In some places plaques bore a resemblance to senile neuritic plaques and in the hippocampus there were abundant typical neuritic plaques giving positive staining reactions for beta-amyloid protein and tau protein, but not PrP.
While amyloid fibrils in SPs are composed of beta-amyloid (A beta), NFTs and SPs contain similar associated components such as ubiquitin, alpha 1-antichymotrypsin (ACT), apolipoprotein E (ApoE), heparan sulfate proteoglycans (HSPGs), and aluminum salts.
Further, since intracerebral injections of PHF tau with and without AlCl3 in rats appear uniquely capable of inducing co-deposits of a number of proteins found in authentic AD SPs and NFTs (including A beta, ubiquitin, ACT, and ApoE), we speculate that the contributions of PHF tau to plaque and tangle formation in AD may be modulated by aluminum.
In Alzheimer's disease, synuclein/NAC (non-amyloid beta component of Alzheimer's disease amyloid) proteins are found in presynaptic cholinergic nerve terminals that degenerate early in Alzheimer's disease, and they are also found closely linked to beta-amyloid fibrils in senile plaques.
Possible significance of aFGF-positive astrocytes in the surroundings of the senile plaque will be discussed in relation to receptor mediated or non-mediated mechanisms.
In Alzheimer's disease, synuclein/NAC (non-amyloid beta component of Alzheimer's disease amyloid) proteins are found in presynaptic cholinergic nerve terminals that degenerate early in Alzheimer's disease, and they are also found closely linked to beta-amyloid fibrils in senile plaques.
A constituent of senile plaques in AD is beta-amyloid, a hydrophobic peptide of 39-43 amino acids and a fragment of the amyloid precursor protein (APP).
The main constituent of senile plaques is amyloid beta-peptide (A beta) and in recent years, pathogenic mutations in the amyloid precursor protein (APP) gene have been discovered in some AD families.
Isoform-specific differences have been identified in the binding of apoE to the microtubule-associated protein tau, which forms the paired helical filament and neurofibrillary tangles, and to amyloid beta peptide, a major component of the neuritic plaque.
Comparisons with ApoE epsilon 3, epsilon 4 and epsilon 2 allele dosage failed to show any significant effect on cortical SP densities in any cortical area.
We obtained APOE genotypes, determined diffuse beta-amyloid plaque (A beta P) and Lewy body densities in multiple brain regions, and graded the intensity of CA2-3 ubiquitin-positive neurites, vacuolar change, nigral pathology, amyloid angiopathy, and subpial amyloid deposition.
Isoform-specific differences have been identified in the binding of apoE to the microtubule-associated protein tau, which forms the paired helical filament and neurofibrillary tangles, and to amyloid beta peptide, a major component of the neuritic plaque.
A central event in Alzheimer's disease is the conformational change from normally circulating soluble amyloid beta peptides (A beta) and tau proteins into amyloid fibrils, in the form of senile plaques and neurofibrillary tangles respectively.
In apoE epsilon 4/AD, the size distribution is unchanged but the number of SP is increased compared to apoE epsilon 3, suggesting increased probability of SP initiation.
These findings suggest that the interaction of ApoE with tau and amyloid-beta proteins in AD could play a important role in the formation of NFT and SP, respectively, contributing to the pathogenesis of AD.
AD cases with larger numbers of neurofibrillary tangles had higher levels of GFAP transcript; AD cases with larger numbers of senile plaques had higher levels of APP695 transcript.
In Alzheimer's disease and Down's syndrome, severely afflicted brain regions exhibit up to 20-fold higher levels of S100 beta protein, and astrocytes surrounding neuritic plaques exhibit highly elevated levels of S100 beta immunostaining.
Gene dose was shown to have an effect on risk of developing AD, age of onset, accumulation of senile plaques in the brain, and reduction of choline acetyltransferase (ChAT) activity in the hippocampus of AD subjects.