Cellular expression of tumor necrosis factor a and its receptors in human ischemic stroke.
We evaluated by immunocytochemistry cellular localization and time-dependent expression of tumor necrosis factor a (TNF-alpha) and its receptors p55 (TNF-RI) and p75 (TNF-R2) in human ischemic brains. We observed them in microglia, neurons, astrocytes, macrophages and blood vessels. Since TNF-alpha expression was very intense and prolonged in microglia, it probably constitutes the main cellular source of the cytokine following cerebral ischemia in humans. Constitutive expression of TNF-alpha receptors was observed in neurons and blood vessels while in other cells it was induced by ischemia. In macrophages, dominant immunolabeling for TNF-R2 was seen. In other cells, immunoreactions for both types of TNF-alpha receptors were similar but the pattern of immunostaining was different: homogenous for TNF-R1 and granular for TNF-R2. Beneficial and detrimental role of TNF-alpha in cerebral ischemia and supposed mechanisms of action are discussed.
Dziewulska
D
D
Department of Neurology, Medical University of Warsaw, Poland. ddziewul@amwaw.edu.pl
Mossakowski
M J
MJ
D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000032:analysis*; D000970:Antineoplastic Agents / Q000032:analysis*; D001921:Brain / Q000098:blood supply / Q000473:pathology; D002545:Brain Ischemia / Q000150:complications* / Q000473:pathology*; D005260:Female; D006801:Humans; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009457:Neuroglia / Q000473:pathology; D009474:Neurons / Q000473:pathology; D018124:Receptors, Tumor Necrosis Factor / Q000032:analysis*; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D020521:Stroke / Q000209:etiology* / Q000473:pathology*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis*
D015703:Antigens, CD; D000970:Antineoplastic Agents; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D047889:Receptors, Tumor Necrosis Factor, Type II; D014409:Tumor Necrosis Factor-alpha