Increased expression of neuronal apolipoprotein E in human brain with cerebral infarction.
OBJECTIVE
Cellular origin of apolipoprotein E (ApoE) in the human brain and its roles in physiological and pathological conditions remain to be clarified.


METHODS
Immunolocalization of ApoE was investigated in a series of autopsied human brains with or without infarction. ApoE expression was also estimated on immunoblot on protein extracts from autopsied brains and a cultured neuroblastoma cell line of human origin (GOTO) subjected to an oxidative stress induced by exposure to hydrogen peroxide (0.2 mmol/L).


RESULTS
In addition to astrocytes and microglia, neurons and degenerated axons in and around the ischemic foci contained ApoE-like immunoreactivity, which was more intense in recent ischemic foci. Immunoblot demonstrated an increase in expression of ApoE in brain extracts from ischemic lesion, and this increase was also pronounced in the cultured neuroblastoma cell line after the stress.


CONCLUSIONS
Accumulation of ApoE in neurons in and around ischemic foci of the human brain is related to an increase in ApoE synthesis in neurons, as seen in cultured neuronal cells after oxidative stress. Intrinsic regenerative activity of neuron in reaction to external insults may be related to this increase in ApoE of neuronal origin.
Aoki
Kazuko
K
Department of Neuropathology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Uchihara
Toshiki
T
Sanjo
Nobuo
N
Nakamura
Ayako
A
Ikeda
Kenji
K
Tsuchiya
Kuniaki
K
Wakayama
Yoshihiro
Y
D000368:Aged; D001057:Apolipoproteins E / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D015153:Blotting, Western; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D002544:Cerebral Infarction / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000378:metabolism*; D018384:Oxidative Stress; D014407:Tumor Cells, Cultured
D001057:Apolipoproteins E