INDUCTION OF A 31,000-DALTON STRESS PROTEIN BY PROSTAGLANDIN-D2 AND PROSTAGLANDIN-J2 IN PORCINE AORTIC ENDOTHELIAL-CELLS

Prostaglandin (PG) D2 and PGJ2 stimulated porcine aortic endothelial cells to synthesize a 31,000-dalton protein (termed p31) in a time- and concentration-dependent manner. The induction of p31 synthesis was specific for PGD2, PGJ2 and PGA1 among the various PGs tested. p31 was also synthesized in response to the thiol-reactive agent diethylmaleate and heavy metal sodium arsenite but not to high temperature treatment, platelet-derived growth factor, and 12-O-tetradecanoylphorbol 13-acetate. Using two-dimensional polyacrylamide gel electrophoresis, p31 induced by PGJ2 had an isoelectric point of 5.4, which overlapped exactly with that induced by arsenite. These results taken together indicate that p31 represents one of the stress proteins whose expression is regulated primarily by thio-active compounds but not by hyperthermia. Furthermore, it was induced by PGD2 and PGJ2 in rat capillary endothelial cells, rat skin fibroblasts, and rat hepatocytes. The data obtained from this study suggest that p31 induced by PGD2 and PGJ2 may play a role in the metabolic regulation of many mammalian cells.