In vitro에서 β-site amyloid precursor protein-cleaving enzyme 활성화 amyloid β protein 생산에 대한 총명탕가미방(聰明湯加味方)

임정화 ( Jung Hwa Lim ),정인철 ( In Chul Jung ),임종순 ( Jong Soon Lim ),김승형 ( Seung Hyung Kim ),이상룡 ( Sang Ryong Lee ) 대한한방신경정신과학회 2010 동의신경정신과학회지 Vol.21 No.2

This experiment was designed to investigate the effect of Chongmyung-Tang Prescription Combination(CmTP-C1-10) extract on the production of amyloid β protein and β-site amyloid precursor protein-cleaving enzyme(BACE) activity. Methods: The effect of CmTP-C1-10 extract on expression of APP mRNA, BACE2 mRNA in BV2 microglia cell line treated by lipopolysacchride(LPS) and amyloid β protein fragment(Aβ fragment) were investigated. The effect of CmTP-C1-10 extract on production of amyloid β protein(Aβ) in BV2 microglia cell line treated by LPS and Aβ fragment were investigated. The effect of CmTP-C1-10 extract on BACE activity were investigated. Results: 1. CmTP-C9 extract the most significantly suppressed the expression of APP mRNA, BACE2 mRNA in BV2 microglia cell line treated by LPS and Aβ fragment. 2. CmTP-C9 extract significantly suppressed the production of Aβ in BV2 microglia cell line treated by LPS and Aβ fragment. 3. CmTP-C9 extract the most significantly inhibited BACE activity. Conclusions: These results suggest that CmTP-C9 may be effective for the prevention and treatment of Alzheimer`s Disease, Investigation into clinical use of CmTP-C9 for Alzheimer`s Disease is suggested for future research.

한국의 알츠하이머병 환자에서 아세틸콜린 에스터레이스 억제제의 뇌척수액 베타아밀로이드 1-42 분획과 인산화타우단백 농도에 미치는 효과

이은희,윤영철,박광열,민주홍,권오상,이현옥,홍현종 대한신경과학회 2008 대한신경과학회지 Vol.26 No.3

Background: Alzheimer’s disease (AD) is characterized by the pathology of amyloid plaques and tau-associated neurofibrillary tangles. Acetylcholine esterase (AChE) transforms the β-amyloid monomer into an oligomer, and increases β-amyloid aggregation in the brain. Increased β-amyloid breaks the cytoskeleton of the brain by hyperphosphorylation of the tau protein. Previous studies support that AChE inhibitor has an inhibitory effect on toxicity of the β-amyloid and phophorylated tau protein. The purpose of this study was to analyze the CSF β-amyloid 1-42 (Aβ1-42) and phosphorylated tau protein in AD and determine their difference depending on whether AChE inhibitor was taken or not. Methods: Subjects included 16 AD, 14 normal controls, and 15 disease controls. Nine of AD group had taken an AChE inhibitor while the remainder had not. The CSF Aβ1-42 and phosphorylated tau were measured by ELISA. Results: The CSF Aβ1-42 levels were lower in AD patients than in other groups (p<0.01). We also found increased CSF Aβ1-42 levels in the AChE inhibitor users, compared with non-users. Conclusions: The level of CSF Aβ1-42 may have a diagnostic value in the patients with cognitive impairments. Also, we may expect the effect of AChE inhibitor on Alzheimer’s pathology by measuring CSF Aβ1-42 levels. Therefore, the level of CSF Aβ1-42 may serve as a biological surrogate marker for AD treatment. Background: Alzheimer’s disease (AD) is characterized by the pathology of amyloid plaques and tau-associated neurofibrillary tangles. Acetylcholine esterase (AChE) transforms the β-amyloid monomer into an oligomer, and increases β-amyloid aggregation in the brain. Increased β-amyloid breaks the cytoskeleton of the brain by hyperphosphorylation of the tau protein. Previous studies support that AChE inhibitor has an inhibitory effect on toxicity of the β-amyloid and phophorylated tau protein. The purpose of this study was to analyze the CSF β-amyloid 1-42 (Aβ1-42) and phosphorylated tau protein in AD and determine their difference depending on whether AChE inhibitor was taken or not. Methods: Subjects included 16 AD, 14 normal controls, and 15 disease controls. Nine of AD group had taken an AChE inhibitor while the remainder had not. The CSF Aβ1-42 and phosphorylated tau were measured by ELISA. Results: The CSF Aβ1-42 levels were lower in AD patients than in other groups (p<0.01). We also found increased CSF Aβ1-42 levels in the AChE inhibitor users, compared with non-users. Conclusions: The level of CSF Aβ1-42 may have a diagnostic value in the patients with cognitive impairments. Also, we may expect the effect of AChE inhibitor on Alzheimer’s pathology by measuring CSF Aβ1-42 levels. Therefore, the level of CSF Aβ1-42 may serve as a biological surrogate marker for AD treatment.

