The lipid peroxidation products 4-oxo-2-nonenal and 4-hydroxy-2-nonenal promote the formation of α-synuclein oligomers with distinct biochemical, morphological, and functional properties

• Oxidative stress has been implicated in the etiology of neurodegenerative disorders with alpha-synuclein pathology. Lipid peroxidation products such as 4-oxo-2-nonenal (ONE) and 4-hydroxy-2-nonenal (HNE) can covalently modify and structurally alter proteins. Herein, we have characterized ONE- or HNE-induced alpha-synuclein oligomers. Our results demonstrate that both oligomers are rich in beta-sheet structure and have a molecular weight of about 2000 kDa. Atomic force microscopy analysis revealed that ONE-induced alpha-synuclein oligomers were relatively amorphous, with a diameter of 40-80 nm and a height of 4-8 nm. In contrast, the HNE-induced alpha-synuclein oligomers had a protofibril-like morphology with a width of 100-200 nm and a height of 2-4 nm. Furthermore, neither oligomer type polymerized into amyloid-like fibrils despite prolonged incubation. Although more SDS and urea stable, because of a higher degree of cross-linking, ONE-induced alpha-synuclein oligomers were less compact and more sensitive to proteinase K treatment. Finally, both ONE- and HNE-induced alpha-synuclein oligomers were cytotoxic when added exogenously to a neuroblastoma cell line, but HNE-induced alpha-synuclein oligomers were taken up by the cells to a significantly higher degree. Despite nearly identical chemical structures, ONE and HNE induce the formation of off-pathway alpha-synuclein oligomers with distinct biochemical, morphological, and functional properties.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Materialteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Materials Engineering (hsv//eng)

Nyckelord

alpha-Synuclein

Oligomers

Lewy bodies

Lipid peroxidation

4-Oxo-2-nonenal

Oxidative stress

4-Hydroxy-2-nonenal

Free radicals

MEDICINE

MEDICIN

Teknisk fysik med inriktning mot mikrosystemteknik

Engineering Science with specialization in Microsystems Technology

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