title: Cholesterol balance in prion diseases and Alzheimer's disease.
abstract: Prion diseases are transmissible and fatal neurodegenerative disorders of humans and animals. They are characterized by the accumulation of PrPSc, an aberrantly folded isoform of the cellular prion protein PrPC, in the brains of affected individuals. PrPC is a cell surface glycoprotein attached to the outer leaflet of the plasma membrane by a glycosyl-phosphatidyl-inositol (GPI) anchor. Specifically, it is associated with lipid rafts, membrane microdomains enriched in cholesterol and sphinoglipids. It has been established that inhibition of endogenous cholesterol synthesis disturbs lipid raft association of PrPC and prevents PrPSc accumulation in neuronal cells. Additionally, prion conversion is reduced upon interference with cellular cholesterol uptake, endosomal export, or complexation at the plasma membrane. Altogether, these results demonstrate on the one hand the importance of cholesterol for prion propagation. On the other hand, growing evidence suggests that prion infection modulates neuronal cholesterol metabolism. Similar results were reported in Alzheimer's disease (AD): whereas amyloid β peptide formation is influenced by cellular cholesterol, levels of cholesterol in the brains of affected individuals increase during the clinical course of the disease. In this review, we summarize commonalities of alterations in cholesterol homeostasis and discuss consequences for neuronal function and therapy of prion diseases and AD.
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, and Hotchkiss Brain Institute, University of Calgary, 3280 Hospital Drive Northwest, Calgary, AB T2N 4Z6, Canada. shannaou@ucalgary.ca.
authors.forename: Samia
authors.initials: S
authors.lastname: Hannaoui
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, and Hotchkiss Brain Institute, University of Calgary, 3280 Hospital Drive Northwest, Calgary, AB T2N 4Z6, Canada. syshim@ucalgary.ca.
authors.forename: Su Yeon
authors.initials: SY
authors.lastname: Shim
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, and Hotchkiss Brain Institute, University of Calgary, 3280 Hospital Drive Northwest, Calgary, AB T2N 4Z6, Canada. ycchen@ucalgary.ca.
authors.forename: Yo Ching
authors.initials: YC
authors.lastname: Cheng
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, and Hotchkiss Brain Institute, University of Calgary, 3280 Hospital Drive Northwest, Calgary, AB T2N 4Z6, Canada. ecorda@ucalgary.ca.
authors.forename: Erica
authors.initials: E
authors.lastname: Corda
authors.affiliation: Department of Ecosystem and Public Health, Faculty of Veterinary Medicine, and Hotchkiss Brain Institute, University of Calgary, 3280 Hospital Drive Northwest, Calgary, AB T2N 4Z6, Canada. sgilch@ucalgary.ca.
authors.forename: Sabine
authors.initials: S
authors.lastname: Gilch
mesh_terms: D000544:Alzheimer Disease / Q000473:pathology / Q000503:physiopathology*; D016229:Amyloid beta-Peptides / Q000378:metabolism; D001921:Brain / Q000473:pathology; D002784:Cholesterol / Q000378:metabolism*; D006801:Humans; D017096:Prion Diseases / Q000473:pathology / Q000503:physiopathology*; D011328:Prions / Q000378:metabolism; D017510:Protein Folding
chemical_list: D016229:Amyloid beta-Peptides; D011328:Prions; D002784:Cholesterol