Cerebral Amyloid Angiopathy: Emerging Concepts

Masahito Yamada 대한뇌졸중학회 2015 Journal of stroke Vol.17 No.1

Cerebral amyloid angiopathy (CAA) involves cerebrovascular amyloid deposition and is classified into several types according to the amyloid protein involved. Of these, sporadic amyloid β-protein (Aβ)-type CAA is most commonly found in older individuals and in patients with Alzheimer’s disease (AD). Cerebrovascular Aβ deposits accompany functional and pathological changes in cerebral blood vessels (CAA-associated vasculopathies). CAA-associated vasculopathies lead to development of hemorrhagic lesions [lobar intracerebral macrohemorrhage, cortical microhemorrhage, and cortical superficial siderosis (cSS)/focal convexity subarachnoid hemorrhage (SAH)], ischemic lesions (cortical infarction and ischemic changes of the white matter), and encephalopathies that include subacute leukoencephalopathy caused by CAA-associated inflammation/angiitis. Thus, CAA is related to dementia, stroke, and encephalopathies. Recent advances in diagnostic procedures, particularly neuroimaging, have enabled us to establish a clinical diagnosis of CAA without brain biopsies. Sensitive magnetic resonance imaging (MRI) methods, such as gradient-echo T2* imaging and susceptibility-weighted imaging, are useful for detecting cortical microhemorrhages and cSS. Amyloid imaging with amyloid-binding positron emission tomography (PET) ligands, such as Pittsburgh Compound B, can detect CAA, although they cannot discriminate vascular from parenchymal amyloid deposits. In addition, cerebrospinal fluid markers may be useful, including levels of Aβ40 for CAA and anti-Aβ antibody for CAA-related inflammation. Moreover, cSS is closely associated with transient focal neurological episodes (TFNE). CAA-related inflammation/angiitis shares pathophysiology with amyloid-related imaging abnormalities (ARIA) induced by Aβ immunotherapies in AD patients. This article reviews CAA and CAA-related disorders with respect to their epidemiology, pathology, pathophysiology, clinical features, biomarkers, diagnosis, treatment, risk factors, and future perspectives.

O-GlcNAcylation of amyloid-β precursor protein at threonine 576 residue regulates trafficking and processing

Chun, Y.S.,Kwon, O.H.,Chung, S. Academic Press 2017 Biochemical and biophysical research communication Vol. No.

The pathological hallmark of Alzheimer's disease (AD) is associated with the accumulation of amyloid-β (Aβ) derived from proteolytic processing of amyloid-β precursor protein (APP). APP undergoes post-translational modification including N- and O-glycosylation. O-GlcNAcylation is a novel type of O-glycosylation, mediated by O-GlcNAc transferase attaching O-β-N-acetylglucosamine (O-GlcNAc) to serine/threonine residues of the target proteins. O-GlcNAc is removed by O-GlcNAcase. We have previously reported that increasing O-GlcNAcylated APP using the O-GlcNAcase inhibitor, PUGNAc, increases its trafficking rate to the plasma membrane and decreases its endocytosis rate, resulting in decreased Aβ production. However, O-GlcNAc modification sites in APP are unknown. In this study, we mutated three predicted O-GlcNAc modification threonine residues of APP into alanines (T291A, T292A, and T576A) and expressed them in HeLa cells. These APP mutants showed reduced O-GlcNAcylation levels, indicating that these sites were endogenously O-GlcNAcylated. Thr 576 was the major O-GlcNAcylation site when cell was treated with PUGNAc. We also showed that the effects of PUGNAc on APP trafficking to the plasma membrane and Aβ production were prevented in the T576A mutant. These results implicate Thr 576 as the major O-GlcNAcylation site in APP and indicate that O-GlcNAcylation of this residue regulates its trafficking and processing. Thus, specific O-GlcNAcylation of APP at Thr 576 may be a novel and promising drug target for AD therapeutics.

