Laboratory for Research on Biologically Compatible Compounds, Faculty of Dentistry, Rue Avicenne, 5019 Monastir, Tunisia.
Food Chem Toxicol. 2012 May;50(5):1680-9. doi: 10.1016/j.fct.2012.01.015. Epub 2012 Jan 17.
Deoxynivalenol (DON) is a widespread trichothecene mycotoxin which contaminates cereal crops and harmfully affects the gastrointestinal tract. Since it is well known that mitochondria play a central role in apoptosis triggered by many stimuli, an effort was made to examine whether DON-induced cytotoxicity occurs through mitochondria-mediated apoptotic pathway. The intestinal system being one of the primary targets of mycotoxins, the human colon carcinoma cell line HCT116 was used in this study. Using flow cytometric analyses and immunofluorescence, we showed that DON at 100 μM induced a mitochondria-dependent apoptotic pathway associated with opening of the mitochondrial permeability transition pore (PTP), loss of the mitochondrial transmembrane potential (ΔΨm), downstream generation of O₂·⁻ and cytochrome c release. The DON-induced apoptosis was accompanied by an activation of caspase 9 and 3, as demonstrated by Western blot and caspase activity assay. In addition, by taking advantage of HCT116 cells invalidated for Bax, we showed that this pro-apoptotic protein favored mitochondrial alterations induced by the mycotoxin. Besides, incubation of purified mitochondria with DON indicated that this mycotoxin does not directly target mitochondria to induce PTP-dependent permeabilization of mitochondrial membranes. Altogether, our results indicate that mitochondria-related caspase-dependent apoptotic pathway is involved in this in vitro model of DON induced-cytotoxicity.
脱氧雪腐镰刀菌烯醇（DON）是一种广泛存在的单端孢霉烯族毒素，污染谷物作物并对胃肠道造成有害影响。由于众所周知，线粒体在许多刺激物引发的细胞凋亡中起着核心作用，因此我们努力研究 DON 是否通过线粒体介导的凋亡途径引起细胞毒性。由于肠道系统是霉菌毒素的主要靶标之一，因此本研究使用了人结肠癌细胞系 HCT116。通过流式细胞术分析和免疫荧光，我们表明 100 μM 的 DON 诱导了与线粒体通透性转换孔（PTP）开放、线粒体跨膜电位（ΔΨm）丧失、下游 O₂·⁻产生和细胞色素 c 释放相关的线粒体依赖性凋亡途径。DON 诱导的凋亡伴随着 caspase 9 和 3 的激活，这通过 Western blot 和 caspase 活性测定得到证实。此外，通过利用 Bax 无效的 HCT116 细胞，我们表明这种促凋亡蛋白有利于霉菌毒素引起的线粒体改变。此外，用 DON 孵育纯化的线粒体表明，这种霉菌毒素不会直接靶向线粒体诱导 PTP 依赖性线粒体膜通透性。总之，我们的结果表明，与线粒体相关的 caspase 依赖性凋亡途径参与了 DON 诱导的体外细胞毒性模型。
