Exercise training-induced different improvement profile of endothelial progenitor cells function in mice with or without myocardial infarction

Neovascularization in response to ischemia after myocardial infarction (MI) has been widely considered as being initiated by endothelial progenitor cells (EPCs). Well-documented evidences in recent years have proved exercise training (ET) improving EPC function. However, whether ET-induced improvement of EPC function under or without ischemic state is different has not been reported.Mice performed ET following an exercise prescription 1week after MI or non-MI surgery respectively. Bone marrow-derived EPCs were isolated at 0day, 3days, 1week, 2weeks, 4weeks, and 8weeks of ET. After 7days cultivation, EPC functions including proliferation, adhesion, migration, and in vitro angiogenesis were measured. AKT/glycogen synthase kinase 3β (GSK3β) signaling pathway was tested by western blotting.EPC function in mice underwent non-MI surgery was attenuated overtime, while ET ameliorated this tendency. EPC function was peaked at 4weeks ET in non-MI surgery mice and maintained with an extended exercise time. Besides, simple ischemia was sufficient to enhanced EPC function, with a maximum at 2weeks of MI surgery. In MI mice, ET further improved EPC function and achieved peak at 2weeks exercise. Furthermore, AKT/GSK3β signaling pathway activation was consistent with EPC function change after ischemia, which was further promoted by 4weeks exercise.ET significantly increased EPC function in mice both with and without MI, but the time points of peak function were different.