Induction of heat shock proteins in short-term cultured hepatocytes derived from normal and chronically griseofulvin-treated mice
✍ Scribed by Kurt Zatloukal; Ruth Sohar; Elisabeth Lackinger; Helmut Denk
- Publisher
- John Wiley and Sons
- Year
- 1988
- Tongue
- English
- Weight
- 691 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0270-9139
No coin nor oath required. For personal study only.
✦ Synopsis
Freshly isolated mouse hepatocytes were tested with respect to the induction of heat shock (stress) proteins by elevated temperature, sodium arsenite and ethanol treatment. With heat, arsenite and ethanol treatments, the synthesis of a protein with a molecular weight of 68 kD (heat shock protein 68) was predominantly elevated; arsenite and ethanol exerted their effects on heat shock protein synthesis in a dose-dependent manner. Hepatocytes derived from livers of chronically griseofulvinpretreated mice differed in their response from normal hepatocytes in that ethanol was ineffective in these cells. These results indicate that different modes and pathways of the stress response exist, depending on the nature of the inducing agent but also on pretreatment conditions. In uiuo, pathologic alterations of cells and organs (e.g., in the course of chronic diseases) can, therefore, be expected to modulate the stress response.
The heat shock (stress) response is a reaction of cells to diverse metabolic, chemical and physical stress conditions, including hyperthermia, hypoxia, lytic viral infections, pH changes, treatment with various chemicals and mechanical trauma, which is highly conserved during evolution [for review, see Refs. (1-3)]. It is regulated at both transcriptional and translational levels and leads to the appearance of a set of proteins, called heat shock or stress proteins (HSPs), often, but not always, followed by reduction of the synthesis of normal proteins (4-6).
HSPs repress their own synthesis at both transcriptional and posttranscriptional levels (4, 7). The heat shock response depends on a variety of factors, particularly nature, intensity and duration of stress. This response is extremely rapid and neither new protein nor RNA synthesis is required. HSPs are not necessarily novel proteins but may be produced at basal rates in cells; synthesis is then increased in response to stress conditions (8). However, some tissues (e.g., in the embryo) do not respond (9). The biological role of the heat shock response is still unclear; the ubiquity of the response and its considerable uniformity after diverse stress conditions suggest a multipurpose system with functions involved t This work is dedicated to Professor H. G. Klingenberg.