Nestin and small heat shock protein expression on reactive astrocytes and endothelial cells in cerebral abscess.

Cerebral abscess results in an extensive capsular formation, which is an important limiting barrier for the spread of microorganism. Reactive astrocytes and endothelial cells are major cellular components of the abscess capsule together with fibrocytes. Molecular pathogenesis that results in the migration and proliferation of these cells remain speculative. Intermediate filament (IF) nestin and small heat shock proteins (sHSP) are developmentally regulated protein. In this study, we found that nestin expression is re-induced in not only reactive astrocytes, but also in endothelial cells in the gliotic area of the capsule. These nestin expressing astrocytes and endothelial cells also expressed sHSPs, such as heat shock protein 27 (HSP27) and alphaB-crystalline. These results indicated that embryonic reversions of cytoskeletal proteins to nestin and the increased expression of sHSPs in in reactive astrocytes and endothelial cells are caused by pathogenic microorganism induced inflammatory stress.