogenesis of skin damage by activating the metalloproteinases (MMP) that break down type I collagen. Adenophora remotiflora (AR) is a perennial wild plant that inhabits Korea, China, and Japan. The present study investigated the protective effects of AR against UVB-induced photo-damage in keratinocytes. MATERIALS/METHODS: An in vitro cell-free system was used to examine the scavenging activity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and nitric oxide (NO). The effect of AR on ROS formation, antioxidant enzymes, elastase, MMP-1 level, and mRNA expression of MMP-1 were determined in UVB-irradiated human keratinocyte HaCaT cells. RESULTS: AR demonstrated strong DPPH free radical and NO scavenging activity in a cell-free system exhibiting $IC_{50}$ values of 1.88 mg/mL and 6.77 mg/mL, respectively. AR pretreatment dose-dependently attenuated the production of UVB-induced intracellular ROS, and antioxidant enzymes (catalase and superoxide dismutase) were enhanced in HaCaT cells. Furthermore, pretreatment of AR prevented UVB-induced elastase and collagen degradation by inhibiting the MMP-1 protein level and mRNA expression. Accordingly, AR treatment elevated collagen content in UVB-irradiated HaCaT cells. CONCLUSION: The present study provides the first evidence of AR inhibiting UVB-induced ROS production and induction of MMP-1 as a result of augmentation of antioxidative activity in HaCaT human keratinocytes. These results suggest that AR might act as an effective inhibitor of UVB-modulated signaling pathways and might serve as a photo-protective agent.

대장균에서 Serratia marcescens 58KD 키티나아제의 발현과 분비 (Expression and Secretion of Serratia marcescens 58 KD Chitinase in Escherichia coli)

  • 장규일;강송옥;신용철
    • 한국미생물·생명공학회지
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    • 제20권5호
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    • pp.511-518
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    • 1992
  • Serratia marcescens ATCC 27117에서 부터 클로닝한 58KD 키티나아제 유전자를 subcloning 하여 2.6Kb DNA 삽입단편을 가진 플라스미드 pCHI26을 제조하고 대장균에서 발현과 분비를 살펴보았다. 키티니아제 유전자는 대장균에서 자신의 prmoter를 이용하여 매우 낮은 수준(<5mU/m$\ell$)으로 발현되었으며 lac promoter를 이용하는 경우 키티니아제 발현이 증가되어 약 80mU/m$\ell$가 되었다. 발현된 키티니아제는 거의 전적으로 대장균의 periplasm에 위치(약 87.8)하고 있었다. 배양시간에 따라서 세포내 키티니아제 활성을 측정해본 결과 초기정지기까지는 균체 성장과 비례해서 세포내 효소활성이 증가되었으나 정지기부터 세포내 효소활성이 급격히 줄어드는 양상을 보였다. 그러나 이 기간 동안 세포의 효소활성의 변화는 거의 없었다. 이러한 결과로 보아 periplasm에 위치한 키티나아제가 대장균의 단백분해효소에 의해서 분해되는 것으로 추정되었다.

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Manila clam, Ruditapes philippinarum Cathepsin D: Molecular analysis and immune response against brown ring disease causing Vibrio tapetis challenge

  • Menike, Udeni;Ariyasiri, Krishan;Choi, Jin-Young;Lee, Youngdeuk;Wickramaarachchi, W.D.N.;Premachandra, H.K.A.;Lee, Jehee;De Zoysa, Mahanama
    • 한국패류학회지
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    • 제29권2호
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    • pp.155-161
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    • 2013
  • Cathepsins are lysosomal/cysteine proteases belong to papain family (C1 family) that is involved in intracellular protein degradation, antigen processing, hormone maturation, and immune responses. In this study, member of cathepsin family was identified from Manila clam (Mc-Cathepsin D) and investigated the immune response against brown ring disease (BRD) causing Vibrio tapetis challenge. The identified Mc-Cathepsin D gene encodes characteristic features typical for the cathepsin family including eukaryotic and viral aspartyl protease signature domain and two highly conserved active sites ($^{84}VVFDTGSSNLWV^{95}$ and $^{270}IADTGTSLLAG^{281}$). Moreover, MC-Cathepsin D shows higher identity values (-50-70%) and conserved amino acids with known cathepsin D members. Transcriptional results (by quantitative real-time RT-PCR) showed that Mc-Cathepsin D was expressed at higher levels in gills and hemocytes than mantle, adductor muscle, foot, and siphon. After the V. tapetis challenge under laboratory conditions, Mc-Cathepsin D mRNA was up-regulated in gills and hemocytes. Present study indicates that Mc-Cathepsin D is constitutively expressed in different tissues and potentially inducible when infecting BRD by V. tapetis. It is further suggesting that Mc-Cathepsin D may be involved in multiple role including immune response reactions against BRD.

