Liang Sun, Hong-Jun Cho, Soumyo Sen, Andres S. Arango, Truc T. Huynh, Yiran
Huang, Nilantha Bandara, Buck E. Rogers, Emad Tajkhorshid, and Liviu M.
Mirica.
Amphiphilic distyrylbenzene derivatives as potential therapeutic and
imaging agents for the soluble amyloid-β oligomers in alzheimer's
disease.
Journal of the American Chemical Society, 143:10462-10476,
2021.
(PMC: PMC8762579)
SUN2021-ET
Alzheimer's Diseases (AD) is the most common neurodegenerative
disease, but efficient therapeutic and early diagnosis agents for
this neurological disorder are still lacking. Herein, we report
the development of a novel amphiphilic compound, LS-4, generated
linking a hydrophobic amyloid fibril-binding fragment with a
hydrophilic azamacrocycle that can dramatically increase the
binding affinity towards various amyloid (A) peptide
aggregates. The developed compound exhibits uncommon fluorescence
turn-on and high binding affinity for A aggregates,
especially for soluble A oligomers. Moreover, upon the
administration of LS-4 to 5xFAD mice, fluorescence imaging of the
LS-4-treated brain sections reveals that LS-4 can readily
penetrate the blood-brain-barrier (BBB) and bind to the A
oligomers in vivo, as confirmed by immunostaining with an A
oligomer-specific antibody. In addition, the treatment of 5xFAD
mice with LS-4 significantly reduces the amount of both amyloid
plaques and associated phosphorylated tau (p-tau) aggregates vs.
the vehicle-treated 5xFAD mice, while microglia activation is also
reduced. Furthermore, molecular dynamics simulations corroborate
the observation that introducing a hydrophilic moiety into the
molecular structure can significantly enhance the electrostatic
interactions with the polar residues of the A peptide
species. Finally, taking advantage of the strong Cu-chelating
property of the azamacrocycle, we performed a series of
radioimaging and biodistribution studies that show the 64Cu-LS-4
complex binds to the amyloid plaques and can accumulate a
significantly larger extent in the 5xFAD mice brains vs. the WT
controls. Overall, these in vitro and in vivo studies illustrate
that the novel strategy to employ an amphiphilic molecule
containing a hydrophilic fragment attached to a hydrophobic
amyloid fibril-binding fragment can increase the binding affinity
of these compounds for the soluble A oligomers and can thus
be used to detect and regulate the soluble A species in AD.