Spatiotemporal changes of apolipoprotein E immunoreactivity and apolipoprotein E mRNA expression after transient middle cerebral artery occlusion in rat brain.
Apolipoprotein E (ApoE) is a constituent of lipoprotein and plays an important role in the maintenance of neural networks. However, spatiotemporal differences in ApoE expression and its long-term role in neural process after brain ischemia have not been studied. We investigated changes of ApoE immunoreactivity and ApoE mRNA expression both in the core and in the periischemic area at 1, 7, 21, or 56 days after 90 min of transient middle cerebral artery occlusion. Double stainings for ApoE plus NeuN or plus ED1 were performed in order to identify cell type of ApoE-positive stainings. The maximal increase of ApoE expression was observed at 7 days in the core and at 7 and 21 days in the periischemic area. In the core, ApoE plus NeuN double-positive cells increased at 1 and 7 days, without ApoE mRNA expression, whereas they increased in the periischemic area, with a peak at 21 days, with ApoE mRNA expression in glial cells but not in neurons. On the other hand, ApoE plus ED1 double-positive cells increased only in the core, with a peak in number at 7 and 21 days and marked ApoE mRNA expression in macrophages. The present study suggests that ApoE plays various important roles in different type of cells, reflecting spatiotemporal dissociation between degenerative and regenerative processes after brain ischemia, and that ApoE is profoundly involved in pathological conditions, such as brain ischemia.
Kamada
Hiroshi
H
Department of Neurology, Graduate School of Medicine and Dentistry, Okayama University, Okayama, Japan. h_kamada@cc.okayama-u.ac.jp
Sato
Keiko
K
Zhang
Wen Ri
WR
Omori
Nobuhiko
N
Nagano
Isao
I
Shoji
Mikio
M
Abe
Koji
K
D000818:Animals; D000951:Antigens, Neoplasm; D001057:Apolipoproteins E / Q000235:genetics / Q000378:metabolism*; D014408:Biomarkers, Tumor; D015153:Blotting, Western; D002545:Brain Ischemia / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D002352:Carrier Proteins; D002452:Cell Count; D004195:Disease Models, Animal; D006023:Glycoproteins / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D020244:Infarction, Middle Cerebral Artery / Q000503:physiopathology; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013194:Staining and Labeling; D013997:Time Factors; D016326:Extracellular Matrix Proteins
D000951:Antigens, Neoplasm; D001057:Apolipoproteins E; D014408:Biomarkers, Tumor; D002352:Carrier Proteins; D006023:Glycoproteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; C081856:LGALS3BP protein, human; D016326:Extracellular Matrix Proteins; C418606:neugrin