阻塞性睡眠呼吸暂停综合征对大鼠海马神经细胞线粒体自噬相关蛋白表达的影响

Effect of obstructive sleep apnea syndrome on expression of nerve cell mitophagy-related protein in hippocampus of rats

摘要:

目的 观察阻塞性睡眠呼吸暂停综合征（OSAS）大鼠海马细胞线粒体自噬相关蛋白的表达。方法 将24只成年雄性SD大鼠随机分为对照组和实验组。实验组进行OSAS模型复制，复制成功后继续饲养，按饲养时长分为2周组、4周组和6周组；对照组无特殊处理。每组6只。Western blotting检测大鼠海马细胞线粒体自噬相关蛋白LC3（LC3Ⅱ/LC3Ⅰ）、p62、PINK1及Parkin蛋白相对表达量；用透射电子显微镜观察其线粒体的变化。结果 实验组大鼠模型复制前后最低血氧饱和度和平均血氧饱和度的比较，差异有统计学意义（P <0.05），即OSAS模型复制成功。与对照组比较，2周组、4周组和6周组大鼠海马神经细胞LC3、LC3Ⅱ/LC3Ⅰ、PINK1及Parkin蛋白相对表达量均高于对照组，p62蛋白相对表达量低于对照组（P <0.05）；进一步两两比较，4周组LC3、LC3Ⅱ/LC3ⅠPINK1及Parkin蛋白相对表达量均高于2周组，p62蛋白相对表达量低于2周组（P <0.05）；6周组LC3、LC3Ⅱ/LC3Ⅰ、PINK1及Parkin蛋白相对表达量均高于4周组，p62蛋白相对表达量低于4周组（P <0.05）。透射电镜观察，与对照组比较，2周组、4周组和6周组大鼠海马区可见被双层或多层磷脂双分子层包裹的线粒体自噬体。结论 OSAS可致大鼠海马神经细胞发生线粒体自噬，其自噬程度随饲养时间延长而加重。

关键词:阻塞性睡眠呼吸暂停综合征;线粒体自噬;海马神经元

Abstract:

Objective To observe the expression of mitophagy-related proteins in hippocampal CA1 neurons of rats with obstructive sleep apnea syndrome (OSAS).Methods Twenty-four adult male SD rats were randomly divided into control group and experimental group. OSAS model was prepared for rats in experimental group. After successful model construction, the rats were divided into 2-week group, 4-week group, and 6-week group, according to the length of continuous feeding. The rats in control group were not modeled and only fed under normal conditions. 6 rats were divided into each group. The expression of mitophagy-related proteins LC3 (LC3 Ⅱ/LC3 I), p62, PINK1, and Parkin in the hippocampus of rats in each group was detected by Western blot. The changes of mitochondria in the hippocampus of rats were observed by transmission electron microscopy.Results The oxyhemoglobin saturation of rats in the experimental group after model establishment was lower than that before model establishment, and the difference was statistically significant (P < 0.05). The OSAS model was made successfully. The expression of LC3 (LC3 Ⅱ/LC3 I), PINK1, and Parkin protein in the hippocampus in the 2-week group, 4-week group, and 6-week group that was higher than that in the control group. The expression of p62 was lower than that in the control group. And the rats in the 4-week group was higher than that in the 2-week group, and the rats in the 6-week group was higher than that in the 4-week group, the differences were statistically significant (P < 0.05). With the extension of feeding time, the expression of LC3 (LC3 Ⅱ/LC3 I), PINK1, and Parkin protein increased, and the expression of p62 showed a trend of decreasing, and the differences were statistically significant (P < 0.05). Transmission electron microscopy showed that mitochondrial autophagosome encapsulated by bilayer or multilayer phospholipid bilayers were observed in the hippocampus of rats in the 2-week, 4-week, and 6-week groups compared with the control group.Conclusions OSAS can induce mitophagy in rat hippocampal neurons, and the degree of autophagy increases with the prolongation of continuous feeding time.

Key words:sleep apnea, obstructive;mitophagy;hippocampal neuron