• 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.

• 노인정신의학
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• 제16권1호
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• pp.17-23
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• 2012

The diagnosis of Alzheimer's disease (AD) is still obscure even to specialists. To improve the diagnostic accuracy, to find at-risk people as early as possible, to predict the efficacy or adverse reactions of pharmacotherapy on an individual basis, to attain more reliable results of clinical trials by recruiting better defined participants, to prove the disease-modifying ability of new candidate drugs, to establish prognosis-based therapeutic plans, and to do more, is now increasing the need for biomarkers for AD. Among AD-related biochemical markers, cerebrospinal beta-amyloid and tau have been paid the most attention since they are materials directly interfacing the brain interstitium and can be obtained through the lumbar puncture. Level of beta-amyloid is reduced whereas tau is increased in cerebrospinal fluid of AD patients relative to cognitively normal elderly people. Remarkably, such information has been found to help predict AD conversion of mild cognitive impairment. Despite inconsistent findings from previous studies, plasma beta-amyloid is thought to be increased before the disease onset, but show decreasing change as the disease progress. Regarding other peripheral biochemical markers, omics tools are being widely used not only to find useful biomarkers but also to generate novel hypotheses for AD pathogenesis and to lead new personalized future medicine.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2021년도 춘계학술대회
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• pp.58-58
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• 2021

Although hypoxic/ischemic injury is thought to contribute to the incidence of Alzheimer disease (AD), the molecular mechanism that determines the relationship between hypoxia-induced β-amyloid (Aβ) generation and development of AD is not yet known. In this study, we investigated the protective effects of Acorus gramineus Soland. (AGS) on oxygen-glucose deprivation/reoxygenation (OGD/R)-induced A β production in SH-SY5Y human neuroblastoma cells. Pretreatment of these cells with AGS significantly attenuated OGD/R-induced production of reactive oxygen species (ROS) and elevation of levels of malondialdehyde, nitrite (NO), prostaglandin E2 (PGE2), cytokines (TNF-α, IL-1β and IL-6) and glutathione, as well as superoxide dismutase activity. AGS also reduced OGD/R-induced expression of the apoptotic protein caspase-3, the apoptosis regulator Bcl-2, and the autophagy protein becn-1. Finally, AGS reduced OGD/R-induced Aβ 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 AGS may prevent neuronal cell damage from OGD/R-induced toxicity.

• 대한영상의학회지
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• 제84권5호
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• pp.1140-1145
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• 2023

대뇌 아밀로이드 혈관병증 관련 염증은 베타 아밀로이드가 혈관에 침착되어 혈관 주위의 급성 염증성 반응으로 발생하는 뇌병증이다. 이 질환은 주로 고령자에게서 발생하는 드문 질환으로, 급격히 진행하는 치매, 두통, 발작, 국소 신경학적 결손을 동반한 증상으로 나타나며 특징적인 뇌자기공명영상 소견을 보인다. 또한 스테로이드 또는 기타 면역억제요법에 반응하는 가역적인 질병이다. 대뇌 아밀로이드 혈관병증 관련 염증을 처음에는 아급성 경색으로 오진하였다가 추적 관찰 중 뇌 자기공명영상 소견을 분석하면서 대뇌 아밀로이드 혈관병증 관련 염증이 진단되었고, 자연 관해가 이뤄진 대뇌 아밀로이드 혈관병증 관련 염증 증례를 보고한다.

• Biomolecules & Therapeutics
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• 제32권3호
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• pp.301-308
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• 2024

Alzheimer's disease (AD) is a progressive and irreversible neurodegenerative disorder characterized by extracellular amyloid plaques composed of amyloid β-peptide (Aβ). Studies have indicated that Ca²⁺ dysregulation is involved in AD pathology. It is reported that decreased capacitative Ca²⁺ entry (CCE), a refilling mechanism of intracellular Ca²⁺, resulting in increased Aβ production. In contrast, constitutive activation of CCE could decrease Aβ production. Panax ginseng Meyer is known to enhance memory and cognitive functions in healthy human subjects. We have previously reported that some ginsenosides decrease Aβ levels in cultured primary neurons and AD mouse model brains. However, mechanisms involved in the Aβ-lowering effect of ginsenosides remain unclear. In this study, we investigated the relationship between CCE and Aβ production by examining the effects of various ginsenosides on CCE levels. Aβ-lowering ginsenosides such as Rk1, Rg5, and Rg3 potentiated CCE. In contrast, ginsenosides without Aβ-lowering effects (Re and Rb2) failed to potentiate CCE. The potentiating effect of ginsenosides on CCE was inhibited by the presence of 2-aminoethoxydiphenyl borate (2APB), an inhibitor of CCE. 2APB alone increased Aβ42 production. Furthermore, the presence of 2APB prevented the effects of ginsenosides on Aβ42 production. Our results indicate that ginsenosides decrease Aβ production via potentiating CCE levels, confirming a close relationship between CCE levels and Aβ production. Since CCE levels are closely related to Aβ production, modulating CCE could be a novel target for AD therapeutics.

• Archives of Pharmacal Research
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• 제27권4호
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• pp.454-459
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• 2004

The present study investigated the effects of gossypin, 3,3',4',5,7,8-hexahydroxyflavone 8-glucoside, on the toxicity induced by oxidative stress or $\beta$-amyloid ($A_{\beta}$) in primary cultured rat cortical cells. The antioxidant properties of gossypin were also evaluated by cell-free assays. Gossypin was found to inhibit the oxidative neuronal damage induced by xanthinelxanthine oxidase or by a glutathione depleting agent, D,L-buthionine (S,R)-sulfoximine. In addition, gossypin significantly attenuated the neurotoxicity induced by $A_{{\beta}(25-35)}$. Furthermore, gossypin dramatically inhibited lipid peroxidation initiated by $Fe^{2+}$ and ascorbic acid in rat brain homogenates. It also exhibited potent radical scavenging activity generated from 1 ,1-diphenyl-2-picrylhydrazyl. These results indicate that gossypin exerts neuroprotective effects in the cultured cortical cells by inhibiting oxidative stress- and $A_{\beta}$-induced toxicity, and that the antioxidant properties of gossypin may contribute to its neuroprotective actions.

