Fig. 7

HPC facilitated the anti-apoptotic and pro-angiogenic effects of BM-MSCs. a Representative terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) images for cell apoptosis in the border zone around the infarcted area in mouse hearts. Apoptotic nuclei were identified as TUNEL positive (green fluorescence). The myocardium was stained using a monoclonal antibody against cTnI (red fluorescence) and total nuclei by 4,6-diamidino-2-phenylindole (DAPI) counterstaining (blue fluorescence). Scale bar = 50 μm. b Capillaries in the infarct border zone were determined by immunohistochemical staining for CD31-positive cells in all groups. Scale bars = 50 μm. Quantitative analysis of apoptotic nuclei (c) and capillaries in the infarct border zone (d). Data are expressed as means ± SEM; n = 5; *p < 0.05. 3-MA 3-methyladenine, ^HPC MSCs hypoxic preconditioned mesenchymal stem cells, HPF high-powered field, MI myocardial infarction, ^NPC MSCs normal preconditioned mesenchymal stem cells, Sham sham-operated, siRNA small interfering RNA