• 통합자연과학논문집
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• 제6권3호
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• pp.143-150
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• 2013

Prevailing role of intracellular amyloid ${\beta}$ ($iA{\beta}$) in Alzheimer's disease (AD) initiation and progression attracts more and more attention in recent years. To address whether $iA{\beta}$ induces early alterations of electrophysiological properties in cultured human primary neurons, we delivered $iA{\beta}$ with adenovirus and measured the electrophysiological properties of infected neurons with whole-cell recordings. Our results show that $iA{\beta}$ induces an increase in neuronal resting membrane potentials, a decrease in $K^+$ currents and a hyperpolarizing shift in voltage-dependent activation of $K^+$ currents. These results suggest the electrophysiological impairments induced by $iA{\beta}$ may be responsible for its neuronal toxicity.

• 대한한방내과학회지
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• 제19권2호
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• pp.381-391
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• 1998

천축황(天竺黃)은 한의학에서 청풍열(淸風熱)과 치담(治痰)하는 효능으로 중풍과 불어증(不語症)을 치료하는데 널리 사용되고 있다. 본 연구에서는 천축황(天竺黃)이 실험적인 치매(Alzheimer Disease; AD)를 유발시키는 물질로 알려진 $amyloid-{\beta}\;(A{\beta}\;peptide)$를 흰쥐의 신경세포의 일종인 astrocyte에 처리하여 그 세포독성과 보호효과 및 세포막 지질의 과산화에 미치는 영향을 검토하였다. 천축황(天竺黃)은 $A{\beta}$에 의한 신경세포에 대한 손상을 억제하여 세포증식을 촉진하여 예방 및 보호효과를 나타내었다. 또한, 세포막 지질의 과산화의 지표인 malondialdehyde (MDA)생성이 $A{\beta}$처리로 크게 증가하였으나 세포막 파괴에 의한 뇌세포 파괴의 전형적인 현상이 천축황(天竺黃)의 전(前)처리와 후(後)처리로 크게 감소되었다. 그리고, 이러한 결과들은 천축황(天竺黃)이 신경세포의 하나인 astrocyte에 대한 보호효과와 세포막지질의 과산화 저해 및 $A{\beta}$처리와 같은 치매유발 독성에 대한 적응능력 향상을 통한 뇌신경의 보호효과를 주는 것으로 노인성 치매 등 임상적 응용에 그 효과가 기대된다.

• 사상체질의학회지
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• 제21권3호
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• pp.138-153
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• 2009

1. Objectives: Yeolda-Hanso tang (YH) has long been used as traditional herbal formula in Korea as various diseases. Now we modified Yeolda-Hanso tang (YH) for neurodegenerative diseases treatment and named New-Yeolda-Hanso tang (NYH). We investigated neuroprotective effects of NYH on NGF-differentiated PC12 cells cytotoxicity induced by $\beta$-Amyloid peptide (A$\beta$25-35) and evaluated the ability of NYH to prevent and treat for neurodegenerative diseases via autophagy enhancement. 2. Methods and Results: 1) Protective effect of NYH on PC12 cells cytotoxity induced by A$\beta$25-35. PC12 cells survival was measured by MTT and lactate dehydrogenase (LDH) assay. $20{\mu}M$ $\beta$-Amyloid peptide (A$\beta$25-35) induced cytotoxicity on NGF-differentiated PC12 cells. NYH attenuated the cytotoxic effects of A$\beta$25-35 in a dose-dependent manner. 2) Pharmacological induction of Autophagy by NYH in PC12 cells Autophagy induction and activation was measured by immunoblot assay. Marker of autophagy, LC3 II expression and the ratio of LC3-II/I was slightly increased in the protein treated with YH, and significantly augmented in the protein treated with NYH. NYH-induced increase of LC3-II protein level was inhibited by 3MA. 3) Induction of Autophagy by NYH on A$\beta$25-35-induced injury in PC12 cells In MTT assay, $100{\mu}g/ml$ re-treated NYH attenuated $20{\mu}M$ A$\beta$25-35-induced cytotoxicity in PC12 cells. Protection effect of NYH was blocked by autophagy inhibitor 3MA. In immunoblot assay, $1200{\mu}g/ml$ pre-treated NYH activated autophagy in $20{\mu}M$ A$\beta$25-35-induced cytotoxicity in PC12 cells. The observed effect was partially blocked by 3MA. 3. Conclusions: All the results indicated that NYH possesses neuroprotective potential partially mediated by autophagy enhancement and NYH may be considered to be a promising new herbal formula to prevent and treat for neurodegenerative diseases including Alzheimer's disease (AD).

