T-2毒素对软骨Ⅱ型胶原蛋白和蛋白聚糖合成的影响以及硒的保护作用

Protective effect of selenium against T-2 toxin-induced inhibition of chondrocyte aggrecan and collagen Ⅱ synthesis

目的探讨T-2毒素对软骨细胞主要间质成分Ⅱ型胶原蛋白和蛋白聚糖合成的影响和硒的保护作用。方法采用 MTT法检测T-2毒素对软骨细胞存活率的影响;用TB染色法检测人软骨细胞蛋白聚糖表达;免疫组织化学检测人软骨细胞胶原蛋白Ⅱ表达;RT-PCR检测人软骨细胞Ⅱ型胶原蛋白和蛋白聚糖mRNA表达。结果 T-2毒素在浓度为 0．001-2 mg／L的范围内,对软骨细胞的作用呈较典型的浓度依赖关系和时间依赖关系,而且随着作用时间的延长,浓度依赖关系更加明显。T-2毒素(10～20μg／L)可以抑制软骨细胞Ⅱ型胶原蛋白和蛋白聚糖的合成及其mRNA表达。而加硒能较明显刺激软骨细胞蛋白聚糖mRNA表达,部分减弱T-2毒素的这种抑制,有一定的保护作用,但不显示对T-2 毒素引起的Ⅱ型胶原蛋白及其mRNA表达的保护作用。结论 T-2毒素对软骨细胞Ⅱ型胶原蛋白和蛋白聚糖合成有明显的抑制作用,微量元素硒对T-2毒素引起的软骨细胞蛋白聚糖改变有一定保护作用。

Objective To study the inhibitory effect of T-2 toxin on the expression of aggrecan and collagen Ⅱ in chondrocytes and the protection of selenium against this effect. Methods Human chondrocytes cultured in vitro were treated with T-2 toxin at different concentrations for varied time periods （1-5 days）, and the cell viability was measured by MTT assay, Aggrecan expression was detected by toluidine blue staining and collagen Ⅱ expression by immunostaining using monoclonal antibody of collagen. Aggrecan and collagen Ⅱ mRNA expressions were measured by semiquantitative RT-PCR. Results T-2 toxin dose- and time-dependently affected chondrocyte viability within the concentration range of 0.001-2 mg/L, the prolonged treatment time further enhanced the dose dependence of the inhibitory effect. T-2 toxin lowered aggrecan and collagen Ⅱ synthesis in the chondrocytes and reduced their mRNA expressions. Selenium could partly attenuate the inhibitory effects of T-2 toxin on aggrecan mRNA expression, but showed no such effect against T-2-induced collagen Ⅱ expression. Conclusion T-2 toxin can obviously inhibit aggrecan and collagen Ⅱ synthesis in human chondrocytes, and selenium can partly antagonize the inhibitory effects of T-2 toxin on aggrecan.