Immediate early gene expression in vascular smooth-muscle cells synergistically induced by hemolysate components

Abstract

Object. Vasospasm after subarachnoid hemorrhage is associated with changes in modulators of vascular tone in the arterial wall and is related to the presence of erythrocyte hemolysate in the subarachnoid space. The purpose of this study was to determine the compounds in erythrocyte hemolysate that are responsible for changing smooth-muscle cell gene expression. Methods. Rat aorta smooth-muscle cells were exposed to erythrocyte hemolysate in vitro and the effects on immediate early gene messenger (m)RNA levels were determined by competitive reverse transcriptase—polymerase chain reaction. Message levels for c-fos, jun B, and c-jun were increased in the presence of hemolysate, reaching maximum expression between 30 and 60 minutes, whereas the level of jun D mRNA was unaffected. Increasing doses of hemolysate caused greater expression of c-fos and jun B, but not c-jun. Adenosine triphosphate and hemoglobin, possible spasmogens present in hemolysate, caused much smaller and more rapid increases in c-fos expre...