西罗莫司抗缺血性脑卒中的自噬机制

Autophagy mechanism of sirolimus on ischemic stroke

目的观察神经元氧糖剥夺(OGD)后自噬的动态变化,并探讨西罗莫司对缺血性脑卒中的保护作用及自噬机制。方法利用OGD神经元,观察神经元氧糖剥夺后不同时间点自噬蛋白LC3-Ⅱ、Beclin-1和β-arrestin的变化,并观察10-6 mol·L-1西罗莫司对正常对照或OGD 6h后神经元LC3-Ⅱ的影响及抗凋亡作用。30只小鼠随机分为模型组、西罗莫司1μg·kg-1组和10μg·kg-1组(均n=10),观察西罗莫司对大脑中动脉阻塞(MCAO)模型小鼠半暗带脑组织LC3-Ⅱ和脑梗死面积的影响。结果神经元OGD 2 h后,自噬蛋白LC3-Ⅱ、Beclin-1和β-arrestin表达均减少,随OGD时间延长,LC3-Ⅱ和Beclin-1表达呈明显下降趋势(P<0.01);西罗莫司能促进神经元OGD 6h后LC3-Ⅱ的表达,并明显减少神经元的凋亡(P<0.01)。MCAO小鼠脑缺血6 h后,西罗莫司10μg·kg-1组梗死面积百分比(37.8±6.3)%显著小于模型组的(48.0±6.7)%(P<0.05)。结论西罗莫司对缺血性脑卒中有保护作用,其机制可能与促进自噬有关。

AIM To observe the dynamic change of autophage on oxygen-glucose deprivation （OGD） neuron and investigate the autophage mechanism of sirolimus on ischemic stroke. METHODS The dynamic changes of LC3- Ⅱ , Beclin- 1 and β-arrestin protein were observed on OGD neuron in the study. The effects of sirolimus （10^-6 mol·L^-1） on LC3- Ⅱ and anti-apoptosis on neuron after OGD 6 hours were also detected. Also the middle cerebral artery occlusion （MCAO） model was used in the study. Thirty mice were divided into model group, sirolimus 1 μg·kg^-1 group and sirolimus 10 μg·kg^-1 group randomly （n = 10 in each group）. The effects of sirolimus on LC3- Ⅱ in ischemic penumbra and the cerebral infract size were detected in the MCAO mouse after 6 hours. RESULTS The expression of LC3- 11 , Beclin- 1 and 15- arrestin lessen after 2 hours in OGD neuron. LC3- Ⅱ and Beclin- 1 significantly decreased with the OGD time prolonged （P 〈 0.01 ）. While sirolimus could increase the expression of LC3- Ⅱ and resist apoptosis in neuron after OGD 6 hours （P 〈 0.01 ）. And also sirolimus 10 μg·kg^-1 can decrease cerebral infract size in mouse after MCAO 6 hours （ （37.8 ± 6.3） % vs. （48.0 ± 6.7） %, P 〈 0.05）. CONCLUSION Sirolimus can exert protective effects on ischemic stroke. It may be associated with promoting autophage.