Upregulation of FoxM1 protects against ischemia/reperfusion-induced myocardial injury

Background. Ischemia/reperfusion (I/R) induced lethal tissue injury in myocardium. FoxM1 (Forkhead Box M1), expressed in proliferating cardiac progenitor cells, could regulate myocardial development. However, the role of FoxM1 in I/R-induced myocardial injury has not been reported yet. Methods. Rats were conducted with regional ischemia followed by reperfusion in myocardium through ligation of the left anterior descending coronary artery. Triphenyl-tetrazolium chloride staining was utilized to assess the infarct size. ELISA was performed to detect activities of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH). Protein expression of FoxM1 in heart tissues and H9c2 were determined by western blot. H9c2 cells were used to establish a hypoxia/reoxygenation cell model, and the cell viability, proliferation and apoptosis were evaluated by MTT, EdU (5-ethynyl-2’-deoxyuridine) staining and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining, respectively. Adenovirus (Ad)-mediated over-expression of FoxM1 was injected into the anterior wall of the left ventricle of rats to evaluate the role of FoxM1 on in vivo I/R-induced myocardial injury. Results. FoxM1 was reduced in heart tissues isolated from rats post myocardial I/R injury. Forced FoxM1 expression increased cell viability and proliferation of hypoxia/reoxygenation-induced H9c2, while repressed the cell apoptosis with increased Bcl-2 and decreased Bax and cleaved caspase-3. Injection of Ad-FoxM1 suppressed infarct size of the heart and decreased activities of CK-MB and LDH. Conclusion. FoxM1 attenuated I/R-induced myocardial injury, providing potential therapeutic target for the disease.