• 대한한방내과학회지
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• 제21권2호
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• pp.235-241
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• 2000

호도(胡桃)(Juglandis semen)가 치매에 미치는 영향을 알아보기 위하여 치매(Alzheimer's disease) 유발물질로 알려진 amyloid-{$\beta}(A{\beta})$ 25-35를 흰쥐의 뇌 신경세포의 일종인 astrocyte에 처리한 후 뇌의 신경세포에 대한 독성 및 세포막에서의 지질 과산화에 미치는 영향을 검토하였다. 호도(胡桃)는 $A{\beta})$ 25-35로 인한 신경세포의 파괴를 억제하는 것으로 나타나 신경세포의 손상을 예방하고 보호하는 효과가 있었다. 그리고, 지질의 과산화 지표인 malondialdehyde 생성은 $A{\beta})$ 25-35 처리로 크게 증가하였으나, 호도(胡桃)의 전처리와 후처리로 크게 감소되어 호도(胡桃)가 세포막 파괴로 인한 뇌세포의 손상을 방지하는 것으로 나타났다. 이러한 결과들을 볼 때, 호도(胡桃)는 신경세포의 하나인 astrocyte에 대한 보호효과와 세포막에서 지질의 과산화를 저해 및 $A{\beta})$ 25-35 처리와 같은 치매 유발 독성에 대한 적응능력 향상을 통하여 뇌 신경세포를 보호하는 효과가 있음을 보여주는 것으로 노인성 치매 등의 임상적 응용에 그 효과가 기대된다.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2006년도 Spring Conference
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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.

• 생약학회지
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• 제46권1호
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• pp.72-77
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• 2015

One of the most common forms of dementia, Alzheimer's disease (AD) is a progressive neurodegenerative disorder symptomatically characterized by impairment in memory and cognitive abilities. AD is characterized pathologically by the presence of intracellular neurofibrillary tangles and deposition of ${\beta}$-amyloid ($A{\beta}$) peptides, believed to be neurotoxic and now is also considered to have a role on the mechanism of memory dysfunction. In this study, we tested that MeOH extract of Impatiens balsamina L. (IBM) affects on the processing of APP from the APPswe over-expressing Neuro2a cell line. We found that IBM increased over 2 folds of the $sAPP{\alpha}$ secretion level, a main metabolite of ${\alpha}$-secretase. We shown that IBM reduced the secretion level of $A{\beta}42$ and $A{\beta}40$ without cytotoxicity. BACE (${\beta}$-site APP cleaving enzyme) FRET assay shown that BACE activity was specifically decreased in the presence of IBM. We suggest that Impatiens balsamina L. may be an useful source to develop a herbal medicine of BACE inhibitor for Alzheimer's disease.

• KSBB Journal
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• 제28권4호
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• pp.230-237
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• 2013

Amyloid ${\beta}$ peptide (A${\beta}$) still best known as a molecule to cause Alzheimer's disease (AD). AD is characterized by the accumulation and deposition of A${\beta}$ within the brain, leading to neuronal cell loss and perturbation of synaptic function by causing free radical formation, inflammation and apoptosis. We investigated the inflammatory action of A${\beta}$ on two types of brain cells, neuronal cells (SH-SY5Y) and neuroglia cells (C6), and its mechanism. We measured the production of NO-iNOS, TNF-${\alpha}$, and ICAM-1 using RT-PCR and Western blot analysis less than the concentration of cytotoxic effects (> 70% survivability). A${\beta}$ had no effect on the production of NO and TNF-${\alpha}$, but significantly increases of iNOS and ICAM-1. Based on this, we suggest that the inflammatory effect of A${\beta}$ results from the action of ICAM-1 in neuronal cells, rather than the release of inflammatory mediators such as NO and TNF-${\alpha}$ in neuroglia cells. In addition, we confirmed whether p53 was related to the action of A${\beta}$ by using SH-SY5Y ($p53^{-/-}$) dominant cells. Neither the expression of p53 nor the cytotoxicity of SH-SY5Y ($p53^{-/-}$) cells were directly affected by A${\beta}$. However, ICAM-1 was not expressed in SH-SY5Y ($p53^{-/-}$) cells. This means that p53- independent pathway exists in the expression of ICAM-1 by A${\beta}$ while p53 plays a role as an on-and-off switch.

