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Molecular Mechanism of Satratoxin-Induced Apoptosis in HL-60 Cells: Activation of caspase-8 and caspase-9 Is Involved in Activation of caspase-3

Masahiro Nagase, Tetsuya Shiota, Akiko Tsushima, Mohammad Murshedul Alam, Satoshi Fukuoka, Takumi Yoshizawa, Nobuo Sakato

Immunol Lett. 2002 Oct 21;84(1):23-7.

PMID: 12161280

Abstract:

Satratoxins have been recognized as potential immunomodulatory agents in outbreaks of building-related illness. Here we report that satratoxin G-treated human leukemia HL-60 cells underwent apoptosis through the action of caspase-3 which was activated by both caspase-8 and caspase-9. Western blot analysis of caspase-3 in the satratoxin G-treated cells apparently indicated the appearance of a catalytically active fragment of 17 kDa. Increased caspase-3 activity was also detected by using a fluorogenic substrate, DEVD-AMC. Next, exposure to satratoxin G led to cleavage of PARP from its native 116 kDa form to a 85 kDa product. Moreover, DFF-45/ICAD were cleaved into a 12.5 kDa fragment via satratoxin G treatment. Enzymic assay on IETD-AMC revealed that caspase-8 is strongly activated by exposure to satratoxin G while T-2 toxin (T-2) could not activate caspase-8 at an early stage of apoptosis. Furthermore, satratoxin G caused a release of cytochrome c from mitochondria into the cytosol and increased the activity of caspase-9 against LEHD-AMC. These findings indicate that satratoxin G-induced apoptosis involves activation of caspase-3 and DFF-40/CAD through both activation of caspase-8 and cytosolic accumulation of cytochrome c along with activation of caspase-9.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
IAR4241003 Caspase 8 Substrate, fluorogenic Caspase 8 Substrate, fluorogenic Price
IAR42415985 Caspase-9 Substrate I, Fluorogenic Caspase-9 Substrate I, Fluorogenic Price
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