College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin 150030, PR China.
College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Xiangfang District, Harbin 150030, PR China; College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang 110161, PR China.
Environ Toxicol Pharmacol. 2013 Sep;36(2):659-666. doi: 10.1016/j.etap.2013.06.013. Epub 2013 Jul 8.
Colistin is increasingly used as the last-line therapy for infections caused by Gram-negative 'superbugs'. Although colistin neurotoxicity was reported in the literature, there has no data on its mechanism. In the present study, we examined the effect of colistin on primary chick neuron cells, which were treated with 0.83, 4.15 and 8.3μg/mL colistin for 6, 12 and 24h. Cell viability was evaluated with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assays after exposure to colistin. Formation of reactive oxygen species (ROS), nuclear morphology, caspase-3 activity and internucleosomal DNA fragmentation were examined. The results showed that, compared with the control, no significant change was observed in cell viability, ROS formation and caspase-3 activity in cells treated for 6, 12 and 24h with 0.83μg/mL colistin. However, in the 4.15 and 8.3μg/mL colistin-treated groups, the viability of chick primary neurons significantly decreased at 12 and 24h, respectively; caspase-3 activities were significantly increased to 5.1 and 7.4 fold at 6h, more earlier than the changes of ROS, which was significant increased to 124.5% and 143.5% (P<0.01) of control at 12h, respectively. The apoptosis of neuron cells was revealed by both nuclear morphological observations and internucleosomal DNA fragmentation in the 4.15 and 8.3μg/mL colistin-treated groups at 6, 12 and 24h. Our data demonstrated that colistin can induce apoptosis in primary chick cortex neurons through caspase-3 activation, which may be contributed with ROS-dependent and independent mechanism.
黏菌素作为治疗革兰氏阴性“超级细菌”感染的最后一线药物，其应用日益广泛。虽然文献中已有黏菌素神经毒性的报道，但关于其作用机制尚无数据。在本研究中，我们用浓度为 0.83、4.15 和 8.3μg/ml 的黏菌素分别处理原代鸡皮质神经元 6、12 和 24h，以观察黏菌素对原代鸡皮质神经元的影响。黏菌素处理后，通过 3-[4,5-二甲基噻唑-2-基]-2,5-二苯基四氮唑溴盐（MTT）检测细胞活力。检测活性氧（ROS）的形成、核形态、半胱天冬酶-3 活性和核小体间 DNA 片段化。结果显示，与对照组相比，浓度为 0.83μg/ml 黏菌素处理的细胞，其细胞活力、ROS 形成和 caspase-3 活性在处理 6、12 和 24h 时无明显变化。然而，在 4.15 和 8.3μg/ml 黏菌素处理组中，鸡原代皮质神经元的活力分别在 12 和 24h 时显著降低；caspase-3 活性在 6h 时分别显著增加到对照组的 5.1 倍和 7.4 倍，早于 ROS 的变化，ROS 分别显著增加到对照组的 124.5%和 143.5%（P<0.01）。4.15 和 8.3μg/ml 黏菌素处理组在 6、12 和 24h 时，通过核形态观察和核小体间 DNA 片段化均显示神经元细胞凋亡。本研究表明，黏菌素可能通过 caspase-3 激活诱导原代鸡皮质神经元凋亡，其作用机制可能与 ROS 依赖和非依赖有关。
