Cardiac cell therapy with mesenchymal stem cell induces cardiac nerve sprouting, angiogenesis, and reduced connexin43-positive gap junctions, but concomitant electrical pacing increases connexin43-positive gap junctions in canine heart.

Background: Although electrical pacing is of great utility in many cardiovascular diseases, its effects on the combined cardiac cell therapy have not been established. We hypothesised that mesenchymal stem cell transplantation changes cardiac sympathetic nerve and gap junction, and concomitant pacing has additional biological effects.

Methods: We monitored cardiac rhythm for 4 weeks after human mesenchymal stem cell transplantation (1 x 107, epicardial injection) in 18 dogs in vivo, seven human mesenchymal stem cell with pacing, six human mesenchymal stem cell, and five sham, and evaluated the sympathetic innervation, nerve growth factor-beta; tyrosine hydroxylase, angiogenesis, von Willebrand factor, and connexin43 expressions by real time (RT)-polymerase chain reaction and immunostaining.