• Title/Summary/Keyword: Alzheimer′s disease (AD)

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Protectors of Oxidative Stress Inhibit AB(1-42) Aggregation in vitro

  • Kong, Byung-Mun;Ueom, Jeong-Hoon;Kim, In-Kyung;Lim, Dong-Yeol;Kang, Jong-Min;Lee, Kyung-Hee
    • Bulletin of the Korean Chemical Society
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    • v.23 no.12
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    • pp.1773-1777
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    • 2002
  • Reactive oxygen species(ROS) have been investigated to have pivotal roles on amyloidogenecity of $\beta-amyloidpeptide(A\beta)$, the major component of senile plaques in Alzheimer's disease(AD) brain. Addition of radical scavengers is one of the on-going strategies for therapeutic treatment for AD patients. Hsp104 protein including two ATP binding sites from Saccharomyces cerevisiae, as a molecular chaperone, was known to function as a protector of ROS generation when exposed to oxidative stress in our previous study. This observation has led us to investigate Hsp104 protein as a molecular mediator of $A{\beta}$ aggregation in this study. We have developed a new way of expression for Hsp104 protein using GST-fusion tag. As we expected, formation of $A{\beta}$ aggregate was protected by wild type Hsp104 protein, but not by the two ATP-binding site mutant, based on Thioflavin-T fluorescence. Interestingly, Hsp104 protein was observed to keep $A{\beta}$ from forming aggregates independent of ATP binding. On the other hand, disaggregation of $A{\beta}$ aggregates by wild type Hsp104 was totally dependent on the presence of ATP. On the other hand, mutant Hsp104 with two ATP binding sites altered exhibited no inhibition. Another effective antioxidant, hydrazine analogs of curcumin were also effective in $A{\beta}$ fibrilization as protectors against oxidative stress. Based on these observations we conclude that Hsp104 and curcumin derivatives, as protectors of oxidative stress, inhibit $A{\beta}$ aggregation in virto and can be candidates for therapeutic approaches in cure of some neurodegenerative disease.

Zinc Inhibits Amyloid ${\beta}$ Production from Alzheimer's Amyloid Precursor Protein in SH-SY5Y Cells

  • Lee, Jin-U;Kim, Chul-Hoon;Kim, Dong-Goo;Ahn, Young-Soo
    • The Korean Journal of Physiology and Pharmacology
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    • v.13 no.3
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    • pp.195-200
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    • 2009
  • Zinc released from excited glutamatergic neurons accelerates amyloid ${\beta}$ (A ${\beta}$) aggregation, underscoring the therapeutic potential of zinc chelation for the treatment of Alzheimer's disease (AD). Zinc can also alter A ${\beta}$ concentration by affecting its degradation. In order to elucidate the possible role of zinc influx in secretase-processed A ${\beta}$ production, SH-SY5Y cells stably expressing amyloid precursor protein (APP) were treated with pyrrolidine dithiocarbamate (PDTC), a zinc ionophore, and the resultant changes in APP processing were examined. PDTC decreased A ${\beta}$ 40 and A ${\beta}$ 42 concentrations in culture media bathing APP-expressing SH-SY5Y cells. Measuring the levels of a series of C-terminal APP fragments generated by enzymatic cutting at different APP-cleavage sites showed that both ${\beta}$-and ${\alpha}$-cleavage of APP were inhibited by zinc influx. PDTC also interfered with the maturation of APP. PDTC, however, paradoxically increased the intracellular levels of A ${\beta}$ 40. These results indicate that inhibition of secretase-mediated APP cleavage accounts -at least in part- for zinc inhibition of A ${\beta}$ secretion.

Effects of Chongmyung-tang, Polygalae Radix and Acori Graminei Rhizoma on $A{\beta}$ Toxicity and Memory Dysfunction in Mice (총명탕, 원지, 석창포가 베타아밀로이드로 유발된 학습과 기억장애에 미치는 영향)

  • Park, Eun-Kyung;Shim, Eun-Shep;Jung, Hyuk-Sang;Sohn, Nak-Won;Sohn, Young-Joo
    • The Journal of Internal Korean Medicine
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    • v.29 no.3
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    • pp.608-620
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    • 2008
  • Objectives : This study investigated the protective effects of the water extracts of Chongmyung-tang, Polygalae Radix, and Acori Graminei Rhizoma in an in vivo Alzheimer's disease (AD) mouse model. Methods : Memory impairment was induced by an intraventricular injection of $A{\beta}25-35$ peptides and subsequently Chongmyung-tang, Polygalae Radix, or Acori Graminei Rhizoma extract were administered orally for 14days. Results : In the water maze task, Chongmyung-tang, Polygalae Radix, and Acori Graminei Rhizoma extracts improved learning ability during the acquisition period and significantly increased memory scores during the retention period versus $A{\beta}-injected$ controls. Furthermore, the toxicity of $A{\beta}25-35$ on hippocampus was assessed immunohistochemically (Tau, MAP2, TUNEL, Bax) and by in vitro study. Chongmyung-tang, Polygalae Radix, and Acori Graminei Rhizoma demonstrated significant neuroprotective effects against oxidative damage and apoptotic cell death of hippocampal neurons damaged by $A{\beta}25-35$. Conclusions : These results suggested that Chongmyung-tang, Polygalae Radix and Acori Graminei Rhizoma extract improve memory impairment and reduce Alzheimer's dementia via anti-apoptotic effects and by modulating the expressions of Tau and MAP2 protein in the hippocampus.

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The Inhibitory Effect of Rivastigmine and Galantamine on Choline Transport in Brain Capillary Endothelial Cells

  • Lee, Na-Young;Kang, Young-Sook
    • Biomolecules & Therapeutics
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    • v.18 no.1
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    • pp.65-70
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    • 2010
  • The blood-brain barrier (BBB) transport of acetylcholinesterase (AChE) inhibitors, donepezil and tacrine suggested to be mediated by choline transport system in our previous study. Therefore, in the present study, we investigated the interaction of other AChE inhibitors, rivastigmine and galantamine with choline transporter at the BBB. The effects of rivastigmine and galantamine on the transport of choline by conditionally immortalized rat brain capillary endothelial cell lines (TR-BBB cells) were characterized by cellular uptake study using radiolabeled choline. The uptake of [$^3H$]choline was inhibited by rivastigmine and galantamine, with $IC_{50}$ values (i.e. concentration necessary for 50% inhibition) for 1.13 and 1.15 mM, respectively. Rivastigmine inhibited the uptake of [$^3H$]choline competitively with $K_i$ of 1.01 mM, but galantamine inhibited noncompetitively. In addition, the efflux of [$^3H$]choline was significantly inhibited by rivastigmine and galantamine. Our results indicated that the BBB choline transporter may be involved in a part of the influx and efflux transport of rivastigmine across the BBB. These findings should be therapeutically relevant to the treatment of Alzheimer's disease (AD) with AChE inhibitors, and, more generally, to the BBB transport of CNS-acting cationic drugs via choline transporter.

Altered APP Carboxyl-Terminal Processing Under Ferrous Iron Treatment in PC12 Cells

  • Kim, Chi Hyun;Yoo, Yeong-Min
    • The Korean Journal of Physiology and Pharmacology
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    • v.17 no.3
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    • pp.189-195
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    • 2013
  • Amyloid-${\beta}$ peptide ($A{\beta}$), generated by proteolytic cleavage of the amyloid precursor protein (APP), plays a pivotal role in the pathogenesis of Alzheimer's disease (AD). The key step in the generation of $A{\beta}$ is cleavage of APP by beta-site APP-cleaving enzyme 1 (BACE1). Levels of BACE1 are increased in vulnerable regions of the AD brain, but the underlying mechanism is unknown. In the present study, we reported the effects of ferrous ions at subtoxic concentrations on the mRNA levels of BACE1 and a-disintegrin-and-metalloproteinase 10 (ADAM10) in PC12 cells and the cell responses to ferrous ions. The cell survival in PC12 cells significantly decreased with 0 to 0.3 mM $FeCl_2$, with 0.6 mM $FeCl_2$ treatment resulting in significant reductions by about 75%. 4,6-diamidino-2-phenylindole (DAPI) staining showed that the nuclei appeared fragmented in 0.2 and 0.3 mM $FeCl_2$. APP-${\alpha}$-carboxyl terminal fragment (APP-${\alpha}$-CTF) associations with ADAM10 and APP-${\beta}$-CTF with BACE1 were increased. Levels of ADAM10 and BACE1 mRNA increased in response to the concentrations of 0.25 mM, respectively. In addition, p-ERK and p-Bad (S112, S155) expressions were increased, suggesting that APP-CTF formation is related to ADAM10/ BACE1 expression. Levels of Bcl-2 protein were increased, but significant changes were not observed in the expression of Bax. These data suggest that ion-induced enhanced expression of AMDA10/BACE1 could be one of the causes for APP-${\alpha}/{\beta}$-CTF activation.

