Biomarkers of glial cell proliferation and differentiation in culture.

The two major intermediate filament (IF) proteins of astrocytes are vimentin and GFAP. Early during development, radial glia and immature astrocytes express mainly vimentin. Towards the end of gestation, a switch occurs whereby vimentin is progressively replaced by GFAP in differentiated astroglial cells. The expression of vimentin and GFAP increased markedly after injury to CNS. GFAP has been widely recognized as an astrocyte differentiation marker, constituting the major IF protein of mature astrocyte. In our recent researches we investigated the interactions between growth factors and dexamethasone on cytoskeletal proteins GFAP and vimentin expression under different experimental conditions. In addition, nestin, a currently used marker of neural stem cells, is transiently co-expressed with GFAP during development and is induced in reactive astrocytes following brain injury. The role of S100B in astrocytes, neurons, and microglia is particularly studied in Alzheimer's disease. In conclusion, such glial biomarkers will help us to understand the more general mechanisms involved in CNS development and can open new perspectives for the control of the neurologic diseases.