Center for Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, China.
Am J Physiol Cell Physiol. 2021 Jul 1;321(1):C17-C25. doi: 10.1152/ajpcell.00077.2021. Epub 2021 May 12.
Sleep deprivation has profound influence on several aspects of health and disease. Mitochondria dysfunction has been implicated to play an essential role in the neuronal cellular damage induced by sleep deprivation, but little is known about how neuronal mitochondrial ultrastructure is affected under sleep deprivation. In this report, we utilized electron cryo-tomography to reconstruct the three-dimensional (3-D) mitochondrial structure and extracted morphometric parameters to quantitatively characterize its reorganizations. Isolated mitochondria from the hippocampus and cerebral cortex of adult male Sprague-Dawley rats after 72 h of paradoxical sleep deprivation (PSD) were reconstructed and analyzed. Statistical analysis of six morphometric parameters specific to the mitochondrial inner membrane topology revealed identical pattern of changes in both the hippocampus and cerebral cortex but with higher significance levels in the hippocampus. The structural differences were indistinguishable by conventional phenotypic methods based on two-dimensional electron microscopy images or 3-D electron tomography reconstructions. Furthermore, to correlate structure alterations with mitochondrial functions, high-resolution respirometry was employed to investigate the effects of PSD on mitochondrial respiration, which showed that PSD significantly suppressed the mitochondrial respiratory capacity of the hippocampus, whereas the isolated mitochondria from the cerebral cortex were less affected. These results demonstrate the capability of the morphometric parameters for quantifying complex structural reorganizations and suggest a correlation between PSD and inner membrane architecture/respiratory functions of the brain mitochondria with variable effects in different brain regions.
睡眠剥夺对健康和疾病的几个方面都有深远的影响。线粒体功能障碍被认为在睡眠剥夺引起的神经元细胞损伤中起着至关重要的作用，但对于睡眠剥夺下神经元线粒体超微结构如何受到影响知之甚少。在本报告中，我们利用电子低温断层扫描技术重建了三维（3-D）线粒体结构，并提取形态计量参数来定量描述其重排。对经过 72 小时的矛盾性睡眠剥夺（PSD）的成年雄性 Sprague-Dawley 大鼠海马体和大脑皮层中的分离线粒体进行了重建和分析。对特定于线粒体内膜拓扑结构的六个形态计量参数的统计分析表明，海马体和大脑皮层都呈现出相同的变化模式，但在海马体中具有更高的显著性水平。基于二维电子显微镜图像或 3-D 电子断层扫描重建的传统表型方法无法区分这些结构差异。此外，为了将结构变化与线粒体功能相关联，我们采用高分辨率呼吸测定法研究了 PSD 对线粒体呼吸的影响，结果表明 PSD 显著抑制了海马体的线粒体呼吸能力，而大脑皮层中的分离线粒体受影响较小。这些结果表明，形态计量参数具有定量复杂结构重排的能力，并提示 PSD 与大脑线粒体的内膜结构/呼吸功能之间存在相关性，在不同脑区的影响不同。
