P2‐060: DRUG SCREENING AGAINST Aβ42 OLIGOMERIZATION

Abstract

Aβ42 is a small pathogenic peptide associated with Alzheimer's disease, whereas its oligomeric forms were more toxic in nerve cells. Thioflavin T (ThT) assay could be used to test the Aβ42 oligomerization. However, ThT only bound to the beta sheet of Aβ42 fibrils, limiting the measurements of Aβ42 oligomers. Multimer detection system (MDS) was developed for detecting Aβ42 oligomers using antibodies that captures the overlapping epitope of Aβ42 and was applied to screen the inhibitory effect of drug on Aβ42 oligomerization. Monomeric Aβ42 (treated with HFIP) was mixed with the drug and incubated overnight for the Aβ42oligomerization. Afterwards, MDS was performed with samples by transferring them to the coated plate with Aβ42 antibody, followed by incubation. Only oligomeric forms of Aβ42 would be measured by HRP conjugated antibody which has competing affinity towards the overlapping epitope of the coated antibody. The result of measuring Aβ42 oligomer MDS method revealed gradually increases of oligomers overtime. However, after long periods of incubation the signal decreased, which would be due to the fibrilization. Several drugs were revealed the decreases in Aβ42 oligomerization with increasing drug concentrations. Several drug candidates could inhibit Aβ42 oligomerization with MDS method, revealing its capacity towards the high-throughput screening. Since Aβ42 oligomers would have toxicity to cells, screened drugs by MDS could be selected more accurately as leads in developing therapeutics against Alzheimer's disease. In addition, the MDS drug screening method could shorten the time by eliminating ineffective drug candidates during the early stage of screening.