Takeshi Kihara (1), Shun Shimohama (1,*) and Akinori Akaike (2)
(1) Department of Neurology, Graduate School of Medicine, Kyoto University,
Kyoto 606-8507, Japan
(2) Department of Pharmacology, Graduate School of Pharmaceutical Sciences,
Kyoto University, Kyoto 606-8501, Japan
(*) To whom correspondence should be addressed.
Abstract: Previously we demonstrated that nicotinic acetylcholine
receptor stimulation protects neurons against beta-amyloid (Abeta)-induced
cytotoxicity. In the present study, the effects of nicotinic receptor agonists
on the beta-sheet formation were investigated using a thioflavin T (ThT)-based
fluorescence assay. Nicotine, cytisine (an alpha4beta2 agonist), and 3-(2,4)-dimethoxybenzylidene
anabaseine (DMXB, an alpha7 agonist) did not reduce fluorescence intensity
when these agents were added to the beta-sheet-formed Abeta. Simultaneous
incubation of Abeta with nicotinic agonists also did not cause a reduction
in fluorescence intensity. This data suggests that nicotinic receptor agonists
do not influence the formation of the beta-sheet structure.
Keywords: Beta-amyloid, Beta-sheet, Nicotine