Endothelins stimulate the production of stromelysin-1 in cultured rat astrocytes

The effects of endothelins (ETs) on the production of stromelysins, a sub-family of matrix metalloproteinases, were examined in cultured astrocytes. The treatment of cultured rat astrocytes with ET-1 increased stromelysin-1 mRNA levels, while stromelysin-2 and -3 mRNAs were not affected. Immunocytochemical observations showed that cultured astrocytes produced stromelysin-1 protein. ET-1 and Ala1,3,11,15-ET-1, an ETB receptor selective agonist, stimulated the release of stromelysin-1 from cultured astrocytes. Accompanying the increase in protein release, the peptidase activity of stromelysin-1 in the medium was also increased by ET-1. The effects of ET-1 on astrocytic stromelysin-1 expression were inhibited by PD98059, staurosporine, and Ca2+ chelation, but not by SB203580 or pyrrolidine dithiocarbamate. These results show that activation of astrocytic ET receptors stimulates the production of stromelysin-1, suggesting a role for ETs in stromelysin production in brain pathologies.