Apoptosis and gene expression in Jurkat human T cells and lymphoid tissues of fusarenon-X-treated mice.

Fusarenon X, a member of the type B trichothecene mycotoxin group, has been frequently observed, along with deoxynivalenol (DON) and nivalenol (NIV) as a contaminant in cereals. Our previous study demonstrated that a 14-day FX exposure caused apoptosis in the lymphoid tissues of mice, especially at 0.5 mg/kg bodyweight. However, the relationship between low concentrations of FX and apoptotic molecular machinery remains unclear. In the present study, we investigated the genetic regulatory mechanisms in the thymus and Peyer's patches of mice after 14 days oral administration of FX at 0.5 mg/kg bodyweight. FX caused the up-regulation of Bax, Bid, Trp53, and Caspase-9 mRNA but the relative expression of Fas, TNF, and Caspase-8 remained unchanged. Furthermore, we also determined the toxicity of FX in Jurkat T-cells. FX exhibited a concentration- and time-dependent inhibition of cell viability. Thus, incubation time and FX concentration influence the percentage of apoptotic cells. These data suggested that treatment with low dosage of FX can induce apoptosis in lymphocytes through an effect on Bax, Bid, Trp53, and Caspase-9 and therefore the mitochondrial apoptotic pathway.