Caspase Cascade Proceeds Rapidly After Cytochrome c Release From Mitochondria in Tumor Necrosis Factor-α-Induced Cell Death
Autor: | Kazutaka Momose, Takuo Suzuki, Haruna Sakurai, Hisayuki Ohata, Tetsu Kobayashi, Kazuo Honda, Akiko Ishii-Watabe, Hiroshi Kawai, Takao Hayakawa, Toru Kawanishi |
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Rok vydání: | 2007 |
Předmět: |
Programmed cell death
Cell Survival Mitochondrion Transfection Mitochondrial apoptosis-induced channel Humans Caspase Cell Size Pharmacology Cell Death biology Tumor Necrosis Factor-alpha Cytochrome c lcsh:RM1-950 Cytochromes c Depolarization Molecular biology Mitochondria Cell biology lcsh:Therapeutics. Pharmacology Microscopy Fluorescence Apoptosis Caspases biology.protein Molecular Medicine Tumor necrosis factor alpha HeLa Cells Plasmids Signal Transduction |
Zdroj: | Journal of Pharmacological Sciences, Vol 103, Iss 2, Pp 159-167 (2007) |
ISSN: | 1347-8648 1347-8613 |
DOI: | 10.1254/jphs.fp0060877 |
Popis: | The caspase activation cascade and mitochondrial changes are major biochemical reactions in the apoptotic cell death machinery. We attempted to clarify the temporal relationship between caspase activation, cytochrome c release, mitochondrial depolarization, and morphological changes that take place during tumor necrosis factor (TNF)-α-induced cell death in HeLa cells. These reactions were analyzed at the single-cell level with 0.5 – 1 min resolution by using green fluorescent protein (GFP)-variant-derived probes and chemical probes. Cytochrome c release, caspase activation, and cellular shrinkage were always observed in this order within 10 min in all dying cells. This sequence of events was thus considered a critical pathway of cell death. Mitochondrial depolarization was also observed in all dying cells observed, but frequently occurred after caspase activation and cellular shrinkage. Mitochondrial depolarization is therefore likely to be a reaction that does not induce caspase activation and subsequent cellular shrinkage. Mitochondrial changes are important for apoptotic cell death; moreover, cytochrome c release, and not depolarization, is a key reaction related to cell death. In addition, we also found that the apoptotic pathway proceeds only when cells are exposed to TNF-α. These findings suggest that the entire cell death process proceeds rapidly during TNF-α exposure. Keywords:: tumor necrosis factor (TNF)-α, cytochrome c, mitochondrial depolarization, caspase, real-time imaging |
Databáze: | OpenAIRE |
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