Degradation of fodrin and MAP 2 after neonatal cerebral hypoxic-ischemia.
Neonatal rats were subjected to transient cerebral hypoxic-ischemia (unilateral occlusion of the common carotid artery + 7.70% O2 for 100 min) and allowed to recover for 3 h, 24 h, 2 days or 14 days. Consecutive tissue sections were stained with antibodies against alpha-fodrin, the 150 kDa breakdown product of alpha-fodrin (FBDP, marker of calpain proteolysis) or microtubule associated protein 2 (MAP 2, marker of dendrosomatic neuronal injury). Cortical tissue pieces were subjected to Western blotting using the antibody against the FBDP. Areas with brain injury displayed a distinct loss of MAP 2 which clearly delineated the infarct. FBDP accumulated in injured and borderline regions ipsilaterally and a less conspicuous, transient increase in FBDP also occurred in the contralateral hemisphere, especially in the white matter. A reciprocal staining pattern could be seen in the cerebral cortex, i.e. loss of MAP 2 and accumulation of FBDP, most pronounced 14 days after the insult. Fodrin and MAP 2 are known calpain substrates, and degradation of these proteins preceded neuronal degeneration, indicating that these proteases may be involved in the early events triggering the cascades leading to neuronal death.
Blomgren
K
K
Institute of Anatomy and Cell Biology, Göteborg University, Sweden.
McRae
A
A
Bona
E
E
Saido
T C
TC
Karlsson
J O
JO
Hagberg
H
H
D000818:Animals; D000831:Animals, Newborn; D000906:Antibodies / Q000276:immunology; D015153:Blotting, Western; D002545:Brain Ischemia / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D000860:Hypoxia; D007150:Immunohistochemistry; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D013049:Spectrin
D000906:Antibodies; D002352:Carrier Proteins; D008840:Microfilament Proteins; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D013049:Spectrin