Islet amyloid polypeptide-induced membrane leakage involves uptake of lipids by forming amyloid fibers.
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.
Sparr
Emma
E
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
Engel
Maarten F M
MF
Sakharov
Dmitri V
DV
Sprong
Mariette
M
Jacobs
Jet
J
de Kruijff
Ben
B
Höppener
Jo W M
JW
Killian
J Antoinette
JA
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
D000682:Amyloid; D005456:Fluorescent Dyes; D058228:Islet Amyloid Polypeptide