[Overexpression of SERCA2a by gene transfer enhances myocardial systolic function in canines]

The present study is aimed to study the effect of sarcoplasmic reticulum Ca(2+)-ATPase 2a (SERCA2a) gene transfer on the contractile function of isolated cardiomyocytes of canines. The cardiomyocytes were isolated with collagenases. The isolated cardiac cells were divided into untransfected group, empty vector group and SERCA2a-transfected group. Recombinant adenovirus vector carrying enhanced green fluorescent protein gene was used for SERCA2a gene delivery. The expression of SERCA2a protein in cardiomyocytes was determined by Western blot. Contractile function of cardiomyocytes was measured with motion edge-detection system of single cell at 48 h after transfection. The results showed, compared with untransfected group, SERCA2a protein level, percentage of peak contraction amplitude under normal condition, percentages of peak contraction amplitude under Ca(2+) or isoproterenol stimulation, time-to-peak contraction (TTP) and time-to-50% relaxation (R50) in SERCA2a-transfected group all increased significantly. While all the above indices in empty vector group did not show any differences with those in untransfected group. These results suggest that the overexpression of SERCA2a by gene transfer may enhance the contraction function of canine myocardial cells.