Cunha-Oliveira Teresa, Rego A Cristina, Cardoso Sandra M, Borges Fernanda, Swerdlow Russell H, Macedo Tice, de Oliveira Catarina R
Institute of Biochemistry, Faculty of Medicine, University of Coimbra, 3004-504 Coimbra, Portugal.
Brain Res. 2006 May 17;1089(1):44-54. doi: 10.1016/j.brainres.2006.03.061. Epub 2006 Apr 25.
Drug abuse is associated with brain dysfunction and neurodegeneration, and various recreational drugs induce apoptotic cell death. This study examined the role of the mitochondrial apoptotic pathway in psychostimulant-induced neuronal dysfunction. Using primary neuronal cultures, we observed that amphetamine (IC50=1.40 mM) was more potent than cocaine (IC50=4.30 mM) in inducing cell toxicity. Apoptotic cell death was further evaluated using cocaine and amphetamine concentrations that moderately decreased cell reduction capacity but did not affect plasma membrane integrity. Compared to cocaine, amphetamine highly decreased the mitochondrial membrane potential, as determined using the fluorescent probe rhodamine-123, whereas both drugs decreased mitochondrial cytochrome c. In contrast to amphetamine, cocaine cytotoxicity was partly mediated through effects on the electron transport chain, since cocaine toxicity was ameliorated in mitochondrial DNA-depleted cells lacking mitochondrially encoded electron transport chain subunits. Cocaine and amphetamine induced activation of caspases-2, -3 and -9 but did not affect activity of caspases-6 or -8. In addition, amphetamine, but not cocaine, was associated with the appearance of evident nuclear apoptotic morphology. These events were not accompanied by differences in the release of the apoptosis-inducing factor (AIF) from mitochondria. Our results demonstrate that although both amphetamine and cocaine activate the mitochondrial apoptotic pathway in cortical neurons, amphetamine is more likely to promote apoptosis.
药物滥用与脑功能障碍和神经退行性变相关，多种消遣性药物可诱导细胞凋亡性死亡。本研究检测了线粒体凋亡途径在精神兴奋剂诱导的神经元功能障碍中的作用。利用原代神经元培养，我们观察到苯丙胺（IC50 = 1.40 mM）在诱导细胞毒性方面比可卡因（IC50 = 4.30 mM）更具效力。使用适度降低细胞还原能力但不影响质膜完整性的可卡因和苯丙胺浓度进一步评估凋亡性细胞死亡。与可卡因相比，使用荧光探针罗丹明 - 123测定，苯丙胺显著降低线粒体膜电位，而两种药物均降低线粒体细胞色素c。与苯丙胺不同，可卡因的细胞毒性部分是通过对电子传递链的影响介导的，因为在缺乏线粒体编码的电子传递链亚基的线粒体DNA缺失细胞中可卡因毒性得到改善。可卡因和苯丙胺诱导半胱天冬酶 - 2、 - 3和 - 9的激活，但不影响半胱天冬酶 - 6或 - 8的活性。此外，苯丙胺而非可卡因与明显的核凋亡形态的出现有关。这些事件并未伴随线粒体中凋亡诱导因子（AIF）释放的差异。我们的结果表明，虽然苯丙胺和可卡因均激活皮质神经元中的线粒体凋亡途径，但苯丙胺更有可能促进细胞凋亡。
