ASTROGLIAL EXPRESSION OF ATL-DERIVED FACTOR, A HUMAN THIOREDOXIN HOMOLOG, IN THE GERBIL BRAIN AFTER TRANSIENT GLOBAL-ISCHEMIA

Distribution of adult T cell leukemia derived factor (ADF/TRX), a huma n thioredoxin homologue, was studied by immunohistochemistry in gerbil brain during reperfusion after transient cerebral ischemia. In contro l brains, immunoreactivity was observed widely in the central nervous system, including the ependyma, tanycytes, endothelial cells as well a s subcommisural organs, and weakly in the neuronal cell bodies. During reperfusion, ADF/TRX was expressed in glial cells in the CA1 and dent ate hilus of the hippocampus, and in a few cases in the lateral portio n of the caudateputamen. ADF/TRX positive glias first appeared after r eperfusion for 24 h, and the intensity of staining peaked at 72 h and diminished after 7 days of reperfusion. They were concentrated around microvessels and identified to be astroglia by double labeling immunoh istochemistry with glial fibrillary acidic protein as marker. Immunobl otting analysis demonstrated an increase of ADF/TRX in the postischemi c hippocampus. Astroglial expression of ADF/TRX in postischemic injuri es suggests a role in neuroprotection by hydrogen peroxide reducing an d protein-refolding activities or in modulation of local immune respon ses.