ASTROCYTE AS THE KEY CELL IN THE PATHOGEN ESIS OF SPONGIFORM ENCEPHALOPATHY

Astrocyte is the major cell type in the central nervous system. This c ell assume numerous functions in the brain development, in the develop ment and the integrity of the blood-brain barrier, in the neuron-glie interaction and in the brain homeostasia. Spongiform encephalopathies are characterized by a major and early astrocyte reactivity with hyper trophy and hyperplasie of this very plastic cell. Binding of the Prion protein with the major component of the gliofilament (GFAP) could ide ntify the astrocyte as responsible for the conversion of the membranal protein in an abnormal protein. Moreover, astrocyte is able to accumu late this protein. The consequent gene alteration, implicate astrocyte in the amyloid formation, and in the neuronal lesions. This show that astrocyte try ro maintain an intact neuron-glie interaction. All thes e feature give to the astrocyte a key role in spongiform encephalopath ie pathogenesis.