Valencia Antonio, Morán Julio
Department of Neuroscience, Institute of Cell Physiology, National University of Mexico, Mexico City, Mexico.
Free Radic Biol Med. 2004 May 1;36(9):1112-25. doi: 10.1016/j.freeradbiomed.2004.02.013.
Apoptosis is characterized by chromatin condensation, phosphatidylserine translocation, and caspase activation. Neuronal apoptotic death involves the participation of reactive oxygen species (ROS), which have also been implicated in necrotic cell death. In this study we evaluated the role of different ROS in neuronal death. Superoxide anion was produced by incubating cells with xanthine and xanthine oxidase plus catalase, singlet oxygen was generated with rose Bengal and luminic stimuli, and hydrogen peroxide was induced with the glucose and glucose oxidase. Cultured cerebellar granule neurons died with the characteristics of apoptotic death in the presence of superoxide anion or singlet oxygen. These two conditions induced caspase activation, nuclear condensation, phosphatidylserine translocation, and a decrease in intracellular calcium levels. On the other hand, hydrogen peroxide led to a necrosis-like cell death that did not induce caspase activation, phosphatidylserine translocation, or changes in calcium levels. Cell death produced by both singlet oxygen and superoxide anion, but not hydrogen peroxide, was partially reduced by an increase in intracellular calcium levels. These results suggest that formation of specific ROS can lead to different molecular cell death mechanisms (necrosis and apoptosis) and that ROS formed under different conditions could act as initiators or executioners on neuronal death.
细胞凋亡的特征是染色质浓缩、磷脂酰丝氨酸易位和半胱天冬酶激活。神经元凋亡性死亡涉及活性氧（ROS）的参与，而活性氧也与坏死性细胞死亡有关。在本研究中，我们评估了不同活性氧在神经元死亡中的作用。通过将细胞与黄嘌呤、黄嘌呤氧化酶加过氧化氢酶一起孵育产生超氧阴离子，用孟加拉玫瑰红和发光刺激产生单线态氧，并用葡萄糖和葡萄糖氧化酶诱导产生过氧化氢。在超氧阴离子或单线态氧存在的情况下，培养的小脑颗粒神经元以凋亡性死亡的特征死亡。这两种情况诱导了半胱天冬酶激活、核浓缩、磷脂酰丝氨酸易位以及细胞内钙水平降低。另一方面，过氧化氢导致类似坏死的细胞死亡，未诱导半胱天冬酶激活、磷脂酰丝氨酸易位或钙水平变化。细胞内钙水平升高可部分减轻单线态氧和超氧阴离子而非过氧化氢所导致的细胞死亡。这些结果表明，特定活性氧的形成可导致不同的分子细胞死亡机制（坏死和凋亡），并且在不同条件下形成的活性氧可能在神经元死亡中充当启动者或执行者。
