• 통합자연과학논문집
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• 제7권1호
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• pp.25-38
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• 2014

Amyloid-${\beta}$-peptide ($A{\beta}$) is important in the pathogenesis of Alzheimer's disease (AD). Calpain ($Ca^{2+}$-dependent protease) and caspase-8 (the initiating caspase for the extrinsic, receptor-mediated apoptosis pathway) have been implicated in $AD/A{\beta}$ toxicity. We found that $A{\beta}$ promoted degradation of calpastatin (the specific endogenous calpain inhibitor); calpastatin degradation was prevented by inhibitors of either calpain or caspase-8. The results implied a cross-talk between the two proteases and suggested that one protease was responsible for the activity of the other one. In neuron-like differentiated PC12 cells, calpain promotes active caspase-8 formation from procaspase-8 via the $A{\beta}$ and CD95 pathways, along with degradation of the procaspase-8 processing inhibitor caspase-8 (FLICE)-like inhibitory protein, short isoform (FLIPS). Inhibition of calpain (by pharmacological inhibitors and by overexpression of calpastatin) prevents the cleavage of procaspase-8 to mature, active caspase-8, and inhibits FLIPS degradation in the $A{\beta}$-treated and CD95-triggered cells. Increased cellular Ca2+ per se results in calpain activation but does not lead to caspase-8 activation or FLIPS degradation. The results suggest that procaspase-8 and FLIPS association with cell membrane receptor complexes is required for calpain-induced caspase-8 activation. The results presented here add to the understanding of the roles of calpain, caspase- 8, and CD95 pathway in $AD/A{\beta}$ toxicity. Calpain-promoted activation of caspase-8 may have implications for other types of CD95-induced cell damage, and for nonapoptotic functions of caspase-8. Inhibition of calpain may be useful for modulating certain caspase-8-dependent processes.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 2006년도 Spring Conference
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• pp.95-105
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• 2006

Alzheimer's disease (AD) is an irreversible, progressive brain disorder that is characterized by dementia. Amounts of p25 and cdk5 kinase activity are specifically upregulated in AD patient's brain samples. Considerable evidence now points importance of p25/cdk5 in generation of A$\beta$ peptides and hyperphosphorylation of tau linking amyloid plaques and neurofibrillary tangles, two major pathological hallmarks of AD. We demonstrated that P25/CDK5 phosphorylates BACE1, the first step protease to produce A$\beta$. P25/CDK5 inhibitors to reduce BACE1 phosphorylation and the secretion of A$\beta$ are screened through in silica, in vitro, and cell-based assays. Out of 4.3 million chemicals we finally selected two compounds to have IC50 of 10 microM in cell-based assays. The inhibitors block Tau phosphrorylation as well as BACE1 phosphorylation. In conclusion P25 should be one of the best targets for AD therapeutics.

• BMB Reports
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• 제52권7호
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• pp.439-444
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• 2019

Although hypoxic/ischemic injury is thought to contribute to the incidence of Alzheimer's disease (AD), the molecular mechanism that determines the relationship between hypoxia-induced ${\beta}$-amyloid ($A{\beta}$) generation and development of AD is not yet known. We have now investigated the protective effects of N,4,5-trimethylthiazol-2-amine hydrochloride (KHG26702), a novel thiazole derivative, on oxygen-glucose deprivation (OGD)-reoxygenation (OGD-R)-induced $A{\beta}$ production in SH-SY5Y human neuroblastoma cells. Pretreatment of these cells with KHG26702 significantly attenuated OGD-R-induced production of reactive oxygen species and elevation of levels of malondialdehyde, prostaglandin $E_2$, interleukin 6 and glutathione, as well as superoxide dismutase activity. KHG26702 also reduced OGD-R-induced expression of the apoptotic protein caspase-3, the apoptosis regulator Bcl-2, and the autophagy protein becn-1. Finally, KHG26702 reduced OGD-R-induced $A{\beta}$ production and cleavage of amyloid precursor protein, by inhibiting secretase activity and suppressing the autophagic pathway. Although supporting data from in vivo studies are required, our results indicate that KHG26702 may prevent neuronal cell damage from OGD-R-induced toxicity.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.55-61
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• 2016

$A{\beta}_{40}$ peptides form oligomers that later aggregate into a plaque, which is deemed to be a leading cause of Alzheimer's Disease. Its non-crystalline morphology has limited an understanding of comprehensive structural study. In this research, computational biomolecular simulations were performed in the following order: solvent and ion addition in a box, energy minimization of protein, equilibration, and periodic boundary condition disaggregation of a monomer from fibril. The result founded the two-fold model is 25% more stable in the simulation environment, and the steric zippers held on most tightly until 220 ps of simulation. The study supports the previous findings that two-fold aggregate $A{\beta}_{40}$ is more stable at 310 K and discusses further how much contribution steric-zipper and hydrogen bonding are making.

