• Applied Microscopy
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• 제42권4호
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• pp.179-185
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• 2012

Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Neuropathological hallmarks of AD are amyloid plaques, dystrophic neurite, and alteration of subcellular organelles. However, the morpho-functional study of this degenerative process and ultimate neuronal death remains poorly elucidated. In this study, immunohistochemical and ultrastructural analyses were performed to clarify the abnormal morphological alterations caused by the progression of AD in APP/PSEN1 transgenic mice, express human amyloid precursor protein, as a model for AD. In transgenic AD mice brain, the accumulation of Amyloid ${\beta}$ plaques and well-developed dystrophic neurites containing anti-LC3 antibody-positive autophagosomes were detected in the hippocampus and cortex regions. We also found severe disruption of mitochondrial cristae using high-voltage electron microscopy and three-dimensional electron tomography (3D tomography). These results provide morpho-functional evidence on the alteration of subcellular organelles in AD and may help in the investigation of the pathogenesis of AD.

• 대한한의학회지
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• 제35권4호
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• pp.10-23
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• 2014

Objectives: This study evaluated the effects of Guibi-tang (GBT) on neuronal apoptosis and cognitive impairment induced by beta amyloid ($A{\beta}$), (1-42) injection in the hippocampus of ICR mice. Methods: $A{\beta}$ (1-42) was injected unilaterally into the lateral ventricle using a Hamilton syringe and micropump ($2{\mu}g/3{\mu}{\ell}$, $0.6{\mu}{\ell}/min$). Water extract of GBT was administered orally once a day (500 mg/kg) for 3 weeks after the $A{\beta}$ (1-42) injection. Acquisition of learning and retention of memory were tested using the Morris water maze. Neuronal damage and $A{\beta}$ accumulation in the hippocampus was observed using cresyl violet and Congo red staining. The anti-apoptotic effect of GBT was evaluated using TUNEL labeling in the hippocampus. Results: GBT significantly shortened the escape latencies during acquisition training trials. GBT significantly increased the number of target headings to the platform site, the swimming time spent in the target quadrant, and significantly shortened the time for the 1st target heading during the retention test trial. GBT significantly attenuated the reduction in thickness and number of CA1 neurons, and $A{\beta}$ accumulation in the hippocampus produced by $A{\beta}$ (1-42) injection. GBT significantly reduced the number of TUNEL-labeled neurons in the hippocampus. Conclusion: These results suggest that GBT improved cognitive impairment by reducing neuronal apoptosis and $A{\beta}$ accumulation in the hippocampus. GBT may be a beneficial herbal formulation in treating cognitive impairment including Alzheimer's disease.

• 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.

• EDISON SW 활용 경진대회 논문집
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• 제4회(2015년)
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• pp.14-23
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• 2015

Alzheimer's disease is one of the most common types of degenerative dementia. As a considerable cause of Alzheimer's disease, neurotoxic plaques composed of 39 to 42 residue-long amyloid beta($A{\beta}$) fibrils have been found in the patient's brain in large quantity. A previous study found that erythrosine B (ER), a red color food dye approved by FDA, inhibits the formation of amyloid beta fibril structures. Here, in an attempt to elucidate the inhibition mechanism, we performed molecular dynamics simulations to demonstrate the conformational change of $A{\beta}40$ induced by 2 ERs in atomistic detail. During the simulation, the ERs bound to the surfaces of both N-terminus and C-terminus regions of $A{\beta}40$ rapidly. The observed stacking of the ERs and the aromatic side chains near the N-terminus region suggests a possible inhibition mechanism in which disturbing the inter-chain stacking of PHEs destabilizes beta-sheet enriched in amyloid beta fibrils. The bound ERs block water molecules and thereby help stabilizing alpha helical structure at the main chain of C-terminus and interrupt the formation of the salt-bridge ASP23-LYS28 at the same time. Our findings can help better understanding of the current and upcoming treatment studies for Alzheimer's disease by suggesting inhibition mechanism of ER on the conformational transition of $A{\beta}40$ at the molecular level.

• 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.

• Journal of Plant Biotechnology
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• 제47권4호
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• pp.283-288
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• 2020

Although the evolution of Arabidopsis thaliana and humans diverged approximately 1.6 billion years ago, recent studies have demonstrated that protein function and cellular processes involved in disease response remain remarkably conserved. Particularly, γ-secretase, a multisubunit protein complex that participates in intramembrane proteolysis (RIP) regulation, is also known to mediate the cleavage of more than 80 substrates including the amyloid precursor protein (APP) and the Notch receptor. Although the genes (PS1/2, APH-1, PEN-2, and NCT) coding for the γ-secretase complex components are present in plant genomes, their function remains largely uncharacterized. Given that the deposition of 42 amino acid long amyloid-β peptides (hAβ₄₂) is thought to be one of the main causes of Alzheimer's disease, we aimed to examine the physiological effects of hAβ₄₂ peptides on plants. Interestingly, we found that Arabidopsis protoplast death increased after 24 h of exposure to 3 or 5 µM hAβ₄₂ peptides. Furthermore, transgenic Arabidopsis plants overexpressing the hAβ₄₂ gene exhibited changes in primary root length and silique phyllotaxy. Taken together, our results demonstrate that hAβ₄₂ peptides, a metazoan protein, significantly affect Arabidopsis protoplast viability and plant morphology.

