Li Li, Tian Jinghua, Long Mitchell King-Wei, Chen Yong, Lu Jianfei, Zhou Changman, Wang Tianlong
Department of Anesthesiology, Xuanwu Hospital, Capital Medical University, Beijing, China.
Department of Anatomy, Heze Medical College, Shandong, China.
PLoS One. 2016 Jan 11;11(1):e0144219. doi: 10.1371/journal.pone.0144219. eCollection 2016.
Ganglioside GM1, which is particularly abundant in the central nervous system (CNS), is closely associated with the protection against several CNS disorders. However, controversial findings have been reported on the role of GM1 following ischemic stroke. In the present study, using a rat middle cerebral artery occlusion (MCAO) model, we investigated whether GM1 can protect against ischemic brain injury and whether it targets the autophagy pathway. GM1 was delivered to Sprague-Dawley male rats at 3 doses (25 mg/kg, 50 mg/kg, 100 mg/kg) by intraperitoneal injection soon after reperfusion and then once daily for 2 days. The same volume of saline was given as a control. Tat-Beclin-1, a specific autophagy inducer, was administered by intraperitoneal injection at 24 and 48 hours post-MCAO. Infarction volume, mortality and neurological function were assessed at 72 hours after ischemic insult. Immunofluorescence and Western blotting were performed to determine the expression of autophagy-related proteins P62, LC3 and Beclin-1 in the penumbra area. No significant changes in mortality and physiological variables (heart rate, blood glucose levels and arterial blood gases) were observed between the different groups. However, MCAO resulted in enhanced conversion of LC3-I into LC3-II, P62 degradation, high levels of Beclin-1, a large area infarction (26.3±3.6%) and serious neurobehavioral deficits. GM1 (50 mg/kg) treatment significantly reduced the autophagy activation, neurobehavioral dysfunctions, and infarction volume (from 26.3% to 19.5%) without causing significant adverse side effects. However, this biological function could be abolished by Tat-Beclin-1.
GM1 demonstrated safe and robust neuroprotective effects that are associated with the inhibition of autophagy following experimental stroke.
神经节苷脂GM1在中枢神经系统（CNS）中含量特别丰富，与预防多种中枢神经系统疾病密切相关。然而，关于GM1在缺血性中风后的作用，已有相互矛盾的研究结果报道。在本研究中，我们使用大鼠大脑中动脉闭塞（MCAO）模型，研究GM1是否能预防缺血性脑损伤以及它是否靶向自噬途径。在再灌注后不久，通过腹腔注射将GM1以3种剂量（25mg/kg、50mg/kg、100mg/kg）给予Sprague-Dawley雄性大鼠，然后每天一次，持续2天。给予相同体积的生理盐水作为对照。在MCAO后24小时和48小时通过腹腔注射给予特异性自噬诱导剂Tat-Beclin-1。在缺血损伤后72小时评估梗死体积、死亡率和神经功能。进行免疫荧光和蛋白质印迹法以确定半暗带区域中自噬相关蛋白P62、LC3和Beclin-1的表达。不同组之间未观察到死亡率和生理变量（心率、血糖水平和动脉血气）的显著变化。然而，MCAO导致LC3-I向LC3-II的转化增强、P62降解、Beclin-1水平升高、大面积梗死（26.3±3.6%）和严重的神经行为缺陷。GM1（50mg/kg）治疗显著降低了自噬激活、神经行为功能障碍和梗死体积（从26.3%降至19.5%），且未引起明显的不良副作用。然而，这种生物学功能可被Tat-Beclin-1消除。
GM1在实验性中风后表现出安全且强大的神经保护作用，这与自噬抑制有关。