• 생명과학회지
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• 제21권11호
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• pp.1636-1640
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• 2011

알츠하이머 질환은 인지능력과 행동능력 두 가지에 모두 영향을 미치는 진행적 노인성 치매증의 일종으로 정확한 발병기전은 아직 알려져 있지 않으나 환경적 요인 및 유전적 요인이 모두 중요한 위험인자로 알려져 있다. 본 연구에서는 8주간 에탄올에 노출된 Aldh2 knockout mouse 뇌조직을 분리하여 알츠하이머 질환의 지표로 잘 알려진 아밀로이드 베타와 NF-kB 발현을 평가하고 이러한 변화가 ALDH2 효소의 활성에 따라 어떻게 달라지는 지 비교하였다. 그 결과, 8주간 에탄올을 경구 투여한 마우스에서 ALDH2 효소의 활성에 따른 NF-kB 농도의 차이는 확인할 수 없었으나, ALDH2 효소 활성은 알코올 노출에 의한 해마조직의 아밀로이드 베타 축적에서 중요한 영향을 미치는 것으로 나타났다(p<0.05). 이러한 결과는 ALDH2 효소가 결핍된 사람이 결핍되지 않은 사람에 비해 알코올에 의한 알츠하이머 질환의 발생에 보다 민감할 수 있음을 시사한다.

• 대한한의학회지
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• 제26권1호
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• pp.161-173
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• 2005

Objective : The water extract of Seokchangpowonji-san (SWS) has traditionally been used for treatment of dementia in oriental medicine. However, little is known about the mechanism by which the water extract of SWS rescues cells from neurodegenerative disease such as Alzheimer's disease. Methods & Results: This study was designed to investigate the protective mechanisms of SWS on $\beta-amyloid$ or $H_2O_2$-induced$ cytotoxicity in neuro 2A cells. $H_2O_2$ markedly decreased the viability of neuro 2A cells, which was characterized by apparent apoptotic features such as membrane blebbing as well as fragmentation of genomic DNA and nuclei. However, the water extract of SWS significantly reduced $H_2O_2-induced$ cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, the. extract prevented the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition (MPT) and the modulation in expression of Bcl-2 family proteins in $H_2O_2­treated$ neuro 2A cells. Furthermore, pretreatment with SWS inhibited the activation of caspase-3, and in turn, degradation of ICAD/DFF45 was completely abolished in $H_2O_2-treated$ cells. Conclusion: Taken together, the data suggest that the protective effects of the water extract of SWS against $\beta-amyloid$ induced oxidative injuries may be achieved through modulation of mitochondrial dysfunction.

• 한국산학기술학회논문지
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• 제20권2호
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• pp.286-293
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• 2019

알츠하이머 질환은 대표적인 신경퇴행성 질환으로, 뇌 내에서 $A{\beta}$ 단백질 축적은 알츠하이머 질환의 원인으로 알려져 있다. 본 연구에서는 amyloid beta ($A{\beta}$)로 손상을 유도한 SH-SY5Y 신경세포에서 kaempferol, kaempferol-3-O-glucoside, quercetin, quercetin-3-${\beta}$-D-glucoside의 신경세포 보호 효과에 대해 검토하였다. SH-SY5Y 신경세포에 $A{\beta}_{25-35}$ ($25{\mu}M$)를 처리하였을 때, 처리하지 않은 normal군에 비해 세포생존율이 유의적으로 감소하였다. 반면, kaempferol, quercetin 및 그 배당체들을 각각 처리하였을 때 $A{\beta}_{25-35}$만을 처리한 control군에 비해 유의적으로 세포생존율의 증가를 나타내었다. 또한, apoptosis에 관여하는 cleaved caspase9, Bcl-2-associated X protein (Bax) 단백질 발현을 측정한 결과, normal군에 비해 control군에서 유의적으로 cleaved caspase9 및 Bax 단백질 발현의 증가를 나타내어 $A{\beta}$ 유도 신경세포 손상으로 인한 apoptosis가 유발됨을 확인 하였으며, kaempferol, quercetin 및 그 배당체들의 처리 시 apoptosis 관련 단백질 발현이 감소함으로써 신경세포 보호 효능이 나타냄을 확인하였다. 이러한 결과는 kaempferol, quercetin 및 그 배당체들이 apoptosis 조절을 통해 신경세포 보호 효과를 나타내며, 신경세포 손상으로 인한 알츠하이머 질환을 예방하는 유용한 소재로써 사용 가능성이 있음을 보여준다.

