Valverde I, Lago J, Vieites J M, Cabado A G
ANFACO-CECOPESCA, Campus Univ de Vigo, Vigo 36310, Spain.
J Appl Toxicol. 2008 Apr;28(3):294-302. doi: 10.1002/jat.1278.
Palytoxin isolated from the genus Palythoa is the most potent marine toxin known. The aim of the present study was to quantify palytoxin-induced cellular injury in the human intestinal cell line Caco-2. Cellular damage was measured by evaluating cell proliferation, cell membrane permeability, cell morphology and apoptotic markers. Furthermore, changes in F-actin were studied after exposure of cells to increasing amounts of palytoxin. The results show that cell proliferation decreased in a concentration-dependent manner with a mean IC(50) value of about 0.1 nM. A noticeable increase of cell detachment correlated with cell rounding and F-actin depolymerization was observed in palytoxin-treated cells. Moreover LDH was released from the cells in a dose and time dependent manner, although under these conditions there was no propidium iodide uptake. On the other hand, palytoxin impaired mitochondrial activity but other apoptotic markers, such as DNA fragmentation or caspases activation, were not observed. The results obtained in this paper suggest that the effects of palytoxin in Caco-2 cells were very potent and unspecific, since a primary necrosis and a secondary apoptosis seem to occur under these conditions.
从沙海葵属中分离出的刺尾鱼毒素是已知最具毒性的海洋毒素。本研究的目的是量化刺尾鱼毒素对人肠上皮细胞系Caco-2造成的细胞损伤。通过评估细胞增殖、细胞膜通透性、细胞形态和凋亡标志物来测定细胞损伤。此外，在细胞暴露于不同剂量的刺尾鱼毒素后，研究了丝状肌动蛋白（F-肌动蛋白）的变化。结果表明，细胞增殖呈浓度依赖性下降，平均半数抑制浓度（IC50）值约为0.1 nM。在经刺尾鱼毒素处理的细胞中，观察到细胞脱离显著增加，这与细胞变圆和F-肌动蛋白解聚相关。此外，乳酸脱氢酶（LDH）以剂量和时间依赖性方式从细胞中释放出来，不过在这些条件下未观察到碘化丙啶摄取。另一方面，刺尾鱼毒素损害了线粒体活性，但未观察到其他凋亡标志物，如DNA片段化或半胱天冬酶激活。本文获得的结果表明，刺尾鱼毒素对Caco-2细胞的作用非常强烈且非特异性，因为在这些条件下似乎会发生原发性坏死和继发性凋亡。
