(191dn) Maximizing P-Glycoprotein Expression and Transport in the Presence of Therapeutic Compounds
It has been recently discovered that the presence of certain forms of AÎ² in the cells of the BBB can reduce P-gp levels through the ubiquitin-proteasome degradation pathway. These findings identify P-gp as a novel therapeutic target for AD. This study seeks to identify therapeutic compounds that will increase the expression levels of P-gp at the blood-brain barrier in order to mitigate the accumulation of AÎ² by allowing for increased clearance of AÎ² from the brain.
Madin-Darby Canine Kidney (MDCK) epithelial cells continuously express the multidrug resistance 1 (MDR1) gene responsible for the presence of P-gp. Cells were treated with three prospective therapeutic compounds: verapamil, caffeine, and rifampicin. Verapamil is a known P-gp substrate recently suggested to up-regulate P-gp expression and has exhibited a neuroprotective effect on AD model rats. Rifampicin, an antibiotic used to treat tuberculosis and leprosy, and caffeine have been shown in epidemiological studies to reduce dementia symptoms.Â Following treatment, alteration of P-gp expression was determined using fluorescent microscopy to visualize cell membrane location of P-gp and SDS-PAGE with Western blotting to quantify P-gp expression. A cell transport assay was used to quantify the transport of AÎ² the treated MDCK cells. Results supporting increased P-gp expression and AÎ² transport highlight the prospective therapeutic potential of these compounds.