背景:脑缺血再灌注损伤(CIRI)通常导致中风患者接受再灌注治疗后的有害并发症。据报道,运动预处理(EP)可以促进脑功能恢复。我们旨在探讨EPinCIRI的具体机制。
方法:Sprague-Dawley大鼠随机分为假,大脑中动脉闭塞(MCAO),和EP组(n=11)。EP组大鼠接受适应性训练3天(10m/min,20分钟/天,以0°倾斜)和3周的正式训练(6天/周,25m/min,30分钟/天,倾斜0°)。然后,大鼠行MCAO手术建立CIRI模型。48小时后,测定大鼠的神经功能缺损和脑梗死。检测到大脑皮层中的神经元死亡和凋亡。此外,进行RNA测序以研究EPonCIRI的特异性机制,进一步应用qPCR和Western印迹来确认RNA测序结果。
结果:EP改善了MCAO大鼠的神经功能缺损评分,减少了脑梗死。此外,缺血前运动也减轻了MCAO大鼠大脑皮层的神经元死亡和凋亡。重要的是,通过RNA测序鉴定出17个差异表达基因(DEGs),这些DEGs主要富集在HIF-1通路,细胞衰老,蛋白聚糖在癌症中,等等。qPCR和Western印迹进一步证实,EP可以抑制MCAO大鼠TIMP1,SOCS3,ANGPTL4,CDO1和SERPINE1的表达。
结论:EP可以改善体内CIRI,机制可能与TIMP1表达和HIF-1通路有关,这为CIRI治疗提供了新的靶点。
BACKGROUND: Cerebral ischemia reperfusion injury (CIRI) often leads to deleterious complications after stroke patients receive reperfusion therapy. Exercise preconditioning (EP) has been reported to facilitate brain function recovery. We aim to explore the specific mechanism of EP in CIRI.
METHODS: Sprague-Dawley rats were randomized into Sham, middle cerebral artery occlusion (MCAO), and EP groups (n = 11). The rats in the EP group received adaptive training for 3 days (10 m/min, 20 min/day, with a 0° incline) and formal training for 3 weeks (6 days/week, 25 m/min, 30 min/day, with a 0° incline). Then, rats underwent MCAO surgery to establish CIRI models. After 48 h, neurological deficits and cerebral infarction of the rats were measured. Neuronal death and apoptosis in the cerebral cortices were detected. Furthermore, RNA sequencing was conducted to investigate the specific mechanism of EP on CIRI, and qPCR and Western blotting were further applied to confirm RNA sequencing results.
RESULTS: EP improved neurological deficit scores and reduced cerebral infarction in MCAO rats. Additionally, pre-ischemic exercise also alleviated neuronal death and apoptosis of the cerebral cortices in MCAO rats. Importantly, 17 differentially expressed genes (DEGs) were identified through RNA sequencing, and these DEGs were mainly enriched in the HIF-1 pathway, cellular senescence, proteoglycans in cancer, and so on. qPCR and Western blotting further confirmed that EP could suppress TIMP1, SOCS3, ANGPTL4, CDO1, and SERPINE1 expressions in MCAO rats.
CONCLUSIONS: EP can improve CIRI in vivo, the mechanism may relate to TIMP1 expression and HIF-1 pathway, which provided novel targets for CIRI treatment.