Memantine inhibits β-amyloid aggregation and disassembles preformed β-amyloid aggregates

Area of Science:

• Neuroscience
• Pharmacology
• Biochemistry

Background:

• Memantine is a medication for Alzheimer's disease (AD).
• Previous studies showed memantine reduces amyloid-beta (Aβ) in AD animal models.
• The exact mechanisms of memantine's effect on Aβ are not fully understood.

Purpose of the Study:

• To investigate the mechanisms by which memantine reduces Aβ levels in the brain.
• To evaluate the effect of memantine on Aβ aggregation and disaggregation.

Main Methods:

• Used thioflavin T assay and transmission electron microscopy to study Aβ aggregation.
• Tested the effect of memantine and amantadine on Aβ(1-42) aggregation.
• Investigated memantine's effect on preformed Aβ fibrils and familial AD mutation-carrying Aβs.

Main Results:

• Memantine inhibited the formation of Aβ(1-42) aggregates in a concentration-dependent manner.
• Amantadine, a similar compound, did not inhibit Aβ aggregation.
• Memantine also inhibited the formation of various Aβ aggregates and disaggregated preformed Aβ fibrils.

Conclusions:

• Memantine directly inhibits Aβ aggregation.
• Memantine can disaggregate preformed Aβ fibrils.
• Inhibition of Aβ aggregation and induction of Aβ disaggregation are potential mechanisms for memantine's therapeutic effects in Alzheimer's disease.