Amyloid beta (Aβ) plaques are one of the hallmarks of Alzheimer's disease (AD). However, currently available anti-amyloid therapies fail to show effectiveness in the treatment of AD in humans. It has been found that there are different types of Aβ plaque (diffuse and focal types) in the postmortem human brain. In this study, we aimed to investigate the correlations among different types of Aβ plaque and AD-related neuropathological and cognitive changes based on a postmortem human brain bank in China. The results indicated that focal plaques, but not diffuse plaques, significantly increased with age in the human hippocampus. We also found that the number of focal plaques was positively correlated with the severity of AD-related neuropathological changes (measured by the "ABC" scoring system) and cognitive decline (measured by the Everyday Cognitive Insider Questionnaire). Furthermore, most of the focal plaques were co-localized with neuritic plaques (identified by Bielschowsky silver staining) and accompanied by microglial and other inflammatory cells. Our findings suggest the potential of using focal-type but not general Aβ plaques as biomarkers for the neuropathological evaluation of AD.
Alzheimer Disease/pathology* ; Amyloid beta-Peptides/metabolism* ; Amyloid beta-Protein Precursor ; Brain/pathology* ; Cognitive Dysfunction/pathology* ; Hippocampus/metabolism* ; Humans ; Neuroinflammatory Diseases ; Plaque, Amyloid/pathology*

BACKGROUND AND PURPOSE: Subjective cognitive decline (SCD) may be the first symptomatic stage of Alzheimer's disease (AD). Hence, a screening tool to characterize the patients' complaints and assess the risk of AD is required. We investigated the SCD neuroimaging biomarker distributions and the relevance between the self-report questionnaire and Alzheimer's pathologic changes. METHODS: Individuals aged 50 and above with consistent cognitive complaints without any objective cognitive impairments were eligible for the study. The newly developed questionnaire consisted of 2 parts; 10 questions translated from the ‘SCD-plus criteria’ and a Korean version of the cognitive failure questionnaire by Broadbent. All the subjects underwent physical examinations such as blood work, detailed neuropsychological tests, the self-report questionnaire, brain magnetic resonance imagings, and florbetaben positron emission tomography (PET) scans. Amyloid PET findings were interpreted using both visual rating and quantitative analysis. Group comparisons and association analysis were performed using SPSS (version 18.0). RESULTS: A total of 31 participants with SCD completed the study and 25.8% showed positive amyloid depositions. The degree of periventricular white matter hyperintensities (WMH) and hippocampal atrophy were more severe in amyloid-positive SCDs compared to the amyloid-negative group. In the self-reported questionnaire, the ‘informant's report a decline’ and ‘symptom's onset after 65 years of age’ were associated with more Alzheimer's pathologic changes. CONCLUSIONS: Amyloid-positive SCDs differed from amyloid-negative SCDs on WMH, hippocampal atrophy, and a few self-reported clinical features, which gave clues on the prediction of AD pathology.
Alzheimer Disease ; Amyloid ; Atrophy ; Biomarkers ; Brain ; Cognition Disorders ; Mass Screening ; Neuroimaging ; Neuropsychological Tests ; Pathology ; Physical Examination ; Plaque, Amyloid ; Positron-Emission Tomography ; White Matter

