Gregory Laurel, Pestka James J, Dearborn Dorr G, Rand Thomas G
Department of Biology Saint Mary's University, Halifax, Nova Scotia, B3H 3C3.
Toxicol Pathol. 2004 Jan-Feb;32(1):26-34. doi: 10.1080/01926230490260790.
Satratoxin-G (SG) is the major macrocyclic trichothecene mycotoxin produced by Stachybotrys chartarum (atra) and has been implicated as a cause of a number of animal and human health problems including pulmonary hemorrhage in infants. However, there is little understanding where this toxin is localized in the spores and mycelial fragments of this species or in the lung impacted by SG-sequestered spores. The purpose of this study was to evaluate the distribution of SG in S. chartarum spores and mycelium in culture, and spore-impacted mouse lung in vivo, using immunocytochemistry. SG was localized predominately in S. chartarum spores with moderate labelling of the phialide-apex walls. Labelling was primarily along the outer plasmalemma surface and in the inner wall layer. Only modest labelling was observed in hyphae. Toxin localization at these sites supports the position that spores contain the highest satratoxin concentrations and that the toxin is constitutively produced. In impacted mouse lung, highest SG labelling was detected in lysosomes, along the inside of the nuclear membrane in nuclear heterochromatin and RER within alveolar macrophages. Alveolar type II cells also showed modest labelling of the nuclear heterochromatin and RER. There was no evidence that the toxin accumulated in the neutrophils, fibroblasts, or other cells associated with the granulomas surrounding spores or mycelial fragments. These observations indicate that SG displays a high degree of cellular specificity with respect to its uptake in mouse lung. They further indicate that the alveolar macrophages play an important role in the sequestration and immobilization of low concentrations of the toxin.
葡萄穗霉毒素-G（SG）是由黄绿青霉（黑青霉）产生的主要大环单端孢霉烯族霉菌毒素，与许多动物和人类健康问题有关，包括婴儿肺出血。然而，对于这种毒素在该物种的孢子和菌丝片段中，或在受SG隔离孢子影响的肺中的定位了解甚少。本研究的目的是使用免疫细胞化学方法评估SG在培养的黄绿青霉孢子和菌丝体以及体内受孢子影响的小鼠肺中的分布。SG主要定位于黄绿青霉孢子中，瓶梗顶端壁有中度标记。标记主要沿着外质膜表面和内壁层。在菌丝中仅观察到适度标记。毒素在这些部位的定位支持了孢子含有最高葡萄穗霉毒素浓度且该毒素是组成性产生的观点。在受影响的小鼠肺中，在溶酶体、核异染色质中核膜内侧以及肺泡巨噬细胞内的粗面内质网中检测到最高的SG标记。II型肺泡细胞的核异染色质和粗面内质网也有适度标记。没有证据表明毒素在中性粒细胞、成纤维细胞或与孢子或菌丝片段周围肉芽肿相关的其他细胞中积累。这些观察结果表明，SG在小鼠肺中的摄取具有高度的细胞特异性。它们还进一步表明，肺泡巨噬细胞在低浓度毒素的隔离和固定中起重要作用。
