• Title/Summary/Keyword: Amyloid ${\beta}$-protein

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Expression of Aβ-Fc Fusion Protein in Transgenic Potato

  • Kim, Hyun-Soon;Youm, Jung Won;Lee, Jeong-Hwan;Jeon, Jae-Heung;Ko, Kisung
    • Horticultural Science & Technology
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    • v.32 no.3
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    • pp.375-381
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    • 2014
  • Transgenic potato was generated to express recombinant 5 repeated ${\beta}$-amyloid ($A{\beta}$) peptides, potential antigens to be applied as a preventive accine for Alzheimer's disease using Agrobacterium mediated transformation. The $A{\beta}$ peptides were fused to the human IgG Fc fragment enhancing protein and KDEL, which is the endoplasmic reticulum (ER) retention signal ($5A{\beta}$-FcK). The $5A{\beta}$-FcK, was expressed under the control of the duplicated 35S promoter. PCR analysis confirmed the presence of the transgene in several transgenic potato lines. Southern blot analysis showed only a single gene copy number in transgenic line 22, whereas multiple gene copy numbers were shown for transgenic lines 31 and 44. Northern blot analysis showed that line 22 had stronger mRNA levels when compared to lines 31 and 44. Immunoblot analysis confirmed that the $5A{\beta}$-FcK protein was expressed in the transgenic potato plant. These results indicate that $5A{\beta}$ fused to Fc can be expressed in potato plants.

Acetylcholinesterase Inhibitory Activity and Protective Effect against Cytotoxicity of Perilla Seed Methanol Extract (들깨 메탄올 추출물의 acetylcholinesterase 억제활성 및 세포독성 보호효과)

  • Choi, Won-Hee;Um, Min-Young;Ahn, Ji-Yun;Kim, Sung-Ran;Kang, Myung-Hwa;Ha, Tae-Youl
    • Korean Journal of Food Science and Technology
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    • v.36 no.6
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    • pp.1026-1031
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    • 2004
  • Acetylcholinesterase inhibitory activity and protective effect against cytotoxicity of PC 12 cell induced by beta-amyloid protein and glutamate were examined in perilla seed methanol extract and its solvent fractions. Methanol extract of perilla seed showed dose-dependent acetylcholinesterase inhibitory activity, with n-butanol fraction showing strongest activity. Perilla seed methanol extract also decreased glutamate- and ${\beta}-amyloid$ protein $(A{\beta})-induced$ cytotoxicities of PC 12 cells dose-dependently. Formation of TBARS induced by $FeSO_{4^-}H_2O_2$ in rat brain was significantly reduced by perilla seed methanol extract, with strongest protective activity formation of TBARS shown in n-butanol fraction. Results suggest perilla seed methanol extract may attenuate actylcholinesterase activity and cytotoxicity induced by glutamate and ${\beta}-amyloid$ protein through suppression of oxidative stress.

Increase of Amyloid-Beta Peptide Generation in High Cholesterol Diet Rabbit Brain

  • Lee, Yong-Kyoung;Son, Dong-Ju;Lee, Jae-Woong;Lee, Hyung-Woo;Yun, Young-Won;Oh, Ki-Wan;Hong, Jin-Tae
    • Biomolecules & Therapeutics
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    • v.15 no.1
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    • pp.34-39
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    • 2007
  • Alzheimer's disease (AD) is an abnormal accumulation of the ${\beta}$-amyloid protein $(A{\beta})$ in specific brain region. It has been speculated that disturbance in cholesterol homeostasis may contribute to the etiology of AD by increasing $A{\beta}$ generation. However, conclusive evidence and possible mechanism has not been reported. In the present study, we demonstrated that rabbits treated with 0.5% cholesterol for 16 weeks increased serum total cholesterol, triacylglycerol, and low-density lipoprotein levels. $A{\beta}$ levels is higher in the hippocampus of brain in cholesterol dieted rabbits than that of normal diet rabbis. Expression and activities of ${\beta}-$ and ${\gamma}-$ secretases, the enzymes that cleave ${\beta}$-amyloid precursor protein to generate $A{\beta}$, were also increased in hippocampus of high cholesterol dieted rabbit than those of normal dieted rabbits. Our results suggest that high cholesterol diet may be associated with increased $A{\beta}$ accumulation in the brain of rabbits, and suggest that high cholesterol diet may be causal factor in the development or progression of AD.

