Exposure of proteins to oxidants leads to increased oxidation followed by p
referential degradation by the proteasomal system. The role of the biologic
al oxidant production in microglial BV-2 cells in the oxidation and turnove
r of endogenous proteins was measured. It could be demonstrated, that BV-2
cells are relatively resistant to fluxes of oxidants, but nevertheless prot
ein oxidation occurs due to activation by LPS, This protein oxidation is fo
llowed by an enhanced degradation of endogenous proteins. Using PEN, a free
radical scavenger and antioxidant, we could demonstrate the involvement of
free radicals in the increased proteolysis in BV-2 cells after LPS-treatme
nt, ii slight but significant up-regulation of the proteasomal system after
LPS activation takes place, indicating the importance of his proteolytic s
ystem in the maintenance of the protein pool of microglial cells.