• Bulletin of the Korean Chemical Society
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• 제25권6호
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• pp.838-842
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• 2004

Amyloid peptide (A${\beta}$) is the major component of senile plaques found in the brain of patient of Alzheimer's disease. ${\beta}$-amyloid peptide (25-35) (A${\beta}$25-35) is biologically active fragment of A${\beta}$. The three-dimensional structure of A${\beta}$25-35 in aqueous solution with 50% (vol/vol) TFE determined by NMR spectroscopy previously adopts an ${\alpha}$-helical conformation from $Ala^{30}$ to $Met^{35}$. It has been proposed that A${\beta}$(25-35) exhibits pH- and concentration-dependent ${\alpha}-helix{\leftrightarrow}{\beta}$sheet transition. This conformational transition with concomitant peptide aggregation is a possible mechanism of plaque formation. Here, in order to gain more insight into the mechanism of ${\alpha}$-helix formation of A${\beta}$25-35 peptide by TFE, which particularly stabilizes ${\alpha}$-helical conformation, we studied the secondary-structural elements of A${\beta}$25-35 peptide by molecular dynamics simulations. Secondary structural elements determined from NMR spectroscopy in aqueous TFE solution are preserved during the MD simulation. TFE/water mixed solvent has reduced capacity for forming hydrogen bond to the peptide compared to pure water solvent. TFE allows A${\beta}$25-35 to form bifurcated hydrogen bonds to TFE as well as to residues in peptide itself. MD simulation in this study supports the notion that TFE can act as an ${\alpha}$-helical structure forming solvent.

• BMB Reports
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• 제50권12호
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• pp.634-639
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• 2017

We aimed to assess the anti-inflammatory and antioxidative properties of KHG26792, a novel azetidine derivative, in amyloid ${\beta}$ ($A{\beta}$)-treated primary microglial cells. KHG26792 attenuated the $A{\beta}-induced$ production of inflammatory mediators such as IL-6, $IL-1{\beta}$, $TNF-{\alpha}$, and nitric oxide. The levels of protein oxidation, lipid peroxidation, ROS, and NADHP oxidase enhanced by $A{\beta}$ were also downregulated by KHG26792 treatment. The effects of KHG26792 against the $A{\beta}-induced$ increases in inflammatory cytokine levels and oxidative stress were achieved by increasing the phosphorylation of $Akt/GSK-3{\beta}$ signaling and by decreasing the $A{\beta}-induced$ translocation of $NF-{\kappa}B$. Our results provide novel insights into the use of KHG26792 as a potential agent against $A{\beta}$ toxicity, including its role in the reduction of inflammation and oxidative stress. Nevertheless, further investigations of cellular signaling are required to clarify the in vivo effects of KHG26792 against $A{\beta}-induced$ toxicity.

• 한국응용과학기술학회지
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• 제35권2호
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• pp.389-398
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• 2018

본 연구는 노루궁뎅이버섯 균사체로 발효시킨 엄나무 추출물의 항산화 및 항아밀로이드 활성을 알아보고자 하였다. 항산화 활성은 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) radical 소거 측정법을 사용하여 관찰하였다. 엄나무추출물(KP), 노루궁뎅이버섯 균사체 추출물(HE), 엄나무 발효물(KP-HE)에서 모두 라디칼 소거활성이 관찰되었다. 그러나 KP-HE가 KP와 HE에 비해서 더 높은 소거 활성을 갖는 것으로 관찰되었다. KP-HE는 peroxyl radical에 의한 DNA의 산화적 손상을 억제하였다. 알츠하이머병 (Alzheimer's disease: AD)과 관련 있는 $A{\beta}_{1-42}$의 응집에 KP, HE, KP-HE가 어떤 영향을 미치는 지를 알아보았다. KP와 HE는 $A{\beta}_{1-42}$의 응집에 거의 영향을 미치지 않았고 KP-HE는 $A{\beta}_{1-42}$의 응집을 효과적으로 억제하였다. 또한 $A{\beta}_{1-42}$에 의한 신경세포 사멸에 엄나무 발효물을 $300{\mu}g/mL$ 농도로 전 처리한 세포생존율은 20.3% 높게 증가되었다. 또한 엄나무 발효물을 $50{\mu}g/mL$ 농도로 처리했을 경우 세포 내 ROS의 축적이 유의적으로 감소되었다. 결론적으로 본 연구에서 관찰된 결과들을 통해 엄나무 발효물은 항산화 및 항아밀로이드 활성을 가지는 것으로 확인되었다. 따라서 엄나무 발효물은 알츠하이머병과 같은 퇴행성 뇌질환을 예방할 수 있는 식품소재로 이용될 수 있을 것으로 사료된다.