Coat protein I depletion-associated Golgi fragmentation in an Alzheimer’s disease model

김미정,제아름,김효정,허양훈,권희석 한국통합생물학회 2015 Animal cells and systems Vol.19 No.1

The onset and progression of Alzheimer’s disease (AD) is closely associated with amyloid β (Aβ) peptide-inducedcytotoxicity and abnormal protein transportation caused by breakdown of endoplasmic reticulum (ER)–Golgi apparatustrafficking network. Although the fragmentation of Golgi apparatus has been reported in AD human patients and variousAD model animals, the molecular mechanisms causing the morpho-functional impairments of Golgi apparatus during ADprogression remain poorly understood. Thus, we investigated the ultrastructure of Golgi apparatus and coat protein I (COPI)expression in β-amyloid precursor protein/presenilin-1 double transgenic mouse and Aβ-stimulated BV-2 cell as an ADmodel using cryo-immunogold electron microscopy. In the neurons of the hippocampus of transgenic mouse and BV-2 cell,the cisternae of Golgi stacks were fragmented in difference with that of wild type mouse and cells. In addition, we furthershowed the COPI depletion in Golgi apparatus, which demonstrated the impairment of molecular integrities of Golgiapparatus. Taken together, our results provide insights into the Golgi apparatus-involved morphopathology of AD and wesuggest that the Golgi fragmentation is caused by the depletion of COPI affecting the intra-Golgi transport throughstimulation and accumulation of Aβ during AD development.

AMYLOIDOGENIC PROCESSING OF ALZHEIMER'S AMYLOID PRECURSOR PROTEIN IN VITRO AND ITS MODULATION BY METAL IONS AND TACRINE

Chong, Young Hae,Suh, Yoo-Hun 이화여자대학교 생명과학연구소 1996 생명과학연구논문집 Vol.7 No.-

Recent studies implicate that excessive amyloidogenic pathway of amyloid precursor protein(APP)processing may be the final commom pathway involved in the pathogensis of AD. In attepmts to identify the proteases or factors leading to excessive amyloid deposition, we evaluated the potential role of acethylcholinesterase(AChE)and its associated protease for amyloidogenic processing of APP in vitro. Prolonged incubation of a recombinant APP770 with AChE produced several amyloidogenic fragments accumulating a relatively stable a 18 kDa Aβ(amyloidβ-protein)bearing carboxy terminal peptide, which was further degraded by an increased concentration of AChE. Protease inhibitory profiles confirmed the trypsin-like serine protease activity present in AChE preparation. This observed APP processing was significantly enhanced by Ca^2+, Mg^2+, or Mn^2+ at 1 mM concentration and modulated in concentration dependent manners by metal ions such as Ca^2+, Zn^2+, Fe^2+/Fe^3+, Al^3+, or a tacrine, a centrally active cholinesterase inhibitor. Our data imply that AChE and its associated protease may be involved in the generation a 18 kDa amyloidogenic peptide under certain physiological condition in vivo and that the gradual changes in their proteolytic activities or locations and the locally disturbed metal homeostasis could be factors associated with abnormal accumulation of APP, evantually leading to amyloid deposition in AD brain. In addition, zinc or tacrine treatment of AD patients with high dosage or in the long term may have effects on the process of amyloidogensis.

Age-dependent Olfactory Dysfunction in a Neurodegenerative Disease Fruit Fly Model

Je Won Jung,Seung Jae Beack,Ji Hyun Park,Hyung Wook Kwon 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.05

Alzheimer’s disease (AD) is a fatal disorder wherein patients suffer from sensory, motor, and cognitive loss. Currently, the identification and validation of biomarkers for diagnosing AD and other forms of dementia are increasingly important. Olfactory dysfunction is present in patients diagnosed with Alzheimer’s disease or idiopathic Parkinson's disease. Alzheimer’s patients show neuropathological changes in areas of the brain central to the olfactory processing center, suggesting the theoretical importance and potential diagnostic utility of investigating functional changes in olfaction in these patients. However, the usefulness of olfactory screens to serve as informative indicators of Alzheimer’s is precluded by the lack of knowledge regarding neural and molecular mechanisms underlying olfactory dysfunction onto Alzheimer's diseases. To test these ultimate questions, we used molecular and electrophysiological recording techniques to find out the difference of olfactory responses and AD related protein expression patterns by using fly model, Drosophila melanogaster that over-expresses the human β -amyloid, tau protein. We postulated that such flies would present with progressive olfactory impairments compared with age-matched wild type control flies. In this study, our hypothesis is that there is a correlation between olfactory deficits and the spatial expression pattern of β-amyloid and tau protein deposition. Therefore, we demonstrate a specific concentration of lesions in central olfactory structures such as antenna and Maxillary palps. Our study indicates that deficits on olfactory identification may occur in AD, which will be valuable as an indicator of neuropathogenesis.

