| Cellular prion protein (PrPc) is a GPI-anchored protein, of unknown function, found in a various cell types throughout the body. It is now widely believed that a misfolded, protease resistant form of this protein is responsible for a group of fatal neurodegenerative diseases called transmissible spongiform encephalopathies (TSE), including Creutzfeldt-Jakob disease (CJD) and kuru in humans, scrapie in sheep, chronic wasting disease (CWD) in deer and elk and bovine spongiform encephalopathy (BSE) in cattle. Although the exact function of PrPc is unknown it binds copper and has been implicated in copper homeostasis, signal transduction and cell adhesion.; The pathogenesis of prion diseases is poorly understood, however the expression of PrPc in target cells is an absolute requirement for disease progression. Platelets have been shown to be the largest reservoir of PrPc in peripheral blood cells and studies in animal models have suggested platelets may also be involved in TSE infectivity.; In this study, we determine the exact location of PrPc within human platelets, examine the mobilization and release of PrPc from activated platelets on both microvesicles and exosomes and suggest a possible role for platelets in prion infectivity. In addition we examine the role of PrPc within normal platelet functions including aggregation, signal transduction and adhesion. |
