Resting membrane potential as a marker of apoptosis:: Studies on Xenopus oocytes microinjected with cytochrome c
Resting membrane potential as a marker of apoptosis:: Studies on Xenopus oocytes microinjected with cytochrome c
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DOI：
10.1038/sj.cdd.4400773
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发表时间：
2001-01-01
影响因子：
12.4
通讯作者：
Mathew, MK
中科院分区：
文献类型：
--
作者：
Bhuyan, AK;Varshney, A;Mathew, MK
观察细胞膜上的电位差是监测单个细胞凋亡的一种新方法。在微注射细胞色素c后，实时记录了爪蟾卵母细胞的静息膜电位（Delta Psi）。微注射后，Delta Psi在所有细胞色素c浓度大于1 muM的情况下，很快变得不那么负，并达到一个新的恒定值，半时间t(m)约为35 (+/-5)min。细胞色素c注射卵母细胞的胞浆提取物显示出天冬氨酸特异性蛋白酶的DEVD蛋白水解活性特征，暗示凋亡死亡途径。作为细胞色素c进入细胞质的反应，半胱天蛋白酶在7分钟内被激活，而δ Psi在大约30分钟后开始发生变化。本文描述的方法将潜在地用于评估合成和生物来源的细胞死亡调节剂和调节剂的有效性，并且提出的结果阐明了当前争论的细胞色素c氧化还原状态在细胞凋亡起始中的重要性。
Observation of the electrical potential difference across the cell membrane is described as a new method for monitoring apoptosis of a single cell. The resting membrane potential (Delta Psi) of Xenopus oocytes has been recorded in real time following microinjection of cytochrome c. Soon after micro-injection, Delta Psi becomes less negative and attains a new constant value with a half time, t(m), of about 35 (+/-5) min at all cytochrome c concentrations greater than 1 muM. The cytosol extract of cytochrome c injected oocytes shows DEVD proteolytic activity characteristic of aspartate specific proteases, implicating an apoptotic death pathway. In response to the delivery of cytochrome c into the cytosol, caspases are activated within 7 min while the changes in Delta Psi begin to occur after about 30 min. The method described here will be potentially useful to assess the effectiveness of cell death regulators and modulators of synthetic and biological origin, and the results presented shed light on the currently debated issue of the importance of the redox state of cytochrome c in the initiation of apoptosis.