Discovery of Isobenzofuran-1(3H)‑one Derivatives as Selective TREK‑1 Inhibitors with In Vitro and In Vivo Neuroprotective Effects

TREK-1 regulates neuronal excitability and neuronal cell apoptosis, and inhibition of TREK-1 is a potential strategy to prevent cell death and achieve neuroprotection in an ischemic stroke. In this work, a series of novel isobenzofuran-1(3H)-one derivatives were designed and synthesized as TREK-1 inhibitors, and extensive structure–activity relationships led to the discovery of potent and selective TREK-1 inhibitors having IC50 values of a low micromolar level. Among them, Cpd8l potently and selectively inhibited TREK-1 (IC50 = 0.81 μM, selectivity >30 fold over other K+, Na+, and TRP channels). Cpd8l remarkably reduced the neuron death in the OGD/R-induced cortical neuronal injury model, while adenovirus silencing TREK-1 reduced its neuroprotective effect. Furthermore, Cpd8l could effectively ameliorate brain injury in MCAO/R model mice. Collectively, this work demonstrates that Cpd8l may serve as a novel lead compound to develop a highly potent and selective TREK-1 inhibitor for ischemic stroke treatment.TREK-1可调控神经元兴奋性与神经元细胞凋亡，抑制TREK-1是预防缺血性脑卒中细胞死亡、实现神经保护的潜在策略。本研究设计并合成了一系列作为TREK-1抑制剂的新型异苯并呋喃-1(3H)-酮衍生物，通过深入的构效关系（structure–activity relationships）研究，筛选得到了强效且具有选择性的TREK-1抑制剂，其半数抑制浓度（IC50）处于低微摩尔级别。其中，Cpd8l可强效且选择性地抑制TREK-1（IC50=0.81 μM，对其他钾离子（K+）、钠离子（Na+）及瞬时受体电位通道（TRP channels）的选择性大于30倍）。Cpd8l可显著降低氧糖剥夺/复氧（OGD/R）诱导的皮层神经元损伤模型中的神经元死亡，而通过腺病毒（adenovirus）介导的TREK-1基因沉默则会削弱其神经保护作用。此外，Cpd8l可有效改善大脑中动脉阻塞/再灌注（MCAO/R）模型小鼠的脑损伤。综上，本研究表明，Cpd8l可作为新型先导化合物（lead compound），用于开发强效且具有选择性的TREK-1抑制剂以治疗缺血性脑卒中。