Annexin 7-immunoreactive microglia in the hippocampus of control and adrenalectomized rats.
Annexin 7 (ANX7), also termed synexin, is a member of the annexin family of calcium-binding proteins. In the present study, we examined the distribution and cellular localization of ANX7-immunoreactivity in the rat hippocampus and its response to adrenalectomy (ADX). ANX7 was co-localized with OX42 in microglia distributed throughout the hippocampus of both control and ADX animals. ANX7-immunoreactivity was not detected in GFAP-positive astrocytes or in hippocampal neurons. At 1-week and 4-weeks following ADX, we observed a population of large, ameboid, ANX7-immunopositive microglia ("reactive microglia") which were largely confined to the granule cell layer of the dentate gyrus throughout its rostrocaudal extent. No reactive microglia were present in the hippocampus of sham-ADX or ADX + corticosterone treated animals. In 4-weeks ADX animals but not 1-week ADX, ANX7-immunostaining was significantly increased in the mossy fiber layer of CA3, due to the presence of many small, dark-staining "activated microglia". Our results show that ANX7 is abundantly expressed in the rat hippocampus by different microglial forms (e.g., ramified, activated and reactive microglia), suggesting an important role for this calcium-binding protein in microglial Ca2+-dependent processes.
Moga
Margaret M
MM
Department Anatomy and Cell Biology, Indiana University School of Medicine, Terre Haute, IN 47809, USA. mmoga@medicine.indstate.edu
Dempah
Dominique
D
Zhou
Dan
D
D000315:Adrenalectomy; D000818:Animals; D017310:Annexin A7 / Q000378:metabolism*; D039481:CD11b Antigen / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology*; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D017628:Microglia / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D017310:Annexin A7; D039481:CD11b Antigen; D005904:Glial Fibrillary Acidic Protein