Expression of glial fibrillary acidic protein in areas of focal cerebral ischemia accompanies neuronal expression of 72-kDa heat shock protein.
We examined the astrocytic GFAP and neuronal HSP-72 responses to transient middle cerebral artery (MCA) occlusion in the rat. Three groups of rats (n = 79) were studied: (1) fixed duration of MCA occlusion (120 min) and variable durations of reperfusion (0.5, 3, 6, 9, 12, 24, 48, 96 and 168 h); (2) variable durations of MCA occlusion (10, 20, 30, 60, 90, and 120 min) and a fixed duration of reperfusion (48 h); and (3) controls: sham operated rats and normal rats. Coronal sections from each brain were reacted with appropriate antibodies to GFAP and HSP-72 and stained with H&E for evaluation of cellular response to ischemia. Our data show that after MCA occlusion: (1) GFAP expression was found in the boundary zone to the infarct or in areas of selective incomplete ischemic necrosis; (2) GFAP expression was localized to the same areas where neurons express HSP-72 and are destined to survive the ischemic insult; and (3) HSP-72 expression was not found in astrocytes in any of the experimental groups. These studies suggest that after transient focal ischemia in the rat: areas where both GFAP and HSP-72 expression are lost are destined to become necrotic, even though cells may appear morphologically intact in the H&E preparations, and expression of GFAP and HSP-72 reflects astrocytic and neuronal viability, respectively.
Li
Y
Y
Department of Neurology, Henry Ford Hospital, Detroit, MI 48202, USA.
Chopp
M
M
Zhang
Z G
ZG
Zhang
R L
RL
D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D015415:Biomarkers; D001921:Brain / Q000473:pathology; D005786:Gene Expression Regulation; D005904:Glial Fibrillary Acidic Protein / Q000096:biosynthesis* / Q000235:genetics; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D002546:Ischemic Attack, Transient / Q000378:metabolism*; D008297:Male; D009336:Necrosis; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000378:metabolism
D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins