P-glycoprotein expression is increased in the brain of BSE affected cattle

P-glycoprotein (P-gp) plays a major role as an efflux pump for endogenous and exogenous substrates at the blood-brain barrier and is localized in the brain at the apical side of capillary endothelial cells. Bovine spongiform encephalopathy (BSE) is marked primarily by the build-up of protease resistant misfolded prion protein (PrPres) in the brain. In the present study, the relationship between P-gp and BSE was investigated. An increase in the expression of vascular P-gp in the obex was found inclassical BSE, more prominent in the pre-clinical cases. This up-regulation of P-gp in the early stages of the disease might be a protective regulatory mechanism to increase the clearance of the abnormal PrPres protein in an attempt to protect the brain from the accumulation of PrPres.