Short-term efficacy of cardiac stem cells in improving the electrophysiological stability and ventricular fibrillation threshold after myocardial infarction / 中国组织工程研究

ABSTRACT

BACKGROUND:Our previous work demonstrated that cardiac stem cel s (CSCs) transplantation could significantly improve the electrophysiological stability and ventricular fibril ation threshold in rats with myocardial infarction. OBJECTIVE:To compare the influence of CSCs and bone marrow mesenchymal stem cel s (BMSCs) transplantation on the electrophysiological stability and ventricular fibril ation threshold in rats with myocardial infarction in the short term. METHODS:Thirty male healthy Sprague-Dawley rats were selected to make myocardial infarction models induced by the left anterior descending coronary artery ligation. Then, animals were randomly divided into three groups, CSCs group, BMSCs group and the PBS group, with 10 rats in each group. Two weeks after modeling, animals were respectively given the injection of 5×106 CSCs labeled with PKH26 in 0.1 mL PBS, 5×106 BMSCs labeled with PKH26 in 0.1 mL PBS or 0.1 mL PBS alone into the infracted anterior ventricular free wal . Two weeks after intervention, the electrophysiological characteristics and ventricular fibril ation threshold were measured respectively at the infarct zone, the infarct marginal zone and the non-infarct zone. Labeled CSCs and BMSCs were detected, and the expression of connexin-43 was examined in 5 μm cryostat sections from the infarct marginal zone of each heart. RESULTS AND CONCLUSION:Compared with the BMSCs group and PBS group, significant differences were revealed in the correct unipolar electrograms activation recovery time dispersion (ARTcd), electrical stimulation-induced malignant ventricular arrhythmias and ventricular fibril ation threshold at the infarct zone, the infarct marginal zone and the non-infarct zone in the CSCs group (P<0.05). Obvious differences were discovered in the ARTcd, electrical stimulation-induced malignant ventricular arrhythmias and ventricular fibril ation threshold on the non-infarct area in the BMSCs group in contrast to the PBS group. Labeled CSCs or BMSCs were identified at the infarct marginal zone and expressed connexin-43. Connexin-43 was abundantly expressed in the CSCs group whereas it was rarely expressed in the BMSCs group, and even not expressed in the PBS group. These findings suggest that CSCs are superior to BMSCs in modulating the electrophysiological stability and the ventricular fibril ation threshold in the short term after transplantation, which is closely correlated with the expression of connexin-43.