Plaques are a defining neuropathological hallmark of Alzheimer's disease (AD) and the major constituent of plaques, the β-amyloid peptide (Aβ), is considered to play an important role in the pathophysiology of AD. But the biological origin of Aβ plaques and the mechanism whereby Aβ is involved in pathogenesis have been unknown. Aβ plaques were thought to form from the gradual accumulation and aggr

Intrinsic optical emissions, such as autofluorescence and second harmonic generation (SHG), are potentially useful for functional fluorescence imaging and biomedical disease diagnosis for neurodegenerative diseases such as Alzheimer's disease (AD). Here, using multiphoton and SHG microscopy, we identified sources of intrinsic emissions in ex vivo, acute brain slices from AD transgenic mouse models

Histochemical analysis of postmortem human brains from subjects who suffered from dementia led to the discovery of Alzheimer’s disease a century ago. The histological lesions that characterized this common age-related dementia were the accumulation of senile plaques (SPs) and neurofibrillary tangles (NFTs). Subsequently, NFTs were found in a variety of degenerative diseases of the brain, while pla

A growing body of evidence suggests a relationship between oxidative stress and β-amyloid (Aβ) peptide accumulation, a hall-mark in the pathogenesis of Alzheimer's disease (AD). However, a direct causal relationship between oxidative stress and Aβ pathology has not been established in vivo. Therefore, we crossed mice with a knockout of one allele of manganese superoxide dismutase (MnSOD), a critic

Multiple lines of evidence implicate β-amyloid (Aβ) in the pathogenesis of Alzheimer's disease (AD), but the mechanisms whereby Aβ is involved remain unclear. Addition of Aβ to the extracellular space can be neurotoxic. Intraneuronal Aβ42 accumulation is also associated with neurodegeneration. We reported previously that in Tg2576 amyloid precursor protein mutant transgenic mice, brain Aβ42 locali

Molecular chaperones and their functions in protein folding have been implicated in several neurodegenerative diseases, including Parkinson's disease and Huntington's disease, which are characterized by accumulation of protein aggregates (e.g., α-synuclein and huntingtin, respectively). These aggregates have been shown in various experimental systems to respond to changes in levels of molecular ch

A central question in Alzheimer's disease concerns the mechanism by which β-amyloid contributes to neuropathology, and in particular whether intracellular versus extracellular β-amyloid plays a critical role. Alzheimer transgenic mouse studies demonstrate brain dysfunction, as β-amyloid levels rise, months before the appearance of β-amyloid plaques. We have now used immunoelectron microscopy to de

Alzheimer's disease (AD) is characterized by the deposition of senile plaques (SPs) and neurofibrillary tangles (NFTs) in vulnerable brain regions. SPs are composed of aggregated β-amyloid (Aβ) 40/42(43) peptides. Evidence implicates a central role for Aβ in the pathophysiology of AD. Mutations in βAPP and presenilin 1 (PS1) lead to elevated secretion of Aβ, especially the more amyloidogenic Aβ42.

Alzheimer's disease (AD) is characterized by the age-related deposition of β-amyloid (Aβ) 40/42 peptide aggregates in vulnerable brain regions. Multiple levels of evidence implicate a central role for Aβ in the pathophysiology of AD. Aβ peptides are generated by the regulated cleavage of an ≃700-aa Aβ precursor protein (βAPP). Full-length βAPP can undergo proteolytic cleavage either within the A β

Alzheimer's disease (AD) is characterized by the accumulation of cerebral plaques composed of 40- and 42-amino acid ̄-amyloid (Aβ) peptides, and autosomal dominant forms of AD appear to cause disease by promoting brain Aβ accumulation. Recent studies indicate that postmenopausal estrogen replacement therapy may prevent or delay the onset of AD. Here we present evidence that physiological levels of

Studies of processing of the Alzheimer β-amyloid precursor protein (βAPP) have been performed to date mostly in continuous cell lines and indicate the existence of two principal metabolic pathways: the 'β- secretase' pathway, which generates β-amyloid (Aβ(1-40/42); ~4 kDa), and the 'α-secretase' pathway, which generates a smaller fragment, the 'p3' peptide (Aβ(17-40/42); ~3 kDa). To determine whet

Early events in Alzheimer's disease (AD) pathogenesis implicate the accumulation of β-amyloid (Aβ) peptide inside neurons in vulnerable brain regions. However, little is known about the consequences of intraneuronal Aβ on signaling mechanisms. Here, we demonstrate, using an inducible viral vector system to drive intracellular expression of Aβ42 peptide in primary neuronal cultures, that this accum

Mutations within the amyloid-β (Aβ) domain of the amyloid precursor protein (APP) typically generate hemorrhagic strokes and vascular amyloid angiopathy. In contrast, the Arctic mutation (APP E693G) results in Alzheimer's disease. Little is known about the pathologic mechanisms that result from the Arctic mutation, although increased formation of Aβ protofibrils in vitro and intraneuronal Aβ aggre

Accumulation of β-amyloid (Aβ) peptides in the cerebral cortex is considered a key event in the pathogenesis of Alzheimer's disease (AD). Presenilin 1 (PS1) plays an essential role in the γ-secretase cleavage of the amyloid precursor protein (APP) and the generation of Aβ peptides. Reduction of Aβ generation via the inhibition of γ-secretase activity, therefore, has been proposed as a therapeutic

Amyloid-β (Aβ) peptide levels are widely measured by enzyme-linked immunosorbent assay (ELISA) in Alzheimer's disease research. Here, we show that oligomerization of Aβ results in underestimated Aβ ELISA levels. The implications are that comprehensive analysis of soluble Aβ requires either sample pretreatment at denaturing conditions or novel conformation-dependent immunoassays. Our findings might

Alzheimer's Disease (AD) is characterized by cerebral accumulation of β-amyloid peptides (Aβ), which are proteolytically derived from β-amyloid precursor protein (βAPP). βAPP metabolism is highly regulated via various signal transduction systems, e.g., several serine/threonine kinases and phosphatases. Several growth factors known to act via receptor tyrosine kinases also have been demonstrated to

The issue of Critical Raw Materials (CRMs) and potential interruptions to their availability due to shortages, trade restrictions or other factors in their supply are topics that are relatively unknown to the general public. For this reason, education has been promoted as a key enabler of a circular economy. One key intervention point is the movement of electronic repair events. Repair events alre

Pathogenic mutations in presenilin 1 (PS1) are associated with ≃50% of early-onset familial Alzheimer disease. PS1 is endoproteolytically cleaved to yield a 30-kDa N-terminal fragment (NTF) and an 18-kDa C-terminal fragment (CTF). Using COS7 cells transfected with human PS1, we have found that phorbol 12,13-dibutyrate and forskolin increase the state of phosphorylation of serine residues of the hu

The excessive generation and accumulation of 40- and 42-aa β-amyloid peptides (Aβ40/Aβ42) in selectively vulnerable brain regions is a major neuropathological feature of Alzheimer's disease. Aβ, derived by proteolytic cleavage from the β-amyloid precursor protein (βAPP), is normally secreted. However, recent evidence suggests that significant levels of Aβ also may remain inside cells. Here, we hav