Alzheimer's Disease (AD) is a progressive neurodegenerative disease, which is pathologically defined by the accumulation of amyloid plaques and hyper-phosphorylated tau aggregates in the brain. Mitochondrial dysfunction is also a prominent feature in AD, and the extracellular Aβ and phosphorylated tau result in the impaired mitochondrial dynamics. In this study, we generated an induced pluripotent stem cell (iPSC) line from an AD patient with amyloid precursor protein (APP) mutation (Val715Met; APP-V715M) for the first time. We demonstrated that both extracellular and intracellular levels of Aβ were dramatically increased in the APP-V715M iPSC-derived neurons. Furthermore, the APP-V715M iPSC-derived neurons exhibited high expression levels of phosphorylated tau (AT8), which was also detected in the soma and neurites by immunocytochemistry. We next investigated mitochondrial dynamics in the iPSC-derived neurons using Mito-tracker, which showed a significant decrease of anterograde and retrograde velocity in the APP-V715M iPSC-derived neurons. We also found that as the Aβ and tau pathology accumulates, fusion-related protein Mfn1 was decreased, whereas fission-related protein DRP1 was increased in the APP-V715M iPSC-derived neurons, compared with the control group. Taken together, we established the first iPSC line derived from an AD patient carrying APP-V715M mutation and showed that this iPSC-derived neurons exhibited typical AD pathological features, including a distinct mitochondrial dysfunction.
Alzheimer Disease ; Amyloid ; Brain ; Carisoprodol ; Humans ; Immunohistochemistry ; Mitochondrial Dynamics ; Neurites ; Neurodegenerative Diseases ; Neurons ; Pathology ; Plaque, Amyloid ; Pluripotent Stem Cells

OBJECTIVES: To identify the genotype of (APP/PS1) transgenic mice and evaluate the changing of cognitive and behavioral fu nctions, provide an effective animal model for the Alzheimer's disease (AD) research. METHODS: Male APP/PS1 transgenic mice mated with female APP/PS1 transgenic mice, and the genotype of their filial mice was identified by PCR. The APP +/PS1 + mice were assigned into AD model group (AD group, =8), and the APP/PS1 mice were assigned into control group (CT group, =8). The Morris water maze test was carried out to detect the capacity of learning and memory of mice. After that, the mice were sacrificed and the brain tissues were sampled and stained by HE and congo red for the pathological examination. RESULTS: ①A APP/PS1 genome DNA about 360 bp size was detected. The methods of feeding and breeding were successful to attain APP/PS1 transgenic mice.②Statistical significance was found in the differences of the capacity of learning and memory between 7-month-old APP/PS1 positive mice and negative mice (<0.05).③The results of HE stain showed that the structure and cellular morphology of hippocampus of AD mice were obviously abnormal. The results of congo red stain showed that positive amyloid plaque was observed in brains of AD mice. CONCLUSIONS APP/PS1 transgenic mice present typical symptoms and behaviors of Alzheimer's disease. The transgenic mouse is an effective tool for the research and prevention of AD.
Alzheimer Disease ; physiopathology ; Amyloid beta-Protein Precursor ; genetics ; Animals ; Disease Models, Animal ; Female ; Genotype ; Hippocampus ; pathology ; Male ; Maze Learning ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; Plaque, Amyloid ; pathology ; Presenilin-1 ; genetics

Alzheimer's disease (AD) is the most common form of dementia among the elderly, characterized by amyloid plaques, neurofibrillary tangles, and neuroinflammation in the brain, as well as impaired cognitive behaviors. A sex difference in the prevalence of AD has been noted, while sex differences in the cerebral pathology and relevant molecular mechanisms are not well clarified. In the present study, we systematically investigated the sex differences in pathological characteristics and cognitive behavior in 12-month-old male and female APP/PS1/tau triple-transgenic AD mice (3×Tg-AD mice) and examined the molecular mechanisms. We found that female 3×Tg-AD mice displayed more prominent amyloid plaques, neurofibrillary tangles, neuroinflammation, and spatial cognitive deficits than male 3×Tg-AD mice. Furthermore, the expression levels of hippocampal protein kinase A-cAMP response element-binding protein (PKA-CREB) and p38-mitogen-activated protein kinases (MAPK) also showed sex difference in the AD mice, with a significant increase in the levels of p-PKA/p-CREB and a decrease in the p-p38 in female, but not male, 3×Tg-AD mice. We suggest that an estrogen deficiency-induced PKA-CREB-MAPK signaling disorder in 12-month-old female 3×Tg-AD mice might be involved in the serious pathological and cognitive damage in these mice. Therefore, sex differences should be taken into account in investigating AD biomarkers and related target molecules, and estrogen supplementation or PKA-CREB-MAPK stabilization could be beneficial in relieving the pathological damage in AD and improving the cognitive behavior of reproductively-senescent females.
Alzheimer Disease ; metabolism ; pathology ; psychology ; Amyloid beta-Protein Precursor ; genetics ; metabolism ; Animals ; Cyclic AMP Response Element-Binding Protein ; metabolism ; Cyclic AMP-Dependent Protein Kinases ; metabolism ; Disease Models, Animal ; Female ; Hippocampus ; metabolism ; pathology ; Humans ; Inflammation ; metabolism ; pathology ; psychology ; Male ; Maze Learning ; physiology ; Mice, Inbred C57BL ; Mice, Transgenic ; Neurofibrillary Tangles ; metabolism ; pathology ; Plaque, Amyloid ; metabolism ; pathology ; psychology ; Presenilin-1 ; genetics ; metabolism ; Sex Characteristics ; Spatial Memory ; physiology ; p38 Mitogen-Activated Protein Kinases ; metabolism ; tau Proteins ; genetics ; metabolism

