Calpain-2 activity promotes aberrant endoplasmic reticulum stress-related apoptosis in hepatocytes

Figure 1 Dithiothreitol exhibits dose-dependent cytotoxicity against BRL-3A cells. A: BRL-3A cells were treated in triplicate with, or without, the indicated doses of dithiothreitol (DTT) for 24 h and their viability was examined by MTT. The percentages (y) of cell viability were calculated by the equation, y = -9.3654x + 95.744 with a correlation (R² = 0.9781), here x represents DTT concentration. Accordingly, the DTT LD₅₀ = 4.88 mM; B, C: Subsequently, BRL-3A cells were treated with 2.0 mmol/L DTT for varying periods and stained with FITC-Annexin-V and PI. The percentages of mechanically damaged (B1 quadrant), healthy (B3), early (B4) and late apoptotic and necrotic (B2) cells were analyzed by flow cytometry. Data are representative flow cytometry charts or expressed as the mean ± SD of each group from three separate experiments. ^aP < 0.05, ^bP < 0.01.