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Roles of compatible osmolytes and heat shock protein 70 in the induction of tolerance to stresses in porcine endothelial cells
Author(s) -
Alfieri Roberta R.,
Petronini Pier Giorgio,
Bonelli Mara A.,
Desenzani Silvia,
Cavazzoni Andrea,
Borghetti Angelo F.,
Wheeler Kenneth P.
Publication year - 2004
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2003.058412
Subject(s) - osmolyte , osmotic shock , hsp70 , heat shock protein , osmotic concentration , betaine , heat shock , osmotic pressure , shock (circulatory) , biophysics , microbiology and biotechnology , chemistry , biology , biochemistry , medicine , gene
Studies of the responses of porcine pulmonary endothelial cells to acute hypertonic stress have been extended by examining the induction and underlying mechanisms of cell tolerance to both osmotic and heat stresses. Preliminary adaptation of these cells to 0.4osmol (kg H 2 O) −1 rendered them tolerant either to subsequent severe osmotic stress (0.7osmol (kg H 2 O) −1 ) or to subsequent severe heat shock (50 min at 49°C). In contrast, preliminary exposure of the cells to mild heat shock (44°C for 30 min) induced tolerance only to severe heat shock, not to hyperosmotic stress. Induction of tolerance to heat shock by either procedure correlated with the induced expression of heat shock protein 70 (HSP70). Induction of tolerance to hyperosmotic stress, on the other hand, was associated with the cellular accumulation of osmolytes, such as amino acids, betaine and myo ‐inositol, and did not correlate with the induced expression of HSP70. It also required a reduction in the final change of osmotic pressure applied to the cells, such that maximum cell shrinkage would not be much more than 40%. In general, therefore, HSP70 and compatible osmolytes have distinct roles in cellular adaptation to these stresses.