Department of Neurology, Hebei General Hospital, Shijiazhuang City, Hebei Province, China.
Braz J Med Biol Res. 2019 Nov 7;52(11):e8371. doi: 10.1590/1414-431X20198371. eCollection 2019.
Oxiracetam (ORC) is a commonly used nootropic drug for improving cognition and memory impairments. The therapeutic effect and underlying mechanism of ORC in vascular dementia (VaD) treatment remain unknown. In this study, 3-month-old male Sprague-Dawley rats with permanent bilateral common carotid artery occlusion-induced VaD were treated orally with low (100 mg/kg) or high (200 mg/kg) dose ORC once a day for 4 weeks. The results of the Morris water maze test and Nissl staining showed that ORC treatment significantly alleviated learning and memory deficits and neuronal damage in rats with VaD. Mechanistically, the protein levels of a panel of genes associated with neuronal apoptosis (Bcl-2, Bax) and autophagy (microtubule-associated protein 1 chain 3, Beclin1, p62) were significantly altered by ORC treatment compared with VaD, suggesting a protective role of ORC against VaD-induced neuronal apoptosis and autophagy. Moreover, the Akt/mTOR pathway, which is known to be the upstream signaling governing apoptosis and autophagy, was found to be activated in ORC-treated rats, suggesting an involvement of Akt/mTOR activation in ORC-rendered protection in VaD rats. Taken together, this study demonstrated that ORC may alleviate learning and memory impairments and neuronal damage in VaD rats by altering the expression of apoptosis/autophagy-related genes and activation of the Akt/mTOR signaling pathway in neurons.
奥拉西坦(ORC)是一种常用于改善认知和记忆障碍的益智药。ORC 治疗血管性痴呆(VaD)的治疗效果和潜在机制尚不清楚。在这项研究中,3 月龄雄性 Sprague-Dawley 大鼠通过永久性双侧颈总动脉闭塞诱导 VaD,然后每天口服低(100mg/kg)或高(200mg/kg)剂量的 ORC,持续 4 周。Morris 水迷宫试验和尼氏染色的结果表明,ORC 治疗可显著改善 VaD 大鼠的学习和记忆障碍以及神经元损伤。从机制上讲,与 VaD 相比,ORC 治疗显著改变了与神经元凋亡(Bcl-2、Bax)和自噬(微管相关蛋白 1 轻链 3、Beclin1、p62)相关的一组基因的蛋白水平,表明 ORC 对 VaD 诱导的神经元凋亡和自噬具有保护作用。此外,已知 Akt/mTOR 通路是调节凋亡和自噬的上游信号通路,在 ORC 处理的大鼠中发现该通路被激活,表明 Akt/mTOR 激活参与了 ORC 对 VaD 大鼠的保护作用。综上所述,这项研究表明,ORC 可能通过改变神经元中凋亡/自噬相关基因的表达和激活 Akt/mTOR 信号通路来减轻 VaD 大鼠的学习和记忆障碍以及神经元损伤。