一些研究人员先前表明,在缺氧损伤之前或之后,RNAi敲除精氨酰-tRNA合成酶(ArgRS)可以挽救动物免于死亡。基于模型生物,C.秀丽隐杆线虫。然而,还没有关于精氨酰-tRNA合成酶敲低在治疗哺乳动物缺血性中风中的应用的研究,其潜在机制和对缺血性脑损伤的影响尚不清楚。这里,我们专注于Rars基因,编码精氨酰tRNA合成酶,并研究了Rars敲除在大鼠永久性大脑中动脉闭塞模型中的作用。为了实现这一目标,成年雄性Sprague-Dawley(SD)大鼠右大脑皮层注射短发夹RNA(shRNA)腺病毒(AV)颗粒以敲除精氨酰-tRNA合成酶,和非靶向对照(NTC)载体或磷酸盐缓冲溶液作为对照。4天后,大鼠暴露于永久性大脑中动脉闭塞(pMCAO)。然后,检查了右大脑皮层的精氨酰-tRNA合成酶水平,通过梗死体积的差异来评估Rars击倒的效果,氧化应激,血脑屏障,线粒体功能,MCAO后1天和3天的葡萄糖代谢。注射shRNA腺病毒颗粒成功抑制了大脑皮层中精氨酰-tRNA合成酶的表达。我们观察到氧化应激的改善,线粒体功能,与非靶向对照大鼠相比,葡萄糖利用和脑水肿的减少,大脑同侧缺血皮质中精氨酸-tRNA合成酶mRNA的表达受到抑制。我们的发现表明,大脑皮层中精氨酰-tRNA合成酶的敲除发挥了神经保护作用,这不仅是通过改善氧化应激和葡萄糖利用,而且还通过维持线粒体形态完整性和保留线粒体功能来实现的。抑制ArgRS给药可能是保护缺血性卒中的一种有希望的方法。
Some researchers have previously shown that RNAi knockdown of arginyl-tRNA synthetase (ArgRS) before or after a hypoxic injury can rescue animals from death, based on the model organism, C. elegans. However, there has been no study on the application of arginyl-tRNA synthetase knockdown in treating mammalian ischemic stroke, and its potential mechanism and effect on ischemic brain damage are still unknown. Here, we focused on the Rars gene, which encodes an arginyl-tRNA synthetase, and examined the effects of Rars knockdown in a permanent middle cerebral artery occlusion model in rats. To achieve this aim, adult male Sprague-Dawley (SD) rats were given right cerebral cortex injections of short hairpin RNA (shRNA) adenovirus (AV) particles to knock down arginyl-tRNA synthetase, and a non-targeting control (NTC) vector or phosphate-buffered solution served as the controls. After 4 days, the rats were exposed to permanent middle cerebral artery occlusion (pMCAO). Then, the right cerebral cortex level of arginyl-tRNA synthetase was examined, and the effects of the Rars knockdown were evaluated by differences in infarction volume, oxidative stress, blood-brain barrier, mitochondrial function, and glucose metabolism at 1 day and 3 days after MCAO. The injection of shRNA adenovirus particles successfully suppressed the expression of arginyl-tRNA synthetase in the cerebral cortex. We observed an improvement in oxidative stress, mitochondrial function, and glucose utilization and a reduction in brain edema compared with the non-targeting control rats with suppressed expression of arginyl-tRNA synthetase mRNA in the ipsilateral ischemic cortex of the brain. Our findings indicate that knockdown of arginyl-tRNA synthetase in the cerebral cortex exerted neuroprotective effects, which were achieved not only by the improvement of oxidative stress and glucose utilization but also by the maintenance of mitochondrial morphological integrity and the preservation of mitochondrial function. Knockdown of ArgRS administration could be a promising approach to protect ischemic stroke.