datasheet1_The Selective SIK2 Inhibitor ARN-3236 Produces Strong Antidepressant-Like Efficacy in Mice via the Hippocampal CRTC1-CREB-BDNF Pathway.docx

Depression is a widespread chronic medical illness affecting thoughts, mood, and physical health. However, the limited and delayed therapeutic efficacy of monoaminergic drugs has led to intensive research efforts to develop novel antidepressants. ARN-3236 is the first potent and selective inhibitor of salt-inducible kinase 2 (SIK2). In this study, a multidisciplinary approach was used to explore the antidepressant-like actions of ARN-3236 in mice. Chronic social defeat stress (CSDS) and chronic unpredictable mild stress (CUMS) models of depression, various behavioral tests, high performance liquid chromatography-tandem mass spectrometry, stereotactic infusion, viral-mediated gene transfer, western blotting, co-immunoprecipitation and immunofluorescence were used together. It was found that ARN-3236 could penetrate the blood-brain barrier. Repeated ARN-3236 administration induced significant antidepressant-like effects in both the CSDS and CUMS models of depression, accompanied with fully preventing the stress-enhanced SIK2 expression and cytoplasmic translocation of cyclic adenosine monophosphate response element binding protein (CREB)-regulated transcription coactivator 1 (CRTC1) in the hippocampus. ARN-3236 treatment also completely reversed the down-regulating effects of CSDS and CUMS on the hippocampal brain-derived neurotrophic factor (BDNF) system and neurogenesis. Moreover, we demonstrated that the hippocampal CRTC1-CREB-BDNF pathway mediated the antidepressant-like efficacy of ARN-3236. Collectively, ARN-3236 possesses strong protecting effects against chronic stress, and could be a novel antidepressant beyond monoaminergic drugs.

抑郁症是一种广泛流行的慢性疾病，可影响个体的思维、情绪与躯体健康。然而单胺类药物的治疗效果有限且起效迟缓，促使学界大力开展新型抗抑郁药物的研发工作。ARN-3236是首个强效且选择性的盐诱导激酶2（salt-inducible kinase 2, SIK2）抑制剂。本研究采用多学科手段，探究ARN-3236在小鼠体内的类抗抑郁作用。实验联合使用了慢性社会挫败应激（chronic social defeat stress, CSDS）、慢性不可预知温和应激（chronic unpredictable mild stress, CUMS）两种抑郁模型，结合多种行为学测试、高效液相色谱-串联质谱、立体定位注射、病毒介导基因转染、蛋白质印迹法、免疫共沉淀以及免疫荧光技术。研究发现，ARN-3236可穿透血脑屏障。反复给予ARN-3236可在CSDS及CUMS两种抑郁模型中产生显著的类抗抑郁效应，同时可完全阻断应激诱导的海马内SIK2表达上调以及环腺苷酸应答元件结合蛋白（cyclic adenosine monophosphate response element binding protein, CREB）调控转录辅激活因子1（cyclic adenosine monophosphate response element binding protein-regulated transcription coactivator 1, CRTC1）的胞质转位。ARN-3236治疗还可完全逆转CSDS与CUMS对海马脑源性神经营养因子（brain-derived neurotrophic factor, BDNF）系统及神经发生的下调作用。此外，本研究证实海马内CRTC1-CREB-BDNF通路介导了ARN-3236的抗抑郁功效。综上，ARN-3236对慢性应激具有强效保护作用，有望成为一类超越单胺类药物的新型抗抑郁候选药物。