缺血面神经元内硝基化亲环蛋白D在线粒体通透性转运孔开放中的作用

The role of nitrated Cyclophilin-D in regulating mitochondrial permeability transition pore opening after facial nucleus ischemia

目的观察大鼠面神经元缺血后不同时间点硝基化亲环蛋白D(CypD)的表达水平,同时检测缺血大鼠面神经元内线粒体通透性转运孔(MPTP)开放程度,探讨硝基化CypD(N-CypD)在MPTP开放中的作用。方法通过阻断大鼠岩动脉建立面神经元缺血模型;取SD大鼠85只,分为对照组(NC)、假手术组(SH)、岩动脉阻断损伤(PAI)组、PAI+生理盐水(PS)组、PAI+亚精胺(SPD)组。PAI、PAI+PS及PAI+SPD组再分为5个亚组(1d、3d、7d、14d、21d),每组5只大鼠。采用免疫沉淀法(IP)及Western blot法(WB)检测N-CypD表达水平,利用分光光度计检测MPTP的开放程度。结果 IP结果显示,PAI组与PAI+PS组各时间点N-CypD表达水平差异无统计学意义(P>0.05);PAI+SPD组各时间点N-CypD表达水平较PAI组均降低,差异有统计学意义(P<0.05);PAI及PAI+PS组各时间点MPTP开放程度差异无统计学意义(P>0.05),PAI+SPD组各时间点MPTP开放程度较PAI组均降低,差异有统计学意义(P<0.05)。相关分析显示,缺血面神经元内N-CypD表达水平与MPTP开放程度呈显著正相关(r=0.783,P<0.01)。结论大鼠面神经元缺血后,神经元内N-CypD表达水平不断增加,降低N-CypD水平可减少MPTP开放,说明N-CypD参与介导损伤神经元中MPTP的开放。

Objective To explore the expression of nitrated Cyclophilin-D in rat facial nucleus during different stages after interrupting the petrosal artery and its role in the regulation of mitochondrial permeability transition pore opening. Meth-ods The models of facial nucleus ischemia were established in rats by interrupting the petrosal artery. 85 SD rats were divided into 5 groups randomly：NC group,SH group,PAI group,PAI＋PS group,PAI＋SPD group. NC group and SH group included 5 rats respectively. Other groups were divided into 5 subgroups （1d,3d,7d,14d,21d）,each group contained 5 rats. The expressions of nitrated CypD were detected by IP and WB. MPTP opening was measured by spectrophotometer. Results The results of IP showed that the level of nitrated CypD in PAI＋SPD group was lower than that in PAI or PAI＋PS group,and the difference was significant （P＆lt;0.05）. Meanwhile the level of the opening MPTP decreased. The correlation analysis showed that the opening of MPTP in facial nucleus was closely associated with the increased expression of N-CypD after interrupting the petrosal artery （r=0.783,P＆lt;0.01）. Conclusion N-CypD mediate the opening of MPTP, and reducing the expression of the N-CypD would de-crease the level of MPTP opening.