• Journal of Korean Neurosurgical Society
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• 제58권1호
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• pp.30-35
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• 2015

Objective : The clinical and pathological characteristics of 10 cases of cerebral amyloid angiopathy (CAA)-related cerebral lobar hemorrhage (CLH) that was diagnosed at autopsy were investigated to facilitate the diagnosis of this condition. Methods : The clinical characteristics of 10 cases of CAA-related CLH were retrospectively reviewed, and a neuropathological examination was performed on autopsy samples. Results : The 10 cases included two with a single lobar hemorrhage and eight with multifocal lobar hemorrhages. In all of the cases, the hemorrhage bled into the subarachnoid space. Pathological examinations of the 10 cases revealed microaneurysms in two, double barrel-like changes in four, multifocal arteriolar clusters in five, obliterative onion skin-like intimal changes in four, fibrinoid necrosis of the vessels in seven, neurofibrillary tangles in eight, and senile plaques in five cases. Conclusion : CAA-related CLHs were located primarily in the parietal, temporal, and occipital lobes. These hemorrhages normally consisted of multiple repeated CLHs that frequently bled into the subarachnoid space. CAA-associated microvascular lesions may be the pathological factor underlying CLH.

• Natural Product Sciences
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• 제26권3호
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• pp.221-229
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• 2020

This study was undertaken to investigate the protective effect of rice bran oil (RBO) on amyloid β protein (Aβ) (25-35)-induced memory impairment and brain damage in an ICR mouse model. Memory impairment was produced by intracerebroventricular microinjection of 15 nmol Aβ (25-35) and assessed using the passive avoidance test. Treatment with RBO at 0.1, 0.5, or 1 mL/kg (p.o. daily for 8 days) protected against Aβ (25-35)-induced memory impairment. Furthermore, Aβ (25-35)-induced decreases in glutathione and increases in lipid peroxidation and cholinesterase activity in brain tissue were inhibited by RBO, and Aβ (25-35)-induced increases of phosphorylated mitogen-activated protein kinases (MAPKs) and inflammatory factors, and changes in the levels of apoptosis-related proteins were significantly inhibited by RBO. Furthermore, Aβ (25-35) suppressed the PI3K/Akt pathway and the phosphorylation of CREB, but increased phosphorylation of tau (p-tau) in mice brain; these effects were significantly inhibited by administration of RBO. These results suggest that RBO inhibits Aβ (25-35)-induced memory impairment by inducing anti-apoptotic and anti-inflammatory effects, promoting PI3K/Akt/CREB signaling, and thus, inhibiting p-tau formation.

• 대한의용생체공학회:의공학회지
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• 제30권2호
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• pp.122-128
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• 2009

Cancer serum biomarkers have advanced our ability to more accurately predict tumor classification, prognostic/metastatic potential, and response potential to novel chemotherapies. Serum amyloid A (SAA) and Vascular endothelial growth factor (VEGF) have potential utility as a serum biomarker for lung cancer. Quantum dots, nanometer-sized crystals, have a high quantum yield, sensitivity, and pronounced photostability. The properties of quantum dots can be efficiently applied to the detection of serum biomarkers in immunoassays as fluorescent probe. We used quantum dots as fluorescent probes in immunoassays and attempted to detect serum amyloid A and vascular endothelial growth factor as serum biomarkers of lung cancer. This fluorescence immunoassay based on the properties of quantum dots is applicable to the detection of serum biomarkers for lung cancer. The fluorescence immunoassay with quantum dots should allow the efficient and specific detection of serum amyloid A (SAA) for the possible diagnosis of lung cancer.

• 통합자연과학논문집
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• 제6권3호
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• pp.125-137
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• 2013

Promising evidence suggests that amyloid beta peptide ($A{\beta}$), a key mediator in age-dependent neuronal and cerebrovascular degeneration, activates death signalling processes leading to neuronal as well as non-neuronal cell death in the central nervous system. A major cellular event in $A{\beta}$-induced apoptosis of non-neuronal cells, including cerebral endothelial cells, astrocytes and oligodendrocytes, is mitochondrial dysfunction. The apoptosis signalling cascade upstream of mitochondria entails $A{\beta}$ activation of neutral sphingomyelinase, resulting in the release of ceramide from membrane sphingomyelin. Ceramide then activates protein phosphatase 2A (PP2A), a member in the ceramide-activated protein phosphatase (CAPP) family. PP2A dephosphorylation of Akt and FKHRL1 plays a pivotal role in $A{\beta}$-induced Bad translocation to mitochondria and transactivation of Bim. Bad and Bim are pro-apoptotic proteins that cause mitochondrial dysfunction characterized by excessive ROS formation, mitochondrial DNA (mtDNA) damage, and release of mitochondrial apoptotic proteins including cytochrome c, apoptosis inducing factor (AIF), endonuclease G and Smac. The cellular events activated by $A{\beta}$ to induce death of non-neuronal cells are complex. Understanding these apoptosis signalling processes will aid in the development of more effective strategies to slow down age-dependent cerebrovascular degeneration caused by progressive cerebrovascular $A{\beta}$ deposition.