OBJECTIVETo research Angelica tenuissima Nakai (ATN) for use in novel Alzheimer's disease (AD) therapeutics.

METHODSThe effect of a 30% ethanol extract of ATN (KH032) on AD-like cognitive impairment and neuropathological and neuroinflammatory changes induced by bilateral intracerebroventricular injections of β-amyloid (Aβ) peptide (Aβ) was investigated. Male C57Bl/6 mice were randomly divided into 4 groups, 10 in each group. KH032-treated groups were administrated with a low or high dose of KH032 (50 and 200 mg/kg, respectively), intragastrically for 16 days; distilled water was applied in the sham and negative groups. Open fifield test, Y maze and Morris water maze test were used for behavior test and cognitive ability. In addition, the neuroprotective effects of KH032 in Aβ-infused mice on the histopathological markers [neuronspecific nuclear protein (NeuN), Aβ] of neurodegeneration were examined. The levels of glial fibrillary acidic protein (GFAP), NeuN, phosphorylation extracellular signal-regulated kinase (ERK)/ERK, brain-derived neurotrophic factor (BDNF), phosphorylation cAMP response element-binding (CREB)/CREB protein expression were measured by Western blot.

RESULTSKH032 treatment ameliorated cognitive impairments, reduced the overexpression of Aβ, and inhibited neuronal loss and neuroinflammatory response in the Aβ-infused mice. Moreover, KH032 treatment enhanced BDNF expression levels in the hippocampus. Finally, KH032 treatment increased phosphorylation of ERK1/2 and CREB, vital for ERK-CREB signaling.

CONCLUSIONSKH032 attenuated cognitive defificits in the Aβ-infused mice by increasing BDNF expression and ERK1/2 and CREB phosphorylation and inhibiting neuronal loss and neuroinflflammatory response, suggesting that KH032 has therapeutic potential in neurodegenerative disorders such as AD.

Alzheimer Disease ; drug therapy ; pathology ; physiopathology ; Amyloid beta-Peptides ; Angelica ; chemistry ; Animals ; Brain ; pathology ; Brain-Derived Neurotrophic Factor ; metabolism ; Cognitive Dysfunction ; complications ; drug therapy ; physiopathology ; Cyclic AMP Response Element-Binding Protein ; metabolism ; Disease Models, Animal ; Male ; Maze Learning ; drug effects ; Memory, Short-Term ; drug effects ; Mice, Inbred C57BL ; Neurogenesis ; drug effects ; Neuroglia ; drug effects ; metabolism ; pathology ; Neurons ; drug effects ; metabolism ; pathology ; Neuroprotective Agents ; pharmacology ; therapeutic use ; Phosphorylation ; drug effects ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Plaque, Amyloid ; drug therapy ; pathology ; physiopathology ; Signal Transduction ; drug effects

