McCrae K C, Rand T G, Shaw R A, Mantsch H H, Sowa M G, Thliveris J A, Scott J E
Department of Oral Biology, Faculty of Dentistry, University of Manitoba, Winnipeg, Canada.
Pediatr Pulmonol. 2007 Jul;42(7):592-9. doi: 10.1002/ppul.20608.
Stachybotrys chartarum (atra) is a toxic mold that grows on water-damaged cellulose-based materials. Research has revealed also that inhalation of S. chartarum spores caused marked changes in respiratory epithelium, especially to developing lungs. We analyzed the epigenetic potential of S. chartarum spore toxins on developing rat lung fibroblasts using single cell gel electrophoresis (comet assay). Isolated fetal lung fibroblasts were exposed to S. chartarum spore toxins for 15 min, 3, 14, or 24 hr and control cells were exposed to saline under the same conditions. Cells were embedded in agarose, electrophoresed under alkaline conditions and silver stained. DNA damage was assessed in terms of fragmentation as measured by comet tail length (DNA migration) and intensity (% DNA contained within head and tail). Upon visual inspection, control fibroblasts showed no DNA fragmentation whereas S. chartarum-treated cells had definable comets of various degrees depending upon the time-course. Analyses of the comets revealed that exposure to S. chartarum spore toxins for at least 15 min to 14 hr, induced increased DNA fragmentation in a time-dependent manner. The fact that exposure to toxins for 24 hr showed less damage suggested that developing lung fibroblasts may have the capability of repairing DNA fragmentation.
黑葡萄穗霉是一种生长在受水损坏的纤维素基材料上的有毒霉菌。研究还表明，吸入黑葡萄穗霉孢子会导致呼吸道上皮发生显著变化，尤其是对发育中的肺部。我们使用单细胞凝胶电泳（彗星试验）分析了黑葡萄穗霉孢子毒素对发育中的大鼠肺成纤维细胞的表观遗传潜力。将分离的胎肺成纤维细胞暴露于黑葡萄穗霉孢子毒素中15分钟、3小时、14小时或24小时，对照组细胞在相同条件下暴露于盐水中。细胞嵌入琼脂糖中，在碱性条件下进行电泳并银染。根据彗星尾长（DNA迁移）和强度（头部和尾部所含DNA的百分比）测量的片段化来评估DNA损伤。通过肉眼检查，对照成纤维细胞未显示DNA片段化，而经黑葡萄穗霉处理的细胞根据时间进程有不同程度的可确定彗星。对彗星的分析表明，暴露于黑葡萄穗霉孢子毒素至少15分钟至14小时，会以时间依赖性方式诱导DNA片段化增加。暴露于毒素24小时显示损伤较小这一事实表明，发育中的肺成纤维细胞可能具有修复DNA片段化的能力。
