The comparison of cardiac stem cells and mesenchymal stem cells transplantation in improving the ventricular fibrillation threshold and electrophysiological stability in rats with myocardial infarction

Abstract

Objective To compare the effects of cardiac stem cells (CSCs) versus mesenchymal stem cells (MSCs) transplantation on the electrophysiological stability and ventricular fibrillation threshold (VFT) in rats with myocardial infarction (MI). Methods In 30 Sprague-Dawley rats, the left anterior descending coronary artery ligation was carried out to induce MI. Two weeks later, animals were randomly (random number) divided into three groups: CSCs group (n=10) , MSCs group (n=10) and phosphate buffer solution (PBS) group (control group, n=10). Rats of each group was received the injection of CSCs labeled with PKH26 (fluorescent stain) in PBS or MSCs labeled with PKH26 in PBS or PBS alone into the local infarct zone. Six weeks after the intervention, the electrophysiological characteristics and VFT were measured at the infarct marginal zone. Labeled CSCs and MSCs were detected and the expression of connexin-43 was examined in 5 μm cryostat sections from each harvested heart, respectively. Results Compared with the MSCs group, there were no significant differences in the unipolar electrogram activation recovery time (ART) and the correct ART (ARTc) in the infarct marginal zone in the CSCs group six weeks after cells transplantation (P >0.05) ; there were significant differences in the ARTc dispersion, induced refratory ventricular arrhythmias and VFT in the CSCs group compared with the MSCs group and PBS group (P 0.05). Labeled CSCs with PKH26 were identified in the infarct marginal zone and expressed as connexin-43. The PKH26 labeled MSCs were identified in the infarct marginal zone and rarely expressed as connexin-43. Conclusions Both CSCs and MSCs were safe and available for the treatment of myocardial infarction, also exerted as non-arrhythmogenic agents. CSCs were superior to MSCs in modulating the electrophysiological stability and improving the VFT six weeks after the cells transplantation. CSCs were ideal seed cells in the treatment of cardiovascular disease. Key words: Cardiac stem cells; Mesenchymal stem cells; Electrophysiological stability; Fibrillation threshold; Myocardial infarction