Department of Molecular Pharmacology and Neurobiology, Yokohama City University Graduate School of Medicine, Japan.
J Pharmacol Sci. 2010;114(2):168-79. doi: 10.1254/jphs.09352fp. Epub 2010 Sep 17.
Axonal transport plays a crucial role in neuronal morphogenesis, survival, and function. Despite its importance, however, the molecular mechanisms of axonal transport remain mostly unknown because a simple and quantitative assay system for axonal transport has been lacking. In order to better characterize the molecular mechanisms involved in axonal transport, we here developed a computer-assisted monitoring system. Using lipophilic fluorochrome chloromethylbenzamido dialkylcarbocyanine (CM-DiI) as a labeling dye, we have successfully labeled membranous organelles in cultured chick dorsal root ganglia neurons. We confirmed that sodium azide, an ATPase inhibitor, and nocodazole, a microtubule-destabilizing agent, markedly suppressed anterograde and retrograde axonal transport of CM-DiI-labeled particles. We further tested the effects of several anti-neoplastic drugs on axonal transport. Paclitaxel, vincristine, cisplatin, and oxaliplatin, all of which are known to be neurotoxic and to cause neurological symptoms, suppressed anterograde and retrograde axonal transport. Another series of anti-neoplastic drugs, including methotrexate and 5-fluorouracil, did not affect the axonal transport. This is the first report of an automated monitoring system for axonal transport. This system will be useful for toxicity assays, characterizing axonal transport, or screening drugs that may modify neuronal functions.
轴突运输在神经元形态发生、存活和功能中起着至关重要的作用。然而，尽管其重要性不言而喻，但轴突运输的分子机制在很大程度上仍然未知，因为缺乏简单且定量的轴突运输检测系统。为了更好地描述参与轴突运输的分子机制，我们在此开发了一种计算机辅助监测系统。我们使用亲脂性荧光染料氯甲基苯甲酰胺二烷基碳菁（CM-DiI）作为标记染料，成功标记了培养的鸡背根神经节神经元中的膜性细胞器。我们证实，ATP 酶抑制剂叠氮化钠和微管去稳定药物诺考达唑显著抑制 CM-DiI 标记颗粒的顺行和逆行轴突运输。我们进一步测试了几种抗肿瘤药物对轴突运输的影响。紫杉醇、长春新碱、顺铂和奥沙利铂均已知具有神经毒性并引起神经症状，它们抑制顺行和逆行轴突运输。另一系列抗肿瘤药物，包括甲氨蝶呤和 5-氟尿嘧啶，并不影响轴突运输。这是首次报道用于轴突运输的自动监测系统。该系统将有助于毒性测定、描述轴突运输或筛选可能改变神经元功能的药物。
