Apoptosis induction by T-2 toxin: Activation of caspase-9, caspase-3, and DFF-40/CAD through cytosolic release of cytochrome c in HL-60 cells

• Published in: Bioscience, biotechnology, and biochemistry biotechnology, and biochemistry, 2001-08, Vol.65 (8), p.1741-1747
• Main Authors: Nagase, M. (Kagawa Univ., Miki (Japan). Faculty of Agriculture), Alam, M.M, Tsushima, A, Yoshizawa, T, Sakato, N
• Format: Article
• Language: English
• Subjects: APOPTOSIS; Apoptosis - drug effects; Biological and medical sciences; Blotting, Western; Caspase 3; Caspase 9; Caspases - metabolism; CELLS; CYTOCHROME C; Cytochrome c Group - metabolism; Cytosol - drug effects; Cytosol - enzymology; Deoxyribonucleases - metabolism; DFF-45/ICAD; DNA Fragmentation; Electrophoresis, Polyacrylamide Gel; Enzyme Activation - drug effects; HL-60 Cells; Humans; Indicators and Reagents; LEUKAEMIA; MAIZE; Medical sciences; Mitochondria - drug effects; Mitochondria - enzymology; MYCOTOXINS; Nucleosomes - chemistry; Nucleosomes - drug effects; Plant poisons toxicology; Poly-ADP-Ribose Binding Proteins; T-2 TOXIN; T-2 Toxin - toxicity; Toxicology; trichothecene mycotoxins
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.65.1741

The molecules participating in apoptosis induced by T-2 toxin in human leukemia HL-60 cells were investigated. The rank order of the potency of trichothecene mycotoxins to induce internucleosomal DNA fragmentation was found to be T-2, satratoxin G, roridin A >> diacetoxyscirpenol > baccharin B-5 >> nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, fusarenon-X, baccharin B-4 = vehicle control. Western blot analysis of caspase-3 in T-2-treated cells clearly indicated the appearance of its catalytically active fragment of 17-kDa. Increased caspase-3 activity was also detected by using a fluorogenic substrate, DEVD-AMC. Next, cells exposed to T-2 led to cleavage of PARP from its native 116-kDa form to the 85-kDa product. Moreover, DFF-45/ICAD were cleaved to give a 12.5-kDa fragment via T-2 treatment. T-2 caused the release of cytochrome c from mitochondria into the cytosol. Increased enzymic activity of caspase-9 on LEHD-AMC was shown. These data indicate that T-2-induced apoptosis involves activation of caspase-3 and DFF-40/CAD through cytosolic accumulation of cytochrome c along with caspase-9 activation.