Interrelations between nuclear-factor kappa B activation, glial response and neuronal apoptosis in gerbil hippocampus after ischemia.
Spatial and temporal relations between transcriptional factor NF kappa B activation and glia reaction in gerbil hippocampus after transient cerebral ischemia has been studied. Activation of protein binding to NF kappa B consensus oligonucleotide was determined by electrophoretic mobility gel shift assay (EMSA) in homogenates from dorsal (DP- an equivalent of CA1 sector) and abdominal (AbP- containing CA2-4 and gyrus dentatus) parts of hippocampus. A significant activation of NF kappa B binding was observed exclusively in DP as early as 3 h after ischemia and at this time that response preceded any other morphological signs of postischemic tissue injury. This early enhancement of NF kappa B binding was followed by microglia activation visualized in CA1 pyramidal region at 24 h of recovery by histochemical staining with lectin from Ricinus communis (RCA-120). Simultaneously, only a moderate increase of immunostaining against glial fibrillary acidic protein (GFAP) was observed homogeneously in all parts of hippocampus. This uniform pattern of astrogliosis was preserved until postischemic day 3-4, when apoptotic DNA fragmentation in CA1 pyramidal neurons had been clearly documented by TUNEL staining. At this period however, continuous elevation of NF kappa B binding in DP corresponded with similar response manifested also in AbP of the hippocampus. These results evidence a preferential NF kappa B involvement in an early microglia activation in the apoptogenic CA1 sector, although its role in a later astrocytic response to ischemia could not be neglected too.
Domańska-Janik
K
K
Laboratory of Molecular Neuropathology, Medical Research Centre, Polish Academy of Sciences, 5 Pawiński St., 02-106 Warsaw, Poland. kd-j@cmdik.pan.pl.
Bronisz-Kowalczyk
A
A
Zajac
H
H
Zabłocka
B
B
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002545:Brain Ischemia / Q000378:metabolism* / Q000473:pathology; D005849:Gerbillinae; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000502:physiology*; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D016328:NF-kappa B / Q000378:metabolism*; D009457:Neuroglia / Q000502:physiology*; D009474:Neurons / Q000502:physiology*
D005904:Glial Fibrillary Acidic Protein; D016328:NF-kappa B