Abstract：
Salidroside, a principal bioactive component of Rhodiola crenulata, is neuroprotective across a wide time window in stroke models. We investigated whether salidroside induced neurogenesis after cerebral ischemia and aimed to identify its primary molecular targets. Rats, subjected to transient 2 h of middle cerebral artery occlusion (MCAO), received intraperitoneal vehicle or salidroside ± intracerebroventricular HSC70 inhibitor VER155008 or TrkB inhibitor ANA-12 for up to 7 days. MRI, behavioural tests, immunofluorescent staining and western blotting measured effects of salidroside. Reverse virtual docking and enzymatic assays assessed interaction of salidroside with purified recombinant HSC70. Salidroside dose-dependently decreased cerebral infarct volumes and neurological deficits, with maximal effects by 50 mg/kg/day. This dose also improved performance in beam balance and Morris water maze tests. Salidroside significantly increased BrdU+/nestin+, BrdU+/DCX+, BrdU+/NeuN+, BrdU-/NeuN+ and BDNF+ cells in the peri-infarct cortex, with less effect in striatum and no significant effect in the subventricular zone. Salidroside was predicted to bind with HSC70. Salidroside dose-dependently increased HSC70 ATPase and HSC70-dependent luciferase activities, but it did not activate HSP70. HSC70 immunoreactivity concentrated in the peri-infarct cortex and was unchanged by salidroside. However, VER155008 prevented salidroside-dependent increases of neurogenesis, BrdU-/NeuN+ cells and BDNF+ cells in peri-infarct cortex. Salidroside also increased BDNF protein and p-TrkB/TrkB ratio in ischemic brain, changes prevented by VER155008 and ANA-12, respectively. Additionally, ANA-12 blocked salidroside-dependent neurogenesis and increased BrdU-/NeuN+ cells in the peri-infarct cortex. Salidroside directly activates HSC70, thereby stimulating neurogenesis and neuroprotection via BDNF/TrkB signalling after MCAO. Salidroside and similar activators of HSC70 might provide clinical therapies for ischemic stroke.
摘要：
Salidroside,大花红景天的主要生物活性成分，在中风模型中具有很宽的时间窗口的神经保护作用。我们研究了红景天苷是否在脑缺血后诱导神经发生，并旨在确定其主要分子靶标。老鼠,进行短暂的2小时大脑中动脉闭塞（MCAO），接受腹膜内溶媒或红景天苷±侧脑室HSC70抑制剂VER155008或TrkB抑制剂ANA-12治疗7天.MRI,行为测试,免疫荧光染色和蛋白质印迹法测定红景天苷的效果。反向虚拟对接和酶测定评估了红景天苷与纯化的重组HSC70的相互作用。红景天苷剂量依赖性地减少脑梗死体积和神经功能缺损，以50mg/kg/天的最大效果。该剂量还改善了光束平衡和Morris水迷宫测试中的性能。红景天苷显著增加BrdU+/nestin+，BrdU+/DCX+,BrdU+/NeuN+,BrdU-/NeuN+和BDNF+细胞在梗死周围皮质,在纹状体的影响较小，在脑室下区没有明显的影响。预测红景天苷与HSC70结合。红景天苷剂量依赖性地增加HSC70ATP酶和HSC70依赖性荧光素酶活性，但它没有激活HSP70。HSC70免疫反应性集中在梗死周围皮质，红景天苷未改变。然而,VER155008预防了红景天苷依赖性神经发生的增加，梗死周围皮质BrdU-/NeuN+细胞和BDNF+细胞。红景天苷还可增加缺血脑中BDNF蛋白和p-TrkB/TrkB比值,分别由VER155008和ANA-12阻止的更改。此外,ANA-12阻断红景天苷依赖性神经发生，并增加梗死周围皮层的BrdU-/NeuN细胞。红景天苷直接激活HSC70,从而在MCAO后通过BDNF/TrkB信号刺激神经发生和神经保护。红景天苷和类似的HSC70激活剂可能为缺血性中风提供临床治疗。
