Department of Physiology, University of Tuebingen, Tuebingen, Germany.
Mol Nutr Food Res. 2011 Sep;55 Suppl 2:S294-302. doi: 10.1002/mnfr.201100156. Epub 2011 Aug 8.
Enniatin A, a peptide antibiotic and common food contaminant, triggers mitochondrial dysfunction and apoptosis. Even though lacking mitochondria, erythrocytes may similarly undergo suicidal cell death or eryptosis. Eryptosis is characterized by cell shrinkage and cell membrane phospholipid scrambling. Triggers of phospholipid scrambling include energy depletion and increase in cytosolic Ca(2+) activity (Ca(2+) ). The present study explored whether enniatin A triggers phospholipid scrambling.
Phospholipid scrambling was estimated from annexin-V-binding, cell volume from forward scatter (FSC), Ca(2+) from Fluo3-fluorescence, cytosolic ATP-concentration (ATP ) using a luciferase assay and hemolysis from hemoglobin release. Exposure of erythrocytes for 48 h to enniatin A (≥ 2.5 μM) significantly increased Ca(2+) , decreased ATP , decreased FSC, triggered annexin-V-binding and elicited hemolysis. Annexin-V-binding affected 25%, and hemolysis 2% of treated erythrocytes. Decreased ATP by glucose depletion for 48 h was similarly followed by increased Ca(2+) , decreased FSC and annexin-V-binding. Enniatin A augmented the effect on Ca(2+) and annexin-V-binding, but not on FSC. Annexin-V-binding was blunted by Ca(2+) removal, by the cation channel inhibitor amiloride (1 mM), by the protein kinase C inhibitor staurosporine (500 nM) but not by the pancaspase inhibitor zVAD (10 μM).
The food contaminant enniatin A triggers ATP depletion and increases cytosolic Ca(2+) activity, effects resulting in suicidal erythrocyte death.
恩镰菌素 A 是一种肽类抗生素，也是常见的食物污染物，它可引发线粒体功能障碍和细胞凋亡。即使缺乏线粒体，红细胞也可能经历自杀性细胞死亡或红细胞皱缩。红细胞皱缩的特征是细胞体积缩小和细胞膜磷脂酰丝氨酸翻转。磷脂酰丝氨酸翻转的触发因素包括能量耗竭和细胞浆 Ca(2+) 活性增加(Ca(2+) )。本研究探讨了恩镰菌素 A 是否会引发磷脂酰丝氨酸翻转。
用 Annexin-V 结合、前向散射 (FSC) 评估细胞膜磷脂酰丝氨酸翻转、用 Fluo3-荧光评估 Ca(2+) 、用荧光素酶法评估细胞浆 ATP 浓度 (ATP )和用血红蛋白释放评估溶血。红细胞暴露于恩镰菌素 A(≥2.5 μM)48 小时后，显著增加了 Ca(2+) 、降低了 ATP 、降低了 FSC 、引发了 Annexin-V 结合并引发了溶血。25%的处理红细胞发生 Annexin-V 结合，2%的处理红细胞发生溶血。48 小时葡萄糖耗竭引起的 ATP 减少，同样导致 Ca(2+) 增加、FSC 降低和 Annexin-V 结合。恩镰菌素 A 增强了对 Ca(2+) 和 Annexin-V 结合的影响，但对 FSC 没有影响。钙去除、阳离子通道抑制剂阿米洛利 (1 mM)、蛋白激酶 C 抑制剂星形孢菌素 (500 nM)可阻断 Annexin-V 结合，但泛半胱天冬酶抑制剂 zVAD (10 μM) 不能阻断 Annexin-V 结合。
食物污染物恩镰菌素 A 可引发 ATP 耗竭和细胞浆 Ca(2+) 活性增加，从而导致红细胞自杀性死亡。
