Expression of CD95 and CD95L on astrocytes in the CA1 area of the immature rat hippocampus after hypoxia-ischemia injury.
The immature brain is affected profoundly by hypoxia-ischemia (HI) injury, which can lead to permanent neurologic sequelae in survivors. Neuronal degeneration after HI injury usually is achieved through apoptosis. Both CD95 and its natural ligand, CD95L, which are key molecules in the regulation of apoptosis, are constitutively expressed by neurons and astrocytes during embryonic and early postnatal stages. Further, CD95 or CD95L may have a functional relationship in glial cells and lead to apoptosis of these cells. The hippocampus, especially the CA1 area, is particularly susceptible to HI injury. We therefore investigated the temporal and spatial alterations in CD95 and CD95L expression in the CA1 area of 7-d-old rats after unilateral ligation of the carotid artery. Using immunohistochemistry and Western blotting, we showed that expression of CD95 and CD95L in the hippocampus peaked at 12 h and then decreased. In addition, we used terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick end-labeling to demonstrate apoptosis among CD95- and CD95L-reactive cells. Our findings show that increases in the expression of CD95 and CD95L after HI injury may involve astrocytic apoptosis in the 7-d-old rat hippocampus, and these molecules may act as targets or inducers of cell death.
Kim
Myeung Ju
MJ
Department of Anatomy, Dankook University College of Medicine, Cheon-an, Chungnam, South Korea.
Lim
Hyoung-Soo
HS
Yoo
Young Bok
YB
Lee
Young Il
YI
Hahm
Dae-Hyun
DH
Lee
Hye-Jung
HJ
Jung
Kee Wook
KW
Kim
Jong-Wan
JW
Yoe
Sung Moon
SM
Chung
David Chanwook
DC
Chang
Young Pyo
YP
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001253:Astrocytes / Q000378:metabolism* / Q000473:pathology; D053222:Fas Ligand Protein / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D006624:Hippocampus / Q000098:blood supply / Q000293:injuries* / Q000378:metabolism* / Q000473:pathology; D020925:Hypoxia-Ischemia, Brain / Q000378:metabolism* / Q000473:pathology; D020287:In Situ Nick-End Labeling; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D019014:fas Receptor / Q000378:metabolism*
D053222:Fas Ligand Protein; D019014:fas Receptor