The Effect Of Selenium And The Metabolites Of Fusarium. Spp Isolated From Wheat On Condrocytes Of Rabbit’s Knees

Kashin-Beck disease(KBD) is a deformative, endemic osteoarthropathy, affecting the growth and development of children seriously. It has a high prevalence and morbidity. Pathogenic factors are mainly focused on the environmental factors currently. One of the hypotheses is that KBD is caused by fungal mycotoxins on food and a low selenium environment. However, the risk pathogenic mechanism of Kashin-Beck disease is still unknow.We isolated Fusarium. spp from the wheat in a KBD area of Qinghai province, and took the metabolites of Fusarium. spp that cultured in different levels of selenium on rabbit’s chondrocytes. Cell viability was detected by MTT assay. The mRNA expression of aggrecan and collagen II was measured by semiquantitative RT-PCR. The expression of aggrecan and collagen II was respectively detected by toluidine blue staining and immunehistochemical. The results showed that the metabolites of all this three strains can reduce cell viability significantly. At the same time, they lowered aggrecan and collagen II synthesis in chondrocytes and reduced their mRNA expressions. Compared with the metabolites of the three Fusarium that cultured without selenium, the metabolites of tested strains that cultured with suitable selenium did smaller effect on condrocytes dose-dependently. For 5-5-1 strain and 6-5-1 strain, the inhibitory effects of aggrecan and collagen II synthesis and their mRNA expressions increased when the concentration of selenium higher than 0.5mg/L. For 1-8-B strain, the inhibitory effects increased when the concentration of selenium higher than 0.5mg/L compared to the suitable selenium, but decreased compared to selenium-free treatment.The 5-5-1 strain could produce T-2 toxin, we took different concentrations of T-2 toxin and metabolites of 5-5-1 strain on rabbit’s chondrocytes. The results showed that they could reduce cell viability and significantly decrease aggrecan and collagen II synthesis in chondrocytes and reduced their mRNA expressions. Compared to the pure T-2 toxin, the inhibitory effects of metabolites of 5-5-1 strain that with equal content of T-2 toxin was more obviously.The metabolites of the strains tested could induce chondrocyte to injury similar to KBD in our experiment, it indicates that suitable concentration of selenium can inhibit the ability of producing toxin of stains, thereby reducing its damage on chondrocytes. Fusarium toxin poisoning is not induced by single toxin, which may contributed by the combined effects of multiple mycotoxin.