Protective effects of Acanthopanax divaricatus extract in mouse models of Alzheimer’s disease

Ji-Jing Yan,Won-Gyun Ahn,Jun-Sub Jung,Hee-Sung Kim,Ashraful Hasan,Dong-Keun Song 한국영양학회 2014 Nutrition Research and Practice Vol.8 No.4

BACKGROUND: Acanthopanax divaricatus var. albeofructus (ADA) extract has been reported to have anti-oxidant, immunomodulatory, and anti-mutagenic activity. MATERIALS/METHODS: We investigated the effects of ADA extract on two mouse models of Alzheimer’s disease (AD); intracerebroventricular injection of β-amyloid peptide (Aβ) and amyloid precursor protein/presenilin 1 (APP/PS1)-transgenic mice. RESULTS: Intra-gastric administration of ADA stem extract (0.25 g/kg, every 12 hrs started from one day prior to injection of Aβ1-42 until evaluation) effectively blocked Aβ1-42-induced impairment in passive avoidance performance, and Aβ1-42-induced increase in immunoreactivities of glial fibrillary acidic protein and interleukin (IL)-1α in the hippocampus. In addition, it alleviated the Aβ1-42-induced decrease in acetylcholine and increase in malondialdehyde levels in the cortex. In APP/PS1-transgenic mice, chronic oral administration of ADA stem extract (0.1 or 0.5 g/kg/day for six months from the age of six to 12 months) resulted in significantly enhanced performance of the novel-object recognition task, and reduced amyloid deposition and IL-1β in the brain. CONCLUSIONS: The results of this study suggest that ADA stem extract may be useful for prevention and treatment of AD.

Inhibitory Effects of Glycyrrhizae Radix and Its Active Component, Isoliquiritigenin, on Aβ(25-35)-induced Neurotoxicity in Cultured Rat Cortical Neurons

이홍규,Yeon Hee Seong,양은주,Joo Youn Kim,Kyung-sik Song 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.5

This study investigated an ethanol extract from Glycyrrhizae radix (GR), the root of Glycyrrhiza uralensis (Leguminosae), for possible neuroprotective effects on neurotoxicity induced by amyloid β protein (Aβ) (25-35) in cultured rat cortical neurons. Exposure of cultured cortical neurons to 10 μM Aβ (25-35) for 36 h induced neuronal apoptotic death. GR (10-50 μg/mL) prevented the Aβ (25-35)-induced neuronal apoptotic death, as assessed by a MTT assay and Hoechst 33342 staining. Furthermore, GR decreased the expression of Bax and active caspase-3, proapoptotic proteins, and increased Bcl-2, an antiapoptotic protein. GR also significantly inhibited Aβ (25-35)-induced elevation of the intracellular Ca2+ concentration ([Ca2+]i) and generation of reactive oxygen species (ROS) measured by fluorescent dyes. Isoliquiritigenin (1-20 μM), isolated from GR as an active component, inhibited Aβ (25-35)-induced neuronal apoptotic death, elevation of [Ca2+]i, ROS generation, and the change of apoptosis-associated proteins in cultured cortical neurons, suggesting that the neuroprotective effect of GR may be, at least partly, attributable to this compound. These results suggest that GR and isoliquiritigenin prevent Aβ (25-35)-induced neuronal apoptotic death by interfering with the increases of [Ca2+]i and ROS, and GR may have a possible therapeutic role for preventing the progression of neurodegenerative disease such as Alzheimer’s disease.

Suppression of β-Secretase (BACE1) Activity and β-Amyloid Protein-Induced Neurotoxicity by Solvent Fractions from Petasites japonicus Leaves

Seung-Young Hong,Inshik Park,Mira Jun 한국식품영양과학회 2011 Preventive Nutrition and Food Science Vol.16 No.1

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by neuronal loss and extracellular senile plaques containing β-amyloid peptide (Aβ). The deposition of the Aβ peptide following proteolytic processing of amyloid precursor protein (APP) by β-secretase (BACE1) and γ-secretase is a critical feature in the progression of AD. Among the plant extracts tested, the ethanol extract of Petasites japonicus leaves showed novel protective effect on B103 neuroblastoma cells against neurotoxicity induced by Aβ, as well as a strong suppressive effect on BACE1 activity. Ethanol extracts of P. japonicus leaves were sequentially extracted with methylene chloride, ethyl acetate and butanol and evaluated for potential to inhibit BACE1, as well as to suppress Aβ-induced neurotoxicity. Exposure to Aβ significantly reduced cell viability and increased apoptotic cell death. However, pretreatment with ethyl acetate fraction of P. japonicus leaves prior to Aβ (50 μM) significantly increased cell viability (p<0.01). In parallel, cell apoptosis triggered by Aβ was also dramatically inhibited by ethyl acetate fraction of P. japonicus leaves. Moreover, the ethyl acetate fraction suppressed caspase-3 activity to the basal level at 30 ppm. Taken together, these results demonstrated that P. japonicus leaves appear to be a useful source for the inhibition and/or prevention of AD by suppression of BACE1 activity and attenuation of Aβ induced neurocytotoxicity.