title: Proteomic identification of an upregulated isoform of annexin A3 in the rat brain following reversible cerebral ischemia.
abstract: We used proteomics to identify regulated proteins following cerebral ischemia in a rat model. Young rats were subjected to reversible middle cerebral artery (MCA) occlusion and proteins were extracted from the peri-infarcted and the corresponding contralateral area at days 3 and 14 postischemia. Proteins were analyzed by two-dimensional polyacrylamide gel electrophoresis followed by mass spectrometry. We report for the first time that an isoform of annexin A3 (ANXA3) was among the upregulated proteins in the postischemic rat brain. The results were confirmed by real-time PCR and by western blotting. Double- and triple-immunostaining with neuronal and microglia/macrophagic markers demonstrated that ANXA3 is produced by resting microglia in control tissue and by activated microglial/macrophage cells in the infarcted area. 3D-images of the infarcted area suggest that ANXA3 is associated with a phagocytic phenotype. Our study identifies ANXA3 as a novel marker of brain microglia, which should be of substantial value in future studies of microglial cells and its role in the postischemic brain.
authors.affiliation: Molecular Neurobiology Laboratory, Clinic of Neurology, Ernst-Moritz-Arndt-University, Greifswald, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Junker
authors.forename: Yalikun
authors.initials: Y
authors.lastname: Suofu
authors.forename: Simone
authors.initials: S
authors.lastname: Venz
authors.forename: Magdalena
authors.initials: M
authors.lastname: Sascau
authors.forename: James G
authors.initials: JG
authors.lastname: Herndon
authors.forename: Christof
authors.initials: C
authors.lastname: Kessler
authors.forename: Reinhard
authors.initials: R
authors.lastname: Walther
authors.forename: Aurel
authors.initials: A
authors.lastname: Popa-Wagner
mesh_terms: D000818:Animals; D017318:Annexin A3 / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism*; D002545:Brain Ischemia / Q000378:metabolism*; D003199:Computer Systems; D015180:Electrophoresis, Gel, Two-Dimensional; D007150:Immunohistochemistry; D008297:Male; D013058:Mass Spectrometry; D017628:Microglia / Q000378:metabolism; D016133:Polymerase Chain Reaction; D020033:Protein Isoforms / Q000378:metabolism; D040901:Proteomics; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation