Multiparametric optical analysis of mitochondrial redox signals during neuronal physiology and pathology in vivo
Multiparametric optical analysis of mitochondrial redox signals during neuronal physiology and pathology in vivo
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DOI：
10.1038/nm.3520
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发表时间：
2014-05-01
期刊：
影响因子：
82.9
通讯作者：
Misgeld, Thomas
中科院分区：
文献类型：
--
作者：
Breckwoldt, Michael;Pfister, Franz M. J.;Misgeld, Thomas
线粒体氧化还原信号在神经元生理和疾病中起核心作用。在这里，我们描述了一种新的光学方法，以单细胞器分辨率测量活小鼠的快速氧化还原信号，这些小鼠在其神经元线粒体中表达遗传编码的氧化还原生物传感器。此外，我们还展示了几种生物传感器的平行测量如何将这些氧化还原信号整合到线粒体功能的综合表征中。这种方法揭示了轴突线粒体经历自发的“收缩”，伴随着可逆的氧化还原变化。这些收缩被神经元活动和急性或慢性神经元损伤放大。多参数成像显示，收缩是呼吸链依赖的去极化发作，与基质碱化相吻合，随后是解耦。相反，脊髓损伤后的永久性线粒体损伤取决于钙内流和线粒体通透性转变。因此，我们的方法使我们能够识别生理和病理氧化还原信号之间的异质性，将这些信号与功能和结构细胞器动力学联系起来，并剖析潜在的机制。
Mitochondrial redox signals have a central role in neuronal physiology and disease. Here we describe a new optical approach to measure fast redox signals with single-organelle resolution in living mice that express genetically encoded redox biosensors in their neuronal mitochondria. Moreover, we demonstrate how parallel measurements with several biosensors can integrate these redox signals into a comprehensive characterization of mitochondrial function. This approach revealed that axonal mitochondria undergo spontaneous 'contractions' that are accompanied by reversible redox changes. These contractions are amplified by neuronal activity and acute or chronic neuronal insults. Multiparametric imaging reveals that contractions constitute respiratory chain-dependent episodes of depolarization coinciding with matrix alkalinization, followed by uncoupling. In contrast, permanent mitochondrial damage after spinal cord injury depends on calcium influx and mitochondrial permeability transition. Thus, our approach allows us to identify heterogeneity among physiological and pathological redox signals, correlate such signals to functional and structural organelle dynamics and dissect the underlying mechanisms.