Morphological analysis of mitochondria for evaluating the toxicity of α-synuclein in transgenic mice and isolated preparations by atomic force microscopy
Morphological analysis of mitochondria for evaluating the toxicity of α-synuclein in transgenic mice and isolated preparations by atomic force microscopy
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DOI：
10.1016/j.biopha.2017.11.057
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发表时间：
2017-12-01
影响因子：
7.5
通讯作者：
Yang, Hui
中科院分区：
文献类型：
--
作者：
Gao, Ge;Wang, Zhipeng;Yang, Hui
帕金森病发病机制中的关键分子事件是由α-突触核蛋白（α-syn）引起的线粒体损伤。线粒体介导的坏死和凋亡，这是与形态学的变化。然而，α-syn改变线粒体形态的机制仍不清楚。为了解决这个问题，我们研究了从Thy 1 alpha-syn小鼠脑中分离的线粒体中线粒体通透性转换孔（mPTP）的开放和心磷脂（CL）水平的变化。细胞质细胞色素C和切割的半胱天冬酶-3蛋白水平在转基因小鼠的脑中上调。原子力显微镜（AFM）的形态学分析表明，在这些动物的线粒体形态和功能之间的相关性。分离的线粒体与重组人α-突触核蛋白N末端（α-syn/N）孵育降低线粒体CL含量。AFM分析表明，α-syn/N诱导线粒体肿胀和孔样结构的形成，这与线粒体跨膜电位和复合物I活性降低有关。所观察到的线粒体功能障碍被废除的mPTP抑制剂环孢菌素A的治疗，虽然没有恢复CL含量。这些结果提供了对alpha-syn/N通过调节mPTP开放和CL水平直接破坏线粒体结构和功能的机制的深入了解，并表明通过AFM对分离的线粒体进行形态学分析是评估线粒体损伤的有用方法。
A key molecular event in the pathogenesis of Parkinson's disease is mitochondrial damage caused by alpha-synuclein (alpha-syn). Mitochondria mediates both necrosis and apoptosis, which are associated with morphological changes. However, the mechanism by which alpha-syn alters mitochondrial morphology remains unclear. To address this issue, we investigated mitochondrial permeability transition pore (mPTP) opening and changes in cardiolipin (CL) levels in mitochondria isolated from the brain of Thy1 alpha-syn mice. Cytoplasmic cytochrome C and cleaved caspase-3 protein levels were upregulated in the brain of transgenic mice. Morphological analysis by atomic force microscopy (AFM) suggested a correlation between mitochondrial morphology and function in these animals. Incubation of isolated mitochondria with recombinant human alpha-synuclein N terminus (alpha-syn/N) decreased mitochondrial CL content. An AFM analysis showed that alpha-syn/N induced mitochondrial swelling and the formation of pore-like structures, which was associated with decreased mitochondrial transmembrane potential and complex I activity. The observed mitochondrial dysfunction was abrogated by treatment with the mPTP inhibitor cyclosporin A, although there was no recovery of CL content. These results provide insight into the mechanism by which alpha-syn/N directly undermines mitochondrial structure and function via modulation of mPTP opening and CL levels, and suggests that morphological analysis of isolated mitochondria by AFM is a useful approach for evaluating mitochondrial injury.