• 생약학회지
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• 제49권2호
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• pp.182-187
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• 2018

Many plant derived phytochemicals have been considered as the main therapeutic strategy against Alzheimer's disease (AD). AD is a progressive neurodegenerative disorder, and the most predominant cause of dementia in the elderly. Cholinergic deficit, senile plaque/${\beta}$-amyloid ($A{\beta}$) peptide deposition and oxidative stress have been identified as three main pathogenic pathways which contribute to the progression of AD. We screened many different plant species for their effective use in both modern and traditional system of medicines. In this study, we tested that MeOH extract of the stem bark of Hopea chinensis (Merr.) Hand.-Mazz. (HCM) affects on the processing of Amyloid precursor portein (APP) from the APPswe over-expressing Neuro2a cell line. We showed that HCM reduced the secretion level of $A{\beta}42$ and $A{\beta}40$ in a dose dependent manner. We found that HCM increased over 1.5 folds of the secretion level of $sAPP{\alpha}$, a metabolite of ${\alpha}$-secretase. Furthermore, we found that HCM inhibited acetylcholinesterase activity in vitro. We suggest that the stem bark of Hopea chinensis may be a useful source to develop a therapeutics for AD.

• 한국컴퓨터정보학회논문지
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• 제25권6호
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• pp.165-170
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• 2020

본 논문에서는 스코폴레틴이 알츠하이머병 신경염증보호제로서의 가능성을 제안하기 위해 미세아교세포 BV-2에서 아밀로이드베타 올리고머(Aβ_1-42)로 유도된 염증을 억제하는지 확인하였다. 또한, 염증관련 사이토카인 및 염증매개인자가 어떠한 메커니즘으로 조절되는지 확인하였다. 알츠하이머병은 가장 흔한 신경 퇴행성 질환이지만, 특정 병인을 알 수 없는 질환이며, 이를 해결하기 위해 많은 연구에서 노력을 기울이고 있다. 우리는 먼저 스코폴레틴과 Aβ_1-42가 BV-2 세포에 독성을 보이는지 확인하기 위해 CCK-8 assay 방법으로 세포 생존율을 측정하였다. Western Blot을 통해 Aβ_1-42로 유도된 염증반응에서 interleukin 1 beta (IL-1β), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), nuclear factor-κB (NF-κB)의 발현정도를 분석하였다. ANOVA 분석법을 통해 Aβ_1-42를 단독 처리한 BV-2 세포와 스코폴레틴을 전 처리한 BV-2 세포에서 단백질 발현 차이를 비교하였다. 그 결과 스코폴레틴을 전 처리한 BV-2 세포에서 IL-1β, COX-2, iNOS, NF-κB 발현수준이 유의미하게 감소되었다 (p value < 0.05). 따라서 본 연구는 향후 스코폴레틴이 알츠하이머병의 신경염증보호제로서 개발 가치가 있음을 제시하였다.

• BMB Reports
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• 제44권11호
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• pp.730-734
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• 2011

Amyloid ${\beta}$-peptide ($A{\beta}$-peptide)-induced oxidative stress is thought to be a critical component of the pathophysiology of Alzheimer's disease (AD). New chalcone derivatives, the Chana series, were recently synthesized from the retrochalcones of licorice. In this study, we investigated the protective effects of the Chana series against neurodegenerative changes in vitro and in vivo. Among the Chana series, Chana 30 showed the highest free radical scavenging activity (90.7%) in the 1,1-diphenyl-2- picrylhydrazyl assay. Chana 30 also protected against $A{\beta}$-induced neural cell injury in vitro. Furthermore, Chana 30 reduced the learning and memory deficits of $A{\beta}_{1-42}$-peptide injected mice. Taken together, these results suggest that Chana 30 may be a promising candidate as a potent therapeutic agent against neurodegenerative diseases.

• 생약학회지
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• 제46권2호
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• pp.109-115
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• 2015

This study was investigated the radical scavenging effect and the protective activity of caffeic acid (CA) against oxidative stress. CA showed strong 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and hydroxyl radical ( OH) scavenging activity, showing 42.00% and 87.22% at 5 μM concentration of DPPH and ·OH scavenging activity, respectively. Furthermore, we studied protective activity of CA from amyloid beta (A${\beta}$_25-35) and lipopolysaccharide (LPS) induced neuronal cell damage and neuronal inflammation using C6 glial cells. The treatment of A${\beta}$_25-35 to C6 glial cell showed declines in cell viability and high generation levels of reactive oxygen species (ROS). However, the treatment of CA increased cell viability. The treatment of 5 ${{\mu}M}$ CA led to the elevation of cell viability from 59.28% to 81.22%. In addition, the production of ROS decreased cellular levels of ROS by the treatment of CA. The treatment of LPS to C6 glial cells increased significant elevation of nitric oxide (NO) production, while CA decreased NO production significantly. The production of NO increased by the treatment of LPS to 131.08%, while CA at the concentration of 1 ${{\mu}M}$ declined the NO production to 104.86%. The present study indicated thatCA attenuated A${\beta}$_25-35-induced neuronal oxidative stress and inflammation by LPS, suggesting as a promising agent for the neurodegenerative diseases.