• 약학회지
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• 제49권1호
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• pp.103-108
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• 2005

Tacrine analogues for degenerative brain disease treatments have been designed. A series of diazaanthrine derivatives as novel analogues of tacrine has been prepared through the alkyl substitution and the ring expansion. They were expected to retain anti-inflammatory activity by inhibition of prostaglandin production with reduction of side effect as the selective prostaglandin synthase inhibitor. Prostaglandin synthase expression is associated with the deposition of beta-amyloid protein in neuritic plaques in brain inflammation. Therefore selective prostaglandin synthase blockade is important for the prevention and treatment of alzheimer's disease. To evaluate inhibitory effect of prostaglandin synthase, synthetic tacrine derivatives were screened with accumulation of prostaglandin biosynthesis by lipopolysaccharide in aspirin-treated murine macrophage cell. Most of synthetic compounds have shown significant prostaglandin synthase activities in vitro screening with $84.3{\sim}33.6\%$ inhibition of the prostaglandin $E_2$ production at $10\;{\mu}g/ml$.

• 한국응용과학기술학회지
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• 제41권1호
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• pp.58-68
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• 2024

본 연구의 목적은 알츠하이머질환(Alzheimer's disease: AD) 동물 모델을 대상으로 트레드밀 운동(Treadmill exercise: TE)과 환경강화(environmental enrichment: EE) 처치가 인지기능, 근 기능, 및 밀착연접 단백질 발현에 미치는 영향을 확인하는데 있다. AD 동물 모델을 제작하기 위해 aluminum chloride(AlCl₃)를 90일간(40mg/kg/하루) 투여 하였으며 동시에 TE(10-12m/min, 40-60min/day) 혹은 EE에 노출시켰다. 그 결과 AlCl₃ 투여에 의한 인지기능 저하와 근 기능 감소가 TE와 EE에 의해 완화된 것으로 나타났다. 또한, TE와 EE는 AD 질환에서 나타나는 β-amyloid(Aβ), alpha-synuclein 및 tumor necrosis factor-α(TNF-α) 단백질의 발현 증가를 감소시킨 것으로 나타났다. 게다가 TE와 EE는 AlCl₃ 투여에 의해 감소된 밀착연접 단백질(Occludin, Claudin-5 및 ZO-1)의 발현을 통계적으로 유의하게 증가시킨 것으로 나타났다. 마지막으로 Aβ 단백질과 밀착연접 단백질과의 상관분석을 실시한 결과 부적 상관관계(Occludin: r=-0.853, p=0.001; Claudin-5 : r=-0.352, p=0.915; ZO-1 : r=-0.424, p=0.0390)로 나타났다. 따라서 이를 종합해 보면 TE 혹은 EE 처치는 AD에 나타나는 병리학적 특징들을 일부 완화시켜 인지기능과 근 기능을 일부 개선 시킬 수 있는 효과적인 운동 방법이라고 생각된다.

• Biomolecules & Therapeutics
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• 제19권3호
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• pp.288-295
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• 2011

Amyloid beta ($A{\beta}$)-induced neurotoxicity is a major pathological mechanism of Alzheimer's disease (AD). In this study, we investigated the inhibitory effect of L-theanine, a component of green tea (Camellia sinensis) on $A{\beta}_{1-42}$-induced neurotoxicity and oxidative damages of macromolecules. L-theanine inhibited $A{\beta}_{1-42}$-induced generation of reactive oxygen species, and activation of extracellular signal-regulated kinase and p38 mitogenic activated protein kinase as well as the activity of nuclear factor kappa-B. L-theanine also signifi cantly reduced oxidative protein and lipid damage, and elevated glutathione level. Consistent with the reduced neurotoxic signals, L-theanine (10-50 ${\mu}g$/ml) concomitantly attenuated $A{\beta}_{1-42}$ (5 ${\mu}M$)-induced neurotoxicity in SK-N-MC and SK-N-SH human neuroblastoma cells. These data indicate that L-theanine on $A{\beta}$-induced neurotoxicity prevented oxidative damages of neuronal cells, and may be useful in the prevention and treatment of neurodegenerative disease like AD.