Heat Shock Protein 70 Expression Kinetics

HSP70 is well known for its major role in cardiac ischemia protection. The purpose of this study was to determine the HSP70 expression kinetics for new protocol design in cardiac surgery, based on HSP70 protection function in clinical applications. Bovine aortic endothelial cells (BAEC) were used in experiments. Cells were heated at 42°C at different time intervals up to 5 hours and subsequently incubated at 37°C for up to 48 hours. Western blot and quantitative protein analysis were performed to measure HSP70 expression. The expression kinetics is a function of thermal stress time as well as poststress time. At least three stages were identified for the kinetics curve: increasing, maximum plateau and decreasing regions. The peak HSP70 concentration is 10 times the basal level for western blot analysis in BAECs. Two hours incubator heating followed by twelve hours post-heating falls in the plateau region. This research result provides information applicable to evaluation of energy sources and heating methods to induce optimal HSP70 expression in a target tissue.