Abstract

Glycogen synthase kinase 3β (GSK-3β) catalyses the hyperphosphorylation of tau protein in the Alzheimer’s disease (AD) pathology. A series of novel thieno[3,2-c]pyrazol-3-amine derivatives were designed and synthesised and evaluated as potential GSK-3β inhibitors by structure-guided drug rational design approach. The thieno[3,2-c]pyrazol-3-amine derivative 16b was identified as a potent GSK-3β inhibitor with an IC₅₀ of 3.1 nM in vitro and showed accepted kinase selectivity. In cell levels, 16b showed no toxicity on the viability of SH-SY5Y cells at the concentration up to 50 μM and targeted GSK-3β with the increased phosphorylated GSK-3β at Ser9. Western blot analysis indicated that 16b decreased the phosphorylated tau at Ser396 in a dose-dependent way. Moreover, 16b effectively increased expressions of β-catenin as well as the GAP43, N-myc, and MAP-2, and promoted the differentiated neuronal neurite outgrowth. Therefore, the thieno[3,2-c]pyrazol-3-amine derivative 16b could serve as a promising GSK-3β inhibitor for the treatment of AD.

摘要

糖原合酶激酶 3β (GSK-3β) 在阿尔茨海默病 (AD) 病理学中催化 tau 蛋白的过度磷酸化。设计并合成了一系列新型噻吩并[3,2 - c ]吡唑-3-胺衍生物，并通过结构指导的药物合理设计方法评估其作为潜在的GSK-3β抑制剂。噻吩并[3,2 - c ]吡唑-3-胺衍生物16b被鉴定为有效的GSK-3β抑制剂，体外IC ₅₀为3.1 nM ，并显示出可接受的激酶选择性。在细胞水平上，16b在高达 50 μM 的浓度下对 SH-SY5Y 细胞的活力没有显示毒性，并且靶向 GSK-3β，在 Ser9 处磷酸化 GSK-3β 增加。蛋白质印迹分析表明，16b以剂量依赖性方式降低了 Ser396 位点的磷酸化 tau。此外，16b有效增加 β-catenin 以及 GAP43、N-myc 和 MAP-2 的表达，并促进分化的神经元神经突生长。因此，噻吩并[3,2 - c ]吡唑-3-胺衍生物16b可作为治疗AD的有前景的GSK-3β抑制剂。