Inhibitory Effect of Myricetin on Matrix Metalloproteinase Expression and Activity in Periodontal Inflammation

  • Ko, Seon-Yle
    • International Journal of Oral Biology
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    • 제41권4호
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    • pp.163-173
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    • 2016
  • Flavonoid myricetin, usually found in tea and medicinal plants, has antioxidant and anti-inflammatory effects. Our objectives in this study were to verify the effects of myricetin on periodontal ligament fibroblasts (PDLFs) under inflammatory conditions and to observe its effects on osteoclast generation and on cytokine expression in RAW264.7 cells. To determine the effects of myricetin on PDLFs, we examined the expression and activity of proteolytic enzymes, including MMP-1, MMP-2, and MMP-8, which all play an important role in chronic periodontitis. We observed the effects of myricetin on intracellular signal transduction to verify the molecular mechanism involved. By measuring the formation of TRAP-positive multinucleated cells and the expression and activity of MMP-8, we were able to assess the effects of myricetin on osteoclast generation. In addition, by measuring the secretion of IL-6 and NO, we could evaluate the effects of myricetin on inflammatory mediators. We found that Myricetin had no effect on the viability of the PDLFs in the presence of inflammation, but it did decrease both the expression of MMP-1 and MMP-8 and the enzyme activity of MMP-2 and MMP-8 in these fibroblasts. Myricetin also decreased the lipopolysaccharide-stimulated phosphorylation of JNK, p38 signaling, IKKB, AKT, and p65RelA in the PDLFs. In the RAW264.7 cells, myricetin inhibited both the expression and the activity of MMP-8. Furthermore, Myricetin not only suppressed the generation of LPS-stimulated osteoclasts, but it also slightly inhibited LPS-stimulated degradation of IkB and decreased the release of LPS-induced IL-6 and NO. These findings suggest that myricetin alleviates the tissue-destructive processes that occur during periodontal inflammation.

Thr-6Pro missense mutation in human lysosomal acid lipase (LAL) gene in patients with familial hypercholesterolemia in Korea

  • Hwang, Hye-Suk;Hwang, Jung-Hee;Kim, Hyun-Sup;Kim, Nam-Keun;Kim, Se-Jae;Lee, Chung-Choo;Chung, Ki-Wha
    • Journal of Genetic Medicine
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    • 제2권2호
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    • pp.65-70
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    • 1998
  • Lysosomal acid lipase (LAL) plays a central role in the intracellular degradation of neutral lipids derived from plasma lipoproteins. In this study, we investigated the missense mutation within exon 2 of human LAL gene changing of codon -6 of prepeptide from threonine to proline. The Thr-6Pro mutation was detected by the HaeIII restriction fragment length polymorphism (RFLP) and single-strand conformation polymorphism (SSCP). We analyzed the mutation in subjects with 221 unrelated randomly selected control samples and 86 patients with familial hypercholesterolemia (FH) in Korea. We observed that mutation is present with high frequency in Korea compared to other populations studied previously. The frequency of PP homozygote in the FH group was observed considerably higher than that of control. However, there was no significant difference of genotype frequency between two groups. These results, together with the fact that plasma lipids and lipoproteins levels between genotypes showed no statistical difference, suggest that the Thr-6Pro mutation in the LAL gene may have no association with the increased risk of FH development.

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혈관내피세포에서 TNF-$\alpha$ 자극에 의해 유도되는 혈관염증에 대한 WK-38의 억제 효과 (Inhibitory Effect of WK-38 on TNF-$\alpha$ Induced Vascular Inflammation in Human Umbilical Vein Endothelial Cells)

  • 황선미;이윤정;김은주;윤정주;이혁;강대길;이호섭
    • 동의생리병리학회지
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    • 제23권5호
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    • pp.1132-1138
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    • 2009
  • Vascular inflammation is an important event in the development of vascular diseases such as tumor progression and atherosclerosis. This study was to investigate the inhibitory effects of WK-38, a new herbal prescription for the treatment of atherosclerosis, on vascular inflammation in human umbilical vein endothelial cells (HUVEC). WK-38 is composed of Rhei Rhizoma, Magonoliae Cortex, Moutan Cortez Radicis. Pretreatment with WK-38 was significantly blocked TNF-$\alpha$-induced expression level of cell adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), and endothelial cell selectin (E-selectin) in a dose-dependent manner. TNF-$\alpha$-induced cell adhesion in co-cultured U937 and HUVEC was also blocked by pretreatment with WK-38. Moreover, WK-38 significantly suppressed p65 NF-${\kappa}B$ translocation into the nucleus by TNF-$\alpha$ as well as the phosphorylation and degradation of $I{\kappa}B-{\alpha}$. In conclusion, the present data suggested that WK-38 could suppress TNF-$\alpha$-induced vascular inflammatory process, though inhibition of NF-${\kappa}B$ activation in HUVEC.