T-2毒素对胎儿软骨细胞凋亡、Bcl-2和Bax表达的影响及硒的保护作用

目的　探讨T 2毒素对软骨细胞凋亡的作用,和对凋亡调控蛋白Bcl 2 与Bax表达的影响,以及微量元素硒对软骨细胞的保护作用。方法　采用电镜,Annexin V/PI法检测T 2 毒素致人软骨细胞凋亡的情况,采用流式细胞仪检测凋亡相关蛋白Bcl 2和Bax的表达。结果　T 2 毒素可引起软骨细胞发生凋亡的典型电镜形态改变;不同浓度(1~20μg/L)的T 2毒素均可以引起软骨细胞早期凋亡率和晚期凋亡率明显增加,且在一定范围内呈浓度依赖性,T 2毒素浓度为20μg/L时早期凋亡率最高达5.60%,晚期凋亡率最高达8.61%。生理浓度的微量元素硒可部分减弱T 2毒素引起的凋亡;不同浓度(1~20μg/L)的T 2毒素都能引起Bcl 2和Bax表达水平提高,浓度为10~20μg/L时,Bax/Bcl 2比值升高;硒能部分对抗T 2 毒素引起的Bcl 2 和Bax 表达的提高,使Bax/Bcl 2 比值下降,以降低凋亡率。结论　T 2毒素在浓度为1 ~ 20μg/L 时,可以引起软骨细胞凋亡; T 2 毒素引起的软骨细胞凋亡与软骨细胞内Bax/Bcl 2比值升高有关,硒对T 2毒素引起的软骨细胞凋亡有一定保护作用。

Effect of T-2 toxin on chondrocyte apoptosis and Bcl-2/Bax expression

Objective To investigate the effects of T-2 toxin on chondrocytes apoptosis and to study the relationship between T-2 toxin-induced chondrocytes apoptosis and its Bcl-2/Bax expression, and inhibitory effect of selenium on chondrocytes apoptosis induced by T-2 toxin. Methods Human chondrocytes cultured in vitro were treated with different concentrations (1～20 μg/L) of T-2 toxin at different times (1～5 day). Apoptotic ultrostructural changes of the treated cells were observed under electron microscope. Apoptotic biological changes were detected by Annexin V/PI FCM. Bcl-2 and Bax expressions were determined by FCM using monoclone FITC-Bcl-2 and FITC-Bax antibodies. Results Apoptotic body was found in T-2 toxin-treated chondrocytes by electron microscopy. Early-stage apoptosis and late-stage apoptosis rate were both increased in T-2 toxin-treated cells when compared with non-treated cells. Dose-dependent effect of T-2 toxin was found on apoptosis of chondrocytes in a certain range. The highest apoptosis rate was at 20 μg/L T-2 toxin treated chondrocytes. Apoptosis were found at different times on 1,3 or 5 day after 10μg/L T-2 toxin treatment, and peak apoptotic rate of chondrocytes was seen on the third day after treatment with T-2 toxin. The overexpression of Bcl-2 and Bax were detected and Bax/Bcl-2 ratio was increased after T-2 toxin treated chondrocytes. Selenium could partly block the apoptosis of chondrocytes induced by T-2 toxin. Conclusion Apoptosis of chondrocytes can be induced by T-2 toxin (1～20 μg/L). Bcl-2 and Bax have inhibitory and promotive effects on T-2 toxin-induced apoptosis of human chondrocytes, and Bax /Bcl-2 index may play an important role in apoptosis induced by T-2 toxin in human chondrocytes.