[Effect of NO and Fas pathway on T-2 induced apoptosis in chondrocytes]

Abstract

Objective: To investigate the relationship of T-2 toxin-induced chondrocytes apoptosis with nitric oxide(NO) and Fas apoptosis pathway.

Methods: Human chondrocytes cultured in vitro were treated with different concentrations of T-2 toxin at different time (1-5 d). Cell viability of the treated cells was measured by MTT assay. Apoptotic ultrostructural changes of the treated cells were observed with electron microscopy. Biological changes of apoptosis were detected by annexin V/PI Flow cytometer (FCM). The levels of NO in culture media were detected by colorimetric method of Griess assay. Nitric oxide synthase (iNOS) and Fas protein were measured by Western blot.

Results: In this study the results shown the dose-dependent and time-dependent effects of T-2 toxin, within a range of concentration (1-2000 ng/mL) and a period of time (1-5 d), on the T-2 toxin-treated chondrocytes. Apoptotic body was found in T-2 toxin-treated chondrocytes by electron microscopy. Early-stage apoptosis rate and late-stage apoptosis rate were both increased in T-2 toxin-treated cells when compared with non-treated cells in a dose-dependent manner. The levels of NO in T-2 toxin-treated culture media were higher than that of normal control. Over-expressions of iNOS and Fas protein were detected in T-2 toxin-treated cells. T-2 toxin-induced apoptosis was noted to be significtnly correlated with the level of NO production and the levels of iNOS and Fas protein expression.

Conclusion: T-2 toxin can enhance NO production and upregulate the expression of iNOS and Fas protein. Both NO and Fas signaling pathway are involved in T-2 toxin-induced apoptosis.