Phosphodiesterase III Inhibitor Cilostazol Protects Amyloid β-Induced Neuronal Cell Injury via Peroxisome Proliferator-Activated Receptor-γ Activation (Amyloid β에 의해 유도된 신경세포 손상에 대한 phosphodiesterase III inhibitor인 cilostazol의 신경보호 효과)

  • Park, Sun-Haeng;Kim, Ji-Hyun;Bae, Sun-Sik;Hong, Ki-Whan;Choi, Byung-Tae;Shin, Hwa-Kyoung
    • Journal of Life Science
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    • v.21 no.5
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    • pp.647-655
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    • 2011
  • The neurotoxicity of aggregated amyloid ${\beta}$ ($A{\beta}$) has been implicated as a critical cause in the pathogenesis of Alzheimer's disease (AD). It can cause neurotoxicity in AD by evoking a cascade of apoptosis to neuron. Here, we investigated the neuroprotective effects of cilostazol, which acts as a phosphodiesterase III inhibitor, on $A{\beta}_{25-35}$-induced cytotoxicity in mouse neuronal cells and cognitive decline in the C57BL/6J AD mouse model via peroxisome proliferator-activated receptor (PPAR)-${\gamma}$ activation. $A{\beta}_{25-35}$ significantly reduced cell viability and increased the number of apoptotic-like cells. Cilostazol treatment recovered cells from $A{\beta}$-induced cell death as well as rosiglitazone, a PPAR-${\gamma}$ activator. These effects were suppressed by GW9662, an antagonist of PPAR-${\gamma}$ activity, indicative of a PPAR-${\gamma}$-mediated signaling. In addition, cilostazol and rosiglitazone also restored PPAR-${\gamma}$ activity levels that had been altered as a result of $A{\beta}_{25-35}$ treatment, which were antagonized by GW9662. Furthermore, cilostazol also markedly decreased the number of apoptotic-like cells and decreased the Bax/Bcl-2 ratio. Intracerebroventricular injection of $A{\beta}_{25-35}$ in C57BL/6J mice resulted in impaired cognitive function. Oral administration of cilostazol (20 mg/kg) for 2 weeks before $A{\beta}_{25-35}$ injection and once a day for 4 weeks post-surgery almost completely prevented the $A{\beta}_{25-35}$-induced cognitive deficits, as did rosiglitazone. Taken together, our findings suggest that cilostazol could attenuate $A{\beta}_{25-35}$-induced neuronal cell injury and apoptosis as well as promote the survival of neuronal cells, subsequently improving cognitive decline in AD, partly because of PPAR-${\gamma}$ activation. The phosphodiesterase III inhibitor cilostazol may be the basis of a novel strategy for the therapy of AD.

Correlation between Depression and Memory According to Apolipoprotein E Genotype in Elderly with Alzheimer's Dementia (알츠하이머 치매노인의 Apolipoprotein E 유전형에 따른 우울과 기억력의 상관관계)

  • Kim, Kwang-Jae;Noh, Dong-hee;Han, Seung-Hyup;Cha, Yun-Jun;Kam, Kyung-Yoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.477-486
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    • 2020
  • This study was undertaken to analyze the correlation between depression and memory, by considering the occurrence of ApoE ɛ4 and clinical dementia rating in the elderly with Alzheimer's dementia. This study included 50 participants over 65 years of age, evaluated with CDR 0.5 to 2. We performed CDR, SVLT-E, RCFT, SGDS-K, and ApoE genotyping. Spearman's correlation analysis was used for determining the correlation between depression and memory. The results indicate a significant negative correlation between depression and immediate recall verbal memory in the CDR 1 and 2 without ApoE ɛ4 carrier group (p<0.05). Furthermore, a significant negative correlation was also determined between depression and delayed recall verbal memory in the CDR 1 of the same group. Ed. Notes: The previous sentence already shows this correlation. I suggest this should be deleted from this statement. However, no significant correlation was observed between depression and visual memory. This study found a significant correlation between depression and immediate recall verbal memory. Also, the presence of ApoE ɛ4 indicates a significant correlation between depression and delayed verbal recall memory. Taken together, our results indicate that verbal memory training rather than visual memory training can be more effective in early AD. Also, the treatment of depression will provide a complementary effect.

The Neuroprotective Effects of InSamYangYoung-tang(Renshenyangrongtang) on Aβ-induced Damages in Mice (인삼양영탕(人蔘養榮湯)이 Aβ를 처리한 PC12 세포와 생쥐의 손상 뇌신경조직에 미치는 영향)

