Background Recent study suggests that transient regeneration potential is latent in neonatal mouse heart. Although the new cardiomyocytes may arise from pre-existing cardiomyocytes, cardiac stem cells still might be considered as a potential resource.

Objective In this study, we tested whether heart injury in neonatal mouse induced the proliferation of c-kit+ cardiac progenitor cells during the process of regeneration.

Methods and Results We performed the apex resection surgery on neonatal mouse, evaluated hearts from operated and sham-operated group. For quantification of c-kit+ stem cells, it was counted and expressed as number per mm². The expression of c-kit was tested by quantitative PCR and western blot. Apex resection in neonatal mouse leads to complete regeneration of heart and brisk increase of cardiac progenitor cells. Gene c-kit expression and synthesis of Kit protein were also significantly elevated shortly after surgery.

Conclusions Understanding the mechanism that leads to an increase of cardiac progenitor cells during mouse heart regeneration might help to explore the enigma of heart regeneration.