Aim: 

Although implantation in infarcted myocardium of mesenchymal stem cells (MSCs) from different tissues may produce beneficial effects, little is know about their early homing. In vitro characterization of DP-MSCs revealed that they are multipotent SCs with excellent differentiation potentially in response to specific stimuli.

Methods: 

Therefore, we studied early homing of DP-MSCs in normal and infarcted rat hearts: 10⁶ DP-MSCs were implanted in the ventricular apex immediately after stabilization (Control group) or after 30 min of ligature of the left anterior descendent coronary artery and 5 min of reperfusion (I/R group). After 4 hours of reperfusion the location and the injured area were assessed with trypan blue staining. Carboxyfluorescin allowed to recognize DP-MSCs in the host tissue by their green color.

Results: 

In Control group DP-MSCs remained in the site of injection as round-shaped clusters, while in infarcted group they migrated towards the injured areas, as evidenced by trypan blue staining. Yet, some DP-MSCs in I/R group were elongated in parallel with cardiomyocytes and showed the presence of connexin-43 on the membrane.

Conclusion: 

The results suggest that DP-MSCs can migrate and integrate within the peri-infarcted area. In a previous investigation bone marrow MSCs maintained their round shape when injected near the infarcted area after 30 min reperfusion. Further studies should identify factors that influence the apparently different responses of these cells.