  • Jang, Young-Joo;Jung, In-Chul;Lee, Sang-Ryong
    • Journal of Oriental Neuropsychiatry
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    • v.21 no.1
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    • pp.109-124
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    • 2010
  • Objectives: This experiment was designed to investigate the effect of the InSamYangYoung-tang(Renshenyangrongtang) extract on $A{\beta}$-induced AD model. Methods: The effects of the InSamYangYoung-tang(Renshenyangrongtang) extract on neural damages of cultured PC12 cells induced by $A{\beta}$ were investigated. The effects of the InSamYangYoung-tang(Renshenyangrongtang) extract on neural damages of hippocampal and cortical neurons in the mouse induced by $\beta$-amyloid were investigated. Results: 1. $A{\beta}$ treatment into neuronal cells activated cell death pathway when analyzed by MTT assay and by histological analysis. Then InSamYangYoung-tang(Renshenyangrongtang) treatment improved cell survival to a similar level as in normal group. 2. $A{\beta}$ treatment increased caspase 3 protein levels but decreased phospho-Erk1/2 in neuronal cells. InSamYangYoung-tang(Renshenyangrongtang) treatment reversed the production levels of two proteins close to those in normal group. 3. $A{\beta}$ treatment induced the atrophy of neuronal cells in terms of neuronal processes and cell body shrinkage, but InSamYangYoung-tang(Renshenyangrongtang) greatly improved their morphology. 4. Neuroprotective activity, as observed in InSamYangYoung-tang(Renshenyangrongtang)-treated groups, was similarly observed in cells treated with galantamine which was used as a positive control. Moreover, overall recovery pattern by InSamYangYoung-tang(Renshenyangrongtang) was similar between cultured PC12 cells and in vivo hippocampal and cerebral cortical neurons in the mouse brain. Conclusions: This experiment shows that the InSamYangYoung-tang(Renshenyangrongtang) may play a protective role in neural tissues damaged by cytotoxic substances. Since neuronal damage seen in degenerative brains such as AD are largely unknown, the current data may provide possible insight into therapeutic strategies for AD treatments. InSamYangYoung-tang(Renshenyangrongtang) might be effective for the treatment of AD. Investigation into the clinical use of the InSamYangYoung-tang(Renshenyangrongtang) for AD is suggested for future research.

A review study of treatment effects for vascular dementia (혈관성 치매 치료 약물에 대한 문헌 고찰 연구 : 외국문헌을 중심으로)

  • Lee, Young-Joon;Han, Chang-Hyun;Jeon, Won-Kyung;Baek, Kyung-Min;Cheon, Woo-Hyun;Choi, Seong-Hun
    • Journal of Society of Preventive Korean Medicine
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    • v.15 no.2
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    • pp.51-67
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    • 2011
  • The average human life span has increased due to the development of modern medicine and science, resulting in prolonged life expectancy and increase in the population counts of the geriatric age group. In particular, a dramatic increase of elderly patients suffering from senile disorders including neurodegenerative diseases, Alzheimer's disease(AD), and vascular dementia has become a serious social problem in public health. Thus, this study is aimed to summarize available clinical trial data on several commonly used medicines include donepezil, rivastigmine, galantamine, memantine and oriental medicine, and examine the effect of oriental medicine combined with western medicine in the treatment of patients with senile disorders using the data from literature reviews and survey studies.

Effects of HX106N, a Water-Soluble Botanical Formulation on Scopolamine-Induced Memory Impairment in Mice (식물성 열수 추출물 HX106N이 스코폴라민으로 유도한 생쥐 기억력 저하에 미치는 효과에 관한 연구)

  • Lee, Doo Suk;Jeong, Jae-Gyun;Kim, Sunyoung
    • The Korean Journal of Food And Nutrition
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    • v.27 no.4
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    • pp.673-677
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    • 2014
  • HX106N은 용안육, 맥문동, 단삼 및 천마 등의 4가지 식물로 구성된 추출물로서, 선행 연구에서 amyloid ${\beta}$ peptide에 의한 생쥐의 기억력 저하 및 산화 손상을 억제하는 것으로 밝혀졌다. 이 연구에서는 HX106N이 비선택적 무스카린 수용체 길항제로 잘 알려진 스코폴라민(scopolamine)으로 유도한 콜린성 건망증(cholinergic amnesia)에 어떤 영향을 미치는지를 평가하였다. ICR 생쥐에게 스코폴라민(1 mg/kg body weight, i.p.)을 주입하기 1시간 전에 HX106N(100 mg/kg body weight, p.o.)을 투여하였다. 30분 후 수행한 Y-미로 시험(Y-maze test) 및 수동 회피 시험(passive avoidance test)에서 HX106N는 스코폴라민에 의해 감소되는 자발적 변경 행동(spontaneous alternation) 및 지체시간(step-through latency)을 유의미하게 억제하여 건망증을 개선시키는 것으로 나타났다. 또한 HX106N을 투약 1시간 후 생쥐의 해마와 대뇌피질 부위의 아세틸콜린에스테라제(acetylcholinesterase; AChE)의 활성을 측정한 결과 통계적으로 유의미한 정도의 활성 감소가 관찰되었다. 이러한 결과들을 종합할 때 HX106N은 AD에서 관찰되는 콜린성신경전달 장애로 인한 기억력 저하 억제에 사용될 수 있는 가능성을 가진 것으로 판단된다.