NR AXJU
AU Brouckova,A.; Holada,K.
TI Platelet Activation Leads to Increase of PrPc Associated with Cytoskeleton and Membrane Rafts
QU International Conference - Prion 2007 (26.-28.9.2007) Edinburgh International Conference Centre, Edinburgh, Scotland, UK - Book of Abstracts: Pathology and Pathogenesis P03.20
IA http://www.prion2007.com/pdf/Prion Book of Abstracts.pdf
PT Konferenz-Poster
AB Four cases of blood transmitted vCJD have been reported recently. Most PrPc in human blood cells resides in platelets. It raises the question about their involvement in propagation of prions in blood. Membrane rafts were suggested to be the site of PrPc transformation to PrPsc. In platelets, membrane rafts have been shown to participate in signaling events. It was also proved that interaction between rafts and actin cytoskeleton takes place in process of platelet activation. This complex event seems to help regulate processes in platelets through reorganization of protein localization. First aim of our study was to follow PrPc association with cytoskeleton, which was isolated as a low speed pellet from Triton X-100 lysed human platelets. Upon platelet activation significant part of PrPc shifted to the cytoskeleton fraction, while distribution of control proteins CD36 and CD62 was not affected. In second part, PrPc association with raft microdomains was studied. Membrane rafts were isolated by density gradient centrifugation after extraction with detergent Igepal CA-630 or Triton X-100. In intact platelets as well as in isolated platelet cytoplasmic membranes only minority of PrPc was detected in membrane rafts. Platelet activation led to increase of raft associated PrPc in isolated membranes. This increase was not caused by cytoskeleton mediated reorganization of PrPc localization as no actin was detected in raft fractions. Distribution of raft marker CD36 in membrane rafts was similar in resting and activated platelets, suggesting that PrPc resides in different raft domains. In the present study we have shown, that platelet activation leads to increase of PrPc association both with actin cytoskeleton and membrane rafts. The role of raft associated PrPc in platelets in the interaction with prions in blood remains to be elucidated.
AD A. Brouckova, K. Holada, 1st Faculty of Medicine, Charles University, Czech Republic
SP englisch
PO Schottland