Cerebral amyloid angiopathy (CAA) is associated with perivascular disruption, which is caused by progressive amyloid-beta (Aβ) deposition in vessels. Previous autopsy studies have shown that the prevalence of CAA in Alzheimer's disease (AD) is 70% to 90%. CAA is principally characterized by restricted lobar microbleeds (MBs), which can be detected by gradient-echo T2* (GRE) and susceptibility-weighted imaging (SWI). We herein report on a 62-year-old man who presented with 8 years of memory impairment. The apolipoprotein E (APOE) genotype was ε4/ε4, and a brain GRE performed 28 months before death revealed mild atrophy and no MBs. At autopsy, the patient scored “A3, B3, C3” according to the National Institute on Aging-Alzheimer's Association guidelines; the patient thus exhibited a high level of AD neuropathological changes. Furthermore, immunohistochemical staining for Aβ showed antibody accumulation and severe cerebral amyloid angiopathic changes in numerous vessels with amyloid deposits. Our case suggests that radiological CAA markers, such as cerebral microbleed (CMB) or cerebral superficial siderosis, may not suffice to detect amyloid angiopathy in cerebral vessels. CAA should therefore be considered as a combined pathology in APOE ε4 homozygotes with AD, even if such patients do not exhibit CMB on MRI.
Alzheimer Disease* ; Amyloid ; Apolipoproteins ; Apolipoproteins E ; Atrophy ; Autopsy ; Brain ; Cerebral Amyloid Angiopathy* ; Genotype ; Homozygote ; Humans ; Magnetic Resonance Imaging ; Memory ; Middle Aged ; Pathology ; Plaque, Amyloid ; Prevalence ; Siderosis

Parkinson's disease dementia (PDD) is notorious for its debilitating clinical course and high mortality rates. Consequently, various attempts to investigate predictors of cognitive decline in Parkinson's disease (PD) have been made. Here we report a case of a 75-year-old female patient with PD who visited the clinic with complaints of recurrent visual hallucinations and cognitive decline, whose symptoms were ameliorated by the titration of rivastigmine. Imaging results showed pronounced diffuse cortical amyloid deposition evidenced by 18F-florbetaben amyloid positron emission tomography (PET) imaging. This observation suggests that pronounced amyloid deposition and visual hallucinations in PD patients could be clinically significant predictors of cognitive decline in PD patients. Future research should concentrate on accumulating more evidence for possible predictors of cognitive decline and their association with PD pathology that can enable an early intervention and standardized treatment in PDD patients.
Aged ; Amyloid* ; Dementia* ; Early Intervention (Education) ; Female ; Hallucinations* ; Humans ; Mortality ; Parkinson Disease* ; Pathology ; Plaque, Amyloid* ; Positron-Emission Tomography ; Rivastigmine

With the intensified aging problem, the study of age-related diseases is becoming more and more significant. Alzheimer's disease is a kind of dementia, with senile plaques and neurofibrillary tangles as the main pathological features, and has become one of the major diseases that endanger the health of the elderly. This review is concentrated on the research of the early assessment of Alzheimer's disease. The current situation of early diagnosis of the disease is analyzed, and a prospect of the future development of early assessment means of the disease is also made in the paper.
Aged ; Aging ; Alzheimer Disease ; diagnosis ; pathology ; Early Diagnosis ; Humans ; Neurofibrillary Tangles ; pathology ; Plaque, Amyloid ; pathology

Cerebral amyloid angiopathy (CAA) involves cerebrovascular amyloid deposition and is classified into several types according to the amyloid protein involved. Of these, sporadic amyloid beta-protein (Abeta)-type CAA is most commonly found in older individuals and in patients with Alzheimer's disease (AD). Cerebrovascular Abeta 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 Abeta40 for CAA and anti-Abeta 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 Abeta 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.
Alzheimer Disease ; Amyloid ; Amyloid beta-Peptides ; Biomarkers ; Biopsy ; Blood Vessels ; Brain ; Cerebral Amyloid Angiopathy* ; Cerebrospinal Fluid ; Cerebrovascular Disorders ; Dementia ; Diagnosis ; Epidemiology ; Humans ; Immunotherapy ; Infarction ; Inflammation ; Leukoencephalopathies ; Ligands ; Magnetic Resonance Imaging ; Neuroimaging ; Pathology ; Plaque, Amyloid ; Positron-Emission Tomography ; Risk Factors ; Siderosis ; Stroke ; Subarachnoid Hemorrhage