INRA, UMR 1331, ToxAlim, Research Centre in Food Toxicology, F 31027 Toulouse, France.
Toxicon. 2013 May;66:31-6. doi: 10.1016/j.toxicon.2013.01.024. Epub 2013 Feb 10.
Trichothecenes induce changes in the intestinal barrier function through decreased expression of cell junction proteins and apoptosis of enterocytes. The mitogen activated protein kinases (MAPK) play an important role in the signaling pathways of cell turnover and differentiation. Using ex vivo and in vivo approaches, the purpose of this study was to investigate the ability of low doses of DON to induce histological changes in the intestine and to activate the MAPK ERK 1/2, p38 and JNK. Twelve weaning piglets received during four weeks a control diet or a DON-contaminated diet (2.3 mg DON/kg feed). Six weaning piglets were used to prepare jejunal explants (ex vivo model). Explants were exposed during 4 h to vehicle, 5 or 10 μM DON. Intestinal changes were graded using a histological score. Pigs fed a DON-diet and explants exposed to DON showed a significant decrease in the jejunal score. In both models, the toxin significantly enhanced phosphorylation of ERK 1/2 and p38, whereas the increased phosphorylation of JNK was non significant. Taken together these results indicate that in vivo or ex vivo exposure of intestinal tissue to DON lead to similar intestinal lesions and activation of MAPK. These effects could impair the homeostasis of intestinal tissue in the aspects of barrier function and immune protection. The similarity of the in vivo and ex vivo results provides also strong evidence that the jejunal explant model is a good alternative for toxicological studies in intestinal tissue.
脱氧雪腐镰刀菌烯醇通过降低细胞连接蛋白的表达和肠上皮细胞凋亡来诱导肠道屏障功能改变。丝裂原活化蛋白激酶(MAPK)在细胞更新和分化的信号通路中发挥重要作用。本研究采用离体和在体方法,旨在研究低剂量 DON 诱导肠道组织学变化和激活 MAPK ERK 1/2、p38 和 JNK 的能力。12 头断奶仔猪在四周内接受对照饮食或 DON 污染饮食(饲料中 DON 含量为 2.3mg/kg)。6 头断奶仔猪用于制备空肠切片(离体模型)。离体模型中,将空肠切片暴露于对照、5 或 10μM DON 中 4 小时。采用组织学评分评价肠道变化。饲喂 DON 日粮的仔猪和暴露于 DON 的空肠切片显示空肠评分显著降低。在这两种模型中,毒素均显著增强了 ERK 1/2 和 p38 的磷酸化,而 JNK 的磷酸化增加则不显著。综上所述,这些结果表明,肠组织在体或离体暴露于 DON 可导致相似的肠道损伤和 MAPK 激活。这些作用可能会损害肠道组织的屏障功能和免疫保护的内稳态。体内和离体结果的相似性也为肠组织毒理学研究提供了强有力的证据,证明空肠切片模型是一个很好的替代方法。