Variable deposition of amyloid beta-protein (A beta) with the carboxy-terminus that ends at residue valine40 (A beta 40) in the cerebral cortex of patients with Alzheimer's disease: a double-labeling immunohistochemical study with antibodies specific for A beta 40 and the A beta that ends at residues alanine42/threonine43 (A beta 42).
Amyloid beta-protein (A beta) deposits in the cerebral cortices of patients with Alzheimer's disease (AD) were investigated immunohistochemically to determine their carboxy terminal sequences. Antibodies specific for A beta terminating at residue valine40 (A beta 40) and at residues alanine42/threonine43 (A beta 42) were used. Virtually all parenchymal A beta deposits were positive for A beta 42. Many of these deposits were also partially or completely labeled for A beta 40. The degree of A beta 40 labeling varied from area to area within a given brain and from AD case to AD case. In contrast to parenchymal deposits, A beta 40 labeled essentially all the vascular deposits which constitute amyloid angiopathy (AA), with A beta 42 occurring variably in some of these deposits. Occasional AA was found, however, in which A beta 42 predominated or was exclusively deposited. Such a diversity of A beta species, both in brain parenchyma and in AA, suggests that multiple C-terminal processing mechanisms occur in the cell types responsible for these deposits.
Akiyama
H
H
Tokyo Institute of Psychiatry, Japan. akiyama@prit.go.jp
Mori
H
H
Sahara
N
N
Kondo
H
H
Ikeda
K
K
Nishimura
T
T
Oda
T
T
McGeer
P L
PL
D000368:Aged; D000369:Aged, 80 and over; D000409:Alanine / Q000737:chemistry; D000544:Alzheimer Disease / Q000378:metabolism* / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000276:immunology* / Q000378:metabolism*; D000906:Antibodies / Q000378:metabolism*; D000918:Antibody Specificity; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D016874:Neurofibrillary Tangles / Q000378:metabolism / Q000473:pathology; D010446:Peptide Fragments / Q000276:immunology; D013194:Staining and Labeling; D013912:Threonine / Q000737:chemistry; D014633:Valine / Q000737:chemistry
D016229:Amyloid beta-Peptides; D000906:Antibodies; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42); D013912:Threonine; D014633:Valine; D000409:Alanine