The Effect Of Three Strains Of Alternaria Metabolites And Selenium On Condrocyte From Rabbit’s Knees

Kashin-beck disease is an endemic chronic disease, which seriously affects the physical and mental health of local residents. Since the discovery of Kaschin-beck disease, its etiology is still unclear. This experiment combined with selenium deficiency theory and hypothesis of fungus toxin poisoning, the study of the relationship between selenium-fungal-cartilage cells, provide some new clues to the pathogenic factors for searching for Kashin Beck disease.In this experiment, we selected Alternaria that was isolated from wheat head of a KBD area in Qinghai province, Determination of selenium on the growth effects of Kashin Beck disease endemic area dominant fungi Alternaria. To study the effect of fungal metabolites on animal cartilage cells, and observe the repair effect of selenium on Alternaria metabolites induced cartilage cell injury. We used synthetic medium to cultivate the strain and determinated fungal growth curve under the conditions of different selenium concentrations. We extracted metabolites of these strians with 75% ethanol, cultured rabbit chondrocytes with DMEM contained in metabolites. Cell viability was detected by MTT, the mRNA of expression by RT-PCR, the expression of collagen Ⅱ and aggrecan by toluidine blue and immunohistochemical staining. We take metabolites and selenium in effect on cartilage cells at the same time, determinated the change of various index of cells.The results showed that different selenium concentrations have different effects on different strains. For Alternaria sp 8-5-B, selenium can delay the arrival of stationary phase. There was no significant effects on 8-5-B biomass when selenium concentrations less than 0.2 mg/L. For Alternaria sp 13-8-A, High concentrations of selenium can advance the arrival of stationary phase. For Alternaria sp conf-1, selenium will promote the growth of the strain when its concentration less than 1.Omg/L. Three strains of metabolites can obviously reduce the vitality of cartilage cells. Fungal culture no Se group and 0.5mg/L plus selenium group metabolite effects on cartilage cell viability was significantly higher than that of the other groups. Aggrecan and collangen Ⅱ mRNA expressions of the groups were higher than other groups. The results showed that selenium can affect the growth of Alternaria. Different concentrations of selenium may affect the metabolites of Alternaria, low concentration of selenium may promote the strains to produce poison, high concentration of selenium can inhibit the strains to produce poison. Selenium could partly attenuate the inhibitory effects of Alternaria metabolites. selenium can partly antagonize the inhibitory effects of Alternaria metabolites on aggrecan and collangen Ⅱ synthesis and its mRNA expressions. Low levels of selenium in the environment may be an indirect effect on the people by the fungus metabolites, aggravated the injury on human cartilage cells, increasing the possibility of KBD occurred.