Deficit of mitochondria-derived ATP during oxidative stress impairs mouse MII oocyte spindles
Deficit of mitochondria-derived ATP during oxidative stress impairs mouse MII oocyte spindles
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DOI：
10.1038/sj.cr.7310095
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发表时间：
2006-09
期刊：
影响因子：
44.1
通讯作者：
Xiao Zhang;Xue-qing Wu;Shuang Lu;Ying Guo;Xu Ma
中科院分区：
文献类型：
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作者：
Xiao Zhang;Xue-qing Wu;Shuang Lu;Ying Guo;Xu Ma
虽然氧化应激在产妇衰老和不孕症中的作用已被提出，但其潜在的机制尚不完全清楚。本研究旨在确定氧化应激下中期II （MII）卵母细胞线粒体功能与纺锤体稳定性之间的关系。在存在或不存在渗透性过渡孔（ptp）阻滞剂环孢素A （CsA）的情况下，用h2o2处理MII小鼠卵母细胞。此外，还采用抗氧化剂n -乙酰半胱氨酸（NAC）、f0 / f1合成酶抑制剂寡霉素A、线粒体解耦剂羰基氰化物4-三氟甲氧基苯腙（FCCP）或thapsigargin + 2.5 mM ca2 +(Th+ 2.5 mM ca2 +)进行机理研究。对卵母细胞纺锤体和染色体进行形态学分析，并测定卵母细胞内线粒体膜电位（ΔΨm）、细胞质游离钙浓度（[ca2 +] c）和细胞质ATP含量。卵母细胞经h2o2处理后，减数分裂纺锤体发生破坏，并呈时间依赖性和剂量依赖性，NAC预处理可防止这种破坏。h2o2的处理导致ΔΨm的耗散，[ca2 +] c的增加和细胞质ATP水平的降低。卵母细胞对h2o2处理的这些有害反应可以通过CsA预孵育来阻断。与h2o2类似，寡霉素A和FCCP都能使ΔΨm消散，降低细胞质ATP含量，并使MII卵母细胞纺锤体解体，而单独使用高[ca2 +] c对纺锤体形态没有影响。综上所述，氧化应激期间线粒体来源ATP的减少可能导致小鼠MII卵母细胞纺锤体的解体，可能是由于线粒体PTPs的打开。
Although the role of oxidative stress in maternal aging and infertility has been suggested, the underlying mechanisms are not fully understood. The present study is designed to determine the relationship between mitochondrial function and spindle stability in metaphase II (MII) oocytes under oxidative stress. MII mouse oocytes were treated with H 2 O 2 in the presence or absence of permeability transition pores (PTPs) blockers cyclosporin A (CsA). In addition, antioxidant N-acetylcysteine (NAC), F 0/F 1 synthase inhibitor oligomycin A, the mitochondria uncoupler carbonyl cyanide 4-trifluoro-methoxyphenylhydrazone (FCCP) or thapsigargin plus 2.5 mM Ca 2+(Th+ 2.5 mM Ca 2+) were used in mechanistic studies. Morphologic analyses of oocyte spindles and chromosomes were performed and mitochondrial membrane potential (ΔΨm), cytoplasmic free calcium concentration ([Ca 2+] c) and cytoplasmic ATP content within oocytes were also assayed. In a time-and H 2 O 2 dose-dependent manner, disruption of meiotic spindles was found after oocytes were treated with H 2 O 2, which was prevented by pre-treatment with NAC. Administration of H 2 O 2 led to a dissipation of ΔΨm, an increase in [Ca 2+] c and a decrease in cytoplasmic ATP levels. These detrimental responses of oocytes to H 2 O 2 treatment could be blocked by pre-incubation with CsA. Similar to H 2 O 2, both oligomycin A and FCCP dissipated ΔΨm, decreased cytoplasmic ATP contents and disassembled MII oocyte spindles, while high [Ca 2+] c alone had no effects on spindle morphology. In conclusion, the decrease in mitochondria-derived ATP during oxidative stress may cause a disassembly of mouse MII oocyte spindles, presumably due to the opening of the mitochondrial PTPs.