Effects of T-2 toxin on the mitochondrial membrane potential and ATP.

<p><b>A.</b> Normal human chondrocytes were exposed to 1 10, 20 ng/ml T-2 toxin and 1 uM Na₂SeO₃+20 ng/ml T-2 toxin for 5 d. The mitochondrial membrane potential of chondrocytes was analyzed using the fluorescent dye JC-1, and quantified by a flow cytometer. <b>B.</b> Effect of different concentrations of T-2 toxin on the cellular ATP. *<i>P</i><0.01 vs. control; #<i>P</i><0.01 vs. 20 ng/ml T-2 toxin group.</p

Effects of different concentrations of T-2 toxin on the cellular viability of chondrocytes were estimated by MTT reduction.

<p>Cells were incubated in absence or presence of several T-2 toxin concentrations for different time periods (1–5 d). *<i>P</i><0.05.</p

The effects of T-2 toxin on caspase-9 and caspase-3 activities in human chondrocytes.

<p>Cells were treated with 1, 10, 20 ng/ml T-2 toxin and 1 uM Na₂SeO₃+20 ng/ml T-2 toxin for 5 d. The activities of caspase-9 (<b>A</b>) and caspase-3 (<b>B</b>) were measured using the substrate Ac-LEHD-pNA and Ac-DEVD-pNA, separately. *<i>P</i><0.05 vs. control; #<i>P</i><0.01 vs. 20 ng/ml T-2 toxin group.</p

Values of mitochondrial respiratory chain complexes in cultures of normal chondrocytes treated with 20 ng/ml T-2 toxin for 5 days.

<p>Values are the mean ± SD. CS = citrate synthase. †CS-corrected complex activity is expressed as (nmoles/minute/mg protein)/(CS specific activity) ×100. *<i>P</i><0.05 versus normal chondrocytes. #<i>P</i><0.05 versus 20 ng/ml T-2 toxin group. Complex I = rotenone-sensitive NADH-coenzyme Q1 reductase; complex II = succinate dehydrogenase; complex III = antimycin-sensitive ubiquinol cytochrome c reductase; complex IV = cytochrome c oxidase; complex V = ATP synthase.</p><p>Values of mitochondrial respiratory chain complexes in cultures of normal chondrocytes treated with 20 ng/ml T-2 toxin for 5 days.</p

Effects of T-2 toxin on ROS and antioxidants generation.

<p>The production of ROS at mitochondrial (<b>A</b>) and cytoplasmic (<b>B</b>) level was assessed by MitoSOX red mitochondrial superoxide indicator and Carboxy-H₂DCFDA probe (both from Invitrogen), respectively. GSH concentration (C) and GPx activity (D) were measured by coupled enzyme assay as described under “Materials and methods”. Chondrocytes were incubated with1, 10, 20 ng/ml T-2 toxin and 1 uM Na₂SeO₃+20 ng/ml T-2 toxin for 5 d. *<i>P</i><0.01 vs. control; #<i>P</i><0.01 vs. 20 ng/ml T-2 toxin group.</p