Thermotolerance and cell death are distinct cellular responses to stress: dependence on heat shock proteins

FEBS Letters

Holmberg, Carina I.¹  Sistonen, Lea¹  Orrenius, Sten²  Samali, Afshin² 

[1] Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, 20521 Turku, Finland;Institute of Environmental Medicine, Division of Toxicology, Karolinska Institutet, Box 210, S-171 77 Stockholm, Sweden

关键词: Apoptosis;    Caspase;    Heat shock protein;    Heat shock factor 1;    Necrosis;    Thermotolerance;   

DOI  :  10.1016/S0014-5793(99)01486-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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°C, Hsp72 and Hsp27 were not induced above 42°C. Moreover, cells underwent apoptosis at 44°C and necrosis at 46°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°C failed to restore Hsp induction despite inhibition of heat-induced apoptosis. Furthermore, accumulation of Hsps after incubation at 42°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.

【 授权许可】

Unknown