Upregulation of Annexin A1 in Reactive Astrocytes and Its Subtle Induction in Microglia at the Boundaries of Human Brain Infarcts.
Annexin A1 (ANXA1) has multiple functions, including anti-inflammatory effects, and is thought to be neuroprotective in various pathophysiologies of the central nervous system. The importance of ANXA1 in microglia and endothelial cells in ischemic environments in the brain has been recognized, but its detailed behavior in astrocytes in the ischemic brain remains unknown. Using immunohistochemistry, we therefore assessed the altered distribution of ANXA1 in human brain infarcts using 14 autopsied samples and 18 surgical samples. Elevated expression of ANXA1 was observed in reactive astrocytes in peri-infarct regions. ANXA1 accumulated at the cell periphery and in swollen cytoplasmic processes of reactive astrocytes, as well as at the rim of vacuoles at the boundary of necrosis, and colocalized with aberrantly distributed aquaporin 4 and excitatory amino acid transporter 1. Foamy macrophages in the necrotic core also expressed abundant ANXA1, whereas resident microglia at the boundary of necrosis rarely showed intrinsic expression of ANXA1. This characteristic distribution of ANXA1 in human brain infarcts may represent the good adaptability of reactive astrocytes to ischemic damage.
['Shijo|Masahiro|M|', 'Hamasaki|Hideomi|H|', 'Honda|Hiroyuki|H|', 'Suzuki|Satoshi O|SO|', 'Tachibana|Masaki|M|', 'Ago|Tetsuro|T|', 'Kitazono|Takanari|T|', 'Iihara|Koji|K|', 'Iwaki|Toru|T|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D017305:Annexin A1 D051401:Aquaporin 4 D001253:Astrocytes D001921:Brain D020520:Brain Infarction D027341:Excitatory Amino Acid Transporter 1 D005260:Female D006801:Humans D008297:Male D017628:Microglia D008875:Middle Aged D015854:Up-Regulation D055815:Young Adult
Annexin A1 Astrocytes Brain infarct