后适应对大鼠脑缺血再灌注后自噬相关基因表达的影响

Effect of Postconditioning on Autophagy Related Factors Expression after Cerebral Ischemia Reperfusion in Rats

目的探究缺血再灌注及缺血后适应后自噬相关基因的表达水平及变化趋势,以及相关作用。方法49只SD成年雄性大鼠随机分为假手术组(Sham组),缺血再灌注组(3、6、24 h亚组),缺血后适应组(3、6、24 h亚组)。于线栓拔除后3、6、24 h后取材进行TTC染色,Western检测Beclin 1、LC3Ⅱ表达,免疫组化检测神经元上Atg5、Atg7表达。结果 (1)缺血后适对神经元的作用在3 h时保护作用不明显(P=0.281),24 h时保护作用最明显(P=0.002);(2) 24 h时,缺血后适应可以有效减小梗死面积(P=0.005 3);(3)与Sham组相比,缺血再灌注和后适应均可诱导Beclin 1、LC3Ⅱ、Atg5、Atg7表达的增加(P <0.05)。24 h后适应能够有效抑制Beclin 1 (P=0.022)、LC3Ⅱ (P=0.039)的表达。而后适应在3 h时明显抑制Atg5的表达(P=0.007),在6 h时开始抑制Atg7的表达(P=0.019)。结论缺血再灌注加重神经元的损伤,有明显的时间依赖性。而缺血后适应在3 h时神经保护作用不明显,随时间延长对自噬作用的抑制增强,对神经元的保护作用明显增强,且自噬相关的基因表达具有时间依赖性。

Objective To investigate the expression level and trend of autophagy related genes after ischemia ischemia reperfusion and postconditioning. Methods Forty-nine SD adult male rats were randomly divided into sham group, ischemia reperfusion group(3, 6, 24 h subgroup), and ischemic post-conditioning group(3, 6,24 h subgroup).TTC staining was performed on the samples 3, 6 and 24 hours after the removal of the cable plug,the expressions of Beclin 1 and LC3Ⅱ were detected by western detection, and the expressions of Atg5 and Atg7 on the neurons were detected by immunohistochemistry. Results( 1) The protective effect of ischemic postconditioning on neurons was not obvious at 3 hours(P = 0.281), but was most obvious at 24 hours(P =0.002).(2) At 24 hours, ischemic post-conditioning can effectively reduce the infarct area(P = 0.0053).(3) Compared with sham group, the expressions of Beclin 1, LC3Ⅱ, Atg5 and Atg7 were increased by ischemia reperfusion and post-conditioning(P < 0.05).After 24 hours, Beclin 1(P = 0.022) and LC3Ⅱ(P = 0.039)were effectively inhibited by post-conditioning.The expression of Atg5 was significantly inhibited after 3 hours of adaptation(P = 0.007), and the expression of Atg7 was inhibited after 6 hours(P = 0.019). Conclusion The injury of neurons aggravated by ischemia-reperfusion is time-dependent. However, the neuroprotective effect of ischemic post-conditioning is not obvious at 3 hours,and the inhibition of autophagy is enhanced with time, and the protective effect of autophagy on neurons is significantly enhanced,and the expression of autophagy-related genes is time-dependent.