title: Islet amyloid polypeptide-induced membrane leakage involves uptake of lipids by forming amyloid fibers.
abstract: Fibril formation of islet amyloid polypeptide (IAPP) is associated with cell death of the insulin-producing pancreatic beta-cells in patients with Type 2 Diabetes Mellitus. A likely cause for the cytotoxicity of human IAPP is that it destroys the barrier properties of the cell membrane. Here, we show by fluorescence confocal microscopy on lipid vesicles that the process of hIAPP amyloid formation is accompanied by a loss of barrier function, whereby lipids are extracted from the membrane and taken up in the forming amyloid deposits. No membrane interaction was observed when preformed fibrils were used. It is proposed that lipid uptake from the cell membrane is responsible for amyloid-induced membrane damage and that this represents a general mechanism underlying the cytotoxicity of amyloid forming proteins.
authors.affiliation: Department Biochemistry of Membranes, Centre of Biomembranes and Lipid Enzymology, Institute of Biomembranes, Utrecht University, Padualaan 8, NL-3584 CH Utrecht, The Netherlands. emma.sparr@fkem1.lu.se
authors.forename: Emma
authors.initials: E
authors.lastname: Sparr
authors.forename: Maarten F M
authors.initials: MF
authors.lastname: Engel
authors.forename: Dmitri V
authors.initials: DV
authors.lastname: Sakharov
authors.forename: Mariette
authors.initials: M
authors.lastname: Sprong
authors.forename: Jet
authors.initials: J
authors.lastname: Jacobs
authors.forename: Ben
authors.initials: B
authors.lastname: de Kruijff
authors.forename: Jo W M
authors.initials: JW
authors.lastname: Höppener
authors.forename: J Antoinette
authors.initials: JA
authors.lastname: Killian
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000096:biosynthesis* / Q000502:physiology*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D005456:Fluorescent Dyes; D058228:Islet Amyloid Polypeptide; D050356:Lipid Metabolism; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D051381:Rats
chemical_list: D000682:Amyloid; D005456:Fluorescent Dyes; D058228:Islet Amyloid Polypeptide