Identification of novel Aβ-LilrB2 inhibitors as potential therapeutic agents for Alzheimer's disease

LilrB2 is an Aβ receptor with high affinity, which not only contributes to memory deficits but also mediates the loss of synaptic plasticity. Thus, Aβ-LilrB2 interaction inhibitors (ALIs) might be a potential therapeutic strategy for Alzheimer's disease. In this study, an ELISA-based interaction assay was established as a novel approach to identify ALIs and was used to screen 110 compounds from a compound library. Among the 110 compounds, four compounds presented IC50 values lower than the positive control flusipirilene. The two phenyl-1,3,5-triazine derivatives (compound 103 and 104) displayed inhibitory activities with the IC50 of 0.23 μM and 0.05 μM respectively. The neuroprotection activities of the hit compounds were evaluated in SH-SY5Y cell line. Compound 104 presented good safety and neuroprotective effects against Aβ. Further study of its effect on the downstream pathway of Aβ indicated that compound 104 was able to reverse the Aβ induced cofilin dephosphorylation, tau hyperphosphorylation and neurite outgrowth inhibition. The docking study showed that fluspirilene and compound 104 were favorably positioned into the Ben 3 and 4 binding pockets via their aromatic ring, which was similar to that reported for Aβ. Based on these facts, compound 104 can be identified as a potential ALI which might be of therapeutic importance for AD treatment.