Identification of Clostridium difficile toxin B cardiotoxicity using a zebrafish embryo model of intoxication
Identification of Clostridium difficile toxin B cardiotoxicity using a zebrafish embryo model of intoxication
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DOI：
10.1073/pnas.0604725103
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发表时间：
2006-09-19
影响因子：
11.1
通讯作者：
Ballard, Jimmy D.
中科院分区：
文献类型：
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作者：
Hamm, Elaine E.;Voth, Daniel E.;Ballard, Jimmy D.
艰难梭菌毒素B（Clostridium difficile toxin B，TcdB）已通过无细胞系统和组织培养被广泛研究，但与许多细菌毒素一样，TcdB的体内靶点是未知的，并且难以用传统的动物模型阐明。在目前的研究中，透明的斑马鱼胚胎被用作体内TcdB定位和器官特异性损伤的成像模型，在真实的时间。在治疗后24小时，发现TcdB定位于心包区域，并且斑马鱼表现出心血管损伤的第一个迹象，包括全身血流量减少90%和心率降低20%。在暴露于TcdB的72小时内，心脏的心室腔变得变形，并且不能收缩或泵血，并且鱼表现出广泛的心包水肿。与观察到的心室收缩缺陷一致，发现TcdB直接破坏原代心肌细胞的协调收缩性和节律性。此外，使用caspase-3抑制剂，我们能够阻断TcdB相关的心血管损伤并防止斑马鱼死亡。这些发现提供了对TcdB体内靶点的深入了解，并证明了斑马鱼胚胎作为鉴定细菌毒素体内靶点和评价新型候选治疗剂的易处理模型的优势。
Clostridium difficile toxin B (TcdB) has been studied extensively by using cell-free systems and tissue culture, but, like many bacterial toxins, the in vivo targets of TcdB are unknown and have been difficult to elucidate with traditional animal models. In the current study, the transparent Danio rerio (zebrafish) embryo was used as a model for imaging of in vivo TcdB localization and organ-specific damage in real time. At 24h after treatment, TcdB was found to localize at the pericardial region, and zebrafish exhibited the first signs of cardiovascular damage, including a 90% reduction in systemic blood flow and a 20% reduction in heart rate. Within 72h of exposure to TcdB, the ventricle chamber of the heart became deformed and was unable to contract or pump blood, and the fish exhibited extensive pericardial edema. In line with the observed defects in ventricle contraction, TcdB was found to directly disrupt coordinated contractility and rhythmicity in primary cardiomyocytes. Furthermore, using a caspase-3 inhibitor, we were able to block TcdB-related cardiovascular damage and prevent zebrafish death. These findings present an insight into the in vivo targets of TcdB, as well as demonstrate the strength of the zebrafish embryo as a tractable model for identification of in vivo targets of bacterial toxins and evaluation of novel candidate therapeutics.