Isolation of Streptomyces sp. KK565 as a Producer of ${\beta}-Amyloid$ Aggregation Inhibitor

  • Hwang, Sung-Eun;Im, Hyung-Min;Kim, Dong-Hoon;Shin, Hyun-Ju;Shin, Dong-Hoon;Park, Jeong-Eun;Jo, In-Ho;Kim, Chang-Jin;Yoo, Jong-Shin;Kang, Jong-Min;Lim, Dong-Yeon;Ahn-Jo, Snag-Mee;Kwon, Ho-Jeong
    • Journal of Microbiology and Biotechnology
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    • v.13 no.5
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    • pp.809-814
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    • 2003
  • ${\beta}-amyloid$ ($A{\beta}$) peptides from the proteolytic processing of ${\beta}-amyloid$ precursor protein (${\beta}-APP$) aggregates in the brain to form senile plaques, and their aggregation plays a key role in pathogenesis of Alzheimer's disease (AD). To isolate an active compound that has an $A{\beta}$ aggregation-inhibitory activity, 2,000 microbial metabolite libraries were screened based on their ability to inhibit $A{\beta}$ aggregation by using both Congo red and thioflavin T assays. As a result, a water-soluble fraction of a soil microorganism, KK565, showed a potent $A{\beta}$ aggregation-inhibitory activity. The strain was identified as Streptomyces species, based on the cultural and morphological characteristics, the presence of diaminopimelic acid in the cell wall, and the sugar patterns for the whole-cell extract. In addition, the purification of active principle resulted in identifying a heat-unstable protein responsible for the $A{\beta}$ aggregation-inhibitory activity.

Effects of 3-Phenyl-1-isoquinolinamine on the Metabolism of ${\beta}$-Amyloid Precursor Protein in Neuroblastoma Cells (3-페닐-1-이소퀴놀린아민이 신경세포에서 베타 아밀로이드 전구단백질의 대사에 미치는 영향)

  • Leem, Jae-Yoon;Cho, Won-Jea
    • YAKHAK HOEJI
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    • v.54 no.6
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    • pp.529-534
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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, which are generated by processing of amyloid precursor protein (APP). 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 effects on the mechanism of memory formation. Recently, we investigated that a quinoline compound from natural product reduced the secretion of $A{\beta}$ from the neuroblastoma N2a cells (NL/N cell line) overexpressing APPswe. In this study, 3-phenyl-1-isoquinolinamine, a synthetic isoquinoline compound was analyzed to determine its effects on the metabolism of APP. It inhibited the secretion of $A{\beta}$ peptides from the N2a NL/N cell line. Beta-site APP cleaving enzyme (BACE) fluorescence resonance energy transfer (FRET) assay revealed that it inhibited BACE activity in a dose dependent manner. Immunoblotting study showed that it inhibited APP stabilization and expression and it slightly increased the stablization and the expression of ${\gamma}$-secreatase component from the N2a NL/N cell line. We suggest that 3-phenyl-1-isoquinolinamine inhibits APP metabolism and $A{\beta}$ generation by the means of BACE inhibitory mechanism. This is the first report that 3-phenyl-1-isoquinolinamine inhibits the secretion of $A{\beta}$ peptides from neuroblastoma cells.

Beta-amyloid peptide degradation by aminopeptidase and its functional role in Alzheimer's disease pathogenesis

  • AhnJo, Sang-Mee
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2006.04a
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    • pp.77-90
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    • 2006
  • Beta-amyloid peptide (A$\beta$) is a major component of senile plaques and its aggregation is considered to play a critical role in pathogenesis of Alzheimer's disease (AD). Aggregation of A$\beta$ could result from both increased synthesis and decreased degradation of A$\beta$. Our laboratory is interested in understanding the mechanism of A$\beta$ degradation in brain. Recently our laboratory identified a bacterial gene (SKAP) from Streptomyces sp KK565 whose protein product has an activity to cleave A$\beta$ and thus reduce the A$\beta$-induced neurotoxicity. The sequence analysis showed that this gene was closely related to aminopeptidase. Maldi-Tof analysis showed that the recombinant SKAP protein expressed in E. coli cleaves both A$\beta$ 40 and A$\beta$ 42 at the N-terminal of A$\beta$ while an aminopeptidase from Streptomyces griseus (SGAP) cleaves at the C-terminal. We also identified a mammalian homolog of SKAP and the recombinant mammalian protein expressed in Sf-9 insect cells showed a similar proteolytic activity to SGAP, cutting A$\beta$ at the C-terminus. I well discuss the detailed mechanism of the enzyme action and its functional implication in AD.

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