• 농업과학연구
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• 제49권2호
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• pp.227-237
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• 2022

Amyloid beta (Aβ) is produced from an amyloid precursor protein by the activation of the amyloidogenic pathway, and it is widely known to cause Alzheimer's disease (AD). In this study, we investigated the neuroprotective effects of three flavonoids, quercitrin, isoquercitrin, and afzelin, from Acer okamotoanum against Aβ-induced neurotoxicity in SH-SY5Y neuronal cells. Aβ_25-35 treatments resulted in decreased cell viability and increased levels of nuclei condensation and fragmentation. However, an isoquercitrin treatment dose-dependently increased cell viability and decreased nuclei condensation and fragmentation levels. SH-SY5Y cells treated with Aβ_25-35 showed increased reactive oxygen species (ROS) production compared to that from cells not treated with Aβ_25-35. However, treatment with the three flavonoids significantly inhibited ROS production compared to an Aβ_25-35-treated control group, indicating that the three flavonoids blocked neuronal oxidative stress. For a closer examination of the neuroprotective mechanisms, we measured the expressions of the non-amyloidogenic pathway-related proteins of a disintegrin and metalloprotease 10 (ADAM10) and the tumor necrosis factor-α converting enzyme (TACE). An isoquercitrin treatment enhanced the expressions of ADAM10 compared to the control group. In addition, the three flavonoids activated the non-amyloidogenic pathway via the upregulation of TACE. In conclusion, we demonstrated neuroprotective effects of three flavonoids from A. okamotoanum, in particular isoquercitrin, on neurotoxicity by the regulation of the non-amyloidogenic pathway in Aβ_25-35-treated SH-SY5Y cells. Therefore, we suggest that flavonoids from A. okamotoanum may have some potential as therapeutics of AD.

• Journal of Applied Biological Chemistry
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• 제64권2호
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• pp.105-112
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• 2021

Excessive accumulation of the amyloid beta (Aβ) peptide has been implicated in the pathogenesis of Alzheimer's disease (AD). Paeonia lactiflora (PL) has been used in treatments of several conditions such as inflammation, arthritis, and cognitive impairment. The purpose of this study was to investigate the neuroprotective effect and mechanisms of PL and its active compound, paeoniflorin (PF), on Aβ_25-35-induced neurotoxicity in SH-SY5Y cells. We evaluated cell viability, lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) production. Furthermore, underlying mechanism of PL and PF on the regulation of amyloidogenic pathway was analyzed by Western blotting. In our results, Aβ_25-35-induced neuronal cell loss was observed, whereas treatment with PL (10, 50, and 100 ㎍/mL) and PF (1, 5, and 10 ㎍/mL) significantly elevated the cell viability, and decreased LDH release and ROS production. In addition, exposure of SH-SY5Y cells to Aβ_25-35 significantly increased the protein levels of amyloid precursor protein (APP)-C-terminal fragment β, β-site APP-cleaving enzyme, and presenilin-1 and -2. However, treatment with PL and PF inhibited the amyloidogenic pathway via the down-regulation of those protein expressions. Taken together, our results indicate that PL, and its active compound PF, could protect SH-SY5Y cells against Aβ_25-35-induced cell neurotoxicity by attenuating LDH release and ROS production, and these effects may be attributed to regulation of amyloidogenic pathway-related protein expression. In conclusion, PL and PF could be a potential to prevent neurodegenerative disorders such as AD.

• 한국응용과학기술학회지
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• 제37권3호
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• pp.418-428
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• 2020

본 연구는 알츠하이머(Alzheimer's disease: AD) 형질전환 생쥐를 대상으로 저항성 운동(resistance exercise: RE)이 해마의 베타 아밀로이드(β-amyloid: Aβ) 단백질 대사, 신경세포사멸 및 인지기능에 미치는 영향을 확인하는데 목적이 있다. AD 비 형질전환 생쥐(non-transgenic: non-tg, n=14)와 형질전환 생쥐(transgenic: Tg, n=14)를 무선 배정하여 비 형질전환 생쥐 대조군 (non-tg-control: NTC, n=7), 비 형질전환 생쥐 저항성 운동군(non-tg-RE: NTRE, n=7), 형질전환 대조군(tg-control: TC, n=7) 및 형질전환 저항성 운동군(tg-RE: TRE, n=7)으로 구분하였다. RE는 특수 제작한 사다리 저항성 운동 기구를 사용하여 점진적으로 set 수를 증가시켜 총 8주간 실시하였다. 운동 후 인지기능 능력을 평가하기 위한 수중미로검사와 Aβ 단백질 대사, 신경세포사멸 지표 및 SIRT1/PGC-1α 단백질 발현 수준을 확인하였다. 수중미로검사 결과 거리와 시간 모두 TC 집단에서 유의하게 증가 되었지만 RE를 실시한 TRE 집단에서 거리와 시간이 감소 되어 인지능력이 개선된 것으로 확인되었다. 또한, TC 집단에서 증가된 Aβ 단백질 발현은 RE를 통해 감소하는 것으로 나타났다. 신경세포사멸 관련 단백질인 Bcl-2/Bax ratio는 TC 집단에서 유의하게 감소되어 신경세포사멸이 증가 된 것으로 나타났지만 RE는 Bcl-2/Bax ratio을 증가시켜 신경세포사멸을 감소시킨 것으로 확인되었다. TC 집단에서 증가된 BACE1 및 ROCK1과 감소된 ADAM10과 RARβ 단백질 발현은 RE를 통해 감소되거나 증가 된 것으로 나타났고, SIRT1/PGC-1α 단백질 발현은 TC 집단에서 감소 되었지만 RE를 통해 증가 된 것으로 나타났다. 따라서 8주간의 RE는 AD의 병리학적 특징인 Aβ 단백질 발현을 감소시키고 관련 생성 기전들을 조절하여(SIRT1/PGC-1α 기전 활성, 아밀로이드 생성기전 억제, 비-아밀로이드 생성기전 활성) 신경세포사멸 억제시키고 결과적으로 인지기능을 개선 시킬 수 있는 효과적인 운동 방법이라고 생각된다.

