Role of Mitochondrial Permeability Transition in Ischemic Neuronal Cell Death

线粒体通透性转变在缺血性神经细胞死亡中的作用

• 批准号: 11671350
• 负责人: KURODA Satoshi
• 金额: $ 2.3万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11671350/
• 关键词: mitochondria; cerebral ischemia; permeability transition; cytochrome c; cyclosporin A; FK506; bcl-2 family; calcineurin; energy metabolism; ischemia; reperfusion; free radical; cytochrome c; cyclosporin A

The present study was aimed to determine biochemical characteristics of mitochondrial, permeability transition (mPT) in brain mitochondria, and to clarify its role in neuronal injury following transient forebrain ischemia. Mitochondria were isolated from rat brain and liver. Changes in mitochondrial volume were measured via light absorbance at 540 nm. By Western blot analysis, we examined release of mitochondrial cytochrome c under these conditions. Transient forebrain ischemia was induced by 5-min occlusion of the bilateral common carotid artery in the gerbil. Cyclosporin A (CsA) and/or trifluoperazine were given 30 min before and 24 hour after ischemia. The number of surviving neurons in hippocampal CA1 sectors was counted 7 days after ischemia. Calcium, but not pro-oxidants, induced a decrease of light absorbance in brain mitochondria, which was inhibited by CsA. However, both stimuli led to a much larger decrease of light absorbance in liver mitochondria. Under these conditions, calcium induced a release of cytochrome c from brain mitochondria, which was not inhibited by CsA. However, the same stimulus led to a release of larger amount of cytochrome c from liver mitochondoria. Selective neuronal injury due to transient forebrain ischemia was significantly ameliorated by treatment with high-dose CsA. The protective effect was enhanced by trifluoperazine. These results suggest that mPT does not readily occur in brain mitochondria, and that cytochrome c is released from brain mitochondria through mPT-independent mechanism. However, the findings from transient forebrain ischemia indicate the possibility of region-specific difference in sensitivity for mPT and/or cytochrome c release in the brain.

本研究旨在确定脑线粒体线粒体通透性转变（mPT）的生化特征，并阐明其在短暂前脑缺血后神经元损伤中的作用。从大鼠脑和肝脏中分离线粒体。通过 540 nm 处的光吸光度测量线粒体体积的变化。通过蛋白质印迹分析，我们检查了这些条件下线粒体细胞色素 c 的释放。沙鼠双侧颈总动脉闭塞 5 分钟，诱发短暂前脑缺血。缺血前 30 分钟和缺血后 24 小时给予环孢素 A (CsA) 和/或三氟拉嗪。缺血7天后计算海马CA1区存活神经元的数量。钙（而不是促氧化剂）会引起脑线粒体光吸收率的降低，而这种降低会被 CsA 抑制。然而，这两种刺激都会导致肝线粒体的光吸光度大幅下降。在这些条件下，钙诱导脑线粒体释放细胞色素 c，而 CsA 不会抑制这种释放。然而，同样的刺激导致肝脏线粒体释放大量细胞色素c。高剂量 CsA 治疗可显着改善短暂前脑缺血引起的选择性神经元损伤。三氟拉嗪增强了保护作用。这些结果表明，mPT 不容易在脑线粒体中发生，并且细胞色素 c 通过不依赖 mPT 的机制从脑线粒体中释放。然而，短暂性前脑缺血的结果表明，大脑中 mPT 和/或细胞色素 c 释放的敏感性可能存在区域特异性差异。

项目成果

小林 徹: "脳虚血におけるmitochondrial permeability transition (mPT)の役割に関する研究"北海道医学雑誌. (掲載予定).

小林彻：“线粒体通透性转变（mPT）在脑缺血中的作用的研究”北海道医学杂志（待出版）。

Kobayashi T, Kuroda S, Tada M, Houkin K, Iwasaki Y, Abe H: "Brain-specific Characteristics of Mitochondrial Permeability Transition : Its Role in Ischemic Neuronal Death"Stroke. (submitted).

Kobayashi T、Kuroda S、Tada M、Houkin K、Iwasaki Y、Abe H：“线粒体通透性转变的脑特异性特征：其在缺血性神经元死亡中的作用”中风。

小林 徹: "脳虚血におけるMitochondrial permeability transition(MPT)の役割に関する研究"北海道医学雑誌. 75(4). 243-252 (2000)

Toru Kobayashi：“线粒体通透性转变（MPT）在脑缺血中的作用的研究”北海道医学杂志 75（4）（2000）。