Neurons containing Alz-50-immunoreactive granules around the cerebral infarction: evidence for the lysosomal degradation of altered tau in human brain?
Little is known about the metabolic process of tau and tau-derived substances. Alz-50- and tau 2-immunoreactivities in intracellular granules of neurons were observed in regions surrounding infarcted foci in the human cerebral cortex. Ultrastructurally, these granules in the fresh infarcted region exhibited primary lysosome-like structures, while those in old infarctions were lipofuscin. These findings indicate that tau is metabolized within lysosomes in neurons damaged by ischemic injury in human cortical penumbra. Alz-50-positive granules were more prominent in fresh infarction than in old infarction. After undergoing degradation and modification, altered tau might remain, at least partially, in secondary lysosomes.
Ikeda
K
K
Department of Neuropathology, Tokyo Institute of Psychiatry, 2-1-8, Kamikitazawa, Setagaya-ku, Tokyo, Japan. kenikeda@prit.go.jp
Akiyama
H
H
Arai
T
T
Kondo
H
H
Haga
C
C
Tsuchiya
K
K
Yamada
S
S
Murayama
S
S
Hori
A
A
D000368:Aged; D000369:Aged, 80 and over; D000941:Antigens / Q000032:analysis* / Q000276:immunology; D002545:Brain Ischemia / Q000378:metabolism / Q000473:pathology; D002540:Cerebral Cortex / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D002544:Cerebral Infarction / Q000378:metabolism* / Q000473:pathology; D003594:Cytoplasmic Granules / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D008062:Lipofuscin / Q000032:analysis; D008247:Lysosomes / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D016253:Microscopy, Immunoelectron; D009474:Neurons / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D013997:Time Factors; D016875:tau Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*
C056167:Alzheimer's disease antigen; D000941:Antigens; D008062:Lipofuscin; D016875:tau Proteins