Retinal ganglion cell axotomy induces an increase in intracellular superoxide anion
Retinal ganglion cell axotomy induces an increase in intracellular superoxide anion
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DOI：
10.1167/iovs.05-0921
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发表时间：
2006-04-01
影响因子：
4.4
通讯作者：
Levin, LA
中科院分区：
文献类型：
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作者：
Lieven, CJ;Hoegger, MJ;Levin, LA
目的.视网膜神经节细胞（RGCS）在轴突损伤后发生凋亡。细胞死亡的时间过程是可变的，部分取决于持续的损伤程度。降低活性氧（ROS）水平或将氧化还原状态转变为还原状态可促进轴突切断后组织培养中RGCs的存活。据推测，一个特定的活性氧，超氧阴离子，作为细胞内信号分子的RGC死亡后轴突切断。在逆行标记的大鼠RGC中解离后，使用超氧化物敏感的荧光团hydroethidium和MitoSOX Red测量细胞内超氧化物水平。在发现了显著增加后，用视神经挤压模型确定了与解离无关的油超氧化物水平。视神经挤压导致RGCs发生超氧化物爆发。这种爆发是异步的，在任何给定的时间都只在一小部分细胞中表现出来。神经营养素剥夺是不负责的超氧化物的爆发，因为它是不防止孵育的神经营养因子脑源性神经营养因子，睫状神经营养因子，毛喉素，或胰岛素。研究了几种细胞内超氧化物生成的抑制剂，但只有抗霉素A，它抑制线粒体电子传递链的复合物III，阻止超氧化物的增加。这些结果表明，线粒体电子传递链中产生的超氧化物可能是轴突损伤后神经营养剥夺信号细胞死亡的平行系统。
PURPOSE. Retinal ganglion cells (RGCS) undergo apoptosis after axonal injury. The time course of cell death is variable and depends in part on the degree of injury sustained. Decreasing reactive oxygen species (ROS) levels or shifting the redox state to reduction promotes the survival of RGCs in tissue culture after axotomy. It was hypothesized that a specific ROS, superoxide anion, acts as an intracellular signaling Molecule for RGC death after axotomy.METHODS. Intracellular Superoxide levels were measured after dissociation in retrograde-labeled rat RGCs with use of the superoxide-sensitive fluorophores hydroethidium and MitoSOX Red. Having found a significant increase, the effect of axotomy was determined oil superoxide levels independent of dissociation with an optic nerve crush model.RESULTS. Optic nerve crush caused RGCs to undergo a superoxide burst. The burst was asynchronous and was manifested in only a fraction of cells at any given time. Neurotrophin deprivation was not responsible for the superoxide burst because it was not prevented by incubation with the neurotrophic factors brain-derived neurotrophic factor, ciliary neurotrophic factor, forskolin, or insulin. Several inhibitors of intracellular superoxide generation were studied, but only antimycin A, which inhibits complex III of the mitochondrial electron transport chain, blocked the increase in superoxide.CONCLUSIONS. These findings suggest that superoxide generated in the mitochondrial electron transport chain Could be a parallel system to neurotrophic deprivation for signaling cell death after axonal injury.