• 생약학회지
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• 제53권2호
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• pp.102-110
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• 2022

Alzheimer's disease (AD) is the most common form of dementia, and the accumulation of β-amyloid (Aβ) in the brain triggers AD, followed by hyperphosphorylation of tau protein, neurofibrillary tangles, and synapses loss, neuronal cell death, and cognitive decline occur in a chain. In APPswe neuronal cell line, 50 ㎍/ml of Campbell early (Vitis labruscana B.) leaves 50% ethanol extract (VLL) treatment inhibited the secretion of Aβ1-42 by about 63% and the secretion of Aβ1-40 by about 50%. VLL did not target the enzymatic activity of the amyloidogenic pathway and decreased the protein expression of APP. As a result of RT-qPCR (Reverse transcription-quantitative real-time PCR) of the APPswe cell line treated with VLL, it is thought that the protein expression of APP was reduced by inhibiting the transcription process of the APP gene. In addition, VLL inhibited acetylcholinesterase (AChE) enzyme activity in vitro by 27.6% and 54.7%, respectively, at 50 and 100 ㎍/ml concentrations. We found that VLL inhibited the production of Aβ, a dementia-inducing substance, by suppressing the transcription of the APP gene, and that VLL inhibited AChE activity. We suggest that VLL has the potential as a natural drug material that modulates the alleviation of dementia symptoms.

• Journal of Web Engineering
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• 제13권12호
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• pp.4370-4388
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• 2021

Amyloid-β (Aβ) accumulation in the hippocampus is an essential event in the pathogenesis of Alzheimer's disease. Insoluble Aβ is formed through the sequential proteolytic hydrolysis of the Aβ precursor protein, which is cleaved by proteolytic secretases. However, the pathophysiological mechanisms of Aβ accumulation remain elusive. Here, we report that rats fed high-phytate diets showed Aβ accumulation and increased apoptotic neuronal cell death in the hippocampus through the activation of the amyloidogenic pathway in the hippocampus. Immunoblotting and immunohistochemical analyses confirmed that the overexpression of BACE1 β-secretase, a critical enzyme for Aβ generation, exacerbated the hippocampal Aβ accumulation in rats fed high-phytate diets. Moreover, we identified that parathyroid hormone, a physiological hormone responding to the phytate-mediated dysregulation of calcium and phosphate homeostasis, plays an essential role in the transcriptional activation of the Aβ precursor protein and BACE1 through the vitamin D receptor and retinoid X receptor axis. Thus, our findings suggest that phytate-mediated dysregulation of calcium and phosphate is a substantial risk factor for elevated Aβ accumulation and apoptotic neuronal cell death in rats.

• 한국산학기술학회논문지
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• 제20권5호
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• pp.241-251
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• 2019

본 연구에서는 Alzheimer's disease(AD) 마우스 모델에서 미세전류의 적용을 통한 인지능력 개선 효과를 확인하였다. ICR 마우스에 amyloid beta($A{\beta}$)를 뇌 내 주입하여 인지능력 손상을 유도한 후, 4가지 파형의 미세전류를 각각 적용하여 손상된 인지능력에 미치는 미세전류의 영향을 검토하였다. AD 마우스의 공간 및 물체 인지능력을 확인하기 위해 행동실험을 실시한 결과, novel object recognition test와 Morris water maze test에서 $A{\beta}$로 인해 손상되었던 인지능력이 미세전류 적용군에서 유의적으로 개선됨을 확인하였으며, 지질과산화 반응으로 인한 malondialdehyde의 뇌 내 생성량 또한 감소하였다. 뇌 조직에서 AD 관련 단백질 발현을 측정한 결과, 특히 미세전류 Wave4 [STEP FORM 파형(0, 1.5, 3, 5V), 중첩Hz 적용] 적용군에서 $A{\beta}$ 생성 관련 단백질인 ${\beta}$-secretase, presenilin 1, presenilin 2의 발현이 감소하였고 신경영양인자인 brain-derived neurotrophic factor 단백질 발현이 증가하였다. 이 결과를 바탕으로 AD 마우스에서 미세전류를 이용한 손상된 인지능력에 대한 개선 효과를 확인하였으며, AD 예방 및 치료를 위한 비약물적인 방법으로서 적용할 수 있을 것으로 기대된다.