Southern Medical University, Guangzhou, China.
Department of Thoracic Cardiovascular Surgery, General Hospital of Central Theater Command, Wuluo Road, 627#, Wuhan, 430070, Hubei, China.
Neurochem Res. 2020 Feb;45(2):322-330. doi: 10.1007/s11064-019-02916-z. Epub 2019 Nov 26.
This study examined the activation of mitophagy following cardiac arrest (CA) and cardiopulmonary resuscitation (CPR) and the relationship between the change with time and apoptosis.
The male Sprague-Dawley rats were randomized into four groups: Sham group, CPR24h group, CPR48h group, CPR72h group. The rat model of cardiac arrest was established by asphyxiation. We employed western blot to analyze the levels of mitophagy related proteins of hippocampus, JC-1 to detect mitochondrial membrane potential (MMP) and flow cytometry to measure the rate of apoptosis of hippocampal neurons. Moreover, we also intuitively observed the occurrence of mitophagy through electron microscopy.
The results showed that the levels of TOMM20 and Tim23 protein were significantly decreased after CPR, which were more remarkable following 72 h of CPR. However, the protein levels of dynamin related protein 1 (Drp1) and cytochrome C (Cyt-c) were strongly up-regulated after CPR. Meanwhile, the hippocampal MMP decreased gradually with time after CPR. Furthermore, we more intuitively verified the activation of mitophagy through electron microscopy. In addition, the rats of apoptosis rate of hippocampus after CPR were significantly increased, which were gradually enhanced over time from 24 h until at least 72 h following CPR.
with the enhancement of mitophagy, the apoptosis of hippocampal neurons was gradually enhanced, which suggested mitophagy may be excessive activated and aggravating brain damage after CA and CPR.
本研究探讨了心脏骤停（CA）和心肺复苏（CPR）后噬线粒体的激活情况，以及其随时间变化的变化与细胞凋亡之间的关系。
雄性 Sprague-Dawley 大鼠随机分为四组：假手术组、CPR24h 组、CPR48h 组、CPR72h 组。通过窒息建立大鼠心脏骤停模型。我们采用蛋白质印迹法分析海马体中与噬线粒体相关蛋白的水平，JC-1 检测线粒体膜电位（MMP），流式细胞术检测海马神经元凋亡率。此外，我们还通过电子显微镜直观地观察噬线粒体的发生情况。
结果显示，CPR 后 TOMM20 和 Tim23 蛋白水平明显下降，CPR 后 72 小时更为明显。然而，动力相关蛋白 1（Drp1）和细胞色素 C（Cyt-c）的蛋白水平在 CPR 后强烈上调。同时，CPR 后海马体 MMP 随时间逐渐下降。此外，我们通过电子显微镜更直观地验证了噬线粒体的激活。此外，CPR 后海马体神经元凋亡率显著增加，从 24 小时开始逐渐增强，至少持续到 CPR 后 72 小时。
随着噬线粒体的增强，海马体神经元的凋亡逐渐增强，提示 CA 和 CPR 后噬线粒体可能过度激活并加重脑损伤。
