Fig. 4From: HIF-1α overexpression in mesenchymal stem cell-derived exosomes mediates cardioprotection in myocardial infarction by enhanced angiogenesisProliferation of hypoxia-injured HUVECs was augmented by Exo-HIF-1α. a EdU has been incorporated into dividing HUVECs and been detected with a fluorescent azide using click chemistry. Bar: 200 μm. b The percentage of EdU positive cells was measured by ImageJ. *P < 0.05, **P < 0.01, ***P < 0.001Back to article page