Abstract
We tested the hypothesis that heat shock protein (Hsp) induction and cell death are mutually exclusive responses to stress. Despite activation of heat shock transcription factor 1 at temperatures ranging from 40 to 46 degrees C, Hsp72 and Hsp27 were not induced above 42 degrees C. Moreover, cells underwent apoptosis at 44 degrees C and necrosis at 46 degrees C, with mitochondrial cytochrome c release at both temperatures. However, only apoptosis was associated with caspase activation. Treatment of cells with z-VAD-fmk prior to heat shock at 44 degrees C failed to restore Hsp induction despite inhibition of heat-induced apoptosis. Furthermore, accumulation of Hsps after incubation at 42 degrees C rendered the cells resistant to apoptosis. These results suggest that lack of Hsp induction is the cause rather than the consequence of cell death.
Original language | English |
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Pages (from-to) | 306–310 |
Number of pages | 5 |
Journal | FEBS Letters |
Volume | 461 |
Issue number | 3 |
DOIs | |
Publication status | Published - 19 Nov 1999 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Apoptosis/genetics
- Caspases/physiology
- Gene Expression Profiling
- Gene Expression Regulation
- Heat-Shock Proteins/physiology
- Hot Temperature
- Humans
- Jurkat Cells
- Kinetics
- Mitochondria/physiology
- Stress, Physiological/genetics