Identifying GSK-3β kinase inhibitors of Alzheimer's disease: Virtual screening, enzyme, and cell assays

• DOI: 10.1016/j.ejps.2016.04.012
• Publication Date: 2016-04-14T06:47:45Z
• Authors: Chih-Hsin Lin; Yu-Shao Hsieh; Yih-Ru Wu; Chia-Jen Hsu; Hsuan-Chiang Chen; Wun-Han Huang; Kuo-Hsuan Chang; Hsiu Mei Hsieh-Li; Ming-Tsan Su; Ying-Chieh Sun; Guan-Chiun Lee; Guey-Jen Lee-Chen
• Keywords: 0301 basic medicine; Glycogen Synthase Kinase 3 beta; tau Proteins; Cell Line; 3. Good health; 03 medical and health sciences; HEK293 Cells; Alzheimer Disease; Neurites; Humans; Enzyme Inhibitors; Phosphorylation; Endoplasmic Reticulum Chaperone BiP

Glycogen synthase kinase 3β (GSK-3β) is widely known as a critical target protein for treating Alzheimer's disease (AD). We utilized virtual screening to search databases for compounds with the potential to be used in drugs targeting GSK-3β kinase, and kinase as well as cell assays to investigate top-scored, selected compounds. Virtual screening of >1.1 million compounds in the ZINC and in-house databases was conducted using an optimized computational protocol in the docking program GOLD. Of the top-ranked compounds, 16 underwent a luminescent kinase assay and a cell assay using HEK293 cells expressing DsRed-tagged ΔK280 in the repeat domain of tau (tauRD). The compounds VB-003 (a potent GSK-3β inhibitor) and VB-008 (AM404, an anandamide transport inhibitor), with determined IC50 values of 0.25 and 5.4μM, respectively, were identified as reducing tau aggregation. Both compounds increased expression of phospho-GSK-3β (Ser9) and reduced endogenous tau phosphorylation at the sites of Ser202, Thr231, and Ser396. In the ∆K280 tauRD-DsRed SH-SY5Y cells, VB-008, but not VB-003, enhanced HSPB1 and GRP78 expression, increased ∆K280 tauRD-DsRed solubility, and promoted neurite outgrowth. Thus VB-008 performed best to the end of the present study. The identified compound VB-008 may guide the identification and synthesis of potential inhibitors analogous to this compound.