CD34+ Stem Cells: Promising Roles in Cardiac Repair and Regeneration

Cell therapy has received significant attention as a novel therapeutic approach to restore cardiac function after injury. CD34-positive (CD34(+)) stem cells have been investigated for their ability to promote angiogenesis and contribute to the prevention of remodelling after infarct. However, there are significant differences between murine and human CD34(+) cells; understanding these differences might benefit the therapeutic use of these cells. Herein we discuss the function of the CD34 cell and highlight the similarities and differences between murine and human CD34 cell function, which might explain some of the differences between the animal and human evolutions. We also summarize the studies that report the application of murine and human CD34(+) cells in preclinical studies and clinical trials and current limitations with the application of cell therapy for cardiac repair. Finally, to overcome these limitations we discuss the application of novel humanized rodent models that can bridge the gap between preclinical and clinical studies as well as rejuvenation strategies for improving the quality of old CD34(+) cells for future clinical trials of autologous cell transplantation.